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Sample records for complexes c9h72lnmu-cl2liet2o2 ln

  1. Rhombus-shaped tetranuclear [Ln4] complexes [Ln = Dy(III) and Ho(III)]: synthesis, structure, and SMM behavior.

    Science.gov (United States)

    Chandrasekhar, Vadapalli; Hossain, Sakiat; Das, Sourav; Biswas, Sourav; Sutter, Jean-Pascal

    2013-06-03

    The reaction of a new hexadentate Schiff base hydrazide ligand (LH3) with rare earth(III) chloride salts in the presence of triethylamine as the base afforded two planar tetranuclear neutral complexes: [{(LH)2Dy4}(μ2-O)4](H2O)8·2CH3OH·8H2O (1) and [{(LH)2Ho4}(μ2-O)4](H2O)8·6CH3OH·4H2O (2). These neutral complexes possess a structure in which all of the lanthanide ions and the donor atoms of the ligand remain in a perfect plane. Each doubly deprotonated ligand holds two Ln(III) ions in its two distinct chelating coordination pockets to form [LH(Ln)2](4+) units. Two such units are connected by four [μ2-O](2-) ligands to form a planar tetranuclear assembly with an Ln(III)4 core that possesses a rhombus-shaped structure. Detailed static and dynamic magnetic analysis of 1 and 2 revealed single-molecule magnet (SMM) behavior for complex 1. A peculiar feature of the χM" versus temperature curve is that two peaks that are frequency-dependent are revealed, indicating the occurrence of two relaxation processes that lead to two energy barriers (16.8 and 54.2 K) and time constants (τ0 = 1.4 × 10(-6) s, τ0 = 7.2 × 10(-7) s). This was related to the presence of two distinct geometrical sites for Dy(III) in complex 1.

  2. Complexation of amidocarbamoyl phosphine oxides with Ln{sup +3} (Ln = La, Nd, Pm, Sm and Eu) cation series: structural and thermodynamical features

    Energy Technology Data Exchange (ETDEWEB)

    Hosseinnejad, Tayebeh; Kazemi, Tayebeh [Alzahra Univ., Tehran (Iran, Islamic Republic of). Dept. of Chemistry

    2016-05-01

    In the present study, we have mainly investigated the nature of interactions in Ln{sup 3+} (Ln = La, Nd, Pm, Sm, Eu) complexes with amidocarbamoyl methyl phosphine oxide (CMPO) and amidocarbamoyl propyl phosphine oxide (CPPO) ligands based on density functional theory (DFT) approaches. In the first step, thermodynamical properties for complexation of CMPO and CPPO ligands with Ln{sup 3+} cation series have been determined in the gas phase and with the presence of three solvents: n-hexane, chloroform and toluene, via polarized continuum model (PCM) computations. The trend of metal-ligand interaction strength has been analyzed and compared with the trend of ionic hardness within the series of lanthanide cations and different size of alkyl chain of amidocarbamoyl phosphine oxide ligand. The calculated thermochemical results in the gas and solution phases reveals that there is a consistency between increasing trend in the hardness of Ln{sup 3+} cation series and also electron-donating property of alkyl chain with increasing in thermodynamical stability of [Ln-CMPO]{sup 3+} and [Ln-CPPO]{sup 3+} complex series. We have also demonstrated that in the complexation reaction of all complex series, using n-hexane as solvent is more favorable thermodynamically than chloroform and toluene. It should be stated that this issue has been observed in many experiments. Finally, analysis of calculated deformation energies and also the variation in bond order of some selected key bonds in CMPO and CPPO ligands and their corresponded Ln{sup 3+} complexes series show a similar trend with increasing in the hardness of Ln{sup 3+} cation series and electron-donating of alkyl chain of amidocarbamoyl phosphine oxide ligand.

  3. Complexation of amidocarbamoyl phosphine oxides with Ln+3 (Ln = La, Nd, Pm, Sm and Eu) cation series: structural and thermodynamical features

    International Nuclear Information System (INIS)

    Hosseinnejad, Tayebeh; Kazemi, Tayebeh

    2016-01-01

    In the present study, we have mainly investigated the nature of interactions in Ln 3+ (Ln = La, Nd, Pm, Sm, Eu) complexes with amidocarbamoyl methyl phosphine oxide (CMPO) and amidocarbamoyl propyl phosphine oxide (CPPO) ligands based on density functional theory (DFT) approaches. In the first step, thermodynamical properties for complexation of CMPO and CPPO ligands with Ln 3+ cation series have been determined in the gas phase and with the presence of three solvents: n-hexane, chloroform and toluene, via polarized continuum model (PCM) computations. The trend of metal-ligand interaction strength has been analyzed and compared with the trend of ionic hardness within the series of lanthanide cations and different size of alkyl chain of amidocarbamoyl phosphine oxide ligand. The calculated thermochemical results in the gas and solution phases reveals that there is a consistency between increasing trend in the hardness of Ln 3+ cation series and also electron-donating property of alkyl chain with increasing in thermodynamical stability of [Ln-CMPO] 3+ and [Ln-CPPO] 3+ complex series. We have also demonstrated that in the complexation reaction of all complex series, using n-hexane as solvent is more favorable thermodynamically than chloroform and toluene. It should be stated that this issue has been observed in many experiments. Finally, analysis of calculated deformation energies and also the variation in bond order of some selected key bonds in CMPO and CPPO ligands and their corresponded Ln 3+ complexes series show a similar trend with increasing in the hardness of Ln 3+ cation series and electron-donating of alkyl chain of amidocarbamoyl phosphine oxide ligand.

  4. Six-Coordinate Ln(III Complexes with Various Coordination Geometries Showing Distinct Magnetic Properties

    Directory of Open Access Journals (Sweden)

    Mei Guo

    2018-01-01

    Full Text Available The syntheses, structural characterization, and magnetic properties of three lanthanide complexes with formulas [Ln(L13] (Ln = Dy (1Dy; Er (1Er; and [Dy(L22] (2Dy were reported. Complexes 1Dy and 1Er are isostructural with the metal ion in distorted trigonal-prismatic coordination geometry, but exhibit distinct magnetic properties due to the different shapes of electron density for DyIII (oblate and ErIII (prolate ions. Complex 1Dy shows obvious SMM behavior under a zero direct current (dc field with an effective energy barrier of 31.4 K, while complex 1Er only features SMM behavior under a 400 Oe external field with an effective energy barrier of 23.96 K. In stark contrast, complex 2Dy with the octahedral geometry only exhibits the frequency dependence of alternating current (ac susceptibility signals without χ″ peaks under a zero dc field.

  5. NMR and TRLFS studies of Ln(iii) and An(iii) C5-BPP complexes.

    Science.gov (United States)

    Adam, Christian; Beele, Björn B; Geist, Andreas; Müllich, Udo; Kaden, Peter; Panak, Petra J

    2015-02-01

    C5-BPP is a highly efficient N-donor ligand for the separation of trivalent actinides, An(iii), from trivalent lanthanides, Ln(iii). The molecular origin of the selectivity of C5-BPP and many other N-donor ligands of the BTP-type is still not entirely understood. We present here the first NMR studies on C5-BPP Ln(iii) and An(iii) complexes. C5-BPP is synthesized with 10% 15 N labeling and characterized by NMR and LIFDI-MS methods. 15 N NMR spectroscopy gives a detailed insight into the bonding of C5-BPP with lanthanides and Am(iii) as a representative for trivalent actinide cations, revealing significant differences in 15 N chemical shift for coordinating nitrogen atoms compared to Ln(iii) complexes. The temperature dependence of NMR chemical shifts observed for the Am(iii) complex indicates a weak paramagnetism. This as well as the observed large chemical shift for coordinating nitrogen atoms show that metal-ligand bonding in Am(C5-BPP) 3 has a larger share of covalence than in lanthanide complexes, confirming earlier studies. The Am(C5-BPP) 3 NMR sample is furthermore spiked with Cm(iii) and characterized by time-resolved laser fluorescence spectroscopy (TRLFS), yielding important information on the speciation of trace amounts of minor complex species.

  6. Effect of the ion force on the stability constants of the complexes LnCl2+ and LnCl2+ of Europium and Lutetium

    International Nuclear Information System (INIS)

    Fernandez R, E.; Jimenez R, M.; Solache R, M.

    2004-01-01

    A study is presented on the determination of the constants of stability of those complex LnCI 3-n n (where Ln = Eu 3+ and Lu 3+ and n = 1 and 2), by means of a method of extraction with solvent, to constant temperature (303 K) and in means of high ionic force (1- 3M H CI/HCIO 4 ). It is also presented the application of the theory of the specific interaction of ions (SIT) of Bronsted-Guggenheim-Scatchard for the extrapolation of the values to infinite dilution. (Author)

  7. Synthesis and Structures of Two Lanthanide Complexes Containing a Mixed Ligand System: [Ln(Phen)2(L)3(HL)]·H2O [Ln = La, Ce; Phen = Phenanthroline; HL = Salicylic Acid

    International Nuclear Information System (INIS)

    Iravani, Effat; Nami, Navabeh; Nabizadeh, Fatemeh; Bayani, Elham; Neumueller, Bernhard

    2013-01-01

    The reaction of LnCl 3 ·7H 2 O [Ln = La (1), Ce (2)] with salicylic acid (HL) and 1,10-phenanthroline (Phen) at 20 .deg. C in H 2 O/ethanol gave after work-up and recrystallization two novel lanthanide complexes with general formula [Ln(Phen) 2 (L) 3 (HL)]·H 2 O. Compounds 1 and 2 were characterized by IR and UV-Vis spectroscopy, TGA, CHN as well as by X-ray analysis. According to these results, compounds 1 and 2 are isostructural and contain Ln 3+ ions with coordination number nine. Complexes 1 and 2 consist of two Phen, one neutral HL and three L anions (two L anions act as monodentate ligands and the third one is chelating to Ln 3+ ). Thermal decomposition led to primary loss of the Phen molecules. Then HL molecules and finally L moieties left the material to give Ln 2 O 3

  8. Magnetism of cyano-bridged hetero-one-dimensional Ln3+-M3+ complexes (Ln3+ = Sm, Gd, Yb; M3+ = FeLS, Co).

    Science.gov (United States)

    Figuerola, Albert; Diaz, Carmen; Ribas, Joan; Tangoulis, Vassilis; Sangregorio, Claudio; Gatteschi, Dante; Maestro, Miguel; Mahía, José

    2003-08-25

    The reaction of Ln(NO(3))(3).aq with K(3)[Fe(CN)(6)] or K(3)[Co(CN)(6)] and 2,2'-bipyridine in water led to five one-dimensional complexes: trans-[M(CN)(4)(mu-CN)(2)Ln(H(2)O)(4) (bpy)](n)().XnH(2)O.1.5nbpy (M = Fe(3+) or Co(3+); Ln = Sm(3+), Gd(3+), or Yb(3+); X = 4 or 5). The structures for [Fe(3)(+)-Sm(3+)] (1), [Fe(3)(+)-Gd(3+)] (2), [Fe(3)(+)-Yb(3+)] (3), [Co(3)(+)-Gd(3+)] (4), and [Co(3)(+)-Yb(3+)] (5) have been solved; they crystallize in the triclinic space P1 and are isomorphous. The [Fe(3+)-Sm(3+)] complex is a ferrimagnet, its magnetic studies suggesting the onset of weak ferromagnetic 3-D ordering at 3.5 K. The [Fe(3+)-Gd(3+)] interaction is weakly antiferromagnetic. The isotropic nature of Gd(3+) allowed us to evaluate the exchange interaction (J = 0.77 cm(-)(1)).

  9. Reaction of Non-Symmetric Schiff Base Metallo-Ligand Complexes Possessing an Oxime Function with Ln Ions

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Costes

    2018-03-01

    Full Text Available The preparation of non-symmetric Schiff base ligands possessing one oxime function that is associated to a second function such as pyrrole or phenol function is first described. These ligands, which possess inner N4 or N3O coordination sites, allow formation of cationic or neutral non-symmetric CuII or NiII metallo-ligand complexes under their mono- or di-deprotonated forms. In presence of Lanthanide ions the neutral complexes do not coordinate to the LnIII ions, the oxygen atom of the oxime function being only hydrogen-bonded to a water molecule that is linked to the LnIII ion. This surprising behavior allows for the isolation of LnIII ions by non-interacting metal complexes. Reaction of cationic NiII complexes possessing a protonated oxime function with LnIII ions leads to the formation of original and dianionic (Gd(NO352− entities that are well separated from each other. This work highlights the preparation of well isolated mononuclear LnIII entities into a matrix of diamagnetic metal complexes. These new complexes complete our previous work dealing with the complexing ability of the oxime function toward Lanthanide ions. It could open the way to the synthesis of new entities with interesting properties, such as single-ion magnets for example.

  10. Utility of Lithium in Rare-Earth Metal Reduction Reactions to Form Nontraditional Ln2+ Complexes and Unusual [Li(2.2.2-cryptand)]1+ Cations.

    Science.gov (United States)

    Huh, Daniel N; Darago, Lucy E; Ziller, Joseph W; Evans, William J

    2018-02-19

    The utility of lithium compared to other alkali metals in generating Ln 2+ rare-earth metal complexes via reduction of Ln 3+ precursors in reactions abbreviated as LnA 3 /M (Ln = rare-earth metal; A = anionic ligand; M = alkali metal) is described. Lithium reduction of Cp' 3 Ln (Cp' = C 5 H 4 SiMe 3 ; Ln = Y, Tb, Dy, Ho) under Ar in the presence of 2.2.2-cryptand (crypt) forms new examples of crystallographically characterizable Ln 2+ complexes of these metals, [Li(crypt)][Cp' 3 Ln]. In each complex, lithium is found in an N 2 O 4 donor atom coordination geometry that is unusual for the cryptand ligand. Magnetic susceptibility data on these new examples of nontraditional divalent lanthanide complexes are consistent with 4f n 5d 1 electronic configurations. The Dy and Ho complexes have exceptionally high single-ion magnetic moments, 11.35 and 11.67 μ B , respectively. Lithium reduction of Cp' 3 Y under N 2 at -35 °C forms the Y 2+ complex (Cp' 3 Y) 1- , which reduces dinitrogen upon warming to room temperature to generate the (N 2 ) 2- complex [Cp' 2 Y(THF)] 2 (μ-η 2 :η 2 -N 2 ). These results provide insight on the factors that lead to reduced dinitrogen complexes and/or stable divalent lanthanide complexes as a function of the specific reducing agent and conditions.

  11. Effect of lanthanide contraction on the mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien): Syntheses and characterizations of lanthanide complexes with a tetraelenidoantimonate ligand

    International Nuclear Information System (INIS)

    Zhao Jing; Liang Jingjing; Pan Yingli; Zhang Yong; Jia Dingxian

    2011-01-01

    Mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) (Ln=lanthanide, en=ethylenediamine, dien=diethylenetriamine, trien=triethylenetetramine) were investigated under solvothermal conditions, and novel mixed-coordinated lanthanide(III) complexes [Ln(en) 2 (dien)(η 2 -SbSe 4 )] (Ln=Ce(1a), Nd(1b)), [Ln(en) 2 (dien)(SbSe 4 )] (Ln=Sm(2a), Gd(2b), Dy(2c)), [Ln(en)(trien)(μ-η 1 ,η 2 -SbSe 4 )] ∞ (Ln=Ce(3a), Nd(3b)) and [Sm(en)(trien)(η 2 -SbSe 4 )] (4a) were prepared. Two structural types of lanthanide selenidoantimonates were obtained across the lanthanide series in both en+dien and en+trien systems. The tetrahedral anion [SbSe 4 ] 3- acts as a monodentate ligand mono-SbSe 4 , a bidentate chelating ligand η 2 -SbSe 4 or a tridentate bridging ligand μ-η 1 ,η 2 -SbSe 4 to the lanthanide(III) center depending on the Ln 3+ ions and the mixed ethylene polyamines, indicating the effect of lanthanide contraction on the structures of the lanthanide(III) selenidoantimonates. The lanthanide selenidoantimonates exhibit semiconducting properties with E g between 2.08 and 2.51 eV. - Graphical Abstract: Two structural types of lanthanide(III) selenidoantimonates are formed in both en-dien and en-trien mixed polyamines across lanthanide series, indicating the lanthanide contraction effect on the structures of the lanthanide(III) selenidoantimonates. Highlights: → Two structural types of lanthanide selenidoantimonates are prepared across the lanthanide series in both Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) systems. → The [SbSe 4 ] 3- anion acts as a mono-SbSe 4 , a η 2 -SbSe 4 or a μ-η 1 ,η 2 -SbSe 4 ligand to the Ln 3+ ions. → The soft base ligand [SbSe 4 ] 3- can be controlled to coordinate to the Ln 3+ ions with en+dien and en+trien as co-ligands.

  12. A family of acetato-diphenoxo triply bridged dimetallic Zn(II)Ln(III) complexes: SMM behavior and luminescent properties.

    Science.gov (United States)

    Oyarzabal, Itziar; Artetxe, Beñat; Rodríguez-Diéguez, Antonio; García, JoséÁngel; Seco, José Manuel; Colacio, Enrique

    2016-06-21

    Eleven dimetallic Zn(II)-Ln(III) complexes of the general formula [Zn(µ-L)(µ-OAc)Ln(NO3)2]·CH3CN (Ln(III) = Pr (1), Nd (2), Sm (3), Eu (4), Gd (5), Tb (6), Dy (7), Ho (8), Er (9), Tm (10), Yb (11)) have been prepared in a one-pot reaction from the compartmental ligand N,N'-dimethyl-N,N'-bis(2-hydroxy-3-formyl-5-bromo-benzyl)ethylenediamine (H2L). In all these complexes, the Zn(II) ions occupy the internal N2O2 site whereas the Ln(III) ions show preference for the O4 external site. Both metallic ions are bridged by an acetate bridge, giving rise to triple mixed diphenoxido/acetate bridged Zn(II)Ln(III) compounds. The Nd, Dy, Er and Yb complexes exhibit field induced single-ion magnet (SIM) behaviour, with Ueff values ranging from 14.12 to 41.55 K. The Er complex shows two relaxation processes, but only the second relaxation process with an energy barrier of 21.0 K has been characterized. The chromophoric L(2-) ligand is able to act as an "antenna" group, sensitizing the near-infrared (NIR) Nd(III) and Yb(III)-based luminescence in complexes 2 and 11 and therefore, both compounds can be considered as magneto-luminescent materials. In addition, the Sm(III), Eu(III) and Tb(III) derivatives exhibit characteristic emissions in the visible region.

  13. Thermodynamics properties of complexation and extraction of LN(3) by diamides

    International Nuclear Information System (INIS)

    Charbonnel, M.C.; Flandin, J.L.; Presson, M.T.; Morel, J.P.

    2000-01-01

    In the frame of the French program SPIN, CEA has undertaken the development of the DIAMEX process which is the first step in the strategy of separation of minor actinides from fission products in High Level Waste. The extractant belongs to the diamide family and lead to a co-extraction actinides(III) - lanthanides(III). The study focuses on thermodynamic properties (ΔH, ΔG, ΔS) related to the extraction of lanthanide elements by malonamide in order to have a better knowledge of the driven force and to explain some extraction differences between extractants. The main experimental technique used is the microcalorimetric titration whose principle will be detailed. Preliminary studies concern reactions of complexation Ln 3+ - diamide in an homogeneous aqueous phase. We can assume that reaction is endothermic but some difficulties were encountered to obtain both K and ΔH because of low complexation constants and small heats of reaction. Additional studies were carried out with spectroscopic methods (UV-Visible and LITRFS) to determine precise ΔG r values. The variation in the lanthanide series was also studied. The main work deals with the thermodynamic constants of extraction for which both micro-calorimetry and classical Vant'Hoff approaches were studied: the results will be presented and discussed. (authors)

  14. Thermodynamics properties of complexation and extraction of LN(3) by diamides

    Energy Technology Data Exchange (ETDEWEB)

    Charbonnel, M.C.; Flandin, J.L.; Presson, M.T. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification, DRRV, 30 - Marcoule (France); Morel, J.P. [Universite Blaise Pascal, Clermont-Ferrand II, Lab. de Chimie Physique des Solutions, (CNRS), 63 - Aubiere (France)

    2000-07-01

    In the frame of the French program SPIN, CEA has undertaken the development of the DIAMEX process which is the first step in the strategy of separation of minor actinides from fission products in High Level Waste. The extractant belongs to the diamide family and lead to a co-extraction actinides(III) - lanthanides(III). The study focuses on thermodynamic properties ({delta}H, {delta}G, {delta}S) related to the extraction of lanthanide elements by malonamide in order to have a better knowledge of the driven force and to explain some extraction differences between extractants. The main experimental technique used is the microcalorimetric titration whose principle will be detailed. Preliminary studies concern reactions of complexation Ln{sup 3+} - diamide in an homogeneous aqueous phase. We can assume that reaction is endothermic but some difficulties were encountered to obtain both K and {delta}H because of low complexation constants and small heats of reaction. Additional studies were carried out with spectroscopic methods (UV-Visible and LITRFS) to determine precise {delta}G{sub r} values. The variation in the lanthanide series was also studied. The main work deals with the thermodynamic constants of extraction for which both micro-calorimetry and classical Vant'Hoff approaches were studied: the results will be presented and discussed. (authors)

  15. Structure and luminescent investigation of new Ln(III)-TTA complexes containing N-methyl-ε-caprolactam as ligand

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alex Santos, E-mail: alexb@ifes.edu.br [Coordenadoria de Química e Biologia, IFES, Vitória, ES 29040-780 (Brazil); Caliman, Ewerton Valadares [Coordenadoria de Engenharia Metalúrgica, IFES, Vitória, ES 29040-780 (Brazil); Dutra, José Diogo L. [Departamento de Química Fundamental, UFPE, Recife, PE 50590-470 (Brazil); Da Silva, Jeferson G. [Departamento de Farmácia, UFJF, Governador Valadares, MG 35010-17 (Brazil); Araujo, Maria Helena, E-mail: maria.araujo@pq.cnpq.br [Departamento de Química, UFMG, Belo Horizonte, MG 31270-901 (Brazil)

    2016-02-15

    The synthesis and photoluminescent properties of Ln(III)-TTA complexes (Ln=Eu(III) and Sm(III) ions; TTA=3-thenoyltrifluoroacetonate) with N-methyl-ε-caprolactam (NMC) are reported. The Ln complexes were characterized by elemental analysis, complexometric titration with EDTA and infrared spectroscopy. The molecular structures of the [Eu(TTA){sub 3}(NMC)(H{sub 2}O)] and [Sm(TTA){sub 3}(NMC)(H{sub 2}O)]·H{sub 2}O compounds were determined by single crystal X-ray crystallography. In these structures, the three TTA molecules are coordinated to the metal in anionic form as bidentate ligands, while the H{sub 2}O and NMC molecules are coordinated to the metal in neutral form as monodentated ligands. The coordination polyhedron around the Ln(III) atom can be described as square antiprismatic molecular geometry. The geometry of the [Eu(TTA){sub 3}(NMC)(H{sub 2}O)] complex was optimized with the Sparkle/RM1 model for Ln(III) complexes, allowing analysis of intramolecular energy transfer processes of the Eu(III) compound. The spectroscopic properties of the 4f{sup 6} intraconfigurational transitions of the Eu(III) complex were then studied experimentally and theoretically. The low value of emission quantum efficiency of {sup 5}D{sub 0} emitting level (η) of Eu(III) ion (ca. 36%) is due to the vibrational modes of the water molecule that act as luminescence quenching. In addition, the luminescence decay curves, the experimental intensity parameters (Ω{sub λ}), lifetimes (τ), radiative (A{sub rad}) and non-radiative (A{sub nrad}) decay rates, theoretical quantum yield (q{sub cal}) were also determined and discussed. - Highlights: • New Ln-TTA complexes with lactam were obtained and their luminescence investigated. • Jablonsky diagram for the Eu(III) complex shows the main channel for the IET process. • Data confirm the potentiality of the Eu(III) complex to produce red luminescence. • LUMPAC has provided useful information on the luminescence of the Eu

  16. Synthesis and Structures of Two Lanthanide Complexes Containing a Mixed Ligand System: [Ln(Phen){sub 2}(L){sub 3}(HL)]·H{sub 2}O [Ln = La, Ce; Phen = Phenanthroline; HL = Salicylic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Iravani, Effat [UNiv. of Applied Science and Technology, Tehran (Iran, Islamic Republic of); Nami, Navabeh; Nabizadeh, Fatemeh; Bayani, Elham [Islamic Azad Univ., Mazandaran (Iran, Islamic Republic of); Neumueller, Bernhard [Philipps-Universitat Marburg, Marburg (Germany)

    2013-11-15

    The reaction of LnCl{sub 3}·7H{sub 2}O [Ln = La (1), Ce (2)] with salicylic acid (HL) and 1,10-phenanthroline (Phen) at 20 .deg. C in H{sub 2}O/ethanol gave after work-up and recrystallization two novel lanthanide complexes with general formula [Ln(Phen){sub 2}(L){sub 3}(HL)]·H{sub 2}O. Compounds 1 and 2 were characterized by IR and UV-Vis spectroscopy, TGA, CHN as well as by X-ray analysis. According to these results, compounds 1 and 2 are isostructural and contain Ln{sup 3+} ions with coordination number nine. Complexes 1 and 2 consist of two Phen, one neutral HL and three L anions (two L anions act as monodentate ligands and the third one is chelating to Ln{sup 3+}). Thermal decomposition led to primary loss of the Phen molecules. Then HL molecules and finally L moieties left the material to give Ln{sub 2}O{sub 3}.

  17. Family of defect-dicubane Ni4Ln2 (Ln = Gd, Tb, Dy, Ho) and Ni4Y2 complexes: rare Tb(III) and Ho(III) examples showing SMM behavior.

    Science.gov (United States)

    Zhao, Lang; Wu, Jianfeng; Ke, Hongshan; Tang, Jinkui

    2014-04-07

    Reactions of Ln(III) perchlorate (Ln = Gd, Tb, Dy, and Ho), NiCl2·6H2O, and a polydentate Schiff base resulted in the assembly of novel isostructural hexanuclear Ni4Ln2 complexes [Ln = Gd (1), Tb (2), Dy (3), Ho (4)] with an unprecedented 3d-4f metal topology consisting of two defect-dicubane units. The corresponding Ni4Y2 (5) complex containing diamagnetic Y(III) atoms was also isolated to assist the magnetic studies. Interestingly, complexes 2 and 3 exhibit SMM characteristics and 4 shows slow relaxation of the magnetization. The absence of frequency-dependent in-phase and out-of-phase signals for the Ni-Y species suggests that the Ln ions' contribution to the slow relaxation must be effectual as previously observed in other Ni-Dy samples. However, the observation of χ″ signals with zero dc field for the Ni-Tb and Ni-Ho derivatives is notable. Indeed, this is the first time that such a behavior is observed in the Ni-Tb and Ni-Ho complexes.

  18. Modelling thermodynamic properties of lanthanide (LnL)3+ and actinide (AnL)3+ complexes with tridentate planar nitrogen ligands (L)

    International Nuclear Information System (INIS)

    Ionova, G.; Rabbe, C.; Charbonnel, M.C.; Hill, C.; Guillaumont, D.; Guillaumont, R.; Ionov, S.; Madic, C.

    2004-01-01

    We report here the results obtained from a systematic theoretical study on the thermodynamic properties of trivalent lanthanide (Ln) and actinide (An) complexes with chelating nitrogen tridentate ligands. The mechanism of chelation has been investigated and the role of cation dissolution is investigated through a comparison of the thermodynamic properties of solvated cations and complexes. The difference in thermodynamic properties of LnL and AnL complexes is analyzed. (authors)

  19. Magnetic properties of cyano-bridged Ln3+-M3+ complexes. Part I: trinuclear complexes (Ln3+ = La, Ce, Pr, Nd, Sm; M3+ = FeLS, Co) with bpy as blocking ligand.

    Science.gov (United States)

    Figuerola, Albert; Ribas, Joan; Llunell, Miquel; Casanova, David; Maestro, Miguel; Alvarez, Santiago; Diaz, Carmen

    2005-10-03

    The reaction of Ln(NO3)3(aq) with K3[Fe(CN)6] or K3[Co(CN)6] and 2,2'-bipyridine in water/ethanol led to eight trinuclear complexes: trans-[M(CN)4(mu-CN)2{Ln(H2O)4(bpy)2}2][M(CN)6].8H2O (M = Fe3+ or Co3+, Ln = La3+, Ce3+, Pr3+, Nd3+, and Sm3+). The structures for the eight complexes [La2Fe] (1), [Ce2Fe] (2), [Pr2Fe] (3), [Nd2Fe] (4), [Ce2Co] (5), [Pr2Co] (6), [Nd2Co] (7), and [Sm2Co] (8) have been solved; they crystallize in the triclinic space group P and are isomorphous. They exhibit a supramolecular 3D architecture through hydrogen bonding and pi-pi stacking interactions. A stereochemical study of the nine-vertex polyhedra of the lanthanide ions, based on continuous shape measures, is presented. No significant magnetic interaction was found between the lanthanide(III) and the iron(III) ions.

  20. Chiroptical methods in a wide wavelength range for obtaining Ln3+ complexes with circularly polarized luminescence of practical interest.

    Science.gov (United States)

    Górecki, Marcin; Carpita, Luca; Arrico, Lorenzo; Zinna, Francesco; Di Bari, Lorenzo

    2018-05-29

    We studied enantiopure chiral trivalent lanthanide (Ln3+ = La3+, Sm3+, Eu3+, Gd3+, Tm3+, and Yb3+) complexes with two fluorinated achiral tris(β-diketonate) ligands (HFA = hexafluoroacetylacetonate and TTA = 2-thenoyltrifluoroacetonate), incorporating a chiral bis(oxazolinyl)pyridine (PyBox) unit as a neutral ancillary ligand, by the combined use of optical and chiroptical methods, ranging from UV to IR both in absorption and circular dichroism (CD), and including circularly polarized luminescence (CPL). Ultimately, all the spectroscopic information is integrated into a total and a chiroptical super-spectrum, which allows one to characterize a multidimensional chemical space, spanned by the different Ln3+ ions, the acidity and steric demand of the diketone and the chirality of the PyBox ligand. In all cases, the Ln3+ ions endow the systems with peculiar chiroptical properties, either allied to f-f transitions or induced by the metal onto the ligand. In more detail, we found that Sm3+ complexes display interesting CPL features, which partly superimpose and partly integrate the more common Eu3+ properties. Especially, in the context of security tags, the pair Sm/Eu may be a winning choice for chiroptical barcoding.

  1. Magnetism of cyano-bridged Ln3+-M3+ complexes. Part II: one-dimensional complexes (Ln3+ = Eu, Tb, Dy, Ho, Er, Tm; M3+ = Fe or Co) with bpy as blocking ligand.

    Science.gov (United States)

    Figuerola, Albert; Ribas, Joan; Casanova, David; Maestro, Miguel; Alvarez, Santiago; Diaz, Carmen

    2005-10-03

    The reaction of Ln(NO3)3(aq) with K3[Fe(CN)6] or K3[Co(CN)6] and 2,2'-bipyridine in water/ethanol led to 13 one-dimensional complexes: trans-[M(CN)4(mu-CN)2Ln(H2O)4(bpy)]n.4nH2O.1.5nbpy (Ln = Eu3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Lu3+; M = Fe3+, Co3+). The structures for [EuFe]n (1), [TbFe]n (2), [DyFe]n (3), [HoFe]n (4), [ErFe]n (5), [TmFe]n (6), [LuFe]n (7), [EuCo]n (8), [TbCo]n (9), [DyCo]n (10), [HoCo]n (11), [ErCo]n (12), and [TmCo]n (13) have been solved: they crystallize in the triclinic space group P and are isomorphous. They exhibit a supramolecular architecture created by the interplay of coordinative, hydrogen bonding, and pi-pi interactions. A stereochemical study of the eight-vertex polyhedra of the lanthanide ions, based on continuous shape measures, is presented. The Ln3+-Fe3+ interaction is antiferromagnetic in [DyFe]n and [TbFe]n. For [EuFe]n, [HoFe]n, [ErFe]n, and [TmFe]n, there is no sign of any significant interaction. The magnetic behavior of [DyFe]n suggests the onset of weak long-range ferromagnetic ordering at 2.5 K.

  2. Series of isostructural planar lanthanide complexes [Ln(III)4(mu3-OH)2(mdeaH)2(piv)8] with single molecule magnet behavior for the Dy4 analogue.

    Science.gov (United States)

    Abbas, Ghulam; Lan, Yanhua; Kostakis, George E; Wernsdorfer, Wolfgang; Anson, Christopher E; Powell, Annie K

    2010-09-06

    A series of five isostructural tetranuclear lanthanide complexes of formula [Ln(4)(mu(3)-OH)(2)(mdeaH)(2)(piv)(8)], (mdeaH(2) = N-methyldiethanolamine; piv = pivalate; Ln = Tb (1), Dy (2), Ho (3), Er (4), and Tm (5)) have been synthesized and characterized. These clusters have a planar "butterfly" Ln(4) core. Magnetically, the Ln(III) ions are weakly coupled in all cases; the Dy(4) compound 2 shows Single Molecule Magnet (SMM) behavior.

  3. Low-Temperature Transformations of Protonic Forms of Layered Complex Oxides HLnTiO4 and H2Ln2Ti3O10 (Ln = La, Nd)

    International Nuclear Information System (INIS)

    Abdulaeva, L.D.; Silyukov, O.I.; Zvereva, I.A.; Petrov, Yu.V.

    2013-01-01

    In the present work protonic forms of layered Ruddlesden-Popper oxides HLnTiO 4 and H 2 Ln 2 Ti 3 O 10 (Ln = La, Nd) were used as the starting point for soft chemistry synthesis of two series of perovskite-like compounds by acid leaching and exfoliation, promoted by vanadyl sulfate. The last route leads to the nano structured VO 2+ containing samples. Characterization by SEM, powder XRD, and TGA has been performed for the determination of the structure and composition of synthesized oxides

  4. Synthesis, Structure, and Magnetism of Tris(amide) {Ln[N(SiMe3)2]3}1- Complexes of the Non-Traditional +2 Lanthanide Ions.

    Science.gov (United States)

    Ryan, Austin Jack; Darago, Lucy E; Balasubramini, Sree Ganesh; Chen, Guo P; Ziller, Joseph W; Furche, Filipp; Long, Jeffrey R; Evans, William J

    2018-02-28

    A new series of Ln2+ complexes has been synthesized that overturns two previous generalizations in rare-earth metal reduction chemistry: that amide ligands do not form isolable complexes of the highly-reducing non-traditional Ln2+ ions and that yttrium is a good model for the late lanthanides in these reductive reactions. Reduction of Ln(NR2)3 (R = SiMe3) complexes in THF under Ar with M = K or Rb in the presence of 2.2.2-cryptand (crypt) forms crystallographically-characterizable [M(crypt)][Ln(NR2)3] complexes not only for the traditional Tm2+ ion and the configurational crossover ions, Nd2+ and Dy2+, but also for the non-traditional Gd2+, Tb2+, Ho2+, and Er2+ ions. Crystallographic data as well as UV-visible, magnetic susceptibility, and density functional theory studies are consistent with the accessibility of 4fn5d1 configurations for Ln2+ ions in this tris(silylamide) ligand environment. The Dy2+ complex, [K(crypt)][Dy(NR2)3], has a higher magnetic moment than previously observed for any monometallic complex: 11.67 µB. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Synthesis, structure, luminescent, and magnetic properties of carbonato-bridged Zn(II)2Ln(III)2 complexes [(μ4-CO3)2{Zn(II)L(n)Ln(III)(NO3)}2] (Ln(III) = Gd(III), Tb(III), Dy(III); L(1) = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato, L(2) = N,N'-bis(3-ethoxy-2-oxybenzylidene)-1,3-propanediaminato).

    Science.gov (United States)

    Ehama, Kiyomi; Ohmichi, Yusuke; Sakamoto, Soichiro; Fujinami, Takeshi; Matsumoto, Naohide; Mochida, Naotaka; Ishida, Takayuki; Sunatsuki, Yukinari; Tsuchimoto, Masanobu; Re, Nazzareno

    2013-11-04

    Carbonato-bridged Zn(II)2Ln(III)2 complexes [(μ4-CO3)2{Zn(II)L(n)Ln(III)(NO3)}2]·solvent were synthesized through atmospheric CO2 fixation reaction of [Zn(II)L(n)(H2O)2]·xH2O, Ln(III)(NO3)3·6H2O, and triethylamine, where Ln(III) = Gd(III), Tb(III), Dy(III); L(1) = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato, L(2) = N,N'-bis(3-ethoxy-2-oxybenzylidene)-1,3-propanediaminato. Each Zn(II)2Ln(III)2 structure possessing an inversion center can be described as two di-μ-phenoxo-bridged {Zn(II)L(n)Ln(III)(NO3)} binuclear units bridged by two carbonato CO3(2-) ions. The Zn(II) ion has square pyramidal coordination geometry with N2O2 donor atoms of L(n) and one oxygen atom of a bridging carbonato ion at the axial site. Ln(III) ion is coordinated by nine oxygen atoms consisting of four from the deprotonated Schiff-base L(n), two from a chelating nitrate, and three from two carbonate groups. The temperature-dependent magnetic susceptibilities in the range 1.9-300 K, field-dependent magnetization from 0 to 5 T at 1.9 K, and alternating current magnetic susceptibilities under the direct current bias fields of 0 and 1000 Oe were measured. The magnetic properties of the Zn(II)2Ln(III)2 complexes are analyzed on the basis of the dicarbonato-bridged binuclear Ln(III)-Ln(III) structure, as the Zn(II) ion with d(10) electronic configuration is diamagnetic. ZnGd1 (L(1)) and ZnGd2 (L(2)) show a ferromagnetic Gd(III)-Gd(III) interaction with J(Gd-Gd) = +0.042 and +0.028 cm(-1), respectively, on the basis of the Hamiltonian H = -2J(Gd-Gd)ŜGd1·ŜGd2. The magnetic data of the Zn(II)2Ln(III)2 complexes (Ln(III) = Tb(III), Dy(III)) were analyzed by a spin Hamiltonian including the crystal field effect on the Ln(III) ions and the Ln(III)-Ln(III) magnetic interaction. The Stark splitting of the ground state was so evaluated, and the energy pattern indicates a strong easy axis (Ising type) anisotropy. Luminescence spectra of Zn(II)2Tb(III)2 complexes were observed, while those

  6. Positive/negative liquid secondary ion mass spectrometry of Ln-EDTA (1:1) complexes. Formation of molecular ion adducts with neutral species of the matrix or Ln-EDTA

    International Nuclear Information System (INIS)

    Plaziak, A.S.; Lis, S.; Elbanowski, M.

    1992-01-01

    The mass spectra of 1:1 complexes of EDTA with lanthanide cations (Ln=Sm, Eu, Gd, Tb or Dy) upon positive/negative LSIMS are presented. In glycerol used as a matrix, adduct-ions such as [M+H] + , [M+H+nGly] + , [2M+H] + , [2M+H+Gly] + (positive LSIMS) or [M-H] - , [M-H+nGly] - , [2M-H] - , [2M-H+Gly] - (negative LSIMS), where n=1-3, are formed. Reactions leading to the formation of adduct-ions are suggested. (authors)

  7. Bifunctional Zn(II)Ln(III) dinuclear complexes combining field induced SMM behavior and luminescence: enhanced NIR lanthanide emission by 9-anthracene carboxylate bridging ligands.

    Science.gov (United States)

    Palacios, María A; Titos-Padilla, Silvia; Ruiz, José; Herrera, Juan Manuel; Pope, Simon J A; Brechin, Euan K; Colacio, Enrique

    2014-02-03

    There were new dinuclear Zn(II)-Ln(III) complexes of general formulas [Zn(μ-L)(μ-OAc)Ln(NO3)2] (Ln(III) = Tb (1), Dy (2), Er (3), and Yb (4)), [Zn(μ-L)(μ-NO3)Er(NO3)2] (5), [Zn(H2O)(μ-L)Nd(NO3)3]·2CH3OH (6), [Zn(μ-L)(μ-9-An)Ln(NO3)2]·2CH3CN (Ln(III) = Tb (7), Dy (8), Er (9), Yb(10)), [Zn(μ-L)(μ-9-An)Yb(9-An)(NO3)3]·3CH3CN (11), [Zn(μ-L)(μ-9-An)Nd(9-An)(NO3)3]·2CH3CN·3H2O (12), and [Zn(μ-L)(μ-9-An)Nd(CH3OH)2(NO3)]ClO4·2CH3OH (13) prepared from the reaction of the compartmental ligand N,N',N″-trimethyl-N,N″-bis(2-hydroxy-3-methoxy-5-methylbenzyl)diethylenetriamine (H2L), with ZnX2·nH2O (X = NO3(-) or OAc(-)) salts, Ln(NO3)3·nH2O, and, in some instances, 9-anthracenecarboxylate anion (9-An). In all these complexes, the Zn(II) ions invariably occupy the internal N3O2 site whereas the Ln(III) ions show preference for the O4 external site, giving rise to a Zn(μ-diphenoxo)Ln bridging fragment. Depending on the Zn(II) salt and solvent used in the reaction, a third bridge can connect the Zn(II) and Ln(III) metal ions, giving rise to triple-bridged diphenoxoacetate in complexes 1-4, diphenoxonitrate in complex 5, and diphenoxo(9-anthracenecarboxylate) in complexes 8-13. Dy(III) and Er(III) complexes 2, 8 and 3, 5, respectively, exhibit field induced single molecule magnet (SMM) behavior, with Ueff values ranging from 11.7 (3) to 41(2) K. Additionally, the solid-state photophysical properties of these complexes are presented showing that ligand L(2-) is able to sensitize Tb(III)- and Dy(III)-based luminescence in the visible region through an energy transfer process (antenna effect). The efficiency of this process is much lower when NIR emitters such as Er(III), Nd(III), and Yb(III) are considered. When the luminophore 9-anthracene carboxylate is incorporated into these complexes, the NIR luminescence is enhanced which proves the efficiency of this bridging ligand to act as antenna group. Complexes 2, 3, 5, and 8 can be considered as dual materials

  8. Ln(III)-malate complexation studies using TRLFS and micro titration calorimetry

    International Nuclear Information System (INIS)

    Taube, F.; Drobot, B.; Acker, M.; Taut, S.; Stumpf, Thorsten

    2017-01-01

    The complexation of trivalent lanthanides was studied using Time-Resolved Laser-Induced Fluorescence Spectroscopy (TRLFS) and Isothermal Titration Calorimetry (ITC). Formation constants, complexation enthalpies and fluorescence lifetimes are determined over a wide pH range at I = 0.5 m NaCl. This subject has the following background: Concrete is widely used as engineering barrier and for waste conditioning in waste repositories. Its binding agent is cement. Organic cement additives, which are used to improve the workability of fresh concrete, are complexation agents for radionuclides after they have been released during the concretes degradation. Thus, these additives might have an impact on the aqueous geochemistry of actinides. Here, the α-hydroxydicarboxylic acid or malic acid is examined. It is used in water-reducers or retarders in cement.

  9. Ln(III)-malate complexation studies using TRLFS and micro titration calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Taube, F.; Drobot, B. [Technische Univ. Dresden (Germany). Professorship Radiochemistry; Acker, M.; Taut, S. [Technische Univ. Dresden (Germany). Central Radionuclide Laboratory; Stumpf, Thorsten [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology

    2017-06-01

    The complexation of trivalent lanthanides was studied using Time-Resolved Laser-Induced Fluorescence Spectroscopy (TRLFS) and Isothermal Titration Calorimetry (ITC). Formation constants, complexation enthalpies and fluorescence lifetimes are determined over a wide pH range at I = 0.5 m NaCl. This subject has the following background: Concrete is widely used as engineering barrier and for waste conditioning in waste repositories. Its binding agent is cement. Organic cement additives, which are used to improve the workability of fresh concrete, are complexation agents for radionuclides after they have been released during the concretes degradation. Thus, these additives might have an impact on the aqueous geochemistry of actinides. Here, the α-hydroxydicarboxylic acid or malic acid is examined. It is used in water-reducers or retarders in cement.

  10. Heterospin systems constructed from [Cu2Ln]3+ and [Ni(mnt)2]1-,2- Tectons: First 3p-3d-4f complexes (mnt = maleonitriledithiolato).

    Science.gov (United States)

    Madalan, Augustin M; Avarvari, Narcis; Fourmigué, Marc; Clérac, Rodolphe; Chibotaru, Liviu F; Clima, Sergiu; Andruh, Marius

    2008-02-04

    New heterospin complexes have been obtained by combining the binuclear complexes [{Cu(H(2)O)L(1)}Ln(O(2)NO)(3)] or [{CuL(2)}Ln(O(2)NO)(3)] (L(1) = N,N'-propylene-di(3-methoxysalicylideneiminato); L(2) = N,N'-ethylene-di(3-methoxysalicylideneiminato); Ln = Gd(3+), Sm(3+), Tb(3+)), with the mononuclear [CuL(1)(2)] and the nickel dithiolene complexes [Ni(mnt)(2)](q)- (q = 1, 2; mnt = maleonitriledithiolate), as follows: (1)infinity[{CuL(1)}(2)Ln(O(2)NO){Ni(mnt)(2)}].Solv.CH(3)CN (Ln = Gd(3+), Solv = CH(3)OH (1), Ln = Sm(3+), Solv = CH(3)CN (2)) and [{(CH(3)OH)CuL(2)}(2)Sm(O(2)NO)][Ni(mnt)(2)] (3) with [Ni(mnt)2]2-, [{(CH(3)CN)CuL(1)}(2)Ln(H(2)O)][Ni(mnt)(2)]3.2CH(3)CN (Ln = Gd(3+) (4), Sm(3+) (5), Tb(3+) (6)), and [{(CH(3)OH)CuL(2)}{CuL(2)}Gd(O(2)NO){Ni(mnt)(2)}][Ni(mnt)(2)].CH(2)Cl(2) (7) with [Ni(mnt))(2]*-. Trinuclear, almost linear, [CuLnCu] motifs are found in all the compounds. In the isostructural 1 and 2, two trans cyano groups from a [Ni(mnt)2]2- unit bridge two trimetallic nodes through axial coordination to the Cu centers, thus leading to the establishment of infinite chains. 3 is an ionic compound, containing discrete [{(CH(3)OH)CuL(2)}(2)Sm(O(2)NO)](2+) cations and [Ni(mnt)(2)](2-) anions. Within the series 4-6, layers of discrete [CuLnCu](3+) motifs alternate with stacks of interacting [Ni(mnt)(2)](*-) radical anions, for which two overlap modes, providing two different types of stacks, can be disclosed. The strength of the intermolecular interactions between the open-shell species is estimated through extended Hückel calculations. In compound 7, [Ni(mnt)(2)](*-) radical anions coordinate group one of the Cu centers of a trinuclear [Cu(2)Gd] motif through a CN, while discrete [Ni(mnt)(2)](*-) units are also present, overlapping in between, but also with the coordinated ones. Furthermore, the [Cu(2)Gd] moieties dimerize each other upon linkage by two nitrato groups, both acting as chelate toward the gadolinium ion from one unit and monodentate toward a

  11. Selection of the DC-60 cyclotron as the basic facility for the Inter-disciplinary research complex in the L.N. Gumilev Eurasian State University. Chapter 2

    International Nuclear Information System (INIS)

    2003-01-01

    In the Chapter 2 the DC-60 specialized accelerator project of the Inter-disciplinary research complex in the L.N. Gumilev Eurasian State University is described. The DC-60 cyclotron is intended for applied studies which can be accomplished on both the ion beams of the electron cyclotron resonance source with voltage up to 25 kV and the accelerated ions from carbon to xenon. The cyclotron is design on the base of compact magnet with weight about 74 tonnes, and it mean magnetic field is 1.6 T, section angle - 50 Deg. Design of the Inter-disciplinary research complex building in the L.N. Gumilev Eurasian State University is described as well. Technical performances of the building and their parameters are given

  12. Synthesis and magnetism of μ-oxamido-bridged Cu2IILnIII - type heterotrinuclear complexes (Ln = Ce, Nd, Sm, Eu, Gd, Tb, Dy, Er)

    International Nuclear Information System (INIS)

    Li, Y.T.; Yan, C.W.

    2001-01-01

    Eight new Cu 2 II Ln III - type (Ln = Ce, Nd, Sm, Eu, Gd, Tb, Dy, Er) heterotrinuclear complexes bridged by N,N'-bis (2-aminopropyl)oxamidocopper(II) [Cu(oxdn)], namely Cu 2 (oxdn)Ln(NO 3 ) 3 , have been synthesized and characterized by elemental analyses, molar conductivity measurements and spectroscopic (IR, UV, ESR) studies. Magnetic susceptibility measurements (4.2 ∼300 K) and studies of Cu 2 (oxdn)Gd(NO 3 ) 3 complex have revealed that the central gadolinium(III) and terminal copper(II) ions are ferromagnetically coupled with the exchange integral J (Cu-Gd) = +2.98 cm -1 , while an antiferromagnetic coupling is detected between the terminal copper(II) metal ions with the exchange integral J' (Cu-Gd) = -0.75 cm -1 , on the basis of the spin Hamiltonian operator [H -2J(S Cu1 -S Gd +S Cu2 +S Gd )-2J'(S Cu1 S Cu2 )]. (author)

  13. Activation of SO2 with [(η(5) -C5 Me5 )2 Ln(THF)2 ] (Ln=Eu, Yb) leading to dithionite and sulfinate complexes.

    Science.gov (United States)

    Klementyeva, Svetlana V; Gamer, Michael T; Schmidt, Anna-Corina; Meyer, Karsten; Konchenko, Sergey N; Roesky, Peter W

    2014-10-13

    The reaction of decamethylytterbocene [(η(5) -C5 Me5 )2 Yb(THF)2 ] with SO2 at low temperature gave two new compounds, namely, the Yb(III) dithionite/sulfinate complex [{(η(5) -C5 Me5 )2 Yb(μ3 ,1κ(2) O(1,3) ,2κ(3) O(2,2',4) -S2 O4 )}2 {(η(5) -C5 Me5 )Yb(μ,1κO,2κO'-C5 Me5 SO2 )}2 ] (1) and the Yb(III) dithionite complex [{(η(5) -C5 Me5 )2 Yb}2 (μ,1κ(2) O(1,3) ,2κ(2) O(2,4) -S2 O4 )] (2). After extraction of 1, the mixture was heated to give the dinuclear tetrasulfinate complex [{(η(5) -C5 Me5 )Yb}2 (μ,κO,κO'-C5 Me5 SO2 )4 ] (3 a). In contrast, from the reaction of [(η(5) -C5 Me5 )2 Eu(THF)2 ] with SO2 only the tetrasulfinate complex [{(η(5) -C5 Me5 )Eu}2 (μ,κO,κO'-C5 Me5 SO2 )4 ] (3 b) was isolated. Two major reaction pathways were observed: 1) reductive coupling of two SO2 molecules to form the dithionite anion S2 O4 (2-) ; and 2) nucleophilic attack of one metallocene C5 Me5 ligand on the sulfur atom of SO2 . The compounds presented are the first dithionite and sulfinate complexes of the f-elements. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Synthesis, Crystal Structures, Magnetic Properties, and Theoretical Investigation of a New Series of NiII-LnIII-WV Heterotrimetallics: Understanding the SMM Behavior of Mixed Polynuclear Complexes.

    Science.gov (United States)

    Vieru, Veacheslav; Pasatoiu, Traian D; Ungur, Liviu; Suturina, Elizaveta; Madalan, Augustin M; Duhayon, Carine; Sutter, Jean-Pascal; Andruh, Marius; Chibotaru, Liviu F

    2016-12-05

    The polynuclear compounds containing anisotropic metal ions often exhibit efficient barriers for blocking of magnetization at fairly arbitrary geometries. However, at variance with mononuclear complexes, which usually become single-molecule magnets (SMM) under the sole requirement of a highly axial crystal field at the metal ion, the factors influencing the SMM behavior in polynuclear complexes, especially, with weakly axial magnetic ions, still remain largely unrevealed. As an attempt to clarify these conditions, we present here the synthesis, crystal structures, magnetic behavior, and ab initio calculations for a new series of Ni II -Ln III -W V trimetallics, [(CN) 7 W(CN)Ni(H 2 O)(valpn)Ln(H 2 O) 4 ]·H 2 O (Ln = Y 1, Eu 2, Gd 3, Tb 4, Dy 5, Lu 6). The surprising finding is the absence of the magnetic blockage even for compounds involving strongly anisotropic Dy III and Tb III metal ions. This is well explained by ab initio calculations showing relatively large transversal components of the g-tensor in the ground exchange Kramers doublets of 1 and 4 and large intrinsic tunneling gaps in the ground exchange doublets of 3 and 5. In order to get more insight into this behavior, another series of earlier reported compounds with the same trinuclear [W V Ni II Ln III ] core structure, [(CN) 7 W(CN)Ni(dmf)(valdmpn)Ln(dmf) 4 ]·H 2 O (Ln = Gd III 7, Tb III 8a, Dy III 9, Ho III 10), [(CN) 7 W(CN)Ni(H 2 O)(valdmpn)Tb(dmf) 2.5 (H 2 O) 1.5 ]·H 2 O·0.5dmf 8b, and [(CN) 7 W(CN)Ni(H 2 O)(valdmpn)Er(dmf) 3 (H 2 O) 1 ]·H 2 O·0.5dmf 11, has been also investigated theoretically. In this series, only 8b exhibits SMM behavior which is confirmed by the present ab initio calculations. An important feature for the entire series is the strong ferromagnetic coupling between Ni(II) and W(V), which is due to an almost perfect trigonal dodecahedron geometry of the octacyano wolframate fragment. The reason why only 8b is an SMM is explained by positive zero-field splitting on the nickel

  15. Carbonato-bridged Ni(II)2Ln(III)2 (Ln(III) = Gd(III), Tb(III), Dy(III)) complexes generated by atmospheric CO2 fixation and their single-molecule-magnet behavior: [(μ4-CO3)2{Ni(II)(3-MeOsaltn)(MeOH or H2O)Ln(III)(NO3)}2]·solvent [3-MeOsaltn = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato].

    Science.gov (United States)

    Sakamoto, Soichiro; Fujinami, Takeshi; Nishi, Koshiro; Matsumoto, Naohide; Mochida, Naotaka; Ishida, Takayuki; Sunatsuki, Yukinari; Re, Nazzareno

    2013-06-17

    Atmospheric CO2 fixation of [Ni(II)(3-MeOsaltn)(H2O)2]·2.5H2O [3-MeOsaltn = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato], Ln(III)(NO3)3·6H2O, and triethylamine occurred in methanol/acetone, giving a first series of carbonato-bridged Ni(II)2Ln(III)2 complexes [(μ4-CO3)2{Ni(II)(3-MeOsaltn)(MeOH)Ln(III)(NO3)}2] (1Gd, 1Tb, and 1Dy). When the reaction was carried out in acetonitrile/water, it gave a second series of complexes [(μ4-CO3)2{Ni(II)(3-MeOsaltn)(H2O)Ln(III)(NO3)}2]·2CH3CN·2H2O (2Gd, 2Tb, and 2Dy). For both series, each Ni(II)2Ln(III)2 structure can be described as two di-μ-phenoxo-bridged Ni(II)Ln(III) binuclear units bridged by two carbonato CO3(2-) units to form a carbonato-bridged (μ4-CO3)2{Ni(II)2Ln(III)2} structure. The high-spin Ni(II) ion has octahedral coordination geometry, and the Ln(III) ion is coordinated by O9 donor atoms from Ni(II)(3-MeOsaltn), bidentate NO3(-), and one and two oxygen atoms of two CO3(2-) ions. The NO3(-) ion for the first series roughly lie on Ln-O(methoxy) bonds and are tilted toward the outside, while for the second series, the two oxygen atoms roughly lie on one of the Ln-O(phenoxy) bonds due to the intramolecular hydrogen bond. The temperature-dependent magnetic susceptibilities indicated a ferromagnetic interaction between the Ni(II) and Ln(III) ions (Ln(III) = Gd(III), Tb(III), Dy(III)) for all of the complexes, with a distinctly different magnetic behavior between the two series in the lowest-temperature region due to the Ln(III)-Ln(III) magnetic interaction and/or different magnetic anisotropies of the Tb(III) or Dy(III) ion. Alternating-current susceptibility measurements under the 0 and 1000 Oe direct-current (dc) bias fields showed no magnetic relaxation for the Ni(II)2Gd(III)2 complexes but exhibited an out-of-phase signal for Ni(II)2Tb(III)2 and Ni(II)2Dy(III)2, indicative of slow relaxation of magnetization. The energy barriers, Δ/kB, for the spin flipping were estimated from the Arrhenius

  16. Hetero-metallic {3d-4f-5d} complexes: preparation and magnetic behavior of trinuclear [(L(Me2)Ni-Ln){W(CN)(8)}] compounds (Ln = Gd, Tb, Dy, Ho, Er, Y; L(Me2) = Schiff base) and variable SMM characteristics for the Tb derivative.

    Science.gov (United States)

    Sutter, Jean-Pascal; Dhers, Sébastien; Rajamani, Raghunathan; Ramasesha, S; Costes, Jean-Pierre; Duhayon, Carine; Vendier, Laure

    2009-07-06

    Assembling bimetallic {Ni-Ln}(3+) units and {W(CN)(8)}(3-) is shown to be an efficient route toward heteronuclear {3d-4f-5d} compounds. The reaction of either the binuclear [{L(Me2)Ni(H(2)O)(2)}{Ln(NO(3))(3)}] complexes or their mononuclear components [L(Me2)Ni] and Ln(NO(3))(3) with (HNBu(3))(3){W(CN)(8)} in dmf followed by diffusion of tetrahydrofuran yielded the trinuclear [{L(Me2)NiLn}{W(CN)(8)}] compounds 1 (Ln = Y), 2a,b (Gd), 3a,b (Tb), 4 (Dy), 5 (Ho), and 6 (Er) as crystalline materials. All of the derivatives possess the trinuclear core resulting from the linkage of the {W(CN)(8)} to the Ni center of the {Ni-Ln} unit. Differences are found in the solvent molecules acting as ligands and/or in the lattice depending on the crystallization conditions. For all the compounds ferromagnetic {Ni-W} and {Ni-Ln} (Ln = Gd, Tb, Dy, and Er} interactions are operative resulting in high spin ground states. Parameterization of the magnetic behaviors for the Y and Gd derivatives confirmed the strong cyano-mediated {Ni-W} interaction (J(NiW) = 27.1 and 28.5 cm(-1)) compared to the {Ni-Gd} interaction (J(NiGd) = 2.17 cm(-1)). The characteristic features for slow relaxation of the magnetization are observed for two Tb derivatives, but these are modulated by the crystal phase. Analysis of the frequency dependence of the alternating current susceptibility data yielded U(eff)/k(B) = 15.3 K and tau(0) = 4.5 x 10(-7) s for one derivative whereas no maxima of chi(M)'' appear above 2 K for the second one.

  17. Implementation of the Inter-disciplinary research complex in the L.N. Gumilev Eurasian State University is the step to a modern knowledge intensive technologies

    International Nuclear Information System (INIS)

    Shkol'nik, V.S.; Zholdasbekov, M.Zh.; Kadyrzhanov, K.K.; Itkis, M.G.; Dmitriev, S.N.

    2003-01-01

    In the book the rationale for the Inter-disciplinary research complex implementation in the L.N. Gumilev Eurasian State University (Astana city, Kazakhstan) is given. The design of key facility of the complex - the heavy ion accelerator (DC-60) is described. Application of nuclear membranes as an integrating factor for development of a new technologies, science and a knowledge intensive business is discussed. In these concerns the problems of an industrial technologies development with use of the nano- and microstructures on the nuclear membranes base are considered. The items of the scientific environment formation on the Inter-disciplinary research complex are analyzed. The book is intended for engineers, postgraduates and students specializing in the field of nuclear physics, radiation solid state physics, physics of films and coatings, accelerator technique, material modification with use of charged particles beams

  18. DFT study of electron absorption and emission spectra of pyramidal LnPc(OAc) complexes of some lanthanide ions in the solid state

    Science.gov (United States)

    Hanuza, J.; Godlewska, P.; Lisiecki, R.; Ryba-Romanowski, W.; Kadłubański, P.; Lorenc, J.; Łukowiak, A.; Macalik, L.; Gerasymchuk, Yu.; Legendziewicz, J.

    2018-05-01

    The electron absorption and emission spectra were measured for the pyramidal LnPc(OAc) complexes in the solid state and co-doped in silica glass, where Ln = Er, Eu and Ho. The theoretical electron spectra were determined from the quantum chemical DFT calculation using four approximations CAM-B3LYP/LANL2DZ, CAM-B3LYP/CC-PVDZ, B3LYP/LANL2DZ and B3LYP/CC-PVDZ. It was shown that the best agreement between the calculated and experimental structural parameters and spectroscopic data was reached for the CAM-B3LYP/LANL2DZ model. The emission spectra were measured using the excitations both in the ligand and lanthanide absorption ranges. The possibility of energy transfer between the phthalocyanine ligand and excited states of lanthanide ions was discussed. It was shown that the back energy transfer from metal states to phthalocyanine state is responsible for the observed emission of the studied complexes both in the polycrystalline state and silica glass.

  19. Slow magnetic relaxation and single-molecule toroidal behaviour in a family of heptanuclear {Cr"I"I"ILn"I"I"I_6} (Ln=Tb, Ho, Er) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Vignesh, Kuduva R. [IITB-Monash Research Academy, IIT Bombay, Powai, Mumbai (India); Langley, Stuart K. [School of Science and the Environment, Division of Chemistry, Manchester Metropolitan University, Manchester (United Kingdom); Swain, Abinash; Rajaraman, Gopalan [Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai (India); Moubaraki, Boujemaa; Murray, Keith S. [School of Chemistry, Monash University, Clayton, VIC (Australia); Damjanovic, Marko; Wernsdorfer, Wolfgang [Institute Neel, CNRS, Universite Grenoble Alpes, Grenoble (France); Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany)

    2018-01-15

    The synthesis, magnetic properties, and theoretical studies of three heterometallic {Cr"I"I"ILn"I"I"I_6} (Ln=Tb, Ho, Er) complexes, each containing a metal topology consisting of two Ln{sub 3} triangles connected via a Cr{sup III} linker, are reported. The {CrTb_6} and {CrEr_6} analogues display slow relaxation of magnetization in a 3000 Oe static magnetic field. Single-crystal measurements reveal opening up of the hysteresis loop for {CrTb_6} and {CrHo_6} molecules at low temperatures. Ab initio calculations predict toroidal magnetic moments in the two Ln{sub 3} triangles, which are found to couple, stabilizing a con-rotating ferrotoroidal ground state in Tb and Ho examples and extend the possibility of observing toroidal behaviour in non Dy{sup III} complexes for the first time. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Design of DC-60 cyclotron with the fair ion energy variation for the Inter-disciplinary laboratory complex by L.N. Gumilev Eurasian State University

    International Nuclear Information System (INIS)

    Gukal, B.N.; Itkis, M.G.; Dmitriev, S.N.; Gul'bekyan, G.G.; Franko, J.; Kadyrzhanov, K.K.; Arzumanov, A.A.; Borisenko, A.N.; Lysukhin, S.N.

    2003-01-01

    The DC-60 heavy ions cyclotron pre-design project is implemented. The cyclotron is the key facility of the Inter-disciplinary laboratory complex by L.N. Gumilev Eurasian State University. In comparison with previous project in a new one the possibility for fair variation of the ions energies on 30 % at the expense of magnetic field level change is planed. The magnet structure of the cyclotron allowing to vary the magnet field from 1.25 to 1.65 T with use the low-power magnet coils system is found. The accelerator provides the opportunity for the ions acceleration from Li to Xe with energies from 0.4 to 1.6 MeV/nucleon. The exterior ion source of the ECR type will be planing to use on the cyclotrons and axial beam injection system development will be created. The extending voltage on the ion source is 10-25 kV. For experiments conducting on the cyclotron complex is expecting to create on channel for low energy beams - 10-25 kV per charge (ECR source beams) and three withdrawn channels for accelerated ion beams, one of those will be packaged with necessary equipment for the nuclear filters manufacture. The cyclotron complex will be used for both the fulfillment of a wide range of scientific and applied problems and a students training

  1. Design of DC-60 specialized accelerator for the Inter-disciplinary Laboratory Complex by the L.N. Gumilev Eurasian State University

    International Nuclear Information System (INIS)

    Gikal, B.N.; Itkis, M.G.; Dmitriev, S.N.; Gul'bekyan, G.G.; Franko, J.; ); Kadyrzhanov, K.K.; Arzumanov, A.A.; Borisenko, A.N.; Lysukhin, S.N.

    2001-01-01

    Design of the Inter-disciplinary Laboratory Complex by the L.N. Eurasian State University allows development and implementation of specialized heavy ion accelerator. According requirements of research programme the most optimal accelerator is compact cyclotron with fixed magnetic field and varying frequency of high-frequency system in dependence on mass rate to accelerated ions charge. The accelerator has two accelerating modes - on 4 and 6 harmonics, that allow to accelerate ions from C to Xe with energies from 0.4 to 1.6 MeV/nucleon. The beam take out is occurring by electrostatic deflector. The beam will be transporting to physical unit for research conducting. The cyclotron is equipped with ECR source and axial beam injection system.The extending voltage on the ion source is 10-25 k W. On the injection line it is planning to create the channel - after analyzing magnet -for using of satellite beams, that allow to conduct experiments on a low energy ions beams. In all accelerating modes the ions energy does not exceeds the Coulomb barrier and so the unit is radiation safe. The cyclotron complex could be used for fulfilment of a wide circle of research and applied tasks, as well as for students and postgraduates training

  2. 2-D and 3-D phosphotungstate-based TM-Ln heterometallic derivatives constructed from dimeric [Ln({alpha}-PW{sub 11}O{sub 39}){sub 2}]{sup 11-} fragments and copper-organic complex linkers

    Energy Technology Data Exchange (ETDEWEB)

    Shang, Sensen [Institute of Molecular and Crystal Engineering, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China); Zhao, Junwei, E-mail: zhaojunwei@henu.edu.cn [Institute of Molecular and Crystal Engineering, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Chen, Lijuan [Institute of Molecular and Crystal Engineering, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China); Basic Experiment Teaching Center, Henan University, Kaifeng, Henan 475004 (China); Li, Yuye; Zhang, Jingli; Li, Yanzhou [Institute of Molecular and Crystal Engineering, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China); Niu, Jingyang, E-mail: jyniu@henu.edu.cn [Institute of Molecular and Crystal Engineering, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China)

    2012-12-15

    Three organic-inorganic hybrid TM-Ln heterometallic phosphotungstates [Cu(dap){sub 2}(H{sub 2}O)][Cu(dap){sub 2}]{sub 3.5}[La({alpha}-HPW{sub 11}O{sub 39}){sub 2}]{center_dot}6H{sub 2}O (1) [Cu(dap){sub 2}(H{sub 2}O)]{sub 0.5}[Cu(dap){sub 2}]{sub 4}[Nd({alpha}-HPW{sub 11}O{sub 39}){sub 2}]{center_dot}4H{sub 2}O (2) and [Cu(dap){sub 2}(H{sub 2}O)]{sub 2}[Cu(dap){sub 2}]{sub 3.5}[Eu({alpha}-PW{sub 11}O{sub 39}){sub 2}]{center_dot}6H{sub 2}O (3) (dap=1,2-diaminopropane) have been hydrothermally synthesized and structurally characterized by elemental analyses, IR spectra, optical diffuse reflectance spectra, powder X-ray diffraction (PXRD), thermogravimetric (TG) analyses and single-crystal X-ray diffraction. Their common features are that 1-3 all consist of asymmetric sandwich-type subunits [Ln({alpha}-PW{sub 11}O{sub 39}){sub 2}]{sup 11-} and [Cu(dap){sub 2}]{sup 2+} bridges. Both 1 and 2 display the 2-D (4,4)-topological sheets whereas 3 exhibits the 3-D 5-connected (4{sup 6}{center_dot}6{sup 4}) topological framework. The magnetic properties of 2 and 3 and the luminescence performance of 3 have been measured. - Graphical Abstract: Three TM-Ln heterometallic phosphotungstates 1-3 have been synthesized and characterized by elemental analyses, IR spectra, optical diffuse reflectance spectra, X-ray diffraction, thermogravimetric analyses magnetic susceptibility and luminescent properties. Highlights: Black-Right-Pointing-Pointer Cu{sup II}-Ln{sup III} heterometallic polyoxometalates. Black-Right-Pointing-Pointer 2-D and 3-D organic-inorganic hybrid phosphotungstates. Black-Right-Pointing-Pointer 2-D and 3-D structures consisting of Cu{sup II}-Ln{sup III} heterometals.

  3. Improving the SMM and luminescence properties of lanthanide complexes with LnO9 cores in the presence of ZnII: an emissive Zn2Dy single ion magnet.

    Science.gov (United States)

    Fondo, Matilde; Corredoira-Vázquez, Julio; Herrera-Lanzós, Antía; García-Deibe, Ana M; Sanmartín-Matalobos, Jesús; Herrera, Juan Manuel; Colacio, Enrique; Nuñez, Cristina

    2017-12-12

    Mononuclear complexes of stoichiometry [Ln(H 3 L)(H 2 O)(NO 3 )](NO 3 ) 2 (Ln = Tb, 1; Dy, 2, Er, 3), which crystallise with different solvates, and the heterotrinuclear compound [Zn 2 Dy(L)(NO 3 ) 3 (OH)] (4) can be obtained with the same H 3 L compartmental ligand. The single X-ray crystal structure of the mononuclear complexes shows a LnO 9 core with a muffin-like disposition while the geometry of the DyO 9 core in 4 seems to be closer to spherical capped square antiprism. The analysis of the magnetic properties of all the complexes demonstrates that the mononuclear lanthanide compounds do not show slow relaxation of the magnetization, even when the samples are diluted with a diamagnetic matrix and subjected to a dc applied field of 1000 Oe. Nevertheless, the heterotrinuclear dysprosium complex 4·3H 2 O is a field-induced single ion magnet, with an estimated U eff barrier of 59 K. The luminescence characterisation of all the metal complexes in methanol solution at 298 K also shows a notable increase in the fluorescence emission of the heterotrinuclear complex with respect to the mononuclear ones, in such a way that 4 can be defined as a fluorescent single ion magnet.

  4. The role of Ln

    NARCIS (Netherlands)

    Katayama, Y.; Kayumi, T.; Ueda, J.; Dorenbos, P.; Viana, B; Tanabe, S

    2017-01-01

    In this paper, Mn2+ and Ln3+ (Ln = Eu, Yb) co-doped MgGeO3 phosphors were prepared using a solid state reaction technique, and their optical properties were investigated. Mn2+-doped samples exhibit persistent luminescence in the red region, peaking at 677 nm, because of the 4T1 → 6A1 transition of

  5. Syntheses, structures, and magnetic properties of a family of heterometallic heptanuclear [Cu5Ln2] (Ln = Y(III), Lu(III), Dy(III), Ho(III), Er(III), and Yb(III)) complexes: observation of SMM behavior for the Dy(III) and Ho(III) analogues.

    Science.gov (United States)

    Chandrasekhar, Vadapalli; Dey, Atanu; Das, Sourav; Rouzières, Mathieu; Clérac, Rodolphe

    2013-03-04

    Sequential reaction of the multisite coordination ligand (LH3) with Cu(OAc)2·H2O, followed by the addition of a rare-earth(III) nitrate salt in the presence of triethylamine, afforded a series of heterometallic heptanuclear complexes containing a [Cu5Ln2] core {Ln = Y(1), Lu(2), Dy(3), Ho(4), Er(5), and Yb(6)}. Single-crystal X-ray crystallography reveals that all the complexes are dicationic species that crystallize with two nitrate anions to compensate the charge. The heptanuclear aggregates in 1-6 are centrosymmetrical complexes, with a hexagonal-like arrangement of six peripheral metal ions (two rare-earth and four copper) around a central Cu(II) situated on a crystallographic inversion center. An all-oxygen environment is found to be present around the rare-earth metal ions, which adopt a distorted square-antiprismatic geometry. Three different Cu(II) sites are present in the heptanuclear complexes: two possess a distorted octahedral coordination sphere while the remaining one displays a distorted square-pyramidal geometry. Detailed static and dynamic magnetic properties of all the complexes have been studied and revealed the single-molecule magnet behavior of the Dy(III) and Ho(III) derivatives.

  6. Synthesis and characterization of charge-substituted garnets YCaLnGa5O12 (Ln = Ce,Pr,Tb)

    International Nuclear Information System (INIS)

    Gramsch, S.A.

    1993-01-01

    A low temperature method is described for the preparation of the new garnet compounds YCaLnGa 5 O l2 (Ln=Ce, Pr, Th). In this set of compounds (Ca 2+ + Ln 4+ ) replaces 2 Y 3+ in the parent gallium based garnet Y 3 Ga 5 O l2 in order to stabilize as effectively as possible the Ln 4+ species in the eight-coordinate ''A'' site of the garnet structure. Characterization of the oxides by x-ray powder diffraction and thermogravimetric analysis is discussed with regard to the structural relationship of the substituted compound to the parent material. The tetravalent ions Pr 4+ and Tb 4+ exhibit increased thermal stability in reducing conditions as compared to the Ln 4+ states in the fluorite (LnO 2 ) and perovskite (BaLnO 3 ) type structures. This result is discussed with reference to the complex crystal chemistry of these systems

  7. Modeling 4f–4f intensity parameters as a function of structural distortions in Ln(2,2′-bipyridine-1,1′-dioxide){sub 4}(ClO{sub 4}){sub 3} complexes (Ln=Pr{sup 3+}, Nd{sup 3+})

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, A.N. [Departamento de Química Fundamental, Universidade Federal de Pernambuco-CCEN, Cidade Universitária, Recife-PE 50670-901 (Brazil); Huskowska, E.; Gawryszewska, P. [Faculty of Chemistry, Wroclaw University, 14 F. Joliot-Curie Street, Wroclaw (Poland); Legendziewicz, J., E-mail: janina.legendziewicz@chem.uni.wroc.pl [Faculty of Chemistry, Wroclaw University, 14 F. Joliot-Curie Street, Wroclaw (Poland); Malta, O.L. [Departamento de Química Fundamental, Universidade Federal de Pernambuco-CCEN, Cidade Universitária, Recife-PE 50670-901 (Brazil)

    2016-01-15

    This work reports on the influence of structural distortions on 4f–4f intensity parameters. These distortions in the first coordination sphere were applied to two complexes with similar structures, Ln(bpyO{sub 2}){sub 4}(ClO{sub 4}){sub 3} (Ln=Pr{sup 3+}, Nd{sup 3+} ions and bpyO{sub 2}=2,2′-bipyridine-1,1′-dioxide). The 4f–4f intensity theory and the PM3/Sparkle model were used. It is concluded that larger distortions are predicted in the case of the Pr complex, and that this point might contribute to the rationalization of the much higher values of the Ω{sub λ} intensity parameters in the Pr complex than in the Nd one. - Highlights: • The influence of structural distortions on 4f–4f intensity parameters was demonstrated for Nd and Pr complexes with 2,2′-bipyridine-1,1′-dioxide.

  8. Solvothermal syntheses, crystal structures, and properties of lanthanide(III) thioarsenates [Ln(dien)2(μ-1κ,2κ2-AsS4)]n (Ln==Sm, Eu, Gd) and [Ln(dien)2(1κ2-AsS4)] (Ln==Tb, Dy, Ho)

    International Nuclear Information System (INIS)

    Wang, Fang; Tang, Chunying; Chen, Ruihong; Zhang, Yong; Jia, Dingxian

    2013-01-01

    Solvothermal reactions of Ln 2 O 3 , As and S in diethylenetriamine (dien) at 170 °C for 6 days afforded two structural types of lanthanide thioarsenates with the general formulae [Ln(dien) 2 (μ-1κ,2κ 2 -AsS 4 )] n [Ln=Sm(1), Eu(2), Gd(3)] and [Ln(dien) 2 (1κ 2 -AsS 4 )] [Ln=Tb(4), Dy(5), Ho(6)]. The Ln 2 O 3 oxides were converted to [Ln(dien) 2 ] 3+ complex units in the solvothermal reactions. The As atom binds four S atoms, forming a tetrahedral AsS 4 unit. In 1−3, the AsS 4 units interconnect the [Ln(dien) 2 ] 3+ cations via Ln−S bonds as tridentate μ-1κ,2κ 2 -AsS 4 bridging ligands, resulting in the neutral coordination polymers [Ln(dien) 2 (μ-1κ,2κ 2 -AsS 4 )] n (Ln1). In 4−6, the AsS 4 units coordinate with the Ln 3+ ion of [Ln(dien) 2 ] 3+ as 1κ 2 -AsS 4 chelating ligands to form neutral coordination compounds [Ln(dien) 2 (1κ 2 -AsS 4 )] (Ln2). The Ln 3+ ions are in nine- and eight-coordinated environments in Ln1 and Ln2, respectively. The formation of Ln1 and Ln2 is related with ionic size of the Ln 3+ ions. Optical absorption spectra showed that 1−6 have potential use as semiconductors with the band gaps in the range 2.18−3.21 eV. - Graphical abstract: Two types of Ln-thioarsenates [Ln(dien) 2 (μ-1κ,2κ 2 -AsS 4 )] n and [Ln(dien) 2 (1κ 2 -AsS 4 )] were prepared by solvothermal methods and the soft Lewis basic AsS 4 3– ligand to Ln(III) centers with polyamine co-ligand was obtained. Display Omitted - Highlights: • Lanthanide thioarsenates were prepared by solvothermal methods. • The soft Lewis basic AsS 4 ligand coordinate Ln 3+ ions with coexistence polyamine ligands. • Two structural types of Ln-thioarsenates with structural turnover at Tb were obtained along Ln series. • The Ln-thioarsenates are potential semiconductors with optical band gaps in the range 2.18−3.21 eV

  9. Lanthanide(III) complexes with μ-SnSe{sub 4} and μ-Sn{sub 2}Se{sub 6} linkers. Solvothermal syntheses and properties of new Ln(III) selenidostannates decorated with linear polyamine

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shuzhen; Sun, Peipei; Shen, Yali; Han, Jingyu; Sun, Hui; Jia, Dingxian [Soochow Univ., Suzhou (China). College of Chemistry, Chemical Engineering and Materials Science

    2017-06-01

    New lanthanide-selenidostannate complexes [{La(peha)(Cl)}{La(peha)(NO_3)}(μ-1κ{sup 2}:2κ{sup 2}-SnSe{sub 4})] (1), [H{sub 2}trien][{La(trien)_2}{sub 2}(μ-1-κ:2κ-Sn{sub 2}Se{sub 6})][Sn{sub 2}Se{sub 6}].H{sub 2}O (2) and [{Ln(tepa)(μ-OH)}{sub 2}(μ-1κ:2κ-Sn{sub 2}Se{sub 6})]{sub n}.nH{sub 2}O (Ln=Sm(3), Eu(4)) were prepared by solvothermal methods in pentaethylenehexamine (peha), triethylenetetramine (trien) and tetraethylenepentamine (tepa), respectively. Acting as a tetradentate chelating and bridging ligand, μ-1κ{sup 2}:2κ{sup 2}-SnSe{sub 4}, the tetrahedral SnSe{sub 4} unit joins {La(peha)(Cl)}{sup 2+} and {La(peha)(NO_3)}{sup 2+} complex fragments to generate the neutral coordination compound 1. The tetradentate μ-1κ{sup 2}:2κ{sup 2} bridge in 1 represents a new coordination mode for the SnSe{sub 4} tetrahedron. In 2, dinuclear [Sn{sub 2}Se{sub 6}]{sup 4-} anions are formed of SnSe{sub 4} tetrahedra via edge-sharing. One [Sn{sub 2}Se{sub 6}]{sup 4-} anion acts as a bidentate bridging ligand in a μ-1κ:2κ coordination mode to join two {La(trien)_2}{sup 3+} units, and the other [Sn{sub 2}Se{sub 6}]{sup 4-} anion exists as a free charge compensating ion. In 3 and 4, the [Sn{sub 2}Se{sub 6}]{sup 4-} anion connects binuclear [{Ln(tepa)(μ-OH)}{sub 2}]{sup 2+}(Ln=Sm, Eu) units with a bidentate μ-1κ:2κ mode, giving neutral coordination polymers [{Ln(tepa)(μ-OH)}{sub 2}(μ-1κ:2κ-Sn{sub 2}Se{sub 6})]{sub n}. The La(2){sup 3+} ion in 1 is in a 10-fold coordination environment of LaN{sub 6}O{sub 2}Se{sub 2}, whereas the La(1){sup 3+} ions in 1 and 2 are in 9-fold coordinated environments forming polyhedra LaN{sub 6}ClSe{sub 2} and LaN{sub 8}Se, respectively. The Sm{sup 3+} and Eu{sup 3+} ions in 3 and 4 are both in an 8-fold coordination environment of LnN{sub 5}O{sub 2}Se. Compounds 1-4 exhibit optical band gaps between 2.21 and 2.42 eV. Their thermal stabilities were investigated by thermogravimetric analyses.

  10. Synthesis and magneto-structural studies on a new family of carbonato bridged 3d-4f complexes featuring a [CoLn(CO3)] (Ln = La, Gd, Tb, Dy and Ho) core: slow magnetic relaxation displayed by the cobalt(ii)-dysprosium(iii) analogue.

    Science.gov (United States)

    Majee, Mithun Chandra; Towsif Abtab, Sk Md; Mondal, Dhrubajyoti; Maity, Manoranjan; Weselski, Marek; Witwicki, Maciej; Bieńko, Alina; Antkowiak, Michał; Kamieniarz, Grzegorz; Chaudhury, Muktimoy

    2018-03-06

    A new family of [3 + 3] hexanuclear 3d-4f complexes [(μ 3 -CO 3 ){Co II Ln III L(μ 3 -OH)(OH 2 )} 3 ]-(ClO 4 )·mC 2 H 5 OH·nH 2 O (1-5) [Ln = La (1), Gd (2), Tb (3), Dy (4), and Ho (5)] have been prepared in moderate to high yields (62-78%) following a self-assembly reaction between the ligand 6,6',6''-(nitrilotris(methylene))tris-(2-methoxy-4-methylphenol) (H 3 L), Co(OAc) 2 ·4H 2 O and the lanthanide ion precursors in the mandatory presence of tetrabutylammonium hydroxide. During the reaction, atmospheric carbon dioxide is fixed in the product molecule as a bridging carbonato ligand which connects all the three lanthanide centers of this molecular assembly through a rare η 2 :η 2 :η 2 -μ 3 mode of bridging as revealed from X-ray crystallography. The metal centers in all these compounds, except the Gd III analogue (2), are coupled in antiferromagnetic manner while the nature of coupling in the CoGd complex is ferromagnetic. DFT calculations revealed that this ferromagnetic interaction occurs most likely by the Co II -Gd III superexchange, mediated via the bridging oxygen atoms. Only the Co II -Dy III compound (4) displayed a slow relaxation of the magnetization at a very low temperature as established by AC susceptibility measurements. The data provides an estimation of the activation energy U/k B = 9.2 K and the relaxation time constant τ 0 = 1.0 × 10 -7 s.

