Attosecond sublevel beating and nonlinear dressing on the 3d-to-5p and 3p-to-5s core-transitions at 91.3 eV and 210.4 eV in krypton.

Science.gov (United States)

Seres, Enikoe; Seres, Jozsef; Namba, Shinichi; Afa, John; Serrat, Carles

2017-12-11

Applying extreme ultraviolet (XUV) transient absorption spectroscopy, the dynamics of the two laser dressed transitions 3d 5/2 -to-5p 3/2 and 3p 3/2 -to-5s 1/2 at photon energies of 91.3 eV and 210.4 eV were examined with attosecond temporal resolution. The dressing process was modeled with density matrix equations which are found to describe very accurately both the experimentally observed transmission dynamics and the linear and nonlinear dressing oscillations at 0.75 PHz and 1.5 PHz frequencies. Furthermore, using Fourier transform XUV spectroscopy, quantum beats from the 3d 5/2 -3d 3/2 and 3p 3/2 -3p 1/2 sublevels at 0.3 PHz and 2.0 PHz were experimentally identified and resolved.

Reduced electric-octupole transition probabilities, B(E3;O1+ → 31-), for even-even nuclides throughout the periodic table

International Nuclear Information System (INIS)

Spear, R.H.

1988-11-01

Adopted values for the excitation energy, E x( 3 1 - ), of the first 3 - state of the even-even nuclei are tabulated. Values of the reduced electric-octupole transition probability, B(E3;O 1 + → 3 1 - ), from the ground state to this state, as determined from Coulomb excitation, lifetime measurements, inelastic electron scattering, deformation parameters β 3 obtained from angular distributions of inelastically scattered nucleons and light ions, and other miscellaneous procedures are listed in separate Tables. Adopted values for B(E3; O 1 + → 3 1 - ) are presented in Table VII, together with the E3 transition strengths, in Weisskopf units, and the product E x( 3 1 - ) x B(E3; O 1 + → 3 1 - - ) expressed as a percentage of the energy-weighted E3 sum-rule strength. An evaluation is made of the reliability of B(E3; O 1 + → 3 1 - ) values deduced from deformation parameters β 3 . The literature has been covered to March 1988

Highly retarded M2 transition in 90Nb

International Nuclear Information System (INIS)

Sergeev, V.O.

2006-01-01

One studied properties of 2.3 keV transition between 124.67 (4 - ) and 122.37 keV (6 + ) in 90 Nb. The mentioned M2-transition is shown to be retarded by approximately 10 4 times and provided explanations of the mentioned extraordinary high factor of deceleration. One evaluated impurity of E3 possible multipolarity constituent in the mentioned transition (δ 2 [ru

Weighted f-values, A-values, and line strengths for the E1 transitions among 3d6, 3d54s, and 3d54p levels of Fe III

International Nuclear Information System (INIS)

Deb, Narayan C.; Hibbert, Alan

2009-01-01

Weighted oscillator strengths, weighted radiative rates, and line strengths for all the E1 transitions between 285 fine-structure levels belonging to the 3d 6 , 3d 5 4s, and 3d 5 4p configurations of Fe III are presented, in ascending order of wavelength. Calculations have been undertaken using the general configuration interaction (CI) code CIV3. The large configuration set is constructed by allowing single and double replacements from any of 3d 6 , 3d 5 4s, 3d 5 4p, and 3d 5 4d configurations to nl orbitals with n≤5,l≤3 as well as 6p. Additional selective promotions from 3s and 3p subshells are also included in the CI expansions to incorporate the important correlation effects in the n=3 shell. Results of some strong transitions between levels of 3d 6 , 3d 5 4s, and 3d 5 4p configurations are also presented and compared with other available calculations. It is found that large disagreements occur in many transitions among the existing calculations

The effect of Coster-Kronig transition on the Auger-photoelectron coincidence spectroscopy spectra of early 3d-transition metals

International Nuclear Information System (INIS)

Ohno, Masahide

2004-01-01

The singles L23-M45M45 Auger-electron spectroscopy (AES) spectrum of early 3d-transition metal can be fitted by a weighted sum of the density of the single-hole states and that of the two-hole states, broadened by the initial L23-hole lifetime width, respectively (in the present paper we denote the atomic shells Lx, My, and Nz by LX, MY and NZ, respectively). With increasing occupancy of the 3d band the probability of creating the two-hole states by the L23-M45M45 Auger transition and the L2-L3M45 Coster-Kronig (CK) transition increases. However, the M45 hole created by the CK transition is delocalized and becomes decoupled (screened out) from the L3-hole decay so that the L3M45 two-hole state 'decays' to the single L3-hole state before the L3-hole decays. Thus the singles AES spectrum by the L2-L3-M45(M45) CK-transition preceded Auger transition and the singles one by the L3-M45(M45) Auger-transition overlap. We can study the M45-hole dynamics by Auger-photoelectron coincidence spectroscopy because the coincidence spectral lineshape depends on the dynamics of the M45 hole created by the CK transition

Structure and physical properties of ternary uranium transition-metal antimonides U3MSb5 (M = Zr, Hf, Nb)

International Nuclear Information System (INIS)

Tkachuk, Andriy V.; Muirhead, Craig P.T.; Mar, Arthur

2006-01-01

The ternary uranium transition-metal antimonides U 3 MSb 5 (M = Zr, Hf, Nb) were prepared by arc-melting reactions followed by annealing at 800 deg. C, or by use of a Sn flux. These compounds extend the previously known series U 3 MSb 5 (M = Ti, V, Cr, Mn) and RE 3 MSb 5 (RE = La, Ce, Pr, Nd, Sm; M = Ti, Zr, Hf, Nb). The crystal structures of U 3 MSb 5 were determined by single-crystal X-ray diffraction data (Pearson symbol hP18, hexagonal, space group P6 3 /mcm, Z = 2; U 3 ZrSb 5 , a = 9.2223(3) A, c = 6.1690(2) A; U 3 HfSb 5 , a = 9.2084(4) A, c = 6.1629(3) A; U 3 NbSb 5 , a = 9.1378(4) A, c 6.0909(6) A). U 3 TaSb 5 has also been identified in microcrystalline form (a = 9.233(3) A, c = 6.142(3) A). Four-probe electrical resistivity measurements on single crystals and dc magnetic susceptibility measurements on powders indicated prominent transitions that are attributed to ferromagnetic ordering. The Curie temperatures, T C , located from ac magnetic susceptibility curves, are 135 K for U 3 ZrSb 5 , 141 K for U 3 HfSb 5 , and 107 K for U 3 NbSb 5

Spectroscopy of 215Ra: the shell model and enhanced E3 transitions

International Nuclear Information System (INIS)

Stuchbery, A.E.; Dracoulis, G.D.; Kibedi, T.; Fabricius, B.; Lane, G.J.; Poletti, A.R.; Baxter, A.M.

1998-01-01

Excited states in the N=127 nucleus 215 Ra have been studied using γ-ray and electron spectroscopy following reactions of 13 C on 206 Pb targets. Levels were identified up to spins of ∝61/2 ℎ and excitation energies of ∝6 MeV. Enhanced octupole transitions are a feature of the level scheme. Lifetimes and magnetic moments were measured for several isomeric levels. The level scheme, transition rates and magnetic moments are compared with empirical shell model calculations and multiparticle octupole-coupled shell model calculations. In general, the experimental data are well described, but in comparison with its success in describing enhanced E3 transitions between related states in the radon isotopes, some limitations of the multiparticle octupole-coupling approach are revealed in 215 Ra. (orig.)

Predicted stability, structures, and magnetism of 3d transition metal nitrides: the M4N phases

NARCIS (Netherlands)

Fang, C.M.; Koster, R.S.; Li, W.F.; van Huis, M.A.

2014-01-01

The 3d transition metal nitrides M4N (Sc4N, Ti4N, V4N, Cr4N, Mn4N, Fe4N, Co4N, Ni4N, and Cu4N) have unique phase relationships, crystal structures, and electronic and magnetic properties. Here we present a systematic density functional theory (DFT) study on these transition metal nitrides, assessing

Mechanisms for the reactions of group 10 transition metal complexes with metal-group 14 element bonds, Bbt(Br)E═M(PCy3)2 (E = C, Si, Ge, Sn, Pb; M = Pd and Pt).

Science.gov (United States)

Liao, Wei-Hung; Ho, Pei-Yun; Su, Ming-Der

2013-02-04

The electronic structures of the Bbt(Br)E═M(PCy(3))(2) (E = C, Si, Ge, Sn, Pb and M = Pt, Pd) complexes and their potential energy surfaces for the formation and water addition reactions were studied using density functional theory (B3LYP/LANL2DZ). The theoretical evidence suggests that the bonding character of the E═M double bond between the six valence-electron Bbt(Br)E: species and the 14 valence-electron (PCy(3))(2)M complexes has a predominantly high s-character. That is, on the basis of the NBO, this theoretical study indicates that the σ-donation from the E element to the M atom prevails. Also, theoretical computations suggest that the relative reactivity decreases in the order: Bbt(Br)C═M(PCy(3))(2) > Bbt(Br)Si═M(PCy(3))(2) > Bbt(Br)Ge═M(PCy(3))(2) > Bbt(Br)Sn═M(PCy(3))(2) > Bbt(Br)Pb═M(PCy(3))(2), irrespective of whether M = Pt or M = Pd is chosen. Namely, the greater the atomic weight of the group 14 atom (E), the larger is the atomic radius of E and the more stable is its Bbt(Br)E═M(PCy(3))(2) doubly bonded species toward chemical reactions. The computational results show good agreement with the available experimental observations. The theoretical results obtained in this work allow a number of predictions to be made.

Electron Excitation Cross Sections for the S II Transitions: 3s(exp 2)3p(exp 3) 4S(exp o) approaches 3s(exp 2)3p(exp 3) 2D(exp o), 2P(exp o), and 3s3p(exp 4) 4P

Science.gov (United States)

Liao, C.; Chutjian, A.; Hitz, D.; Tayal, S. S.

1997-01-01

Experimental and theoretical collisional excitation cross sections are reported for the transitions 3s(exp 2)3p(exp 3)4S(exp o) approaches 3s(exp 2)3p(exp 3) 2D(exp o), 2P(exp o), and 3s3P(exp 4) 4P in S II. The transition wavelengths (energies) are 6716 A (1.85 eV), 4069 A (3.05 eV), and 1256 A (9.87 eV), respectively. In the experiments, use is made of the energy-loss merged-beams method. The metastable fraction of the S II beam was assessed and minimized. The contribution of elastically scattered electrons was reduced by the use of a lowered solenoidal magnetic field and a modulated radio-frequency voltage on the analyzing plates and by retarding grids to reject the elastically scattered electrons with larger Larmor radii. For each transition, comparisons are made among experiments, the new 19 state R-matrix calculation, and three other close-coupling calculations.

E2 and M1 transition strengths in heavy deformed nuclei revisited

International Nuclear Information System (INIS)

Draayer, J.P.; Popa, G.; Hirsch, J.G.; Vargas, C.E.

2003-01-01

An update on the status of pseudo-SU(3) shell-model calculations in strongly deformed nuclei in the rare earth region is presented. Representative results for energy levels as well as E2 (quadrupole) and M1 (scissors) transitions strengths in 162 Dy (even-even) and 163 Dy (odd-mass) are given. The calculations use realistic single-particle energies and quadrupole-quadrupole and pairing interaction strengths fixed from systematics. The strengths of rotor-like terms included in the Hamiltonian- all small relative to the other terms in the interaction were adjusted to give an overall best fit to the energy spectra. The results present a paradox: for even-even nuclei (integer angular momentum) non-zero pseudo-spin configurations seems to be unimportant while for the odd-mass systems (half-integer angular momentum) pseudo-spin mixing is essential as spin-flip couplings appear to dominate the M1 transition strengths. (Author)

Micro-Raman study of the microheterogeneity in the MA-MC phase transition in 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 single crystal

KAUST Repository

Yang, Y.

2011-04-20

Polarized Raman spectroscopy has been employed to investigate the evolution of the microstructure of 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 (PMN-33%PT) single crystal in the temperature range from −195 to 300 °C. The M A-M C-cubic transition sequence was observed in the microareas with M A-type (space group Cm) and M C-type (space group Pm) monoclinic structures. Interestingly, the M A-M Cphase transition temperature exhibited remarkable microareal dependence due to the spatial inhomogeneity of polar nanoregions (PNRs). The M C-cubic phase transition took place at 155 °C in both microareas, which consisted well with previous reports. These results reveal that the phase transition in PMN-33%PT single crystal is closely related with the thermal dynamics of PNRs, which will be useful for understanding the microheterogeneity in this compound.

The clinical value of HPV E6/E7 and STAT3 mRNA detection in cervical cancer screening.

Science.gov (United States)

Fan, Yibing; Shen, Zongji

2018-02-11

To explore the value of human papillomavirus (HPV) E6/E7 and signal transducer and activator of transcription 3 (STAT3) mRNA detection in the screening of cervical lesions. 192 patients with abnormal ThinPrep cytology test (TCT) results and/or high-risk HPV infection were screened to identify possible cervical lesions in cases. Diagnoses were confirmed by histopathology. Fluorescence in situ hybridization (FISH) was performed to detect and qualify the mRNAs of HPV E6/E7, STAT3, and Survivin in cervical exfoliated cells. In addition, the performance of separate and combined mRNA detection methods were compared with TCT, HR-HPV DNA schemes respectively. 1. Compared with HPVE6/E7 and STAT3 mRNA methods, Survivin mRNA assay had poor specificity (Sp), Youden index (YI) and concordance rate. 2. HPV E6/E7, STAT3, and STAT3 + HR-HPV methods had the best Sp, concordance rate and positive predictive value (PPV) for cervical lesions screening and atypical squamous cells of undetermined significance (ASCUS) triage. For screening of high grade squamous intraepithelial lesions or greater (HSILs+), no difference was observed in the Se of mRNA detection methods in comparison with that of TCT, HR-HPV and TCT + HR-HPV, whereas the false positive rate (FPR) decreased by 41.48%/55.99%/17.19% and the colposcopy referral rate reduced by about 20.00%/25.00%/11.17%. For triage of women with ASCUS, no difference was observed in the Se of mRNA detection methods as compared to that of HR-HPV (χ 2  = 1.05, P > 0.75), while the FPR decreased by 45.83%/37.50%/41.66% and the colposcopy referral rate reduced by 32.42%/22.60%/25.28%, respectively. The Se, YI, and PPV of the combined methods increased in comparison to each method alone. 3. Compared with the TCT + HR-HPV method, HPV E6/E7 + STAT3 method had perfect Sp (95.92%) and PPV (95.40%) for screening HSILs+, the FPR and colposcopy referral rate decreased by 31.06% and 22.48% respectively. 1. The expression of HPV E6/E

Effect of gold subsurface layer on the surface activity and segregation in Pt/Au/Pt3M (where M = 3d transition metals) alloy catalyst from first-principles.

Science.gov (United States)

Kim, Chang-Eun; Lim, Dong-Hee; Jang, Jong Hyun; Kim, Hyoung Juhn; Yoon, Sung Pil; Han, Jonghee; Nam, Suk Woo; Hong, Seong-Ahn; Soon, Aloysius; Ham, Hyung Chul

2015-01-21

The effect of a subsurface hetero layer (thin gold) on the activity and stability of Pt skin surface in Pt3M system (M = 3d transition metals) is investigated using the spin-polarized density functional theory calculation. First, we find that the heterometallic interaction between the Pt skin surface and the gold subsurface in Pt/Au/Pt3M system can significantly modify the electronic structure of the Pt skin surface. In particular, the local density of states projected onto the d states of Pt skin surface near the Fermi level is drastically decreased compared to the Pt/Pt/Pt3M case, leading to the reduction of the oxygen binding strength of the Pt skin surface. This modification is related to the increase of surface charge polarization of outmost Pt skin atoms by the electron transfer from the gold subsurface atoms. Furthermore, a subsurface gold layer is found to cast the energetic barrier to the segregation loss of metal atoms from the bulk (inside) region, which can enhance the durability of Pt3M based catalytic system in oxygen reduction condition at fuel cell devices. This study highlights that a gold subsurface hetero layer can provide an additional mean to tune the surface activity toward oxygen species and in turn the oxygen reduction reaction, where the utilization of geometric strain already reaches its practical limit.

Magnetic order in Pu2M3Si5 (M = Co, Ni)

International Nuclear Information System (INIS)

Bauer, E D; Tobash, P H; Mitchell, J N; Kennison, J A; Ronning, F; Scott, B L; Thompson, J D

2011-01-01

The physical properties including magnetic susceptibility, specific heat, and electrical resistivity of two new plutonium compounds Pu 2 M 3 Si 5 (M = Co, Ni) are reported. Pu 2 Ni 3 Si 5 crystallizes in the orthorhombic U 2 Co 3 Si 5 structure type, which can be considered a variant of the BaAl 4 tetragonal structure, while Pu 2 Co 3 Si 5 adopts the closely related monoclinic Lu 2 Co 3 Si 5 type. Magnetic order is observed in both compounds, with Pu 2 Ni 3 Si 5 ordering ferromagnetically at T C = 65 K then undergoing a transition into an antiferromagnetic state below T N = 35 K. Two successive magnetic transitions are also observed at T mag1 = 38 K and T mag2 = 5 K in Pu 2 Co 3 Si 5 . Specific heat measurements reveal that these two materials have a moderately enhanced Sommerfeld coefficient γ ∼ 100 mJ/mol Pu K 2 in the magnetic state with comparable RKKY and Kondo energy scales.

Spin dependence of intra-ground-state-band E2 transitions in the SU(3) limit of the sdg interacting boson model

Science.gov (United States)

Long, G. L.; Ji, H. Y.

1998-04-01

B(E2, L+2-->L) transitions in the sdg interacting boson model SU(3) limit are studied with a general E2 transition operator. Analytical expressions are obtained using a group theoretic method. It is found that when using transition operators of the form (d†g~+g†d~)2 or (g†g~)2, the B(E2, L+2-->L) values in the ground-state band have an L(L+3) dependent term. As L increases, the B(E2) values can be larger than the rigid rotor model value. Application to 236,238U is discussed.

12 CFR 3.3 - Transitional rules.

Science.gov (United States)

2010-01-01

... DIRECTIVES Authority and Definitions § 3.3 Transitional rules. Intangible assets, other than mortgage... other qualifying intangible assets, these intangibles may not exceed 25 percent of Tier 1 capital. After December 31, 1992, only those intangible assets that meet the criteria contained in section 2(c)(2) of...

Absolute M1 and E2 Transition Probabilities in 2{sup 33}U

Energy Technology Data Exchange (ETDEWEB)

Malmskog, S G; Hoejeberg, M

1967-08-15

Using the delayed coincidence technique, the following half lives have been determined for different excited states in {sup 233}U: T{sub 1/2} (311.9 keV level) = (1.20 {+-} 0.15) x 10{sup -10} sec, T{sub 1/2} (340.5 keV level) = (5.2 {+-} 1.0) x 10{sup -11} sec, T{sub 1/2} (398.6 keV level) = (5.5 {+-} 2.0) x 10{sup -11} sec and T{sub 1/2} (415.8 keV level) < 3 x 10{sup -11}sec. From these half life determinations, together with earlier known electron intensities and conversion coefficients, 22 reduced B(Ml) and B(E2) transition probabilities (including 9 limits) have been deduced. The rotational transitions give information on the parameters {delta} and (g{sub K} - g{sub R}) . The experimental M1 and E2 transition rates between members of different bands have been analysed in terms of the predictions of the Nilsson model, taking also pairing correlations and Coriolis coupling effects into account.

First HIBP Measurement of Plasma Potential During the H-Mode Transition on the TUMAN-3M Tokamak

International Nuclear Information System (INIS)

Askinazi, L.G.; Golant, V.E.; Kornev, V.A.; Lebedev, S.V.; Shevkin, E.A.; Tukachinsky, A.S.; Zhubr, N.A.; Chmyga, A.A.; Dreval, N.B.; Khrebtov, S.M.; Komarov, A.S.; Krupnik, L.I.; Oost, G. van; Tendler, M.

2003-01-01

The difficulty of Heavy Ion Beam Probe (HIBP) application on the TUMAN-3M (R=0.53m, a=0.22m, BT=0.8T, Ip=140kA, Te=0.5keV, n<4 1019m-3) -- significant toroidal shift of beam trajectory -- is caused by high ratio of poloidal field to toroidal one. Strong UV radiation from the plasma loads the energy analyzer's detector and complicates the problem even more. This paper presents the results of first measurement of plasma potential evolution in the discharges performed in ohmic H-mode using 80 keV K+ beam and a Proca-Green secondary ion energy analyzer. Spatial region covered by the diagnostic in the experiments discussed was 0< r<0.6a. Spatial scan was performed utilizing the toroidal field decrease due to capacity power supply battery discharge. The change in plasma potential of the order of 100V has been measured during the H-mode formation. The potential in core plasma (r<0.6a) starts to change simultaneously with L-H transition, and than changes during ∼6-8ms after the transition. Thus, the potential changes rather slowly in a comparison with L-H transition timescale (∼2ms for TUMAN-3M ohmic H-mode). Possible explanation to the slow change in central plasma potential may be a formation of potential well structure at the plasma edge, in which radial electric field changes direction. This kind of structure is beneficial for the edge turbulent transport suppression because of high |∂Er/∂r|, but not necessary requires a strong change in central plasma potential to occur immediately. The results from microwave reflectometry support this hypothesis

Energies and E1, M1, E2, and M2 transition rates for states of the 2s{sup 2}2p{sup 3}, 2s2p{sup 4}, and 2p{sup 5} configurations in nitrogen-like ions between F III and Kr XXX

Energy Technology Data Exchange (ETDEWEB)

Rynkun, P., E-mail: pavel.rynkun@gmail.com [Department of Physics and Information Technologies, Lithuanian University of Educational Science, Studentu 39, LT-08106 Vilnius (Lithuania); Jönsson, P. [Group for Materials Science and Applied Mathematics, Malmö University, 20506 Malmö (Sweden); Gaigalas, G. [Department of Physics and Information Technologies, Lithuanian University of Educational Science, Studentu 39, LT-08106 Vilnius (Lithuania); Vilnius University, Institute of Theoretical Physics and Astronomy, A. Goštauto 12, LT-01108 Vilnius (Lithuania); Froese Fischer, C. [National Institute of Standards and Technology, Gaithersburg, MD 20899-8420 (United States)

2014-03-15

Based on relativistic wavefunctions from multiconfiguration Dirac–Hartree–Fock and configuration interaction calculations, E1, M1, E2, and M2 transition rates, weighted oscillator strengths, and lifetimes are evaluated for the states of the (1s{sup 2})2s{sup 2}2p{sup 3},2s2p{sup 4}, and 2p{sup 5} configurations in all nitrogen-like ions between F III and Kr XXX. The wavefunction expansions include valence, core–valence, and core–core correlation effects through single–double multireference expansions to increasing sets of active orbitals. The computed energies agree very well with experimental values, with differences of only 300–600 cm{sup −1} for the majority of the levels and ions in the sequence. Computed transitions rates are in close agreement with available data from MCHF-BP calculations by Tachiev and Froese Fischer [G.I. Tachiev, C. Froese Fischer, A and A 385 (2002) 716].

Effect of gold subsurface layer on the surface activity and segregation in Pt/Au/Pt{sub 3}M (where M = 3d transition metals) alloy catalyst from first-principles

Energy Technology Data Exchange (ETDEWEB)

Kim, Chang-Eun [Fuel Cell Research Center, Korea Institute of Science and Technology (KIST), 39-1 Hawolgok, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Global E3 Institute and Department of Materials Science and Engineering, Yonsei University, 120-749 Seoul (Korea, Republic of); Lim, Dong-Hee [Fuel Cell Research Center, Korea Institute of Science and Technology (KIST), 39-1 Hawolgok, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Department of Environmental Engineering, Chungbuk National University, 1 Chungdae-ro, Seowon-Gu, Cheongju, Chungbuk 362-763 (Korea, Republic of); Jang, Jong Hyun; Kim, Hyoung Juhn; Yoon, Sung Pil; Han, Jonghee; Nam, Suk Woo [Fuel Cell Research Center, Korea Institute of Science and Technology (KIST), 39-1 Hawolgok, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Hong, Seong-Ahn [Fuel Cell Research Center, Korea Institute of Science and Technology (KIST), 39-1 Hawolgok, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Department of Advanced Materials Chemistry, Korea University, Sejong-city 339-700 (Korea, Republic of); Soon, Aloysius, E-mail: aloysius.soon@yonsei.ac.kr, E-mail: hchahm@kist.re.kr [Global E3 Institute and Department of Materials Science and Engineering, Yonsei University, 120-749 Seoul (Korea, Republic of); Ham, Hyung Chul, E-mail: aloysius.soon@yonsei.ac.kr, E-mail: hchahm@kist.re.kr [Fuel Cell Research Center, Korea Institute of Science and Technology (KIST), 39-1 Hawolgok, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Clean Energy and Chemical Engineering, University of Science and Technology (UST), 217 Gajungro, Yuseong-gu, Daejeon 305-333 (Korea, Republic of)

2015-01-21

The effect of a subsurface hetero layer (thin gold) on the activity and stability of Pt skin surface in Pt{sub 3}M system (M = 3d transition metals) is investigated using the spin-polarized density functional theory calculation. First, we find that the heterometallic interaction between the Pt skin surface and the gold subsurface in Pt/Au/Pt{sub 3}M system can significantly modify the electronic structure of the Pt skin surface. In particular, the local density of states projected onto the d states of Pt skin surface near the Fermi level is drastically decreased compared to the Pt/Pt/Pt{sub 3}M case, leading to the reduction of the oxygen binding strength of the Pt skin surface. This modification is related to the increase of surface charge polarization of outmost Pt skin atoms by the electron transfer from the gold subsurface atoms. Furthermore, a subsurface gold layer is found to cast the energetic barrier to the segregation loss of metal atoms from the bulk (inside) region, which can enhance the durability of Pt{sub 3}M based catalytic system in oxygen reduction condition at fuel cell devices. This study highlights that a gold subsurface hetero layer can provide an additional mean to tune the surface activity toward oxygen species and in turn the oxygen reduction reaction, where the utilization of geometric strain already reaches its practical limit.

Energy Transfer between Er3+ and Pr3+ for 2.7 μm Fiber Laser Material

Directory of Open Access Journals (Sweden)

Xiangtan Li

2014-01-01

Full Text Available Energy transfer mechanisms between Er3+ and Pr3+ in Er3+/Pr3+ codoped germinate glass are investigated in detail. Under 980 nm LD pumping, 2.7 μm fluorescence intensity enhanced greatly. Meanwhile, 1.5 μm lifetime and fluorescence were suppressed deeply due to the efficient energy transfer from Er3+:4I13/2 to Pr3+:3F3,4, which depopulates the 4I13/2 level and promotes the 2.7 μm transition effectively. The obvious change in J-O parameters indicates that Pr3+ influences the local environment of Er3+ significantly. The increased spontaneous radiative probability in Er3+/Pr3+ glass is further evidence for enhanced 4I11/2 → 4I13/2 transition. The Er3+:4I11/2→Pr3+:1G4 process is harmful to the population accumulation on 4I11/2 level, which inhibits the 2.7 μm emission. The microscopic energy transfer coefficient of Er3+:4I13/2→Pr3+:3F3,4 is 42.25 × 10−40 cm6/s, which is 11.5 times larger than that of Er3+:4I11/2→Pr3+:1G4. Both processes prefer to be non-phonon assisted, which is the main reason why Pr3+ is so efficient in Er3+:2.7 μm emission.

Electric-dipole allowed and intercombination transitions among the 3d5, 3d44s and 3d44p levels of Fe IV

International Nuclear Information System (INIS)

Deb, Narayan C.; Hibbert, Alan

2010-01-01

Oscillator strengths and transition rates for the electric-dipole (E1) allowed and intercombination transitions among 3d 5 , 3d 4 4s and 3d 4 4p levels of Fe IV are calculated using the CIV3 code of Hibbert and coworkers. Using the Hartree-Fock functions up to 3d orbitals we have also optimized 4s, 4p, 4d, 4f, 5s, 5p and 5d orbitals of which 4s and 4p are taken to be spectroscopic and the remaining orbitals represent corrections to the spectroscopic orbitals or the correlation effects. The J-dependent levels of 108 LS states are included in the calculation and the relativistic effects are accounted for via the Breit-Pauli operator. Configurations are chosen in two steps: (a) two promotions were allowed from the 3p, 3d, 4s and 4p subshells, using all the orbitals; and (b) selective promotions from the 3s subshell are included, but only to the 3s and 4s orbitals. The ab initio fine-structure levels are then fine tuned to reproduce observed energy levels as closely as possible, and the resulting wavefunctions are used to calculate oscillator strengths and transition rates for all possible E1 transitions. For many of these transitions, the present results show good agreement between the length and velocity forms while for some transitions, some large disagreements are found with other available results. The complete list of weighted oscillator strengths, transition rates, and line strengths for transitions among the fine structure levels of the three lowest configurations are presented in ascending order of wavelength.

High-spin yrast isomers in 211Rn and 212Rn with enhanced E3 decays

International Nuclear Information System (INIS)

Dracoulis, G.D.; Byrne, A.P.; Fabricius, B.

1990-01-01

New isomeric states with J π =69/2 + ,τ m = 13 (1) ns in 211 Rn and J π =33 - ,τ m = 7(1) ns in 212 Rn have been identified. They decay by enchanced E3 transitions with strengths of 33(3) and 43(6) single particle units to the known 63/2 - and 30 + isomers 211 Rn and 212 Rn, respectively. The excitation energies and transition strengths agree well with predictions of the multi-particle, octupole-vibration coupled model. 13 refs., 2 tabs., 3 figs

Photoluminescence characterization of Dy3+ and Eu2+ ion in M5(PO4)3F (M = Ba, Sr, Ca) phosphors

International Nuclear Information System (INIS)

Nagpure, I.M.; Shinde, K.N.; Dhoble, S.J.; Kumar, Animesh

2009-01-01

Photoluminescence investigation of Eu and Dy activated phosphate based phosphors prepared by combustion synthesis, characterized by XRD (X-ray diffraction) and photoluminescence techniques, has been reported. PL excitation spectrum of M 5 (PO 4 ) 3 F:Dy phosphors shows the excitation peaks ranging from 300 to 400 nm due to 4f → 4f transitions of Dy 3+ ions. PL emission spectrum of Dy 3+ ion under 348 nm excitation gives PL emission at 482 nm (blue) due to 4 F 9/2 → 6 H 15/2 transitions, 574 nm (yellow) emission due to 4 F 9/2 → 6 H 13/2 transitions and 670 nm (red) due to 4 F 9/2 → 6 H 11/2 transitions, gives BYR (blue-yellow-red) emissions. The Eu 2+ broad band PL emission spectrum was observed in M 5 (PO 4 ) 3 F:Eu phosphor at 440 nm in the blue region of the spectrum due to 5d → 4f transition at 352 nm excitation. The 300-400 nm is Hg-free excitation (Hg excitation is 85% 254 nm wavelength of light and 15% other wavelengths), which is characteristic of solid-state lighting phosphors. Hence PL emission in divalent europium and trivalent dysprosium may be efficient photoluminescent materials for solid-state lighting phosphors.

Acoustic emission during the ferroelectric transition Pm3{sup ¯}m to P4mm in BaTiO{sub 3} and the ferroelastic transition R3{sup ¯}m-C2/c in Pb{sub 3}(PO{sub 4}){sub 2}

Energy Technology Data Exchange (ETDEWEB)

Salje, E. K. H. [Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ (United Kingdom); Dul' kin, E.; Roth, M. [Department of Applied Physics, The Hebrew University of Jerusalem, Jerusalem 91904 (Israel)

2015-04-13

Acoustic emission (AE) spectroscopy without frequency filtering (∼broadband AE) and moderate time integration is shown to be sensitive enough to allow the investigation of subtle nano-structural changes in ferroelectric BaTiO{sub 3} and ferroelastic Pb{sub 3}(PO{sub 4}){sub 2}. AE signals during weak phase transitions are compatible with avalanche statistics as observed previously in large-strain systems. While the data are too sparse to determine avalanche exponents, they are well suited to determine other thermodynamic parameters such as transition temperatures and critical stresses.

Temperature-dependent Raman spectra and electrical properties of 0.69Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.31PbTiO{sub 3} single crystals

Energy Technology Data Exchange (ETDEWEB)

Fang, Bijun [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Liu, Xing [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Chinese Academy of Sciences, Key Laboratory of Inorganic Function Material and Device, Shanghai (China); Li, Xiaobing; Zhao, Xiangyong; Luo, Haosu [Chinese Academy of Sciences, Key Laboratory of Inorganic Function Material and Device, Shanghai (China); Ding, Jianning [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Jiangsu University, School of Material Science and Engineering, Zhenjiang (China)

2016-09-15

The temperature-dependent Raman spectra and electrical properties of the 0.69Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.31PbTiO{sub 3} (0.69PMN-0.31PT) single crystals were investigated. Based on the group theory, the poled 0.69PMN-0.31PT single crystals belong to the monoclinic crystal system, which was confirmed by the room-temperature Raman spectra. The 0.69PMN-0.31PT single crystals experience successive structural phase transitions, i.e., a monoclinic-tetragonal (FE{sub M}-FE{sub T}) phase transition at T{sub M-T} and a tetragonal-cubic (FE{sub T}-P{sub C}) phase transition at T{sub m} determined by the dielectric measurement. Due to the enhancement of long-range order, their FE{sub M}-FE{sub T} phase transition becomes more obvious after the poling process. The wavenumbers and line widths of the 271, 502, 575, 795 cm{sup -1} Raman modes, and the intensity ratios of I{sub 271cm}{sup {sub -}{sub 1}}/I{sub 795cm}{sup {sub -}{sub 1}} and I{sub 502cm}{sup {sub -}{sub 1}}/I{sub 575cm}{sup {sub -}{sub 1}} exhibit obvious anomalies around T{sub M-T} and T{sub m}, which are closely related to the FE{sub M}-FE{sub T} and FE{sub T}-P{sub C} phase transitions. The temperature and electric field (E)-induced phase transitions are observed in the unipolar strain-E (S-E) curves. The converse piezoelectric constant (d{sub 33}), maximum strain value (S{sub max}%) and longitudinal electrostrictive coefficient (Q) increase considerably around the ferroelectric phase transition temperature T{sub M-T}. (orig.)

Atmospheric chemistry of Z- and E-CF3CH=CHCF3

DEFF Research Database (Denmark)

Østerstrøm, Freja From; Andersen, Simone Thirstrup; Sølling, Theis Ivan

2017-01-01

radicals. The atmospheric lifetimes of Z- and E-CF3CH[double bond, length as m-dash]CHCF3 are estimated as 27 and 67 days, respectively. IR absorption cross sections are reported and the global warming potentials (GWPs) of Z- and E-CF3CH[double bond, length as m-dash]CHCF3 for the 100 year time horizon...

Magnetic and electronic properties of La3 M O7 and possible polaron formation in hole-doped La3 M O7 (M   =  Ru and Os)

International Nuclear Information System (INIS)

Gao, Bin; Weng, Yakui; Zhang, Jun-Jie; Zhang, Huimin; Zhang, Yang; Dong, Shuai

2017-01-01

Oxides with 4 d /5 d transition metal ions are physically interesting for their particular crystalline structures as well as the spin–orbit coupled electronic structures. Recent experiments revealed a series of 4 d /5 d transition metal oxides R 3 M O 7 (R : rare earth; M : 4 d /5 d transition metal) with unique quasi-one-dimensional M chains. Here first-principles calculations have been performed to study the electronic structures of La 3 OsO 7 and La 3 RuO 7 . Our study confirm both of them to be Mott insulating antiferromagnets with identical magnetic order. The reduced magnetic moments, which are much smaller than the expected value for ideal high-spin state (3 t 2g orbitals occupied), are attributed to the strong p   −   d hybridization with oxygen ions, instead of the spin–orbit coupling. The Ca-doping to La 3 OsO 7 and La 3 RuO 7 can not only modulate the nominal carrier density but also affect the orbital order as well as the local distortions. The Coulombic attraction and particular orbital order would prefer to form polarons, which might explain the puzzling insulating behavior of doped 5 d transition metal oxides. In addition, our calculations predict that the Ca-doping can trigger ferromagnetism in La 3 RuO 7 but not in La 3 OsO 7 . (paper)

Monitoring and understanding the paraelectric-ferroelectric phase transition in the metal-organic framework [NH4 ][M(HCOO)3 ] by solid-state NMR spectroscopy.

Science.gov (United States)

Xu, Jun; Lucier, Bryan E G; Sinelnikov, Regina; Terskikh, Victor V; Staroverov, Viktor N; Huang, Yining

2015-10-05

The paraelectric-ferroelectric phase transition in two isostructural metal-organic frameworks (MOFs) [NH4 ][M(HCOO)3 ] (M=Mg, Zn) was investigated by in situ variable-temperature (25) Mg, (67) Zn, (14) N, and (13) C solid-state NMR (SSNMR) spectroscopy. With decreasing temperature, a disorder-order transition of NH4 (+) cations causes a change in dielectric properties. It is thought that [NH4 ][Mg(HCOO)3 ] exhibits a higher transition temperature than [NH4 ][Zn(HCOO)3 ] due to stronger hydrogen-bonding interactions between NH4 (+) ions and framework oxygen atoms. (25) Mg and (67) Zn NMR parameters are very sensitive to temperature-induced changes in structure, dynamics, and dielectric behavior; stark spectral differences across the paraelectric-ferroelectric phase transition are intimately related to subtle changes in the local environment of the metal center. Although (25) Mg and (67) Zn are challenging nuclei for SSNMR experiments, the highly spherically symmetric metal-atom environments in [NH4 ][M(HCOO)3 ] give rise to relatively narrow spectra that can be acquired in 30-60 min at a low magnetic field of 9.4 T. Complementary (14) N and (13) C SSNMR experiments were performed to probe the role of NH4 (+) -framework hydrogen bonding in the paraelectric-ferroelectric phase transition. This multinuclear SSNMR approach yields new physical insights into the [NH4 ][M(HCOO)3 ] system and shows great potential for molecular-level studies on electric phenomena in a wide variety of MOFs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Total internal conversion coefficient of the 260. 9 keV (7/sup +/->3/sup -/) transition in sup(198m)Tl

Energy Technology Data Exchange (ETDEWEB)

Venkateswara Rao, N.; Suryanarayana, C.; Narayana, D.G.S.; Bhuloka Reddy, S.; Satynarayana, G.; Sastry, D.L.; Chintalapudi, S.N.

1986-02-21

The 1.87 hours 543.7 keV (7/sup +/) isomeric state in /sup 198/Tl is produced via /sup 197/Au(..cap alpha.., 3n)sup(198m)Tl (Esub(..cap alpha..) = 35 MeV) reaction. The total conversion coefficient of 260.9 keV (7/sup +/ -> 3/sup -/) is determined for the first time by the intensity balance method. The value of ..cap alpha..sub(T)(260.9 keV) is found to be 40.1 +- 8.6 which is in good agreement with the theoretical value of Hager and Seltzer for pure M4 transition. The gamma transition probability of the 260.9 keV (M4) is calculated using the present value of ..cap alpha..sub(T) and compared with the single-particle estimate.

Structural phase transition in La2/3Ba1/3MnO3 perovskite: Elastic, magnetic, and lattice anomalies and microscopic mechanism

Directory of Open Access Journals (Sweden)

E. Fertman

2015-07-01

Full Text Available The temperature dependences of the elastic and magnetic properties of polycrystalline perovskite manganite La2/3Ba1/3MnO3 were studied using ultrasonic and SQUID magnetometer techniques. The minimum of the temperature-dependent sound velocity v(T and corresponding maximum of the decrement δ(T were found in the vicinity of the structural phase transition R 3 ̄ c ↔ I m m a at Ts ∼ 200 K. Large alterations of v and δ indicate a structural phase transition of the soft mode type. A high sensitivity of dc magnetization to a low uniaxial pressure caused by the softening was found in the Ts region. A negative value of the linear thermal expansion coefficient along one of the crystallographic axis was found in the Imma phase near Ts. The proposed microscopic mechanism explains the appearance of the soft mode in the vicinity of the structural phase transition temperature associated with the displacement of the manganese atom from the center of the oxygen octahedron.

Lifshitz transition with interactions in high magnetic fields: Application to CeIn3

Science.gov (United States)

Schlottmann, Pedro

2012-02-01

The N'eel ordered state of CeIn3 is suppressed by a magnetic field of 61 T at ambient pressure. There is a second transition at ˜45 T, which has been associated with a Lifshitz transition [1,2]. Skin depth measurements [2] indicate that the transition is discontinuous as T ->0. Motivated by this transition we study the effects of Landau quantization and interaction among carriers on a Lifshitz transition. The Landau quantization leads to quasi-one-dimensional behavior for the direction parallel to the field. Repulsive Coulomb interactions give rise to a gas of strongly coupled carriers [3]. The density correlation function is calculated for a special long-ranged potential [4]. It is concluded that in CeIn3 a pocket is being emptied as a function of field in a discontinuous fashion in the ground state. This discontinuity is gradually smeared by the temperature [4] in agreement with the skin depth experiments [2]. 0.05in [1] S.E. Sebastian et al, PNAS 106, 7741 (2009). [2] K.M. Purcell et al, Phys. Rev. B 79, 214428 (2009). [3] P. Schlottmann and R. Gerhardts, Z. Phys. B 34, 363 (1979). [4] P. Schlottmann, Phys. Rev. B 83, 115133 (2011); J. Appl. Phys., in print.

mPGES-1-derived prostaglandin E2 stimulates Stat3 to promote podocyte apoptosis.

Science.gov (United States)

Yu, Jing; Wu, Yimei; Wang, Lu; Zhang, Wen; Xu, Man; Song, Jiayu; Fu, Yu; Cui, Yiyun; Gong, Wei; Li, Shuzhen; Xia, Weiwei; Huang, Songming; Zhang, Aihua; Jia, Zhanjun

2017-11-01

We previously reported that microsomal prostaglandin E synthase-1 (mPGES-1) contributed to adriamycin (Adr)-induced podocyte apoptosis. However, the molecular mechanism remains unclear. Here we studied the role of mPGES-1/PGE2 cascade in activating Stat3 signaling and the contribution of Stat3 in PGE2- and Adr-induced podocyte apoptosis. In murine podocytes, PGE2 dose- and time-dependently increased the phosphorylation of Stat3 in line with the enhanced cell apoptosis and reduced podocyte protein podocin. In agreement with the increased Stat3 phosphorylation, Stat3-derived cytokines including IL-6, IL-17, MCP-1, and ICAM-1 were significantly upregulated following PGE2 treatment. By application of a specific Stat3 inhibitor S3I-201, PGE2-induced podocyte apoptosis was largely abolished in parallel with a blockade of podocin reduction. Next, we observed that Adr treatment also enhanced p-Stat3 and activated mPGES-1/PGE2 cascade. Blockade of Stat3 by S3I-201 significantly ameliorated Adr-induced cell apoptosis and podocin reduction. More interestingly, silencing mPGES-1 in podocytes by mPGES-1 siRNA blocked Adr-induced increments of Stat-3 phosphorylation, PGE2 production, and Stat3-derived inflammatory cytokines. Taken together, this study suggested that mPGES-1-derived PGE2 could activate Stat3 signaling to promote podocyte apoptosis. Targeting mPGES-1/PGE2/Stat3 signaling might be a potential strategy for the treatment of podocytopathy.

Photon Echoes in the 3P0 ← 3H4 Transition of Pr3+/LaF3

NARCIS (Netherlands)

Morsink, Jos B.W.; Wiersma, Douwe A.

1979-01-01

Photon-echo quantum beats observed in the two-pulse and three-pulse photon echo of the 3P0 ← 3H4 transition in Pr3+/LaF3 were used to determine the excited-state spin-hamiltonian. In addition we report on the anomalous stimulated photon echo observed in the same transition which in a magnetic field

Energy confinement in Ohmic H-mode in TUMAN-3M

International Nuclear Information System (INIS)

Andrejko, M.V.; Askinazi, L.G.; Golant, V.E.; Kornev, V.A.; Lebedev, S.V.; Levin, L.S.; Tukachinsky, A.S.

