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Sample records for von yb isotopen

  1. Productie en gebruik van medische radio-isotopen in Nederland : Huidige situatie en toekomstverkenning

    NARCIS (Netherlands)

    Roobol LP; van der Reijden A; de Waard-Schalk IR; Bijwaard H; M&M; M&V

    2017-01-01

    Radioactieve stoffen worden gebruikt voor de diagnose en behandeling van verschillende soorten kanker. De meeste van deze zogeheten isotopen worden wereldwijd in zes kernreactoren gemaakt, waarvan er één in Nederland (Petten) staat. Zeker tot 2020 en waarschijnlijk tot 2025 zal de markt voor

  2. Determination of strontium-isotopes using Hidex 300 SL with TDCR-Cerenkov-counting; Messung von Strontium-Isotopen im Hidex 300 SL mittels TDCR-Cerenkov-counting

    Energy Technology Data Exchange (ETDEWEB)

    Wisser, S. [FCI, Mainz (Germany); Oikari, T. [Hidex Oy, Turku (Finland); Frenzel, E.

    2014-01-20

    A new rapid method for the determination of Sr-89/Sr-90 has been introduced due to the advances in the LSC-Technology. By means of the TDCR-Technique (Triple-to-Double-Coincidence-Ratio) in combination with Cerenkov-Counting, the samples can be measured directly after the sample preparation without significant waiting times. The prompt availability of results allows the competent authorities and radiation protection experts a faster reaction after a nuclear incident. The TDCR-Technique can also be applied for the routine analysis of Sr-90/Y-90. This method is also suitable for the determination of Sr-90/Y-90 directly after the radiochemical sample preparation. On the first step, the activity of Y-90 has to be determined by TDCR-Cerenkov-Counting. After adding LSC-Cocktail, the sum of Sr-90 und Y-90 can then be determined by TDCR-LSC measurement. The results obtained so far are very promising. The counting efficiencies obtained with Hidex 300 SL for the TDCR-LSC-measurement of Sr-90 were above 97%. The counting efficiencies for Sr-89 and Y-90 by TDCR-Cerenkov-Counting were higher than 60%.

  3. Balance of groundwaterstreams below dumps with the application of environmental isotopes within hydrogeological examinations. Final report; Bilanzierung von Grundwasserstroemen unter Deponien mit Hilfe von umweltisotopen-hydrologischen Analysen im Rahmen hydrogeologischer Untersuchungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Geyh, M.A.; Ays, G.

    1995-08-15

    Deponiesickerwaesser eine von der natuerlichen Isotopenzusammensetzung abweichende Markierung haben koennten, die vom Deponieinhalt und Isotopen-Fraktionierungen bei dessen Abbau gepraegt ist. Die Isotopenwerte des Grundwassers ober- oder unterstrom der Deponien wurden zu verschiedenen Jahreszeiten gemessen, um natuerliche und anthropogene Veraenderungen der Isotopenzusammensetzungen im Deponiebereich zu erfassen. Es wurde erwartet, dass die Mobilitaet der chemischen Kontaminanten durch physikalische, chemische und biologische Retardation gegenueber der der isotopisch markierten Wassermolekuele eingeschraenkt sei. Im Abstrom von Hausmuelldeponien koennen mit Hilfe der Sauerstoff- und Kohlenstoff-Isotopenzusammensetzung im Sickerwasser unterschiedlich stark von der Deponie beeinflusste Bereiche voneinander abgegrenzt werden. Die Kohlenstoff-Isotopenzusammensetzung kann zur Verfolgung der Phasen des chemischen Abbaus organischer Inhaltsstoffe eingesetzt werden. In Sonderabfalldeponien treten spezielle Isotopen-Effekte auf, die mit der andersartigen Zusammensetzung der Inhaltsstoffe zu erklaeren sind. (orig.)

  4. YB0 HAS LANDED

    CERN Multimedia

      On Feb 28th after a majestic descent of 90m taking 11 hours, the 2000t YB0 central wheel of CMS, containing the superconducting solenoid, gently touched down on the floor of the experimental cavern UXC55.

  5. Electronic Configuration of Yb Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Temmerman, W.M.; Szotek, Z. [Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, Cheshire (United Kingdom); Svane, A. [Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Strange, P. [Physics Department, Keele University, Keele, Staffordshire, ST5 5BG (United Kingdom); Winter, H. [INFP, Forschungszentrum Karlsruhe GmbH, Postfach 3640, D-76021 Karlsruhe (Germany); Delin, A.; Johansson, B.; Eriksson, O.; Fast, L. [Condensed Matter Theory Group, Department of Physics, University of Uppsala, Box 530, 75121 Uppsala (Sweden); Wills, J.M. [Center of Materials Science and Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

    1999-11-01

    The total energy differences between divalent and trivalent configurations of Yb ions in a number of Yb compounds are studied. Two different band theoretical methods, which differ in the treatment of the localized f electrons, are used. The results show that in all Yb compounds the valence energy differences are equal to the energy needed to localize an f electron. These valence energy differences correlate with the number of f electrons hybridizing with the conduction bands in the trivalent configuration. For divalent YbS, the pressure induced f -electron delocalization implies an intermediate valency, as also indicated by experiment. {copyright} {ital 1999} {ital The American Physical Society }

  6. YB0 SERVICES INSTALLATION COMPLETED

    CERN Multimedia

    The beauty of the completed YB0 was briefly visible at P5 as preparations continue for Tracker installation. A tremendous effort, lasting 7 months and involving more than 100 workers on the busiest days, resulted in 5700 electrical cables, 780 optical cables with 65k fibre channels, and 550 pipes laid on YB0 for HB, EB and Tracker.

  7. Comparison of spectroscopic properties of Yb:YAP and Yb:YAG crystals

    Institute of Scientific and Technical Information of China (English)

    Xiaoming He; Guangjun Zhao; Xiaodong Xu; Xionghui Zeng; Jun Xu

    2007-01-01

    The Yb:YAG and Yb:YAP crystals have been grown by Czochralski method. The absorption spectra and the fluorescence spectra of Yb:YAG and Yb:YAP crystals have been investigated. It is shown that the Yb:YAG crystal has better laser properties and smaller threshold power than Yb:YAP crystal. In addition, the absorption cross-section of the Yb:YAP crystal is 2.16 times of that of the Yb:YAG crystal,so laser diode pumped Yb:YAG lasing can be easily realized. Because YAP single crystal is anisotropic, it is provided with polarization characteristics.

  8. von Neumann Morgenstern Preferences

    DEFF Research Database (Denmark)

    Vind, Karl

    von Neumann Morgenstern utility is generalized to von Neumann Morgenstern preferences. The proof is an application of simple hyperplane theorems......von Neumann Morgenstern utility is generalized to von Neumann Morgenstern preferences. The proof is an application of simple hyperplane theorems...

  9. von Neumann Morgenstern Preferences

    DEFF Research Database (Denmark)

    Vind, Karl

    2000-01-01

    von Neumann Morgenstern utility is generalized to von Neumann Morgenstern preferences. The proof is an application of simple hyperplane theorems......von Neumann Morgenstern utility is generalized to von Neumann Morgenstern preferences. The proof is an application of simple hyperplane theorems...

  10. Yb:S-FAP Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Schaffers, K I

    2004-01-20

    It has recently been reported that several high power, diode-pumped laser systems have been developed based on crystals of Yb:S-FAP [Yb{sup 3+}:Sr{sub 5}(PO{sub 4}){sub 3}F]. The Mercury Laser, at Lawrence Livermore National Laboratory, is the most prominent system using Yb:S-FAP and is currently producing 23J at 5 Hz in a 15 nsec pulse, based on partial activation of the system. In addition, a regenerative amplifier is being developed at Waseda University in Japan and has produced greater than 12 mJ with high beam quality at 50Hz repetition rate. Q-peak has demonstrated 16 mJ of maximum energy/output pulse in a multi-pass, diode side-pumped amplifier and ELSA in France is implementing Yb:S-FAP in a 985 nm pump for an EDFA, producing 250 mW. Growth of high optical quality crystals of Yb:S-FAP is a challenge due to multiple crystalline defects. However, at this time, a growth process has been developed to produce high quality 3.5 cm diameter Yb:S-FAP crystals and a process is under development for producing 6.5 cm diameter crystals.

  11. Odonaten von Sumatra, gesammelt von Edward Jacobson

    NARCIS (Netherlands)

    Ris, F.

    1927-01-01

    Die folgende Bearbeitung sumatranischer Libellen schliesst sich an zwei frühere Aufsätze über Libellen von Java und von Simalur an, die mir Herr Jacobson anvertraute. Die hier beschriebene wesentlich grössere Sammlung aus den Jahren 1913—15 kam gegen Ende 1920 in meine Hände, sie hätte also längst e

  12. Rheologie von Beschichtungen

    Science.gov (United States)

    Schäffler, Michael

    Die Rheologie beschreibt die Fließ- und Deformationseigenschaften von Materialien. Der Begriff Rheologie ist aus dem Griechischen abgeleitet: rhein - fließen. Erst im Jahre 1930 entwickelte E.C. Bingham und M. Reiner in Easton (USA) die Rheologie zu einer eigenständigen Wissenschaft. Aber bereits seit dem 17. Jahrhundert wurden wesentliche Einzelbeiträge zu Fließphänomenen veröffentlich, so z.B. 1676 von R. Hooke (Hookesches Gesetz) und 1687 von I. Newton (Newtonsches Gesetz). Die Rheologie hat sich bis heute immer mehr zu einer interdisziplinären Wissenschaft entwickelt, die die mechanischen Eigenschaften von Materialien charakterisiert.

  13. Von Triers kristendom

    DEFF Research Database (Denmark)

    Søndergaard, Leif

    2009-01-01

    Lars von Trier er i hans film Antichrist i sin negation af kristendommen stærkt bundet til kristendommens dualistiske verdensbillede. Samtidig er filmen kvindefjendsk. Udgivelsesdato: 2. september......Lars von Trier er i hans film Antichrist i sin negation af kristendommen stærkt bundet til kristendommens dualistiske verdensbillede. Samtidig er filmen kvindefjendsk. Udgivelsesdato: 2. september...

  14. Planung von Hochschulbibliotheken - Tagungsbericht

    Directory of Open Access Journals (Sweden)

    Felicitas Hundhausen

    2015-07-01

    Full Text Available Am 18. November 2014 veranstalteten das HIS-Institut für Hochschulentwicklung und die beiden Herausgeber des "Handbuchs Hochschulbibliothekssysteme", Konstanze Söllner und Wilfried Sühl-Strohmenger, in Hannover eine Tagung zum Thema "Planung von Hochschulbibliotheken". Hier ging es um ausgewählte Aspekte der Planung und Steuerung von Hochschulbibliotheken.

  15. Oligocaene Gastropoden von Buton

    NARCIS (Netherlands)

    Martin, K.

    1935-01-01

    Vor einiger Zeit besehrieb ich eine kleine, eigenartige Molluskenfauna aus tertiären Asphaltkalken von der unbedeutenden Insel Buton, im Südosten von Celebes¹). Seither empfing Herr Prof. Ir. Chr. K. Visser in Delft weitere Versteinerungen aus den Asphaltkalken des Eilands, die nach ihm wahrscheinli

  16. Untersuchungen ueber den Bau von Orbitolina (Patellina auct.) von Borneo

    NARCIS (Netherlands)

    Martin, K.

    1884-01-01

    Vor einer Reihe von Jahren (1856—57) entdeckte Everwijn am Seberoeang, linken Nebenflusse des Kapoeas, in der West-Abtheilung von Borneo, Schichten mit Versteinerungen, welche von ihm für Nummuliten gehalten wurden. Der Fundort befand sich am rechten Ufer, 4—5 Kilometer von der Mündung des

  17. Upconversion luminescence in Yb 3+-doped yttrium aluminum garnets

    Science.gov (United States)

    Xu, Xiaodong; Zhao, Zhiwei; Song, Pingxin; Jiang, Benxue; Zhou, Guoqing; Xu, Jun; Deng, Peizhen; Bourdet, Gilbert; Christophe Chanteloup, Jean; Zou, Ji-Ping; Fulop, Annabelle

    2005-03-01

    In this paper, we present results on upconversion luminescence performed on Yb 3+-doped yttrium aluminum garnets under 940 nm excitation. The upconversion luminescence was ascribed to Yb 3+ cooperative luminescence and the presence of rare earth impurity ions. The cooperative luminescence spectra as a function of Yb concentration were measured and the emission intensity variation with Yb concentration was discussed. Yb 3+ energy migration quenched the cooperative luminescence of Yb:YAG crystals with doping level over 15 at%.

  18. RbYb(PO34

    Directory of Open Access Journals (Sweden)

    Hui Chen

    2013-01-01

    Full Text Available Rubidium ytterbium(III tetrakis(polyphosphate, RbYb(PO34, was synthesized by solid-state reaction. It adopts structure type IV of the MRE(PO34 (M = alkali metal and RE = rare earth metal family of compounds. The structure is composed of a three-dimensional framework made up from double spiral polyphosphate chains parallel to [10-1] and irregular [YbO8] polyhedra. There are eight PO4 tetrahedra in the repeat unit of the polyphosphate chains. The Rb+ cation is located in channels extending along [100] that are delimited by the three-dimensional framework. It is surrounded by 11 O atoms, defining an irregular polyhedron.

  19. XPS Studies of Yb14MnSb11 and Yb14ZnSb11

    Energy Technology Data Exchange (ETDEWEB)

    Holm, A P; Ozawa, T C; Kauzlarich, S M; Morton, S A; Waddill, G D; Pickett, W E; Tobin, J G

    2003-10-02

    Measurements of core and valence electronic states of single crystals of the rare earth transition metal Zintl phases Yb{sub 14}MnSb{sub 11} and Yb{sub 14}ZnSb{sub 11} were performed using the X-ray photoelectron spectroscopy station of Beamline 7 at the Advanced Light Source. Sample surfaces of Yb{sub 14}MnSb{sub 11} and Yb{sub 14}ZnSb{sub 11} were measured as received, after Ar{sup +} ion bombardment, and after cleaving in situ. Detailed analysis of the clean Mn and Zn analog sample surfaces reveal a significant contribution of both Yb{sup 3+} and Yb{sup 2+} 4f states in the valence band region for the Zn analog and no contribution of Yb{sup 3+} states to the valence band for the Mn analog. This result is predicted for the Zn analog by Zintl counting rules, and single crystal X-ray diffraction studies presented here also support the mixed valency of Yb for Yb{sub 14}ZnSb{sub 11}. Further detailed analysis of the core and valence band structure of both Yb{sub 14}MnSb{sub 11} and Yb{sub 14}ZnSb{sub 11} will be presented.

  20. Local symmetry lowering in the cubic intermetallics YbPdBi and YbNiSb

    Energy Technology Data Exchange (ETDEWEB)

    LeBras, G.; Bonville, P.; Hodges, J.A.; Hammann, J.; Besnus, M.J.; Schmerber, G.; Dhar, S.K.; Aliev, F.G.; Andre, G. [DRECAM/SPEC, CE Saclay, Gif-sur-Yvette (France)

    1995-07-10

    A microscopic investigation of the cubic ternary alloys YbPdBi and YbNiSb, using {sup 170}Yb Mossbauer spectroscopy, reveals that the point symmetry at the site of the Yb{sup 3+} is far from cubic in both compounds. An analysis of the thermal variation of the quadrupolar 4f moment shows that the energy of the first crystal electric field transition is close to 20 K in YbPdBi and to 10 K in YbNiSb. Specific heat measurements are also presented in YbPdBi, and magnetic ordering is detected below 1 K in YbPdBi, with saturated Yb{sup 3+} moments of 1.25 {mu}{sub B}, and below 0.85 K in YbNiSb, with saturated moments of 1 {mu}{sub B}. A tentative explanation of the Yb site symmetry breaking is made in terms of a Jahn-Teller distortion within the {gamma}{sub 8} cubic quartet. (author)

  1. Ellis Von Creveld Syndrome

    Directory of Open Access Journals (Sweden)

    Afshar H

    1999-01-01

    Full Text Available One patient with Ellis Von Creveld syndrome contains: dwarfism, congenital heart"ndisease, ectodermal dysplasia, polyductyly, an abnormally wide labial frenum and maxillary"nmolars with single root.

  2. Lars von Triers film

    DEFF Research Database (Denmark)

    Nielsen, Lisbeth Overgaard

    2007-01-01

    Afhandlingen undersøger Lars von Triers filmæstetik, som den kommer til udtryk i spillefilmene fra perioden 1984-2007. Afhandlingen analyserer de enkelte films stil, virkningsstrategi og betydningsdannelse.......Afhandlingen undersøger Lars von Triers filmæstetik, som den kommer til udtryk i spillefilmene fra perioden 1984-2007. Afhandlingen analyserer de enkelte films stil, virkningsstrategi og betydningsdannelse....

  3. Photoelectron spectroscopy of strongly correlated Yb compounds

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, J.J.; Andrews, A.B.; Arko, A.J.; Bartlett, R.J.; Blythe, R.I. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Olson, C.G.; Benning, P.J.; Canfield, P.C. [Ames Laboratory, U. S. Department of Energy, Ames, Iowa 50011 (United States); Poirier, D.M. [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    1996-12-01

    The electronic properties of the Yb compounds YBCu{sub 2}Si{sub 2}, YBAgCu{sub 4}, and YbAl{sub 3} along with purely divalent Yb metal, have been investigated by means of high-resolution ultraviolet and x-ray photoelectron spectroscopy. We present the intrinsic characteristic features of the 4{ital f} levels of Yb while accounting for lattice vibrations and the manifestation of corelike energy levels degenerate with the valence states and modified by the temperature-dependent Fermi function. For these strongly correlated Yb-based compounds, the hole occupancy values ({ital n}{sub {ital f}}{approximately}0.6) directly obtained from integration of the divalent and trivalent portions of the 4{ital f} photoemission features indicate that these compounds are strongly mixed valent. The small intensity modulation with temperature in the divalent Yb 4{ital f} levels (0{endash}10{percent} over a {ital T}=20{minus}300 K range) is discussed within the conventional framework of the photoemission process and nominal allowances for lattice variations with temperature. Results from photoemission experiments on the divalent 4{ital f} levels of strongly correlated Yb compounds are remarkably similar to the 4{ital f} levels of purely divalent Yb metal. {copyright} {ital 1996 The American Physical Society.}

  4. Scintillation properties of YAG:Yb crystals

    CERN Document Server

    Antonini, P; Carugno, Giovanni; Iannuzzi, D

    2001-01-01

    We report on measurements of the light yield, emission spectrum, and time response of YAG:Yb crystals. The temperature dependence of light yield was investigated. Data show that YAG:Yb crystals are good scintillators, suitable for applications to neutrino detection and spectroscopy.

  5. Bifunctional chelate formers for Tc and Re isotope complexing - preparation, disengagement of conjugated compounds, diagnostic and therapeutical uses. Bifunktionelle Chelatbildner zur Komplexierung von Tc- und Re-Isotopen, Verfahren zu ihrer Herstellung und Darstellung von Konjugaten daraus sowie deren Verwendung in Diagnostik und Therapie

    Energy Technology Data Exchange (ETDEWEB)

    Neumeier, R.; Kramp, W.; Maecke, H.R.

    1991-03-21

    The proposed bifunctional chelate formers have a functional and/or activated group for selective-compound coupling and functional groups for dative bonding of metal ions from carrying groups. The new compounds are used for Tc and Re isotope complexing. The respective conjugated compounds are used in medical diagnostics and therapy.

  6. Time-dependent relativistic density functional study of Yb and YbO

    Institute of Scientific and Technical Information of China (English)

    XU WenHua; ZHANG Yong; LIU WenJian

    2009-01-01

    The low-lying electronic states of Yb and YbO are investigated by using time-dependent relativistic density functional theory,which is based on the newly developed exact two-component Hamiltonian resulting from symmetrized elimination of the small component.The nature of the excited states is analyzed by using the full molecular symmetry.The calculated results support the previous experimental assignment of the ground and excited states of YbO.

  7. Energetisches Verhalten von Doppelfassaden

    OpenAIRE

    2002-01-01

    Durch die Forderung nach einer natürlichen Lüftung von Bürogebäuden und einem effektiven Sonnenschutz in Hochhäusern haben Doppelfassaden einen hohen Stellenwert erreicht. Das energetische Verhalten von Doppelfassaden ist Gegenstand zahlreicher Veröffentlichungen. Bisher liegen jedoch nur wenige Messungen in ausgeführten Gebäuden vor.Im Rahmen dieser Arbeit wurden drei Gebäude mit Doppelfassaden detailliert vermessen. Die Langzeitmessungen erfassten über mindestens ein Jahr unter anderem die ...

  8. Kontextualisierung von Queer Theory

    Directory of Open Access Journals (Sweden)

    Anna Voigt

    2008-03-01

    Full Text Available Christine M. Klapeer legt in diesem Einführungsband dar, aus welchen politischen und theoretischen Kontexten heraus sich ‚queer‘ zu einem Begriff mit besonderem politischem und theoretischem Gehalt entwickelt hat. Wesentlich zielt sie dabei auf eine kritische Kontextualisierung von „queer theory”. Die Autorin geht zunächst auf das Gay Liberation Movement ein, grenzt die Queer Theory vom Poststrukturalismus, von feministischen Theorien und den Lesbian and Gay Studies ab, beleuchtet Eckpunkte queeren Denkens und zeichnet schließlich die Entwicklungen in Österreich sowohl politisch-rechtlich als auch bewegungsgeschichtlich und in der Wissenschaftslandschaft nach.

  9. LiYbCl4(THF4

    Directory of Open Access Journals (Sweden)

    Lukas Richtera

    2011-06-01

    Full Text Available The title compound, di-μ-chlorido-dichlorido-1κ2Cl-tetrakis(tetrahydrofuran-1κ2O,2κ2O-lithiumytterbium(III, [LiYbCl4(C4H8O4], was prepared by the reaction of YbCl3(THF3 with LiCl in THF (THF is tetrahydrofuran. The central motif of the structure is a Yb(μ-Cl2Li ring. The Yb atom is hexacoordinated to four Cl atoms and two THF molecules oriented in a trans fashion. The Li atom has a tetrahedral environment and is coordinated to two Cl atoms and two THF molecules. No intermolecular interactions other than van der Waals forces were observed. Two of the THF molecules are disordered over two positions.

  10. Properties of Yb:YAG scintillators

    CERN Document Server

    Antonini, P; Bressi, G; Carugno, Giovanni; Santilli, P

    2002-01-01

    Relative light yield (LY) dependence on temperature for Yb:YAG crystals containing from 10% to 100% of Yb dopant is studied for gamma and alpha excitations. The maximum LY is achieved at 120 KYb 25%)YAG. Linearity of the light output is checked. alpha/gamma ratio is found to be 0.42+-0.02. Pulse shapes induced by gamma and alpha particles and cosmic rays are investigated by analyzing a set of single events recorded. Gamma events are fast tau<4 ns), while other kinds of radiation give rise to more complicated and longer profiles, allowing particle discrimination. Dependence of scintillation properties on concentration of Yb and purity is discussed.