  11. Complexation of trivalent actinides and lanthanides with hydrophilic N-donor ligands for Am(III)/Cm(III) and An(III)/Ln(III) separation; Komplexierung von trivalenten Actiniden und Lanthaniden mit hydrophilen N-Donorliganden zur Am(III)/Cm(III)- bzw. An(III)/Ln(III)-Trennung

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Christoph

    2017-07-24

    The implementation of actinide recycling processes is considered in several countries, aiming at the reduction of long-term radiotoxicity and heat load of used nuclear fuel. This requires the separation of the actinides from the fission and corrosion products. The separation of the trivalent actinides (An(III)) Am(III) and Cm(III), however, is complicated by the presence of the chemically similar fission lanthanides (Ln(III)). Hydrophilic N-donor ligands are employed as An(III) or Am(III) selective complexing agents in solvent extraction to strip An(III) or Am(III) from an organic phase loaded with An(III) and Ln(III). Though they exhibit excellent selectivity, the complexation chemistry of these ligands and the complexes formed during solvent extraction are not sufficiently characterized. In the present thesis the complexation of An(III) and Ln(III) with hydrophilic N-donor ligands is studied by time resolved laser fluorescence spectroscopy (TRLFS), UV/Vis, vibronic sideband spectroscopy and solvent extraction. TRLFS studies on the complexation of Cm(III) and Eu(III) with the Am(III) selective complexing agent SO{sub 3}-Ph-BTBP (tetrasodium 3,3{sup '},3'',3{sup '''}-([2,2{sup '}-bipyridine]-6,6{sup '}-diylbis(1,2,4-triazine-3,5,6-triyl)) tetrabenzenesulfonate) revealed the formation of [M(SO{sub 3}-Ph-BTBP){sub n}]{sup (4n-3)-} complexes (M = Cm(III), Eu(III); n = 1, 2). The conditional stability constants were determined in different media yielding two orders of magnitude larger β{sub 2}-values for the Cm(III) complexes, independently from the applied medium. A strong impact of ionic strength on the stability and stoichiometry of the formed complexes was identified, resulting from the stabilization of the pentaanionic [M(SO{sub 3}-Ph-BTBP){sub 2}]{sup 5-} complex with increasing ionic strength. Thermodynamic studies of Cm(III)-SO{sub 3}-Ph-BTBP complexation showed that the proton concentration of the applied medium impacts

  12. Magnetic properties and structural transitions of fluorite-related rare earth osmates Ln3OsO7 (Ln=Pr, Tb)

    International Nuclear Information System (INIS)

    Hinatsu, Yukio; Doi, Yoshihiro

    2013-01-01

    Ternary rare-earth osmates Ln 3 OsO 7 (Ln=Pr, Tb) have been prepared. They crystallize in an ortho-rhombic superstructure of cubic fluorite with space group Cmcm. Both of these compounds undergo a structural phase transition at 130 K (Ln=Pr) and 580 K (Ln=Tb). These compounds show complex magnetic behavior at low temperatures. Pr 3 OsO 7 exhibits magnetic transitions at 8 and 73 K, and Tb 3 OsO 7 magnetically orders at 8 and 60 K. The Os moments become one-dimensionally ordered, and when the temperature is furthermore decreased, it provokes the ordering in the Ln 3+ sublattice that simultaneously becomes three-dimensionally ordered with the Os sublattice. - Graphical abstract: Ternary rare-earth osmates Ln 3 OsO 7 (Ln=Pr, Tb) have been prepared. They crystallize in an orthorhombic superstructure of cubic fluorite with space group Cmcm. Both of these compounds undergo a structural phase transition at 130 K (Ln=Pr) and 580 K (Ln=Tb). These compounds show complex magnetic behavior at low temperatures. Pr 3 OsO 7 exhibits magnetic transitions at 8 and 73 K, and Tb 3 OsO 7 magnetically orders at 8 and 60 K. Highlights: ► Ternary rare-earth osmates Ln 3 OsO 7 (Ln=Pr, Tb) with an ordered defect-fluorite structure have been prepared. ► Both of these compounds undergo a structural phase transition at 130 K (Ln=Pr) and 580 K (Ln=Tb). ► These compounds show complex magnetic behavior at low temperatures due to magnetic ordering of Ln and Os.

  13. Magnetic properties and structural transitions of fluorite-related rare earth osmates Ln{sub 3}OsO{sub 7} (Ln=Pr, Tb)

    Energy Technology Data Exchange (ETDEWEB)

    Hinatsu, Yukio, E-mail: hinatsu@sci.hokudai.ac.jp [Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Doi, Yoshihiro [Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan)

    2013-02-15

    Ternary rare-earth osmates Ln{sub 3}OsO{sub 7} (Ln=Pr, Tb) have been prepared. They crystallize in an ortho-rhombic superstructure of cubic fluorite with space group Cmcm. Both of these compounds undergo a structural phase transition at 130 K (Ln=Pr) and 580 K (Ln=Tb). These compounds show complex magnetic behavior at low temperatures. Pr{sub 3}OsO{sub 7} exhibits magnetic transitions at 8 and 73 K, and Tb{sub 3}OsO{sub 7} magnetically orders at 8 and 60 K. The Os moments become one-dimensionally ordered, and when the temperature is furthermore decreased, it provokes the ordering in the Ln{sup 3+} sublattice that simultaneously becomes three-dimensionally ordered with the Os sublattice. - Graphical abstract: Ternary rare-earth osmates Ln{sub 3}OsO{sub 7} (Ln=Pr, Tb) have been prepared. They crystallize in an orthorhombic superstructure of cubic fluorite with space group Cmcm. Both of these compounds undergo a structural phase transition at 130 K (Ln=Pr) and 580 K (Ln=Tb). These compounds show complex magnetic behavior at low temperatures. Pr{sub 3}OsO{sub 7} exhibits magnetic transitions at 8 and 73 K, and Tb{sub 3}OsO{sub 7} magnetically orders at 8 and 60 K. Highlights: Black-Right-Pointing-Pointer Ternary rare-earth osmates Ln{sub 3}OsO{sub 7} (Ln=Pr, Tb) with an ordered defect-fluorite structure have been prepared. Black-Right-Pointing-Pointer Both of these compounds undergo a structural phase transition at 130 K (Ln=Pr) and 580 K (Ln=Tb). Black-Right-Pointing-Pointer These compounds show complex magnetic behavior at low temperatures due to magnetic ordering of Ln and Os.

  14. Construction of Polynuclear Lanthanide (Ln = Dy(III), Tb(III), and Nd(III)) Cage Complexes Using Pyridine-Pyrazole-Based Ligands: Versatile Molecular Topologies and SMM Behavior.

    Science.gov (United States)

    Bala, Sukhen; Sen Bishwas, Mousumi; Pramanik, Bhaskar; Khanra, Sumit; Fromm, Katharina M; Poddar, Pankaj; Mondal, Raju

    2015-09-08

    Employment of two different pyridyl-pyrazolyl-based ligands afforded three octanuclear lanthanide(III) (Ln = Dy, Tb) cage compounds and one hexanuclear neodymium(III) coordination cage, exhibiting versatile molecular architectures including a butterfly core. Relatively less common semirigid pyridyl-pyrazolyl-based asymmetric ligand systems show an interesting trend of forming polynuclear lanthanide cage complexes with different coordination environments around the metal centers. It is noteworthy here that construction of lanthanide complex itself is a challenging task in a ligand system as soft N-donor rich as pyridyl-pyrazol. We report herein some lanthanide complexes using ligand containing only one or two O-donors compare to five N-coordinating sites. The resultant multinuclear lanthanide complexes show interesting magnetic and spectroscopic features originating from different spatial arrangements of the metal ions. Alternating current (ac) susceptibility measurements of the two dysprosium complexes display frequency- and temperature-dependent out-of-phase signals in zero and 0.5 T direct current field, a typical characteristic feature of single-molecule magnet (SMM) behavior, indicating different energy reversal barriers due to different molecular topologies. Another aspect of this work is the occurrence of the not-so-common SMM behavior of the terbium complex, further confirmed by ac susceptibility measurement.

  15. Solvothermal syntheses, crystal structures, and properties of lanthanide(III) thioarsenates [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} (Ln==Sm, Eu, Gd) and [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] (Ln==Tb, Dy, Ho)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Fang; Tang, Chunying; Chen, Ruihong; Zhang, Yong; Jia, Dingxian, E-mail: jiadingxian@suda.edu.cn

    2013-10-15

    Solvothermal reactions of Ln{sub 2}O{sub 3}, As and S in diethylenetriamine (dien) at 170 °C for 6 days afforded two structural types of lanthanide thioarsenates with the general formulae [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} [Ln=Sm(1), Eu(2), Gd(3)] and [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] [Ln=Tb(4), Dy(5), Ho(6)]. The Ln{sub 2}O{sub 3} oxides were converted to [Ln(dien){sub 2}]{sup 3+} complex units in the solvothermal reactions. The As atom binds four S atoms, forming a tetrahedral AsS{sub 4} unit. In 1−3, the AsS{sub 4} units interconnect the [Ln(dien){sub 2}]{sup 3+} cations via Ln−S bonds as tridentate μ-1κ,2κ{sup 2}-AsS{sub 4} bridging ligands, resulting in the neutral coordination polymers [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} (Ln1). In 4−6, the AsS{sub 4} units coordinate with the Ln{sup 3+} ion of [Ln(dien){sub 2}]{sup 3+} as 1κ{sup 2}-AsS{sub 4} chelating ligands to form neutral coordination compounds [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] (Ln2). The Ln{sup 3+} ions are in nine- and eight-coordinated environments in Ln1 and Ln2, respectively. The formation of Ln1 and Ln2 is related with ionic size of the Ln{sup 3+} ions. Optical absorption spectra showed that 1−6 have potential use as semiconductors with the band gaps in the range 2.18−3.21 eV. - Graphical abstract: Two types of Ln-thioarsenates [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} and [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] were prepared by solvothermal methods and the soft Lewis basic AsS{sub 4}{sup 3–} ligand to Ln(III) centers with polyamine co-ligand was obtained. Display Omitted - Highlights: • Lanthanide thioarsenates were prepared by solvothermal methods. • The soft Lewis basic AsS{sub 4} ligand coordinate Ln{sup 3+} ions with coexistence polyamine ligands. • Two structural types of Ln-thioarsenates with structural turnover at Tb were obtained along Ln series. • The Ln-thioarsenates are potential semiconductors

  16. Water-soluble tetrapodal N, O ligands incorporating soft N-heterocycles for the selective complexation of Am(III) over Ln(III)

    Energy Technology Data Exchange (ETDEWEB)

    Heitzmann, M.; Gateau, Ch.; Delangle, P. [CEA Grenoble, Inac, Service de Chimie Inorganique et Biologique, UMR E 3 CEA UJF, FRE CNRS 3200, F-38054 Grenoble (France); Chareyre, L.; Miguirditchian, M.; Charbonnel, M.Ch. [CEA Marcoule, DEN, DRCP, SCPS, F-30207, Bagnols-sur-Ceze (France)

    2010-07-01

    A series of four water-soluble N, O-tetrapodal ligands derived from ethylenediamine, bearing hard acetate groups and soft N-heterocycles, either pyridine or pyrazine, was developed to study the impact of the softness of N-donors on the complexation properties with trivalent f ions. Two novel ligands of enhanced soft character, bearing three pyridines (L{sup 3py}) or three pyrazines (L{sup 3pz}), were synthesized and the related lanthanide complexes were studied in solution. The ligand containing three pyridyl-methyl moieties L{sup 3py} gives complexes with a coordination similar to EDTA, i.e. a hexa-dentate coordination mode as indicated by NMR and luminescence decays (q = 3) and stability constants in the range log {beta}{sub 110} = 6.99-9.3 (La-Lu). On the other hand, the softest molecule L{sup 3pz} forms much less stable complexes with log {beta}{sub 110} = 4.0-4.4 (La-Eu). The selective back-extraction of Am(III) from organic solutions containing 4f and 5f elements was tested with the four water-soluble complexing agents. The ligand L{sup 3pz} demonstrates poor stripping ability and selectivity. In contrast, the three ligands L{sup py}, L{sup pz} and L{sup 3py} give interesting back-extraction results with Eu/Am separation factors ranging from 36 to 46, which are significantly higher than with HEDTA. This exemplifies the role of the N-hetero-cycle softness in enhancing the separation between Am(III) and Eu(III). Interestingly, the pyrazine-based ligand, L{sup pz}, demonstrates the best stripping properties, with a distribution factor that approaches that of HEDTA in the same conditions (D{sub Am{approx}}0.3). This molecule is a good compromise between softness and hardness and forms complexes still stable at pH 3 due to its low basicity. (authors)

  17. Efficient NIR (near-infrared) luminescent ZnLn-grafted (Ln=Nd, Yb or Er) PNBE (Poly(norbornene))

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lin; Feng, Hei-Ni; Fu, Guo-Rui; Li, Bao-Ning [School of Chemical Engineering, Shaanxi Key Laboratory of Degradable Medical Material, Northwest University, Xi’an 710069, Shaanxi (China); Lü, Xing-Qiang, E-mail: lvxq@nwu.edu.cn [School of Chemical Engineering, Shaanxi Key Laboratory of Degradable Medical Material, Northwest University, Xi’an 710069, Shaanxi (China); Wong, Wai-Kwok [Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Hong Kong (China); Jones, Richard A. [Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, TX 78712-0165 (United States)

    2017-06-15

    Through the ring-opening metathesis polymerization (ROMP) of norbornene (NBE) with each of allyl-containing complex monomers [Zn(L){sub 2}(µ{sub 1}-OAc)Ln(µ{sub 2}-OAc){sub 2}] (Ln=La, 1; Nd, 2; Yb, 3; Er, 4 or Gd, 5; HL=4-allyl-2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol), a series of ZnLn-grafted polymers Poly([Zn(L){sub 2}(µ{sub 1}-OAc)Ln(µ{sub 2}-OAc){sub 2}]-co-NBE) with desired physical properties were obtained, respectively. Within near-infrared (NIR) luminescent polymers, Poly(3-co-NBE) endows an attractive quantum yield of 1.47% in solid state, and exhibits an effective prevention of high-concentration self-quenching. - Graphical abstract: Through grafting of [Zn(L){sub 2}(µ{sub 1}-OAc)Ln(µ{sub 2}-OAc){sub 2}] (Ln=Nd, 2; Yb, 3 or Er, 4) into PNBE with desired physical properties including NIR luminescence, Poly(3-co-NBE) exhibits an attractive quantum yield of 1.47% and an effective emitters' clustering prevention.

  18. Stability and Unimolecular Reactivity of Palladate(II) Complexes [Ln PdR3 ]- (L=Phosphine, R=Organyl, n=0 and 1).

    Science.gov (United States)

    Kolter, Marlene; Koszinowski, Konrad

    2016-10-24

    The reduction of Pd II precatalysts to catalytically active Pd 0 species is a key step in many palladium-mediated cross-coupling reactions. Besides phosphines, the stoichiometrically used organometallic reagents can afford this reduction, but do so in a poorly understood way. To elucidate the mechanism of this reaction, we have treated solutions of Pd(OAc) 2 and a phosphine ligand L in tetrahydrofuran with RMgCl (R=Ph, Bn, Bu) as well as other organometallic reagents. Analysis of these model systems by electrospray- ionization mass spectrometry found palladate(II) complexes [L n PdR 3 ] - (n=0 and 1), thus pointing to the occurrence of transmetallation reactions. Upon gas-phase fragmentation, the [L n PdR 3 ] - anions preferentially underwent a reductive elimination to yield Pd 0 species. The sequence of the transmetallation and reductive elimination, thus, constitutes a feasible mechanism for the reduction of the Pd(OAc) 2 precatalyst. Other species of interest observed include the Pd IV complex [PdBn 5 ] - , which did not fragment via a reductive elimination but lost BnH instead. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Decanuclear Ln10 Wheels and Vertex-Shared Spirocyclic Ln5 Cores: Synthesis, Structure, SMM Behavior, and MCE Properties.

    Science.gov (United States)

    Das, Sourav; Dey, Atanu; Kundu, Subrata; Biswas, Sourav; Narayanan, Ramakirushnan Suriya; Titos-Padilla, Silvia; Lorusso, Giulia; Evangelisti, Marco; Colacio, Enrique; Chandrasekhar, Vadapalli

    2015-11-16

    The reaction of a Schiff base ligand (LH3) with lanthanide salts, pivalic acid and triethylamine in 1:1:1:3 and 4:5:8:20 stoichiometric ratios results in the formation of decanuclear Ln10 (Ln = Dy (1), Tb (2), and Gd (3)) and pentanuclear Ln5 complexes (Ln = Gd (4), Tb (5), and Dy (6)), respectively. The formation of Ln10 and Ln5 complexes are fully governed by the stoichiometry of the reagents used. Detailed magnetic studies on these complexes (1-6) have been carried out. Complex 1 shows a SMM behavior with an effective energy barrier for the reversal of the magnetization (Ueff) = 16.12(8) K and relaxation time (τo) = 3.3×10(-5) s under 4000 Oe direct current (dc) field. Complex 6 shows the frequency dependent maxima in the out-of-phase signal under zero dc field, without achieving maxima above 2 K. Complexes 3 and 4 show a large magnetocaloric effect with the following characteristic values: -ΔSm = 26.6 J kg(-1) K(-1) at T = 2.2 K for 3 and -ΔSm = 27.1 J kg(-1) K(-1) at T = 2.4 K for 4, both for an applied field change of 7 T. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Magnetic properties and structural transitions of fluorite-related rare earth osmates Ln3OsO7 (Ln=Pr, Tb)

    Science.gov (United States)

    Hinatsu, Yukio; Doi, Yoshihiro

    2013-02-01

    Ternary rare-earth osmates Ln3OsO7 (Ln=Pr, Tb) have been prepared. They crystallize in an ortho-rhombic superstructure of cubic fluorite with space group Cmcm. Both of these compounds undergo a structural phase transition at 130 K (Ln=Pr) and 580 K (Ln=Tb). These compounds show complex magnetic behavior at low temperatures. Pr3OsO7 exhibits magnetic transitions at 8 and 73 K, and Tb3OsO7 magnetically orders at 8 and 60 K. The Os moments become one-dimensionally ordered, and when the temperature is furthermore decreased, it provokes the ordering in the Ln3+ sublattice that simultaneously becomes three-dimensionally ordered with the Os sublattice.

  1. Lattice dynamics of cubic Cs2NaLnX6 and CsNaLn1-xLn'xX6 elpasolites

    International Nuclear Information System (INIS)

    Acevedo, R.; Poblete, V.; Alzamora, R.; Venegas, R.; Navarro, G.; Henriquez, C.

    1999-01-01

    Crystal lattice dynamics of stoichiometric Cs 2 NaLnX 6 and nonstoichiometric CsNaLn 1-x Ln' x X 6 , 0.01 ≤ x ≤ 0.10, Ln and Ln' are trivalent positive lanthanide ions and X is chlorine or bromine, were studied.. Phonon dispersion relations were computed for similar compound, Cs 2 UBr 6 , and vibronic absorption spectra with reduced number of required input parameters are considered on the basis of proposed model. (author)

  2. A new continuous two-step molecular precursor route to rare-earth oxysulfides Ln2O2S

    International Nuclear Information System (INIS)

    De Crom, N.; Devillers, M.

    2012-01-01

    A continuous two-step molecular precursor pathway is designed for the preparation of rare-earth oxysulfides Ln 2 O 2 S (Ln=Y, La, Pr, Nd, Sm–Lu). This new route involves a first oxidation step leading to the rare-earth oxysulfate Ln 2 O 2 SO 4 which is subsequently reduced to the rare-earth oxysulfide Ln 2 O 2 S by switching to a H 2 –Ar atmosphere. The whole process occurs at a temperature significantly lower than usual solid state synthesis (T≤650 °C) and avoids the use of dangerous sulfur-based gases, providing a convenient route to the synthesis of the entire series of Ln 2 O 2 S. The molecular precursors consist in heteroleptic dithiocarbamate complexes [Ln(Et 2 dtc) 3 (phen)] and [Ln(Et 2 dtc) 3 (bipy)] (Et 2 dtc=N,N-diethyldithiocarbamate; phen=1,10-phenanthroline; bipy=2,2′-bipyridine) and were synthesized by a new high yield and high purity synthesis route. The nature of the molecular precursor determines the minimum synthesis temperature and influences therefore the purity of the final Ln 2 O 2 S crystalline phase. - Graphical abstract: A continuous two-step molecular precursor pathway was designed for the preparation of rare-earth oxysulfides Ln 2 O 2 S (Ln=Y, La, Pr, Nd, Sm–Lu), starting from heteroleptic dithiocarbamate complexes. The influence of the nature of the molecular precursor on the minimum synthesis temperature and on the purity of the final Ln 2 O 2 S crystalline phase is discussed. Highlights: ► A new high yield and high purity synthesis route of rare earth dithiocarbamates is described. ► These compounds are used as precursors in a continuous process leading to rare-earth oxysulfides. ► The oxysulfides are obtained under much more moderate conditions than previously described.

  3. Perspectives for development of technologies, science, knowledge intensive business and personnel training on the Inter-disciplinary research complex in the L.N. Gumilev Eurasian State University base. Chapter 3

    International Nuclear Information System (INIS)

    2003-01-01

    In the Chapter 3 the problems of nano- and microstructures formation on the base on nuclear membranes are considered. The role of accelerating technique in the obtaining of nano- and microstructures is emphasized. In particular an importance of ion implantation synthesis of nano-size cluster structures (radiation defects, phase segregations) in a solid state matter volume; formation of metallic nano-structures (nano-wires and submicron tubes, nano-clusters on the solid state surfaces) with use nuclear technology on the track membranes base is noted. It is shown, that during study of the fundamental properties of radiation defects the DC-60 cyclotron allows to create in the material the cascades of atom-atom collisions. Creation and put into operation in the L.N. Gumilev Eurasian State University the DC-60 cyclotron gives possibility to formation of experimental and laboratory research bases for it collective use by researches, academics, students and postgraduates

  4. Constants of hyperfine interaction of lanthanoid-phosphorus for [LnCl2Hmpa4]BPh4 composition compounds from data on 1H and 31P NMR

    International Nuclear Information System (INIS)

    Skopenko, V.V.; Amirkhanov, V.M.; Turov, A.V.; Trachevskij, V.V.

    1991-01-01

    By the method of 1 H and 31 P NMR at 233 and 298 K acetone solutions of lanthanide complexes of the composition [LnCl 2 Hmpa 4 ]BPh 4 (Hmpa=OP[N(CH 3 ) 2 ] 3 , Ln=La, Ce-Lu) have been considered. Two series of complexes having similar structure of coordination sphere (Ln=Pr-Ho and Ln=Er-Yb) are revealed and for each series the values of hyperfine interaction constants, which are 0.49 and 0.28 MHz respectively, have been determined

  5. Coordination polyhedra LnFn (Ln=La-Lu) in crystal structure

    International Nuclear Information System (INIS)

    Vologzhanina, A.V.; Pushkin, D.V.; Serezhkin, V.N.

    2006-01-01

    Peculiarities of stereochemistry of lanthanides (Ln) surrounded by fluorine atoms were studied by means of the Voronoi-Dirichlet polyhedra (PVD) and method of crossing spheres, 118 compounds are presented in the structure. It has been found that coordination numbers (CN) of Ln atoms change from 6 to 12, nine types of LnF n coordination polyhedra are formed in the process, Ln-F bond lengths have changes by 0.2-0.7 A in accordance to CN. It is found that in spite of significant variation of bond lengths volume of PVD Ln atoms is determined by their nature and oxidation state. It has been found that the change in radii of spherical domains, which volume is equal to the volume of PVD Ln atoms, is accompanied by tetrad-effect [ru

  6. Influence of lead oxide addition on LnTiTaO 6 (Ln = Ce, Pr and Nd)

    Indian Academy of Sciences (India)

    The effect of PbO addition on the structural, processing and microwave dielectric properties of LnTiTaO6 (Ln = Ce, Pr and Nd) ceramics are reported. Conventional solid state ceramic route was used for the preparation of samples. Phase pure LnTiTaO6 (Ln = Ce, Pr and Nd) ceramics are prepared at a calcination ...

  7. Structures, magnetic, and thermal properties of Ln3MoO7 (Ln=La, Pr, Nd, Sm, and Eu)

    International Nuclear Information System (INIS)

    Nishimine, Hiroaki; Wakeshima, Makoto; Hinatsu, Yukio

    2005-01-01

    Ternary lanthanide-molybdenum oxides Ln 3 MoO 7 (Ln=La, Pr, Nd, Sm, Eu) have been prepared. Their structures were determined by X-ray diffraction measurements. They crystallize in a superstructure of cubic fluorite and the space group is P2 1 2 1 2 1 . The Mo ion is octahedrally coordinated by six oxygens and the slightly distorted octahedra share corners forming a zig-zag chain parallel to the b-axis. These compounds have been characterized by magnetic susceptibility and specific heat measurements. The La 3 MoO 7 shows complex magnetic behavior at 150 and 380K. Below these temperatures, there is a large difference in the temperature-dependence of the magnetic susceptibility measured under zero-field-cooled condition and under field-cooled condition. The Nd 3 MoO 7 show a clear antiferromagnetic transition at 2.5K. From the susceptibility measurements, both Pr 3 MoO 7 and Sm 3 MoO 7 show the existence of magnetic anomaly at 8.0 and 2.5K, respectively. The results of the specific heat measurements also show anomalies at the corresponding magnetic transition temperatures. The differential scanning calorimetry measurements indicate that two phase-transitions occur for any Ln 3 MoO 7 compound in the temperature range between 370 and 710K

  8. 3d-4f {Co(II)3Ln(OR)4} Cubanes as Bio-Inspired Water Oxidation Catalysts.

    Science.gov (United States)

    Evangelisti, Fabio; Moré, René; Hodel, Florian; Luber, Sandra; Patzke, Greta Ricarda

    2015-09-02

    Although the {CaMn4O5} oxygen evolving complex (OEC) of photosystem II is a major paradigm for water oxidation catalyst (WOC) development, the comprehensive translation of its key features into active molecular WOCs remains challenging. The [Co(II)3Ln(hmp)4(OAc)5H2O] ({Co(II)3Ln(OR)4}; Ln = Ho-Yb, hmp = 2-(hydroxymethyl)pyridine) cubane WOC series is introduced as a new springboard to address crucial design parameters, ranging from nuclearity and redox-inactive promoters to operational stability and ligand exchange properties. The {Co(II)3Ln(OR)4} cubanes promote bioinspired WOC design by newly combining Ln(3+) centers as redox-inactive Ca(2+) analogues with flexible aqua-/acetate ligands into active and stable WOCs (max. TON/TOF values of 211/9 s(-1)). Furthermore, they open up the important family of 3d-4f complexes for photocatalytic applications. The stability of the {Co(II)3Ln(OR)4} WOCs under photocatalytic conditions is demonstrated with a comprehensive analytical strategy including trace metal analyses and solution-based X-ray absorption spectroscopy (XAS) investigations. The productive influence of the Ln(3+) centers is linked to favorable ligand mobility, and the experimental trends are substantiated with Born-Oppenheimer molecular dynamics studies.

  9. Lanthanide complexes with pivaloylacetone

    International Nuclear Information System (INIS)

    Eliseeva, S.V.; Chugarov, N.V.; Kuz'mina, N.P.; Martynenko, L.I.; Nichiporuk, R.V.; Ivanov, S.A.

    2003-01-01

    Complexes Ln(pa) 3 ·2H 2 O (Ln=La, Gd, Lu, Hpa - pivaloylacetone) are synthesized and investigated by the methods of element, IR spectroscopic and thermal analyses. Behaviour of the complexes during heating in vacuum is compared with such one for acetylacetonates and dipivaloylmethanates. Structure of the complexes in solution is studied by 1 H NMR and MALDI-MS [ru

  10. Ordered oxygen deficient '112'perovskites, LnBaCo2 O5⋅ 50 ...

    Indian Academy of Sciences (India)

    ... Refresher Courses · Symposia · Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 32; Issue 3. Ordered oxygen deficient '112' perovskites, LnBaCo2O5.50+: complex magnetism and transport properties. B Raveau Md Motin Seikh V Pralong V Caignaert. Volume 32 Issue 3 June 2009 pp 305-312 ...

  11. Vibrational spectra of mixed oxides of Ln2MgTiO6 composition

    International Nuclear Information System (INIS)

    Porotnikov, N.V.; German, M.; Kovba, L.M.

    1984-01-01

    In the range 33-4000 cm -1 IR and Raman spectra of complex oxides of the composition Ln 2 MgTiO 6 (Ln=La-Yb and Y) have been studied. Using the Magnesium isotope-substituted compositions Lasub(2)sup(24,26)MgTiOsub(6), Smsub(2)sup(24,26)MgTiOsub(6) and Ybsub(2)sup(24,26)MgTiOsub(6), it has been shoWn that in Ln 2 MgTiO 6 titanium and magnesium ions are located in sites With octahedral coordination, of rare earth ions highly-coordinated polyhedrons with coordination number 10-12 are characteristic

  12. Synthesis and electronic properties of LnRhAsO and LnIrAsO compositions

    International Nuclear Information System (INIS)

    Muir, Sean; Sleight, A.W.; Subramanian, M.A.

    2011-01-01

    The synthesis and characterization of the new compositions LnRhAsO (Ln=Ce, Nd) and LnIrAsO (Ln=La, Ce, Nd) are reported. These compounds crystallize in the ZrCuSiAs type structure, isostructural to iron pnictide LnFeAsO materials. Upon substitution of Rh for Fe, both a and c lattice parameters increase relative to 3d transition metal compounds; however, when Ir is substituted for Rh the a-parameter decreases slightly while the c-parameter expands. The decrease in a lattice parameter corresponds to a short metal-metal distance in Ir compounds. CeRhAsO and CeIrAsO compositions show abrupt decreases in resistivity at 7 and 10 K, respectively, coinciding with a small shift in magnetization at the transition temperature. - Graphical abstract: LnIrAsO (Ln=La, Ce, Nd) and LnRhAsO (Ln=Ce, Rh) have been synthesized. These new transition metal oxypnictide compositions are isostructural to LaFeAsO. The 5d Ir compositions demonstrate a shorter metal-metal interaction than the 4d Rh compositions. Highlights: → LnIrAsO (Ln=La, Ce, Nd) and LnRhAsO (Ln=Ce, Nd) have been synthesized. → Ir compositions show a decreased a-parameter and increased c-parameter relative to Rh compositions. → All LnIrAsO and LnRhAsO compositions are metallic while CeIrAsO and CeRhAsO show a sudden drop in resistivity at 10 and 7 K, respectively.

  13. Mixed complexes formed by rare earths with nitrilotriacetic and malic acids

    International Nuclear Information System (INIS)

    Samir Abu Ali; Dobrynina, N.A.; Martynenko, L.I.; Borisova, L.I.

    1980-01-01

    The composition of the mixed ligand and homogeneous complexes, forming in the Ln 3+ system-nitrilotriacetic acid (H 3 X)-malic acid (H 2 Mal) is determined and stability constants are calculated according to the data of the spectrography and pH-metry with the help of the mathematical statistics. The LnHMal 2+ , LnX 0 , LnX 2 - 3 and LnXMal 2- complexes are found in the solutions with the LnCl 3 : H 3 X : H 2 Mal= 1 : 1 : 1 and 1 : 1 : 2 composition

  14. Axially symmetric U-O-Ln- and U-O-U-containing molecules from the control of uranyl reduction with simple f-block halides

    International Nuclear Information System (INIS)

    Arnold, Polly L.; Cowie, Bradley E.; Suvova, Marketa; Zegke, Markus; Love, Jason B.; Magnani, Nicola; Colineau, Eric; Griveau, Jean-Christophe; Caciuffo, Roberto

    2017-01-01

    The reduction of U"V"I uranyl halides or amides with simple Ln"I"I or U"I"I"I salts forms highly symmetric, linear, oxo-bridged trinuclear U"V/Ln"I"I"I/U"V, Ln"I"I"I/U"I"V/Ln"I"I"I, and U"I"V/U"I"V/U"I"V complexes or linear Ln"I"I"I/U"V polymers depending on the stoichiometry and solvent. The reactions can be tuned to give the products of one- or two-electron uranyl reduction. The reactivity and magnetism of these compounds are discussed in the context of using a series of strongly oxo-coupled homo- and heterometallic poly(f-block) chains to better understand fundamental electronic structure in the f-block. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Axially symmetric U-O-Ln- and U-O-U-containing molecules from the control of uranyl reduction with simple f-block halides

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, Polly L.; Cowie, Bradley E.; Suvova, Marketa; Zegke, Markus; Love, Jason B. [EaStCHEM School of Chemistry, University of Edinburgh (United Kingdom); Magnani, Nicola; Colineau, Eric; Griveau, Jean-Christophe; Caciuffo, Roberto [European Commission, Directorate for Nuclear Safety and Security, Joint Research Centre, Karlsruhe (Germany)

    2017-08-28

    The reduction of U{sup VI} uranyl halides or amides with simple Ln{sup II} or U{sup III} salts forms highly symmetric, linear, oxo-bridged trinuclear U{sup V}/Ln{sup III}/U{sup V}, Ln{sup III}/U{sup IV}/Ln{sup III}, and U{sup IV}/U{sup IV}/U{sup IV} complexes or linear Ln{sup III}/U{sup V} polymers depending on the stoichiometry and solvent. The reactions can be tuned to give the products of one- or two-electron uranyl reduction. The reactivity and magnetism of these compounds are discussed in the context of using a series of strongly oxo-coupled homo- and heterometallic poly(f-block) chains to better understand fundamental electronic structure in the f-block. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Effect of A-TIG Welding Process on the Weld Attributes of Type 304LN and 316LN Stainless Steels

    Science.gov (United States)

    Vasudevan, M.

    2017-03-01

    The specific activated flux has been developed for enhancing the penetration performance of TIG welding process for autogenous welding of type 304LN and 316LN stainless steels through systematic study. Initially single-component fluxes were used to study their effect on depth of penetration and tensile properties. Then multi-component activated flux was developed which was found to produce a significant increase in penetration of 10-12 mm in single-pass TIG welding of type 304LN and 316LN stainless steels. The significant improvement in penetration achieved using the activated flux developed in the present work has been attributed to the constriction of the arc and as well as reversal of Marangoni flow in the molten weld pool. The use of activated flux has been found to overcome the variable weld penetration observed in 316LN stainless steel with TIG welds compared to that of the welds produced by conventional TIG welding on the contrary the transverse strength properties of the 304LN and 316LN stainless steel welds produced by A-TIG welding exceeded the minimum specified strength values of the base metals. Improvement in toughness values were observed in 316LN stainless steel produced by A-TIG welding due to refinement in the weld microstructure in the region close to the weld center. Thus, activated flux developed in the present work has greater potential for use during the TIG welding of structural components made of type 304LN and 316LN stainless steels.

  17. Structural, magnetic and electronic properties of rare earth ternary oxides Li Ln(II) 2 Ln(III)O4

    International Nuclear Information System (INIS)

    Malki, M.

    1987-06-01

    Properties of a new class of rare earth ternary oxides Li Ln(II) 2 Ln(III)O 4 where Ln(II) is a divalent metal (Sr, Eu) and Ln(III) a trivalent rare earth (Eu, Gd, Dy, Er and Y). These orthorhombic compounds (type Li Eu 3 O 4 ) allow the study of many magnetic phenomena and their evolution in function of the nature of Ln(II) and Ln(III): diamagnetic ions Sr 2+ , Y 3+ ; isotrope magnetic ions: Eu 2+ , Gd 3+ and anisotrope magnetic ions Dy 3+ , Er 3+ . Magnetic and electric properties are obtained by classical techniques and from hyperfine interaction by Moessbauer spectroscopy. The possibility to use several Moessbauer resonance (nuclei Eu 151, Gd 155, Dy 161 and Er 166) completes informations obtained by the macroscopic study [fr

  18. Intrapartální fetální monitoring, senzitivita a specificita metod

    Czech Academy of Sciences Publication Activity Database

    Hájek, Z.; Srp, B.; Pavlíková, Markéta; Zvárová, Jana; Liška, K.; Haddad El, R.; Pašková, A.; Pařízek, A.

    2006-01-01

    Roč. 71, č. 4 (2006), s. 263-267 ISSN 1210-7832 Grant - others:GA MZd(CZ) NH7664 Institutional research plan: CEZ:AV0Z10300504 Keywords : senzitivita * specificita * diagnostika hypoxie * kardiotokografie * fetální pulzní oxymetrie * ST analýza EKG plodu Subject RIV: BB - Applied Statistics, Operational Research

  19. Model-free nuclear magnetic resonance study of intermolecular free energy landscapes in liquids with paramagnetic Ln3+ spotlights: theory and application to Arg-Gly-Asp.

    Science.gov (United States)

    Fries, Pascal H

    2012-01-28

    We propose an easily applicable method for investigating the pair distribution function of a lanthanide Ln(3+) complex LnL (L = ligand) with respect to any solvent or solute molecule A carrying observable nuclear spins. Let r be the distance of Ln(3+) to the observed nuclear spin I. We derive a simple expression of the experimental value of the configurational average of 1/r(6) in terms of longitudinal paramagnetic relaxation (rate) enhancements (PREs) of the spin I measured on a standard high-resolution NMR spectrometer and due to well-chosen concentrations of LnL complexes in which Ln(3+) is a fast-relaxing paramagnetic lanthanide or the slowly-relaxing gadolinium Gd(3+). The derivation is justified in the general case of a molecule A which is by turns in a bound state where it follows the complex and a free state where it moves independently. It rests on the expression of the underlying PRE theory in terms of the angle-dependent pair distribution function of LnL and A. The simplifications of this theory in the high-field regime and under the condition of fast exchange between bound and free states are carefully discussed. We also show that original information on the angle dependence of the molecular pair distribution function can be gained from the measured paramagnetic dipolar shifts induced by complexed fast-relaxing Ln(3+) ions. The method is illustrated by the case study of the anionic Lnttha(3-) = [Ln(3+)(ttha)](3-) (ttha(6-) = triethylene tetraamine hexacetate) complex interacting with the biologically important tripeptide Arg-Gly-Asp (RGD) which carries peripheral ionic groups. The usefulness of an auxiliary reference outer sphere probe solute is emphasized. © 2012 American Institute of Physics

  20. Catalytic Oligomerization of Terminal Alkynes by Lanthanide Carbyls (η5-C5Me5)2LnCH(SiMe3)2 (Ln = Y, La, Ce)

    NARCIS (Netherlands)

    Heeres, H.J.; Teuben, J.H.

    1991-01-01

    Lanthanide and group 3 carbyls Cp*2LnCH(SiMe3)2 (1, Ln = Y; 2, Ln = La; 3, Ln = Ce) are active catalyst precursors for the oligomerization of terminal alkynes HC≡CR (R = alkyl, aryl, SiMe3). The regioselectivity and the extent of oligomerization depend strongly on the lanthanide applied as well as

  1. Crystallographic and infrared spectroscopic study of bond distances in Ln[Fe(CN)6].4H2O (Ln=lanthanide)

    International Nuclear Information System (INIS)

    Zhou Xianju; Wong, W.-T.; Faucher, Michele D.; Tanner, Peter A.

    2008-01-01

    Along with crystallographic data of Ln[Fe(CN) 6 ].4H 2 O (Ln=lanthanide), the infrared spectra are reassigned to examine bond length trends across the series of Ln. The changes in mean Ln-O, Ln-N, C≡N and Fe-C distances are discussed and the bond natures of Ln-N and Ln-O are studied by bond length linear or quadratic fitting and comparisons with relevant ionic radii. The two different C≡N bond distances have been simulated by the covalo-electrostatic model. - Graphical abstract: Crystallographic and FTIR data for Ln[Fe(CN) 6 ].4H 2 O enable the changes in Ln-O, Ln-N, C≡N and Fe-C distances to be determined and modeled across the lanthanide series

  2. Synthesis and characterization of K{sub 2}Ln{sub 2/3}Ta{sub 2}O{sub 7}·nH{sub 2}O (Ln= La, Pr, Nd), layered tantalates photo catalysts for water splitting

    Energy Technology Data Exchange (ETDEWEB)

    Valencia S, H.; Tavizon, G. [UNAM, Instituto de Quimica, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Pfeiffer, H. [UNAM, Instituto de Investigaciones en Materiales, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Acosta, D. [UNAM, Instituto de Fisica, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Negron M, A., E-mail: hvalencia@utp.edu.co [UNAM, Instituto de Ciencias Nucleares, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico)

    2015-07-01

    Three compounds of the K{sub 2}Ln{sub 2/3}Ta{sub 2}O{sub 7} (Ln = La, Nd, Pr) cation-deficient Ruddlesden-Popper series were prepared by the Pechini (polymeric complex) method. The crystal structures of the hydrated form of these compounds were determined by Rietveld analysis of the X-ray power diffraction data and High Resolution Transmission Electron Microscopy (HRTEM). The samples were also analyzed to determine specific area (Bet), degree of hydration (Thermogravimetric analysis), and photo catalytic activity for hydrogen evolution from water and aqueous methanol solution. (Author)

  3. Synthesis and characterization of K2Ln2/3Ta2O7·nH2O (Ln= La, Pr, Nd), layered tantalates photo catalysts for water splitting

    International Nuclear Information System (INIS)

    Valencia S, H.; Tavizon, G.; Pfeiffer, H.; Acosta, D.; Negron M, A.

    2015-01-01

    Three compounds of the K 2 Ln 2/3 Ta 2 O 7 (Ln = La, Nd, Pr) cation-deficient Ruddlesden-Popper series were prepared by the Pechini (polymeric complex) method. The crystal structures of the hydrated form of these compounds were determined by Rietveld analysis of the X-ray power diffraction data and High Resolution Transmission Electron Microscopy (HRTEM). The samples were also analyzed to determine specific area (Bet), degree of hydration (Thermogravimetric analysis), and photo catalytic activity for hydrogen evolution from water and aqueous methanol solution. (Author)

  4. Phase diagrams for the M2MoO4–Ln2(MoO43–Hf(MoO42 systems, where M = Li–Cs, Tl and Ln = La–Lu

    Directory of Open Access Journals (Sweden)

    Zh. G. Bazarova

    2017-12-01

    Full Text Available In this paper, the results of systematic studies of complex molybdate systems M2MoO4–Ln2(MoO43–Hf(MoO42 (M = Li–Cs, Tl; Ln = La–Lu are presented. Subsolidus phase diagrams of ternary systems were constructed and new triple molybdates were obtained. The optimum synthesis conditions for poly- and monocrystalline form were determined. According to single-crystal data, the structure of one of the representatives of triple molybdates was determined.

  5. Magnetic characterization of microcrystalline Na3Ln0.99–xEr0.01Crx(PO42 orthophosphates synthesized by Pechini method (Ln = La, Gd

    Directory of Open Access Journals (Sweden)

    Kaczmarek S.M.

    2018-03-01

    Full Text Available Na3Ln(PO42 orthophosphates (Ln = La, Gd doped with Er3+ and co-doped with Cr3+ ions were synthesized by Pechini method and characterized by electron paramagnetic resonance (EPR and magnetic susceptibility measurements. Low temperature EPR spectra were detected and analyzed in terms of temperature dependence and the structure of the obtained materials. They show that erbium and chromium ions substitute Ln3+ and also Na+ ions or Na+ channels forming complex EPR spectra. Both kinds of ions reveal ferromagnetic type of interaction which shows some anomaly at the temperature between 10 K and 15 K. Magnetic susceptibility reveals a weak antiferromagnetic kind of interaction dominating in the whole temperature range, from 3.5 to 300 K.

  6. Bi3+ sensitized Y2WO6:Ln3+ (Ln=Dy, Eu, and Sm) phosphors for solar spectral conversion.

    Science.gov (United States)

    Huang, M N; Ma, Y Y; Xiao, F; Zhang, Q Y

    2014-01-01

    The phosphors of Y2WO6:Bi3+, Ln3+ (Ln=Dy, Eu and Sm) were synthesized by solid-state reaction in this study. The crystal structure, photoluminescence properties and energy transfer mechanism were investigated. By introducing Bi3+ ions, the excitation band of the phosphors was broadened to be 250-380 nm, which could be absorbed by the dye-sensitized solar cells (DSSCs). The overlap between excitation of W-O groups/Bi3+ and the emission of Ln3+ (Dy, Eu, and Sm) indicated that the probability of energy transfer from W-O groups and Bi3+ to Ln3+. The energy transfer efficiency from Bi3+ to Ln3+ (Ln=Dy, Eu and Sm) are calculated to be 16%, 20% and 58%. This work suggested that Y2WO6:Bi3+, Ln3+ (Ln=Dy, Eu and Sm) might be a promising ultraviolet-absorbing luminescent converter to enhance the photoelectrical conversion efficiency of dye-sensitized solar cells (DSSCs). Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Lanthanide stannate pyrochlores (Ln2Sn2O7; Ln = Nd, Gd, Er) at high pressure.

    Science.gov (United States)

    Turner, Katlyn M; Tracy, Cameron L; Mao, Wendy L; Ewing, Rodney C

    2017-11-09

    Lanthanide stannate pyrochlores (Ln2Sn2O7; Ln=Nd, Gd, and Er) were investigated in situ to 50 GPa in order to determine their structural response to compression and compare it to that of lanthanide titanate, zirconate, and hafnate pyrochlores. The cation radius ratio of A3+/B4+ in pyrochlore oxides (A2B2O7) is thought to be the dominant property that influences their compression response. The ionic radius of Sn4+ is intermediate to that of Ti4+, Zr4+, and Hf4+, but the bond in stannate pyrochlore is more covalent than the bonds in titanates, zirconate, and hafnates. In stannates, the pyrochlore cation and anion sublattices begin to disorder at 0.3 GPa. The extent of sublattice disorder vs. pressure is greater in stannates with a smaller Ln3+ cation. Stannate pyrochlores (Fd-3m) begin a sluggish transformation to a cotunnite-like structure (Pnma) at ~28 GPa; similar transitions have been observed in titanate, zirconate, and hafnate pyrochlore at varying pressures with cation radius ratio. The extent of the phase transition vs. pressure varies directly with the size of the Ln3+ cation. Post-decompression from ~50 GPa, Er2Sn2O7 and Gd2Sn2O7 adopt a pyrochlore structure, rather than the multiscale defect-fluorite + weberite structure adopted by Nd2Sn2O7 that is characteristic of titanate, zirconate, and hafnate pyrochlore treated to similar conditions. Like pyrochlore titanates, zirconates, and hafnates, the bulk modulus, B0, of stannates varies linearly and inversely with cation radius ratio. The trends of bulk moduli in stannates in this study are in excellent agreement with previous experimental studies on stannates, and suggest that the size of the Ln3+ cation is a primary determining factor of B0. Additionally, when normalized to rA/rB, the bulk moduli of stannates are comparable to those of zirconates and hafnates, which vary from titanates. Our results suggest that the cation radius ratio strongly influences the bulk moduli of stannates as well as

  8. Femtomolar Ln(III) affinity in peptide-based ligands containing unnatural chelating amino acids.

    Science.gov (United States)

    Niedźwiecka, Agnieszka; Cisnetti, Federico; Lebrun, Colette; Delangle, Pascale

    2012-05-07

    The incorporation of unnatural chelating amino acids in short peptide sequences leads to lanthanide-binding peptides with a higher stability than sequences built exclusively from natural residues. In particular, the hexadentate peptide P(22), which incorporates two unnatural amino acids Ada(2) with aminodiacetate chelating arms, showed picomolar affinity for Tb(3+). To design peptides with higher denticity, expected to show higher affinity for Ln(3+), we synthesized the novel unnatural amino acid Ed3a(2) which carries an ethylenediamine triacetate side-chain and affords a pentadentate coordination site. The synthesis of the derivative Fmoc-Ed3a(2)(tBu)(3)-OH, with appropriate protecting groups for direct use in the solid phase peptide synthesis (Fmoc strategy), is described. The two high denticity peptides P(HD2) (Ac-Trp-Ed3a(2)-Pro-Gly-Ada(2)-Gly-NH(2)) and P(HD5) (Ac-Trp-Ada(2)-Pro-Gly-Ed3a(2)-Gly-NH(2)) led to octadentate Tb(3+) complexes with femtomolar stability in water. The position of the high denticity amino acid Ed3a(2) in the hexapeptide sequence appears to be critical for the control of the metal complex speciation. Whereas P(HD5) promotes the formation of polymetallic species in excess of Ln(3+), P(HD2) forms exclusively the mononuclear complex. The octadentate coordination of Tb(3+) by both P(HD) leads to total dehydration of the metal ion in the mononuclear complexes with long luminescence lifetimes (>2 ms). Hence, we demonstrated that unnatural amino acids carrying polyaminocarboxylate side-chains are interesting building blocks to design high affinity Ln-binding peptides. In particular the novel peptide P(HD2) forms a unique octadentate Tb(3+) complex with femtomolar stability in water and an improvement of the luminescence properties with respect to the trisaquo TbP(22) complex by a factor of 4.

  9. Enhanced visible light-responsive photocatalytic activity of LnFeO3 (Ln = La, Sm) nanoparticles by synergistic catalysis

    International Nuclear Information System (INIS)

    Li, Li; Wang, Xiong; Zhang, Yange

    2014-01-01

    Highlights: • LnFeO 3 (Ln = La, Sm) nanoparticles were prepared by a facile sol–gel method. • The samples exhibit superior visible-light-responsive photocatalytic activity. • Synergistic effect will enhance the photodegradation of RhB under visible light. - Abstract: LnFeO 3 (Ln = La, Sm) nanoparticles were prepared by a facile sol–gel method with assistance of glycol at different calcination temperatures. The as-synthesized LnFeO 3 was characterized by X-ray diffraction, transmission electron microscopy, differential scanning calorimeter and thermogravimetric analysis, and UV–vis absorption spectroscopy. The photocatalytic behaviors of LnFeO 3 nanoparticles were evaluated by photodegradation of rhodamine B under visible light irradiation. The results indicate that the visible light-responsive photocatalytic activity of LnFeO 3 nanoparticles was enhanced remarkably by the synergistic effect between the semiconductor photocatalysis and Fenton-like reaction. And a possible catalytic mechanism was also proposed based on the experimental results

  10. Investigation of BaMoO4-Ln2(MoO4)3 systems (Ln = Nd, Sm, Yb)

    International Nuclear Information System (INIS)

    Vakulyuk, V.V.; Evdokimov, A.A.; Khomchenko, G.P.

    1982-01-01

    Using the methods of X-ray phase and differential-thermal analyses phase ratios in the systems BaMoO 4 -Ln 2 (MoO 4 ) 3 (Ln=Nd, Sm, Yb); BaNd 2 (MoO 4 ) 4 -MaGd 2 (MoO 4 ) are studied. Unit cell parameters and the character of melting of the compounds BaLn 2 (MoO 4 ) 4 are specified. Effect of growth conditions on laminated nature of BaGd 2 (MoO 4 ) 4 monocrystals is studied

  11. Magnetic properties of the layered oxypnictides (LnOMnAs (Ln = La, Ce, Pr, Nd

    Directory of Open Access Journals (Sweden)

    Morosawa Y.

    2014-07-01

    Full Text Available We have investigated the rare earth elements dependence on the magnetism to understand the contribution to physical properties of the 4f electrons of (LnOMnAs (Pn = La, Ce, Pr, Nd. (CeOMnAs, (PrOMnAs and (NdOMnAs shows the antiferromagnetic behaviors at low temperature. (CeOMnAs and (NdOMnAs have the magnetic anomalies around 34 K and 24 K, respectively. So, it is speculated that the anomalies depend on the Mn -Mn distance directly

  12. High Specific Power Motors in LN2 and LH2

    Science.gov (United States)

    Brown, Gerald V.; Jansen, Ralph H.; Trudell, Jeffrey J.

    2007-01-01

    A switched reluctance motor has been operated in liquid nitrogen (LN2) with a power density as high as that reported for any motor or generator. The high performance stems from the low resistivity of Cu at LN2 temperature and from the geometry of the windings, the combination of which permits steady-state rms current density up to 7000 A/sq cm, about 10 times that possible in coils cooled by natural convection at room temperature. The Joule heating in the coils is conducted to the end turns for rejection to the LN2 bath. Minimal heat rejection occurs in the motor slots, preserving that region for conductor. In the end turns, the conductor layers are spaced to form a heat-exchanger-like structure that permits nucleate boiling over a large surface area. Although tests were performed in LN2 for convenience, this motor was designed as a prototype for use with liquid hydrogen (LH2) as the coolant. End-cooled coils would perform even better in LH2 because of further increases in copper electrical and thermal conductivities. Thermal analyses comparing LN2 and LH2 cooling are presented verifying that end-cooled coils in LH2 could be either much longer or could operate at higher current density without thermal runaway than in LN2.

  13. Theoretical aspects of photonic band gap in 1D nano structure of LN: MgLN periodic layer

    International Nuclear Information System (INIS)

    Sisodia, Namita

    2015-01-01

    By using the transfer matrix method, we have analyzed the photonic band gap properties in a periodic layer of LN:MgLN medium. The Width of alternate layers of LN and MgLN is in the range of hundred nanometers. The birefringent and ferroelectric properties of the medium (i.e ordinary, extraordinary refractive indices and electric dipole moment) is given due considerations in the formulation of photonic band gap. Effect of electronic transition dipole moment of the medium on photonic band gap is also taken into account. We find that photonic band gap can be modified by the variation in the ratio of the width of two medium. We explain our findings by obtaining numerical values and the effect on the photonic band gap due to variation in the ratio of alternate medium is shown graphically

  14. New intermetallic compounds Ln(Ag, AL)4 (Ln-Y, Gd, Tb, Dy) and their structure

    International Nuclear Information System (INIS)

    Kuz'ma, Yu.B.; Stel'makhovich, B.M.

    1990-01-01

    By the methods of X-ray analysis crystal structure of compounds Ln(Ag,Al) 4 , where Ln-Y, Gd, Tb, Dy, posessing rhombic structure, is determined. The intermetallics have been prepared for the first time. Ways of atom distribution and their coordinates in DyAg 0.55 Al 3.45 structure (a=0.4296(1), b=04179(1), c=0.9995(3), R=0.093) are specified. Other compounds are formed in case of LnAgAl 3 compositions. Interatomic distances in Dy(Ag,Al) 4 structure are considered. A supposition is made on the formation in Ln-Ag-Al systems of a greater number of intermetallic compounds

  15. The system analysis of temperature and melting enthalpy of intermetallic compounds of antimony-lanthanoids system of Sb Ln, Sb2Ln composition

    International Nuclear Information System (INIS)

    Badalova, M.A.; Chamanova, M.; Dodkhoev, E.S.; Badalov, A.; Abdusalyamova, M.N.

    2015-01-01

    Present article is devoted to system analysis of temperature and melting enthalpy of intermetallic compounds of antimony-lanthanoids system of Sb Ln, Sb 2 Ln composition. The melting enthalpy was estimated. The temperature value was determined.

  16. Optical and crystal chemistry studies of Na3Ln(PO4)2-K3Ln(PO4)2 (Ln=Eu, Gd)

    International Nuclear Information System (INIS)

    Mesnaoui, M.; Maazaz, M.

    1987-01-01

    In these systems, large single phase domains are separated by two phase regions. The structural evolution as a function of composition is analysed both by X-ray diffraction and by using Eu 3+ and Gd 3+ as luminescent local structural probes. Due to layer type structure of the K 3 Ln(PO 4 ) 2 phases an exchange reaction resulting in total substitution of sodium for potassium can be carried out with formation of metastable Na 3 Ln(PO 4 ) 2 phases, the structure of which is close to those of the potassium compounds. 10 refs.; 18 figs [fr

  17. Behaviour of LaAlO 3 +LnTiTaO 6 (Ln= Ce, Pr or Nd)

    Indian Academy of Sciences (India)

    The 0.1LaAlO3+0.9LnTiTaO6 (Ln= Ce, Pr or Nd) ceramics are prepared through solid state ceramic route. The structure of the materials is studied using X-ray diffraction analysis. The microstructure is analysed using scanning electron microscopy. The dielectric properties in the radio as well as in the microwave frequencies ...

  18. XPS study of the Ln 5p,4f-electronic states of lanthanides in Ln2O3

    International Nuclear Information System (INIS)

    Teterin, Yu.A.; Teterin, A.Yu.; Utkin, I.O.; Ryzhkov, M.V.

    2004-01-01

    The present work analyses the fine structure of the low binding energy (E b , 0-50 eV) X-ray photoelectron spectra XPS of lanthanide (La through Lu excepted for Pm) oxides, and compares it with the non-relativistic X α -discrete variation calculation results for the clusters reflecting the close environment of lanthanides in oxides. The obtained results show that the Ln 4f n -electrons of lanthanides in oxides by their spectral parameters have much in common with the M 3d-electrons in oxides of the 3d-transition metals. According to these data, the Ln 4f shell of lanthanides is rather outer and can participate in the formation of molecular orbitals in compounds. The XPS data at least do not contradict the theoretical suggestion about the significant participation of the Ln 4f-electrons in formation of the molecular orbitals in the studied materials. The spectra in the Ln 5p-O 2s binding energy region of the studied lanthanide oxides were found to exhibit the complicated structure instead of separated peaks due to the electrons of the Ln 5p 3/2,5/2 and O 2s atomic shells. Taking into account the energy differences between the inner (Ln 3d) and outer (Ln 5p) electronic shells for some metallic lanthanides and their oxides, the Ln 5p atomic shells were shown to participate in the formation of the inner valence molecular orbitals (IVMO). That agrees qualitatively with the calculation results

  19. Mixed phosphates of the Na3PO4 - LnPO4 systems

    International Nuclear Information System (INIS)

    Slivko, T.A.; Smirnova, I.N.; Zimina, G.V.; Spiridonov, F.M.; Chudinova, N.N.

    2002-01-01

    The phase relationships in the systems Na 3 PO 4 - LnPO 4 (subsolidus 950 Deg C cross-sections), where Ln=Sm, Eu, Tb, Dy, Ho, Tm, Yb, Lu, were studied by X-ray analysis. Reactions of the components were deduced, formed phases were separated and identified. The Na 6 Ln 3 (PO 4 ) 5 (Ln=Dy, Ho, Tm), Na 3 Ln 2 (PO 4 ) 3 (Ln=Tm, Yb, Lu) compounds and phases of the unstable composition Na 6+x Ln 3-x/3 (PO 4 ) 5 (Ln=Yb, Lu, 0 ≤ x ≤ 1.5) were detected for the first time. In all systems the existence of the Na 3-x Ln x/3 PO 4 unstable composition phase on the basis of the high temperature modification of sodium phosphate (sp. gr. Fm3m) is established, suggesting that stabilization of this modification by rare earth ions is possible [ru

  20. Syntheses, crystal structures and properties of series of 4d–4f ln(III)–Ag(I) heterometallic coordination polymers

    Energy Technology Data Exchange (ETDEWEB)

    Ran, Xing-Rui [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Wang, Ning [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Xie, Wei-Ping; Xiong, Yan-Ju; Cheng, Qian [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Long, Yi [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Yue, Shan-Tang, E-mail: yuesht@scnu.edu.cn [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, Guangzhou (China); Liu, Ying-Liang [College of Science, South China Agricultural University, Guangzhou 510642 (China)

    2015-05-15

    By control of the experimental parameters such as ligands, pH value and reacting temperature, series of three-dimensional (3D) 4d–4f Ln(III)–Ag(I) porous coordination polymers (PCPs) with interesting chain-layer construction, namely, ([Ln{sup III}Ag{sup I}(na)(ina)(ox)]·2(H{sub 2}O)){sub n} [Ln=Sm(1), Eu(2), Gd(3), Tb(4), Dy(5), Ho(6), Y(7), Yb(8)], have been successfully synthesized under hydrothermal conditions and structurally characterized. All the complexes are characterized by elemental analyses, FT-IR spectroscopy, Powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). Furthermore, the luminescence properties of compounds 2 and 4 and the magsnetic properties of complexes 3 and 5 were also investigated in detail. - Graphical abstract: Series of three-dimensional (3D) 4d–4f Ln(III)–Ag(I) porous coordination polymers (PCPs) with interesting chain-layer construction which are featured by tetranuclear Ln{sub 2}Ag{sub 2} and ‘non-linear’ N–Ag–N linkages. - Highlights: • Complexes 1–8 are first built by three kinds of organic ligands based on nicotinic acid and isonicotinic acid. • PCPs 1–8 are featured by tetranuclear Ln{sub 2}Ag{sub 2} and ‘non-linear’ N–Ag–N linkages. • The total solvent-accessible volume of PCP 2 comprises 11.6% of the crystal volume after dislodging the free water molecules. • Complexes 2 and 4 exhibit characteristic lanthanide-centered luminescence, while compounds 3 and 5 show antiferromagnetic behaviors.

  1. Structure and bulk modulus of Ln-doped UO{sub 2} (Ln = La, Nd) at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Rittman, Dylan R., E-mail: drittman@stanford.edu [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States); Park, Sulgiye; Tracy, Cameron L. [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States); Zhang, Lei [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California Davis, Davis, CA 95616 (United States); Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616 (United States); Palomares, Raul I.; Lang, Maik [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Navrotsky, Alexandra [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California Davis, Davis, CA 95616 (United States); Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616 (United States); Mao, Wendy L. [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Ewing, Rodney C. [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States)

    2017-07-15

    The structure of lanthanide-doped uranium dioxide, Ln{sub x}U{sub 1-x}O{sub 2-0.5x+y} (Ln = La, Nd), was investigated at pressures up to ∼50–55 GPa. Samples were synthesized with different lanthanides at different concentrations (x ∼ 0.2 and 0.5), and all were slightly hyperstoichiometric (y ∼ 0.25–0.4). In situ high-pressure synchrotron X-ray diffraction was used to investigate their high-pressure phase behavior and determine their bulk moduli. All samples underwent a fluorite-to-cotunnite phase transformation with increasing pressure. The pressure of the phase transformation increased with increasing hyperstoichiometry, which is consistent with results from previous computational simulations. Bulk moduli are inversely proportional to both the ionic radius of the lanthanide and its concentration, as quantified using a weighted cationic radius ratio. This trend was found to be consistent with the behavior of other elastic properties measured for Ln-doped UO{sub 2}, such as Young's modulus. - Highlights: •Ln-doped UO{sub 2} transforms from fluorite to cotunnite at high pressure. •Transition pressure increases with increasing hyperstoichiometry. •Bulk modulus decreases with increasing Ln-dopant radius and concentration.

  2. DIMENSI METRIK GRAPH LOBSTER Ln (q;r

    Directory of Open Access Journals (Sweden)

    PANDE GDE DONY GUMILAR

    2013-05-01

    Full Text Available The metric dimension of connected graph G is the cardinality of minimum resolving set in graph G. In this research, we study how to find the metric dimension of lobster graph Ln (q;r. Lobster graph Ln (q;r is a regular lobster graph with vertices backbone on the main path, every backbone vertex is connected to q hand vertices and every hand vertex is connected to r finger vertices, with n, q, r element of N. We obtain the metric dimension of lobster graph L2 (1;1 is 1, the metric dimension of lobster graph L2 (1;1 for n > 2 is 2.

  3. Phase transition of the orthorhombic fluorite-related compounds Ln{sub 3}IrO{sub 7} (Ln = Pr, Nd, Sm, Eu)

    Energy Technology Data Exchange (ETDEWEB)

    Hinatsu, Yukio, E-mail: hinatsu@sci.hokudai.ac.j [Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Doi, Yoshihiro; Nishimine, Hiroaki; Wakeshima, Makoto [Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Sato, Mineo [Department of Chemistry and Chemical Engineering, Faculty of Engineering, Niigata University, 8050 Ikarashi 2-nocho, Niigata 950-2181 (Japan)

    2009-12-04

    Rare earth iridium oxides Ln{sub 3}IrO{sub 7} (Ln = Pr, Nd, Sm, and Eu) were prepared and their structures were determined by X-ray diffraction measurements. At room temperature, Pr{sub 3}IrO{sub 7} crystallized in an orthorhombic superstructure of cubic fluorite with space group Cmcm. The differential thermal analysis (DTA) and specific heat measurements for Ln{sub 3}IrO{sub 7} (Ln = Pr, Nd, Sm, and Eu) showed a phase transition at 262, 342, 420, and 485 K, respectively. At low temperatures, Ln{sub 3}IrO{sub 7} crystallized in a monoclinic structure with the space group P2{sub 1}/n. The transition temperatures increased with decreasing the ionic radius of rare earths, which indicates that the transition is stress-induced and occurs with the lattice contraction on cooling. These results for Ln{sub 3}IrO{sub 7} were compared with the phase transitions observed for Ln{sub 3}MoO{sub 7}, Ln{sub 3}RuO{sub 7}, Ln{sub 3}ReO{sub 7}, and Ln{sub 3}OsO{sub 7}.

  4. Phase relations and crystal structures in the systems (Bi,Ln)2WO6 and (Bi,Ln)2MoO6 (Ln=lanthanide)

    International Nuclear Information System (INIS)

    Berdonosov, Peter S.; Charkin, Dmitri O.; Knight, Kevin S.; Johnston, Karen E.; Goff, Richard J.; Dolgikh, Valeriy A.; Lightfoot, Philip

    2006-01-01

    Several outstanding aspects of phase behaviour in the systems (Bi,Ln) 2 WO 6 and (Bi,Ln) 2 MoO 6 (Ln=lanthanide) have been clarified. Detailed crystal structures, from Rietveld refinement of powder neutron diffraction data, are provided for Bi 1.8 La 0.2 WO 6 (L-Bi 2 WO 6 type) and BiLaWO 6 , BiNdWO 6 , Bi 0.7 Yb 1.3 WO 6 and Bi 0.7 Yb 1.3 WO 6 (all H-Bi 2 WO 6 type). Phase evolution within the solid solution Bi 2- x La x MoO 6 has been re-examined, and a crossover from γ(H)-Bi 2 MoO 6 type to γ-R 2 MoO 6 type is observed at x∼1.2. A preliminary X-ray Rietveld refinement of the line phase BiNdMoO 6 has confirmed the α-R 2 MoO 6 type structure, with a possible partial ordering of Bi/Nd over the three crystallographically distinct R sites. - Graphical abstract: A summary of phase relations in the lanthanide-doped bismuth tungstate and bismuth molybdate systems is presented, together with some additional structural data on several of these phases

  5. Damage on 316LN stainless steel transformed by powder metallurgy

    International Nuclear Information System (INIS)

    Couturier, R.; Burlet, H.

    1998-01-01

    This study deals with the 316 LN stainless steel elaboration by powder metallurgy. This method allows the realization of structures in austenitic steel less affected by the thermal aging than the cast austenitic-ferritic components. The components are performed by the method of HIP (Hot Isostatic Pressing). Mechanical tests are provided to control mechanical properties

  6. Systems Ln-Fe-O ( Ln=Eu, Gd): thermodynamic properties of ternary oxides using solid-state electrochemical cells

    Science.gov (United States)

    Parida, S. C.; Rakshit, S. K.; Dash, S.; Singh, Ziley; Prasad, R.; Venugopal, V.

    2003-05-01

    The standard molar Gibbs energies of formation of LnFeO 3(s) and Ln3Fe 5O 12(s) where Ln=Eu and Gd have been determined using solid-state electrochemical technique employing different solid electrolytes. The reversible e.m.f.s of the following solid-state electrochemical cells have been measured in the temperature range from 1050 to 1255 K. Cell (I): (-)Pt / { LnFeO 3(s)+ Ln2O 3(s)+Fe(s)} // YDT/CSZ // {Fe(s)+Fe 0.95O(s)} / Pt(+); Cell (II): (-)Pt/{Fe(s)+Fe 0.95O(s)}//CSZ//{ LnFeO 3(s)+ Ln3Fe 5O 12(s)+Fe 3O 4(s)}/Pt(+); Cell (III): (-)Pt/{ LnFeO 3(s)+ Ln3Fe 5O 12(s)+Fe 3O 4(s)}//YSZ//{Ni(s)+NiO(s)}/Pt(+); and Cell(IV):(-)Pt/{Fe(s)+Fe 0.95O(s)}//YDT/CSZ//{ LnFeO 3(s)+ Ln3Fe 5O 12(s)+Fe 3O 4(s)}/Pt(+). The oxygen chemical potentials corresponding to the three-phase equilibria involving the ternary oxides have been computed from the e.m.f. data. The standard Gibbs energies of formation of solid EuFeO 3, Eu 3Fe 5O 12, GdFeO 3 and Gd 3Fe 5O 12 calculated by the least-squares regression analysis of the data obtained in the present study are given by Δ fG°m(EuFeO 3, s) /kJ mol -1 (± 3.2)=-1265.5+0.2687( T/K) (1050 ⩽ T/K ⩽ 1570), Δ fG°m(Eu 3Fe 5O 12, s)/kJ mol -1 (± 3.5)=-4626.2+1.0474( T/K) (1050 ⩽ T/K ⩽ 1255), Δ fG°m(GdFeO 3, s) /kJ mol -1 (± 3.2)=-1342.5+0.2539( T/K) (1050 ⩽ T/K ⩽ 1570), and Δ fG°m(Gd 3Fe 5O 12, s)/kJ·mol -1 (± 3.5)=-4856.0+1.0021( T/K) (1050 ⩽ T/K ⩽ 1255). The uncertainty estimates for Δ fG°m include the standard deviation in the e.m.f. and uncertainty in the data taken from the literature. Based on the thermodynamic information, oxygen potential diagrams for the systems Eu-Fe-O and Gd-Fe-O and chemical potential diagrams for the system Gd-Fe-O were computed at 1250 K.

  7. 1,3-thiazole as suitable antenna ligand for lanthanide photoluminescence in [LnCl{sub 3}(thz){sub 4}].0.5thz, Ln = Sm, Eu, Gd, Tb, Dy

    Energy Technology Data Exchange (ETDEWEB)

    Dannenbauer, Nicole; Mueller-Buschbaum, Klaus [Wuerzburg Univ. (Germany). Inst. for Inorganic Chemistry; Kuzmanoski, Ana; Feldmann, Claus [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). Inst. for Inorganic Chemistry

    2014-02-15

    The series of luminescent monomeric lanthanide thiazole complexes [LnCl{sub 3}(thz){sub 4}].0.5thz (Ln = Sm, Eu, Gd, Tb, Dy; thz = 1,3-thiazole) has been synthesised and characterised by powder and single-crystal X-ray diffraction, IR and photoluminescence spectroscopy, DTA/TG as well as elemental analysis. The colourless compounds exhibit photoluminescence in the visible region with varying quantum efficiencies up to QY = 48 % for [LnCl{sub 3}(thz){sub 4}].0.5thz. Both, the lanthanide ions as well as the thiazole ligand contribute to the luminescence. Excitation can be achieved via intra-4f transitions and by exciting the ligand, emission is observed mainly from the lanthanide ions again by 4f transitions. Thiazole can transfer energy to the lanthanide ions, which further feeds the lanthanide emission by an efficient antenna effect even at room temperature. The lanthanide ions show pentagonal-bipyramidal coordination by three chloride anions and four N atoms of 1,3-thiazole, which leads to a strong {sup 5}D{sub 0} → {sup 7}F{sub 4} transition for europium. Significant differences arise as compared to thiophene complexes because no sulphur atom is involved in the metal coordination, as the thiazole ligand is solely coordinated via its nitrogen function. (orig.)

  8. Investigation of phase relationships in subsolidus region of Ln2O3-MoO3-B2O3 systems

    International Nuclear Information System (INIS)

    Lysanova, C.V.; Dzhurinskij, B.F.; Komova, M.G.; Tananaev, I.V.

    1983-01-01

    Phase formation in subsolidus region of Ln 2 O 3 -MoO 3 B 2 O 3 systems (Ln-La, Nd) is studied. Three compounds with mixed oxyanions-boratomolybdates of LnMoBO 6 composition (Ln-La, Ce, Pr, Nd), Ln 2 MoB 2 O 9 (Ln-La, Ce, Pr, Nd, Sm, EU, Gde Tb) Ln 6 Mo 3 B 4 0 24 (Ln-Pr, Nd) are revealed and described

  9. Systematics in the electron transport and magnetic properties of LnBO3 perovskites

    International Nuclear Information System (INIS)

    Ganguly, P.; Rao, C.N.R.

    1980-01-01

    Systematics in the electrical and magnetic properties of transition metal perovskites LnBO 3 (Ln = rare-earth ion, B = 3d transition metal) with the variation of Ln and B ions are reviewed. The electrical resistivity and activation energy of LnBO 3 compounds increase with the decreasing size of the Ln 3+ ion for a given B ion. The low-spin to high-spin transition temperature of Co 3+ ion in LnCoO 3 similarly increase with the decrease in size of Ln 3+ while the magnetic ordering temperatures in LnVO 3 , LnFeO 3 , LnCrO 3 and LnSrCo 2 O 6 decrease with decreasing size of the rare-earth ion. These results may be understood in terms of the increasing acidity of the rare earth ion with decreasing size and the competition between the Ln 3+ and the B 3+ ions for covalency with the oxygen ions. The effect of this competition on the metal oxygen covalency and crystal field parameter is discussed in relation to the results obtained and Goodenough's phase diagram. The possibility of d-f exchange interaction in Lasub(1-x)Lnsub(x)NiOsub(3) is also discussed in the light of ESR results. (auth.)

  10. Crystallochemical analysis of rare-earth halogen-containing π-complexes

    International Nuclear Information System (INIS)

    Blatova, O.A.; Blatov, V.A.; Serezhkin, V.N.

    2001-01-01

    Dependence of the size of Ln atom action in coordination polyhedrons LnC n X m (X = F, Cl, Br) on its nature, coordination number, oxidation state and number of Ln-X bonds, was studied using 96 halogen-containing π-complexes of rare earth and yttrium (Ln) by way of example. A method of estimating ligand sizes in coordination sphere using the Voronoi-Dirichlet molecular polyhedrons was suggested. Influence of the ligands sizes on stability of π-complexes and presence of specific interactions in their structure was analyzed [ru

  11. Heterometallic Zn3 Ln3 Ensembles Containing (μ6 -CO3 ) Ligand and Triangular Disposition of Ln3+ ions: Analysis of Single-Molecule Toroic (SMT) and Single-Molecule Magnet (SMM) Behavior.

    Science.gov (United States)

    Goura, Joydeb; Colacio, Enrique; Herrera, Juan Manuel; Suturina, Elizaveta A; Kuprov, Ilya; Lan, Yanhua; Wernsdorfer, Wolfgang; Chandrasekhar, Vadapalli

    2017-11-21

    Two new heterometallic Zn 3 Ln 3 (Ln 3+ =Dy, Tb) complexes, with a double triangular topology of the metal ions, have been assembled from the polytopic Mannich base ligand 6,6'-{[2-(dimethylamino)ethylazanediyl]bis(methylene)}bis(2-methoxy-4-methylphenol) (H 2 L) with the aid of an in situ generated carbonate ligand from atmospheric CO 2 fixation. Theoretical calculations indicate axial ground states for the Ln 3+ ions in these complexes, with their local magnetic moments being almost coplanar and tangential to the Ln 3+ atoms that define the equilateral triangle. Therefore, they can be considered as single-molecule toroics (SMTs) with almost zero total magnetic moment. Micro-SQUID measurements on the Dy 3+ counterpart show hysteresis loops below 3 K that have an S-shape, with large coercive fields opening upon cooling. This behavior is typical of a single molecule magnet (SMM) with very slow zero-field relaxation. At around ±0.35 T, the loops have a broad step, which is due to a direct relaxation process and corresponds to an acceleration of the relaxation of the magnetization, also observed at this magnetic field from ac susceptibility measurements. Simulations suggest that the broad step corresponds to two level avoidance of crossing points where the spin chiral Kramers doublet meets excited states of the coupled manifold, whose position is defined by exchange and dipole interactions. The Tb 3+ counterpart does not exhibit SMM behavior, which is due to the fact that the degeneracy of the ground state of the exchange coupled system is lifted at zero field, thus favoring quantum tunneling of magnetization (QTM). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Synthesis and photoluminescence properties of GdBO3:Ln3+ (Ln = Eu, Tb) nanofibers by electrospinning

    International Nuclear Information System (INIS)

    Shen, Hongzhi; Feng, Shuo; Wang, Ying; Gu, Yipeng; Zhou, Jing; Yang, Hang; Feng, Guanlin; Li, Liang; Wang, Wenquan; Liu, Xiaoyang; Xu, Dapeng

    2013-01-01

    Highlights: ► GdBO 3 :Ln 3+ nanofibers were synthesized successfully by electrospinning. ► The samples have the average diameter of 150 nm and the flexible morphology. ► The GdBO 3 : Eu 3+ nanofibers have the stronger orange emission. ► The luminescence properties are different from the reported bulk material. ► We describe the energy transform process of GdBO 3 :Ln 3+ system. - Abstract: GdBO 3 :Ln 3+ (Ln = Eu, Tb) nanofibers were synthesized using electrospinning combined with heat treatment. The synthesized nanofibers were characterized by X-ray diffraction, Raman spectroscopy, field emission-scanning electron microscopy, thermogravimetric and differential thermal analyses, and photoluminescence. The experimental results show that the flexible synthesized nanofibers have an average diameter of approximately 150 nm. The nanofibers consist of crystalline grains with diameters of about 40 nm and have a vaterite-type structure of GdBO 3 . The GdBO 3 :Eu 3+ nanofibers exhibit strong orange and weak red emissions with a low ratio of red to orange emission intensities, which is different from those of the reported bulk materials and nanoparticles. The luminescence properties of the synthesized GdBO 3 :Tb 3+ nanofibers are essentially consistent with those of the synthesized GdBO 3 :Tb 3+ powders by solid-state reaction.

  13. Influence of lead oxide addition on LnTiTaO6 (Ln = Ce, Pr and Nd) microwave ceramics

    International Nuclear Information System (INIS)

    Padma Kumar, H.; Thomas, J.K.; John, Annamma; Solomon, Sam

    2011-01-01

    The effect of PbO addition on the structural, processing and microwave dielectric properties of LnTiTaO 6 (Ln = Ce, Pr and Nd) ceramics are reported. Conventional solid state ceramic route was used for the preparation of samples. Phase pure LnTiTaO 6 (Ln = Ce, Pr and Nd) ceramics are prepared at a calcination temperature of 1300 deg C. The samples are sintered at optimized temperatures. Addition of PbO reduces the sintering temperature. The crystal structure of the materials was analysed using X-ray diffraction techniques and the surface morphology of the sintered samples was analysed using scanning electron microscopy. The dielectric constant at microwave frequency range decreases for higher PbO addition for all the samples but the quality factor improves on small PbO addition. The thermal stability of resonant frequency was also improved with PbO addition on all the systems. A number of samples with improved microwave dielectric properties were obtained on all the systems suitable for practical applications. (author)

  14. Bi2(Sr, Ln)2CuOz (Ln = Nd, Sm) phases: stability, crystal growth and superconducting properties

    International Nuclear Information System (INIS)

    Faqir, H.; Kikuchi, M.; Syono, Y.; Mansori, M.; Satre, P.; Sebaoun, A.; Vacquier, G.

    2000-01-01

    Bi 2 (Sr,Ln) 2 CuO z (Ln = Nd, Sm) single crystals were successfully grown by a self-flux method from stoichiometric and (Bi, Cu)-rich melts. Thermal analysis and thermogravimetry were used to determine stability and the melting sequence of Bi 2 (Sr,Ln) 2 CuO z phases in air. As-grown crystals of the ideal Bi 2 (Sr,Ln) 2 CuO z phase, of dimensions 1x0.5x0.03 mm 3 , exhibit superconducting behaviour with critical temperature T c = 21 K for the Bi 1.9 Sr 1.6 Nd 0.6 CuO z crystal and Tc = 14 K for the Bi 1.8 Sr 1.6 Sm 0.6 CuO z crystal. The compositions of these crystals were homogeneous and close to the stoichiometric composition. We report on the growth of Bi 2 Sr 2-x Sm x CuO z single crystals of large dimensions 9x3x0.03 mm 3 using Bi 2 Sr 1.5 Sm 0.5 CuO z as precursor and Bi 2 CuO 4 as flux. (author)

  15. Series of edge-sharing bi-triangle Ln4 clusters with a μ4-NO3- bridge: syntheses, structures, luminescence, and the SMM behavior of the Dy4 analogue.

    Science.gov (United States)

    Zou, Hua-Hong; Wang, Rong; Chen, Zi-Lu; Liu, Dong-Cheng; Liang, Fu-Pei

    2014-02-14

    A series of Ln4 clusters, [Ln4L2(μ3-OH)2(μ4-NO3)(NO3)4(OCH3)(H2O)]·xMeCN·yMeOH (Ln = Gd (1), Tb (2), Dy (3), Ho (4), Er (5), Yb (6), L = 2-{[2-(2-hydroxy-ethoxy)-ethylimino]-methyl}-6-methoxyphenol), have been synthesized by the reaction of Ln(NO)3 and a Schiff-base ligand formed in situ. The six complexes display similar structures, with an overall metal core comprising two edge-sharing triangular Ln3 units linked by a μ4-NO3(-) bridge. The luminescence spectrum of complex 2 shows the characteristic emission of the Tb(III) ions. The magnetic susceptibility studies reveal that the Ln(III) ions are very weakly interacting in all six compounds. Frequency dependence of the ac-susceptibility was found for 3, suggesting a typical single-molecule magnet (SMM) behavior with an anisotropic barrier of 28 K.

  16. Lanthanoplatins: emissive Eu(iii) and Tb(iii) complexes staining nucleoli targeted through Pt-DNA crosslinking.

    Science.gov (United States)

    Singh, Khushbu; Singh, Swati; Srivastava, Payal; Sivakumar, Sri; Patra, Ashis K

    2017-06-01

    Two highly luminescent water-soluble heterometallic LnPt 2 complexes, [{cis-PtCl(NH 3 ) 2 } 2 Ln(L)(H 2 O)](NO 3 ) 2 (Ln = Eu (1), Tb (2)), have been designed for their selective nucleoli staining through formation of Pt-DNA crosslinks. The complexes showed significant cellular uptake and distinctive nucleoli localization through intrinsic emission from Eu III or Tb III observed through confocal fluorescence microscopy.

  17. Distribuce digitálního obsahu

    OpenAIRE

    Voborník, Vojtěch

    2016-01-01

    Bakalářská práce reaguje na současné způsoby distribuce digitálního obsahu na internetu (například audia, videa, softwaru, videoher, e-knih, fotografií apod.) mezi autorem a spotřebitelem, jejich výhody a nevýhody a nabízí alternativní způsob distribuce dosud nezveřejněných digitálních děl, prostřednictvím vytvořené webové stránky, která je výstupem této práce. Bachelor thesis responds to the current distribution methods of digital content on the internet (for example, audio, video, softwa...

  18. LN2 Dewar 42 Delivery Overfill Inlet Solution

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J.; Mulholland, G.T.; /Fermilab

    1991-02-26

    Pressure vessels must be protected against overpressure scenarios. A scenario of particular concern is that from a high pressure LN2 pump, now standard on LN2 delivery trailers. A safety mechanism must be in place to prevent the overfilling, and subsequent overpressure from occurring because these pumps have a higher mass flow output than reasonably sized relief valves provide. The original solution to the problem was to close a valve on the fill line when a certain liquid level in the dewar is reached. The valve remains closed until the level drops below that threshold. The trigger level was about 13,000 gallons for the 20,000 gallon capacity dewar. The solution was in place from 1989 until present, 2004.

  19. Dynamic Recrystallization and Hot Workability of 316LN Stainless Steel

    Directory of Open Access Journals (Sweden)

    Chaoyang Sun

    2016-07-01

    Full Text Available To identify the optimal deformation parameters for 316LN austenitic stainless steel, it is necessary to study the macroscopic deformation and the microstructural evolution behavior simultaneously in order to ascertain the relationship between the two. Isothermal uniaxial compression tests of 316LN were conducted over the temperature range of 950–1150 °C and for the strain rate range of 0.001–10 s−1 using a Gleeble-1500 thermal-mechanical simulator. The microstructural evolution during deformation processes was investigated by studying the constitutive law and dynamic recrystallization behaviors. Dynamic recrystallization volume fraction was introduced to reveal the power dissipation during the microstructural evolution. Processing maps were developed based on the effects of various temperatures, strain rates, and strains, which suggests that power dissipation efficiency increases gradually with increasing temperature and decreasing stain rate. Optimum regimes for the hot deformation of 316LN stainless steel were revealed on conventional hot processing maps and verified effectively through the examination of the microstructure. In addition, the regimes for defects of the product were also interpreted on the conventional hot processing maps. The developed power dissipation efficiency maps allow optimized processing routes to be selected, thus enabling industry producers to effectively control forming variables to enhance practical production process efficiency.

  20. Creep modelling of type 316LN stainless steel

    International Nuclear Information System (INIS)

    Kim, W. G.; Kim, D. H.; Ryu, W. S.

    2000-01-01

    Creep curve for type 316LN stainless steel was modelled by using the K-R damage equations. Seven coefficients used in the model, i. e., A, B, κ, m, λ, r, and q were determined from theoretical and calculated data, and their meanings were also analyzed. To quantify damage formation parameter(ω), cavity amount was measured on the crept specimen taken from an interrupted creep test with time variation, and then the amount was reflected into K-R damage equations. Coefficient λ which is regarded as a creep tolerance feature of a material increased with increase of creep strain. Theoretical curve in λ= 3.0 well coincided with an experimental one to the full level of lifetime. Master curve between damage parameter and life fraction matched with the theoretical one in exponent γ= 24 value, which decreased with increase of parameter ω which increased rapidly after 80% life fraction. It is concluded that K-R equation was reliable as the modelling equation for 316LN stainless steel. Coefficient data obtained from 316LN stainless steel can be utilized for remaining life prediction of operating material

  1. Synthesis, crystal structure, optical and thermal properties of lanthanide hydrogen-polyphosphates Ln[H(PO3)4] (Ln = Tb, Dy, Ho).