1997-01-01

The spontaneous transition from Ohmically heated limiter discharges into the regime with improved confinement termed as ''Ohmic H-mode'' has been investigated in ''TUMAN-3''. The typical signatures of H-mode in tokamaks with powerful auxiliary heating have been observed: sharp drop of D α radiation with simultaneous increase in the electron density and stored energy, suppression of the density fluctuations and establishing the steep gradient near the periphery. In 1994 new vacuum vessel had been installed in TUMAN-3 tokamak. The vessel has the same sizes as old one (R 0 =0.55 m, a 1 =0.24 m). New vessel was designed to reduce mechanical stresses in the walls during B T ramp phase of a shot. Therefore modified device - TUMAN-3M is able to produce higher B T and I p , up to 2 T and 0.2 MA respectively. During first experimental run device was operated in Ohmic Regime. In these experiments the possibility to achieve Ohmic H-mode was studied. The study of the parametric dependencies of the energy confinement time in both OH and Ohmic H-mode was performed. In Ohmic H-mode strong dependencies of τ E on plasma current and on input power and weak dependence on density were found. Energy confinement time in TUMAN-3/TUMAN-3M Ohmic H-mode has revealed good agreement with JET/DIII-D/ASDEX scaling for ELM-free H-mode, resulting in very long τ E at the high plasma current discharges. (author)

2D to 3D transition of polymeric carbon nitride nanosheets

Energy Technology Data Exchange (ETDEWEB)

Chamorro-Posada, Pedro [Dpto. de Teoría de la Señal y Comunicaciones e IT, Universidad de Valladolid, ETSI Telecomunicación, Paseo Belén 15, 47011 Valladolid (Spain); Vázquez-Cabo, José [Dpto. de Teoría de la Señal y Comunicaciones, Universidad de Vigo, ETSI Telecomunicación, Lagoas Marcosende s/n, Vigo (Spain); Sánchez-Arévalo, Francisco M. [Instituto de Investigaciones en Materiales (IIM), Universidad Nacional Autónoma de México, Apdo. Postal 70–360, Cd. Universitaria, México D.F. 04510 (Mexico); Martín-Ramos, Pablo [Dpto. de Teoría de la Señal y Comunicaciones e IT, Universidad de Valladolid, ETSI Telecomunicación, Paseo Belén 15, 47011 Valladolid (Spain); Laboratorio de Materiales Avanzados (Advanced Materials Laboratory) ETSIIAA, Universidad de Valladolid, Avenida de Madrid 44, 34004 Palencia (Spain); Martín-Gil, Jesús; Navas-Gracia, Luis M. [Laboratorio de Materiales Avanzados (Advanced Materials Laboratory) ETSIIAA, Universidad de Valladolid, Avenida de Madrid 44, 34004 Palencia (Spain); Dante, Roberto C., E-mail: rcdante@yahoo.com [Laboratorio de Materiales Avanzados (Advanced Materials Laboratory) ETSIIAA, Universidad de Valladolid, Avenida de Madrid 44, 34004 Palencia (Spain)

2014-11-15

The transition from a prevalent turbostratic arrangement with low planar interactions (2D) to an array of polymeric carbon nitride nanosheets with stronger interplanar interactions (3D), occurring for samples treated above 650 °C, was detected by terahertz-time domain spectroscopy (THz-TDS). The simulated 3D material made of stacks of shifted quasi planar sheets composed of zigzagged polymer ribbons, delivered a XRD simulated pattern in relatively good agreement with the experimental one. The 2D to 3D transition was also supported by the simulation of THz-TDS spectra obtained from quantum chemistry calculations, in which the same broad bands around 2 THz and 1.5 THz were found for 2D and 3D arrays, respectively. This transition was also in accordance with the tightening of the interplanar distance probably due to an interplanar π bond contribution, as evidenced also by a broad absorption around 2.6 eV in the UV–vis spectrum, which appeared in the sample treated at 650 °C, and increased in the sample treated at 700 °C. The band gap was calculated for 1D and 2D cases. The value of 3.374 eV for the 2D case is, within the model accuracy and precision, in a relative good agreement with the value of 3.055 eV obtained from the experimental results. - Graphical abstract: 2D lattice mode vibrations and structural changes correlated with the so called “2D to 3D transition”. - Highlights: • A 2D to 3D transition has been detected for polymeric carbon nitride. • THz-TDS allowed us to discover and detect the 2D to 3D transition of polymeric carbon nitride. • We propose a structure for polymeric carbon nitride confirming it with THz-TDS.

2D to 3D transition of polymeric carbon nitride nanosheets

International Nuclear Information System (INIS)

Chamorro-Posada, Pedro; Vázquez-Cabo, José; Sánchez-Arévalo, Francisco M.; Martín-Ramos, Pablo; Martín-Gil, Jesús; Navas-Gracia, Luis M.; Dante, Roberto C.

2014-01-01

The transition from a prevalent turbostratic arrangement with low planar interactions (2D) to an array of polymeric carbon nitride nanosheets with stronger interplanar interactions (3D), occurring for samples treated above 650 °C, was detected by terahertz-time domain spectroscopy (THz-TDS). The simulated 3D material made of stacks of shifted quasi planar sheets composed of zigzagged polymer ribbons, delivered a XRD simulated pattern in relatively good agreement with the experimental one. The 2D to 3D transition was also supported by the simulation of THz-TDS spectra obtained from quantum chemistry calculations, in which the same broad bands around 2 THz and 1.5 THz were found for 2D and 3D arrays, respectively. This transition was also in accordance with the tightening of the interplanar distance probably due to an interplanar π bond contribution, as evidenced also by a broad absorption around 2.6 eV in the UV–vis spectrum, which appeared in the sample treated at 650 °C, and increased in the sample treated at 700 °C. The band gap was calculated for 1D and 2D cases. The value of 3.374 eV for the 2D case is, within the model accuracy and precision, in a relative good agreement with the value of 3.055 eV obtained from the experimental results. - Graphical abstract: 2D lattice mode vibrations and structural changes correlated with the so called “2D to 3D transition”. - Highlights: • A 2D to 3D transition has been detected for polymeric carbon nitride. • THz-TDS allowed us to discover and detect the 2D to 3D transition of polymeric carbon nitride. • We propose a structure for polymeric carbon nitride confirming it with THz-TDS

Phase transformations, ionic conductivity and dipole ordering of NASICON-like double phosphates Na3M2(PO4)3 (M-Sc,Fe,Cr)

International Nuclear Information System (INIS)

Kalinin, V.B.

1990-01-01

Experimental data obtained using ceramic samples of Na 3 M 2 (PO 4 ) 3 and solid solutions on their basis have been analyzed and generalized. It is shown that isostoichiometry of Na 3 M 2 (PO 4 ) 3 compounds and different types of dipole ordering in their α-phases stimulate investigations of subsolidus regions in the systems Na 3 Sc 2 (PO 4 ) 3 -Na 3 Fe 2 (PO 4 ) 3 , Na 3 Sc 2 (PO 4 ) 3 -Na 3 Cr 2 (PO 4 ) 3 , Na 3 Fe 2 (PO 4 ) 3 -Na 3 Cr 2 (PO 4 ) 3 .It proved possible to detect changes of the properties in case of ferroelectric-antiferroelectric, antiferroelectric-antiferroelectric transitions

Theoretical descriptions of novel triplet germylenes M1-Ge-M2-M3 (M1 = H, Li, Na, K; M2 = Be, Mg, Ca; M3 = H, F, Cl, Br).

Science.gov (United States)

Kassaee, Mohamad Zaman; Ashenagar, Samaneh

2018-02-06

In a quest to identify new ground-state triplet germylenes, the stabilities (singlet-triplet energy differences, ΔE S-T ) of 96 singlet (s) and triplet (t) M 1 -Ge-M 2 -M 3 species were compared and contrasted at the B3LYP/6-311++G**, QCISD(T)/6-311++G**, and CCSD(T)/6-311++G** levels of theory (M 1  = H, Li, Na, K; M 2  = Be, Mg, Ca; M 3  = H, F, Cl, Br). Interestingly, F-substituent triplet germylenes (M 3  = F) appear to be more stable and linear than the corresponding Cl- or Br-substituent triplet germylenes (M 3  = Cl or Br). Triplets with M 1  = K (i.e., the K-Ge-M 2 -M 3 series) seem to be more stable than the corresponding triplets with M 1  = H, Li, or Na. This can be attributed to the higher electropositivity of potassium. Triplet species with M 3  = Cl behave similarly to those with M 3  = Br. Conversely, triplets with M 3  = H show similar stabilities and linearities to those with M 3  = F. Singlet species of formulae K-Ge-Ca-Cl and K-Ge-Ca-Br form unexpected cyclic structures. Finally, the triplet germylenes M 1 -Ge-M 2 -M 3 become more stable as the electropositivities of the α-substituents (M 1 and M 2 ) and the electronegativity of the β-substituent (M 3 ) increase.

Glycogen Synthase Kinase 3 (GSK-3) influences epithelial barrier function by regulating Occludin, Claudin-1 and E-cadherin expression

International Nuclear Information System (INIS)

Severson, Eric A.; Kwon, Mike; Hilgarth, Roland S.; Parkos, Charles A.; Nusrat, Asma

2010-01-01

The Apical Junctional Complex (AJC) encompassing the tight junction (TJ) and adherens junction (AJ) plays a pivotal role in regulating epithelial barrier function and epithelial cell proliferative processes through signaling events that remain poorly characterized. A potential regulator of AJC protein expression is Glycogen Synthase Kinase-3 (GSK-3). GSK-3 is a constitutively active kinase that is repressed during epithelial-mesenchymal transition (EMT). In the present study, we report that GSK-3 activity regulates the structure and function of the AJC in polarized model intestinal (SK-CO15) and kidney (Madin-Darby Canine Kidney (MDCK)) epithelial cells. Reduction of GSK-3 activity, either by small molecule inhibitors or siRNA targeting GSK-3 alpha and beta mRNA, resulted in increased permeability to both ions and bulk solutes. Immunofluorescence labeling and immunoblot analyses revealed that the barrier defects correlated with decreased protein expression of AJC transmembrane proteins Occludin, Claudin-1 and E-cadherin without influencing other TJ proteins, Zonula Occludens-1 (ZO-1) and Junctional Adhesion Molecule A (JAM-A). The decrease in Occludin and E-cadherin protein expression correlated with downregulation of the corresponding mRNA levels for these respective proteins following GSK-3 inhibition. These observations implicate an important role of GSK-3 in the regulation of the structure and function of the AJC that is mediated by differential modulation of mRNA transcription of key AJC proteins, Occludin, Claudin-1 and E-cadherin.

Glycogen Synthase Kinase 3 (GSK-3) influences epithelial barrier function by regulating Occludin, Claudin-1 and E-cadherin expression

Energy Technology Data Exchange (ETDEWEB)

Severson, Eric A.; Kwon, Mike; Hilgarth, Roland S.; Parkos, Charles A. [Epithelial Pathobiology Research Unit, Dept. of Pathology, Emory University, Atlanta, GA 30322 (United States); Nusrat, Asma, E-mail: anusrat@emory.edu [Epithelial Pathobiology Research Unit, Dept. of Pathology, Emory University, Atlanta, GA 30322 (United States)

2010-07-02

The Apical Junctional Complex (AJC) encompassing the tight junction (TJ) and adherens junction (AJ) plays a pivotal role in regulating epithelial barrier function and epithelial cell proliferative processes through signaling events that remain poorly characterized. A potential regulator of AJC protein expression is Glycogen Synthase Kinase-3 (GSK-3). GSK-3 is a constitutively active kinase that is repressed during epithelial-mesenchymal transition (EMT). In the present study, we report that GSK-3 activity regulates the structure and function of the AJC in polarized model intestinal (SK-CO15) and kidney (Madin-Darby Canine Kidney (MDCK)) epithelial cells. Reduction of GSK-3 activity, either by small molecule inhibitors or siRNA targeting GSK-3 alpha and beta mRNA, resulted in increased permeability to both ions and bulk solutes. Immunofluorescence labeling and immunoblot analyses revealed that the barrier defects correlated with decreased protein expression of AJC transmembrane proteins Occludin, Claudin-1 and E-cadherin without influencing other TJ proteins, Zonula Occludens-1 (ZO-1) and Junctional Adhesion Molecule A (JAM-A). The decrease in Occludin and E-cadherin protein expression correlated with downregulation of the corresponding mRNA levels for these respective proteins following GSK-3 inhibition. These observations implicate an important role of GSK-3 in the regulation of the structure and function of the AJC that is mediated by differential modulation of mRNA transcription of key AJC proteins, Occludin, Claudin-1 and E-cadherin.

M3 User's Manual. Version 3.0

International Nuclear Information System (INIS)

Laaksoharju, Marcus; Skaarman, Erik; Gomez, Javier B.

2009-11-01

bedrock minerals is not reached and where biological processes seem to play a central role in the groundwater altering process. The major purpose of standard groundwater chemical codes is to describe the measured groundwater composition in terms of reactions. The constituents that cannot be described by reactions are described by mixing using one or several conservative tracer. The M3 model uses an opposite approach compared to the standard methods. In M3 the mixing processes are evaluated and calculated first. This is possible due to the use of multivariate techniques to construct an ideal mixing model of a site. Many variables employed in multivariate analysis are needed to trace and describe the complex mixing processes taking place in the groundwater. The information is used to construct an ideal mixing model of a site. The complexity of the measured groundwater data determines the configuration of this ideal mixing model. The constituents that cannot be described by mixing are described by reactions. The M3 model consists of three steps; the first step is a standard Principal Component Analysis (PCA), followed by mixing and finally mass balance calculations. In order to take as many relevant elements as possible into consideration PCA is used to summarise and simplify the groundwater information. The M3 model compares the measured groundwater composition of each sample to known well-sampled waters named reference waters by using the results of the PCA. All the measured groundwater compositions at a site are compared to these reference waters. The mixing calculations (i.e. mixing portions as a percentage of a selected reference water) determine how much of the observed groundwater composition is due to mixing from the selected reference water. The mass balance calculations (reported in terms of sinks/sources of groundwater constituents in mg/l or moles) determine how much of the measured groundwater constituents is a result from water-rock interaction. Since the

Micro-Raman study of the microheterogeneity in the MA-MC phase transition in 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 single crystal

KAUST Repository

Yang, Y.; Zhang, L. Y.; Zhu, K.; Liu, Y. L.

2011-01-01

Polarized Raman spectroscopy has been employed to investigate the evolution of the microstructure of 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 (PMN-33%PT) single crystal in the temperature range from −195 to 300 °C. The M A-M C-cubic transition sequence

M1 and E2 transitions in the ground-state configuration of atomic ...

Indian Academy of Sciences (India)

have calculated the forbidden transition (M1 and E2) parameters such as transition energies, log- arithmic weighted ... Keywords. Forbidden transitions; transition energies; logarithmic weighted oscillator strengths; .... optimizing the energy function based on the non-relativistic Hamiltonian of an atom,. HNR = N. ∑ j=1. (12∇ ...

Electroweak phase transition in the economical 3-3-1 model

Energy Technology Data Exchange (ETDEWEB)

Phong, Vo Quoc; Van, Vo Thanh; Minh, Le Hoang [Ho Chi Minh City University of Science, Department of Theoretical Physics, Ho Chi Minh City (Viet Nam); Long, Hoang Ngoc [Vietnamese Academy of Science and Technology, Institute of Physics, Hanoi (Viet Nam)

2015-07-15

We consider the EWPT in the economical 3-3-1 (E331) model. Our analysis shows that the EWPT in the model is a sequence of two first-order phase transitions, SU(3) → SU(2) at the TeV scale and SU(2) → U(1) at the 100 GeV scale. The EWPT SU(3) → SU(2) is triggered by the new bosons and the exotic quarks; its strength is about 1-13 if the mass ranges of these new particles are 10{sup 2}-10{sup 3} GeV. The EWPT SU(2) → U(1) is strengthened by only the new bosons; its strength is about 1-1.15 if the mass parts of H{sub 1}{sup 0}, H{sub 2}{sup ±} and Y{sup ±} are in the ranges 10-10{sup 2} GeV. The contributions of H{sub 1}{sup 0} and H{sub 2}{sup ±} to the strengths of both EWPTs may make them sufficiently strong to provide large deviations from thermal equilibrium and B violation necessary for baryogenesis. (orig.)

Structural study on cubic-tetragonal transition of CH3NH3PbI3

International Nuclear Information System (INIS)

Kawamura, Yukihiko; Mashiyama, Hiroyuki; Hasebe, Katsuhiko

2002-01-01

The cubic-tetragonal phase transition of CH 3 NH 3 PbI 3 was investigated by single crystal X-ray diffractometry. The crystal structure was refined at five temperatures in the tetragonal phase. The PbI 6 octahedron rotates around the c-axis alternatively to construct the SrTiO 3 -type tetragonal structure. A methylammonium ion is partially ordered; 24 disordered states in the cubic phase are reduced to 8. With decreasing temperature, the rotation angle of the octahedron increases monotonically, which indicates it is an order parameter of the cubic-tetragonal transition. (author)

Hydrothermal syntheses, structural, Raman, and luminescence studies of Cm[M(CN)2]3.3H2O and Pr[M(CN)2]3.3H2O (M=Ag, Au)

International Nuclear Information System (INIS)

Assefa, Zerihun; Haire, Richard G.; Sykora, Richard E.

2008-01-01

We have prepared Cm[Au(CN) 2 ] 3 .3H 2 O and Cm[Ag(CN) 2 ] 3 .3H 2 O as a part of our continuing investigations into the chemistry of the 5f-elements' dicyanometallates. Single crystals of Cm[Au(CN) 2 ] 3 .3H 2 O were obtained from the reaction of CmCl 3 and KAu(CN) 2 under mild hydrothermal conditions. Due to similarities in size, the related praseodymium compounds were also synthesized and characterized for comparison with the actinide systems. The compounds crystallize in the hexagonal space group P6 3 /mcm, where the curium and the transition metals interconnect through cyanide bridging. Crystallographic data (Mo Kα, λ=0.71073 A): Cm[Au(CN) 2 ] 3 .3H 2 O (1), a=6.6614(5) A, c=18.3135(13) A, V=703.77(9), Z=2; Pr[Au(CN) 2 ] 3 .3H 2 O (3), a=6.6662(8) A, c=18.497(3) A, V=711.83(17), Z=2; Pr[Ag(CN) 2 ] 3 .3H 2 O (4), a=6.7186(8) A, c=18.678(2) A, V=730.18(14), Z=2. The Cm 3+ and/or Pr 3+ ions are coordinated to six N-bound CN - groups resulting in a trigonal prismatic arrangement. Three oxygen atoms of coordinated water molecules tricap the trigonal prismatic arrangement providing a coordination number of nine for the f-elements. The curium ions in both compounds exhibit a strong red emission corresponding to the 6 D 7/2 → 8 S 7/2 transition. This transition is observed at 16,780 cm -1 , with shoulders at 17,080 and 16,840 cm -1 for the Ag complex, while the emission is red shifted by ∼100 cm -1 in the corresponding gold complex. The Pr systems also provide well-resolved emissions upon f-f excitation. - Graphical abstract: Coordination polymeric compounds between a trans-plutonium element, curium and transition metal ions, gold(I) and silver(I), were prepared using the hydrothermal synthetic procedure. The curium ion and the transition metals are interconnected through cyanide bridging. The Cm ion has a tricapped trigonal prismatic coordination environment with coordination number of nine. Detail photoluminescence studies of the complexes are also reported

3s--3p, 3p--3d, and 3d--4f transitions of sodiumlike ions

International Nuclear Information System (INIS)

Reader, J.; Kaufman, V.; Sugar, J.; Olof Ekberg, J.; Feldman, U.; Brown, C.M.; Seely, J.F.; Rowan, W.L.

1987-01-01

New measurements have been made for wavelengths of the 3s--3p, 3p--3d, and 3d--4f transitions of the sodiumlike ions Cu/sup 18+/, Zn/sup 19+/, Ga/sup 20+/, Ge/sup 21+/, As/sup 22+/, Se/sup 23+/, Br/sup 24+/, Kr/sup 25+/, Y/sup 28+/, Zr/sup 29+/, Nb/sup 30+/, Mo/sup 31+/, Ru/sup 33+/, Rh/sup 34+/, Pd/sup 35+/, Ag/sup 36+/, and Sn/sup 39+/. The measurements were made by photographing laser-produced plasmas and tokamak plasmas with grazing-incidence spectrographs. The energies of the transitions were also calculated with Dirac--Fock computer codes. By fitting the differences between the observed and calculated wave numbers to simple formulas, least-squares-fitted wavelengths for all sodiumlike ions from Ar 7+ to Xe/sup 43+/ were determined. The estimated uncertainty of the fitted wavelengths is +- 0.007 A, which makes them useful as reference values. The wavelengths range from 9 to 713 A

Magnetic moments, E3 transitions and the structure of high spin core excited states in 211Rn

International Nuclear Information System (INIS)

Poletti, A.R.; Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.; Poletti, S.J.; Gerl, J.; Lewis, P.M.

1985-03-01

The results of g-factor measurements of high spin states in 211 Rn are: Esub(x)=8856+Δsup(') keV (Jsup(π)=63/2 - ), g=0.626(7); 6101+Δsup(') keV (49/2 + ), 0.766(8); 5247+Δsup(') keV (43/2 - ), 0.74(2); 3927+Δsup(') keV (35/2 + ), 1/017(12); 1578+Δsup(') keV (17/2 - ), 0.912(9). These results together with measured E3 transition strengths and shell model calculations are used to assign configurations to the core excited states in 211 Rn. Mixed configurations are required to explain the g-factors and enhanced E3 strengths simultaneously

Magnetic moments, E3 transitions and the structure of high-spin core excited states in 211Rn

International Nuclear Information System (INIS)

Poletti, A.R.; Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.; Poletti, S.J.; Gerl, J.; Lewis, P.M.

1985-01-01

The results of g-factor measurements of high-spin states in 211 Rn are: Esub(x)=8856+Δ' keV (Jsup(π)=63/2 - ), g=0.626(7); 6101+Δ' keV (49/2 + ), 0.766(8); 5347+Δ' keV (43/2 - ), 0.74(2); 3927+Δ keV (35/2 + ), 1.017(12); 1578+Δ keV (17/2 - ), 0.912(9). These results together with measured E3 transition strengths and shell model calculations are used to assign configurations to the core excited states in 211 Rn. Mixed configurations are required to explain the g-factors and enhanced E3 strengths simultaneously. (orig.)

Thermal properties and phase transition in the fluoride, (NH4)3SnF7

International Nuclear Information System (INIS)

Kartashev, A.V.; Gorev, M.V.; Bogdanov, E.V.; Flerov, I.N.; Laptash, N.M.

2016-01-01

Calorimetric, dilatometric and differential thermal analysis studies were performed on (NH 4 ) 3 SnF 7 for a wide range of temperatures and pressures. Large entropy (δS 0 =22 J/mol K) and elastic deformation (δ(ΔV/V) 0 =0.89%) jumps have proven that the Pa-3↔Pm-3m phase transition is a strong first order structural transformation. A total entropy change of ΔS 0 =32.5 J/mol K is characteristic for the order–disorder phase transition, and is equal to the sum of entropy changes in the related material, (NH 4 ) 3 TiF 7 , undergoing transformation between the two cubic phases through the intermediate phases. Hydrostatic pressure decreases the stability of the high temperature Pm-3m phase in (NH 4 ) 3 SnF 7 , contrary to (NH 4 ) 3 TiF 7 , characterised by a negative baric coefficient. The effect of experimental conditions on the chemical stability of (NH 4 ) 3 SnF 7 was observed. - Graphical abstract: Strong first order structural transformation Pa-3↔Pm-3m in (NH 4 ) 3 SnF 7 is associated with very large total entropy change of ΔS 0 =32.5 J/mol K characteristic for the ordering processes and equal to the sum of entropy changes in the related (NH 4 ) 3 TiF 7 undergoing transformation between the same two cubic phases through the intermediate phases. - Highlights: • (NH 4 ) 3 SnF 7 undergoes strong first order Pa-3↔Pm-3m phase transition. • Anomalous behaviour of ΔC p and ΔV/V exists far below phase transition temperature. • Structural distortions are accompanied by huge total entropy change ΔS≈Rln50. • High pressure strongly increases the stability of Pa-3 phase in (NH 4 ) 3 SnF 7 . • Entropy of the Pa-3↔Pm-3m phase transition does not depend on pressure.

Lanthanide Single-Molecule Magnets Framed by Alkali Metals & Magnetic and Spectroscopic Studies of 3d Transition Metal Complexes

DEFF Research Database (Denmark)

Konstantatos, Andreas

-molecule magnets (SMMs). Starting from the archetype SMM Mn12 we present the details of the mechanisms governing the relaxation of the magnetization of these systems. In Chapter 2 we present our work on the coordination chemistry of lanthanides with a new Schiff-base ligand, H3L [(E)-3-((2-hydroxyphenyl...... complexes of M3+ or M2+ metal ions (M: 3d transition metal) with the preference to either approximate octahedral or trigonal prismatic coordination geometry. A detailed magnetic characterization for most of the complexes is presented where a trinuclear Co2+ cluster stands out for its pronounced SMM...

Processes arising in the edge and diverted plasmas during ITB formation in the U-3M torsatron

Energy Technology Data Exchange (ETDEWEB)

Chechkin, V V [Institute of Plasma Physics, National Science Center ' Kharkov Institute of Physics and Technology' , Akademicheskaya st. 1, 61108 Kharkov (Ukraine); Grigor' eva, L I [Institute of Plasma Physics, National Science Center ' Kharkov Institute of Physics and Technology' , Akademicheskaya st. 1, 61108 Kharkov (Ukraine); Sorokovoy, E L [Institute of Plasma Physics, National Science Center ' Kharkov Institute of Physics and Technology' , Akademicheskaya st. 1, 61108 Kharkov (Ukraine); Sorokovoy, Ye L [Institute of Plasma Physics, National Science Center ' Kharkov Institute of Physics and Technology' , Akademicheskaya st. 1, 61108 Kharkov (Ukraine); Slavnyj, A S [Institute of Plasma Physics, National Science Center ' Kharkov Institute of Physics and Technology' , Akademicheskaya st. 1, 61108 Kharkov (Ukraine); Volkov, Ye D [Institute of Plasma Physics, National Science Center ' Kharkov Institute of Physics and Technology' , Akademicheskaya st. 1, 61108 Kharkov (Ukraine); Beletskij, A A [Institute of Plasma Physics, National Science Center ' Kharkov Institute of Physics and Technology' , Akademicheskaya st. 1, 61108 Kharkov (Ukraine); Burchenko, P Ya [Institute of Plasma Physics, National Science Center ' Kharkov Institute of Physics and Technology' , Akademicheskaya st. 1, 61108 Kharkov (Ukraine); Tsybenko, S A [Institute of Plasma Physics, National Science Center ' Kharkov Institute of Physics and Technology' , Akademicheskaya st. 1, 61108 Kharkov (Ukraine); Lozin, A V [Institute of Plasma Physics, National Science Center ' Kharkov Institute of Physics and Technology' , Akademicheskaya st. 1, 61108 Kharkov (Ukraine); Kulaga, A Ye; Letvinov, A P [Institute of Plasma Physics, National Science Center ' Kharkov Institute of Physics and Technology' , Akademicheskaya st. 1, 61108 Kharkov (Ukraine); Masuzaki, S; Yamazaki, K [National Institute for Fusion Science, Oroshi-cho 322-6, Toki-shi 509-5292 (Japan)

2006-05-15

Spontaneous changes in confined plasma parameters have been observed recently in the l = 3/m = 9 Uragan-3M torsatron with an RF produced and heated plasma, these being interpreted as transition to an improved confinement mode due to ITB formation near the {iota} = 1/4 rational magnetic surface. In the work presented joint studies are carried out of changes in some edge and diverted plasma characteristics that accompany ITB formation. It is shown that ITB formation induces a hard E{sub r} bifurcation at the boundary presumably driven by the ion orbit loss. As a result, E{sub r} becomes more negative, and an E{sub r} shear layer occurs, where the low-frequency microturbulence and the turbulence-induced anomalous transport are suppressed, i.e. an ETB is formed. At the pre-bifurcation phase of transition a reduction of fast ion loss takes place. The bifurcation results in an improvement of electron confinement, while the ion loss increases.

M3 version 3.0: Verification and validation

International Nuclear Information System (INIS)

Gomez, Javier B.; Laaksoharju, Marcus; Skaarman, Erik; Gurban, Ioana

2009-01-01

when using M3 outside its realm of applicability. The verification exercises are designed to test the correct functioning of each part of the M3 code (Principal Components Analysis, mixing routines, mass balance routines, End-member Selection Module, and End-member Variability Module). Each test focuses on a particular algorithm or module. Synthetic datasets have been used in many tests as this is the best way to verify the results when dealing with mixing proportions and mass balance calculations. All the verification tests have been passed by M3, except the one dealing with the two-principal component mixing routine. This way of computing mixing proportions only gives consistent results with three end-members, and should not be used for cases with four or more end-members. The validation exercises go one step forward and test the ability of M3 methodology to solve mixing and reaction problems. Some tests focus on the uncertainties in the mixing proportions and others on the uncertainties in the calculated mass balances. Many validation exercises use a number of synthetic water samples inserted in a real groundwater dataset from the Laxemar- Simpevarp area in Sweden in order to assess the accuracy of the computed mixing proportions and deviations, to determine the limits of M3 applicability. In this respect, several validation exercises give clear indications that an incorrect use of M3 (i.e. for systems in which mixing is not the dominant process controlling the chemistry of the waters) can give rise to erroneous results. Most tests insist on the need for an independent assessment of the validity of the results given by M3 using, for example, expert judgment, other geochemical codes, or several lines of reasoning. In general, M3 deals successfully with most validation tests, although several clearly indicate where the limits of applicability are. This is particularly evident when chemical reactions significantly change the composition of the resulting mixed water

Effects of irradiation on TGF-β1 mRNA expression and calcific nodule formation in MC3T3-E1 osteoblastic cell line

International Nuclear Information System (INIS)

Song, Ju Seop; Kim, Kyoung A; Koh, Kwang Joon

2008-01-01

To investigate the effects of irradiation on transforming growth factor β1 (TGF-β 1 ) mRNA expression and calcific nodule formation in MC3T3-E1 osteoblastic cell line. Cells were cultured in alpha-minimum essential medium (α-MEM) supplemented with 10% fetal bovine serum and antibiotics. When the cells reached the level of 70-80% confluence, culture media were changed with α-MEM supplemented with 10% FBS, 5 mM β-glycerol phosphate, and 50 μg/mL ascorbic acid. Thereafter the cells were irradiated with a single dose of 2, 4, 6, 8 Gy at a dose rate of 1.5 Gy/min. The expression pattern of TGF-β 1 mRNA, calcium content and calcific nodule formation were examined on day 3, 7, 14, 21, 28, respectively, after the irradiation. The amount of TGF-β 1 mRNA expression decreased significantly on day 7 after irradiation of 4, 6, 8 Gy. It also decreased on day 14 after irradiation of 6, 8 Gy, and decreased on day 21 after irradiation of 8 Gy. The amount of calcium deposition decreased significantly on day 7 after irradiation of 4, 8 Gy (P 1 mRNA expression that was associated with proliferation and the production of extracellular matrix in MC3T3-E1 osteoblastic cell line

Structural phase transitions in CsPbCl/sub 3/ and RbCdCl/sub 3/

Energy Technology Data Exchange (ETDEWEB)

Plesko, S; Kind, R; Roos, J [Swiss Federal Inst. of Technology, Zuerich. Lab. of Solid State Physics

1978-08-01

Structural phase transitions in CsPbCl/sub 3/ have been investigated by /sup 133/Cs and /sup 87/Rb nuclear magnetic resonance. The space groups of the room temperature phase in CsPbCl/sub 3/ and of two unknown phases in RbCdCl/sub 3/ could be clarified. Thus both perovskites show the same phase sequence from cubic Pm3m-O sub(h)sup(1) to tetragonal P4/mbm-D sub(4h)sup(5), orthorhombic Cmcm-D sub(2h)sup(17) and further orthorhombic Pnma-D sub(2h)sup(16).

Rapid Communication: v= 2 seniority changing transitions in yrast 3 ...

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 89; Issue 5. Rapid Communication: Δ υ = 2 seniority changing transitions in yrast 3 − states and B ( E 3 ) systematics of Sn isotopes. BHOOMIKA MAHESHWARI SWATI GARG ASHOK KUMAR JAIN. Research Article Volume 89 Issue 5 November 2017 Article ID 75 ...

On the Properties of the s{sub 1/2} -> d{sub 3/2} Transition in {sup 199}Au

Energy Technology Data Exchange (ETDEWEB)

Baecklin, A [Swedish Research Councils' Laboratory, Studsvik, Nykoeping (Sweden); Malmskog, S G [AB Atomenergi, Nykoeping (Sweden)

1967-02-15

The half-life of the first excited level in Au has been measured by the delayed coincidence technique to be 1.1 {+-} 0.1 nsec. From a measurement of the intensity ratios of the L sub shell conversion lines the E2/M1 ratio of the deexciting transition has been found to be (4.9 {sup +1.4}{sub -0.8})10{sup -2} The energy of the transition was measured to 77.21 {+-} 0.03 keV. The absolute values of the reduced M1 and E2 transition probabilities have been calculated and included in a systematic survey of s{sub 1/2} <-> d{sub 3/2} transitions in odd Z isotopes in the Au region. This result has been compared with the predictions of the nuclear models of Sorensen and de Shalit.

Schmidt Reaction of E-3-Benzylidenechromanones and E-3-Benzylidenethiochromanones

Directory of Open Access Journals (Sweden)

Tapas K. Mandal

2013-01-01

Full Text Available On treatment with NaN3/c. H2SO4-HOAc or NaN3/TFA, E-3-benzylidenechromanones are mostly converted to E-β-aminobenzylidenechromanones while E-3-benzylidenethiochromanones are converted to 3-benzoylthiochromones. A structurally new type of product has been isolated for the reaction of E-3-benzylidene-4′-methoxychromanone with NaN3/TFA. Mechanistic paths have been suggested for formation of the products.

Theoretical Characteristics of Metalloporphyrins (OEP) M (CH 3 ) (M=Al, Ga, In and Tl)

OpenAIRE

Lepetit , M.B.; Kabbaj , O.K.; Zrineh , A.

2017-01-01

International audience; A theoretical study of metalloporphyrins molecules (OEP) M (CH 3) (M=Al, Ga, In and Tl) are brought to a few experimental data and to give background for future development of these complexes. The Quantum Chemistry Program (ORCA) program package based on Density Functional Theory (DFT) and Time-dependent Density Functional Theory (TDDFT) for transitions at the B3LYP level with ANO 2ζ+P base was used for calculations and determination of structural properties, electroni...

Role of radial electric field in LH transition triggered by counter-NBI at low plasma density in the TUMAN-3M tokamak

International Nuclear Information System (INIS)

Tukachinsky, A.S.; Askinazi, L.G.; Chernyshev, F.V. and others; Krupnik, L.I.; Rushkevich, A.A.

2008-01-01

Threshold power needed to attain H-mode in a tokamak is a critical parameter for designing of future devices and in particular fusion reactor ITER [1]. According to commonly accepted scaling [2] the threshold power P t hr increases with average density n e when the density exceeds some n em in at which P t hr is minimal. An increase in the P t hr towards low density was observed in many experiments [3-6], prevents the transition at lower n e as well. Physics of the threshold power increase at low ne is not well understood. Since the radial electric field E r and E r xB sheared flow play important roles in the LH transition one could expect these quantities effect the low n-bar e transitions. Toroidal rotation and radial electric field generation during counter-NBI have been studied in [7] and recently reconsidered theoretically in [8]. Thus, motivation for the presented study is to analyze effect of counter-NBI on the LH transition at low density

Molecular mechanisms of 3,3′4,4′,5-pentachlorobiphenyl-induced epithelial-mesenchymal transition in human hepatocellular carcinoma cells

International Nuclear Information System (INIS)

Song, Li; Guo, Linlin; Li, Zhuoyu

2017-01-01

Polychlorinated biphenyls (PCBs) are classic persistent organic pollutants (POPs). Many studies have found a positive association between the progression of hepatocellular carcinoma (HCC) and PCBs exposure. However, the influence of PCBs on epithelial-mesenchymal transition (EMT) of HCC remains to be unclear. In this study, we explored the effect of PCB126 on EMT in HCC cells and its underlying mechanisms. The data showed that PCB126, exposing both Bel-7402 and SMMC-7721 cells for 48 h, promoted EMT that was demonstrated by E-cadherin repression, up-regulation of N-cadherin and vimentin, and morphological alteration. We found that signal transducer and activator of transcription 3 (STAT3)/Snail1 signaling was activated after PCB126 exposure, and the addition of STAT3 inhibitor WP1066 blocked PCB126-induced down-regulation of E-cadherin as well as up-regulation of N-cadherin and vimentin. Moreover, PCB126 exposure increased pyruvate kinase M2 (PKM2) expression and its nuclear translocation, whereas treatment with PKM2 shRNA suppressed the activation of STAT3/Snail1 signaling and the alternation of EMT-related molecules (E-cadherin, N-cadherin and vimentin). Furthermore, this study indicated estrogen receptor (ER) and aryl hydrocarbon receptor (AhR) were involved in PCB126-induced effects on PKM2, STAT3/Snail1 signaling and EMT by according treatment using ER inhibitor ICI and AhR shRNA. Notably, PCB126-increased reactive oxygen species (ROS) production via AhR is associated with activation of PKM2/STAT3/Snail1 cascades and contributes to EMT. Taken together, these results indicated that PCB126 promotes EMT process of HCC cells via PKM2/STAT3/Snail1 signaling which is mediated by ER and AhR. - Highlights: • PCB126 promotes epithelial-mesenchymal transition of HCC cells. • PCB126 regulates EMT through the activation of STAT3/Snail1 signaling. • PKM2 is responsible for PCB126-induced activation of STAT3/Snail1 signaling. • AhR-induced ROS generation regulates

Molecular mechanisms of 3,3′4,4′,5-pentachlorobiphenyl-induced epithelial-mesenchymal transition in human hepatocellular carcinoma cells

Energy Technology Data Exchange (ETDEWEB)

Song, Li; Guo, Linlin [Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan 030006 (China); Li, Zhuoyu, E-mail: lzy@sxu.edu.cn [Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan 030006 (China); College of Life Science, Zhejiang Chinese Medical University, Hangzhou 310053 (China)

2017-05-01

Polychlorinated biphenyls (PCBs) are classic persistent organic pollutants (POPs). Many studies have found a positive association between the progression of hepatocellular carcinoma (HCC) and PCBs exposure. However, the influence of PCBs on epithelial-mesenchymal transition (EMT) of HCC remains to be unclear. In this study, we explored the effect of PCB126 on EMT in HCC cells and its underlying mechanisms. The data showed that PCB126, exposing both Bel-7402 and SMMC-7721 cells for 48 h, promoted EMT that was demonstrated by E-cadherin repression, up-regulation of N-cadherin and vimentin, and morphological alteration. We found that signal transducer and activator of transcription 3 (STAT3)/Snail1 signaling was activated after PCB126 exposure, and the addition of STAT3 inhibitor WP1066 blocked PCB126-induced down-regulation of E-cadherin as well as up-regulation of N-cadherin and vimentin. Moreover, PCB126 exposure increased pyruvate kinase M2 (PKM2) expression and its nuclear translocation, whereas treatment with PKM2 shRNA suppressed the activation of STAT3/Snail1 signaling and the alternation of EMT-related molecules (E-cadherin, N-cadherin and vimentin). Furthermore, this study indicated estrogen receptor (ER) and aryl hydrocarbon receptor (AhR) were involved in PCB126-induced effects on PKM2, STAT3/Snail1 signaling and EMT by according treatment using ER inhibitor ICI and AhR shRNA. Notably, PCB126-increased reactive oxygen species (ROS) production via AhR is associated with activation of PKM2/STAT3/Snail1 cascades and contributes to EMT. Taken together, these results indicated that PCB126 promotes EMT process of HCC cells via PKM2/STAT3/Snail1 signaling which is mediated by ER and AhR. - Highlights: • PCB126 promotes epithelial-mesenchymal transition of HCC cells. • PCB126 regulates EMT through the activation of STAT3/Snail1 signaling. • PKM2 is responsible for PCB126-induced activation of STAT3/Snail1 signaling. • AhR-induced ROS generation regulates

3.3 CM JVLA OBSERVATIONS OF TRANSITIONAL DISKS: SEARCHING FOR CENTIMETER PEBBLES

International Nuclear Information System (INIS)

Zapata, Luis A.; Rodríguez, Luis F.; Palau, Aina

2017-01-01

We present sensitive (rms-noises ∼4–25 μ Jy) and high angular resolution (∼1″–2″) 8.9 GHz (3.3 cm) Karl G. Jansky Very Large Array radio continuum observations of 10 presumed transitional disks associated with young low-mass stars. We report the detection of radio continuum emission in 5 out of the 10 objects (RXJ1615, UX Tau A, LkCa15, RXJ1633, and SR 24s). In the case of LkCa15, the centimeter emission is extended, and has a similar morphology to that of the transitional disk observed at millimeter wavelengths with an inner depression. For these five detections, we construct the spectral energy distributions from the centimeter to submillimeter wavelengths, and find that they can be well fitted with a single (RXJ1633 and UX Tau A) or a two-component power law (LkCa15, RXJ1615, and SR 24s). For the cases where a single power law fits the data well, the centimeter emission is likely produced by optically thin dust with large grains (i.e., centimeter-size pebbles) present in the transitional disks. For the cases where a double power law fits the data, the centimeter emission might be produced by the combination of photoevaporation and a free–free jet. We conclude that RXJ1633 and UX Tau A are excellent examples of transitional disks where the structure of the emission from centimeter/millimeter pebbles can be studied. In the other cases, some other physical emitting mechanisms are also important in the centimeter regime.

3.3 CM JVLA OBSERVATIONS OF TRANSITIONAL DISKS: SEARCHING FOR CENTIMETER PEBBLES

Energy Technology Data Exchange (ETDEWEB)

Zapata, Luis A.; Rodríguez, Luis F.; Palau, Aina, E-mail: lzapata@crya.unam.mx [Instituto de Radioastronomía y Astrofísica, UNAM, Apdo. Postal 3-72 (Xangari), 58089 Morelia, Michoacán, México (Mexico)

2017-01-10

We present sensitive (rms-noises ∼4–25 μ Jy) and high angular resolution (∼1″–2″) 8.9 GHz (3.3 cm) Karl G. Jansky Very Large Array radio continuum observations of 10 presumed transitional disks associated with young low-mass stars. We report the detection of radio continuum emission in 5 out of the 10 objects (RXJ1615, UX Tau A, LkCa15, RXJ1633, and SR 24s). In the case of LkCa15, the centimeter emission is extended, and has a similar morphology to that of the transitional disk observed at millimeter wavelengths with an inner depression. For these five detections, we construct the spectral energy distributions from the centimeter to submillimeter wavelengths, and find that they can be well fitted with a single (RXJ1633 and UX Tau A) or a two-component power law (LkCa15, RXJ1615, and SR 24s). For the cases where a single power law fits the data well, the centimeter emission is likely produced by optically thin dust with large grains (i.e., centimeter-size pebbles) present in the transitional disks. For the cases where a double power law fits the data, the centimeter emission might be produced by the combination of photoevaporation and a free–free jet. We conclude that RXJ1633 and UX Tau A are excellent examples of transitional disks where the structure of the emission from centimeter/millimeter pebbles can be studied. In the other cases, some other physical emitting mechanisms are also important in the centimeter regime.

Anti-M(3) muscarinic cholinergic autoantibodies from patients with primary Sjögren's syndrome trigger production of matrix metalloproteinase-3 (MMP-3) and prostaglandin E(2) (PGE(2)) from the submandibular glands.