  11. Energetische Verwertung von Biomasse

    Science.gov (United States)

    Zahoransky, Richard; Allelein, Hans-Josef; Bollin, Elmar; Oehler, Helmut; Schelling, Udo

    Etwa 0,1% der Solarenergie wandeln sich durch Photosynthese aus dem Kohlendioxid der Luft in Biomasse um. Die Biomassen sind als Festbrennstoff nutzbar oder zu gasförmigen Brennstoffen weiterverarbeitbar. Zwei Arten von Biomassen sind zu unterscheiden: Anfallende Biomasse

  12. Rhizostomeen von Manila

    NARCIS (Netherlands)

    Stiasny, G.

    1924-01-01

    Die hier beschriebene kleine Scyphomedusen-Sammlung wurde von Herrn Director P. B. Sivickis, Dept. of Zoology, University of Philippines, Manila, dem Rijksmuseum van Natuurlijke Historie in Leiden überwiesen. Das Material wurde im December 1922 in Manila-bay gefischt und befindet sich in bestem Erha

  13. Abschied von Ingeborg Pomp

    OpenAIRE

    Hänsel, Rosemarie

    2007-01-01

    Am 4. Juni 2007 erhielten wir die traurige Nachricht, dass Ingeborg Barbara Pomp, Leiterin i. R. der Stenografischen Sammlung von 1996 bis 2006 nach kurzer schwerer Krankheit verstorben ist. Die Mitarbeiterinnen und Mitarbeiter der Sächsischen Landesbibliothek – Staats- und Universitätsbibliothek trauern um eine liebenswerte Kollegin, die sich immer mit einem Höchstmaß an persönlichem Einsatz für die Weiterentwicklung der Stenografischen Sammlung engagiert hat.

  14. Optical study of Yb{sup 3+}/Yb{sup 2+} conversion in CaF{sub 2} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kaczmarek, Slawomir M [Institute of Physics, Szczecin University of Technology, Aleja Piastow 48, 70-310 Szczecin (Poland); Tsuboi, Taiju [Faculty of Engineering, Kyoto Sangyo University, Kamigamo, Kita-ku, Kyoto 603-8555 (Japan); Ito, Masahiko [Physical Chemistry of Luminescent Materials, Claude Bernard/Lyon 1 University, UMR CNRS 5620, Batiment A Kastler, 10 rue Ampere, 69622 Villeurbanne (France); Boulon, Georges [Physical Chemistry of Luminescent Materials, Claude Bernard/Lyon 1 University, UMR CNRS 5620, Batiment A Kastler, 10 rue Ampere, 69622 Villeurbanne (France); Leniec, Grzegorz [Institute of Physics, Szczecin University of Technology, Aleja Piastow 48, 70-310 Szczecin (Poland)

    2005-06-29

    Yb{sup 3+} ions with various site symmetries have been observed in the absorption and emission spectra of Yb{sup 3+}:CaF{sub 2} crystals, both {gamma}-irradiated and annealed in hydrogen. The absorption intensity value is found to be much higher for the {gamma}-irradiated crystal and strongly dependent on the gamma dose. The UV absorption spectra of {gamma}-irradiated and H{sub 2}-annealed CaF{sub 2}:5 at.% Yb{sup 3+} crystals are quite similar. Yb{sup 2+} absorption bands are observed at 360, 315, 271, 260, 227 and 214 nm, which are called A, B, C, D, F and G bands, respectively. For {gamma}-irradiated CaF{sub 2}:30 at.% Yb{sup 3+}, an additional band at 234 nm can be seen. It is suggested that only a negligible amount of Yb{sup 3+} ions are converted into Yb{sup 2+} under the {gamma}-irradiation. The presence of Yb{sup 2+} is confirmed by the 565 and 540 nm luminescence under 357 nm excitation. It is also suggested that the excitation in the A, C, D and F absorption bands of Yb{sup 2+} gives rise to photo-ionization of Yb{sup 2+} ions and electrons in the conduction band to form the excited Yb{sup 3+} ions which emit IR Yb{sup 3+} luminescence. The UV absorption and emission spectra obtained for {gamma}-irradiated and H{sub 2}-annealed crystals have different structures. This suggests that different mechanisms are responsible for the creation of Yb{sup 2+} ions. {gamma}-irradiation favours Yb{sup 2+} isolated centres by reduction of Yb{sup 3+} ions located at Ca{sup 2+} lattice sites, whereas annealing in hydrogen favours Yb{sup 2+} centres neighbouring Yb{sup 3+} ions when a Yb{sup 3+} ion pair captures a Compton electron. Also, {gamma}-irradiation does not change the position of Yb{sup 3+} ions converted into Yb{sup 2+} in the CaF{sub 2} lattice. In the case of H{sub 2} annealing, a Yb{sup 3+} ion converted to Yb{sup 2+} is shifted to the Ca{sup 2+} position in the lattice.

  15. Nutzerorientiertes Management von materiellen und immateriellen Informationsobjekten

    OpenAIRE

    Hübsch, Chris

    2001-01-01

    Schaffung einer stabilen, erweiterbaren und skalierbaren Infrastruktur für die Bereitstellung von Diensten im Umfeld von Bibliotheken und ähnlichen wissensanbietenden Einrichtungen unter Verwendung von XML-RPC und Python.

  16. Nutzerorientiertes Management von materiellen und immateriellen Informationsobjekten

    OpenAIRE

    Hübsch, Chris

    2001-01-01

    Schaffung einer stabilen, erweiterbaren und skalierbaren Infrastruktur für die Bereitstellung von Diensten im Umfeld von Bibliotheken und ähnlichen wissensanbietenden Einrichtungen unter Verwendung von XML-RPC und Python.

  17. Synthesis and Characterization of YB4 Ceramics

    Science.gov (United States)

    2011-06-24

    Sci., 39 [19] 5887 904 (2004). 2W. G. Fahrenholtz, G. E. Hilmas, I. G. Talmy, and J. A. Zaykoski, “Refractory Diborides of Zirconium and Hafnium ,” J...the Electronic Properties of YB4 and YB6 using 11B NMR and First-Principles Calculations,” J. Alloys Compd., 383 [1 2] 232 8 (2004). 8J. Günster, T...Compounds and Alloys ,” Akademia Nauk Ukrainskoi SSR, Kiev, 422 511 (1960) (in Russian) 15 J. F. Lynch, Engineering Properties of Selected Ceramic Materials

  18. Cryogenic Yb: YAG Thin-Disk Laser

    Science.gov (United States)

    2016-09-09

    Spitzberg, "Cryogenic Yb3+-Doped Solid-State Lasers," IEEE Journ. of Sel. Topics in Quant. Elect., 13(3), 448-459 (2007). [3] S. Tokita, J. Kawanaka, M...Europe ( IEEE ,2005) ,CTu3 (2005). [4] D. C. Brown, J. M. Singley, E. Yager, J. W. Kuper, B. J. Lotito, L. L. Bennett, "Innovative high-power CW...Y. Sun, and R. W. Equall, "Yb:YAG Absorption at Ambient and Cryogenic Temperatures," IEEE Journ. Sel. Topics Quant. Elect. 11(3), 604-612 (2005

  19. Photoassociative production of ultracold heteronuclear YbLi* molecules

    Science.gov (United States)

    Roy, Richard; Shrestha, Rajendra; Green, Alaina; Gupta, Subhadeep; Li, Ming; Kotochigova, Svetlana; Petrov, Alexander; Yuen, Chi Hong

    2016-09-01

    We report on the production of ultracold heteronuclear YbLi* molecules in a dual-species magneto-optical trap by photoassociation (PA). The formation of the electronically excited molecules close to dissociation was observed by trap loss spectroscopy. We find 4 rovibrational states within a range of 250 GHz below the Yb (S10) +Li (1/2 2P) asymptote and observe isotopic PA line shifts in mixtures of 6Li with 174Yb, 172Yb, and 176Yb. We also describe our theoretical ab initio calculation for the relevant electronic potentials and utilize it to analyze and identify the lines in the experimentally observed spectrum.

  20. Photoassociative production of ultracold heteronuclear YbLi* molecules

    CERN Document Server

    Roy, Richard; Green, Alaina; Gupta, Subhadeep; Li, Ming; Kotochigova, Svetlana; Petrov, Alexander; Yuen, Chi Hong

    2016-01-01

    We report on the production of ultracold heteronuclear YbLi* molecules in a dual-species magneto-optical trap by photoassociation (PA). The formation of the electronically excited molecules close to dissociation was observed by trap loss spectroscopy. We find 4 rovibrational states within a range of $250\\,$GHz below the Yb($^1S_0$) + Li($^2P_{1/2}$) asymptote and observe isotopic PA line shifts in mixtures of $^6$Li with $^{174}$Yb, $^{172}$Yb, and $^{176}$Yb. We also describe our theoretical ab-initio calculation for the relevant electronic potentials and utilize it to analyze and identify the lines in the experimentally observed spectrum.

  1. Theodore von Karman

    Science.gov (United States)

    1950-01-01

    Dr. Theodore von Karman, co-founder of the Jet Propulsion Laboratory (JPL) Pasadena, California was an aeronautical theoretician. His contributions in the fields of aerodynamics and aeronautical engineering are well documented and well known to every aerospace engineer. He was the first winner of the prestigious U.S. Medal of Science presented to him by President John F. Kennedy. As well as being co-founder of JPL, he also was principal founder of a major rocket propulsion firm (Aerojet-General Corp.), the top science advisor to the U.S. Air Force during its transition to jet propulsion aircraft and the top science advisor to NATO. He was, during much of this time, the fountainhead of aerodynamic thought as head of the Guggenheim Aeronautical Laboratory at the California Institute of Technology (GALCIT) in Pasadena, California. In the May 1956 issue of the Journal of Aeronautical Sciences, it was said of him that 'No other man has had so great an impact on the development of aeronautical science in this country. Hundreds of young men became his students and scientific collaborators and were inspired to greater effort.' Dr. William H. Pickering, then director of JPL said in 1960 'We wouldn't have an aeronautical science as we know it today, if it weren't for Dr. Thoedore von Karman.' Under his guidance, Caltech's 10 foot wind tunnel was designed, built and operated. Industry firms such as Douglas, Northrop, Hughes, Lockheed, North American, Vultee and Consolidated all tested new aeronautical designs and concepts in GALCIT's tunnel. Even Boeing's own high-speed wind tunnel was heavily influenced by suggestions from von Karman. The National Advisory Committee for Aeronautics (NACA) became so concerned about GALCIT's growing influence over West coast aviation, it erected the Ames Laboratory in Sunnyvale, California in part to deter an ever widening aeronautical gap that had formed between NACA and GALCIT. From 1936 to 1940, Caltech stood alone as the only university

  2. Acquired von Willebrand Syndrome

    Institute of Scientific and Technical Information of China (English)

    郭涛

    2005-01-01

    @@ Acquired von Willebrand syndrome (AvWS) is kind of bleeding disorder with laboratory findings similar to those in congenital yon Willebrand disease (vWD).AvWS doesn's have any personal or family history of bleeding, but is associated with certain diseases or abnormal conditions or drugs. Although AvWS is being stated as a rare disease, it has gained more and more attention during the past years. Not because of the severity of the disease, but it is more common than we thought and most patients don' t have a proper diagnosis.

  3. Struktur von ABCE1

    OpenAIRE

    Karcher, Annette

    2007-01-01

    ABCE1 ist ein Mitglied der ATP Binding Cassette (ABC) Superfamilie. ABC Proteine binden und hydrolysieren ATP und verändern dabei ihre Konformation. Dadurch können sie mechanochemische Arbeit leisten. Durch drei zusätzliche Domänen unterscheidet sich ABCE1 von allen bislang bekannten und charakterisierten Mitgliedern dieser Familie. Neben den ATP-bindenden Regionen enthält ABCE1 eine cysteinreiche, N-terminale Domäne, welche zwei Eisen-Schwefel-Cluster bindet. Diese Domäne hat hohe s...

  4. Spectroscopic studies of Yb3+-doped rare earth orthosilicate crystals

    Science.gov (United States)

    Campos, S.; Denoyer, A.; Jandl, S.; Viana, B.; Vivien, D.; Loiseau, P.; Ferrand, B.

    2004-06-01

    Infrared transmission and Raman scattering have been used to study Raman active phonons and crystal-field excitations in Yb3+-doped yttrium, lutetium and scandium orthosilicate crystals (Y2SiO5 (YSO), Lu2SiO5 (LSO) and Sc2SiO5 (SSO)), which belong to the same C2h6 crystallographic space group. Energy levels of the Yb3+ ion 2F5/2 manifold are presented. In the three hosts, Yb3+ ions experience high crystal field strength, particularly in Yb:SSO. Satellites in the infrared transmission spectra have been detected for the first time in the Yb3+-doped rare earth orthosilicates. They could be attributed to perturbed Yb3+ sites of the lattices or to magnetically coupled Yb3+ pairs.

  5. Thermal Expansion in YbGaGe

    OpenAIRE

    Bobev, Svilen; Williams, Darrick J.; Thompson, J.D.; Sarrao, J L

    2004-01-01

    Thermal expansion and magnetic susceptibility measurements as a function of temperature are reported for YbGaGe. Despite the fact that this material has been claimed to show zero thermal expansion over a wide temperature range, we observe thermal expansion typical of metals and Pauli paramagnetic behavior, which perhaps indicates strong sample dependence in this system.

  6. Additive colouring of CaF2:Yb crystals: determination of Yb2+ concentration in CaF2:Yb crystals and ceramics

    Science.gov (United States)

    Shcheulin, A. S.; Angervaks, A. E.; Semenova, T. S.; Koryakina, L. F.; Petrova, M. A.; Fedorov, P. P.; Reiterov, V. M.; Garibin, E. A.; Ryskin, A. I.

    2013-06-01

    When growing CaF2 crystal doped with rare-earth ions, most of these ions are present in a trivalent state. However, due to contact with graphite crucible, a small proportion of a number of ions (Eu, Sm, Yb and Tm) are reduced to a bivalent state. A similar situation takes place during fabrication of CaF2 ceramics doped with rare-earth metals. This fact is of particular importance for laser CaF2:Yb crystals (ceramics), a promising material for short-pulse, high-power, high-energy diode-pumped solid state lasers since the presence of bivalent Yb ions can be a source of thermal losses. To date, there has been no technique to determine Yb2+ concentration in as-grown crystals. The proposed technique is based on a total reduction of Yb3+ ions via the heating of as-grown CaF2 crystals with known concentration of Yb in the reducing atmosphere of metal vapour and determining the cross section of absorption bands of Yb2+ ions. The knowledge of these parameters allows estimation of the Yb2+ content in CaF2:Yb crystals or ceramics by analysing their absorption spectra. Examples of using this technique are given. The technology of CdF2 crystals reduction (an "additive colouring") and features of colouring of crystals doped with rare-earth ions are considered.

  7. Alejandro Von Humboldt

    Directory of Open Access Journals (Sweden)

    Gerardo Paz Otero

    1965-09-01

    Full Text Available Diverso fue y sigue siéndolo, el destino de los dos hermanos Humboldt, Guillermo y Alejandro. Sino que se inicia con el nacimiento: Guillermo, el mayor, nace el 22 de junio de 1767 en Potsdam, residencia de los emperadores prusianos, la ciudad de los palacios imperiales, el imperio del militarismo germano; su cuna se meció cerca al palacete de Sans-Soussi, donde Federico el Grande forja ba el poderío de Prusia, cultivaba las ciencias y las artes, anfitrionaba a los intelectuales de Europa, y era "vasallo espiritual de Volta ire", según la aguda frase de Goethe. Alejandro viene al mundo dos años después (14 de septiembre de 1769 en Berlín, en la casa burguesa de la Jagerstrasse (calle del cazador que su madre Elizabeth von Humboldt heredara de su primer esposo.

  8. Mikrochirurgische Entfernung von Hirnstammkavernomen

    Directory of Open Access Journals (Sweden)

    Pfisterer W

    2002-01-01

    Full Text Available Der Anteil der Kavernome an allen intrakraniellen vaskulären Malformationen beträgt 14 %. Davon liegen etwa 20 % im Hirnstamm. Bei einer Rezidivblutungsrate von 21 % jährlich ist auch eine Exstirpation im Hirnstamm indiziert. Wir berichten über 3 Patienten mit Hirnstammkavernomen, die in mikrochirurgischer Technik bei geringer Morbidität und ohne Mortalität an unserer Abteilung total exstirpiert wurden. Wir halten die subakute Phase für den besten Zeitpunkt zur Entfernung des Kavernoms, wenn dies der klinisch-neurologische Zustand des Patienten erlaubt. Die mikrochirurgische Exstirpation wurde durch Elektrophysiologie (akustisch und somatosensorisch evozierte Potentiale, Endoskopie und Neuronavigation unterstützt.

  9. Studies on the uptake and incorporation of anthropogenic nitrogen oxides (NO{sub x}) by sunflowers and maize by using {sup 15}N isotope tracers; Untersuchungen zur Aufnahme und zum Einbau von anthropogenen Stickoxiden (NO{sub x}) durch Sonnenblumen und Mais mittels {sup 15}N-Isotopen-Markierung

    Energy Technology Data Exchange (ETDEWEB)

    Segschneider, H.J.

    1994-05-01

    The aim of the present thesis was to quantify the uptake of nitrogen dioxide (NO{sub 2}) and nitrogen monoxide (NO) by sunflowers (Helianthus annuus L.) and maize (Zea mays L.) in a concentration range corresponding to the concentration range in the present atmosphere. Furthermore, work was carried out on characterizing the parameters responsible for NO{sub 2} and NO uptake by varying the different exposure conditions. In addition by applying {sup 15}N-enriched nitrogen oxides ({sup 15}NO{sub 2}; {sup 15}NO) it was also possible to investigate the incorporation and distribution of the {sup 15}NO{sub x} nitrogen in the plants. After an appropriate cultivation phase, the plants were transferred individually into a specially designed exposure system (Latus, 1989). Quantification of the NO{sub 2} or NO uptake was carried out by two independent measuring methods. On the one hand, the quantities of NO{sub 2} or NO taken up by the plants were determined via the NO{sub 2} concentration difference between the chamber inlet and outlet. On the other hand, the NO{sub 2} and NO uptake was calculated after exposure to {sup 15}N-enriched nitrogen oxides by determining the {sup 15}N/{sup 14}N ratio in the exposed plants using mass spectrometry. Furthermore, by using various analytical procedures it was possible to determine the sizes of the different nitrogen pools in the plants and to evaluate them by mass spectrometry. (orig./UG)

  10. Shape Co-Existence in the Transitional Nuclide 157Yb

    Institute of Scientific and Technical Information of China (English)

    徐川; 华辉; 李湘庆; 张双全; 许甫荣; 石跃; 竺礼华; 吴晓光; 李广生; 贺创业

    2012-01-01

    High-spin states in 157Yb have been populated in the 144Sm(160, 3n)157yb fusion- evaporation reaction at a beam energy of 85 MeV, and two rotational bands have been established for the first time. Within the framework of the triaxial particle-rotor model, the energy spectra and single-particle configurations of 157Yb are investigated. The calculated energy spectra agree well with the experimental data. The newly observed vf7/2 band, and the previously known vi13/2 band in 157Yb, are also discussed by means of Total-Routhian-Surface methods. The structural characters observed in 157Yb provide evidence for the shape coexistence of three distinct shapes: prolate, triaxial and oblate. At higher spins, both the vf7/2 band and the vi13/2 band in 157Yb undergo a shape evolution with sizable alignments occurring.

  11. von Willebrand Disease (For Parents)

    Science.gov (United States)

    ... to classify the type of von Willebrand disease platelet function tests, which determine how well the platelets work ... for pain or fever. These drugs interfere with platelet function and can increase the risk of bleeding. It ...

  12. Kleben von Kunststoff mit Metall

    CERN Document Server

    Brockmann, W; Käufer, H

    1989-01-01

    Das Buch behandelt das Kleben von Kunststoffen mit Metallen in einer fur den Praktiker verstandlichen und umsetzbaren Form. Es leitet zu Klebeverfahren an, die optimale Ergebnisse hinsichtlich Qualitat, Dauerhaftigkeit und Wirtschaftlichkeit liefern.

  13. Planung und Bewertung von Montagesystemen

    Science.gov (United States)

    Hartel, Marko; Lotter, Bruno

    Die Gestaltung von Montagesystemen ist eine wesentliche Aufgabenstellung an die planenden Bereiche eines Unternehmens. Anhand von Praxis-beispielen werden Planungssystematiken and Bewertungsverfahren — sei es fur die Effizienzsteigerung einer bestehenden Montage oder die Entscheidung zwischen Varianten eines geplanten Montagesystems — aufzeigt. Die folgende Planungssystematik nach REFA wird für Produktionssysteme im Allgemeinen angewandt; die Planungssystematik nach Lotter ist speziell auf Montagesysteme ausgelegt.

  14. Theorie und Praxis von Hochschulrankings

    OpenAIRE

    Hornbostel, Stefan

    2007-01-01

    Der Beitrag gibt einen Überblick über die theoretische Grundlage von Hochschulrankings, welche in der qualitativ stark differenzierten Hochschullandschaft in Deutschland entscheidend für öffentliche Reputationsurteile sein können. Ausgehend von einem formal gleichrangigen Institutionengefüge der Hochschullandschaft in Deutschland haben die Stichworte Profilbildung, Exzellenz und Wettbewerb in den letzten Jahren zunehmend an Bedeutung gewonnen. Der daraus resultierende große Informationsbedarf...

  15. Cryogenic Yb:YAG thin-disk laser

    Science.gov (United States)

    Vretenar, N.; Carson, T.; Lucas, T.; Newell, T.; Latham, W. P.; Peterson, P.; Bostanci, H.; Lindauer, J. J.; Saarloos, B. A.; Rini, D. P.

    2011-11-01

    At cryogenic temperatures, Yb:YAG behaves as a 4-level laser. Its absorption and emission cross-sections increase, and its thermal conductivity improves. Yb:YAG thin disk laser performance at room and cryogenic (80°K) temperatures will be presented. The Yb:YAG gain media is cooled using either a pressurized R134A refrigerant system or by a two-phase liquid nitrogen spray boiler. Interchangeable mounting caps allow the same Yb:YAG media to be switched between the two systems. This allows direct comparison of lasing, amplified spontaneous emission, and temperature performance between 20°C and -200°C.

  16. Power scaling of cryogenic Yb:LiYF(4) lasers.

    Science.gov (United States)

    Zapata, Luis E; Ripin, Daniel J; Fan, Tso Yee

    2010-06-01

    We demonstrate a cryogenically cooled Yb:LiYF(4) (Yb:YLF) laser with 224W linearly polarized output power (pump-power limited) and a slope efficiency of 68%. The beam quality is characterized by an M(2) approximately 1.1 at 60W output and M(2) approximately 2.6 at 180W output. This level of average laser power is approximately 2 orders of magnitude higher than demonstrated previously in cryogenic Yb:YLF. Yb:YLF is attractive for femtosecond pulse generation because of its wide gain bandwidth, and this demonstration shows the potential for high-average-power subpicosecond pulse lasers.