    Science.gov (United States)

    Förg, Katharina; Höppe, Henning A

    2015-11-28

    Lanthanide hydrogen-polyphosphates Ln[H(PO3)4] (Ln = Tb, Dy, Ho) were synthesised as colourless (Ln = Tb, Dy) and light pink (Ln = Ho) crystalline powders by reaction of Tb4O7/Dy2O3/Ho2O3 with H3PO3 at 380 °C. All compounds crystallise isotypically (P2(1)/c (no. 14), Z = 4, a(Tb) = 1368.24(4) pm, b(Tb) = 710.42(2) pm, c(Tb) = 965.79(3) pm, β(Tb) = 101.200(1)°, 3112 data, 160 parameters, wR2 = 0.062, a(Ho) = 1363.34(5) pm, b(Ho) = 709.24(3) pm, c(Ho) = 959.07(4) pm, β(Ho) = 101.055(1)°, 1607 data, 158 parameters, wR2 = 0.058). The crystal structure comprises two different infinite helical chains of corner-sharing phosphate tetrahedra. In-between these chains the lanthanide ions are located, coordinated by seven oxygen atoms belonging to four different polyphosphate chains. Vibrational, UV/Vis and fluorescence spectra of Ln[H(PO3)4] (Ln = Tb, Dy, Ho) as well as Dy[H(PO3)4]:Ln (Ln = Ce, Eu) and the magnetic and thermal behaviour of Tb[H(PO3)4] are reported.

  2. Characteristic charge transport in oxygen-deficiency-controlled LnFeAsO1-y (Ln = La and Nd)

    International Nuclear Information System (INIS)

    Ishida, Shigeyuki; Nakajima, Masamichi; Tomioka, Yasuhide; Ito, Toshimitsu; Miyazawa, Kiichi; Kito, Hijiri; Lee, Chul-Ho; Ishikado, Motoyuki; Shamoto, Shin-ichi; Iyo, Akira; Eisaki, Hiroshi; Kojima, Kenji M.; Uchida, Shin-ichi

    2010-01-01

    We have investigated the transport properties of LnFeAsO 1-y (Ln = La, Nd) over a wide range of doping. When we compare the exponent n of resistivity ρ(T)∼T n , a marked difference is found between La and Nd system. In the La system with lower T C ,ρ(T) is always dominated by a T 2 term at low temperatures, showing relatively large magnetoresistance. On the other hand, in the Nd system with higher T C ,ρ(T) is linear on T with a small magnetoresistance. These results indicate that the carriers are subject to stronger scattering in NdFeAsO 1-y , which might be linked to the higher T C .

  3. Effect of crystalline electric field on heat capacity of LnBaCuFeO5 (Ln = Gd, Ho, Yb)

    Science.gov (United States)

    Lal, Surender; Mukherjee, K.; Yadav, C. S.

    2018-02-01

    Structural, magnetic and thermodynamic properties of layered perovskite compounds LnBaCuFeO5 (Ln = Ho, Gd, Yb) have been investigated. Unlike the iso-structural compound YBaCuFeO5, which shows commensurate antiferromagnetic to incommensurate antiferromagnetic ordering below ∼200 K, the studied compounds do not show any magnetic transition in measured temperature range of 2-350 K. The high temperature heat capacity of the compounds is understood by employing contributions from both optical and acoustic phonons. At low temperature, the observed upturn in the heat capacity is attributed to the Schottky anomaly. The magnetic field dependent heat capacity shows the variation in position of the anomaly with temperature, which appears due to the removal of ground state degeneracy of the rare earth ions, by the crystalline electric field.

  4. Surprising luminescent properties of the polyphosphates Ln(PO3)3:Eu (Ln = Y, Gd, Lu).

    Science.gov (United States)

    Höppe, Henning A; Kazmierczak, Karolina; Kacprzak, Sylwia; Schellenberg, Inga; Pöttgen, Rainer

    2011-10-21

    The optical emission properties of the lanthanoid catena-polyphosphates Ln(PO(3))(3) (Ln = Y, Gd, Lu) doped with europium were investigated. Incommensurately modulated β-Y(PO(3))(3):Eu (super space group Cc (0|0.364|0)0) and Gd(PO(3))(3):Eu (space group I2/a) show the usual emission characteristics of Eu(3+), while in Lu(PO(3))(3):Eu (space group Cc) the europium is unprecedentedly partially reduced to the divalent state, as proven by both a broad emission band at 406 nm excited at 279 nm and an EPR spectroscopic investigation. (151)Eu-Mössbauer spectroscopy showed that only a very small part of the europium is reduced in Lu(PO(3))(3):Eu. An explanation for this unusual behaviour is given. This journal is © The Royal Society of Chemistry 2011

  5. The orthorhombic fluorite related compounds Ln/sub 3/RuO/sub 7/, Ln=Nd, Sm and Eu

    International Nuclear Information System (INIS)

    Van Berkel, F.P.F.; Ijdo, D.J.W.

    1986-01-01

    Fluorite-related Ru(V) compound with composition Ln/sub 3/RuO/sub 7/ have been found. These compounds with space group Cmcm adopt a superstructure of the cubic fluorite structure with a/sub orth/=2a/sub c/, b/sub orth/=c/sub orth/=a/sub c/√2. These compounds have the same structure as La/sub 3/NbO/sub 7/

  6. Controllable synthesis of Ln3+ (Ln = Tb, Eu) doped zinc phosphate nano-/micro-structured materials: phase, morphology and luminescence properties

    Science.gov (United States)

    Yue, Dan; Lu, Wei; Li, Chunyang; Zhang, Xinlei; Liu, Chunxia; Wang, Zhenling

    2014-01-01

    Ln3+ (Ln = Tb, Eu) doped zinc phosphate tetrahydrate (ZPT:Ln3+) and ammonium zinc phosphate (AZP:Ln3+) nano-/micro-structured materials were synthesized in aqueous solution without the addition of any structure-directing agent. The phase structures, morphologies and luminescence properties of the as-synthesized samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and lifetime. These investigations indicate that different phosphate sources MnH(3-n)PO4 (M = NH4+ or Na+, n = 1, 2, 3) can lead to the altering of morphology from nanosheet to microflower, but have no significant effect on the phase structure of the samples. The microlump, nanosheet, and microflower (constructed by the primary microlumps or nanosheets) of orthorhombic ZPT:Ln3+ could be selectively prepared by adjusting the pH value from 3.5 to 7.0. A mixture of orthorhombic ZPT:Ln3+ and monoclinic AZP:Ln3+ with a microflower morphology was obtained when the pH value was adjusted to 8.0. Monoclinic AZP:Ln3+ microplate, microcube and nanoparticle morphologies were obtained at pH values of 8.5, 9.0 and 11.0 respectively. The phase transformation and growth mechanism of the diverse morphologies were proposed, and ZPT:Ln3+ (Ln3+ = Eu or Tb) samples exhibit red or green emission under the excitation of UV light.Ln3+ (Ln = Tb, Eu) doped zinc phosphate tetrahydrate (ZPT:Ln3+) and ammonium zinc phosphate (AZP:Ln3+) nano-/micro-structured materials were synthesized in aqueous solution without the addition of any structure-directing agent. The phase structures, morphologies and luminescence properties of the as-synthesized samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and lifetime. These

  7. The single crystal structure determination of Ln{sub 6}MnSb{sub 15} (Ln=La, Ce), Ln{sub 6}Mn{sub 1-x}Zn{sub x}Sb{sub 15} (x∝0.5), and Ln{sub 6}ZnSb{sub 15} (Ln=La-Pr)

    Energy Technology Data Exchange (ETDEWEB)

    Benavides, Katherine A.; McCandless, Gregory T.; Chan, Julia Y. [Texas Univ., Dallas, Richardson, TX (United States). Dept. of Chemistry and Biochemistry

    2017-09-01

    Single crystals of Ln{sub 6}MnSb{sub 15} (Ln=La, Ce), Ln{sub 6}Mn{sub 1-x}Zn{sub x}Sb{sub 15} (x∝0.5), and Ln{sub 6}ZnSb{sub 15} (Ln=La-Pr) have been successfully grown and the compounds adopt the orthorhombic Ln{sub 6}MnSb{sub 15} structure type (space group Immm), with a∝4.3 Aa, b∝15 Aa, and c∝19 Aa. This structure is comprised of antimony nets and antimony ribbons which exhibit positional disorder at connecting points between antimony substructures, in addition to two partially occupied transition metal sites. The unit cell volumes of the La analogs displayed a systematic decrease upon Zn substitution. However, for the Ce{sub 6}Mn{sub 1-x}Zn{sub x}Sb{sub 15} and Pr{sub 6}Mn{sub 1-x}Zn{sub x}Sb{sub 15} (x∝0.5), the volumes deviate from linearity as observed in the parent compounds.

  8. A new promising phosphor, Na3La2(BO3)3:Ln (Ln=Eu, Tb)

    International Nuclear Information System (INIS)

    Li Zhihua; Zeng Jinghui; Zhang Guochun; Li Yadong

    2005-01-01

    We present an efficient way to search a host for ultraviolet (UV) phosphor from UV nonlinear optical (NLO) materials. With the guidance, Na 3 La 2 (BO 3 ) 3 (NLBO), as a promising NLO material with a broad transparency range and high damage threshold, was adopted as a host material for the first time. The lanthanide ions (Tb 3+ and Eu 3+ )-doped NLBO phosphors have been synthesized by solid-state reaction. Luminescent properties of the Ln-doped (Ln=Tb 3+ , Eu 3+ ) sodium lanthanum borate were investigated under UV ray excitation. The emission spectrum was employed to probe the local environments of Eu 3+ ions in NLBO crystal. For red phosphor, NLBO:Eu, the measured dominating emission peak was at 613 nm, which is attributed to 5 D - 7 F 2 transition of Eu 3+ . The luminescence indicates that the local symmetry of Eu 3+ in NLBO crystal lattice has no inversion center. Optimum Eu 3+ concentration of NLBO:Eu 3+ under UV excitation with 395 nm wavelength is about 30 mol%. The green phosphor, NLBO:Tb, showed bright green emission at 543 with 252 nm excited light. The measured concentration quenching curve demonstrated that the maximum concentration of Tb 3+ in NLBO was about 20%. The luminescence mechanism of Ln-doped NLBO (Tb 3+ and Eu 3+ ) was analyzed. The relative high quenching concentration was also discussed

  9. KCa4(BO33:Ln3+ (Ln = Dy, Eu, Tb phosphors for near UV excited white–light–emitting diodes

    Directory of Open Access Journals (Sweden)

    Allu Amarnath Reddy

    2013-02-01

    Full Text Available A series of doped KCa4(BO33:Ln3+ (Ln: Dy, Eu and Tb compositions were synthesized by solid–state reaction method and their photoluminescent properties were systematically investigated to ascertain their suitability for application in white light emitting diodes. The X–ray diffraction (XRD and nuclear magnetic resonance (MAS–NMR data indicates that Ln3+–ions are successfully occupied the non–centrosymmetric Ca2+ sites, in the orthorhombic crystalline phase of KCa4(BO33 having space group Ama2, without affecting the boron chemical environment. The present phosphor systems could be efficiently excitable at the broad UV wavelength region, from 250 to 350 nm, compatible to the most commonly available UV light–emitting diode (LED chips. Photoluminescence studies revealed optimal near white–light emission for KCa4(BO33 with 5 wt.% Dy3+ doping, while warm white–light (CIE; X = 0.353, Y = 0.369 is obtained at 1wt.% Dy3+ ion concentration. The principle of energy transfer between Eu3+ and Tb3+ also demonstrates the potential white–light from KCa4(BO33:Eu3+,Tb3+ phosphor. Whereas, single Tb3+ and Eu3+–doped systems showed bright green (Tb3+ and red (Eu3+ emissions, respectively. Having structural flexibility along with remarkable chemical/thermal stability and suitable quantum efficiency these phosphors can be promising candidates as white–light–emitter for near UV LEDs.

  10. Structural trends in a series of isostructural lanthanide-copper metallacrown sulfates (Ln(III) = Pr, Nd, Sm, Eu, Gd, Dy and Ho): hexaaquapentakis[μ3-glycinehydroxamato(2-)]sulfatopentacopper(II)lanthanide(III) heptaaquapentakis[μ3-glycinehydroxamato(2-)]sulfatopentacopper(II)lanthanide(III) sulfate hexahydrate.

    Science.gov (United States)

    Pavlishchuk, Anna V; Kolotilov, Sergey V; Fritsky, Igor O; Zeller, Matthias; Addison, Anthony W; Hunter, Allen D

    2011-07-01

    The seven isostructural complexes, [Cu(5)Ln(C(2)H(4)N(2)O(2))(5)(SO(4))(H(2)O)(6.5)](2)(SO(4))·6H(2)O, where Ln(III) = Pr, Nd, Sm, Eu, Gd, Dy and Ho, are representatives of the 15-metallacrown-5 family. Each dianion of glycinehydroxamic acid (GlyHA) links two Cu(II) cations forming a cyclic [CuGlyHA](5) frame. The Ln(III) cations are located at the centre of the [CuGlyHA](5) rings and are bound by the five hydroxamate O atoms in the equatorial plane. Five water molecules are coordinated to Cu(II) cations, and one further water molecule, located close to an inversion centre between two adjacent [Cu(5)Ln(GlyHA)(5)](2+) cations, is disordered around this inversion centre and coordinated to a Cu(II) cation of either the first or second metallacrown ether. Another water molecule and one of the two crystallographically independent sulfate anions are coordinated, the latter in a bidentate fashion, to the Ln(III) cation in the axial positions. The second sulfate anion is not coordinated to the cation, but is located in an interstitial position on a crystallographic inversion centre, thus leading to disorder of the O atoms around the centre of inversion. The Ln-O bond distances follow the trend of the lanthanide contraction. The apical Ln-O bond distances are very close to the sums of the ionic radii. However, the Ln-O distances within the metallacrown units are slightly compressed and the Ln(III) cations protrude significantly from the plane of the otherwise flat metallacrown ligand, thus indicating that the cavity is somewhat too small to accommodate the Ln(III) ions comfortably. This effect decreases with the size of the lanthanide cation from complex (I) (Ln(III) = Pr; 0.459) to complex (VII) (Ln(III) = Ho; 0.422), which indicates that the smaller lanthanide cations fit the cavity of the pentacopper metallacrown ring better than the larger ones. The diminished contraction of Ln-O distances within the metallacrown planes leads to an aniostropic contraction of the unit

  11. Dymethyl sulfoxide complexes of rare earth perrhenates

    International Nuclear Information System (INIS)

    Osorio, V.K.L.; Kawano, Y.; Kuya, M.K.; Perrier, M.

    1980-01-01

    The complexes Ln(ReO 4 ) 3 .8dmso (Ln = La-Lu, Y) and La(ReO 4 ) 3 .8dmso-d 6 have been prepared and characterized by conductance, infrared and Raman measurements. All the complexes have structures involving complex cation and non-coordinated anions in the solid state. The conductance values in nitromethane solution indicate a behavior near to a 1:1 electrolyte type. A comparative study with the data accumulated on the literature shows that perrhenate anion has higher coordinating capacity than perchlorate and hexafluorophosphate ones. (Author) [pt

  12. Structure of X-ray photoelectron spectra of low-energy and core electrons of Ln(C6H4OCH3COO-3

    Directory of Open Access Journals (Sweden)

    Teterin Yury A.

    2005-01-01

    Full Text Available This paper deals with the results of an X-ray photo electron spectroscopy of lanthanide ortho-metoxybenzoates Ln(C6H4OCH3COO-3, where Ln represents lanthanides La through Lu except for Pm and C6H4OCH3COO- - residuum of ortho-metoxybenzoic acid. The core and outer electron X-ray photo electron spectroscopy spectra in the binding energy range of 0-1250 eV were shown to exhibit a complex, fine structure. The said structure was established due to the outer (0-15 eV binding energy and inner (15-50 eV binding energy valence molecular orbital from the filled Ln5p and O2s atomic shells multiple splitting, many-body perturbation, dynamic effect, etc. The mechanisms of such a fine structure formation were shown to manifest different probabilities in the spectrum of a certain electronic shell. There fore, the fine X-ray photo electron spectroscopy spectral structure resulting from a certain mechanism can be interpreted and its quantitative parameters related to the physical and chemical properties of the studied com pounds (degree of delocalization and participation of Ln4f electrons in the chemical bond, electronic configuration and oxidation states, density of uncoupled electrons on paramagnetic ions, degree of participation of the low binding energy filled electronic shells of lanthanide and ligands information of the outer and in nervalence molecular orbitals, lanthanide close environment structure in amorphous materials, etc.

  13. Microstructure, local mechanical properties and stress corrosion cracking susceptibility of an SA508-52M-316LN safe-end dissimilar metal weld joint by GTAW

    Energy Technology Data Exchange (ETDEWEB)

    Ming, Hongliang; Zhu, Ruolin [Key Laboratory of Nuclear Materials and Safety Assessment, Liaoning KeyLaboratory for Safety and Assessment Technique of Nuclear Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049 (China); Zhang, Zhiming [Key Laboratory of Nuclear Materials and Safety Assessment, Liaoning KeyLaboratory for Safety and Assessment Technique of Nuclear Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, Jianqiu, E-mail: wangjianqiu@imr.ac.cn [Key Laboratory of Nuclear Materials and Safety Assessment, Liaoning KeyLaboratory for Safety and Assessment Technique of Nuclear Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Han, En.-Hou.; Ke, Wei [Key Laboratory of Nuclear Materials and Safety Assessment, Liaoning KeyLaboratory for Safety and Assessment Technique of Nuclear Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Su, Mingxing [Shanghai Research Center for Weld and Detection Engineering Technique of Nuclear Equipment, Shanghai 201306 (China)

    2016-07-04

    The microstructure, local mechanical properties and local stress corrosion cracking susceptibility of an SA508-52M-316LN domestic dissimilar metal welded safe-end joint used for AP1000 nuclear power plant prepared by automatic gas tungsten arc welding was studied in this work by optical microscopy, scanning electron microscopy (with electron back scattering diffraction and an energy dispersive X-ray spectroscopy system), micro-hardness testing, local mechanical tensile testing and local slow strain rate tests. The micro-hardness, local mechanical properties and stress corrosion cracking susceptibility across this dissimilar metal weld joint vary because of the complex microstructure across the fusion area and the dramatic chemical composition change across the fusion lines. Briefly, Type I boundaries and Type II boundaries exist in 52Mb near the SA508-52Mb interface, a microstructure transition was found in SA508 heat affected zone, the residual strain and grain boundary character distribution changes as a function of the distance from the fusion boundary in 316LN heat affected zone, micro-hardness distribution and local mechanical properties along the DMWJ are heterogeneous, and 52Mw-316LN interface has the highest SCC susceptibility in this DMWJ while 316LN base metal has the lowest one.

  14. First-principle calculations of the structural, elastic and bonding properties of Cs{sub 2}NaLnCl{sub 6} (Ln=La–Lu) cubic elpasolites

    Energy Technology Data Exchange (ETDEWEB)

    Ma, C.G.; Liu, D.X.; Feng, B.; Tian, Y.; Li, L. [College of Sciences, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China); Brik, M.G., E-mail: mikhail.brik@ut.ee [College of Sciences, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China); Institute of Physics, University of Tartu, Ravila 14C, Tartu 50411 (Estonia); Institute of Physics, Jan Dlugosz University, Armii Krajowej 13/15, PL-42200 Czestochowa (Poland)

    2016-01-15

    For the first time the structural, elastic and bonding properties of 15 elpasolite crystals Cs{sub 2}NaLnCl{sub 6} (Ln denotes all lanthanides from La to Lu) were calculated systematically using the CRYSTAL09 program. Several trends in the variation of these properties in relation to the atomic number Z of the Ln ions were found; in particular, the lattice parameter of these compounds decreases with Z (which can lead to the increased crystal field splittings of the 5d states for the heavier Ln ions), whereas the elastic constants and Debye temperature increase. The degree of covalency of the Ln–Cl chemical bonds is increased toward the end of the lanthanide series. - Highlights: • Structural, elastic and bonding properties of 15 cubic elpasolites Cs{sub 2}NaLnCl{sub 6} (Ln=La,…,Lu) are calculated. • Relations between these quantities and Ln atomic number were found. • Possible correlation between the elastic properties and Stokes shift is proposed.

  15. New lanthanide hydrogen phosphites LnH (P03H)2 2H20

    International Nuclear Information System (INIS)

    Durand, J.; Tijani, N.; Cot, L.; Loukili, M.; Rafiq, M.

    1988-01-01

    LnH ((P0 3 H) 2 2H 2 0 is prepared from lanthanide oxide and phosphorous acid with Ln = La, Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er or Tm. By thermal gravimetric analysis LnH (P0 3 H) 2 and LnH 2 P 2 0 5 (P0 3 H) 2 are obtained. The three salts are orthorhombic. Parameters and space groups are given for the three salts of each lanthanide. 4 tabs., 13 refs

  16. Fatigue crack nucleation of type 316LN stainless steel

    International Nuclear Information System (INIS)

    Kim, Dae Whan; Kim, Woo Gon; Hong, Jun Hwa; Ryu, Woo Seog

    2000-01-01

    Low Cycle Fatigue (LCF) life decreases drastically with increasing temperature but increases with the addition of nitrogen at room and high temperatures. The effect of nitrogen on LCF life may be related to crack nucleation at high temperatures in austenitic stainless steel because the fraction of crack nucleation in LCF life is about 40%. The influence of nitrogen on the crack nucleation of LCF in type 316LN stainless steel is investigated by observations of crack population and crack depth after testing at 40% of fatigue life. Nitrogen increases the number of cycles to nucleate microcracks of 100 μm but decreases the crack population

  17. Synthesis and luminescent spectroscopy of lanthanide complexes with dimethylpyridine-2,6-dicarboxylate (dmpc)

    Energy Technology Data Exchange (ETDEWEB)

    Taha, Ziyad A., E-mail: tahaz33@just.edu.jo [Department of Applied Chemical Sciences, Faculty of Arts and Sciences, Jordan University of Science and Technology, Irbid 22110 (Jordan); Ajlouni, Abdulaziz M.; Hijazi, Ahmed K. [Department of Applied Chemical Sciences, Faculty of Arts and Sciences, Jordan University of Science and Technology, Irbid 22110 (Jordan); Al-Rawashdeh, Nathir A. [Department of Applied Chemical Sciences, Faculty of Arts and Sciences, Jordan University of Science and Technology, Irbid 22110 (Jordan); Department of Chemistry, United Arab Emirates University, Al Ain 15551 (United Arab Emirates); Al-Hassan, Khader A.; Al-Haj, Yaser A. [Department of Chemistry, Faculty of Science, Yarmouk University, 1163 Irbid (Jordan); Ebqa' ai, Mohammad A. [Al-Qunfudah Center For Scientific Research, Umm Al-Qura University, College in Al-Qunfudah, Makkah (Saudi Arabia); Altalafha, Ammar Y. [Department of Chemistry, Faculty of Science, Yarmouk University, 1163 Irbid (Jordan)

    2015-05-15

    A series of lanthanide complexes with the general formulae [Ln(dmpc)(NO{sub 3}){sub 2}(H{sub 2}O){sub 2}]NO{sub 3} (Ln=Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Er) and [La(dmpc)(NO{sub 3}){sub 2}(H{sub 2}O){sub 2}]NO{sub 3} were prepared by direct reaction between hydrated lanthanide(III) nitrate and dimethylpyridine-2,6-dicarboxylate (dmpc) in a 1:1 M ratio in ethylacetate–chloroform mixture. The luminescence properties of the dmpc and its Ln(III) complexes were investigated in solid state and in methanol, DMF and DMSO solutions. The Tb–dmpc, Eu–dmpc, Sm–dmpc and Dy–dmpc complexes exhibit characteristic luminescence of Tb(III), Eu(III), Sm(III) and Dy(III) ions indicating energy transfer from the dmpc to the Ln(III) ions. Scavenging activities of the dmpc and its Ln(III) complexes on DPPH{sup •} free radical were investigated in DMSO solution at a different concentrations ranges. - Highlights: • Nine new lanthanide complexes with dmpc ligand are prepared and characterized. • Ln–dmpc {Ln=Eu, Tb, Sm, Dy} complexes exhibit characteristic emissions of Ln ions. • The solvent effect on the luminescence intensity is investigated. • The antioxidant activity of the dmpc is enhanced upon complexation with lanthanide.

  18. Ternary phosphates in Ca3(PO4)2-Na3Ln(PO4)2 (Ln-Nd, Eu, Er) systems

    International Nuclear Information System (INIS)

    Lazoryak, B.I.; Ivanov, L.N.; Strunenkova, T.V.; Golubev, V.N.; Viting, B.N.

    1990-01-01

    Ternary phosphates, formed in Ca 3 (PO 4 ) 2 -Na 3 Ln(PO 4 ) 2 (Ln-Nd, Eu, Er) systems were investigated by the methods of X-ray phase, luminescent analyses and IR spectroscopy. 5 regions of homogeneity were found. Two of them (I and II) were distinguished for all systems. Samples in the region of up to 14.285 mol.% Na 3 Ln(PO 4 ) 2 crystallize on the basis of β-Ca 3 (PO 4 ) 2 structure, and in other homogeneity regions - on the basis of β-K 2 SO 4 structure

  19. A determination of the oxygen non-stoichiometry of the oxygen storage materials LnBaMn{sub 2}O{sub 5+δ} (Ln=Gd, Pr)

    Energy Technology Data Exchange (ETDEWEB)

    Jeamjumnunja, Kannika; Gong, Wenquan; Makarenko, Tatyana; Jacobson, Allan J., E-mail: ajjacob@uh.edu

    2016-07-15

    The A-site ordered double-perovskite oxides, LnBaMn{sub 2}O{sub 5+δ} (Ln=Gd, Pr), were synthesized and investigated to understand the effect of A site cation substitution on the oxygen storage properties of these materials. The present results are compared with our previous data for YBaMn{sub 2}O{sub 5+δ}. The results clearly reveal that changing the Ln cation strongly influences the oxidation/reduction behavior of LnBaMn{sub 2}O{sub 5+δ}. Based on thermogravimetric analysis data, oxygen uptake begins at lower temperatures in both air and oxygen in compounds with Ln{sup 3+} ions larger than Y{sup 3+}. These oxides exhibit almost complete and reversible oxygen uptake/release between fully-reduced LnBaMn{sub 2}O{sub 5} and fully-oxidized LnBaMn{sub 2}O{sub 6} during changes of the oxygen partial pressure between air and 1.99% H{sub 2}/Ar. In addition, the oxygen non-stoichiometries of GdBaMn{sub 2}O{sub 5+δ} and PrBaMn{sub 2}O{sub 5+δ} were determined as a function of pO{sub 2} at 600, 650, 700 and 750 °C by Coulometric titration at near-equilibrium conditions. The results confirm that these materials have two distinct phases on oxidation/reduction with δ≈0, 0.5 and a third phase with a range of composition with an oxygen content (5+δ) approaching ~6. The stabilities of the LnBaMn{sub 2}O{sub 5+δ} phases extend over a wide range of oxygen partial pressures (∼10{sup −25}≤pO{sub 2} (atm)≤∼1) depending on temperature. Isothermal experiments show that the larger the Ln{sup 3+} cation the lower pO{sub 2} for phase conversion. At some temperatures and pO{sub 2} conditions, the LnBaMn{sub 2}O{sub 5+δ} compounds are unstable with respect to decomposition to BaMnO{sub 3−δ} and LnMnO{sub 3}. This instability is more apparent in Coulometric titration experiments than in thermogravimetric analysis. The Coulometric titration experiments are necessarily slow in order to achieve equilibrium oxygen compositions. - Graphical abstract: Structure of Ln

  20. Formation enthalpies of LaLn'O{sub 3} (Ln'=Ho, Er, Tm and Yb) interlanthanide perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Jianqi [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States); College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics of Ministry of Education, Sichuan University, Chengdu 610064 (China); Guo, Xiaofeng [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States); Mielewczyk-Gryn, Aleksandra [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States); Faculty of Applied Physics and Mathematics, Department of Solid State Physics, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk (Poland); Navrotsky, Alexandra, E-mail: anavrotsky@ucdavis.edu [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States)

    2015-07-15

    High-temperature oxide melt solution calorimetry using 3Na{sub 2}O·MoO{sub 3} at 802 °C was performed for interlanthanide perovskites LaLn'O{sub 3} (Ln'=Ho, Er, Tm and Yb) and lanthanide oxides (La{sub 2}O{sub 3}, Ho{sub 2}O{sub 3}, Er{sub 2}O{sub 3}, Tm{sub 2}O{sub 3} and Yb{sub 2}O{sub 3}). The enthalpies of formation of these interlanthanide perovskites from binary lanthanide oxides at room temperature (25 °C) were determined to be −8.3±3.4 kJ/mol for LaHoO{sub 3}, −9.9±3.0 kJ/mol for LaErO{sub 3}, −10.8±2.7 kJ/mol for LaTmO{sub 3} and −12.3±2.9 kJ/mol for LaYbO{sub 3}. There is a roughly linear relationships between these enthalpy values and the tolerance factor for these and for other LaM{sup 3+}O{sub 3} (M=In, Sc, Ga, Al, Fe and Cr) perovskites, confirming that the distortion of the perovskites as results from ionic radius difference of A-site and B-site cations, is the main factor determining the stability of these compounds. - Graphical abstract: A linear relationship between the enthalpy of formation and the tolerance factor for interlanthanide LaLn'O{sub 3} (Ln'=Ho, Er, Tm, and Yb) and other LaM{sup 3+}O{sub 3} (M=In, Sc, Ga, Al, Fe and Cr) perovskites. - Highlights: • Interlanthanide perovskites were synthesized by solid state reactions. • Their enthalpies of formation were measured by oxide melt solution calorimetry. • ΔH{sub f,ox} shows a linear relationship with tolerance factor.

  1. Study of creep crack growth behavior of 316LN welds

    International Nuclear Information System (INIS)

    Venugopal, S.; Kumar, Yatindra; Sasikala, G.

    2016-01-01

    Creep crack growth (CCG) behavior plays an important role in the assessment of structural integrity of components operating at elevated temperature under load/stress condition. Integrity of the welded components is decided primarily by that of the weld. Creep crack growth behavior of 316LN welds prepared using consumables developed indigenously for welding the 316L(N) SS components for the Prototype Fast Breeder Reactor has been studied. The composition of the consumable is tailored to ensure about 5 FN (ferrite number) of δ ferrite in the weld deposit. Constant load CCG tests were carried out as per ASTM E1457 at different applied loads at temperatures in the range 823-923 K on CT specimens fabricated from 'V-type' weld joints with notch in the weld centre. The creep crack growth rate (α) is commonly correlated to a time dependent fracture mechanics parameter known as C*. The α3-C* correlations (α=D(C*) φ ) were established in the temperature range 823-923 K. The crack growth rates at different temperature have been compared with that given in RCC-MR. Extensive microstructural and fractographic studies using optical and scanning electron microscopy were carried out on the CCG tested specimens to understand the effect of transformation of delta ferrite on the creep damage and fracture mechanisms associated with CCG in the weld metal at different test conditions. (author)

  2. A determination of the oxygen non-stoichiometry of the oxygen storage materials LnBaMn2O5+δ (Ln=Gd, Pr)

    Science.gov (United States)

    Jeamjumnunja, Kannika; Gong, Wenquan; Makarenko, Tatyana; Jacobson, Allan J.

    2016-07-01

    The A-site ordered double-perovskite oxides, LnBaMn2O5+δ (Ln=Gd, Pr), were synthesized and investigated to understand the effect of A site cation substitution on the oxygen storage properties of these materials. The present results are compared with our previous data for YBaMn2O5+δ. The results clearly reveal that changing the Ln cation strongly influences the oxidation/reduction behavior of LnBaMn2O5+δ. Based on thermogravimetric analysis data, oxygen uptake begins at lower temperatures in both air and oxygen in compounds with Ln3+ ions larger than Y3+. These oxides exhibit almost complete and reversible oxygen uptake/release between fully-reduced LnBaMn2O5 and fully-oxidized LnBaMn2O6 during changes of the oxygen partial pressure between air and 1.99% H2/Ar. In addition, the oxygen non-stoichiometries of GdBaMn2O5+δ and PrBaMn2O5+δ were determined as a function of pO2 at 600, 650, 700 and 750 °C by Coulometric titration at near-equilibrium conditions. The results confirm that these materials have two distinct phases on oxidation/reduction with δ≈0, 0.5 and a third phase with a range of composition with an oxygen content (5+δ) approaching 6. The stabilities of the LnBaMn2O5+δ phases extend over a wide range of oxygen partial pressures (∼10-25≤pO2 (atm)≤∼1) depending on temperature. Isothermal experiments show that the larger the Ln3+ cation the lower pO2 for phase conversion. At some temperatures and pO2 conditions, the LnBaMn2O5+δ compounds are unstable with respect to decomposition to BaMnO3-δ and LnMnO3. This instability is more apparent in Coulometric titration experiments than in thermogravimetric analysis. The Coulometric titration experiments are necessarily slow in order to achieve equilibrium oxygen compositions.

  3. The effect of gamma irradiation on thermoelectric power and thermal conductivity of Ln0.01Sn0.99Se (Ln-Pr,Tb,Er) single crystals

    International Nuclear Information System (INIS)

    Guseynov, D.I.; Murguzov, M.I.; Ismaylov, Sh.S.; Mamedova, R.F.

    2013-01-01

    The present paper contains research results on the effect of gamma irradiation on thermal electromotive force and thermal conductivity of Ln 0 .01Sn 0 .99Se (Ln-Pr,Tb,Er) crystals. It is studied some electrical properties of the samples obtained before and after irradiation in a wide temperature range (80-420 K). As a source it was used an isotope 60Co with photon energies 1.25 MeV, the radiation dose was 65 Mrad

  4. Host-Sensitized and Tunable Luminescence of GdNbO4:Ln3+ (Ln3+ = Eu3+/Tb3+/Tm3+) Nanocrystalline Phosphors with Abundant Color.

    Science.gov (United States)

    Liu, Xiaoming; Chen, Chen; Li, Shuailong; Dai, Yuhua; Guo, Huiqin; Tang, Xinghua; Xie, Yu; Yan, Liushui

    2016-10-17

    Up to now, GdNbO 4 has always been regarded as an essentially inert material in the visible region with excitation of UV light and electron beams. Nevertheless, here we demonstrate a new recreating blue emission of GdNbO 4 nanocrystalline phosphors with a quantum efficiency of 41.6% and host sensitized luminescence in GdNbO 4 :Ln 3+ (Ln 3+ = Eu 3+ /Tb 3+ /Tm 3+ ) nanocrystalline phosphors with abundant color in response to UV light and electron beams. The GdNbO 4 and GdNbO 4 :Ln 3+ (Ln 3+ = Eu 3+ /Tb 3+ /Tm 3+ ) nanocrystalline phosphors were synthesized by a Pechini-type sol-gel process. With excitation of UV light and low-voltage electron beams, the obtained GdNbO 4 nanocrystalline phosphor presents a strong blue luminescence from 280 to 650 nm centered around 440 nm, and the GdNbO 4 :Ln 3+ nanocrystalline phosphors show both host emission and respective emission lines derived from the characterize f-f transitions of the doping Eu 3+ , Tb 3+ , and Tm 3+ ions. The luminescence color of GdNbO 4 :Ln 3+ nanocrystalline phosphors can be tuned from blue to green, red, blue-green, orange, pinkish, white, etc. by varying the doping species, concentration, and relative ratio of the codoping rare earth ions in GdNbO 4 host lattice. A single-phase white-light-emission has been realized in Eu 3+ /Tb 3+ /Tm 3+ triply doped GdNbO 4 nanocrystalline phosphors. The luminescence properties and mechanisms of GdNbO 4 and GdNbO 4 :Ln 3+ (Ln 3+ = Eu 3+ /Tb 3+ /Tm 3+ ) are updated.

  5. Magnetic upconverting fluorescent NaGdF4:Ln3+ and iron-oxide@NaGdF4:Ln3+ nanoparticles

    Science.gov (United States)

    Shrivastava, Navadeep; Rocha, Uéslen; Muraca, Diego; Jacinto, Carlos; Moreno, Sergio; Vargas, J. M.; Sharma, S. K.

    2018-05-01

    Microwave assisted solvothermal method has been employed to synthesize multifunctional upconverting β-NaGdF4:Ln3+ and magnetic-upconverting Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (Ln = Yb and Er) nanoparticles. The powder x-ray diffraction data confirms the hexagonal structure of NaGdF4:Ln3+ and high resolution transmission electron microscopy shows the formation of rod shaped NaGdF4:Ln3+ (˜ 20 nm) and ovoid shaped Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (˜ 15 nm) nanoparticles. The magnetic hysteresis at 300 K for β-NaGdF4:Ln3+ demonstrates paramagnetic features, whereas iron-oxide@β-NaGdF4:Ln3+ exhibits superparamagnetic behavior along with a linear component at large applied field due to paramagnetic NaGdF4 matrix. Both nanoparticle samples provide an excellent green emitting [(2H11/2, 4S3/2)→4I15/2 (˜ 540 nm)] upconversion luminescence emission under excitation at 980 nm. The energy migration between Yb and Er in NaGdF4 matrix has been explored from 300-800 nm. Intensity variation of blue, green and red lines and the observed luminescence quenching due to the presence of Fe3O4/γ-Fe2O3 in the composite has been proposed. These kinds of materials contain magnetic and luminescence characteristics into single nanoparticle open new possibility for bioimaging applications.

  6. Structure, photo- and triboluminescence of the lanthanoid dibenzoylmethanates: HNEt3[Ln(dbm)4

    International Nuclear Information System (INIS)

    Akerboom, Sebastiaan; Meijer, Michael S.; Siegler, Maxime A.; Fu, Wen Tian; Bouwman, Elisabeth

    2014-01-01

    A series of lanthanoid coordination compounds with the general formula HNEt 3 [Ln(dbm) 4 ] (Ln=La, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb; dbm=dibenzoylmethanate) has been prepared and characterized. In addition, single crystals with Ln=La, Nd and Sm were obtained. Single crystal X-ray diffraction studies reveal that the compounds with Ln=La and Nd crystallize in the P2 1 /c space group, while the Sm-compound crystallizes in the Pc space group. Based on powder XRD data, the compounds with Ln=Eu–Yb can be described with a monoclinic cell. Photoluminescence studies indicate that compounds with Ln=Sm and Eu exhibit bright photoluminescence characteristic of the lanthanoid ion upon excitation in the near UV range. Furthermore, HNEt 3 [Sm(dbm) 4 ] has been identified as a novel triboluminescent compound. -- Highlights: • The compounds HNEt 3 [Ln(dbm) 4 ], Ln=La, Nd, Sm, Eu, Tb, Dy, Ho Er, Tm, and Yb, have been prepared and their photophysical properties have been studied. • Crystal structures of HNEt 3 [La(dbm) 4 ], HNEt 3 [Nd(dbm) 4 ] and HNEt 3 [Sm(dbm) 4 ] are reported for the first time. • A novel, brightly triboluminescent Sm compound is reported

  7. Estudo de alguns compostos organolantanídeos: [LnCp2Cl.PPh3

    Directory of Open Access Journals (Sweden)

    Gatti Paula M.

    2000-01-01

    Full Text Available In this work we present the synthesis and characterization of some organolanthanide compounds [LnCp2Cl.PPh3], Ln = La, Nd, Eu, Yb and Lu. The catalytic activity of these compounds has been verified in cyclohexene hydrogenation. Cyclohexane was identified by¹H NMR analysis in the reaction products.

  8. Formation of high oxide ion conductive phases in the sintered oxides of the system Bi2O3-Ln2O3 (Ln = La-Yb)

    International Nuclear Information System (INIS)

    Iwahara, H.; Esaka, T.; Sato, T.; Takahashi, T.

    1981-01-01

    The electrical conduction in various phases of the system Bi 2 O 3 -Ln 2 O 3 (Ln = La, Nd, Sm, Dy, Er, or Yb) was investigated by measuring ac conductivity and the emf of the oxygen gas concentration cell. High-oxide-ion conduction was observed in the rhombohedral and face-centered cubic (fcc) phase in these systems. The fcc phase could be stabilized over a wide range of temperature by adding a certain amount of Ln 2 O 3 . In these cases, the larger the atomic number of Ln, the lower the content of Ln 2 O 3 required to form the fcc solid solution, except in the case of Yb 2 O 3 . The oxide ion conductivity of this phase decreased with increasing content of Ln 2 O 3 . Maximum conductivity was obtained at the lower limit of the fcc solid solution formation range in each system, which was more than one order of magnitude higher than those of conventional stabilized zirconias. Lattice parameters of the fcc phase were calculated from the x-ray diffraction patterns. The relationship between the oxide ion conductivity and the lattice parameter was also discussed

  9. Crystal structure and luminescence of complexes of Eu(III) and Tb(III) with furan-2,5-dicarboxylate

    NARCIS (Netherlands)

    Akerboom, S.; Fu, W.T.; Lutz, M.; Bouwman, E.

    2012-01-01

    Four new Ln(III) complexes (Ln = Eu, Tb) with furan-2,5-dicarboxylic acid (H2FDA) as a ligand have been synthesized and characterized in the solid state. Luminescence studies indicate that the compounds exhibit line-like luminescence characteristic of the lanthanide centre upon excitation in the

  10. Microstructure in 316LN stainless steel fatigued at low temperature

    International Nuclear Information System (INIS)

    Kruml, T.; Polak, J.

    2000-01-01

    The internal structure of AISI 316LN austenitic stainless steel cyclically strained at liquid nitrogen temperature has been studied using transmission electron microscopy and electron diffraction. High amplitude cyclic straining promotes the transformation of austenite with face centred cubic (f.c.c.) structure into ε-martensite with hexagonal close packed (h.c.p.) structure and α'-martensite with distorted base centred cubic (b.c.c.) structure. Thin plates containing ε-martensite were identified in all grains. α'-martensite nucleates at the intersection of the plates in grains with two or more systems of plates and can grow in the bands. The orientation of transformed phases follows the Shoji-Nichiyama and Kurdjumov-Sachs relations. Mechanisms of low temperature cyclic straining are discussed. (orig.)

  11. Study of the mechanical properties of stainless steel 316LN prepared by hot isostatic compression. Influence of preparation parameters

    International Nuclear Information System (INIS)

    Couturier, Raphael

    1999-01-01

    This research thesis has been performed within an R and D programme which aimed at optimising and certifying the HIP process (hot isostatic pressing) from a technological as well as metallurgical point of view. The objective has been to improve dimensional reproducibility of fabricated parts, and metallurgical properties of the dense material. Reference parts are those belonging to PWR primary circuit, and are made in cast austenitic-ferritic steel. Thus, the objective has been to show that these parts can be beneficially fabricated by powder metallurgy in austenitic grade. A mock part (a primary circuit pump wheel at the 1/2 scale) has first been fabricated by HIP, and a more complex shape generator has been designed. The author reports the determination of microstructure and mechanical characteristics of the austenitic 316LN steel produced by HIP and used to fabricate mock parts and demonstrator parts, the study of the relationship between dense material properties and fabrication parameters (temperature, pressure, consolidation time), and the analysis of the consequences of an elaboration by HIP on the 316LN steel with comparison with forged parts. After a presentation of the Powder Metallurgy elaboration technique, the author reports a bibliographical study on the precipitation at Prior Particle Boundaries (PPB), reports the study of microstructure and mechanical properties of the HIPed 316LN, and discusses the possibility of a decrease of precipitation at PPBs by adjusting powder degassing or a granulometric sorting. The last part reports the extension of the study of steel coherence to a temperature range which encompasses the primary circuit operation temperature (350 C). Resilience tests are performed as well as mechanical tests on notched axisymmetric samples. A finite element calculation of these samples allows the validation of the use of a Thomson-type model to describe the emergence of defects which are typical of a steel elaborated by powder

  12. Polymorphism of Bi1-xLnxO1.5 phases (04Ln2O9 (x=0.33; Ln=La, Pr, Nd)

    International Nuclear Information System (INIS)

    Drache, Michel; Huve, Marielle; Roussel, Pascal; Conflant, Pierre

    2003-01-01

    The Bi 1-x Ln x O 1.5 solid solutions (Ln=La, Pr, Nd), of the β 2 /β 1 /ε (Bi-Sr-O) structural type, have been investigated in their Ln-rich domains. For Ln=La, Pr, and Nd, the upper limits are 0.35, 0.35 and 0.33, respectively. The Bi 4 Ln 2 O 9 ε phase (x=0.33) appears to be the single definite compound. For Bi 4 La 2 O 9 , Bi 4 Pr 2 O 9 and Bi 4 Nd 2 O 9 , the ε-type cells are respectively: a=9.484(4) A, b=3.982(2) A, c=7.030(3) A, β=104.75(3) deg.; a=9.470(5) A, b=3.945(2) A, c=6.968(4) A, β=104.73(3) deg. and a=9.439(3) A, b=3.944(2) A, c=6.923(2) A, β=105.03(3) deg. . Upon heating, each monoclinic (ε) compound transforms successively into rhombohedral phases (β 2 /β 1 ) and finally into a cubic fluorite-type phase. For La- and Pr-based compounds, all transitions are reversible; for Nd, depending on the thermal treatment, the reversibility of ε→β 2 can be incomplete. These transformations are characterized using X-ray thermodiffractometry, differential thermal analysis, dilatometry and impedance spectroscopy versus temperature. Examination of Bi 4 (Ln, Ln') 2 O 9 samples allows to correlate the evolution of the thermal behavior and of the unit cell parameters, to the lanthanide size. A partial plot of the (Bi 2 O 3 ) 1-x -(La 2 O 3 ) x phase diagram (0≤x≤0.40) is proposed

  13. Magnetic interactions in rhenium-containing rare earth double perovskites Sr{sub 2}LnReO{sub 6} (Ln=rare earths)

    Energy Technology Data Exchange (ETDEWEB)

    Nishiyama, Atsuhide; Doi, Yoshihiro; Hinatsu, Yukio, E-mail: hinatsu@sci.hokudai.ac.jp

    2017-04-15

    The perovskite-type compounds containing both rare earth and rhenium Sr{sub 2}LnReO{sub 6} (Ln=Y, Tb-Lu) have been prepared. Powder X-ray diffraction measurements and Rietveld analysis show that Ln{sup 3+} and Re{sup 5+} ions are structurally ordered at the B site of the perovskite SrBO{sub 3}. Magnetic anomalies are found in their magnetic susceptibility and specific heat measurements at 2.6–20 K for Ln=Y, Tb, Dy, Yb, Lu compounds. They are due to magnetic interactions between Re{sup 5+} ions. The results of the magnetic hysteresis and remnant magnetization measurements for Sr{sub 2}YReO{sub 6} and Sr{sub 2}LuReO{sub 6} indicate that the antiferromagnetic interactions between Re{sup 5+} ions below transition temperatures have a weak ferromagnetic component. The analysis of the magnetic specific heat data for Sr{sub 2}YbReO{sub 6} shows that both the Yb{sup 3+} and Re{sup 5+} ions magnetically order at 20 K. For the case of Sr{sub 2}DyReO{sub 6}, magnetic ordering of the Re{sup 5+} moments occurs at 93 K, and with decreasing temperature, the moments of Dy{sup 3+} ferromagnetically order at 5 K from the measurements of magnetic susceptibility and specific heat. - Graphical abstract: Crystal structure of double perovskite Sr{sub 2}LnReO{sub 6}. Red and black lines show cubic and monoclinic unit cells, respectively. - Highlights: • Double perovskites Sr{sub 2}LnReO{sub 6} (Ln=rare earths) were prepared. • They show an antiferromagnetic transition at 2.6–20 K. • In Sr{sub 2}DyReO{sub 6}, Dy and Re moments magnetically order at 5 and 93 K, respectively.

  14. Upgradation in SCADA and PLC of existing LN_2 control system for SST-1

    International Nuclear Information System (INIS)

    Panchal, Pradip; Mahesuria, Gaurang; Panchal, Rohit; Patel, Rakesh; Sonara, Dashrath; Pitroda, Dipen; Nimavat, Hiren; Tanna, Vipul; Pradhan, Subrata

    2016-01-01

    Highlights: • The control system of LN_2 Management System of SST-1 is designed on PLC and SCADA. • The implementation and results of up-gradation in PLC and SCADA are reported. • The up-gradation in PLC and SCADA has improved the reliability & availability of SST-1 LN_2 system. - Abstract: Helium Refrigerator/Liquefier system of Steady State Superconducting Tokamak (SST-1) incorporates Liquid Nitrogen (LN_2) pre-cooling system. LN_2 is used for 80 K thermal shields of SST-1, current feeder system and integrated flow distribution and control system. The LN_2 management system is distributed system and requires automatic control. Initially LN_2 control system had Citect based Supervisory Control and Data Acquisition (SCADA) and Koyo make Programmable Logic Controller (PLC). With the passage of time and due to unavailability of their hardware, it is being obsoleted. So, the requirements of new PLC and SCADA systems have been envisaged to make uninterruptable operation of SST-1 cryogenic system. Therefore, Wonderware SCADA and Schneider Electric make PLC is programmed to replace Citect SCADA and Koyo PLC. New control features have been added in upgraded control system for better management of LN_2 system. This upgradation of SCADA and PLC is completed, tested successfully and in operation. Operational performance highlights of the new upgraded system are presented in this paper.

  15. Upgradation in SCADA and PLC of existing LN{sub 2} control system for SST-1

    Energy Technology Data Exchange (ETDEWEB)

    Panchal, Pradip, E-mail: pradip@ipr.res.in; Mahesuria, Gaurang; Panchal, Rohit; Patel, Rakesh; Sonara, Dashrath; Pitroda, Dipen; Nimavat, Hiren; Tanna, Vipul; Pradhan, Subrata

    2016-11-15

    Highlights: • The control system of LN{sub 2} Management System of SST-1 is designed on PLC and SCADA. • The implementation and results of up-gradation in PLC and SCADA are reported. • The up-gradation in PLC and SCADA has improved the reliability & availability of SST-1 LN{sub 2} system. - Abstract: Helium Refrigerator/Liquefier system of Steady State Superconducting Tokamak (SST-1) incorporates Liquid Nitrogen (LN{sub 2}) pre-cooling system. LN{sub 2} is used for 80 K thermal shields of SST-1, current feeder system and integrated flow distribution and control system. The LN{sub 2} management system is distributed system and requires automatic control. Initially LN{sub 2} control system had Citect based Supervisory Control and Data Acquisition (SCADA) and Koyo make Programmable Logic Controller (PLC). With the passage of time and due to unavailability of their hardware, it is being obsoleted. So, the requirements of new PLC and SCADA systems have been envisaged to make uninterruptable operation of SST-1 cryogenic system. Therefore, Wonderware SCADA and Schneider Electric make PLC is programmed to replace Citect SCADA and Koyo PLC. New control features have been added in upgraded control system for better management of LN{sub 2} system. This upgradation of SCADA and PLC is completed, tested successfully and in operation. Operational performance highlights of the new upgraded system are presented in this paper.

  16. Changes of serum HA and LN level in patients with pulmonary tuberculosis after therapy

    International Nuclear Information System (INIS)

    Yu Jing Zhang Hongwei; Li Jie

    2007-01-01

    Objective: To study the serum HA and LN level in patients with pulmonary tuberculosis and their response to therapy. Methods: Serum HA and LN levels were measured with RIA in: (1) 42 patients with active pulmonary tuberculosis both before and after 2 months' therapy, (2) 40 patients with non-active pulmonary TB and 330 controls. Results: The serum HA and LN level in patients with active pulmonary tubemulosis were significantly higher than those in controls (P < 0.01 ), while no significant difference could Be found Between the levels in patients with non-active pulmonary tuberculosis and controls. The serum HA and LN level in patients with active pulmonary tuberculosis dropped after therapy, but were still higher than those in controls. Significant correlation could Be found between HA and LN levels (P<0.01). The HA and LN levels were positively correlated with severity of the disease, ESR and CRP contents. Conclusion: The measurement of serum HA and LN is valuable for early diagnosis, monitoring development and assessment of therapeutic effect in patients with pulmonary tubemulosis. (authors)

  17. Low temperature phase transition of the stoichiometric Ln2NiO4 oxides

    International Nuclear Information System (INIS)

    Fernandez, F.; Saez-Puche, R.; Botto, I.L.; Baran, E.J.

    1991-01-01

    In this paper we will present a comparative study of the structural phase transition in Ln 2 NiO 4 oxides, by means of neutron diffraction and infrared(IR) spectroscopy. In the Ln 2 NiO 4 oxides (Ln=La, Pr and Nd), there is a low temperature structural phase transition from the orthorhombic symmetry to a tetragonal phase, of first order character. The IR spectra show, at low temperature, a splitting of the bands related with the stretching Ni-O, strongly correlated with the phase transformation. From the neutron data, the phase transition can be visualized as a sudden tilt of the nickel octahedra

  18. Potentiometric study of rare earth complexing with trans-1,2-diaminocyclohexane-N,N'-dimalonic acid

    International Nuclear Information System (INIS)

    Smirnova, T.I.; Gorelov, I.P.

    1980-01-01

    Complexing of rare earths (Ln) and yttrium with trans-1,2-diaminocyclohexane-N, N'-dimalonic acid in aqueous solutions is studied using indirect potentiometric method with an aid of stationary mercury electrode and by the method of pH-potentiometric titration. It is shown that in the investigated solutions the LnL - and LnL 2 5- complexes are formed. At 25 deg C and ion force 0.1 stability constants of the complexes detected are determined [ru

  19. In pursuit of the rhabdophane crystal structure: from the hydrated monoclinic LnPO{sub 4}.0.667H{sub 2}O to the hexagonal LnPO{sub 4} (Ln = Nd, Sm, Gd, Eu and Dy)

    Energy Technology Data Exchange (ETDEWEB)

    Mesbah, Adel, E-mail: adel.mesbah@cea.fr [ICSM, UMR 5257 CNRS – CEA – ENSCM – Université de Montpellier, Site de Marcoule - Bât 426, BP 17171, 30207 Bagnols/Cèze (France); Clavier, Nicolas [ICSM, UMR 5257 CNRS – CEA – ENSCM – Université de Montpellier, Site de Marcoule - Bât 426, BP 17171, 30207 Bagnols/Cèze (France); Elkaim, Erik [Synchrotron SOLEIL, L' Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Szenknect, Stéphanie; Dacheux, Nicolas [ICSM, UMR 5257 CNRS – CEA – ENSCM – Université de Montpellier, Site de Marcoule - Bât 426, BP 17171, 30207 Bagnols/Cèze (France)

    2017-05-15

    The dehydration process of the hydrated rhabdophane LnPO{sub 4}.0.667H{sub 2}O (Ln = La to Dy) was thoroughly studied over the combination of in situ high resolution synchrotron powder diffraction and TGA experiments. In the case of SmPO{sub 4}.0.667H{sub 2}O (monoclinic, C2), a first dehydration step was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2) with Z =12 and a =17.6264(1) Å, b =6.9704(1) Å, c =12.1141(1) Å, β=133.74(1) °, V =1075.33(1) Å{sup 3}. In agreement with the TGA and dilatometry experiments, all the water molecules were evacuated above 220 °C yielding to the anhydrous form, which crystallizes in the hexagonal P3{sub 1}21 space group with a =7.0389(1) Å, c =6.3702(1) Å and V =273.34(1) Å{sup 3}. This study was extended to selected LnPO{sub 4}.0.667H{sub 2}O samples (Ln= Nd, Gd, Eu, Dy) and the obtained results confirmed the existence of two dehydration steps before the stabilization of the anhydrous form, with the transitory formation of LnPO{sub 4}.0.5H{sub 2}O. - Graphical abstract: The dehydration process of the rhabdophane SmPO{sub 4}.0.667H{sub 2}O was studied over combination of in situ high resolution synchrotron powder diffraction and TGA techniques, a first dehydration was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2). Then above 220 °C, the anhydrous form of the rhabdophane SmPO{sub 4} was stabilized and crystallizes in the hexagonal P3{sub 1}21 space group. - Highlights: • In situ synchrotron powder diffraction was carried out during the dehydration of the rhabdopahe LnPO{sub 4}.0.667H{sub 2}O. • The heat of the rhabdophane LnPO{sub 4}.0.667H{sub 2}O leads to LnPO{sub 4}.0.5H{sub 2}O then to anhydrous rhabdophane LnPO{sub 4}. • LnPO{sub 4}.0.5H{sub 2}O (monoclinic, C2) and LnPO{sub 4} (Hexagonal, P3{sub 1}21) were solved over the use of direct methods.

  20. Synthesis and characterisation of some lanthanide perchlorate complexes of 4-nitrosoantipyrine

    International Nuclear Information System (INIS)

    Jayasankar, H.; Indrasenan, P.

    1988-01-01

    Seven lanthanide perchlorate complexes of 4-nitrosoantipyrine (NAP) of the general formula [Ln(NAP) 4 ClO 4 ](ClO 4 ) 2 (where Ln=La, Pr, Nd, Sm, Gd, Dy and Y), have been synthesised and characterised by elemental analyses, molecular weights, conductances, magnetic moments and infrared and electronic spectral data. In these nine-coordinated complexes, all the four NAP molecules are coordinated bidentately and one of the perchlorate groups is coordinated monodentately. (author). 12 refs

  1. Synthesis, chemistry and catalytic activity of complexes of lanthanide and actinide metals in unusual oxidation states and coordination environments. Progress report, February 1, 1978--January 31, 1979

    International Nuclear Information System (INIS)

    Evans, W.J.

    1978-11-01

    Previous syntheses of Ln(olefin) complexes and their catalytic effect on the hydrogenation of the olefin are discussed. The tert-butyl complexes of Sn, Er, and Yb were synthesized and their decomposition studied

  2. On determination of enthalpies of complex formation reactions by means of temperature coefficient of complexing degree

    International Nuclear Information System (INIS)

    Povar, I.G.

    1995-01-01

    Equations describing the relation between temperature coefficient of ∂lnα/∂T complexing degree and the sum of changes in the enthalpy of complex formation of the composition M m L n δH mn multiplied by the weight coefficients k mm , are presented. A method to determine changes in the enthalpy of certain ΔH mm reactions from ∂lnα/∂T derivatives has been suggested. The best approximating equation from lnα/(T) dependence has been found. Errors of thus determined δH mm values are estimated and the results of calculation experiment for the system In 3+ -F - are provided. 10 refs., 2 figs., 3 tabs

  3. Syntheses, crystal structures and photoluminescence properties of two rare-earth molybdates CsLn(MoO{sub 4}){sub 2} (Ln=Eu, Tb)

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dan; Ma, Fa-Xue; Liu, Bao-Zhong; Fan, Yun-Chang; Han, Xue-Feng; Zhang, Lei; Nie, Cong-Kui [Henan Polytechnic Univ. (China). College of Chemistry and Chemical Engineering

    2018-04-01

    Single crystals of two cesium rare-earth molybdates CsLn(MoO{sub 4}){sub 2} (Ln=Eu, Tb) have been prepared using the high temperature molten salt (flux) method. Single-crystal X-ray diffraction analyses reveal that they crystallize in the orthorhombic space group Pccm (No. 49) and features a 2D layer structure that is composed of [Ln(MoO{sub 4}){sub 2}]{sub ∞} and [Cs]{sub ∞} layers. Under near-UV light excitation, emission spectrum of CsEu(MoO{sub 4}){sub 2} consists of several sharp lines due to the characteristic electronic transitions of Eu{sup 3+} ions, whereas CsTb(MoO{sub 4}){sub 2} exhibits characteristic green emission of Tb{sup 3+} ions.

  4. Three isostructural one-dimensional Ln(III) chains with distorted cubane motifs showing dual fluorescence and slow magnetic relaxation/magnetocaloric effect.

    Science.gov (United States)

    Li, Yan; Yu, Jia-Wen; Liu, Zhong-Yi; Yang, En-Cui; Zhao, Xiao-Jun

    2015-01-05

    Three new homometallic lanthanide complexes with mixed carboxylate-modified rigid ligands, [Ln(μ3-OH)(na)(pyzc)]n (na(-) = 1-naphtholate, pyzc(-) = 2-pyrazinecarboxylate, Ln = Dy (1), Yb (2), and Gd (3)), were solvothermally synthesized, and their structures and magnetic as well as photophysical properties were completely investigated. Complexes 1-3 are crystallographically isostructural, exhibiting linear chains with four bidentate bridging μ-COO(-) moieties encapsulated cubic {Ln4(μ3-OH)4}(8+) clusters repeatedly extended by 4-fold chelating-bridging-pyzc(-) connectors. Magnetically, the former two complexes with highly anisotropic Dy(III) and weak anisotropic Yb(III) ions in the distorted NO7 triangular dodecahedron coordination environment display field-induced slow relaxation of magnetization. Fitting the dynamic magnetic data to the Arrhenius law gives energy barrier ΔE/kB = 39.6 K and pre-exponential factor τo = 1.52 × 10(-8) s for 1 and ΔE/kB = 14.1 K and τo = 2.13 × 10(-7) s for 2. By contrast, complex 3 with isotropic Gd(III) ion and weak intracluster antiferromagnetic coupling shows a significant cryogenic magnetocaloric effect, with a maximum -ΔSm value of 30.0 J kg(-1) K(-1) at 2.5 K and 70 kOe. Additionally, the chromophoric na(-) and pyzc(-) ligands can serve as antenna groups, selectively sensitizing the Dy(III)- and Yb(III)-based luminescence of 1 and 2 in the UV-visible region by an intramolecular energy transfer process. Thus, complexes 1-3, incorporating field-induced slow magnetic magnetization and interesting luminescence together, can be used as composite magneto-optical materials. More importantly, these interesting results further demonstrate that the mixed-ligand system with rigid carboxylate-functionalized chromophores can be excellent candidates for the preparations of new bifunctional magneto-optical materials.

  5. Red emitting phosphors of Eu3+ doped Na2Ln2Ti3O10 (Ln = Gd, Y) for white light emitting diodes

    International Nuclear Information System (INIS)

    Zhang, Niumiao; Guo, Chongfeng; Yin, Luqiao; Zhang, Jianhua; Wu, Mingmei

    2015-01-01

    Highlights: • Layered red phosphors Na 2 Ln 2 Ti 3 O 10 (Ln = Gd, Y):Eu 3+ were prepared. • The synthesis parameters of phosphors were optimized. • PL and thermal stability of the samples were investigated. • LED devices were also fabricated including the present red phosphor. - Abstract: A series of Eu 3+ doped Na 2 Ln 2 Ti 3 O 10 (Ln = Gd, Y) red-emitting phosphors for application in ultraviolet based light emitting diodes (LEDs) were successfully synthesized by a modified sol–gel method. Their structure and luminescent properties were characterized by powder X-ray diffraction (XRD), photoluminescence excitation (PLE) and emission (PL) spectra and absorption spectra, according to these results the optimal compositions and synthesis parameters were determined. In addition, the thermal stabilities of the phosphors were investigated according to the temperature-dependent PL spectra. The red and white-LEDs (W-LEDs) comprising the Na 2 Ln 2 Ti 3 O 10 :Eu 3+ (Ln = Gd, Y) red emitting phosphors were fabricated with a near-ultraviolet (n-UV) chip. In comparison with Na 2 Y 1.4 Eu 0.6 Ti 3 O 10 , the Na 2 Gd 0.6 Eu 1.4 Ti 3 O 10 phosphor offers higher brightness, quantum efficiency, and excellent thermal stability. W-LEDs comprising Na 2 Gd 0.6 Eu 1.4 Ti 3 O 10 showed bright white emission with a color rendering index (Ra) of 82, a color temperature of 2151 K, and Commission Internationale de I’Eclairage (CIE) color coordinates of (0.34, 0.37). The phosphor Na 2 Gd 0.6 Eu 1.4 Ti 3 O 10 is more suitable candidate for application in LEDs

  6. Reconsideration of Orth I and Orth II Phases in Ln-System Superconductors

    Science.gov (United States)

    Liu, Yue-Wei; Wang, Lu; Zhang, Han

    2006-02-01

    A block model is used to calculate the combinative energy in LnBa2Cu3O7-x (Ln=Y, Er, Nd) systems, and the energy has no difference for orth-I and orth-II in the plateau range. Namely, no matter what phase it is, when the oxygen deficiency is in the range of δ~0.35-0.55, the plateau appears in the energy -δ curves, and the combinative energy has close correlation with the Tc value. The result in the present work gives some hints to reconsider the role of the order of oxygen defects or its effect on superconductivity in LnBa2Cu3O7-x. The existence of the orth-II seems not to be the reason for the plateau in the Tc curve. This is an important problem for LnBa2Cu3O7-x and some suggestion is given in the discussion.

  7. AgLnSb/sub 2/O/sub 7/ compounds with weberite structure

    Energy Technology Data Exchange (ETDEWEB)

    Lopatin, S S; Aver' yanova, L N; Belyaev, I N; Zvyagintsev, B I; Dyatlov, Eh V [Rostovskij-na-Donu Gosudarstvennyj Univ. (USSR)

    1982-11-01

    The interaction between AgSbO/sub 3/ and LnSbO/sub 4/ in the solid phase at 1100-1150 deg C has been investigated. AgLnSb/sub 2/O/sub 7/ compounds with weberite crystal structure are formed in Ln=La, Pr, Nd, Sm cases but in Ln=Eu, Cd, Dy, Er cases the formation of termary oxides of the indicated composition has not been observed. Inasmuch as compounds of the general formula A/sub 2/B/sub 2/O/sub 7/ with average cation radii Rsub(B) >0.60 A and 1.65 <= Rsub(A)/Rsub(B) <= 2.20 can crystallize in weberite, pyrochlore and laminated perovskite-like structurer, conditions of the existence of the above mentioned structures depending on A and B dimensions and electronegativity are discussed.

  8. Predictable self-assembled [2×2] Ln(III)4 square grids (Ln = Dy,Tb)-SMM behaviour in a new lanthanide cluster motif.

    Science.gov (United States)

    Anwar, Muhammad Usman; Thompson, Laurence Kenneth; Dawe, Louise Nicole; Habib, Fatemah; Murugesu, Muralee

    2012-05-14

    The ditopic carbohydrazone ligand (L1) produces the square, self-assembled [2×2] grids [Dy(4)(L1)(4)(OH)(4)]Cl(2) (1) and [Ln(4)(L1)(4)(μ(4)-O)(μ(2)-1,1-N(3))(4)] (Ln = Dy (2), Tb (3)), with 2 exhibiting SMM behaviour. Two relaxation processes occur with U(eff) = 51 K, 91 K in the absence of an external field, and one with U(eff) = 270 K in the presence of a 1600 Oe optimum field. This journal is © The Royal Society of Chemistry 2012

  9. On the structure of rare earth periodates of LnIO5x4H2O (Ln=Pr-Lu, Y)

    International Nuclear Information System (INIS)

    Shamraj, N.B.; Varfolomeev, M.B.; Saf'yanov, Yu.N.; Kuz'min, Eh.A.; Ilyukhin, V.V.; AN SSSR, Moscow. Inst. Kristallografii)

    1977-01-01

    The crystal structure of three representatives of an isotypic series of monoclinic periodates of rare earth elements in the series from Pr to Lu and Y was deciphered. The monoclinic cell for all LnIO 5 x4H 2 O contains Z=4 formula units. The architectural motif consists in layers of octahedra of IO 4 (OH) 2 and polyhedra of LnO 5 (H 2 O 3 ) parallel to the (100) plane. Adhesion between the layers is achieved through H-bonds

  10. Hydrothermal synthesis and luminescent properties of LnPO4:Tb,Bi (Ln=La,Gd) phosphors under UV/VUV excitation

    International Nuclear Information System (INIS)

    Wang Yuhua; Wu Chunfang; Wei Jie

    2007-01-01

    Monoclinic LnPO 4 :Tb,Bi (Ln=La,Gd) phosphors were prepared by hydrothermal reaction and their luminescent properties under ultraviolet (UV) and vacuum ultraviolet (VUV) excitation were investigated. LaPO 4 :Tb,Bi phosphor and GdPO 4 :Tb phosphor showed the strongest emission intensity under 254 and 147 nm excitation, respectively, because of the different energy transfer models. In UV region, Bi 3+ absorbed most energy then transferred to Tb 3+ , but in VUV region it was the host which absorbed most energy and transferred to Tb 3+

  11. Síntesis hidrotermal de monocristales LnMn2O5 (Ln= Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho y Er

    Directory of Open Access Journals (Sweden)

    Señarís Rodríguez, M. A.

    2008-08-01

    Full Text Available Ten single crystals of the series LnMn2O5 (Ln= Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho and Er were synthesized by hydrothermal synthesis in a single step and without subsequent thermal treatments from aqueous solutions of metals salts at 240 ºC. The obtained single crystals have a size of various micrometers and their morphology changes throughout the serie: they are polygonal in the case of the compounds with Ln= Pr, Nd, Sm, Eu and Gd and needle-like in the case of the compounds with Ln= Y, Tb, Dy, Ho and Er. After the analysis of the obtained products employing different conditions of synthesis we attributed the different morphology to a greater growth rate along the c axis when the smaller ions (Y, Tb, Dy, Ho y Er are involved, due to their better adaptation to the compound’s crystal structure.Se han conseguido preparar monocristales de 10 óxidos mixtos de la serie LnMn2O5 (Ln= Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho y Er mediante síntesis hidrotermal optimizada, en un único paso y sin tratamientos térmicos posteriores partiendo de las correspondientes sales metálicas en disolución acuosa a 240 ºC. Los monocristales obtenidos son relativamente grandes, de varias micras y su morfología varía a lo largo de la serie: es poligonal en el caso de los compuestos de los lantánidos del inicio de la serie (Ln= Pr, Nd, Sm, Eu y Gd y acicular en el caso de los compuestos de Y y de los lantánidos del final de la serie (Ln= Tb, Dy, Ho y Er. Tras el análisis de los productos obtenidos empleando distintas condiciones de síntesis atribuimos la diferente morfología a una mayor velocidad de crecimiento cristalino a lo largo del eje c cuando intervienen los iones más pequeños (Y, Tb, Dy, Ho y Er debido a la mejor adaptación de éstos últimos a la estructura cristalina del compuesto.

  12. Engineering [Ln(DPA){sub 3}]{sup 3-} binding sites in proteins: a widely applicable method for tagging proteins with lanthanide ions

    Energy Technology Data Exchange (ETDEWEB)

    Jia Xinying; Yagi, Hiromasa; Su Xuncheng; Stanton-Cook, Mitchell; Huber, Thomas; Otting, Gottfried, E-mail: gottfried.otting@anu.edu.au [Australian National University, Research School of Chemistry (Australia)

    2011-08-15

    Paramagnetic relaxation enhancements from unpaired electrons observed in nuclear magnetic resonance (NMR) spectra present powerful long-range distance restraints. The most frequently used paramagnetic tags, however, are tethered to the protein via disulfide bonds, requiring proteins with single cysteine residues for covalent attachment. Here we present a straightforward strategy to tag proteins site-specifically with paramagnetic lanthanides without a tether and independent of cysteine residues. It relies on preferential binding of the complex between three dipicolinic acid molecules (DPA) and a lanthanide ion (Ln{sup 3+}), [Ln(DPA){sub 3}]{sup 3-}, to a pair of positively charged amino acids whose charges are not compensated by negatively charged residues nearby. This situation rarely occurs in wild-type proteins, allowing the creation of specific binding sites simply by introduction of positively charged residues that are positioned far from glutamate or aspartate residues. The concept is demonstrated with the hnRNPLL RRM1 domain. In addition, we show that histidine- and arginine-tags present binding sites for [Ln(DPA){sub 3}]{sup 3-}.

  13. Lanthanide (III) complexes of 2-(N-salicylideneamino)-4-phenylthiazole

    International Nuclear Information System (INIS)

    Sasidharan, G.N.; Mohanan, K.; Lakshmi Prabha, A.N.

    2002-01-01

    Lanthanide(III) complexes of 2-(N-salicylideneamino)-4- phenylthiazole (HSAT) have been synthesised and characterised by elemental, analytical, thermogravimetric, molar conductance, UV- visible, IR and NMR spectral data. The ligand coordinates to the lanthanide(III) ion in a tridentate fashion without deprotonation, giving complexes of the type [Ln(HSAT) 2 (NO 3 ) 3 ] and [Ln(HSAT) 2 (H 2 0) 3 Cl 3 ]. The spectral data reveal that the ligand is bonded to the lanthanide ion through azomethine nitrogen, ring nitrogen and phenolic oxygen without deprotonation. The nitrate group acts in a bidentate fashion. The ligand and the metal complexes exhibit antibacterial and antifungal activities. (author)

  14. Imaging of the human heart after administration of l-(N-13)glutamate

    International Nuclear Information System (INIS)

    Gelbard, A.S.; Benua, R.S.; Reiman, R.E.; McDonald, J.M.; Vomero, J.J.; Laughlin, J.S.

    1980-01-01

    In normal volunteers and cancer patients, studies using L-(N-13)glutamate as an imaging agent showed localization of N-13 activity in the heart. Other organs that were well visualized include the liver, pancreas, and salivary glands. The concentration of N-13 activity in the human heart could not be predicted from previous studies involving myocardial uptake in dogs and rodents after administration of L-(N-13)glutamate

  15. Pressure induced Amorphization of Ln1/3(Nb,Ta)O3

    International Nuclear Information System (INIS)

    Melchior, A.; Noked, O.; Sterer, E.; Shuker, R.

    2014-01-01

    The research focuses on the phenomenon of pressure induced amorphization (PIA) in Ln1/3MO3, Ln - La,Pr,Nd and M-Nb,Ta. In most pressure induced phase transitions the material changes from a crystalline phase to another crystalline phase. However, if this transition is kinetically hindered, the increased free energy due to the applied pressure will result in a structural collapse to an amorphous intermediate phase. This phenomenon is known as pressure induced amorphization

  16. Digital LN2 control system for superconducting linac at PLF, Mumbai

    International Nuclear Information System (INIS)

    Karande, J.N.; Dhumal, P.; Takke, A.N.; Pal, S.; Nanal, V.; Pillay, R.G.

    2013-01-01

    The superconducting LINAC at PLF, Mumbai has a modular structure with eight cryostats divided in two groups. Each cryostat has a LN2 vessel of ∼ 40L capacity, which serves as a thermal shield for helium vessel. A coaxial capacitance type sensor is developed in house to measure the LN2 level. Monostable multi-vibrator based readout electronics is designed to measure the change in capacitance due to LN2 level change. The sensor capacitance with a fixed value resistor decides the 'ON' time of the monostable multi-vibrator. A 16 bit timer of microcontroller 8051 is used to measure the pulse width. The change in pulse width is converted into a LN2 level and displayed on a 4*20 LCD screen. The control unit is also equipped with automatic control of LN2 filling valves triggered by levels. The digital LN2 control can be operated locally or remotely via a serial RS232 communication line.Two control stations are designed and developed to take care of eight cryostats. (author)

  17. Cutting characteristics and deformed layer of type 316LN stainless steel

    International Nuclear Information System (INIS)

    Oh, Sun Sae; Yi, Won

    2004-01-01

    The cutting characteristics and the deformed layer of Nitrogen(N)-added type 316LN stainless steel were comparatively investigated to type 316L stainless steel. The cutting force, the surface roughness(Ra) and the tool wear in face milling works were measured with cutting conditions, and the deformed layers were obtained from micro-hardness testing method. The cutting resistance of type 316LN was similar to type 316L in spite of its high strength. The surface roughness of type 316LN was superior to type 316L for all the cutting conditions. In particular, in the high cutting speed above 345m/min, the surface roughness of the two stainless steels was closely same. The deformed layer thickness of the two stainless steels was generated in the 150μm-300μm ranges, and its value of type 316LN was lower than that of type 316L. This is due to the high strength properties by nitrogen effect. It was found that type 316LN was higher in the tool wear than that type 316L, and flank wear was dominant to crater wear. In face milling works of type 316LN steel, tool wear is regarded as a important problem

  18. Determination of the stability constants of lanthanum, praseodymium, europium, erbium and lutetium complexes with chloride ions

    International Nuclear Information System (INIS)

    Fernandez R, E.

    2008-01-01

    The stability constants of La 3+ , Pr 3+ , Eu 3+ , Er 3+ and Lu 3+ chloride complexes were determined in perchloric acid media using a liquid-liquid extraction method. The dinonyl napthalene sulfonic acid in n-heptane was used as extractant. The lanthanide (Ln) concentrations were measured by a radiochemical (Eu and Lu) and a spectrophotometric (La, Pr, and Er) methods. In the last method, xylenol orange was used for the determinations at ph 6. The stability constants of lanthanum, praseodymium, erbium and lutetium chloride complexes were determined in 2, 3 and 4 M ionic strength and europium in 1, 2 and 3 M, at 303 K. The fitting of experimental data to the equations for the calculation of the stability constants, was carry out considering both one chemical species (LnCl 2+ ) or two chemical species (LnCl 2+ and LnCl 2 + ). The Specific Ion Interaction Theory was applied to the values of log β I Ln , Cl and the first stability constants at zero ionic strength were calculated by extrapolation. The same theory could not be applied to the log β I Ln , 2Cl , due to its low abundance and the values determined for the stability constants were similar. The distribution diagrams of the chemical species were obtained using the program MEDUSA and considering log β I Ln , CI , log β I Ln , 2CI values obtained in this work and the hydrolysis constants taken from the literature. The lanthanide chloride complexes are present in solution at specific conditions of ionic strength, concentration and in the absence of hydrolysis. The log β I Ln , Cl data were related to the charge density and the corresponding equations were obtained. These equations could be used to determine the stability constants along the lanthanide series. (Author)

  19. Interplay of structural chemistry and magnetism in perovskites; A study of CaLn2Ni2WO9; Ln=La, Pr, Nd

    Science.gov (United States)

    Chin, Chun-Mann; Paria Sena, Robert; Hunter, Emily C.; Hadermann, Joke; Battle, Peter D.

    2017-07-01

    Polycrystalline samples of CaLn2Ni2WO9 (Ln=La, Pr, Nd) have been synthesized and characterised by a combination of X-ray and neutron diffraction, electron microscopy and magnetometry. Each composition adopts a perovskite-like structure with a 5.50, b 5.56, c 7.78 Å, β 90.1° in space group P21/n. Of the two crystallographically distinct six-coordinate sites, one is occupied entirely (Ln=Pr) or predominantly (Ln=La, Nd) by Ni2+ and the other by Ni2+ and W6+ in a ratio of approximately 1:2. None of the compounds shows long-range magnetic order at 5 K. The magnetometry data show that the magnetic moments of the Ni2+ cations form a spin glass below 30 K in each case. The Pr3+ moments in CaPr2Ni2WO9 also freeze but the Nd3+ moments in CaNd2Ni2WO9 do not. This behaviour is contrasted with that observed in other (A,A')B2B'O9 perovskites.

  20. Phase equilibria in the MgMoO4-Ln2(MoO4)3 (Ln=La,Gd) systems

    International Nuclear Information System (INIS)

    Fedorov, N.F.; Ipatov, V.V.; Kvyatkovskij, O.V.

    1980-01-01

    Phase equilibria in the MgMoO 4 -Ln 2 (MoO 4 ) 3 systems (Ln=La, Gd) have been studied by static and dynamic methods of the physico-chemical analysis, using differential thermal, visual-polythermal, crystal-optical, X-ray phase, and infrared spectroscopic methods, and their phase diagrams have been constructed. Phase equilibria in the systems studied are characterized by limited solubility of components in the liquid state, formation of solid solutions on the base of α- and β-forms of Gd 2 (MoO 4 ) 3 . Eutectics in the MgMoO 4 -Ln 2 (MoO 4 ) 3 (Ln=La, Gd) systems corresponds to the composition of 71 mode % La 2 (MoO 4 ) 3 -29 mole % MgMoO 4 , tsub(melt)--935+-5 deg C and 57 mole % Gd 2 (MoO 4 ) 3 -43 mole % MgMoO 4 , tsub(melt)=1020+-5 deg C. The region of glass formation has been established [ru

  1. Phase relations in Ca(Sr)MoO4-Ln2(NoO4)3 systems (Ln = Pr-Lu)

    International Nuclear Information System (INIS)

    Vakalyuk, V.V.; Evdokimov, A.A.; Berezina, T.A.

    1982-01-01

    Using the methods of X-ray phase and differential thermal analyses phase ratios in the systems Ca(Sr)MoO 4 -Ln 2 (MoO 4 ) 3 at Ln=Pr-Lu are studied and phase diagrams of the systems CaMoO 4 -Ln 2 (MoO 4 ) 3 , for Ln=Nd, Gd, Yb and SrMoO 4 -Sm 2 (MoO 4 ) 3 are built. It is shown that phase ratios in the systems are similar for the following groups of rare earths: Pr-Sm, Eu-Tb, Ho-Lu. In the first group of systems ordered phase over all subsolidus region are formed, in the second one - ordered phases with scheelite-like structure and wide regions of homogeneity on the basis of Ca(Sr)MoO 4 are formed above the temperature of polymorphous transformation of rare earth molybdates, for the third group of systems intermediate compounds are not detected

  2. Complexation of biological ligands with lanthanides(III) for MRI: Structure, thermodynamic and methods; Complexation des cations lanthanides trivalents par des ligands d'origine biologique pour l'IRM: Structure, thermodynamique et methodes

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, C

    2006-07-15

    New cyclic ligands derived from sugars and amino-acids form a scaffold carrying a coordination sphere of oxygen atoms suitable to complex Ln(III) ions. In spite of their rather low molecular weights, the complexes display surprisingly high relaxivity values, especially at high field. The ACX and BCX ligands, which are acidic derivatives of modified and cyclo-dextrins, form mono and bimetallic complexes with Ln(III). The LnACX and LnBCX complexes show affinities towards Ln(III) similar to those of tri-acidic ligands. In the bimetallic Lu2ACX complex, the cations are deeply embedded in the cavity of the ligand, as shown by the X-ray structure. In aqueous solution, the number of water molecules coordinated to the cation in the LnACX complex depends on the nature and concentration of the alkali ions of the supporting electrolyte, as shown by luminescence and relaxometric measurements. There is only one water molecule coordinated in the LnBCX complex, which enables us to highlight an important second sphere contribution to relaxivity. The NMR study of the RAFT peptidic ligand shows the complexation of Ln(III), with an affinity similar to those of natural ligands derived from calmodulin. The relaxometric study also shows an important second sphere contribution to relaxivity. To better understand the intricate molecular factors affecting relaxivity, we developed new relaxometric methods based on probe solutes. These methods allow us to determine the charge of the complex, weak affinity constants, trans-metallation constants, and the electronic relaxation rate. (author)

  3. Complexation of biological ligands with lanthanides(III) for MRI: Structure, thermodynamic and methods; Complexation des cations lanthanides trivalents par des ligands d'origine biologique pour l'IRM: Structure, thermodynamique et methodes

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, C

    2006-07-15

    New cyclic ligands derived from sugars and amino-acids form a scaffold carrying a coordination sphere of oxygen atoms suitable to complex Ln(III) ions. In spite of their rather low molecular weights, the complexes display surprisingly high relaxivity values, especially at high field. The ACX and BCX ligands, which are acidic derivatives of modified and cyclo-dextrins, form mono and bimetallic complexes with Ln(III). The LnACX and LnBCX complexes show affinities towards Ln(III) similar to those of tri-acidic ligands. In the bimetallic Lu2ACX complex, the cations are deeply embedded in the cavity of the ligand, as shown by the X-ray structure. In aqueous solution, the number of water molecules coordinated to the cation in the LnACX complex depends on the nature and concentration of the alkali ions of the supporting electrolyte, as shown by luminescence and relaxometric measurements. There is only one water molecule coordinated in the LnBCX complex, which enables us to highlight an important second sphere contribution to relaxivity. The NMR study of the RAFT peptidic ligand shows the complexation of Ln(III), with an affinity similar to those of natural ligands derived from calmodulin. The relaxometric study also shows an important second sphere contribution to relaxivity. To better understand the intricate molecular factors affecting relaxivity, we developed new relaxometric methods based on probe solutes. These methods allow us to determine the charge of the complex, weak affinity constants, trans-metallation constants, and the electronic relaxation rate. (author)

  4. Weld metal design data for 316L(N)

    Energy Technology Data Exchange (ETDEWEB)

    Tavassoli, A.A.F. [Commissariat a l' Energie Atoique, CEA, Saclay (France)

    2007-07-01

    This paper extends the ITER materials properties documentations to weld metal types 316L, 19-12-2 and 16-8-2, used for welding of Type 316L(N), i.e. the structural material retained for manufacturing of ITER main components such as the vacuum vessel. The data presented include those of the low temperature (316L) and high temperature (19-12-2) grades, as well as, the more readily available grade (16-8-2). Weld metal properties data for all three grades are collected, sorted and analyzed according to the French design and construction rules for nuclear components (RCC-MR). Particular attention is paid to the type of weld metal (e.g. wire for TIG, covered electrode for manual arc, flux wire for automatic welding), and the type and the position of welding. Design allowables are derived for each category of weld and compared with those of the base metal. The data sheets established for each physical and mechanical properties follow the presentation established for the ITER Materials Properties Handbook (MPH). They are part of the documentation that when combined with codification and inspection documents should satisfy ITER licensing needs. In most cases, the analyses performed, go beyond conventional analyses required in present international codes and pay attention to specific needs of ITER. These include, possible effects of exposures to high temperatures during various manufacturing stages e.g. HIPing, and effects of irradiation at low and medium temperatures. In general, it is noticed that all three weld metals satisfy the RCC-MR requirements, provided compositions and types of welds used correspond to those specified in RCC-MR. (orig.)