Science.gov (United States)

Reina, Silvia; Sterin-Borda, Leonor; Passafaro, Daniela; Borda, Enri

2011-05-01

We demonstrated that serum immunoglobulin G (IgG) from patients with primary Sjögren's syndrome (pSS), interacting with the second extracellular loop of human glandular M(3) muscarinic acetylcholine receptors (M(3) mAChR), trigger the production of matrix metalloproteinase-3 (MMP-3) and prostaglandin E(2) (PGE(2)). Enzyme-linked immunosorbent assays (ELISAs) were performed in the presence of M(3) mAChR synthetic peptide as antigen to detect in serum the autoantibodies. Further, MMP-3 and PGE(2) production were determined in the presence of anti-M(3) mAChR autoantibodies. An association was observed between serum and anti-M(3) mAChR autoantibodies and serum levels of MMP-3 and PGE(2) in pSS patients. Thus, we established that serum anti-M(3) mAChR autoantibodies, MMP-3 and PGE(2) may be considered to be early markers of pSS associated with inflammation. Affinity-purified anti-M(3) mAChR peptide IgG from pSS patients, whilst stimulating salivary-gland M(3) mAChR, causes an increase in the level of MMP-3 and PGE(2) as a result of the activation of phospholipase A(2) (PLA(2)) and cyclooxygenase-2 (COX-2) (but not COX-1). These results provide a novel insight into the role that cholinoceptor antibodies play in the development of glandular inflammation. This is the first report showing that an antibody interacting with glandular mAChR can induce the production of pro-inflammatory mediators (MMP-3/PGE(2)). Copyright © 2010 Elsevier Ltd. All rights reserved.

Wavelengths of the 3p-3d transitions of the Co- and Fe-like ions: The effects of electron correlation

International Nuclear Information System (INIS)

Chen, Mau Hsiung.

1987-01-01

The experimental observations of the 3p 6 3d 9 2 D - 3p 5 3d 10 2 p transitions of the Co-like ions and 3p 6 3d 8 3 F 4 - 3p 5 3d 9 3 F 3 of the Fe-like ions have recently been extended to highly charged ions of heavy elements up to uranium (Z = 92). A comparison between the observed energies and calculated values from the Dirac-Fock model indicated persistent discrepancies of 3 to 4 eV for all ions. Systematic multiconfiguration Dirac-Fock calculations for these transitions have been carried out with emphases on the effects of electron correlation. The previously found discrepancies theory and experiment have mostly removed after the inclusion of the electron-electron correlation effects in the theoretical calculations. 13 refs

Phase transition in SO(3) gauge theory

International Nuclear Information System (INIS)

Datta, Saumen; Gavai, Rajiv V.

1998-01-01

The phase transition in SO(3) lattice gauge theory is investigated by Monte Carlo techniques with a view (i) to understand the relationship between the bulk transition and the deconfinement transition, and (ii) to resolve the current ambiguity about the nature of the high temperature phase. By introduction of a magnetic field, it was shown that the +ve and -ve values of a > correspond to the same phase. Studies on different sized lattices lead to the conclusion that in SO(3), there is only one transition, which is deconfining in nature. (author)

M3 User's Manual. Version 3.0

Energy Technology Data Exchange (ETDEWEB)

Laaksoharju, Marcus (Geopoint AB, Sollentuna (Sweden)); Skaarman, Erik (Abscondo Utveckling, Bromma (Sweden)); Gomez, Javier B. (Univ. of Zaragoza (Spain). Geochemical modelling Group); Gurban, Ioana (3D Terra (Canada))

2006-07-15

of the bedrock minerals is not reached and where biological processes seem to play a central role in the groundwater altering process. The major purpose of standard groundwater chemical codes is to describe the measured groundwater composition in terms of reactions. The constituents that cannot be described by reactions are described by mixing using one or several conservative tracer. The M3 model uses an opposite approach compared to the standard methods. In M3 the mixing processes are evaluated and calculated first. This is possible due to the use of multivariate techniques to construct an ideal mixing model of a site. Many variables employed in multivariate analysis are needed to trace and describe the complex mixing processes taking place in the groundwater. The information is used to construct an ideal mixing model of a site. The complexity of the measured groundwater data determines the configuration of this ideal mixing model. The constituents that cannot be described by mixing are described by reactions. The M3 model consists of three steps; the first step is a standard Principal Component Analysis (PCA), followed by mixing and finally mass balance calculations. In order to take as many relevant elements as possible into consideration PCA is used to summarise and simplify the groundwater information. The M3 model compares the measured groundwater composition of each sample to known well-sampled waters named reference waters by using the results of the PCA. All the measured groundwater compositions at a site are compared to these reference waters. The mixing calculations (i.e. mixing portions as a percentage of a selected reference water) determine how much of the observed groundwater composition is due to mixing from the selected reference water. The mass balance calculations (reported in terms of sinks/sources of groundwater constituents in mg/l or moles) determine how much of the measured groundwater constituents is a result from water-rock interaction

Absolute M1 and E2 Transition Probabilities in 233U

International Nuclear Information System (INIS)

Malmskog, S.G.; Hoejeberg, M.

1967-08-01

Using the delayed coincidence technique, the following half lives have been determined for different excited states in 233 U: T 1/2 (311.9 keV level) = (1.20 ± 0.15) x 10 -10 sec, T 1/2 (340.5 keV level) = (5.2 ± 1.0) x 10 -11 sec, T 1/2 (398.6 keV level) = (5.5 ± 2.0) x 10 -11 sec and T 1/2 (415.8 keV level) -11 sec. From these half life determinations, together with earlier known electron intensities and conversion coefficients, 22 reduced B(Ml) and B(E2) transition probabilities (including 9 limits) have been deduced. The rotational transitions give information on the parameters δ and (g K - g R ) . The experimental M1 and E2 transition rates between members of different bands have been analysed in terms of the predictions of the Nilsson model, taking also pairing correlations and Coriolis coupling effects into account

ULE design considerations for a 3m class light weighted mirror blank for E-ELT M5

Science.gov (United States)

Fox, Andrew; Hobbs, Tom; Edwards, Mary; Arnold, Matthew; Sawyer, Kent

2016-07-01

It is expected that the next generation of large ground based astronomical telescopes will need large fast-steering/tip-tilt mirrors made of ultra-lightweight construction. These fast-steering mirrors are used to continuously correct for atmospheric disturbances and telescope vibrations. An example of this is the European Extremely Large Telescope (E-ELT) M5 lightweight mirror, which is part of the Tip-Tilt/Field-Stabilization Unit. The baseline design for the E-ELT M5 mirror, as presented in the E-ELT Construction Proposal, is a closed-back ULE mirror with a lightweight core using square core cells. Corning Incorporated (Corning) has a long history of manufacturing lightweight mirror blanks using ULE in a closed-back construction, going back to the 1960's, and includes the Hubble Space Telescope primary mirror, Subaru Telescope secondary and tertiary mirrors, the Magellan I and II tertiary mirrors, and Kepler Space Telescope primary mirror, among many others. A parametric study of 1-meter class lightweight mirror designs showed that Corning's capability to seal a continuous back sheet to a light-weighted core structure provides superior mirror rigidity, in a near-zero thermal expansion material, relative to other existing technologies in this design space. Corning has investigated the parametric performance of several design characteristics for a 3-meter class lightweight mirror blank for the E-ELT M5. Finite Element Analysis was performed on several design scenarios to obtain weight, areal density, and first Eigen frequency. This paper presents an overview of Corning ULE and lightweight mirror manufacturing capabilities, the parametric performance of design characteristics for 1-meter class and 3-meter class lightweight mirrors, as well as the manufacturing advantages and disadvantages of those characteristics.

Progress in Spectroscopy of the 1S–3S Transition in Hydrogen

International Nuclear Information System (INIS)

Galtier, Sandrine; Fleurbaey, Hélène; Thomas, Simon; Julien, Lucile; Biraben, François; Nez, François

2015-01-01

We report the latest advances in the Doppler-free spectroscopy of the 1S–3S transition in hydrogen. A new continuous ultra-violet source has been developed and delivers a power level of 15 mW. With this setup, the statistical uncertainty on the 1S–3S transition frequency measurement is 2.2 kHz. Combined with the 1S–2S frequency, absolute accuracy at that level would significantly enlighten the proton radius puzzle

Thermochemistry of 1,1,3,3-tetramethylguanidine and 1,1,3,3-tetramethylguanidinium nitrate

International Nuclear Information System (INIS)

Vitorino, Joana; Agapito, Filipe; Piedade, M. Fátima M.; Bernardes, Carlos E.S.; Diogo, Hermínio P.; Leal, João P.

2014-01-01

Graphical abstract: - Highlights: • The enthalpy of formation of 1,1,3,3-tetramethylguanidinium nitrate was determined by combustion calorimetry. • The cohesive energy of liquid 1,1,3,3-tetramethylguanidinium nitrate was evaluated. • The crystal structure of 1,1,3,3-tetramethylguanidinium nitrate was determined by single crystal X-ray diffraction. • Δ f H m o (l/g) of 1,1,3,3-tetramethylguanidine (tmg) were obtained by solution and Calvet calorimetry. • Δ f H m o (g) calculated by the W1-F12 procedure was in excellent agreement with the corresponding experimental value. - Abstract: Considerable efforts have recently been made to investigate how the structure of protic ionic liquids determines some of their most important properties for technological applications (e.g. low vapour pressure, conductivity). In contrast, the assessment of cohesive energies (which are also linked to those properties) based on thermodynamic results is still practically unexplored. This problem is addressed here for 1,1,3,3-tetramethylguanidinium nitrate, [Htmg][NO 3 ], through a combination of experimental and computational chemistry results at the reference temperature of 298.15 K. The standard molar enthalpies of formation, Δ f H m o ([Htmg][NO 3 ],cr)=-(311.8±2.3)kJ·mol -1 , and fusion, Δ fus H m o ([Htmg][NO 3 ])=16.2±3.8kJ·mol -1 , of solid 1,1,3,3-tetramethylguanidinium nitrate (form I polymorph) were obtained by combustion and differential scanning calorimetry, respectively. From these results Δ f H m o ([Htmg][NO 3 ],l)=-(295.6±4.4)kJ·mol -1 could be derived. Also determined were the standard molar enthalpies of formation, Δ f H m o (tmg, l)=7.7±2.8kJ·mol -1 , and vaporisation, Δ vap H m o (tmg,l)=50.0±1.2kJ·mol -1 , of 1,1,3,3-tetramethylguanidine, by reaction solution and Calvet-drop microcalorimetry, respectively, leading to Δ f H m o (tmg,g)=57.7±3.0kJ·mol -1 . This result is in excellent agreement with Δ f H m o (tmg,g)=58.4±4.0kJ·mol -1

Higher Order Lagrange Finite Elements In M3D

International Nuclear Information System (INIS)

Chen, J.; Strauss, H.R.; Jardin, S.C.; Park, W.; Sugiyama, L.E.; Fu, G.; Breslau, J.

2004-01-01

The M3D code has been using linear finite elements to represent multilevel MHD on 2-D poloidal planes. Triangular higher order elements, up to third order, are constructed here in order to provide M3D the capability to solve highly anisotropic transport problems. It is found that higher order elements are essential to resolve the thin transition layer characteristic of the anisotropic transport equation, particularly when the strong anisotropic direction is not aligned with one of the Cartesian coordinates. The transition layer is measured by the profile width, which is zero for infinite anisotropy. It is shown that only higher order schemes have the ability to make this layer converge towards zero when the anisotropy gets stronger and stronger. Two cases are considered. One has the strong transport direction partially aligned with one of the element edges, the other doesn't have any alignment. Both cases have the strong transport direction misaligned with the grid line by some angles

Light refraction in PbMgsub(1/3)Nbsub(2/3)Osub(3) ferroelectric with a diffuse phase transition

International Nuclear Information System (INIS)

Korshunov, O.Yu.; Markovin, P.A.; Pisarev, R.V.

1983-01-01

In PbMgsub(1/2)Nbsub(2/3)Osub(3) ferroelectric with a diffuse phase transition refractive indeX variations with temperature are studied for two wavelengths of 0.63 and 0.44 μm in the 140-600 K temperature range, and refractive index dispersion is measured at room temperature. A broad smooth peak of rate of light refraction temperation changes in the 300-310 K range that coincides with the previously observed by other authors on the temperatUre dependence of microwave dielectric permittivity. A refractive properties anomaly is also observed at 156 K that is related with another phase transition at this temperature. Mechanisms of refractive index thermal variations are analyzed and a ferroelectric contribution into light refraction that equals approximately 4x10 -2 at 140 K is found. The contribution remains up to 600 K due to polarization fluctuations. It is shown that within the frames of dispersion theory the effect of ferroelectric ordering on light refraction can be explained by changes of both frequency and effective oscillator force

Study of 3-jet events in e/sup +/e/sup -/ annihilation into hadrons at 34. 6 c. m. energy

Energy Technology Data Exchange (ETDEWEB)

Althoff, M; Braunschweig, W; Kirschfink, F J; Martyn, H U; Rosskamp, R; Schmitz, D; Siebke, H; Wallraff, W; Eisenmann, J; Fischer, H M

1985-10-01

Three-jet events produced by e/sup +/e/sup -/ annihilation into hadrons at 34.6 GeV c.m. energy were studied by comparing them with 2nd order QCD and two different models of fragmentation. The distribution of low energy particles in the 3-jet plane is found to be better described by the LUND color string model than by the independent jet model. The opposite is true for more energetic particles flowing between the 3 jets. The average transverse momenta in jets can be described with values of sigmasub(q) between 350 and 500 MeV/c for the gluon jet.

Morphological Analysis of CDC2 and Glycogen Synthase Kinase 3β Phosphorylation as Markers of G2 → M Transition in Glioma

Directory of Open Access Journals (Sweden)

José Javier Otero

2011-01-01

Full Text Available G2 → M transition is a strategic target for glioma chemotherapy. Key players in G2 → M transition include CDC2 and glycogen synthase kinase 3β (GSK3β, which are highly regulated by posttranslational phosphorylation. This report is a morphological analysis of CDC2 and GSK3β phosphorylation using immunohistochemistry in gliomas with different biological properties. GBM showed a 2.8-fold and 5.6-fold increase in number of cells positive for pThr161CDC2 and a 4.2- and 6.9-fold increase in number of cells positive for pTyr15CDC2 relative to oligodendroglioma and ependymoma, respectively. Elevated labeling for inhibited phospho-CDC2 (pTyr15CDC correlates with elevated levels of phosphorylated glycogen synthase kinase 3β (GSK3β. 71% of the GBM cases showed intermediate to high intensity staining for pSer9SGK3β 53% of oligodendroglioma, and 73% of ependymoma showed low intensity staining. CDC2 gene amplification correlates with increased survival in glioblastoma multiforme (GBM and astrocytoma WHO grades II-III, but not in oligodendroglioma WHO grades II-III.

Confinement bifurcation by current density profile perturbation in TUMAN-3M tokamak

International Nuclear Information System (INIS)

Lebedev, S.V.; Andreiko, M.V.; Askinazi, L.G.

2001-01-01

In the recent experiments performed on TUMAN-3M the possibility to switch on/off the H-mode by current density profile perturbations has been shown. The j(r) perturbations were created by fast Current Ramp Up/Down or by Magnetic Compression produced by a fast increase of the toroidal magnetic field. It was found that the Current Ramp Up (CRU) and Magnetic Compression (MC) are useful means for H-mode triggering. The Current Ramp Down (CRD) triggers H-L transition. The difference in the j(r) behavior in these experiments suggests the peripheral current density may not be the critical parameter controlling L-H and H-L transitions. Confinement bifurcation in the above experiments could be explained by the unified mechanism: variation of a turbulent transport resulting from radial electric field emerging near the edge in the conditions of alternating toroidal electric field Ej and different electron and ion collisionalities. According to the suggested model the toroidal field E φ arising in the periphery during the CRU and MC processes amplifies Ware drift, which mainly influences electron component. As a result the favorable for the transition negative (inward directed) E r emerges. In the CRD scenario, when E φ is opposite to the total plasma current direction, the mechanism should generate positive E r , which is thought to be unfavorable for the H-mode. The experimental data on L-H and H-L transitions in various scenarios and the results of the modeling of E r emerging in the CRU experiment are presented in the paper. (author)

SU(3) breaking in hyperon transition vector form factors

International Nuclear Information System (INIS)

Shanahan, P.E.; Thomas, A.W.; Young, R.D.; Zanotti, J.M.; Rakow, P.E.L.

2015-08-01

We present a calculation of the SU(3)-breaking corrections to the hyperon transition vector form factors to O(p 4 ) in heavy baryon chiral perturbation theory with finite-range regularisation. Both octet and decuplet degrees of freedom are included. We formulate a chiral expansion at the kinematic point Q 2 =-(M B 1 -M B 2 ) 2 , which can be conveniently accessed in lattice QCD. The two unknown low-energy constants at this point are constrained by lattice QCD simulation results for the Σ - →n and Ξ 0 →Σ + transition form factors. Hence we determine lattice-informed values of f 1 at the physical point. This work constitutes progress towards the precise determination of vertical stroke V us vertical stroke from hyperon semileptonic decays.

Ho3+/Yb3+ co-doped TeO2-BaF2-Y2O3 glasses for ∼1.2 μm laser applications

Science.gov (United States)

Wang, Shunbin; Li, Chengzhi; Yao, Chuanfei; Jia, Shijie; Jia, Zhixu; Qin, Guanshi; Qin, Weiping

2017-02-01

Intense ∼1.2 μm fluorescence is observed in Ho3+/Yb3+ co-doped TeO2-BaF2-Y2O3 glasses under 915 nm laser diode excitation. The 1.2 μm emission can be ascribed to the transition 5I6→5I8 of Ho3+. With the introducing of BaF2, the content of OH in the glasses drops markedly, and the 1.2 μm emission intensity increases gradually as increasing the concentration percentage of BaF2. Furthermore, microstructured fibers based on the TeO2-BaF2-Y2O3 glasses are fabricated by using a rod-in-tube method, and a relative positive gain of ∼9.42 dB at 1175.3 nm is obtained in a 5 cm long fiber.

Pressure-induced phase transitions of multiferroic BiFeO3

OpenAIRE

XiaoLi, Zhang; Ye, Wu; Qian, Zhang; JunCai, Dong; Xiang, Wu; Jing, Liu; ZiYu, Wu; DongLiang, Chen

2013-01-01

Pressure-induced phase transitions of multiferroic BiFeO3 have been investigated using synchrotron radiation X-ray diffraction with diamond anvil cell technique at room temperature. Present experimental data clearly show that rhombohedral (R3c) phase of BiFeO3 first transforms to monoclinic (C2/m) phase at 7 GPa, then to orthorhombic (Pnma) phase at 11 GPa, which is consistent with recent theoretical ab initio calculation. However, we observe another peak at 2{\\theta}=7{\\deg} in the pressure ...

Spectroscopic properties of 1.8 μm emission in Tm3+ doped bismuth silicate glass

International Nuclear Information System (INIS)

Zhao, Guoying; Tian, Ying; Wang, Xin; Fan, Huiyan; Hu, Lili

2013-01-01

The emission properties around 1.8 μm in Tm 3+ doped bismuth silicate glass have been investigated. Based on the obtained Raman spectroscopy and differential scanning calorimetry curves, it is found the introduced Bi 2 O 3 can efficiently reduce the phonon energy of silicate glass to 926 cm −1 . The energy gap between glass transition temperature and onset temperature of crystallization is 169 °C. The OH − content maintains lower in glass by bubbling dry O 2 during the melting process. The cut-off wavelength in mid-infrared range is as long as 5 μm. Bismuth silicate glass has high radiative transition probability of 238.80 s −1 corresponding to the Tm 3+ : 3 F 4 → 3 H 6 transition compared with conventional silicate glasses. The strongest emission at 1.8 μm with a large full width at half-maximum of 238 nm is achieved from this bismuth silicate glass doped with 0.9 mol% Tm 2 O 3 . Its fluorescence lifetime at 1.8 μm is 640 μs. - Highlights: ► The 1.8 μm fluorescence of Tm 3+ -doped bismuth silicate glass is investigated. ► The prepared glass has lower phonon energy than other typical silicate glasses. ► A broadband 1.8 μm emission with the FWHM of 238 nm is observed. ► The fluorescence lifetime of Tm 3+ : 3 F 4 level reaches 640 μs.

E1-forbidden transition rates in ions of astrophysical interest

International Nuclear Information System (INIS)

Träbert, E

2014-01-01

Transition rates in atomic systems may appear to be of little importance in steady-state plasmas that are observed at great distances from Earth. However, some of the transition rates compete with collision rates, and in these cases certain line intensity ratios are affected and can serve as remote indicators of density. In the low-density environments of stellar coronae and planetary nebulae, the transition rates of interest are mostly spin-forbidden E1 decays, higher-multipole order transitions (M1, E2, M2, M3), and hyperfine-induced transitions. On Earth, measurements of the long upper level lifetimes of these atomic systems require the use of ion traps. A fair number of test cases with lifetimes in the range from nanoseconds to many seconds have been treated successfully, and the evolution of calculations along with the experimental progress is notable. A new generation of cold ion traps is expected to extend the atomic lifetime measurements on multiply charged ions into the range of many minutes. (paper)

Functional analysis of NopM, a novel E3 ubiquitin ligase (NEL domain effector of Rhizobium sp. strain NGR234.

Directory of Open Access Journals (Sweden)

Da-Wei Xin

Full Text Available Type 3 effector proteins secreted via the bacterial type 3 secretion system (T3SS are not only virulence factors of pathogenic bacteria, but also influence symbiotic interactions between nitrogen-fixing nodule bacteria (rhizobia and leguminous host plants. In this study, we characterized NopM (nodulation outer protein M of Rhizobium sp. strain NGR234, which shows sequence similarities with novel E3 ubiquitin ligase (NEL domain effectors from the human pathogens Shigella flexneri and Salomonella enterica. NopM expressed in Escherichia coli, but not the non-functional mutant protein NopM-C338A, showed E3 ubiquitin ligase activity in vitro. In vivo, NopM, but not inactive NopM-C338A, promoted nodulation of the host plant Lablab purpureus by NGR234. When NopM was expressed in yeast, it inhibited mating pheromone signaling, a mitogen-activated protein (MAP kinase pathway. When expressed in the plant Nicotiana benthamiana, NopM inhibited one part of the plant's defense response, as shown by a reduced production of reactive oxygen species (ROS in response to the flagellin peptide flg22, whereas it stimulated another part, namely the induction of defense genes. In summary, our data indicate the potential for NopM as a functional NEL domain E3 ubiquitin ligase. Our findings that NopM dampened the flg22-induced ROS burst in N. benthamiana but promoted defense gene induction are consistent with the concept that pattern-triggered immunity is split in two separate signaling branches, one leading to ROS production and the other to defense gene induction.

Analysis of 3d7-3d64p transitions in the sixth spectrum of zinc: Zn VI

International Nuclear Information System (INIS)

Kleef, T.A.M. van; Joshi, Y.N.; Barakat, M.M.; Meijer, F.G.

1984-01-01

The spectrum of zinc was photographed in the 160-550 A region on a 6.65 m grazing incidence spectrograph. The sources used were a triggered spark and a sliding spark. On the basis of our new observations, all levels of the 3d 7 configuration and 161 out of 180 levels of the 3d 6 4p configuration of Zn VI have been established. The least-squares-fit (LSF) and Hartree-Fock (HF) parameter calculations support the analysis. Two hundred and seventy seven (277) lines have been classified in the 3d 7 -3d 6 4p transition array. (orig.)

Sequential structural and antiferromagnetic transitions in BaFe2Se3 under pressure

Science.gov (United States)

Zhang, Yang; Lin, Ling-Fang; Zhang, Jun-Jie; Dagotto, Elbio; Dong, Shuai

2018-01-01

The discovery of superconductivity in the two-leg ladder compound BaFe2S3 has established the 123-type iron chalcogenides as a novel and interesting subgroup of the iron-based superconductor family. However, in this 123 series, BaFe2Se3 is an exceptional member, with a magnetic order and crystalline structure different from all others. Recently, an exciting experiment reported the emergence of superconductivity in BaFe2Se3 at high pressure [J. Ying et al., Phys. Rev. B 95, 241109(R) (2017), 10.1103/PhysRevB.95.241109]. In this paper, we report a first-principles study of BaFe2Se3 . Our analysis unveils a variety of qualitative differences between BaFe2S3 and BaFe2Se3 , including in the latter an unexpected chain of transitions with increasing pressure. First, by gradually reducing the tilting angle of iron ladders, the crystalline structure smoothly transforms from P n m a to C m c m at ˜6 GPa. Second, the system becomes metallic at 10.4 GPa. Third, its unique ambient-pressure Block antiferromagnetic ground state is replaced by the more common stripe (so-called CX-type) antiferromagnetic order at ˜12 GPa, the same magnetic state as the 123-S ladder. This transition is found at a pressure very similar to the experimental superconducting transition. Finally, all magnetic moments vanish at 30 GPa. This reported theoretical diagram of the complete phase evolution is important because of the technical challenges to capture many physical properties in high-pressure experiments. The information obtained in our calculations suggests different characteristics for superconductivity in BaFe2Se3 and BaFe2S3 : in 123-S pairing occurs when magnetic moments vanish, while in 123-Se the transition region from Block- to CX-type magnetism appears to catalyze superconductivity. Finally, an additional superconducting dome above ˜30 GPa is expected to occur.

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)).

3.3 μm mapping of NGC 7027

International Nuclear Information System (INIS)

Isaacman, R.

1984-01-01

Among the principal unknowns regarding planetary nebulae is the nature of several unidentified infrared spectral lines. Probably the best-studied of these features are the 3.3 and 11.3 μm lines, which usually appear together. In the present work the bright planetary nebula NGC 7027 has been mapped using UKIRT, and a crosscut has been taken using the 3.0 m NASA Infrared Telescope Facility. Implications of the results for the possible excitation mechanisms are discussed. (U.K.)

Enhanced lithium-ion storage performance by structural phase transition from two-dimensional rhombohedral Fe_2O_3 to cubic Fe_3O_4

International Nuclear Information System (INIS)

Ren, Yurong; Wang, Jiawei; Huang, Xiaobing; Ding, Jianning

2016-01-01

Highlights: • The rhombohedral Fe_2O_3 transforms to the cubic Fe_3O_4 via a calcination treatment. • Phase structure of anodes has great influences on their electrochemical performances. • Fe_3O_4/reduced graphene oxide shows a high capacity of 825.3 mAh g"−"1 at 50 mA g"−"1. - Abstract: The electrochemical performance of a material varies with its structural phase transition. It is found that the rhombohedral Fe_2O_3 can transform to the cubic Fe_3O_4 via a calcination treatment in a nitrogen atmosphere, and lithium-ion storage performances of Fe_3O_4 get an obvious improvement due to its structural advantages. On the basis of data calculated by X-ray diffraction, the larger unit cell volume as well as the higher void fraction of cubic Fe_3O_4 provides lithium-ions with more transport channels for Li ions diffusion and storage without serious volume change, and thus the cubic Fe_3O_4 delivers an excellent reversible capacity of 921.1 mAh g"−"1 after 15 cycles at the current density of 50 mA g"−"1, which is much higher than 328.3 mAh g"−"1 for the rhombohedral Fe_2O_3. To further enhance the structural stability of electrodes, reduced graphene oxide is introduced. The Fe_3O_4/reduced graphene oxide show an excellent specific capacity of 825.3 mAh g"−"1 after 40 cycles and impressive rate performance of 600 mAh g"−"1 at the current density of 400 mA g"−"1, which are much higher than that of Fe_3O_4 (417 and 300 mAh g"−"1), Fe_2O_3 (137.4 and 95 mAh g"−"1) and Fe_2O_3/reduced graphene oxide (390.1 and 480 mAh g"−"1). These results demonstrate that the structural phase transition and reduced graphene oxide of Fe_3O_4/reduced graphene oxide composites offer unique characteristics suitable for high-performance energy storage application.

Thermal properties and phase transition in the fluoride, (NH{sub 4}){sub 3}SnF{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Kartashev, A.V. [Kirensky Institute of Physics, Siberian Department of the Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Astafijev Krasnoyarsk State Pedagogical University, 660049 Krasnoyarsk (Russian Federation); Gorev, M.V. [Kirensky Institute of Physics, Siberian Department of the Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Institute of Engineering Physics and Radio Electronics, Siberian State University, 660074 Krasnoyarsk (Russian Federation); Bogdanov, E.V. [Kirensky Institute of Physics, Siberian Department of the Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Krasnoyarsk State Agrarian University, 660049 Krasnoyarsk (Russian Federation); Flerov, I.N. [Kirensky Institute of Physics, Siberian Department of the Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Institute of Engineering Physics and Radio Electronics, Siberian State University, 660074 Krasnoyarsk (Russian Federation); Laptash, N.M. [Institute of Chemistry, Far Eastern Department of the Russian Academy of Sciences, 690022 Vladivostok (Russian Federation)

2016-05-15

Calorimetric, dilatometric and differential thermal analysis studies were performed on (NH{sub 4}){sub 3}SnF{sub 7} for a wide range of temperatures and pressures. Large entropy (δS{sub 0}=22 J/mol K) and elastic deformation (δ(ΔV/V){sub 0}=0.89%) jumps have proven that the Pa-3↔Pm-3m phase transition is a strong first order structural transformation. A total entropy change of ΔS{sub 0}=32.5 J/mol K is characteristic for the order–disorder phase transition, and is equal to the sum of entropy changes in the related material, (NH{sub 4}){sub 3}TiF{sub 7}, undergoing transformation between the two cubic phases through the intermediate phases. Hydrostatic pressure decreases the stability of the high temperature Pm-3m phase in (NH{sub 4}){sub 3}SnF{sub 7}, contrary to (NH{sub 4}){sub 3}TiF{sub 7}, characterised by a negative baric coefficient. The effect of experimental conditions on the chemical stability of (NH{sub 4}){sub 3}SnF{sub 7} was observed. - Graphical abstract: Strong first order structural transformation Pa-3↔Pm-3m in (NH{sub 4}){sub 3}SnF{sub 7} is associated with very large total entropy change of ΔS{sub 0}=32.5 J/mol K characteristic for the ordering processes and equal to the sum of entropy changes in the related (NH{sub 4}){sub 3}TiF{sub 7} undergoing transformation between the same two cubic phases through the intermediate phases. - Highlights: • (NH{sub 4}){sub 3}SnF{sub 7} undergoes strong first order Pa-3↔Pm-3m phase transition. • Anomalous behaviour of ΔC{sub p} and ΔV/V exists far below phase transition temperature. • Structural distortions are accompanied by huge total entropy change ΔS≈Rln50. • High pressure strongly increases the stability of Pa-3 phase in (NH{sub 4}){sub 3}SnF{sub 7}. • Entropy of the Pa-3↔Pm-3m phase transition does not depend on pressure.

Chronostratigraphic framework for the late Miocene interval of IODP Exp. 355 Site U1457: timing of the C3-C4 transition

Science.gov (United States)

Tauxe, L.; Feakins, S. J.; Liddy, H.; Kulhanek, D. K.; Scardia, G.; Routledge, C.

2017-12-01

Combining magnetostratigraphic, biostratigraphic, and isotopic data for the Late Miocene interval of U1457 provides a tight temporal framework for the C3-C4 isotopic transition first documented by Quade et al. (1989) in northern Pakistan. We have re-evaluated the chronological constraints for the shifts recorded in Pakistan, Nepal and India. Records include those from Rhotas (Behrensmeyer et al., 2007), Jalalpur (Johnson et al., 1982, Quade and Cerling, 1995) from Pakistan, Jawalamukhti and Haripur Kola (NW India) in Voegeli et al. (2017) with magnetostratigraphic control from Meigs et al. (1995), and Sangode et al. (1996) and records from Nepal summarized by Quade et al. (1995) with magnetostratigraphic control documented by Ojha et al. (2009). An age for the C3-C4 transition at ca. 7.0 Ma is consistent with all records in hand suggesting that it is possible that the transition occurred simultaneously in the Indian subcontinent Ma (although differences are allowed but not demanded by the data). We also updated the magnetic and nannofossil stratigraphies for IODP Expedition 355, Site U1457, revising the calibration of certain nannofossil datums. These data, combined with geochemical proxy data sensitive to the C3-C4 transition (d13C values of C35 n-alkanes (per mil relative to PD Belemnite) which shows a transition at 648 mcd, lead to the tentative conclusion that the C3-C4 transition recorded at Site U1457 occurred within C3Ar, or also at ca. 7; it is apparently synchronous with the records on the Indian subcontinent. A.K. Behrensmeyer, J. Quade, T. E. Cerling , J. Kappelman, I. A. Khan, P. Copeland, L. Roe, J. Hicks, P. Stubblefield, B. J. Willis, C. Latorre, Geol. Soc. Am. Bull 119 1486-1505 (2007). F. M. Gradstein, J. G. Ogg, M. D. Schmitz, G. M. Ogg, (2012). N. M. Johnson, N. D. Opdyke, G. D. Johnson, E. H. Lindsay, R. A. K. Tahirkheli, Paleogeo. Paleoclim. and Paleoecol. 37 17-42 (1982). A.J. Meigs, D. W. Burbank, R. A. Beck, Geology 23 423-426 (1995). Ojha

Electron collisions with Fe-peak elements: Forbidden transitions between the low lying valence states 3d6, 3d54s, and 3d54p of Fe III

International Nuclear Information System (INIS)

McLaughlin, B.M.; Scott, M.P.; Sunderland, A.G.; Noble, C.J.; Burke, V.M.; Ramsbottom, C.A.; Reid, R.H.G.; Hibbert, A.; Bell, K.L.; Burke, P.G.

2007-01-01

Effective collision strengths are presented for the Fe-peak element Fe III at electron temperatures (T e in degrees Kelvin) in the range 2 x 10 3 to 1 x 10 6 . Forbidden transitions results are given between the 3d 6 , 3d 5 4s, and the 3d 5 4p manifolds applicable to the modeling of laboratory and astrophysical plasmas

Particle Trajectory and Icing Analysis of the E(sup 3) Turbofan Engine Using LEWICE3D Version 3

Science.gov (United States)

Bidwell, Colin S.

2011-01-01

Particle trajectory and ice shape calculations were made for the Energy Efficient Engine (E(sup 3)) using the LEWICE3D Version 3 software. The particle trajectory and icing computations were performed using the new "block-to-block" collection efficiency method which has been incorporated into the LEWICE3D Version 3 software. The E(sup 3) was developed by NASA and GE in the early 1980 s as a technology demonstrator and is representative of a modern high bypass turbofan engine. The E(sup 3) flow field was calculated using the NASA Glenn ADPAC turbomachinery flow solver. Computations were performed for the low pressure compressor of the E(sup 3) for a Mach 0.8 cruise condition at 11,887 m assuming a standard warm day for three drop sizes and two drop distributions typically used in aircraft design and certification. Particle trajectory computations were made for water drop sizes of 5, 20, and 100 microns. Particle trajectory and ice shape predictions were made for a 20 micron Langmuir-D distribution and for a 92 mm Super-cooled Large Droplet (SLD) distribution with and without splashing effects for a Liquid Water Content (LWC) of 0.3 g/cu m and an icing time of 30 min. The E3 fan and spinner combination proved to be an effective ice removal mechanism as they removed greater than 36 percent of the mass entering the inlet for the icing cases. The maximum free stream catch fraction for the fan and spinner combination was 0.60 while that on the elements downstream of the fan was 0.03. The non-splashing trajectory and collection efficiency results showed that as drop size increased impingement rates increased on the spinner and fan leaving less mass to impinge on downstream components. The SLD splashing case yielded more mass downstream of the fan than the SLD non-splashing case due to mass being splashed from the upstream inlet lip, spinner and fan components. The ice shapes generated downstream of the fan were either small or nonexistent due to the small available mass

4s24p3--4s4p4 and 4s24p3--4s2fp25s transitions in Y VII, Zr VIII, Nb IX, and MoX

International Nuclear Information System (INIS)

Reader, J.; Acquista, N.

1981-01-01

Spectra of ionized Y, Zr, Nb, and Mo have been observed in sliding-spark and triggered-spark discharges on 10.7-m normal- and grazing-incidence spectrographs at the National Bureau of Standards in Washington, D. C. From these observations the 4s 2 4p 3 --4s4p 4 transitions in Y VII, Zr VIII, Nb IX, and Mo X have been identified. The 4s 2 4p 3 --4s 2 4p 2 5s transitions in Y VII-Mo X, previously identified by Rahimullah et al. [Phys. Scr. 14, 221--223 (1976); 18, 96--106 (1978)], have been confirmed. In Y VII the 4s 2 4p 3 --4s 2 4p 2 6s and 4s4p 4 --4p 5 transition also have been found. The parameters obtained from least-squares fits to the energy levels are compared with Hartree--Fock calculations. Preliminary values of the ionization energies have been determined as 110.02 +- 0.15 eV for Y VII, 133.7 +- 0.5 eV for Zr VIII, 159.2 +- 0.7 eV for Nb IX, and 186.4 +- 1.2 eV for Mo X

Pressure-induced phase transitions in nanocrystalline ReO3

International Nuclear Information System (INIS)

Biswas, Kanishka; Muthu, D V S; Sood, A K; Kruger, M B; Chen, B; Rao, C N R

2007-01-01

Pressure-induced phase transitions in the nanocrystals of ReO 3 with an average diameter of ∼12 nm have been investigated in detail by using synchrotron x-ray diffraction and the results compared with the literature data of bulk samples of ReO 3 . The study shows that the ambient-pressure cubic I phase (space group Pm3-barm) transforms to a monoclinic phase (space group C 2/c), then to a rhombohedral I phase (space group R3-barc), and finally to another rhombohedral phase (rhombohedral II, space group R3-barc) with increasing pressure over the 0.0-20.3 GPa range. The cubic I to monoclinic transition is associated with the largest volume change (∼5%), indicative of a reconstructive transition. The transition pressures are generally lower than those known for bulk ReO 3 . The cubic II (Im3-bar) or tetragonal (P4/mbm) phases do not occur at lower pressures. The nanocrystals are found to be more compressible than bulk ReO 3 . On decompression to ambient pressure, the structure does not revert back to the cubic I structure

Synthesis and some properties of hydrogen phosphites M3(H2PO3)3, where M = Ga, V, Fe, or In

International Nuclear Information System (INIS)

Zakharova, B.S.; Tarnopol'skij, V.A.; Chudinova, N.N.

2001-01-01

The conditions on production and the properties of the acid phosphites M 3 (H 2 PO 3 ) 3 (M = Ga, V, Fe, In) are demonstrated. The compounds were investigated by X-ray diffraction, thermal gravimetric analysis, IR spectroscopy and conductometry. Interaction of M 2 O 3 (M = Ga, V, Fe, In) with the melt of phosphorous acid was studied in the P : M = 1. 5 : 1 - 10 : 1 interval of compositions. The lattice parameters are given, the hypothesis on the available of superstructure in the M 3 (H 2 PO 3 ) 3 compounds is corroborated. From the measurements the proton conductivity in vanadium and indium phosphites is comprised of 2.5 x 10 -5 and 1.9 x 10 8- S/cm correspondingly. Acid vanadium and indium phosphites are behaved similarly during heating. The limit of thermal stability of the acid phosphites V(H 2 PO 3 ) 3 , V(H 2 PO 3 ) 3 grows [ru

Semiconductor-metal transition in CaMO3-CaTiO2 (M-Ru,Ir) systems

International Nuclear Information System (INIS)

Lazarev, V.B.; Shaplygin, I.S.

1982-01-01

Properties of CaRusub(x)Tisub(1-x)Osub(3) and CaIsub(2x)Tisub(1-x)Osub(3) solid solutions were studied in the whole range of concentrations by the methods of X-ray diffraction, electric conductivity and magnetic susceptibility. It was ascertained that the transition of semiconductor-metal type proceeded in the both families of solid solutions at x approximately 0.77 and 0.85 respectively and was accompanied by the change of structural type of solid solutions

Photoluminescent properties of LiSrxBa1-xPO4:RE3+ (RE = Sm3+, Eu3+) f-f transition phosphors

International Nuclear Information System (INIS)

Tu Dong; Liang Yujun; Liu Rong; Cheng Zheng; Yang Fan; Yang Wenlong

2011-01-01

Highlights: → Novel phosphors LiSr x Ba 1-x PO 4 : Sm 3+ and LiSr x Ba 1-x PO 4 : Eu 3+ have been synthesized by solid-state reaction method. → The LiSr x Ba 1-x PO 4 : Sm 3+ and LiSr x Ba 1-x PO 4 : Eu 3+ phosphors may be potential f-f transition phosphors used in LED. → The emission intensity of the LiSr x Ba 1-x PO 4 : Sm 3+ and LiSr x Ba 1-x PO 4 : Eu 3+ phosphors can be enhanced by increasing the value of x. - Abstract: Rare-earth ions (Sm 3+ or Eu 3+ ) doped LiSr x Ba 1-x PO 4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) f-f transition phosphor powders were prepared by a high temperature solid-state reaction. The resulted phosphors were characterized by X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy. The results of XRD indicate that the phase structure of the sample changes from LiBaPO 4 to LiSrPO 4 when x changes from 0 to 1.0. The excitation spectra indicate that only direct excitation of rare earth ions (Sm 3+ or Eu 3+ ) can be observed. The doped rare earth ions show their characteristic emission in LiSr x Ba 1-x PO 4 , i.e., Eu 3+5 D 0 - 7 F J (J = 0, 1, 2, 3, 4), Sm 3+4 G 5/2 → 6 H J (J = 5/2, 7/2, 9/2, 11/2), respectively. The dependence of the emission intensities of the LiSr x Ba 1-x PO 4 :Sm 3+ and LiSr x Ba 1-x PO 4 :Eu 3+ phosphors on the x value and Ln 3+ (Ln 3+ = Sm 3+ , Eu 3+ ) concentration is also investigated.

Phospholipase C-independent effects of 3M3FBS in murine colon.

Science.gov (United States)

Dwyer, Laura; Kim, Hyun Jin; Koh, Byoung Ho; Koh, Sang Don

2010-02-25

The muscarinic receptor subtype M(3) is coupled to Gq/11 proteins. Muscarinic receptor agonists such as carbachol stimulate these receptors that result in activation of phospholipase C (PLC) which hydrolyzes phosphatidylinositol 4,5-bisphosphate into diacylglycerol and Ins(1,4,5)P(3). This pathway leads to excitation and smooth muscle contraction. In this study the PLC agonist, 2, 4, 6-trimethyl-N-(meta-3-trifluoromethyl-phenyl)-benezenesulfonamide (m-3M3FBS), was used to investigate whether direct PLC activation mimics carbachol-induced excitation. We examined the effects of m-3M3FBS and 2, 4, 6-trimethyl-N-(ortho-3-trifluoromethyl-phenyl)-benzenesulfonamide (o-3M3FBS), on murine colonic smooth muscle tissue and cells by performing conventional microelectrode recordings, isometric force measurements and patch clamp experiments. Application of m-3M3FBS decreased spontaneous contractility in murine colonic smooth muscle without affecting the resting membrane potential. Patch clamp studies revealed that delayed rectifier K(+) channels were reversibly inhibited by m-3M3FBS and o-3M3FBS. The PLC inhibitor, 1-(6-((17b-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122), did not prevent this inhibition by m-3M3FBS. Both m-3M3FBS and o-3M3FBS decreased two components of delayed rectifier K(+) currents in the presence of tetraethylammonium chloride or 4-aminopyridine. Ca(2+) currents were significantly suppressed by m-3M3FBS and o-3M3FBS with a simultaneous increase in intracellular Ca(2+). Pretreatment with U73122 did not prevent the decrease in Ca(2+) currents upon m-3M3FBS application. In conclusion, both m-3M3FBS and o-3M3FBS inhibit inward and outward currents via mechanisms independent of PLC acting in an antagonistic manner. In contrast, both compounds also caused an increase in [Ca(2+)](i) in an agonistic manner. Therefore caution must be employed when interpreting their effects at the tissue and cellular level.

Glass transition behavior and crystallization kinetics of Cu0.3(SSe20)0.7 chalcogenide glass

International Nuclear Information System (INIS)

Soliman, A.A.