  17. Ultrasonic study of the Yb-based heavy fermion compound YbRh{sub 2}Zn{sub 20}

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Y; Ito, K; Nakamura, M; Yoshizawa, M [Graduate School of Engineering, Iwate University, Morioka 020-8551 (Japan); Saiga, Y; Kosaka, M [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Uwatoko, Y, E-mail: yoshiki@iwate-u.ac.j [Institute for Solid State Physics, University of Tokyo, Kashiwa 227-8581 (Japan)

    2009-03-01

    We report ultrasonic measurements on the high quality single crystal of the Yb-based heavy fermion compound YbRh{sub 2}Zn{sub 20} over a temperature range from 200 K to 0.5 K. A shallow, but clear minimum was observed in the temperature dependent elastic constants C{sub 11}, (C{sub 11} - C{sub 12})/2 and C{sub 44} around 15 K, probably attributed to the ground state and low-lying excited states of Yb{sup 3} in the cubic CEF. We discuss the low-temperature elastic properties and possible energy level scheme of localized 4f state of Yb{sup 3} ions in YbRh{sub 2}Zn{sub 20}. CEF ground state developed at the low temperatures and physical parameters relating to a quadrupolar moment in YbRh{sub 2}Zn{sub 20}

  18. YB-1 protein: functions and regulation.

    Science.gov (United States)

    Lyabin, Dmitry N; Eliseeva, Irina A; Ovchinnikov, Lev P

    2014-01-01

    The Y-box binding protein 1 (YB-1, YBX1) is a member of the family of DNA- and RNA-binding proteins with an evolutionarily ancient and conserved cold shock domain. It falls into a group of intrinsically disordered proteins that do not follow the classical rule 'one protein-one function' but introduce a novel principle stating that a disordered structure suggests many functions. YB-1 participates in a wide variety of DNA/RNA-dependent events, including DNA reparation, pre-mRNA transcription and splicing, mRNA packaging, and regulation of mRNA stability and translation. At the cell level, the multiple activities of YB-1 are manifested as its involvement in cell proliferation and differentiation, stress response, and malignant cell transformation. WIREs RNA 2014, 5:95-110. doi: 10.1002/wrna.1200 CONFLICT OF INTEREST: The authors have declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website.

  19. Yb3+ Ion Upconversion Luminescence from YbEr:ZBLAN Glass Excited by 966 nm Laser Light

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-Bo; NIE Yu-Xin; WEN Ou

    2001-01-01

    The upconversion lumiuescence of several YbEr co-doped Zr-Ba-La-AI-Na (ZBLAN) glass samples (Er(0.5) Yb(3): ZBLAN, Er(0.5)Yb(1):ZBLAN and Er(0.5):ZBLAN) has been studied. A new kind of upconversion cooperative radiation fluorescence, which comes from coupled cluster states of two Yb3+ ions has been observed. This is significant in that it may lead to a new path to achieve blue upconversion luminescence, which has promising upconversion applications.

  20. Thermal analysis of a diffusion bonded Er3+,Yb3+:glass/Co2+: MgAl2O4 microchip lasers

    Science.gov (United States)

    Belghachem, Nabil; Mlynczak, Jaroslaw; Kopczynski, krzysztof; Mierczyk, Zygmunt; Gawron, Michal

    2016-10-01

    The analysis of thermal effects in a diffusion bonded Er3+,Yb3+:glass/Co2+:MgAl2O4 microchip laser is presented. The analysis is performed for both wavelengths at 940 nm and at 975 nm as well as for two different sides of pumping, glass side and saturable absorber side. The heat sink effect of Co2+:MgAl2O4, as well as the impact of the thermal expansion and induced stress on the diffusion bonding are emphasised. The best configurations for reducing the temperature peaks, the Von Mises stresses on the diffusion bonding, and the thermal lensing are determined.

  1. Structure induced Yb valence changes in the solid solution Yb(x)Ca(1-x)C2.

    Science.gov (United States)

    Link, Pascal; Glatzel, Pieter; Kvashnina, Kristina; Trots, Dmytro M; Smith, Ronald I; Ruschewitz, Uwe

    2013-06-17

    The solid solution Yb(x)Ca(1-x)C2 (0 ≤ x ≤ 1) was synthesized by reaction of the elements at 1323 K. The crystal structures within this solid solution, as elucidated from synchrotron powder diffraction data, depend on x and exhibit some interesting features that point to a structure dependent valence state of Yb. Compounds with x ≥ 0.75 crystallize in the tetragonal CaC2 type structure (I4/mmm, Z = 2) and obey Vegard's law; for x ≤ 0.75 the monoclinic ThC2 type structure (C2/c, Z = 4) is found, which coexists with the monoclinic CaC2-III type structure (C2/m, Z = 4) for x ≤ 0.25. The monoclinic modifications show a strong deviation from Vegard's law. Their unit cell volumes are remarkably larger than expected for a typical Vegard system. HERFD-XANES spectroscopic investigations reveal that different Yb valence states are responsible for the observed volume anomalies. While all tetragonal compounds contain mixed-valent Yb with ∼75% Yb(3+) (similar to pure YbC2), all monoclinic modifications contain exclusively Yb(2+). Therefore, Yb(x)Ca(1-x)C2 is a very rare example of a Yb containing compound showing a strong structure dependence of the Yb valence state. Moreover, temperature dependent synchrotron powder diffraction, neutron TOF powder diffraction, and HERFD-XANES spectroscopy experiments reveal significant Yb valence changes in some compounds of the Yb(x)Ca(1-x)C2 series that are induced by temperature dependent phase transitions. Transitions from the tetragonal CaC2 type structure to the monoclinic ThC2 or the cubic CaC2-IV type structure (Fm3m, Z = 4) are accompanied by drastic changes of the mean Yb valence from ∼2.70 to 2.0 in compounds with x = 0.75 and x = 0.91. Finally, the determination of lattice strain arising inside the modifications with ordered dumbbells (ThC2 and CaC2 type structures) by DSC measurements corroborated our results concerning the close relationship between crystal structure and Yb valence in the solid solution Yb(x)Ca(1-x

  2. Vergleich von simulierten und reellen Schleppkurven von Landmaschinen

    Directory of Open Access Journals (Sweden)

    Steffen Hürter

    2014-02-01

    Full Text Available An das landwirtschaftliche Wegenetz werden durch die kontinuierliche Größenentwicklung von Landmaschinen neue Anforderungen gestellt. Die Maschinen werden breiter und länger und besitzen mehr Achsen und komplexere Lenksysteme als in der Vergangenheit. Beim landwirtschaftlichen Wegebau hat dies insbesondere Auswirkungen auf die Planung der Kurven. In der Untersuchung wurden die Schleppkurven aktueller Landmaschinen aufgenommen und es wurde geprüft, ob sie mithilfe einer Software simuliert werden können. Dabei zeigt sich, dass die verwendete Simulationssoftware für die Bestimmung von Schleppkurven für Landmaschinen mit komplexen Lenksystemen hinreichend genau ist.

  3. Ethnographische Filme und die Darstellung von Frauen

    Directory of Open Access Journals (Sweden)

    Judith Keilbach

    2002-03-01

    Full Text Available In dieser Filmographie werden ethnographische und koloniale Filme aus dem Bestand des Nederlands Filmmuseum kommentiert, die für die Frage nach der Darstellung von Frauen und Geschlechterverhältnissen von Interesse sind.

  4. Bibliographie der Werke von Herbert Spencer

    OpenAIRE

    Schmid, Michael (Prof.)

    1991-01-01

    Bibliographie der Werke von Herbert Spencer / bearb., hrsg., mit e. Einl. u. e. Kurzbiogr. vers. von Michael Schmid u. Margit Weihrich. - München : Inst. für Soziologie u. Gesellschaftspolitik, Univ. d. Bundeswehr, 1991. - 159 S.

  5. Thermodynamic assessment of Ni-Yb binary system%Ni-Yb 二元系的热力学评估

    Institute of Scientific and Technical Information of China (English)

    朱代漫; 李长荣; 郭翠萍; 杜振民; 李均钦

    2016-01-01

    On the basis of the experimental data of phase equilibria and thermochemical properties available from literatures, a critical assessment for the Ni−Yb binary system was carried out using the CALPHAD (calculation of phase diagrams) method. The liquid phase is modeled as the associate model with the constituent species Ni, Yb and YbNi3, owing to the sharp change of the enthalpy of mixing of liquid phase at the composition of around 25% Yb (mole fraction). The terminal solid solutions FCC_A1 (Ni/Yb) and BCC_A2 (Yb) are described by the substitutional solution model with the Redlich−Kister polynomial. The intermetallic compounds, Yb2Ni17, YbNi5, YbNi3, YbNi2, α-YbNi and β-YbNi, are treated as strict stoichiometric compounds, since there are no noticeable homogeneity ranges reported for these compounds. A set of self-consistent thermodynamic parameters for the Ni−Yb binary system are obtained. According to the presently assessed results, the thermochemical properties and the phase boundary data can be well reproduced.%基于文献报道的相平衡和热化学实验数据,利用相图计算(Calphad)方法对 Ni−Yb 二元系进行热力学评估。考虑到液相混合焓在25% Yb(摩尔分数)附近有急剧变化,液相采用缔合物模型,组份为 Ni、YbNi3和 Yb;端际固溶体相包括 FCC_A1(Ni)、FCC_A1(Yb)和 BCC_A2(Yb),均采用亚规则溶体模型,并按照 Redlich−Kister 多项式进行描述;中间化合物 Yb2Ni17、YbNi5、YbNi3、YbNi2、α-YbNi 和β-YbNi 都没有明显的固溶度实验数据,均按严格计量比处理。优化得到的 Ni−Yb 二元系热力学参数自洽合理,能够很好地再现该体系的热化学性质和相图数据。

  6. Diskriminierung von Enantiomeren mit chiralen Selektoren

    OpenAIRE

    Würthner, Stefan

    2007-01-01

    Die vorliegende Dissertation befasst sich mit der systematischen Aufklärung von zwischenmolekularen Wirt-Gast-Wechselwirkungen von Arzneistoffen mit Cyclodextrinen. In einem sich trichterförmig verengenden Erkenntnisprozeß wird im ersten Schritt eine breite Datenbasis von Kapillarelektrophorese-Daten von 86 chiralen Arzneistoffen mit 3 nativen CDs (alpha, beta und gamma) sowie 11 CD-Derivaten gewonnen. Sowohl die Trennfaktoren der Enantiomeren (alpha_m) als auch die Retardierungsfaktoren (R_m...

  7. Femtosecond pulse generation at 50 W average powers from an Yb:KYW-Yb:YAG planar-waveguide MOPA

    Directory of Open Access Journals (Sweden)

    Baker H. J.

    2013-03-01

    Full Text Available An Yb:YAG planar-waveguide power amplifier seeded by an Yb:KYW master oscillator is reported. The system produced 700-fs pulses at 1032 nm at average output powers of 50 W and a frequency of 53 MHz.

  8. [Pheochromocytoma and von Recklinghausen's disease].

    Science.gov (United States)

    Rabii, R; Fekak, H; Moufid, K; Joual, A; Bennani, S; el Mrini, M; Benjelloun, S

    2002-07-01

    The association between von Recklinghausen's disease and pheochromocytoma is present about 10% of cases. We report a case of 49 years old women who presented with elevated blood pressure and von Recklinghausen's neurofibromatosis. Laboratory examination showed a marked level in the urinary excretion of cathecholamine. The computed tomography showed a right adrenal tumor suggesting a pheochromocytoma. The adrenalectomy was realised by transabdominal approach and the histological examination confirmed a benign pheochromocytoma. The authors discuss the pathogenetic hypothesis of this rare pathological association, the diagnostic methods and the therapeutic procedure.

  9. An Invitation from Lars von Trier

    DEFF Research Database (Denmark)

    Skadhauge, Troels; Tønder, Lars

    2015-01-01

    Translation of Martin Krasnik interview with Lars von Trier broadcast on DR2, January 12, 2015. The following is an interview of Lars von Trier (LvT) by the Danish journalist Martin Krasnik (MK). The interview took place in Lars von Trier’s home in Brede, a small town just outside Copenhagen...

  10. Homopteren von Java, gesammelt von Herrn Edw. Jacobson

    NARCIS (Netherlands)

    Melichar, L.

    1914-01-01

    Herr Edw. Jacobson hat auf Java in den Jahren 1908— 1910 Homopteren gesammelt und mir die Bearbeitung des gesammelten Materiales übertragen. Die Jacobson’sche Ausbeute ist insoferne bemerkenswert, als dieselbe viele Mikrohomopteren enthält, welche von nichtfachkundigen Sammlern gewöhnlich nicht

  11. Homopteren von Java, gesammelt von Herrn Edw. Jacobson

    NARCIS (Netherlands)

    Melichar, L.

    1914-01-01

    Herr Edw. Jacobson hat auf Java in den Jahren 1908— 1910 Homopteren gesammelt und mir die Bearbeitung des gesammelten Materiales übertragen. Die Jacobson’sche Ausbeute ist insoferne bemerkenswert, als dieselbe viele Mikrohomopteren enthält, welche von nichtfachkundigen Sammlern gewöhnlich nicht beac

  12. Integration von Erkennung und Interpretation von gesprochener Sprache

    OpenAIRE

    Fink, Gernot A.; Kummert, Franz; Sagerer, Gerhard; Kunze, Jürgen

    1994-01-01

    Die Mehrzahl der heutigen sprachverstehenden Systeme sind aus zwei sehr unterschiedlichen Verarbeitungskomponenten aufgebaut, einer meist statistischen Spracherkennungskomponente und einer in der Regel wissensbasiert arbeitenden Komponente zur Interpretation. Die Kommunikation zwischen diesen Verarbeitungseinheiten ist stark eingeschränkt. In der Regel werden von der Spracherkennung nur Worthypothesenmengen berechnet und an die Interpretationskomponente weitergereicht ohne weitere Interaktion...

  13. Laser spectroscopy and cooling of Yb+ ions on a deep-UV transition

    CERN Document Server

    Meyer, Hendrik M; Ratschbacher, Lothar; Zipkes, Christoph; Köhl, Michael

    2011-01-01

    We perform laser spectroscopy of Yb+ ions on the 4f14 6s 2S_{1/2} - 4f13 5d 6s 3D[3/2]_{1/2} transition at 297 nm. The frequency measurements for 170Yb+, 172Yb+, 174Yb+, and 176Yb+ reveal the specific mass shift as well as the field shifts. In addition, we demonstrate laser cooling of Yb+ ions using this transition and show that light at 297 nm can be used as the second step in the photoionization of neutral Yb atoms.

  14. Sindrom Von Hippel–Lindau

    Directory of Open Access Journals (Sweden)

    E V Ershova

    2011-06-01

    Full Text Available Von Hippel-Lindau syndrome - a systemic disease manifesting with multiple tumor growth, inherited by autosomal-dominant type with high penetrance. Understanding the pathogenesis of the disease is important for determining the start time of screening for the presence of the tumors and adequate treatment, including metabolic disorders.

  15. Zur Soziologie von Ctenidium molluscum

    NARCIS (Netherlands)

    Zijlstra, Gea

    1979-01-01

    Bei einer Untersuchung in einer Anzahl von niederländischen „blauwgraslanden“ (d. h. „blaue Wiesen“, Cirsio-Molinietum, Junco-Molinion) wurde Ctenidium molluscum angetroffen, eine Art, welche in den Niederlanden mehr oder weniger zum Mesobromion gerechnet wird. Untersuchungen an altem Herbarmaterial

  16. Optogalvanic Spectroscopy of Metastable States in Yb^{+}

    CERN Document Server

    Petrasiunas, M J; Weinhold, T J; Norton, B G; Kielpinski, D

    2011-01-01

    The metastable ^{2}F_{7/2} and ^{2}D_{3/2} states of Yb^{+} are of interest for applications in metrology and quantum information and also act as dark states in laser cooling. These metastable states are commonly repumped to the ground state via the 638.6 nm ^{2}F_{7/2} -- ^{1}D[5/2]_{5/2} and 935.2 nm ^{2}D_{3/2} -- ^{3}D[3/2]_{1/2} transitions. We have performed optogalvanic spectroscopy of these transitions in Yb^{+} ions generated in a discharge. We measure the pressure broadening coefficient for the 638.6 nm transition to be 70 \\pm 10 MHz mbar^{-1}. We place an upper bound of 375 MHz/nucleon on the 638.6 nm isotope splitting and show that our observations are consistent with theory for the hyperfine splitting. Our measurements of the 935.2 nm transition extend those made by Sugiyama et al, showing well-resolved isotope and hyperfine splitting. We obtain high signal to noise, sufficient for laser stabilisation applications.

  17. Optical properties of Yb ions in GaN epilayer

    Science.gov (United States)

    Jadwisienczak, W. M.; Lozykowski, H. J.

    2003-07-01

    In recent years, an important effort in semiconductor materials research has been devoted to III-nitrides semiconductors doped with rare earth ions due to the high potential of these materials in light-emitting device applications. Ytterbium (Yb 3+) is one of a few lanthanide ions which have not been investigated as an optically active center in these materials yet. In this paper we report the observation of luminescence from GaN films grown on sapphire (0 0 0 1) substrate by metal organic chemical vapor deposition and doped by implantation with Yb 3+ ions. The high resolution photo- and cathodoluminescence spectra of GaN:Yb 3+ were studied at different excitation conditions in temperatures ranging from 8 to 330 K and revealed weak thermal quenching. The luminescence emission lines are assigned to transitions between the spin-orbit levels 2F 5/2 → 2F 7/2 of Yb 3+ (4f 13). The analysis of the Yb luminescence spectra allowed us to suggest the energy level diagram of the crystal-field-split 4f 13 levels for the Yb ion center. The most probable lattice location of Yb in GaN is the substitutional Ga site. Furthermore, the luminescence kinetics of internal transitions of Yb 3+ incorporated in GaN was investigated by means of decay and time-resolved luminescence measurements. It was found that the ytterbium decay is non-exponential with dominant exponential term of ˜100 μs with little dependence on the ambient temperature. The results indicate that Yb-doped GaN epilayer may be suitable as a material for near infrared optoelectronic devices.

  18. [Friedrich Ludwig von Maydelli pildid Baltimaade ajaloost = Friedrich Ludwig von Maydells Baltische Geschichte in Bildern = Friedrich Ludwig von Maydell ́s Baltic history in images] / Ulrike Plath

    Index Scriptorium Estoniae

    Plath, Ulrike, 1972-

    2014-01-01

    Arvustus: Friedrich Ludwig von Maydelli pildid Baltimaade ajaloost = Friedrich Ludwig von Maydells Baltische Geschichte in Bildern = Friedrich Ludwig von Maydell ́s Baltic history in images. Eesti kunstimuuseum, Kadrioru kunstimuuseum. Tallinn 2013

  19. [Friedrich Ludwig von Maydelli pildid Baltimaade ajaloost = Friedrich Ludwig von Maydells Baltische Geschichte in Bildern = Friedrich Ludwig von Maydell ́s Baltic history in images] / Ulrike Plath

    Index Scriptorium Estoniae

    Plath, Ulrike, 1972-

    2014-01-01

    Arvustus: Friedrich Ludwig von Maydelli pildid Baltimaade ajaloost = Friedrich Ludwig von Maydells Baltische Geschichte in Bildern = Friedrich Ludwig von Maydell ́s Baltic history in images. Eesti kunstimuuseum, Kadrioru kunstimuuseum. Tallinn 2013

  20. Sympathetic cooling of 171 Yb+ qubit ions on a scalable ion trap chip using Yb isotopes

    Science.gov (United States)

    Kwon, Yeong-Dae; Ahn, Jun Sik; Hong, Seokjun; Lee, Minjae; Cheon, Hongjin; Cho, Dongil ``Dan''; Kim, Taehyun

    2016-05-01

    To achieve ion trap based large-scale quantum computing devices, motional states of qubit ions must be regulated against heating from ion transportation or noise on the chip surface while leaving internal states of the ions intact. Sympathetic cooling is a natural solution for this problem, but trapping two different species of ions generally requires two sets of optical devices including separate lasers for each ion type, increasing the complexity and the cost of the setup. We tested Doppler-cooled 174 Yb+ ions to sympathetically cool 171 Yb+ qubit ions. Since these two isotopes have energy levels close to each other, the optical setup can be vastly simplified. We also verified that the tail of non-ideally focused cooling beam and the scattered light from the surface create excited state population in the 171 Yb+ qubit ions, as expected. This leads to occasional spontaneous emission events, which currently limits the coherence time of our qubit to a few seconds. We will also discuss our plans for optimizing the experiment, which may increase the coherence time by one or two orders of magnitude. This work was partially supported by ICT R&D program of MSIP/IITP. [10043464, Development of quantum repeater technology for the application to communication systems].

  1. Isotope separation of the Yb-168 stable isotope for low energy gamma ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyun Min; Kwon, Duck Hee; Cha, Yong Ho; Lee, Ki Tae; Nam, Sung Mo; Yoo, Jaek Won; Han, Jae Min; Rhee, Yong Joo [Lab. of Quantum Optics, Korea Atomic Energy Research Institute, Taejeon (Korea, Republic of)

    2003-07-01

    We developed laser isotope separation technology of stable isotope of low melting point metals. Yb-168 can be effectively used in non-destructive testing (NDT) after it is transformed to Yb-168 by neutron irradiation in a nuclear reactor. For this application of Yb-168, the isotope purity of it should be enhanced to more than 15% from the natural abundance of 0.135%. Our isotope separation system consist of laser system, Yb vapor generating system, and photoionized particle extraction system. For the system, we developed a diode-pumped slid-state laser of high-repetition rate and 3-color dye lasers. Yb vapor was generated by heating solid Yb sample resistively. The photo-ion produced by resonance ionization were extracted by a devised extractor. We produced enriched Yb metal more than 20 mg with the abundance of 25.8% of Yb-168 in the Yb (NO{sub 3}){sub 3}.

  2. Optical properties of epitaxial YAG:Yb films

    Science.gov (United States)

    Ubizskii, S. B.; Matkovskii, A. O.; Melnyk, S. S.; Syvorotka, I. M.; Müller, V.; Peters, V.; Petermann, K.; Beyertt, A.; Giesen, A.

    2004-03-01

    This work deals with the investigation of the optical properties of epitaxial YAG:Yb films and their suitability as gain media for thin disk lasers. Epitaxial films of YAG:Yb were grown by the liquid phase epitaxy method in air on the (111)-oriented YAG substrates. The thickness of the grown layers was from 30 to 260 m. The melt composition was varied to obtain the desired doping level from 10 to 15% and to optimize the optical properties. The best epitaxial films were colourless and had an Yb3+ luminescence lifetime of more than 950 s, which is very close to the intrinsic lifetime of the Yb ions in the bulk YAG single crystals. These films were tested in a thin disk laser setup with 24 absorption passes of the 940 nm pumping beam. The maximum output power at 1.03 m wavelength in CW operation reached more than 60 W and the optical efficiency was close to 30%.