  5. Tricolor emission Ca3Si2O7:Ln (Ln=Ce, Tb, Eu) phosphors for near-UV white light-emitting-diode

    International Nuclear Information System (INIS)

    Mao, Zhi-yong; Zhu, Ying-chun; Gan, Lin; Zeng, Yi; Xu, Fang-fang; Wang, Yang; Tian, Hua; Li, Jian; Wang, Da-jian

    2013-01-01

    Tricolor emission in a same Ca 3 Si 2 O 7 host with independent Ln (Ln=Ce 3+ , Eu 2+ , Tb 3+ ) dopants is demonstrated to construct a near-UV white light emitting diode (LED). The luminescence properties and thermal quenching properties, as well as the applications in near-UV white LED are investigated. These phosphors show typical blue, red, and green, three-basal-color, luminescence in the CIE chromaticity diagram for Ce 3+ , Eu 2+ and Tb 3+ dopants, respectively. Thermal quenching properties show that the luminescence thermal stability strongly depends on the different dopant types; better thermal quenching property of Ce 3+ and Tb 3+ is recorded in comparison with that of Eu 2+ . The white LED prototype fabricated with near-UV chip and as-prepared tricolor phosphors exhibits acceptable CIE chromaticity coordinates (0.32, 0.30) with a CCT of 6000 K and a CRI of 87, indicating the potential application of Ca 3 Si 2 O 7 :Ln phosphors in near-UV white LED. - Highlights: ► Tricolor Ca 3 Si 2 O 7 : Ln phosphors were demonstrated to construct near-UV white LED. ► Eu 2+ doped Ca 3 Si 2 O 7 red-emitting phosphor was confirmed by this work once again. ► Thermal quenching properties for Ca 3 Si 2 O 7 :Ln phosphors were reported for the first time. ► Performances of fabricated white LED indicated the potential application of phosphors.

  6. High-pressure syntheses of lanthanide polysulfides and polyselenides LnX_1_._9 (Ln = Gd-Tm, X = S, Se)

    International Nuclear Information System (INIS)

    Mueller, Carola J.; Schwarz, Ulrich; Doert, Thomas

    2012-01-01

    The polysulfides LnS_1_._9 and polyselenides LnSe_1_._9 of the lanthanide metals from gadolinium to thulium were prepared by high-pressure high-temperature synthesis. The compounds adopt the tetragonal CeSe_1_._9 structure type in space group P4_2/n (No. 86) with lattice parameters of 8.531 Aa ≤ a ≤ 8.654 Aa and 15.563 Aa ≤ c ≤ 15.763 Aa for the sulfides and 8.869 Aa ≤ a ≤ 9.076 Aa and 16.367 Aa ≤ c ≤ 16.611 Aa for the selenides. The atomic pattern consists of puckered double slabs [LnX]"+ and planar chalcogenide layers with ten possible chalcogen positions, of which eight are occupied by chalcogen atoms forming dinuclear X_2"2"- dianions, one by a single X"2"- ion and one remaining vacant. This resembles a √5 x √5 x 2 superstructure of the ZrSSi aristotype. Structural relationships to the aristotype and the related lanthanide polychalcogenides LnX_2_-_δ (Ln = La-Tm, X = S-Te, δ = 0 - 0.3) are discussed. The samples synthesized under high-pressure conditions (p > 1 GPa) decompose slowly under release of sulfur or selenium at ambient conditions. The crystal structure of a partially degraded thulium-polysulfide sample can be described as an incommensurate variant of the original TmS_1_._9 motif. Additionally, the isostructural ternary compound Gd(S_1_-_xSe_x)_1_._9 was synthesized and characterized by powder X-ray diffraction. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Synthesis and study of rare earth complexes with ortho-hydroxyphenyliminodiacetic acid containing lactone ring

    International Nuclear Information System (INIS)

    Martynenko, L.I.; Mitrofanova, N.D.; Muratova, N.M.; Kurbatova, S.V.

    1978-01-01

    Solid complex compounds of o-oxyphenyliminodiacetic acid with rare earth elements of the composition of LnA 2 Clx6H 2 O and LnA 3 x5H 2 O (where Ln=La, Pr, Nd, Eu, Dy, Er, and Y) not described earlier, have been synthesized. The thermographic analysis of the compounds has been performed. It is shown by infrared spectroscopy that a lactone ring is retained in the dicomplex structure. The presence of the absorption bands of non-ionized COOH-groups in the infrared spectra of tricomplexonates of heavy r.e.e. points to opening of the lactone ring in the ligand part

  8. Ordered oxygen deficient '112' perovskites, LnBaCo2 : complex ...

    Indian Academy of Sciences (India)

    Administrator

    are labeled on the graph. .... in agreement with Kanamori Goodenough rules. In sum- mary, these results ... exhibit very rich phase diagrams as illustrated in figure 9. The latter .... which make that the control of oxygen content in these phases is ...

  9. Versatile lanthanide-azide complexes with azide/carboxylate/hydroxy mixed bridged chain exhibiting magnetic and luminescent properties

    International Nuclear Information System (INIS)

    Wang Haichao; Xue Min; Guo Qian; Zhao Jiongpeng; Liu Fuchen; Ribas, Joan

    2012-01-01

    Two new lanthanide-azide complexes, [Ln 2 (N 3 )(isonic) 2 (OH) 3 (Hisonic)(H 2 O)] n (Ln=Yb for 1 and Tb for 2, isonic=isonicotinate), were obtained in hydrothermal condition. X-ray diffraction analysis indicated the two complexes are isomorphic chain structure in which the Ln III ions are mixed bridged by the azide anions, hydroxyl anions and carboxylate groups of the isonicotinate ligands. Further studies indicated weak antiferromagnetic interactions between the Ln III ions in 1 and 2, and complex 2 exhibit green sensitized Luminescent character of Tb III ion. - Graphical abstract: Two new 1D lanthanide-azide complexes, [Ln 2 (N 3 )(isonic) 2 (OH) 3 (Hisonic)(H 2 O)] n (Ln=Yb III for 1 and Tb III for 2, isonic=isonicotinate), were synthesized by hydrothermal reaction and exhibit interesting magnetism and fluorescence properties. Highlights: ► The research provided a new method for synthesizing lanthanide-azide complexes. ► The complexes have an interesting azide/hydroxyl/carboxylate mixed bridged1D chain structure. ► The antiferromagnetic coupling between the complexes and 2 displays green luminescence.

  10. Single-ion 4f element magnetism: an ab-initio look at Ln(COT)2(-).

    Science.gov (United States)

    Gendron, Frédéric; Pritchard, Benjamin; Bolvin, Hélène; Autschbach, Jochen

    2015-12-14

    The electron densities associated with the Ln 4f shell, and spin and orbital magnetizations ('magnetic moment densities'), are investigated for the Ln(COT)2(-) series. The densities are obtained from ab-initio calculations including spin-orbit coupling. For Ln = Ce, Pr the magnetizations are also derived from crystal field models and shown to agree with the ab-initio results. Analysis of magnetizations from ab-initio calculations may be useful in assisting research on single molecule magnets.

  11. Direct nano ESI time-of-flight mass spectrometric investigations on lanthanide BTP complexes in the extraction-relevant diluent 1-octanol

    International Nuclear Information System (INIS)

    Steppert, M.; Walther, C.; Geist, A.; Fanghanel, Th.

    2009-01-01

    The present work focuses on investigations of a highly selective ligand for Am(III)/Ln(III) separation: bis-triazinyl-pyridine (BTP). By means of nano-electro-spray mass spectrometry, complex formation of BTP with selected elements of the lanthanide series is investigated. We show that the diluent drastically influences complex speciation. Measurements obtained in the extraction-relevant diluent 1-octanol show the occurrence of Ln(BTP) i (i 1-3) species in different relative abundances, depending on the lanthanide used. Here, the relative abundances of the Ln(BTP) 3 complexes correlate with the distribution ratios for extraction to the organic phase of the respective lanthanide. (authors)

  12. Study on feasibility of replacing 321 with 316LN stainless steel for main reactor coolant pipe material

    International Nuclear Information System (INIS)

    Luo Yijun

    2013-01-01

    The metallurgical, physical and mechanical performance, and the corrosion and welding properties of 00Cr17Ni12Mo2 (controlled Nitrogen, ANSI316LN) and 0Cr18Ni10Ti (ANSI321SS) for main pipe material were analyzed comparatively in this paper. The feasibility of 316LN pipe material manufacturing was studied too. The analysis results showed that under the operation condition of the nuclear reactor, the general properties of 316LN are better than that of 321SS. Therefore, 316LN could be used for main pipe material, replacing 321SS. (authors)

  13. Detection of the Unstable Hb Köln (HBB: c.295G>A) by a Capillary Electrophoresis Method.

    Science.gov (United States)

    Li, You-Qiong; Ye, Li-Hua; Mo, Yun

    2016-11-01

    Hb Köln (HBB: c.295G>A) is an unstable β-globin gene variant with a GTG>ATG substitution at codon 98. This variant is quite frequent in Europe and the USA but rare in China. It can easily be misdiagnosed as Hb Constant Spring (Hb CS; HBA2: c.427T>C) by high performance liquid chromatography (HPLC), but detection and quantification of both Hb Köln and degraded Hb Köln by capillary electrophoresis (CE) are possible. Thus, we concluded that CE was the preferred method for Hb Köln detection.

  14. Estimation of tau1 for the host Kramers' Ln3+ ions (Ln = Nd, Sm and Yb) from the EPR linewidths of Gd3+ impurity ions in Ln2(SO4)3.8H2O

    International Nuclear Information System (INIS)

    Malhotra, V.M.; Buckmaster, H.A.

    1981-01-01

    It is shown that the EPR linewidth data published by Misra and Mikolajczak for Gd 3+ impurity ions in Ln 2 (SO 4 ) 3 .8H 2 O (Ln = Nd, Sm and Yb) single crystals at 77 and 300 K can be used to estimate the effective spin-lattice relaxation time of Kramers' host ions. The various relaxation mechanisms which are operative in the lanthanides are reviewed and discussed. The estimated relaxation times are shown to be a sensitive function of the host ion energy level splittings and the temperature. The estimated effective spin-lattice relaxation times in these hosts are in reasonable agreement with those expected from a resonance Orbach process

  15. Serum expression of HA and LN in lewis rat models of autoimmune myocarditis

    International Nuclear Information System (INIS)

    Han Li'na; Li Tieling; Zhang Yajing; Yang Tingshu; Ding Yu; Guo Shuli; Zhao Xiaoning

    2011-01-01

    Objective: To study the clinical significance of dynamic changes of serum expressions of hyaluronic acid (HA) and laminin (LN) in Lewis rat models of experimental autoimmune myocarditis (EAM). Methods: Fifty Lewis rat models of experimental autoimmune myocarditis (EAM) were established with injection of recombinant cardiac C protein with complete freund adjuvant into two foot-pads plus intraperitoneal injection of pertussis toxin. At 1w, 2w, 4w, 6w and 8w, 10 models were sacrificed each time;cardiac tissues were examined with HE stain for myocardial inflammatory score and examined with picrosirius red stain for myocardial fibrosis score, also, serum HA and LN expressions were determined with RIA. These examinations were performed in 10 undisturbed animals as controls. Results: The myocardial inflammatory scores of the models at 1w were about the same as those in the controls, but the scores rapidly increased from 2w on to 4w then fell gradually. The myocardial fibrosis scores of the models at 1wk were also not much different from those in controls. The fibrosis scores increased rapidly at 4w and maintained at high level up to 8w. The changes of serum expressions of HA and LN roughly paralleled those of myocardial fibrosis scores i. e. rapidly increased at 4w up to 8w. Conclusion: Serum expressions of HA and LN could faithfully reflect the degree of myocardial fibrosis in rat models of EAM. HA and LN were useful markers of myocardial fibrois and were of prognostic importance. (authors)

  16. Synthesis, density functional theory calculations and luminescence of lanthanide complexes with 2,6-bis[(3-methoxybenzylidene)hydrazinocarbonyl] pyridine Schiff base ligand.

    Science.gov (United States)

    Taha, Ziyad A; Ababneh, Taher S; Hijazi, Ahmed K; Abu-Salem, Qutaiba; Ajlouni, Abdulaziz M; Ebwany, Shroq

    2018-02-01

    A pyridine-diacylhydrazone Schiff base ligand, L = 2,6-bis[(3-methoxy benzylidene)hydrazinocarbonyl]pyridine was prepared and characterized by single crystal X-ray diffraction. Lanthanide complexes, Ln-L, {[LnL(NO 3 ) 2 ]NO 3 .xH 2 O (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Er)} were prepared and characterized by elemental analysis, molar conductance, thermal analysis (TGA/DTGA), mass spectrometry (MS), Fourier transform infra-red (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. Ln-L complexes are isostructural with four binding sites provided by two nitro groups along with four coordination sites for L. Density functional theory (DFT) calculations on L and its cationic [LnL(NO 3 ) 2 ] + complexes were carried out at the B3LYP/6-31G(d) level of theory. The FT-IR vibrational wavenumbers were computed and compared with the experimentally values. The luminescence investigations of L and Ln-L indicated that Tb-L and Eu-L complexes showed the characteristic luminescence of Tb(III) and Eu(III) ions. Ln-L complexes show higher antioxidant activity than the parent L ligand. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Ion-irradiation resistance of the orthorhombic Ln_2TiO_5 (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb and Dy) series

    International Nuclear Information System (INIS)

    Aughterson, Robert D.; Lumpkin, Gregory R.; Ionescu, Mihail; Reyes, Massey de los; Gault, Baptiste; Whittle, Karl R.; Smith, Katherine L.; Cairney, Julie M.

    2015-01-01

    The response of Ln_2TiO_5 (where Ln is a lanthanide) compounds exposed to high-energy ions was used to test their suitability for nuclear-based applications, under two different but complementary conditions. Eight samples with nominal stoichiometry Ln_2TiO_5 (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb and Dy), of orthorhombic (Pnma) structure were irradiated, at various temperatures, with 1 MeV Kr"2"+ ions in-situ within a transmission electron microscope. In each case, the fluence was increased until a phase transition from crystalline to amorphous was observed, termed critical dose D_c. At certain elevated temperatures, the crystallinity was maintained irrespective of fluence. The critical temperature for maintaining crystallinity, T_c, varied non-uniformly across the series. The T_c was consistently high for La, Pr, Nd and Sm_2TiO_5 before sequential improvement from Eu to Dy_2TiO_5 with T_c's dropping from 974 K to 712 K. In addition, bulk Dy_2TiO_5 was irradiated with 12 MeV Au"+ ions at 300 K, 723 K and 823 K and monitored via grazing-incidence X-ray diffraction (GIXRD). At 300 K, only amorphisation is observed, with no transition to other structures, whilst at higher temperatures, specimens retained their original structure. The improved radiation tolerance of compounds containing smaller lanthanides has previously been attributed to their ability to form radiation-induced phase transitions. No such transitions were observed here. - Highlights: • First ion-irradiation studies on a number of novel compounds including Pr_2TiO_5, Eu_2TiO_5 and Tb_2TiO_5. • Systematic in-situ ion-irradiation study of almost complete Ln_2TiO_5 series (Ln = lanthanides) with orthorhombic crystal structure type. • The first grazing incidence study of bulk irradiated Dy_2TiO_5 looking for irradiation induced phase transition.

  18. Mechanism of S-oxygenation by a cysteine dioxygenase model complex

    OpenAIRE

    Kumar, Devesh; Sastry, G. Narahari; Goldberg, David P.; de Visser, Sam P.

    2011-01-01

    In this work we present the first computational study on a biomimetic cysteine dioxygenase model complex, [FeII(LN3S)]+ where LN3S is a tetradentate ligand with a bis(imino)pyridyl scaffold and a pendant arylthiolate group. The reaction mechanism of sulfur dioxygenation with O2 was examined by density functional theory (DFT) methods, and compared to results obtained for cysteine dioxygenase. The reaction proceeds via multistate reactivity patterns on competing singlet, triplet and quintet spi...

  19. Cationic rare-earth metal SALEN complexes.

    Science.gov (United States)

    Liu, Qiancai; Meermann, Christian; Görlitzer, Hans W; Runte, Oliver; Herdtweck, Eberhardt; Sirsch, Peter; Törnroos, Karl W; Anwander, Reiner

    2008-11-28

    Complexes (Salpren(tBu,tBu))Y[N(SiHMe2)2](thf) and (SALEN(tBu,tBu))La[N(SiHMe2)2](thf) (SALEN(tBu,tBu) = Salcyc(tBu,tBu) and Salpren(tBu,tBu)) were prepared from Ln[N(SiHMe2)2]3(thf)2 and H2SALEN(tBu,tBu). The yttrium complex was characterized by X-ray crystallography revealing intrinsic solid-state structural features: the metal centre is displaced by 1.05 angstroms from the [N2O2] least squares plane of a highly bent Salpren(tBu,tBu) ligand (angle(Ph,Ph) dihedral angle of 80.4(1) degrees ) and is coordinated asymmetrically by the silylamide ligand exhibiting one significant Y---(HSi) beta-agostic interaction (Y-N1-Si1, 106.90(9) degrees; Y---Si1, 3.2317(6) angstroms). Complexes (SALEN(tBu,tBu))Ln[N(SiHMe2)2](thf)n (n = 1, Sc; n = 2, Y, La) react with ammonium tetraphenylborate to form the ion pairs [(SALEN(tBu,tBu))Ln(thf)n][BPh4]. The cationisation was proven by X-ray crystal structure analyses of [(Salpren(tBu,tBu))Sc(thf)2][B(C6H5)4].2(thf) and [(Salpren(tBu,tBu))Ln(thf)3][B(C6H5)4].4(thf) (Ln = Y, La), showing an octahedral and pentagonal-bipyramidal coordination geometry, respectively.

  20. Cathodoluminescence response of natural and synthetic lanthanide-rich phosphates (Ln3+: Ce, Nd)

    Science.gov (United States)

    Barrera-Villatoro, A.; Boronat, C.; Rivera-Montalvo, T.; Correcher, V.; Garcia-Guinea, J.; Zarate-Medina, J.

    2017-12-01

    This paper reports on the cathodoluminescence (CL) emission of both natural and synthetic lanthanide-rich phosphates (Ln3+: Ce, Nd) previously characterized by X-ray Diffraction (XRD), Environmental Scanning Electronic Microscopy (ESEM) and Energy Dispersive Spectroscopy. The thermal treatment at 700 °C performed on the synthetic sample obtained by chemical precipitation, promotes increasing of the crystallinity degree giving rise to a phase transition from the hexagonal (comprising monazite and rabdophane) into the monoclinic (cerianite and monazite) structures detected by XRD. Despite the size and the morphology of the grains are similar under ESEM, it could be appreciated significant differences among CL signals attending to the shape (with well-defined peaks for the annealed sample) and intensity (with lower emission for the non-thermally pretreated synthetic phosphate). The main wavebands centered at (i) 360, 380 and 490 nm are associated respectively with 5D3/2 → 2F5/2 and 5D3/2 → 2F7/2 transitions as well as a redox reaction assigned to the presence of Ce3+, (ii) 276, 424, 516 and 531 nm are linked respectively to 2G9/2→4I9/2, 2P1/2→4I9/2, 4G9/2→4I9/2 and 4G7/2→4I9/2 Nd3+ transitions and (iii) 400-490 nm is due to non-bridging oxygen hole centers related to the tetrahedral PO43- groups or structural defects for the heated synthetic samples. The natural sample from Madagascar, with a very complex CL spectrum, displays a characteristic band emission in the green-yellow and red regions corresponding to [UO2]2+ groups and Sm3+ respectively.

  1. Xafs studies on actinide-pyridine-diamide complexes for development of an innovative separation process

    International Nuclear Information System (INIS)

    Hideaki, Shiwaku; Tsuyoshi, Yaita; Tohru, Kobayashi; Masahiko, Numakura; Tsuyoshi, Yaita; Shinichi, Suzuki; Yoshihiro, Okamoto

    2007-01-01

    We have been studying the bond properties and the structures of actinide (An) and lanthanide (Ln) complexes in detail using several kinds of X-ray analyses by synchrotron radiation in order to elucidate the ionic recognition mechanism of organic ligands. Generally, an oxygen donor type ligand separates both An and Ln from solutions of spent fuel or high level radioactive waste. Separation ability of this type of ligand for An and Ln follows the order of the surface charge density of an ion, i.e., An 4+ > AnO 2 2+ > An 3+ = Ln 3+ > AnO 2+ and/or a few structural factors. Therefore, this type of ligand is ineffective for the separation of An 3+ and Ln 3+ due to their similar chemical properties. Recently, new extractants like aromatic N-donor ligands have been developed using the preference of soft-donors to achieve the An 3+ /Ln 3+ separation. However, aromatic N-donor ligands often show a few problems such as protonation. In this developing process, we synthesized a new type of ligand, N,N'-dimethyl-N,N'-diphenyl-pyridine-2,6-carboxy-amide (DMDPh-PDA). The PDA is hybrid type ligand having oxygen and nitrogen as donor atoms and follows a unique separation order, i.e., An 4+ > An 3+ > AnO 2 2+ > Ln 3+ > AnO 2 + , probably arising from the combined effects of covalent bonding and steric hindrance. Hence, clarification of any ionic recognition mechanism of the PDA is very interesting from the view point of structural analysis. In this presentation, we will show XAFS results of An and Ln complexes with PDA in solution and discuss separation mechanism of An and Ln by PDA. Various kinds of complexes between Ln/An and PDA were prepared for XAFS analysis. The Ln complexes were measured in transmission mode at the K absorption edge on the BL11XU at SPring-8. On the other hand, the U complexes were measured in fluorescence mode at the L III absorption edge on the BL-27B at Photon Factory, High-energy Accelerator Research Organization (KEK). (authors)

  2. Strain-rate dependent fatigue behavior of 316LN stainless steel in high-temperature water

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Jibo [CAS Key Laboratory of Nuclear Materials and Safety Assessment, Liaoning Key Laboratory for Safety and Assessment Technique of Nuclear Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wu, Xinqiang, E-mail: xqwu@imr.ac.cn [CAS Key Laboratory of Nuclear Materials and Safety Assessment, Liaoning Key Laboratory for Safety and Assessment Technique of Nuclear Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Han, En-Hou; Ke, Wei; Wang, Xiang [CAS Key Laboratory of Nuclear Materials and Safety Assessment, Liaoning Key Laboratory for Safety and Assessment Technique of Nuclear Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Sun, Haitao [Nuclear and Radiation Safety Center, SEPA, Beijing 100082 (China)

    2017-06-15

    Low cycle fatigue behavior of forged 316LN stainless steel was investigated in high-temperature water. It was found that the fatigue life of 316LN stainless steel decreased with decreasing strain rate from 0.4 to 0.004 %s{sup −1} in 300 °C water. The stress amplitude increased with decreasing strain rate during fatigue tests, which was a typical characteristic of dynamic strain aging. The fatigue cracks mainly initiated at pits and slip bands. The interactive effect between dynamic strain aging and electrochemical factors on fatigue crack initiation is discussed. - Highlights: •The fatigue lives of 316LN stainless steel decrease with decreasing strain rate. •Fatigue cracks mainly initiated at pits and persistent slip bands. •Dynamic strain aging promoted fatigue cracks initiation in high-temperature water.

  3. Synthesis and characterization of LnAg(WO{sub 4})(MoO{sub 4})

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Martinez, F. [Universidad Politecnica de Madrid, E.U.I.T. Industrial, Ronda de Valencia 3, 28012 Madrid (Spain)], E-mail: francisco.fernandezm@upm.es; Colon, C.; Montero, J.L.; Atanes, E. [Universidad Politecnica de Madrid, E.U.I.T. Industrial, Ronda de Valencia 3, 28012 Madrid (Spain); Rivero, C. [Universidad Politecnica de Madrid, E.T.S.I. Telecomunicaciones, Avda. Complutense s/n, Ciudad Universitaria, 28040 Madrid (Spain)

    2008-02-28

    Polycrystalline LnAg(WO{sub 4})(MoO{sub 4}) powders, with Ln = La to Lu and Y, have been obtained by ceramic method. Rietveld refinement for all compounds reveals that they present tetragonal symmetry, space group I4{sub 1}/a (No. 88), where the Ln{sup 3+}/Ag{sup +} ions are located in the 4a atomic positions, since the W/Mo are randomly distributed into 4b crystal sites. In these compounds, a and b lattice parameters take values between those corresponding to tungstate and molybdate compounds. A progressive decrease in the lattice parameters is observed in going from La to Lu derivatives as a consequence of the well-known lanthanide contraction.

  4. Problematika personální politiky ve vybraném podniku

    OpenAIRE

    Vaňková, Kateřina Bc.

    2007-01-01

    Teoretická část se věnuje obecným pojmům personální práce, vytváření a analýze pracovních míst, personálnímu plánování, získávání a výběru zaměstnanců a řízení kariéry. V praktické části jsou tyto oblasti analyzovány v konkrétním podniku, kterým je Toyota Peugeot Citroen Automobile. Vzávěru je provedena SWOT analýza vybraných personálních činností a zhodnocení a návrhy.

  5. Ln28Ti2O7 (Ln = La, Nd, Sm, Gd): a novel series of defective Ruddlesden–Popper phases formed by topotactic dehydration of HLnTiO4

    OpenAIRE

    Thangadurai, V; Subbanna, GN; Gopalakrishnan, J

    1998-01-01

    Topotactic dehydration of HLnTiO4 (Ln = La, Nd, Sm or Gd) around 480–500 °C yields a new series of metastable layered perovskite oxides, Ln28Ti2O7, that possess a defective Sr3Ti2O7 structure, where the cubooctahedral sites within the double-perovskite layers are most likely vacant.

  6. Structures and magnetic properties of rare earth double perovskites containing antimony or bismuth Ba{sub 2}LnMO{sub 6} (Ln=rare earths; M=Sb, Bi)

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Shumpei, E-mail: m-nis-s-o@ec.hokudai.ac.jp; Hinatsu, Yukio

    2015-07-15

    A series of double perovskite-type oxides Ba{sub 2}LnMO{sub 6} (Ln=lanthanides; M=Sb, Bi) were synthesized and their structures were studied. The Ln and M are structurally ordered in the rock-salt type at the B-site of the perovskite ABO{sub 3}. For Ba{sub 2}PrBiO{sub 6} and Ba{sub 2}TbBiO{sub 6}, it has been found that the disordering between Ln ion and Bi ion occurs at the B-site of the double perovskite and both the Pr (Tb) and Bi exist in two oxidation state in the same compound from the analysis of the X-ray diffraction and magnetic susceptibility data. Magnetic susceptibility measurements show that all these compounds are paramagnetic and have no magnetic ordering down to 1.8 K. - Graphical abstract: Tolerance factor for Ba{sub 2}LnMO{sub 6} (M=Sb, Bi) plotted against the ionic radius of Ln{sup 3+}. We have found that there is a clear relation between crystal structures and tolerance factors. - Highlights: • The Ln and M ions are structurally ordered in the rock-salt type at the B-site. • The disordering between Pr (Tb) ion and Bi ion occurs at the B-site. • Ba{sub 2}LnMO{sub 6} (M=Sb, Bi) have no magnetic ordering down to 1.8 K.

  7. Evidence of different stoichiometries for the limiting carbonate complexes of lanthanides(3)

    International Nuclear Information System (INIS)

    Philippini, V.

    2007-12-01

    Two stoichiometries have been proposed by different laboratories to interpret measurements on the limiting carbonate complexes of An 3+ and Ln 3+ cations. The study of the solubility of double carbonates (AlkLn(CO 3 ) 2 ,xH 2 O) in concentrated carbonate solutions at room temperature and high ionic strengths has shown that on the one hand the lightest lanthanides (La and Nd) form Ln(CO 3 ) 4 5- whereas the heaviest (Eu and Dy) form Ln(CO 3 ) 3 3- in the studied chemical conditions, and on the other hand, that the kinetics of precipitation of double carbonates depends on the alkali metal and the lanthanide ions. The existence of two stoichiometries for the limiting carbonate complexes was confirmed by capillary electrophoresis hyphenated to an inductively coupled plasma mass spectrometer (CE-ICP-MS), used to extend the study to the whole series of lanthanides (except Ce, Pm and Yb). Two behaviours have been put forward comparing the electrophoretic mobilities: La to Tb form Ln(CO 3 ) 4 5- while Dy to Lu form Ln(CO 3 ) 3 3- . Measurements by time resolved laser fluorescence spectroscopy (TRLFS) on Eu(III) indicate small variations of the geometry of Eu(CO 3 ) 3 3- complex, specially with Cs + . Although analogies are currently used among the 4f-block trivalent elements, different aqueous speciations are evidenced in concentrated carbonate solutions across the lanthanide series. (author)

  8. Nanostructured LnBaCo2O6− (Ln = Sm, Gd with layered structure for intermediate temperature solid oxide fuel cell cathodes

    Directory of Open Access Journals (Sweden)

    Augusto E. Mejía Gómez

    2017-04-01

    Full Text Available In this work, we present the combination of two characteristics that are beneficial for solid oxide fuel cell (SOFC cathodic performance in one material. We developed and evaluated for the first time nanostructured layered perovskites of formulae LnBaCo2O6-d with Ln = Sm and Gd (SBCO and GBCO, respectively as SOFC cathodes, finding promising electrochemical properties in the intermediate temperature range. We obtained those nanostructures by using porous templates to confine the chemical reagents in regions of 200-800 nm. The performance of nanostructured SBCO and GBCO cathodes was analyzed by electrochemical impedance spectroscopy technique under different operating conditions using Gd2O3-doped CeO2 as electrolyte. We found that SBCO cathodes displayed lower area-specific resistance than GBCO ones, because bulk diffusion of oxide ions is enhanced in the former. We also found that cathodes synthesized using smaller template pores exhibited better performance.

  9. Phase transformations during HLnTiO{sub 4} (Ln=La, Nd) thermolysis and photocatalytic activity of obtained compounds

    Energy Technology Data Exchange (ETDEWEB)

    Silyukov, Oleg I., E-mail: olegsilyukov@yandex.ru; Abdulaeva, Liliia D.; Burovikhina, Alena A.; Rodionov, Ivan A.; Zvereva, Irina A.

    2015-03-15

    Layered HLnTiO{sub 4} (Ln=La, Nd) compounds belonging to Ruddlesden–Popper phases were found to form partially hydrated compounds Ln{sub 2}Ti{sub 2}O{sub 7}·xH{sub 2}O during thermal dehydration as well as defect oxides Ln{sub 2}□Ti{sub 2}O{sub 7} as final products. Further heating of metastable defect Ln{sub 2}□Ti{sub 2}O{sub 7} substances leads to the formation of pyrochlore-type oxides Ln{sub 2}Ti{sub 2}O{sub 7} {sub (p)}, with subsequent transformation under higher temperatures to stable layered 110-type perovskites Ln{sub 2}Ti{sub 2}O{sub 7}. The occurring structure transformations lead to an increase of photocatalytic activity in the order of HLnTiO{sub 4}<Ln{sub 2}Ti{sub 2}O{sub 7}·yH{sub 2}O<Ln{sub 2}□Ti{sub 2}O{sub 7}<Ln{sub 2}Ti{sub 2}O{sub 7} {sub (p)}<Ln{sub 2}Ti{sub 2}O{sub 7} in the reaction of hydrogen evolution from aqueous isopropanol solution. - Graphical abstract: Layered HLnTiO{sub 4} (Ln=La, Nd) compounds form partially hydrated Ln{sub 2}Ti{sub 2}O{sub 7}·xH{sub 2}O compounds during thermal dehydration, further heating results to the formation to defect oxides Ln{sub 2}□Ti{sub 2}O{sub 7}, pyrochlor-type oxides Ln{sub 2}Ti{sub 2}O{sub 7} {sub (p)}, with subsequent transformation to layered 110-type perovskites Ln{sub 2}Ti{sub 2}O{sub 7}. Structure transformations lead to an increase of photocatalytic activity in the order of HLnTiO{sub 4}<Ln{sub 2}Ti{sub 2}O{sub 7}·yH{sub 2}O<Ln{sub 2}□Ti{sub 2}O{sub 7}<Ln{sub 2}Ti{sub 2}O{sub 7} {sub (p)}<Ln{sub 2}Ti{sub 2}O{sub 7}. - Highlights: • We studied dehydration and further thermolysis of HLnTiO{sub 4} (Ln=La, Nd) compounds. • XRD, STA and solid state IR studies were carried out. • A new series of metastable Ln{sub 2}Ti{sub 2}O{sub 7}·yH{sub 2}O compounds was obtained. • We examined the photocatalytic activity of all obtained compounds. The hydrogen evolution rate increased in the course of the structure changes during thermolysis.

  10. Design and validation of the high performance and low noise CQU-DTU-LN1 airfoils

    DEFF Research Database (Denmark)

    Cheng, Jiangtao; Zhu, Wei Jun; Fischer, Andreas

    2014-01-01

    with the blade element momentum theory, the viscous-inviscid XFOIL code and an airfoil self-noise prediction model, an optimization algorithm has been developed for designing the high performance and low noise CQU-DTU-LN1 series of airfoils with targets of maximum power coefficient and low noise emission...... emission between the CQU-DTU-LN118 airfoil and the National Advisory Committee for Aeronautics (NACA) 64618 airfoil, which is used in modern wind turbine blades, are carried out. Copyright © 2013 John Wiley & Sons, Ltd....

  11. Validation of the CQU-DTU-LN1 series of airfoils

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Zhu, Wei Jun; Fischer, Andreas

    2014-01-01

    The CQU-DTU-LN1 series of airfoils were designed with an objective of high lift and low noise emission. In the design process, the aerodynamic performance is obtained using XFOIL while noise emission is obtained with the BPM model. In this paper we present some validations of the designed CQU......, the designed Cl and Cl/Cd agrees well with the experiment and are in general higher than those of the NACA airfoil. For the acoustic features, the noise emission of the LN118 airfoil is compared with the acoustic measurements and that of the NACA airfoil. Comparisons show that the BPM model can predict...

  12. The pressure of hot QCD up to $g^{6}$ ln(1/g)

    CERN Document Server

    Kajantie, Keijou; Rummukainen, K; Schröder, Y

    2003-01-01

    The free energy density, or pressure, of QCD has at high temperatures an expansion in the coupling constant g, known so far up to order g^5. We compute here the last contribution which can be determined perturbatively, g^6 ln(1/g), by summing together results for the 4-loop vacuum energy densities of two different three-dimensional effective field theories. We also demonstrate that the inclusion of the new perturbative g^6 ln(1/g) terms, together with the so far unknown perturbative and non-perturbative g^6 terms, could potentially extend the applicability of the resummed coupling constant series down to surprisingly low temperatures.

  13. X-ray photoelectron spectroscopic study of direct reforming catalysts Ln{sub 0.5}Sr{sub 0.5}Ti{sub 0.5}Mn{sub 0.5}O{sub 3±d} (Ln = La, Nd, and Sm) for high temperature-operating solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Keunsoo [Department of Engine Research, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Daejeon 305-343 (Korea, Republic of); Jeong, Jihoon [Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712 (United States); Azad, Abul K. [Faculty of Integrated Technologies, University Brunei Darussalam, Jalan Tunku Link, Gadong BE1410 (Brunei Darussalam); Jin, Sang Beom [Department of Advanced Materials Science and Engineering, Hanbat National University, 125, Dongseo-Daero, Yusung-Gu, Daejeon 305-719 (Korea, Republic of); Kim, Jung Hyun, E-mail: jhkim2011@hanbat.ac.kr [Department of Advanced Materials Science and Engineering, Hanbat National University, 125, Dongseo-Daero, Yusung-Gu, Daejeon 305-719 (Korea, Republic of)

    2016-03-01

    Graphical abstract: Measured Ti 2p peaks and deconvolution peaks of Nd{sub 0.5}Sr{sub 0.5}Ti{sub 0.5}Mn{sub 0.5}O{sub 3±d} under oxidizing condition (left) and NSTM under reducing condition (right). - Highlights: • Chemical states of Ln{sub 0.5}Sr{sub 0.5}Ti{sub 0.5}Mn{sub 0.5}O{sub 3±d} (Ln: La, Nd and Sm) were analyzed. • Charge compensation occurred with the reduction of Mn and Ti. • The Nd substitution effect allowed some Ti to convert into a metallic behavioral component. • NSTM and SSTM had a large amount of lattice oxygen; however, LSTM retained a large quantity of adsorbed oxygen. - Abstract: Chemical states of lanthanide doped perovskite for direct reforming anode catalysts, Ln{sub 0.5}Sr{sub 0.5}Ti{sub 0.5}Mn{sub 0.5}O{sub 3±d} (Ln = La, Nd, and Sm) have been studied by X-ray Photoelectron Spectroscopy (XPS) in order to determine the effects of various lanthanide substitution in complex perovskites for high temperature-operating solid oxide fuel cells (HT-SOFC). The charge state of lanthanide ions remained at 3+ and the binding energies of the lanthanide ions in Ln{sub 0.5}Sr{sub 0.5}Ti{sub 0.5}Mn{sub 0.5}O{sub 3±d} were located in a relatively lower range compared to those of conventional lanthanide oxides. Mn and Ti were regarded as charge compensation components in Ln{sub 0.5}Sr{sub 0.5}Ti{sub 0.5}Mn{sub 0.5}O{sub 3±d}; Mn was more influential than Ti. In the cases of substituting Nd and Sm into Ln{sub 0.5}Sr{sub 0.5}Ti{sub 0.5}Mn{sub 0.5}O{sub 3±d}, some portion of Ti showed metallic behavior; the specific Mn satellite peak indicating an electro-catalytic effect had occurred. Three types of oxygen species comprised of lattice oxygen, carbonate species, and adsorbed oxygen species were observed in Ln{sub 0.5}Sr{sub 0.5}Ti{sub 0.5}Mn{sub 0.5}O{sub 3±d} from the O 1s spectra; a high portion of lattice oxygen was observed in both Nd{sub 0.5}Sr{sub 0.5}Ti{sub 0.5}Mn{sub 0.5}O{sub 3±d} (NSTM) and Sm{sub 0.5}Sr{sub 0.5}Ti{sub 0.5}Mn{sub 0.5}O

  14. K2Ln2As2Se9 (Ln = Sm, Gd): the first quaternary rare-earth selenoarsenate compounds with a 3D framework containing chairlike As2Se4 units.

    Science.gov (United States)

    Wu, Yuandong; Bensch, Wolfgang

    2009-04-06

    The new compounds K(2)Ln(2)As(2)Se(9) (Ln = Sm, Gd) were obtained by applying the reactive flux method. The structure consists of a three-dimensional (3D) [Ln(2)As(2)Se(9)](2-) framework with K(+) ion-filling tunnels running along the b axis. The two unique Ln(3+) cations are coordinated by two Se(2)(2-) dumbbells, two AsSe(3)(3-) pyramids, and one chairlike As(2)Se(4)(2-) unit in a bicapped trigonal-prismatic geometry. The Ln(3+)-centered trigonal prisms share triangular faces with neighboring prisms, forming one-dimensional chains along the b axis. These chains are linked to each other to form layers by sharing Se(2-) anions on the capped sites of the trigonal prisms. The As(2)Se(4) units connect these layers to form the 3D framework.

  15. PMR investigation into complexes of lanthanum and lutetium with ethylenediaminediacetic acid

    International Nuclear Information System (INIS)

    Kostromina, N.A.; Novikova, L.B.

    1975-01-01

    Proton resonance spectra of ethylendiaminediacetic acid (EDDA) and EDDA mixtures with La and Lu as function of pH of solution was studied. Sequence of EDDA (A 2- ) protonation was established; cations H 3 A + and H 4 A 2+ were found; dissociation constants of above mentioned cations were determined. Formation of H 2 LnA 3+ , HLnA 2+ and LnA + complexes in EDDA-Ln (1:1) system was found. Difference in the bonds mobility of lanthanum and lutetium complexes was determined: lanthanum forms complexes with labile, lutetium with non-labile bonds. Information on complexes structure is collected. Acid dissociation constants of protonated complexes of lanthanum with EDDA were determined

  16. Investigation of different-ligand complexes of holmium and erbium with NTA and carbonate ion

    International Nuclear Information System (INIS)

    Nazarenko, N.A.; Bel'tyukova, S.V.; Poluehktov, N.S.

    1979-01-01

    Found out have been the optimum conditions for the formation of the lantanides (Ln) multiligand complexes with the nitriletriacetic acid (NTA) and the carbonate-ion. It has been established that the components correlation in complex compounds is equal to 1:1:1. Computed have been the values of the oscillator forces of the absorption bands, that conform to the ''supersensitive'' migration of the multiligand complexes, It is shown that the increment in the oscillator forces, the induced entering of one carbonate-ion into the Ln-NTA complex molecule conforms to about 1/4 of the oscillator forces increment during the migration from the aquo ion to the [Ln(CO 3 ) 4 ] 5- complex carbonaceous ion

  17. Prism inside. Spectroscopic and magnetic properties of the lanthanide(III) chloride oxidotungstates(VI) Ln{sub 3}Cl{sub 3}[WO{sub 6}] (Ln = La - Nd, Sm - Tb)

    Energy Technology Data Exchange (ETDEWEB)

    Dorn, Katharina V.; Blaschkowski, Bjoern; Hartenbach, Ingo [Institute for Inorganic Chemistry, University of Stuttgart (Germany); Foerg, Katharina; Netzsch, Philip; Hoeppe, Henning A. [Institute for Physics, University of Augsburg (Germany)

    2017-11-17

    The lanthanide(III) chloride oxidotungstates(VI) with the formula Ln{sub 3}Cl{sub 3}[WO{sub 6}] for Ln = La - Nd, Sm - Tb were synthesized by solid-state reactions utilizing the respective lanthanide trichloride, lanthanide sesquioxide (where available), and tungsten trioxide together with lithium chloride as flux. The title compounds crystallize hexagonally in space group P6{sub 3}/m (no. 176, a = 941-909, c = 543-525 pm, Z = 2). The structures comprise crystallographically unique Ln{sup 3+} cations surrounded by six O{sup 2-} and four Cl{sup -} anions (C.N. = 10) forming distorted tetracapped trigonal prisms as well as rather uncommon trigonal prismatic [WO{sub 6}]{sup 6-} units, whose edges are coordinated by nine Ln{sup 3+} cations. Thus, a {sup 3}{sub ∞}{([WO_6]Ln"e_9_/_3)"3"+} framework (e = edge-sharing) is created, which contains tube-shaped channels along [001] lined with chloride anions. To elucidate the spectroscopic and magnetic properties of the obtained pure phase samples, single-crystal Raman (for Ln = La - Nd, Sm-Tb), diffuse reflectance (for Ln = La, Pr, Nd, Gd), and luminescence spectroscopy (for bulk Ln{sub 3}Cl{sub 3}[WO{sub 6}] (Ln = La, Eu, Gd, Tb) and Eu{sup 3+}- or Tb{sup 3+}-doped derivatives of La{sub 3}Cl{sub 3}[WO{sub 6}] and Gd{sub 3}Cl{sub 3}[WO{sub 6}], respectively) were performed and their temperature-dependent magnetic moments (for Ln = Pr, Nd, Gd) were determined. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Natural and EDTA-complexed lanthanides used as a geochemical probe for aquifers: a case study of Orleans valley's alluvial and karstic aquifers

    International Nuclear Information System (INIS)

    Le Borgne, F.; Treuil, M.; Joron, J.L.; Lepiller, M.

    2005-01-01

    The transit of chemical elements within the different parts of Orleans valley's aquifer is studied by two complementary methods. Those methods rely on the fractionation of lanthanides (Ln) during their migration in natural waters. The first method consists in studying natural lanthanides patterns within the watershed, at its entries and exits. second one lies on multi-tracer experiments with Ln-EDTA complexes. This work is completed through an observation network consisting of 52 piezometers set on a sand and gravel quarry, and the natural entries and exits of the aquifer. Orleans valley's aquifer, which is made of an alluvial watershed lying on a karstic aquifer, is mainly fed by Loire river via a large karstic network. At the entries of the aquifer (Loire river at Jargeau), the Ln concentrations in the dissolved fraction ( heavy Ln. On the other hand, the filtration of alluvial groundwater with high colloids content induces no significant Ln fractionation when the solution contains no strong chelating agent. Hence, the transit of natural and artificial Ln in Orleans valley aquifer can be explained by two complementary processes. (I) Decanting/filtering or, on the opposite, stirring of colloids. Those processes induce no important Ln fractionation. (2) Exchanges of Ln between solute complexes, colloids and sediments due to the presence of strong chelating agents. Those exchanges fractionate the Ln in the order of their stability constants. Considering the natural Ln fractionation that occurs in the Loire river and in the studied aquifer, the carbonates, the stability constants of which follow the order light Ln < heavy Ln, are the best candidates as natural strong chelating agents. From the hydrodynamic point of view, both tracer experiments and natural Ln concentrations show that the transfer of elements within the alluvial watershed is pulsed by the Loire river movements. During an ascent phase, the elements migrate away from and perpendicularly to the karstic

  19. Magneto, spectral and thermal studies of lanthanum and lanthanide(3) bromide and nitrate complexes of 2,2'bipyridine mono N-oxide

    International Nuclear Information System (INIS)

    Agarwal, R.K.

    1988-01-01

    Lanthanide(3) bromide and nitrate complexes of 2,2'-bipyridine mono N-oxide (BipyNO) having the composition Ln(BipyNO) 3 Br 3 and Ln(BipyNO) 2 (NO 3 ) 3 (Ln=La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Yb) have been prepared and characterized by means of conductance, molecular weight, magnetic and spectral studies. The ligand acts as a bidentate O,N-chelating agent. The coordination number nine or ten for lanthanide ions has been assigned to these complexes. 3 tabs., 25 refs. (author)

  20. A Study of Submicron Grain Boundary Precipitates in Ultralow Carbon 316LN Steels

    Science.gov (United States)

    Downey, S.; Han, K.; Kalu, P. N.; Yang, K.; Du, Z. M.

    2010-04-01

    This article reports our efforts in characterization of an ultralow carbon 316LN-type stainless steel. The carbon content in the material is one-third that in a conventional 316LN, which further inhibits the formation of grain boundary carbides and therefore sensitizations. Our primary effort is focused on characterization of submicron size precipitates in the materials with the electron backscatter diffraction (EBSD) technique complemented by Auger electron spectroscopy (AES). Thermodynamic calculations suggested that several precipitates, such as M23C6, Chi, Sigma, and Cr2N, can form in a low carbon 316LN. In the steels heat treated at 973 K (700 °C) for 100 hours, a combination of EBSD and AES conclusively identified the grain boundary precipitates (≥100 nm) as Cr2N, which has a hexagonal closed-packed crystallographic structure. Increases of the nitrogen content promote formation of large size Cr2N precipitates. Therefore, prolonged heat treatment at relatively high temperatures of ultralow carbon 316LN steels may result in a sensitization.

  1. Virtuální měna v prostředí MMORPG

    OpenAIRE

    Procházka, Ondřej

    2008-01-01

    Tato práce se zabývá virtuální měnou v prostředí počítačových her MMORPG (Massive Multiplayer Online Role-Playing Game). Práce popisuje v tomto prostředí různé systémy virtuální měny, celkovou nabídku, poptávku a směnné kurzy virtuálních měn. Závěrem se práce zabývá skupinou MMORPG her, která neumožňuje nakupování virtuální měny za reálnou.V této části je také znázorněn vznik a stahování peněz z oběhu hry. Analyzován vznik inflace a navrženy možné dílčí úpravy....

  2. The phase transition of the incommensurate phases β-Ln(PO3)3(Ln=Y,Tb...Yb), crystal structures of α-Ln(PO3)3(Ln=Y,Tb...Yb) and Sc(PO3)3

    International Nuclear Information System (INIS)

    Hoeppe, Hennig A.

    2009-01-01

    The incommensurately modulated room-temperature phases β-Ln(PO 3 ) 3 (Ln=Y,Tb...Yb) undergo a topotactic phase transition monitored by vibrational spectroscopy below 180 K leading to α-Ln(PO 3 ) 3 (Ln=Y,Dy...Yb), above 200 K the incommensurate phases are reobtained. The low-temperature phases exhibit a new structure type (α-Dy(PO 3 ) 3 ,P2 1 /c,Z=12,a=14.1422(6),b=20.0793(9),c=10.1018(4)A, β=127.532(3) 0 ). α-Tb(PO 3 ) 3 is isotypic with Gd(PO 3 ) 3 (α-Tb(PO 3 ) 3 ,I2/a,Z=16,a=25.875(6),b=13.460(3),c=10.044(2)A, β=119.13(3) 0 ). The symmetry relations between the involved phases of the phase transition are discussed. The crystal structure of Sc(PO 3 ) 3 is isotypic with that of Lu(PO 3 ) 3 and C-type phosphates. The polyphosphates consist of infinite zig-zag chains of corner-sharing PO 4 tetrahedra, the cations are coordinated sixfold in an almost octahedral arrangement. To confirm the quality of the determined crystal structures the deviation of the phosphate tetrahedra from ideal symmetry was determined and discussed. - Abstract: Basic structure from which all crystal structures of the late lanthanoids' polyphosphates at room temperature and below can be derived.

  3. The phase transition of the incommensurate phases β-Ln(PO3)3(Ln=Y,Tb…Yb), crystal structures of α-Ln(PO3)3(Ln=Y,Tb…Yb) and Sc(PO3)3

    Science.gov (United States)

    Höppe, Hennig A.

    2009-07-01

    The incommensurately modulated room-temperature phases β-Ln(PO3)3(Ln=Y,Tb…Yb) undergo a topotactic phase transition monitored by vibrational spectroscopy below 180 K leading to α-Ln(PO3)3(Ln=Y,Dy…Yb), above 200 K the incommensurate phases are reobtained. The low-temperature phases exhibit a new structure type (α-Dy(PO3)3, P21/c, Z=12,a=14.1422(6), b=20.0793(9),c=10.1018(4) A˚, β=127.532(3)∘). α-Tb(PO3)3 is isotypic with Gd(PO3)3(α-Tb(PO3)3, I2/a,Z=16,a=25.875(6), b=13.460(3), c=10.044(2) A˚, β=119.13(3)∘). The symmetry relations between the involved phases of the phase transition are discussed. The crystal structure of Sc(PO3)3 is isotypic with that of Lu(PO3)3 and C-type phosphates. The polyphosphates consist of infinite zig-zag chains of corner-sharing PO4 tetrahedra, the cations are coordinated sixfold in an almost octahedral arrangement. To confirm the quality of the determined crystal structures the deviation of the phosphate tetrahedra from ideal symmetry was determined and discussed.

  4. On the radiative corrections α2lnα to the positronium decay rate

    International Nuclear Information System (INIS)

    Khriplovich, I.B.; Elkhovskij, A.S.

    1990-01-01

    The radiative corrections ∼α 2 ln α to the positronium decay rate are calculated in the Breit approximation which is shown to be quite adequate for the problem. For orthopositronium the result coincides with the previous one, for parapositronium it differs from the old results. 9 refs

  5. Temporální rozšíření pro PostgreSQL

    OpenAIRE

    Jelínek, Radek

    2015-01-01

    Tato práce se zabývá temporálním rozšířením databázového systému PostgreSQL. Čtenář se tu seznámí se stručným úvodem do temporálních databází, databázovým systémem PostgreSQL, návrhem rozšíření pro PostgreSQL a konkrétní implementací doplněnou příklady. Jsou tu uvedeny i používané temporální databázové systémy a využití temporálních databází v praxi. This thesis is focused on PostgreSQL database system. You can find here introducing to temporal databases, database system PostgreSQL, propos...

  6. Transitory and steady analysis of grounding structures using the LN-FDTD method

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Rodrigo Melo e Silva de; Souza Sobrinho, Carlos Leonidas da S. [Federal University of Para (UFPA), Belem, PA (Brazil). Electrical and Computer Engineering Dept.], Emails: rodrigo@lane.ufpa.br, leonidas@ufpa.br

    2007-07-01

    This work presents an overview of the LN-FDTD method (FDTD in local and non orthogonal coordinate system) to solve Maxwell's Equations. This method has been used to simulate curved grounding structures. Results are obtained by employing the presented methodology and they are compared to reference equations available in literature. (author)

  7. Analyses of Small Punch Creep Deformation Behavior of 316LN Stainless Steel Having Different Nitrogen Contents

    Science.gov (United States)

    Ganesh Kumar, J.; Laha, K.; Ganesan, V.; Prasad Reddy, G. V.

    2018-04-01

    The small punch creep (SPC) behavior of 316LN stainless steel (SS) containing 0.07, 0.11 and 0.14 wt.% nitrogen has been investigated at 923 K. The transient and tertiary SPC deformation of 316LN SS with various nitrogen contents have been analyzed according to the equation proposed for SPC deflection, δ = δ0 + δT (1 - e^{ - κ t} ) + \\dot{δ }s t + δ3 e^[ φ( t - tr ) ]. The relationships among the rate of exhaustion of transient creep (κ), steady-state deflection rate (\\dot{δ }s ) and the rate of acceleration of tertiary creep (φ) revealed the interrelationships among the three stages of SPC curve. The first-order reaction rate theory was found to be applicable to SPC deformation throughout the transient as well as tertiary region, in all the investigated steels. The initial and final creep deflection rates were decreased, whereas time to attain steady-state deflection rate increased with the increase in nitrogen content. By increasing the nitrogen content in 316LN SS from 0.07 to 0.14 wt.%, each stage of SPC was prolonged, and consequently, the values of κ, \\dot{δ }s and φ were lowered. Using the above parameters, the master curves for both transient and tertiary SPC deflections were constructed for 316LN SS containing different nitrogen contents.

  8. Thermal decomposition of heavy rare-earth butanoates, Ln(C3H7CO2)3 (Ln = Er, Tm, Yb and Lu) in argon

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Yue, Zhao; Tang, Xiao

    2016-01-01

    was observed in all four compounds, but its course depends on the rare-earth element. Decomposition to sesquioxides proceeds via the formation of dioxymonocarbonates (Ln2O2CO3) and release of 4-heptanone (C3H7COC3H7) as well as carbon dioxide (CO2) without evidence for an intermediate oxobutanoate stage...... of Ln2O2CO3 and Ln2O3. The stability of this intermediate state seems to decrease with the mass of the rare-earth elements. Complete conversion to Ln2O3 is reached at about 1100 °C. The overall thermal decomposition behaviour of the title compounds is different from previous reports for other rare....... During the decomposition of Ln2O2CO3 into the respective sesquioxides (Ln2O3), an intermediate plateau extending from approximately 550 to 850 °C appears in the TG traces. The overall composition during this stage corresponds approximately to Ln2O2.8(CO3)0.2, but the state is more probably a mixture...

  9. Construction of exact complex dynamical invariant of a two ...

    Indian Academy of Sciences (India)

    system possesses a complex invariant, namely u = ln(p + imωx) − iωt [6]. ... gaining importance for explaining several phenomena [10] such as the resonance .... then H1 and H2 satisfy the Cauchy–Riemann conditions [18] and after employing.

  10. スクッテルド鉱型化合物LnRu4P12(Ln=ランタニド)の構造と電子物性

    OpenAIRE

    内海, 貴徳; 関根, ちひろ; 木村, 繁之; 井上, 雅士; 城谷, 一民

    1999-01-01

    Ternary ruthenium phosphides LnRu4P12 (Ln=La,Ce,Pr,Nd,Sm,Eu,Gd and Tb) with the filled skutterudite-type structure have been prepared at high temperatures and high pressures. The crystal structure of a new compound TbRu4P12 is refined by the Rietveld analysis of the powder X-ray diffraction data. The physical properties of LnRu4P12 have been studied by means of electrical resistivity, magnetic susceptibility, magnetization and specific-heat measurements at low temperatures. LaRu4P12 is a supe...

  11. Digitální nomádství

    OpenAIRE

    Petráková, Veronika

    2017-01-01

    This bachelor thesis deals with the complex introduction of the new trend of livelihood - digital nomadism and examines the economic aspect of this phenomenon. In the theoretical part, digital nomadism is introduced and explains how digital nomads can earn money and what types of work they perform most often. Furthermore, the specifics of distance learning and the specifics of employment of remote workers are described here. In the practical part is described and evaluated questionnaire surve...

  12. Intergranular Corrosion Behavior of 304LN Stainless Steel Heat Treated at 623 K (350 °C)

    Science.gov (United States)

    Singh, Raghuvir; Kumar, Mukesh; Ghosh, Mainak; Das, Gautam; Singh, P. K.; Chattoraj, I.

    2013-01-01

    Low temperature sensitization of 304LN stainless steel from the two pipes, differing slightly in chemical composition, has been investigated; specimens were aged at 623 K (350 °C) for 20,000 hours and evaluated for intergranular corrosion and degree of sensitization. The base and heat-affected zone (HAZ) of the 304LN-1 appear resistant to sensitization, while 304LN-2 revealed a "dual" type microstructure at the transverse section and HAZ. The microstructure at 5.0-mm distance from the fusion line indicates qualitatively less sensitization as compared to that at 2.0 mm. The 304LN-2 base alloy shows overall lower degree of sensitization values as compared to the 304LN-1. A similar trend of degree of sensitization was observed in the HAZ where it was higher in the 304LN-1 as compared to the 304LN-2. The weld zone of both the stainless steels suffered from cracking during ASTM A262 practice E, while the parent metals and HAZs did not show such fissures. A mottled image within the ferrite lamella showed spinodal decomposition. The practice E test and transmission electron microscopy results indicate that the interdendritic regions may suffer from failure due to carbide precipitation and due to the evolution of brittle phase from spinodal decomposition.

  13. [Post-transplant recurrence of glomerulonephritis: a complex clinical case].

    Science.gov (United States)

    Bonucchi, Decenzio; Leonelli, Marco; Damiano, Francesca; Granito, Maria; Ghiandai, Giulia; De Amicis, Sara; Americo, Claudio; Ligabue, Giulia; Albertazzi, Vittorio; Cappelli, Gianni

    2010-01-01

    Lupus nephritis (LN) seldom recurs in a grafted kidney. By contrast, primary membranoproliferative glomerulonephritis (MPGN), which has been included, along with hemolytic uremic syndrome and age-related maculopathy, among the complement dysregulation diseases, has a high recurrence rate and is considered a contraindication to living-donor kidney transplant because of the poor prognosis. We report the case of a young girl with LN-related chronic renal failure who underwent a living donor transplant from her mother. After four months she had a recurrence that did not match the criteria for LN. Graft biopsies and revision of the clinical course pointed to type II MPGN on the basis of a lack of ARA criteria, persistent isolated low C3 levels, and response to plasma therapy. If confirmed by genetic analysis, the patient might benefit from treatment with the monoclonal antibody against the C5-C9 complex, eculizumab.

  14. Ultrafast atomic layer-by-layer oxygen vacancy-exchange diffusion in double-perovskite LnBaCo2O5.5+δ thin films.

    Science.gov (United States)

    Bao, Shanyong; Ma, Chunrui; Chen, Garry; Xu, Xing; Enriquez, Erik; Chen, Chonglin; Zhang, Yamei; Bettis, Jerry L; Whangbo, Myung-Hwan; Dong, Chuang; Zhang, Qingyu

    2014-04-22

    Surface exchange and oxygen vacancy diffusion dynamics were studied in double-perovskites LnBaCo2O5.5+δ (LnBCO) single-crystalline thin films (Ln = Er, Pr; -0.5 atoms in the LnBCO thin films is taking the layer by layer oxygen-vacancy-exchange mechanism. The first principles density functional theory calculations indicate that hydrogen atoms are present in LnBCO as bound to oxygen forming O-H bonds. This unprecedented oscillation phenomenon provides the first direct experimental evidence of the layer by layer oxygen vacancy exchange diffusion mechanism.

  15. Crystal structure of fluorite-related Ln3SbO7 (Ln=La–Dy) ceramics studied by synchrotron X-ray diffraction and Raman scattering

    International Nuclear Information System (INIS)

    Siqueira, K.P.F.; Borges, R.M.; Granado, E.; Malard, L.M.; Paula, A.M. de; Moreira, R.L.; Bittar, E.M.; Dias, A.

    2013-01-01

    Ln 3 SbO 7 (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb and Dy) ceramics were synthesized by solid-state reaction in optimized conditions of temperature and time to yield single-phase ceramics. The crystal structures of the obtained ceramics were investigated by synchrotron X-ray diffraction, second harmonic generation (SHG) and Raman scattering. All samples exhibited fluorite-type orthorhombic structures with different oxygen arrangements as a function of the ionic radius of the lanthanide metal. For ceramics with the largest ionic radii (La–Nd), the ceramics crystallized into the Cmcm space group, while the ceramics with intermediate and smallest ionic radii (Sm–Dy) exhibited a different crystal structure belonging to the same space group, described under the Ccmm setting. The results from SHG and Raman scattering confirmed these settings and ruled out any possibility for the non-centrosymmetric C222 1 space group describing the structure of the small ionic radii ceramics, solving a recent controversy in the literature. Besides, the Raman modes for all samples are reported for the first time, showing characteristic features for each group of samples. - Graphical abstract: Raman spectrum for La 3 SbO 7 ceramics showing their 22 phonon modes adjusted through Lorentzian lines. According to synchrotron X-ray diffraction and Raman scattering, this material belongs to the space group Cmcm. - Highlights: • Ln 3 SbO 7 ceramics belonging to the space groups Cmcm and Ccmm are synthesized. • SXRD, SHG and Raman scattering confirmed the orthorhombic structures. • Ccmm instead of C222 1 is the correct one based on SHG and Raman data

  16. Synthesis, structure, and polymorphism of A{sub 3}LnSi{sub 2}O{sub 7} (A=Na, K; Ln=Sm, Ho, Yb)

    Energy Technology Data Exchange (ETDEWEB)

    Latshaw, Allison M.; Yeon, Jeongho; Smith, Mark D.; Loye, Hans-Conrad zur, E-mail: zurloye@mailbox.sc.edu

    2016-03-15

    Four new members of the A{sub 3}LnSi{sub 2}O{sub 7} family, K{sub 3}SmSi{sub 2}O{sub 7}, Na{sub 3}HoSi{sub 2}O{sub 7}, and two polymorphs of Na{sub 3}YbSi{sub 2}O{sub 7}, are reported. K{sub 3}SmSi{sub 2}O{sub 7} crystallizes in the hexagonal space group P6{sub 3}/mcm, Na{sub 3}HoSi{sub 2}O{sub 7} and Na{sub 3}YbSi{sub 2}O{sub 7} crystallize in the hexagonal space group P6{sub 3}/m, and Na{sub 3}YbSi{sub 2}O{sub 7} crystallizes in the trigonal space group P31c. The Na{sub 3}YbSi{sub 2}O{sub 7} composition that crystallizes in P31c is a new structure type. The magnetic properties for the Ho and Yb analogs are reported. - Graphical abstract: The different structure types and polymorphs of the A{sub 3}LnSi{sub 2}O{sub 7} family reported. - Highlights: • Four new members of the A{sub 3}LnSi{sub 2}O{sub 7} family are presented. • Na{sub 3}YbSi{sub 2}O{sub 7} is reported as two polymorphs, one is a new structure type. • Crystals synthesized out of molten fluoride fluxes.

  17. Li{sub 35}Ln{sub 9}Si{sub 30}N{sub 59}O{sub 2}F with Ln = Ce, Pr - highly condensed nitridosilicates

    Energy Technology Data Exchange (ETDEWEB)

    Lupart, Saskia; Durach, Dajana; Schnick, Wolfgang [Department Chemie, Lehrstuhl fuer Anorganische Festkoerperchemie, Ludwig-Maximilians-Universitaet Muenchen (Germany)

    2011-10-15

    The isotypic nitridosilicates Li{sub 35}Ln{sub 9}Si{sub 30}N{sub 59}O{sub 2}F (Ln = Ce, Pr) were synthesized by reaction of LnF{sub 3} and LiN{sub 3} with Si(NH){sub 2} in liquid lithium flux in weld shut tantalum ampoules. The crystal structures of the isotypic compounds were solved and refined on the basis of single-crystal X-ray diffraction (P anti 3c1 (no. 165), Z = 2; Li{sub 35}Ce{sub 9}Si{sub 30}N{sub 59}O{sub 2}F:, a = 1479.9(2), c = 1538.3(3) pm, R{sub 1} = 0.0526, 1671 data, 175 parameters; Li{sub 35}Pr{sub 9}Si{sub 30}N{sub 59}O{sub 2}F: a = 1477.3(2), c = 1533.9(3) pm, R{sub 1} = 0.0441, 1331 data, 175 parameters). The silicate substructure represents a 3D network of all side corner sharing SiN{sub 4} tetrahedra. At one discrete and not condensed mixed anion position an atomic ratio O:F = 2:1 is assumed in order to achieve charge neutrality. With an atomic ratio Si:N = 30:59, the degree of condensation of the silicate substructure is slightly above κ = 1/2. Accordingly, there are triply crosslinking N{sup [3]} atoms in the silicate substructure. The obtained structures prove that by employing the lithium flux technique not only nitridosilicates with a low degree of condensation can be obtained by using rather mild reaction conditions at low temperatures. Lattice energy calculations (MAPLE) and EDX measurements confirmed the electrostatic bonding interactions and the chemical composition. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Studies on the Ln/sub 2/O/sub 3/ (Ln: rare-earth elements)-SrO-V/sub 2/O/sub 3/ system, 2. Some physical properties for Ln sub(1-x)Sr sub(x)VO sub(3-0. 1x) and SrO. Ln sub(1-x)Sr sub(x)VO sub(3-0. 1x) (Ln: Nd or Eu)

    Energy Technology Data Exchange (ETDEWEB)

    Shin-ike, T [Osaka Dental Coll., Hirakata (Japan); Adachi, G; Shiokawa, J

    1981-01-01

    Electrical and magnetic properties of the perovskite type solid solutions, Ln sub(1-x)Sr sub(x)VO sub(3-0.1x) (Ln: Nd or Eu), and the K/sub 2/NiF/sub 4/ type solid solutions, SrO.Ln sub(1-x)Sr sub(x)VO sub(3-0.1x) (Ln: Nd or Eu), were studied in the temperature range 77 - 300 K. The electrical conductivity increased with x for the perovskite type solid solutions and the reverse behavior was observed for the K/sub 2/NiF/sub 4/ type compounds. All the solid solutions examined exhibited a metal-insulator transition at some values of x. Both Nd sub(1-x)Sr sub(x)VO sub(3-0.1x) and Eu sub(1-x)Sr sub(x)VO sub(3-0.1x) were antiferromagnets having a weak ferromagnetism at a low value of x at a low temperature. The K/sub 2/NiF/sub 4/ type solid solutions revealed a weak ferromagnetism at a high value of x at a low temperature.

  19. Mono(pyridine-N-oxide) analog of DOTA as a suitable organic reagent for a sensitive and selective fluorimetric determination of Ln(III) ions

    Energy Technology Data Exchange (ETDEWEB)

    Vanek, Jakub [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 625 00 Brno (Czech Republic); Lubal, Premysl, E-mail: lubal@chemi.muni.cz [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 625 00 Brno (Czech Republic); Sevcikova, Romana [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Polasek, Miloslav; Hermann, Petr [Department of Inorganic Chemistry, Faculty of Science, Charles University, Hlavova 2030, 128 40, Prague (Czech Republic)

    2012-08-15

    The mono(pyridine-N-oxide) analog of the H{sub 4}dota macrocylic ligand, H{sub 3}do3a-py{sup NO}, is capable of forming thermodynamically stable and kinetically inert Ln(III) complexes. Its Eu(III) and Tb(III) complexes display a strong long-lived fluorescence as a result of the antenna effect of the pyridine-N-oxide fluorophore in the reagent. It is shown that H{sub 3}do3a-py{sup NO} can be used as a fluorogenic reagent for the determination of Eu(III) and Tb(III) at pH 6.5 and c{sub L}=1 mM. At an excitation wavelength of 286 nm, the emission maxima are 615 nm (Eu(III)-complex), and 547 nm (Tb(III)complex). Detection limits are at concentrations around 1.0 {mu}M and linearity of the method spans over 2 orders of magnitude. The method was applied to artificial and real samples (spiked mineral waters, extracts from cathode ray tube luminophore dust) and gave satisfactory results. The method is simple, rapid, and hardly interfered by other metal ions. - Graphical Abstract: A DOTA-like ligand with pyridine-N-oxide pendant arm is used for a quick, selective and sensitive determination of Eu{sup 3+} and Tb{sup 3+} ions through sensitized emission with excitation at 286 nm. The presented fluorimetric method is not interfered by transition metal or other lanthanide(III) ions and has a high dynamic range. Highlights: Black-Right-Pointing-Pointer Quick, selective and sensitive determination of Eu{sup 3+}/Tb{sup 3+} ions was developed. Black-Right-Pointing-Pointer Sensitized emission with excitation at 286 nm through pyridine-N-oxide pendant arm. Black-Right-Pointing-Pointer No interference of transition metal or other Ln(III) ions within high dynamic range.

  20. A comparative study on the compatibility of liquid lead–gold eutectic and liquid lead–bismuth eutectic with T91 and SS 316LN steels

    International Nuclear Information System (INIS)

    Dai, Y.; Gao, W.; Zhang, T.; Platacis, E.; Heinitz, S.; Thomsen, K.

    2012-01-01

    Liquid lead–gold eutectic (LGE) is considered as a potential target material for high power spallation sources. In the present work, the corrosion effects of LGE on T91 and SS 316LN steels have been investigated in comparison with that of liquid lead–bismuth eutectic (LBE) under the same testing conditions. Two tests were conducted at 400 °C for 1800 h and at 450 °C for 1300 h, in which specimens of the two steels were exposed to 1 m/s flowing LGE and LBE. Surface inspections showed that the specimens underwent a mixed corrosion mode of dissolution and oxidation. The results obtained from the SS 316LN specimens are very interesting. Firstly, EDX (electron energy dispersion X-ray spectrometry) analyses revealed that Ni, Cr and Mn have a higher dissolution rate in LGE than in LBE. Secondly, it was observed that LBE attacked strongly on grain-boundaries (GBs) and twin-boundaries (TBs), while LGE did not preferentially attack GBs and TBs. Further, the diffusion or penetration paths of LBE look straight, while those of LGE look like a complex network. In the attacked regions the chemical composition of the steel did not change much in the LBE case, but changed greatly in the LGE case. The T91 specimens exhibited considerably weaker corrosion effects under the present testing conditions.

  1. Study of LnBaCo{sub 2}O{sub 6-d}elta (Ln = Pr, Nd, Sm and Gd) double perovskites as new cathode material for IT-SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, E; Mueller, M; Mogni, L; Caneiro, A, E-mail: mogni@cab.cnea.gov.a [Centro Atomico Bariloche-CNEA, Instituto Balseiro. Av. Bustillo 9500, S. C. de Bariloche 8400 (Argentina)

    2009-05-01

    Oxides with double perovskites structures of general composition LnBaCo{sub 2}O{sub 6-d}elta (Ln = Pr, Nd, Sm and Gd) were synthesized by solid state reaction with the purpose to evaluate new materials to be used as cathodes in intermediate temperature solid oxide fuel cell (IT-SOFC). A preliminary study about electrochemical properties was performed by impedance spectroscopy between 500 and 800 deg. C under atmosphere of pure O{sub 2}. Symmetrical cells were obtained by spray deposition of LnBaCo{sub 2}O{sub 6-d}elta (Ln = Pr, Nd, Sm and Gd) at both sides of a dense ceramic electrolyte. The impedance spectroscopy measurements as a function of temperatures show a hysteresis loop which could be associated to a tetragonal/orthorhombic phase transition. The existence of this transition was corroborated by high temperature X-Ray diffraction and Differential Scanning Calorimetry measurements.

  2. Small-x behavior of the structure function F2 and its slope ∂lnF2/∂ln(1/x) for ''frozen'' and analytic strong-coupling constants

    International Nuclear Information System (INIS)

    Cvetic, G.; Kniehl, B.A.; Kotikov, A.V.

    2009-06-01

    Using the leading-twist approximation of the Wilson operator product expansion with ''frozen'' and analytic versions of the strong-coupling constant, we show that the Bessel-inspired behavior of the structure function F 2 and its slope ∂lnF 2 /∂ln(1/x) at small values of x, obtained for a at initial condition in the DGLAP evolution equations, leads to good agreement with experimental data of deep-inelastic scattering at DESY HERA. (orig.)

  3. Steric hindrances create a discrete linear Dy4 complex exhibiting SMM behaviour.

    Science.gov (United States)

    Lin, Shuang-Yan; Zhao, Lang; Ke, Hongshan; Guo, Yun-Nan; Tang, Jinkui; Guo, Yang; Dou, Jianmin

    2012-03-21

    Two linear tetranuclear lanthanide complexes of general formula [Ln(4)(L)(2)(C(6)H(5)COO)(12)(MeOH)(4)], where HL = 2,6-bis((furan-2-ylmethylimino)methyl)-4-methylphenol, () and Ln(III) = Dy(III) (1) and Gd(III) (2), have been synthesized and characterized. The crystal structural analysis demonstrates that two Schiff-base ligands inhibit the growth of benzoate bridged 1D chains, leading to the isolation of discrete tetranuclear complexes due to their steric hindrances. Every Ln(III) ion is coordinated by eight donor atoms in a distorted bicapped trigonal-prismatic arrangement. Alternating current (ac) susceptibility measurements of complex 1 reveal a frequency- and temperature-dependent out-of-phase signal under zero dc field, typical of single-molecule magnet (SMM) behaviour with an anisotropic barrier Δ(eff) = 17.2 K.

  4. Phase-Tunable Synthesis of Monodisperse YPO4:Ln3+ (Ln = Ce, Eu, Tb) Micro/Nanocrystals via Topotactic Transformation Route with Multicolor Luminescence Properties.

    Science.gov (United States)

    Shao, Baiqi; Feng, Yang; Zhao, Shuang; Yuan, Senwen; Huo, Jiansheng; Lü, Wei; You, Hongpeng

    2017-06-05

    A novel aqueous-based and phase-selected synthetic strategy toward YPO 4 :Ln 3+ (Ln = Ce, Eu, Tb) micro/nanocrystals was developed by selecting specific precursors whose structure topotactically matches with the target ones. It was found that layered yttrium hydroxide (LYH) induced the formation of hexagonal-phased h-YPO 4 ·0.8H 2 O with the crystalline relationship of [001]LYH//[0001]h-YPO 4 ·0.8H 2 O, while the amorphous Y(OH)CO 3 favored the formation of tetragonal-phased t-YPO 4 . We also systematically investigated the influence of Na 2 CO 3 /NaH 2 PO 4 feeding ratio on the evolutions of morphology and size of the h-YPO 4 ·0.8H 2 O sample, and we also obtained a novel mesoporous nanostructure for t-YPO 4 single crystalline with closed octahedron shape for the first time. Besides, the multicolor and phase-dependent luminescence properties of the as-obtained h-YPO 4 ·0.8H 2 O and t-YPO 4 micro/nanocrystals were also investigated in detail. Our work may provide some new guidance in synthesis of nanocrystals with target phase structure by rational selection of precursor with topotactic structural matching.

  5. Relaxor-ferroelectric BaLnZT (Ln = La, Nd, Sm, Eu, and Sc) ceramics for actuator and energy storage application

    Science.gov (United States)

    Ghosh, Sarit K.; Mallick, Kaushik; Tiwari, B.; Sinha, E.; Rout, S. K.

    2018-01-01

    Lead free ceramics Ba1-x Ln2x/3Zr0.3Ti0.7O3 (Ln = La, Nd, Sm, Eu and Sc), x = 0.02-0.10 are investigated for electrostrictive effect and energy storage properties in the proximity of relaxor-paraelectric phase boundary. Relaxor phase evidence from slim hysteresis loop and low remnant polarization are the key parameters responsible for improve the electrostrictive effect and energy storage properties simultaneously. With increase in rare earth content negative strain disappeared and almost hysteresis free strain is achieved. Strain-hysteresis profile in term of S-E, S-E 2 and S-P 2 is used to analyze the electrostrictive behavior of these ceramics. An average strain (S%) ˜ 0.03%, is accomplished at initial concentrations of x = 0.02-0.04 and electrostrictive coefficients (Q 11, and M 11) as well as the energy storage density is improved by a factor of 1.2 and 2.6 respectively when compare with pure (x = 0.0) ceramic. Above x ≥ 0.06, all compositions show a stable behavior which suggested the possibilities of these relaxor ceramics towards high precision actuators and energy storage application.

  6. Structure of trihydrated rare-earth acid diphosphates LnHP2O7·3H2O (Ln=La, Er)

    International Nuclear Information System (INIS)

    Ben Moussa, S.; Ventemillas, S.; Cabeza, A.; Gutierrez-Puebla, E.; Sanz, J.

    2004-01-01

    In trihydrated lanthanum acid-diphosphates LnHP 2 O 7 ·3H 2 O, prepared from acid LnCl 3 and Na 4 P 2 O 7 solutions (pH=1), two crystal forms were obtained. Layered structures of two representative members of this family have been determined by single-crystal X-ray diffraction (XRD) technique. In the case of orthorhombic LaHP 2 O 7 ·3H 2 O (type I), lanthanum cations are ninefold coordinated and diphosphate groups adopt a staggered (alternated) configuration. In the case of triclinic ErHP 2 O 7 ·3H 2 O (type II), erbium cations are eightfold coordinated and diphosphate groups adopt an eclipsed configuration. In agreement with Infrared (IR) spectroscopic data, a bended configuration for diphosphate groups has been deduced. In both structures, one-dimensional chains of edge-sharing rare-earth polyhedra are linked together by diphosphate groups to form the phosphate layers. In both diphosphates, PO 4 and HPO 4 environments have been identified by 31 P MAS-NMR technique. In the two compounds, OH groups of HPO 4 tetrahedra point out of diphosphate planes interacting with adjacent layers. In La-diphosphate, the interaction between HPO 4 groups and water molecules of adjacent layers is favored; however, in Er-diphosphate, the interaction between phosphate acid groups of contiguous layers is produced. Based on structural information deduced, differences detected in IR and NMR spectra of two disphosphates are discussed

  7. Study of electron spectra of lanthanide complexes with carbonyl-containing reagents

    International Nuclear Information System (INIS)

    Tishchenko, M.A.; Gerasimenko, G.I.; Markina, A.I.; Tishchenko, V.V.; Rybalka, V.B.; Tsitko, A.S.

    1990-01-01

    Interaction of lanthanide complexes (Ln=Er, Nd, Ho) of 2-acetylindandione-1,3 with polyphenols was investigated by the methods of electron spectroscopy. Position, intensity, oscillator strengths of supersensitive transitions, formed in the system of different-ligand complexes were determined. 10 refs.; 4 figs.; 3 tabs

  8. Creep rupture strength of activated-TIG welded 316L(N) stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Sakthivel, T., E-mail: tsakthivel@igcar.gov.in [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Vasudevan, M.; Laha, K.; Parameswaran, P.; Chandravathi, K.S.; Mathew, M.D.; Bhaduri, A.K. [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)

    2011-06-01

    316L(N) stainless steel plates were joined using activated-tungsten inert gas (A-TIG) welding and conventional TIG welding process. Creep rupture behavior of 316L(N) base metal, and weld joints made by A-TIG and conventional TIG welding process were investigated at 923 K over a stress range of 160-280 MPa. Creep test results showed that the enhancement in creep rupture strength of weld joint fabricated by A-TIG welding process over conventional TIG welding process. Both the weld joints fractured in the weld metal. Microstructural observation showed lower {delta}-ferrite content, alignment of columnar grain with {delta}-ferrite along applied stress direction and less strength disparity between columnar and equiaxed grains of weld metal in A-TIG joint than in MP-TIG joint. These had been attributed to initiate less creep cavitation in weld metal of A-TIG joint leading to improvement in creep rupture strength.

  9. FItness programy a individuální přístup ve fitness

    OpenAIRE

    Rambous, Milan

    2008-01-01

    Souhrn: Tato diplomová práce se zabývá problematikou fitness programů a individuálru'ho přístupu ve fitness centrech. Celé téma zahrnuje rozpracování postupu při vytváření fitness programů a roli osobního trenéra ve fitness. Dále jsou zde uvedeny specifika některých fitness programů a v empirické části pak příklad dvou individuálních fitness programů. Název práce: Fitness programy a individuálnípřístup ve fitness Title: FITNESS PROGRAMS AND INDIVIDUAL CARE IN FITNESS Cíle práce: 1. podrobný p...

  10. Some crystal chemistry of (Ln,Ce)2CuO4-δ superconductors

    International Nuclear Information System (INIS)

    Goodman, P.; Keating, A.; Myhra, S.; White, T.J.

    1989-01-01

    Compounds of the form (Ln, Sr, Ce) 2 CuO 4-δ (Ln = rare earth element) crystallise as the Nd 2 CuO 4 structure type, K 2 NiF 4 structure type or perfectly and imperfectly ordered intergrowths of these parent structures. These structurally similar phases exhibit superconductivity in which the charge carriers are holes (in Sr-doped material) or electrons (in Ce doped material). In this study, X-ray Photoelectron Spectroscopy (XPS) and High Resolution Electron Microscopy (HREM) were used to investigate the charge balancing mechanisms operating in each superconducting regime and the structural changes accompanying compositional variation. It was found that under slightly reducing conditions charge coupled cation substitutions predominate, whilst at low pO 2 ( -5 atm) perfectly ordered oxygen superlattices form. The structural and electronic changes which accompany deoxygenation were observed in situ during XPS and HREM observations. 29 refs., 8 figs., 3 tabs

  11. Insertion of water into rare earth oxocuprates (Ln)Ba 2Cu 3O 7-δ

    Science.gov (United States)

    Günther, Wulf; Schöllhorn, Robert

    1996-02-01

    The solid state reaction of LnBa 2Cu 3O 7-δ bulk material with water vapour corresponds to a quantitative topotactic reaction of the solid with H 2O to a maximum stoichiometry of LnBa 2Cu 3O 7-δ(H 2O) 1. The reaction proceeds in a temperature window which depends upon the oxygen content (δ) of the starting phase and is correlated with a structural transition via intermediate states. Although the integral copper oxidation state is not affected by the water intercalation, electronic and transport properties are strongly influenced. The insertion of water into these defect perovskites has to be described as a topotactic acid/base process.

  12. Creep rupture strength of activated-TIG welded 316L(N) stainless steel

    International Nuclear Information System (INIS)

    Sakthivel, T.; Vasudevan, M.; Laha, K.; Parameswaran, P.; Chandravathi, K.S.; Mathew, M.D.; Bhaduri, A.K.

    2011-01-01

    316L(N) stainless steel plates were joined using activated-tungsten inert gas (A-TIG) welding and conventional TIG welding process. Creep rupture behavior of 316L(N) base metal, and weld joints made by A-TIG and conventional TIG welding process were investigated at 923 K over a stress range of 160-280 MPa. Creep test results showed that the enhancement in creep rupture strength of weld joint fabricated by A-TIG welding process over conventional TIG welding process. Both the weld joints fractured in the weld metal. Microstructural observation showed lower δ-ferrite content, alignment of columnar grain with δ-ferrite along applied stress direction and less strength disparity between columnar and equiaxed grains of weld metal in A-TIG joint than in MP-TIG joint. These had been attributed to initiate less creep cavitation in weld metal of A-TIG joint leading to improvement in creep rupture strength.

  13. Creep rupture strength of activated-TIG welded 316L(N) stainless steel

    Science.gov (United States)

    Sakthivel, T.; Vasudevan, M.; Laha, K.; Parameswaran, P.; Chandravathi, K. S.; Mathew, M. D.; Bhaduri, A. K.

    2011-06-01

    316L(N) stainless steel plates were joined using activated-tungsten inert gas (A-TIG) welding and conventional TIG welding process. Creep rupture behavior of 316L(N) base metal, and weld joints made by A-TIG and conventional TIG welding process were investigated at 923 K over a stress range of 160-280 MPa. Creep test results showed that the enhancement in creep rupture strength of weld joint fabricated by A-TIG welding process over conventional TIG welding process. Both the weld joints fractured in the weld metal. Microstructural observation showed lower δ-ferrite content, alignment of columnar grain with δ-ferrite along applied stress direction and less strength disparity between columnar and equiaxed grains of weld metal in A-TIG joint than in MP-TIG joint. These had been attributed to initiate less creep cavitation in weld metal of A-TIG joint leading to improvement in creep rupture strength.