2005-01-01

The glass transition behavior and crystallization kinetics of Cu 0.3 (SSe 20 ) 0.7 chalcogenide glass were investigated using differential scanning calorimetry (DSC), X-ray diffraction (XRD). Two crystalline phases (SSe 20 and Cu 2 Se) were identified after annealing the glass at 773 K for 24 h. The activation energy of the glass transition (E g ), the activation energy of crystallization (E c ), the Avrami exponent (n) and the dimensionality of growth (m) were determined. Results indicate that this glass crystallizes by a two-stage bulk crystallization process upon heating. The first transformation, in which SSe 20 precipitates from the amorphous matrix with a three-dimensional crystal growth. The second transformation, in which the residual amorphous phase transforms into Cu 2 Se compound with a two-dimensional crystal growth

Strongly extended diffusion length for the nonequilibrium magnons in Y3F e5O12 by photoexcitation

Science.gov (United States)

Wang, S. H.; Li, G.; Guo, E. J.; Zhao, Y.; Wang, J. Y.; Zou, L. K.; Yan, H.; Cai, J. W.; Zhang, Z. T.; Wang, M.; Tian, Y. Y.; Zheng, X. L.; Sun, J. R.; Jin, K. X.

2018-05-01

Y3F e5O12 (YIG) is known for its long magnon diffusion length. Although it has the known lowest damping rate, an even longer diffusion distance is still highly desired since it may lead to a much more efficient information transmission and processing. While most of previous works focused on the generation and detection of magnons in YIG, here we demonstrate how to depress the damping rate during the diffusion of magnon. By selectively exciting the spin state transition of the Fe ions in YIG, we successfully increase magnon diffusion length by one order of magnitude, i.e., from the previous reported ˜10 μm up to ˜156 μm (for the sample prepared by liquid phase epitaxy) and ˜180 μm (for the sample prepared by pulsed laser deposition) at room temperature. The diffusion length, determined by nonlocal geometry, is ˜30 μm for the magnons induced by visible light and above 150 μm for the laser of 980 nm. In addition to thermal gradient, light excitation affects the electron configuration of the F e3 + ion in YIG. Long-wavelength laser is more effective since it causes a transition of the F e3 + ions in Fe O6 octahedron from a high spin to a low spin state and thus causes a magnon softening which favors a long-distance diffusion. The present work paves the way toward an efficient tuning of magnon transport which is crucially important for magnon spintronics.

Identification of factors required for m6 A mRNA methylation in Arabidopsis reveals a role for the conserved E3 ubiquitin ligase HAKAI.

Science.gov (United States)

Růžička, Kamil; Zhang, Mi; Campilho, Ana; Bodi, Zsuzsanna; Kashif, Muhammad; Saleh, Mária; Eeckhout, Dominique; El-Showk, Sedeer; Li, Hongying; Zhong, Silin; De Jaeger, Geert; Mongan, Nigel P; Hejátko, Jan; Helariutta, Ykä; Fray, Rupert G

2017-07-01

N6-adenosine methylation (m 6 A) of mRNA is an essential process in most eukaryotes, but its role and the status of factors accompanying this modification are still poorly understood. Using combined methods of genetics, proteomics and RNA biochemistry, we identified a core set of mRNA m 6 A writer proteins in Arabidopsis thaliana. The components required for m 6 A in Arabidopsis included MTA, MTB, FIP37, VIRILIZER and the E3 ubiquitin ligase HAKAI. Downregulation of these proteins led to reduced relative m 6 A levels and shared pleiotropic phenotypes, which included aberrant vascular formation in the root, indicating that correct m 6 A methylation plays a role in developmental decisions during pattern formation. The conservation of these proteins amongst eukaryotes and the demonstration of a role in writing m 6 A for the E3 ubiquitin ligase HAKAI is likely to be of considerable relevance beyond the plant sciences. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

M1 transitions between superdeformed states in 195Tl

International Nuclear Information System (INIS)

Zheng Xing; Xingqu Chen; Xiaochun Wang

1996-01-01

Using a triaxial-particle-rotor model, the quadrupole and dipole transition energies, kinematic and dynamic moments of inertia, electromagnetic transition probabilities and the relative intensity of the E2 γ-transitions are calculated for superdeformed bands in 195 Tl. A strong perturbation effect of rotation on transition energies and M1 and E2 transitions of superdeformed states is investigated. The total M1 transitions, enhanced by internal conversion, are expected to compete strongly with the E2 γ-ray at low spins in the superdeformed 195 Tl nucleus. (author)

Imaging of HER3-expressing xenografts in mice using a 99mTc(CO)3-HEHEHE-ZHER3:08699 affibody molecule

International Nuclear Information System (INIS)

Orlova, Anna; Rosestedt, Maria; Varasteh, Zohreh; Selvaraju, Ram Kumar; Malm, Magdalena; Andersson, Ken; Staahl, Stefan; Loefblom, John; Altai, Mohamed; Honarvar, Hadis; Strand, Joanna; Tolmachev, Vladimir

2014-01-01

Human epidermal growth factor receptor type 3 (HER3) is a transmembrane receptor tyrosine kinase belonging to the HER (ErbB) receptor family. Membranous expression of HER3 is associated with trastuzumab resistance in breast cancer and the transition to androgen independence in prostate cancer. Imaging of HER3 expression in malignant tumors may provide important diagnostic information that can influence patient management. Affibody molecules with low picomolar affinity to HER3 were recently selected. The aim of this study was to investigate the feasibility of HER3 imaging using radiolabeled Affibody molecules. A HER3-binding Affibody molecule, Z 08699 , with a HEHEHE-tag on N-terminus was labeled with 99m Tc(CO) 3 using an IsoLink kit. In vitro and in vivo binding specificity and the cellular processing of the labeled binder were evaluated. Biodistribution of 99m Tc(CO) 3 -HEHEHE-Z 08699 was studied over time in mice bearing HER3-expressing xenografts. HEHEHE-Z 08699 was labeled with 99m Tc(CO) 3 with an isolated yield of >80 % and a purity of >99 %. Binding of 99m Tc(CO) 3 -HEHEHE-Z 08699 was specific to BT474 and MCF7 (breast cancer), and LS174T (colon cancer) cells. Cellular processing showed rapid binding and relatively quick internalization of the receptor/Affibody molecule complex (70 % of cell-associated radioactivity was internalized after 24 h). The tumor targeting was receptor mediated and the excretion was predominantly renal. Receptor-mediated uptake was also found in the liver, lung, stomach, intestine, and salivary glands. At 4 h pi, tumor-to-blood ratios were 7 ± 3 for BT474, and 6 ± 2 for LS174T xenografts. LS174T tumors were visualized by microSPECT 4 h pi. The results of this study suggest the feasibility of HER3-imaging in malignant tumors using Affibody molecules. (orig.)

) m /SrVO3 ( m = 5, 6) Superlattices

KAUST Repository

Dai, Qingqing; Lü ders, Ulrike; Fré sard, Raymond; Eckern, Ulrich; Schwingenschlö gl, Udo

2018-01-01

The (LaV3+O3)m/SrV4+O3 (m = 5, 6) superlattices are investigated by first principles calculations. While bulk LaVO3 is a C‐type antiferromagnetic semiconductor and bulk SrVO3 is a paramagnetic metal, semiconducting A‐type antiferromagnetic states

MASCARA-1 b. A hot Jupiter transiting a bright mV = 8.3 A-star in a misaligned orbit

Science.gov (United States)

Talens, G. J. J.; Albrecht, S.; Spronck, J. F. P.; Lesage, A.-L.; Otten, G. P. P. L.; Stuik, R.; Van Eylen, V.; Van Winckel, H.; Pollacco, D.; McCormac, J.; Grundahl, F.; Fredslund Andersen, M.; Antoci, V.; Snellen, I. A. G.

2017-10-01

We report the discovery of MASCARA-1 b, which is the first exoplanet discovered with the Multi-site All-Sky CAmeRA (MASCARA). This exoplanet is a hot Jupiter orbiting a bright mV = 8.3, rapidly rotating (vsini⋆ > 100 km s-1) A8 star with a period of 2.148780 ± 8 × 10-6 days. The planet has a mass and radius of 3.7 ± 0.9 MJup and 1.5 ± 0.3 RJup, respectively. As with most hot Jupiters transiting early-type stars, we find a misalignment between the planet orbital axis and the stellar spin axis, which may be a signature of the formation and migration histories of this family of planets. MASCARA-1 b has a mean density of 1.5 ± 0.9 g cm-3 and an equilibrium temperature of 2570+50-30K, that is one of the highest temperatures known for a hot Jupiter to date. The system is reminiscent of WASP-33, but the host star lacks apparent delta-scuti variations, making the planet an ideal target for atmospheric characterization. We expect this to be the first of a series of hot Jupiters transiting bright early-type stars that will be discovered by MASCARA. Tables of the photometry and the reduced spectra as FITS files are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/606/A73

Pressure induced structural phase transition in solid oxidizer KClO3: A first-principles study

Science.gov (United States)

Yedukondalu, N.; Ghule, Vikas D.; Vaitheeswaran, G.

2013-05-01

High pressure behavior of potassium chlorate (KClO3) has been investigated from 0 to 10 GPa by means of first principles density functional theory calculations. The calculated ground state parameters, transition pressure, and phonon frequencies using semiempirical dispersion correction scheme are in excellent agreement with experiment. It is found that KClO3 undergoes a pressure induced first order phase transition with an associated volume collapse of 6.4% from monoclinic (P21/m) → rhombohedral (R3m) structure at 2.26 GPa, which is in good accord with experimental observation. However, the transition pressure was found to underestimate (0.11 GPa) and overestimate (3.57 GPa) using local density approximation and generalized gradient approximation functionals, respectively. Mechanical stability of both the phases is explained from the calculated single crystal elastic constants. In addition, the zone center phonon frequencies have been calculated using density functional perturbation theory at ambient as well as at high pressure and the lattice modes are found to soften under pressure between 0.6 and 1.2 GPa. The present study reveals that the observed structural phase transition leads to changes in the decomposition mechanism of KClO3 which corroborates with the experimental results.

Radiative rates for E1, E2, M1, and M2 transitions in the Br-like ions Sr IV, Y V, Zr VI, Nb VII, and Mo VIII

International Nuclear Information System (INIS)

Aggarwal, Kanti M.; Keenan, Francis P.

2015-01-01

Energies and lifetimes are reported for the lowest 375 levels of five Br-like ions, namely Sr IV, Y V, Zr VI, Nb VII, and Mo VIII, mostly belonging to the 4s 2 4p 5 , 4s 2 4p 4 4ℓ, 4s4p 6 , 4s 2 4p 4 5ℓ, 4s 2 4p 3 4d 2 , 4s4p 5 4ℓ, and 4s4p 5 5ℓ configurations. Extensive configuration interaction has been included and the general-purpose relativistic atomic structure package (GRASP) has been adopted for the calculations. Additionally, radiative rates are listed among these levels for all E1, E2, M1, and M2 transitions. From a comparison with the measurements, the majority of our energy levels are assessed to be accurate to better than 2%, although discrepancies between theory and experiment for a few are up to 6%. An accuracy assessment of the calculated radiative rates (and lifetimes) is more difficult, because no prior results exist for these ions

Reexamination of $L_{3}$ and $M_{1}$ atomic-level widths of elements 54 $\\le$ Z $\\le$ 77

CERN Document Server

Mauron, O; Baechler, S; Berset, M; Maillard, Y P; Raboud, P A; Hoszowska, J

2003-01-01

High-resolution measurements of the photoinduced L/sub 3/-M/sub 1/ and L/sub 3/-M/sub 4,5/ X-ray emission lines were performed with a reflection-type bent-crystal spectrometer for a variety of elements ranging from xenon (Z=54) to iridium (Z=77). The measurements were performed at the European Synchrotron Radiation Facility in Grenoble, France. From the observed linewidths of the L/sub 3/-M/sub 1/ x-ray transitions, the widths of the M/sub 1/ levels were determined using the L/sub 3/ level widths extracted from the measured L/sub 3/-M/sub 5/ transitions, and assuming for the M/sub 5/ levels the widths reported recently by Campbell and Papp ÝAt. Data Nucl. Data Tables 77, 1 (2001)¿. In the rare-earth region a Z-dependent broadening of the M/sub 1/ level was observed. (51 refs).

Marginalizing Instrument Systematics in HST WFC3 Transit Light Curves

Science.gov (United States)

Wakeford, H. R.; Sing, D. K.; Evans, T.; Deming, D.; Mandell, A.

2016-03-01

Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) infrared observations at 1.1-1.7 μm probe primarily the H2O absorption band at 1.4 μm, and have provided low-resolution transmission spectra for a wide range of exoplanets. We present the application of marginalization based on Gibson to analyze exoplanet transit light curves obtained from HST WFC3 to better determine important transit parameters such as Rp/R*, which are important for accurate detections of H2O. We approximate the evidence, often referred to as the marginal likelihood, for a grid of systematic models using the Akaike Information Criterion. We then calculate the evidence-based weight assigned to each systematic model and use the information from all tested models to calculate the final marginalized transit parameters for both the band-integrated and spectroscopic light curves to construct the transmission spectrum. We find that a majority of the highest weight models contain a correction for a linear trend in time as well as corrections related to HST orbital phase. We additionally test the dependence on the shift in spectral wavelength position over the course of the observations and find that spectroscopic wavelength shifts {δ }λ (λ ) best describe the associated systematic in the spectroscopic light curves for most targets while fast scan rate observations of bright targets require an additional level of processing to produce a robust transmission spectrum. The use of marginalization allows for transparent interpretation and understanding of the instrument and the impact of each systematic evaluated statistically for each data set, expanding the ability to make true and comprehensive comparisons between exoplanet atmospheres.

) m /SrVO3 ( m = 5, 6) Superlattices

KAUST Repository

Dai, Qingqing

2018-05-04

The (LaV3+O3)m/SrV4+O3 (m = 5, 6) superlattices are investigated by first principles calculations. While bulk LaVO3 is a C‐type antiferromagnetic semiconductor and bulk SrVO3 is a paramagnetic metal, semiconducting A‐type antiferromagnetic states for both superlattices are found due to epitaxial strain. At the interfaces, however, the V spins couple antiferromagnetically for m = 5 and ferromagnetically for m = 6 (m‐dependence of the magnetization). Electronic reconstruction in form of charge ordering is predicted to occur with V3+ and V4+ states arranged in a checkerboard pattern on both sides of the SrO layer. As compared to bulk LaVO3, the presence of V4+ ions introduces in‐gap states that strongly reduce the bandgap and influence the orbital occupation and ordering.

Winding transitions at finite energy and temperature: An O(3) model

International Nuclear Information System (INIS)

Habib, S.; Mottola, E.; Tinyakov, P.

1996-01-01

Winding number transitions in the two-dimensional softly broken O(3) nonlinear σ model are studied at finite energy and temperature. New periodic instanton solutions which dominate the semiclassical transition amplitudes are found analytically at low energies, and numerically for all energies up to the sphaleron scale. The Euclidean period β of these finite energy instantons increases with energy, contrary to the behavior found in the Abelian Higgs model or simple one-dimensional systems. This results in a sharp crossover from instanton-dominated tunneling to sphaleron-dominated thermal activation at a certain critical temperature. Since this behavior is traceable to the soft breaking of conformal invariance by the mass term in the σ model, semiclassical winding number transition amplitudes in the electroweak theory in 3+1 dimensions should exhibit a similar sharp crossover. We argue that this is indeed the case in the standard model for M H W . copyright 1996 The American Physical Society

The participant Coster-Kronig preceded Auger transition in the resonant L2,3-M2,3V Auger electron spectrum of Ti metal

International Nuclear Information System (INIS)

Ohno, Masahide

2008-01-01

The L 2,3 -M 2,3 V resonant Auger electron spectroscopy (RAES) spectrum of Ti metal measured by Le Fevre et al. [P. Le Fevre, J. Danger, H. Magnan, D. Chandesris, J. Jupille, S. Bourgeois, M.-A. Arrio, R. Gotter, A. Verdini, A. Morgante, Phys. Rev. B69 (2004) 155421] is analyzed in the light of relaxation and decay of the resonantly excited L 2,3 -hole states. The relaxation time of the resonantly excited L 2,3 -hole state to the fully relaxed (screened) one is much shorter than the L 2,3 -hole Auger decay time, whereas the participant Coster-Kronig (CK) decay time of the resonantly excited L 2 -hole state to the fully relaxed L 3 -hole state at the L 2 resonance is as short as the relaxation time of the resonantly excited L 2 -hole state to the fully relaxed one. The excited electron is predominantly either rapidly decoupled from the L 2,3 -hole decay or annihilated by the participant CK decay. Thus, near the L 2,3 edges the L 2,3 -M 2,3 V RAES spectral peak appears at constant kinetic energy. The L 2,3 -M 2,3 V RAES spectrum shows a normal L 2,3 -M 2,3 V Auger decay profile not modulated by the density of empty d states probed by the resonant excitation. Not only the relaxation time but also the participant CK decay time depends on photon energy because they depend on the density of empty d states probed by the resonant excitation. As a result, the L 2,3 X-ray absorption spectroscopy spectral line broadening depends on photon energy

Alkali metal and ammonium fluoro(trifluoroacetato)metallates M'[ M''3(μ3-F)(CF3COO)6(CF3COOH)3], where M' = Li, Na, K, NH4, Rb, or Cs and M'' = Ni or Co. Synthesis and crystal structures

Science.gov (United States)

Tereshchenko, D. S.; Morozov, I. V.; Boltalin, A. I.; Karpova, E. V.; Glazunova, T. Yu.; Troyanov, S. I.

2013-01-01

A series of fluoro(trifluoroacetato)metallates were synthesized by crystallization from solutions in trifluoroacetic acid containing nickel(II) or cobalt(II) nitrate hydrates and alkali metal or ammonium fluorides: Li[Ni3(μ3-F)(CF3COO)6(CF3COOH)3](CF3COOH)3 ( I), M'[Ni3(μ3-F)(CF3COO)6(CF3COOH)3] ( M' = Na ( II), NH4 ( IV), Rb ( V), and Cs ( VI)), NH4[Co3(μ3-F) (CF3COO)6(CF3COOH)3] ( III), and Cs[Ni3(μ3-F)(CF3COO)6(CF3COOH)3](CF3COOH)0.5 ( VII). The crystal structures of these compounds were determined by single-crystal X-ray diffraction. All structures contain triangular trinuclear complex anions [ M 3″(μ3-F)(CF3COO)6(CF3COOH)3]- ( M″ = Ni, Co) structurally similar to trinuclear 3d metal oxo carboxylate complexes. The three-coordinated F atom is located at the center of the triangle formed by Ni(II) or Co(II) atoms. The metal atoms are linked in pairs by six bridging trifluoroacetate groups located above and below the plane of the [ M″3 F] triangle. The oxygen atoms of the axial CF3COOH molecules complete the coordination environment of M″ atoms to an octahedron.

Density functional calculations on the geometric structure and properties of the 3d transition metal atom doped endohedral fullerene M@C20F20 (M = Sc–Ni)

International Nuclear Information System (INIS)

Chun-Mei, Tang; Wei-Hua, Zhu; Kai-Ming, Deng

2010-01-01

This paper uses the generalised gradient approximation based on density functional theory to analyse the geometric structure and properties of the 3d transition metal atom doped endohedral fullerene M@C 20 F 20 (M = Sc–Ni). The geometric optimization shows that the cage centre is the most stable position for M, forming the structure named as M@C 20 F 20 -4. The inclusion energy, zero-point energy, and energy gap calculations tell us that N@C 20 F 20 -4 should be thermodynamically and kinetically stablest. M@C 20 F 20 -4 (M = Sc–Co) possesses high magnetic moments varied from 1 to 6 μ B , while Ni@C 20 F 20 -4 is nonmagnetic. The Ni–C bond in Ni@C 20 F 20 -4 contains both the covalent and ionic characters

E3 Staff Database

Data.gov (United States)

US Agency for International Development — E3 Staff database is maintained by E3 PDMS (Professional Development & Management Services) office. The database is Mysql. It is manually updated by E3 staff as...

Generalized Michailov plot analysis of inband E2 transitions of deformed nuclei

International Nuclear Information System (INIS)

Long, G.L.; Zhang, W.L.; Ji, H.Y.; Gao, J.F.

1998-01-01

Intraband E2 transitions of some 30 deformed nuclei are analysed using a generalized Michailov plot, based on an E2 transition formula in the SU(3) limit of the sdg interacting boson model. The general E2 transition formula in the sdg-IBM has an L(L+3) term in addition to the usual SU(3) model result. It is found that the general E2 formula can describe the inband transitions well. Comparisons with other models are made. The implications of the results are also discussed. (author)

Spectroscopic investigation of Er{sup 3+} in fluorotellurite glasses for 2.7 μm luminescence

Energy Technology Data Exchange (ETDEWEB)

Zhang, Feng; Bi, Zhuanfang; Chen, Jiayang; Huang, Anping [Key Laboratory of Micro-nano Measurement, Manipulation and Physics (Ministry of Education), School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China); Zhu, Yongchang [China Building Materials Academy, Beijing, 100024 (China); Chen, Baojie [Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Xiao, Zhisong, E-mail: zsxiao@buaa.edu.cn [Key Laboratory of Micro-nano Measurement, Manipulation and Physics (Ministry of Education), School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China)

2015-11-15

Er{sup 3+} doped fluorotellurite glass (TeO{sub 2}–BaF{sub 2}–NaF) with different Er{sup 3+} concentrations were prepared, glass thermal stability and structure were investigated by differential scanning calorimetry (DSC) test and Raman spectrum, respectively. 2.7 μm light emission was observed under 980 nm excitation in these fluorotellurite glasses. The 2.7 μm emission properties were investigated through the measured absorption and emission spectra. The spontaneous transition probability (A), branching ratio (β), emission and absorption cross sections were calculated and the values were relatively larger than some reported values, which indicated that this kind of fluorotellurite glass has potential application as host material for 2.7 μm lasers. - Highlights: • High T{sub g} (375 °C) provides good thermal stability to resist thermal damage. • The introduction of F{sup −} decreases the connectivity of the tellurite former network. • Er{sup 3+} doped TBN glasses have been investigated using Judd–Ofelt (JO) theory. • TBN glasses possess high stimulated emission cross section σ{sub e} for 2.7 μm emission.

Reconstructive phase transition in (NH4)3TiF7 accompanied by the ordering of TiF6 octahedra.

Science.gov (United States)

Molokeev, Maxim; Misjul, S V; Flerov, I N; Laptash, N M

2014-12-01

An unusual phase transition P4/mnc → Pa\\bar 3 has been detected after cooling the (NH4)3TiF7 compound. Some TiF6 octahedra, which are disordered in the room-temperature tetragonal structure, become ordered in the low-temperature cubic phase due to the disappearance of the fourfold axis. Other TiF6 octahedra undergo large rotations resulting in huge displacements of the F atoms by 1.5-1.8 Å that implies a reconstructive phase transition. It was supposed that phases P4/mbm and Pm\\bar 3m could be a high-temperature phase and a parent phase, respectively, in (NH4)3TiF7. Therefore, the sequence of phase transitions can be written as Pm\\bar 3m → P4/mbm → P4/mnc → Pa\\bar 3. The interrelation between (NH4)3TiF7, (NH4)3GeF7 and (NH4)3PbF7 is found, which allows us to suppose phase transitions in relative compounds.

Optical transitions of Er3+/Yb3+ codoped TeO2-WO3-Bi2O3 glass.

Science.gov (United States)

Shen, Xiang; Nie, Qiuhua; Xu, Tiefeng; Gao, Yuan

2005-10-01

Optical absorption and emission properties of the Er3+/Yb3+ codoped TeO2-WO3-Bi2O3 (TWB) glass has been investigated. The transition probabilities, excited state lifetimes, and the branching ratios have been predicted for Er3+ based on the Judd-Ofelt theory. The broad 1.5 microm fluorescence was observed under 970 nm excitation, and its full width at half maximum (FWHM) is 77 nm. The emission cross-section is calculated using the McCumber theory, and the peak emission cross-section is 1.03 x 10(-21) cm2 at 1.531 microm. This value is much larger than those of the silicate and phosphate glasses. Efficient green and weak red upconversion luminescence from Er3+ centers in the glass sample was observed at room temperature, and the upconversion excitation processes have been analyzed.

Raman study of molecular motions in relation to phase transitions in [Ni(NH3)6](NO3)2

International Nuclear Information System (INIS)

Janik, J.M.; Pick, R.M.; Le Postollec, M.

1987-01-01

A Raman band at 710 cm -1 has been used for the study of the NO 3 - ions reorientation and of the phase transitions in [Ni(NH 3 ) 6 ](NO 3 ) 2 . The strong temperature dependence of the width of this band in phase 1 gives evidence for the NO 3 - reorientations in this phase. The reorientations stop in phase 2. The same band was used for studying the phase 2/phase 3 transition. The large thermal hysteresis of this transition has ben confirmed. 16 refs., 4 figs. (author)

9 CFR 3.140 - Care in transit.

Science.gov (United States)

2010-01-01

... Warmblooded Animals Other Than Dogs, Cats, Rabbits, Hamsters, Guinea Pigs, Nonhuman Primates, and Marine... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Care in transit. 3.140 Section 3.140 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL...

9 CFR 3.116 - Care in transit.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Care in transit. 3.116 Section 3.116 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of Marine...

9 CFR 3.39 - Care in transit.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Care in transit. 3.39 Section 3.39 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of Guinea...

9 CFR 3.17 - Care in transit.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Care in transit. 3.17 Section 3.17 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of Dogs and...

9 CFR 3.64 - Care in transit.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Care in transit. 3.64 Section 3.64 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment and Transportation of Rabbits...

9 CFR 3.90 - Care in transit.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Care in transit. 3.90 Section 3.90 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of Nonhuman...

The transition of mouse pluripotent stem cells from the naïve to the primed state requires Fas signaling through 3-O sulfated heparan sulfate structures recognized by the HS4C3 antibody

International Nuclear Information System (INIS)

Hirano, Kazumi; Van Kuppevelt, Toin H.; Nishihara, Shoko

2013-01-01

Highlights: ► Fas transcript increases during the transition from the naïve to the primed state. ► 3OST-5 transcript, the HS4C3 epitope synthesis gene, increases during the transition. ► Fas signaling regulates the transition from the naïve to the primed state. ► HS4C3-binding epitope regulates the transition from the naïve to the primed state. ► Fas signaling is regulated by the HS4C3 epitope during the transition. -- Abstract: The characteristics of pluripotent embryonic stem cells of human and mouse are different. The properties of human embryonic stem cells (hESCs) are similar to those of mouse epiblast stem cells (mEpiSCs), which are in a later developmental pluripotency state, the so-called “primed state” compared to mouse embryonic stem cells (mESCs) which are in a naïve state. As a result of the properties of the primed state, hESCs proliferate slowly, cannot survive as single cells, and can only be transfected with genes at low efficiency. Generating hESCs in the naïve state is necessary to overcome these problems and allow their application in regenerative medicine. Therefore, clarifying the mechanism of the transition between the naïve and primed states in pluripotent stem cells is important for the establishment of stable methods of generating naïve state hESCs. However, the signaling pathways which contribute to the transition between the naïve and primed states are still unclear. In this study, we carried out induction from mESCs to mEpiSC-like cells (mEpiSCLCs), and observed an increase in the activation of Fas signaling during the induction. The expression of Fgf5, an epiblast marker, was diminished by inhibition of Fas signaling using the caspase-8 and -3 blocking peptides, IETD and DEVD, respectively. Furthermore, during the induction, we observed increased expression of 3-O sulfated heparan sulfate (HS) structures synthesized by HS 3-O-sulfotransferase (3OST), which are recognized by the HS4C3 antibody (HS4C3-binding epitope

The transition of mouse pluripotent stem cells from the naïve to the primed state requires Fas signaling through 3-O sulfated heparan sulfate structures recognized by the HS4C3 antibody

Energy Technology Data Exchange (ETDEWEB)

Hirano, Kazumi [Laboratory of Cell Biology, Department of Bioinformatics, Faculty of Engineering, Soka University, 1-236 Tangi-cho, Hachioji, Tokyo 192-8577 (Japan); Van Kuppevelt, Toin H. [Department of Biochemistry, Nijmegen Center for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, 280 P.O. Box 9101, 6500 HB Nijmegen (Netherlands); Nishihara, Shoko, E-mail: shoko@soka.ac.jp [Laboratory of Cell Biology, Department of Bioinformatics, Faculty of Engineering, Soka University, 1-236 Tangi-cho, Hachioji, Tokyo 192-8577 (Japan)

2013-01-18

Highlights: ► Fas transcript increases during the transition from the naïve to the primed state. ► 3OST-5 transcript, the HS4C3 epitope synthesis gene, increases during the transition. ► Fas signaling regulates the transition from the naïve to the primed state. ► HS4C3-binding epitope regulates the transition from the naïve to the primed state. ► Fas signaling is regulated by the HS4C3 epitope during the transition. -- Abstract: The characteristics of pluripotent embryonic stem cells of human and mouse are different. The properties of human embryonic stem cells (hESCs) are similar to those of mouse epiblast stem cells (mEpiSCs), which are in a later developmental pluripotency state, the so-called “primed state” compared to mouse embryonic stem cells (mESCs) which are in a naïve state. As a result of the properties of the primed state, hESCs proliferate slowly, cannot survive as single cells, and can only be transfected with genes at low efficiency. Generating hESCs in the naïve state is necessary to overcome these problems and allow their application in regenerative medicine. Therefore, clarifying the mechanism of the transition between the naïve and primed states in pluripotent stem cells is important for the establishment of stable methods of generating naïve state hESCs. However, the signaling pathways which contribute to the transition between the naïve and primed states are still unclear. In this study, we carried out induction from mESCs to mEpiSC-like cells (mEpiSCLCs), and observed an increase in the activation of Fas signaling during the induction. The expression of Fgf5, an epiblast marker, was diminished by inhibition of Fas signaling using the caspase-8 and -3 blocking peptides, IETD and DEVD, respectively. Furthermore, during the induction, we observed increased expression of 3-O sulfated heparan sulfate (HS) structures synthesized by HS 3-O-sulfotransferase (3OST), which are recognized by the HS4C3 antibody (HS4C3-binding epitope

Electron-impact excitation of atomic-argon 3p54s-3p55p spectral transitions

International Nuclear Information System (INIS)

Bogdanova, I.P.; Yurgenson, S.V.

1990-01-01

Cross sections of excitation of some spectral lines of argon corresponding to transitions from 3p 5 5p-levels are measured using a pulsed electron beam. Cross sections of level excitation are estimated. It is shown that in transition from 3p 5 4p-levels to 3p 5 5p-levels, the cross section of levels by means of the electron impact decreases 20 times

Effect of closed shells on the multipole mixing parameter δ(E2/M1)

International Nuclear Information System (INIS)

Morozov, V.A.

1992-01-01

The behavior of the magnitude and sign of the mixing parameter δ(E2/M1) in even-even nuclei has been studied in a number of papers. The most extensive data has been given for transitions of the type 3 γ + , 2 γ + , 2 β + →2 g + . The data on δ are relatively scarce for mixed transitions in odd nuclei with magic or semimagic cores. However, certain conclusions can be drawn about the behavior of δ in transitions in odd nuclei near magic numbers, and also in transitions in even-even nuclei when passing through quasishells: (1) the absolute value of the reduced mixing parameter in transitions between particle and cluster-vibrational states in odd nuclei decreases as a closed shell is approached; (2) δ has the same sign for transitions between particle and cluster-vibrational levels in nuclei with Z=83 and 85 and N=83, 85, and 87; (3) in odd nuclei the sign of δ is positive for transitions between positive-parity states s 1/2 -d 3/2 in Cd, Sm, and Tl isotopes and is negative for transitions between negative-parity states f 7/2 π and h 9/2 π in Sm, Gd, Bi, and At isotopes, independently of whether these transitions are neutron or proton transitions; (4) the removal of ±2 nucleons in an even shell from a magic core (and in certain nuclei a larger number of pairs of nucleons) does not lead to a change in sign of δ in transitions producing an odd nucleus; (5) the closure of quasishells at N=96 and 104 in even-even nuclei is associated with an increase in the absolute value of δ(E2/M1)/E γ , but the sign of δ does not change

Magnetic phase transitions and large mass enhancement in single crystal CaFe4As3

International Nuclear Information System (INIS)

Zhang Xiao-Dong; Wu Wei; Zheng Ping; Wang Nan-Lin; Luo Jian-Lin

2012-01-01

High quality single crystal CaFe 4 As 3 was grown by using the Sn flux method. Unlike layered CaFe 2 As 2 , CaFe 4 As 3 crystallizes in an orthorhombic three-dimensional structure. Two magnetic ordering transitions are observed at ∼ 90 K and ∼ 27 K, respectively. The high temperature transition is an antiferromagnetic(AF) ordering transition. However, the low temperature transition shows complex properties. It shows a ferromagnetic-like transition when a field is applied along b-axis, while antiferromagnetism-like transition when a field is applied perpendicular to b-axis. These results suggest that the low temperature transition at 27 K is a first-order transition from an AF state to a canted AF state. In addition, the low temperature electron specific heat coefficient reaches as high as 143 mJ/mol·K 2 , showing a heavy fermion behavior. (rapid communication)

Pressure-induced phase transitions of multiferroic BiFeO3

International Nuclear Information System (INIS)

Zhang Xiaoli; Dong Juncai; Liu Jing; Chen Dongliang; Wu Ye; Zhang Qian; Wu Xiang; Wu Ziyu

2013-01-01

Pressure-induced phase transitions of multiferroic BiFeO 3 have been investigated using synchrotron radiation X-ray diffraction with diamond anvil cell technique at room temperature. Present experimental data clearly show that rhombohedral (R3c) phase of BiFeO 3 first transforms to monoclinic (C2/m) phase at 7 GPa, then to orthorhombic (Pnma) phase at 11 GPa, which is consistent with recent theoretical ab initio calculation. However, we observe another peak at 2θ=7° in the pressure range of 5-7 GPa that has not been reported previously. Further analysis reveals that this reflection peak is attributed to the orthorhombic (Pbam) phase, indicating the coexistence of monoclinic phase with orthorhombic phase in low pressure range. (authors)

E3Net: a system for exploring E3-mediated regulatory networks of cellular functions.

Science.gov (United States)

Han, Youngwoong; Lee, Hodong; Park, Jong C; Yi, Gwan-Su

2012-04-01

Ubiquitin-protein ligase (E3) is a key enzyme targeting specific substrates in diverse cellular processes for ubiquitination and degradation. The existing findings of substrate specificity of E3 are, however, scattered over a number of resources, making it difficult to study them together with an integrative view. Here we present E3Net, a web-based system that provides a comprehensive collection of available E3-substrate specificities and a systematic framework for the analysis of E3-mediated regulatory networks of diverse cellular functions. Currently, E3Net contains 2201 E3s and 4896 substrates in 427 organisms and 1671 E3-substrate specific relations between 493 E3s and 1277 substrates in 42 organisms, extracted mainly from MEDLINE abstracts and UniProt comments with an automatic text mining method and additional manual inspection and partly from high throughput experiment data and public ubiquitination databases. The significant functions and pathways of the extracted E3-specific substrate groups were identified from a functional enrichment analysis with 12 functional category resources for molecular functions, protein families, protein complexes, pathways, cellular processes, cellular localization, and diseases. E3Net includes interactive analysis and navigation tools that make it possible to build an integrative view of E3-substrate networks and their correlated functions with graphical illustrations and summarized descriptions. As a result, E3Net provides a comprehensive resource of E3s, substrates, and their functional implications summarized from the regulatory network structures of E3-specific substrate groups and their correlated functions. This resource will facilitate further in-depth investigation of ubiquitination-dependent regulatory mechanisms. E3Net is freely available online at http://pnet.kaist.ac.kr/e3net.

Isospin symmetry of Tz =±3/2→±1/2 Gamow-Teller transitions in A=41 nuclei

Science.gov (United States)

Fujita, Y.; Shimbara, Y.; Adachi, T.; Berg, G. P.; Brown, B. A.; Fujita, H.; Hatanaka, K.; Kamiya, J.; Nakanishi, K.; Sakemi, Y.; Sasaki, S.; Shimizu, Y.; Tameshige, Y.; Uchida, M.; Wakasa, T.; Yosoi, M.

2004-11-01

Under the assumption that isospin T is a good quantum number, isobaric analog states and various analogous transitions are expected in isobars with mass number A . The strengths of Tz =±3/2→±1/2 analogous Gamow-Teller (GT) transitions and analogous M1 transitions within the A=41 isobar quartet are compared in detail. The Tz =+3/2→+1/2 GT transitions from the Jπ = 3/2+ ground state of 41K leading to excited Jπ = 1/2+ , 3/2+ , and 5/2+ states in 41Ca were measured using the ( 3He ,t) charge-exchange reaction. With a high energy resolution of 35 keV , many fragmented states were observed, and the GT strength distribution was determined up to 10 MeV excitation energy ( Ex ) . The main part of the strength was concentrated in the Ex =4 6 MeV region. A shell-model calculation could reproduce the concentration, but not so well details of the strength distribution. The obtained distribution was further compared with two results of 41Ti β decay studying the analogous Tz =-3/2→-1/2 GT strengths. They reported contradicting distributions. One-to-one correspondences of analogous transitions and analog states were assigned up to Ex =6 MeV in the comparison with one of these 41Ti β -decay results. Combining the spectroscopic information of the analog states in 41Ca and 41Sc , the most probable Jπ values were deduced for each pair of analog states. It was found that 5/2+ states carry the main part of the observed GT strength, while much less GT strength was carried by 1/2+ and 3/2+ states. The gross features of the GT strength distributions for each J were similar for the isospin analogous Tz =±3/2→±1/2 transitions, but the details were somewhat different. From the difference of the distributions, isospin-asymmetry matrix elements of ≈8 keV were deduced. The Coulomb displacement energy, which is sensitive to the configuration of states, showed a sudden increase of about 50 keV at the excitation energy of 3.8 MeV . The strengths of several M1 transitions to the

Isospin symmetry of T-z=+/- 3/2 ->+/- 1/2 Gamow-Teller transitions in A=41 nuclei

NARCIS (Netherlands)

Fujita, Y; Shimbara, Y; Adachi, T; Berg, GPA; Fujita, H; Hatanaka, K; Kamiya, J; Nakanishi, K; Sakemi, Y; Sasaki, S; Shimizu, Y; Tameshige, Y; Uchida, M; Wakasa, T; Yosoi, M

2004-01-01

Under the assumption that isospin T is a good quantum number, isobaric analog states and various analogous transitions are expected in isobars with mass number A. The, strengths of T-z = +/-3/2 --> 1/2 analogous Gamow-Teller (GT) transitions and analogous M1 transitions within the A = 41 isobar

Isospin symmetry of T-z=+/- 3/2 ->+/- 1/2 Gamow-Teller transitions in A=41 nuclei

NARCIS (Netherlands)

Fujita, Y; Shimbara, Y; Adachi, T; Berg, GPA; Fujita, H; Hatanaka, K; Kamiya, J; Nakanishi, K; Sakemi, Y; Sasaki, S; Shimizu, Y; Tameshige, Y; Uchida, M; Wakasa, T; Yosoi, M

Under the assumption that isospin T is a good quantum number, isobaric analog states and various analogous transitions are expected in isobars with mass number A. The, strengths of T-z = +/-3/2 --> 1/2 analogous Gamow-Teller (GT) transitions and analogous M1 transitions within the A = 41 isobar

Temperature dependent optical dispersion and electronic transitions of highly a-axis oriented 0.8Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-0.2PbTiO{sub 3} films on SrTiO{sub 3} crystals: An ellipsometric evidence

Energy Technology Data Exchange (ETDEWEB)

Li, C.Q.; Zhang, J.Z.; Xu, L.P.; Zhu, J.J.; Duan, Z.H.; Hu, Z.G., E-mail: zghu@ee.ecnu.edu.cn; Chu, J.H.

2016-03-31

The relaxor ferroelectric 0.8Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-0.2PbTiO{sub 3} (0.8PZN-0.2PT) films have been fabricated on (100) SrTiO{sub 3} substrates by the sol–gel method. The structure, optical properties and electronic transitions have been investigated using X-ray diffraction (XRD), atomic force microscopy, scanning electron microscopy and ellipsometric spectra. The pure perovskite phase with highly a-axis (100)-preferential orientation as well as low screw dislocation are extracted based on high resolution XRD. Moreover, the red-shift trend of the electronic transitions at about 3.01 eV as a function of temperature follows the Bose-Einstein law induced by the electron–phonon interactions and lattice thermal expansion. Interestingly, the different optical behavior and structure variation can be observed at about 500 K, which reveal tetragonal to cubic structural transformations for the 0.8PZN-0.2PT films. It indicates that the potential application of ellipsometric spectra in judging the phase transitions and symmetries of ferroelectric material. - Highlights: • The highly a-axis oriented as well as low screw dislocated films were fabricated. • The temperature-dependent evolution of band gap was investigated. • The tetragonal to cubic structural transformations were observed at about 500 K. • The electronic transition mechanism was discussed mainly by first-principles calculations.

30 years of ergonomics at 3M: a case study.

Science.gov (United States)

Larson, N; Wick, H

2012-01-01

The added value of the Ergonomics Program at 3M was found to be improved employee safety, compliance with regulations and reduction of work-related illness, increases in productivity, and quality and operating efficiency. This paper describes the thirty years of existence of this program. For the first twenty years, the program objectives were to: respond to requests for assistance related to work-related musculoskeletal disorder (WMSD) concerns, raise employee awareness of MSDs and ergonomics; educate engineers in ergonomics design; and develop ergonomics teams at manufacturing locations. Since the year 2000, 3M's Ergonomics Program has been in transition from a US-centric and corporate-based technical-expertled program to a global program applying participatory ergonomics strategies within a macroergonomics framework. During that transition, the existing program requirements were revised, new methods and program tools were created, and expectations for implementation at the manufacturing locations clarified. This paper focuses on the company's manufacturing ergonomics program activities during the past ten years and includes specifics of the program's objectives, risk assessment reduction process, and ergonomics technical expertise development. The main benefit achieved throughout the company is reducing employee injury while also increasing productivity and operating efficiency.

Water promoted allylic nucleophilic substitution reactions of (E)-1,3 diphenylallyl acetate

KAUST Repository

Ghorpade, Seema Arun; Sawant, Dinesh N; Makki, Arwa; Sekar, N; Eppinger, Jö rg

2017-01-01

Transition metal free, water based, greener protocol for allylic alkylation, allylic amination, O-allylation of (E)-1,3-diphenylallyl acetate is described. The developed methodology is applicable for a wide range of nucleophiles furnishing excellent yields of corresponding products up to 87% under mild reaction conditions. A Distinct effect of water and base is explored for allylic nucleophilic substitution reactions of (E)-1,3-diphenylallyl acetate.

Water promoted allylic nucleophilic substitution reactions of (E)-1,3 diphenylallyl acetate

KAUST Repository

Ghorpade, Seema Arun

2017-11-30

Transition metal free, water based, greener protocol for allylic alkylation, allylic amination, O-allylation of (E)-1,3-diphenylallyl acetate is described. The developed methodology is applicable for a wide range of nucleophiles furnishing excellent yields of corresponding products up to 87% under mild reaction conditions. A Distinct effect of water and base is explored for allylic nucleophilic substitution reactions of (E)-1,3-diphenylallyl acetate.

Absorption intensities and emission cross sections of principal intermanifold and inter-Stark transitions of Er3+(4f 11) in polycrystalline ceramic garnet Y3Al5O12

International Nuclear Information System (INIS)

Sardar, Dhiraj K.; Russell, Charles C. III; Gruber, John B.; Allik, Toomas H.

2005-01-01

A comparative spectroscopic study is performed on Er 3+ (4f 11 ) ions doped in polycrystalline ceramic garnet Y 3 Al 5 O 12 (YAG) and single-crystal laser rod, both containing nominal 50 at. % of Er 3+ . The standard Judd-Ofelt (JO) model is applied to the room-temperature absorption intensities of Er 3+ (4f 11 ) transitions in both hosts to obtain the phenomenological intensity parameters. These parameters are subsequently used to determine the radiative decay rates, radiative lifetimes, and branching ratios of the Er 3+ transitions from the upper multiplet manifolds to the corresponding lower-lying multiplet manifolds 2S+1 L J of Er 3+ (4f 11 ) in these garnet hosts. The emission cross sections of the intermanifold Er 3+ 4 I 13/2 → 4 I 15/2 (1.5 μm) transition as well as the principal inter-Stark transition Y 1 →Z 4 (1550 nm) within the corresponding multiplet manifolds have been determined. The room-temperature fluorescence lifetimes of the 4 I 13/2 → 4 I 15/2 (1.5 μm) transition in both polycrystalline ceramic and single-crystal YAG samples were measured. From the radiative lifetimes determined from the JO model and the measured fluorescence lifetimes, the quantum efficiencies for both samples were determined. The comparative study of Er 3+ (4f 11 ) ions performed suggests that polycrystalline ceramic YAG is an excellent alternative to single-crystal YAG rod for certain applications

Some properties of tetravalent actinide phosphates of M1M42(PO4)3 type and peculiarities of their structure

International Nuclear Information System (INIS)

Burnaeva, A.A.; Volkov, Yu.F.; Kryukova, A.I.; Skiba, O.V.; Spiryakov, V.I.; Korshunov, I.A.; Samojlova, T.K.