  3. Schätzung von Vegetationsparametern aus multispektralen Fernerkundungsdaten

    OpenAIRE

    2007-01-01

    In der vorliegenden Arbeit wird ein Verfahren zur Schätzung von Vegetationsparametern aus multispektralen Fernerkundungsdaten unter Verwendung von physikalischen Strahlungstransfer-Modellen und einer geringen Anzahl von Bodenmessungen vorgestellt. Dieses Verfahren wurde über einen Zeitraum von zwei Jahren exemplarisch an verschiedenen Winterweizenfeldern getestet, die mit einem Daedalus ATM Multispektralscanner aufgenommen wurden. Von besonderem Interesse sind hierbei die Schwankungen der Veg...

  4. Shock, diaschisis and von Monakow

    Directory of Open Access Journals (Sweden)

    Eliasz Engelhardt

    2013-07-01

    Full Text Available The concept of shock apparently emerged in the middle of the 18th century (Whyett as an occurrence observed experimentally after spinal cord transection, and identified as "shock" phenomenon one century later (Hall. The concept was extended (Brown-Séquard and it was suggested that brain lesions caused functional rupture in regions distant from the injured one ("action à distance". The term "diaschisis" (von Monakow, proposed as a new modality of shock, had its concept broadened, underpinned by observations of patients, aiming at distinguishing between symptoms of focal brain lesions and transitory effects they produced, attributable to depression of distant parts of the brain connected to the injured area. Presently, diaschisis is related mainly to cerebrovascular lesions and classified according to the connection fibers involved, as proposed by von Monakow. Depression of metabolism and blood flow in regions anatomically separated, but related by connections with the lesion, allows observing diaschisis with neuroimaging.

  5. Preparation and Characterization of Yb - doped YAG Ceramics

    OpenAIRE

    2011-01-01

    Rare-earth doped yttrium aluminum garnet (YAG) ceramics are among the most widely produced transparent ceramics for laser applications. Yb:YAG ceramics are an interesting IR laser material [1], which allows significantly higher doping compared to the generally more used Nd:YAG [2,3]. This work presents the preparation of polycrystalline Yb:YAG ceramics with dopant concentration from 0 up to 20 at.% via solid state reactive sintering. Samples were prepared via cold isostatic pressing of spray ...

  6. Polarizing 50micrometers Core Yb-Doped Photonic Bandgap Fiber

    Science.gov (United States)

    2015-02-08

    properly. Recent reports demonstrate that the birefringence in photonic bandgap fibers (PBFs) can provide single-polarization operation by shifting the...add ref]. Here, we demonstrate a 50µm core Yb-doped polarizing photonic bandgap fiber (PBF) for single-polarization operation 1. REPORT DATE (DD-MM...19-08-2015 Approved for public release; distribution is unlimited. Polarizing 50µm core Yb-doped photonic bandgap fiber The views, opinions and/or

  7. Moose von Inselbergen in Benin

    OpenAIRE

    Frahm, Jan-Peter; Porembski, Stefan

    1998-01-01

    Acht Leber- und zehn Laubmoosarten werden von Inselbergen aus Benin angegeben. Fünf der Lebermoose (Acrolejeunea emergens, Riccia atropurpurea, R. congoana, R. discolor, R. moenkemeyeri) und alle Laubmoose (Archidium ohioense, Brachymenium acuminatum, B. exile, Bryum arachnoideum, B. argenteum, Bryum deperssum, Garckea moenkemeyeri, Hyophila involuta, Philonotis mniobryoides und Weissia cf. edentula) werden neu für Benin angegeben. Eight liverworts and ten mosses are reported from inselber...

  8. [Direct upconversion sensitization luminescence comparison of the ErYb co-doped oxyfluoride fluoride pentaphosphate glass].

    Science.gov (United States)

    Chen, Xiao-bo; Chen, Luan; Zhao, Chen-yi; Sawanobori, N; Ma, Hui; Song, Zeng-fu

    2003-02-01

    This paper investigates the direct upconversion sensitization luminescence of the ErYb co-doped oxyfluoride glass (ErYb: FOG), fluoride glass (ErYb: ZBLAN) and pentaphosphate noncrystalline (ErYb: PP) excited by a 966 nm diode laser. The splendid upconversion luminescence phenomenon is found. It is resulted from that the Yb3+ concentration in rather high, the energy transfer among Er(3+)-Yb3+ and Yb(3+)-Yb3+ ions is rather strong. An important fact is found that the direct upconversion sensitization luminescence of ErYb: FOG is about 100-100,000 times greater than that of ErYb: PP. And meanwhile it is interesting that the upconversion luminescence intensity of ErYb: FOG is near to that of ErYb: ZBLAN. It is significant to enhance the comprehensive level of up-conversion luminescence.

  9. Didaktische Konzeption von Serious Games: Zur Verknüpfung von Spiel- und Lernangeboten

    Directory of Open Access Journals (Sweden)

    Michael Kerres

    2009-08-01

    Full Text Available Serious Games versuchen Spielen mit Lernen zu verbinden. Der Beitrag problematisiert die Machbarkeit einer solchen Verknüpfung in digitalen Welten und diskutiert verschiedene didaktische Konzepte einer Nutzbarmachung digitaler Spiele für das Lernen und Lehren. Ausgehend von einer Analyse des Erlernens von Spielen werden drei didaktische Konzepte von Serious Games im Hinblick auf ihre didaktischen Potenziale untersucht: (1 der unmittelbare Transfer von Wissen, das im Spiel erworben wird (keine zusätzliche Didaktisierung, (2 Didaktisierung durch Einbettung des Spiels in einer Lernsituation oder (3 Didaktisierung durch Einbettung von Lernaufgaben in ein Spiel. Ergebnisse zur Nutzung von Spielen, bei denen Lernaufgaben in eine Spielwelt eingebettet sind, zeigen, dass Personen die Aufnahme von Wissen in einem expliziten Lernmodus eher zu reduzieren versuchen, um möglichst zügig wieder in den Spielmodus zu wechseln. Diskutiert werden die Konsequenzen dieser Problematik für die didaktische Konzeption von Serious Games.

  10. Lifetimes of high-spin states in {sup 162}Yb

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.P.; Janssens, R.V.F.; Henry, R.G. [and others

    1995-08-01

    A measurement on lifetimes of high-spin states in the yrast and near-yrast rotational bands in {sup 162}Yb was carried out at ATLAS in order to determine the evolution of collectivity as a function of angular momentum using the {sup 126}Te({sup 40}Ar,4n){sup 162}Yb reaction at 170 MeV. Previous lifetime measurements in the {sup 164,166,168}Yb isotopes showed a dramatic decrease in the transition quadrupole moment Q{sub t} with increasing spin. It was suggested that this decrease in Q{sub t} is brought about by the rotationally-induced deoccupation of high-j configurations, mainly i{sub 13/2} neutrons. If this interpretation is correct, the heavier isotopes should have a larger decrease in Q{sub t} than the lighter mass nuclides due to the position of the Fermi surface in the i{sub 13/2} subshell. Indeed, {sup 160}Yb does not show a clear decrease in Q{sub t} at high spin. No high spin lifetime information exists for {sup 162}Yb, thus this experiment fills the gap of measured Q{sub t}`s in the light Yb series. The data is currently being analyzed.

  11. Scattering lengths in isotopologues of the RbYb system

    CERN Document Server

    Borkowski, Mateusz; Ciuryło, Roman; Julienne, Paul S; K{\\ke}dziera, Dariusz; Mentel, Łukasz; Tecmer, Paweł; Münchow, Frank; Bruni, Christian; Görlitz, Axel

    2013-01-01

    We model the binding energies of rovibrational levels of the RbYb molecule using experimental data from two-color photoassociation spectroscopy in mixtures of ultracold $^{87}$Rb with various Yb isotopes. The model uses a theoretical potential based on state-of-the-art \\emph{ab initio} potentials, further improved by least-squares fitting to the experimental data. We have fixed the number of bound states supported by the potential curve, so that the model is mass scaled, that is, it accurately describes the bound state energies for all measured isotopic combinations. Such a model enables an accurate prediction of the s-wave scattering lengths of all isotopic combinations of the RbYb system. The reduced mass range is broad enough to cover the full scattering lengths range from $-\\infty$ to $+\\infty$. For example, the $^{87}$Rb$^{174}$Yb system is characterized by a large positive scattering length of $+880(120)$~a.u., while $^{87}$Rb$^{173}$Yb has $a=-626(88)$~a.u.. On the other hand $^{87}$Rb$^{170}$Yb has a ...

  12. Preparation and Characterization of Downconversion Luminescent LaVO4: Tm3+ , Yb3+ and Tm3+ /Yb3+ Nanosheets

    Directory of Open Access Journals (Sweden)

    M. Zahedifar

    2012-03-01

    Full Text Available Tm3+ , Yb3+  and Tm3+ /Yb3+  doped LaVO4 nanostructures were synthe- sized for the first time by using the hydrothermal method with the aid of La(CH3CO23 as  lanthanum source in presence of oleic acid as surfactant. The products were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM, photoluminescence (PL spectroscopy and UV– Vis diffuse reflectance spectroscopy. Besides, the effects of activator concentration and sensitizer on the emission intensity were investi- gated. The PL spectrum revealed that the emission intensity decreases with increase in the concentration of Tm3+ , while adding Yb3+ as sensi- tizer causes the emission intensity to increase. The LaVO4: Tm3+ /Yb3+   may possibly have potential application in enhancing the conversion efficiency of dye-sensitized solar cells by increasing the absorption of dyes.

  13. Studies on fractionation of ytterbium isotopes in Yb(III)-acetate/Yb-amalgam system. Even-odd effect

    Energy Technology Data Exchange (ETDEWEB)

    Dembinski, W.; Poninski, M.; Fiedler, R.

    1997-12-31

    The fractionation of ytterbium isotopes with the even and odd numbers of neutrons was investigated in a Yb(III)-acetate/Yb-amalgam exchange systems. The light isotope was preferentially fractionated to the amalgam phase. The values of the unit separation gain per mass difference,{epsilon}, were found to be -0.00054 for {sup 176/171}Yb and -0.00069 for {sup 176/174}Yb The difference which amounted to 0.00015 is an evidence for the occurrence of the so called `even-odd` effect. It was also found that the chemical isotope shift of ytterbium was monitored by optical isotope shift its atomic spectra. (author). 23 refs, 7 figs, 4 tabs.

  14. Dr. von Braun Briefing Walt Disney

    Science.gov (United States)

    1965-01-01

    Dr. von Braun began his association with Walt Disney in the 1950s when the rocket scientist appeared in three Disney television productions related to the exploration of space. Years later, Dr. von Braun invited Disney and his associates to tour the Marshall Space Flight Center (MSFC) in Huntsville, Alabama. This photograph is dated April 13, 1965. From left are R.J. Schwinghamer from the MSFC, Disney, B.J. Bernight, and Dr. von Braun.

  15. Beta-Decay Study of ^{150}Er, ^{152}Yb, and ^{156}Yb: Candidates for a Monoenergetic Neutrino Beam Facility

    Energy Technology Data Exchange (ETDEWEB)

    Estevez Aguado, M. E. [CSIC-Universidad de Valencia; Algora, A. [CSIC-Universidad de Valencia; Rubio, B. [CSIC-Universidad de Valencia; Bernabeu, J. [CSIC-Universidad de Valencia; Nacher, E. [CSIC-Universidad de Valencia; Tain, J. L. [CSIC-Universidad de Valencia; Gadea, A. [CSIC-Universidad de Valencia; Agramunt, J. [CSIC-Universidad de Valencia; Burkard, K. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Hueller, W. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Doring, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kirchner, R. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mukha, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Plettner, C. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Roeckl, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Grawe, H. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Collatz, R. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Hellstrom, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Cano-Ott, D. [CIEMAT, Madrid; Karny, M. [University of Warsaw; Janas, Z. [University of Warsaw; Gierlik, M. [University of Warsaw; Plochocki, A. [University of Warsaw; Rykaczewski, Krzysztof Piotr [ORNL; Batist, L. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Moroz, F. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Wittman, V. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Blazhev, A. [University of Cologne; Valiente, J. J. [INFN, Laboratori Nazionali di Legnaro, Italy; Espinoza, C. [CFPT-IST, Lisbon

    2011-01-01

    The beta decays of ^{150}Er, ^{152}Yb, and ^{156}Yb nuclei are investigated using the total absorption spectroscopy technique. These nuclei can be considered possible candidates for forming the beam of a monoenergetic neutrino beam facility based on the electron capture (EC) decay of radioactive nuclei. Our measurements confirm that for the cases studied, the EC decay proceeds mainly to a single state in the daughter nucleus.

  16. Preparation of Mg-Yb alloy film by electrolysis in the molten LiCl-KCl-YbCl_3 system at low temperature

    Institute of Scientific and Technical Information of China (English)

    陈野; 叶克; 张密林

    2010-01-01

    The electrochemical behavior of Yb3+ and electrodeposition of Mg-Yb alloy film at solid magnesium cathode in the molten LiCl-KCl-YbCl3(2 wt.%) system at 773 K was investigated.Transient electrochemical techniques,such as cyclic voltammetry,chronopotentiometry and chronoamperometry were used in order to explore the deposition mechanism of Yb.The reduction process of Yb3+ is stepwise reactions which are single-electron and double-electron reversible charge transfer reactions.The speed control step was a diffu...

  17. MHz Repetion Rate Yb:YAG and Yb:CaF2 Regenerative Picosecond Laser Amplifiers with a BBO Pockels Cell

    Directory of Open Access Journals (Sweden)

    Fedor Bergmann

    2015-10-01

    Full Text Available We present picosecond Yb:YAG and Yb:CaF2 regenerative laser amplifiers with ultra-high repetition rates in the MHz range. A maximum pulse energy of 40 μJ was obtained at 20 kHz while we achieved around 1 μJ at 1 MHz. We demonstrated a pulse duration of 2.1 ps for Yb:YAG and 4.8 ps for Yb:CaF2 when seeded by a mode-locked Yb:KGW fs-oscillator without pulse stretching or phase compensation.

  18. Unusual weak magnetic exchange in two different structure types: YbPt2Sn and YbPt2In.

    Science.gov (United States)

    Gruner, T; Jang, D; Steppke, A; Brando, M; Ritter, F; Krellner, C; Geibel, C

    2014-12-03

    We present the structural, magnetic, thermodynamic and transport properties of the two new compounds YbPt(2)Sn and YbPt(2)In. X-ray powder diffraction shows that they crystallize in different structure types, the hexagonal ZrPt(2)Al and the cubic Heusler type, respectively. Despite quite different lattice types, both compounds present very similar magnetic properties: a stable trivalent Yb(3+), no evidence for a sizeable Kondo interaction and very weak exchange interactions with a strength below 1 K as deduced from specific heat C(T). Broad anomalies in C(T) suggest short range magnetic ordering at about 250 mK and 180 mK for YbPt(2)Sn and YbPt(2)In, respectively. The weak exchange and the low ordering temperature result in a large magnetocaloric effect as deduced from the magnetic field dependence of C(T), making these compounds interesting candidates for magnetic cooling. In addition we found in YbPt(2)In evidences for a charge density wave transition at about 290 K. The occurrence of such transitions within several RET2X compound series (RE = rare earth, T = noble metal, X = In, Sn) is analyzed.

  19. The Yb-Zn-In system at 400 deg. C: Partial isothermal section with 0-33.3 at.% Yb

    Energy Technology Data Exchange (ETDEWEB)

    Verbovytskyy, Yu., E-mail: yuryvv@bigmir.ne [Departamento de Quimica, Instituto Tecnologico e Nuclear/CFMC-UL, Estrada Nacional 10, P-2686 Sacavem Codex (Portugal); Goncalves, A.P. [Departamento de Quimica, Instituto Tecnologico e Nuclear/CFMC-UL, Estrada Nacional 10, P-2686 Sacavem Codex (Portugal)

    2009-11-03

    The phase relations in the ternary system Yb-Zn-In have been established for the partial isothermal section in the 0-33.3 at.% ytterbium concentration range at 400 deg. C, by researching of more than forty alloys. X-ray powder diffraction (XRPD), optical microscopy (OM) and scanning electron microscopy (SEM), complemented with energy dispersive X-ray spectroscopy (EDS), were used to study the microstructures, identify the phases and characterize their crystal structures and compositions. The phase equilibria of this Yb-Zn-In partial section at 400 deg. C are characterized by the presence of three extended homogeneity ranges, indium solubility in Yb{sub 13}Zn{sub 58} and YbZn{sub 2} and of zinc solubility in YbIn{sub 2}, and the existence of one ternary intermetallic compound, YbZn{sub 1-x}In{sub 1+x}, x = approx0.3. This new compound crystallizes in the UHg{sub 2} structure type (space group P6/mmm), with a = 4.7933(5) A, c = 3.6954(5) A. The studied partial isothermal section has eight ternary phase fields at 400 deg. C.

  20. Hard x-ray photoemission study of Yb1-x Zr x B12: the effects of electron doping on the Kondo insulator YbB12

    Science.gov (United States)

    Rousuli, A.; Sato, H.; Iga, F.; Hayashi, K.; Ishii, K.; Wada, T.; Nagasaki, T.; Mimura, K.; Anzai, H.; Ichiki, K.; Ueda, S.; Kondo, A.; Kindo, K.; Takabatake, T.; Shimada, K.; Namatame, H.; Taniguchi, M.

    2017-07-01

    We have carried out hard x-ray photoemission spectroscopy (HAXPES) of Yb1-x Zr x B12 (0≤slant x≤slant 0.875 ) to study the effects of electron doping on the Kondo insulator YbB12. The Yb valences of Yb1-x Zr x B12 at 300 K estimated from the Yb 3d HAXPES spectra decreased after substituting Yb with Zr from 2.93 for YbB12 to 2.83 for Yb0.125Zr0.875B12. A temperature dependent valence decrease was found upon cooling for all doping concentrations. We found peak shifts of the B 1s and Zr 3d5/2, and Yb3+ 4f spectra toward the deeper binding-energy with increasing Zr concentration, which indicates a shift of the Fermi level to the higher energy and that of the Yb 4f hole level close to the Fermi level, respectively, due to electron doping. These results qualitatively show the enhanced hybridization between the Yb 4f and conduction-band states with Zr substitution, consistent with magnetic susceptibility measurements.

  1. Reflexionseigenschaften von Windenergieanlagen im Funkfeld von Funknavigations- und Radarsystemen

    Science.gov (United States)

    Sandmann, S.; Divanbeigi, S.; Garbe, H.

    2015-11-01

    Die hier behandelte Untersuchung befasst sich mit den Störungen des elektrischen Feldes einer Doppler Very High Frequency Omnidirectional Radio Range Navigationsanlage (DVOR) in der Gegenwart von Windenergieanlagen (WEA). Hierfür wird die Feldstärke auf 25 konzentrischen Kreisbahnen, sog. Orbit Flights verschiedener Höhen und mit verschiedenen Radien rund um die DVOR-Anlage numerisch simuliert. Insbesondere werden die Einflüsse diverser Parameter der WEA wie deren Anzahl, Position, Rotorwinkel, Turmhöhe und Rotordurchmesser auf die Feldverteilung herausgestellt, sowie die Anwendbarkeit der Simulationsmethode Physical Optics (PO) durch Vergleich der Simulationsergebnisse mit denen der Multi Level Fast Multipol Method (MLFMM) untersucht.

  2. Crystal field excitations of YbMn2Si2

    Science.gov (United States)

    Mole, R. A.; Hofmann, M.; Adroja, D. T.; Moze, O.; Campbell, S. J.

    2013-12-01

    The crystal field excitations of the rare earth intermetallic compound YbMn2Si2 have been measured by inelastic neutron scattering over the temperature range 2.5-50 K. The YbMn2Si2 spectra exhibit three low energy excitations (~3-7 meV) in the antiferromagnetic AFil region above the magnetic phase transition at TN2 = 30(5) K. The crystal field parameters have been determined for YbMn2Si2 in the antiferromagnetic AFil region. A further two inelastic excitations (~9 meV, 17 meV) are observed below TN2=30(5) K, the temperature at which the high temperature antiferromagnetic structure is reported to exhibit doubling of the magnetic cell. Energy level diagrams have been determined for Yb3+ ions in the different sites above (single site) and below the magnetic transition temperature (two sites). The excitation energies for both sites are shown to be temperature independent with the temperature dependences of the transition intensities for the two sites described well by a simple Boltzmann model. The spectra below TN2 cannot be described fully in terms of molecular field models based on either a single Yb3+ site or two Yb3+ sites. This indicates that the magnetic behaviour of YbMn2Si2 is more complicated than previously considered. The inability to account fully for excitations below the magnetic phase transition may be due to an, as yet, unresolved structural transition associated with the magnetic transition.

  3. Planung von CLIL-Unterricht

    Directory of Open Access Journals (Sweden)

    Josef Leisen

    2015-10-01

    Full Text Available Der Beitrag formuliert die Sprachlernbedingungen und die Leitlinien des Sprachlernens im Fach und nennt Merkmale des guten integrierten Fach- und Sprachlehrens. Ausgehend von den Sprachproblemen, die sich im CLIL-Unterricht auftun, wird der sprachsensible CLIL-Unterricht definiert, und es werden Anregungen zur Gestaltung gegeben. Sprachliche Standardsituationen umfassen die kommunikativen Situationen im CLIL-Unterricht, die beim fachlichen Lernen auftreten und von der CLIL-Lehrkraft professionell bewältigt werden müssen. Im Beitrag wird ein Lehr-Lern-Modell ausführlich beschrieben und erläutert. Die Steuerungen von Sprachlernprozessen im CLIL durch Aufgabenstellungen, Methoden-Werkzeuge, Moderation und Diagnose/Rückmeldung werden ausführlich beschrieben. Die Planung einer Lernlinie in sechs Schritten wird dargestellt und erläutert. Planungsraster für CLIL-Lernlinien schließen den Beitrag ab. The article sets out the conditions for language learning in general as well as guiding principles of language learning in the subject and puts forward criteria for successfully integrated content and language learning. Based on typical language problems arising in CLIL-classrooms, the language-sensitive CLIL-classroom is defined and organisational suggestions are given. Linguistic standard situations comprise the communicative situations in the CLIL-classroom which are encountered in subject-related learning and have to be professionally mastered by the CLIL-teacher. The article extensively describes and explains a model of teaching and learning that can be used for the CLIL-classroom. It gives detailed information on managing language learning processes in CLIL by means of tasks, resources and methods as well as discourse facilitation, evaluation and feedback. In addition, a six-step lesson unit is outlined and explained. The article concludes by giving a planning matrix for CLIL lesson units.

  4. Walt Disney and Dr. Wernher von Braun

    Science.gov (United States)

    1954-01-01

    Dr. Werhner von Braun, then Chief, Guided Missile Development Operation Division at Army Ballistic Missile Agency (ABMA) in Redstone Arsenal, Alabama, was visited by Walt Disney in 1954. In the 1950's, von Braun worked with Disney Studio as a technical director, making three films about space exploration for television. A model of the V-2 rocket is in background.