  14. N2 gas egress from patients' airways during LN2 spray cryotherapy.

    Science.gov (United States)

    O'Connor, John P; Hanley, Brian M; Mulcahey, Thomas I; Sheets, Ellen E; Shuey, Kacey W

    2017-06-01

    Spray cryotherapy using liquid nitrogen (LN 2 ) is a general surgical tool used to ablate benign or malignant lesions. Adequate egress of the gaseous nitrogen (N 2 ) generated during this process must be provided for safe use when LN 2 is used within the body rather than topically. When delivered to either the gastrointestinal tract (requiring active venting via a suction tube) or body cavities open to room barometric pressure (such as lung airways) allowing for passive venting, the N 2 gas generated from the boiling process must be evacuated. This work will examine the egress of N 2 during procedures requiring passive venting from human airways undergoing liquid nitrogen spray cryotherapy. Venting characteristics for safe N 2 egress will be presented and discussed based on analytical modeling using fluid mechanics simulations and experimental studies of N 2 venting with laboratory and porcine models. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  15. Equivalence of chemical and external pressures in RCoLnO

    Energy Technology Data Exchange (ETDEWEB)

    Prando, Giacomo; Ortix, Carmine; Kataev, Vladislav [Leibniz-Institut fuer Festkoerper- und Werkstoffforschung (IFW), Dresden (Germany); Profeta, Gianni [SPIN-CNR e Dipartimento di Fisica, Universita dell' Aquila (Italy); Sanna, Samuele [Dipartimento di Fisica, Universita di Pavia (Italy); Khasanov, Rustem [Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, Villigen (Switzerland); Pal, Anand; Awana, Veer [National Physical Laboratory (CSIR), New Delhi (India); Buechner, Bernd [Leibniz-Institut fuer Festkoerper- und Werkstoffforschung (IFW), Dresden (Germany); Institut fuer Festkoerperphysik, Technische Universitaet Dresden (Germany); De Renzi, Roberto [Dipartimento di Fisica, Universita di Parma e CNISM (Italy)

    2015-07-01

    We report on the local magnetic properties of the series of ferromagnetic (FM) materials RCoLnO (R = La, Pr, Nd, Sm; Ln = As, P) as investigated by means of muon spin spectroscopy under pressure P and electron spin resonance (ESR). The effect of P is shown to be quantitatively equivalent to the chemical lattice shrinkage triggered by the different ionic radii of R ions. This is verified for both experimental-dependent quantities (i.e., magnetic field at the muon site) and for intrinsically material-dependent properties (i.e., FM critical temperature T{sub C}). Results of ESR in a wide range of temperature and magnetic field clearly display that magnetism is of localized nature, despite the overall metallic behaviour of these materials.

  16. Complexes of o-Vanillin oxime with La(III), Ce(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III), Ho(III) and Yb(III)

    International Nuclear Information System (INIS)

    Dhar, M.L.; Gupta, V.K.; Singh, Onkar

    1988-01-01

    Ten complexes of lanthanides with o-vanillin oxime have been swynthesised and characterised. The composition of the complexes as determined by elemental and thermal analyses, infrared electronic spectral and magnetic moment studies is [Ln(C 8 H 8 NO 3 ) 3 .XH 2 O], where X=2 when Ln=La, Ce, Pr, Nd, Sm and X=3 when Ln=Gd, Dy, Tb, Ho, Yb; C 8 H 8 NO 3 - represents the anion of the ligand. (author). 16 refs., 2 figs., 2 tables

  17. Structuring effects of [Ln6O(OH)8(NO3)6(H2O)12]2+ entities

    International Nuclear Information System (INIS)

    Guillou, O.; Daiguebonne, C.; Calvez, G.; Le Dret, F.; Car, P.-E.

    2008-01-01

    In order to obtain highly porous lanthanide-based coordination polymers we are currently investigating reactions between [Ln 6 O(OH) 8 (NO 3 ) 6 (H 2 O) 12 ] 2+ di-cationic hexanuclear entities and sodium salts of benzene-poly-carboxylic acids. Two new coordination polymers obtained during this study are reported here. In both cases, the hexanuclear entity has been destroyed during the reaction. However the resulting compounds are original thanks to a structuring effect of the poly-metallic complex. The first compound of chemical formula [Y 2 (C 8 H 4 O 4 ) 3 (DMF)(H 2 O)],2DMF crystallizes in the monoclinic system, space group P121/n (n o 14) with a = 16.0975(3) A, b = 14.4605(3) A, c = 17.7197(4) A, β = 92.8504(9) o and Z = 4. The second compound of chemical formula Y 2 (NO 3 ) 2 (C 10 H 2 O 8 )(DMF) 4 crystallizes in the triclinic system, space group P-1 (n o 2) with a = 7.5312(3) A, b = 9.0288(3) A, c = 13.1144(6) A, α = 92.6008(14) o , β = 94.9180(14) o , γ = 112.1824(16) o and Z = 2. Both crystal structures are 2D. Both crystal structures are described and the original structural features are highlighted and related to a potential structuring effect of the hexanuclear precursor

  18. The Laser Welding with Hot Wire of 316LN Thick Plate Applied on ITER Correction Coil Case

    CERN Document Server

    Fang, Chao; Wu, Weiyue; Wei, Jing; Zhang, Shuquan; Li, Hongwei; Dolgetta, N; Libeyre, P; Cormany, C; Sgobba, S

    2014-01-01

    ITER correction coil (CC) cases have characteristics of small cross section, large dimensions, and complex structure. The cases are made of heavy thick (20 mm), high strength and high toughness austenitic stainless steel 316LN. The multi-pass laser welding with hot wire technology is used for the case closure welding, due to its low heat input and deformation. In order to evaluate the reliability of this welding technology, 20 mm welding samples with the same groove structure and welding depth as the cases were welded. High purity argon was used as the shielding gas to prevent oxidation because of the narrowness and depth of the weld. In this paper investigation of, microstructure characteristics and mechanical properties of welded joints using optimized welding parameters are presented. The results show that the base metal, fusion metal, and heat affected zone (HAZ) are all have fully austenitic microstructure, and that the grain size of fusion metal was finer than that of the base metal. The welding resulte...

  19. The heavy quarkonium spectrum at order $m\\alpha_{s}^{5}\\ln\\alpha_{s}$

    CERN Document Server

    Brambilla, Nora; Soto, Joan; Vairo, Antonio

    1999-01-01

    We compute the complete leading-log terms of the next-to-next-to-next-to-leading-order corrections to potential NRQCD. As a by-product we obtain the leading logs at $O(m\\alpha_s^5)$ in the heavy quarkonium spectrum. These leading logs, when $\\Lambda_{QCD} \\ll m\\alpha_s^2$, give the complete $O(m\\alpha_s^5 \\ln \\alpha_s)$ corrections to the heavy quarkonium spectrum.

  20. Structural anomalies, spin transitions and charge disproportionation in LnCoO.sub.3./sub..

    Czech Academy of Sciences Publication Activity Database

    Knížek, Karel; Jirák, Zdeněk; Hejtmánek, Jiří; Henry, P.; André, G.

    2008-01-01

    Roč. 103, č. 7 (2008), 07B703/1-07B703/3 ISSN 0021-8979 R&D Projects: GA ČR GA202/06/0051 Institutional research plan: CEZ:AV0Z10100521 Keywords : LnCoO 3 * neutron diffraction * thermal expansion * spin-state transition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.201, year: 2008

  1. A high-power narrow-linewidth optical parametric oscillator based on PPMgLN

    International Nuclear Information System (INIS)

    Peng, Y F; Wei, X B; Xie, G; Gao, J R; Li, D M; Wang, W M

    2013-01-01

    A high-power and narrow-linewidth tunable optical parametric oscillator based on PPMgLN is presented. The phase matching type e → e + e is used to avoid the walk-off effect and utilize the maximum nonlinear coefficient d 33 (27.4 pm V −1 ) of the PPMgLN crystal (5 mol% MgO doped). When the pump power of the 1064 nm laser is 50 W and the temperature of the PPMgLN crystal is 100 °C, average output power of 15.8 W is obtained with a slope efficiency of 40.6%. The 1.655 μm signal and 2.98 μm idler output powers are 9.5 W and 6.3 W, respectively. The linewidth of the 1.655 μm signal laser is 1.00 nm before compression and 0.05 nm after compression. The compression ratio is 20. The linewidth of the 2.98 μm idler laser is within 0.30–0.63 nm based on theoretical analysis of the linewidth of the 1064 nm pump laser and 1.655 μm signal laser. The output wavelength can be tuned from 1.6 to 1.8 μm and from 3.1 to 2.7 μm by changing the temperature of the 31.2 μm PPMgLN crystal from 30 to 200 °C. (paper)

  2. ''114''-type nitrides LnAl(Si{sub 4-x}Al{sub x})N{sub 7}O{sub δ} with unusual [AlN{sub 6}] octahedral coordination

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Saifang; Ouyang, Xin [School of Materials Science and Technology, China University of Geosciences, Beijing (China); Department of Chemical and Materials Engineering, University of Auckland (New Zealand); Huang, Zhaohui; Fang, Minghao; Liu, Yan-gai [School of Materials Science and Technology, China University of Geosciences, Beijing (China); Cao, Peng; Gao, Wei [Department of Chemical and Materials Engineering, University of Auckland (New Zealand); Zujovic, Zoran; Soehnel, Tilo [School of Chemical Sciences, University of Auckland (New Zealand); Price, Jason R. [Australian Synchrotron, Clayton, VIC (Australia); Avdeev, Maxim [Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Que, Meidan [School of Electronic and Information Engineering, Xi' an Jiaotong University (China); Suzuki, Furitsu; Kido, Tsuyoshi; Kaji, Hironori [Institute for Chemical Research, Kyoto University (Japan)

    2017-03-27

    Aluminum-nitrogen six-fold octahedral coordination, [AlN{sub 6}], is unusual and has only been seen in the high-pressure rocksalt-type aluminum nitride or some complex compounds. Herein we report novel nitrides LnAl(Si{sub 4-x}Al{sub x})N{sub 7}O{sub δ} (Ln=La, Sm), the first inorganic compounds with [AlN{sub 6}] coordination prepared via non-high-pressure synthesis. Structure refinements of neutron powder diffraction and single-crystal X-ray diffraction data show that these compounds crystallize in the hexagonal Swedenborgite structure type with P6{sub 3}mc symmetry where Ln and Al atoms locate in anticuboctahedral and octahedral interstitials, respectively, between the triangular and Kagome layers of [SiN{sub 4}] tetrahedra. Solid-state NMR data of high-purity La-114 powders confirm the unusual [AlN{sub 6}] coordination. These compounds are the first examples of the ''33-114'' sub-type in the ''114'' family. The additional site for over-stoichiometric oxygen in the structure of 114-type compounds was also identified. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Photogalvanic self-pulsing of electro-wetting of LC droplet on LN-crystal

    International Nuclear Information System (INIS)

    Kukhtarev, N; Kukhtareva, T; Geng, J; Zhang, XZ; Xu, JJ

    2017-01-01

    Photogalvanic current photoinduced by CW laser illumination of Fe-doped LN reveals quasi-periodic pulsing due to microplasmas discharges. This transformation of constant external influence into periodic response is interesting as example of self-excited systems, resembling pulsations of biological systems (including heart beats). Microplasmas is also interesting for potential applications in various fields, such as surface treatment, sterilization, water splitting, light sources, micro jets. Self-pulsing regime of microplasmas discharges in microhollow cathode discharges was observed and modeled in plasmas physics. In this paper, we analyze self-pulsing of photogalvanic current visualized by dynamic electrowetting in a simple LC-cell, formed by a nematic LC droplet placed on Fe-doped LN crystal. We have developed model of self-pulsing regime based on nonlinear discharge resistance. Experimental phase-space plot may be used to find parameters of the nonlinear discharge resistance. In the dynamic modeling contributions from both photogalvanic and pyroelectric effect are included. The analysis of dynamic regime reveals that a current pulse (in microsecond range) have asymmetric shape with extremely sharp rise with longer decay time. These self-pulsations are visualized by reflection of laser light from a LC droplet placed on LN-crystal. Reflected interference patterned was modulated by the dynamic electro-wetting effect. (paper)

  4. Separation of minor actinides from a genuine MA/LN fraction

    International Nuclear Information System (INIS)

    Satmark, B.; Courson, O.; Malmbeck, R.; Pagliosa, G.; Romer, K.; Glatz, J.P.

    2001-01-01

    Separation of the trivalent Minor Actinides (MA), Am and Cm, has been performed from a genuine MA(III) + Ln(III) solution using Bis-Triazine-Pyridine (BTP) as organic extractant. The representative MA/Ln fraction was obtained from a dissolved commercial LWR fuel (45.2 GWd/tM) submitted subsequently too a PUREX process followed by a DIAMEX process. A centrifugal extractor set-up (16-stages), working in a continuous counter-current mode, was used for the liquid-liquid separation. In the nPr-BTP process, feed decontamination factors for Am and Cm above 96 and 65, respectively were achieved. The back-extraction was more efficient for Am (99.1% recovery) than for Cm (97.5%). This experiment, using the Bis-Triazine-Pyridine molecule is the first successful demonstration of the separation of MA from lanthanides in a genuine MA/Ln fraction with a nitric acid concentration of ca. 1 M. It represents an important break through in the difficult field of minor actinide partitioning of high level liquid waste. (author)

  5. Research on damage evolution and damage model of 316LN steel during forging

    Energy Technology Data Exchange (ETDEWEB)

    Duan, X.W., E-mail: dxwmike1998@sina.com; Liu, J.S.

    2013-12-20

    The tensile tests and unloading tensile experiments of 316LN steel were conducted. The damage evolution processes were investigated by optical microscope. The fracture was studied using a Scanning Electron Microscope (SEM) and optical microscope, of which, the chemical compositions were analyzed by Energy Dispersive Spectrometer (EDS). The results show that voids nucleate by decohesion of Al{sub 2}O{sub 3} inclusions–matrix interface and mainly along the grain boundary, especially, at triangular grain boundary junctions. The tensile processes were simulated by Deform2D under different deformation conditions. The critical damage values were obtained. The model between the critical damage value, temperature and strain rate was established by regression analysis. A combination of numerical simulation and upsetting experiments was applied for verifying the accuracy and reliability of critical damage value. These damage values can be used to predict the initiation of voids during 316LN steel hot forging. So, they have important instructional effects on designing forging technology of 316LN steel.

  6. NMR studies of structures of lanthanide dicarboxylate complexes in solution

    International Nuclear Information System (INIS)

    Choppin, G.R.; Kullberg, L.

    PMR pand 13 C shift data were measured for complexes of Pr(III), Eu(III) and Yb(III) with ethylene 1,2-dioxydiacetate (EDODA), ethylene 1,2-dithiodiacetate (EDSDA), and ethylene, 1,2-diaminodiacetate (EDDA). Solubility problems limited analysis of the EDSDA and EDDA data to qualitative evaluation. In the EDSDA complexes, the data indicate that the sulfur atoms do not participate in bonding to the lanthanide cations. Moreover, both carboxylate groups seem to bind Pr and Eu while Yb interacts with only a single carboxylate group. The EDDA complexes are tetradentate with long lived (NMR scale) Ln-N bonds. Shift theory allowed more quantitative analysis of the EDODA complexes. They are tetradentate with a puckered chelate ring and Ln-O(ether) distances of 2.3 A

  7. Lanthanide complexes of macrocyclic polyoxovanadates by VO4 units: synthesis, characterization, and structure elucidation by X-ray crystallography and EXAFS spectroscopy.

    Science.gov (United States)

    Nishio, Masaki; Inami, Shinnosuke; Katayama, Misaki; Ozutsumi, Kazuhiko; Hayashi, Yoshihito

    2012-01-16

    Reactions of a tetravanadate anion, [V(4)O(12)](4-), with a series of lanthanide(III) salts yield three types of lanthanide complexes of macrocyclic polyoxovanadates: (Et(4)N)(6)[Ln(III)V(9)O(27)] [Ln = Nd (1), Sm (2), Eu (3), Gd (4), Tb (5), Dy (6)], (Et(4)N)(5)[(H(2)O)Ho(III)(V(4)O(12))(2)] (7), and (Et(4)N)(7)[Ln(III)V(10)O(30)] [Ln = Er (8), Tm (9), Yb (10), Lu (11)]. Lanthanide complexes 1-11 are isolated and characterized by IR, elemental analysis, single-crystal X-ray diffraction, and extended X-ray absorption fine structure spectroscopy (EXAFS). Lanthanide complexes 1-6 are composed of a square-antiprism eight-coordinated Ln(III) center with a macrocyclic polyoxovanadate that is constructed from nine VO(4) tetrahedra through vertex sharing. The structure of 7 is composed of a seven-coordinated Ho(III) center, which exhibits a capped trigonal-prism coordination environment by the sandwiching of two cyclic tetravanadates with a capping H(2)O ligand. Lanthanide complexes 8-11 have a six-coordinated Ln(III) center with a 10-membered vanadate ligand. The structural trend to adopt a larger coordination number for a larger lanthanide ion among the three types of structures is accompanied by a change in the vanadate ring sizes. These lanthanide complexes are examined by EXAFS spectroscopies on lanthanide L(III) absorption edges, and the EXAFS oscillations of each of the samples in the solid state and in acetonitrile are identical. The Ln-O and Ln···V bond lengths obtained from fits of the EXAFS data are consistent with the data from the single-crystal X-ray studies, reflecting retention of the structures in acetonitrile.

  8. Synthesis, surface modification/decoration of luminescent–magnetic core/shell nanomaterials, based on the lanthanide doped fluorides (Fe3O4/SiO2/NH2/PAA/LnF3)

    International Nuclear Information System (INIS)

    Runowski, Marcin; Lis, Stefan

    2016-01-01

    The synthesized magnetite nanoparticles (10–15 nm) were successfully coated with amine modified silica nanoshell, which led to the formation of core/shell type nanostructures (30–50 nm). The as-prepared nanoparticles were surface modified with polyacrylic acid (PAA) via electrostatic interactions of –NH 2 and –COOH groups. Afterwards, the surface PAA molecules acted as complexing agents of the introduced lanthanide (Ln 3+ ) ions. Subsequently, the as-prepared nanostructures were surface decorated with luminescent LnF 3 nanoparticles, forming Eu 3+ or Tb 3+ doped Fe 3 O 4 /SiO 2 /NH 2 /PAA/LnF 3 nanomaterials (50–100 nm). The obtained luminescent–magnetic products exhibited simultaneously bright red or green emission under UV lamp irradiation (λ ex =254 nm), and a response for the applied magnetic field (strong magnet attracts the colloidal particles, dispersed in aqueous medium). After the synthesis, properties of the nanomaterials were investigated by powder X-ray diffraction (XRD) technique, transmission electron microscopy (TEM), infrared spectroscopy (IR) and spectrofluorometry (analysis of excitation/emission spectra and luminescence decay curves). Such advanced nanomaterials can be potentially used in multimodal imaging, targeted therapies and as multifunctional contrast agents, novel luminescent–magnetic tracers, protection of documents, etc. - Highlights: • Luminescent–magnetic nanomaterials Fe 3 O 4 /SiO 2 /NH 2 /PAA/LnF 3 were synthesized. • Core/shell nanostructures were obtained by surface modification of nanoparticles. • Luminescent lanthanide fluoride nanoparticles doped with Eu 3+ and Tb 3+ ions. • Multifunctional core/shell nanostructures exhibited red or green emission. • Nanomaterials formed stable aqueous colloids.

  9. Uranyl and/or rare-earth mellitates in extended organic-inorganic networks: A unique case of hetero-metallic cation-cation interaction with U-VI=O-Ln(III) bonding (Ln = Ce, Nd)

    International Nuclear Information System (INIS)

    Volkringer, Christophe; Henry, Natacha; Grandjean, Stephane; Loiseau, Thierry

    2012-01-01

    A series of uranyl and lanthanide (trivalent Ce, Nd) mellitates (mel) has been hydrothermally synthesized in aqueous solvent. Mixtures of these 4f and 5f elements also revealed the formation of a rare case of lanthanide-uranyl coordination polymers. Their structures, determined by XRD single-crystal analysis, exhibit three distinct architectures. The pure lanthanide mellitate Ln 2 (H 2 O) 6 (mel) possesses a 3D framework built up from the connection of isolated LnO 6 (H 2 O) 3 polyhedra (tri-capped trigonal prism) through the mellitate ligand. The structure of the uranyl mellitate (UO 2 ) 3 (H 2 O) 6 - (mel).11.5H 2 O is lamellar and consists of 8-fold coordinated uranium atoms linked to each other through the organic ligand giving rise to the formation of a 2D 3 6 net. The third structural type, (UO 2 ) 2 Ln(OH)(H 2 O) 3 (mel).2.5H 2 O, involves direct oxygen bondings between the lanthanide and uranyl centers, with the isolation of a hetero-metallic dinuclear motif. The 9-fold coordinated Ln cation, LnO 5 (OH)(H 2 O) 3 , is linked to the 7-fold coordinated uranyl (UO 2 )O-4(OH) (pentagonal bipyramid) via one μ 2 -hydroxo group and one μ 2 -oxo group. The latter is shared between the uranyl bonding (U=O = 1.777(4)1.779(6) angstrom) and a long Ln-O bonding (Ce-O = 2.822(4) angstrom; Nd-O = 2.792(6) angstrom). This unusual linkage is a unique illustration of the so-called cation cation interaction associating 4f and 5f metals. The dinuclear motif is then further connected through the mellitate ligand, and this generates organic inorganic layers that are linked to each other via discrete uranyl (UO 2 )O 4 units (square bipyramid), which ensure the three-dimensional cohesion of the structure. The mixed U-Ln carboxylate is thermally decomposed from 260 to 280 degrees C and then transformed into the basic uranium oxide (U 3 O 8 ) together with U-Ln oxide with the fluorite structural type ('(Ln,U)O 2 '). At 1400 degrees C, only fluorite type '(Ln,U)O 2 ' is formed with

  10. Synthesis, structures, and luminescent properties of lanthanide complexes with triphenylphospine oxide

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yan; Xu, Shan; Wang, Xin; Li, Yue-Xue; Jin, Qiong-Hua [Department of Chemistry, Capital Normal University, Beijing (China); Liu, Min [The College of Materials Science and Engineering, Beijing University of Technology (China); Xin, Xiu-Lan [School of Food and Chemical Engineering, Beijing Technology and Business University (China)

    2017-07-03

    Seven lanthanide complexes [Ln(OPPh{sub 3}){sub 3}(NO{sub 3}){sub 3}] (1-3) (OPPh{sub 3} = triphenylphosphine oxide, Ln = Nd, Sm, Gd), [Dy(OPPh{sub 3}){sub 4}(NO{sub 3}){sub 2}](NO{sub 3}) (4), [Ln(OPPh{sub 3}){sub 3}(NO{sub 3}){sub 3}]{sub 2} (5-7) (Ln = Pr, Eu, Gd) were synthesized by the reactions of different lanthanide salts and OPPh{sub 3} ligand in the air. These complexes were characterized by single-crystal X-ray diffraction analysis, elemental analysis, IR and fluorescence spectra. Structure analysis shows that complexes 1-4 are mononuclear complexes formed by OPPh{sub 3} ligands and nitrates. The asymmetric units of complexes 5-7 consist of two crystallographic-separate molecules. Complex 1 is self-assembled to construct a 2D layer-structure of (4,4) net topology by hydrogen bond interactions. The other complexes show a 1D chain-like structure that was assembled by OPPh{sub 3} ligands and nitrate ions through C-H..O interactions. Solid emission spectra of compounds 4 and 6 are assigned to the characteristic fluorescence of Tb{sup 3+} (λ{sub em} = 480, 574 nm) and Eu{sup 3+} (λ{sub em} = 552, 593, 619, 668 nm). (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Observation of Vacancies, Faults, and Superstructures in Ln5Mo2O12 (Ln = La, Y, and Lu) Compounds with Direct Mo-Mo Bonding.

    Science.gov (United States)

    Colabello, Diane M; Sobalvarro, Elizabeth M; Sheckelton, John P; Neuefeind, Joerg C; McQueen, Tyrel M; Khalifah, Peter G

    2017-11-06

    Among oxide compounds with direct metal-metal bonding, the Y 5 Mo 2 O 12 (A 5 B 2 O 12 ) structural family of compounds has a particularly intriguing low-dimensional structure due to the presence of bioctahedral B 2 O 10 dimers arranged in one-dimensional edge-sharing chains along the direction of the metal-metal bonds. Furthermore, these compounds can have a local magnetic moment due to the noninteger oxidation state (+4.5) of the transition metal, in contrast to the conspicuous lack of a local moment that is commonly observed when oxide compounds with direct metal-metal bonding have integer oxidation states resulting from the lifting of orbital degeneracy typically induced by the metal-metal bonding. Although a monoclinic C2/m structure has been previously proposed for Ln 5 Mo 2 O 12 (Ln = La-Lu and Y) members of this family based on prior single crystal diffraction data, it is found that this structural model misses many important structural features. On the basis of synchrotron powder diffraction data, it is shown that the C2/m monoclinic unit cell represents a superstructure relative to a previously unrecognized orthorhombic Immm subcell and that the superstructure derives from the ordering of interchangeable Mo 2 O 10 and LaO 6 building blocks. The superstructure for this reason is typically highly faulted, as evidenced by the increased breadth of superstructure diffraction peaks associated with a coherence length of 1-2 nm in the c* direction. Finally, it is shown that oxygen vacancies can occur when Ln = La, producing an oxygen deficient stoichiometry of La 5 Mo 2 O 11.55 and an approximately 10-fold reduction in the number of unpaired electrons due to the reduction of the average Mo valence from +4.5 to +4.05, a result confirmed by magnetic susceptibility measurements. This represents the first observation of oxygen vacancies in this family of compounds and provides an important means of continuously tuning the magnetic interactions within the one

  12. NMR and TRLFS studies of Ln(iii) and An(iii) C5-BPP complexes† †Electronic supplementary information (ESI) available: LIFDI-MS spectra and additional NMR spectra. See DOI: 10.1039/c4sc03103b

    Science.gov (United States)

    Beele, Björn B.; Geist, Andreas; Müllich, Udo; Kaden, Peter; Panak, Petra J.

    2015-01-01

    C5-BPP is a highly efficient N-donor ligand for the separation of trivalent actinides, An(iii), from trivalent lanthanides, Ln(iii). The molecular origin of the selectivity of C5-BPP and many other N-donor ligands of the BTP-type is still not entirely understood. We present here the first NMR studies on C5-BPP Ln(iii) and An(iii) complexes. C5-BPP is synthesized with 10% 15N labeling and characterized by NMR and LIFDI-MS methods. 15N NMR spectroscopy gives a detailed insight into the bonding of C5-BPP with lanthanides and Am(iii) as a representative for trivalent actinide cations, revealing significant differences in 15N chemical shift for coordinating nitrogen atoms compared to Ln(iii) complexes. The temperature dependence of NMR chemical shifts observed for the Am(iii) complex indicates a weak paramagnetism. This as well as the observed large chemical shift for coordinating nitrogen atoms show that metal–ligand bonding in Am(C5-BPP)3 has a larger share of covalence than in lanthanide complexes, confirming earlier studies. The Am(C5-BPP)3 NMR sample is furthermore spiked with Cm(iii) and characterized by time-resolved laser fluorescence spectroscopy (TRLFS), yielding important information on the speciation of trace amounts of minor complex species. PMID:29560242

  13. Synthesis and characterisation of the n = 2 Ruddlesden–Popper phases Ln2Sr(Ba)Fe2O7 (Ln = La, Nd, Eu)

    International Nuclear Information System (INIS)

    Gurusinghe, Nicola N.M.; Figuera, Juand de la; Marco, José F.; Thomas, Michael F.; Berry, Frank J.; Greaves, Colin

    2013-01-01

    Graphical abstract: - Highlights: • Some Ruddlesden–Popper phases have been characterised. • Substitution on the A site influences cationic order. • The magnetic moment redirects with temperature - Abstract: A series of n = 2 Ruddlesden–Popper phases A 2 B 2 O 7 of composition Ln 2 Sr(Ba)Fe 2 O 7 (Ln = La, Nd, Eu) have been prepared. La 2 SrFe 2 O 7 and La 2 BaFe 2 O 7 crystallise in the tetragonal space group I4/mmm. The structures of Eu 2 SrFe 2 O 7 and Nd 2 SrFe 2 O 7 are best described in space group P4 2 /mnm. Substitution on the A site with smaller lanthanide- and larger alkaline metal- ions leads to enhanced cationic order in these phases and reflects increasing differences in cationic radii. All the compounds are antiferromagnetically ordered between 298 and 2 K. In La 2 SrFe 2 O 7 the magnetic moment lies along [1 1 0] at all temperatures between 298 and 2 K whereas in La 2 BaFe 2 O 7 the magnetic moment at 298 K lies along the crystallographic x-axis but redirects from the [1 0 0] to the [1 1 0] direction between 210 and 190 K and is retained in this direction until 2 K. In Nd 2 SrFe 2 O 7 the magnetic moment at 298 K lies along [1 1 0] but rotates from [1 1 0] to [0 0 1] between 17 and 9 K. A series of 57 Fe Mössbauer spectra recorded from La 2 SrFe 2 O 7 between 290 and 600 K indicate a magnetic ordering temperature of T N ≥ 535 K

  14. Dissolution of LnYSiAlO glass (Ln=La or Ce) in aqueous media. Part 3. Influence of β irradiation on structure and hydrolysis mechanisms

    International Nuclear Information System (INIS)

    Gavarini, S.; Carrot, F.; Trocellier, P.; Boizot, B.; Matzen, G.

    2003-01-01

    LnYSiAlO glasses (Ln=La or Ce) are considered as potential matrices for the specific storage of minor actinides. β particles emitted during the disintegration of fission products may cause important modifications to the glass network through electronic excitation and ionization. The influence of these processes on the structure of two analogous compositions of glass, involving La or Ce, and the consequences for their chemical durability were studied. Monoliths of glasses were irradiated with electrons that had been accelerated to 2.5 MeV and samples were then leached in static bidistilled water for one month at 90 C. Raman spectrometry, 27 Al MAS-NMR and EPR spectrometry experiments, performed after irradiation, globally indicated weak structural modifications. The two main effects of irradiation were an increase of the (Al IV )/(Al VI +Al V ) ratio and the formation of a paramagnetic center in the case of La-glass (g∼1.99). The former observation could indicate a slight migration and segregation of the rare earth, preferentially surrounded by highly charged Al V and Al VI units initially. The second point could be correlated with a change in the oxidation state of one of the La-glass component. The reason why no similar paramagnetic center is created during irradiation for Ce-glass is not well understood but a possible charge trapping process involving Ce(III)/Ce(IV) is developed. Finally, leaching solution analysis indicated that normalized elemental releases are almost unchanged after irradiation for both of the La and Ce-glass. The globally weak influence of β irradiation on this family of glass is subsequent to the low mobility of the major components that form high field strength bonds with oxygen

  15. Host-sensitized luminescence properties in CaNb2O6:Ln(3+) (Ln(3+) = Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+)) phosphors with abundant colors.

    Science.gov (United States)

    Li, Kai; Liu, Xiaoming; Zhang, Yang; Li, Xuejiao; Lian, Hongzhou; Lin, Jun

    2015-01-05

    A series of Ln(3+) (Ln(3+) = Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+)) ion doped CaNb2O6 (CNO) phosphors have been prepared via the conventional high-temperature solid-state reaction route. The X-ray diffraction (XRD) and structure refinement, diffuse reflection, photoluminescence (PL), and fluorescent decay curves were used to characterize the as-prepared samples. Under UV radiation, the CNO host present a broad emission band from about 355 to 605 nm centered around 460 nm originating from the NbO6 octahedral groups, which has spectral overlaps with the excitation of f-f transitions of Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+) in CNO:Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+) samples. They show both host emission and respective emission lines derived from the characteristic f-f transitions of activators, which present different emission colors owing to the energy transfer from the NbO6 group in the host to Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+) with increasing activator concentrations. The decreases of decay lifetimes of host emissions in CNO:Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+) demonstrate the energy transfer from the hosts to Eu(3+)/Tb(3+)/Dy(3+)/Sm(3+). The energy transfer mechanisms in CNO:Eu(3+)/Tb(3+)/Dy(3+) phosphors have been determined to be a resonant type via dipole-dipole mechanisms. For CNO:Sm(3+), the metal-metal charge transfer transition (MMCT) might contribute to the different variations of decay lifetimes and emission intensity from CNO:Eu(3+)/Tb(3+)/Dy(3+) samples. The best quantum efficiency is 71.2% for CNO:0.01/0.02Dy(3+). The PL properties of as-prepared materials indicate the promising application in UV-pumped white-emitting lighting diodes field.

  16. Expanding rare-earth oxidation state chemistry to molecular complexes of holmium(II) and erbium(II).

    Science.gov (United States)

    MacDonald, Matthew R; Bates, Jefferson E; Fieser, Megan E; Ziller, Joseph W; Furche, Filipp; Evans, William J

    2012-05-23

    The first molecular complexes of holmium and erbium in the +2 oxidation state have been generated by reducing Cp'(3)Ln [Cp' = C(5)H(4)SiMe(3); Ln = Ho (1), Er (2)] with KC(8) in the presence of 18-crown-6 in Et(2)O at -35 °C under argon. Purification and crystallization below -35 °C gave isomorphous [(18-crown-6)K][Cp'(3)Ln] [Ln = Ho (3), Er (4)]. The three Cp' ring centroids define a trigonal-planar geometry around each metal ion that is not perturbed by the location of the potassium crown cation near one ring with K-C(Cp') distances of 3.053(8)-3.078(2) Å. The metrical parameters of the three rings are indistinguishable within the error limits. In contrast to Ln(2+) complexes of Eu, Yb, Sm, Tm, Dy, and Nd, 3 and 4 have average Ln-(Cp' ring centroid) distances only 0.029 and 0.021 Å longer than those of the Ln(3+) analogues 1 and 2, a result similar to that previously reported for the 4d(1) Y(2+) complex [(18-crown-6)K][Cp'(3)Y] (5) and the 5d(1) La(2+) complex [K(18-crown-6)(Et(2)O)][Cp″(3)La] [Cp″ = 1,3-(Me(3)Si)(2)C(5)H(3)]. Surprisingly, the UV-vis spectra of 3 and 4 are also very similar to that of 5 with two broad absorptions in the visible region, suggesting that 3-5 have similar electron configurations. Density functional theory calculations on the Ho(2+) and Er(2+) species yielded HOMOs that are largely 5d(z(2)) in character and supportive of 4f(10)5d(1) and 4f(11)5d(1) ground-state configurations, respectively.

  17. Tetraphenylborate as a non - coordinating anion in hexamethyphosphoramine (HMPA) and tetramethylurea (TMU) lanthanide complexes

    International Nuclear Information System (INIS)

    Kuya, M.K.; Serra, O.A.

    1979-01-01

    The synthesis of the HMPA and TMU complexes of rare earth ions using tetraphenylborate, a non-coordinating anion, as a precipitating agent is reported. The compounds obtained conform to the general formula LnL 6 (B PHI 4 ) 3 (Ln=Ce-Lu,Y, whe L=HMPA and Ln=nd, Sm,Eu,Er,Y when L=TMU). The characterization by conductance, infrared and visible measurements is consistent with the lack of donor capacity of tetraphenylborate ion, and with a coordination number six in a nearly octahedral site symmetry for both type of compounds. The TMU complexes seem to be more stable than the corresponding HMPA ones, indicating that the steric factor can be more important than the donor capacity of the ligands in this type of lanthanide compounds. (author) [pt

  18. Hydrothermal synthesis, structure, and optical properties of two nanosized Ln{sub 26} rate at CO{sub 3} (Ln=Dy and Tb) cluster-based lanthanide-transition-metal-organic frameworks (Ln MOFs)

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Huang, Lian; Miao, Hao; Wan, Hong Xiang; Mei, Hua; Liu, Ying [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University (China); Xu, Yan [State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University (China); State Key Laboratory of Coordination Chemistry, Nanjing Tech University (China)

    2015-02-16

    Two Ln{sub 26} rate at CO{sub 3} (Ln=Dy and Tb) cluster-based lanthanide-transition-metal-organic frameworks (Ln MOFs) formulated as [Dy{sub 26}Cu{sub 3}(Nic){sub 24}(CH{sub 3}COO){sub 8}(CO{sub 3}){sub 11}(OH){sub 26}(H{sub 2}O){sub 14}]Cl . 3 H{sub 2}O (1; HNic=nicotinic acid) and [Tb{sub 26}NaAg{sub 3}(Nic){sub 27}(CH{sub 3}COO){sub 6}(CO{sub 3}){sub 11}(OH){sub 26}Cl(H{sub 2}O){sub 15}] . 7.5 H{sub 2}O (2) have been successfully synthesized by hydrothermal methods and characterized by IR, thermogravimetric analysis (TGA), elemental analysis, and single X-ray diffraction. Compound 1 crystallizes in the monoclinic space group Cc with a=35.775(12) Aa, b=33.346(11) Aa, c=24.424(8) Aa, β=93.993(5) , V=29065(16) Aa{sup 3}, whereas 2 crystallizes in the triclinic space group P anti 1 with a=20.4929(19) Aa, b=24.671(2) Aa, c=29.727(3) Aa, α=81.9990(10) , β=88.0830(10) , γ=89.9940(10) , V=14875(2) Aa{sup 3}. Structural analysis indicates the framework of 1 is a 3D perovskite-like structure constructed out of CO{sub 3} rate at Dy{sub 26} building units and Cu{sup +} centers by means of nicotinic acid ligand bridging. In 2, however, nanosized CO{sub 3} rate at Tb{sub 26} units and [Ag{sub 3}Cl]{sup 2+} centers are connected by Nic{sup -} bridges to give rise to a 2D structure. It is worth mentioning that this kind of 4d-4f cluster-based MOF is quite rare as most of the reported analogous compounds are 3d-4f ones. Additionally, the solid-state emission spectra of pure compound 2 at room temperature suggest an efficient energy transfer from the ligand Nic{sup -} to Tb{sup 3+} ions, which we called the ''antenna effect''. Compound 2 shows a good two-photon absorption (TPA) with a TPA coefficient of 0.06947 cm GM{sup -1} (1 GM = 10{sup -50} cm{sup 4} s photon{sup -1}), which indicates that compound 2 might be a good choice for third-order nonlinear optical materials. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Gaseous complexes of trichlorides, tetrachlorides, and pentachlorides with aluminium chloride

    International Nuclear Information System (INIS)

    Schaefer, H.; Floerke, U.

    1981-01-01

    The equilibria MClsub(x,s) + 0.5nAl 2 Clsub(6,g) = MClsub(x).nAlClsub(3,g) have been determined with the solid chlorides TiCl 3 , VCl 3 , ScCl 3 , NdCl 3 , ZrCl 4 , TaCl 5 , (NbCl 5 ) (double cells which contain AlCl 3 and MClsub(x) respectively; mass spectrometer). The complexes contain 1 AlCl 3 /MClsub(x). ZrAlCl 10 molecules also have been observed. With MoCl 3 and WCl 6 AlCl 3 complexes could not be found. The ΔH 0 and ΔS 0 values have been discussed in connection with literature data. Complexes containing more as 1 AlCl 3 /LnCl 3 (Ln = Nd, Sm, Gd) also are included in the discussion. (author)

  20. Host composition dependent tunable multicolor emission in the single-phase Ba2(Ln1-zTbz)(BO3)2Cl:Eu phosphors

    NARCIS (Netherlands)

    Xia, Z.; Zhuang, J.; Meijerink, A.; Jing, X.

    2013-01-01

    A new strategy based on the host composition design has been adopted to obtain efficient color-tunable emission from Ba2Ln0.97−zTbz(BO3)2Cl:0.03Eu (Ln = Y, Gd and Lu, z = 0–0.97) phosphors. This study reveals that the single-phase Ba2Ln1−zTbz(BO3)2Cl compounds can be applied to use allowed Eu2+

  1. Facile in-situ reduction: Crystal growth and magnetic studies of reduced vanadium (III/IV) silicates CaxLn1-xVSiO5 (Ln = Ce-Nd, Sm-Lu, Y)

    Science.gov (United States)

    Abeysinghe, Dileka; Smith, Mark D.; Morrison, Gregory; Yeon, Jeongho; zur Loye, Hans-Conrad

    2018-04-01

    A series of lanthanide containing mixed-valent vanadium (III/IV) silicates of the type CaxLn1-xVSiO5 (Ln = Ce-Nd, Sm-Lu, Y) was synthesized as high quality single crystals from a molten chloride eutectic flux, BaCl2/NaCl. Utilizing Ca metal as the reducing agent, an in-situ reduction of V5+ to V3+/4+ as well as of Ce4+ to Ce3+ was achieved. The structures of 14 reported isostructural compounds were determined by single crystal X-ray diffraction. They crystallize in the tilasite (CaMgAsO4F) structure type in the monoclinic space group C2/c. The extended structure contains 1D chains of VO6 octahedra that are connected to each other via SiO4 groups and (Ca/Ln)O7 polyhedra. The magnetic susceptibility and the field dependent magnetization data were measured for CaxLn1-xVSiO5 (Ln = Ce-Nd, Sm, Gd-Lu, Y), and support the existence of antiferromagnetic behavior at low temperatures.

  2. A series of noncentrosymmetric antimony sulfides Ln{sub 8}Sb{sub 2}S{sub 15} (Ln = La, Pr, Nd) - syntheses, crystal and electronic structures, and NLO properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Hua-Jun [Laboratory of Applied Research on the Characteristic Resources in the North of Guizhou Province, School of Chemistry and Chemical Engineering, Zunyi Normal College, Guizhou (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou (China); Zhou, Liu-Jiang [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou (China)

    2015-02-15

    A series of noncentrosymmetric sulfides Ln{sub 8}Sb{sub 2}S{sub 15} (Ln = La, Pr, Nd) were prepared from stoichiometric mixtures of the elements at 1223 K in an evacuated silica tube. The compounds Ln{sub 8}Sb{sub 2}S{sub 15} with Ln = La and Nd are isostructural to Pr{sub 8}Sb{sub 2}S{sub 15} and crystallize in the tetragonal noncentrosymmetric space group I4{sub 1}cd. Their structure contains discrete [SbS{sub 3}]{sup 3-} trigonal pyramids separated by Ln{sup 3+} cations and S{sup 2-} anions. La{sub 8}Sb{sub 2}S{sub 15} shows second harmonic generation with intensities 1.2 times that of the commercially used IR NLO (nonlinear optics) material AgGaS{sub 2} (at 2.05 μm laser). It exhibits excellent thermal stability up to 663 C. Studies with UV/Vis-NIR diffuse reflectance spectroscopy show that La{sub 8}Sb{sub 2}S{sub 15} has an optical gap of around 2.3 eV, and a DFT study indicates a direct band gap with an electronic transfer excitation of S 3p electrons to a La 5d orbital. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Thermometric nanosize NMR-sensors for temperature determination in weakly polar non-aqueous media on the base of ion pairs of paramagnetic complexes of lanthanides(III)

    International Nuclear Information System (INIS)

    Babajlov, S.P.

    2008-01-01

    For temperature determination in solutions it is suggested that the temperature dependence of the paramagnetic lanthanide-induced shifts (LIS) in the NMR spectra on the ligand nuclei be used for [Ln(PTA) 2 (18-crown-6)] + [Ln(PTA) 4 ] - complex ion pairs formed in CCl 4 , CDCl 3 , CD 2 Cl 2 , CD 3 C 6 D 5 , and C 2 D 3 N type low-polar solvents (Ln = La, Ce, Pr, Nd, Eu; PTA is the pivalyltrifluoroacetonate anion). It was found experimentally that the [Ln(PTA) 2 (18-crown-6)] + complex cation molecules (Ln = Ce and Pr) proved most suitable for use as nanosized (∼1.1 nm) probes for temperature determinations in nonaqueous solutions. A linear dependence of the LIS on the 1 H nuclei of different groups and the difference between the LIS corresponding to the CH 2 groups of the 18-crown-6 molecules and the CH groups of the PTA anions on the reciprocal temperature (1/T) was found. The LIS of the individual signals of different groups in Ln paramagnetic complexes (relative to the signals of the diamagnetic analogs, e.g., La or Lu) may be used for temperature control in the sample, although the temperature measurement error is smaller (≤0.04 K) when the difference between the LIS of the CH 2 and CH groups is used. Due to the high thermodynamic and kinetic stability combined with small sizes of [Ln(PTA) 2 (18-crown-6)] + [Ln(PTA) 4 ] - molecules in nonaqueous solutions, these compounds may be used as thermometric NMR sensors directly in reaction media for in situ control over temperature [ru

  4. On the laws of disordering of the Ln3+ -ion crystal field in insulating crystals

    International Nuclear Information System (INIS)

    Kaminskij, A.A.

    1988-01-01

    Results of the study of fundamental regularities, which cause crystal field (CF) disordering on Ln 3+ ions in dielectric crystals are summed up. Analysis and systematization of the investigation results of atomic structure of disordered laser crystals and conducted investigations on spectroscopic properties and induced radiation (IR) permitted to come to the conclusion that the nature of disordering on CF is related to two fundamental regularities. The first regularity- the structural-dynamic one- is pronounced in numerous nonstoichiometric phases; the second one - determines spectroscopic properties and IR character

  5. FATIGUE PROPERTIES OF MODIFIED 316LN STAINLESS STEEL AT 4 K FOR HIGH FIELD CABLE-IN-CONDUIT APPLICATIONS

    International Nuclear Information System (INIS)

    Toplosky, V. J.; Walsh, R. P.; Han, K.

    2010-01-01

    Cable-In-Conduit-Conductor (CICC) alloys, exposed to Nb 3 Sn reaction heat-treatments, such as modified 316LN require a design specific database. A lack of fatigue life data (S-n curves) that could be applied in the design of the ITER CS and the NHMFL Series Connected Hybrid magnets is the impetus for the research presented here. The modified 316LN is distinguished by a lower carbon content and higher nitrogen content when compared to conventional 316LN. Because the interstitial alloying elements affect the mechanical properties significantly, it is necessary to characterize this alloy in a systematic way. In conjunction, to ensure magnet reliability and performance, several criteria and expectations must be met, including: high fatigue life at the operating stresses, optimal stress management at cryogenic temperatures and thin walled conduit to reduce coil mass. Tension-tension load control axial fatigue tests have good applicability to CICC solenoid magnet design, thus a series of 4 K strength versus fatigue life curves have been generated. In-situ samples of 316LN base metal, seam welded, butt welded and seam plus butt welded are removed directly from the conduit in order to address base and weld material fatigue life variability. The more than 30 fatigue tests show good grouping on the fatigue life curve and allow discretionary 4 K fatigue life predictions for conduit made with modified 316LN.

  6. In situ hydrothermal syntheses, structures and photoluminescent properties of four novel metal-organic frameworks constructed by lanthanide (Ln=Ce(III), Pr(III), Eu(III)) and Cu(I) metals with flexible dicarboxylate acids and piperazine-based ligands

    Energy Technology Data Exchange (ETDEWEB)

    Ay, Burak; Karaca, Serkan [Department of Chemistry, Arts and Science Faculty, Çukurova University, 01330 Adana (Turkey); Yildiz, Emel, E-mail: eeyildiz@cu.edu.tr [Department of Chemistry, Arts and Science Faculty, Çukurova University, 01330 Adana (Turkey); Lopez, Valerie [Department of Chemistry, Syracuse University, Syracuse, NY 13244 (United States); Nanao, Max H. [European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9 (France); University Grenoble Alpes-Centre National de la Recherche Scientifique-EMBL Unit of Virus Host-Cell Interactions, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9 (France); Zubieta, Jon [Department of Chemistry, Syracuse University, Syracuse, NY 13244 (United States); Université Grenoble Alpes Laboratoire de Physiologie Cellulaire & Végétale, Institut de Recherches en Technologies et Sciences pour le Vivant, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France)

    2016-01-15

    Four novel metal-organic frameworks,[Cu{sub 2}Cl{sub 2}(pyrz)]{sub n} (1) and (H{sub 2}pip){sub n}[Ln{sub 2}(pydc){sub 4}(H{sub 2}O){sub 2}]{sub n} (Ln=Ce (2), Pr (3) and Eu (4), H{sub 2}pzdc=2,3-pyrazinedicarboxylic acid, pyrz=pyrazine, H{sub 2}pydc=2,6-pyridinedicarboxylic acid, H{sub 2}pip=piperazine) have been synthesized under hydrothermal conditions and characterized by the elemental analysis, ICP, Far IR (FIR), FT-IR spectra, TGA, single crystal X-ray diffraction analysis and powder X-ray diffraction (PXRD). Compound 1 is two-dimensional containing Cl-Cu-Cl sites, while the lanthanide complexes contain one-dimensional infinite Ln–O-Ln chains. All the complexes show high thermal stability. The complexes 1–3 exhibit luminescence emission bands at 584, 598 and 614 nm at room temperature when excited at 300 nm. Complex 4 exhibits bright red solid-state phosphorescence upon exposure to UV radiation at room temperature. - Graphical abstract: Four novel metal-organic frameworks have been synthesized under hydrothermal conditions. Thermal and luminescent properties of the compounds have been investigated.

  7. Phase formation in the Li2MoO4-Rb2MoO4-Ln2(MoO4)3 systems and the properties of LiRbLn2(MoO4)4

    International Nuclear Information System (INIS)

    Basovich, O.M.; Khajkina, E.G.; Vasil'ev, E.V.; Frolov, A.M.

    1995-01-01

    Phase equilibria within subsolidus range of ternary salt systems Li 2 MoO 4 -Rb 2 MoO 4 -Ln 2 (MoO 4 ) 4 (Ln - Nd, Er) are analyzed. Formation of ternary molybdate LiRbNd 2 (MoO 4 ) 4 is proved along LiNd(MoO 4 ) 2 -RbNd(MoO 4 )-2 cross-section. Phase diagram of this cross-section is plotted. Similar compounds are synthesized for Ln = La-Eu. The parameters of their monoclinic elementary cells are determined. Luminescent properties of LiRbLa 2 (MoO 4 ) 4 -Nd 3+ are studied. 17 refs., 4 figs., 2 tabs

  8. Synthesis, structure and luminescence properties of binary and ternary complexes of lanthanide (Eu{sup 3+}, Sm{sup 3+} and Tb{sup 3+}) with salicylic acid and 1,10-phenanthroline

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Chen-Qi; Yan, Tian-Lu; Wang, Yi-Ting; Ye, Zi-Jun; Xu, Cun-Jin, E-mail: cjxu@hznu.edu.cn; Zhou, Wen-Jun

    2017-04-15

    A series of binary and ternary complexes of lanthanide (Eu{sup 3+}, Sm{sup 3+} and Tb{sup 3+}) with salicylic acid (Hsal) and 1,10-phenanthroline (phen) were synthesized, and characterized by element analysis, coordination titration analysis, IR, UV and TG-DTA. Their compositions were (NH{sub 4})[Ln(sal){sub 4}(H{sub 2}O){sub 2}] (Ln=Eu (1), Sm (2), Tb (3)) and (NH{sub 4})[Ln(sal){sub 4}(phen){sub 2}] (Ln=Eu (4), Sm (5), Tb (6)), respectively. In particular, the ternary complex of Eu{sup 3+}, 4, was characterized by X-ray diffraction, and luminescence intensities of binary and ternary complexes were compared. In case of Eu{sup 3+} and Sm{sup 3+} complexes, ternary complexes emitted stronger luminescence than corresponding binary complexes of salicylic acid and Ln{sup 3+}. On the other hand, the ternary Tb{sup 3+} complex had weaker luminescence than the binary complex because of back energy transfer from Tb{sup 3+} to phen. The CIE coordinates of 1–6 were calculated as (0.65, 0.35), (0.52, 0.48), (0.33, 0.59), (0.67, 0.33), (0.62, 0.38) and (0.36, 0.58), respectively, which enable these complexes to be promising candidates for red, green, or yellow component in OLEDs.

  9. Enhancement of superconductivity near the pressure-induced semiconductor-metal transition in the BiS₂-based superconductors LnO₀.₅F₀.₅BiS₂ (Ln = La, Ce, Pr, Nd).

    Science.gov (United States)

    Wolowiec, C T; White, B D; Jeon, I; Yazici, D; Huang, K; Maple, M B

    2013-10-23

    Measurements of electrical resistivity were performed between 3 and 300 K at various pressures up to 2.8 GPa on the BiS2-based superconductors LnO0.5F0.5BiS2 (Ln=Pr, Nd). At lower pressures, PrO0.5F0.5BiS2 and NdO0.5F0.5BiS2 exhibit superconductivity with critical temperatures Tc of 3.5 and 3.9 K, respectively. As pressure is increased, both compounds undergo a transition at a pressure Pt from a low Tc superconducting phase to a high Tc superconducting phase in which Tc reaches maximum values of 7.6 and 6.4 K for PrO0.5F0.5BiS2 and NdO0.5F0.5BiS2, respectively. The pressure-induced transition is characterized by a rapid increase in Tc within a small range in pressure of ∼0.3 GPa for both compounds. In the normal state of PrO0.5F0.5BiS2, the transition pressure Pt correlates with the pressure where the suppression of semiconducting behaviour saturates. In the normal state of NdO0.5F0.5BiS2, Pt is coincident with a semiconductor-metal transition. This behaviour is similar to the results recently reported for the LnO0.5F0.5BiS2 (Ln=La, Ce) compounds. We observe that Pt and the size of the jump in Tc between the two superconducting phases both scale with the lanthanide element in LnO0.5F0.5BiS2 (Ln=La, Ce, Pr, Nd).

  10. Thermochemistry of rare earth doped uranium oxides Ln{sub x}U{sub 1−x}O{sub 2−0.5x+y} (Ln = La, Y, Nd)

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lei; Navrotsky, Alexandra, E-mail: anavrotsky@ucdavis.edu

    2015-10-15

    Lanthanum, yttrium, and neodymium doped uranium dioxide samples in the fluorite structure have been synthesized, characterized in terms of metal ratio and oxygen content, and their enthalpies of formation measured by high temperature oxide melt solution calorimetry. For oxides doped with 10–50 mol % rare earth (Ln) cations, the formation enthalpies from constituent oxides (LnO{sub 1.5}, UO{sub 2} and UO{sub 3} in a reaction not involving oxidation or reduction) become increasingly exothermic with increasing rare earth content, while showing no significant dependence on the varying uranium oxidation state. The oxidation enthalpy of Ln{sub x}U{sub 1−x}O{sub 2−0.5x+y} is similar to that of UO{sub 2} to UO{sub 3} for all three rare earth doped systems. Though this may suggest that the oxidized uranium in these systems is energetically similar to that in the hexavalent state, thermochemical data alone can not constrain whether the uranium is present as U{sup 5+}, U{sup 6+}, or a mixture of oxidation states. The formation enthalpies from elements calculated from the calorimetric data are generally consistent with those from free energy measurements. - Highlights: • We synthesize, characterize Ln{sub x}U{sub 1−x}O{sub 2−0.5x+y} solid solutions (Ln = La, Y, Nd). • Formation enthalpies become more exothermic with increasing rare earth content. • Oxidation enthalpy of Ln{sub x}U{sub 1−x}O{sub 2−0.5x+y} is similar to that of UO{sub 2} to UO{sub 3}. • Direct calorimetric measurements are in good agreement with free energy data.

  11. Thick-section weldments in 21-6-9 and 316LN stainless steel for fusion energy applications

    International Nuclear Information System (INIS)

    Alexander, D.J.; Goodwin, G.M.

    1991-01-01

    The Burning Plasma Experiment (BPX), formerly known as the Compact Ignition Tokomak, will be a major advance in the design of a fusion reactor. The successful construction of fusion reactors will require extensive welding of thick-section stainless steel plates. Severe service conditions will be experienced by the structure. Operating temperatures will range from room temperature (300 K) to liquid nitrogen temperature (77 K), and perhaps even lower. The structure will be highly stressed, and subject to sudden impact loads if plasma disruptions occur. This demands a combination of high strength and high toughness from the weldments. Significant portions of the welding will be done in the field, so preweld and postweld heat treatments will be difficult. The thick sections to be welded will require a high deposition rate process, and will result in significant residual stresses in the materials. Inspection of these thick sections in complex geometries will be very difficult. All of these constraints make it essential that the welding procedures and alloys be well understood, and the mechanical properties of the welds and their heat-affected zones must be adequately characterized. The candidate alloy for structural applications in the BPX such as the magnet cases was initially selected as 21-6-9 austenitic stainless steel, and later changed to 316LN stainless steel. This study examined several possible filler materials for thick-section (25 to 50 mm) weldments in these two materials. The tensile and Charpy V-notch properties were measured at room temperature and 77 K. The fracture toughness was measured for promising materials

  12. β-Y(BO{sub 2}){sub 3}. A new member of the β-Ln(BO{sub 2}){sub 3} (Ln = Nd, Sm, Gd-Lu) structure family

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Martin K.; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

    2017-07-01

    β-Y(BO{sub 2}){sub 3} was synthesized in a Walker-type multianvil module at 5.9 GPa/1000 C. The crystal structure has been elucidated through single-crystal X-ray diffraction. β-Y(BO{sub 2}){sub 3} crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a = 15.886(2), b = 7.3860(6), and c = 12.2119(9) Aa. Its crystal structure will be discussed in the context of the isotypic lanthanide borates β-Ln(BO{sub 2}){sub 3} (Ln = Nd, Sm, Gd-Lu).

  13. Topotactic Transformation Route to Monodisperse β-NaYF4:Ln(3+) Microcrystals with Luminescence Properties.

    Science.gov (United States)

    Shao, Baiqi; Feng, Yang; Song, Yan; Jiao, Mengmeng; Lü, Wei; You, Hongpeng

    2016-02-15

    A novel nonorganic wet route for direct synthesis of uniform hexagonal β-NaYF4:Ln(3+) (Ln = Eu, Tb, Ce/Tb, Yb/Er, and Yb/Tm) microcrystals with various morphologies has been developed wherein the intermediate routine cubic-hexagonal (α → β) phase transfer process was avoided. The morphology can be effectively tuned into hexagonal disc, prism, and novel hierarchical architectures by systematically fine manipulating the Na2CO3/F(-) feeding ratio. It has been found that the routine α → β phase transfer for NaYF4 was not detected during the growth, while NaY(CO3)F2 emerged in the initial reaction stage and fast transformed into β-NaYF4 via a novel topotactic transformation behavior. Detailed structural analysis showed that β-NaYF4 preferred the [001] epitaxial growth direction of NaY(CO3)F2 due to the structural matching of [001]NaY(CO3)F2//[0001]β-NaYF4. Besides, the potential application of the as-prepared products as phosphors is emphasized by demonstrating multicolor emissions including downconversion, upconversion, and energy transfer (Ce-Tb) process by lanthanides doping.

  14. Kramers non-magnetic superconductivity in LnNiAsO superconductors.

    Science.gov (United States)

    Li, Yuke; Luo, Yongkang; Li, Lin; Chen, Bin; Xu, Xiaofeng; Dai, Jianhui; Yang, Xiaojun; Zhang, Li; Cao, Guanghan; Xu, Zhu-an

    2014-10-22

    We investigated a series of nickel-based oxyarsenides LnNiAsO (Ln=La, Ce, Pr, Nd, Sm) compounds. CeNiAsO undergoes two successive anti-ferromagnetic transitions at TN1=9.3 K and TN2=7.3 K; SmNiAsO becomes an anti-ferromagnet below TN≃3.5 K; NdNiAsO keeps paramagnetic down to 2 K but orders anti-ferromagnetically below TN≃1.3 K. Superconductivity was observed only in Kramers non-magnetic LaNiAsO and PrNiAsO with Tc=2.7 K and 0.93 K, respectively. The superconductivity of PrNiAsO is further studied by upper critical field and specific heat measurements, which reveal that PrNiAsO is a weakly coupled Kramers non-magnetic superconductor. Our work confirms that the nickel-based oxyarsenide superconductors are substantially different in mechanism to iron-based ones, and are likely to be described by the conventional superconductivity theory.

  15. High-energy-beam welding of type 316LN stainless steel for cryogenic applications

    International Nuclear Information System (INIS)

    Siewert, T.A.; Gorni, D.; Kohn, G.

    1988-01-01

    Laser and electron beam welds in 25-mm-thick AISI 316LN specimens containing 0.16 wt.$% N were evaluated for fusion reactor applications and their mechanical properties were compared with those of welds generated by lower productivity processes such as shielded-metal-arc and gas-metal-arc welding. Tensile tests were performed on transverse tensile specimens at 4 K. For both welding processes the fractures occurred in the base metal at a strength level near 950 MPa. This indicated that the weld and heat affected zone had a strength similar to that of the base metal. The 4 K weld fracture toughness was only slightly less than that for the base metal and comparable to the best values achieved with conventional welding processes in 316Ln weld metal. The Charpy V-notch absorbed energies averaged near 70 J at 76 K. Metallographic analysis revealed cellular and fully austenitic solidification with little porosity and no evidence of hot cracking

  16. Microstructural features of dissimilar welds between 316LN austenitic stainless steel and alloy 800

    International Nuclear Information System (INIS)

    Sireesha, M.; Sundaresan, S.

    2000-01-01

    For joining type 316LN austenitic stainless steel to modified 9Cr-1Mo steel for power plant application, a trimetallic configuration using an insert piece (such as alloy 800) of intermediate thermal coefficient of expansion (CTE) has been sometimes suggested for bridging the wide gap in CTE between the two steels. Two joints are thus involved and this paper is concerned with the weld between 316LN and alloy 800. These welds were produced using three types of filler materials: austenitic stainless steels corresponding to 316,16Cr-8Ni-2Mo, and the nickel-base Inconel 182 1 . The weld fusion zones and the interfaces with the base materials were characterised in detail using light and transmission electron microscopy. The 316 and Inconel 182 weld metals solidified dendritically, while the 16-8-2(16%Cr-8%Ni-2%Mo) weld metal showed a predominantly cellular substructure. The Inconel weld metal contained a large number of inclusions when deposited from flux-coated electrodes, but was relatively inclusion-free under inert gas-shielded welding. Long-term elevated-temperature aging of the weld metals resulted in embrittling sigma phase precipitation in the austenitic stainless steel weld metals, but the nickel-base welds showed no visible precipitation, demonstrating their superior metallurgical stability for high-temperature service. (orig.)

  17. Study on the dynamic recrystallization model and mechanism of nuclear grade 316LN austenitic stainless steel

    International Nuclear Information System (INIS)

    Wang, Shenglong; Zhang, Mingxian; Wu, Huanchun; Yang, Bin

    2016-01-01

    In this study, the dynamic recrystallization behaviors of a nuclear grade 316LN austenitic stainless steel were researched through hot compression experiment performed on a Gleeble-1500 simulator at temperatures of 900–1250 °C and strain rates of 0.01–1 s −1 . By multiple linear regressions of the flow stress-strain data, the dynamic recrystallization mathematical models of this steel as functions of strain rate, strain and temperature were developed. Then these models were verified in a real experiment. Furthermore, the dynamic recrystallization mechanism of the steel was determined. The results indicated that the subgrains in this steel are formed through dislocations polygonization and then grow up through subgrain boundaries migration towards high density dislocation areas and subgrain coalescence mechanism. Dynamic recrystallization nucleation performs in grain boundary bulging mechanism and subgrain growth mechanism. The nuclei grow up through high angle grain boundaries migration. - Highlights: •Establish the DRX mathematical models of nuclear grade 316LN stainless steel •Determine the DRX mechanism of this steel •Subgrains are formed through dislocations polygonization. •Subgrains grow up through subgrain boundaries migration and coalescence mechanism. •DRX nucleation performs in grain boundary bulging mechanism and subgrain growth mechanism.

  18. Remote refilling of LN2 cryostats for high sensitivity astronomical applications

    Science.gov (United States)

    l'Allemand, J. L. Lizon a.

    2017-12-01

    The most sensitive observation mode of the ESO VLT (European Southern Observatory Very Large Telescope) is the interferometric mode, where the 4 Units Telescopes are directed to the same stellar object in order to operate as a gigantic interferometer. The beam is then re-combined in the main interferometry laboratory and fed into the analyzing instruments. In order not to disturb the performance of the Interferometer, this room is considered as a sanctuary where one enters only in case of extreme need. A simple opening of the door would create air turbulences affecting the stability for hours. Any cold spot in the room could also cause convection which might change the optical path by fraction of a micron. Most of the instruments are operating at cryogenic temperatures using passive cooling based on LN2 bath cryostat. For this reason, dedicated strategy has been developed for the transfer of LN2 to the various instruments. The present document describes the various aspects and care taken in order to guarantee the very high thermal and mechanical environmental stability.

  19. Influence of prior deformation on the sensitization of AISI Type 316LN stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Parvathavarthini, N. (Metallurgy Div., Indira Gandhi Centre for Atomic Research, Tamilnadu (India)); Dayal, R.K. (Metallurgy Div., Indira Gandhi Centre for Atomic Research, Tamilnadu (India)); Gnanamoorthy, J.B. (Metallurgy Div., Indira Gandhi Centre for Atomic Research, Tamilnadu (India))

    1994-02-01

    The sensitization behaviour of a nuclear grade AISI 316LN stainless steel (SS) was studied for various cold-work levels ranging from 0% (mill-annealed) to 25% reduction in thickness. ASTM standard A262 Practices A and E were adopted to detect the susceptibility to intergranular corrosion. The results obtained in these tests were used to construct time-temperature-sensitization (TTS) diagrams. Using these data, the critical linear cooling rate was calculated, above which there is no risk of sensitization. In order to predict the sensitization behaviour during practical cooling conditions, Continuous-cooling-sensitization (CCS) diagrams were established utilising the TTS diagrams by a mathematical method. The influences of prior deformation and nitrogen in the alloy on the sensitization kinetics are discussed. It was found that nitrogen addition retards the sensitization kinetics and that t[sub min] (minimum time required for sensitization at nose temperature) increases by two orders of magnitude in Type 316LN SS compared to that of Type 316 SS at the different prior deformation levels. Cold-working up to 15% accelerates the onset of carbide precipitation and on further cold working there is not much difference in the kinetics. Desensitization is faster in highly cold-worked material, especially at high temperatures. (orig.)

  20. Changes in irradiated LnSiAlO(N) glasses at a microscopic scale

    Energy Technology Data Exchange (ETDEWEB)

    Dauce, R. [UMR CNRS 6512, Verres et ceramiques, Institut de Chimie, Universite de Rennes 1, F-35042 Rennes Cedex (France) and CE Cadarache, DEC/SESC, F-13018 St. Paul Lez Durances Cedex (France)]. E-mail: rachel.dauce@freenet.de; Sangleboeuf, J.-C. [LARMAUR, FRE CNRS 2717, Universite de Rennes 1, F-35042 Rennes Cedex (France); Verdier, P. [UMR CNRS 6512, Verres et ceramiques, Institut de Chimie, Universite de Rennes 1, F-35042 Rennes Cedex (France)

    2006-06-15

    Six oxide and oxynitride glasses from three different M-Ln-Si-Al-O(-N) systems (where M is an alkaline-earth and Ln a rare earth) have been irradiated by Kr, Ni and S ions, with different energies varying from 350 to 700 MeV. Neither micro-bubble formation nor crystallisation are evidenced, but the irradiated glasses exhibit an anisotropic deformation under the ion beam. The main crack mode developed during scratching is shifted from radial for the pristine glasses to lateral for all the irradiated glasses. The hardness of each glass decreases when irradiated for all the incident ions used. This decrease appears to be in close relation with the electronic stopping power of the incident particle, and is associated with a change in the indentation mechanism (from normal to anomalous behaviour). The evolution of the scratches in the material depth confirms the change in deformation mechanism and the strong dependence between the hardness of the irradiated material and the electronic stopping power of the incident ion. Three phenomena can be the source of the changes in the properties: the creation of internal stresses during irradiation, the creation of point defects and the cross-linking of the silicate network.

  1. Time dependent design curves for a high nitrogen grade of 316LN stainless steel for fast reactor applications

    Energy Technology Data Exchange (ETDEWEB)

    Ganesh Kumar, J.; Ganesan, V.; Laha, K.; Mathew, M.D., E-mail: mathew@igcar.gov.in

    2013-12-15

    Highlights: • 316LN SS is an important high temperature structural material for sodium cooled fast reactors. • Creep strength of 316LN SS has been increased substantially by increasing the nitrogen content. • Creep design curves based on RCC-MR code procedures have been generated for this new material. • 100,000 h allowable stress at 600 °C increased by more than 40% as a result of doubling the nitrogen content in the steel. - Abstract: Type 316L(N) stainless steel (SS) containing 0.06–0.08 wt.% nitrogen is the major material for reactor assembly components of sodium cooled fast reactors (SFRs). With a view to increase the design life of SFRs to 60 years from the current life of 40 years, studies are being carried out to improve the high temperature creep and low cycle fatigue properties of 316LN SS by increasing the nitrogen content above 0.08 wt.%. In this investigation, the creep properties of a high nitrogen grade of 316LN SS containing 0.14 wt.% nitrogen have been studied. Creep tests were carried out at 550 °C, 600 °C and 650 °C at various stress levels in the range of 140–350 MPa. Creep strength was found to be significantly improved by doubling the nitrogen content in this steel. The maximum rupture life in these tests was 33,000 h. The creep data has been analyzed according to RCC-MR nuclear code procedures in order to generate the creep design curves for the high nitrogen grade of 316LN SS. Allowable stress for 100,000 h at 600 °C increased by more than 38% as a result of doubling the nitrogen content in the steel.

  2. Exchange coupling and magnetic anisotropy in a family of bipyrimidyl radical-bridged dilanthanide complexes: density functional theory and ab initio calculations.

    Science.gov (United States)

    Zhang, Yi-Quan; Luo, Cheng-Lin; Zhang, Qiang

    2014-05-05

    The origin of the magnetic anisotropy energy barriers in a series of bpym(-) (bpym = 2,2'-bipyrimidine) radical-bridged dilanthanide complexes [(Cp*2Ln)2(μ-bpym)](+) [Cp* = pentamethylcyclopentadienyl; Ln = Gd(III) (1), Tb(III) (2), Dy(III) (3), Ho(III) (4), Er(III) (5)] has been explored using density functional theory (DFT) and ab initio methods. DFT calculations show that the exchange coupling between the two lanthanide ions for each complex is very weak, but the antiferromagnetic Ln-bpym(-) couplings are strong. Ab initio calculations show that the effective energy barrier of 2 or 3 mainly comes from the contribution of a single Tb(III) or Dy(III) fragment, which is only about one third of a single Ln energy barrier. For 4 or 5, however, both of the two Ho(III) or Er(III) fragments contribute to the total energy barrier. Thus, it is insufficient to only increase the magnetic anisotropy energy barrier of a single Ln ion, while enhancing the Ln-bpym(-) couplings is also very important. Copyright © 2014 Wiley Periodicals, Inc.

  3. Glass Ceramic Waste Forms for Combined CS+LN+TM Fission Products Waste Streams

    International Nuclear Information System (INIS)

    Crum, Jarrod V.; Turo, Laura A.; Riley, Brian J.; Tang, Ming; Kossoy, Anna; Sickafus, Kurt E.

    2010-01-01

    In this study, glass ceramics were explored as an alternative waste form for glass, the current baseline, to be used for immobilizing alkaline/alkaline earth + lanthanide (CS+LN) or CS+LN+transition metal (TM) fission-product waste streams generated by a uranium extraction (UREX+) aqueous separations type process. Results from past work on a glass waste form for the combined CS+LN waste streams showed that as waste loading increased, large fractions of crystalline phases precipitated upon slow cooling.(1) The crystalline phases had no noticeable impact on the waste form performance by the 7-day product consistency test (PCT). These results point towards the development of a glass ceramic waste form for treating CS+LN or CS+LN+TM combined waste streams. Three main benefits for exploring glass ceramics are: (1) Glass ceramics offer increased solubility of troublesome components in crystalline phases as compared to glass, leading to increased waste loading; (2) The crystalline network formed in the glass ceramic results in higher heat tolerance than glass; and (3) These glass ceramics are designed to be processed by the same melter technology as the current baseline glass waste form. It will only require adding controlled canister cooling for crystallization into a glass ceramic waste form. Highly annealed waste form (essentially crack free) with up to 50X lower surface area than a typical High-Level Waste (HLW) glass canister. Lower surface area translates directly into increased durability. This was the first full year of exploring glass ceramics for the Option 1 and 2 combined waste stream options. This work has shown that dramatic increases in waste loading are achievable by designing a glass ceramic waste form as an alternative to glass. Table S1 shows the upper limits for heat, waste loading (based on solubility), and the decay time needed before treatment can occur for glass and glass ceramic waste forms. The improvements are significant for both combined waste

  4. Glass Ceramic Waste Forms for Combined CS+LN+TM Fission Products Waste Streams

    Energy Technology Data Exchange (ETDEWEB)

    Crum, Jarrod V.; Turo, Laura A.; Riley, Brian J.; Tang, Ming; Kossoy, Anna; Sickafus, Kurt E.

    2010-09-23

    In this study, glass ceramics were explored as an alternative waste form for glass, the current baseline, to be used for immobilizing alkaline/alkaline earth + lanthanide (CS+LN) or CS+LN+transition metal (TM) fission-product waste streams generated by a uranium extraction (UREX+) aqueous separations type process. Results from past work on a glass waste form for the combined CS+LN waste streams showed that as waste loading increased, large fractions of crystalline phases precipitated upon slow cooling.[1] The crystalline phases had no noticeable impact on the waste form performance by the 7-day product consistency test (PCT). These results point towards the development of a glass ceramic waste form for treating CS+LN or CS+LN+TM combined waste streams. Three main benefits for exploring glass ceramics are: (1) Glass ceramics offer increased solubility of troublesome components in crystalline phases as compared to glass, leading to increased waste loading; (2) The crystalline network formed in the glass ceramic results in higher heat tolerance than glass; and (3) These glass ceramics are designed to be processed by the same melter technology as the current baseline glass waste form. It will only require adding controlled canister cooling for crystallization into a glass ceramic waste form. Highly annealed waste form (essentially crack free) with up to 50X lower surface area than a typical High-Level Waste (HLW) glass canister. Lower surface area translates directly into increased durability. This was the first full year of exploring glass ceramics for the Option 1 and 2 combined waste stream options. This work has shown that dramatic increases in waste loading are achievable by designing a glass ceramic waste form as an alternative to glass. Table S1 shows the upper limits for heat, waste loading (based on solubility), and the decay time needed before treatment can occur for glass and glass ceramic waste forms. The improvements are significant for both combined waste

  5. Site-selective fluorescence spectroscopy investigations of LnPO{sub 4} xenotime ceramics for radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, A.; Peters, L. [RWTH Aachen Univ. (Germany). Inst. of Crystallography; Holthausen, J.; Neumeier, S. [Forschungszentrum Juelich (Germany); Huittinen, Nina [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes; Loesch, Henry

    2017-06-01

    Europium incorporation in different LnPO{sub 4} (Ln=Tb, Lu and Gd{sub 1-x}Lu{sub x}) phases crystallizing in the xenotime structure was investigated with site-selective TRLFS, PXRD and Rietveld analyses. Based on recorded emission spectra and diffraction patterns, the formation of three different crystal systems (xenotime, anhydrite, and monazite) could be identified. Aging of the ceramic samples and a second sintering step led to an accumulation of europium in the grain boundaries and on the surface.

  6. Was the Pyx of Mělník (with the Image of Christ on the Mount of Olives) Utraquist?

    Czech Academy of Sciences Publication Activity Database

    Všetečková, Zuzana

    2011-01-01

    Roč. 59, Spec.iss.3 (2011), s. 315-331 ISSN 0015-1831. [Symposium on the Bohemian Reformation and Religious Practice /8./. Praha, 17.06.2008-20.06.2008] Institutional research plan: CEZ:AV0Z80330511 Keywords : Bohemia * about 1500 * goldsmith * pyx with Mount of Olives * Church of Sts. Peter and Paul in Mělník or Augustian Monastery in Mělník-Pšovka Subject RIV: AL - Art, Architecture, Cultural Heritage http://www.brrp.org/proceedings/brrp8/vseteckova.pdf

  7. Crystal structure and phase transition studies in perovskite-type oxides using powder-diffraction techniques and symmetry-mode analysis : SrLnMRuO6 (Ln=La,Pr,Nd; M=Zn,Co,Mg,Ni,Fe) and ALn2CuTi2O9 (A=Ca,Ba; Ln=La,Pr,Nd,Sm)

    OpenAIRE

    Iturbe Zabalo, Edurne

    2013-01-01

    La tesis se ha centrado en la síntesis y caracterización estructural de materiales tipo perovskita: SrLnMRuO6 (Ln=La,Pr,Nd; M=Zn,Co,Mg,Ni,Fe) y ALn2CuTi2O9 (A=Ca,Ba; Ln=La,Pr,Nd,Sm). El estudio de las estructuras de los materiales se ha realizado mediante el análisis de los patrones de difracción en polvo de rayos-X, sincrotrón y/o neutrones. En el refinamiento por el método de Rietveld de las estructuras se han sustituido las coordenadas atómicas (el método más común), por coordenadas colect...

  8. Magneto and spectral behaviour of lanthanide(III) perchlorate complexes of n-isonicotinamidoanisalaldimine

    International Nuclear Information System (INIS)

    Agarwal, R.K.; Agarwal, Himanshu; Sarin, R.K.

    1996-01-01

    A new series of lanthanide(III) perchlorate complexes of N-isonicotinamidoanisalaldimine (INH-SAL) with the general composition (Ln(INH-SAL) 4 )(ClO) 4 ) 3 (Ln=La, Pr, Nd, Sm, Gd, Tb or Dy) were synthesized and characterized by elemental analyses, conductance, molecular weight, infrared and electronic spectral data. INH-SAL acts as a bidentate (N, O) chelating agents. The tentative coordination number eight has been assigned. Thermal behaviour of some representative chelates has also been investigated. (author). 14 refs., 2 tabs

  9. Synthesis, characterization and properties of lanthanide trifluoroacetate complexes with N-(1-adamantyl) acetamide

    International Nuclear Information System (INIS)

    Miranda Junior, P.; Isolani, P.C.; Vicentini, G.; Zinner, L.B.

    1999-01-01

    Complexes of lanthanide trifluoacetates and N-(1-adamantyl) acetamide (ADA) with composition Ln (TFA) 3 .ADA (Ln=Nd, Sm, Eu, Gd, Tb, Dy; TFA trifluoroacetate) were synthesized by titration of lanthanides with EDTA and CHN microanalytical procedures. According to IR spectra the bonding of ADA occurs through the carbonyl oxygen. Compounds of Nd 3+ , Sm 3+ and Eu 3+ present two bands attributed to v aa COO and that of Gd 3+ Tb 3+ only one. In all cases only one band is attributed to v a -s COO. The absorption spectra of the neodymium and the emission spectra of the europium compounds were determined and interpreted. (author)

  10. Radioluminescence studies of colloidal oleate-capped β-Na(Gd,Lu)F4:Ln3+ nanoparticles (Ln = Ce, Eu, Tb).

    Science.gov (United States)

    Cooper, Daniel R; Capobianco, John A; Seuntjens, Jan

    2018-04-26

    We report on the synthesis, characterization, and radioluminescence quantification of several new varieties of nanoparticles with the general composition β-NaLnF4, incorporating known luminescent activator/sensitizer pairs. Using Monte Carlo modeling to complement luminescence measurements, we have calculated the radioluminescence yields and intrinsic conversion efficiencies of colloidally-dispersed nanoparticles by comparison to an organic liquid scintillator. While five of the compositions had low to modest radioluminescence yields relative to bulk materials, colloidal β-Na(Lu0.65Gd0.2Tb0.15)F4 displayed a strong output of 39 460 photons per MeV absorbed, comparable to some of the best non-hygroscopic bulk crystal scintillators and X-ray phosphors such as Gd2O2S:Tb. Measurements of β-Na(Lu0.65Gd0.2Tb0.15)F4 powder samples revealed persistent luminescence as well as stable charge trapping, warranting further investigation.

  11. Solution-combustion synthesis of Bi1–xLnxO1⋅ 5 (Ln= Y and La–Yb ...

    Indian Academy of Sciences (India)

    combustion synthesis of Bi1–LnO1.5 (Ln = Y and La–Yb) oxide ion conductors. Manjunath B Bellakki A S Prakash C Shivakumara M S Hegde A K Shukla. Ceramics and Glasses Volume 29 Issue 4 August 2006 pp 339-345 ...

  12. A comparative study of the structure and luminescence of mono- and dinuclear crown-ether lanthanide complexes

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Keyla M.N. de [Departamento de Química, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, S/N – Dois Irmãos, 52171-900 Recife, Pernambuco (Brazil); Batista, Hélcio J., E-mail: helciojb@gmail.com [Departamento de Química, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, S/N – Dois Irmãos, 52171-900 Recife, Pernambuco (Brazil); Belian, Mônica F. [Departamento de Química, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, S/N – Dois Irmãos, 52171-900 Recife, Pernambuco (Brazil); Silva, Wagner E. [Unidade Acadêmica do Cabo de Santo Agostinho, Universidade Federal Rural de Pernambuco, 54510-000 Cabo de Santo Agostinho, Pernambuco (Brazil); Silva, Juliana A.B. da [Centro Acadêmico do Agreste, Universidade Federal de Pernambuco, 55002-970 Caruaru, Pernambuco (Brazil)

    2016-02-15

    Using as precursor the mononuclear lanthanide (Ln) macrocyclic complex, based on the 15-crown-5 ether (C) ligand and coordinated water (W) molecules, [LnCW{sub 4}]{sup 3+}, four novel analogous complexes for each of the three Ln(III) ions (Ln=Eu, Tb and Gd) were synthesized through systematic substitution of water molecules by the antenna-type ligands: 2,2′-dipyridyl (D), 1,10-phenanthroline (P) and 2,2′;6',2′′-terpyridine (T). The corresponding formulae of the complexes, obtained in a trichloride salt form, were the following: [LnCW{sub 4}]{sup 3+}, [LnCP{sub 2}]{sup 3+}, [LnCDW]{sup 3+}, [LnCDP]{sup 3+}, and [LnCT]{sup 3+}. The compounds were characterized by elemental analysis, UV and infrared spectroscopy and investigated through luminescence spectroscopy. For the Eu(III) and Tb(III) complex series, the most luminescent ones were [EuCDP]{sup 3+} and [TbCT]{sup 3+}, respectively. Motivated by this fact, two dinuclear analogous Eu(III) and Tb(III) complexes, based on the two-site coordinating macrocyclic ligand lariat-silacrown ether (S), as well as analogous Gd(III) complexes, were obtained as hexachloride salts with the following formulae: [Eu{sub 2}SD{sub 2}P{sub 2}]{sup 6+}, [Gd{sub 2}SD{sub 2}P{sub 2}]{sup 6+}, [Tb{sub 2}ST{sub 2}]{sup 6+} and [Gd{sub 2}ST{sub 2}]{sup 6+}. Also, [Eu{sub 2}SW{sub 8}]{sup 6+}, [Tb{sub 2}SW{sub 8}]{sup 6+} and [Gd{sub 2}SW{sub 8}]{sup 6+} complexes were prepared and used as reference non-antenna type dinuclear compounds. Comparing the luminescence between the antenna mononuclear complexes with the analogous dinuclear ones, for Eu(III) and Tb(III) ions, almost no change was observed. On the other hand, in the particular case of Eu(III), comparing the mono- and dinuclear non-antenna reference complexes [EuCW{sub 4}]{sup 3+} and [Eu{sub 2}SW{sub 8}]{sup 6+}, a surprisingly much higher luminescence intensity was observed for the dinuclear complex (~ one order of magnitude). The proposed cause for this behavior is the

  13. Rethinking Sensitized Luminescence in Lanthanide Coordination Polymers and MOFs: Band Sensitization and Water Enhanced Eu Luminescence in [Ln(C15H9O5)3(H2O)3]n (Ln = Eu, Tb).

    Science.gov (United States)

    Einkauf, Jeffrey D; Kelley, Tanya T; Chan, Benny C; de Lill, Daniel T

    2016-08-15

    A coordination polymer [Ln(C15H9O9)3(H2O)3]n (1-Ln = Eu(III), Tb(III)) assembled from benzophenonedicarboxylate was synthesized and characterized. The organic component is shown to sensitize lanthanide-based emission in both compounds, with quantum yields of 36% (Eu) and 6% (Tb). Luminescence of lanthanide coordination polymers is currently described from a molecular approach. This methodology fails to explain the luminescence of this system. It was found that the band structure of the organic component rather than the molecular triplet state was able to explain the observed luminescence. Deuterated (Ln(C15H9O9)3(D2O)3) and dehydrated (Ln(C15H9O9)3) analogues were also studied. When bound H2O was replaced by D2O, lifetime and emission increased as expected. Upon dehydration, lifetimes increased again, but emission of 1-Eu unexpectedly decreased. This reduction is reasoned through an unprecedented enhancement effect of the compound's luminescence by the OH/OD oscillators in the organic-to-Eu(III) energy transfer process.