1987-01-01

Generalizing analysis of data on crystallographic and IR spectral properties of double phosphates of actinide and alkali elements of M (1) M 2 (4) (PO 4 ) 3 type is conducted. It is shown, that Li - , Na - , K - , Rb - , CsTh 2 (PO 4 ) 3 , Li - , Na - , KU 2 (PO 4 ) 3 , NaNp 2 (PO 4 ) 3 compounds crystallize in a monoclinic type structure and form an isostructural phosphate series. It is ascertained, that in rubidium-uranium, uranium-cesium systems double salt formation is not observed. Plutonium-sodium phosphate has a rhombic-type structure, which points out to the existence of a morphotropic transition in NaM 2 4 (PO 4 ) 3 phosphate series at the Np-Pu boundary. Some regularities of structure and effect of M 1 and M 4 nature on the double phosphate structure are revealed

Conformal Gauge Mediation and Light Gravitino of Mass m3/2 < O(10) eV

International Nuclear Information System (INIS)

Ibe, M.; SLAC; Nakayama, Y.; Yanagida, T.T.

2008-01-01

We discuss a class of gauge mediated supersymmetry breaking models with conformal invariance above the messenger mass scale (conformal gauge mediation). The spectrum of the supersymmetric particles including the gravitino is uniquely determined by the messenger mass. When the conformal fixed point is strongly interacting, it predicts a light gravitino of mass m 3/2 < O(10) eV, which is attractive since such a light gravitino causes no problem in cosmology

TOR and S6K1 promote translation reinitiation of uORF-containing mRNAs via phosphorylation of eIF3h.

Science.gov (United States)

Schepetilnikov, Mikhail; Dimitrova, Maria; Mancera-Martínez, Eder; Geldreich, Angèle; Keller, Mario; Ryabova, Lyubov A

2013-04-17

Mammalian target-of-rapamycin (mTOR) triggers S6 kinase (S6K) activation to phosphorylate targets linked to translation in response to energy, nutrients, and hormones. Pathways of TOR activation in plants remain unknown. Here, we uncover the role of the phytohormone auxin in TOR signalling activation and reinitiation after upstream open reading frame (uORF) translation, which in plants is dependent on translation initiation factor eIF3h. We show that auxin triggers TOR activation followed by S6K1 phosphorylation at T449 and efficient loading of uORF-mRNAs onto polysomes in a manner sensitive to the TOR inhibitor Torin-1. Torin-1 mediates recruitment of inactive S6K1 to polysomes, while auxin triggers S6K1 dissociation and recruitment of activated TOR instead. A putative target of TOR/S6K1-eIF3h-is phosphorylated and detected in polysomes in response to auxin. In TOR-deficient plants, polysomes were prebound by inactive S6K1, and loading of uORF-mRNAs and eIF3h was impaired. Transient expression of eIF3h-S178D in plant protoplasts specifically upregulates uORF-mRNA translation. We propose that TOR functions in polysomes to maintain the active S6K1 (and thus eIF3h) phosphorylation status that is critical for translation reinitiation.

Second order magnetic phase transition and scaling analysis in iron doped manganite La0.7Ca0.3Mn1−xFexO3 compounds

International Nuclear Information System (INIS)

Ginting, Dianta; Nanto, Dwi; Denny, Yus Rama; Tarigan, Kontan; Hadi, Syamsul; Ihsan, Mohammad; Rhyee, Jong-Soo

2015-01-01

We investigated magnetic properties of La 0.7 Ca 0.3 Mn 1−x Fe x O 3 (x=0.09 and 0.11) compounds in terms of isothermal magnetization analysis and scaling behavior with various critical exponents. From the Landau theory of magnetic phase transition, we found that the paramagnetic to ferromagnetic phase transition in La 0.7 Ca 0.3 Mn 1−x Fe x O 3 (x=0.09 and 0.11) compounds is the type of second order magnetic transition (SOMT), which contrary to the first order magnetic transition (FOMT) for low Fe-doped compounds (x<0.09) in previous reports. When we investigate the critical behavior of the compounds near T=T c by the modified Arrott plot, Kouvel–Fisher plots, and critical isothermal analysis, the estimated critical exponents β, γ, and δ are in between the theoretically predicted values for three-dimensional Heisenberg and mean-field interaction models. It is noteworthy that the scaling relations are obeyed in terms of renormalization magnetization m=ε −β M(H,ε) and renormalized field h=|ε| β+γ H. Temperature-dependent effective exponents β eff and γ eff correspond to the ones of disordered ferromagnets. It is shown that the magnetic state of the compounds is not fully described by the conventional localized-spin interaction model because the ferromagnetic interaction has itinerant character by increasing Fe-doping concentration. - Highlights: • The ferromagnetic phase transition is of second order in La 0.7 Ca 0.3 Mn 1−x Fe x O 3 . • The critical exponents are in between the 3D Heisenberg and mean-field models. • The ferromagnetic interaction becomes more itinerant by Fe-doping

Analysis of the spectrum six times ionized zinc (Zn VII): the 3d6-3d54p transition array

International Nuclear Information System (INIS)

Hof, G.H. van het; Joshi, Y.N.; Raassen, A.J.J.; Ryabtsev, A.N.

1993-01-01

The spectrum of zinc was photographed in the 100-300 A region on a 10.7 m grazing incidence spectrograph using a triggered spark light source. 335 lines were classified in the Zn VII 3d 6 -3d 5 4p transition array, resulting in the establishment of 30 of the 34 levels of the 3d 6 configuration and 103 of the 214 levels of the 3d 5 4p. The ground configuration 3d 6 was described by a generalized least-squares fit (GLSF) involving orthogonal operators to a set of 3d N configurations. This yielded a mean error of 3 cm -1 for its level values. The excited configruation was described by the conventional Slater Condon parameter set, giving a mean error of 105 cm -1 . (orig.)

Dimensional crossover of effective orbital dynamics in polar distorted He 3 -A : Transitions to antispacetime

Science.gov (United States)

Nissinen, J.; Volovik, G. E.

2018-01-01

Topologically protected superfluid phases of He 3 allow one to simulate many important aspects of relativistic quantum field theories and quantum gravity in condensed matter. Here we discuss a topological Lifshitz transition of the effective quantum vacuum in which the determinant of the tetrad field changes sign through a crossing to a vacuum state with a degenerate fermionic metric. Such a transition is realized in polar distorted superfluid He 3 -A in terms of the effective tetrad fields emerging in the vicinity of the superfluid gap nodes: the tetrads of the Weyl points in the chiral A-phase of He 3 and the degenerate tetrad in the vicinity of a Dirac nodal line in the polar phase of He 3 . The continuous phase transition from the A -phase to the polar phase, i.e., the transition from the Weyl nodes to the Dirac nodal line and back, allows one to follow the behavior of the fermionic and bosonic effective actions when the sign of the tetrad determinant changes, and the effective chiral spacetime transforms to antichiral "anti-spacetime." This condensed matter realization demonstrates that while the original fermionic action is analytic across the transition, the effective action for the orbital degrees of freedom (pseudo-EM) fields and gravity have nonanalytic behavior. In particular, the action for the pseudo-EM field in the vacuum with Weyl fermions (A-phase) contains the modulus of the tetrad determinant. In the vacuum with the degenerate metric (polar phase) the nodal line is effectively a family of 2 +1 d Dirac fermion patches, which leads to a non-analytic (B2-E2)3/4 QED action in the vicinity of the Dirac line.

Structural phase transition and precursor phenomena in V3Si

International Nuclear Information System (INIS)

Kobayashi, T.; Fukase, T.; Toyota, N.; Muto, Y.

1982-01-01

Thermal dilation experiments on the transforming single crystals V 3 Si indicated that the precursor of the structural transformation at Tsub(m) of about 21 K starts at anomalously high temperatures (proportional70 K) and grows drastically near Tsub(m). This anomaly is also accompanied by the critical increment of electrical resistivity showing a sharp peak at Tsub(m). The application of the uniaxial stress suppresses the resistivity anomaly and makes the superconducting transition width narrower. We propose a model for the precursor phenomena in terms of (1) the directional strain fields (non-cubic) pinned near the defects and (2) the memory effect of orientation of the tetragonal domains born by the defects such as dislocations. (orig.)

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.

Polarization dependence of resonant X-ray emission spectra in 3dn transition metal compounds with n=0, 1, 2, 3

International Nuclear Information System (INIS)

Matsubara, Masahiko; Kotani, Akio; Shin, Shik; Uozumi, Takayuki; Harada, Yoshihisa

2002-01-01

The polarization dependence of 2p → 3d → 2p resonant X-ray emission spectroscopy (RXES) in 3d 1 , 3d 2 and 3d 3 systems (TiF 3 , VF 3 and Cr 2 O 3 , respectively) is measured and analyzed by means of the MX 6 (M denotes a transition metal and X denotes a ligand, respectively) cluster model. The results are compared with a previous one for the 3d 0 system (TiO 2 ). Generally, with increasing 3d electron number, the spectral structure of RXES becomes more complicated by the influence of the crystal field and the multiplet coupling effect. Moreover, we point out that the selection rules on the polarization dependence of RXES change with the 3d electron number and that a drastic resonance enhancement corresponding to the excitation to an antibonding state in the 3d 0 system is almost absent for the 3d n systems with n=1, 2 and 3. (author)

Countering the Segregation of Transition-Metal Ions in LiMn1/3 Co1/3 Ni1/3 O2 Cathode for Ultralong Life and High-Energy Li-Ion Batteries.

Science.gov (United States)

Luo, Dong; Fang, Shaohua; Tamiya, Yu; Yang, Li; Hirano, Shin-Ichi

2016-08-01

High-voltage layered lithium transition-metal oxides are very promising cathodes for high-energy Li-ion batteries. However, these materials often suffer from a fast degradation of cycling stability due to structural evolutions. It seriously impedes the large-scale application of layered lithium transition-metal oxides. In this work, an ultralong life LiMn1/3 Co1/3 Ni1/3 O2 microspherical cathode is prepared by constructing an Mn-rich surface. Its capacity retention ratio at 700 mA g(-1) is as large as 92.9% after 600 cycles. The energy dispersive X-ray maps of electrodes after numerous cycles demonstrate that the ultralong life of the as-prepared cathode is attributed to the mitigation of TM-ions segregation. Additionally, it is discovered that layered lithium transition-metal oxide cathodes with an Mn-rich surface can mitigate the segregation of TM ions and the corrosion of active materials. This study provides a new strategy to counter the segregation of TM ions in layered lithium transition-metal oxides and will help to the design and development of high-energy cathodes with ultralong life. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification of forbidden vibration-rotation transitions in 15NH3

Science.gov (United States)

Urban, Š.; D'Cunha, Romola; Narahari Rao, K.

1984-07-01

Forbidden Δk - l = 3 vibration-rotation transitions have been observed in the ν4 band of 15NH3. The analysis of these transitions, together with previously published data on the allowed transitions, has made it possible to determine a set of molecular parameters, including for the first time the rotational constant C as well as the centrifugal distortion constants DK and HKKK, which are necessary for the calculation of energy levels. Some weak forbidden transitions in the ν2 band have also been observed.

Absence of Mass Renormalization upon the Metal-Insulator Transition in La_1-xSr_xMnO_3

Science.gov (United States)

Okuda, T.; Asamitsu, A.; Tokura, Y.

1998-03-01

The low-temperature specific heat as well as the resistivity of La_1-xSr_xMnO3 crystals has been measured under magnetic fields to investigate the critical behavior of the metal-insulator (MI) transition, which is induced by carrier doping around a critical composition of x_c=0.17. We observed the reduction of specific heat by application of magnetic fields, which is due to the suppression of the contribution of spin wave. Thus, the magnetic contribution to the specific heat was carefully removed to extract the electronic contribution. The effective mass, derived from obtained electronic specific heat coefficient γ, is a few times as large as a bare mass in the ferromagnetic metallic state, e.g. γ = 3.5 (mJ/K^2 mole) at x=0.3, and does not critically increase around the critical point while showing the maximum value γ = 5.1 (mJ/K^2 mole) at x=0.18. This is in contrast with the conspicuous mass renormalization effect as observed for other transition metal oxide, eg. V_2O3 and LaTiO_3. The γ value rather decreases with the decrease of x from 0.18 to 0.15, namely in the immediate vicinity of the MI boundary. This suggests that the Fermi surface gradually shrinks towards the insulating phase and finally disappears at the MI phase boundary. This work was supported by New Energy and Industrial Technology Development Organization (NEDO) of Japan.

GSTA3 Attenuates Renal Interstitial Fibrosis by Inhibiting TGF-Beta-Induced Tubular Epithelial-Mesenchymal Transition and Fibronectin Expression.

Directory of Open Access Journals (Sweden)

Yun Xiao

Full Text Available Tubular epithelial-mesenchymal transition (EMT has been widely accepted as the underlying mechanisms of renal interstitial fibrosis (RIF. The production of reactive oxygen species (ROS plays a vital role in tubular EMT process. The purpose of this study was to investigate the involved molecular mechanisms in TGF-beta-induced EMT and identify the potential role of glutathione S-transferase alpha 3 (GSTA3 in this process. The iTRAQ screening was performed to identify protein alterations of the rats underwent unilateral-ureteral obstruction (UUO. Protein expression of GSTA3 in patients with obstructive nephropathy and UUO rats was detected by immunohistochemistry. Protein and mRNA expression of GSTA3 in UUO rats and NRK-52E cells were determined by Western blot and RT-PCR. siRNA and overexpression plasmid were transfected specifically to assess the role of GSTA3 in RIF. The generation of ROS was measured by dichlorofluorescein fluorescence analysis. GSTA3 protein and mRNA expression was significantly reduced in UUO rats. Immunohistochemical analysis revealed that GSTA3 expression was reduced in renal cortex in UUO rats and patients with obstructive nephropathy. Treating with TGF-β1 down-regulated GSTA3 expression in NRK-52E cells, which have been found to be correlated with the decreased expression in E-cadherin and megalin and increased expression in α-smooth muscle actin. Furthermore, knocking down GSTA3 in NRK-52 cells led to increased production of ROS and tubular EMT, whereas overexpressing GSTA3 ameliorated ROS production and prevented the occurrence of tubular EMT. GSTA3 plays a protective role against tubular EMT in renal fibrosis, suggesting GSTA3 is a potential therapeutic target for RIF.

Heterobimetallic coordination polymers involving 3d metal complexes and heavier transition metals cyanometallates

Energy Technology Data Exchange (ETDEWEB)

Peresypkina, Eugenia V. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Samsonenko, Denis G. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Vostrikova, Kira E., E-mail: vosk@niic.nsc.ru [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); LMI, Université Claude Bernard Lyon 1, 69622 Villeurbanne Cedex (France)

2015-04-15

The results of the first steps in the design of coordination polymers based on penta- and heptacyanometallates of heavier d transitions metals are presented. The 2D structure of the coordination polymers: [(Mn(acacen)){sub 2}Ru(NO)(CN){sub 5}]{sub n} and two complexes composed of different cyanorhenates, [Ni(cyclam)]{sub 2}[ReO(OH)(CN){sub 4}](ClO{sub 4}){sub 2}(H{sub 2}O){sub 1.25} and [Cu(cyclam)]{sub 2}[Re(CN){sub 7}](H{sub 2}O){sub 12}, was confirmed by single crystal XRD study, the rhenium oxidation state having been proved by the magnetic measurements. An amorphism of [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2} (M=Ni, Cu) polymers does not allow to define strictly their dimensionality and to model anisotropic magnetic behavior of the compounds. However, with high probability a honey-comb like layer structure could be expected for [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2} complexes, studied in this work, because such an arrangement is the most common among the bimetallic assemblies of hexa- and octacyanometallates with a ratio [M(cyclam)]/[M(CN){sub n}]=3/2. For the first time was prepared and fully characterized a precursor (n-Bu{sub 4}N){sub 2}[Ru(NO)(CN){sub 5}], soluble in organic media. - Graphical abstract: The very first results in the design of 2D coordination polymers based on penta- and heptacyanometallates of 4d and5d transitions metals are presented. - Highlights: • Design of coordination polymers based on penta- and heptacyanometallates. • New Ru and Re cyanide based heterobimetallic coordination complexes. • Hydrolysis and ox/red processes involving [Re(CN){sub 7}]{sup 3+} during crystallization. • High magnetic anisotropy of [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2}(H{sub 2}O){sub n}, M=Cu, Ni, complexes.

Combustion synthesis and characterization of MV0.5P0.5O4: Sm3+, Tm3+ (M = Gd, La, Y)

Science.gov (United States)

Motloung, Selepe J.; Lephoto, Mantwa A.; Tshabalala, Kamohelo G.; Ntwaeaborwa, Odireleng M.

2018-04-01

In this paper, GdV0.5P0.5O4: Sm3+, Tm3+, LaV0.5P0.5O4: Sm3+, Tm3+ and YV0.5P0.5O4: Sm3+, Tm3+ phosphor powders were prepared by solution combustion method using urea as a fuel. The phase purity, surface morphology, optical and photoluminescence properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis spectroscopy and photoluminescence spectroscopy. The XRD results indicated that the prepared powders are of a single phase and crystallized in tetragonal structure for Gd and Y systems while monoclinic phase was observed for La system. SEM showed that the samples consisted of mixed structures. The estimated band gaps were 2.2, 2.4 and 2.3 eV for Y, Gd and La systems respectively. The photoluminescence results showed four emission peaks. One peak is assigned to 1G4 - 3H6 transition of Tm3+, and three other emission peaks are attributed to 6G5/2 - 6H5/2, 6G5/2 - 6H7/2 and 6G5/2 - 6H9/2 transitions of Sm3+. The photoluminescent intensity was the highest in the gadolinium system.

Crystal structure and phase transitions in perovskite-like C(NH2)3SnCl3

International Nuclear Information System (INIS)

Szafranski, Marek; Stahl, Kenny

2007-01-01

X-ray single-crystal diffraction, high-temperature powder diffraction and differential thermal analysis at ambient and high pressure have been employed to study the crystal structure and phase transitions of guanidinium trichlorostannate, C(NH 2 ) 3 SnCl 3 . At 295 K the crystal structure is orthorhombic, space group Pbca, Z=8, a=7.7506(2) A, b=12.0958(4) A and c=17.8049(6) A, solved from single-crystal data. It is perovskite-like with distorted corner-linked SnCl 6 octahedra and with ordered guanidinium cations in the distorted cuboctahedral voids. At 400 K the structure shows a first-order order-disorder phase transition. The space group is changed to Pnma with Z=4, a=12.1552(2) A, b=8.8590(2) A and c=8.0175(1) A, solved from powder diffraction data and showing disordering of the guanidinium cations. At 419 K, the structure shows yet another first-order order-disorder transformation with disordering of the SnCl 3 - part. The space group symmetry is maintained as Pnma, with a=12.1786(2) A, b=8.8642(2) A and c=8.0821(2) A. The thermodynamic parameters of these transitions and the p-T phase diagram have been determined and described. - Graphical abstract: The perovskite-like crystals of C(NH 2 ) 3 SnCl 3 undergo two successive first-order phase transitions at 400 and 419 K, both accompanied by an essential order-disorder contribution. The p-T phase diagram exhibits a singular point at 219 MPa and 443 K

Lasing transition at 1.06 μm emission in Nd3+ -doped borate-based tellurium calcium zinc niobium oxide glasses for high-power solid-state lasers.

Science.gov (United States)

Ravi, O; Prasad, K; Jain, Rajiv; Venkataswamy, M; Chaurasia, Shivanand; Deva Prasad Raju, B

2017-08-01

The spectroscopic properties of Tellurium Calcium Zinc Niobium oxide Borate (TCZNB) glasses of composition (in mol%) 10TeO 2  + 15CaO + 5ZnO + 10 Nb 2 O 5  + (60 - x)B 2 O 3  + Nd 2 O 3 (x = 0.1, 0.5, 1.0 or 1.5 mol%) have been investigated experimentally. The three phenomenological intensity parameters Ω 2 , Ω 4, Ω 6 have been calculated using the Judd-Ofelt theory and in turn radiative properties such as radiative transition probabilities, emission cross-sections, branching ratios and radiative lifetimes have been estimated. The trend found in the JO intensity parameter is Ω 2  > Ω 6  > Ω 4 If Ω 6  > Ω 4 , the glass system is favourable for the laser emission 4 F 3 /2  →  4 I 11 /2 in the infrared (IR) wavelength. The experimental values of branching ratio of 4 F 3 /2  →  4 I 11 /2 transition indicate favourable lasing action with low threshold power. The evaluated total radiative transition probabilities (A T ), stimulated emission cross-section (σ e ) and gain bandwidth parameters (σ e  × Δλ p ) were compared with earlier reports. An energy level analysis has been carried out considering the experimental energy positions of the absorption and emission bands. Copyright © 2016 John Wiley & Sons, Ltd.

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.

Tm3+/Yb3+ co-doped tellurite glass with silver nanoparticles for 1.85 μm band laser material

Science.gov (United States)

Huang, Bo; Zhou, Yaxun; Cheng, Pan; Zhou, Zizhong; Li, Jun; Jin, Wei

2016-10-01

Tm3+/Yb3+ co-doped tellurite glasses with different silver nanoparticles (Ag NPs) concentrations were prepared using the conventional melt-quenching technique and characterized by the UV/Vis/NIR absorption spectra, 1.85 μm band fluorescence emission spectra, transmission electron microscopy (TEM) images, differential scanning calorimeter (DSC) curves and X-ray diffraction (XRD) patterns to investigate the effects of Ag NPs on the 1.85 μm band spectroscopic properties of Tm3+ ions, thermal stability and structural nature of glass hosts. Under the excitation of 980 nm laser diode (LD), the 1.85 μm band fluorescence emission of Tm3+ ions enhances significantly in the presence of Ag NPs with average diameter of ∼8 nm and local surface Plasmon resonance (LSPR) band of ∼590 nm, which is mainly attributed to the increased local electric field induced by Ag NPs at the proximity of doped rare-earth ions on the basis of energy transfer from Yb3+ to Tm3+ ions. An improvement by about 110% of fluorescence intensity is observed in the Tm3+/Yb3+ co-doped tellurite glass containing 0.5 mol% amount of AgNO3 while the prepared glass samples possess good thermal stability and amorphous structural nature. Meanwhile, the Judd-Ofelt intensity parameters Ωt (t = 2,4,6), spontaneous radiative transition probabilities, fluorescence branching ratios and radiative lifetimes of relevant excited levels of Tm3+ ions were determined based on the Judd-Ofelt theory to reveal the enhanced effects of Ag NPs on the 1.85 μm band spectroscopic properties, and the energy transfer micro-parameters and phonon contribution ratios were calculated based on the non-resonant energy transfer theory to elucidate the energy transfer mechanism between Yb3+ and Tm3+ ions. The present results indicate that the prepared Tm3+/Yb3+ co-doped tellurite glass with an appropriate amount of Ag NPs is a promising lasing media applied for 1.85 μm band solid-state lasers and amplifiers.

Magnetic order of Y{sub 3}NiSi{sub 3}-type R{sub 3}NiSi{sub 3} (R=Gd–DY) compounds

Energy Technology Data Exchange (ETDEWEB)

Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Yapaskurt, V.O. [Department of Petrology, Faculty of Geology, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Nirmala, R. [Indian Institute of Technology Madras, Chennai 600036 (India); Malik, S.K.; Quezado, S. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Natal 59082-970 (Brazil); Yao, Jinlei; Mozharivskyj, Y. [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1 (Canada); Nigam, A.K. [Tata Institute of Fundamental Research, Mumbai 400005 (India); Isnard, O. [Université Grenoble Alpes, Inst NEEL, BP166, F-38042 Grenoble (France); CNRS, Institut NEEL, 25 rue des martyrs, F-38042 Grenoble (France)

2016-01-15

Magnetic measurements and neutron powder diffraction investigations on the Y{sub 3}NiSi{sub 3}-type R{sub 3}NiSi{sub 3} compounds (R=Gd, Tb, Dy) reveal their complex antiferromagnetic ordering. Magnetic measurements on Gd{sub 3}NiSi{sub 3}, Tb{sub 3}NiSi{sub 3} and Dy{sub 3}NiSi{sub 3} indicate antiferromagnetic-like transition at temperatures 260 K, 202 K and 140 K, respectively. Also, the Tb{sub 3}NiSi{sub 3} and Dy{sub 3}NiSi{sub 3} compounds show spin-reorientation transition at 132 K and 99 K, respectively. Below the spin-reorientation transition, the isothermal magnetization curves indicate the metamagnetic-like behavior of Tb{sub 3}NiSi{sub 3} and Dy{sub 3}NiSi{sub 3}. The magnetocaloric effect of Dy{sub 3}NiSi{sub 3} is calculated in terms of isothermal magnetic entropy change and it reaches a maximum value of −1.2 J/kg K and −1.1 J/kg K for a field change of 50 kOe near 146 K and 92 K, respectively. The neutron diffraction studies of Tb{sub 3}NiSi{sub 3} suggest the magnetic ordering of the Tb2 4j sublattice and no magnetic ordering of the Tb1 2a sublattice. Tb{sub 3}NiSi{sub 3} transforms from the high temperature paramagnetic state to the commensurate high-temperature a- and c-axis antiferromagnet of I′2/m magnetic space group below 250 K. Below 150 K, the high-temperature antiferromagnet transforms into the low-temperature a-, b- and c-axis antiferromagnet of I′i magnetic space group. At 1.5 K, the terbium magnetic moment in Tb2 sublattice and its a-, b- and c-axis components reach the values of M{sub Tb2}=8.2(1) μ{sub B}, M{sub aTb2}=5.9(1) μ{sub B}, M{sub bTb2}=4.3(2) μ{sub B} and M{sub cTb2}=3.7(2) μ{sub B}, respectively. - Highlights: • Gd{sub 3}NiSi{sub 3}, Tb{sub 3}NiSi{sub 3} and Dy{sub 3}NiSi{sub 3} have Neel points of 260. 202 and 140 K. • Tb{sub 3}NiSi{sub 3} and Dy{sub 3}NiSi{sub 3} show spin-reorientation transition at 132 and 99 K. • Tb{sub 3}NiSi{sub 3} exhibits the commensurate magnetic ordering of Tb2 4j sublattice

The QCD phase transition with 2, 3, and 4 flavors of dynamical quarks

International Nuclear Information System (INIS)

Christ, N.H.

1991-01-01

Recent results from the 256-node Columbia machine are presented on 16 3 xN t lattices for N t = 4 and 6 using Kogut-Susskind fermions with quark masses ranging between 0.01 and 1.0 lattice units. It is argued that for four flavors the region for small quark mass where the transition is first order shrinks more rapidly than suggested by naive scaling gas N t increases from 4 to 6. For N t = 4 and three degenerate flavors of quarks the transition remains first order at m = 0.025 however it is weaker than for four flavors. For 2 flavors no first order signal is seen even when the quark mass decreased to 0.01. Finally, the location and nature of the transition as the strange quark mass is varied (interpolating between the case of 2 and 3 degenerate flavors) is discussed. (orig.)

Comparison of 3D transitional CFD simulations for rotating wind turbine wings with measurements

DEFF Research Database (Denmark)

Schaffarczyk, A P; Boisard, R; Boorsma, K

2018-01-01

. In addition, during MN3, high-frequency Kulite data from experiments were used to detect traces of transitional effects. Complementary, the following set of codes were applied to cases 1.1 and 1.2 (axial inflow with 10 m/s and 15 m/s respectively) – elsA, CFX, OpenFOAM (with 2 different turbulence...

Tunable luminescence in Bi{sup 3+} and Eu{sup 3+} co-doped Sr{sub 3}AlO{sub 4}F Oxyfluorides phosphors

Energy Technology Data Exchange (ETDEWEB)

Noh, Minhee [Center for Green Fusion Technology and Department of Engineering in Energy & Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Cho, So-Hye [Center for Materials Architecturing, Institute of Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of); Park, Sangmoon, E-mail: spark@silla.ac.kr [Center for Green Fusion Technology and Department of Engineering in Energy & Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of)

2015-05-15

Luminescent materials composed of Sr{sub 3−3(m+n)/2}Bi{sub m}Eu{sub n}AlO{sub 4}F (m=0.001–0.05, n=0–0.1) were prepared by the solid-state reaction method. The excitation and emission spectra of Sr{sub 3−3m/2}Bi{sub m}AlO{sub 4}F (m=0.001–0.05) were investigated using photoluminescence spectroscopy; broad-band emission peaks owing to the {sup 3}P{sub 1}→{sup 1}S{sub 0} transitions of the Bi{sup 3+} activator were observed centered near 427 nm. Critical emission quenching, as a function of Bi{sup 3+} content in Sr{sub 3−3m/2}Bi{sub m}AlO{sub 4}F, was observed at relatively low concentrations of the activator. The quantum efficiency of Sr{sub 2.985}Bi{sub 0.01}AlO{sub 4}F in comparison with sodium salicylate was explored. When Sr{sup 2+} ions in the oxyfluoride host were replaced by Bi{sup 3+} and Eu{sup 3+} ions, the effective s{sup 2}–sp and f–f transitions of the Bi{sup 3+} and Eu{sup 3+} ions, respectively, were simultaneously observed. The diverse excitation and emission photoluminescence spectra and color CIE coordinates, as well as the blue to orange-red emission, obtained using Sr{sub 3−3(m+n)/2}Bi{sub m}Eu{sub n}AlO{sub 4}F (m=0–0.05, n=0–0.1) phosphors are also discussed. - Highlights: • Sr{sub 3−3(m+n)/2}Bi{sub m}Eu{sub n}AlO{sub 4}F (m=0.001–0.05, n=0–0.1) phosphors was prepared. • Emission owing to the {sup 3}P{sub 1}→{sup 1}S{sub 0} transitions of the Bi{sup 3+} activator was observed. • Quantum efficiency of Sr{sub 2.985}Bi{sub 0.01}AlO{sub 4}F was explored. • s{sup 2}–sp and f–f transitions of the Bi{sup 3+} and Eu{sup 3+} ions were simultaneously observed. • CIE values including the emissions from blue to red regions were achieved.

A Transcript-Specific eIF3 Complex Mediates Global Translational Control of Energy Metabolism

Directory of Open Access Journals (Sweden)

Meera Shah

2016-08-01

Full Text Available The multi-subunit eukaryotic translation initiation factor eIF3 is thought to assist in the recruitment of ribosomes to mRNA. The expression of eIF3 subunits is frequently disrupted in human cancers, but the specific roles of individual subunits in mRNA translation and cancer remain elusive. Using global transcriptomic, proteomic, and metabolomic profiling, we found a striking failure of Schizosaccharomyces pombe cells lacking eIF3e and eIF3d to synthesize components of the mitochondrial electron transport chain, leading to a defect in respiration, endogenous oxidative stress, and premature aging. Energy balance was maintained, however, by a switch to glycolysis with increased glucose uptake, upregulation of glycolytic enzymes, and strict dependence on a fermentable carbon source. This metabolic regulatory function appears to be conserved in human cells where eIF3e binds metabolic mRNAs and promotes their translation. Thus, via its eIF3d-eIF3e module, eIF3 orchestrates an mRNA-specific translational mechanism controlling energy metabolism that may be disrupted in cancer.

A Study of the 3.3 and 3.4 μm Emission Features in Proto-Planetary Nebulae

Science.gov (United States)

Hrivnak, Bruce J.; Geballe, T. R.; Kwok, Sun

2007-06-01

Medium-resolution spectra have been obtained of seven carbon-rich proto-planetary nebulae (PPNs) and one young planetary nebula from 3.2 to 3.8 μm, an interval containing the prominent hydrocarbon CH stretches at 3.3 and 3.4 μm due to aromatic and aliphatic structures, respectively. The 3.3 μm feature is newly identified in IRAS 23304+6147, 22223+4327, and 06530-0213 and is confirmed in Z02229+6208. Three of the PPNs emit in the 3.4 μm feature, two of these being new identifications, IRAS 20000+3239 and 01005+7910, with two others showing possible detections. The 3.3 and 3.4 μm emission features in IRAS 22272+5435 are seen in the nebula offset from the star but not at the position of the central star, consistent with the 2003 results of Goto et al. A similar distribution is seen for the 3.3 μm feature in IRAS 22223+4327. All of the PPNs except IRAS 22272+5435 show Class A 3 μm emission features. These observations, when combined with those of the approximately equal number of other carbon-rich PPNs previously observed, demonstrate that there are large differences in the 3 μm emission bands, even for PPNs with central stars of similar spectral type, and thus that the behavior of the bands does not depend solely on spectral type. We also investigated other possible correlations to help explain these differences. These differences do not depend on the C/O value, since the Class B sources fall within the C/O range found for Class A. All of these 3.3 μm sources also show C2 absorption and 21 μm emission features, except IRAS 01005+7910, which is the hottest source at B0. This research is based on observations made at the W. M. Keck Observatory by Gemini staff, supported by the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., on behalf of the international Gemini partnership of Argentina, Australia, Brazil, Canada, Chile, the United Kingdom, and the United States of America. The W. M. Keck Observatory is

Regional Gastrointestinal Transit Times in Patients With Carcinoid Diarrhea: Assessment With the Novel 3D-Transit System.

Science.gov (United States)

Gregersen, Tine; Haase, Anne-Mette; Schlageter, Vincent; Gronbaek, Henning; Krogh, Klaus

2015-07-30

The paucity of knowledge regarding gastrointestinal motility in patients with neuroendocrine tumors and carcinoid diarrhea re-stricts targeted treatment. 3D-Transit is a novel, minimally invasive, ambulatory method for description of gastrointestinal motility. The system has not yet been evaluated in any group of patients. We aimed to test the performance of 3D-Transit in patients with carcinoid diarrhea and to compare the patients' regional gastrointestinal transit times (GITT) and colonic motility patterns with those of healthy subjects. Fifteen healthy volunteers and seven patients with neuroendocrine tumor and at least 3 bowel movements per day were inves-tigated with 3D-Transit and standard radiopaque markers. Total GITT assessed with 3D-Transit and radiopaque markers were well correlated (Spearman's rho = 0.64, P = 0.002). Median total GITT was 12.5 (range: 8.5-47.2) hours in patients versus 25.1 (range: 13.1-142.3) hours in healthy (P = 0.007). There was no difference in gastric emptying (P = 0.778). Median small intestinal transit time was 3.8 (range: 1.4-5.5) hours in patients versus 4.4 (range: 1.8-7.2) hours in healthy subjects (P = 0.044). Median colorectal transit time was 5.2 (range: 2.9-40.1) hours in patients versus 18.1 (range: 5.0-134.0) hours in healthy subjects (P = 0.012). Median frequency of pansegmental co-lonic movements was 0.45 (range: 0.03-1.02) per hour in patients and 0.07 (range: 0-0.61) per hour in healthy subjects (P = 0.045). Three-dimensional Transit allows assessment of regional GITT in patients with diarrhea. Patients with carcinoid diarrhea have faster than normal gastrointestinal transit due to faster small intestinal and colorectal transit times. The latter is caused by an increased frequency of pansegmental colonic movements.

19 CFR 148.3 - Customs treatment after transiting the Panama Canal.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false Customs treatment after transiting the Panama Canal. 148.3 Section 148.3 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND... § 148.3 Customs treatment after transiting the Panama Canal. Passengers' baggage and effects and...

Post-perovskite transitions in CaB4+O3 at high pressure

International Nuclear Information System (INIS)

Akaogi, M; Shirako, Y; Kojitani, H; Takamori, S; Yamaura, K; Takayama-Muromachi, E

2010-01-01

High-pressure phase transitions in CaRhO 3 were examined using a multianvil apparatus up to 27 GPa and 1930 o C. CaRhO 3 perovskite transforms to post-perovskite via a monoclinic intermediate phase with increasing pressure. Volume changes for the transitions of perovskite - intermediate phase and of intermediate phase - post-perovskite are -1.1 and -0.7 %, respectively. CaRhO 3 post-perovskite is the fourth quenchable post-perovskite oxide found so far. By high-temperature calorimetric experiments, enthalpy of the perovskite - post-perovskite transition in CaRuO 3 was measured as 15.2±3.3 kJ/mol. Combining the datum with those of CaIrO 3 , it is shown that CaIrO 3 perovskite is energetically less stable than CaRuO 3 perovskite. This is consistent with the fact that orthorhombic distortion of CaIrO 3 perovskite is larger than CaRuO 3 , as indicated with the tilt-angle of octahedral framework of perovskite structure. The transition pressure from perovskite to post-perovskite in CaBO 3 (B = Ru, Rh, Ir) increases almost linearly with decreasing the tilt-angle, suggesting that the perovskite - post-perovskite transition may result from instability of the perovskite structure with pressure.

Ultraviolet transitions from the 2 3P states of helium-like argon

International Nuclear Information System (INIS)

Davis, W.A.

1976-09-01

This thesis describes the observation of two allowed electric dipole transitions in helium-like argon. The transitions are 2 3 P 2 --2 3 S 1 and 2 3 P 0 --2 3 S 1 . These transitions were observed by using a vacuum ultraviolet monochromator to collect photons from decays-in-flight of a beam-foil excited argon ion beam. The ion beam was generated by the Lawrence Berkeley Laboratory heavy ion linear accelerator (SuperHILAC) and had a beam energy of 138 MeV with a charge current of roughly 500 nanoamperes. After initial observation, the lifetimes and absolute wavelengths of these transitions were measured. The results are tau(2 3 P 2 ) = 1.62 +- 0.08 X 10 -9 sec, tau(2 3 P 0 ) = 4.87 +- 0.44 X 10 -9 sec, lambda(2 3 P 2 --2 3 S 1 ) = 560.2 +- 0.9A, and lambda(2 3 P 0 --2 3 S 1 ) = 660.7 +- 1.1A. This work has demonstrated the observability of these transitions in high-Z ions using beam-foil excitation. Employing a new grazing-incidence spectrometer this work will be pursued in ions of higher Z. Accuracies of at least one part in a thousand should be attainable and will probe the radiative contributions to these transitions to better than 10 percent in a previously unstudied region

Spatiotemporal dynamics of the spin transition in [Fe (HB(tz)3) 2] single crystals

Science.gov (United States)

Ridier, Karl; Rat, Sylvain; Shepherd, Helena J.; Salmon, Lionel; Nicolazzi, William; Molnár, Gábor; Bousseksou, Azzedine

2017-10-01

The spatiotemporal dynamics of the spin transition have been thoroughly investigated in single crystals of the mononuclear spin-crossover (SCO) complex [Fe (HB (tz )3)2] (tz = 1 ,2 ,4-triazol-1-yl) by optical microscopy. This compound exhibits an abrupt spin transition centered at 334 K with a narrow thermal hysteresis loop of ˜1 K (first-order transition). Most single crystals of this compound reveal exceptional resilience upon repeated switching (several hundred cycles), which allowed repeatable and quantitative measurements of the spatiotemporal dynamics of the nucleation and growth processes to be carried out. These experiments revealed remarkable properties of the thermally induced spin transition: high stability of the thermal hysteresis loop, unprecedented large velocities of the macroscopic low-spin/high-spin phase boundaries up to 500 µm/s, and no visible dependency on the temperature scan rate. We have also studied the dynamics of the low-spin → high-spin transition induced by a local photothermal excitation generated by a spatially localized (Ø = 2 μ m ) continuous laser beam. Interesting phenomena have been evidenced both in quasistatic and dynamic conditions (e.g., threshold effects and long incubation periods, thermal activation of the phase boundary propagation, stabilization of the crystal in a stationary biphasic state, and thermal cutoff frequency). These measurements demonstrated the importance of thermal effects in the transition dynamics, and they enabled an accurate determination of the thermal properties of the SCO compound in the framework of a simple theoretical model.

Electronic transport and conduction mechanism transition in La1∕3Sr2∕3FeO3 thin films

International Nuclear Information System (INIS)

Devlin, R. C.; Krick, A. L.; Sichel-Tissot, R. J.; Xie, Y. J.; May, S. J.

2014-01-01

We report on the electronic transport properties of epitaxial La 1∕3 Sr 2∕3 FeO 3 films using temperature dependent resistivity, Hall effect, and magnetoresistance measurements. We show that the electronic phase transition, which occurs near 190 K, results in a change in conduction mechanism from nonadiabatic polaron transport at high temperatures to resistivity behavior following a power law temperature dependence at low temperatures. The phase transition is also accompanied by an abrupt increase in apparent mobility and Hall coefficient below the critical temperature (T*). We argue that the exotic low temperature transport properties are a consequence of the unusually long-range periodicity of the antiferromagnetic ordering, which also couples to the electronic transport in the form of a negative magnetoresistance below T* and a sign reversal of the Hall coefficient at T*. By comparing films of differing thicknesses, stoichiometry, and strain states, we demonstrate that the observed conduction behavior is a robust feature of La 1∕3 Sr 2∕3 FeO 3 .

Click chemistry for [99mTc(CO)3] labeling of Lys3-bombesin

International Nuclear Information System (INIS)

Ferro-Flores, G.; Rivero, I.A.; Santos-Cuevas, C.L.; Sarmiento, J.I.; Arteaga de Murphy, C.; Ocampo-Garcia, B.E.; Garcia-Becerra, R.; Ordaz-Rosado, D.

2010-01-01

99m Tc-HYNIC labeled Lys 3 -bombesin has shown specific binding to gastrin-releasing peptide receptors (GRP-r) over-expressed in cancer cells. Click chemistry offers an innovative functionalization strategy for biomolecules such as bombesin. The aim of this research was to apply a click chemistry approach for [ 99m Tc(CO) 3 ] labeling of Lys 3 -bombesin and to compare the in vitro MCF7 breast cancer cell uptake and biodistribution profile in mice with that of 99m Tc-EDDA/HYNIC-Lys 3 -bombesin. The results suggest a higher lipophilicity for 99m Tc(CO) 3 -triazole-Lys 3 -bombesin which explains its higher in vivo hepatobiliary elimination. Pancreas-to-blood ratio for 99m Tc(CO) 3 -triazole-Lys 3 -bombesin was 4.46 at 3 h and both bombesin radiopharmaceuticals showed specific recognition for GRP receptors in MCF7 cancer cells. Click chemistry is a reliable approach for [ 99m Tc(CO) 3 ] labeling of Lys 3 -bombesin.