  5. Von Neumann Was Not a Quantum Bayesian

    CERN Document Server

    Stacey, Blake C

    2014-01-01

    Wikipedia has claimed for over two years now that John von Neumann was the "first quantum Bayesian." In context, this reads as stating that von Neumann inaugurated QBism, the approach to quantum theory promoted by Fuchs, Mermin and Schack. This essay explores how such a claim is, historically speaking, unsupported.

  6. Kultuuriakadeemias saab kaeda Von Krahli ime tabamist

    Index Scriptorium Estoniae

    2006-01-01

    Marianne Kõrver, Jaak Kilmi, Andres Maimik, Marko Raat, Rainer Sarnet ja Arbo Tammiksaar tegid Eduard Vilde näidendist "Tabamata ime" kuus lühimängufilmi Von Krahli teatris ettekandmiseks. 25. mail tuleb Von Krahli Teater Viljandisse ja näitab teatrifilmi Kultuuriakadeemias

  7. Mixing subalgebras of finite von Neumann algebras

    CERN Document Server

    Cameron, Jan; Mukherjee, Kunal

    2010-01-01

    Jolissaint and Stalder introduced the definitions of mixing and weak mixing for von Neumann subalgebras of finite von Neumann algebras. In this paper, we study various algebraic and analytical properties of mixing and weakly mixing von Neumann subalgebras. We prove some basic results about mixing inclusions of von Neumann algebras and establish a connection between mixing properties and normalizers of von Neumann subalgebras. The special case of mixing subalgebras arising from inclusions of group von Neumann algebras finds applications to ergodic theory. For a finite von Neumann algebra $M$ and von Neumann subalgebras $A$, $B$ of $M$, we introduce a notion of weak mixing of $B\\subseteq M$ relative to $A$. If $B$ is abelian and $A\\subset B$, we show that weak mixing of $B \\subset M$ relative to $A$ is equivalent to the following property: if $x\\in M$ and $xAx^*\\subset B$ then $x\\in B$. In the general case, we show that weak mixing of $B\\subset M$ relative to $A$ is equivalent to the following property: if $x\\i...

  8. Ludwig von Mises: An Annotated Bibliography.

    Science.gov (United States)

    Gordon, David

    A 117-item annotated bibliography of books, articles, essays, lectures, and reviews by economist Ludwig von Mises is presented. The bibliography is arranged chronologicaly, and is followed by an alphabetical listing of the citations, excluding books. An index and information on the Ludwig von Mises Institute at Auburn University (Alabama) are…

  9. Quasi-CW Diode Laser End-pumped Yb3+∶GlassMicrochip Laser

    Institute of Scientific and Technical Information of China (English)

    DAI Shixun; HU Lili; LIU Zhuping; HUANG Guosong; JIANG Zhonghong; YASUKAZU Izawa

    2002-01-01

    Quasi-CW diode-pumped Yb3+∶borate glass and Yb3+∶phosphate glass microchip lasers have been reported. From Yb3+∶phosphate glass laser, the maximum average output power was 31 mW and the optical-optical conversion efficiency was 5%.The maximum average output power was 18 mW, and optical-optical conversion efficiency was 3% for Yb3+∶borate glass laser.

  10. Cyclic Electrodeposition of Yb-Bi Thin Films

    Institute of Scientific and Technical Information of China (English)

    李高仁; 柯琴芳; 童叶翔; 刘冠昆

    2004-01-01

    Deposition of Yb-Bi thin films was carried out from a nonaqueous solution by using cyclic electrodepositon.During electrodeposition the substrate potential was continuously cycled between two potentials.The effects of several factors including the potential of deposition,time of deposition and sweep rate on the Yb content in the thin films and surface morphology were studied.Experimental results indicate that the amorphous Yb-Bi thin films containing Yb 21.04%~36.36%(mass fraction)can be prepared in 0.10 mol·L-1 YbCl3+0.10 mol*L-1 Bi(NO3)3+0.10 mol·L-1 LiCl+DMSO by controlling deposition conditions of the system.They are black,uniform,metallic luster and adhered firmly to the copper substrates.The films were characterized by X-ray energy dispersive analysis(EDS),scanning electron microcoscope(SEM)and X-ray diffraction(XRD).

  11. Charge transfer in the cold Yb$^+$ + Rb collisions

    CERN Document Server

    Sayfutyarova, Elvira R; Yakovleva, Svetlana A; Belyaev, Andrey K

    2013-01-01

    Charge-transfer cold Yb$^+$ + Rb collision dynamics is investigated theoretically using high-level {\\it ab initio} potential energy curves, dipole moment functions and nonadiabatic coupling matrix elements. Within the scalar-relativistic approximation, the radiative transitions from the entrance $A^1\\Sigma^+$ to the ground $X^1\\Sigma^+$ state are found to be the only efficient charge-transfer pathway. The spin-orbit coupling does not open other efficient pathways, but alters the potential energy curves and the transition dipole moment for the $A-X$ pair of states. The radiative, as well as the nonradiative, charge-transfer cross sections calculated within the $10^{-3}-10$ cm$^{-1}$ collision energy range exhibit all features of the Langevin ion-atom collision regime, including a rich structure associated with centrifugal barrier tunneling (orbiting) resonances. Theoretical rate coefficients for two Yb isotopes agree well with those measured by immersing Yb$^+$ ion in an ultracold Rb ensemble in a hybrid trap....

  12. Towards a quantum gas of polar YbCs molecules

    Science.gov (United States)

    Freytag, R.; Petersen, M.; Hinds, E. A.; Tarbutt, M.; Butler, K.; Kemp, S.; Hopkins, S. A.; Brue, D. A.; Hutson, J. M.; Cornish, S. L.

    2013-05-01

    The potentials of ultracold polar molecules have been discussed with respect to quantum information processing and quantum simulation. This experiment focuses on the production of quantum degenerate YbCs molecules. We propose to magneto-associate the atoms over a Feshbach resonance and transfer them to the ground state using Stimulated Raman Adiabatic Passage (STIRAP). Ground state YbCs will, due to its single valence electron, exhibit an electric as well as a magnetic dipole moment. It should therefore demonstrate spin dependent interactions in addition to long-range dipole-dipole interactions. Here we outline the theoretical and experimental progress on creating a dual species Magneto-Optical Trap (MOT) of Yb and Cs. ESPRC

  13. Structure change of 156Yb at high-spin states

    Institute of Scientific and Technical Information of China (English)

    HUA Hui; LI Zhong-Yu; WANG Shou-Yu; MENG Jie; LI Zhi-Huan; LI Xiang-Qing; XU Fu-Rong; LIU Hong-Liang; ZHANG Shuang-Quan; ZHOU Shan-Gui; YE Yan-Lin; JIANG Dong-Xing; ZHENG Tao; ZHU Li-Hua; WU Xiao-Guang; LI Guang-Sheng; HE Chuang-Ye; MA Li-Ying; LU Fei; FAN Feng-Ying; HAN Li-Ying; WANG He; XIAO Jun; LI Xue-Qin; CHEN Dong; FANG Xiao; LOU Jian-Lin; LIU Ying; HAO Xin; PAN Bo; LI Li-Hua

    2009-01-01

    High-spin states of 156Yb have been studied via the 144Sm(16O,4n)156Yb fusion-evaporation reaction at beam energy 102 MeV. The positive-parity yrast band and negative-parity cascade have been extended up to higher-spin states, respectively. The characteristics of the negative-parity sequence above the 25- state may related to the excitation from the nucleon in the Z = 64, N = 82 core. The E-GOS curve for the positive-parity yrast sequence in 156Yb indicate that this nucleus may undergo an evolution from quasivibrational to quasirotational structure with increasing angular momentum. The Cranked Woods-Saxon-Strutinsky calculations by means of Total-Routhian-Surface (TRS) methods has been made to understand this structure change.

  14. Er3+-Yb3+ codoped borosilicate glass for optical thermometry

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Infrared to green up-conversion emissions centered at the wavelengths of about 524 and 550 nm of the Er3+-Yb3+ codoped borosilicate glass are recorded,using a 978 nm semiconductor laser diode(LD) as an excitation source.The fluorescence intensity ratio(FIR) of the green up-conversion emissions at about 524 and 550 nm in the Er3+-Yb3+ codoped borosilicate glass has been studied as a function of temperature over the temperature range of 295-873 K.The maximum sensitivity and the temperature resolution derived from the FIR of the green up-conversion emissions are approximately 0.0038 K-1 and 0.2 K,respectively.It is demonstrated that the prototype optical temperature sensor based on the FIR technique from the green up-conversion emissions in the Er3+-Yb3+ codoped borosilicate glass plays a major role in temperature measurement.

  15. Functional conservation of rice OsNF-YB/YC and Arabidopsis AtNF-YB/YC proteins in the regulation of flowering time

    KAUST Repository

    Hwang, Yoon-Hyung

    2016-01-11

    Plant NUCLEAR FACTOR Y (NF-Y) transcription factors play important roles in plant development and abiotic stress. In Arabidopsis thaliana, two NF-YB (AtNF-YB2 and AtNF-YB3) and five NF-YC (AtNF-YC1, AtNF-YC2, AtNF-YC3, AtNF-YC4, and AtNF-YC9) genes regulate photoperiodic flowering by interacting with other AtNF-Y subunit proteins. Three rice NF-YB (OsNF-YB8, OsNF-YB10, and OsNF-YB11) and five rice OsNF-YC (OsNF-YC1, OsNF-YC2, OsNF-YC4, OsNF-YC6, and OsNF-YC7) genes are clustered with two AtNF-YB and five AtNF-YC genes, respectively. To investigate the functional conservation of these NF-YB and NF-YC genes in rice and Arabidopsis, we analyzed the flowering phenotypes of transgenic plants overexpressing the respective OsNF-YB and OsNF-YC genes in Arabidopsis mutants. Overexpression of OsNF-YB8/10/11 and OsNF-YC2 complemented the late flowering phenotype of Arabidopsis nf-yb2 nf-yb3 and nf-yc3 nf-yc4 nf-yc9 mutants, respectively. The rescued phenotype of 35S::OsNF-YC2 nf-yc3 nf-yc4 nf-yc9 plants was attributed to the upregulation of FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1). In vitro and in planta protein–protein analyses revealed that OsNF-YB8/10/11 and OsNF-YC1/2/4/6/7 interact with AtNF-YC3/4/9 and AtNF-YB2/3, respectively. Our data indicate that some OsNF-YB and OsNF-YC genes are functional equivalents of AtNF-YB2/3 and AtNF-YC3/4/9 genes, respectively, and suggest functional conservation of Arabidopsis and rice NF-Y genes in the control of flowering time.

  16. Measurement of thermal lensing in end-pumped Yb-doped yttrium vanadate crystal and sesquioxide laser ceramics

    Science.gov (United States)

    Pestryakov, E. V.; Petrov, V. V.; Trunov, V. I.; Kirpichnikov, A. V.; Merzliakov, M. A.; Laptev, A. V.; Polyakov, K. V.

    2011-02-01

    The results of theoretical and experimental study of thermal lensing in diode-pumped Yb:YVO4 laser crystal, Yb:Y2O3 and Yb:Sc2O3 laser ceramics are presented. Shown, that influence of thermo-lensing effect is necessary to consider for creation of effective high-intensity femtosecond Yb-doped laser systems.

  17. Investigation of lasing characteristics of domestic Yb : YAG laser ceramics

    Science.gov (United States)

    Snetkov, I. L.; Palashov, O. V.; Osipov, V. V.; Mukhin, I. B.; Maksimov, R. N.; Shitov, V. A.; Luk'yashin, K. E.

    2016-07-01

    We report on the synthesis and laser characteristics of Yb3+-doped yttrium aluminium garnet (Y3Al5O12) optical ceramics. The ceramics was produced by solid-phase reactive sintering of a mixture of Yb (5 at %) : Y2O3 and Al2O3 nanopowders synthesised by laser ablation, using additional calcination of the mixture before compaction. In a thin disk geometry, multiwatt laser oscillation was obtained at a wavelength of 1030 nm with a power of 5.2 W and a slope efficiency of 37.0% at a pump pulse period-toduration ratio of 5.72.

  18. CW Yb:YAG LASER FOR PORTABLE MEASURING SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. M. Ivashko

    2014-01-01

    Full Text Available The theoretical and experimental results of longitudinally continuous-wave diode-pumped Yb:Y3Al5O12 (YAG laser performance for compact field-condition measuring systems were demonstrated. Optimization of laser setup in terms of operation condition in the range of -40 ˚С – +65 ˚С without active thermal stabilization was carried out. Using Yb (10 ат.%:YAG crystal with the length of 3 mm the maximal output power more than 2 W was obtained in the whole of temperature range.

  19. Jacob Stael von Holstein ja palladionism eesti arhitektuuris / Ants Hein

    Index Scriptorium Estoniae

    Hein, Ants, 1952-

    2005-01-01

    Sõjaväeinsenerist ja arhitektist Jacob Stael von Holsteinist (1628, Pärnu-1679), tema kavandatud hoonetest ja rollist 17. sajandi II poole arhitektuuris. Fabian von Ferseni Toompeal Lossiplatsil asunud elamust (lammutati 1894) ja Maardu mõisahoonest, Hans von Ferseni Mäo mõisahoonest Järvamaal, Otto Wilhelm von Ferseni majast Toompeal, Axel von Roseni majast Tallinnas Pikk t. 28 (1670-74), Otto Reinhold von Taube majast Tartus (hävinud), J. S. von Holsteini enda hoonetest: majast Tallinnas Toompea 1, Anija mõisahoonest, elamust Riias jm. Bibliograafia lk. 452

  20. Jacob Stael von Holstein ja palladionism eesti arhitektuuris / Ants Hein

    Index Scriptorium Estoniae

    Hein, Ants, 1952-

    2005-01-01

    Sõjaväeinsenerist ja arhitektist Jacob Stael von Holsteinist (1628, Pärnu-1679), tema kavandatud hoonetest ja rollist 17. sajandi II poole arhitektuuris. Fabian von Ferseni Toompeal Lossiplatsil asunud elamust (lammutati 1894) ja Maardu mõisahoonest, Hans von Ferseni Mäo mõisahoonest Järvamaal, Otto Wilhelm von Ferseni majast Toompeal, Axel von Roseni majast Tallinnas Pikk t. 28 (1670-74), Otto Reinhold von Taube majast Tartus (hävinud), J. S. von Holsteini enda hoonetest: majast Tallinnas Toompea 1, Anija mõisahoonest, elamust Riias jm. Bibliograafia lk. 452

  1. Properties of the divalent-Yb compound YbAu{sub 2}Si{sub 2} under extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kaštil, J.; Míšek, M.; Kamarád, J.; Arnold, Z. [Institute of Physics AS CR, v.v.i., Na Slovance 1999/2, 182 21 Prague 8 (Czech Republic); Vlášková, K. [Charles University, Faculty of Mathematics and Physics, Department of Condensed Matter Physics, Ke Karlovu 5, 12116 Prague 2 (Czech Republic); Prchal, J., E-mail: prchal@karlov.mff.cuni.cz [Charles University, Faculty of Mathematics and Physics, Department of Condensed Matter Physics, Ke Karlovu 5, 12116 Prague 2 (Czech Republic); Diviš, M.; Doležal, P.; Prokleška, J.; Valenta, J.; Fikáček, J.; Rudajevová, A.; Kriegner, D. [Charles University, Faculty of Mathematics and Physics, Department of Condensed Matter Physics, Ke Karlovu 5, 12116 Prague 2 (Czech Republic)

    2017-01-15

    Polycrystalline YbAu{sub 2}Si{sub 2} has been prepared by arc melting and a non-standard anisotropic thermal expansion is observed at low temperatures. A non-magnetic Yb{sup 2+} valence state is derived from magnetization, magnetic-susceptibility, heat-capacity and electrical-conductivity measurements in the temperature range from 0.3 to 300 K and at external pressures up to 3.2 GPa. By both experimental and theoretical investigations, YbAu{sub 2}Si{sub 2} is confirmed to be a system with a weak electron-electron correlations and a small electron-phonon interaction. Application of hydrostatic pressure does not reveal any change of state in the range of applied pressures.

  2. Existing form and effect of zirconium in pure Mg, Mg-Yb, and Mg-Zn-Yb alloys

    Institute of Scientific and Technical Information of China (English)

    YU Wenbin; HE Hong; LI Chunmei; LI Qing; LIU Zhiyi; QIN Bing

    2009-01-01

    The existing form and grain refining effects of small zirconium addition in pure Mg, Mg-Yb and Mg-Zn binary alloys, and Mg-Zn-Yb ternary alloy (ZK60-Yb) were investigated. The results show that Zr element exists mainly in single and cluster particles of pure α-Zr or Zn-Zr compounds inside grains and at grain boundaries. Only the particles located in the interior of grains can act as the nucleus for α-Mg growth and effectively promote the formation of Fine equiaxed grains. The broken and dispersed Zr-rich particles produced during the hot extrusion process can form nebulous banded structure in which these free particles may act as obstacles to dislocation motion in wrought magnesium alloys.

  3. [Von Hippel-Lindau syndrome].

    Science.gov (United States)

    Reich, H; Hollwich, F

    1984-06-01

    The von Hippel-Lindau syndrome is an autosomal dominant condition that comprises, apart from angiomas of the retina, the cerebellum, the spinal cord, and the cerebrum, also cystic and blastomatous dysplasias resulting from maldevelopment, namely cystic kidney and pancreas, hypernephroma, and pheochromocytoma. Early observers of the syndrome were the English neurologist John Hughlings Jackson (1872) and the German ophthalmologist Hugo Magnus (1874). The typical association of angiomas of the retina with the cerebellum was first described in 1905 by the Prague ophthalmologist Wilhelm Czermak, long before Lindau (1926). The fact that hypernephromas and pheochromocytomas may form parts of it characterizes the syndrome as a polyneoplastic hereditary disease and the sufferers as members of families at risk. Since the ophthalmologist is often the first to recognize this disease by direct inspection of the fundi, he is responsible for ensuring proper medical care for the affected person and his or her entire family.

  4. The Digital Von Fahrenheid Pyramid

    Science.gov (United States)

    Bura, M.; Janowski, J.; Wężyk, P.; Zięba, K.

    2017-08-01

    3D Scanners Lab from Digital Humanities Laboratory at the University of Warsaw initiated the scientific project, the purpose of which was to call attention to systematically penetrated and devastated pyramid-shaped tomb from the XVIII/XIX century, of family von Fahrenheid in Rapa in Banie Mazurskie commune (NE Poland). By conducting a series of non-invasive studies, such as 3D inventory using terrestrial laser scanning (TLS), thermal imaging, georadar measurements (around and inside the tomb) and anthropological research of mummified remains as well - the complete dataset was collected. Through the integration of terrestrial (TLS) and airborne laser scanning (ALS) authors managed to analyse the surroundings of Fahrenheid pyriamid and influence of some objects (like trees) on the condition and visibility of the Pyramids in the landscape.

  5. Neues über das Tertiär von Java und die mesozoischen Schichten von West-Borneo

    NARCIS (Netherlands)

    Martin, K.

    1888-01-01

    Die Monographie, welche unter dem Titel Die Fossilien von Java herausgegeben wird ¹), ist so weit fortgeschritten, dass sich aus den in ihr beschriebenen Gastropoden bereits eine Anzahl von Schlussfolgerungen ableiten lässt, welche für die in Bearbeitung begriffene, geologische Karte von Java von

  6. Neues über das Tertiär von Java und die mesozoischen Schichten von West-Borneo

    NARCIS (Netherlands)

    Martin, K.

    1888-01-01

    Die Monographie, welche unter dem Titel Die Fossilien von Java herausgegeben wird ¹), ist so weit fortgeschritten, dass sich aus den in ihr beschriebenen Gastropoden bereits eine Anzahl von Schlussfolgerungen ableiten lässt, welche für die in Bearbeitung begriffene, geologische Karte von Java von Be

  7. Sequential growth of sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles for photodynamic therapy

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Huang-Yong; Ding, Bin-Bin; Ma, Yin-Chu [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Sun, Shi-Qi [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Tao, Wei [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Guo, Yan-Chuan [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Guo, Hui-Chen, E-mail: ghch-2004@hotmail.com [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Yang, Xian-Zhu, E-mail: yangxz@hftu.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Qian, Hai-Sheng, E-mail: shqian@hfut.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China)

    2015-12-01

    Graphical abstract: The monodisperse elliptical NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles have been synthesized successfully by a facile sequential growth process, which can be used as transducer for photodynamic therapy of cancer cells. - Highlights: • The NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb nanoparticles have been fabricated successfully. • The as-prepared nanoparticles show strong fluorescence excited at 980 or 808 nm. • The nanoparticles were transferred into the aqueous phase via a facile process. • Photosensitizers were loaded into the composites for photodynamic therapy. - Abstract: Upconversion (UC) nanostructures have attracted much interest for their extensive biological applications. In this work, we describe a sequential synthetic route to prepare sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles. The as-prepared products were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM, JEM 2100F), respectively. The as-prepared core–shell nanoparticles of NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb are composed of elliptical nanoparticles with a length of 80 nm and width of 42 nm, which show efficient upconversion fluorescence excited at 808 nm indicating the formation of core–shell–shell sandwiched nanostructures. In addition, the as-prepared sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles also show strong upconversion fluorescence excited at 980 nm. Amphiphilic mPEG{sub 2k}-b-PEBEP{sub 6K} copolymers (denoted as PPE) were chosen to transfer these hydrophobic UCNPs into the aqueous phase for biological application. In vitro photodynamic therapy of cancer cells show that the viability of cells incubated with the nanoparticles loaded with MC 540 was significantly lower as compared to the nanoparticles without photosensitizers exposed to NIR laser.

  8. Einfluss der Koordination von Spurenelementen in Silikatschmelzen auf Verteilungsprozesse

    OpenAIRE

    Sebastian Simon

    2016-01-01

    Das Wissen um die lokale Struktur von Seltenen Erden Elementen (SEE) in silikatischen und aluminosilikatischen Schmelzen ist von fundamentalem Interesse für die Geochemie der magmatischen Prozesse, speziell wenn es um ein umfassendes Verständnis der Verteilungsprozesse von SEE in magmatischen Systemen geht. Es ist allgemein akzeptiert, dass die SEE-Verteilungsprozesse von Temperatur, Druck, Sauerstofffugazität (im Fall von polyvalenten Kationen) und der Kristallchemie kontrolliert werden. All...

  9. Charakterisierung von Radiolyseprodukten in gammabestrahlten Polyamiden Thermodesorption-Gaschromatographie Massenspekroskopie

    OpenAIRE

    Selmi, Hany

    2008-01-01

    Der Verbrauch von Polyamiden in allen technischen Bereichen, darunter im Bereich der Verpackung von Lebensmitteln sowie im Bereich der Herstellung von medizinischen Artikeln und Geräten steigt stetig an. Dies beruht auf ihren Eigenschaften wie hohe Festigkeit, ausgezeichnete Thermoformbarkeit, hohe Wärmeformbeständigkeit, Sterilisierbarkeit und sehr gute Barriereeigenschaften gegen Gase, insbesondere gegenüber Sauerstoff und Aromen. Die Anwendung von Gammastrahlen zur Sterilisation von Verpac...