  14. Kulturní krajina Černínů z Chudenic. Obrazová mapa panství Lnáře (1698) a Dietzlerův prospekt Lnář (1725)

    Czech Academy of Sciences Publication Activity Database

    Šimůnek, Robert

    2015-01-01

    Roč. 84, č. 1 (2015), s. 410-450 ISSN 0323-004X R&D Projects: GA ČR(CZ) GBP410/12/G113 Institutional support: RVO:67985963 Keywords : historical landscape * prospect of landscape * old maps * vedute * nobility * representation * Černín of Chudenice * Lnáře Subject RIV: AB - History

  15. Vliv perinatální zánětlivé reakce na rozvoj psychóze podobného chování: experimentální studie

    Czech Academy of Sciences Publication Activity Database

    Tejkalová, H.; Jelínek, F.; Klaschka, Jan; Šťastný, František

    2007-01-01

    Roč. 11, Suppl. 3 (2007), s. 12-15 ISSN 1211-7579 R&D Projects: GA MŠk(CZ) 1M0517 Institutional research plan: CEZ:AV0Z10300504; CEZ:AV0Z50110509 Keywords : schizofrenie * animální model * lipopolysacharid * mikroglie * prepulzní inhibice Subject RIV: FL - Psychiatry, Sexuology

  16. Reaction of (CP(2)asterisk-lnH)(2) (ln=Y, La) and CP(2)asterisk-Y(2-C(6)H(4)CH(2)NMe(2)) with esters and amides and molecular-structure of [CP(2)asterisk-Y(mu- ocme=chc(oet)o)](2)

    NARCIS (Netherlands)

    Deelman, B.J; Wierda, F.; Meetsma, A.; Teuben, J.H

    1995-01-01

    The activation of esters and amides by (Cp(2)*LnH)(2) [Ln = Y (1a), Ln = La (1b), Cp*=C(5)Me] and Cp(2)*Y(2-C(6)H(4)CH(2)NMe(2)) (2) is described. Compounds 1a and 1b react with ethyl acetate to form Cp(2)*YOEt (3a) and Cp(2)*LaOEt (30). With 1a and ethyl benzoate a 1:1 mixture of 3a and

  17. A [Cyclentetrakis(methylene)]tetrakis[2-hydroxybenzamide]Ligand That Complexes and Sensitizes Lanthanide(III) Ions

    Energy Technology Data Exchange (ETDEWEB)

    D' Aleo, Anthony; Xu, Jide; Do, King; Muller, Gilles; Raymond, Kenneth N.

    2009-04-30

    The synthesis of a cyclen derivative containing four isophthalamide groups (L{sup 1}) is described. The spectroscopic properties of the Ln(III) complexes of L{sup 1} (Ln = Gd, Tb, Yb, Eu) reveal changes of the UV/visible absorption, circular dichroism absorption, luminescence and circularly polarized luminescence properties. It is shown that at least two metal complex species are present in solution, whose relative amounts are pH dependent. When at pH > 8.0, an intense long lived emission is observed (for [L{sup 1}Tb] and [L{sup 1}Yb]) while at pH < 8.0, a weaker, shorter-lived species predominates. Unconventional Ln(III) emitters (Pr, Nd, Sm, Dy and Tm) were sensitized in basic solution, both in the visible and in the near infra-red, to measure the emission of these ions.

  18. Covalency in lanthanides. An X-ray absorption spectroscopy and density functional theory study of LnCl6(x-) (x = 3, 2).

    Science.gov (United States)

    Löble, Matthias W; Keith, Jason M; Altman, Alison B; Stieber, S Chantal E; Batista, Enrique R; Boland, Kevin S; Conradson, Steven D; Clark, David L; Lezama Pacheco, Juan; Kozimor, Stosh A; Martin, Richard L; Minasian, Stefan G; Olson, Angela C; Scott, Brian L; Shuh, David K; Tyliszczak, Tolek; Wilkerson, Marianne P; Zehnder, Ralph A

    2015-02-25

    Covalency in Ln-Cl bonds of Oh-LnCl6(x-) (x = 3 for Ln = Ce(III), Nd(III), Sm(III), Eu(III), Gd(III); x = 2 for Ln = Ce(IV)) anions has been investigated, primarily using Cl K-edge X-ray absorption spectroscopy (XAS) and time-dependent density functional theory (TDDFT); however, Ce L3,2-edge and M5,4-edge XAS were also used to characterize CeCl6(x-) (x = 2, 3). The M5,4-edge XAS spectra were modeled using configuration interaction calculations. The results were evaluated as a function of (1) the lanthanide (Ln) metal identity, which was varied across the series from Ce to Gd, and (2) the Ln oxidation state (when practical, i.e., formally Ce(III) and Ce(IV)). Pronounced mixing between the Cl 3p- and Ln 5d-orbitals (t2g* and eg*) was observed. Experimental results indicated that Ln 5d-orbital mixing decreased when moving across the lanthanide series. In contrast, oxidizing Ce(III) to Ce(IV) had little effect on Cl 3p and Ce 5d-orbital mixing. For LnCl6(3-) (formally Ln(III)), the 4f-orbitals participated only marginally in covalent bonding, which was consistent with historical descriptions. Surprisingly, there was a marked increase in Cl 3p- and Ce(IV) 4f-orbital mixing (t1u* + t2u*) in CeCl6(2-). This unexpected 4f- and 5d-orbital participation in covalent bonding is presented in the context of recent studies on both tetravalent transition metal and actinide hexahalides, MCl6(2-) (M = Ti, Zr, Hf, U).

  19. Structural, luminescence and biological studies of trivalent lanthanide complexes with N,N Prime -bis(2-hydroxynaphthylmethylidene)-1,3-propanediamine Schiff base ligand

    Energy Technology Data Exchange (ETDEWEB)

    Taha, Ziyad A., E-mail: tahaz33@just.edu.jo [Department of Applied Chemistry, Faculty of Arts and Sciences, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110 (Jordan); Ajlouni, Abdulaziz M. [Department of Applied Chemistry, Faculty of Arts and Sciences, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110 (Jordan); Al Momani, Waleed [Department of Allied Medical Sciences, Al Balqa Applied University (Jordan)

    2012-11-15

    New eight lanthanide metal complexes were prepared. These complexes were characterized by elemental analysis, molar conductivity measurements, spectral analysis ({sup 1}H NMR, FT-IR, UV-vis), luminescence and thermal gravimetric analysis. All Ln(III) complexes were 1:1 electrolytes as established by their molar conductivities. The microanalysis and spectroscopic analysis revealed eight-coordinated environments around lanthanide ions with two nitrate ligands behaving in a bidentate manner. The other four positions were found to be occupied with tetradentate L{sub III} ligand. Tb-L{sub III} and Sm-L{sub III} complexes exhibited characteristic luminescence emissions of the central metal ions and this was attributed to efficient energy transfer from the ligand to the metal center. The L{sub III} and Ln-L{sub III} complexes showed antibacterial activity against a number of pathogenic bacteria. - Highlights: Black-Right-Pointing-Pointer Ln(III) ion adopts an eight-coordinate geometry. Black-Right-Pointing-Pointer Luminescence spectra of Sm-L{sub III} and Tb-L{sub III} complexes display the metal centered line emission. Black-Right-Pointing-Pointer Energy transfer process from L{sub III} to Sm in Sm-L{sub III} complex is more efficient than to Tb in Tb-L{sub III} complex. Black-Right-Pointing-Pointer Ln(III) complexes may serve as models for biologically important species.

  20. Substitution studies of Mn and Fe in Ln{sub 6}W{sub 4}Al{sub 43} (Ln=Gd, Yb) and the structure of Yb{sub 6}Ti{sub 4}Al{sub 43}

    Energy Technology Data Exchange (ETDEWEB)

    Treadwell, LaRico J.; Watkins-Curry, Pilanda [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Department of Chemistry, University of Texas at Dallas, Richardson, TX 75080 (United States); McAlpin, Jacob D. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Prestigiacomo, Joseph; Stadler, Shane [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Chan, Julia Y., E-mail: Julia.Chan@utdallas.edu [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Department of Chemistry, University of Texas at Dallas, Richardson, TX 75080 (United States)

    2014-02-15

    The synthesis and characterization of Mn- and Fe-substituted Ln{sub 6}W{sub 4}Al{sub 43} (Ln=Gd, Yb) and Yb{sub 6}Ti{sub 4}Al{sub 43} are reported. The compounds adopt the Ho{sub 6}Mo{sub 4}Al{sub 43} structure type with lattice parameters of a∼11 Å and c∼17.8 Å with structural site preferences for Mn and Fe. The magnetization of Yb{sub 6}W{sub 4}Al{sub 43} is sensitive to Mn and Fe doping, which is evident by an increase in the field dependent magnetization. Gd{sub 6}W{sub 4}Al{sub 43}, Gd{sub 6}W{sub 4}Al{sub 42.31(11)}Mn{sub 0.69(11)}, and Gd{sub 6}W{sub 4}Al{sub 41.69(12)}Fe{sub 1.30(12)} order antiferromagnetically in the ab- and c-directions at 15, 14, and 13 K, respectively, with positive Weiss constants, suggesting the presence of ferromagnetic exchange interactions. Anisotropic magnetization data of Gd{sub 6}W{sub 4}Al{sub 43−y}T{sub y} (T=Mn, Fe) analogs are discussed. - Graphical abstract: The magnetic susceptibility of Ln{sub 6}W{sub 4−x}Al{sub 43−y}T{sub x+y} (Ln = Gd, Yb; T= Mn, Fe). Display Omitted - Highlights: • Single crystals of Ln{sub 6}W{sub 4−x}Al{sub 43−y}T{sub x+y} were grown with Al-flux. • Anisotropic magnetic behavior were determined on single crystals. • Gd{sub 6}W{sub 4−x}Al{sub 43−y}T{sub x+y} (T=Mn, Fe) analogs order antiferromagnetically.

  1. Systematic evaluation of Co-free LnBaFe2O5+δ (Ln = Lanthanides or Y) oxides towards the application as cathodes for intermediate-temperature solid oxide fuel cells

    International Nuclear Information System (INIS)

    Chen Dengjie; Wang Fucun; Shi Huangang; Ran Ran; Shao Zongping

    2012-01-01

    Co-free oxides with a nominal composition of LnBaFe 2 O 5+δ , where Ln = La, Pr, Nd, Sm, Gd, and Y, were synthesized and phase structure, oxygen content, electronic conductivity, oxygen desorption, thermal expansion, microstructure and electrochemical performance were systematically investigated. Among the series of materials tested, LaBaFe 2 O 5+δ oxide showed the largest electronic conductivity and YBaFe 2 O 5+δ oxide had the smallest thermal expansion coefficient (TEC) of 14.6 × 10 −6 K −1 within a temperature range of 200–900 °C. All LnBaFe 2 O 5+δ oxides typically possess the TEC values smaller than 20 × 10 −6 K −1 . The oxygen content, electronic conductivity and TEC values are highly dependent on the cation size of the Ln 3+ dopant. The lowest electrode polarization resistance in air under open circuit voltage condition was obtained for SmBaFe 2 O 5+δ electrode and was approximately 0.043, 0.084, 0.196, 0.506 and 1.348 Ω cm 2 at 800, 750, 700, 650 and 600 °C, respectively. The SmBaFe 2 O 5+δ oxide also demonstrated the best performance after a cathodic polarization. A cell with a SmBaFe 2 O 5+δ cathode delivered peak power densities of 1026, 748, 462, 276 and 148 mW cm −2 at 800, 750, 700, 650 and 600 °C, respectively. The results suggest that certain LnBaFe 2 O 5+δ oxides have sufficient electrochemical performance to be promising candidates for cathodes in intermediate-temperature solid oxide fuel cells.

  2. Room temperature synthesis of hydrophilic Ln(3+)-doped KGdF4 (Ln = Ce, Eu, Tb, Dy) nanoparticles with controllable size: energy transfer, size-dependent and color-tunable luminescence properties.

    Science.gov (United States)

    Yang, Dongmei; Li, Guogang; Kang, Xiaojiao; Cheng, Ziyong; Ma, Ping'an; Peng, Chong; Lian, Hongzhou; Li, Chunxia; Lin, Jun

    2012-06-07

    In this paper, we demonstrate a simple, template-free, reproducible and one-step synthesis of hydrophilic KGdF(4): Ln(3+) (Ln = Ce, Eu, Tb and Dy) nanoparticles (NPs) via a solution-based route at room temperature. X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) and cathodoluminescence (CL) spectra are used to characterize the samples. The results indicate that the use of water-diethyleneglycol (DEG) solvent mixture as the reaction medium not only allows facile particle size control but also endows the as-prepared samples with good water-solubility. In particular, the mean size of NPs is monotonously reduced with the increase of DEG content, from 215 to 40 nm. The luminescence intensity and absolute quantum yields for KGdF(4): Ce(3+), Tb(3+) NPs increase remarkably with particle sizes ranging from 40 to 215 nm. Additionally, we systematically investigate the magnetic and luminescence properties of KGdF(4): Ln(3+) (Ln = Ce, Eu, Tb and Dy) NPs. They display paramagnetic and superparamagnetic properties with mass magnetic susceptibility values of 1.03 × 10(-4) emu g(-1)·Oe and 3.09 × 10(-3) emu g(-1)·Oe at 300 K and 2 K, respectively, and multicolor emissions due to the energy transfer (ET) process Ce(3+)→ Gd(3+)→ (Gd(3+))(n)→ Ln(3+), in which Gd(3+) ions play an intermediate role in this process. Representatively, it is shown that the energy transfer from Ce(3+) to Tb(3+) occurs mainly via the dipole-quadrupole interaction by comparison of the theoretical calculation and experimental results. This kind of magnetic/luminescent dual-function materials may have promising applications in multiple biolabels and MR imaging.

  3. High-pressure investigations of lanthanoid oxoarsenates. I. Single crystals of scheelite-type Ln[AsO{sub 4}] phases with Ln = La-Nd from monazite-type precursors

    Energy Technology Data Exchange (ETDEWEB)

    Metzger, Sebastian J.; Ledderboge, Florian; Schleid, Thomas [Stuttgart Univ. (Germany). Inst. fuer Anorganische Chemie; Heymann, Gunter; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

    2016-08-01

    Transparent single crystals of the scheelite-type Ln[AsO{sub 4}] phases with Ln = La-Nd are obtained by the pressure-induced monazite-to-scheelite type phase transition in a Walker-type module under high-pressure and high-temperature conditions of 11 GPa at 1100-1300 C. Coinciding with this transition, there is an increase in density and a reduction in molar volume of about 4.5 % for the scheelite-type phases (tetragonal, I4{sub 1}/a) for La[AsO{sub 4}] (a = 516.92(4), c = 1186.1(9) pm), Ce[AsO{sub 4}] (a = 514.60(1), c = 1175.44(2) pm), Pr[AsO{sub 4}] (a = 512.63(4), c = 1168.25(9) pm), and Nd[AsO{sub 4}] (a = 510.46(4), c = 1160.32(11) pm) as compared to the well-known monazite-type phases (monoclinic, P2{sub 1}/n). Surprisingly enough, the scheelite-type oxoarsenates(V) exhibit a lower coordination number for the Ln{sup 3+} cations (CN = 8 versus CN = 8 + 1), whereas the isolated tetrahedral [AsO{sub 4}]{sup 3-} anions (d(As-O) = 168.9-169.3 pm for the scheelites as compared to d(As-O) = 167.1-169.9 pm for the monazites) remain almost unchanged. So the densification must occur because of the loss of two edge-connections of the involved [LnO{sub 8+1}]{sup 15-} polyhedra with the [AsO{sub 4}]{sup 3-} tetrahedra in the monazite- resulting in exclusively vertex connected [LnO{sub 8}]{sup 13-} and [AsO{sub 4}]{sup 3-} units in the scheelite-type structure.

  4. New family of lanthanide-based inorganic-organic hybrid frameworks: Ln2(OH)4[O3S(CH2)nSO3]·2H2O (Ln = La, Ce, Pr, Nd, Sm; n = 3, 4) and their derivatives.

    Science.gov (United States)

    Liang, Jianbo; Ma, Renzhi; Ebina, Yasuo; Geng, Fengxia; Sasaki, Takayoshi

    2013-02-18

    We report the synthesis and structure characterization of a new family of lanthanide-based inorganic-organic hybrid frameworks, Ln(2)(OH)(4)[O(3)S(CH(2))(n)SO(3)]·2H(2)O (Ln = La, Ce, Pr, Nd, Sm; n = 3, 4), and their oxide derivatives. Highly crystallized samples were synthesized by homogeneous precipitation of Ln(3+) ions from a solution containing α,ω-organodisulfonate salts promoted by slow hydrolysis of hexamethylenetetramine. The crystal structure solved from powder X-ray diffraction data revealed that this material comprises two-dimensional cationic lanthanide hydroxide {[Ln(OH)(2)(H(2)O)](+)}(∞) layers, which are cross-linked by α,ω-organodisulfonate ligands into a three-dimensional pillared framework. This hybrid framework can be regarded as a derivative of UCl(3)-type Ln(OH)(3) involving penetration of organic chains into two {LnO(9)} polyhedra. Substitutional modification of the lanthanide coordination promotes a 2D arrangement of the {LnO(9)} polyhedra. A new hybrid oxide, Ln(2)O(2)[O(3)S(CH(2))(n)SO(3)], which is supposed to consist of alternating {[Ln(2)O(2)](2+)}(∞) layers and α,ω-organodisulfonate ligands, can be derived from the hydroxide form upon dehydration/dehydroxylation. These hybrid frameworks provide new opportunities to engineer the interlayer chemistry of layered structures and achieve advanced functionalities coupled with the advantages of lanthanide elements.

  5. Design Guidelines for Collaboration and Participation with Examples from the LN4LD (Learning Network for Learning Design)

    NARCIS (Netherlands)

    Burgos, Daniel; Hummel, Hans; Tattersall, Colin; Brouns, Francis; Koper, Rob

    2007-01-01

    Burgos, D., Hummel, H. G. K., Tattersall, C., Brouns, F., & Koper, R. (2009). Design Guidelines for Collaboration and Participation with Examples from the LN4LD (Learning Network for Learning Design). In L. Lockyer, S. Bennett, S. Agostinho & B. Harper (Eds.), Handbook of Research on Learning Design

  6. Lanthanide complexes of 2-aminoacetophenone and 2-acetylaminoacetophenone 2-thenoylhydrazone

    International Nuclear Information System (INIS)

    Singh, Praveen K.; Singh, B.

    1998-01-01

    The reaction of lanthanide chlorides with 2-aminoacetophenone-2-thenoyl- hydrazone and 2-acetylaminoacetophenone-2-thenoylhydrazone yield complexes of the type [Ln(aath) 2 Cl 2 (H 2 )O]Cl and [Ln(acaath) 2 Cl 2 ]Cl. These complexes have been characterized by molar conductance, magnetic susceptibility, TGA, DTA and various spectroscopic techniques such as mass, IR, NMR, UV - visible and emission spectra. Mass spectral data indicate the aath complexes to be monomeric. Thermal stability of the complexes and presence of one water molecule in aath complex is indicated by TGA and DTA studies. Electronic spectra of Pr(III) and Nd(III) complexes show the coordination number to be nine and eight around the metal ions in the aath and acaath complexes, respectively. This has also been inferred from the spectral features of the hypersensitive transition in the Nd(III) complexes. The lowering in coordination number from aath to acaath complexes may be attributed to increase in chelate ring size and/or steric/inductive effect of methyl group. Emission spectral studies of the [Eu(aath) 2 Cl 2 (H 2 O)]Cl and [Eu(acaath) 2 Cl 2 ]Cl suggest tricapped trigonal prismatic (D 3h ) and square antiprismatic (D 4d ) geometry, respectively. (author)

  7. Study of ln s Physics in $\\bar{p}p$ Interactions at the Split Field Magnet

    CERN Multimedia

    2002-01-01

    This experiment uses the Split Field Magnet detector to investigate the low p^t, ``ln~s'', type of interactions that dominate the @*p cross-section. Systematic comparisons will be made to pp interactions. \\\\ \\\\ Specific areas to be studied include elastic scattering in the regions 0.05 $<$ !t! $<$ 0.8 GeV|2 and 0.8 $<$ !t! $<$ 4.0 GeV|2, and the use of a minimum bias trigger to study topological cross-sections, inclusive spectra, and two-body correlations. Some specialized triggers, run simultaneously with the high t elastic scattering trigger, are being studied. Examples are a trigger requiring Cerenkov identification in a limited region of phase space, and a trigger to select diffractively produced events.

  8. Tensile Deformation Temperature Impact on Microstructure and Mechanical Properties of AISI 316LN Austenitic Stainless Steel

    Science.gov (United States)

    Xiong, Yi; He, Tiantian; Lu, Yan; Ren, Fengzhang; Volinsky, Alex A.; Cao, Wei

    2018-03-01

    Uniaxial tensile tests were conducted on AISI 316LN austenitic stainless steel from - 40 to 300 °C at a rate of 0.5 mm/min. Microstructure and mechanical properties of the deformed steel were investigated by optical, scanning and transmission electron microscopies, x-ray diffraction, and microhardness testing. The yield strength, ultimate tensile strength, elongation, and microhardness increase with the decrease in the test temperature. The tensile fracture morphology has the dimple rupture feature after low-temperature deformations and turns to a mixture of transgranular fracture and dimple fracture after high-temperature ones. The dominating deformation microstructure evolves from dislocation tangle/slip bands to large deformation twins/slip bands with temperature decrease. The deformation-induced martensite transformation can only be realized at low temperature, and its quantity increases with the decrease in the temperature.

  9. Influence of Heat Treatment on Mercury Cavitation Resistance of Surface Hardened 316LN Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, Steven J [ORNL; Hsu, Julia [Massachusetts Institute of Technology (MIT)

    2010-11-01

    The cavitation-erosion resistance of carburized 316LN stainless steel was significantly degraded but not destroyed by heat treatment in the temperature range 500-800 C. The heat treatments caused rejection of some carbon from the carburized layer into an amorphous film that formed on each specimen surface. Further, the heat treatments encouraged carbide precipitation and reduced hardness within the carburized layer, but the overall change did not reduce surface hardness fully to the level of untreated material. Heat treatments as short as 10 min at 650 C substantially reduced cavitation-erosion resistance in mercury, while heat treatments at 500 and 800 C were found to be somewhat less detrimental. Overall, the results suggest that modest thermal excursions perhaps the result of a weld made at some distance to the carburized material or a brief stress relief treatment will not render the hardened layer completely ineffective but should be avoided to the greatest extent possible.

  10. Synthesis, spectral characterization and in vitro antifungal activity of Lanthanum(III) and Praseodymium(III) complexes with Schiff bases derived from 5-substituted-4-amino-5-hydrazino-1,2,4-triazoles and isatin

    International Nuclear Information System (INIS)

    Singh, Shweta; Tripathi, Priti; Pandey, Om P.; Sengupta, Soumitra K.

    2013-01-01

    The new lanthanum(III) and praseodymium(III) complexes of the general formula (LnCl(L)(H 2 O) 2 ) (Ln = La III or Pr III ; H 2 L = Schiff bases derived from 3-substituted-4-amino-5-hydrazino-1,2,4-triazoles and isatin) have been prepared. The complexes have been characterized by elemental analyses, molecular weight by FAB-mass, thermogravimetry, electrical conductance, magnetic moment and spectral (electronic, infrared, far-infrared, 1 H NMR and 13 C NMR) data. The ligands and all prepared complexes were assayed for antifungal (Aspergillus niger and Helminthosporium oryzae) activities. The activities have been correlated with the structures of the complexes. (author)

  11. Fatigue properties of type 316LN stainless steel in air and mercury

    International Nuclear Information System (INIS)

    Strizak, J.P.; Tian, H.; Liaw, P.K.; Mansur, L.K.

    2005-01-01

    An extensive fatigue testing program on 316LN stainless steel was recently carried out to support the design of the mercury target container for the spallation neutron source (SNS) that is currently under construction at the Oak Ridge National Laboratory in the United States. The major objective was to determine the effects of mercury on fatigue behavior. The S-N fatigue behavior of 316LN stainless steel is characterized by a family of bilinear fatigue curves which are dependent on frequency, environment, mean stress and cold work. Generally, fatigue life increases with decreasing stress and levels off in the high cycle region to an endurance limit below which the material will not fail. For fully reversed loading as well as tensile mean stress loading conditions mercury had no effect on endurance limit. However, at higher stresses a synergistic relationship between mercury and cyclic loading frequency was observed at low frequencies. As expected, fatigue life decreased with decreasing frequency, but the response was more pronounced in mercury compared with air. As a result of liquid metal embrittlement (LME), fracture surfaces of specimens tested in mercury showed widespread brittle intergranular cracking as opposed to typical transgranular cracking for specimens tested in air. For fully reversed loading (zero mean stress) the effect of mercury disappeared as frequency increased to 10 Hz. For mean stress conditions with R-ratios of 0.1 and 0.3, LME was still evident at 10 Hz, but at 700 Hz the effect of mercury had disappeared (R 0.1). Further, for higher R-ratios (0.5 and 0.75) fatigue curves for 10 Hz showed no environmental effect. Finally, cold working (20%) increased tensile strength and hardness, and improved fatigue resistance. Fatigue behavior at 10 and 700 Hz was similar and no environmental effect was observed

  12. Fatigue properties of type 316LN stainless steel in air and mercury

    Science.gov (United States)

    Strizak, J. P.; Tian, H.; Liaw, P. K.; Mansur, L. K.

    2005-08-01

    An extensive fatigue testing program on 316LN stainless steel was recently carried out to support the design of the mercury target container for the spallation neutron source (SNS) that is currently under construction at the Oak Ridge National Laboratory in the United States. The major objective was to determine the effects of mercury on fatigue behavior. The S- N fatigue behavior of 316LN stainless steel is characterized by a family of bilinear fatigue curves which are dependent on frequency, environment, mean stress and cold work. Generally, fatigue life increases with decreasing stress and levels off in the high cycle region to an endurance limit below which the material will not fail. For fully reversed loading as well as tensile mean stress loading conditions mercury had no effect on endurance limit. However, at higher stresses a synergistic relationship between mercury and cyclic loading frequency was observed at low frequencies. As expected, fatigue life decreased with decreasing frequency, but the response was more pronounced in mercury compared with air. As a result of liquid metal embrittlement (LME), fracture surfaces of specimens tested in mercury showed widespread brittle intergranular cracking as opposed to typical transgranular cracking for specimens tested in air. For fully reversed loading (zero mean stress) the effect of mercury disappeared as frequency increased to 10 Hz. For mean stress conditions with R-ratios of 0.1 and 0.3, LME was still evident at 10 Hz, but at 700 Hz the effect of mercury had disappeared ( R = 0.1). Further, for higher R-ratios (0.5 and 0.75) fatigue curves for 10 Hz showed no environmental effect. Finally, cold working (20%) increased tensile strength and hardness, and improved fatigue resistance. Fatigue behavior at 10 and 700 Hz was similar and no environmental effect was observed.

  13. Fatigue and fatigue crack growth properties of 316LN and Incoloy 908 below 10 K

    International Nuclear Information System (INIS)

    Nyilas, A.; Zhang, J.; Obst, B.; Ulbricht, A.

    1992-01-01

    The cyclic loading characteristics of Tokamak type thermonuclear machines demand study of the fatigue response of the materials used in critical components. The large superconducting magnets and their superconductors will operate under cyclic mechanical stress conditions. The present paper is biased towards the current superconductor design of the NET (Next European Torus) model coil concept. The superconductor of this coil will be a cable-in-conduit Nb 3 Sn type with an enveloped stiff external jacket structure. The wall thickness of the jacket structure is within the range of 4-5 mm. The manufacturing of the jacket lengths for several hundred meters require an appropriate joining process due to the prefabricated section pieces available only in short lengths of 5-7 meters. The recently anticipated solution favors the flash butt welding technique. The performance of the superconductors jacket will depend on the material selection and the proper structural design according to the existing low temperature structural materials data base. The wind and react Nb 3 Sn-manufacturing process must also account the materials properties after ageing. A program was set up to elucidate the fatigue-life behavior and fatigue crack growth rate (FCGR) of the selected two candidate materials. These materials were the AISI 316LN with a specified low carbon content to avoid the embrittlement after the ageing process and the Incoloy 908. The 316LN material in the as received condition was tested with respect to its fatigue-life for specimens bearing predefined flaws and cracks. The propagation of surface cracks at 12 K and at 295 K was characterized with non standard specimens. The tests were performed in a cryogenic dynamic test facility under helium gas environment between 7 K and 20 K. Using the reference growth laws obtained from these measurements the total crack propagation starting with the initial crack length of the specimen could be predicted by numerical computation

  14. Long-term Creep Life Prediction for Type 316LN Stainless Steel

    International Nuclear Information System (INIS)

    Kim, Woo Gon; Ryu, Woo Seog; Kim, Sung Ho; Lee, Chan Bok

    2007-01-01

    Since Sodium Fast Cooled Reactor (SFR) components are designed to be use for more than 30 years at a high temperature of 550 .deg. C, one of the most important properties of these components is the long term creep behavior. To accurately predict the long-term creep life of the components, it is essential to achieve reliable long-term test data beyond their design life. But, it is difficult to actually obtain long duration data because it is time-consuming work. So far, a variety of time-temperature parameters (TTPs) have been developed to predict a long-term creep life from shorter-time tests at higher temperatures. Among them, the Larson-Miller, the Orr-Sherby-Dorn, the Manson-Harferd and the Manson-Succop parameters have been typically used. None of these parameters has an overwhelming preference, and they have certain inherent restrictions imposed on their data in the application of the TTPs parameters. Meanwhile, it has been reported that the Minimum Commitment Method (MCM) proposed by Manson and Ensign has a greater flexibility for a creep rupture analysis. Thus, the MCM will be useful as another approach. Until now, the applicability of the MCM has not been investigated for type 316LN SS because of insufficient creep data. In this paper, the MCM was applied to predict a long-term creep life of type 316LN stainless steel (SS). Lots of creep rupture data was collected through literature surveys and the experimental data of KAERI. Using the short-term experimental data for under 2,000 hours, a longer-time rupture above 105 hours was predicted by the MCM at temperatures from 550 .deg. C to 800 .deg. C

  15. Crystallization and structural approaches of rare earths aluminosilicate glasses (Ln = La, Y, Sc)

    International Nuclear Information System (INIS)

    Sadiki, N.; Coutures, J.P.; Hennet, L.; Florian, P.; Vaills, Y.; Massiot, D.

    2010-01-01

    The crystallization behaviour of aluminosilicate glasses of lanthanum, yttrium and scandium has been studied by DTA, XRD, SEM-EDX and EPMA analysis. Young modulus E and hardness H have been measured by using nano-indentation and elastic modulus C 11 and C 44 by Brillouin scattering. The Young modulus measured by nano-indentation agree to those determined by Brillouin scattering and those calculated using Makishima-Mackenzie and Rocherulle model's. The results of DTA analysis indicate that (a) the glass transition temperatures T g are higher for yttrium and scandium containing glasses than their lanthanum counterparts, the melting observed in the yttrium glasses and recently in the scandium glasses correspond to the ternary eutectic Ln 2 O 3 -Al 2 O 3 -SiO 2 (Ln = Y, Sc) (b) the thermal stability is strongly related to the ionic radii of the rare earth. The last results obtained on scandium containing glasses confirm this hypothesis. The XRD results show that the nature of the observed crystallized phases is consistent with the phase diagrams. We also have investigated by NMR-MAS of 27 Al (high field- 17.6 T) these glasses. The results indicate that Al(V) species are correlated to the ionic radii of the rare earth. X-rays and neutron scattering experiments have been respectively performed on the high energy diffraction beam lines ID11 and ID15 at ESRF. The interatomic distances and first-shell coordination numbers were determined. The results are consistent with those performed by NMR-MAS. (authors)

  16. U(SMes*)n, (n=3, 4) and Ln(SMes*)3 (Ln = La, Ce, Pr, Nd): Lanthanide(III)/actinide(III) differentiation in agostic interactions and an unprecedented eta(3) Ligation mode of the aryl-thiolate ligand, from X-ray diffraction and DFT analysis

    International Nuclear Information System (INIS)

    Roger, Mathieu; Barros, Noemi; Arliguie, Therese; Thuery, Pierre; Maron, Laurent; Ephritikhine, Michel

    2006-01-01

    Reaction of U(NEt 2 ) 4 with HS-2,4,6- t Bu 3 C 6 H 2 (HSMes*) gave U(SMes*) 3 (NEt 2 )(py) (1), whereas similar treatment of U[N(SiMe 3 )SiMe 2 CH 2 ][N(SiMe 3 ) 2 ] 2 afforded U(SMes*)[N(SiMe 3 ) 2 ] 3 (2) and U(SMes*) 3 [N(SiMe 3 ) 2 ]. The first neutral homoleptic uranium(IV) thiolate to have been crystallographically characterized, U(SMes*) 4 (4), was isolated from the reaction of U(BH 4 ) 4 and KSMes*. The first homoleptic thiolate complex of uranium(III), U(SMes*) 3 (5), was synthesized by proton-lysis of U[N(SiMe 3 ) 2 ] 3 with HSMes* in cyclohexane. The crystal structure of 5 exhibits the novel η 3 ligation mode for the aryl-thiolate ligand. Comparison of the crystal structure of 5 with those of the isomorphous lanthanide congeners Ln(SMes*) 3 (Ln) La, Ce, Pr, and Nd) indicates that the U-S, U-C ipso , and U-C ortho bond lengths are shorter than the corresponding ones in the 4f-element analogues, when taking into account the variation in the ionic radii of the metals. The distance between the uranium and the carbon atoms involved in the U center dot center dot center dot H-C ε agostic interaction of each thiolate ligand is shorter, by ∼ 0.05 angstrom, than that expected from a purely ionic bonding model. The lanthanide( III)/actinide(III) differentiation was analyzed by density functional theory (DFT). The nature of the M-S bond is shown to be ionic strongly polarized at the sulfur for M) U and ion-covalent (i.e. strongly ionic with low orbital interaction), for M) Ln. The strength of the U center dot center dot center dot H-C ε agostic interaction is proposed to be controlled by the maximization of the interaction between U + and S - under steric constraints. The η 3 ligation mode of the aryl-thiolate ligand is also obtained from DFT. (authors)

  17. U(SMes*)n, (n = 3, 4) and Ln(SMes*)3 (Ln = La, Ce, Pr, Nd): lanthanide(III)/actinide(III) differentiation in agostic interactions and an unprecedented eta3 ligation mode of the arylthiolate ligand, from X-ray diffraction and DFT analysis.

    Science.gov (United States)

    Roger, Mathieu; Barros, Noémi; Arliguie, Thérèse; Thuéry, Pierre; Maron, Laurent; Ephritikhine, Michel

    2006-07-12

    Reaction of U(NEt(2))(4) with HS-2,4,6-(t)Bu(3)C(6)H(2) (HSMes) gave U(SMes)(3)(NEt(2))(py) (1), whereas similar treatment of U[N(SiMe(3))SiMe(2)CH(2)][N(SiMe(3))(2)](2) afforded U(SMes)[N(SiMe(3))(2)](3) (2) and U(SMes)(3)[N(SiMe(3))(2)]. The first neutral homoleptic uranium(IV) thiolate to have been crystallographically characterized, U(SMes)(4) (4), was isolated from the reaction of U(BH(4))(4) and KSMes. The first homoleptic thiolate complex of uranium(III), U(SMes)(3) (5), was synthesized by protonolysis of U[N(SiMe(3))(2)](3) with HSMes in cyclohexane. The crystal structure of 5 exhibits the novel eta(3) ligation mode for the arylthiolate ligand. Comparison of the crystal structure of 5 with those of the isomorphous lanthanide congeners Ln(SMes)(3) (Ln = La, Ce, Pr, and Nd) indicates that the U-S, U-C(ipso)(), and U-C(ortho)() bond lengths are shorter than the corresponding ones in the 4f-element analogues, when taking into account the variation in the ionic radii of the metals. The distance between the uranium and the carbon atoms involved in the U...H-C epsilon agostic interaction of each thiolate ligand is shorter, by approximately 0.05 A, than that expected from a purely ionic bonding model. The lanthanide(III)/actinide(III) differentiation was analyzed by density functional theory (DFT). The nature of the M-S bond is shown to be ionic strongly polarized at the sulfur for M = U and iono-covalent (i.e. strongly ionic with low orbital interaction), for M = Ln. The strength of the U...H-C epsilon agostic interaction is proposed to be controlled by the maximization of the interaction between U(+) and S(-) under steric constraints. The eta(3) ligation mode of the arylthiolate ligand is also obtained from DFT.

  18. Synthesis, Characterization, Luminescence and Biological Activity of Two Lanthanide Complexes Involving Mixed Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Deyun; Guo, Haifu; Qin, Liang [Zhaoqing Univ., Zhaoqing (China); Xu, Jun [Jinan Univ., Guangzhou (China)

    2013-09-15

    Two new isostructural dinuclear complexes, Ln{sub 2}(4-cpa){sub 6}(bpy){sub 2} (Ln = Eu (1); Tb (2), 4-cpa = 4-chlorophenyl-acetate, bpy = 2,2'-bipyridine), have been hydrothermally synthesized and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffraction and single-crystal X-ray diffraction. The lanthanide ions are bridged by two bidentate and two terdentate carboxylate groups to give centrosymmetric dimers with Ln···Ln separations of 3.967(2) and 3.956(3) A, respectively. Each metal atom is nine-coordinate and exhibits a distorted tricapped trigonal prismatic geometry. Three-dimensional fluorescence spectra show that both 1 and 2 emit bright red and green luminescence at room temperature, with long lifetimes of up to 0.369 ms (at 614 nm) and 0.432 ms (at 543 nm), respectively. Moreover, poor luminescence efficiency has been noted for complex 2. The 4-Hcpa ligand and complexes 1-2 have been screened for their phytogrowth-inhibitory activities against Brassica napus L. and Echinochloa crusgalli L., and the results are compared with the activity of quizalofop-P-ethyl.

  19. Effect of ligand substitution on the SMM properties of three isostructural families of double-cubane Mn4Ln2 coordination clusters.

    Science.gov (United States)

    Akhtar, Muhammad Nadeem; Lan, Yanhua; AlDamen, Murad A; Zheng, Yan-Zhen; Anson, Christopher E; Powell, Annie K

    2018-03-06

    Three isostructural lanthanide series with a core of MnMnLn 2 are reported. These three families have the formulae of [MnMnLn 2 (μ 4 -O) 2 (H 2 edte) 2 (piv) 6 (NO 3 ) 2 ] {no crystallization solvent, Ln = La, Ce, Pr, Nd, Eu (1-4, 6); solv = 3MeCN, Ln = Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Y (5, 7-13)}, where H 2 edte = N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine and piv = pivalate; [MnMnLn 2 (μ 4 -O) 2 (H 2 edte) 2 (benz) 6 (NO 3 ) 2 ], where benz = benzoate, or [MnMnLn 2 (μ 4 -O) 2 (edteH 2 ) 2 (benz) 6 (NO 3 ) 2 ]·2MeCN {Ln = Gd, Tb, Dy (14-16); and [MnMnLn 2 (μ 4 -O) 2 (edteH 2 ) 2 (piv) 8 ].solv {solv = 4MeCN, Ln = La (17); solv = 2MeCN·tol·H 2 O, Ln = Pr, Nd, Sm, Tb (18-20, 22); solv = 2MeCN·H 2 O, Ln = Gd (21). These compounds crystallize in two different systems, namely, monoclinic in the space groups P2 1 /n for 1-4, 6, and 14-16 and C2/c for 5, 7-13, 18-20, and 22 and triclinic in the space group P1[combining macron] for 17 and 21. The crystal structures of these compounds display a face-fused dicubane structure connected by different types of bridged oxygen atoms. Solid-state dc magnetic susceptibility characterization was carried out for 1-22, and fitting showed that Mn III Mn III is antiferromagnetically (AF) coupled and Mn II Mn III , Mn II Ln and Mn III Ln are weakly ferromagnetically coupled. In addition, ac measurements were carried out and showed that only 7, 15, and 22 for Tb, 8 and 16 for Dy, and 20 for Sm exhibited slow magnetization relaxation. In the case of 15, it was possible to determine the energy barrier of the slow-relaxation behavior by fitting peak temperatures to the Arrhenius law, which gave a value of U eff = 21.2 K and a pre-exponential factor of τ 0 = 4.0 × 10 -9 s.

  20. Influence of metal loading and humic acid functional groups on the complexation behavior of trivalent lanthanides analyzed by CE-ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Kautenburger, Ralf, E-mail: r.kautenburger@mx.uni-saarland.de [Institute of Inorganic Solid State Chemistry, Saarland University, Campus Dudweiler, Am Markt Zeile 3-5, D-66125 Saarbrücken (Germany); Hein, Christina; Sander, Jonas M. [Institute of Inorganic Solid State Chemistry, Saarland University, Campus Dudweiler, Am Markt Zeile 3-5, D-66125 Saarbrücken (Germany); Beck, Horst P. [Institute of Inorganic and Analytical Chemistry and Radiochemistry, Saarland University, Campus Dudweiler, Am Markt Zeile 5, D-66125 Saarbrücken (Germany)

    2014-03-01

    Highlights: • Free and complexed HA-Ln species are separated by CE-ICP-MS. • Weaker and stronger HA-binding sites for Ln-complexation can be detected. • Complexation by original and modified humic acid (HA) with blocked phenolic hydroxyl- and carboxyl-groups is compared. • Stronger HA-binding sites for Ln³⁺ can be assumed as chelating complexes. • Chelates consist of trivalent Ln and a combination of both OH- and COOH-groups. Abstract: The complexation behavior of Aldrich humic acid (AHA) and a modified humic acid (AHA-PB) with blocked phenolic hydroxyl groups for trivalent lanthanides (Ln) is compared, and their influence on the mobility of Ln(III) in an aquifer is analyzed. As speciation technique, capillary electrophoresis (CE) was hyphenated with inductively coupled plasma mass spectrometry (ICP-MS). For metal loading experiments 25 mg L⁻¹ of AHA and different concentrations (c Ln(Eu+Gd)} = 100–6000 μg L⁻¹) of Eu(III) and Gd(III) in 10 mM NaClO₄ at pH 5 were applied. By CE-ICP-MS, three Ln-fractions, assumed to be uncomplexed, weakly and strongly AHA-complexed metal can be detected. For the used Ln/AHA-ratios conservative complex stability constants log βLnAHA decrease from 6.33 (100 μg L⁻¹ Ln³⁺) to 4.31 (6000 μg L⁻¹ Ln³⁺) with growing Ln-content. In order to verify the postulated weaker and stronger humic acid binding sites for trivalent Eu and Gd, a modified AHA with blocked functional groups was used. For these experiments 500 μg L⁻¹ Eu and 25 mg L⁻¹ AHA and AHA-PB in 10 mM NaClO₄ at pH-values ranging from 3 to 10 have been applied. With AHA-PB, where 84% of the phenolic OH-groups and 40% of the COOH-groups were blocked, Eu complexation was significantly lower, especially at the strong binding sites. The log β-values decrease from 6.11 (pH 10) to 5.61 at pH 3 (AHA) and for AHA-PB from 6.01 (pH 7) to 3.94 at pH 3. As a potential consequence, particularly humic acids with a high amount of

  1. Studies on mixed ligand complexes of lanthanide (III) ions

    International Nuclear Information System (INIS)

    Rajendran, G.; Usha Devi, K.G.

    2002-01-01

    As part of our research programme, we have prepared and characterized a few nitrato, thiocyanato and perchlorato complexes of lanthanide(III) ions with ligands, viz., a Schiff base derived from p-anisidine and vanillin and diphenyl sulphoxide. The complexes were characterized by the measurement of electrical conductances and magnetic susceptibilities, molecular mass and metal percentage and spectral analysis. The thermal decompositions were studied by TG and DTG techniques. The thiocyanato complexes were prepared by substitution method from nitrato complexes. p-Anisidine-vanillin (HDDA) and diphenyl sulphoxide (DPSO) are coordinated to the metal ion in unidentate fashion. All the anions were involved in coordination in these complexes. Thus they were found to have non- electrolytic behaviour with composition [Ln(HDDA) 2 (DPSO)X 3 ] where X = NO 3 ) or SCN perchlorato complexes were prepared from metal perchlorate as done in the case of nitrato complexes. They were found to have electrical conductance which corresponds to 1 : 1 electrolyte. Hence one of the perchlorate ions is outside the coordination sphere. The composition of this complex is found to be [Ln(HDDA) 3 (DPSO)(ClO 4 ) 2 ]ClO 4 . (author)

  2. Syntheses, crystal structures and solid-state properties of the lanthanoid-containing nanoclusters [(Ln{sub 2}PW{sub 10}O{sub 38}){sub 4}(W{sub 3}O{sub 8})(OH){sub 4}(H{sub 2}O){sub 2}]{sup 26-}

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Rakesh; Saini, Mukesh Kumar; Hussain, Firasat [Department of Chemistry, University of Delhi (India)

    2014-12-15

    A series of lanthanoid-substituted polyoxometalates have been synthesized by a self-assembly process in potassium chloride solution by the reaction of dilacunary [P{sub 2}W{sub 19}O{sub 69}(H{sub 2}O)]{sup 14-} with mid- and late-lanthanoid Ln(NO{sub 3}){sub 3}.nH{sub 2}O salts leading to the formation of the tetrameric tungstophosphates [(Ln{sub 2}PW{sub 10}O{sub 38}){sub 4}(W{sub 3}O{sub 8})(OH){sub 4}(H{sub 2}O){sub 2}]{sup 26-} [Ln = Y{sup 3+} (1), Sm{sup 3+} (2), Eu{sup 3+} (3), Gd{sup 3+} (4), Tb{sup 3+} (5), Dy{sup 3+} (6), Ho{sup 3+} (7), Er{sup 3+} (8), Tm{sup 3+} (9), Yb{sup 3+} (10)]. The polyanions were isolated as potassium or mixed-alkali salts. Most of the compounds were characterized by single-crystal X-ray diffraction and various analytical techniques, such as FTIR, UV/Vis, {sup 31}P NMR and photoluminescence spectroscopy, magnetism, as well as thermogravimetric analysis. The FTIR spectra suggest that all the compounds are isomorphous. The crystal structures of these complexes consist of four A-[α-PW{sub 10}O{sub 36}]{sup 7-} units, each incorporating two Ln{sup III} ions to create four Keggin-like anions that further assemble with three additional tungstate units to form a tetramer species with C{sub 2} symmetry. The photoluminescent properties of 3a and 6a were investigated following photoexcitation at room temperature. The magnetic properties of 3a, 4a, 5a and 6a were investigated at room temperature, the complexes exhibiting paramagnetic behaviour. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Red emitting phosphors of Eu{sup 3+} doped Na{sub 2}Ln{sub 2}Ti{sub 3}O{sub 10} (Ln = Gd, Y) for white light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Niumiao [National Key Laboratory of Photoelectric Technology and Functional Materials Culture Base in Shaanxi Province, National Photoelectric Technology and Functional Materials & Application of Science and Technology International Cooperation Base, Institute of Photonics & Photon-Technology, Northwest University, Xi’an 710069 (China); Guo, Chongfeng, E-mail: guocf@nwu.edu.cn [National Key Laboratory of Photoelectric Technology and Functional Materials Culture Base in Shaanxi Province, National Photoelectric Technology and Functional Materials & Application of Science and Technology International Cooperation Base, Institute of Photonics & Photon-Technology, Northwest University, Xi’an 710069 (China); Yin, Luqiao; Zhang, Jianhua [Key Laboratory of Advanced Display and System Applications (Shanghai University), Ministry of Education, Shanghai 200072 (China); Wu, Mingmei, E-mail: ceswmm@mail.sysu.edu.cn [School of Chemistry and Chemical Engineering, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275 (China)

    2015-06-25

    Highlights: • Layered red phosphors Na{sub 2}Ln{sub 2}Ti{sub 3}O{sub 10} (Ln = Gd, Y):Eu{sup 3+} were prepared. • The synthesis parameters of phosphors were optimized. • PL and thermal stability of the samples were investigated. • LED devices were also fabricated including the present red phosphor. - Abstract: A series of Eu{sup 3+} doped Na{sub 2}Ln{sub 2}Ti{sub 3}O{sub 10} (Ln = Gd, Y) red-emitting phosphors for application in ultraviolet based light emitting diodes (LEDs) were successfully synthesized by a modified sol–gel method. Their structure and luminescent properties were characterized by powder X-ray diffraction (XRD), photoluminescence excitation (PLE) and emission (PL) spectra and absorption spectra, according to these results the optimal compositions and synthesis parameters were determined. In addition, the thermal stabilities of the phosphors were investigated according to the temperature-dependent PL spectra. The red and white-LEDs (W-LEDs) comprising the Na{sub 2}Ln{sub 2}Ti{sub 3}O{sub 10}:Eu{sup 3+} (Ln = Gd, Y) red emitting phosphors were fabricated with a near-ultraviolet (n-UV) chip. In comparison with Na{sub 2}Y{sub 1.4}Eu{sub 0.6}Ti{sub 3}O{sub 10}, the Na{sub 2}Gd{sub 0.6}Eu{sub 1.4}Ti{sub 3}O{sub 10} phosphor offers higher brightness, quantum efficiency, and excellent thermal stability. W-LEDs comprising Na{sub 2}Gd{sub 0.6}Eu{sub 1.4}Ti{sub 3}O{sub 10} showed bright white emission with a color rendering index (Ra) of 82, a color temperature of 2151 K, and Commission Internationale de I’Eclairage (CIE) color coordinates of (0.34, 0.37). The phosphor Na{sub 2}Gd{sub 0.6}Eu{sub 1.4}Ti{sub 3}O{sub 10} is more suitable candidate for application in LEDs.

  4. Luminescent, magnetic and ferroelectric properties of noncentrosymmetric chain-like complexes composed of nine-coordinate lanthanide ions.

    Science.gov (United States)

    Li, Xi-Li; Chen, Chun-Lai; Xiao, Hong-Ping; Wang, Ai-Ling; Liu, Cai-Ming; Zheng, Xianjun; Gao, Li-Jun; Yang, Xiao-Gang; Fang, Shao-Ming

    2013-11-21

    Reaction of the chiral ligand (-)-4,5-pinenepyridyl-2-pyrazine (L) with Ln(hfac)3·2H2O precursors [hfac(-) = 1,1,1,5,5,5-hexafluoroacetylacetonate, Ln = Sm(3+) (1), Eu(3+) (2), Tb(3+) (3) and Dy(3+) (4)] in methanol solution led to the formation of four noncentrosymmetric lanthanide complexes with the general formula [Ln(hfac)3L]n·H2O. The single-crystal X-ray diffraction analyses revealed that they are isostructural and take a one-dimensional (1D) chain structure based on the Ln(hfac)3L repeating units, in which the nine-coordinate Ln(3+) ions reside in a tricapped trigonal prism (TTP) environment never reported in previous 1D chain lanthanide complexes. The investigations of their photophysical properties showed that complexes 1, and 3 exhibit characteristic emissions of Sm(3+), Eu(3+) and Tb(3+) ions with respective luminescent lifetime values of 0.065, 1.066 and 0.129 ms, while complex 4 does not display any emission. The different luminescent intensities and lifetimes among them were further discussed in detail. Moreover, the magnetic properties of complexes 1-4 were assessed with a special emphasis on the Dy(3+) complex 4. Alternating-current (ac) magnetic susceptibility measurements indicated that field-induced two-step slow magnetic relaxation processes were observed in 4, indicating the single-molecule magnet (SMM) behavior of 4. In addition, the noncentrosymmetric complexes 1-4 crystallizing in the same polar point group (Cs) exhibit both ferroelectric and nonlinear optical properties at room temperature. All these features make them multifunctional crystalline molecule materials.

  5. Evidence of different stoichiometries for the limiting carbonate complexes of lanthanides(3); Mise en evidence d'un changement de stoechiometrie du complexe carbonate limite au sein de la serie des lanthanides(3)

    Energy Technology Data Exchange (ETDEWEB)

    Philippini, V

    2007-12-15

    Two stoichiometries have been proposed by different laboratories to interpret measurements on the limiting carbonate complexes of An{sup 3+} and Ln{sup 3+} cations. The study of the solubility of double carbonates (AlkLn(CO{sub 3}){sub 2},xH{sub 2}O) in concentrated carbonate solutions at room temperature and high ionic strengths has shown that on the one hand the lightest lanthanides (La and Nd) form Ln(CO{sub 3}){sub 4}{sup 5-} whereas the heaviest (Eu and Dy) form Ln(CO{sub 3}){sub 3}{sup 3-} in the studied chemical conditions, and on the other hand, that the kinetics of precipitation of double carbonates depends on the alkali metal and the lanthanide ions. The existence of two stoichiometries for the limiting carbonate complexes was confirmed by capillary electrophoresis hyphenated to an inductively coupled plasma mass spectrometer (CE-ICP-MS), used to extend the study to the whole series of lanthanides (except Ce, Pm and Yb). Two behaviours have been put forward comparing the electrophoretic mobilities: La to Tb form Ln(CO{sub 3}){sub 4}{sup 5-} while Dy to Lu form Ln(CO{sub 3}){sub 3}{sup 3-}. Measurements by time resolved laser fluorescence spectroscopy (TRLFS) on Eu(III) indicate small variations of the geometry of Eu(CO{sub 3}){sub 3}{sup 3-} complex, specially with Cs{sup +}. Although analogies are currently used among the 4f-block trivalent elements, different aqueous speciations are evidenced in concentrated carbonate solutions across the lanthanide series. (author)

  6. Entropy and complexity analysis of hydrogenic Rydberg atoms

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Rosa, S. [Instituto Carlos I de Fisica Teorica y Computacional, Universidad de Granada, 18071-Granada (Spain); Departamento de Fisica Aplicada II, Universidad de Sevilla, 41012-Sevilla (Spain); Toranzo, I. V.; Dehesa, J. S. [Instituto Carlos I de Fisica Teorica y Computacional, Universidad de Granada, 18071-Granada (Spain); Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Granada, 18071-Granada (Spain); Sanchez-Moreno, P. [Instituto Carlos I de Fisica Teorica y Computacional, Universidad de Granada, 18071-Granada (Spain); Departamento de Matematica Aplicada, Universidad de Granada, 18071-Granada (Spain)

    2013-05-15

    The internal disorder of hydrogenic Rydberg atoms as contained in their position and momentum probability densities is examined by means of the following information-theoretic spreading quantities: the radial and logarithmic expectation values, the Shannon entropy, and the Fisher information. As well, the complexity measures of Cramer-Rao, Fisher-Shannon, and Lopez Ruiz-Mancini-Calvet types are investigated in both reciprocal spaces. The leading term of these quantities is rigorously calculated by use of the asymptotic properties of the concomitant entropic functionals of the Laguerre and Gegenbauer orthogonal polynomials which control the wavefunctions of the Rydberg states in both position and momentum spaces. The associated generalized Heisenberg-like, logarithmic and entropic uncertainty relations are also given. Finally, application to linear (l= 0), circular (l=n- 1), and quasicircular (l=n- 2) states is explicitly done.

  7. A study of the complex formation of bivalent lanthanides with tetraphenylborate-ion in organic solvents. Izuchenie kompleksoobrazovaniya dvukhvalentnykh lantanoidov s tetrafenilborat-ionom v organicheskikh rastvoritelyakh

    Energy Technology Data Exchange (ETDEWEB)

    Veleshko, I E; Mikheev, N B; Kulyukhin, S A

    1992-01-01

    Interaction of bivalent lanthanides with tetraphenylborate-ion (BPh[sub 4][sup -]) in solutions of CH[sub 3]CN and C[sub 2]H[sub 5]OH was studied by the methods of cocrystallization, conductometry and spectrophotometry.It is shown that no complexing between Ln[sup 2+] and BPh[sub 4][sup -] takes place in ethanol, wheras in CH[sub 3]CN formation of second sphere complexes of the composition [Ln(CH[sub 3]CN)[sub n

  8. Spectroscopic studies of some lanthanide(III nitrate complexes synthesized from a new ligand 2,6-bis-(salicylaldehyde hydrazone-4-chlorophenol

    Directory of Open Access Journals (Sweden)

    A.S. Sall

    2003-06-01

    Full Text Available The ligand 2,6-bis-(salicylaldehydehydrazone-4-chlorophenol (H5L and its binuclear lanthanide(III nitrate complexes {[Ln2(H4L3(NO3](NO32.mH2O} where Ln = La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb and Y, have been synthesized. The complexes were characterized by chemical analysis, conductance, magnetic moment measurements and infrared spectra. Infrared study indicates that the ligand behaves both as neutral and ionic O donors and as neutral N donors.

  9. Effects of Out-of-Plane Disorder on the Nodal Quasiparticle and Superconducting Gap in Single-Layer Bi_2Sr_1.6Ln_0.4CuO_6 delta (Ln = La, Nd, Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, M.

    2011-01-04

    How out-of-plane disorder affects the electronic structure has been investigated for the single-layer cuprates Bi{sub 2}Sr{sub 1.6}Ln{sub 0.4}CuO{sub 6+{delta}} (Ln = La, Nd, Gd) by angle-resolved photoemission spectroscopy. We have observed that, with increasing disorder, while the Fermi surface shape and band dispersions are not affected, the quasi-particle width increases, the anti-nodal gap is enhanced and the superconducting gap in the nodal region is depressed. The results indicate that the superconductivity is significantly depressed by out-of-plane disorder through the enhancement of the anti-nodal gap and the depression of the superconducting gap in the nodal region.

  10. Near-infrared photoluminescence in La0.98AlO3: 0.02Ln3+(Ln = Nd/Yb) for sensitization of c-Si solar cells

    Science.gov (United States)

    Sawala, N. S.; Koparkar, K. A.; Bajaj, N. S.; Omanwar, S. K.

    2016-05-01

    The host matrix LaAlO3 was synthesized by conventional solid state reaction method in which the Nd3+ ions and Yb3+ ions successfully doped at 2mol% concentrations. The phase purity was confirmed by X ray powder diffraction (XRD) method. The photoluminescence (PL) properties were studied by spectrophotometer in near infra red (NIR) and ultra violet visible (UV-VIS) region. The Nd3+ ion doped LaAlO3 converts a visible (VIS) green photon (587 nm) into near infrared (NIR) photon (1070 nm) while Yb3+ ion doped converts ultra violet (UV) photon (221 nm) into NIR photon (980 nm). The La0.98AlO3: 0.02Ln3+(Ln = Nd / Yb) can be potentiality used for betterment of photovoltaic (PV) technology. This result further indicates its potential application as a luminescence converter layer for enhancing solar cells performance.

  11. Synthesis and characterization of La(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III) and Dy(III) complexes of 2-acetylfuran-2-thenoylhydrazone

    International Nuclear Information System (INIS)

    Singh, B.; Singh, Praveen K.

    1998-01-01

    The reaction of 2-acetylfuran-2-thenoylhydrazone(afth) with Ln(III) trichlorides yields complexes of the type [Ln(afth)Cl 2 (H 2 O)(EtOH)]Cl, [Ln(III) = La, Pr, Nd, Sm, Eu, Gd, Tb and Dy]. The complexes have been characterized by molar conductance, magnetic susceptibility and TGA and DTA measurements, magnetic susceptibility and TGA and DTA measurements, FAB mass, infrared, proton NMR, electronic absorption and emission spectra. The terbium complex is found to be monomer from the FAB mass spectrum. The IR and NMR spectra suggest neutral tridentate behaviour of the Schiff base. A coordination number seven is proposed around the metal ions. Emission spectra suggest C 3v , symmetry around the metal ion with capped octahedron geometry for the europium complex. (author)

  12. Hydrothermal synthesis of 4ZnO·B2O3·H2O:Ln3 + (Ln = Eu, Tb) phosphors: Morphology-tunable and luminescence properties

    Science.gov (United States)

    Cao, Shiwei; Jiao, Yang; Han, Weifang; Ge, Chunhua; Song, Bo; Wang, Jie; Zhang, Xiangdong

    2018-02-01

    4ZnO·B2O3·H2O:Ln3 + (Ln = Eu, Tb) phosphors with different morphologies have been successfully synthesized via one-step hydrothermal method through regulating the molar amount of Eu3 + and Tb3 +. Comprehensive scanning electron microscopy (SEM), X-ray diffraction (XRD) Fourier transform infrared spectrum (FT-IR) and inductively coupled plasma atomic emission spectrometer (ICP-AES) characterizations all confirm that obtained products are 4ZnO·B2O3·H2O:Ln3 + (Ln = Eu, Tb). The experimental results displayed that the morphology and photoluminescence of compounds is regularly changed with increased the molar amount of rare earth ions. For the Eu3 +-doped, Tb3 +-doped and Eu3 +/Tb3 + co-doped 4ZnO·B2O3·H2O phosphors of morphologies, the rod-like structures gradually changed to flower-like structures, fine wire-like structure and hybrid structure, respectively. To their photoluminescence, the Eu3 + shows a red emission (615 nm); the Tb3 + shows a green emission (545 nm); for the Eu3 +/Tb3 + co-doped 4ZnO·B2O3·H2O phosphors, a combination of blue (5d-4f of Eu2 +), green (5D4-7F5 of Tb3 +) and red (5D0-7F2 of Eu3 +) emissions emerges to achieve white emission. In addition, the energy transfer among Eu3 +, Eu2 + and Tb3 + ions was also discussed.

  13. Rare earth ruthenium gallides with the ideal composition Ln_2Ru_3Ga_5 (Ln = La-Nd, Sm) crystallizing with U_2Mn_3Si_5 (Sc_2Fe_3Si_5) type structure

    International Nuclear Information System (INIS)

    Jeitschko, Wolfgang; Schlueter, Martin

    2010-01-01

    The rare earth ruthenium gallides Ln_2Ru_3Ga_5 (Ln = La, Ce, Pr, Nd, Sm) were prepared by arc-melting of cold-pressed pellets of the elemental components. They crystallize with a tetragonal structure (P4/mnc, Z = 4) first reported for U_2Mn_3Si_5. The crystal structures of the cerium and samarium compounds were refined from single-crystal X-ray data, resulting in significant deviations from the ideal compositions: Ce_2Ru_2_._3_1_(_1_)Ga_5_._6_9_(_1_), a = 1135.10(8) pm, c = 580.58(6) pm, R_F = 0.022 for 742 structure factors; Sm_2Ru_2_._7_3_(_2_)Ga_5_._2_7_(_2_), a = 1132.95(9) pm, c = 562.71(6) pm, R_F = 0.026 for 566 structure factors and 32 variable parameters each. The deviations from the ideal compositions 2:3:5 are discussed. A mixed Ru/Ga occupancy occurs only for one atomic site. The displacement parameters are relatively large for atoms with mixed occupancy within their coordination shell and small for atoms with no neighboring sites of mixed occupancy. Chemical bonding is analyzed on the basis of interatomic distances. Ln-Ga bonding is stronger than Ln-Ru bonding. Ru-Ga bonding is strong and Ru-Ru bonding is weak. The Ga-Ga interactions are of similar strength as in elemental gallium. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  14. High-pressure synthesis and magnetic behavior of A-site columnar-ordered double perovskites, LnMn(Ga{sub 0.5}Ti{sub 0.5}){sub 2}O{sub 6} (Ln = Sm, Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Shimura, Gen; Niwa, Ken; Shirako, Yuichi; Hasegawa, Masashi [Department of Crystalline Materials Science, Nagoya University, 464-8601, Nagoya (Japan)

    2017-01-26

    A-site columnar-ordered double perovskites, LnMn(Ga{sub 0.5}Ti{sub 0.5}){sub 2}O{sub 6} (Ln = Sm, Gd), were successfully synthesized under high pressure and high temperature (6 GPa, 1375 K). From the synchrotron powder X-ray diffraction patterns, all of the diffraction peaks can be indexed by the P4{sub 2}/nmc space group with lattice parameters a, c ∼ 2a{sub p} (a{sub p}: primitive cubic perovskite lattice) and no ordering of the B-site cations. Rietveld analysis of the synchrotron powder X-ray diffraction patterns and Curie-Weiss fitting of their magnetizations reveal that the ionic formulae of these perovskites are Ln{sup 3+}Mn{sup 2+}(Ga{sup 3+}{sub 0.5}Ti{sup 4+}{sub 0.5}){sub 2}O{sup 2-}{sub 6}. SmMn(Ga{sub 0.5}Ti{sub 0.5}){sub 2}O{sub 6} shows canted-antiferromagnetic behavior, whereas GdMn(Ga{sub 0.5}Ti{sub 0.5}){sub 2}O{sub 6} exhibits two different magnetic states at low temperature depending on the applied magnetic field and shows an unusual magnetization curve. These magnetic behaviors originate by decreasing the antiferromagnetic interaction by substituting Ga{sup 3+}(d{sup 10}) for Ti{sup 4+}(d{sup 0}) and by decreasing the ferromagnetic interaction between columnar-ordered Ln{sup 3+} and Mn{sup 2+}. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Hydrothermal synthesis and photoluminescent properties of hierarchical GdPO4·H2O:Ln3+ (Ln3+ = Eu3+, Ce3+, Tb3+) flower-like clusters

    Science.gov (United States)

    Amurisana, Bao.; Zhiqiang, Song.; Haschaolu, O.; Yi, Chen; Tegus, O.

    2018-02-01

    3D hierarchical GdPO4·H2O:Ln3+ (Ln3+ = Eu3+, Ce3+, Tb3+) flower clusters were successfully prepared on glass slide substrate by a simple, economical hydrothermal process with the assistance of disodium ethylenediaminetetraacetic acid (Na2H2L, where L4- = (CH2COO)2N(CH2)2N(CH2COO)24-). In this process, Na2H2L was used as both a chelating agent and a structure-director. The hierarchical flower clusters have an average diameter of 7-12 μm and are composed of well-aligned microrods. The influence of the molar ratio of Na2H2L/Gd3+ and reaction time on the morphology was systematically studied. A possible crystal growth and formation mechanism of hierarchical flower clusters is proposed based on the evolution of morphology as a function of reaction time. The self-assembled GdPO4·H2O:Ln3+ superstructures exhibit strong orange-red (Eu3+, 5D0 → 7F1), green (Tb3+, 5D4 → 7F5) and near ultraviolet emissions (Ce3+, 5d → 7F5/2) under ultraviolet excitation, respectively. This study may provide a new channel for building hierarchically superstructued oxide micro/nanomaterials with optical and new properties.

  16. Re-dispersion and film formation of GdVO4 :  Ln3+ (Ln3+ = Dy3+, Eu3+, Sm3+, Tm3+) nanoparticles: particle size and luminescence studies.

    Science.gov (United States)

    Shanta Singh, N; Ningthoujam, R S; Phaomei, Ganngam; Singh, S Dorendrajit; Vinu, A; Vatsa, R K

    2012-04-21

    GdVO(4) : Ln(3+) (Ln(3+) = Dy(3+), Eu(3+), Sm(3+), Tm(3+)) nanoparticles are prepared by a simple chemical route at 140 °C. The crystallite size can be tuned by varying the pH of the reaction medium. Interestingly, the crystallite size is found to increase significantly when pH increases from 6 to 12. This is related to slower nucleation of the GdVO(4) formation with increase of VO(4)(3-) present in solution. The luminescence study shows an efficient energy transfer from vanadate absorption of GdVO(4) to Ln(3+) and thereby enhanced emissions are obtained. A possible reaction mechanism at different pH values is suggested in this study. As-prepared samples are well dispersed in ethanol, methanol and water, and can be incorporated into polymer films. Luminescence and its decay lifetime studies confirm the decrease in non-radiative transition probability with the increase of heat treatment temperature. Re-dispersed particles will be useful in potential applications of life science and the film will be useful in display devices.

  17. Corrections to O(α7(lnα)mc2) fine-structure splittings and O(α6(lnα)mc2) energy levels in helium

    International Nuclear Information System (INIS)

    Zhang, T.

    1996-01-01

    Fully relativistic formulas for the energy-level shifts arising from no-pair exchange diagrams of two transverse photons plus an arbitrary number of Coulomb photons are derived in closed form within the external potential Bethe-Salpeter formalism. O(α 7 (lnα)mc 2 ) corrections to the fine-structure splittings of helium are obtained and expressed in terms of expectation values of nonrelativistic operators. O(α 7 mc 2 ) operators from exchange diagrams are found in nonrelativistic approximation. O(α 6 m 2 c 2 /M) nucleus-electron operators contributing to the fine-structure splittings are derived. Nonrelativistic operators of O(α 6 mc 2 ) corrections to the triplet levels of helium are presented. Nonrelativistic operators of O(α 6 (lnα)mc 2 ) corrections to the helium singlet levels and to positronium S levels are derived. O(α 6 m 2 c 2 /M) hydrogen and O(α 6 mc 2 ) positronium P levels, and O(α 6 (lnα)mc 2 ) corrections of first order to positronium S levels, are calculated using the derived operators for helium, in agreement with those obtained previously by others, except for one term in corrections to positronium P levels. In addition, the O(α 6 mc 2 ) Dirac energies for hydrogenic non-S levels are exactly reproduced in a perturbative calculation. copyright 1996 The American Physical Society

  18. Formation constants of lanthanide(III)- aminopolycarboxylate- ATP mixed ligand complexes and their systematics

    International Nuclear Information System (INIS)

    Verma, Sangeeta; Limaye, S.N.; Saxena, M.C.

    1993-01-01

    Formation constants (log Ksub(MAL)sup(MA), log Ksub(ML)sup(M) and log Ksub(ML)sup(ML) of mixed ligand lanthanide(III) complexes of the type [Ln(III).A.ATP[ 2 , where LN(III)=La 3+ , Ce 3+ , Pr 3+ , Nd 3+ , Sm 3+ , Eu 3+ , Gd 3+ , Tb 3+ or Dy 3+ ' A=NTA(nitrilotriacetate) or HEDTA (2-hydroxyethylethylenediamine triacetate) and ATP=adenosine 5'-triphosphate (L), and of the binary [Ln(III).ATP[ and [Ln(III).(ATP) 2 [ complexes have been determined by potentiometric pH titrations using the Irving-Rossotti approach at three temperatures 20, 30 and 40 degC and at a fixed ionic strength, I=0.2 mol dm -3 (NAclO 4 ). The solution stabilities (log Ksub(MAL)sup(MA) values) are influenced by the electrostatic effect involved in ternary complexation and increase with temperature. The enthalpy factor (ΔH) has been found to be small but unfavourable and the entropy factor (ΔS) large and favourable. The log Ksub(MAL)sup(MA) values lie in the order NTA>HEDTA with respect to A and La 3+ 3+ 3+ 3+ 3+ 3+ >Gd 3+ 3+ 3+ with respect to lanthanides. Tetrad effect is present in the formation constant values; its magnitude has been found to lie in the sequence f 7 >f 3 -f 4 ≅ f 10 -f 11 for the Ln(III) ions. Systematics in the formation constant values has been further studied by evaluating changes in the inter-electronic repulsion Racah parameters, extra stabilisation of specific 4f 9 -configurations and nephelauxetic ratio using experimental values of the formation constants. (author). 24 refs., 2 figs., 3 tabs

  19. A Study on Thermal Desorption of Deuterium in D-loaded SS316LN for ITER Tritium Removal System

    Energy Technology Data Exchange (ETDEWEB)

    Park, Myungchul; Kim, Heemoon; Ahn, Sangbok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Jaeyong; Lee, Sanghwa; LanAhn, Nguyen Thi [Hanyang University, Seoul (Korea, Republic of)

    2016-10-15

    Because Type B radwaste includes tritium on its inside, especially at vicinity of surface, tritium removal from the radwaste is a matter of concern in terms of the radwaste processes. Tritium behavior in materials is related with temperature. Considering a diffusion process, it is expected that tritium removal efficiency is enhanced with increasing baking temperature. However, there is a limitation about temperature due to facility capacity and economic aspect. Therefore, it is necessary to investigate the effect of temperature on the desorption behavior of Tritium in ITER materials. TDS analysis was performed in SS316LN loaded at 120, 240 and 350 °C. D2 concentration and the desorption peak temperature increased with increasing loading temperature. Using peak shift method with three ramp rates of 0.166, 0.332, and 0.5 °C/sec, trap activation energy of D in SS316LN loaded at 350 °C was 56 kJ/mol.

  20. The effect of lanthanides on color properties of the (Bi2O30.7(Ln2O30.3 compounds

    Directory of Open Access Journals (Sweden)

    Šulcová P.

    2008-01-01

    Full Text Available (Bi2O30.7(Ln2O30,3 solid solutions were synthesized as new inorganic yellow and orange pigments and their color properties have been investigated as possible ecological materials. The pigments were prepared by the solid state reaction of mixed oxides (Bi2O30.7(Ln2O30.3 of various rare earth cations (Ln = Eu, Gd, Tm, Yb and Lu. All the synthesized pigment samples were found to have color coordinates, low a* and high b* and exhibit the color from pale light yellow to orange. Reflectance spectra of the samples show high reflectance percentage in the 600 - 700 nm range. Characterization of the (Bi2O30.7(Ln2O30,3 solid solutions suggests that they have a potential to be alternative yellow colorants for paints, inks, plastics, and ceramics.

  1. Perspectives of cooperation of the L.N. Gumilev Eurasian State University and Institute of Nuclear Physics of the National Nuclear Center of the Republic of Kazakhstan

    International Nuclear Information System (INIS)

    Zholdasbekov, M.Zh.; Donbaev, K.M.; Kadyrzhanov, K.K.

    2001-01-01

    It is noted, that one of a modern tendency in development both science and education in CIS and Kazakhstan is its step-by-step integration. For purpose of further development of scientific trends in physics field the agreement on cooperative activity between the L.N. Gumilev Eurasian State University and Institute of Nuclear Physics of the National Nuclear Center of the Republic of Kazakhstan was concluded (2000, November 18). The principle aim of the cooperative activity of the sides is conducting of fundamental and applied studies on solid state physics, nuclear physics, radioecological problems of the Astana town and development of science-intensive technologies. For realization of this task the Astana Filial of Institute of Nuclear Physics is established at the University. In particularly, on the ground of this cooperation the implementation of Inter-disciplinary Research Complex with heavy ion accelerator was initiated. Such accelerator could be used for the scientific researches, training of students and postgraduates, and different technological purposes

  2. Aqueous Binary Lanthanide(III) Nitrate Ln(NO3)3 Electrolytes Revisited: Extended Pitzer and Bromley Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Sayandev; Campbell, Emily L.; Neiner, Doinita; Pence, Natasha; Robinson, Troy; Levitskaia, Tatiana G.

    2015-09-11

    To date, only limited thermodynamic models describing activity coefficients of the aqueous solutions of lanthanide ions are available. This work expands the existing experimental osmotic coefficient data obtained by classical isopiestic technique for the aqueous binary trivalent lanthanide nitrate Ln(NO3)3 solutions using a combination of water activity and vapor pressure osmometry measurements. The combined osmotic coefficient database for each aqueous lanthanide nitrate at 25°C, consisting of literature available data as well as data obtained in this work, was used to test the validity of Pitzer and Bromley thermodynamic models for the accurate prediction of mean molal activity coefficients of the Ln(NO3)3 solutions in wide concentration ranges. The new and improved Pitzer and Bromley parameters were calculated. It was established that the Ln(NO3)3 activity coefficients in the solutions with ionic strength up to 12 mol kg-1 can be estimated by both Pitzer and single-parameter Bromley models, even though the latter provides for more accurate prediction, particularly in the lower ionic strength regime (up to 6 mol kg-1). On the other hand for the concentrated solutions, the extended three-parameter Bromley model can be employed to predict the Ln(NO3)3 activity coefficients with remarkable accuracy. The accuracy of the extended Bromley model in predicting the activity coefficients was greater than ~95% and ~90% for all solutions with the ionic strength up to 12 mol kg-1 and and 20 mol kg-1, respectively. This is the first time that the activity coefficients for concentrated lanthanide solutions have been predicted with such a remarkable accuracy.

  3. Sr2+ and Cs+ ion exchange properties of KLn(PO3)4: Ln = Ce and Eu

    International Nuclear Information System (INIS)

    Samatha, B.; Achary, S.N.; Tyagi, A.K.; Ramkumar, Jayshree; Chandramouleeswaran, S.

    2014-01-01

    With the aim to study the potential of layered phosphates as ion exchangers two stoichiometric compositions as KLn(PO 3 ) 4 with Ln = Ce and Eu were prepared by solid state reaction and characterized by powder X-ray diffraction method. The Cs + and Sr 2+ exchange properties of both materials were investigated using standard solutions of Sr 2 + or Cs + in low acidic aqueous medium

  4. Isothiocyanato complexes of Gd(III), Tb(III), Dy(III) and Ho(III) with 2-(2'-pyridyl)benzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, A; Singh, V K

    1982-01-01

    Six-coordinated complexes of the type (Ln(PyBzH)/sub 2/NCS.H/sub 2/O) (NCS)/sub 2/.nH/sub 2/O/mC/sub 2/H/sub 5/OH (Ln = Gd(III), Tb(III), Dy(III) and Ho(III), n=1-2; m=1) have been prepared from Ln(NCS)/sub 6//sup 3 -/. The room temperature magnetic moment values confirm the terpositive state of the lanthanide ions. Infrared spectra suggest the N-coordination of thiocyanate group. Electronic spectral studies of Tb(III), Dy(III) and Ho(III) complexes have been made in terms of LSJ term energies. 13 refs.

  5. Metal–organic frameworks assembled from lanthanide and 2,5-pyridinedicaboxylate with cubane-like [Ln{sub 4}(OH){sub 4}] building units

    Energy Technology Data Exchange (ETDEWEB)

    Abdelbaky, Mohammed S.M. [Departamentos de Química Física y Analítica y Química Orgánica e Inorgánica, University of Oviedo—CINN, Oviedo 33006 (Spain); Amghouz, Zakariae, E-mail: amghouz.uo@uniovi.es [Departamentos de Química Física y Analítica y Química Orgánica e Inorgánica, University of Oviedo—CINN, Oviedo 33006 (Spain); Servicios Científico-Técnicos, University of Oviedo—CINN, Oviedo 33006 (Spain); Fernández-Zapico, Eva; García-Granda, Santiago; García, José R. [Departamentos de Química Física y Analítica y Química Orgánica e Inorgánica, University of Oviedo—CINN, Oviedo 33006 (Spain)

    2015-09-15

    tremendous attention due to the unique characteristic of lanthanide cations, such as variable coordination numbers and geometries which often lead to novel complex structures, and also to their magnetic and photoluminescence properties. Herein, three LOFs formulated as [Ln{sub 4}(OH){sub 4}(25p){sub 4}(H{sub 2}O){sub 3}]·H{sub 2}O (Ln=Y, Yb) and [Y{sub 6}(OH){sub 8}(25p){sub 5}(H{sub 2}O){sub 2}] have been obtained by hydrothermal method and characterized, and the photoluminescence properties of the Eu and Tb doped compounds are discussed. - Highlights: • Three novel LnOFs has been synthesized and characterized. • Crystal structures are based on tetranuclear cuban-like [Ln{sub 4}(OH){sub 4}]{sup 8+} clusters. • 25pYb and 25pY-1 are based on isolated [Ln{sub 4}(OH){sub 4}]{sup 8+} clusters. • 25pY-2 is based on infinite inorganic chains built up from [Y{sub 4}(OH){sub 4}]{sup 8+} clusters. • Photoluminescence studies show strong red and green light emissions.

  6. Pairing in the BCS and LN approximations using continuum single particle level density

    International Nuclear Information System (INIS)

    Id Betan, R.M.; Repetto, C.E.

    2017-01-01

    Understanding the properties of drip line nuclei requires to take into account the correlations with the continuum spectrum of energy of the system. This paper has the purpose to show that the continuum single particle level density is a convenient way to consider the pairing correlation in the continuum. Isospin mean-field and isospin pairing strength are used to find the Bardeen–Cooper–Schrieffer (BCS) and Lipkin–Nogami (LN) approximate solutions of the pairing Hamiltonian. Several physical properties of the whole chain of the Tin isotope, as gap parameter, Fermi level, binding energy, and one- and two-neutron separation energies, were calculated and compared with other methods and with experimental data when they exist. It is shown that the use of the continuum single particle level density is an economical way to include explicitly the correlations with the continuum spectrum of energy in large scale mass calculation. It is also shown that the computed properties are in good agreement with experimental data and with more sophisticated treatment of the pairing interaction.

  7. Effect of nitrogen on creep properties of type 316L(N) stainless steels

    International Nuclear Information System (INIS)

    Kim, Dae Whan; Lee, Yoon Kyu; Kim, Woo Gon; Ryu, Woo Seog

    2001-01-01

    The effects of nitrogen on the creep properties of type 316(N) stainless steels with three different nitrogen contents from 0.04% to 0.15% were investigated. Creep tests were carried out using constant-load single-lever machines at 550∼650 .deg. C in the air. The time to rupture increased and the minimum creep rate decreased with the addition of nitrogen. At constant stress, the rupture elongation decreased with the addition of nitrogen. Intergranular and transgranular fracture mode were mixed in all specimens. Cavity and carbides were nucleated at grain boundary and the number of cavity and carbide at constant stress was increased with the addition of nitrogen because of the increase in the time to rupture and carbide precipitation due to the addition of nitrogen. The increase of rupture time with the addition of nitrogen for type 316L(N) stainless steel was attributed to the combined effect of the decrease of minimum creep rate due to the increase of tensile strength and the rupture elongation due to the precipitation at grain boundaries

  8. Effects of Thermal Aging on Microstructure and Impact Properties of 316LN Stainless Steel Weld

    Directory of Open Access Journals (Sweden)

    LUO Qiang

    2017-12-01

    Full Text Available To study the thermal aging of nuclear primary pipe material 316LN stainless steel weld, accelerated thermal aging experiment was performed at 400℃ for 15000h. Microstructure evolution of weld after aging was investigated by TEM and HREM. Impact properties of weld thermally aged at different time was measured by Charpy impact test. Meanwhile, taking Charpy impact energy as the standard of thermal aging embrittlement, the thermal kinetics formula was obtained by the fitting method. Finally, the Charpy impact properties of the weld during 60 years of service at the actual operation temperature were estimated by the thermal kinetics formula. The results indicate that the spinodal decomposition occurs in the ferrite of the weld after thermal aging at 400℃ for 1000h, results in α (Fe-rich and α'(Cr-rich phases, and meanwhile, the G-phase is precipitated in the ferrite; the spinodal decomposition and the G-phase precipitation lead to the decrease in the impact energy of weld as time prolongs; the prediction results show that the Charpy impact energy of weld decreases quickly in the early 25 years, and then undergoes a slow decrease during the subsequent operation process.

  9. Effects of pre-creep on the dislocations of 316LN Austenite stainless steel

    Science.gov (United States)

    Pei, Hai-xiang; Hui, Jun; Hua, Hou; Feng, Zai-xin; Xu, Xiao-long

    2017-09-01

    The 316LN Austenite stainless steels (316LNASS) were pre-creep treated, the evolution of microstructure were investigated. The samples were pre-creep at 593 K and from 500 to 2000 h at 873 K with a stress in the range of 20 to 150 MPa, Then the evolution of microstructure and precipitation were investigated by optical microscope (OM), and transmission electron microscope (TEM). The results show that the crystal surface slipping resulted in dislocations and original dislocations decomposition during the pre-creep process, and generate quadrilateral or hexagonal dislocation network was obviously. The sub-grain boundary gradually became narrow with the increasing of pre-creep treatment time and temperature. When the pre-creep temperature was 593 K and 873 K, dislocation network gradually disappear with the increasing of pre-creep time and load. When the pre-creep temperature was 873 K under 120 MPa, and the treatment time was 2000 h, the hexagonal dislocation network (HDN) would completely disappeared. When the pre-creep temperature was 593 K under 20 MPa, and the treatment time was 500 h, the quadrilateral dislocation network (QDN) would completely disappeared.

  10. Z phase stability in AISI 316LN + Nb austenitic steels during creep at 650 C

    Energy Technology Data Exchange (ETDEWEB)

    Vodarek, Vlastimil [Technical Univ. Ostrava (Czech Republic)

    2010-07-01

    The creep resistance of austenitic CrNi(Mo) steels strongly depends on microstructural stability during creep exposure. Nitrogen additions to CrNi(Mo) austenitic steels can significantly improve the creep strength. One of the most successful methods of improving the long-term creep resistance of austenitic steels is based on increasing the extent of precipitation strengthening during creep exposure. The role of precipitates in the achievements of good creep properties has been extensively studied for a long time. Although many minor phases are now well documented there are still contractions and missing thermodynamic data about some minor phases. This contribution deals with results of microstructural studies on the minor phase evolution in wrought AISI 316LN niobium stabilised steels during long-term creep exposure at 650 C. Microstructural investigations were carried out on specimens taken from both heads and gauge lengths of ruptured test-pieces by means of optical metallography, transmission and scanning electron microscopy. The attention has been paid to evaluation of thermodynamic and dimensional stability of Z phase and other nitrogen bearing minor phases. Only two nitrogen-bearing minor phases formed in the casts investigated: Z phase and M{sub 6}X. The dimensional stability of Z phase particles was very high. (orig.)