Imaging of HER3-expressing xenografts in mice using a {sup 99m}Tc(CO){sub 3}-HEHEHE-Z{sub HER3:08699} affibody molecule

Energy Technology Data Exchange (ETDEWEB)

Orlova, Anna; Rosestedt, Maria; Varasteh, Zohreh; Selvaraju, Ram Kumar [Uppsala University, Preclinical PET Platform, Department of Medicinal Chemistry, Uppsala (Sweden); Malm, Magdalena; Andersson, Ken; Staahl, Stefan; Loefblom, John [KTH Royal Institute of Technology, Division of Protein Technology, School of Biotechnology, Stockholm (Sweden); Altai, Mohamed; Honarvar, Hadis; Strand, Joanna; Tolmachev, Vladimir [Uppsala University, Division of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala (Sweden)

2014-07-15

Human epidermal growth factor receptor type 3 (HER3) is a transmembrane receptor tyrosine kinase belonging to the HER (ErbB) receptor family. Membranous expression of HER3 is associated with trastuzumab resistance in breast cancer and the transition to androgen independence in prostate cancer. Imaging of HER3 expression in malignant tumors may provide important diagnostic information that can influence patient management. Affibody molecules with low picomolar affinity to HER3 were recently selected. The aim of this study was to investigate the feasibility of HER3 imaging using radiolabeled Affibody molecules. A HER3-binding Affibody molecule, Z{sub 08699}, with a HEHEHE-tag on N-terminus was labeled with {sup 99m}Tc(CO){sub 3} using an IsoLink kit. In vitro and in vivo binding specificity and the cellular processing of the labeled binder were evaluated. Biodistribution of {sup 99m}Tc(CO){sub 3}-HEHEHE-Z{sub 08699} was studied over time in mice bearing HER3-expressing xenografts. HEHEHE-Z{sub 08699} was labeled with {sup 99m}Tc(CO){sub 3} with an isolated yield of >80 % and a purity of >99 %. Binding of {sup 99m}Tc(CO){sub 3}-HEHEHE-Z{sub 08699} was specific to BT474 and MCF7 (breast cancer), and LS174T (colon cancer) cells. Cellular processing showed rapid binding and relatively quick internalization of the receptor/Affibody molecule complex (70 % of cell-associated radioactivity was internalized after 24 h). The tumor targeting was receptor mediated and the excretion was predominantly renal. Receptor-mediated uptake was also found in the liver, lung, stomach, intestine, and salivary glands. At 4 h pi, tumor-to-blood ratios were 7 ± 3 for BT474, and 6 ± 2 for LS174T xenografts. LS174T tumors were visualized by microSPECT 4 h pi. The results of this study suggest the feasibility of HER3-imaging in malignant tumors using Affibody molecules. (orig.)

Extreme UV observation of 3-3 transitions of niobium in near neon-like charge states

Energy Technology Data Exchange (ETDEWEB)

Buchet-Poulizac, M.C. E-mail: marie-claude.buchet-poulizac@lasim.univ-lyon1.fr; Cassimi, A.; Cremer, G.; Grandin, J.-P.; Hennecart, D.; Husson, X.; Jacquet, E.; Wyart, J.-F

2003-05-01

The emission spectra of highly ionised niobium ions generated by beam-foil excitation in the range 7-21 nm show most 3-3 transitions belonging to the neon-like ions and neighbouring Na-, Mg- and F- sequences. Wavelengths have been determined in reference to {delta}n=1 transitions between Rydberg states. Line identification have been made by comparison to extra- or interpolation of wavenumbers along isoelectronic sequences when data were available and to ab initio atomic structure calculations, using either a Cowan code or a fully relativistic parametric code for Ne- and F-sequences.

Structure of a yeast 40S-eIF1-eIF1A-eIF3-eIF3j initiation complex.

Science.gov (United States)

Aylett, Christopher H S; Boehringer, Daniel; Erzberger, Jan P; Schaefer, Tanja; Ban, Nenad

2015-03-01

Eukaryotic translation initiation requires cooperative assembly of a large protein complex at the 40S ribosomal subunit. We have resolved a budding yeast initiation complex by cryo-EM, allowing placement of prior structures of eIF1, eIF1A, eIF3a, eIF3b and eIF3c. Our structure highlights differences in initiation-complex binding to the ribosome compared to that of mammalian eIF3, demonstrates a direct contact between eIF3j and eIF1A and reveals the network of interactions between eIF3 subunits.

Ice Particle Transport Analysis With Phase Change for the E(sup 3) Turbofan Engine Using LEWICE3D Version 3.2

Science.gov (United States)

Bidwell, Colin, S.

2012-01-01

Ice Particle trajectory calculations with phase change were made for the Energy Efficient Engine (E(sup 3)) using the LEWICE3D Version 3.2 software. The particle trajectory computations were performed using the new Glenn Ice Particle Phase Change Model which has been incorporated into the LEWICE3D Version 3.2 software. The E(sup 3) was developed by NASA and GE in the early 1980 s as a technology demonstrator and is representative of a modern high bypass turbofan engine. The E(sup 3) flow field was calculated using the NASA Glenn ADPAC turbomachinery flow solver. Computations were performed for the low pressure compressor of the E(sup 3) for a Mach 0.8 cruise condition at 11,887 m assuming a standard warm day for ice particle sizes of 5, 20, and 100 microns and a free stream particle concentration of 0.3 g/cu m. The impingement efficiency results showed that as particle size increased average impingement efficiencies and scoop factors increased for the various components. The particle analysis also showed that the amount of mass entering the inner core decreased with increased particle size because the larger particles were less able to negotiate the turn into the inner core due to particle inertia. The particle phase change analysis results showed that the larger particles warmed less as they were transported through the low pressure compressor. Only the smallest 5 micron particles were warmed enough to produce melting and the amount of melting was relatively small with a maximum average melting fraction of 0.836. The results also showed an appreciable amount of particle sublimation and evaporation for the 5 micron particles entering the engine core (22 percent).

Heat flux measurements of Tb{sub 3}M series (M=Co, Rh and Ru): Specific heat and magnetocaloric properties

Energy Technology Data Exchange (ETDEWEB)

Monteiro, J.C.B., E-mail: jolmiui@gmail.com [Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin, Campinas, SP 13083-859 (Brazil); Lombardi, G.A. [Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin, Campinas, SP 13083-859 (Brazil); Reis, R.D. dos [Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden (Germany); Freitas, H.E.; Cardoso, L.P.; Mansanares, A.M.; Gandra, F.G. [Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin, Campinas, SP 13083-859 (Brazil)

2016-12-15

We report on the magnetic properties and magnetocaloric effect (MCE) for the Tb{sub 3}M series, with M=Co, Rh and Ru, obtained using a heat flux technique. The specific heat of Tb{sub 3}Co and Tb{sub 3}Rh are very similar, with a first order type transition occurring around 6 K below the magnetic ordering temperature without any corresponding feature on the magnetization. The slightly enhanced electronic specific heat, the Debye temperature around 150 K and the presence of the magnetic specific heat well above the ordering temperature are also characteristic of many other compounds of the R{sub 3}M family (R=Rare Earth). The specific heat for Tb{sub 3}Ru, however, presents two peaks at 37 K and 74 K. The magnetization shows that below the first peak the system presents an antiferromagnetic behavior and is paramagnetic above 74 K. We obtained a magnetocaloric effect for M=Co and Rh, −∆S=12 J/kg K, but for Tb{sub 3}Ru it is less than 3 J/kg K (μ{sub 0}∆H=5 T). We believe that the experimental results show that the MCE is directly related with the process of hybridization of the (R)5d-(M)d electrons that occurs in the R{sub 3}M materials.

Potential energy surface, dipole moment surface and the intensity calculations for the 10 μm, 5 μm and 3 μm bands of ozone

Science.gov (United States)

Polyansky, Oleg L.; Zobov, Nikolai F.; Mizus, Irina I.; Kyuberis, Aleksandra A.; Lodi, Lorenzo; Tennyson, Jonathan

2018-05-01

Monitoring ozone concentrations in the Earth's atmosphere using spectroscopic methods is a major activity which undertaken both from the ground and from space. However there are long-running issues of consistency between measurements made at infrared (IR) and ultraviolet (UV) wavelengths. In addition, key O3 IR bands at 10 μm, 5 μm and 3 μm also yield results which differ by a few percent when used for retrievals. These problems stem from the underlying laboratory measurements of the line intensities. Here we use quantum chemical techniques, first principles electronic structure and variational nuclear-motion calculations, to address this problem. A new high-accuracy ab initio dipole moment surface (DMS) is computed. Several spectroscopically-determined potential energy surfaces (PESs) are constructed by fitting to empirical energy levels in the region below 7000 cm-1 starting from an ab initio PES. Nuclear motion calculations using these new surfaces allow the unambiguous determination of the intensities of 10 μm band transitions, and the computation of the intensities of 10 μm and 5 μm bands within their experimental error. A decrease in intensities within the 3 μm is predicted which appears consistent with atmospheric retrievals. The PES and DMS form a suitable starting point both for the computation of comprehensive ozone line lists and for future calculations of electronic transition intensities.

Sandwich structure of plasma edge during transition to improved confinement regime in L-2M stellarator

International Nuclear Information System (INIS)

Shchepetov, S V; Kholnov, Yu V; Fedyanin, O I; Kuznetsov, A B; Vasilkov, D G; Akulina, D K; Batanov, G M; Gladkov, G A; Grebenshchikov, S E; Meshcheryakov, A I

2008-01-01

Transitions to the regime with better confinement in the L-2M stellarator are presented. Transitions are indicated only at sufficiently high plasma densities, and for a given value of average density they appear only at higher heating powers. Each transition is easily identified by a sudden fast ( e ). In the bulk of the plasma parameters evolve slowly. Drastic changes are observed in the region close to the plasma boundary where two moderate order rational magnetic surfaces are located with the rotational transform μ taking the values 2/3 and 3/4. Relative values of plasma parameters' fluctuations and their spectrum widths decrease significantly in this region. The region has a definite sandwich structure being subdivided by the above-named moderate order rational magnetic surfaces into three smaller zones with different plasma parameter dynamics. Transition is triggered by local disturbances of plasma parameters that are caused by instabilities in the vicinity of magnetic surfaces where μ is equal to 2/3 or 3/4. Different hypotheses on the nature of the phenomenon are discussed

Effects of Δ-isobar degrees of freedom on the reactions 3He(n,γ)4He and 3He(p,e+νe)4He at low-energy

International Nuclear Information System (INIS)

Schiavilla, R.

1991-01-01

The cross sections of the radiative 3 He(n,γ) 4 He and weak 3 He(p,e + ν e ) 4 He capture reactions at thermal neutron and keV proton energies have been calculated with the Variational Monte Carlo method. The ground state and low-energy continuum wave functions have been determined variationally from a realistic Hamiltonian, and include both nucleon and Δ-isobar degrees of freedom. The electroweak transition operator contains one- and two-body components in the N + Δ Hilbert space

Differential electron scattering cross sections for the 3 (2)S to 3 (2)P0 h, k transitions in Mg II - Comparison of experiment and theory

Science.gov (United States)

Williams, I. D.; Chutjian, A.; Msezane, A. Z.; Henry, R. J. W.

1985-01-01

Angular differential electron scattering cross sections are reported for the unresolved inelastic 3s (2)S to 3p (2)P0 h, k transitions in Mg II for the first time. Relative differential cross sections have been measured at 35 eV and 50 eV in the angular range of Theta between 6 and 17 deg using the newly developed electron energy loss technique in a crossed electron-ion beam geometry. Theoretical values have been calculated in a five-state close-coupling approximation in which 3s, 3p, 3d, 4s, and 4p states were included, and to which measurements were normalized at Theta = 12 deg.

Transition metal modified bulk BiFeO3 with improved magnetization and linear magneto-electric coupling

International Nuclear Information System (INIS)

Puli, Venkata Sreenivas; Kumar, A.; Panwar, N.; Panwar, I.C.; Katiyar, R.S.

2011-01-01

Highlights: → Present composition (Bi 0.9 Sm 0.10 Fe 0.95 Co 0.05 O 3 (BSFCO) have shown very high magnetization compared to parent BFO. → The magnetic hysteresis loops are well saturated with high saturation magnetization 2.89 emu/gm (unpoled and unleached) and 2.18 emu/gm (poled and unleached) respectively. → Converse ME coupling were found 0.8e-10 s m -1 (H||E) and 0.6-0.8 x 10 -10 s m -1 (H-perpendicular E) which are better than the single phase multiferroic obeying linear ME coupling. - Abstract: At present BiFeO 3 (BFO) is the most attractive and sole example, which possesses low magnetization value, high leakage current and low polarization in ceramic form. Single-phase room temperature multiferroics are rare in nature. This paper deals with the improved magnetic and observed linear magneto-electric coupling in Co and Sm co-doped BiFeO 3 ceramics synthesized by sol-gel process at low temperature ∼600 deg. C. As synthesized Bi 0.9 Sm 0.10 Fe 0.95 Co 0.05 O 3 (BSFCO) showed high impurities phases (20%) over wide range of calcination temperatures. Impurity phases reduced drastically from 20% to 5% after leaching with nitric acid. However the electrical and the magnetic properties were almost the same for both phases. Well-defined magnetic hysteresis with high magnetic moment was found at room temperature. Ferroelectric polarization studies demonstrated similar values and shape as reported in literature for the pure bulk BFO. Linear magneto-electric (ME) coupling and weak ME coefficient (α) ∼ 0.6 e-10 s m -1 were observed in the co-doped BFO. The origin of the strong ferromagnetic property in our samples may be due to the presence of rare earth and transition metal ions at the lattice sites of BFO or due to impurity phase, since we have not seen any change in magnetization with reduction of impurity phase the later effect is more unlikely.

A Transcript-Specific eIF3 Complex Mediates Global Translational Control of Energy Metabolism.

Science.gov (United States)

Shah, Meera; Su, Dan; Scheliga, Judith S; Pluskal, Tomáš; Boronat, Susanna; Motamedchaboki, Khatereh; Campos, Alexandre Rosa; Qi, Feng; Hidalgo, Elena; Yanagida, Mitsuhiro; Wolf, Dieter A

2016-08-16

The multi-subunit eukaryotic translation initiation factor eIF3 is thought to assist in the recruitment of ribosomes to mRNA. The expression of eIF3 subunits is frequently disrupted in human cancers, but the specific roles of individual subunits in mRNA translation and cancer remain elusive. Using global transcriptomic, proteomic, and metabolomic profiling, we found a striking failure of Schizosaccharomyces pombe cells lacking eIF3e and eIF3d to synthesize components of the mitochondrial electron transport chain, leading to a defect in respiration, endogenous oxidative stress, and premature aging. Energy balance was maintained, however, by a switch to glycolysis with increased glucose uptake, upregulation of glycolytic enzymes, and strict dependence on a fermentable carbon source. This metabolic regulatory function appears to be conserved in human cells where eIF3e binds metabolic mRNAs and promotes their translation. Thus, via its eIF3d-eIF3e module, eIF3 orchestrates an mRNA-specific translational mechanism controlling energy metabolism that may be disrupted in cancer. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

The 3d84s-3d84p transitions in Br IX

International Nuclear Information System (INIS)

Zeng, X.T.; Jupen, C.; Livingston, A.E.; Westerlind, M.; Engstroem, L.; Martinson, I.

1990-01-01

The spectrum of bromine was studied in the region 450-1100 A, using the beam-foil method with 6 MeV ions from a tandem accelerator. On the basis of isoelectronic extrapolations and theoretical calculations, 32 lines were classified as transitions between the 3p 6 3d 8 4s and 3p 6 3d 8 4p configurations of Co-like BrIX. Fo the 16 possible 4s levels 13 have been located, and 11 new 4p levels have been added to the previously known ones. Only 4 of all the 4p levels (45 in total) remain to be found. (orig.)

Phase transitions in 3D gravity and fractal dimension

Science.gov (United States)

Dong, Xi; Maguire, Shaun; Maloney, Alexander; Maxfield, Henry

2018-05-01

We show that for three dimensional gravity with higher genus boundary conditions, if the theory possesses a sufficiently light scalar, there is a second order phase transition where the scalar field condenses. This three dimensional version of the holographic superconducting phase transition occurs even though the pure gravity solutions are locally AdS3. This is in addition to the first order Hawking-Page-like phase transitions between different locally AdS3 handlebodies. This implies that the Rényi entropies of holographic CFTs will undergo phase transitions as the Rényi parameter is varied, as long as the theory possesses a scalar operator which is lighter than a certain critical dimension. We show that this critical dimension has an elegant mathematical interpretation as the Hausdorff dimension of the limit set of a quotient group of AdS3, and use this to compute it, analytically near the boundary of moduli space and numerically in the interior of moduli space. We compare this to a CFT computation generalizing recent work of Belin, Keller and Zadeh, bounding the critical dimension using higher genus conformal blocks, and find a surprisingly good match.

BAG3 regulates epithelial-mesenchymal transition and angiogenesis in human hepatocellular carcinoma.

Science.gov (United States)

Xiao, Heng; Cheng, Shaobing; Tong, Rongliang; Lv, Zheng; Ding, Chaofeng; Du, Chengli; Xie, Haiyang; Zhou, Lin; Wu, Jian; Zheng, Shusen

2014-03-01

Bcl2-associated athanogene 3 (BAG3) protein is a co-chaperone of heat-shock protein (Hsp) 70 and may regulate major physiological and pathophysiological processes. However, few reports have examined the role of BAG3 in human hepatocellular carcinoma (HCC). In this study, we show that BAG3 regulates epithelial-mesenchymal transition (EMT) and angiogenesis in HCC. BAG3 was overexpressed in HCC tissues and cell lines. BAG3 knockdown resulted in reduction in migration and invasion of HCC cells, which was linked to reversion of EMT by increasing E-cadherin expression and decreasing N-cadherin, vimentin and slug expression, as well as suppressing matrix metalloproteinase 2 (MMP-2) expression. In a xenograft tumorigenicity model, BAG3 knockdown effectively inhibited tumor growth and metastasis through reduction in CD34 and VEGF expression and reversal of the EMT pathway. In conclusion, BAG3 is associated with the invasiveness and angiogenesis in HCC, and the BAG3 gene may be a novel therapeutic approach against HCC.

Nano-hydroxyapatite particles induce apoptosis on MC3T3-E1 cells and tissue cells in SD rats

Science.gov (United States)

Wang, Liting; Zhou, Gang; Liu, Haifeng; Niu, Xufeng; Han, Jingyun; Zheng, Lisha; Fan, Yubo

2012-04-01

While the advantages of nanomaterials are being increasingly recognized, their potential toxicity is drawing more and more attention and concern. In this study, we explore the toxicity mechanism of 20-30 nm rod-shaped hydroxyapatite (HA) nanoparticles in vitro and in vivo. The nanoparticles were prepared by precipitation and characterized by IR, XRD and TEM. Concentrations of 0 μg mL-1, 10 μg mL-1, 100 μg mL-1, 1 mg mL-1, and 10 mg mL-1 were applied to the MC3T3-E1 cells for viability (MTT-test). Based on the characteristic differences of the two methods of cell death, the morphological features of the MC3T3-E1 cell line co-cultured with nano-hydroxyapatite (n-HA) (10 mg mL-1) for 24 h were also observed by TEM. Furthermore, important serum biochemical markers and histopathological examinations were used to evaluate the potential toxicological effect of n-HA on the major organs of SD rats injected intraperitoneally with n-HA (33.3 mg kg-1 body weight). In the results, we found cell growth inhibition and apoptosis in MC3T3-E1 cells co-cultured with n-HA. Moreover, apoptosis but not necrosis was illustrated in liver and renal tissue by using histopathology slices and serum biochemical markers. It suggests that apoptosis may be the possible mechanism of n-HA toxicity and provides a better understanding of the biocompatibility of nanomaterials applied in human bone repair.

A Switchable Molecular Dielectric with Two Sequential Reversible Phase Transitions: [(CH3)4P]4[Mn(SCN)6].

Science.gov (United States)

Li, Qiang; Shi, Ping-Ping; Ye, Qiong; Wang, Hui-Ting; Wu, De-Hong; Ye, Heng-Yun; Fu, Da-Wei; Zhang, Yi

2015-11-16

A new organic-inorganic hybrid switchable and tunable dielectric compound, [(CH3)4P]4[Mn(SCN)6] (1), exhibits three distinct dielectric states above room temperature and undergoes two reversible solid-state phase transitions, including a structural phase transition at 330 K and a ferroelastic phase transition with the Aizu notation of mmmF2/m at 352 K. The variable-temperature structural analyses disclose that the origin of the phase transitions and dielectric anomalies can be ascribed to the reorientation or motion of both the [(CH3)4P](+) cations and [Mn(SCN)6](4-) anions in solid-state crystals.

Crystal structure and phase transition in (NH4)3WO2F5: from dynamic to static orientational disorder.

Science.gov (United States)

Udovenko, Anatoly; Laptash, Natalia

2015-08-01

Single crystals of tungsten double salt (NH4)3WO2F5 = (NH4)3[WO2F4]F have been synthesized by solid-state reaction or from fluoride solution and its crystal structures at 296 and 193 K were determined by X-ray diffraction. At room temperature, the crystal structure of the compound is dynamically disordered with the ligand atoms statistically distributed on two positions (6e and 24m) of the Pm3m unit cell [a = 6.0298 (1) Å], and the tungsten atom dynamically disordered on 12 orientations forming a spatial cuboctahedron [W12] that enables the real geometry of cis-WO2F4 octahedron to be determined with two short W-O distances. On cooling, the compound undergoes a first-order phase transition with the symmetry change Pm3m → Pa3 and a doubling of the unit-cell parameter [a = 11.9635 (7) Å]. The ligand F(O) atoms statistically occupy two general 24d sites and form W1X6 and W2X6 octahedra, in which the O and F atoms are not crystallographically different that means a static orientational disorder of (NH4)3WO2F5.

Luminescent properties of UV excitable blue emitting phosphors MSr4(BO3)3:Ce3+ (M = Li and Na)

International Nuclear Information System (INIS)

Guo Chongfeng; Ding Xu; Seo, Hyo Jin; Ren Zhaoyu; Bai Jintao

2011-01-01

Research highlights: → Novel blue emitting phosphors borate MSr 4 (BO 3 ) 3 (M = Li or Na) were prepared first. → Luminescent properties of phosphors borate MSr 4 (BO 3 ) 3 (M = Li or Na) were investigated extensively as candidates of blue emitting phosphor used for UV excited LED. → The optimal concentrations of dopant Ce 3+ ions in compound MSr 4 (BO 3 ) 3 (M = Li or Na) were determined as 0.05 for Li and x = 0.09 for Na excited by UV light respectively. - Abstract: A series of Ce 3+ doped novel borate phosphors MSr 4 (BO 3 ) 3 (M = Li or Na) were successfully synthesized by traditional solid-state reaction. The crystal structures and the phase purities of samples were characterized by powder X-ray diffraction. The optimal concentrations of dopant Ce 3+ ions in compound MSr 4 (BO 3 ) 3 (M = Li or Na) were determined through the measurements of photoluminescence spectra of phosphors. Ce 3+ doped phosphors MSr 4 (BO 3 ) 3 (M = Li or Na) show strong broad band absorption in UV spectral region and bright blue emission under the excitation of 345 nm light. In addition, the temperature dependences of emission spectra of M 1+x Sr 4-2x Ce x (BO 3 ) 3 (M = Li or Na) phosphors with optimal composition x = 0.05 for Li and x = 0.09 for Na excited under 355 nm pulse laser were also investigated. The experimental results indicate that the M 1+x Sr 4-2x Ce x (BO 3 ) 3 (M = Li or Na) phosphors are promising blue emitting phosphors pumped by UV light.

Corrections to the Goldberger-Treiman relation for the /sup 3/H-/sup 3 /He transition

CERN Document Server

Jarlskog, C

1972-01-01

The authors have calculated the correction to the Goldberger-Treiman relation for the /sup 3/H-/sup 3/He transition due to the deuteron- nucleon break-up mechanism. The magnitude of the correction to the residue of the pion pole is found to be considerable. (14 refs).

Lysophosphatidic acid induces chemotaxis in MC3T3-E1 osteoblastic cells

Energy Technology Data Exchange (ETDEWEB)

Masiello, Lisa M.; Fotos, Joseph S.; Galileo, Deni S.; Karin, Norm J.

2006-07-01

Lysophosphatidic acid (LPA) is a bioactive lipid that has pleiotropic effects on a variety of cell types and enhances the migration of endothelial and cancer cells, but it is not known if this lipid can alter osteoblast motility. We performed transwell migration assays using MC3T3-E1 osteoblastic cells and found LPA to be a potent chemotactic agent. Quantitative time-lapse video analysis of osteoblast migration after wounds were introduced into cell monolayers indicated that LPA stimulated both migration velocity and the average migration distance per cell. LPA also elicited substantial changes in cell shape and actin cytoskeletal structure; lipid-treated cells contained fewer stress fibers and displayed long membrane processes that were enriched in F-actin. Quantitative RT-PCR analysis showed that MC3T3-E1 cells express all four known LPA-specific G protein-coupled receptors (LPA1-LPA4) with a relative mRNA abundance of LPA1 > LPA4 > LPA2 >> LPA3. LPA-induced changes in osteoblast motility and morphology were antagonized by both pertussis toxin and Ki16425, a subtype-specific blocker of LPA1 and LPA3 receptor function. Cell migration in many cell types is linked to changes in intracellular Ca2+. Ki16425 also inhibited LPA-induced Ca2+ signaling in a dose-dependent manner, suggesting a link between LPA-induced Ca2+ transients and osteoblast chemotaxis. Our data show that LPA stimulates MC3T3-E1 osteoblast motility via a mechanism that is linked primarily to the G protein-coupled receptor LPA1.

Ferroelectric Nd3+:SrxBa1-x(NbO3)2-a new nonlinear laser crystal: cw 1-μm stimulated emission (4F3/2→4I11/2) and diffuse self-frequency doubling

International Nuclear Information System (INIS)

Kaminskii, Alexandr A; Garsia, Sole J; Jaque, D; Capmany, J; Bagayev, S N

1998-01-01

Stimulated emission as a result of the inter-Stark transition in the 1-μm 4 F 3/2 → 4 I 11/2 channel of Nd 3+ ions was excited for the first time in an acentric disordered Sr x Ba 1-x (NbO 3 ) 2 (x∼0.6) crystal. The low-threshold lasing of this crystal at the 1.0626 μm wavelength was accompanied by diffuse intracavity generation of the second harmonic. (letters to the editor)

Absolute transition probabilities in the NeI 3p-3s fine structure by beam-gas-dye laser spectroscopy

International Nuclear Information System (INIS)

Hartmetz, P.; Schmoranzer, H.

1983-01-01

The beam-gas-dye laser two-step excitation technique is further developed and applied to the direct measurement of absolute atomic transition probabilities in the NeI 3p-3s fine-structure transition array with a maximum experimental error of 5%. (orig.)

N = 3 - 3 Transitions of Ne-like Ions in the Iron Group, Especially Ca(10+) and Ti(12+)

Energy Technology Data Exchange (ETDEWEB)

Ishikawa, Y; Encarnacion, J L; Trabert, E

2008-10-09

The Ti XIII 2s{sup 2}2p{sup 5}3l-3l{prime} and 2s2p{sup 6}3l-3l{prime} transitions that have been discussed previously on the basis of beam-foil spectra and laser-produced plasmas in comparison to semi-empirically scaled computations have now been treated by accurate ab initio Multi-reference Moller-Plesset calculations. While most 2s{sup 2}2p{sup 5}3l-3l{prime} line identifications are supported by the new calculations, the 2s2p{sup 6}3l-3l{prime} transition arrays are revised. Theoretical level positions are given for all elements from Ca through Fe. The quality of the calculation is demonstrated on the beam-foil spectra of Ca.

Magnetic phase transitions in Er7Rh3 studied on single crystals

International Nuclear Information System (INIS)

Tsutaoka, Takanori; Obata, Keisuke; Cheyvuth, Seng; Koyama, Keiichi

2014-01-01

Highlights: • Magnetic and electrical properties of Er 7 Rh 3 were studied on single crystals. • The magnetic phase diagram along the c-axis was constructed. • The field-induced magnetic transitions in Er 7 Rh 3 can be explained by the magnetic structure with two magnetic propagation vectors. • The anomalies of electrical resistivity can also be described by the magnetic structure in Er 7 Rh 3 . - Abstract: Magnetic phase transitions in Er 7 Rh 3 with the Th 7 Fe 3 type hexagonal structure have been studied on single crystals by measuring magnetization, magnetic susceptibility and electrical resistivity. Er 7 Rh 3 possesses antiferromagnetic state below T N = 13 K. In the ordered state, the two successive magnetic transitions at T t1 = 6.2 K and T t2 = 4.5 K were observed. Several field-induced magnetic transitions were also observed along the a- and c-axes below T N ; magnetic field H – temperature T phase diagram along the c-axis was constructed. The field-induced magnetic transitions in Er 7 Rh 3 can be explained by the magnetic structure with two magnetic propagation vectors which were derived by the previous neutron diffraction studies. Electrical resistivity shows humps just below the magnetic transition temperatures, T N and T t1 due to the super-zone gap formation at the Fermi level; these anomalies can also be described by the magnetic structure changes in Er 7 Rh 3

Structure and phase transition of BiFeO3 cubic micro-particles prepared by hydrothermal method

International Nuclear Information System (INIS)

Zhou, Jian-Ping; Yang, Ruo-Lin; Xiao, Rui-Juan; Chen, Xiao-Ming; Deng, Chao-Yong

2012-01-01

Graphical abstract: Bismuth ferrite (BiFeO 3 ) cubic micro-particles with smooth surfaces were synthesized. BiFeO 3 has a hexagonal perovskite structure with a space group R3c below 370 °C and rhombohedral perovskite structure with a space group R3m below 755 °C, undergoes a phase transition in the temperature range of 755–817 °C to a cubic structure, then decompose to liquid and Fe 2 O 3 above 939 °C. Highlights: ► BiFeO 3 micro-particles with smooth surface were synthesized by hydrothermal method. ► BiFeO 3 enjoys hexagonal structure with well element ratio and chemical valence. ► BiFeO 3 transition from rhombohedral phase to cubic phase lasts 60 °C. -- Abstract: Single-phase bismuth ferrite (BiFeO 3 ) powders were synthesized with a hydrothermal method by controlling the experimental conditions carefully. The powder structure, morphology and composition were characterized by using X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscope, Raman measurement and X-ray photoelectron spectroscopy. The particles change from irregular agglomerations to regular cubes with increasing KOH concentration. The large BiFeO 3 cubic particles enjoy much smooth surfaces with well-matched element ratio (Bi:Fe:O = 1:1:3) and chemical valence (Bi 3+ , Fe 3+ and O 2− ). The high temperature XRD and differential scanning calorimetry show that BiFeO 3 powders have a hexagonal perovskite structure with a space group R3c below 370 °C and a rhombohedral structure with a space group R3m below 755 °C. BiFeO 3 undergoes a phase transition in the temperature range of 755–817 °C from rhombohedral structure to a cubic phase, then decomposes to liquid and Fe 2 O 3 above 939 °C.

Thermally induced A'-A site exchange in novel layered perovskites Ag2[Ca1.5M3O10] (M = Nb, Ta).

Science.gov (United States)

Bhuvanesh, Nattamai S P; Woodward, Patrick M

2002-12-04

We have synthesized and characterized new layered perovskites Ag2[A1.5M3O10] (A = Ca, M = Nb, Ta), from their lithium analogues, by soft-chemical ion exchange. These oxides show topotactic irreversible thermally induced A'-A site exchange, resulting in Ag1.1Ca0.9[Ca0.6Ag0.9M3O10], conferred from our high-temperature X-ray and ionic conductivity studies. The latter phases are the first compounds where Ag+ ions reside in both A' and A sites in layered perovskites. The absence of similar phase transition for A = Sr suggests that these transitions strongly depend on the size, charge, and the coordination preference of A' and A cations. This result provides a new synthetic tool for modifying the occupation of the 12-coordinate A site of layered perovskites using soft chemical routes.

Ricostruzione di una scena urbana 3D utilizzando VisualSfM.

Directory of Open Access Journals (Sweden)

Laura Inzerillo

2013-10-01

Full Text Available Le tecniche di computer vision oggi danno la possibilità di costruire in maniera rapida e automatica modelli 3D dettagliati a partire da dataset fotografici. La comunità accademica ha visto una crescente attenzione alla ricostruzione 3D a scala urbana. Tra i vari strumenti oggi a disposizione spicca VisualSfM sviluppato dall’università di Washingthon e Google. Si tratta di una Interfaccia grafica open source strutturata in algoritmi dedicati alla tecnica di Structure from Motion (SfM. VisualSfM utilizza un estrattore di features chiamato SIFTGPU e un algoritmo di Bundle Adjustment Multicore. Inoltre è possibile ottenere una nuvola di punti densa utilizzando gli algoritmi CMVS/PMVS2. La finalità di questo studio è di verificare l’accuratezza metrica delle ricostruzioni attraverso l’utilizzo integrato di VisualSfM e CMVS/PMVS2. L’approccio quindi è stato testato su diversi dataset di una certa entità strutturati da collezioni fotografiche ragionate. 

Identification of the transition arrays 3d74s-3d74p in Br X and 3d64s-3d64p in Br XI

International Nuclear Information System (INIS)

Zeng, X.T.; Jupen, C.; Bengtsson, P.; Engstroem, L.; Westerlind, M.; Martinson, I.

1991-01-01

We report a beam-foil study of multiply ionized bromine in the region 400-1300A, performed with 6 and 8 MeV Br ions from a tandem accelerator. At these energies transitions belonging to Fe-like Br X and Mn-like Br XI are expected to be prominent. We have identified 31 lines as 3d 7 4s-3d 7 4p transitions in Br X, from which 16 levels of the previously unknown 3d 7 4s configuration could be established. We have also added 6 new 3d 7 4p levels to the 99 previously known. For Br XI we have classified 9 lines as 3d 6 4s-3d 6 4p combinations. The line identifications have been corroborated by isoelectronic comparisons and theoretical calculations using the superposition-of-configurations technique. (orig.)

On the Origin of the 3.3 μ m Unidentified Infrared Emission Feature

Energy Technology Data Exchange (ETDEWEB)

Sadjadi, Seyedabdolreza; Zhang, Yong; Kwok, Sun, E-mail: sunkwok@hku.hk [Laboratory for Space Research, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

2017-08-20

The 3.3 μ m unidentified infrared emission feature is commonly attributed to the C–H stretching band of aromatic molecules. Astronomical observations have shown that this feature is composed of two separate bands at 3.28 and 3.30 μ m, and the origin of these two bands is unclear. In this paper, we perform vibrational analyses based on quantum mechanical calculations of 153 organic molecules, including both pure aromatic molecules and molecules with mixed aromatic/olefinic/aliphatic hydridizations. We find that many of the C–H stretching vibrational modes in polycyclic aromatic hydrocarbon (PAH) molecules are coupled. Even considering the uncoupled modes only, the correlation between the band intensity ratios and the structure of the PAH molecule is not observed, and the 3.28 and 3.30 μ m features cannot be directly interpreted in the PAH model. Based on these results, the possible aromatic, olefinic, and aliphatic origins of the 3.3 μ m feature are discussed. We suggest that the 3.28 μ m feature is assigned to aromatic C–H stretch whereas the 3.30 μ m feature is olefinic. From the ratio of these two features, the relative olefinic to aromatic content of the carrier can be determined.

Order-disorder transition and electrical conductivity of the brownmillerite solid-solutions system Ba2(In, M)2O5 (M=Ga, Al)

International Nuclear Information System (INIS)

Yamamura, Hiroshi; Hamazaki, Hirohumi; Kakinuma, Katsuyoshi; Mori, Toshiyuki; Haneda, Hajime

1999-01-01

The brownmillerite solid-solution systems Ba 2 (In 1-x M x ) 2 O 5 (M=Ga, Al) were investigated by means of high-temperature X-ray diffraction (XRD), dilatometry, and electrical-conductivity measurements. XRD showed that the Ba 2 (In 1-x Ga x ) 2 O 5 system had orthorhombic symmetry in the composition range 0.0≤x≤0.2 and cubic symmetry in the range 0.3≤x. The Al system also changed to cubic symmetry from orthorhombic symmetry in the range 0.2≤x. While the orthorhombic phase showed an order-disorder transition in the electrical conductivity measurements, the transition temperature decreased with increasing the M content. The order-disorder transition temperature and the crystal-structure transition temperature were very different. Such a transition was not observed in the cubic phases, and their electrical conductivity were fairly low compared to those of the disordered cubic phase after the transition due to the heating process. These phenomena are discussed in terms of disordering of the tetrahedral site in the brownmillerite structure, which is occupied by the smaller Ga 3+ or Al 3+ rather than ny In 3+

The histone H3.3K36M mutation reprograms the epigenome of chondroblastomas

Science.gov (United States)

Fang, Dong; Gan, Haiyun; Lee, Jeong-Heon; Han, Jing; Wang, Zhiquan; Riester, Scott M.; Jin, Long; Chen, Jianji; Zhou, Hui; Wang, Jinglong; Zhang, Honglian; Yang, Na; Bradley, Elizabeth W.; Ho, Thai H.; Rubin, Brian P.; Bridge, Julia A.; Thibodeau, Stephen N; Ordog, Tamas; Chen, Yue; van Wijnen, Andre J.; Oliveira, Andre M.; Xu, Rui-Ming; Westendorf, Jennifer J.; Zhang, Zhiguo

2016-01-01

Over 90% of chondroblastomas contain a heterozygous mutation replacing lysine 36 with methionine (K36M) in the histone H3 variant H3.3. Here, we show that H3K36 methylation is reduced globally in chondroblastomas and in chondrocytes harboring the same genetic mutation due to inhibition of at least two H3K36 methyltransferases, MMSET and SETD2, by the H3.3K36M mutant proteins. Genes with altered expression as well as H3K36 di- and trimethylation in H3.3K36M cells are enriched in cancer pathways. In addition, H3.3K36M chondrocytes exhibit several hallmarks of cancer cells including increased ability to form colonies, resistance to apoptosis and defects in differentiation. Thus, H3.3K36M proteins reprogram H3K36 methylation landscape and contribute to tumorigenesis in part through altering the expression of cancer-associated genes. PMID:27229140

Energetic M1 transitions as a probe of nuclear collectivity at high temperatures

International Nuclear Information System (INIS)

Baktash, C.

1987-01-01

At ORNL, we have recently utilized the Spin Spectrometer setup to investigate the differential effects of increasing spin and excitation energy on nuclear shape and collectivity in 158 Yb. Along the yrast line of this and other N = 88 nuclei, weakly prolate shapes gradually give way to triaxial, and then finally to non-collective oblate shapes as the spin approaches 40 h-bar. However, above the yrast line, large deformation and collectivity once again sets in. This is evidenced by the emergence of a broad quadrupole structure (E/sub γ/ ≅ 1.2 MeV) in the continuum gamma-ray spectra that grows with increasing temperature. The short (sub ps) lifetimes of these transitions attest to the collective nature of these structures. The emergence and growth of the quadrupole structure at high excitation energies is closely correlated with the appearance of energetic (E/sub γ/ ≅ 2.5 MeV), fast M1 transitions which form another broad structure in the continuum spectra. From the centroid of the M1 bump, a quadrupole deformation parameter of 0.35 is inferred. Because of this sensitivity, these energetic M1 transitions provide a unique probe of nuclear shape in the excitation energy range of ≅ 3 to 10 MeV. 6 refs., 2 figs

Structural phase transition of BaZrO3 under high pressure

International Nuclear Information System (INIS)

Yang, Xue; Li, Quanjun; Liu, Ran; Liu, Bo; Zhang, Huafang; Jiang, Shuqing; Zou, Bo; Cui, Tian; Liu, Bingbing; Liu, Jing

2014-01-01

We studied the phase transition behavior of cubic BaZrO 3 perovskite by in situ high pressure synchrotron X-ray diffraction experiments up to 46.4 GPa at room temperature. The phase transition from cubic phase to tetragonal phase was observed in BaZrO 3 for the first time, which takes place at 17.2 GPa. A bulk modulus 189 (26) GPa for cubic BaZrO 3 is derived from the pressure–volume data. Upon decompression, the high pressure phase transforms into the initial cubic phase. It is suggested that the unstable phonon mode caused by the rotation of oxygen octahedra plays a crucial role in the high pressure phase transition behavior of BaZrO 3

Crystal growth of Sm0.3Tb0.7FeO3 and spin reorientation transition in Sm1−xTbxFeO3 orthoferrite

International Nuclear Information System (INIS)

Wu, Anhua; Wang, Bo; Zhao, Xiangyang; Xie, Tao; Man, Peiwen; Su, Liangbi; Kalashnikova, A.M.; Pisarev, R.V.

2017-01-01

In this work, Sm 0.3 Tb 0.7 FeO 3 single crystal was successfully grown by optical floating zone method. Sm 0.3 Tb 0.7 FeO 3 samples with a-, b-, and c-orientation were manufactured by means of Laue photograph. Magnetic properties of Sm 0.3 Tb 0.7 FeO 3 single crystals are studied over a wide temperature range from 2 to 400 K. Spin reorientation transition from Γ 2 to Γ 4 are observed by means of the temperature dependence of magnetization It indicated the reorientation transition temperature of Sm 1−x Tb x FeO 3 single crystals is lowered with the contents of Tb contents rising based on this work and our previous works, thus the spin reorientation transition temperature can be adjusted through changing the compound in orthoferrites materials, which means that we can get orthoferrites single crystals with high magnetism property in various temperature through material design. - Highlights: • Sm 0.3 Tb 0.7 FeO 3 single crystals with various compounds were successfully grown by optical floating zone method. • The relation between SRT temperature and composition in Sm 1−x Tb x FeO 3 orthoferrite was indicated. • The spin reorientation transition temperature of Sm 1−x Tb x FeO 3 single crystals can be adjusted through changing the compound in orthoferrites materials.

The Chemical Composition Contrast between M3 and M13 Revisited: New Abundances for 28 Giant Stars in M3

Science.gov (United States)

Sneden, Christopher; Kraft, Robert P.; Guhathakurta, Puragra; Peterson, Ruth C.; Fulbright, Jon P.

2004-04-01

We report new chemical abundances of 23 bright red giant members of the globular cluster M3, based on high-resolution (R~45,000) spectra obtained with the Keck I telescope. The observations, which involve the use of multislits in the HIRES Keck I spectrograph, are described in detail. Combining these data with a previously reported small sample of M3 giants obtained with the Lick 3 m telescope, we compare metallicities and [X/Fe] ratios for 28 M3 giants with a 35-star sample in the similar-metallicity cluster M13, and with Galactic halo field stars having [Fe/H]=A(Si), we derive little difference in [X/Fe] ratios in the M3, M13, or halo field samples. All three groups exhibit C depletion with advancing evolutionary state beginning at the level of the red giant branch ``bump,'' but the overall depletion of about 0.7-0.9 dex seen in the clusters is larger than that associated with the field stars. The behaviors of O, Na, Mg, and Al are distinctively different among the three stellar samples. Field halo giants and subdwarfs have a positive correlation of Na with Mg, as predicted from explosive or hydrostatic carbon burning in Type II supernova sites. Both M3 and M13 show evidence of high-temperature proton-capture synthesis from the ON, NeNa, and MgAl cycles, while there is no evidence for such synthesis among halo field stars. But the degree of such extreme proton-capture synthesis in M3 is smaller than it is in M13: the M3 giants exhibit only modest deficiencies of O and corresponding enhancements of Na, less extreme overabundances of Al, fewer stars with low Mg and correspondingly high Na, and no indication that O depletions are a function of advancing evolutionary state, as has been claimed for M13. We have also considered NGC 6752, for which Mg isotopic abundances have been reported by Yong et al. Giants in NGC 6752 and M13 satisfy the same anticorrelation of O abundances with the ratio (25Mg+26Mg)/24Mg, which measures the relative contribution of rare to

Co-existence of long-range order and spin fluctuation in a new geometric frustration series M2(OH)3Cl

International Nuclear Information System (INIS)

Zheng, X.G.; Hagihala, Masato; Toriyi, Takato

2007-01-01

Recently, we observed the co-existence of a long-range magnetic order and spin fluctuation in a clean compound of clinoatacamite, Cu 2 (OH) 3 Cl (PRL95 (2005) 057201). The present work reports magnetic studies on other compounds of this transition metal series M 2 (OH) 3 Cl, where M represents three-dimensional (3D)-electron magnetic ions of Co 2+ , Fe 2+ , etc., respectively. The present study shows that this co-existence is a common feature of the M 2 Cl(OH) 3 series, no matter whether it is anti-ferromagnetic, as in the case of Fe 2 (OH) 3 Cl (T N =15 K), or ferromagnetic, as in the case of Co 2 (OH) 3 Cl (T C =10.5 K). These compounds show a 3D network of corner-sharing tetrahedrons for the magnetic ions. The tetrahedron is slightly tilted with roughly 10% longer distance between the M-M bonded by Cl than those bonded by O and this distortion is suspected to be responsible for the partial order. This research suggests that the transition metal hydroxyhalide M 2 Cl(OH) 3 series are new geometric frustration system on tetrahedral lattice for d-electron spins

Flex-prints for the Mu3e experiment

Energy Technology Data Exchange (ETDEWEB)

Dittmeier, Sebastian [Physikalisches Institut, Universitaet Heidelberg (Germany); Collaboration: Mu3e-Collaboration

2016-07-01

Mu3e is a novel experiment dedicated to the search for the charged lepton flavor violating decay μ{sup +} → e{sup +}e{sup -}e{sup +} with a targeted sensitivity of a branching ratio (BR) down to 10{sup -16}. Within the standard model of particle physics this process is extremely suppressed to BR<10{sup -54}. Thus, any observation would be a clear sign for new physics beyond the standard model. The Mu3e detector consists of a silicon pixel tracking detector using the novel HV-MAPS (High Voltage Monolithic Active Pixel Sensor) technology to measure the momentum of the decay products, and scintillating fibres and tiles for precise timing. The pixel sensors are thinned to 50 μ m to achieve a material budget of about 0.1% radiation length per tracking layer. The pixel sensors are powered and connected to readout frontend boards using custom designed flex-prints, which are low material interconnects with a high signal density. We present studies of high speed data transmission up to 3.2 Gb/s over flex-print prototypes produced in-house. The design of the flex-prints for the Mu3e detector will be discussed. A 3-layer design including power, ground and slow control distribution, as well as 9 1.25 Gb/s data transmission lines for the readout of the pixel sensors is foreseen.