  10. Growth and spectroscopic investigations of Yb,Ho: YAP and Yb,Ho,Pr:YAP laser crystals

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Huili [The Key Laboratory of Photonic Devices and Materials, Anhui Province, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230022 (China); Sun, Dunlu, E-mail: dlsun@aiofm.ac.cn [The Key Laboratory of Photonic Devices and Materials, Anhui Province, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Luo, Jianqiao [The Key Laboratory of Photonic Devices and Materials, Anhui Province, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Cao, Shihao [The Key Laboratory of Photonic Devices and Materials, Anhui Province, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Cheng, Maojie; Zhang, Qingli; Yin, Shaotang [The Key Laboratory of Photonic Devices and Materials, Anhui Province, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China)

    2015-02-15

    Yb,Ho:YAP and Yb,Ho,Pr:YAP laser crystals with high optical quality are successfully grown using the Czochralski method. The absorption coefficient and band width of the two crystals at 970 nm are increased because of the doping of Yb{sup 3+} sensitizer. The three strongest fluorescence peaks of the two crystals are located at approximately 2844, 2853, and 2912 nm, which correspond to the {sup 5}I{sub 6}→{sup 5}I{sub 7} level transitions of Ho{sup 3+} ions. Lifetime measurements indicate that the deactivator Pr{sup 3+} ions can efficiently decrease the lifetime of the lower level {sup 5}I{sub 7} from 8.848 ms to 1.258 ms. Energy-transfer mechanisms are also studied and analyzed, and up-conversion luminescence spectra provide the further evidence that Pr{sup 3+} ions can efficiently depopulate Ho{sup 3+} ions at the {sup 5}I{sub 7} level. All these results show that Yb,Ho,Pr:YAP crystal may be a promising laser medium for realizing 2.8–3.1 μm lasers pumped using a 970 nm laser diode. - Highlights: • New Yb,Ho:YAP and Yb,Ho,Pr:YAP laser crystals are grown by the CZ method. • The absorption and FWHM at 970 nm are increased due to the doping of Yb sensitizer. • The lifetime of lower laser level {sup 5}I{sub 7} decreases from 8.848 to 1.258 ms because of the doping of Pr{sup 3+} deactivator. • The up-conversion luminescence provides the further evidence that Pr{sup 3+} ions can efficiently depopulate Ho{sup 3+} ions at the {sup 5}I{sub 7}. • The Yb,Ho,Pr:YAP crystal may be a promising laser medium for realizing the 2.8–3.1 μm lasers using 970 nm LD.

  11. Electron spin resonance in Yb-based Kondo-lattice systems; Elektronenspinresonanz in Yb-basierten Kondogitter-Systemen

    Energy Technology Data Exchange (ETDEWEB)

    Wykhoff, Jan

    2010-07-07

    The systems Yb{sub 1-w}A{sub 1-w}(Rh{sub 1-x}Co{sub x})(Si{sub 1-y}Ge{sub y}){sub 2} with A=La respectively Lu, as well as YbIr{sub 2}Si{sub 2} are studied. The measurements are presented sortedly for systems, dopings, and external parameters. Beside these external parameters furthermore the orientation of the sample related to the quasistatic magnetic field and the microwave magnetic field was varied.

  12. Genome-wide analysis of the human Alu Yb-lineage

    Directory of Open Access Journals (Sweden)

    Carter Anthony B

    2004-03-01

    Full Text Available Abstract The Alu Yb-lineage is a 'young' primarily human-specific group of short interspersed element (SINE subfamilies that have integrated throughout the human genome. In this study, we have computationally screened the draft sequence of the human genome for Alu Yb-lineage subfamily members present on autosomal chromosomes. A total of 1,733 Yb Alu subfamily members have integrated into human autosomes. The average ages of Yb-lineage subfamilies, Yb7, Yb8 and Yb9, are estimated as 4.81, 2.39 and 2.32 million years, respectively. In order to determine the contribution of the Alu Yb-lineage to human genomic diversity, 1,202 loci were analysed using polymerase chain reaction (PCR-based assays, which amplify the genomic regions containing individual Yb-lineage subfamily members. Approximately 20 per cent of the Yb-lineage Alu elements are polymorphic for insertion presence/absence in the human genome. Fewer than 0.5 per cent of the Yb loci also demonstrate insertions at orthologous positions in non-human primate genomes. Genomic sequencing of these unusual loci demonstrates that each of the orthologous loci from non-human primate genomes contains older Y, Sg and Sx Alu family members that have been altered, through various mechanisms, into Yb8 sequences. These data suggest that Alu Yb-lineage subfamily members are largely restricted to the human genome. The high copy number, level of insertion polymorphism and estimated age indicate that members of the Alu Yb elements will be useful in a wide range of genetic analyses.

  13. Von Laue's theorem and its applications

    CERN Document Server

    Wang, Changbiao

    2012-01-01

    Von Laue's theorem is strictly proved in detail to clarify confusions in textbook and literature. This theorem is used to analyze the classical electron and the static electric field confined in a finite region of space.

  14. Arbeit von Frauen in Zeiten der Globalisierung

    NARCIS (Netherlands)

    D. Grunow

    2010-01-01

    Hohe Erwerbsquote, Dienstleistungsberufe und Minijobs: Die weibliche Erwerbstätigkeit hat sich in den letzten Jahrzehnten in Deutschland stark verändert. Wie hängen die Prozesse zusammen mit der Globalisierung von Wirtschaft und Arbeit?

  15. Level statistics for the even-even Yb isotopes

    Institute of Scientific and Technical Information of China (English)

    CHEN Fang-Qi; SUN Yang; ZHOU Xian-Rong

    2009-01-01

    The level statistics of the even-even Yb isotopes are studied by using the energy levels calculated by the projected shell model. The spectrum of intrinsic states and band energies are also studied to discuss the generation of chaoticity. The energy dependence of the chaoticity is investigated, and a chaos to order transition is found.

  16. Coherent combining in an Yb doped double core fiber laser

    CERN Document Server

    Boullet, Johan; Desfarges-Berthelemot, Agnès; Kermène, Vincent; Pagnoux, Dominique; Roy, Philippe; Dussardier, Bernard; Blanc, Wilfried; 10.1364/OL.30.001962

    2012-01-01

    Coherent combining is demonstrated in a clad pumped Yb doped double core fiber laser. A slope efficiency of more than 70 % is achieved with 96 % of the total output power on the fundamental mode of one of the two cores. This high combining efficiency is obtained when both cores are coupled via a biconical fused taper in a Michelson interferometer configuration.

  17. Optical properties of epitaxial YAG:Yb films

    Energy Technology Data Exchange (ETDEWEB)

    Ubizskii, S.B. [Institute for Telecommunication, Radioelectronics and Electronic Engineering, Lviv Polytechnic National University, 12, Bandera St., Lviv, 79013 (Ukraine); Matkovskii, A.O. [Institute for Telecommunication, Radioelectronics and Electronic Engineering, Lviv Polytechnic National University, 12, Bandera St., Lviv, 79013 (Ukraine); Institute of Physics, University Rzezsow, 16 Rejtana St., Rzeszow, 35310 (Poland); Melnyk, S.S.; Syvorotka, I.M. [R and D Institute for Materials, Scientific Research Company ' ' Carat' ' , 202, Stryjska St., Lviv, 79031 (Ukraine); Mueller, V.; Peters, V.; Petermann, K. [Institut fuer Laser-Physik, Universitaet Hamburg, Jungiusstrasse 9a, 20355 Hamburg (Germany); Beyertt, A.; Giesen, A. [Institut fuer Strahlwerkzeuge, Universitaet Stuttgart, Pfaffenwaldring 43, 70569 Stuttgart (Germany)

    2004-03-01

    This work deals with the investigation of the optical properties of epitaxial YAG:Yb films and their suitability as gain media for thin disk lasers. Epitaxial films of YAG:Yb were grown by the liquid phase epitaxy method in air on the (111)-oriented YAG substrates. The thickness of the grown layers was from 30 to 260 {mu}m. The melt composition was varied to obtain the desired doping level from 10 to 15% and to optimize the optical properties. The best epitaxial films were colourless and had an Yb{sup 3+} luminescence lifetime of more than 950 {mu}s, which is very close to the intrinsic lifetime of the Yb ions in the bulk YAG single crystals. These films were tested in a thin disk laser setup with 24 absorption passes of the 940 nm pumping beam. The maximum output power at 1.03 {mu}m wavelength in CW operation reached more than 60 W and the optical efficiency was close to 30%. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Graphene Q-switched Yb:KYW planar waveguide laser

    NARCIS (Netherlands)

    Kim, Jun Wan; Choi, Sun Young; Aravazhi, Shanmugam; Pollnau, Markus; Griebner, Uwe; Petrov, Valentin; Bae, Sukang; Ahn, Kwang Jun; Yeom, Dong-Il; Rotermund, Fabian

    2015-01-01

    A diode-pumped Yb:KYW planar waveguide laser, single-mode Q-switched by evanescent-field interaction with graphene, is demonstrated for the first time. Few-layer graphene grown by chemical vapor deposition is transferred onto the top of a guiding layer, which initiates stable Q-switched operation in

  19. Electronic structure of Yb/H-Si (111) interface

    Institute of Scientific and Technical Information of China (English)

    Li Hong-Nian; Wang Xiao-Xiong; He Shao-Long; Zhang Han-Jie; Li Hai-Yang; Bao Shi-Ning

    2004-01-01

    Photoemission spectra are measured for Yb covered surface of wet-chemically-etched H-Si (111). The results reveal that the lattice structure of the H-Si (111) surface is stable against the deposition of Yb atoms. X-ray photoemission spectra indicate the formation of a polarized (dipole) surface layer, with the silicon negatively charged. Ultraviolet photoemission spectra exhibit the semiconducting property of the interface below one monolayer coverage. Work function variation during the formation of the Yb/H-Si (111) interface is measured by the secondary-electron cutoff in the ultraviolet photoemission spectral line. The largest decrease of work function is~1.65eV. The contributions of the dipole surface layer and the band bending to the work function change are determined to be~1.15eV and~0.5eV,respectively. The work function of metal Yb is determined to be~2.8040.05eV.

  20. Upconversion processes in Yb-sensitized Tm:ZBLAN

    Energy Technology Data Exchange (ETDEWEB)

    Carrig, T.J. [Coherent Technologies, Inc., Lafayette, CO (United States); Cockroft, N.J. [Los Alamos National Lab., NM (United States)

    1996-10-01

    A spectroscopic study of 22 rare-earth-ion doped ZBLAN (fluorozirconate) glass was done to study feasibility of sensitizing Tm:ZBLAN with Yb to facilitate development of an efficient, conveniently pumped blue upconversion fiber laser. it was found that, under single-color pumping, 480 nm emission from Tm{sup 3+} was strongest when Yb,Tm:ZBLAN is excited at 975 nm; the strongest blue blue emission was obtained from a glass sample with 2.0 wt% Yb + 0.3 wt% Tm. Also, for weak 975 nm pump intensities, strength of blue upconversion emission can be greatly enhanced by simultaneously pumping at 785 nm. This increased upconversion efficiency is due to reduced number of energy transfer steps needed to populate the Tm{sup 3+} {sup 1}G{sub 4} energy level. Measurements of fluorescence lifetimes vs dopant concentration were also made for Yb{sup 3+}, Tm{sup 3+}, and Pr{sup 3+} transitions in ZBLAN in order to better characterize concentration quenching effects. Energy transfer between Tm{sup 3+} and Pr{sup 3+} in ZBLAN is also described.

  1. Titanisierung von Implantatoberflächen

    Science.gov (United States)

    Zimmermann, Hanngörg; Heinlein, Markus; Guldner, Norbert W.

    Titan gilt seit Jahrzehnten als einer der wichtigsten Implantatwerkstoffe in der Medizin. Neben den guten mechanischen Eigenschaften (Leichtigkeit, hohe Festigkeit etc.), besitzen Titanimplantate vor allem eine hervorragende Körperverträglichkeit, so dass die Implantate optimal in den humanen Organismus integriert werden [1]. Ist jedoch aufgrund der Anforderungen an das Implantat eine hohe Flexibilität und/ oder Elastizität gefragt, so scheidet der Werkstoff Titan aufgrund seiner spröden und unflexiblen Materialeigenschaften aus. Die Folge ist der Einsatz von Implantatmaterialien, sowohl künstlichen als auch biologischen Ursprungs, welche nicht selten eine unzureichende Biokompatibilität aufweisen und somit zu Fremdköper- und immunologischen Reaktionen und Einkapselung des Implantates führen können. Die Erhöhung der Körperverträglichkeit, eine Adaption an das biologische Umfeld und eine hohe Biokompatibilität sind demzufolge die wichtigsten Eigenschaften bei der bedarfsgerechten Herstellung von Implantaten und Implantatoberflächen. Zur Gestaltung von innovativen, biokompatiblen Oberflächen stehen unterschiedliche technische Lösungsansätze zur Verfügung. Zum einen besteht die Möglichkeit, geeignete Oberflächeneigenschaften aus dem Grundmaterial selbst zu optimieren. Dies geschieht unter anderem durch Modifikation der Werkstoffoberflächen in Form von Texturierungen und Oberflächenrauhigkeiten. Zum anderen können die Oberflächeneigenschaften unabhängig von denen des Trägermaterials gestaltet werden. Durch Funktionalisierung der Oberflächen mit geeigneten Beschichtungen oder der Zugabe von Medikamenten (Drug Eluting) werden die Kunststoffimplantate dahingehend verändert, dass eine Steigerung der Körperakzeptanz erreicht wird. Die Titanbeschichtung von Implantatoberflächen kombiniert die positiven Materialeigenschaften von Titan und Polymer.

  2. Beschichtung von Kohlenstofffasern durch Chemische Gasphasenabscheidung (CVD)

    OpenAIRE

    Schmidt, Stephan

    2005-01-01

    Der Einsatz faserverstärkter Verbundwerkstoffe mit metallischer und keramischer Matrix bietet den Vorteil von Kombination und optimaler Ausnutzung verschiedenster Werkstoffeigenschaften. Die Verwendung einer durch Kohlenstofffasern verstärkten keramischen Matrix erlangte dabei in der kürzeren Vergangenheit vermehrtes Interesse. Grundlegend für den erfolgreichen Einsatz von Faserverbundwerkstoffen ist dabei ein optimiertes Faser-Matrix-Interface, also eine "optimale" Haftung der Fasern innerha...

  3. Studien zur didaktischen Nutzung von Concept Maps

    OpenAIRE

    Jüngst, Karl Ludwig

    1995-01-01

    In einer ersten Studie wurde geprüft, ob elaborierendes Durcharbeiten von Concept Maps lerneffektiver ist als elaborierendes Durcharbeiten von analogen Texten. Es wurden 13 Exemplare in unterschiedlichen Schulfächern im Sekundarschulwesen durchgeführt. Die Versuchs- Klassen arbeiten Concept Maps zu einem bestimmten Begriff durch, die Kontrollklassen analoge Texte. Die Behaltensleistung auf einfacherem Anforderungsniveau war in den Klassen mit Concept Maps besser als in den Klassen mit Texten....

  4. Hullud päevad von Krahlis

    Index Scriptorium Estoniae

    2006-01-01

    Von Krahli Teatris mängitakse neil päevi neli korda Peeter Jalaka lavastuses Tõnu Kõrvitsa kammeroopereid "Tuliaed" ja "Mu luiged, mu mõtted", mille aluseks on luuletaja Marie Heibergi saatus. Libreto autor on Maarja Kangro. Kammerooperid tulevad lavale Von Krahli Teatri ja Nargen Opera koostöös. Esitavad Kädy Plaas, Helen Lokuta, Nargen Opera koor ja Tallinna Kammerorkester, dirigent Tõnu Kaljuste

  5. 50th birthday of Christian von Ferber

    Directory of Open Access Journals (Sweden)

    2011-06-01

    Full Text Available On May 15, 2011 Christian von Ferber - member of the Editorial Board of "Condensed Matter Physics" and renowned expert in the fields of soft matter physics and complex systems - celebrated his 50th birthday. The Editorial board of CMP, colleagues and friends warmy congratulate Christian von Ferber and wish him and his family continuing good health and to enjoy many adventures and discoveries in his future scientific travels!

  6. Charakterisierung von Wechselwirkungsprozessen in sensitiven Schichten

    OpenAIRE

    Rathgeb, Frank

    1999-01-01

    Die vorliegende Arbeit soll verschiedene Strategien aufzeigen, um eine selektive Anreicherung gasförmiger Analytmoleküle in sensitiven Schichten zu erzielen. Im Mittelpunkt des Interesses lagen hierbei pH-responsive Polymere, mikroporöse Schichten und Cyclohexapeptide. Mit den pH-responsiven Polymeren konnte eine selektive und sensitive Detektion von Ammoniak mit Nachweisgrenzen von 150 ppb erreicht werden. Die Stabilität der sensitiven Schicht konnte im Vergleich zu farbstoffdotie...

  7. Hullud päevad von Krahlis

    Index Scriptorium Estoniae

    2006-01-01

    Von Krahli Teatris mängitakse neil päevi neli korda Peeter Jalaka lavastuses Tõnu Kõrvitsa kammeroopereid "Tuliaed" ja "Mu luiged, mu mõtted", mille aluseks on luuletaja Marie Heibergi saatus. Libreto autor on Maarja Kangro. Kammerooperid tulevad lavale Von Krahli Teatri ja Nargen Opera koostöös. Esitavad Kädy Plaas, Helen Lokuta, Nargen Opera koor ja Tallinna Kammerorkester, dirigent Tõnu Kaljuste

  8. Fabrication and Lasing Property of YbYb3+-doped Double-Clad Fibers with Novel Inner Cladding

    Institute of Scientific and Technical Information of China (English)

    Ding Ning; Yang Xiang; Zhaowen Xu; Wande Fan; Yongqing Yi; Shuzhong Yuan; Xiaoyi Dong

    2003-01-01

    The Yb3+-doped double-clad fibers with novel inner cladding have been made by using MCVD process, solution-doping method and optical machining together. The laser power and slope efficiency of the fiber lasers are higher than 1.8W and 50% respectively.

  9. Positive feedback loop of YB-1 interacting with Smad2 promotes liver fibrosis.

    Science.gov (United States)

    Xiong, Panpan; Zhang, Jun; Xu, Diannan; Zhu, Jie; Li, Wenshuai; Liu, Jie; Liu, Fei

    2017-03-18

    Y-box binding protein (YB-1), known as a multifunctional cellular protein in various biological processes, was recently reported to be associated with liver fibrosis. The critical role of TGF-β/Smad signaling pathway in stimulating the transcription of fibrotic genes in fibroblasts have already been identified, however, whether and how YB-1 modulated liver fibrosis via TGF-β/Smad signaling pathway remains largely unknown. In our previous study, we proved that ectopic TGF-β was associated with YB-1 expression. Herein, by combining in vitro experiments in LX2 human hepatic stellate cells and in vivo studies by building CCl4 based mice liver fibrosis model, we showed that YB-1 and p-YB-1 were upregulated in liver fibrosis tissue, and YB-1 promoted the deposition of excess extracellular matrix. Mechanistically, Smad2, a key member in TGF-β signaling pathway, acted as a transcription factor that triggered YB-1 promoter, while on the other hand, p-YB-1 stabilized Smad2 by attenuating its ubiquitination. Knockdown of Smad2 could reduce YB-1 expression, which in turn shorter the half time of Smad2. Furthermore, the serine102 residue of YB-1 both affected its binding and stabilizing activity to Smad2. These finding demonstrated that YB-1 and Smad2 played as a positive feedback loop in promoting liver fibrosis. In conclusion, TGF-β signaling pathway may influence liver fibrosis by incorporating with YB-1, indicating that YB-1 could be a potential target for therapies against liver fibrosis.

  10. Effects of Yb3+ codoping on visible and near infrared emissions of Er3+-Yb3+ codoped AI203 powders by the sol-sol method

    Institute of Scientific and Technical Information of China (English)

    DONG Bin; SUN Min; FENG ZhiOing; SONG ZhaoYuan; LIU XiaoDong

    2008-01-01

    The 0.1 mol% Er3+ and 0-2 mol% Yb3+ codoped AI2O3 powders were prepared by the sol-gel method, and the phase structure, including only two crystalline types of doped AI2O3 phase, γ-(AI,Er, Yb)2O3 andO-(AI,Er, Yb)2O3, was detected at the sintering temperature of 1000. The visible and near infrared emissions properties depended strongly on the Yb3+ codoping, and the corresponding maximal peak intensities centered at about 523, 545, 660 and 1533 nm were obtained respectively for the 0.1 mol% Er3+ and 0.5 mol% Yb3+ codoped AI2O3 powders, which were composed of 0-(AI,Er, Yb)O3 and a smallamount of γ-(AI,Er, Yb)2O3 phases. The two-photon absorption process was responsible for the visible up-conversion emissions, and the one-photon absorption process was involved in the near infrared emissions of the Er3+-Yb3+ codoped AI2O3 powders.

  11. Activation cross sections of the {sup nat}Yb(p,xn){sup 169}Lu reaction for indirect production of the therapeutic radionuclide {sup 169}Yb

    Energy Technology Data Exchange (ETDEWEB)

    Tarkanyi, F. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), 4026 Debrecen, Bem ter 18/c (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), 1090 Brussels (Belgium); Takacs, S.; Ditroi, F. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), 4026 Debrecen, Bem ter 18/c (Hungary); Kiraly, B. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), 4026 Debrecen, Bem ter 18/c (Hungary)], E-mail: kiralyb@atomki.hu; Yamazaki, H.; Baba, M.; Mohammadi, A. [Cyclotron and Radioisotope Center (CYRIC), Tohoku University, Sendai 980-8578 (Japan); Ignatyuk, A.V. [Institute of Physics and Power Engineering (IPPE), Obninsk 249020 (Russian Federation)

    2009-09-01

    Activation cross sections of the {sup nat}Yb(p,xn){sup 169}Lu reaction have been measured for the first time up to 70 MeV to investigate the production possibility of the radionuclide {sup 169}Yb through decay of its parent {sup 169}Lu. The cross sections were measured using the stacked foil irradiation technique and gamma spectrometry. The experimental data were compared with the results of the ALICE-IPPE theoretical model code. Different production routes were compared for the internal radiotherapy related radioisotope {sup 169}Yb. Above 30 MeV proton energy the integral yield of the {sup nat}Yb(p,xn){sup 169}Lu reaction is higher than that of the earlier investigated {sup 169}Tm(p,n){sup 169}Yb, {sup 169}Tm(d,2n){sup 169}Yb, {sup nat}Er({alpha},xn){sup 169}Yb, {sup nat}Yb({alpha},x){sup 169}Lu and {sup nat}Hf(p,x){sup 169}Lu reactions at the equivalent particle energies.