  11. Carburization behavior of AISI 316LN austenitic stainless steel - Experimental studies and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Sudha, C. [Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India); Sivai Bharasi, N. [Corrosion Science and Technology Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India); Anand, R. [Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India); Shaikh, H., E-mail: hasan@igcar.gov.i [Corrosion Science and Technology Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India); Dayal, R.K. [Corrosion Science and Technology Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India); Vijayalakshmi, M. [Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India)

    2010-07-31

    AISI type 316LN austenitic stainless steel was exposed to flowing sodium at 798 K for 16,000 h in the bi-metallic (BIM) sodium loop. A modified surface layer of 10 {mu}m width having a ferrite structure was detected from X-ray diffraction and electron micro probe based analysis. Beneath the modified surface layer a carburized zone of 60 {mu}m width was identified which was found to consist of M{sub 23}C{sub 6} carbides. A mathematical model based on finite difference technique was developed to predict the carburization profiles in sodium exposed austenitic stainless steel. In the computation, effect of only chromium on carbon diffusion was considered. Amount of carbon remaining in solution was determined from the solubility parameter. The predicted profile showed a reasonably good match with the experimental profile. Calculations were extended to simulate the thickness of the carburized layer after exposure to sodium for a period of 40 years. Attempt was also made to predict the carburization profiles based on equilibrium calculations using Dictra and Thermocalc which contain both thermodynamic and kinetic databases for the system under consideration.

  12. Delayed cracking in 301LN austenitic steel after deep drawing: Martensitic transformation and residual stress analysis

    International Nuclear Information System (INIS)

    Berrahmoune, M.R.; Berveiller, S.; Inal, K.; Patoor, E.

    2006-01-01

    The main objective of this work is to study the delayed cracking phenomenon of the 301LN unstable austenitic steel, by determining the distribution of residual stresses after deep drawing, taking into account the phase transformation. Deep drawing for different ratios is done for two different temperatures. Cracks appear for the highest drawing ratio (DR = 2.00) in the top of the cup. The breaking patterns observed using a scanning electron microscope show ductile fracture in the middle region, and both intergranular and transgranular rupture in the edges. Martensite contents throughout the cup wall and through the thickness are determined. Increasing the martensite content was found to have a great effect on the cracking sensitivity. X-ray diffraction allows us to determine the residual stresses in the martensitic phase. These last are positive, increase with increasing drawing ratios. The maximum value is located at the middle height of the cup, it exceeds 500 MPa for the 2.00 drawing ratio, and is less than 350 MPa for the 1.89 drawing ratio

  13. Optimization of hybrid laser - TIG welding of 316LN steel using response surface methodology (RSM)

    Science.gov (United States)

    Ragavendran, M.; Chandrasekhar, N.; Ravikumar, R.; Saxena, Rajesh; Vasudevan, M.; Bhaduri, A. K.

    2017-07-01

    In the present study, the hybrid laser - TIG welding parameters for welding of 316LN austenitic stainless steel have been investigated by combining a pulsed laser beam with a TIG welding heat source at the weld pool. Laser power, pulse frequency, pulse duration, TIG current were presumed as the welding process parameters whereas weld bead width, weld cross-sectional area and depth of penetration (DOP) were considered as the process responses. Central composite design was used to complete the design matrix and welding experiments were conducted based on the design matrix. Weld bead measurements were then carried out to generate the dataset. Multiple regression models correlating the process parameters with the responses have been developed. The accuracy of the models were found to be good. Then, the desirability approach optimization technique was employed for determining the optimum process parameters to obtain the desired weld bead profile. Validation experiments were then carried out from the determined optimum process parameters. There was good agreement between the predicted and measured values.

  14. Environmentální aspekty provozu vozů na CNG

    OpenAIRE

    Raiskup, Martin

    2016-01-01

    Tato bakalářská práce je zaměřená na téma environmentální aspekty provozu vozů na CNG. Nejprve je představen zemní plyn jako palivo pro spalovací motory. Jsou zhodnoceny jeho výhody a nevýhody. Dále jsou popsány jednotlivé spalovací systémy a komponenty motoru na stlačený zemní plyn. Hlavní část práce je zaměřená na ekologii. Je popsán vliv na životní prostředí u spalování stlačeného zemního plynu v porovnání s konvenčními palivy. Toto porovnání je provedeno také podle objektivnější Well to W...

  15. Classification of PD sources in HV cables using neural networks and the LN-FDTD method

    Energy Technology Data Exchange (ETDEWEB)

    Barros, W.H.; Oliveira, R.M.; Sobrinho, C.L.; Leite, R.C. [Univ. Federal do Para, Para (Brazil). Dept. of Computational and Electrical Engineering

    2008-07-01

    Partial discharges can be generated by the presence of several defects, and are often the cause of failures in electrical equipment insulators. In this study, a local non-orthogonal finite difference time-domain method (LN-FDTD) was used to simulate the sources of partial discharges in a high voltage coaxial cable model. The artificial neural network (ANN) technique used a Marquandt-Levenberg training algorithm to detect and classify cable PD sources. A set of harmonics obtained from the difference between the registered signals in the time domain was used as part of the training procedure. A failure was inserted on an electrical cable in each simulation in order to obtain the correlated data. Input signals were injected using a voltage pulse represented by a Gaussian function. A total of 90 simulations were conducted to generate 360 data groups in order to consider 6 different types of failures. Results of the study showed that the method can be used to detect and classify partial discharges in cables. 12 refs., 21 figs.

  16. Low temperature tensile deformation and acoustic emission signal characteristics of AISI 304LN stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Barat, K.; Bar, H.N. [Material Science and Technology Division, CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Mandal, D. [Material Processing and Technology Division, CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Roy, H., E-mail: himadri9504@gmail.com [NDT and Metallurgy Group, CSIR-Central Mechanical Engineering Research Institute, Durgapur 713209 (India); Sivaprasad, S.; Tarafder, S. [Material Science and Technology Division, CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India)

    2014-03-01

    This investigation examines low temperature tensile deformation behavior of AISI 304LN stainless steel along with synergistic analysis of acoustic emission signals. The tensile tests are done at a range of temperatures starting from 283 K till 223 K. The fracture surfaces of the broken specimens are investigated using scanning electron microscope. The amount of deformation induced martensite is measured using a feritscope. The obtained results reveal that with decrease in test temperature, both strength and ductility increase. The increase in strength and ductility with decreasing temperature is explained in terms of void morphologies and formation of deformation induced martensite. The rapid increment in strength and ductility at 223 K is associated with the burst of martensitic transformation at that temperature; which has been clarified from acoustic emission signals. An additional initiative has been taken to model the evolution of martensite formation from the observed cumulative emission counts using a non linear logarithmic functional form. The fitted curves from the recorded acoustic emission cumulative count data are found to be better correlated compared to earlier obtained results. However, at 223 K normal non-linear logarithmic fit is not found suitable due to presence of burst type signals at intervals, therefore; piecewise logarithmic function to model acoustic emission bursts is proposed.

  17. Reversed Microstructures and Tensile Properties after Various Cold Rolling Reductions in AISI 301LN Steel

    Directory of Open Access Journals (Sweden)

    Antti Järvenpää

    2018-02-01

    Full Text Available Heavy cold rolling is generally required for efficient grain size refinement in the martensitic reversion process, which is, however, not desirable in practical processing. In the present work, the influence of cold rolling reductions of 32%, 45% and 63% on the microstructure evolution and mechanical properties of a metastable austenitic AISI 301LN type steel were investigated in detail adopting scanning electron microscopy with the electron backscatter diffraction method and mechanical testing. A completely austenitic microstructure and a partially reversed counterpart were created. It was found that the fraction of grains with a size of 3 µm or larger, called medium-sized grains, increased with decreasing the prior cold rolling reduction. These grains are formed mainly from the shear-reversed austenite, transformed from slightly-deformed martensite, by gradual evolution of subgrains to grains. However, in spite of significant amounts of medium-sized grains, the tensile properties after the 32% or 45% cold rolling reductions were practically equal to those after the 63% reduction. The austenite stability against the formation of deformation-induced martensite in subsequent straining was reduced by lowering the cold rolling reduction, due to the larger grain size of medium-sized grains and the shift of their orientation towards {211} .

  18. Effect of cold works on creep-rupture life of type 316LN stainless steel

    International Nuclear Information System (INIS)

    Kim, W. G.; Han, C. H.; Ryu, W. S.

    2003-01-01

    Effect of cold works on creep-rupture life of the cold-worked type 316LN stainless steels, which are fabricated with the various reductions ; 0%(solution annealing), 20%, 30%, 40%, and 50%, was investigated. The creep-rupture time increased gradually up to 30% reduction, but it decreased inversely over 30% reduction. The longest rupture time exhibited at cold-worked reduction of 30%. The reason for this is that fine carbide precipitates are uniformly generated in grain boundary and the dislocations are pinned in the precipitates and the dislocations are sustained for a long time at high temperature. However, it is assumed that the higher cold-work reductions over 30% lead to excessive generation of deformation faults. The SEM fractrographs of the cold-worked specimens showed dense fracture micrographs, and they did not show intergranular structures in creep fracture mode. From this result, it is believed that the cold-worked specimens were superior in creep-rupture time to solution annealed ones

  19. A comprising steady-state creep model for the austenitic AISI 316 L(N) steel

    International Nuclear Information System (INIS)

    Rieth, Michael

    2007-01-01

    Low-stress creep data of a recently finished special long-term program now allows for much better long-term predictions of the ITER related material 316 L(N) and also enables deformation modeling for a broader stress range. The present work focuses mainly on the set-up of a steady-state creep model with help of well-known rate-equations for different deformation mechanisms. In addition, the impact of microstructure changes and precipitation formation on steady-state creep is studied. The resulting creep model consists of a summation of contributions for diffusion creep, power-law creep, and power-law breakdown. The final creep model agrees well with experimental data for temperatures between 550 and 750 deg C and for shear stresses above 30 MPa. The most important finding of this work is that for very low stresses the model predicts far higher creep rates than can be extrapolated from tests performed at the usual stress range of experimental programs

  20. Sorption of trivalent lanthanides and actinides onto montmorillonite: Macroscopic, thermodynamic and structural evidence for ternary hydroxo and carbonato surface complexes on multiple sorption sites.

    Science.gov (United States)

    Fernandes, M Marques; Scheinost, A C; Baeyens, B

    2016-08-01

    The credibility of long-term safety assessments of radioactive waste repositories may be greatly enhanced by a molecular level understanding of the sorption processes onto individual minerals present in the near- and far-fields. In this study we couple macroscopic sorption experiments to surface complexation modelling and spectroscopic investigations, including extended X-ray absorption fine structure (EXAFS) and time-resolved laser fluorescence spectroscopies (TRLFS), to elucidate the uptake mechanism of trivalent lanthanides and actinides (Ln/An(III)) by montmorillonite in the absence and presence of dissolved carbonate. Based on the experimental sorption isotherms for the carbonate-free system, the previously developed 2 site protolysis non electrostatic surface complexation and cation exchange (2SPNE SC/CE) model needed to be complemented with an additional surface complexation reaction onto weak sites. The fitting of sorption isotherms in the presence of carbonate required refinement of the previously published model by reducing the strong site capacity and by adding the formation of Ln/An(III)-carbonato complexes both on strong and weak sites. EXAFS spectra of selected Am samples and TRLFS spectra of selected Cm samples corroborate the model assumptions by showing the existence of different surface complexation sites and evidencing the formation of Ln/An(III) carbonate surface complexes. In the absence of carbonate and at low loadings, Ln/An(III) form strong inner-sphere complexes through binding to three Al(O,OH)6 octahedra, most likely by occupying vacant sites in the octahedral layers of montmorillonite, which are exposed on {010} and {110} edge faces. At higher loadings, Ln/An(III) binds to only one Al octahedron, forming a weaker, edge-sharing surface complex. In the presence of carbonate, we identified a ternary mono- or dicarbonato Ln/An(III) complex binding directly to one Al(O,OH)6 octahedron, revealing that type-A ternary complexes form with the one

  1. Magnetic properties and crystal field effects in TlLnX2 compounds (X=S, Se, Te)

    International Nuclear Information System (INIS)

    Duczmal, M.; Pawlak, L.

    1997-01-01

    Ternary thallium lanthanide chalcogenides TlLnX 2 (X=S, Se or Te) crystallize in the α-NaFeO 2 type of structure (R anti 3m). Each kind of the metal ions, surrounded by the distorted chalcogenide octahedra, forms separate layers. The TlX 6 octahedra are strongly elongated and the LnX 6 octahedra slightly shrunk along the threefold axis. The deformations of the coordination polyhedra and the cell volumes change regularly with the lanthanide ionic radii. The difference between the experimental and the calculated M-X distances increases on going from sulphides to tellurides, as a result of the growing covalent character of the bonds. The crystal field parameters were estimated from the high field magnetization (0-14 T) assuming trigonal distortion of the octahedral symmetry of LnX 6 polyhedra. The second-order crystal field parameters were found to correlate with the deformation of the lanthanide ions' environments. No magnetic transition was observed down to 4.2 K. (orig.)

  2. A Conceptual Framework for the Electronic Performance Support Systems within IBM Lotus Notes 6 (LN6 Example

    Directory of Open Access Journals (Sweden)

    Servet BAYRAM

    2005-10-01

    Full Text Available A Conceptual Framework for the Electronic PerformanceSupport Systems within IBM Lotus Notes 6 (LN6 Example Assoc. Prof. Dr. Servet BAYRAM Computer Education & Instructional Technologies Marmara University, TURKEYsbayram@marmara.edu.tr ABSTRACT The concept of Electronic Performance Support Systems (EPSS is containing multimedia or computer based instruction components that improves human performance by providing process simplification, performance information and decision support system. EPSS has become a hot topic for organizational development, human resources, performance technology, training, and educational development professionals. A conceptual framework of EPSS is constructed under five interrelated and interdependent domains for educational implications. The domains of the framework are online collaboration, cost-effectiveness, motivation, service management, and performance empowering. IBM Lotus Notes 6 (LN6 is used as an example application tool to illustrate the power of this framework. The framework describes a set of relevant events based upon deductive analyses for improving our understanding of the EPSS and its implications on education and training. The article is also pointed out that there are some similarities between the EPSS’ and the LN6’s specific features within this conceptual framework. It can provide some guidelines and benefits to researchers, educators, and designers as well.

  3. Použití erozní potenciální metody v České republice

    OpenAIRE

    Hloušek, Jakub

    2016-01-01

    V rámci bakalářské práce bylo provedeno vyhodnocení ztráty půdy pro zájmové území nacházející se v severozápadní části povodí Němčického potoka, v okresu Blansko. Výpočet byl stanoven dvěma metodami, a to erozně potenciální metodou EPM, využívanou v Srbsku a metodou universální rovnice Wischmeiera a Smithe - USLE, využívanou pro podmínky v ČR. Nakonec byly obě tyto metody vzájemně porovnány. Obě metody využívají jiný způsob výpočtu. Metoda USLE využívá univerzální rovnici pro výpočet průměrné...

  4. Cold deformation effect on the microstructures and mechanical properties of AISI 301LN and 316L stainless steels

    International Nuclear Information System (INIS)

    Silva, Paulo Maria de O.; Abreu, Hamilton Ferreira G. de; Albuquerque, Victor Hugo C. de; Neto, Pedro de Lima; Tavares, Joao Manuel R.S.

    2011-01-01

    As austenitic stainless steels have an adequate combination of mechanical resistance, conformability and resistance to corrosion they are used in a wide variety of industries, such as the food, transport, nuclear and petrochemical industries. Among these austenitic steels, the AISI 301LN and 316L steels have attracted prominent attention due to their excellent mechanical resistance. In this paper a microstructural characterization of AISI 301LN and 316L steels was made using various techniques such as metallography, optical microscopy, scanning electronic microscopy and atomic force microscopy, in order to analyze the cold deformation effect. Also, the microstructural changes were correlated with the alterations of mechanical properties of the materials under study. One of the numerous uses of AISI 301LN and 316L steels is in the structure of wagons for metropolitan surface trains. For this type of application it is imperative to know their microstructural behavior when subjected to cold deformation and correlate it with their mechanical properties and resistance to corrosion. Microstructural analysis showed that cold deformation causes significant microstructural modifications in these steels, mainly hardening. This modification increases the mechanical resistance of the materials appropriately for their foreseen application. Nonetheless, the materials become susceptible to pitting corrosion.

  5. Creep characterization of type 316LN and HT-9 stainless steels by the K-R creep damage model

    International Nuclear Information System (INIS)

    Kim, Woo Gon; Kim, Sung Ho; Ryu, Woo Seog

    2001-01-01

    The Kachanov and Rabotnov (K-R) creep damage model was interpreted and applied to type 316LN and HT-9 stainless steels. Seven creep constants of the model, A, B, k, m, λ, γ, and q were determined for type 316LN stainless steel. In order to quantify a damage parameter, the cavity was interruptedly traced during creep for measuring cavity area to be reflected into the damage equation. For type 316LN stainless steel, λ=ε R /ε * and λ f =ε/ε R were 3.1 and increased with creep strain. The creep curve with λ=3.1 depicted well the experimental data to the full lifetime and its damage curve showed a good agreement when γ=24. However for the HT-9 stainless steel, the values of λ and λ f were different as λ=6.2 and λ f =8.5, and their K-R creep curves did not agree with the experimental data. This mismatch in the HT-9 steel was due to the ductile fracture by softening of materials rather than the brittle fracture by cavity growth. The differences of the values in the above steels were attributed to creep ductilities at the secondary and the tertiary creep stages

  6. Photoluminescence properties of lanthanide-organic frameworks (LnOFs) with thiophene-2,5-dicarboxylate and acetate

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jing; Wei, Qing; Xie, Gang; Chen, Sanping [Key Lab. of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest Univ., Xi' an, Shaanxi (China); Zhang, Sheng [Key Lab. of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest Univ., Xi' an, Shaanxi (China); College of Chemistry and Chemical Engineering, Baoji Univ. of Arts and Science, Baoji, Shaanxi (China)

    2017-07-17

    S-heterocyclic dicarboxylic acid, thiophene-2,5-dicarboxylic acid (H{sub 2}TDC), was employed to construct a series of lanthanide-organic frameworks (LnOFs) with coligand acetate, formulated as [Ln(TDC)(OAc)(H{sub 2}O)]{sub n} [Ln = Eu (1), Tb (2), Gd (3), Dy (4), Sm (5)] under hydrothermal conditions. Structure analysis reveals that 1-5 have dinuclear 3D metal organic frameworks (MOFs), in which TDC{sup 2-} and OAc{sup -} display (κ{sup 1}-κ{sup 1})-(κ{sup 1}-κ{sup 1})-μ{sub 4} and (κ{sup 2}-κ{sup 1})-μ{sub 2} coordination fashions, respectively. The dehydrated products of all compounds show high thermal stability above 410 C. As for 1, 2, 4, and 5, the photoluminescence analyses exhibit characteristic luminescence emission bands of the corresponding lanthanide ions in the visible region. In particular, compound 2 displays bright green luminescence in the solid state with {sup 5}D{sub 4} lifetime of 0.510 ms and relative high overall quantum yield of 16 %, based on an ideal energy gap between the lowest triplet state energy level of H{sub 2}TDC ligand and the {sup 5}D{sub 4} state energy level of Tb{sup 3+}. The energy transfer mechanisms in compounds 1 and 2 were also discussed. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Synthesis, surface modification/decoration of luminescent–magnetic core/shell nanomaterials, based on the lanthanide doped fluorides (Fe{sub 3}O{sub 4}/SiO{sub 2}/NH{sub 2}/PAA/LnF{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Runowski, Marcin; Lis, Stefan, E-mail: blis@amu.edu.pl

    2016-02-15

    The synthesized magnetite nanoparticles (10–15 nm) were successfully coated with amine modified silica nanoshell, which led to the formation of core/shell type nanostructures (30–50 nm). The as-prepared nanoparticles were surface modified with polyacrylic acid (PAA) via electrostatic interactions of –NH{sub 2} and –COOH groups. Afterwards, the surface PAA molecules acted as complexing agents of the introduced lanthanide (Ln{sup 3+}) ions. Subsequently, the as-prepared nanostructures were surface decorated with luminescent LnF{sub 3} nanoparticles, forming Eu{sup 3+} or Tb{sup 3+} doped Fe{sub 3}O{sub 4}/SiO{sub 2}/NH{sub 2}/PAA/LnF{sub 3} nanomaterials (50–100 nm). The obtained luminescent–magnetic products exhibited simultaneously bright red or green emission under UV lamp irradiation (λ{sub ex}=254 nm), and a response for the applied magnetic field (strong magnet attracts the colloidal particles, dispersed in aqueous medium). After the synthesis, properties of the nanomaterials were investigated by powder X-ray diffraction (XRD) technique, transmission electron microscopy (TEM), infrared spectroscopy (IR) and spectrofluorometry (analysis of excitation/emission spectra and luminescence decay curves). Such advanced nanomaterials can be potentially used in multimodal imaging, targeted therapies and as multifunctional contrast agents, novel luminescent–magnetic tracers, protection of documents, etc. - Highlights: • Luminescent–magnetic nanomaterials Fe{sub 3}O{sub 4}/SiO{sub 2}/NH{sub 2}/PAA/LnF{sub 3} were synthesized. • Core/shell nanostructures were obtained by surface modification of nanoparticles. • Luminescent lanthanide fluoride nanoparticles doped with Eu{sup 3+} and Tb{sup 3+} ions. • Multifunctional core/shell nanostructures exhibited red or green emission. • Nanomaterials formed stable aqueous colloids.

  8. Heteropentanuclear Oxalato-Bridged nd–4f (n=4, 5) Metal Complexes with NO Ligand: Synthesis, Crystal Structures, Aqueous Stability and Antiproliferative Activity

    KAUST Repository

    Kuhn, Paul-Steffen; Cremer, Laura; Gavriluta, Anatolie; Jovanović, Katarina K.; Filipović, Lana; Hummer, Alfred A.; Bü chel, Gabriel E.; Dojčinović, Biljana P.; Meier, Samuel M.; Rompel, Annette; Radulović, Siniša; Tommasino, Jean Bernard; Luneau, Dominique; Arion, Vladimir B.

    2015-01-01

    A series of heteropentanuclear oxalate-bridged Ru(NO)-Ln (4d–4f) metal complexes of the general formula (nBu4N)5[Ln{RuCl3(μ-ox)(NO)}4], where Ln=Y (2), Gd (3), Tb (4), Dy (5) and ox=oxalate anion, were obtained by treatment of (nBu4N)2[RuCl3(ox)(NO)] (1) with the respective lanthanide salt in 4:1 molar ratio. The compounds were characterized by elemental analysis, IR spectroscopy, electrospray ionization (ESI) mass spectrometry, while 1, 2, and 5 were in addition analyzed by X-ray crystallography, 1 by Ru K-edge XAS and 1 and 2 by 13C NMR spectroscopy. X-ray diffraction showed that in 2 and 5 four complex anions [RuCl3(ox)(NO)]2− are coordinated to YIII and DyIII, respectively, with formation of [Ln{RuCl3(μ-ox)(NO)}4]5− (Ln=Y, Dy). While YIII is eight-coordinate in 2, DyIII is nine-coordinate in 5, with an additional coordination of an EtOH molecule. The negative charge is counterbalanced by five nBu4N+ ions present in the crystal structure. The stability of complexes 2 and 5 in aqueous medium was monitored by UV/Vis spectroscopy. The antiproliferative activity of ruthenium-lanthanide complexes 2–5 were assayed in two human cancer cell lines (HeLa and A549) and in a noncancerous cell line (MRC-5) and compared with those obtained for the previously reported Os(NO)-Ln (5d–4f) analogues (nBu4N)5[Ln{OsCl3(ox)(NO)}4] (Ln=Y (6), Gd (7), Tb (8), Dy (9)). Complexes 2–5 were found to be slightly more active than 1 in inhibiting the proliferation of HeLa and A549 cells, and significantly more cytotoxic than 5d–4f metal complexes 6–9 in terms of IC50 values. The highest antiproliferative activity with IC50 values of 20.0 and 22.4 μM was found for 4 in HeLa and A549 cell lines, respectively. These cytotoxicity results are in accord with the presented ICP-MS data, indicating five- to eightfold greater accumulation of ruthenium versus osmium in human A549 cancer cells.

  9. Heteropentanuclear Oxalato-Bridged nd–4f (n=4, 5) Metal Complexes with NO Ligand: Synthesis, Crystal Structures, Aqueous Stability and Antiproliferative Activity

    KAUST Repository

    Kuhn, Paul-Steffen

    2015-08-10

    A series of heteropentanuclear oxalate-bridged Ru(NO)-Ln (4d–4f) metal complexes of the general formula (nBu4N)5[Ln{RuCl3(μ-ox)(NO)}4], where Ln=Y (2), Gd (3), Tb (4), Dy (5) and ox=oxalate anion, were obtained by treatment of (nBu4N)2[RuCl3(ox)(NO)] (1) with the respective lanthanide salt in 4:1 molar ratio. The compounds were characterized by elemental analysis, IR spectroscopy, electrospray ionization (ESI) mass spectrometry, while 1, 2, and 5 were in addition analyzed by X-ray crystallography, 1 by Ru K-edge XAS and 1 and 2 by 13C NMR spectroscopy. X-ray diffraction showed that in 2 and 5 four complex anions [RuCl3(ox)(NO)]2− are coordinated to YIII and DyIII, respectively, with formation of [Ln{RuCl3(μ-ox)(NO)}4]5− (Ln=Y, Dy). While YIII is eight-coordinate in 2, DyIII is nine-coordinate in 5, with an additional coordination of an EtOH molecule. The negative charge is counterbalanced by five nBu4N+ ions present in the crystal structure. The stability of complexes 2 and 5 in aqueous medium was monitored by UV/Vis spectroscopy. The antiproliferative activity of ruthenium-lanthanide complexes 2–5 were assayed in two human cancer cell lines (HeLa and A549) and in a noncancerous cell line (MRC-5) and compared with those obtained for the previously reported Os(NO)-Ln (5d–4f) analogues (nBu4N)5[Ln{OsCl3(ox)(NO)}4] (Ln=Y (6), Gd (7), Tb (8), Dy (9)). Complexes 2–5 were found to be slightly more active than 1 in inhibiting the proliferation of HeLa and A549 cells, and significantly more cytotoxic than 5d–4f metal complexes 6–9 in terms of IC50 values. The highest antiproliferative activity with IC50 values of 20.0 and 22.4 μM was found for 4 in HeLa and A549 cell lines, respectively. These cytotoxicity results are in accord with the presented ICP-MS data, indicating five- to eightfold greater accumulation of ruthenium versus osmium in human A549 cancer cells.

  10. Complexes of light lanthanides with 2,4-dimethoxybenzoic acid

    Directory of Open Access Journals (Sweden)

    WIESLAWA FERENC

    2000-01-01

    Full Text Available The complexes of light lanthanides with 2,4-dimethoxybenzoic acid of the formula: Ln(C9H9O43·nH2O where Ln = La(III, Ce(III, Pr(III, Nd(III, Sm(III, Eu(III, Gd(IIII, and n = 3 for La(III, Gd(III, n = 2 for Sm(III, Eu(III, and n = 0 for Ce(III, Pr(III, Nd(III have been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric studies and X-ray diffraction measurements. The complexes have colours typical for Ln3+ ions (La, Ce, Eu, Gd-white, Sm-cream, Pr-green, Nd-violet. The carboxylate group in these complexes is a symmetrical, bidentate, chelating ligand. They are crystalline compounds characterized by various symmetry. On heating in air to 1273 K the 2,4-dimethoxybenzoates of the light lanthanides decompose in various ways. The hydrated complexes decompose in two or three steps while those of anhydrous ones only in one or two. The trihydrate of lanthanum 2,4-dimethoxybenzoate first dehydrates to form the anhydrous salt, which then decomposes to La2O3via the intermediate formation of La2O2CO3. The hydrates of Sm(III, Eu(III, Gd(III decompose in two stages. First, they dehydrate forming the anhydrous salts, which then decompose directly to the oxides of the respective metals. The anhydrous complexes of Ce(III, Pr(III decompose in one step, while that of Nd(III in two. The solubilities of the 2,4-dimethoxybenzoates of the light lanthanides in water and ethanol at 293 K are in the order of: 10-3 mol dm-3 and 10-4-10-3 mol dm-3, respectively.

  11. Synthesis, structure and luminescence properties of lanthanide complex with a new tetrapodal ligand featuring salicylamide arms

    International Nuclear Information System (INIS)

    Song Xueqin; Wen Xiaoguang; Liu Weisheng; Wang Daqi

    2010-01-01

    A new tetrapodal ligand 1,1,1-tetrakis{[(2'-(2-furfurylaminoformyl))phenoxyl]methyl}methane (L) has been prepared and their coordination chemistry with Ln III ions has been investigated. The structure of {[Ln 4 L 3 (NO 3 ) 12 ].H 2 O} ∞ (Ln=Nd, Eu)] shows the binodal 4,3-connected three-dimensional interpenetration coordination polymers with topology of a (8 6 ) 3 (8 3 ) 4 notation. [DyL(NO 3 ) 3 (H 2 O) 2 ].0.5CH 3 OH and [ErL(NO 3 ) 3 (H 2 O) (CH 3 OH)].CH 3 COCH 3 is a 1:1 mononuclear complex with interesting supramolecular features. The structure of [NdL(H 2 O) 6 ].3ClO 4 .3H 2 O is a 2:1 mononuclear complex which further self-assembled through hydrogen bond to form a three-dimensional supramolecular structures. The result presented here indicates that both subtle variation of the terminal group and counter anions can be applied in the modulation of the overall molecular structures of lanthanide complex of salicylamide derivatives due to the structure specialties of this type of ligand. The luminescence properties of the Eu III complex are also studied in detail. - Grapical Abstract: We present here a series of zero- to three-dimensional lanthanide coordination structures and luminescence properties of Eu(III) complex of a new tetrapodal ligand.

  12. Genetic and proteomic characterization of rpoB mutations and their effect on nematicidal activity in Photorhabdus luminescens LN2.

    Directory of Open Access Journals (Sweden)

    Xuehong Qiu

    Full Text Available Rifampin resistant (Rif(R mutants of the insect pathogenic bacterium Photorhabdus luminescens LN2 from entomopathogenic nematode Heterorhabditis indica LN2 were genetically and proteomically characterized. The Rif(R mutants showed typical phase one characters of Photorhabdus bacteria, and insecticidal activity against Galleria mellonella larvae, but surprisingly influenced their nematicidal activity against axenic infective juveniles (IJs of H. bacteriophora H06, an incompatible nematode host. 13 out of 34 Rif(R mutants lost their nematicidal activity against H06 IJs but supported the reproduction of H06 nematodes. 7 nematicidal-producing and 7 non-nematicidal-producing Rif(R mutants were respectively selected for rpoB sequence analysis. rpoB mutations were found in all 14 Rif(R mutants. The rpoB (P564L mutation was found in all 7 mutants which produced nematicidal activity against H06 nematodes, but not in the mutants which supported H06 nematode production. Allelic exchange assays confirmed that the Rif-resistance and the impact on nematicidal activity of LN2 bacteria were conferred by rpoB mutation(s. The non-nematicidal-producing Rif(R mutant was unable to colonize in the intestines of H06 IJs, but able to colonize in the intestines of its indigenous LN2 IJs. Proteomic analysis revealed different protein expression between wild-type strain and Rif(R mutants, or between nematicidal-producing and non nematicidal-producing mutants. At least 7 putative proteins including DsbA, HlpA, RhlE, RplC, NamB (a protein from T3SS, and 2 hypothetical proteins (similar to unknown protein YgdH and YggE of Escherichia coli respectively were probably involved in the nematicidal activity of LN2 bacteria against H06 nematodes. This hypothesis was further confirmed by creating insertion-deletion mutants of three selected corresponding genes (the downregulated rhlE and namB, and upregulated dsbA. These results indicate that the rpoB mutations greatly influence the

  13. Synthesis and characterization of heterobinuclear (La-Zn, Pr-Zn, Nd-Zn, Sm-Zn, Eu-Zn, Gd-Zn, Tb-Zn, Dy-Zn) azine-bridged complexes

    International Nuclear Information System (INIS)

    Singh, Bachcha; Srivastav, A.K.; Singh, P.K.

    1997-01-01

    Zinc(II) complex of 2-acetylpyridine salicyl aldazine (Haps) of the type Zn(aps) 2 (H 2 O) 2 has been synthesised. The reaction of Zn(aps) 2 (H 2 O) 2 with lanthanide chlorides, LnCl 3 (where Ln=La, Pr, Nd, Sm, Eu, Gd, Tb and Dy) yields azine-bridged heterobinuclear complexes of the formulae LnCl 3 Zn(aps) 2 (H 2 O) 2 . These complexes have been characterized by elemental analyses, molecular weight, conductance (solid and solution) and magnetic susceptibility measurements, mass, IR and electronic spectral data. X-ray powder diffraction data indicate the tetragonal unit lattice for Zn(aps) 2 (H 2 O) 2 and PrCl 3 Zn(aps) 2 (H 2 O) 2 . (author)

  14. Synthesis, structures, and luminescent properties of sodium rare-earth metal(III) chloride oxotellurates(IV), Na{sub 2}Ln{sub 3}Cl{sub 3}[TeO{sub 3}]{sub 4} (Ln = Sm, Eu, Gd, Tb, Dy, and Ho)

    Energy Technology Data Exchange (ETDEWEB)

    Charkin, Dmitri O.; Dorofeev, Sergey G.; Berdonosov, Peter S.; Dolgikh, Valery A. [Department of Chemistry, Lomonosov Moscow State University (Russian Federation); Zitzer, Sabine; Greiner, Stefan; Schleid, Thomas [Institut fuer Anorganische Chemie, Universitaet Stuttgart (Germany); Olenev, Andrei V. [Department of Chemistry, Lomonosov Moscow State University (Russian Federation); Sine Theta Ltd., Moscow (Russian Federation)

    2017-11-17

    Six sodium rare-earth metal(III) chloride oxotellurates(IV), Na{sub 2}Ln{sub 3}Cl{sub 3}[TeO{sub 3}]{sub 4}, isostructural to Na{sub 2}Y{sub 3}Cl{sub 3}[TeO{sub 3}]{sub 4}, were synthesized by flux techniques and characterized by single-crystal XRD. The compounds crystallize in the monoclinic space group C2/c with lattice constants a = 23.967(1), b = 5.6342(3), c = 16.952(1) Aa, β = 134.456(5) for Ln = Sm, a = 23.932(2), b = 5.6044(5), c = 17.134(1) Aa, β = 135.151(6) for Ln = Eu, a = 23.928(1), b = 5.5928(1), c = 17.1133(8) Aa, β = 135.366(3) for Ln = Gd, a = 23.907(1), b = 5.569(3), c = 16.745(1) Aa, β = 134.205(3) for Ln = Tb, a = 23.870(1), b = 5.547(3), c = 16.665(1) Aa, β = 134.102(3) for Ln = Dy, and a = 23.814(1), b = 5.526(3), c = 16.626(1) Aa, β = 134.016(3) for Ln = Ho and Z = 4. Their crystal structure can be considered as a framework built of intergrowing Ln-O and Na-(O,Cl) slabs with channel walls decorated by tellurium atoms of [TeO{sub 3}]{sup 2-} groups. The luminescent properties of the new compounds due to the Ln{sup 3+} cations are described and discussed. We also discuss the crystal chemistry of various alkali-metal rare-earth metal(III) halide oxochalcogenates(IV). (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Complexity explained

    CERN Document Server

    Erdi, Peter

    2008-01-01

    This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

  16. Estimation of Low Cycle Fatigue Response of 316 LN Stainless Steel in the Presence of Notch

    Science.gov (United States)

    Agrawal, Richa; Veerababu, J.; Goyal, Sunil; Sandhya, R.; Uddanwadiker, Rashmi; Padole, Pramod

    2018-02-01

    Notches introduced in the plain specimen result in the multiaxial state of stress that exists in the actual components due to the presence of flaws and defects. In the present work, low cycle fatigue life estimation of plain and notched specimens of 316 LN stainless steel is carried out at room temperature and 823 K. The plain and notched specimens with different notch radii were subjected to varying strain amplitudes ranging from ± 0.25 to ± 1.0% at a strain rate of 3 × 10-3 s-1. The fatigue life decreased in the presence of notch for all strain amplitudes at both the temperatures. The decrease in fatigue life was found to be more at room temperature than at 823 K. The fatigue life of the notched specimen decreased by approximately 94.2% compared to plain specimen at room temperature. However, at 823 K the decrease in fatigue life for notched specimen was approximately 84.6%. Low cycle fatigue life of the plain and notched specimens was estimated by Neuber's rule and finite element analysis approach. Neuber's rule overestimated the fatigue life by maximum factor of 2.6 for specimens at room temperature and by maximum factor of 5 for specimens at 823 K. However, it gives closer approximation at higher strain amplitudes at 823 K. Life estimation by finite element analysis at room temperature was within a factor of 1.5 as compared to experimental life, whereas it underestimated the fatigue life within a factor of 6 at high temperature.

  17. 16-8-2 weld metal design data for 316L(N) steel

    Energy Technology Data Exchange (ETDEWEB)

    Tavassoli, A.-A.F. [Commissariat a l' Energie Atomique, CEA/Saclay, 91191 Gif sur Yvette (France)], E-mail: tavassoli@cea.fr

    2008-12-15

    ITER materials properties documentation is extended to weld metals used for welding Type 316L(N) steel, i.e. the structural material retained for manufacturing ITER major components, such as the vacuum vessel. The data presented here are mainly for the Type 16-8-2 and complete those already reported for the low temperature (Type 316L) and the high temperature (Type 19-12-2) filler metals. The weld metal properties data for Type 16-8-2 filler metal and its joints are collected, sorted and analysed according to the French design and construction rules for nuclear components (RCC-MR). Particular attention is paid to the type of weld metal (e.g. wire for TIG, covered electrode for manual arc, flux wire for automatic welding), as well as, to the weld geometry and welding position. Design allowables are derived from validated data for each category of weld and compared with those of the base metal. In most cases, the analyses performed are extended beyond the conventional analyses required for codes to cover specific needs of ITER. These include effects of exposures to high temperature cycles during component fabrication, e.g. HIPing and low dose neutron irradiation at low and medium temperatures. The ITER Materials Properties Handbook (MPH) is, here, enriched with files for physical and mechanical properties of Type 16-8-2 weld metal. These files, combined with the codification and inspection files, are part of the documentation required for ITER licensing needs. They show that all three weld-metals satisfy the code requirements, provided compositions and types of welds used correspond to those specified in RCC-MR.

  18. Antiferromagnetic coupling between rare earth ions and semiquinones in a series of 1:1 complexes.

    Science.gov (United States)

    Caneschi, Andrea; Dei, Andrea; Gatteschi, Dante; Poussereau, Sandrine; Sorace, Lorenzo

    2004-04-07

    We use the strategy of diamagnetic substitution for obtaining information on the crystal field effects in paramagnetic rare earth ions using the homologous series of compounds with the diamagnetic tropolonato ligand, Ln(Trp)(HBPz(3))(2), and the paramagnetic semiquinone ligand, Ln(DTBSQ)(HBPz(3))(2), (DTBSQ = 3,5-di-tert-butylsemiquinonato, Trp = tropolonate, HBPz(3)= hydrotrispyrazolylborate) for Ln = Sm(iii), Eu(iii), Gd(iii), Tb(iii), Dy(iii), Ho(iii), Er(iii) or Yb(iii). The X-ray crystal structure of a new form of tropolonate derivative is presented, which shows, as expected, a marked similarity with the structure of the semiquinonate derivative. The Ln(Trp)(HBPz(3))(2) derivatives were then used as a reference for the qualitative determination of crystal field effects in the exchange coupled semiquinone derivatives. Through magnetisation and susceptibility measurements this empirical diamagnetic substitution method evidenced for Er(iii), Tb(iii), Dy(iii) and Yb(iii) derivatives a dominating antiferromagnetic coupling. The increased antiferromagnetic contribution compared to other radical-rare earth metal complexes formed by nitronyl nitroxide ligands may be related to the increased donor strength of the semiquinone ligand.

  19. Complex chemistry

    International Nuclear Information System (INIS)

    Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

    2006-06-01

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  20. Cadmium (II) macrocyclic Schiff-base complexes containing piperazine moiety: Synthesis, spectroscopic, X-ray structure, theoretical and antibacterial studies

    Science.gov (United States)

    Keypour, Hassan; Mahmoudabadi, Masoumeh; Shooshtari, Amir; Bayat, Mehdi; Mohsenzadeh, Fariba; Gable, Robert William

    2018-03-01

    The new Cd(II) macrocyclic Schiff-base complexes were prepared via the metal templated [1 + 1] cyclocondensation of 2,2'-(piperazine-1,4-diylbis (methylene))dianiline (A) and 2,6-pyridinedicarbaldehyde or 2,6-diacetylpyridine. The products were characterized by elemental analysis, mass spectrometry and spectroscopic methods such as: FT-IR, 1H and 13C-NMR, the crystal structure of [CdL1(ClO4)2](CH3CN) (1) complex was also obtained by single-crystal X-ray crystallography. The complexes were tested for in vitro antibacterial properties against some bacteria. The complexes had antibacterial properties and in some cases were active even more than standards. The geometries of the [CdLn (ClO4)2], (n = 1,2) complexes have been optimized at the BP86/def2-SVP level of theory. Also the nature of Cd←Ln (n = 1, 2) bonds in [CdLn (ClO4)2], (n = 1,2) complexes are studied with the help of NBO and Energy decomposition analysis (EDA). Results showed that the nature of metal-ligand bond in the complexes is slightly more electrostatic with a contribution of about 52% in total interaction energy.

  1. Complexes of macrocyclic dibenzo-18-crown-6 polyether with nitrates of some rare earths

    International Nuclear Information System (INIS)

    Gren', A.I.; Zakhariya, N.F.; Vityuk, N.V.; Kalishevich, V.S.

    1984-01-01

    The purpose of the investigation is to obtain and study the structure of complexes of macrocyclic polyether dibenzo-18-crown-6(D-18-C-6) with REE nitrates (Ln, Pr, Nd, Er). Synthesis has been realized by mixing the solutions 2 mol Ln(NO 3 ) 3 and 2 mmol D-18-C-6 into 30-50 ml acetonitrile and boiling during 40-60 minutes. Study on the prepared compounds by means of UV- and IR-spectroscopy proved formation of D-18-C-6 complexes with lanthanide nitrates-Ln(NO 3 ) 3 D-18-C-6. Based on studying IR-spectra a conclusion is made on deformation of D-18-C-6 structure under complexing. Distortion of the ring structure of macrocyclic polyether manifests itself in increase of CH 2 -O-CH 2 bond lengths with simultaneous reduction of four other types of bonds C 6 H 5 -O-CH 2 . Synthesized complexes are stated to have different solubility in acetonitrile which increases in the La 3 ) 3 xD-18-C-6 is noted

  2. A comparative study of the magnetic properties and phase separation behavior of the rare earth cobaltates, Ln 0.5Sr0.5CoO3 (Ln=rare earth)

    International Nuclear Information System (INIS)

    Kundu, Asish; Sarkar, R.; Pahari, B.; Ghoshray, A.; Rao, C.N.R.

    2007-01-01

    A comparative study of the magnetic properties of a few members of the Ln 0.5 Sr 0.5 CoO 3 family with different radii of the A-site cations, A >, in the range 1.19-1.40 A has been carried out. The apparent T c (where the magnetization undergoes an abrupt increase) decreases markedly with A > as well as the size-disorder arising from the mismatch in the size of the A-site cations. The value of the magnetization at low temperatures decreases markedly with decrease in A > or increase in size-disorder, suggesting that the relative proportion of the ferromagnetic (FM) species decreases relative to that of the paramagnetic (PM) species. Such a variation of the FM/PM ratio with composition and temperature is evidenced from the Moessbauer spectra of La 0.5 Sr 0.5 CoO 3 as well. The variation of the FM/PM ratio with A > and size-disorder, as well as a local-probe study using 59 Co Nuclear magnetic resonance spectroscopy suggest that electronic phase separation is an inherent feature of the Ln 0.5 Sr 0.5 CoO 3 type cobaltates, with the nature of the different magnetic species in the phase-separated system varying with A > and size disorder. - Graphical abstract: Variation of (a) T c and (b) FC magnetization at 1000 Oe with A > at 120 K in Ln 0.5 Sr 0.5 CoO 3 and Dy 0.34 Nd 0.16 Sr 0.40 Ca 0.10 CoO 3

  3. On the role of the ground state Tb(3)/acetylacetone complex in sensitized emission of Tb(3) in ethanol solution

    International Nuclear Information System (INIS)

    Lis, S.; Elbanowski, M.; Marciniak, B.

    1989-01-01

    The Tb(3)-acetylacetone system in ethanol solution has been studied by spectroscopic methods. The formation of a Tb(3)/acetylacetone (1:1) complex in the ground state has been proved and its stability constant determined, K = (0,97 ± 0,06).10 4 dm 3 mol -1 . The role of this complex in the spectrofluorimetric determination of Ln(3) ions in the presence of acetylacetone has been discussed. (Authors)

  4. Yttrium and lanthanide nitrate complexes of N,N1-bis(4-antipyryl methylidene) ethylenediamine

    International Nuclear Information System (INIS)

    Joseph, Siby; Radhakrishnan, P.K.

    1998-01-01

    Complexes of yttrium and lanthanide nitrates with a Schiff base, N, N 1 -bis(4-antipyrylmethylidene)ethylenediamine (BAME) having the general formula [Ln(BAME) 2 (NO 3 )](NO 3 ) 2 , where Ln = Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho and Er have been synthesised and characterised by elemental analyses, molar conductance in non-aqueous solvents, electronic, infrared and proton NMR spectra. BAME acts as a neutral bidentate ligand coordinating through both azomethine nitrogen atoms. One of the nitrate groups is coordinated in a bidentate manner. A coordination number of six may be assigned to the metal ion in these complexes. The covalency parameters evaluated from the solid state electronic spectra suggest weak covalent character of the metal-ligand bond. (author)

  5. Bis(pentamethylene)urea complexes of the lanthanide nitrates: synthesis, characterization, properties

    International Nuclear Information System (INIS)

    Souza, H.K.S. de; Pedrosa, A.M.G.; Marinho, E.P.M.; Batista, M.K.S.; Melo, D.M.A.; Zinner, K.; Zinner, L.B.; Zukerman-Schpector, J.; Vicentini, G.

    2003-01-01

    Lanthanide nitrate complexes of bis(pentamethylene)urea (BPMU) with general formula Ln(NO 3 ) 3 3BPMU, where Ln: La, Nd, Sm, Eu, Ho and Er have been prepared and characterized based on CHN elemental analyses, lanthanide titration with EDTA, molar conductivity, spectroscopic data and thermal studies. The infrared spectra show that ligands (BPMU) are bonded through the carbonyl oxygen, nitrate counter-ions are bidentate linked to the central ions. The structure of the neodymium complex was determined. The crystal is monoclinic, P2 1/c ,Z=4, with the following parameters: a=10.148(1) A, b=21.879(2), c=19.154(2) A, β=104.11(1) deg., V=4124.3(7) A 3 . The polyhedron is a distorted tricapped trigonal prism, coordination number nine

  6. Complexes of Th(IV) perchlorates, nitrates and thiocyanates with some heterocyclic bases

    International Nuclear Information System (INIS)

    Agarwal, R.K.; Srivastava, A.K.; Srivastava, M.; Bhakru, N.; Srivastava, T.N.

    1980-01-01

    Some Th(IV) perchlorate complexes of heterocyclic bases have been reported previously. Adducts of Th(IV) nitrates and thiocyanates with some heterocyclic N-oxides have been prepared and physico-chemical properties investigated. Comparatively little is known about the complexes of Th(IV) ion with the ligands containing nitrogen atom acting as electron donating centres. In view of this, the adducts of Th(IV) ion with certain nitrogen heterocyclic bases such as pyridine (Py), α-picoline (Pic), 2-amino pyridine (NH 2 Py), 2:4-lutidine (2,4LN), 2:6-lutidine, (2,6LN), quinoline (Q), isoquinoline (Isoq), 2,2'-bipyridine (Bipy) and 1,10-phenanthroline (Phen) were synthesised and characterised by analysis and IR absorption spectra. The results are presented and discussed. (author)

  7. Relating surface chemistry and oxygen surface exchange in LnBaCo2O(5+δ) air electrodes.

    Science.gov (United States)

    Téllez, Helena; Druce, John; Kilner, John A; Ishihara, Tatsumi

    2015-01-01

    The surface and near-surface chemical composition of electroceramic materials often shows significant deviations from that of the bulk. In particular, layered materials, such as cation-ordered LnBaCo2O(5+δ) perovskites (Ln = lanthanide), undergo surface and sub-surface restructuring due to the segregation of the divalent alkaline-earth cation. These processes can take place during synthesis and processing steps (e.g. deposition, sintering or annealing), as well as at temperatures relevant for the operation of these materials as air electrodes in solid oxide fuel cells and electrolysers. Furthermore, the surface segregation in these double perovskites shows fast kinetics, starting at temperatures as low as 400 °C over short periods of time and leading to a decrease in the transition metal surface coverage exposed to the gas phase. In this work, we use a combination of stable isotope tracer labeling and surface-sensitive ion beam techniques to study the oxygen transport properties and their relationship with the surface chemistry in ordered LnBaCo2O(5+δ) perovskites. Time-of-Flight Secondary-Ion Mass Spectrometry (ToF-SIMS) combined with (18)O isotope exchange was used to determine the oxygen tracer diffusion (D*) and surface exchange (k*) coefficients. Furthermore, Low Energy Ion Scattering (LEIS) was used for the analysis of the surface and near surface chemistry as it provides information from the first mono-atomic layer of the materials. In this way, we could relate the compositional modifications (e.g. cation segregation) taking place at the electrochemically-active surface during the exchange at high temperatures and the oxygen transport properties in double perovskite electrode materials to further our understanding of the mechanism of the surface exchange process.

  8. Evaluation of DC electric field distribution of PPLP specimen based on the measurement of electrical conductivity in LN2

    Science.gov (United States)

    Hwang, Jae-Sang; Seong, Jae-Kyu; Shin, Woo-Ju; Lee, Jong-Geon; Cho, Jeon-Wook; Ryoo, Hee-Suk; Lee, Bang-Wook

    2013-11-01

    High temperature superconducting (HTS) cable has been paid much attention due to its high efficiency and high current transportation capability, and it is also regarded as eco-friendly power cable for the next generation. Especially for DC HTS cable, it has more sustainable and stable properties compared to AC HTS cable due to the absence of AC loss in DC HTS cable. Recently, DC HTS cable has been investigated competitively all over the world, and one of the key components of DC HTS cable to be developed is a cable joint box considering HVDC environment. In order to achieve the optimum insulation design of the joint box, analysis of DC electric field distribution of the joint box is a fundamental process to develop DC HTS cable. Generally, AC electric field distribution depends on relative permittivity of dielectric materials but in case of DC, electrical conductivity of dielectric material is a dominant factor which determines electric field distribution. In this study, in order to evaluate DC electric field characteristics of the joint box for DC HTS cable, polypropylene laminated paper (PPLP) specimen has been prepared and its DC electric field distribution was analyzed based on the measurement of electrical conductivity of PPLP in liquid nitrogen (LN2). Electrical conductivity of PPLP in LN2 has not been reported yet but it should be measured for DC electric field analysis. The experimental works for measuring electrical conductivity of PPLP in LN2 were presented in this paper. Based on the experimental works, DC electric field distribution of PPLP specimen was fully analyzed considering the steady state and the transient state of DC. Consequently, it was possible to determine the electric field distribution characteristics considering different DC applying stages including DC switching on, DC switching off and polarity reversal conditions.

  9. Oxidation Behavior of Surface-modified Stainless Steel 316LN in Supercritical-CO{sub 2} Environment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hwan; Heo, Jin Woo; Kim, Hyunm Yung; Jang, Chang Heui [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    Compared to other working fluids such as helium or nitrogen, S-CO{sub 2} offers a higher efficiency at operating temperatures of advanced reactors above 550 .deg. C. Moreover, the S-CO{sub 2} cycle is expected to have a significantly smaller footprint compared to other power conversion cycles, resulting in a broader range of applications with lower capital costs. Currently, stainless steel 316 is considered as the candidate structural material for the SFR. In comparison, it is well known that alumina (Al{sub 2}O{sub 3}) have superior oxidation and carburization resistance specifically at higher temperatures where α-Al{sub 2}O{sub 3} may form. Thus, various surface modification techniques have been applied to mostly Ni-base alloys so that a protective and continuous Al-rich oxide layer forms on the surface, conferring superior oxidation and carburization resistance. In this study, SS 316LN was deposited with Al via physical vapor deposition (PVD) method followed by heat treatment processes to develop an Al-rich layer at the surface. The specimens are to be exposed to high temperature S-CO{sub 2} environment to evaluate the oxidation and carburization resistance. Stainless steel 316LN was surface-modified to develop an Al-rich layer for improvement of oxidation behavior in S-CO{sub 2} environment. As the test temperature of 600 .deg. C is not sufficiently high for the formation of protective α-Al{sub 2}O{sub 3} formation, pre-oxidation of surface modified SS 316LN was conducted.

  10. Lanthanide stannate pyrochlores (Ln2Sn2O7; Ln  =  Nd, Gd, Er) at high pressure

    Science.gov (United States)

    Turner, Katlyn M.; Tracy, Cameron L.; Mao, Wendy L.; Ewing, Rodney C.

    2017-12-01

    Lanthanide stannate pyrochlores (Ln2Sn2O7; Ln  =  Nd, Gd, and Er) were investigated in situ to 50 GPa in order to determine their structural response to compression and compare their response to that of lanthanide titanate, zirconate, and hafnate pyrochlores. The cation radius ratio of A3+/B4+ in pyrochlore oxides (A2B2O7) is thought to be the dominant feature that influences their response on compression. The ionic radius of Sn4+ is intermediate to that of Ti4+, Zr4+, and Hf4+, but the 〈Sn-O〉 bond in stannate pyrochlore is more covalent than the 〈B-O〉 bonds in titanates, zirconate, and hafnates. In stannates, based on in situ Raman spectroscopy, pyrochlore cation and anion sublattices begin to disorder with the onset of compression, first measured at 0.3 GPa. The extent of sublattice disorder versus pressure is greater in stannates with a smaller Ln3+ cation. Stannate pyrochlores (Fd-3m) begin a sluggish transformation to an orthorhombic, cotunnite-like structure at ~28 GPa similar transitions have been observed in titanate, zirconate, and hafnate pyrochlores at varying pressures (18-40 GPa) with cation radius ratio. The extent of the phase transition versus pressure varies directly with the size of the Ln3+ cation. Post-decompression from ~50 GPa, Er2Sn2O7 and Gd2Sn2O7 adopt a pyrochlore structure, rather than the multi-scale defect-fluorite  +  weberite-type structure adopted by Nd2Sn2O7 that is characteristic of titanate, zirconate, and hafnate pyrochlores under similar conditions. Like pyrochlore titanates, zirconates, and hafnates, the bulk modulus, B 0, of stannates varies linearly and inversely with cation radius ratio from 1 1 1 GPa (Nd2Sn2O7) to 251 GPa (Er2Sn2O7). The trends of bulk moduli in stannates in this study are in excellent agreement with previous experimental studies on stannates and suggest that the size of the Ln3+ cation is the primary determining factor of B 0. Additionally, when normalized to r A

  11. Evaluation of DC electric field distribution of PPLP specimen based on the measurement of electrical conductivity in LN2

    International Nuclear Information System (INIS)

    Hwang, Jae-Sang; Seong, Jae-Kyu; Shin, Woo-Ju; Lee, Jong-Geon; Cho, Jeon-Wook; Ryoo, Hee-Suk; Lee, Bang-Wook

    2013-01-01

    Highlights: •The electrical conductivity of PPLP in LN 2 was successfully measured. •Based on the measured value of PPLP, DC field analysis was performed. •The electric field distribution was altered according to the DC applying stages. •The maximum electric field was observed during polarity reversal situation. •DC field analysis is important to determine the optimum design of DC HTS devices. -- Abstract: High temperature superconducting (HTS) cable has been paid much attention due to its high efficiency and high current transportation capability, and it is also regarded as eco-friendly power cable for the next generation. Especially for DC HTS cable, it has more sustainable and stable properties compared to AC HTS cable due to the absence of AC loss in DC HTS cable. Recently, DC HTS cable has been investigated competitively all over the world, and one of the key components of DC HTS cable to be developed is a cable joint box considering HVDC environment. In order to achieve the optimum insulation design of the joint box, analysis of DC electric field distribution of the joint box is a fundamental process to develop DC HTS cable. Generally, AC electric field distribution depends on relative permittivity of dielectric materials but in case of DC, electrical conductivity of dielectric material is a dominant factor which determines electric field distribution. In this study, in order to evaluate DC electric field characteristics of the joint box for DC HTS cable, polypropylene laminated paper (PPLP) specimen has been prepared and its DC electric field distribution was analyzed based on the measurement of electrical conductivity of PPLP in liquid nitrogen (LN 2 ). Electrical conductivity of PPLP in LN 2 has not been reported yet but it should be measured for DC electric field analysis. The experimental works for measuring electrical conductivity of PPLP in LN 2 were presented in this paper. Based on the experimental works, DC electric field distribution of

  12. Low x Double ln2(1/x) Resummation Effects at the Sum Rules for Nucleon Structure Function g1

    International Nuclear Information System (INIS)

    Ziaja, B.

    2001-01-01

    We have estimated the contributions to the moments of polarized nucleon structure function g 1 (x,Q 2 ) coming from the region of the very low x (10 -5 2 (1/x) resummation. The Q 2 evolution of g 1 was described by the unified evolution equations incorporating both the leading order Altarelli-Parisi evolution at large and moderate x, and the double ln 2 (1/x) resummation at small x. The moments were obtained by integrating out the extrapolated nucleon structure function in the region 10 -5 < x<1. (author)

  13. Postsynthesis Modification of a Metallosalen-Containing Metal-Organic Framework for Selective Th(IV)/Ln(III) Separation.

    Science.gov (United States)

    Guo, Xiang-Guang; Qiu, Sen; Chen, Xiuting; Gong, Yu; Sun, Xiaoqi

    2017-10-16

    An uncoordinated salen-containing metal-organic framework (MOF) obtained through postsynthesis removal of Mn(III) ions from a metallosalen-containing MOF material has been used for selective separation of Th(IV) ion from Ln(III) ions in methanol solutions for the first time. This material exhibited an adsorption capacity of 46.345 mg of Th/g. The separation factors (β) of Th(IV)/La(III), Th(IV)/Eu(III), and Th(IV)/Lu(III) were 10.7, 16.4, and 10.3, respectively.

  14. Alpha Radiolysis of Nuclear Solvent Extraction Ligands Used for An(III) and Ln(III) Separations

    Energy Technology Data Exchange (ETDEWEB)

    Mezyk, Stephen P. [California State Univ. (CalState), Long Beach, CA (United States); Mincher, Bruce J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Nilsson, Mikael [Univ. of California, Irvine, CA (United States)

    2016-08-01

    This document is the final report for the Nuclear Energy Universities Program (NEUP) grant 10-910 (DE-AC07-05ID14517) “Alpha Radiolysis of Nuclear Solvent Extraction Ligands used for An(III) and Ln(III) Separations”. The goal of this work was to obtain a quantitative understanding of the impacts of both low Linear Energy Transfer (LET, gamma-rays) and high LET (alpha particles) radiation chemistry occurring in future large-scale separations processes. This quantitative understanding of the major radiation effects on diluents and ligands is essential for optimal process implementation, and could result in significant cost savings in the future.

  15. Radiosensitizing effect of Chitosan on HeLa and LN 18 brain tumor cells exposed to electron beam radiation

    International Nuclear Information System (INIS)

    Rao, Shama; Shetty, Sukanya; Suchetha Kumari, N.; Madhu, L.N.

    2014-01-01

    Chitosan has been widely used for multiple applications because it is a non-toxic biocompatible, biodegradable, and adsorptive material. A previous study has shown that low-molecular-weight chitosan (LMWC) exerts a cytotoxic effect on oral cancer cells. Although a higher concentration of LMWC in comparison to cisplatin was needed in order to kill cancer cells, it was relatively less cytotoxic to non-cancer cells. Some of the well known anticancer drugs have the property of sensitizing the cell to radiation, which will be more applicable during combination therapy of cancer. The present study was undertaken to find the radiosensitizing effect of chitosan on Hela and Brain tumor (LN18) cells against electron beam radiation (EBR). Both the cancer cell lines, Hela and LN 18 were treated with different concentration of chitosan (50 and 100 μg/ml) pre and post exposure to 4 Gy EBR. The percentage of cell viability, percentage of apoptosis and ssDNA damage in the treated cells were assessed by MTT assay, DNA diffusion assay and comet assay respectively. The obtained results showed 62.13 1 5.08 and 65.24 1 2.45 percent Hela and LN 18 viable cells at 24 hour after the exposure to 4 Gy EBR. The percentage of viability was found to be decreased in cells exposed to EBR in the presence of chitosan. Supporting to this, percentage of apoptotic cells was found to be more in treated groups (28.13 1 4.34 and 25.13 1 3.76) when compared with control (23.19 1 1.07 and 20.79 1 4.86). Treatment of HeLa and LN18 before and after the exposure of EBR showed significantly (P<0.05) more frequency of micronucleus and % of DNA damage than the 4 Gy EBR control group. These results conclude the sensitizing effect of chitosan on cancer cell line against EBR exposure. (author)

  16. Tunable emission in Ln3+ (Ce3+/Dy3+, Ce3+/Tb3+) doped KNa3Al4Si4O16 phosphor synthesized by combustion method

    Science.gov (United States)

    Kolte, M. M.; Pawade, V. B.; Bhattacharya, A. B.; Dhoble, S. J.

    2018-05-01

    Ln3+ (Ln = Ce3+/Dy3+, Ce3+/Tb3+) doped KNa3Al4Si4O16 phosphor has been synthesized by Combustion method (CS) at 550° C successfully. Ln3+ (Ln = Ce3+, Dy3+, Tb3+) ions when doped in KNa3Al4Si4O16 host lattice, it shows blue and green emission band under the near Ultraviolet (NUV) excitation wavelength. The Photoluminescence excitation (PLE) and emission spectra are observed due to f-f and d-f transition of rare earth ions. Also, an effective energy transfer (ET) study from Ce3+ → Dy3+ and Ce3+ → Tb3+ ions has been studied and confirmed on the basis of Dexter-Foster theory. Further synthesized phosphor is well characterized by XRD, SEM, TEM and decay time measurement. However, the analysis of crystallite size, lattice strain has been studied by using theoretical as well as experimental techniques. Hence, the observed tunable emission in Ln3+ doped KNa3Al4Si4O16 phosphor may be applicable for solid state lighting technology.

  17. Mixed ligand complexes of some of the rare earths. La(III)-, Pr(III)- or Nd-(III)-CDTA-Hydroxy Acids

    Energy Technology Data Exchange (ETDEWEB)

    Rana, H S; Tandon, J P [Rajasthan Univ., Jaipur (India). Chemical Labs.

    1975-11-01

    Biligand complexes of the 1:1 Ln(III)-1,2-diaminocyclohexane-tetraacetic acid (CDTA) chelate with hydroxy acids (where hydroxy acids = salicylic acid (SA); Sulphosalicylic acid (SSA) and 8-hydroxyquinoline-5-sulphonic acid (HQSA)) have been investigated by potentiometric titration. Their formation constants have been calculated (..mu..=0.1M-KNO/sub 3/; and t=30+-1 deg C) as 4.60 +-0.03, 5.46+-0.03, 5.87+-0.05; 3.12+-0.04, 3.95+-0.05, 4.42+-0.07; 2.73+-0.06, 3.45+-0.05 and 3.90+-0.08 for Ln(III)-CDTA-SA,-SSA, and -HQSA respectively (where Ln=La, Pr or Nd). The value of log Ksub(MAB) follows the order: La(III)

  18. Daily mortality and air pollutants: findings from Köln, Germany.

    Science.gov (United States)

    Spix, C; Wichmann, H E

    1996-04-01

    For the APHEA study, the short term effects of air pollutants on human health were investigated in a comparable way in various European cities. Daily mortality was used as one of the health effects indicators. This report aims to demonstrate the steps in epidemiological model building in this type of time series analysis aimed at detecting short term effects under a poisson distribution assumption and shows the tools for decision making. In addition, it assesses the impact of these steps on the pollution effect estimates. Köln, Germany, is a city of one million inhabitants. It is densely populated with a warm, humid, unfavourable climate and a high traffic density. In previous studies, smog episodes were found to increase mortality and higher sulphur dioxide (SO2) levels were connected with increases in the number of episodes of croup. Daily total mortality was obtained for 1975-85. SO2, total suspended particulates, and nitrogen dioxide (NO2) data were available from two to five stations for the city area, and size fractionated PM7 data from a neighbouring city. The main tools were time series plots of the raw data, predicted and residual data, the partial autocorrelation function and periodogram of the residuals, cross correlations of prefiltered series, plots of categorised influences, chi 2 statistics of influences and sensitivity analyses taking overdispersion and autocorrelation into account. With regard to model building, it is concluded that seasonal and epidemic correction are the most important steps. The actual model chosen depends very much on the properties of the data set. For the pollution effect estimates, trend, season, and epidemic corrections are important to avoid overestimation of the effect, while an appropriate short term meterology influence correction model may actually prevent underestimation. When the model leaves very little over-dispersion and autocorrelation in the residuals, which indicates a good fit, correction for them has

  19. Application of Leak Before Break concept in 316LN austenitic steel pipes welded using 316L

    International Nuclear Information System (INIS)

    Cunto, Gabriel Giannini de

    2017-01-01

    This work presents a study of application of the Leak Before Break (LBB) concept, usually applied in nuclear power plants, in a pipe made from steel AISI type 316LN welded a coated electrode AISI type 316L. LBB concept is a criterion based on fracture mechanics analysis to show that a crack leak, present in a pipe, can be detected by leak detection systems, before this crack reaches a critical size that results in pipe fail. In the studied pipe, tensile tests and Ramberg-Osgood analyses were performed, as well as fracture toughness tests for obtaining the material resistance curve J-R. The tests were performed considering the base metal, weld and heat affected zone (HAZ), at the same operating temperatures of a nuclear power plant. For the mechanical properties found in these tests, load limit analyses were performed in order to determine the size of a crack which could cause a detectable leakage and the critical crack size, considering failure by plastic collapse. For the critical crack size found in the weld, which is the region that presented the lowest toughness, Integral J and tearing modulus T analyses were performed, considering failure by tearing instability. Results show a well-defined behavior between the base metal, HAZ and weld zones, where the base metal has a high toughness behavior, the weld has a low toughness behavior and the HAZ showed intermediate mechanical properties between the base metal and the weld. Using the PICEP software, the leak rate curves versus crack size and also the critical crack size were determined by considering load limit analysis. It was observed that after a certain crack size, the leak rate in base metal is much higher than for the HAZ and the weld, considering the same crack length. This occurs because in the base metal crack, it is expected that the crack grows in a more rounded form due to its higher toughness. The lowest critical crack size was found for the base metal presenting circumferential cracks. For the

  20. Metal(IV) Complexes [M(LN,O,S)2]n (M = Ru, Os) of a Redox-Active o-Amidophenolate Ligand (LN,O,S)2-with Coordinating Thioether Appendix

    Czech Academy of Sciences Publication Activity Database

    Hübner, R.; Sarkar, B.; Fiedler, Jan; Záliš, Stanislav; Kaim, W.

    2012-01-01

    Roč. 2012, č. 11 (2012), s. 3569-3576 ISSN 1434-1948 R&D Projects: GA MŠk LD11086 Institutional support: RVO:61388955 Keywords : noninnocent ligands * osmium * ruthanium Subject RIV: CG - Electrochemistry Impact factor: 3.120, year: 2012

  1. An anti CuO{sub 2}-type metal hydride square net structure in Ln{sub 2}M{sub 2}As{sub 2}H{sub x} (Ln = La or Sm, M = Ti, V, Cr, or Mn)

    Energy Technology Data Exchange (ETDEWEB)

    Mizoguchi, Hiroshi; Park, SangWon; Hosono, Hideo [Tokyo Institute of Technology, Yokohama (Japan). Materials Research Center for Element Strategy; Hiraka, Haruhiro; Ikeda, Kazutaka; Otomo, Toshiya [High-Energy Accelerator Research Organization (KEK), Tsukuba (Japan). Inst. of Materials Structure Science

    2015-03-02

    Using a high pressure technique and the strong donating nature of H{sup -}, a new series of tetragonal La{sub 2}Fe{sub 2}Se{sub 2}O{sub 3}-type layered mixed-anion arsenides, Ln{sub 2}M{sub 2}As{sub 2}H{sub x}, was synthesized (Ln=La or Sm, M=Ti, V, Cr, or Mn; x∼3). In these compounds, an unusual M{sub 2}H square net, which has anti CuO{sub 2} square net structures accompanying two As{sup 3-} ions, is sandwiched by (LaH){sub 2} fluorite layers. Notably, strong metal-metal bonding with a distance of 2.80 Aa was confirmed in La{sub 2}Ti{sub 2}As{sub 2}H{sub 2.3}, which has metallic properties. In fact, these compounds are situated near the boundary between salt-like ionic hydrides and transition-metal hydrides with metallic characters.

  2. An anti CuO{sub 2}-type metal hydride square net structure in Ln{sub 2}M{sub 2}As{sub 2}H{sub x} (Ln = La or Sm, M = Ti, V, Cr, or Mn)

    Energy Technology Data Exchange (ETDEWEB)

    Mizoguchi, Hiroshi; Park, SangWon; Hosono, Hideo [Materials Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); Hiraka, Haruhiro; Ikeda, Kazutaka; Otomo, Toshiya [Institute of Materials Structure Science, High-Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan)

    2015-03-02

    Using a high pressure technique and the strong donating nature of H{sup -}, a new series of tetragonal La{sub 2}Fe{sub 2}Se{sub 2}O{sub 3}-type layered mixed-anion arsenides, Ln{sub 2}M{sub 2}As{sub 2}H{sub x}, was synthesized (Ln=La or Sm, M=Ti, V, Cr, or Mn; x∼3). In these compounds, an unusual M{sub 2}H square net, which has anti CuO{sub 2} square net structures accompanying two As{sup 3-} ions, is sandwiched by (LaH){sub 2} fluorite layers. Notably, strong metal-metal bonding with a distance of 2.80 Aa was confirmed in La{sub 2}Ti{sub 2}As{sub 2}H{sub 2.3}, which has metallic properties. In fact, these compounds are situated near the boundary between salt-like ionic hydrides and transition-metal hydrides with metallic characters. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Electronic phase separation in the rare-earth manganates (La sub 1 sub - sub x Ln sub x) sub 0 sub . sub 7 Ca sub 0 sub . sub 3 MnO sub 3 (Ln = Nd, Gd and Y)

    CERN Document Server

    Sudheendra, L

    2003-01-01

    Electron transport and magnetic properties of three series of manganates of the formula (La sub 1 sub - sub x Ln sub x) sub 0 sub . sub 7 Ca sub 0 sub . sub 3 MnO sub 3 with Ln = Nd, Gd and Y, wherein only the average A-site cation radius (r sub A ) and associated disorder vary, without affecting the Mn sup 4 sup + /Mn sup 3 sup + ratio, have been investigated in an effort to understand the nature of phase separation. All three series of manganates show saturation magnetization characteristic of ferromagnetism, with the ferromagnetic T sub c decreasing with increasing x up to a critical value of x, x sub c (x sub c = 0.6, 0.3, 0.2 respectively for Nd, Gd, Y). For x > x sub c , the magnetic moments are considerably smaller, showing a small increase around T sub M , the value of T sub M decreasing slightly with increase in x or decrease in (r sub A ). The ferromagnetic compositions (x x sub c are insulating. The magnetic and electrical resistivity behaviour of these manganates is consistent with the occurrence...

  4. Color tunable emission in Ce3+ and Tb3+ co-doped Ba2Ln(BO3)2Cl (Ln=Gd and Y) phosphors for white light-emitting diodes.

    Science.gov (United States)

    Zhang, Niumiao; Guo, Chongfeng; Jing, Heng; Jeong, Jung Hyun

    2013-12-01

    Ce(3+) and Tb(3+) co-doped Ba2Ln(BO3)2Cl (Ln=Y and Gd) green emitting phosphors were prepared by solid state reaction in reductive atmosphere. The emission and excitation spectra as well as luminescence decays were investigated, showing the occurrence of efficient energy transfer from Ce(3+) to Tb(3+) in this system. The phosphors exhibit both a blue emission from Ce(3+) and a green emission from Tb(3+) under near ultraviolet light excitation with 325-375 nm wavelength. Emission colors of phosphors could be tuned from deep blue through cyan to green by adjusting the Tb(3+) concentrations. The energy transfer efficiency and emission intensity of Ba2Y(BO3)2Cl:Ce(3+), Tb(3+) precede those of Ba2Gd(BO3)2Cl:Ce(3+), Tb(3+), and the sample Ba2Y(BO3)2Cl:0.03Ce(3+), 0.10Tb(3+) is the best candidate for n-UV LEDs. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Near-infrared photoluminescence in La{sub 0.98}AlO{sub 3}: {sub 0.02}Ln{sup 3+}(Ln = Nd/Yb) for sensitization of c-Si solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sawala, N. S., E-mail: nssawala@gmail.com; Koparkar, K. A.; Omanwar, S. K. [Department of Physics, SantGadge Baba Amravati University, Amravati - MH, 444602 (India); Bajaj, N. S. [Department of Physics, Toshniwal Art, Commerce and Science College, Sengoan, Hingoli - MH (India)

    2016-05-06

    The host matrix LaAlO{sub 3} was synthesized by conventional solid state reaction method in which the Nd{sup 3+} ions and Yb{sup 3+} ions successfully doped at 2mol% concentrations. The phase purity was confirmed by X ray powder diffraction (XRD) method. The photoluminescence (PL) properties were studied by spectrophotometer in near infra red (NIR) and ultra violet visible (UV-VIS) region. The Nd{sup 3+} ion doped LaAlO{sub 3} converts a visible (VIS) green photon (587 nm) into near infrared (NIR) photon (1070 nm) while Yb{sup 3+} ion doped converts ultra violet (UV) photon (221 nm) into NIR photon (980 nm). The La{sub 0.98}AlO{sub 3}: {sub 0.02}Ln{sup 3+}(Ln = Nd / Yb) can be potentiality used for betterment of photovoltaic (PV) technology. This result further indicates its potential application as a luminescence converter layer for enhancing solar cells performance.

  6. Effect of lanthanide on the microstructure and structure of LnMn0.5Fe0.5O3 nanoparticles with Ln=La, Pr, Nd, Sm and Gd prepared by the polymer precursor method

    International Nuclear Information System (INIS)

    Romero, Mariano; Faccio, Ricardo; Martínez, Javier; Pardo, Helena; Montenegro, Benjamín; Plá Cid, Cristiani Campos; Pasa, André A.

    2015-01-01

    The synthesis of LnMn 0.5 Fe 0.5 O 3 perovskite nanoparticles by the polymer precursor method showed a strong intrinsic dependence with different lanthanides (Ln=La, Pr, Nd, Sm and Gd). The polymerization level reached in the polymer precursor was proportional to the atomic number of lanthanide with exception of samarium, which showed the formation of a different precursor based in a citrate chelate with ethyleneglycol bonded as adduct. The increasing level of polymerization of the polymer precursors showed the formation of large-size perovskite nanoparticles after its calcination. SAXS and TEM analyses suggested that nanoparticles obtained, using this method, have a squared-like microstructure in connection with the polymer precursor microstructure. Structural analysis showed an orthorhombic structure with a slight decline in the Jahn–Teller distortion when the atomic number of lanthanide increases. Mössbauer spectroscopy showed the presence of a majority site in agreement with the Pbnm orthorhombic structure best fitted with Rietveld refinements and in some cases, a more distorted site attributed to local inhomogeneities and oxygen vacancies. - Highlights: • Precursor polymerization level is lower in the presence of lighter lanthanides. • Lighter lanthanide perovskite nanoparticles after calcination are lower-sized. • Nanoparticles obtained by this method have lamellae microstructure. • Jahn–Teller distortion declines for heavier lanthanide perovskites. • Oxygen vacancy phase was observed in lighter lanthanide perovskites

  7. Eu(III) and Tb(III) complexes with the nonsteroidal anti-inflammatory drug carprofen: synthesis, crystal structure, and photophysical properties.

    Science.gov (United States)

    Zhou, Xianju; Zhao, Xiaoqi; Wang, Yongjie; Wu, Bing; Shen, Jun; Li, Li; Li, Qingxu

    2014-12-01

    Two new lanthanide complexes with general formula [Ln2(carprofen)6(DMF)2] (Ln = Eu (1), Tb (2), DMF = N,N-dimethylformamide, carprofen = 6-chloro-α-methylcarbazole-2-acetic acid) have been synthesized by a hydrothermal method. Complex 1 was characterized by single-crystal X-ray diffraction (XRD), and it was found to crystallize in the monoclinic space group C2/c. The coordination of the ligand to the lanthanide ion has been investigated by Fourier-transform infrared (FTIR) spectra and ultraviolet-visible (UV-vis) absorption spectra. Complex 1 emits red light, but the antenna effect of the ligand is not effective, whereas complex 2 presents intense green emission with effective energy transfer from the ligand. The different performance of the two complexes is related to the energy matching between the excited states of the lanthanide ion and the triplet state of the ligand. The intramolecular energy transfer mechanisms are also discussed.

  8. Chemical and structural changes in Ln{sub 2}NiO{sub 4+δ} (Ln=La, Pr or Nd) lanthanide nickelates as a function of oxygen partial pressure at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Flura, Aurélien; Dru, Sophie; Nicollet, Clément; Vibhu, Vaibhav; Fourcade, Sébastien; Lebraud, Eric; Rougier, Aline; Bassat, Jean-Marc; Grenier, Jean-Claude, E-mail: grenier@icmcb-bordeaux.cnrs.fr

    2015-08-15

    The chemical stability of lanthanide nickelates Ln{sub 2}NiO{sub 4+δ} (Ln=La, Pr or Nd) has been studied in the temperature range 25–1300 °C, either in air or at low pO{sub 2} (down to 10{sup −4} atm). Thermal gravimetry analysis (TGA) measurements coupled with X-ray diffraction (XRD) characterization have shown that all compounds retain their K{sub 2}NiF{sub 4}-type structure in these conditions, while remaining over-stoichiometric in oxygen up to 1000 °C. Only Nd{sub 2}NiO{sub 4+δ} starts to decompose into Nd{sub 2}O{sub 3} and NiO above 1000 °C, at pO{sub 2}=10{sup −4} atm. In addition, a careful analysis of the lanthanide nickelates structural features has been performed by in situ XRD, as a function of temperature and pO{sub 2}. For all compounds, a structural transition has been always observed in the temperature range 200–400 °C, in air or at pO{sub 2}=10{sup −4} atm. In addition, their cell volume did not vary upon the variation of the oxygen partial pressure. Therefore, these materials do not exhibit a chemical expansion in these conditions, which is beneficial for a fuel cell application as cathode layers. Additional dilatometry measurements have revealed that a temperature as high as 950 °C for Pr{sub 2}NiO{sub 4+δ} or 1100 °C for La{sub 2}NiO{sub 4+δ} and Nd{sub 2}NiO{sub 4+δ} has to be reached in order to begin the sintering of the material particles, which is of primary importance to obtain an efficient electronic/ionic conduction in the corresponding designed cathode layers. Besides, excellent matching was found between the thermal expansion coefficients of lanthanide nickelates and SOFC electrolytes such as 8wt% yttria stabilized zirconia (8YSZ) or Ce{sub 0.8}Gd{sub 0.2}O{sub 2−δ} (GDC), at least from 400 °C up to 1400 °C in air or up to 1200 °C at pO{sub 2}=10{sup −4} atm. - Graphical abstract: This study reports the good chemical stability of oxygen overstoichiometric Ln2NiO4+δ(Ln = La, Pr or Nd) at high temperatures

  9. General synthesis and structural evolution of a layered family of Ln8(OH)20Cl4 x nH2O (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y).

    Science.gov (United States)

    Geng, Fengxia; Matsushita, Yoshitaka; Ma, Renzhi; Xin, Hao; Tanaka, Masahiko; Izumi, Fujio; Iyi, Nobuo; Sasaki, Takayoshi

    2008-12-03

    The synthesis process and crystal structure evolution for a family of stoichiometric layered rare-earth hydroxides with general formula Ln(8)(OH)(20)Cl(4) x nH(2)O (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y; n approximately 6-7) are described. Synthesis was accomplished through homogeneous precipitation of LnCl(3) x xH(2)O with hexamethylenetetramine to yield a single-phase product for Sm-Er and Y. Some minor coexisting phases were observed for Nd(3+) and Tm(3+), indicating a size limit for this layered series. Light lanthanides (Nd, Sm, Eu) crystallized into rectangular platelets, whereas platelets of heavy lanthanides from Gd tended to be of quasi-hexagonal morphology. Rietveld profile analysis revealed that all phases were isostructural in an orthorhombic layered structure featuring a positively charged layer, [Ln(8)(OH)(20)(H(2)O)(n)](4+), and interlayer charge-balancing Cl(-) ions. In-plane lattice parameters a and b decreased nearly linearly with a decrease in the rare-earth cation size. The interlamellar distance, c, was almost constant (approximately 8.70 A) for rare-earth elements Nd(3+), Sm(3+), and Eu(3+), but it suddenly decreased to approximately 8.45 A for Tb(3+), Dy(3+), Ho(3+), and Er(3+), which can be ascribed to two different degrees of hydration. Nd(3+) typically adopted a phase with high hydration, whereas a low-hydration phase was preferred for Tb(3+), Dy(3+), Ho(3+), Er(3+), and Tm(3+). Sm(3+), Eu(3+), and Gd(3+) samples were sensitive to humidity conditions because high- and low-hydration phases were interconvertible at a critical humidity of 10%, 20%, and 50%, respectively, as supported by both X-ray diffraction and gravimetry as a function of the relative humidity. In the phase conversion process, interlayer expansion or contraction of approximately 0.2 A also occurred as a possible consequence of absorption/desorption of H(2)O molecules. The hydration difference was also evidenced by refinement results. The number of coordinated water

  10. Operation of bare HPGe detectors in LAr/LN{sub 2} for the GERDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Heider, M Barnabe; Chkvorets, O; Schoenert, S [MPI fuer Kernphysik, Heidelberg (Germany); Cattadori, C [INFN-Milano Bicocca, Milano (Italy); Vacri, A di [INFN-LNGS, L' Aquila (Italy); Gusev, K; Shirchenko, M [Russian Research Center Kurchatov Institute, Moscow, Russia and JINR, Dubna (Russian Federation)], E-mail: assunta.divacri@lngs.infn.it

    2008-11-01

    refurbishment technology on long term stability and spectroscopy performance. The study started on prototype 1 (fully passivated on the borehole side). {sup 60}Co {gamma}-irradiation of the detector in LAr resulted in an increase of the leakage current (LC), depending on the rate of LAr ionization which however is reversible. The radiation induced LC is believed to produce pairs of Ar{sup +}/e{sup -} that are drifted towards the passivation layer by the diode bias electric field (E) dispersed in LAr. In fact, E, numerically calculated by the Maxwell 2D code, resulted strong enough to drift charges before recombination, in the volume surrounding the passivation layer. Charges collected and trapped at the passivation layer cause a decrease of the its resistivity, i.e. an increase of the surface LC. The increase rate depends on the charge collection rate, on the density of trapped charge and on the starting value of the passivation layer resistivity. To study this mechanism two other detector configurations were tested. They have been irradiated in LAr to investigate the influence of both geometry and extension of the passivation layer and measurements with prototype 1 have been also repeated in LN{sub 2}: prototype 2 (passivation layer only in the groove) shows a {approx}30 times lower LC increase rate than the case of prototype 1; prototype 3 (no passivation layer) does not show any increase of LC and prototype 1 operated in LN{sub 2} does not show any increase. The observed LC is cured by irradiation without HV, explained either by {gamma} ionization of the passivation layer or by effect of the UV LAr scintillation light.

  11. Creep-fatigue propagation of semi-elliptical crack at 650 deg. C in 316L(N) stainless steel plates with or without welded joints

    International Nuclear Information System (INIS)

    Curtit, F.