Crystal orientation dependence of the optical bandgap of (1 - x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 single crystals

International Nuclear Information System (INIS)

Wan Xinming; Zhao Xiangyong; Chan, H.L.W.; Choy, C.L.; Luo Haosu

2005-01-01

The transmission spectra of rhombohedral 0.71Pb(Mg 1/3 Nb 2/3 )O 3 -0.29PbTiO 3 (PMN-0.29PT) and tetragonal PMN-0.38PT single crystals were obtained in the main crystallographic directions , and . The absorption coefficients were computed and the optical bandgaps were calculated in both direct and indirect transitions. The energy of phonons contributing in the indirect transition was also calculated. For PMN-0.38PT single crystal in all the three directions, the values of direct bandgaps E gd are all slightly lower than those of PMN-0.29PT single crystal, while the indirect bandgaps E gi are all higher. For different crystallographic directions, the values of E gi for -direction are lower compared with and directions, both for PMN-0.29PT and PMN-0.38PT single crystals. Some discussions about the B-site cation d-orbits and the O-anion 2p orbits that determine the basic energy level of the single crystals are presented. The optical transition mechanism was also discussed

3-dimensional lattice studies of the electroweak phase transition at MHiggs∼ 70 GeV

International Nuclear Information System (INIS)

Guertler, M.; Perlt, H.; Schiller, A.; Ilgenfritz, E.M.; Kripfganz, J.

1996-06-01

We study the electroweak phase transition by lattice simulations of an effective 3-dimensional theory, for a Higgs mass of about 70 GeV. Exploiting, among others, a variant of the equal weight criterion of phase equilibrium, we obtain transition temperature, latent heat and surface tension, and compare with M H ∼35 GeV. In the broken phase masses and Higgs condensates are compared to perturbation theory. For the symmetric phase, bound state masses and the static force are determined. (orig.)

Dis3- and exosome subunit-responsive 3′ mRNA instability elements

International Nuclear Information System (INIS)

Kiss, Daniel L.; Hou, Dezhi; Gross, Robert H.; Andrulis, Erik D.

2012-01-01

Highlights: ► Successful use of a novel RNA-specific bioinformatic tool, RNA SCOPE. ► Identified novel 3′ UTR cis-acting element that destabilizes a reporter mRNA. ► Show exosome subunits are required for cis-acting element-mediated mRNA instability. ► Define precise sequence requirements of novel cis-acting element. ► Show that microarray-defined exosome subunit-regulated mRNAs have novel element. -- Abstract: Eukaryotic RNA turnover is regulated in part by the exosome, a nuclear and cytoplasmic complex of ribonucleases (RNases) and RNA-binding proteins. The major RNase of the complex is thought to be Dis3, a multi-functional 3′–5′ exoribonuclease and endoribonuclease. Although it is known that Dis3 and core exosome subunits are recruited to transcriptionally active genes and to messenger RNA (mRNA) substrates, this recruitment is thought to occur indirectly. We sought to discover cis-acting elements that recruit Dis3 or other exosome subunits. Using a bioinformatic tool called RNA SCOPE to screen the 3′ untranslated regions of up-regulated transcripts from our published Dis3 depletion-derived transcriptomic data set, we identified several motifs as candidate instability elements. Secondary screening using a luciferase reporter system revealed that one cassette—harboring four elements—destabilized the reporter transcript. RNAi-based depletion of Dis3, Rrp6, Rrp4, Rrp40, or Rrp46 diminished the efficacy of cassette-mediated destabilization. Truncation analysis of the cassette showed that two exosome subunit-sensitive elements (ESSEs) destabilized the reporter. Point-directed mutagenesis of ESSE abrogated the destabilization effect. An examination of the transcriptomic data from exosome subunit depletion-based microarrays revealed that mRNAs with ESSEs are found in every up-regulated mRNA data set but are underrepresented or missing from the down-regulated data sets. Taken together, our findings imply a potentially novel mechanism of m

Pyrosequencing-Based Assays for Rapid Detection of HER2 and HER3 Mutations in Clinical Samples Uncover an E332E Mutation Affecting HER3 in Retroperitoneal Leiomyosarcoma

Directory of Open Access Journals (Sweden)

Paula González-Alonso

2015-08-01

Full Text Available Mutations in Human Epidermal Growth Factor Receptors (HER are associated with poor prognosis of several types of solid tumors. Although HER-mutation detection methods are currently available, such as Next-Generation Sequencing (NGS, alternative pyrosequencing allow the rapid characterization of specific mutations. We developed specific PCR-based pyrosequencing assays for identification of most prevalent HER2 and HER3 mutations, including S310F/Y, R678Q, L755M/P/S/W, V777A/L/M, 774-776 insertion, and V842I mutations in HER2, as well as M91I, V104M/L, D297N/V/Y, and E332E/K mutations in HER3. We tested 85 Formalin Fixed and Paraffin Embbeded (FFPE samples and we detected three HER2-V842I mutations in colorectal carcinoma (CRC, ovarian carcinoma, and pancreatic carcinoma patients, respectively, and a HER2-L755M mutation in a CRC specimen. We also determined the presence of a HER3-E332K mutation in an urothelial carcinoma sample, and two HER3-D297Y mutations, in both gastric adenocarcinoma and CRC specimens. The D297Y mutation was previously detected in breast and gastric tumors, but not in CRC. Moreover, we found a not-previously-described HER3-E332E synonymous mutation in a retroperitoneal leiomyosarcoma patient. The pyrosequencing assays presented here allow the detection and characterization of specific HER2 and HER3 mutations. These pyrosequencing assays might be implemented in routine diagnosis for molecular characterization of HER2/HER3 receptors as an alternative to complex NGS approaches.

Enhancement of CdSiO3: Tb3+ green long-lasting phosphors by co-doping with Re3+ (Re3+=Gd3+, Y3+, La3+) ions

International Nuclear Information System (INIS)

Zeng, Wei; Wang, Yuhua; Han, Shaochun; Chen, Wenbo; Li, Gen

2014-01-01

CdSiO 3 : Tb 3+ , Re 3+ long-lasting phosphors were synthesized by the conventional high temperature solid-state method. A green-light phosphorescence phenomenon, which was associated with the 5 D 4 → 7 F J (J=6, 5, 4, 3) transitions of the Tb 3+ ion, was observed. Introduction of Re 3+ (Re 3+ =Gd 3+ , Y 3+ , La 3+ ) ions, which deepens the depth (E t ) or/and increases the density (n 0 ) of traps, greatly improved the afterglow properties of CdSiO 3 : Tb 3+ . Possible mechanism of CdSiO 3 : Tb 3+ , Re 3+ was discussed in this work. - Highlights: • CdSiO 3 : Tb 3+ , Re 3+ samples enrich the color of long-lasting afterglow phosphors in CdSiO 3 host. • Both the afterglow intensity and the lasting time are greatly enhanced for the co-doped samples, especially for Cd 0.96 SiO 3 : Tb 0.03 3+ , La 0.01 3+ . • Introduction of Re 3+ (Re 3+ =Gd 3+ , Y 3+ , La 3+ ) ions, which deepens the depth (E t ) or increase density(n 0 ) of traps, greatly improved the afterglow properties of CdSiO 3 : Tb 3+

La interstitial defect-induced insulator-metal transition in the oxide heterostructures LaAl O3 /SrTi O3

Science.gov (United States)

Zhou, Jun; Yang, Ming; Feng, Yuan Ping; Rusydi, Andrivo

2017-11-01

Perovskite oxide interfaces have attracted tremendous research interest for their fundamental physics and promising all-oxide electronic applications. Here, based on first-principles calculations, we propose a surface La interstitial promoted interface insulator-metal transition in LaAl O3 /SrTi O3 (110). Compared with surface oxygen vacancies, which play a determining role on the insulator-metal transition of LaAl O3 /SrTi O3 (001) interfaces, we find that surface La interstitials can be more experimentally realistic and accessible for manipulation and more stable in an ambient atmospheric environment. Interestingly, these surface La interstitials also induce significant spin-splitting states with a Ti dy z/dx z character at a conducting LaAl O3 /SrTi O3 (110) interface. On the other hand, for insulating LaAl O3 /SrTi O3 (110) (<4 unit cells LaAl O3 thickness), a distortion between La (Al) and O atoms is found at the LaAl O3 side, partially compensating the polarization divergence. Our results reveal the origin of the metal-insulator transition in LaAl O3 /SrTi O3 (110) heterostructures, and also shed light on the manipulation of the superior properties of LaAl O3 /SrTi O3 (110) for different possibilities in electronic and magnetic applications.

Isoelectronic comparison of the Al-like 3s23p 2P-3s3p24P transitions in the ions P III-Mo XXX

International Nuclear Information System (INIS)

Jupen, C.; Curtis, L.J.

1996-01-01

New observations of the 3s 2 3p 2 P-3s3p 2 4 P intercombination transitions in Al-like ions have been made for Cl V from spark spectra recorded at Lund and for Kr XXIV and Mo XXX from spectra obtained at the JET tokamak. The new results have been combined with other identifications of these transitions along the sequence and empirically systematized and compared with theoretical calculations. A set of smoothed and interpolated values for the excitation energies of the 3s3p 2 4 P levels in P III-Mo XXX is presented. (orig.)

(E-3-Methyl-6-(3-oxo-3-(thiophen-2-yl-1-propenyl-2(3H-benzothiazolone

Directory of Open Access Journals (Sweden)

Yordanka Ivanova

2016-04-01

Full Text Available The title compound, (E-3-methyl-6-(3-oxo-3-(thiophen-2-yl-1-propenyl-2(3H-benzothiazolone, was synthesized by Claisen-Schmidt condensation of 3-methyl-2(3H-benzothiazolone-6-carbaldehyde with 2-acetylthiophene in 94% yield. The structure of the target compound was confirmed using 1H-NMR, 13C-NMR, IR, MS, and elemental analysis.

La transición de fase I4/mcm→Pm3m en Sr0.5Ba0.5HfO3-δ

Directory of Open Access Journals (Sweden)

Lamas, D.

2001-08-01

Full Text Available The effect of partial substitution of cations in AMO3 compounds have been studied because the physical properties and applications of these materials can be improved. In particular we are interested in the Sr1-xBaxHfO3 family. In SrHfO3 the phase transition to cubic structure has been observed to occur when the angle between two consecutive oxygen octahedra tends to zero. Instead in BaHfO3 no phase transition was observed. These facts were attributed to depend on the atomic radius of A cation. In this contribution the study of Sr0.5Ba0.5HfO3 oxide is shown. The compound was prepared by the high temperature solid state reaction method and analyzed by X-ray diffraction and Perturbed Angular Correlation (PAC Spectroscopy at different temperatures. Diffraction studies revealed that about 400-420º C a structural phase transition from I4/mcm to Pm3m occurred by tending to zero the rotation angle. By PAC this transition was also observed. In the cubic phase the electric field gradient EFG measured were produced by defects. The same model applied to interpreted the results of BaTi1-xHfxO3 and the atomic positions determined by X-ray diffraction were used. This calculation reproduces reasonably the temperature dependence of the EFG measured by PAC.Los AMO3, llamados perovskitas, forman una gran familia de compuestos que presentan a su vez diversas propiedades físicas así como enormes aplicaciones tecnológicas. Es posible expandir esta familia y sus propiedades y aplicaciones, sustituyendo los cationes Ay M originales por diferentes A’ y M’. En este trabajo presentamos el estudio del compuesto Sr1-xBaxHfO3 con x=0.5. El óxido fue preparado por el método de reacción en fase sólida. La muestra fue analizada por difracción de Rayos X y por espectroscopía de Correlaciones Angulares Perturbadas (PAC a diferentes temperaturas. El estudio cristalográfico del material reveló que entre 400 y 420ºC se produce la transición de fase de estructura I4

Rate coefficients of the CF3CHFCF3 + H → CF3CFCF3 + H2 reaction at different temperatures calculated by transition state theory with ab initio and DFT reaction paths.

Science.gov (United States)

Ng, Maggie; Mok, Daniel K W; Lee, Edmond P F; Dyke, John M

2013-03-15

The minimum energy path (MEP) of the reaction, CF(3)CHFCF(3) + H → transition state (TS) → CF(3)CFCF(3) + H(2), has been computed at different ab initio levels and with density functional theory (DFT) using different functionals. The computed B3LYP/6-31++G**, BH&HLYP/cc-pVDZ, BMK/6-31++G**, M05/6-31+G**, M05-2X/6-31+G**, UMP2/6-31++G**, PUMP2/6-31++G**//UMP2/6-31++G**, RCCSD(T)/aug-cc-pVDZ//UMP2/6-31++G**, RCCSD(T)/aug-cc-pVTZ(spd,sp)//UMP2//6-31++G**, RCCSD(T)/CBS//M05/6-31+G**, and RCCSD(T)/CBS//UMP2/6-31++G** MEPs, and associated gradients and Hessians, were used in reaction rate coefficient calculations based on the transition state theory (TST). Reaction rate coefficients were computed between 300 and 1500 K at various levels of TST, which include conventional TST, canonical variational TST (CVT) and improved CVT (ICVT), and with different tunneling corrections, namely, Wigner, zero-curvature, and small-curvature (SCT). The computed rate coefficients obtained at different ab initio, DFT and TST levels are compared with experimental values available in the 1000-1200 K temperature range. Based on the rate coefficients computed at the ICVT/SCT level, the highest TST level used in this study, the BH&HLYP functional performs best among all the functionals used, while the RCCSD(T)/CBS//MP2/6-31++G** level is the best among all the ab initio levels used. Comparing computed reaction rate coefficients obtained at different levels of theory shows that, the computed barrier height has the strongest effect on the computed reaction rate coefficients as expected. Variational effects on the computed rate coefficients are found to be negligibly small. Although tunneling effects are relatively small at high temperatures (~1500 K), SCT corrections are significant at low temperatures (~300 K), and both barrier heights and the magnitudes of the imaginary frequencies affect SCT corrections. Copyright © 2012 Wiley Periodicals, Inc.

Cyclic fatigue resistance, torsional resistance, and metallurgical characteristics of M3 Rotary and M3 Pro Gold NiTi files

Science.gov (United States)

2018-01-01

Objectives To evaluate the mechanical properties and metallurgical characteristics of the M3 Rotary and M3 Pro Gold files (United Dental). Materials and Methods One hundred and sixty new M3 Rotary and M3 Pro Gold files (sizes 20/0.04 and 25/0.04) were used. Torque and angle of rotation at failure (n = 20) were measured according to ISO 3630-1. Cyclic fatigue resistance was tested by measuring the number of cycles to failure in an artificial stainless steel canal (60° angle of curvature and a 5-mm radius). The metallurgical characteristics were investigated by differential scanning calorimetry. Data were analyzed using analysis of variance and the Student-Newman-Keuls test. Results Comparing the same size of the 2 different instruments, cyclic fatigue resistance was significantly higher in the M3 Pro Gold files than in the M3 Rotary files (p Rotary files showed 1 small peak on the heating curve and 1 small peak on the cooling curve. Conclusions The M3 Pro Gold files showed greater flexibility and angular rotation than the M3 Rotary files, without decrement of their torque resistance. The superior flexibility of M3 Pro Gold files can be attributed to their martensite phase. PMID:29765904

Split of the superconducting transition and magnetism in UPt3

International Nuclear Information System (INIS)

Marikhin, V.G.

1992-01-01

A possible reason for splitting the superconducting phase transition in UPt 3 is discussed. The strong coupling of conduction electrons with uranium atom magnetic moments may be such a cause. The given assertion is based on the simple model described by the two-component order parameter φ Ginzburg -Landau functional. The Ginzburg - Landau functional without coupling has the whole symmetry D 6h of hexagonal crystal. Due to the presence of uranium atom magnetic moments M the symmetry is broken locally with the coupling term γ|Mφ| 2 in the Ginzburg - Landau functional. Averaging over the vector M configurations with the involment of the finite correlation radius a is performed. The inequality a 6h . This means that in a real crystal the hexagonal symmetry is not broken at the scales larger ξ. In the framework of the given theory the expressions for the specific heat jumps and equation combining the upper critical field H c2 and the phase transition split ΔT c with the pressure variation are obtained. The difficulties connencted with the small experimental magnitude of uranium atom magnetic moments are discussed

Mechanics and cooling of the Mu3e detector

Energy Technology Data Exchange (ETDEWEB)

Austermuehl, Rene Philipp; Henkelmann, Lars; Herkert, Adrian; Ng, Yanwing [Physikalisches Institut, Uni Heidelberg (Germany); Collaboration: Mu3e-Collaboration

2016-07-01

The Mu3e experiment will search for the charged lepton flavour violating decay μ{sup +} → e{sup +}e{sup -}e{sup +}, which is suppressed to unobservable levels in the Standard Model. A signal would be a clear sign of new physics. The aim is to reach a sensitivity for the branching ratio of 10{sup -16}, which requires high momentum resolution. Since the muons will decay at rest on target, the energy of the decay electrons will be E≤53 MeV. In this energy regime the momentum resolution is limited by multiple scattering in the detector material. Therefore, the Mu3e detector, including support structure and services, has to consist of as little material as possible in the active region. The main component of the detector is a pixel tracker consisting of four barrels of high voltage monolithic active pixel sensors (HV-MAPS) that can be thinned to 50 μm. A power consumption of 400 mW/cm{sup 2} is expected. To keep the material budget low, it is planned to cool with gaseous helium. In this talk results of computational fluid dynamics simulations of the Mu3e cooling system and experimental tests concerning the detector's stability against flow-induced vibrations are presented.

(E-3-Methyl-6-(3-oxo-3-(3,4,5-trimethoxyphenylprop-1-en-1-yl-2(3H-benzothiazolone

Directory of Open Access Journals (Sweden)

Yordanka Ivanova

2016-09-01

Full Text Available The title compound, (E-3-methyl-6-(3-oxo-3-(3,4,5-trimethoxyphenylprop-1-en-1-yl-2(3H-benzothiazolone, was synthesized by both an acid- and base-catalyzed aldol condensation of 3-methyl-6-acetyl-2(3H-benzothiazolone and 3,4,5-trimethoxyacetophenone. The structure of the target compound was confirmed using 1H-NMR, 13C-NMR, IR, MS, and elemental analysis.

N{sup 3} entropy of M5 branes from dielectric effect

Energy Technology Data Exchange (ETDEWEB)

Hatefi, E., E-mail: ehatefi@ictp.it [International Centre for Theoretical Physics, Strada Costiera 11, Trieste (Italy); Nurmagambetov, A.J., E-mail: ajn@kipt.kharkov.ua [A.I. Akhiezer Institute for Theoretical Physics of NSC KIPT, 1 Akademicheskaya St., Kharkov, UA 61108 (Ukraine); Park, I.Y., E-mail: inyongpark05@gmail.com [Department of Natural and physical Sciences, Philander Smith College, Little Rock, AR 72223 (United States)

2013-01-01

We observe that the N{sup 3} entropy behavior of near-extremal M5 branes can be reproduced from SYM side with the role of Myers' terms. We start by generalizing the Klebanov-Tseytlin (KT) supergravity solution that displays the N{sup 3} entropy behavior. The new feature of the general solution is visibility of the 'internal' degrees of the M5 branes, i.e., the M0 branes and the M2 branes. With the rationale provided by the supergravity analysis, we consider a D0 brane quantum mechanical setup with Myers' terms. Using localization technique, we show that the leading N{sup 3} behavior of the free energy comes from the 'classical contribution' with the rest subleading.

Studies of the energy transfer processes from Er{sup 3+} and Ho{sup 3+} to Nd{sup 3+}, Tb{sup 3+} or Eu{sup 3+} in LiYF{sub 4} crystal and ZBLAN glass for the laser media optimization operating near 3{mu}m region; Estudos dos processos de transferencia de energia dos ions de Er{sup 3+} e Ho{sup 3+} para os ions de Nd{sup 3+}, Tb{sup 3+} e Eu{sup 3+} no cristal de LiYF{sub 4} e no vidro ZBLAN para a otimizacao de meios laser ativos que operam na regiao de 3{mu}m

Energy Technology Data Exchange (ETDEWEB)

Jagosich, Fabio Henrique

2006-07-01

The energy transfer processes (ET) from the {sup 4}I{sub 13/2}; {sup 4}I{sub 11/2} levels of Er{sup 3+} and {sup 5}I{sub 6} levels of Ho{sup 3+} ions in LiYF{sub 4} (YLF) crystal and ZBLAN glass to Nd{sup 3+}, Tb{sup 3+} or Eu{sup 3+} deactivators ions were studied. The micro parameters of these energy transfer processes were determined using the overlap integral method, and showed that Eu{sup 3+} ion is the best deactivator of the first excited state of the Ho{sup 3+} in YLF, and Nd{sup 3+} is the best deactivator of the Er{sup 3+} in YLF and ZBLAN materials. The 1.5 and 2.7{mu}m emissions of Er{sup 3+} and 2.1 and 2.9{mu}m fluorescence of Ho{sup 3+} were measured using short laser pulses excitations from a tunable OPO pumped 2w-Nd:YAG laser system. We proposed a criterion for discriminating the energy transfer processes assisted by excitation migration (diffusion or hopping) among donors. It was observed that diffusion model describes the ET process from the second excited state of the donor (Er{sup 3+} or Ho{sup 3+}) independently of the C{sub D-D}/C{sub D-A} ratio, while the hopping model can describe the ET process involving the first excited state of donor. We proposed a modification of the hopping model in order to describe the experimental results for systems having C{sub D-D}/C{sub D-A} {>=} 10. Using the ET parameters, we determined that the best systems for laser action at 3{mu}m are the Ho:Eu:YLF, Ho:Nd:YLF and Er:Nd:YLF systems. On the other hand, we found that Er{sup 3+} doped (1.5 mol%) ZBLAN glasses, single and co-doped with Nd{sup 3+}, Tb{sup 3+} or Eu{sup 3+}, do not show potential for laser action at 2.8{mu}m. The up-conversion processes were studied in Er:YLF systems as a function of the Er{sup 3+} concentration, and the excited state absorption (ESA) and up conversion by energy transfer (ETU) processes were discriminated using a time resolved fluorescence decays. It was observed that 980 nm is the most convenient wavelength for pumping the Er

ROLE OF PI3K-AKT-mTOR AND Wnt SIGNALING PATHWAYS IN G1-S TRANSITION OF CELL CYCLE IN CANCER CELLS

Directory of Open Access Journals (Sweden)

LAKSHMIPATHI eVADLAKONDA

2013-04-01

Full Text Available The PI3K–Akt pathway together with one of its downstream targets, the mechanistic target of rapamycin (mTOR is a highly deregulated pathway in cancers. There is a reciprocal relation between the Akt phosphorylation and mTOR complexes. Akt phosphorylated at T308 activates mTORC1 by inhibition of the tuberous sclerosis complex (TSC1/2, where as mTORC2 is recognized as the kinase that phosphorylates Akt at S473. Recent developments in the research on regulatory mechanisms of autophagy places mTORC1 mediated inhibition of autophagy at the central position in activation of proliferation and survival pathways in cells. Autophagy is a negative regulator of Wnt signaling pathway and the downstream effectors of Wnt signaling pathway, cyclin D1 and the c-Myc, are the key players in initiation of cell cycle and regulation of the G1-S transition in cancer cells. Production of reaction oxygen species (ROS, a common feature of a cancer cell metabolism, activates several downstream targets like the transcription factors FoxO, which play key roles in promoting the progression of cell cycle. A model is presented on the role of PI3K -Akt - mTOR and Wnt pathways in regulation of the progression of cell cycle through Go-G1-and S phases.

Investigation of the Morin transition in α-Fe2O3 by the Moessbauer effect

International Nuclear Information System (INIS)

Tobler, L.; Kuendig, W.; Savic, I.

1981-01-01

Hematite (α-Fe 2 O 3 ) is an antiferromagnet with the corundum structure D 63 sub(d). Below the Morin temperature (Tsub(M) approx. equal to 260 K) the Fe-spins are parallel to the trigonal axis. Between Tsub(M) and the Neel temperature (Tsub(N) = 960 K), the spins lie in the basal plane. A small angle between the spins of the two magnetic sublattices leads to a weak ferromagnetism at T > Tsub(M). In the experiment to be described the Morin transition was investigated by the Moessbauer effect. This work was stimulated by μSR-investigations on α-Fe 2 O 3 . (orig.)

A multiple-field coupled resistive transition model for superconducting Nb3Sn

Science.gov (United States)

Yang, Lin; Ding, He; Zhang, Xin; Qiao, Li

2016-12-01

A study on the superconducting transition width as functions of the applied magnetic field and strain is performed in superconducting Nb3Sn. A quantitative, yet universal phenomenological resistivity model is proposed. The numerical simulation by the proposed model shows predicted resistive transition characteristics under variable magnetic fields and strain, which in good agreement with the experimental observations. Furthermore, a temperature-modulated magnetoresistance transition behavior in filamentary Nb3Sn conductors can also be well described by the given model. The multiple-field coupled resistive transition model is helpful for making objective determinations of the high-dimensional critical surface of Nb3Sn in the multi-parameter space, offering some preliminary information about the basic vortex-pinning mechanisms, and guiding the design of the quench protection system of Nb3Sn superconducting magnets.

Effect of concentration variation on 2.0 μm emission of Ho3+-doped SiO2-Al2O3-Na2CO3-SrF2-CaF2 oxyfluorosilicate glasses

International Nuclear Information System (INIS)

Gelija, Devarajulu; Borelli, Deva Prasad Raju

2018-01-01

The concentration variation of Ho 3+ ion-doped SiO 2 -Al 2 O 3 -Na 2 CO 3 -SrF 2 -CaF 2 glasses has been prepared by conventional melt quenching method. The thermal stability of 1 mol % of Ho 3+ -doped oxyfluorosilicate glass has been calculated using the differential thermal analysis (DTA) spectra. The phenomenological Judd-Ofelt intensity parameters Ω λ (λ = 2, 4 and 6) were calculated for all concentrations of Ho 3+ ions. The luminescence spectra in visible region of Ho 3+ ion-doped glasses were recorded under the excitation wavelength of 452 nm. The spectra consists of several intense emission bands ( 5 F 4 , 5 S 2 ) → 5 I 8 (547 nm), 5 F 3 → 5 I 8 (647 nm), 5 F 5 → 5 I 7 (660 nm) and ( 5 F 4 , 5 S 2 ) → 5 I 7 (750 nm) in the range 500-780 nm. The fluorescence emission at ∝ 2.0 μm ( 5 I 7 → 5 I 8 ) was observed under the excitation of 488 nm Ar-ion laser. The stimulated emission cross section for 5 I 7 → 5 I 8 transition (∝ 2.0 μm) varies from 8.46 to 9.52 x 10 -21 cm 2 , as calculated by the Fuchtbauer-Ladenburg (FL) theory. However, Mc-Cumber theory was used to calculate emission cross section values about 4.24-5.75 x 10 -21 cm 2 for the 5 I 7 → 5 I 8 transition in all concentrations of Ho 3+ -doped oxyfluorosilicate glasses. Therefore, these results reveal that the 0.5 mol % of Ho 3+ -doped oxyfluorosilicate glasses, exhibiting higher emission cross section, has potentially been used for laser applications at ∝ 2.0 μm. (orig.)

Modelaje Molecular de E-1-[4’-(3-(sustituido) acriloil) fenil]-3-tosilureas

OpenAIRE

León, Caritza; Colman, Trina; Domínguez, José

2012-01-01

Se presentan resultados del estudio de modelado molecular de una serie de compuestos del tipo E-1-[4’-(3-(sustituido) acriloil)fenil]-3- tosilureas, para las cuales se ha reportado actividad antimalárica como inhibidores del desarrollo in vitro de cepas de P. falciparum resistentes a la Cloroquina. El estudio revela que los compuestos más activos biológicamente muestran una clara superposición en el fragmento comprendido entre el carbono carbonilo del sistema α,β-insaturado y el átomo de azuf...

Overview of 3-year experience with large-scale electronic portal imaging device-based 3-dimensional transit dosimetry

NARCIS (Netherlands)

Mijnheer, Ben J.; González, Patrick; Olaciregui-Ruiz, Igor; Rozendaal, Roel A.; van Herk, Marcel; Mans, Anton

2015-01-01

To assess the usefulness of electronic portal imaging device (EPID)-based 3-dimensional (3D) transit dosimetry in a radiation therapy department by analyzing a large set of dose verification results. In our institution, routine in vivo dose verification of all treatments is performed by means of 3D

Site-specific conjugation and labelling of prostate antibody 7E11C5.3 (CYT-351) with technetium-99m

International Nuclear Information System (INIS)

Stalteri, M.A.; Mather, S.J.; Belinka, B.A.; Coughlin, D.J.; Chengazi, V.U.; Britton, K.E.

1997-01-01

Attachment of chelating agents to the sugar residues of antibodies for subsequent radiolabelling is an attractive approach since it may have less effect on the immunoreactivity than attachment through lysine residues, which are distributed throughout the antibody and may be present near the antigen binding site. We have attached a new hydrazide-linked chelator CYT-395 (Cytogen Corp., Princeton, N.J.) to the sugar residues of the anti-prostate monoclonal antibody 7E11C5.3 and optimised the conditions for labelling the conjugate with technetium-99m in order to compare the conjugate to 7E11C5.3 antibody labelled directly with technetium using a mercaptoethanol reduction technique. Labelling yields of 70%-90% were obtained at specific activities up to 2000 MBq/mg antibody. The stability of the technetium-labelled conjugate in plasma or to a challenge with 0.1 or 1.0 mM cysteine was similar to that of direct-labelled antibody. In nine patients with prostate cancer, the plasma clearance of the labelled conjugate followed a two-compartment model, with an average β-phase half-life of 31.4±3.9 h. The average urinary clearance at 24 h was 15.3±5.0% of the injected dose. In this group of patients there was no significant difference between the blood and urine clearance of the labelled conjugate, and the clearances of the direct-labelled antibody. (orig.). With 5 figs

Intensity ratio among Ne-like FeXVII n=3-2 transitions

International Nuclear Information System (INIS)

Morita, Shigeru; Oishi, Tetsutarou; Murakami, Izumi; Goto, Motoshi; Huang, Xianli; Zhang, Hongming

2016-01-01

Radial profiles of FeXVII 3s-2p and 3d-2p transitions emitted in wavelength range of 15-17A have been observed in Large Helical Device (LHD). The Chord-integrated radial profiles are converted into radial emissivity profile by means of Abel inversion. The emissivity ratios among FeXVII n=3-2 transitions calculated from the radial emissivity profile are compared with calculation based on a collisional-radiative (CR) model developed for Fe ions. The result reasonably confirms the effect of electron temperature and density on the emissivity ratios. However, the emissivity of 3C (2p"53d "1P_1 → 2p"6) transition is obviously lower than the prediction from the CR model. This discrepancy is consistent with measurements in the solar corona and other laboratory plasmas. (author)

Study of charge symmetry in 4He by simultaneous 4He(e,e'p)3H and 4He(e,e'n)3He measurements

International Nuclear Information System (INIS)

Spahn, M.; Kihm, T.; Knopfle, K.T.; Friedrich, J.; Voegler, N.; Schmitt, C.; Walther, V.H.; Unkelbach, M.; Hofmann, H.M.

1989-01-01

We have measured the ( 3 H+p) and ( 3 He+n) breakup of 4 He by 4 He(e,e'c) coincidence experiments at low momentum transfer (q∼0.39 fm -1 ) in the excitation energy region 22≤E x ≤36 MeV. Both channels were studied simultaneously by detecting the charged fragments c=p, 3 H, and 3 He in the same detector system. The measured 4 He(e,e'p) 3 H and 4 He(e,e'n) 3 He angular correlations as well as the deduced total 4 He(e,e'p) 3 H and 4 He(e,e'n) 3 He cross sections are reproduced by microscopic model calculations with a charge-symmetric nuclear Hamiltonian

Photoemission spectra and density functional theory calculations of 3d transition metal-aqua complexes (Ti-Cu) in aqueous solution.

Science.gov (United States)

Yepes, Diana; Seidel, Robert; Winter, Bernd; Blumberger, Jochen; Jaque, Pablo

2014-06-19

Photoelectron spectroscopy measurements and density functional calculations are combined to determine the lowest electron binding energies of first-row transition-metal aqua ions, titanium through copper, with 3d(1) through 3d(9) electronic configurations, in their most common oxidation states. Vertical ionization energies are found to oscillate considerably between 6.76 and 9.65 eV for the dications and between 7.05 and 10.28 eV for the respective trivalent cations. The metal cations are modeled as [M(H2O)n](q+) clusters (q = 2, 3, and 4; n = 6 and 18) surrounded by continuum solvent. The performance of 10 exchange-correlation functionals, two GGAs, three MGGAs, two HGGAs and three HMGGAs, combined with the MDF10(ECP)/6-31+G(d,p) basis set is assessed for 11 M-O bond distances, 10 vertical ionization energies, 6 adiabatic ionization energies, and the associated reorganization free energies. We find that for divalent cations the HGGA and HMGGA functionals in combination with the 18 water model show the best agreement with experimental vertical ionization energies and geometries; for trivalent ions, the MGGA functionals perform best. The corresponding reorganization free energies (λo) of the oxidized ions are significantly underestimated with all DFT functionals and cluster models. This indicates that the structural reorganization of the solvation shell upon ionization is not adequately accounted for by the simple solvation models used, emphasizing the importance of extended sampling of thermally accessible solvation structures for an accurate computation of this quantity. The photoelectron spectroscopy measurements reported herein provide a comprehensive set of transition-metal redox energetic quantities for future electronic structure benchmarks.

Mechanism and microstructures in Ga2O3 pseudomartensitic solid phase transition.

Science.gov (United States)

Zhu, Sheng-Cai; Guan, Shu-Hui; Liu, Zhi-Pan

2016-07-21

Solid-to-solid phase transition, although widely exploited in making new materials, challenges persistently our current theory for predicting its complex kinetics and rich microstructures in transition. The Ga2O3α-β phase transformation represents such a common but complex reaction with marked change in cation coordination and crystal density, which was known to yield either amorphous or crystalline products under different synthetic conditions. Here we, via recently developed stochastic surface walking (SSW) method, resolve for the first time the atomistic mechanism of Ga2O3α-β phase transformation, the pathway of which turns out to be the first reaction pathway ever determined for a new type of diffusionless solid phase transition, namely, pseudomartensitic phase transition. We demonstrate that the sensitivity of product crystallinity is caused by its multi-step, multi-type reaction pathway, which bypasses seven intermediate phases and involves all types of elementary solid phase transition steps, i.e. the shearing of O layers (martensitic type), the local diffusion of Ga atoms (reconstructive type) and the significant lattice dilation (dilation type). While the migration of Ga atoms across the close-packed O layers is the rate-determining step and yields "amorphous-like" high energy intermediates, the shearing of O layers contributes to the formation of coherent biphase junctions and the presence of a crystallographic orientation relation, (001)α//(201[combining macron])β + [120]α//[13[combining macron]2]β. Our experiment using high-resolution transmission electron microscopy further confirms the theoretical predictions on the atomic structure of biphase junction and the formation of (201[combining macron])β twin, and also discovers the late occurrence of lattice expansion in the nascent β phase that grows out from the parent α phase. By distinguishing pseudomartensitic transition from other types of mechanisms, we propose general rules to predict the

A multiple-field coupled resistive transition model for superconducting Nb3Sn

Directory of Open Access Journals (Sweden)

Lin Yang

2016-12-01

Full Text Available A study on the superconducting transition width as functions of the applied magnetic field and strain is performed in superconducting Nb3Sn. A quantitative, yet universal phenomenological resistivity model is proposed. The numerical simulation by the proposed model shows predicted resistive transition characteristics under variable magnetic fields and strain, which in good agreement with the experimental observations. Furthermore, a temperature-modulated magnetoresistance transition behavior in filamentary Nb3Sn conductors can also be well described by the given model. The multiple-field coupled resistive transition model is helpful for making objective determinations of the high-dimensional critical surface of Nb3Sn in the multi-parameter space, offering some preliminary information about the basic vortex-pinning mechanisms, and guiding the design of the quench protection system of Nb3Sn superconducting magnets.

M₅Si₃(M=Ti, Nb, Mo) Based Transition-Metal Silicides for High Temperature Applications

Energy Technology Data Exchange (ETDEWEB)

Tang, Zhihong [Iowa State Univ., Ames, IA (United States)

2007-01-01

Transition metal silicides are being considered for future engine turbine components at temperatures up to 1600 C. Although significant improvement in high temperature strength, room temperature fracture toughness has been realized in the past decade, further improvement in oxidation resistance is needed. Oxidation mechanism of Ti₅Si₃-based alloys was investigated. Oxidation behavior of Ti₅Si₃-based alloy strongly depends on the atmosphere. Presence of Nitrogen alters the oxidation behavior of Ti₅Si₃ by nucleation and growth of nitride subscale. Ti₅Si_3.2and Ti₅Si₃C_0.5 alloys exhibited an excellent oxidation resistance in nitrogen bearing atmosphere due to limited dissolution of nitrogen and increased Si/Ti activity ratio. MoSi₂ coating developed by pack cementation to protect Mo-based Mo-Si-B composites was found to be effective up to 1500 C. Shifting coating composition to T1+T2+Mo₃Si region showed the possibility to extend the coating lifetime above 1500 C by more than ten times via formation of slow growing Mo₃Si or T2 interlayer without sacrificing the oxidation resistance of the coating. The phase equilibria in the Nb-rich portion of Nb-B system has been evaluated experimentally using metallographic analysis and differential thermal analyzer (DTA). It was shown that Nb_ss (solid solution) and NbB are the only two primary phases in the 0-40 at.% B composition range, and the eutectic reaction L {leftrightarrow} Nb_SS + NbB was determined to occur at 2104 ± 5 C by DTA.

A 3D Virtual Space for the E-Commerce Strategy Model

OpenAIRE

Gong Cheng; Changrui Yu; Kecheng Liu

2014-01-01

In recent years, innovative applications of electronic commerce (e-commerce) are facing the challenges of mobile commerce (m-commerce) and ubiquitous commerce (u-commerce). To address these challenges and improve the competitiveness of e-commerce, the three-dimensional e-commerce (3DEC) theory is proposed and a 3DEC business strategy model is built up in this study. The new conceptual 3DEC model incorporates the industrial environment analysis, SWOT analysis, and business model canvas (BMC). ...

Probing the electronic properties of ternary A n M3n-1B2n (n = 1: A = Ca, Sr; M = Rh, Ir and n = 3: A = Ca, Sr; M = Rh) phases: observation of superconductivity.

Science.gov (United States)

Takeya, Hiroyuki; ElMassalami, Mohammed; Terrazos, Luis A; Rapp, Raul E; Capaz, Rodrigo B; Fujii, Hiroki; Takano, Yoshihiko; Doerr, Mathias; Granovsky, Sergey A

2013-06-01

We follow the evolution of the electronic properties of the titled homologous series when n as well as the atomic type of A and M are varied where for n = 1, A = Ca, Sr and M = Rh, Ir while for n = 3, A = Ca, Sr and M = Rh. The crystal structure of n = 1 members is known to be CaRh 2 B 2 -type ( Fddd ), while that of n = 3 is Ca 3 Rh 8 B 6 -type ( Fmmm ); the latter can be visualized as a stacking of structural fragments from AM 3 B 2 ( P 6/ mmm ) and AM 2 B 2 . The metallic properties of the n = 1 and 3 members are distinctly different: on the one hand, the n = 1 members are characterized by a linear coefficient of the electronic specific heat γ ≈ 3 mJ mol -1 K -2 , a Debye temperature θ D ≈ 300 K, a normal conductivity down to 2 K and a relatively strong linear magnetoresistivity for fields up to 150 kOe. The n = 3 family, on the other hand, exhibits γ ≈ 18 mJ mol -1 K -2 , θ D ≈ 330 K, a weak linear magnetoresistivity and an onset of superconductivity (for Ca 3 Rh 8 B 6 , T c = 4.0 K and H c2 = 14.5 kOe, while for Sr 3 Rh 8 B 6 , T c = 3.4 K and H c2 ≈ 4.0 kOe). These remarkable differences are consistent with the findings of the electronic band structures and density of state (DOS) calculations. In particular, satisfactory agreement between the measured and calculated γ was obtained. Furthermore, the Fermi level, E F , of Ca 3 Rh 8 B 6 lies at almost the top of a pronounced local DOS peak, while that of CaRh 2 B 2 lies at a local valley: this is the main reason behind the differences between the, e.g., superconducting properties. Finally, although all atoms contribute to the DOS at E F , the contribution of the Rh atoms is the strongest.

Heat Increases the Editing Efficiency of Human Papillomavirus E2 Gene by Inducing Upregulation of APOBEC3A and 3G.

Science.gov (United States)

Yang, Yang; Wang, Hexiao; Zhang, Xinrui; Huo, Wei; Qi, Ruiqun; Gao, Yali; Zhang, Gaofeng; Song, Bing; Chen, Hongduo; Gao, Xinghua

2017-04-01

Apolipoprotein B mRNA-editing catalytic polypeptide (APOBEC) 3 proteins have been identified as potent viral DNA mutators and have broad antiviral activity. In this study, we demonstrated that apolipoprotein B mRNA-editing catalytic polypeptide 3A (A3A) and A3G expression levels were significantly upregulated in human papillomavirus (HPV)-infected cell lines and tissues. Heat treatment resulted in elevated expression of A3A and A3G in a temperature-dependent manner in HPV-infected cells. Correspondingly, HPV-infected cells heat-treated at 44 °C showed accumulated G-to-A or C-to-T mutation in HPV E2 gene. Knockdown of A3A or A3G could promote cell viability, along with the lower frequency of A/T in HPV E2 gene. In addition, regressing genital viral warts also harbored high G-to-A or C-to-T mutation in HPV E2 gene. Taken together, we demonstrate that apolipoprotein B mRNA-editing catalytic polypeptide 3 expression and editing function was heat sensitive to a certain degree, partly explaining the mechanism of action of local hyperthermia to treat viral warts. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Structure and phase transition of BiFeO{sub 3} cubic micro-particles prepared by hydrothermal method

Energy Technology Data Exchange (ETDEWEB)

Zhou, Jian-Ping, E-mail: zhoujp@snnu.edu.cn [College of Physics and Information Technology, Shaanxi Normal University, Xi’an 710062 (China); Yang, Ruo-Lin; Xiao, Rui-Juan; Chen, Xiao-Ming [College of Physics and Information Technology, Shaanxi Normal University, Xi’an 710062 (China); Deng, Chao-Yong [Department of Electronic Science, Guizhou University, Guizhou Guiyang 550025 (China)

2012-11-15

Graphical abstract: Bismuth ferrite (BiFeO{sub 3}) cubic micro-particles with smooth surfaces were synthesized. BiFeO{sub 3} has a hexagonal perovskite structure with a space group R3c below 370 °C and rhombohedral perovskite structure with a space group R3m below 755 °C, undergoes a phase transition in the temperature range of 755–817 °C to a cubic structure, then decompose to liquid and Fe{sub 2}O{sub 3} above 939 °C. Highlights: ► BiFeO{sub 3} micro-particles with smooth surface were synthesized by hydrothermal method. ► BiFeO{sub 3} enjoys hexagonal structure with well element ratio and chemical valence. ► BiFeO{sub 3} transition from rhombohedral phase to cubic phase lasts 60 °C. -- Abstract: Single-phase bismuth ferrite (BiFeO{sub 3}) powders were synthesized with a hydrothermal method by controlling the experimental conditions carefully. The powder structure, morphology and composition were characterized by using X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscope, Raman measurement and X-ray photoelectron spectroscopy. The particles change from irregular agglomerations to regular cubes with increasing KOH concentration. The large BiFeO{sub 3} cubic particles enjoy much smooth surfaces with well-matched element ratio (Bi:Fe:O = 1:1:3) and chemical valence (Bi{sup 3+}, Fe{sup 3+} and O{sup 2−}). The high temperature XRD and differential scanning calorimetry show that BiFeO{sub 3} powders have a hexagonal perovskite structure with a space group R3c below 370 °C and a rhombohedral structure with a space group R3m below 755 °C. BiFeO{sub 3} undergoes a phase transition in the temperature range of 755–817 °C from rhombohedral structure to a cubic phase, then decomposes to liquid and Fe{sub 2}O{sub 3} above 939 °C.