  12. YB-1 overexpression promotes a TGF-β1-induced epithelial–mesenchymal transition via Akt activation

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Bin; Lee, Eun Byul; Cui, Jun; Kim, Yosup [Department of Molecular Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 406-799 (Korea, Republic of); Jang, Ho Hee, E-mail: hhjang@gachon.ac.kr [Department of Molecular Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 406-799 (Korea, Republic of); Gachon Medical Research Institute, Gil Medical Center, Gachon University, Incheon (Korea, Republic of)

    2015-03-06

    The Y-box binding protein-1 (YB-1) is a transcription/translation regulatory protein, and the expression thereof is associated with cancer aggressiveness. In the present study, we explored the regulatory effects of YB-1 during the transforming growth factor-β1 (TGF-β1)-induced epithelial-to-mesenchymal transition (EMT) in lung adenocarcinoma cells. Downregulation of YB-1 increased E-cadherin promoter activity, and upregulation of YB-1 decreased promoter activity, suggesting that the YB-1 level may be correlated with the EMT. TGF-β1 induced YB-1 expression, and TGF-β1 translocated cytosolic YB-1 into the nucleus. YB-1 overexpression promoted TGF-β1-induced downregulation of epithelial markers, upregulation of mesenchymal markers, and cell migration. Moreover, YB-1 overexpression enhanced the expression of E-cadherin transcriptional repressors via TGF-β1-induced Akt activation. Our findings afford new insights into the role played by YB-1 in the TGF-β1 signaling pathway. - Highlights: • YB-1 regulates E-cadherin expression in A549 cells. • TGF-β1 induces upregulating and nuclear localization of YB-1. • YB-1 overexpression accelerates TGF-β1-induced EMT and cell migration. • YB-1 regulates Snail and Slug expression via Akt activation.

  13. Antireflective downconversion ZnO:Er3+,Yb3+ thin film for Si solar cell applications

    Science.gov (United States)

    Elleuch, R.; Salhi, R.; Deschanvres, J.-L.; Maalej, R.

    2015-02-01

    Hexagonal wurtzite phased ZnO:Er3+/Yb3+ thin films with various Yb concentrations were deposited on Si(111) substrate by Aerosol Assisted Chemical Vapor Deposition process. Post-annealed films at 1000 °C in air atmosphere showed a crystallinity enhancement. Yb3+ (4F7/2 → 4F5/2) 1000 nm emission increased with the increase of Yb3+ concentration emanating from an Er-Yb energy transfer. The reflectance percentage of 12% was achieved in the [250-1000 nm] range, and the refractive index of 1.97 was obtained for 632 nm wavelength. These results suggest that the (3 mol. % Er, 9 mol. % Yb) codoped film is a highly efficient antireflective downconversion layer for enhancing Si solar cell efficiency.

  14. The relationship between viscosity and glass forming ability of Al-(Ni)-Yb alloy systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The dynamic viscosity of Al-Yb and Al-Ni-Yb superheated melts was measured using a torsional oscillation viscometer. The results show that the temperature dependence of viscosity fits the Arrhenius law well and the fitting factors are calculated. The amorphous ribbons of these alloys were produced by the melt spinning technique and the thermal properties were characterized by using a differential scanning calorimetry (DSC). E (the activation energy for viscous flow), which reflects the change rate of viscosity, has a good negative relation with the GFA in both Al-Yb and Al-Ni-Yb systems. However, there is no direct relation between liquidus viscosity (ηL) and GFA. The superheated fragility M can predict GFA in Al-Yb or Al-Ni-Yb alloy system.

  15. Thermal Stability and Spectroscopic Properties of Yb3+-Doped New Gallium-Lead-Germanate Glass

    Institute of Scientific and Technical Information of China (English)

    XU Shi-Qing; FENG Ai-Ming; ZHANG Li-Yan; ZHAO Shi-Long; WANG Bao-Ling; ZHANG Jue; WANG Wei; BAO Ren-Qiang

    2006-01-01

    @@ Yb3+-doped new gallium-lead-germanate glass is presented. Thermal stability, spectroscopic and laser performance parameters of the Yb3+-doped new gallium-lead-germanate glass are calculated. The results show that the Yb3+-doped new gallium-lead-germanate glass has good thermal stability (△T = 198 ℃), high stimulated emission cross section (0.79pm2), and long fluorescence lifetime (1.46ms). Compared with other Yb3+-doped glass hosts, the Yb3+-doped new gallium-lead-germanate glass has better laser performance parameters and laser properties, indicating that Yb3+-doped new gallium-lead-germanate glass is a promising laser material for short pulse generation in diode pumped lasers, short pulse generation tunable laser, high-peak power and high-average power lasers.

  16. An MRI Von Economo - Koskinas atlas.

    Science.gov (United States)

    Scholtens, Lianne H; de Reus, Marcel A; de Lange, Siemon C; Schmidt, Ruben; van den Heuvel, Martijn P

    2016-12-28

    The cerebral cortex displays substantial variation in cellular architecture, a regional patterning that has been of great interest to anatomists for centuries. In 1925, Constantin von Economo and George Koskinas published a detailed atlas of the human cerebral cortex, describing a cytoarchitectonic division of the cortical mantle into over 40 distinct areas. Von Economo and Koskinas accompanied their seminal work with large photomicrographic plates of their histological slides, together with tables containing for each described region detailed morphological layer-specific information on neuronal count, neuron size and thickness of the cortical mantle. Here, we aimed to make this legacy data accessible and relatable to in vivo neuroimaging data by constructing a digital Von Economo - Koskinas atlas compatible with the widely used FreeSurfer software suite. In this technical note we describe the procedures used for manual segmentation of the Von Economo - Koskinas atlas onto individual T1 scans and the subsequent construction of the digital atlas. We provide the files needed to run the atlas on new FreeSurfer data, together with some simple code of how to apply the atlas to T1 scans within the FreeSurfer software suite. The digital Von Economo - Koskinas atlas is easily applicable to modern day anatomical MRI data and is made publicly available online.

  17. Positive Effekte von NSAR auf den Gastrointestinaltrakt

    Directory of Open Access Journals (Sweden)

    Lang M

    2015-01-01

    Full Text Available Ein protektiver Effekt von nichtsteroidalen Antirheumatika (NSAR auf die Tumorentstehung im Kolon wird in diversen präklinischen, epidemiologischen und auch randomisierten Arbeiten postuliert. Der Hauptwirkungsmechanismus von NSAR wird der Hemmung der Prostaglandinsynthese über die Cyclooxygenasen (COX zugeschrieben. Es existieren aber auch COX-unabhängige Mechanismen. Hier wollen wir einen Überblick über die Studienlage mit Aspirin, Sulindac und COX-2-Hemmern im Hinblick auf die Entstehung von Adenomen und Kolorektalkarzinomen geben. Die Wirkung dieser Substanzen ist besonders für Patienten mit familiärer Disposition relevant, aber auch für Patienten, die NSAR oder Aspirin aufgrund anderer Indikationen einnehmen. Es bestehen Abhängigkeiten von Dosis und Zeit sowie Interaktionen mit speziellen Mutationen (BRAF, PI3K und der zellulären COX-2-Expression. Beim Lynch-Syndrom ist die Wirksamkeit von Aspirin letztlich nicht sicher und eine multinationale klinische Studie mit 5-Aminosalizylsäure (Mesalazin wurde vom europäischen TRANSCAN-Programm gefördert.

  18. The green light generation by self-frequency-doubled Yb:YCOB crystal

    CERN Document Server

    Fang, Qiannan; Zhang, Huaijin; Wang, Jiyang

    2016-01-01

    Taking advantages of the broad emission bands of a Yb3+ doped calcium yttrium oxoborate (Yb:YCOB) crystal cut along the optimized direction out of principle planes with the maximum effective nonlinear coefficient, the self-frequency-doubled green light based on the self-frequency-doubling behavior of Yb:YCOB was achieved with a maximum output power of 710 mW at 523 nm.

  19. Links between the oncoprotein YB-1 and small non-coding RNAs in breast cancer.

    Directory of Open Access Journals (Sweden)

    Cherie Blenkiron

    Full Text Available BACKGROUND: The nucleic acid-binding protein YB-1, a member of the cold-shock domain protein family, has been implicated in the progression of breast cancer and is associated with poor patient survival. YB-1 has sequence similarity to LIN28, another cold-shock protein family member, which has a role in the regulation of small noncoding RNAs (sncRNAs including microRNAs (miRNAs. Therefore, to investigate whether there is an association between YB-1 and sncRNAs in breast cancer, we investigated whether sncRNAs were bound by YB-1 in two breast cancer cell lines (luminal A-like and basal cell-like, and whether the abundance of sncRNAs and mRNAs changed in response to experimental reduction of YB-1 expression. RESULTS: RNA-immunoprecipitation with an anti-YB-1 antibody showed that several sncRNAs are bound by YB-1. Some of these were bound by YB-1 in both breast cancer cell lines; others were cell-line specific. The small RNAs bound by YB-1 were derived from various sncRNA families including miRNAs such as let-7 and miR-320, transfer RNAs, ribosomal RNAs and small nucleolar RNAs (snoRNA. Reducing YB-1 expression altered the abundance of a number of transcripts encoding miRNA biogenesis and processing proteins but did not alter the abundance of mature or precursor miRNAs. CONCLUSIONS: YB-1 binds to specific miRNAs, snoRNAs and tRNA-derived fragments and appears to regulate the expression of miRNA biogenesis and processing machinery. We propose that some of the oncogenic effects of YB-1 in breast cancer may be mediated through its interactions with sncRNAs.

  20. Ytterbium Doped Gadolinium Oxide (Gd2O3:Yb3+) Phosphor: Topology, Morphology, and Luminescence Behaviour

    OpenAIRE

    Raunak Kumar Tamrakar; Durga Prasad Bisen; Chandra Shekher Robinson; Ishwar Prasad Sahu; Nameeta Brahme

    2014-01-01

    Gd2O3:Yb3+ phosphor has been synthesized by the solid state reaction method with boric acid used as a flux. The resulting Gd2O3:Yb3+ phosphor was characterized by X-ray diffraction (XRD) technique, Fourier transmission infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM), and photoluminescence and thermoluminescence. The results of the XRD show that obtained Gd2O3:Yb3+ phosphor has a cubic structure. The average crystallite sizes could...

  1. Doença de von Willebrand e anestesia Enfermedad de von Willebrand y anestesia Von Willebrand's disease and anesthesia

    Directory of Open Access Journals (Sweden)

    Fabiano Timbó Barbosa

    2007-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: A doença de von Willebrand ocorre devido à mutação no cromossomo 12 e é caracterizada por deficiência qualitativa ou quantitativa do fator de von Willebrand. A diversidade de mutações leva ao aparecimento das mais variadas manifestações clínicas possibilitando a divisão dos pacientes em vários tipos e subtipos clínicos. A coagulopatia se manifesta basicamente através da disfunção plaquetária associada à diminuição dos níveis séricos do fator VIII coagulante. O objetivo dessa revisão foi mostrar os cuidados relacionados aos pacientes portadores da doença de von Willebrand durante o período perioperatório. CONTEÚDO: Foram definidas as características da doença de von Willebrand quanto à fisiopatologia, à classificação, ao diagnóstico laboratorial, ao tratamento atual e aos cuidados com o manuseio do paciente no período perioperatório. CONCLUSÕES: A doença de von Willebrand é o distúrbio hemorrágico hereditário mais comum, porém ela é subdiagnosticada pela complexidade da própria doença. A correta classificação do paciente, o uso apropriado da desmopressina e a transfusão do fator de von Willebrand são medidas fundamentais para a realização do procedimento anestésico bem-sucedido.JUSTIFICATIVA Y OBJETIVOS: La enfermedad de von Willebrand ocurre debido a la mutación en el cromosoma 12 y se caracteriza por la deficiencia cualitativa o cuantitativa del factor de von Willebrand. La diversidad de mutaciones conlleva al aparecimiento de las más variadas manifestaciones clínicas posibilitando la división de los pacientes en varios tipos y subtipos clínicos. La coagulopatía se manifiesta básicamente a través de la disfunción plaquetaria asociada con la disminución de los niveles séricos del factor VIII coagulante. El objetivo de esa revisión fue mostrar los cuidados relacionados con las pacientes portadoras de la enfermedad de von Willebrand durante el per

  2. p-Wave cold collisions in a Yb lattice clock

    CERN Document Server

    Lemke, N D; von Stecher, J; Sherman, J A; Rey, A M; Oates, C W

    2011-01-01

    State-of-the-art optical clocks with neutral atoms employ an optical lattice to tightly confine the atoms, enabling high-resolution spectroscopy and the potential for high-accuracy timekeeping. Interrogating many atoms simultaneously facilitates high measurement precision, but also yields high atomic density and the potential for cold collisions. To suppress these atom-atom interactions, the use of ultracold, spin-polarized fermions was proposed to exploit the Fermi suppression of s-wave collisions while freezing out higher-wave contributions. However, small collision shifts have been measured in Sr and Yb. For Sr, the shifts were attributed to s-wave interactions enabled by excitation inhomogeneity. Here, we report definitive experimental evidence and a quantitative theoretical treatment of p-wave collisions in Yb. We also demonstrate a novel suppression of the collisional frequency shift utilizing strong interactions in a two-dimensional optical lattice. Understanding these interactions and dynamics for two...

  3. Kerttu Wagner. Die historischen romane von Jaan Kross / Wolfgang Drechsler

    Index Scriptorium Estoniae

    Drechsler, Wolfgang, 1963-

    2001-01-01

    Arvustus: Wagner, Kerttu. Die historischen Romane von Jaan Kross : am Beispiel einer Untersuchung der deutschen und englischen Übersetzungen von "Professor Martensi ärasõit" (1984). Frankfurt am Main [etc.] : P. Lang, 2001.

  4. Kerttu Wagner. Die historischen romane von Jaan Kross / Wolfgang Drechsler

    Index Scriptorium Estoniae

    Drechsler, Wolfgang, 1963-

    2001-01-01

    Arvustus: Wagner, Kerttu. Die historischen Romane von Jaan Kross : am Beispiel einer Untersuchung der deutschen und englischen Übersetzungen von "Professor Martensi ärasõit" (1984). Frankfurt am Main [etc.] : P. Lang, 2001.

  5. Von Willebrand's disease: case report and review of literature ...

    African Journals Online (AJOL)

    Abstract. Von Willebrand Disease (VWD) is the most common human ... The most bleeding forms of VWD usually do not concern type 1 patients with the ... and collagen binding test and genanalysis allow diagnosing the different types of von.

  6. Gemeinsam hilfreich oder einsam lästig? Beurteilung von praktikumsbegleitenden Weblogs von angehenden Lehrpersonen

    Directory of Open Access Journals (Sweden)

    Nives Egger

    2017-02-01

    Full Text Available Weblogs werden an Hochschulen vermehrt zur Unterstützung von Lern- und Reflexionsprozessen eingesetzt, in der Lehrer/innenbildung auch zunehmend während der berufspraktischen Ausbildung. Die Studierenden beurteilen den Einsatz von Weblogs jedoch unterschiedlich. Dabei ist wenig bekannt, welchen Einfluss die Vergabe und das Erhalten von Peerfeedback auf den Beurteilungsprozess von praktikumsbegleitenden Weblogs sowie auf den Umfang von Blogpostings haben. Im folgenden Beitrag wird dieser Frage mittels einer Befragung von 74 angehenden Lehrpersonen nachgegangen, die praktikumsbegleitende Weblogs mit oder ohne Peerfeedback nutzten, um über herausfordernde Ereignisse im Praktikum zu reflektieren. Die Ergebnisse zeigen, dass Studierende, die Peerfeedback erhielten und andere Blogbeiträge kommentierten, den Weblogeinsatz nützlicher einschätzen sowie eine höhere Motivation und positivere Einstellung gegenüber den Einsatz von Weblogs aufweisen als Studierende, die ohne Peerfeedback bloggen. Keinen Einfluss hat Peerfeedback auf den Umfang der Blogbeiträge und auf die dafür aufgewendete Zeit.

  7. X-RAY ABSORPTION SPECTROSCOPY OF YB3+-DOPED OPTICAL FIBERS

    Energy Technology Data Exchange (ETDEWEB)

    Citron, Robert; Kropf, A.J.

    2008-01-01

    Optical fibers doped with Ytterbium-3+ have become increasingly common in fiber lasers and amplifiers. Yb-doped fibers provide the capability to produce high power and short pulses at specific wavelengths, resulting in highly effective gain media. However, little is known about the local structure, distribution, and chemical coordination of Yb3+ in the fibers. This information is necessary to improve the manufacturing process and optical qualities of the fibers. Five fibers doped with Yb3+ were studied using Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy and X-ray Absorption Near Edge Spectroscopy (XANES), in addition to Yb3+ mapping. The Yb3+ distribution in each fiber core was mapped with 2D and 1D intensity scans, which measured X-ray fluorescence over the scan areas. Two of the five fibers examined showed highly irregular Yb3+ distributions in the core center. In four of the five fibers Yb3+ was detected outside of the given fiber core dimensions, suggesting possible Yb3+ diffusion from the core, manufacturing error, or both. X-ray absorption spectroscopy (XAS) analysis has so far proven inconclusive, but did show that the fibers had differing EXAFS spectra. The Yb3+ distribution mapping proved highly useful, but additional modeling and examination of fiber preforms must be conducted to improve XAS analysis, which has been shown to have great potential for the study of similar optical fi bers.

  8. Yb-based heavy fermion compounds and field tuned quantum chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Mun, Eundeok [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    The motivation of this dissertation was to advance the study of Yb-based heavy fermion (HF) compounds especially ones related to quantum phase transitions. One of the topics of this work was the investigation of the interaction between the Kondo and crystalline electric field (CEF) energy scales in Yb-based HF systems by means of thermoelectric power (TEP) measurements. In these systems, the Kondo interaction and CEF excitations generally give rise to large anomalies such as maxima in ρ(T) and as minima in S(T). The TEP data were use to determine the evolution of Kondo and CEF energy scales upon varying transition metals for YbT2Zn20 (T = Fe, Ru, Os, Ir, Rh, and Co) compounds and applying magnetic fields for YbAgGe and YbPtBi. For YbT2Zn20 and YbPtBi, the Kondo and CEF energy scales could not be well separated in S(T), presumably because of small CEF level splittings. A similar effect was observed for the magnetic contribution to the resistivity. For YbAgGe, S(T) has been successfully applied to determine the Kondo and CEF energy scales due to the clear separation between the ground state and thermally excited CEF states. The Kondo temperature, TK, inferred from the local maximum in S(T), remains finite as magnetic field increases up to 140 kOe. In this dissertation we have examined the heavy quasi-particle behavior, found near the field tuned AFM quantum critical point (QCP), with YbAgGe and YbPtBi. Although the observed nFL behaviors in the vicinity of the QCP are different between YbAgGe and YbPtBi, the constructed H-T phase diagram including the two crossovers are similar. For both YbAgGe and YbPtBi, the details of the quantum criticality turn out to be complicated. We expect that YbPtBi will provide an additional example of field tuned quantum criticality, but clearly there are further experimental investigations left and more ideas needed to understand the basic physics of field-induced quantum

  9. The Cold Shock Domain of YB-1 Segregates RNA from DNA by Non-Bonded Interactions.

    Directory of Open Access Journals (Sweden)

    Vladislav Kljashtorny

    Full Text Available The human YB-1 protein plays multiple cellular roles, of which many are dictated by its binding to RNA and DNA through its Cold Shock Domain (CSD. Using molecular dynamics simulation approaches validated by experimental assays, the YB1 CSD was found to interact with nucleic acids in a sequence-dependent manner and with a higher affinity for RNA than DNA. The binding properties of the YB1 CSD were close to those observed for the related bacterial Cold Shock Proteins (CSP, albeit some differences in sequence specificity. The results provide insights in the molecular mechanisms whereby YB-1 interacts with nucleic acids.

  10. A MAGNUS EXPANSION FOR THE EQUATION Y′ = AY - YB

    Institute of Scientific and Technical Information of China (English)

    Arieh Iserles

    2001-01-01

    The subject matter of this paper is the representation of the solution of the linear differential equation Y′ = AY - YB, Y(O) = Yo, in the form Y(t) = eΩ(t)Yo and the representation of the function Ω as a generalisation of the classical Magnus expansion.An immediate application is a new recursive algorithm for the derivation of the BakerCampbell-Hausdorff formula and its symmetric generalisation.

  11. Diode-pumped Yb3+:KYF4 femtosecond laser.

    Science.gov (United States)

    Coluccelli, Nicola; Galzerano, Gianluca; Tonelli, Mauro; Laporta, Paolo; Svelto, Orazio

    2008-05-15

    Passive mode locking of a diode-pumped Yb(3+):KYF(4) laser is demonstrated using a semiconductor saturable absorber mirror. A high-stability, transform-limited pulse train with a repetition rate of 57 MHz is generated. Solitonlike pulses with maximum average output power of 250 mW, minimum pulse duration of 170 fs, and rms time jitter of 360 fs were obtained.

  12. Efficient lasing in Yb:(YLa)2O3 ceramics

    Science.gov (United States)

    Snetkov, I. L.; Mukhin, I. B.; Balabanov, S. S.; Permin, D. A.; Palashov, O. V.

    2015-02-01

    A high-optical-quality sample of Yb0.1Y1.7La0.2O3 ceramics is prepared using a recently developed technique of selfpropagating high-temperature synthesis of rare-earth-doped yttrium oxide nanopowder from acetate - nitrates of metals. Its optical and spectral characteristics are studied, and quasi-cw lasing at a wavelength of 1033 nm is achieved with a power of 7 W and a slope efficiency of 25%.

  13. Liouville-von Neumann molecular dynamics

    Science.gov (United States)

    Jakowski, Jacek; Morokuma, Keiji

    2009-06-01

    We present a novel first principles molecular dynamics scheme, called Liouville-von Neumann molecular dynamics, based on Liouville-von Neumann equation for density matrices propagation and Magnus expansion of the time-evolution operator. The scheme combines formally accurate quantum propagation of electrons represented via density matrices and a classical propagation of nuclei. The method requires a few iterations per each time step where the Fock operator is formed and von Neumann equation is integrated. The algorithm (a) is free of constraint and fictitious parameters, (b) avoids diagonalization of the Fock operator, and (c) can be used in the case of fractional occupation as in metallic systems. The algorithm is very stable, and has a very good conservation of energy even in cases when a good quality conventional Born-Oppenheimer molecular dynamics trajectories is difficult to obtain. Test simulations include initial phase of fullerene formation from gaseous C2 and retinal system.