    2000-01-01

    This study realised in LISN Laboratory of CEA Saclay, deals with the creep fatigue propagation of semi elliptical crack at the temperature of 650 deg C in 316L(N) stainless steel plates with or without welded joints. A vast majority of the studies on creep fatigue propagation models are based on specimen (CT) especially designed for crack propagation study. The PLAQFLU program performed in LISN laboratory deals with the application and adaptation of these models to complex crack shape, which are more representative of the cracks observed in industrial components. In this scope, we use propagation tests realised at the temperature of 650 deg C with wide plates containing semi elliptical defects. For some of them, the initial defect is machined in the middle of a welded joint, which constitute a privileged site for the crack initiation. The approach used in this study is based on global parameters of fracture mechanics. At first, tests on CT specimen are used in order to determine the propagation laws correlating the crack growth rate to the global parameters K or C * . These laws are then supposed to be intrinsic to our materials and are used to analysed the semi elliptical crack propagation. The analysis of the comportment of the crack during the hold time demonstrates the possibility to establish a correlation between the crack propagation both in the deepest and the surface point and the local value of C * . These correlations are coherent in the different points of the crack front for the different applied hold times, and they present a reasonably good agreement with the creep propagation law identified on CT specimen. The simulation of test performed on based metal specimen with a model of summation of both creep and pure fatigue crack growth gives acceptable results when the calculus of the simplified expression of C * s considers a continuous evolution of creep deformations rate during the all test. (author)

  12. First principles investigation of structural, electronic, elastic and thermal properties of rare-earth-doped titanate Ln2TiO5

    Directory of Open Access Journals (Sweden)

    Hui Niu

    2012-09-01

    Full Text Available Systematic first-principles calculations based on density functional theory were performed on a wide range of Ln2TiO5 compositions (Ln = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy and Y in order to investigate their structural, elastic, electronic, and thermal properties. At low temperature, these compounds crystallize in orthorhombic structures with a Pnma symmetry, and the calculated equilibrium structural parameters agree well with experimental results. A complete set of elastic parameters including elastic constants, Hill's bulk moduli, Young's moduli, shear moduli and Poisson's ratio were calculated. All Ln2TiO5 are ductile in nature. Analysis of densities of states and charge densities and electron localization functions suggests that the oxide bonds are highly ionic with some degree of covalency in the Ti-O bonds. Thermal properties including the mean sound velocity, Debye temperature, and minimum thermal conductivity were obtained from the elastic constants.

  13. Crystallization of rare earth germanates in the K2O-Ln2O3-GeO2-H2O at 280 deg C

    International Nuclear Information System (INIS)

    Panasenko, E.B.; Begunova, R.G.; Sklokina, N.F.

    1980-01-01

    Crystallization of rare earth germanates in potassium hydroxide solutions is studied at 280 deg C. Stability limits for different crystalline phases are established. Diorthogermanates Ln 2 O 3 x2GeO 3 (three structural modifications) are formed with all lanthanides except lanthanum. Germanates-apatites 7Ln 2 O 3 x9GeO 2 are characteristic for ''large'' lanthanides La-Nd. Alkali germanate of the composition 0.5 K 2 OxLn 2 O 3 xGeO 2 xnH 2 O is realized with the elements of the end of rare earth series, i.e., Tm-Lu. Some properties of the germanates synthesized are considered [ru

  14. Liquid-liquid reductive extraction in molten fluoride salt/liquid aluminium as a core of process for the An/Ln group separation

    International Nuclear Information System (INIS)

    Conocar, O.

    2007-06-01

    This report concerns a pyrochemical process based on liquid-liquid extraction in a molten fluoride/liquid aluminium system as a core process for actinide (An)/lanthanide (Ln) group separation, studied at CEA. The basic and demonstrative experiments have established the feasibility of the An/Ln group separation in the molten fluoride/liquid aluminium system (U, Pu, Np, Am, Cm traces from Nd, Ce, Eu, Sm, Eu, La - An/Ln separation factors over 1000 - An recovery yield over 98 % in one batch). The main experimental efforts must now be targeted on the recovery of actinides from the Al matrix. A thermodynamic and bibliographical survey has been done. It shows that back-extraction in a molten chloride melt could be a promising technique for this purpose

  15. Liquid-liquid reductive extraction in molten fluoride salt/liquid aluminium as a core of process for the An/Ln group separation

    Energy Technology Data Exchange (ETDEWEB)

    Conocar, O

    2007-06-15

    This report concerns a pyrochemical process based on liquid-liquid extraction in a molten fluoride/liquid aluminium system as a core process for actinide (An)/lanthanide (Ln) group separation, studied at CEA. The basic and demonstrative experiments have established the feasibility of the An/Ln group separation in the molten fluoride/liquid aluminium system (U, Pu, Np, Am, Cm traces from Nd, Ce, Eu, Sm, Eu, La - An/Ln separation factors over 1000 - An recovery yield over 98 % in one batch). The main experimental efforts must now be targeted on the recovery of actinides from the Al matrix. A thermodynamic and bibliographical survey has been done. It shows that back-extraction in a molten chloride melt could be a promising technique for this purpose.

  16. New lanthanide(III) complexes of chiral nonadendate macrocyclic amine derived from (1R,2R)-1,2-diaminocyclohexane and 2,6-diformyl-4-methylphenol

    Energy Technology Data Exchange (ETDEWEB)

    Paluch, Marta [Department of Chemistry, University of Wroclaw, 14 F. Joliot-Curie, 50-383 Wroclaw (Poland); Lisowski, Jerzy [Department of Chemistry, University of Wroclaw, 14 F. Joliot-Curie, 50-383 Wroclaw (Poland)], E-mail: jurekl@wchuwr.chem.uni.wroc.pl

    2008-02-28

    The series of complexes [LnH{sub 4}L(NO{sub 3}){sub 2}](NO{sub 3}){sub 2}.nH{sub 2}O (Ln = La, Ce, Pr, Nd, Gd, Tb, Ho, Er, Tm) of the positively charged protonated form of a chiral macrocyclic amine H{sub 4}L{sup +}, derived from the 3 + 3 condensation product of (1R,2R)-1,2-diaminocyclohexane and 2,6-diformyl-4-methylphenol, have been synthesized. The series of complexes Na{sub x}[LnL](X){sub y}(OH){sub x-y}.n(solv) (X = NO{sup 3-} or Cl{sup -}, and Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) of the deprotonated anionic form of the ligand, L{sup 3-}, have also been synthesised. The complexes have been characterised by elemental analyses, {sup 1}H NMR and ESI MS spectra. The X-ray crystal structures of the [LaH{sub 4}L(NO{sub 3}){sub 2}](NO{sub 3}){sub 2}.5CH{sub 3}OH and [GdH{sub 4}L(NO{sub 3}){sub 2}](NO{sub 3}){sub 2}.5CH{sub 3}OH complexes have been determined. The two complexes are isostructural, and the protonated macrocycle acts as pentadentate ligand. The Ln(III) ion is bound to three phenolate oxygen atoms and two amine nitrogen atoms of the macrocyclic ligand and its coordination sphere is completed by the two axial bidendate nitrate anions.

  17. (II) complexes

    African Journals Online (AJOL)

    activities of Schiff base tin (II) complexes. Neelofar1 ... Conclusion: All synthesized Schiff bases and their Tin (II) complexes showed high antimicrobial and ...... Singh HL. Synthesis and characterization of tin (II) complexes of fluorinated Schiff bases derived from amino acids. Spectrochim Acta Part A: Molec Biomolec.

  18. Mechanical properties of electron beam welds of 316LN austenitic steels at low temperature for ITER gravity support system

    International Nuclear Information System (INIS)

    Lee, P.Y.; Huo, B.L.; Kuai, K.W.

    2007-01-01

    The gravity support system in ITER not only sustains magnet system, the vacuum vessel and in-vessel components, but also endures several large forces, such as electromagnetic force, thermal load and seismic loads. Based on the ITER design report, the maximum displacement of the gravity support system is estimated to be 32 mm in radial direction at the top flange of the flexible plates during the TF coil cool down from room temperature to 80 k. Welds are located in the peak stress region and subject to cyclic loads in the top flange is a potential problem. Therefore, the mechanical properties of the welds are extremely important for this system. 316LN austenitic stainless steel has been selected as the gravity support structure materials. However, there is still lack of the related mechanical data of the welding components of 316LN stainless steel at present. In this study, we are systematically investigated the mechanical properties of the welding components at low temperature. (authors)

  19. Analytic amplitudes for hadronic forward scattering and the Heisenberg ln{sup 2} s behaviour of total cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Nicolescu, Basarab [LPNHE, Unite de Recherche des Universites Paris 6 et Paris 7, associee au CNRS, Theory Group, Universite Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05 (France)

    2004-07-01

    We consider several classes of analytic parametrizations of hadronic scattering amplitudes (the COMPETE analysis), and compare their predictions to all available forward data (pp, {pi}p, Kp, {gamma}p, {gamma}{gamma}, {sigma}p). Although these parametrizations are very close for {radical}s {>=} 9 GeV, it turns out that they differ markedly at low energy, where a universal Pomeron term {approx} ln{sup 2} s enables one to extend the fit down to {radical}s = 4 GeV. We present predictions on the total cross sections and on the ratio of the real part to the imaginary part of the elastic amplitude ({rho} parameter) for present and future pp colliders, and on total cross sections for {gamma}p {yields} hadrons at cosmic-ray energies and for it{gamma}{gamma} {yields} hadrons up to {radical}s = 1 TeV. The ln{sup 2} s behaviour of total cross sections, first obtained by Heisenberg 50 years ago, receives now increased interest both on phenomenological and theoretical levels. We present a modification of the Heisenberg's model in connection with the presence of glueballs and we show that it leads to a realistic description of all existing hadron total cross-sections data, in agreement with the COMPETE analysis.

  20. Thick-section weldments in 21-6-9 and 316LN stainless steel for fusion energy applications

    International Nuclear Information System (INIS)

    Alexander, D.J.; Goodwin, G.M.

    1991-01-01

    The mechanical properties of several weldments in 21-6-9 and 316LN stainless steel metals have been measured at 77 K and room temperature. Filler metals for the 211-6-9 included Nitronic 35W and 40W, 21-6-9, Inconel 82, 182, 625, and 625 PLUS. For the 316LN base metal, 316L, 316L-T3, 316L-4K-O, and Inconel 82 filler metals were used. At room temperature all of the filler metals had yield strengths that exceeded those of the base metals. At 77K only the Nitronics and the 21-6-9 filler metals exceeded those of the base metals, and the Inconel filler metals were significantly weaker. The impact properties of the weld metals were very good at room temperature, with the exception of Inconel 625. At 77 K the impact toughness was greatly reduced for all of the filler metals, with the dramatic exception of Inconel 82. The 316L-4K-O filler metal showed higher impact energies than the other ferrite-containing filler metals, although the levels were still much lower than for the Inconel filler metals. The Inconel 82 filler had excellent fracture toughness at both temperatures

  1. Characterisation of Ceramic-Coated 316LN Stainless Steel Exposed to High-Temperature Thermite Melt and Molten Sodium

    Science.gov (United States)

    Ravi Shankar, A.; Vetrivendan, E.; Shukla, Prabhat Kumar; Das, Sanjay Kumar; Hemanth Rao, E.; Murthy, S. S.; Lydia, G.; Nashine, B. K.; Mallika, C.; Selvaraj, P.; Kamachi Mudali, U.

    2017-11-01

    Currently, stainless steel grade 316LN is the material of construction widely used for core catcher of sodium-cooled fast reactors. Design philosophy for core catcher demands its capability to withstand corium loading from whole core melt accidents. Towards this, two ceramic coatings were investigated for its application as a layer of sacrificial material on the top of core catcher to enhance its capability. Plasma-sprayed thermal barrier layer of alumina and partially stabilised zirconia (PSZ) with an intermediate bond coat of NiCrAlY are selected as candidate material and deposited over 316LN SS substrates and were tested for their suitability as thermal barrier layer for core catcher. Coated specimens were exposed to high-temperature thermite melt to simulate impingement of molten corium. Sodium compatibility of alumina and PSZ coatings were also investigated by exposing samples to molten sodium at 400 °C for 500 h. The surface morphology of high-temperature thermite melt-exposed samples and sodium-exposed samples was examined using scanning electron microscope. Phase identification of the exposed samples was carried out by x-ray diffraction technique. Observation from sodium exposure tests indicated that alumina coating offers better protection compared to PSZ coating. However, PSZ coating provided better protection against high-temperature melt exposure, as confirmed during thermite melt exposure test.

  2. Effect of welding processes on the impression creep resistance of type 316 LN stainless steel weld joints

    International Nuclear Information System (INIS)

    Vasudevan, M.; Vasantharaja, P.; Sisira, P.; Divya, K.; Ganesh Sundara Raman, S.

    2016-01-01

    Type 316 LN stainless steel is the major structural material used in the construction of fast breeder reactors. Activated Tungsten Inert Gas (A-TIG) welding , a variant of the TIG welding process has been found to enhance the depth of penetration significantly during autogenous welding and also found to enhance the creep rupture life in stainless steels. The present study aims at comparing the effect of TIG and A-TIG welding processes on the impression creep resistance of type 316 LN stainless steel base metal, fusion zone and heat affected zone (HAZ) of weld joints. Optical and TEM have been used to correlate the microstructures with the observed creep rates of various zones of the weld joints. Finer microstructure and higher ferrite content was observed in the TIG weld joint fusion zone. Coarser grain structure was observed in the HAZ of the weld joints. Impression creep rate of A-TIG weld joint fusion zone was almost equal to that of the base metal and lower than that of the TIG weld joint fusion zone. A-TIG weld joint HAZ was found to have lower creep rate compared to that of conventional TIG weld joint HAZ due to higher grain size. HAZ of the both the weld joints exhibited lower creep rate than the base metal. (author)

  3. ALnS2:RE (A=K, Rb; Ln=La, Gd, Lu, Y): New optical materials family

    International Nuclear Information System (INIS)

    Jarý, V.; Havlák, L.; Bárta, J.; Mihóková, E.; Buryi, M.; Nikl, M.

    2016-01-01

    In the presented review paper, new potentially interesting material family, RE-doped ternary sulfides ALnS 2 (RE=Ce, Pr, Sm, Eu, Tb, Tm; A=Rb, K; Ln=La, Gd, Lu, Y) is discussed. Their synthesis is described and the structural and optical properties, characterized by methods of X-ray diffraction, time-resolved luminescence spectroscopy and electron paramagnetic resonance, are summarized and reviewed especially with respect to the influence of their composition. All samples discussed were synthesized in the form of transparent crystalline hexagonal platelets by chemical reaction under the flow of hydrogen sulfide. Their luminescence characteristics, including absorption, radioluminescence, photoluminescence excitation and emission spectra and decay kinetics, were measured and evaluated in a broad temperature (8–800 K) and concentration (0.002–20% of dopants) range. The application potential of mentioned compounds in the field of white LED solid state lightings or X-ray phosphors is thoroughly discussed. - Highlights: • RE-doped ALnS 2 (A=K, Rb; Ln=La, Gd, Lu, Y) were synthesized. • Their optical characteristics are summarized. • Concentration and temperature dependences of luminescence features investigated. • EPR technique is employed to explain Eu 2+ incorporation into KLuS 2 host. • The application potential in white LED and X-ray phosphors is discussed.

  4. Improved method for Hf separation from silicate rocks for isotopic analysis using Ln-spec resin column

    International Nuclear Information System (INIS)

    Shinjo, Ryuichi; Ginoza, Yuko; Meshesha, Daniel

    2010-01-01

    An improved chemical separation method for Hf isotope ratio measurement using both the thermal ionization mass spectrometer (TIMS) and the multiple collector-inductively coupled plasma-mass spectrometer (MC-ICP-MS) is presented in this paper. In the first column (2.5-ml Eichrom Ln-spec resin), Hf cut was collected with 2M HCl-0.2M HF after washing the major elements, HREE, Ti, Nb, and Zr. For further Hf purification, the second column (1-ml Ln-spec resin) chemistry was conducted in a manner similar to that of the first column. The first column is designed for treatment with a 0.5-g silicate rock sample for TIMS analysis. Thus, because the Hf amount required for MC-ICP-MS analysis is much lesser than that required for TIMS analysis, the column chemistry for MC-ICP-MS analysis can be scaled down, depending on the amount of digested sample. Although there is a need to improve the TIMS technique, the TIMS Hf data obtained for geological reference rocks and Ethiopian flood basalts after the application of the proposed separation methods are consistent, within analytical error, with the previously reported data obtained using the MC-ICP-MS. The advantages of the proposed method include a reduction in the amount of reagents used (hence, a consequent reduction in the blank contribution), reduction in the time required, and a simplified preparation requiring a fewer number of acids. (author)

  5. Synthesis, thermodynamic properties and antibacterial activities of lanthanide complexes with 3,5-dimethoxybenzoic acid and 1,10-phenanthroline

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jun-Ru [Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024 (China); College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024 (China); Ren, Shu-Xia [Material Science and Engineering School, Shijiazhuang Tiedao University, Shijiazhaung 050043 (China); Ren, Ning [Department of Chemistry, Handan College, Handan 056005 (China); Zhang, Jian-Jun, E-mail: jjzhang6@126.com [Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024 (China); College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024 (China); Zhang, Da-Hai [Department of Chemistry, Handan College, Handan 056005 (China); Wang, Shu-Ping [College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024 (China)

    2013-11-20

    Graphical abstract: Four novel complexes ([Ln(3,5-DmeoxBA){sub 3}(phen)]{sub 2} (Ln = Tb(1), Dy(2), Er(3), Yb(4); 3,5-DmeoxBA = 3,5-dimethoxybenzoic acid; phen = 1,10-phenanthroline))were synthesized and characterized by elemental analysis, IR and TG/DSC-FTIR technology. Heat capacities of the four complexes were measured by differential scanning calorimetry (DSC). The antibacterial action of the four complexes on bacteria and fungus such as Escherichia coli, Staphylococcus aureus and Candida albicans were studied by filter paper approach. - Highlights: • Four novel complexes ([Ln(3,5-DmeoxBA){sub 3}(phen)]{sub 2} were synthesized and characterized. • The thermal decomposition processes of the title complexes were studied using the TG/DSC–FTIR coupling techniques. • The heat capacities of the complexes were measured by (DSC). • The antibacterial action of the four complexes on Escherichia coli, Staphylococcus aureus and Candida albicans were studied. - Abstract: Four lanthanide complexes with a general formula [Ln(3,5-DmeoxBA){sub 3}(phen)]{sub 2} (Ln = Tb(1), Dy(2), Er(3), Yb(4); 3,5-DmeoxBA = 3,5-dimethoxybenzoic acid; phen = 1,10-phenanthroline) were synthesized and characterized by elemental analysis, infrared spectra (IR), and thermogravimetric, differential scanning calorimetry techniques, combined with Fourier transform infrared (TG/DSC–FTIR) technology. The thermal decomposition processes of the four complexes were investigated by TG/DSC–FTIR techniques. Heat capacities were measured by DSC. The values of the experimental heat capacities were fitted to a polynomial equation with the least-squares method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions (H{sub T} − H{sub 298.15} {sub K}), (S{sub T} − S{sub 298.15} {sub K}), and (G{sub T} − G{sub 298.15} {sub K}) were calculated. The antibacterial action of the four complexes on bacteria and fungus such as Escherichia coli, Staphylococcus aureus and

  6. On dependence of stability of lanthanide(3) complexes with coloured ligands on the element nature

    International Nuclear Information System (INIS)

    Poluehktov, N.S.; Meshkova, S.B.; Rusakova, N.V.

    1984-01-01

    The change in the colour intensity of Ln(3) complexes with coloured ligands (methyl thymol blue, glycine cresol red, stilbazo, glycine thymol blue, methyl ortanyl S, ortanyl B, phthalexone S, semiphthalexone S, cresolphtalexone, sulfarsazen) in the natural series of lanthanoids is considered. A correlation equation is suggested that permits to describe the relative colour intensity (quenching molar coefficients, stability constants) of complexes in the series of lanthanide(3) ions versus the number of f-electrons, spin and orbital quantum numbers of the ground states. Using the ratio obtained it is possible to calculate the values of appropriate functions of complexes of elements for which such data are not available

  7. Dependence of stability of lanthanide(3) complexes with coloured ligands on the element nature

    Energy Technology Data Exchange (ETDEWEB)

    Poluehktov, N S; Meshkova, S B; Rusakova, N V [AN Ukrainskoj SSR, Odessa. Fiziko-Khimicheskij Inst.

    1984-07-01

    The change in the colour intensity of Ln(3) complexes with coloured ligands (methyl thymol blue, glycine cresol red, stilbazo, glycine thymol blue, methyl ortanyl S, ortanyl B, phthalexone S, semiphthalexone S, cresolphtalexone, sulfarsazen) in the natural series of lanthanoids is considered. A correlation equation is suggested that permits to describe the relative colour intensity (quenching molar coefficients, stability constants) of complexes in the series of lanthanide(3) ions versus the number of f-electrons, spin and orbital quantum numbers of the ground states. Using the ratio obtained it is possible to calculate the values of appropriate functions of complexes of elements for which such data are not available.

  8. Use of Electro-spray Ionization Mass Spectrometry (ESI-MS) for the characterization of complexes 'ligand - metallic cations' in solution

    Energy Technology Data Exchange (ETDEWEB)

    Berthon, Laurence; Zorz, Nicole; Lagrave, Stephanie; Gannaz, Benoit; Hill, Clement [CEA-Marcoule DEN-DRCP-SCPS-LCSE, BP 17171, 30207 Bagnols sur Ceze cedex (France)

    2008-07-01

    In the framework of nuclear waste reprocessing, separation processes of minor actinides from fission products are developed by Cea. In order to understand the mechanisms involved in the extraction processes, the 'ligand/metallic cation' complexes, formed in the organic phases are characterized by electro-spray-mass-spectrometry (ESI-MS). This paper deals with the extraction of lanthanides (III) and americium (III) cations by an organic phase composed of a malonamide or / and a dialkyl phosphoric acid, diluted in an aliphatic diluent. For the dialkyl phosphoric acid, Ln(DEHP){sub 3}(HDEHP){sub 3} complexes are observed and in the presence of a large excess of Ln(NO{sub 3}){sub 3}, dinuclear species are also observed. For the malonamide extractant, it appears that the complexes formed in the organic phase are of the Nd(NO{sub 3}){sub 3}D{sub x} type, with 2 {<=} x {<=} 4: their distributions depend on the ratio [Ln]/[DMDOHEMA]. When the two extractants are present in the organic phase, mixed 'Ln-malonamide-dialkyl phosphoric acid' species are observed. The influence of several parameters, such as extractant concentration, solute concentration, aqueous acidity and the nature of the cations (lanthanides or americium) are studied. (authors)

  9. Solution Synthesis, Structure, and CO2 Reduction Reactivity of a Scandium(II) Complex, {Sc[N(SiMe3 )2 ]3 }.

    Science.gov (United States)

    Woen, David H; Chen, Guo P; Ziller, Joseph W; Boyle, Timothy J; Furche, Filipp; Evans, William J

    2017-02-13

    The first crystallographically characterizable complex of Sc 2+ , [Sc(NR 2 ) 3 ] - (R=SiMe 3 ), has been obtained by LnA 3 /M reactions (Ln=rare earth metal; A=anionic ligand; M=alkali metal) involving reduction of Sc(NR 2 ) 3 with K in the presence of 2.2.2-cryptand (crypt) and 18-crown-6 (18-c-6) and with Cs in the presence of crypt. Dark maroon [K(crypt)] + , [K(18-c-6)] + , and [Cs(crypt)] + salts of the [Sc(NR 2 ) 3 ] - anion are formed, respectively. The formation of this oxidation state of Sc is also indicated by the eight-line EPR spectra arising from the I=7/2 45 Sc nucleus. The Sc(NR 2 ) 3 reduction differs from Ln(NR 2 ) 3 reactions (Ln=Y and lanthanides) in that it occurs under N 2 without formation of isolable reduced dinitrogen species. [K(18-c-6)][Sc(NR 2 ) 3 ] reacts with CO 2 to produce an oxalate complex, {K 2 (18-c-6) 3 }{[(R 2 N) 3 Sc] 2 (μ-C 2 O 4 -κ 1 O:κ 1 O'')}, and a CO 2 - radical anion complex, [(R 2 N) 3 Sc(μ-OCO-κ 1 O:κ 1 O')K(18-c-6)] n . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Determination of the stability constants of lanthanum, praseodymium, europium, erbium and lutetium complexes with chloride ions; Determinacion de las constantes de estabilidad de los complejos de lantano, praseodimio, europio, erbio y lutecio con iones cloruro

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez R, E [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2008-07-01

    The stability constants of La{sup 3+}, Pr{sup 3+}, Eu{sup 3+}, Er{sup 3+} and Lu{sup 3+} chloride complexes were determined in perchloric acid media using a liquid-liquid extraction method. The dinonyl napthalene sulfonic acid in n-heptane was used as extractant. The lanthanide (Ln) concentrations were measured by a radiochemical (Eu and Lu) and a spectrophotometric (La, Pr, and Er) methods. In the last method, xylenol orange was used for the determinations at ph 6. The stability constants of lanthanum, praseodymium, erbium and lutetium chloride complexes were determined in 2, 3 and 4 M ionic strength and europium in 1, 2 and 3 M, at 303 K. The fitting of experimental data to the equations for the calculation of the stability constants, was carry out considering both one chemical species (LnCl{sup 2+}) or two chemical species (LnCl{sup 2+} and LnCl{sub 2}{sup +}). The Specific Ion Interaction Theory was applied to the values of log {beta}{sup I}{sub Ln},{sub Cl} and the first stability constants at zero ionic strength were calculated by extrapolation. The same theory could not be applied to the log {beta}{sup I}{sub Ln},{sub 2Cl}, due to its low abundance and the values determined for the stability constants were similar. The distribution diagrams of the chemical species were obtained using the program MEDUSA and considering log {beta}{sup I}{sub Ln},{sub CI}, log {beta}{sup I}{sub Ln},{sub 2CI} values obtained in this work and the hydrolysis constants taken from the literature. The lanthanide chloride complexes are present in solution at specific conditions of ionic strength, concentration and in the absence of hydrolysis. The log {beta}{sup I}{sub Ln},{sub Cl} data were related to the charge density and the corresponding equations were obtained. These equations could be used to determine the stability constants along the lanthanide series. (Author)

  11. Communication complexity and information complexity

    Science.gov (United States)

    Pankratov, Denis

    Information complexity enables the use of information-theoretic tools in communication complexity theory. Prior to the results presented in this thesis, information complexity was mainly used for proving lower bounds and direct-sum theorems in the setting of communication complexity. We present three results that demonstrate new connections between information complexity and communication complexity. In the first contribution we thoroughly study the information complexity of the smallest nontrivial two-party function: the AND function. While computing the communication complexity of AND is trivial, computing its exact information complexity presents a major technical challenge. In overcoming this challenge, we reveal that information complexity gives rise to rich geometrical structures. Our analysis of information complexity relies on new analytic techniques and new characterizations of communication protocols. We also uncover a connection of information complexity to the theory of elliptic partial differential equations. Once we compute the exact information complexity of AND, we can compute exact communication complexity of several related functions on n-bit inputs with some additional technical work. Previous combinatorial and algebraic techniques could only prove bounds of the form theta( n). Interestingly, this level of precision is typical in the area of information theory, so our result demonstrates that this meta-property of precise bounds carries over to information complexity and in certain cases even to communication complexity. Our result does not only strengthen the lower bound on communication complexity of disjointness by making it more exact, but it also shows that information complexity provides the exact upper bound on communication complexity. In fact, this result is more general and applies to a whole class of communication problems. In the second contribution, we use self-reduction methods to prove strong lower bounds on the information

  12. Synthesis and Ligand Non-Innocence of Thiolate-Ligated (N4S) Iron(II) and Nickel(II) Bis(imino)pyridine Complexes

    Science.gov (United States)

    Widger, Leland R.; Jiang, Yunbo; Siegler, Maxime; Kumar, Devesh; Latifi, Reza; de Visser, Sam P.; Jameson, Guy N.L.; Goldberg, David P.

    2013-01-01

    The known iron(II) complex [FeII(LN3S)(OTf)] (1) was used as starting material to prepare the new biomimetic (N4S(thiolate)) iron(II) complexes [FeII(LN3S)(py)](OTf) (2) and [FeII(LN3S)(DMAP)](OTf) (3), where LN3S is a tetradentate bis(imino)pyridine (BIP) derivative with a covalently tethered phenylthiolate donor. These complexes were characterized by X-ray crystallography, UV-vis, 1H NMR, and Mössbauer spectroscopy, as well as electrochemistry. A nickel(II) analogue, [NiII(LN3S)](BF4) (5), was also synthesized and characterized by structural and spectroscopic methods. Cyclic voltammetric studies showed 1 – 3 and 5 undergo a single reduction process with E1/2 between −0.9 to −1.2 V versus Fc+/Fc. Treatment of 3 with 0.5% Na/Hg amalgam gave the mono-reduced complex [Fe(LN3S)(DMAP)]0 (4), which was characterized by X-ray crystallography, UV-vis, EPR (g = [2.155, 2.057, 2.038]) and Mössbauer (δ = 0.33 mm s−1; ΔEQ = 2.04 mm s−1) spectroscopies. Computational methods (DFT) were employed to model complexes 3 – 5. The combined experimental and computational studies show that 1 – 3 are 5-coordinate, high-spin (S = 2) FeII complexes, whereas 4 is best described as a 5-coordinate, intermediate-spin (S = 1) FeII complex antiferromagnetically coupled to a ligand radical. This unique electronic configuration leads to an overall doublet spin (Stotal = ½) ground state. Complexes 2 and 3 are shown to react with O2 to give S-oxygenated products, as previously reported for 1. In contrast, the mono-reduced 4 appears to react with O2 to give a mixture of S- and Fe-oxygenates. The nickel(II) complex 5 does not react with O2, and even when the mono-reduced nickel complex is produced, it appears to undergo only outer-sphere oxidation with O2. PMID:23992096

  13. Coordination, non-coordination and semi-coordination of perchlorates in the lanthanide adducts Ln (CLO4)3. 6dmba

    International Nuclear Information System (INIS)

    Tfouni, E.; Giesbrecht, E.

    1983-01-01

    The coordination or not of the perchlorate anions in the previously reported Ln(CLO 4 ) 3 .6 dmba is discussed. The analysis of the infrared spectral data and molar conductance data indicate that they may be formulated as [Ln(dmba) 6 (CLO 4 )n] (CLO 4 ) sub(3-n), n=0,1,2. The individual compounds may be a mixture of species with different n values and/or pure compounds with semi-coordinated and non-coordinated perchlorates. (Author) [pt

  14. SoSIReČR – sociální sít informatiků v regionech ČR

    Czech Academy of Sciences Publication Activity Database

    Vojtáš, P.; Pokorný, J.; Skopal, T.; Nečaský, M.; Matoušek, K.; Kubalík, J.; Šíma, Jiří; Žák, Stanislav; Víta, Martin; Novotný, O.; Maryška, M.

    -, 2-příloha (2011), s. 259-269 ISSN 1210-9479 Grant - others:Strukturální fond EU CZ.1.07/2.4.00/12.0039 Source of funding: O - operačné programy Keywords : sociální síť * web ový portál * profil Subject RIV: IN - Informatics, Computer Science http://www.cssi.cz/cssi/ system /files/all/si-2011-02p-24-Vojtas-et-all.pdf

  15. Hydrazinium lanthanide oxalates: synthesis, structure and thermal reactivity of N_2H_5[Ln_2(C_2O_4)_4(N_2H_5)].4H_2O, Ln = Ce, Nd

    International Nuclear Information System (INIS)

    De Almeida, Lucie; Grandjean, Stephane; Abraham, Francis; Rivenet, Murielle; Patisson, Fabrice

    2014-01-01

    New hydrazinium lanthanide oxalates N_2H_5[Ln_2(C_2O_4)_4(N_2H_5)].4H_2O, Ln = Ce (Ce-H_yO_x) and Nd (Nd- H_yO_x), were synthesized by hydrothermal reaction at 150 C between lanthanide nitrate, oxalic acid and hydrazine solutions. The structure of the Nd compound was determined from single-crystal X-ray diffraction data, space group P2_1/c with a = 16.315(4), b = 12.127(3), c = 11.430(2) Angstroms, β = 116.638(4) degrees, V = 2021.4(7) Angstroems"3, Z = 4, and R1 = 0.0313 for 4231 independent reflections. Two distinct neodymium polyhedra are formed, NdO_9 and NdO_8N, an oxygen of one monodentate oxalate in the former being replaced by a nitrogen atom of a coordinated hydrazinium ion in the latter. The infrared absorption band at 1005 cm"-"1 confirms the coordination of N_2H_5"+ to the metal. These polyhedra are connected through μ"2 and μ"3 oxalate ions to form an anionic three-dimensional neodymium-oxalate arrangement. A non-coordinated charge-compensating hydrazinium ion occupies, with water molecules, the resulting tunnels. The N-N stretching frequencies of the infrared spectra demonstrate the existence of the two types of hydrazine ions. Thermal reactivity of these hydrazinium oxalates and of the mixed isotypic Ce/Nd (CeNd-H_yO_x) oxalate were studied by using thermogravimetric and differential thermal analyses coupled with gas analyzers, and high temperature X-ray diffraction. Under air, fine particles of CeO_2 and Ce_0_._5Nd_0_._5O_1_._7_5 are formed at low temperature from Ce-H_yO_x and CeNd-H_yO_x, respectively, thanks to a decomposition/oxidation process. Under argon flow, dioxy-mono-cyanamides Ln_2O_2CN_2 are formed. (authors)

  16. Monodisperse and hollow structured Y{sub 2}O{sub 3}:Ln{sup 3+} (Ln = Eu, Dy, Er, Tm) nanospheres: A facile synthesis and multicolor-tunable luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ruiqing; Zi, Wenwen; Li, Linlin; Liu, Lu; Zhang, Junjun [College of Chemistry, Jilin University, Changchun 130026 (China); Zou, Lianchun, E-mail: zoulianchun@126.com [Teaching Center of Basic Courses, Jilin University, Changchun 130062 (China); Gan, Shucai, E-mail: gansc@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130026 (China)

    2014-12-25

    Highlights: • We reported a simple route to synthesize the Y{sub 2}O{sub 3} HNSs. • A possible formation mechanism of the Y{sub 2}O{sub 3} HNSs was proposed. • The Ln-doped Y{sub 2}O{sub 3} HNSs exhibit characteristic emission with different colors. • White-light-emitting phosphor Y{sub 2}O{sub 3}:Tm{sup 3+}, Dy{sup 3+} was also successfully synthesized. - Abstract: A novel, fast and simple method was developed to synthesize the undoped and lanthanide-doped yttrium oxide hollow nanospheres (Y{sub 2}O{sub 3}⋅HNSs) with multicolored downconversion emission under mild conditions by employing poly (acrylic acid sodium salt) microspheres (PAAS MSs) as active templates followed by a subsequent calcination process. The structure, morphology, formation process, and fluorescent properties are well investigated using various techniques. The results show that the samples can be well indexed to the pure cubic phase of Y{sub 2}O{sub 3}. The possible formation mechanism of the PAAS MSs, PAA-Y precursor, and Y{sub 2}O{sub 3} HNSs are proposed and discussed in detail. Upon ultraviolet excitation, the obtained Y{sub 2}O{sub 3}:Ln{sup 3+} (Ln = Eu, Dy, Er, Tm) HNSs exhibit strong red, yellow–green, blue, yellow emission, respectively. Moreover, a novel single-phased and near-UV-pumped white-light-emitting phosphor Y{sub 2}O{sub 3}:Tm{sup 3+}, Dy{sup 3+} was also successfully fabricated through optimizing the molar ratio among Tm{sup 3+} and Dy{sup 3+} in the Y{sub 2}O{sub 3} host. This material may find potential applications in field-emission display devices and white ultraviolet light-emitting diodes (UV LEDs). Furthermore, this synthesis route may be of great significance in the preparation of other hollow spherical materials.

  17. Hydrazinium lanthanide oxalates: synthesis, structure and thermal reactivity of N2H5[Ln2(C2O4)4(N2H5)]·4H2O, Ln = Ce, Nd.

    Science.gov (United States)

    De Almeida, Lucie; Grandjean, Stéphane; Rivenet, Murielle; Patisson, Fabrice; Abraham, Francis

    2014-03-28

    New hydrazinium lanthanide oxalates N2H5[Ln2(C2O4)4(N2H5)]·4H2O, Ln = Ce (Ce-HyOx) and Nd (Nd-HyOx), were synthesized by hydrothermal reaction at 150 °C between lanthanide nitrate, oxalic acid and hydrazine solutions. The structure of the Nd compound was determined from single-crystal X-ray diffraction data, space group P2₁/c with a = 16.315(4), b = 12.127(3), c = 11.430(2) Å, β = 116.638(4)°, V = 2021.4(7) Å(3), Z = 4, and R1 = 0.0313 for 4231 independent reflections. Two distinct neodymium polyhedra are formed, NdO9 and NdO8N, an oxygen of one monodentate oxalate in the former being replaced by a nitrogen atom of a coordinated hydrazinium ion in the latter. The infrared absorption band at 1005 cm(-1) confirms the coordination of N2H5(+) to the metal. These polyhedra are connected through μ2 and μ3 oxalate ions to form an anionic three-dimensional neodymium-oxalate arrangement. A non-coordinated charge-compensating hydrazinium ion occupies, with water molecules, the resulting tunnels. The N-N stretching frequencies of the infrared spectra demonstrate the existence of the two types of hydrazine ions. Thermal reactivity of these hydrazinium oxalates and of the mixed isotypic Ce/Nd (CeNd-HyOx) oxalate were studied by using thermogravimetric and differential thermal analyses coupled with gas analyzers, and high temperature X-ray diffraction. Under air, fine particles of CeO2 and Ce(0.5)Nd(0.5)O(1.75) are formed at low temperature from Ce-HyOx and CeNd-HyOx, respectively, thanks to a decomposition/oxidation process. Under argon flow, dioxymonocyanamides Ln2O2CN2 are formed.

  18. Facile synthesis of NaYF4:Yb, Ln/NaYF4:Yb core/shell upconversion nanoparticles via successive ion layer adsorption and one-pot reaction technique

    NARCIS (Netherlands)

    Zeng, Q.; Xue, B.; Zhang, Y.; Wang, D.; Liu, X.; Tu, L.; Zhao, H.; Kong, X.; Zhang, H.

    2013-01-01

    The facile one-pot synthesis of NaYF4:Yb, Ln/NaYF4:Yb core/shell (CS) upconversion nanoparticles (UCNPs) was firstly developed through the successive ion layer adsorption and reaction (SILAR) technique, which represents an attractive alternative to conventional synthesis utilizing the chloride of Ln

  19. Complexity Plots

    KAUST Repository

    Thiyagalingam, Jeyarajan

    2013-06-01

    In this paper, we present a novel visualization technique for assisting the observation and analysis of algorithmic complexity. In comparison with conventional line graphs, this new technique is not sensitive to the units of measurement, allowing multivariate data series of different physical qualities (e.g., time, space and energy) to be juxtaposed together conveniently and consistently. It supports multivariate visualization as well as uncertainty visualization. It enables users to focus on algorithm categorization by complexity classes, while reducing visual impact caused by constants and algorithmic components that are insignificant to complexity analysis. It provides an effective means for observing the algorithmic complexity of programs with a mixture of algorithms and black-box software through visualization. Through two case studies, we demonstrate the effectiveness of complexity plots in complexity analysis in research, education and application. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  20. Scaling of Ln(Permeability) in Sediments and Velocity Distributions in Turbulence: The Possibility of an Analogy.

    Science.gov (United States)

    Molz, F. J.; Kozubowski, T. J.; Miller, R. S.; Podgorski, K.

    2005-12-01

    The theory of non-stationary stochastic processes with stationary increments gives rise to stochastic fractals. When such fractals are used to represent measurements of (assumed stationary) physical properties, such as ln(k) increments in sediments or velocity increments "delta(v)" in turbulent flows, the resulting measurements exhibit scaling, either spatial, temporal or both. (In the present context, such scaling refers to systematic changes in the statistical properties of the increment distributions, such as variance, with the lag size over which the increments are determined.) Depending on the class of probability density functions (PDFs) that describe the increment distributions, the resulting stochastic fractals will display different properties. Until recently, the stationary increment process was represented using mainly Gaussian, Gamma or Levy PDFs. However, measurements in both sediments and fluid turbulence indicate that these PDFs are not commonly observed. Based on recent data and previous studies referenced and discussed in Meerschaert et al. (2004) and Molz et al. (2005), the measured increment PDFs display an approximate double exponential (Laplace) shape at smaller lags, and this shape evolves towards Gaussian at larger lags. A model for this behavior based on the Generalized Laplace PDF family called fractional Laplace motion, in analogy with its Gaussian counterpart - fractional Brownian motion, has been suggested (Meerschaert et al., 2004) and the necessary mathematics elaborated (Kozubowski et al., 2005). The resulting stochastic fractal is not a typical self-affine monofractal, but it does exhibit monofractal-like scaling in certain lag size ranges. To date, it has been shown that the Generalized Laplace family fits ln(k) increment distributions and reproduces the original 1941 theory of Kolmogorov when applied to Eulerian turbulent velocity increments. However, to make a physically self-consistent application to turbulence, one must adopt a

  1. Crystal structures of [Ln(NO33(μ2-bpydo2], where Ln = Ce, Pr or Nd, and bpydo = 4,4′-bipyridine N,N′-dioxide: layered coordination networks containing 44 grids

    Directory of Open Access Journals (Sweden)

    Michael L. Stromyer

    2016-01-01

    Full Text Available Three isostructural coordination networks of Ce, Pr, and Nd nitrate with 4,4′-bipyridine N,N′-dioxide (bpydo are reported, namely poly[[tris(nitrato-κ2O,O′cerium(III]-bis(μ2-4,4′-bipyridine N,N′-dioxide-κ2N:N′], [Ce(NO33(C10H8N2O22], poly[[tris(nitrato-κ2O,O′praeseodymium(III]-bis(μ2-4,4′-bipyridine N,N′-dioxide-κ2N:N′], [Pr(NO33(C10H8N2O22], and poly[[tris(nitrato-κ2O,O′neodymium(III]-bis(μ2-4,4′-bipyridine N,N′-dioxide-κ2N:N′], [Nd(NO33(C10H8N2O22]. All three compounds are isostructural to the previously reported La analogue. The asymmetric unit of [Ln(NO33(μ2-bpydo2] contains one lanthanide cation, two bpydo ligands, and three nitrate anions. Both bpydo ligands act as end-to-end μ2-bridges and display nearly ideal cis and gauche conformations, respectively. The bpydo ligands link the ten-coordinate LnIII cations, forming interdigitating 44 grid-like layers extending parallel to (-101, where interdigitation of layers is promoted by C—H...O interactions between nitrate anions and bpydo ligands. The interdigitated layers are linked to sets of neighboring layers via further C—H...O and π–π interactions.

  2. Studies on the Ln/sub 2/O/sub 3/ (Ln: rare-earth elements)-SrO-V/sub 2/O/sub 3/ system, 1. Phase diagrams at 1400/sup 0/C

    Energy Technology Data Exchange (ETDEWEB)

    Shin-ike, T [Osaka Dental Coll., Hirakata (Japan); Adachi, G; Shiokawa, J

    1980-11-01

    Rare-earth oxides Ln/sub 2/O/sub 3/ (Ln : Nd, Eu or Er), strontium oxide SrO and vanadium oxide V/sub 2/O/sub 3/ were mixed in a given molecular ratio, heated at 1400/sup 0/C in vacuum. The products were examined by an x-ray diffraction method to study the phase relations of the ternary systems. On heating, part of the trivalent vanadium was oxidized to the tetravalent state by atmospheric oxygen. In this experimental condition, the following ternary-phase solid solutions were identified: perovskite type Nd sub(1-x)Sr sub(x)VO sub(3-0.1x) (x > 0.3. cubic, x < 0.3: orthorhombic) and Eu sub(1-x)Sr sub(x)VO sub(3-0.1x) (x > 0.4: cubic, x < 0.4: orthorhombic), K/sub 2/NiF/sub 4/ type SrO.Nd sub(1-x)Sr sub(x)VO sub(3-0.1x) (x > 0.3) and SrO.Eu sub(1-x)Sr sub(x)VO sub(3-0.1x) (x > 0.4) and Eu/sub 3/Ti/sub 2/O/sub 7/ type SrO.2Nd sub(1-x)Sr sub(x)VO sub(3-0.1x) (x > 0.3) and SrO.2Eu sub(1-x)Sr sub(x)VO sub(3-0.1x) (x > 0.4). For the Er/sub 2/O/sub 3/-SrO-V/sub 2/O/sub 3/ system, only a mixture of Er/sub 2/O/sub 3/, SrVO sub(2.9), ErVO/sub 3/, SrO and V/sub 2/O/sub 3/ was obtained.

  3. New approaches to the study of lanthanide/actinide chloride: aluminum chloride vapor phase complexes

    International Nuclear Information System (INIS)

    Peterson, E.J.; Caird, J.A.; Carnall, W.T.; Hessler, J.P.; Hoekstra, H.R.; Williams, C.W.

    1979-01-01

    The spectrophotometric technique for vapor density measurements of complexed metal ions has been reformulated to account for temperature dependent effects and multi-species systems. Analysis of vapor pressure information indicates that the NdCl 3 --AlCl 3 and HoCl 3 --AlCl 3 systems are adequately explained by the existence of three vapor species. The two higher molecular weight complexes LnAl 4 Cl 15 and LnAl 3 Cl 12 were first proposed by Oeye and Gruen. The newly identified higher temperature species, HoAl 2 Cl 9 , contributes significantly to the vapor density above 750 0 K and below 3 atm of dimer pressure. In view of the consistency of the Nd +3 and Ho +3 chemistry the data for the Sm +3 system should be viewed with reservation. A new method for vapor density measurements involving use of radioactive tracers has been discussed in terms of its applicability to the study of (Ln,An)Cl 3 (AlCl 3 )/sub x/ systems

  4. Inorganic pigments doped with tris(pyrazol-1-yl)borate lanthanide complexes: A photoluminescence study

    Energy Technology Data Exchange (ETDEWEB)

    Gheno, Giulia, E-mail: giulia.gheno@unive.it [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Bortoluzzi, Marco; Ganzerla, Renzo [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Enrichi, Francesco [CIVEN, Coordinamento Interuniversitario Veneto per le Nanotecnologie, Via delle Industrie 5, 30175 Marghera, Venezia (Italy)

    2014-01-15

    The inorganic pigments malachite, Egyptian blue, Ercolano blue and chrome yellow have been doped with the neutral homoleptic Ln(III) complex Ln(Tp){sub 3} (Ln=Eu, Tb; Tp=hydrotris(pyrazol-1-yl)borate) in the presence of arabic gum or acrylic emulsion as binders, in order to obtain photoluminescent materials of interest for cultural heritage restoration. The doped pigments have shown emissions associated to f–f transitions in the visible range upon excitation with UV light. Thermal and UV-light ageings have been carried out. In all the cases the photoluminescent behaviour is maintained, but in the cases of acrylic-based paints emission spectra and lifetimes are strongly influenced by thermal treatments. The choice of binder and pigments influences the photoluminescent behaviour of the corresponding film paints. -- Highlights: • Inorganic pigments doped with photoluminescent lanthanide complexes. • Hydrotris(pyrazol-1-yl)borate (Tp) as antenna-ligand for Eu(III) and Tb(III). • Emission associated to f–f transitions upon excitation with UV light. • Photoluminescence of paints influenced by the choice of binder and pigments. • Photoluminescence after ageing depending upon the type of binder.

  5. Three phenoxo-bridged dinuclear lanthanide complexes. Syntheses, crystal structures, and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhi-Chao; Dai, Rui-Peng; Yang, En-Cui [College of Chemistry, Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Tianjin Normal University (China); Dong, Hui-Ming; Zhao, Xiao-Jun [College of Chemistry, Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Tianjin Normal University (China); Department of Chemistry, Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin (China)

    2018-03-15

    Three dinuclear lanthanide complexes [Ln{sub 2}(H{sub 2}L){sub 2}(NO{sub 3}){sub 4}] [Ln = Dy (1), Tb (2), and Gd (3)] [H{sub 3}L = 2-hydroxyimino-N'-[(2-hydroxy-3-methoxyphenyl)methylidene]- propanohydrazone] were solvothermally synthesized by varying differently anisotropic rare earth ions. Single-crystal structural analyses demonstrate that all the three complexes are crystallographically isostructural with two centrosymmetric Ln{sup III} ions aggregated by a pair of monodeprotonated H{sub 2}L{sup -} anions. Weak intramolecular antiferromagnetic interactions with different strength were mediated by a pair of phenoxo bridges due to superexchange and/or single-ion anisotropy. Additionally, the Dy{sup III}-based entity shows the strongest anisotropy exhibits field-induced single-molecule magnetic behavior with two thermally activated relaxation processes. In contrast, 3 with isotropic Gd{sup III} ion has a significant cryogenic magnetocaloric effect with the maximum entropy change of 25.7 J.kg{sup -1}.K{sup -1} at 2.0 K and 70.0 kOe. (copyright 2018 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Reduced expression of α-L-Fucosidase-1 (FUCA-1) predicts recurrence and shorter cancer specific survival in luminal B LN+ breast cancer patients.

    Science.gov (United States)

    Bonin, Serena; Parascandolo, Alessia; Aversa, Cinzia; Barbazza, Renzo; Tsuchida, Nobuo; Castellone, Maria Domenica; Stanta, Giorgio; Vecchio, Giancarlo

    2018-03-16

    The lysosomal enzyme α-L-Fucosidase-1 (FUCA-1) catalyzes the hydrolytic cleavage of terminal fucose residues. FUCA-1 gene is down-regulated in highly aggressive and metastatic human tumors as its inactivation perturbs the fucosylation of proteins involved in cell adhesion, migration and metastases. Negativity to FUCA-1 was significantly related to the development of later recurrences in breast cancer patients with lymph node involvement at diagnosis. Cancer specific survival of luminal B LN+ patients was influenced by FUCA-1 expression as luminal B LN+ patients with positive expression had a longer cancer specific survival. FUCA-1 mRNA expression was inversely related to cancer stage and lymph node involvement. WB and qPCR analysis of FUCA-1 expression in breast cancer-derived cell lines confirmed an inverse relationship with tumor aggressiveness. This study shows that, within LN+ breast cancer patients, FUCA-1 is able to identify a sub-set of non recurrent patients characterized by the positive expression of FUCA-1 and that, within luminal B LN+ patients, the expression of FUCA-1 predicts longer cancer specific survival. We have analyzed FUCA-1 in 305 breast cancer patients by Immunohistochemistry (IHC), and by qPCR in breast cancer patients and in breast cancer cell lines.

  7. Systém pro obchodování s virtuálními předměty

    OpenAIRE

    Sedláček, Lukáš

    2007-01-01

    Cílem této práce je seznámit čtenáře s problematikou systémů pro obchodování s virtuálními předměty. Práce je zaměřena hlavně na virtuální ekonomiky MMORPG (Massive(ly)-Multiplayer Online Role-Playing Game). Pro hlubší pochopení MMORPG světů, je v této práci zpracován jejich vznik, vývoj, historie, psychologické aspekty, náhled do problematiky jejich virtuálních ekonomik, stručná charakteristika elektronických platebních systémů a informace o dvou virtuálních ekonomikách (Entropia Universe a ...

  8. Colloidal Nanoparticles of Ln3+-Doped LaVO4: Energy Transfer to Visible- and Near-Infrared-Emitting Lanthanide Ions

    NARCIS (Netherlands)

    Stouwdam, J.W.; Raudsepp, Mati; van Veggel, F.C.J.M.

    2005-01-01

    Colloidal, organic solvent-soluble Ln3+-doped LaVO4 nanoparticles have been synthesized by a precipitation reaction in the presence of (C18H37O)2PS2- as ligand, that coordinates to the surface of the nanoparticles. The materials are well soluble in chlorinated solvent such as chloroform. Energy

  9. Complexity Theory

    Science.gov (United States)

    Lee, William H K.

    2016-01-01

    A complex system consists of many interacting parts, generates new collective behavior through self organization, and adaptively evolves through time. Many theories have been developed to study complex systems, including chaos, fractals, cellular automata, self organization, stochastic processes, turbulence, and genetic algorithms.

  10. Structure, magnetic behavior, and anisotropy of homoleptic trinuclear lanthanoid 8-quinolinolate complexes.

    Science.gov (United States)

    Chilton, Nicholas F; Deacon, Glen B; Gazukin, Olga; Junk, Peter C; Kersting, Berthold; Langley, Stuart K; Moubaraki, Boujemaa; Murray, Keith S; Schleife, Frederik; Shome, Mahasish; Turner, David R; Walker, Julia A

    2014-03-03

    Three complexes of the form [Ln(III)3(OQ)9] (Ln = Gd, Tb, Dy; OQ = 8-quinolinolate) have been synthesized and their magnetic properties studied. The trinuclear complexes adopt V-shaped geometries with three bridging 8-quinolinolate oxygen atoms between the central and peripheral eight-coordinate metal atoms. The magnetic properties of these three complexes differ greatly. Variable-temperature direct-current (dc) magnetic susceptibility measurements reveal that the gadolinium and terbium complexes display weak antiferromagnetic nearest-neighbor magnetic exchange interactions. This was quantified in the isotropic gadolinium case with an exchangecoupling parameter of J = -0.068(2) cm(-1). The dysprosium compound displays weak ferromagnetic exchange. Variable-frequency and -temperature alternating-current magnetic susceptibility measurements on the anisotropic cases reveal that the dysprosium complex displays single-molecule-magnet behavior, in zero dc field, with two distinct relaxation modes of differing time scales within the same molecule. Analysis of the data revealed anisotropy barriers of Ueff = 92 and 48 K for the two processes. The terbium complex, on the other hand, displays no such behavior in zero dc field, but upon application of a static dc field, slow magnetic relaxation can be observed. Ab initio and electrostatic calculations were used in an attempt to explain the origin of the experimentally observed slow relaxation of the magnetization for the dysprosium complex.

  11. Effect of flowing sodium on corrosion and tensile properties of AISI type 316LN stainless steel at 823 K

    Science.gov (United States)

    Sivai Bharasi, N.; Thyagarajan, K.; Shaikh, H.; Balamurugan, A. K.; Bera, Santanu; Kalavathy, S.; Gurumurthy, K.; Tyagi, A. K.; Dayal, R. K.; Rajan, K. K.; Khatak, H. S.

    2008-07-01

    AISI type 316LN stainless steel was exposed to flowing sodium in mass transfer loop (MTL) at 823 K for 16 000 h and then examined for changes in the tensile properties due to the mass transfer and corrosion effects. Comparisons in microstructural and mechanical properties were made between annealed, thermally aged and sodium exposed materials. Microstructural examination of thermally aged and sodium exposed materials revealed precipitation of carbides at the grain boundaries. The sodium exposed samples contained a degraded layer at the surface up to a depth of around 10 μm and a surface carburized layer of about 30 μm. There was about 15% increase in yield strength and a decrease of about 20% in ductility for the sodium exposed material vis-a-vis thermally aged material and this was attributed to carburization effects and microstructural changes.

  12. Effect of flowing sodium on corrosion and tensile properties of AISI type 316LN stainless steel at 823 K

    International Nuclear Information System (INIS)

    Sivai Bharasi, N.; Thyagarajan, K.; Shaikh, H.; Balamurugan, A.K.; Bera, Santanu; Kalavathy, S.; Gurumurthy, K.; Tyagi, A.K.; Dayal, R.K.; Rajan, K.K.; Khatak, H.S.

    2008-01-01

    AISI type 316LN stainless steel was exposed to flowing sodium in mass transfer loop (MTL) at 823 K for 16 000 h and then examined for changes in the tensile properties due to the mass transfer and corrosion effects. Comparisons in microstructural and mechanical properties were made between annealed, thermally aged and sodium exposed materials. Microstructural examination of thermally aged and sodium exposed materials revealed precipitation of carbides at the grain boundaries. The sodium exposed samples contained a degraded layer at the surface up to a depth of around 10 μm and a surface carburized layer of about 30 μm. There was about 15% increase in yield strength and a decrease of about 20% in ductility for the sodium exposed material vis-a-vis thermally aged material and this was attributed to carburization effects and microstructural changes

  13. Influence of martensitic transformation on the low-cycle fatigue behaviour of 316LN stainless steel at 77 K

    International Nuclear Information System (INIS)

    Botshekan, M.; Degallaix, S.; Desplanques, Y.

    1997-01-01

    Tensile and low-cycle fatigue tests were performed on a 316LN austenitic stainless steel at 300 and 77 K. The tensile and low-cycle fatigue properties were obtained and analysed in terms of influence of temperature on the plastic deformation process, and particularly on the strain-induced martensite formation. The martensite content was measured by a magnetic-at-saturation method. No martensite was detected at 300 K. On the contrary, strain-induced martensite transformation is responsible for the higher tensile elongation at 77 K and for the secondary hardening observed on softening-hardening curves in low-cycle fatigue at 77 K. The induced martensite content in tensile tests is a function of the strain according to Angel's model, and in low-cycle fatigue it is a function of the strain level and of the accumulated plastic strain. (orig.)

  14. Process parameter optimization during EDM of AISI 316 LN stainless steel by using fuzzy based multi-objective PSO

    Energy Technology Data Exchange (ETDEWEB)

    Majumder, Arindam [National Institute of Technology Agartala, Tripura (India)

    2013-07-15

    The present contribution describes an application of a hybrid approach using fuzzy logic and particle swarm optimization (PSO) for optimizing the process parameters in the electric discharge machining (EDM) of AISI 316LN Stainless Steel. In this study, each experimentation was performed under different machining conditions of pulse current, pulse on-time, and pulse off-time. Machining performances such as MRR and EWR were evaluated. A Taguchi L9 orthogonal array was produced to plan the experimentation and the regression method was applied to model the relationship between the input factors and responses. A fuzzy model was employed to provide a fitness function to PSO by unifying the multiple responses. Finally, PSO was used to predict the optimal process parametric settings for the multi-performance optimization of the EDM operation. The experimental results confirm the feasibility of the strategy and are in good agreement with the predicted results over a wide range of machining conditions employed in the process.

  15. Significance of measurement of serum fibrosis markers (HA, LN, P III P, IV C) in patients with pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Zhou Mingxian

    2006-01-01

    Objective: To study the clinical significance of determination of serum fibrosis markers in patients with pulmonary tuberculosis. Methods: Serum hyaluronic acid (HA), laminin (LN), procollagen III peptide (P III P) and Type IV collagen (IV C) contents were determined with RIA in 128 patients with pulmonary tuberculosis both before and after treatment as well as in 40 controls. Results: Before treatment, the serum contents of the four markers in the patients were significantly higher than those in the controls (P 0.05). Decreases of the levels in treatment failures were not significant and the levels remained significantly higher than those in controls (P<0.01 or P<0.05). Conclusion: Determination of serum fibrosis markers levels in patients with pulmonary tuberculosis is valuable for early diagnosis as well as for evaluation of the effect of chemotherapy. (authors)

  16. Synthesis, characterization and magnetic properties of novel μ-oxamido heterodinuclear copper(II) - lanthanide(III) complexes

    International Nuclear Information System (INIS)

    Li, Y.T.; Miao, M.M.; Liao, D.Z.; Jiang, Z.H.; Wang, G.L.

    1995-01-01

    Six novel μ-oxamido heterobinuclear complexes have been prepared and identified as Cu(oxpn)Ln(L) 2 (ClO 4 ) 3 , where oxpn denotes the N, N'-bis(3-aminopropyl)oxamido dianion, L, 1,10-phenanthroline (phen) and Ln stands for La, Nd, Gd, Tb, Ho, Er. The complexes Cu(oxpn)Gd(oxpn)Gd(phen) 2 (ClO 4 ) 3 were characterized with variable temperature magnetic susceptibility (4-300 K). The exchange integral J (Cu-Gd) was found to be 2.03 cm -1 . The result is commensurate with ferromagnetic interaction between the adjacent metal ions. One plausible mechanism that can cause a ferromagnetic coupling between Gd(III) and Cu(II) is also discussed in terms of spin polarized. (author). 32 refs, 3 figs, 3 tabs

  17. Introduction to crystal structure determination methods using x-ray diffraction: application to some rare earth complexes

    International Nuclear Information System (INIS)

    Oliveira, M.A. de.

    1986-01-01

    This work is composed by a theoretical introduction studying crystal concept, interaction between X-ray and crystal medium, and methods for determining small molecular structures applied in solution of crystal structures of praseodymium, neodymium and europium complexes with perrhenate and trans - 1,4 - dithiane - 1,4 - dioxide, (TDTD), which general formula is [ Ln (H sub(2) O) sub(4) (η-TDTD) (η'Re O sub(4)) (μ-η sup(2)-TDTD)] sub(n) (Re O sub(4)) sub(2n). nTDTD, where, Ln = Eu, Pr, Nd and methyl-2,6-anhydrous-3-azido-4-0-benzoyl-3-deoxy-α-D-iodo pyranoside. The structure of C sub(14) H sub(15) N sub(3) O sub(5) organic complex was determined using direct methods. (M.C.K.)

  18. Non local approach in crystalline plasticity: study of mechanical behaviour of AISI 316LN stainless steel during low cycle fatigue

    International Nuclear Information System (INIS)

    Schwartz, J.

    2011-01-01

    If fatigue crack initiation is currently quite well understood for pure single crystals, its comprehension and prediction in cases of polycrystal alloys such as AISI 316LN stainless steel remain complicated. Experimentally our study focuses on the characterisation of the mechanical behaviour and on the study at different scales of the phenomenon leading to low cycle fatigue crack initiation in 316LN stainless steel. For straining amplitudes of?e/2 = 0,3 and 0,5%, the cyclic softening observed during testing has been related to the organisation of dislocations in band structures. These bands, formed due to the activation of slip systems having the greatest Schmid's factor, carry the most part of the deformation. Their emergence at free surfaces leads to the formation of intrusions and extrusions which help cracks initiate and spread. Numerically we worked on the mesoscopic scale, proposing a new model of crystalline plasticity. This model integrates geometrically necessary dislocations (GND) directly computed from the lattice curvature. Implemented in the finite element code Abaqus TM and Cast3m TM , it is based on single crystal finite deformations laws proposed by Peirce et al. (1983) and Teodosiu et al. (1993). Extended for polycrystals by Hoc (2001) and Erieau (2003), it has been improved by the introduction of GND (Acharya and Bassani, 2000). The simulations performed on different types of aggregates (2D/3D) have shown that taking GND into account enables:- the prediction of the grain size effect on a macroscopic and on a local scale,- a finer computation of local stress field.The influence of the elasticity and interaction matrices on the values and the evolution of the isotropic and kinematic mean stresses has been shown. The importance of boundary conditions on computed mechanical fields could also be pointed out. (author)

  19. Functional PEG–PAMAM-Tetraphosphonate Capped NaLnF4 Nanoparticles and their Colloidal Stability in Phosphate Buffer

    Science.gov (United States)

    2015-01-01

    Developing surface coatings for NaLnF4 nanoparticles (NPs) that provide long-term stability in solutions containing competitive ions such as phosphate remains challenging. An amine-functional polyamidoamine tetraphosphonate (NH2-PAMAM-4P) as a multidentate ligand for these NPs has been synthesized and characterized as a ligand for the surface of NaGdF4 and NaTbF4 nanoparticles. A two-step ligand exchange protocol was developed for introduction of the NH2-PAMAM-4P ligand on oleate-capped NaLnF4 NPs. The NPs were first treated with methoxy-poly(ethylene glycol)-monophosphoric acid (Mn = 750) in tetrahydrofuran. The mPEG750-OPO3-capped NPs were stable colloidal solutions in water, where they could be ligand-exchanged with NH2-PAMAM-4P. The surface amine groups on the NPs were available for derivatization to attach methoxy-PEG (Mn = 2000) and biotin-terminated PEG (Mn = 2000) chains. The surface coverage of ligands on the NPs was examined by thermal gravimetric analysis, and by a HABA analysis for biotin-containing NPs. Colloidal stability of the NPs was examined by dynamic light scattering. NaGdF4 and NaTbF4 NPs capped with mPEG2000–PAMAM-4P showed colloidal stability in DI water and in phosphate buffer (10 mM, pH 7.4). A direct comparison with NaTbF4 NPs capped with a mPEG2000-lysine-based tetradentate ligand that we reported previously (Langmuir2012, 28, 12861−1287022906305) showed that both ligands provided long-term stability in phosphate buffer, but that the lysine-based ligand provided better stability in phosphate-buffered saline. PMID:24898128

  20. Functional PEG-PAMAM-tetraphosphonate capped NaLnF₄ nanoparticles and their colloidal stability in phosphate buffer.

    Science.gov (United States)

    Zhao, Guangyao; Tong, Lemuel; Cao, Pengpeng; Nitz, Mark; Winnik, Mitchell A

    2014-06-17

    Developing surface coatings for NaLnF4 nanoparticles (NPs) that provide long-term stability in solutions containing competitive ions such as phosphate remains challenging. An amine-functional polyamidoamine tetraphosphonate (NH2-PAMAM-4P) as a multidentate ligand for these NPs has been synthesized and characterized as a ligand for the surface of NaGdF4 and NaTbF4 nanoparticles. A two-step ligand exchange protocol was developed for introduction of the NH2-PAMAM-4P ligand on oleate-capped NaLnF4 NPs. The NPs were first treated with methoxy-poly(ethylene glycol)-monophosphoric acid (M(n) = 750) in tetrahydrofuran. The mPEG750-OPO3-capped NPs were stable colloidal solutions in water, where they could be ligand-exchanged with NH2-PAMAM-4P. The surface amine groups on the NPs were available for derivatization to attach methoxy-PEG (M(n) = 2000) and biotin-terminated PEG (M(n) = 2000) chains. The surface coverage of ligands on the NPs was examined by thermal gravimetric analysis, and by a HABA analysis for biotin-containing NPs. Colloidal stability of the NPs was examined by dynamic light scattering. NaGdF4 and NaTbF4 NPs capped with mPEG2000-PAMAM-4P showed colloidal stability in DI water and in phosphate buffer (10 mM, pH 7.4). A direct comparison with NaTbF4 NPs capped with a mPEG2000-lysine-based tetradentate ligand that we reported previously (Langmuir 2012, 28, 12861-12870) showed that both ligands provided long-term stability in phosphate buffer, but that the lysine-based ligand provided better stability in phosphate-buffered saline.

  1. Diffusion-bonded 16MND5-Inconel 690-316LN junction: elaboration and process residual stresses modeling

    International Nuclear Information System (INIS)

    Martinez, Michael

    1999-01-01

    The objective of this research thesis is, on the one hand, to elaborate and to characterise a bonded junction of 16MND5 and 316LN steels, and, on the other hand, to develop a simulation tool for the prediction of microstructures after bonding, as well as residual stresses related to this process. The author first reports the study of the use of diffusion bonding by hot isostatic pressing (HIP diffusion bonding) for the bonding of 16MND5 (steel used in French PWR vessel) and 316LN (austenitic stainless steel used in piping), in order to obtain junctions adapted to a use within PWRs. In this case, the use of an Inconel insert material appeared to be necessary to avoid stainless steel carburization. Thus, inserts in Inconel 600 and 690 have been tested. The objective has then been to develop a realistic calculation of residual stresses in this assembly. These stresses are stimulated by quenching. The author notably studied the simulation of temperature dependent phase transformations, and stress induced phase transformations. An existing model is validated and applied to HIP and quenching cycles. The last part reports the calculation of residual stresses by simulation of the mechanical response of the three-component material cooled from 900 C to room temperature and thus submitted to a loading of thermal origin (dilatation) and metallurgical origin (phase transformations in the 16MND5). The effect of carbon diffusion on mechanical properties has also been taken into account. The author discusses problems faced by existing models, and explains the choice of conventional macro-mechanical models. The three materials are supposed to have a plastic-viscoplastic behaviour with isotropic and kinematic strain hardening, and this behaviour is identified between 20 and 900 C [fr

  2. A new family of NxOy pyridine-containing macrocycles: synthesis and characterization of their Y(III), Ln(III), Zn(II), and Cd(II) coordination compounds

    International Nuclear Information System (INIS)

    Lodeiro, C.; Bastida, R.; Bertolo, E.; Rodriguez, A.

    2004-01-01

    Reaction between 2,6-bis(2-formylphenoxymethyl)pyridine and N,N-bis(3-aminopropyl)methylamine or tris(2-aminoethyl)amine has been used as the starting point for the synthesis of seven oxa-aza macrocyclic ligands, five of them never reported previously. They all feature different pendant arms, which provide a wide range of coordination possibilities. The Schiff base macrocycles L 1 and L 4 and their reduced ligands L 2 and L 5 are derived from 2,6-bis(2-formylphenoxymethyl)pyridine and tris(2-aminoethyl)amine or N,N-bis(3-aminopropyl)methylamine, respectively. The reaction of L 1 with salicylaldehyde forms L 3 , which features an imine bond in the pendant arm. The ligand L 5 has been the precursor for the pendant-armed L 6 and L 7 , by alkylation of the free NH groups with methyl-imidazole or methyl-indole. By a template or a nontemplate approach, we have synthesized different mono- and dinuclear complexes with Y(III), Ln(III), Zn(II), and Cd(II) cations. Both the free macrocyclic ligands and their corresponding metal complexes have been characterized by microanalysis, IR, UV-vis, 1 H and 13 C NMR spectroscopy, FAB mass spectrometry, MS electrospray, and conductivity measurements. (author)

  3. Hydrolytic cleavage of ammonia-borane complex for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Mohajeri, Nahid; T-Raissi, Ali; Adebiyi, Olawale [Hydrogen R and D Division, Florida Solar Energy Center, University of Central Florida 1679 Clearlake Rd., Cocoa, FL 32955 (United States)

    2007-05-15

    A new process for generating hydrogen via near room temperature hydrolysis of AB complex using small amounts of platinum group metal catalyst has been studied. Using in situ {sup 11}B NMR spectroscopy, the overall rate of K{sub 2}Cl{sub 6}Pt catalyzed hydrolysis of AB complex was calculated to be third-order. The pre-exponential factor (A) and the activation energy (E{sub a}) of Arrhenius equation, ln k = ln A - E{sub a}/RT, were determined to be: A = 1.6 x 10{sup 11} L mol{sup -1} s{sup -1} and E{sub a} = 86.6 kJ mol{sup -1} for temperature range of (25-35 C). X-ray photoelectron spectroscopy of the residue suggested that the platinum salt was reduced from Pt{sup 4+} to Pt{sup 0} within the course of the reaction and X-ray diffraction analysis pattern for the residue showed crystallized single-phase boric acid. (author)

  4. Host composition dependent tunable multicolor emission in the single-phase Ba2(Ln(1-z)Tb(z))(BO3)2Cl:Eu phosphors.

    Science.gov (United States)

    Xia, Zhiguo; Zhuang, Jiaqing; Meijerink, Andries; Jing, Xiping

    2013-05-14

    A new strategy based on the host composition design has been adopted to obtain efficient color-tunable emission from Ba2Ln(0.97-z)Tb(z)(BO3)2Cl:0.03Eu (Ln = Y, Gd and Lu, z = 0-0.97) phosphors. This study reveals that the single-phase Ba2Ln(1-z)Tb(z)(BO3)2Cl compounds can be applied to use allowed Eu(2+) absorption transitions to sensitize Eu(3+) emission via the energy transfer Eu(2+) → (Tb(3+))n → Eu(3+). The powder X-ray diffraction (XRD) and Rietveld refinement analysis shows single-phase Ba2Ln(1-z)Tb(z)(BO3)2Cl. As-prepared Ba2Ln(0.97-z)Tb(z)(BO3)2Cl:0.03Eu phosphors show intense green, yellow, orange and red emission under 377 nm near ultraviolet (n-UV) excitation due to a variation in the relative intensities of the Eu(2+), Tb(3+) and Eu(3+) emission depending on the Tb content (z) in the host composition, allowing color tuning. The variation in emission color is explained by energy transfer and has been investigated by photoluminescence and lifetime measurements and is further characterized by the Commission Internationale de l'éclairage (CIE) chromaticity indexes. The quantum efficiencies of the phosphors are high, up to 74%, and show good thermal stabilities up to 150 °C. This investigation demonstrates the possibility to sensitize Eu(3+) line emission by Eu(2+)via energy migration over Tb(3+) resulting in efficient color tunable phosphors which are promising for use in solid-state white light-emitting diodes (w-LEDs).

  5. Theoretical study of trivalent element complexes for the nuclear waste reprocessing; Etude theorique de complexes d'elements f trivalents pour le retraitement des dechets nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Petit, L

    2007-10-15

    Current energetic and environmental concerns have made the nuclear waste reprocessing to be a major issue in numerous countries. One avenue to treat nuclear spent fuel requires separating selectively trivalent minor actinides An (Am{sup 3+}, Cm{sup 3+}) from lanthanides Ln. In this regard, nitrogen extractants are under study. Their selectivity toward actinides is still unclear, but could be the result of enhanced covalency effects with trivalent minor actinides with respect to lanthanides (III). In this thesis, we have performed DFT calculations (Density Functional Theory) to study covalency effects within the actinide-ligand bond, following three main axes of research: advanced study of the nature of the chemical bonding, spectroscopic characterization of covalency, and preliminary tests of ab initio molecular dynamics for future calculations in solvent. Methods that are not regularly applied to trivalent actinides complexes have been used: topological methods, TDDFT, LDDFT, ab initio molecular dynamics. We have managed to show that the selectivity of the BTP ligand - the most effective An/Ln extractant to date - comes at least for a part from stronger covalency effects within the An-BTP bond with respect to the Ln-BTP bond, which has never been proved before. (author)

  6. Managing Complexity

    DEFF Research Database (Denmark)

    Maylath, Bruce; Vandepitte, Sonia; Minacori, Patricia

    2013-01-01

    and into French. The complexity of the undertaking proved to be a central element in the students' learning, as the collaboration closely resembles the complexity of international documentation workplaces of language service providers. © Association of Teachers of Technical Writing.......This article discusses the largest and most complex international learning-by-doing project to date- a project involving translation from Danish and Dutch into English and editing into American English alongside a project involving writing, usability testing, and translation from English into Dutch...

  7. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  8. GLP-1 suppresses gastrointestinal motility and inhibits the migrating motor complex in healthy subjects and patients with irritable bowel syndrome

    DEFF Research Database (Denmark)

    Hellström, P M; Näslund, E; Edholm, T

    2008-01-01

    hormones, and gut tissue expression of GLP-1 receptor was studied. In healthy subjects, GLP-1 0.7 pmol kg(-1) min(-1) reduced the migrating motor complexes (MMCs) from a median of 2 (range 2-3) to 0.5 (0-2), and motility index from 4.9 +/- 0.1 to 4.3 +/- 0.3 ln Sigma(mmHg*s min(-1)) in jejunum, while GLP-1...

  9. Creep-fatigue propagation of semi-elliptical crack at 650 deg. C in 316L(N) stainless steel plates with or without welded joints; Propagation de fissures semi-elliptiques en fatigue-fluage a 650 deg. C dans des plaques d'acier 316L(N) avec ou sans joints soudes

    Energy Technology Data Exchange (ETDEWEB)

    Curtit, F

    2000-07-01

    This study realised in LISN Laboratory of CEA Saclay, deals with the creep fatigue propagation of semi elliptical crack at the temperature of 650 deg C in 316L(N) stainless steel plates with or without welded joints. A vast majority of the studies on creep fatigue propagation models are based on specimen (CT) especially designed for crack propagation study. The PLAQFLU program performed in LISN laboratory deals with the application and adaptation of these models to complex crack shape, which are more representative of the cracks observed in industrial components. In this scope, we use propagation tests realised at the temperature of 650 deg C with wide plates containing semi elliptical defects. For some of them, the initial defect is machined in the middle of a welded joint, which constitute a privileged site for the crack initiation. The approach used in this study is based on global parameters of fracture mechanics. At first, tests on CT specimen are used in order to determine the propagation laws correlating the crack growth rate to the global parameters K or C{sup *}. These laws are then supposed to be intrinsic to our materials and are used to analysed the semi elliptical crack propagation. The analysis of the comportment of the crack during the hold time demonstrates the possibility to establish a correlation between the crack propagation both in the deepest and the surface point and the local value of C{sup *}. These correlations are coherent in the different points of the crack front for the different applied hold times, and they present a reasonably good agreement with the creep propagation law identified on CT specimen. The simulation of test performed on based metal specimen with a model of summation of both creep and pure fatigue crack growth gives acceptable results when the calculus of the simplified expression of C{sup *}{sub s} considers a continuous evolution of creep deformations rate during the all test. (author)

  10. Complexation of trivalent cationic lanthanides by N.O donor ligands: physico-chemical studies of the association and selectivity in solution

    International Nuclear Information System (INIS)

    Bravard, F.

    2004-01-01

    The aim of this work is to study the complexation of f-elements in solution by ligands incorporating N-heterocyclic donors. These ligands display interesting properties for the selective separation of An(III)/Ln(III) have been studied to obtain a better understanding of the coordination properties with f-elements and to develop more selective extractants. The hepta-dentate ligand tpaam shows an affinity for Ln(III) similar to the tetradentate ligand tpa in water even when the three additional amide groups are bonded to the metal. Even though the complexation with tpa is exothermic, that with tpaam is endothermic with a more positive entropy. The dehydration of the cation disfavours the formation of Ln(III) complexes with ligands containing weak donors. The analysis of the solution paramagnetic relaxation times of the tpaam complexes is in agreement with data in the solid-state. There is little difference between the formation constants of the Ln 3+ complexes with different ligands (tpaam, tpzen, tpa and tpza) as determined by UV-vis spectrophotometry in anhydrous acetonitrile. The limitations encountered during this study are intrinsic to the ligands studied. The preliminary study of two tetrapodal ligands containing acid and pyridine groups (L py )or pyrazine (L pz ) show the formation of 1:1 complexes in water. Analysis of the formation constants of the corresponding Gd(III) complexes shows that replacement of a pyridine group by pyrazine result in a loss of stability of 1.6 logarithmic units. (author) [fr

  11. Preparation, thermodynamic property and antimicrobial activity of some rare-earth (III) complexes with 3-bromo-5-iodobenzoic acid and 1,10-phenanthroline

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jing-Yu [Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024 (China); College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024 (China); Ren, Ning [Department of Chemistry, Handan College, Handan 056005 (China); Zhang, Jian-Jun, E-mail: jjzhang6@126.com [Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024 (China); College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024 (China); Zhang, Cun-Ying [No.1 High School of Shijiazhuang, Shijiazhuang 050011 (China)

    2013-10-20

    Graphical abstract: Four new rare-earth complexes of general formula [Ln(3-Br-5-IBA){sub 3}phen]{sub 2} [Ln = Er (1), Tb (2), Dy (3) and Ho (4); 3-Br-5-IBA = 3-bromo-5-iodobenzoate; phen = 1,10-phenanthroline] were synthesized and characterized by elemental analysis, IR, UV and TG/DSC-FTIR technology. Heat capacities of the four complexes were measured by differential scanning calorimetry (DSC). The antimicrobial activity against Escherichia coli, Staphylococcus aureus and Candida albicans were tested using disc diffusion method. - Highlights: • Four new complexes [Ln(3-Br-5-IBA){sub 3}phen]{sub 2} were synthesized and characterized. • The non-isothermal kinetics of the first stage for the complexes was studied. • The heat capacities of the complexes were measured by differential scanning calorimeter. • The antimicrobial activities for these complexes were tested. • The fluorescence properties of the complexes 2 and 3 were studied. - Abstract: Four new rare-earth complexes of general formula [Ln(3-Br-5-IBA){sub 3}phen]{sub 2} (Ln(III) = Er (1), Tb (2), Dy (3) and Ho (4); 3-Br-5-IBA = 3-bromo-5-iodobenzoate; phen = 1,10-phenanthroline) were synthesized by solution-precipitation method, and investigated using elemental analysis, infrared spectra, ultraviolet spectra and TG/DSC-FTIR technology. The non-isothermal kinetics of the first stage for the complexes was studied by using non-linear integral isoconversional method and double equal-double steps method. The heat capacities of the complexes were measured between 263.15 and 485.55 K by means of differential scanning calorimeter, and the values of the experimental heat capacities were fitted to a polynomial equation with the least-squares method. And the thermodynamic functions [H{sub T} − H{sub 298.15}], [S{sub T} − S{sub 298.15}] and [G{sub T} − G{sub 298.15}] were also derived based on the fitted polynomials and thermodynamic relationships with temperature interval of 10 K. Moreover, the

  12. Softball Complex

    Science.gov (United States)

    Ellis, Jim

    1977-01-01

    The Parks and Recreation Department of Montgomery, Alabama, has developed a five-field softball complex as part of a growing community park with facilities for camping, golf, aquatics, tennis, and picnicking. (MJB)

  13. Lecithin Complex

    African Journals Online (AJOL)

    1Department of Food Science and Engineering, Xinyang College of Agriculture and ... Results: The UV and IR spectra of the complex showed an additive effect of polydatin-lecithin, in which .... Monochromatic Cu Ka radiation (wavelength =.

  14. Nonheme oxoiron(IV) complexes of pentadentate N5 ligands: spectroscopy, electrochemistry, and oxidative reactivity

    OpenAIRE

    Wang, Dong; Ray, Kallol; Collins, Michael J.; Farquhar, Erik R.; Frisch, Jonathan R.; Gomez, Laura; Jackson, Timothy A.; Kerscher, Marion; Waleska, Arkadius; Comba, Peter; Costas, Miquel; Que, Lawrence, Jr.

    2013-01-01

    Oxoiron(IV) species have been found to act as the oxidants in the catalytic cycles of several mononuclear nonheme iron enzymes that activate dioxygen. To gain insight into the factors that govern the oxidative reactivity of such complexes, a series of five synthetic S = 1 [FeIV(O)(LN5)]2+ complexes has been characterized with respect to their spectroscopic and electrochemical properties as well as their relative abilities to carry out oxo transfer and hydrogen atom abstraction. The Fe=O units...

  15. 2,2',-bipyridine and 1,10-phenanthroline complexes of lanthanide(III) trifluoroacetates

    International Nuclear Information System (INIS)

    Misra, S.N.; Singh, M.

    1983-01-01

    The syntheses and characterization of lanthanide(III) triflloroacetate complexes with 2,2'-bipyridine and 1,10-phenanthroline are reported. Lanthanide(III) trifluoroacetates yield compounds of the type Ln(CF 3 COO) 3 .bipy or phen with 2,2'-bipyridine and 1,10-phenanthroline. Their properties and structures have been studied using chemical analyses. electronic and infrared spectra. Thermal analysis of a few complexes have also been done. The infrared data show that the trifluoroacetate group acts as a bidentate ligand making the coordination number of lanthanide eight. (author)

  16. The influence of carboxilate, phosphinate and seleninate groups on luminescent properties of lanthanides complexes

    International Nuclear Information System (INIS)

    Monteiro, Jorge H.S.K.; Formiga, André L.B.; Sigoli, Fernando A.

    2014-01-01

    The lanthanides(III) complexes [Ln(bza) 3 (H 2 O) n ]·mH 2 O, [Ln(ppa) 3 (H 2 O) n ]·mH 2 O and [Ln(abse) 3 (H 2 O) n ]·mH 2 O where Ln=Eu 3+ , Gd 3+ or Tb 3+ were synthesized using sodium benzoate (Nabza), sodium phenylseleninate (Naabse) and sodium phenylphosphinate (Nappa) in order to verify the influence on coordination modes and the luminescence parameters when the carbon is exchanged by phosphorus or selenium in those ligands. The complexes' stoichiometries were determined by lanthanide(III) titration, microanalysis and TGA. The coordination modes were determined as bidentate bridging and chelate by the FT-IR. The triplet state energies of the ligands were obtained by two different approaches giving a difference of about ∼2000 cm −1 between them. The [Eu(abse) 3 (H 2 O)] complex shows the higher degree of covalence which was verified by the centroid of 5 D 0 → 7 F 0 transition (17,248 cm −1 ). On the other hand the [Ln(abse) 3 (H 2 O) n ]·mH 2 O complexes have an inefficient antenna effect verified by the low values of absolute emission quantum yields. The [Ln(ppa) 3 (H 2 O) n ]·mH 2 O complexes have higher emission decay lifetime values among the complexes which is a result of the ability of this ligand to form coordination polymers avoiding water molecules in the first coordination sphere. The [Eu(ppa) 3 ] complex has the highest point symmetry around europium(III) among the synthesized complexes, followed by the [Eu(bza) 3 (H 2 O) 2 ]·3/2(H 2 O) and [Eu(abse) 3 (H 2 O)] complexes where europium(III) show similar point symmetries. As one may expect, the triplet state energy position would change the transfer and/or back energy transfer rates from ligand to metal. The calculation of these rates show that the back energy transfer rates are more affected than the transfer ones by changing the triplet state energy in the range of ∼2000 cm −1 . The changes in the energy transfer rates from triplet state to europium(III) levels are not

  17. Synthesis and study on complexes of some lanthanides to L-isoleucine

    International Nuclear Information System (INIS)

    Le Minh Tuan; Pham Minh Tuan; Tran The Dinh

    2007-01-01

    The formation of lanthanide (La, Pr and Nd) complexes with L-isoleucine have been studied as a function of pH values. The titrations were performed at 25 o C, and the ionic strength of the medium was maintained at 0.10 M by using potassium nitrate. The formation curves of their