Formal Valence, 3 d Occupation, and Charge Ordering Transitions

Science.gov (United States)

Pickett, Warren

2014-03-01

The metal-insulator transition (MIT), discovered by Verwey in the late 1930s, has been thought to be one of the best understood of MITs, the other ones being named after Wigner, Peierls, Mott, and Anderson. Continuing work on these transitions finds in some cases less and less charge to order, raising the fundamental question of just where the entropy is coming from, and just what is ordering. To provide insight into the mechanism of charge-ordering transitions, which conventionally are pictured as a disproportionation, I will (1) review and reconsider the charge state (or oxidation number) picture itself, (2) introduce new theoretical results for the rare earth nickelates (viz. YNiO3), the putative charge ordering compound AgNiO2, and the dual charge state insulator AgO, and (3) analyze cationic occupations of actual (not formal) charge, and work to reconcile the conundrums that arise. Several of the clearest cases of charge ordering transitions involve no disproportion; moreover, the experimental data used to support charge ordering can be accounted for within density functional based calculations that contain no charge transfer The challenge of modeling charge ordering transitions with model Hamiltonians will be discussed. Acknowledgment: Y. Quan, V. Pardo. Supported by NSF award DMR-1207622-0.

Direct measurement of the low temperature spin state transitions in La1-xSrxCoO3 (0.05 < x < 0.3)

Science.gov (United States)

Gulec, A.; Klie, R. F.

2014-12-01

Sr-doped LaCoO3 has a complex magnetic phase diagram, which is believed to be directly correlated to changes in the crystal structure and ordering of the Co3+ spin states. In this work, we study the low temperature Co3+-ion spin state transitions in Sr-doped LaCoO3 around the critical doping concentration where a metal to insulator transition has been observed using electron energy-loss spectroscopy of the O K-edge combined with the Co L-edge fine structure. We measure the local spin state of the Co3+-ions and we demonstrate that the Co3+ spin-state transition only occurs in La0.95Sr0.05CoO3 single-crystal materials in the temperature range accessible by LN2 in-situ cooling, while no structural symmetry change is observed. The presence of this low-temperature spin-state transition in La1-xSrxCoO3 (x < 0.17) has been proposed as the origin of the percolative magnetic ordering in doped LaCoO3.

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.

The 3d4-3d34p transitions of triply ionized manganese (Mn IV)

International Nuclear Information System (INIS)

Tchang-Brillet, W.Ue.L.; Artru, M.C.; Wyart, J.F.

1986-01-01

The analysis of Mn IV is extended in the wavelength range 473-847 A. A total of 600 classified lines are given, of which 372 are newly observed. All of them are due to 3d 4 -3d 3 4p transitions. Their classification and the identification of 59 new levels are supported by the parametric studies of the 3d 4 and 3d 3 4p configurations. The ground configuration 3d 4 is calculated by taking into account the effective magnetic interactions which improve by an order of magnitude the theoretical fine structure of the quintet and triplet terms. The analysis was guided by the prediction of relative line strengths in intermediate coupling. Calculated energies and LS composition are given for all levels of the configuration, 3d 4 and 3d 3 4p. (orig).

Optical spectroscopy, 1.06μm emission properties of Nd3+-doped phosphate based glasses.

Science.gov (United States)

Sk Nayab, Rasool; T, Sasikala; A, Mohan Babu; L, Rama Moorthy; C K, Jayasankar

2017-06-05

Neodymium doped phosphate based glasses with composition of (P 2 O 5 +K 2 O+Al 2 O 3 +CaF 2 ) were prepared. The samples were analysed through differential thermal analysis (DTA), Fourier transform infrared (FTIR), absorption, emission and decay measurements. Judd-Ofelt parameters (Ω λ ) have been determined from the spectral intensities of absorption bands in order to calculate the radiative parameters like radiative transition probabilities (A R ), radiative lifetime (τ R ) and branching ratios (β R ) for the 4 F 3/2 → 4 I 11/2 laser transition of Nd 3+ ion. The effective emission bandwidths (Δλ eff ), experimental branching ratios (β exp ) and stimulated emission cross-sections (σ e ) have been determined from the emission spectrum. The decay curves of the 4 F 3/2 level exhibited almost single exponential nature for all the Nd 3+ ion concentrations. Copyright © 2017 Elsevier B.V. All rights reserved.

Optical transitions of Ho(3+) in oxyfluoride glasses and upconversion luminescence of Ho(3+)/Yb(3+)-codoped oxyfluoride glasses.

Science.gov (United States)

Feng, Li; Wu, Yinsu

2015-05-05

Optical properties of Ho(3+)-doped SiO2-BaF2-ZnF2 glasses have been investigated on the basis of the Judd-Ofelt theory. Judd-Ofelt intensity parameters, radiative transition probabilities, fluorescence branching ratios and radiative lifetimes have been calculated for different glass compositions. Upconversion emissions were observed in Ho(3+)/Yb(3+)-codoped SiO2-BaF2-ZnF2 glasses under 980nm excitation. The effects of composition, concentration of the doping ions, and excitation pump power on the upconversion emissions were also systematically studied. Copyright © 2015 Elsevier B.V. All rights reserved.

Electron impact excitation of Fe-peak elements: forbidden transitions in the 3d5 manifold of Fe IV

International Nuclear Information System (INIS)

McLaughlin, B M; Hibbert, A; Scott, M P; Noble, C J; Burke, V M; Burke, P G

2005-01-01

Electron-impact excitation collision strengths of the Fe-peak element Fe IV are calculated in the close-coupling approximation using the R-matrix suite of codes PRMAT designed for parallel processors. One hundred and eight LS-coupled states arising from the 3d 5 , 3d 4 4s and 3d 4 4p configurations of Fe IV, are retained in the present calculations. Detailed multi-configuration interaction target wavefunctions are used with the aid of 3p 2 → 3d 2 electron promotions and a 4dbar correlation orbital in the present calculations. Effective collision strengths for optically forbidden transitions, which are extremely important in the analysis of lines in the Fe IV spectra, are obtained by averaging the electron collision strengths for a wide range of incident electron energies, over a Maxwellian distribution of velocities. Results are presented for electron temperatures (T e in Kelvin) in the range 3.3 ≤ Log T e ≤ 6.0 applicable to many laboratory and astrophysical plasmas for transitions within the 3d 5 manifold. The present results compared to previous investigations provide improved results for important lines in the Fe IV spectrum

Determination of the B(E3,0$^{+}$ $\\rightarrow$ 3$^{-}$) strength in the octupole correlated nuclei $^{142,144}$Ba using Coulomb excitation

CERN Multimedia

We propose to exploit the unique capability of ISOLDE to provide intense post-accelerated $^{142}$Ba and $^{144}$Ba ion beams from the HIE-ISOLDE facility to enable the Coulomb excitation of the first 3$^-$ state in these nuclei. By measuring the $\\gamma$-ray yields of the E1 decays from the 3$^-$ state using the MINIBALL array, we can obtain the interesting transition matrix element. The results will give quantitative information about octupole correlations in these nuclei.

Determination of the B(E3;0$^+\\!\\rightarrow$ 3$^{-}$) strength in the octupole correlated nucleus $^{144}$Ba using Coulomb excitation

CERN Multimedia

We propose to exploit the unique capability of ISOLDE to provide intense post-accelerated $^{144}$Ba ion beams from the REX facility to enable the Coulomb excitation of the first 3$^{-}$ state in this nucleus. By measuring the $\\gamma$-ray yields of the E1 decay connecting the 3$^{-}$ and 2$^{+}$ states using the MINIBALL array, we can obtain the interesting transition matrix element. The result will give quantitative information about octupole correlations in this nucleus. We require 27 shifts to fulfill the aims of the experiment.

Optimizing Concurrent M3-Transactions: A Fuzzy Constraint Satisfaction Approach

Directory of Open Access Journals (Sweden)

Peng LI

2004-10-01

Full Text Available Due to the high connectivity and great convenience, many E-commerce application systems have a high transaction volume. Consequently, the system state changes rapidly and it is likely that customers issue transactions based on out-of-date state information. Thus, the potential of transaction abortion increases greatly. To address this problem, we proposed an M3-transaction model. An M3-transaction is a generalized transaction where users can issue their preferences in a request by specifying multiple criteria and optional data resources simultaneously within one transaction. In this paper, we introduce the transaction grouping and group evaluation techniques. We consider evaluating a group of M3-transactions arrived to the system within a short duration together. The system makes optimal decisions in allocating data to transactions to achieve better customer satisfaction and lower transaction failure rate. We apply the fuzzy constraint satisfaction approach for decision-making. We also conduct experimental studies to evaluate the performance of our approach. The results show that the M3-transaction with group evaluation is more resilient to failure and yields much better performance than the traditional transaction model.

Charge driven metal-insulator transitions in LaMnO3|SrTiO3 (111) superlattices

KAUST Repository

Cossu, Fabrizio; Tahini, Hassan Ali; Singh, Nirpendra; Schwingenschlö gl, Udo

2017-01-01

Interfaces of perovskite oxides, due to the strong interplay between the lattice, charge and spin degrees of freedom, can host various phase transitions, which is particularly interesting if these transitions can be tuned by external fields. Recently, ferromagnetism was found together with a seemingly insulating state in superlattices of manganites and titanates. We therefore study the (111) oriented $(\\text{LaMnO}_3)_{6-x}\\vert(\\text{SrTiO}_3)_{6+x}~(x = -0.5, 0, 0.5)$ superlattices by means of ab initio calculations, predicting a ferromagnetic ground state due to double exchange in all cases. We shed light on the ferromagnetic coupling in the LaMnO3 region and at the interfaces. The insulating states of specific superlattices can be understood on the basis of Jahn-Teller modes and electron/hole doping.

Charge driven metal-insulator transitions in LaMnO3|SrTiO3 (111) superlattices

KAUST Repository

Cossu, Fabrizio

2017-08-01

Interfaces of perovskite oxides, due to the strong interplay between the lattice, charge and spin degrees of freedom, can host various phase transitions, which is particularly interesting if these transitions can be tuned by external fields. Recently, ferromagnetism was found together with a seemingly insulating state in superlattices of manganites and titanates. We therefore study the (111) oriented $(\\\\text{LaMnO}_3)_{6-x}\\\\vert(\\\\text{SrTiO}_3)_{6+x}~(x = -0.5, 0, 0.5)$ superlattices by means of ab initio calculations, predicting a ferromagnetic ground state due to double exchange in all cases. We shed light on the ferromagnetic coupling in the LaMnO3 region and at the interfaces. The insulating states of specific superlattices can be understood on the basis of Jahn-Teller modes and electron/hole doping.

The translation initiation factor 3 subunit eIF3K interacts with PML and associates with PML nuclear bodies

Energy Technology Data Exchange (ETDEWEB)

Salsman, Jayme; Pinder, Jordan; Tse, Brenda [Department of Pathology, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia, Canada B3H 4R2 (Canada); Corkery, Dale [Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia (Canada); Dellaire, Graham, E-mail: dellaire@dal.ca [Department of Pathology, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia, Canada B3H 4R2 (Canada); Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia (Canada)

2013-10-15

The promyelocytic leukemia protein (PML) is a tumor suppressor protein that regulates a variety of important cellular processes, including gene expression, DNA repair and cell fate decisions. Integral to its function is the ability of PML to form nuclear bodies (NBs) that serve as hubs for the interaction and modification of over 90 cellular proteins. There are seven canonical isoforms of PML, which encode diverse C-termini generated by alternative pre-mRNA splicing. Recruitment of specific cellular proteins to PML NBs is mediated by protein–protein interactions with individual PML isoforms. Using a yeast two-hybrid screen employing peptide sequences unique to PML isoform I (PML-I), we identified an interaction with the eukaryotic initiation factor 3 subunit K (eIF3K), and in the process identified a novel eIF3K isoform, which we term eIF3K-2. We further demonstrate that eIF3K and PML interact both in vitro via pull-down assays, as well as in vivo within human cells by co-immunoprecipitation and co-immunofluorescence. In addition, eIF3K isoform 2 (eIF3K-2) colocalizes to PML bodies, particularly those enriched in PML-I, while eIF3K isoform 1 associates poorly with PML NBs. Thus, we report eIF3K as the first known subunit of the eIF3 translation pre-initiation complex to interact directly with the PML protein, and provide data implicating alternative splicing of both PML and eIF3K as a possible regulatory mechanism for eIF3K localization at PML NBs. - Highlights: • The PML-I C-terminus, encoded by exon 9, interacts with translation factor eIF3K. • We identify a novel eIF3K isoform that excludes exon 2 (eIF3K-2). • eIF3K-2 preferentially associates with PML bodies enriched in PML-I vs. PML-IV. • Alternative splicing of eIF3K regulates association with PML bodies.

In-plain electric properties of [CaMnO3/REMO3] (RE=Bi, La M=Fe, Fe0.8Mn0.2) superlattices grown by pulsed laser deposition method

NARCIS (Netherlands)

Iwata, N.; Watabe, Y.; Oikawa, T.; Takase, K.; Huijben, Mark; Inaba, T.; Oshima, K.; Rijnders, Augustinus J.H.M.; Yamamoto, H.

2014-01-01

The [CaMnO3 (CMO)/REMO3] (RE = Bi, La M = Fe, Fe0.8Mn0.2) superlattices show semiconducting behavior with transition temperatures (TEg) of 71, 127, and 151 K in the [CMO/BiFe0.8Mn0.2O3], [CMO/BiFeO3], and [CMO/LaFeO3] superlattices. The formation of a magnetic polaron is expected in the CMO layer of

14-3-3 σ expression effects G2/M response to oxygen and correlates with ovarian cancer metastasis.

Directory of Open Access Journals (Sweden)

Dashnamoorthy Ravi

2011-01-01

Full Text Available In vitro cell culture experiments with primary cells have reported that cell proliferation is retarded in the presence of ambient compared to physiological O₂ levels. Cancer is primarily a disease of aberrant cell proliferation, therefore, studying cancer cells grown under ambient O₂ may be undesirable. To understand better the impact of O₂ on the propagation of cancer cells in vitro, we compared the growth potential of a panel of ovarian cancer cell lines under ambient (21% or physiological (3% O₂.Our observations demonstrate that similar to primary cells, many cancer cells maintain an inherent sensitivity to O₂, but some display insensitivity to changes in O₂ concentration. Further analysis revealed an association between defective G2/M cell cycle transition regulation and O₂ insensitivity resultant from overexpression of 14-3-3 σ. Targeting 14-3-3 σ overexpression with RNAi restored O₂ sensitivity in these cell lines. Additionally, we found that metastatic ovarian tumors frequently overexpress 14-3-3 σ, which in conjunction with phosphorylated RB, results in poor prognosis.Cancer cells show differential proliferative sensitivity to changes in O₂ concentration. Although a direct link between O₂ insensitivity and metastasis was not determined, this investigation showed that an O₂ insensitive phenotype in cancer cells to correlate with metastatic tumor progression.

First-principles analysis of ferroelectric transition in MnSnO3 and MnTiO3 perovskites

Science.gov (United States)

Kang, Sung Gu

2018-06-01

The ferroelectric instabilities of an artificially adopted Pnma structure in low tolerance perovskites have been explored (Kang et al., 2017) [4], where an unstable A-site environment was reported to be the major driving source for the low tolerance perovskites to exhibit ferroelectric instability. This study examined the ferroelectric transition of two magnetic perovskite materials, MnSnO3 and MnTiO3, in Pnma phase. Phase transitions to the Pnma phase at elevated pressures were observed. MnSnO3, which has a lower (larger) tolerance factor (B-site cation radius), showed a higher ferroelectric mode amplitude than MnTiO3. The distribution of the bond length of Mn-O and the mean quadratic elongation (QE) of octahedra (SnO6 or TiO6) were investigated for structural analysis. However, MnTiO3 showed a larger spontaneous polarization than MnSnO3 due to high Born effective charges of titanium. This study is useful because it provides a valuable pathway to the design of promising multiferroic materials.

Spin-State Transition in La1-xSrxCoO3 Single Crystals

Science.gov (United States)

Bhardwaj, S.; Prabhakaran, D.; Awasthi, A. M.

2011-07-01

We present a study of the thermal conductivity (κ), specific heat (Cp) and Raman spectra of La1-xSrxCoO3 (x = 0,0.1) single crystals. Both the specimens have low thermal conductivity and board Raman peaks, arising from strong scattering of phonons by lattice disorder, produced by (and doping-enhanced) spin-states admixture of the Co3+ ions. The thermal conductivity anomalously deviates from ˜1/T behaviour at high (room) temperatures, expected of an insulator. High-temperature specific heat reveals large decrease in the metal-insulator (M-I) transition temperature with Sr-doping.

The interactions in K{sub μ3} and K{sub e3} decay

Energy Technology Data Exchange (ETDEWEB)

McDowell, S. W. [Brazilian Centre of Research in Physics, Rio de Janeiro (Brazil)

1963-01-15

An attractive feature common to all present theories of weak interactions is the assumption that they result from the coupling (either direct or via intermediate bosons) of vector-axial vector currents. The V-A coupling of leptonic currents and baryonic currents conserving strangeness successfully explains the characteristic properties of μ-decay, π-decay and μ-decay. On the other hand, the leptonic decay modes of K-mesons provide the best source of information on the nature of the currents carrying strangeness. From K{sub μ2} one learns that there must exist an axial-vector current carrying strangeness; further, if the leptonic weak interaction is universal, one can explain the absence of the K{sub e2} mode by excluding a pseudo-scalar interaction. From K{sub μ3} and K{sub e3} decay one can obtain information on scalar, vector and tensor coupling of strangeness non-conserving currents with leptons. In recent experiments on K{sub e3} decay a good fitting of the pion spectrum was obtained with a constant vector form factor. Although regarding this result as strong evidence of pure vector coupling, one might still argue that other possibilities, such as a mixture of vector and tensor couplings with energy-dependent form factors, are not excluded. I shall discuss here, in the first place, some properties of the transition amplitudes which are independent of the structure of form factors. They provide a test of universality and a criterion for unambiguous determination of the nature of the weak interaction involved in these processes. Secondly, I shall discuss the structure of form factors, by means of dispersion relations and introducing explicitly the effect of the K*-resonance in the Kπ-interaction.

M3: Matrix Multiplication on MapReduce

DEFF Research Database (Denmark)

Silvestri, Francesco; Ceccarello, Matteo

2015-01-01

M3 is an Hadoop library for performing dense and sparse matrix multiplication in MapReduce. The library is based on multi-round algorithms exploiting the 3D decomposition of the problem.......M3 is an Hadoop library for performing dense and sparse matrix multiplication in MapReduce. The library is based on multi-round algorithms exploiting the 3D decomposition of the problem....

Thermoreflectance characterization of beta-Ga2O3 thin-film nanostrips.

Science.gov (United States)

Ho, Ching-Hwa; Tseng, Chiao-Yeh; Tien, Li-Chia

2010-08-02

Nanostructure of beta-Ga(2)O(3) is wide-band-gap material with white-light-emission function because of its abundance in gap states. In this study, the gap states and near-band-edge transitions in beta-Ga(2)O(3) nanostrips have been characterized using temperature-dependent thermoreflectance (TR) measurements in the temperature range between 30 and 320 K. Photoluminescence (PL) measurements were carried to identify the gap-state transitions in the beta-Ga(2)O(3) nanostrips. Experimental analysis of the TR spectra revealed that the direct gap (E(0)) of beta-Ga(2)O(3) is 4.656 eV at 300 K. There are a lot of gap-state and near-band-edge (GSNBE) transitions denoted as E(D3), E(W1), E(W2), E(W3), E(D2), EDBex, E(DB), E(D1), E(0), and E(0)' can be detected in the TR and PL spectra at 30 K. Transition origins for the GSNBE features in the beta-Ga(2)O(3) nanostrips are respectively evaluated. Temperature dependences of transition energies of the GSNBE transitions in the beta-Ga(2)O(3) nanostrips are analyzed. The probable band scheme for the GSNBE transitions in the beta-Ga(2)O(3) nanostrips is constructed.

(E,Z)-3-(3',5'-Dimethoxy-4'-hydroxy-benzylidene)-2-indolinone blocks mast cell degranulation.

Science.gov (United States)

Kiefer, S; Mertz, A C; Koryakina, A; Hamburger, M; Küenzi, P

2010-05-12

(E,Z)-3-(3',5'-Dimethoxy-4'-hydroxy-benzylidene)-2-indolinone (indolinone) is an alkaloid that has been identified as a pharmacologically active compound in extracts of the traditional anti-inflammatory herb Isatis tinctoria. Indolinone has been shown to inhibit compound 48/80-induced mast cell degranulation in vitro. Application of indolinone to bone marrow derived mast cells showed that it was uniformly distributed in the cytoplasm and that cellular uptake was terminated within minutes. Pre-treatment of IgE-sensitized mast cells with 100nM indolinone rendered them insensitive against FcvarepsilonRI-receptor dependent degranulation. However, upstream signalling induced by antigen such as activation of PI3-K and MAPK remained unaffected. We conclude that indolinone blocks mast cell degranulation at the level of granule exocitosis with an IC(50) of 54nm.

Electronic transport and conduction mechanism transition in La{sub 1∕3}Sr{sub 2∕3}FeO{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Devlin, R. C.; Krick, A. L.; Sichel-Tissot, R. J.; Xie, Y. J.; May, S. J., E-mail: smay@coe.drexel.edu [Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States)

2014-06-21

We report on the electronic transport properties of epitaxial La{sub 1∕3}Sr{sub 2∕3}FeO{sub 3} films using temperature dependent resistivity, Hall effect, and magnetoresistance measurements. We show that the electronic phase transition, which occurs near 190 K, results in a change in conduction mechanism from nonadiabatic polaron transport at high temperatures to resistivity behavior following a power law temperature dependence at low temperatures. The phase transition is also accompanied by an abrupt increase in apparent mobility and Hall coefficient below the critical temperature (T*). We argue that the exotic low temperature transport properties are a consequence of the unusually long-range periodicity of the antiferromagnetic ordering, which also couples to the electronic transport in the form of a negative magnetoresistance below T* and a sign reversal of the Hall coefficient at T*. By comparing films of differing thicknesses, stoichiometry, and strain states, we demonstrate that the observed conduction behavior is a robust feature of La{sub 1∕3}Sr{sub 2∕3}FeO{sub 3}.

Bi∼3.785Cd∼3.575Cu∼1.5(PO4)3.5O5.5, a new arrangement of double (n=2) and triple (n=3) [M4Bi2n-2O2n]x+ polycationic ribbons in the bismuth-transition metal oxy-phosphate series

International Nuclear Information System (INIS)

Colmont, Marie; Huve, Marielle; Abraham, Francis; Mentre, Olivier

2004-01-01

This work is dedicated to investigation of new disordered bismuth-containing oxy-phosphates compounds with an original structure type. As previously observed in this series, they are formed of [M 4 Bi 2n-2 O 2n ] x+ polycationic ribbons of width n O(Bi,M) 4 tetrahedra, surrounded by PO 4 groups. In the new crystal structure type, double (=D), triple (=T) and tunnels (=t) alternate along a common axis obeying the TtDtTtDt/TTtTTt sequence in respect to a nomenclature previously described and recalled in this work. The existence this new polymorph has first been detected by electron diffraction in a multi-phased sample. Then, the crystal structure type, i.e., the TtDtTtDt/TTtTTt sequence, has been deduced from HREM images help to a contrast-interpreting code available for these series of polycations-formed compounds. The subsequent compounds formulation leads to a number of new materials that verify the general formula: [Bi 2 (Bi,M) 4 O 4 ] 2 [Bi 4 (Bi,M) 4 O 6 ] 6 (PO 4 ) 28 M x , with x= 2+ , Cd 2+ cations. Single crystals of the nominal [O6Bi 4.57 Cd 3.43 ] 4 +8.57 [O 6 Bi 4 Cd 4 ] 2 +8 [O 4 Bi 2 Cd 3.56 Cu 0.44 ] 2 +6 (PO 4 ) 28 Cu 10.86 have been prepared in a further stage and confirms the predicted crystal structure, Bi ∼3.785 Cd ∼3.575 Cu ∼1.5 (PO 4 ) 3.5 O 5.5 , a=11.506(8)A, b=5.416(4)A, c=53.94 (4)A, β=90.10(1) o , RF=0.0835, RwF=0.0993, SG=A2/m, Z=8. As already observed for other elements of this family such as Bi ∼1.2 M ∼1.2 O 1.5 (PO 4 ), Bi ∼6.2 Cu ∼6.2 O 8 (PO 4 ) 5 or Bi ∼3 Cd ∼3.72 M ∼1.28 O 5 (PO 4 ) 3 (M=Cu, Co, Zn), this compound shows an additional example of PO 4 disorder due to the presence of mixed Bi 3+ /M 2+ sites at the edges of ribbons. The origin and consequence of this so-called disorder mostly occurring on PO 4 configurations is intensively discussed and has been characterized by infrared spectroscopy and by neutron diffraction on similar compounds. It is noticeable that the great number of antagonist PO 4

K2-137 b: an Earth-sized planet in a 4.3-h orbit around an M-dwarf

DEFF Research Database (Denmark)

Smith, A. M. S.; Cabrera, J.; Csizmadia, Sz

2018-01-01

We report the discovery in K2's Campaign 10 of a transiting terrestrial planet in an ultra-short-period orbit around an M3-dwarf. K2-137 b completes an orbit in only 4.3 h, the second shortest orbital period of any known planet, just 4 min longer than that of KOI 1843.03, which also orbits an M-d...

Spherical resonator for vapor-phase speed of sound and measurements of 1,1,1,2,2,3,3-heptafluoro-3-methoxypropane (RE347mcc) and trans-1,3,3,3-tetrafluoropropene [R1234ze(E)

International Nuclear Information System (INIS)

Perkins, Richard A.; McLinden, Mark O.

2015-01-01

Highlights: • A spherical acoustic resonator for gas-phase speed of sound over the range T = (265 to 500) K, p < 10 MPa is described. • The sphere diameter was calibrated with argon and measurements on methane and ethane verified the performance of the system. • The sound speed of RE347mcc was measured over the range T = (325 to 500) K, p < 1.6 MPa. • The sound speed of R1234ze(E) was measured over the range T = (280 to 420) K, p < 2.8 MPa. • The average combined, expanded uncertainties for sound speed were 0.035 m · s"−"1 for RE347mcc and 0.064 m · s"−"1 for R1234ze(E). - Abstract: We describe an apparatus to measure the speed of sound of gas samples at temperatures from (265 to 500) K with pressures up to 10 MPa. The speed of sound was determined from the frequency of the three lowest-order radial resonance modes for the gas in a spherical cavity machined from type 321 stainless steel for corrosion resistance. The spherical resonator was contained in an isothermal copper block that was maintained at the temperature of interest by a multilayer thermostat with vacuum insulation. The dimensions of the spherical cavity were characterized as a function of temperature and pressure though calibration measurements with high-purity argon. The performance of the apparatus was demonstrated with measurements of high-purity methane and ethane. Measurements of the sound speed of 1,1,1,2,2,3,3-heptafluoro-3-methoxypropane (RE347mcc) are reported at temperatures from (325 to 500) K with pressures up to 1.6 MPa. Measurements on trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) are reported at temperatures from (280 to 420) K with pressures up to 2.8 MPa. The average relative combined expanded uncertainties of the measured sound speed for RE347mcc and R1234ze(E) are (0.029 and 0.041)%, respectively.

Dc transport and optical measurements on the charge-density-wave compounds (K,Rb){sub 0.3}(Mo,W)O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Al-Hadeethi, Ali Khairi Abdul-Qader

2013-04-26

The temperature dependence of the linear and the non-linear transport properties in K{sub 0.3}MoO{sub 3}, (K{sub 0.5}Rb{sub 0.5}){sub 0.3}MoO{sub 3}, and K{sub 0.3}Mo{sub 0.99}W{sub 0.01}O{sub 3} are presented. The temperature dependence of the dc resistivity of the pure sample has shown the Peierls metal-insulator phase transition at 180 K, where the transition is very sharp. The rubidium doping shifts the transition temperature to a lower temperature (170 K) and smears out the metal-insulator phase transition, i.e., the rubidium doping broadens the transition peak. Compared with the rubidium doping, the tungsten doping broadens the transition peak more and shifts the transition temperature to a lower temperature (140 K). The temperature-dependent dc resistivity curves of pure, Rb-doped, and W-doped blue bronze K{sub 0.3}MoO{sub 3} single crystals are analyzed in terms of the pseudogap just above TP and the Peierls energy gap below TP. The non-linear transport properties of pure, Rb-doped, and W-doped blue bronze K{sub 0.3}MoO{sub 3} single crystals have shown a nonlinear conductivity due to an incoherent CDW sliding, when the applied electric field exceeds the first threshold field (E{sub T}). Furthermore, above a second threshold field (E{sub T}{sup *} > E{sub T}) a coherent CDW-sliding sets in. For all studied samples, we find a monotonic increase of E{sub T} and E{sub T}{sup *} with decreasing temperature. This finding is discussed mainly in terms of the incommensurate-commensurate transition of the CDW. The coherent and incoherent CDW movements are discussed within the frame of the Fukuyama-Lee-Rice model.

Theoretical formulation of optical conductivity of La0.7Ca0.3MnO3 exhibiting paramagnetic insulator - ferromagnetic metal transition

Science.gov (United States)

Satiawati, L.; Majidi, M. A.

2017-07-01

A theory of high-energy optical conductivity of La0.7Ca0.3MnO3 has been proposed previously. The proposed theory works to explain the temperature-dependence of the optical conductivity for the photon energy region above ˜0.5 eV for up to ˜22 eV, but fails to capture the correct physics close to the dc limit in which metal-insulator transition occurs. The missing physics at the low energy has been acknowledged as mainly due to not incorporating phonon degree of freedom and electron-phonon interactions. In this study, we aim to complete the above theory by proposing a more complete Hamiltonian incorporating additional terms such as crystal field, two modes of Jahn-Teller vibrations, and coupling between electrons and the two Jahn-Teller vibrational modes. We solve the model by means of dynamical mean-field theory. At this stage, we aim to derive the analytical formulae involved in the calculation, and formulate the algorithmic implementation for the self-consistent calculation process. Our final goal is to compute the density of states and the optical conductivity for the complete photon energy range from 0 to 22 eV at various temperatures, and compare them with the experimental data. We expect that the improved model preserves the correct temperature-dependent physics at high photon energies, as already captured by the previous model, while it would also reveal ferromagnetic metal - paramagnetic insulator transition at the dc limit.

microRNA 126 inhibits the transition of endothelial progenitor cells to mesenchymal cells via the PIK3R2-PI3K/Akt signalling pathway.

Science.gov (United States)

Zhang, Junfeng; Zhang, Zongqi; Zhang, David Y; Zhu, Jianbing; Zhang, Tiantian; Wang, Changqian

2013-01-01

Endothelial progenitor cells (EPCs) are capable of proliferating and differentiating into mature endothelial cells, and they have been considered as potential candidates for coronary heart disease therapy. However, the transition of EPCs to mesenchymal cells is not fully understood. This study aimed to explore the role of microRNA 126 (miR-126) in the endothelial-to-mesenchymal transition (EndMT) induced by transforming growth factor beta 1 (TGFβ1). EndMT of rat bone marrow-derived EPCs was induced by TGFβ1 (5 ng/mL) for 7 days. miR-126 expression was depressed in the process of EPC EndMT. The luciferase reporter assay showed that the PI3K regulatory subunit p85 beta (PIK3R2) was a direct target of miR-126 in EPCs. Overexpression of miR-126 by a lentiviral vector (lenti-miR-126) was found to downregulate the mRNA expression of mesenchymal cell markers (α-SMA, sm22-a, and myocardin) and to maintain the mRNA expression of progenitor cell markers (CD34, CD133). In the cellular process of EndMT, there was an increase in the protein expression of PIK3R2 and the nuclear transcription factors FoxO3 and Smad4; PI3K and phosphor-Akt expression decreased, a change that was reversed markedly by overexpression of miR-126. Furthermore, knockdown of PIK3R2 gene expression level showed reversed morphological changes of the EPCs treated with TGFβ1, thereby giving the evidence that PIK3R2 is the target gene of miR-126 during EndMT process. These results show that miR-126 targets PIK3R2 to inhibit EPC EndMT and that this process involves regulation of the PI3K/Akt signalling pathway. miR-126 has the potential to be used as a biomarker for the early diagnosis of intimal hyperplasia in cardiovascular disease and can even be a therapeutic tool for treating cardiovascular diseases mediated by the EndMT process.

Conventional and inverse magnetocaloric effect in Pr2CuSi3 and Gd2CuSi3 compounds

International Nuclear Information System (INIS)

Wang, Fang; Yuan, Feng-ying; Wang, Jin-zhi; Feng, Tang-fu; Hu, Guo-qi

2014-01-01

Highlights: • Two phase transitions in a narrow temperature range were observed and studied. • Both typical and inverse magnetocaloric effect were observed and discussed. • The inverse magnetocaloric effect was attributed to the spin-glass behavior. - Abstract: Magnetic properties and magnetocaloric effect (MCE) in Pr 2 CuSi 3 and Gd 2 CuSi 3 compounds were investigated systematically. Both Pr 2 CuSi 3 and Gd 2 CuSi 3 compounds experienced two phase transitions in a relatively narrow temperature range: first a paramagnet (PM)–ferromagnet (FM) second-order phase transition at 12 and 26 K and then a FM–spin glass (SG) transition at 6 K and 7.5 K, respectively. The magnetic entropy change (ΔS M ) was calculated based on Maxwell relation using the collected magnetization data. The maximum of ΔS M for Pr 2 CuSi 3 and Gd 2 CuSi 3 compounds was 7.6 and 5 J kg −1 K −1 , respectively, at the applied filed change of 0–5 T. The shape of the temperature dependence of ΔS M (ΔS M –T) curve was obviously different from that of the conventional magnetic materials undergoing only one typical phase transition. In the left half part of ΔS M –T curve, ΔS M is not very sensitive to the applied field and they tend to intersect with the decrease of temperature. Both typical conventional and inverse MCE behavior were observed in Gd 2 CuSi 3 , which would be originated from the two transition features at the low temperatures

Superacid univalent metal phosphites (MH2PO3)2·H3PO3 (M Rb, Tl+) and MH2PO3·H3PO3 (M = K, Cs): synthesis and structure

International Nuclear Information System (INIS)

Kosterina, E.V.; Troyanov, S.I.; Aslanov, L.A.; Kemnits, Eh.

2001-01-01

Crystal superacid phosphites α-CsH 2 PO 3 ·H 3 PO 3 (1) and β-CsH 2 PO 3 ·H 3 PO 3 (2) were prepared by means of interaction between cesium carbonate and phosphoric acid excess. The structure of the compounds, i.e.: 1-rhombic crystal system, sp.gr. P2 1 2 1 2 1 , a = 6.033 (1), b = 6.444 (1), c = 18.345 (4) A: 2-monoclinic crystal system, sp.gr. C2/c, a = 9.990 (3), b = 12.197 (4), c = 6.866 (2) A, β = 118.14 (3) deg, was determined by the method of X-ray diffraction analysis of monocrystals at 150 K. Comparative analysis of the crystal structure and hydrogen bond systems in acid phosphites of different composition was conducted [ru

Microstructure and wear resistance of Al2O3-M7C3/Fe composite coatings produced by laser controlled reactive synthesis

Science.gov (United States)

Tan, Hui; Luo, Zhen; Li, Yang; Yan, Fuyu; Duan, Rui

2015-05-01

Based on the principle of thermite reaction of Al and Fe2O3 powders, the Al2O3 ceramic reinforced Fe-based composite coatings were fabricated on a steel substrate by laser controlled reactive synthesis and cladding. The effects of different additions of thermite reactants on the phase transition, microstructure evolution, microhardness and wear resistance of the composite coatings were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Vickers microhardness and block-on-ring wear test, respectively. The results show that Al2O3 ceramic and M7C3 carbide are in situ synthesized via the laser controlled reactive synthesis. The Al2O3 ceramic and M7C3 carbides prefer to distribute along the γ-Fe phase boundary continuously, which separates the γ-Fe matrix and is beneficial to the grain refinement. With the increase of thermite reactants, the amount of Al2O3 ceramic and M7C3 carbide in the composite coatings increases gradually. Moreover the cladding layer changes from dendritic structure to columnar structure and martensite structure in the heat affected zone becomes coarse. The increased thermite reactants improve the microhardness and wear resistance of the in situ composite coatings obviously and enhance the hardness of the heat affected zone, which should be ascribed to the grain refinement, ceramic and carbide precipitation and solid solution strengthening.

Pairing transition, coherence transition, and the irreversibility line in granular GdBa2Cu3O7-δ

Science.gov (United States)

Roa-Rojas, J.; Menegotto Costa, R.; Pureur, P.; Prieto, P.

2000-05-01

We report on electrical magnetoconductivity experiments near the superconducting transition of a granular sample of GdBa2Cu3O7-δ. The measurements were performed in magnetic fields ranging from 0 to 500 Oe applied parallel to the current orientation. The results show that the transition proceeds in two steps. When the temperature is decreased we first observe the pairing transition, which stabilizes superconductivity within the grains at a temperature practically coincident with the bulk critical temperature Tc. Analysis of the fluctuation contributions to the conductivity shows that the universality class for this transition is that of the three dimensional (3D)-XY model in the ordered case, with dynamic critical exponent z=3/2. Close to the zero-resistance state, the measurements reveal the occurrence of a coherence transition, where the phases of the order parameter in individual grains become long-range ordered. The critical temperature Tco for this transition is close to the point where the resistivity vanishes. A strong enlargement of the fluctuation interval preceding the coherence transition is caused by the applied magnetic field. In this region, a 3D-Gaussian regime and an asymptotic critical regime were clearly identified. The critical conductivity behavior for the coherence transition is interpreted within a 3D-XY model where disorder and frustration are relevant. The irreversibility line is determined from magnetoconductivity measurements performed according to the zero-field-cooled (ZFC) and field-cooled data collected on cooling (FCC) recipes. The locus of this line coincides with the upper temperature limit for the fluctuation region above the coherence transition. The irreversibility line is interpreted as an effect of the formation of small clusters with closed loops of Josephson-coupled grains.

Irradiation facilities in JRR-3M

International Nuclear Information System (INIS)

Ohtomo, Akitoshi; Sigemoto, Masamitsu; Takahashi, Hidetake

1992-01-01

Irradiation facilities have been installed in the upgraded JRR-3 (JRR-3M) in Japan Atomic Energy Research Institute (JAERI). There are hydraulic rabbit facilities (HR), pneumatic rabbit facilities (PN), neutron activation analysis facility (PN3), uniform irradiation facility (SI), rotating irradiation facility and capsule irradiation facilities to carry out the neutron irradiation in the JRR-3M. These facilities are operated using a process control computer system to centerize the process information. Some of the characteristics for the facilities were satisfactorily measured at the same time of reactor performance test in 1990. During reactor operation, some of the tests are continued to confirm the basic characteristics on facilities, for example, PN3 was confirmed to have enough performance for activation analysis. Measurement of neutron flux at all irradiation positions has been carried out for the equilibrium core. (author)

Síntese e estudo microestrutural de perovsquitas tipo La0,8Ca0,2MO3 (M: Co e Mn para aplicação em catálise automotiva Synthesis and microstructural study of La0.8Ca0.2MO3 (M: Mn and Co perovskites for automotive catalysis

Directory of Open Access Journals (Sweden)

J. P. Ribeiro

2011-09-01

Full Text Available Materiais com estrutura perovsquita são potenciais catalisadores para prevenir a emissão de componentes indesejáveis ao meio ambiente. Diferentes métodos têm sido propostos para a síntese desses materiais, visando produzir materiais homogêneos com tamanho nanométrico de partículas. Os compostos La0,8Ca0,2MnO3 e La0,8Ca0,2CoO3 foram preparados pelo método dos precursores poliméricos visando sua utilização como catalisadores automotivos. Este método de síntese foi utilizado porque permite a obtenção de pós homogêneos e fases cristalinas a temperaturas mais baixas que os outros métodos tradicionais de síntese. Os materiais foram calcinados a 700 e 900 ºC por 4 h e caracterizados pelas técnicas de análise térmica, difração de raios X e microscopia eletrônica de varredura. As perovsquitas obtidas são nanométricas, monofásicas e com propriedades adequadas para utilização em catálise automotiva.Materials with perovskite structure are potential catalysts for preventing greenhouse gas emissions to the environment. Several methods have been proposed for the synthesis of these materials in order to produce homogeneous powders with nanometric particle size. In the present work, the La0.8Ca0.2MnO3 and La0.8Ca0.2CoO3 systems were prepared by the polymeric precursor method for application in automotive catalysis. This method was chosen because it allows obtaining homogeneous powders and crystalline phases at lower temperatures. The powders were calcined at 700 and 900 ºC for 4 h and characterized by thermal analysis, X-ray diffraction and scanning electron microscopy techniques. The perovskites are nanometric, single phased and present suitable properties for use in automotive catalysis.

High-resolution study of Gamow-Teller transitions in the 47Ti(3He,t)47V reaction

Science.gov (United States)

Ganioǧlu, E.; Fujita, H.; Fujita, Y.; Adachi, T.; Algora, A.; Csatlós, M.; Deaven, J. M.; Estevez-Aguado, E.; Guess, C. J.; Gulyás, J.; Hatanaka, K.; Hirota, K.; Honma, M.; Ishikawa, D.; Krasznahorkay, A.; Matsubara, H.; Meharchand, R.; Molina, F.; Okamura, H.; Ong, H. J.; Otsuka, T.; Perdikakis, G.; Rubio, B.; Scholl, C.; Shimbara, Y.; Susoy, G.; Suzuki, T.; Tamii, A.; Thies, J. H.; Zegers, R. G. T.; Zenihiro, J.

2013-01-01

Given the importance of Gamow-Teller (GT) transitions in nuclear structure and astrophysical nuclear processes, we have studied Tz=+3/2→+1/2, GT transitions starting from the 47Ti nucleus in the (3He,t) charge-exchange reaction at 0∘ and at an intermediate incident energy of 140 MeV/nucleon. The experiments were carried out at the Research Center for Nuclear Physics (RCNP), Osaka, using the high-resolution facility with a high-dispersion beam line and the Grand-Raiden spectrometer. With an energy resolution of 20 keV, individual GT transitions were observed and GT strength was derived for each state populated up to an excitation energy (Ex) of 12.5 MeV. The GT strength was widely distributed from low excitation energy up to 12.5 MeV, where we had to stop the analysis because of the high level density. The distribution of the GT strengths was compared with the results of shell model calculations using the GXPF1 interaction. The calculations could reproduce the experimental GT distributions well. The GT transitions from the ground state of 47Ti and the M1 transitions from the isobaric analog state in 47V to the same low-lying states in 47V are analogous. It was found that the ratios of GT transition strengths to the ground state, the 0.088-MeV state, and the 0.146-MeV state are similar to the ratios of the strengths of the analogous M1 transitions from the isobaric analog state (IAS) to these states. The measured distribution of the GT strengths was also compared with those starting from the Tz=+3/2 nucleus 41K to the Tz=+1/2 nucleus 41Ca.

Weak transitions in the quasi-elastic reaction 12C(e,e'p)11B