  14. Gasification of liquid manure; Vergasung von Guelle

    Energy Technology Data Exchange (ETDEWEB)

    Gudenau, H.W.; Hoberg, H.; Hirsch, U. [Technische Hochschule Aachen (Germany). Inst. fuer Eisenhuettenkunde

    1996-12-31

    The potential of thermal use of liquid manure is investigated. It is recommended to separate the liquid and solid fraction. While the liquid fraction can be used as fertilizer, the solid fraction can be used for generating a fuel gas for combined heat and power generation. (orig) [Deutsch] Die Untersuchungen haben ergeben, dass in der thermischen Verwertung von Guelle ein bisher nur wenig genutztes Potential vorliegt. Die zum Anbau von Getreide notwendige Duengung kann durch Separation von Guelle in Fest- und Duennfraktion effektiver und kostenguenstiger durchgefuehrt werden. Der Naehrstoffgehalt des Guellefeststoffs sollte durch thermische Aufbereitung aufkonzentriert werden, so dass eine Vermarktung auch mit laengeren Transpoertwegen darstellbar ist. Die bei der thermischen Behandlung gewonnene Waerme kann prozessintern genutzt und ueberschuessige Waerme an Abnehmer in der naeheren Umgebung geliefert werden. Genauso besteht die Moeglichkeit, ein Brenngas zu erzeugen und die Energie mit Kraft-Waerme-Kopplung zu nutzen. (orig)

  15. Multivariate Herkunftsanalyse von Marmor auf petrographischer und geochemischer Basis

    OpenAIRE

    Cramer, Thomas

    2004-01-01

    Am Beispiel von aus Kleinasien stammenden Grabungsfunden in der Antikensammlung Berlin wird die Methodik der Herkunftsanalyse von Marmoren, d.h. der Zuordnung zu ihren Lagerstätten, weiterentwickelt und erprobt. Dazu wird der aktuelle Forschungsstand kritisch gewürdigt, die Voraussetzungen, Bedingungen und Grenzen der Provenienzbestimmung werden systematisiert und von den zahlreichen Gesteinsmerkmalen und Untersuchungsmethoden die geeignetsten ausgewählt. Marmore von 38 Sammlungsobjekten, die...

  16. Experimentelle Untersuchung von Konzentrations- und Verweilzeiteffekten in Membranreaktoren

    OpenAIRE

    Tota, A.; Hamel, C.; Thomas, S.; Joshi, M.; Klose, F.; Seidel-Morgenstern, A.

    2003-01-01

    Heterogen katalysierte Oxidationsreaktionen von kurzkettigen Kohlenwasserstoffen werden in der Industrie zur Erzeugung von Ausgangsmaterialien für wertvollere Syntheseprodukte (selektive Oxidation) oder zur Entsorgung von Abgasen eingesetzt. Bei selektiven Oxidationen ist das gewünschte Produkt gewöhnlich ein thermodynamisch instabiles Zwischenprodukt. Mit dem Einsatz von Membranreaktoren verspricht man sich hohe Selektivitäten. bei gleichzeitig hohen Ausbeuten. Als Modellreaktion für systema...

  17. Comparative toxicity of nanoparticulate/bulk Yb₂O₃ and YbCl₃ to cucumber (Cucumis sativus).

    Science.gov (United States)

    Zhang, Peng; Ma, Yuhui; Zhang, Zhiyong; He, Xiao; Guo, Zhi; Tai, Renzhong; Ding, Yayun; Zhao, Yuliang; Chai, Zhifang

    2012-02-01

    With the increasing utilization of nanomaterials, there is a growing concern for the potential environmental and health effects of them. To assess the environmental risks of nanomaterials, better knowledge about their fate and toxicity in plants are required. In this work, we compared the phytotoxicity of nanoparticulate Yb(2)O(3), bulk Yb(2)O(3), and YbCl(3)·6H(2)O to cucumber plants. The distribution and biotransformation of the three materials in plant roots were investigated in situ by TEM, EDS, as well as synchrotron radiation based methods: STXM and NEXAFS. The decrease of biomass was evident at the lowest concentration (0.32 mg/L) when exposed to nano-Yb(2)O(3), while at the highest concentration, the most severe inhibition was from YbCl(3). The inhibition was dependent on the actual amount of toxic Yb uptake by the cucumber plants. In the intercellular regions of the roots, Yb(2)O(3) particles and YbCl(3) were all transformed to YbPO(4). We speculate that the dissolution of Yb(2)O(3) particles induced by the organic acids exuded from roots played an important role in the phytotoxicity. Only under the nano-Yb(2)O(3) treatment, YbPO(4) deposits were found in the cytoplasm of root cells, so the phytotoxicity might also be attributed to the Yb internalized into the cells.

  18. Nanostructured Yb:GGG polycrystalline powders via gel combustion method

    Institute of Scientific and Technical Information of China (English)

    HUANG Dexin; ZHANG Xuejian; LIU Jinghe; ZHANG Dan

    2009-01-01

    Gadolinium gallium garnet (GGG) nanopowders doped with ytterbium ions (Yb:GGG) were synthesized with citric acid as a fuel via gel combustion method. The optimized conditions for preparing Yb3+:Gd3Ga5O12 nanopowders were discussed. The heat behavior, struc-ture and morphology of powders were analyzed with thermal analysis (TG-DTA), X-ray diffraction (XRD), infrared spectra (IR) and trans-mission electron microscope (TEM). TG-DTA analysis revealed that the weight loss of the precursor occured below 800 ℃ and its crystalli-zation temperature was 830.6 ℃. XRD and IR analysis showed that the precursor converted directly into pure GGG at a relatively lower tem-perature (900 ℃) without any other intermediate phase. The lattice constant was 1.2377 calculated by extrapolation method. TEM results in-dicated that the spherical powders showed good dispersity and had a relatively narrow size distribution with average particle size of approxi-mately 40-50 nm, which was favorable for good sinterability of Yb:GCG laser ceramic.

  19. Approximate equivalence in von Neumann algebras

    Institute of Scientific and Technical Information of China (English)

    DING; Huiru; Don; Hadwin

    2005-01-01

    One formulation of D. Voiculescu's theorem on approximate unitary equivalence is that two unital representations π and ρ of a separable C*-algebra are approximately unitarily equivalent if and only if rank o π = rank o ρ. We study the analog when the ranges of π and ρ are contained in a von Neumann algebra R, the unitaries inducing the approximate equivalence must come from R, and "rank" is replaced with "R-rank" (defined as the Murray-von Neumann equivalence of the range projection).

  20. Von Mumien, Cyborgs und Röntgenbildern

    Directory of Open Access Journals (Sweden)

    Regina Schleicher

    2004-03-01

    Full Text Available Unter dem Titel Techniken der Reproduktion liegt ein Sammelband vor, der die Beiträge einer Tagung an der Universität Paderborn vom Dezember 2001 enthält. In enger Verknüpfung verschiedener disziplinärer Perspektiven werden Schlaglichter auf eine Vielzahl von Themen geworfen, die sich mit dem Begriff „Reproduktion“ verbinden. Dabei wird deutlich, wie eng die Geschichte der Medien und die Entwicklung von Technologien der biologischen Fortpflanzung miteinander verzahnt sind.

  1. Verwertung von Prozessbieren in der Brauerei

    OpenAIRE

    Schneeberger, Mark

    2007-01-01

    Die betriebsinterne Verwertung von Prozessbieren (PB) zur Minimierung des Bierschwandes stellt den Kern der Arbeit dar. Als mengenmäßig bedeutsamste PB haben sich Hefebiere (HB), Vor-, Zwischen- und Nachläufe (VZNL) aus der Filtration, Biere aus unterfüllten bzw. falsch etikettierten Flaschen aus der Abfüllung sowie Rückbiere herausgestellt. Verschiedene Indikatoren in Hefezellen und im HB wurden zur Kontrolle von Hefebierrückgewinnungsanlagen ermittelt. Um eine hohe Qualität der wiedergewinn...

  2. [Anja Wilhelmi. Lebensweltlen von Frauen der deutschen Oberschicht im Baltikum (1800-1939). Eine Untersuchung anhand von Autobiographien] / Alexander Ewig

    Index Scriptorium Estoniae

    Ewig, Alexander, 1980-

    2011-01-01

    Arvustus: Wilhelmi, Anja. Lebenswelten von Frauen der deutschen Oberschicht im Baltikum (1800-1939). Eine Untersuchung anhand von Autobiographien. (Veröffentlichungen des Nordost-Instituts, 10.) (Wiesbaden : HArrassowitz 2008)

  3. [Anja Wilhelmi. Lebensweltlen von Frauen der deutschen Oberschicht im Baltikum (1800-1939). Eine Untersuchung anhand von Autobiographien] / Alexander Ewig

    Index Scriptorium Estoniae

    Ewig, Alexander, 1980-

    2011-01-01

    Arvustus: Wilhelmi, Anja. Lebenswelten von Frauen der deutschen Oberschicht im Baltikum (1800-1939). Eine Untersuchung anhand von Autobiographien. (Veröffentlichungen des Nordost-Instituts, 10.) (Wiesbaden : HArrassowitz 2008)

  4. Updated level scheme of 172Yb from 171Yb(nth, γ) reaction studied via gamma-gamma coincidence spectrometer

    Science.gov (United States)

    Nguyen, Ngoc Anh; Nguyen, Xuan Hai; Pham, Dinh Khang; Nguyen, Quang Hung; Ho, Huu Thang

    2017-08-01

    This paper provides the updated information on the level scheme of 172Yb nucleus studied via 171Yb(nth, γ) reaction using the gamma-gamma coincidence spectrometer at Dalat Nuclear Research Institute (Viet Nam). The latter is used because of its advantages in achieving the low Compton background as well as in identifying the correlated gamma transitions. We have detected in total the energies and intensities of 128 two-step gamma cascades corresponding to 79 primary transitions. By comparing the measured data with those extracted from the ENSDF library, 61 primary gamma transitions and corresponding energy levels together with 20 secondary gamma transitions are found to be the same as the ENSDF data. Beside that, 18 additional primary gamma transitions and corresponding energy levels plus 108 secondary ones are not found to currently exist in this library and they are therefore considered as the new data.

  5. Spectral properties of hydrothermally-grown Nd:LuAG, Yb:LuAG, and Yb:Lu{sub 2}O{sub 3} laser materials

    Energy Technology Data Exchange (ETDEWEB)

    Brown, David C., E-mail: DBrown@snakecreeklasers.com [Snake Creek Lasers LLC, Friendsville, PA 18818 (United States); McMillen, Colin D.; Moore, Cheryl; Kolis, Joseph W. [Department of Chemistry and Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634-0973 (United States); Envid, Victoria [Snake Creek Lasers LLC, Friendsville, PA 18818 (United States)

    2014-04-15

    We have investigated the hydrothermal growth of, and spectrally characterized, the lutetium based laser materials Nd:LuAG, Yb:LuAG, and Yb:Lu{sub 2}O{sub 3}. Absorption cross-section data are presented for Nd:LuAG at 83, 175, and 295 K. Absorption cross-section data was also obtained for Yb:LuAG at 83, 175, and 295 K; the 295 K data was used to generate emission cross-sections using the method of reciprocity. For Yb:Lu{sub 2}O{sub 3}, we present absorption cross-sections at 295 K as well as emission cross-sections derived using reciprocity. -- Highlights: • We present spectral properties for hydrothermally-grown laser crystals. • Absorption cross-section data are presented for Nd:LuAG and Yb:LuAG at 83, 175, and 295 K. • Emission cross-sections are presented for Yb:LuAG at 295 K derived by reciprocity. • We present absorption cross-sections at 295 K as well as emission cross-sections derived using reciprocity for the laser material Yb:Lu{sub 2}O{sub 3}.

  6. Single crystal growth of the heavy fermion compounds YbRh{sub 2}Si{sub 2} and YbNi{sub 4}P{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Butzke, Constantin; Kliemt, Kristin; Krellner, Cornelius [Physikalisches Institut, Goethe Universitaet Frankfurt, 60438 Frankfurt am Main (Germany)

    2015-07-01

    Heavy fermion systems are model systems to unravel the exciting physics around quantum-phase transitions. Studying these emergent phenomena necessitates the preparation of large and high-quality single crystals. We report on the optimization of the single crystal growth for two Yb-based quantum critical materials, YbRh{sub 2}Si{sub 2} and YbNi{sub 4}P{sub 2}. The prototype heavy-fermion system YbRh{sub 2}Si{sub 2} is situated extremely close to an unconventional antiferromagnetic (AF) quantum critical point (QCP). The AF ordering (T{sub N} = 70 mK) can be further lowered by chemically induced negative pressure using Ir-substitution. The QCP is reached for an Ir-substitution of x ∼ 0.1 in Yb(Rh{sub 1-x}Ir{sub x}){sub 2}Si{sub 2}. Here, we report on the optimization of the crystal growth of the substitution series as well as of the unsubstituted compound. We also report on our attempts to determine the melting point of YbRh{sub 2}Si{sub 2} and present a phase analysis of the molten compound. In the heavy fermion metal, YbNi{sub 4}P{sub 2}, a ferromagnetic (FM) transition at T{sub C} = 0.17 K was observed recently and a FM QCP is reached at x ∼ 0.1 in YbNi{sub 4}(P{sub 1-x}As{sub x}){sub 2}. We report on the crystal growth of YbNi{sub 4}P{sub 2} by Czochralski method out of a Ni-P flux from a levitated melt. The obtained crystals were characterized by Laue X-ray scattering, X-ray powder diffraction, EDX microprobe analysis and resistivity measurements.

  7. Die Verteilung und Eigenschaften von Bodenformen in der Deutschen Bucht, eine Rekonstruktion der Karten von Ulrich (1973)

    DEFF Research Database (Denmark)

    Winter, Christian; Lefebvre, Alice; Benninghoff, Markus

    2015-01-01

    Entstehung, Gestalt und Dynamik von Bodenformen in vergleichsweise kleinen Untersuchungsgebieten ist die Arbeit von ULRICH (1973) über die Verteilung von Bodenformen in der Deutschen Bucht bis heute die einzige verfügbare zusammenhängende Darstellung für die deutsche Nordseeküste. Die analogen Karten und die...

  8. Prognostic association of YB-1 expression in breast cancers: a matter of antibody.

    Directory of Open Access Journals (Sweden)

    Adele G Woolley

    Full Text Available The literature concerning the subcellular location of Y-box binding protein 1 (YB-1, its abundance in normal and cancer tissues, and its prognostic significance is replete with inconsistencies. An explanation for this could be due in part to the use of different antibodies in immunohistochemical and immunofluorescent labeling of cells and tissues. The inconsistencies could also be due to poor resolution of immunohistochemical data. We analyzed two cohorts of breast tumours for both abundance and subcellular location of YB-1 using three different antibodies; two targeting N-terminal epitopes (AB-a and AB-b and another (AB-c targeting a C-terminal epitope. We also investigated stress-induced nuclear translocation of YB-1 in cell culture. We report that both AB-a and AB-c detected increased YB-1 in the cytoplasm of high-grade breast cancers, and in those lacking estrogen and progesterone receptors; however the amount of YB-1 detected by AB-a in these cancers is significantly greater than that detected by AB-c. We confirm our previously published findings that AB-b is also detecting hnRNP A1, and cannot therefore be used to reliably detect YB-1 by immunohistochemistry. We also report that AB-a detected nuclear YB-1 in some tumour tissues and stress treated cells, whereas AB-c did not. To understand this, cancer cell lines were analyzed using native gel electrophoresis, which revealed that the antibodies detect different complexes in which YB-1 is a component. Our data suggest that different YB-1 antibodies show different staining patterns that are determined by the accessibility of epitopes, and this depends on the nature of the YB-1 complexes. It is important therefore to standardize the protocols if YB-1 is to be used reproducibly as a prognostic guide for different cancers.

  9. Herstellung von Bio-Fleisch- und Wurstwaren ohne Einsatz von Pökelstoffen

    OpenAIRE

    2008-01-01

    Bei der ökologischen Herstellung von Fleisch- und Wurstwaren werden vielfach auf die in der konventionellen Wurstherstellung verwendeten Konservierungsstoffe E 250 (Natriumnitrit) bzw. E 252 (Kaliumnitrat) verzichtet oder reduzierte Zugabemengen der Zusatzstoffe verwendet.

  10. Der Briefwechsel zwischen Alexander von Humboldt und Karl Ernst von Baer

    Directory of Open Access Journals (Sweden)

    Thomas Schmuck

    2012-10-01

    Full Text Available Zusammenfassung Der kurze, nicht vollständig erhaltene Briefwechsel zwischen Alexander von Humboldt und Karl Ernst von Baer behandelt sehr verschiedene Themen: Politik, Kriegsgefahr, den Wissenschaftsbetrieb, Auszeichnungen und Tagungen, Embryologie und Cholera. Gemeinsam mit Briefen und Reden ergibt sich dabei ein differenziertes Bild der Beurteilung der beiden Wissenschaftler durch den jeweils anderen. Während Baer sich als Bewunderer Humboldts erweist, erscheint umgekehrt Humboldts Einschätzung Baers als ambivalent. Abstract The short, not completely preserved correspondence between Alexander von Humboldt and Karl Ernst von Baer deals with a wide range of subjects: politics and the danger of war, academic activities, scientific awards and conferences, aspects of embryology and the cholera. Letters to third persons and speeches, together with the correspondence between Humboldt and Baer show a differentiated pattern of mutual appraisal: While Baer always remained an admirer of the elder naturalist, Humboldt’s estimation was characterized by ambivalence.

  11. Von der Medienwirkungsbehauptung zur erziehungswissenschaftlichen Medienrezeptionsforschung. Vorschlag zur Analyse von Filmkommunikaten

    Directory of Open Access Journals (Sweden)

    Barbara Drinck

    2001-04-01

    Full Text Available Im Hinblick auf die Erforschung spezifischer Zusammenhänge von Medienkonsum und der Herausbildung von Einstellungen und Handlungen wird eine konstruktivistische Theorieorientierung plausibilisiert, indem zunächst auf den Stand der Medienwirkungsforschung eingegangen und vor dem Hintergrund einer begründeten Kritik des Wirkungsverständnisses auf die Notwendigkeit einer medienrezeptionswissenschaftlichen Forschungsalternative hingewiesen wird. Weiterhin wird der Stand der (erziehungswissenschaftlichen Medienrezeptionsforschung erörtert. Sodann werden Elemente einer konstruktivistischen Methodologie von Medienrezeptionsforschung beschrieben, die am Beispiel der Rezeption von Filmen konkretisiert werden. Dabei wird das Konzept des Kommunikates (S.J. Schmidt als Ausgangspunkt genommen, ein Vorschlag für eine Beschreibungssprache für (Film- Kommunikate entwickelt und eine Adaption des Ansatzes filmischer Narration zur Sprache gebracht.

  12. Auswirkung von Umweltchemikalien auf die Biologie von Chironomiden und Fischen als deren Prädatoren

    OpenAIRE

    Langer-Jaesrich, Miriam

    2012-01-01

    Im Rahmen der Dissertation wurden in mehreren Teilprojekten die Auswirkungen von Umweltchemikalien auf Chironomiden als Schlüsselorganismen in aquatisch-benthischen Lebensräumen untersucht. Dabei lag der Fokus besonders auf der Erfassung von nicht-standardisierten Endpunkten und Bioindikatoren sowie auf der Bearbeitung einer weiterführenden ökologisch relevanten Fragestellung zum Räuber-Beute-Verhältnis unter Schadstoffeinfluss. Im ersten Teil der Dissertation wurde das herkömmliche Standa...

  13. Synthese von grenzflächenaktiven Monomeren zur Herstellung von funktionalen Metall-Chalkogenid/Polymer-Hybridnanopartikeln

    OpenAIRE

    Fischer, V.

    2013-01-01

    In dieser Arbeit wurde gezeigt, wie oberflächenfunktionalisierte Polystyrolnanopartikel zur Herstellung von Metallchalkogenid/Polymer-Hybridnanopartikeln eingesetzt werden können. Dazu wurden zunächst phosphonsäure- und phosphorsäurefunktionalisierte Surfmere synthetisiert, die anschließend bei der Miniemulsionspolymerisation von Styrol verwendet wurden. Die Surfmere dienten dabei zugleich zur Stabilisierung und als Comonomer. Die oberflächenfunktionalisierten Polystyrolnanopartikel wurden an...

  14. Untersuchung der Rolle von Rhodopsin 7 und Cryptochrom im Sehprozess von Drosophila melanogaster

    OpenAIRE

    Grebler, Rudi

    2015-01-01

    Ausgangspunkt für die Detektion von Licht ist im gesamten Tierreich die Absorption von Photonen durch photorezeptive Proteine, die sogenannten Opsine und in geringerem Ausmaß die Typ 1 Cryptochrome. Die Taufliege Drosophila melanogaster besitzt sechs eingehend charakterisierte, auch als Rhodopsine bezeichnete Opsine (Rh1-Rh6) und ein Cryptochrom (CRY). Neben den Ocellen und den Hofbauer-Buchner Äuglein werden die Rhodopsine in erster Linie in den Photorezeptorzellen der Komplexaugen, den Haup...

  15. Untersuchungen zur Trockenentschwefelung von Brenngasen durch Partialoxidation von H2S an Herdofenkoks

    OpenAIRE

    Bauersfeld, Dirk

    2009-01-01

    Die vorliegende Arbeit befasst sich mit Untersuchungen zur Trockenentschwefelung von Brenngasen durch Partialoxidation von H2S an Herdofenkoks. Hierzu wurden Versuche in der Technikumsanlage VTE 2004 mit einem simulierten PHTW Gas durchgeführt. Es zeigte sich, dass der COS-Abbau nicht wie bisher angenommen durch die COS-Partialoxidation sondern durch die COS-Hydrolyse erfolgt. Die COS-Hydrolyse gewinnt dabei mit abnehmender Raumbelastung an Bedeutung. Der Entschwefelungsgrad erhöht sich mit s...

  16. Dentinhaftung von Zementen. Der Haftverbund von Zementen mit Dentin in Kombination mit verschiedenen indirekten Restaurationsmaterialien

    OpenAIRE

    Peutzfeldt, Anne; Sahafi, Alireza; Flury, Simon

    2011-01-01

    Einleitung: Die Anzahl zahnärztlicher Zemente sowie Restaurationsmaterialien steigt stetig. Die richtige Zementwahl für einen zuverlässigen Haftverbund zwischen Restaurationsmaterial und Zahnsubstanz ist von Interesse für den Kliniker. Ziel der vorliegenden in vitro-Studie war es daher, den Dentinhaftverbund von verschiedenen Zementen in Kombination mit verschiedenen indirekten Restaurationsmaterialien zu untersuchen. Material und Methoden: Zylindrische Probekörper aus sechs Restaurations...

  17. [The Costantin Von Economo's lethargic encefalitis

    Science.gov (United States)

    Pistacchio, E.

    1998-01-01

    Starting from the Constantin Von Economo's description of a "new" disease, the lethargic encephalitis, the author delineates the history of an infectious sleeping sickness that caused epidemics in Europe from 1917 to 1928 and led to create, in Italy, the "Institutes for Encephalitis".

  18. Die larvale Entwicklung von Chirocentrus dorab (Forsk.)

    NARCIS (Netherlands)

    Delsman, H.C.

    1922-01-01

    Wer sich mit dem Studium der Lebensweise indischer Fische befassen will, hat dabei den grossen Vorteil, sich beim Bestimmen der Species auf die zahlreichen Arbeiten BLEEKER’S stützen zu können, während ihm das Determinieren ganz besonders erleichtert wird durch das von dichotomischen Tabellen

  19. Soolopartiid Von Krahli katuse all / Kristi Eberhart

    Index Scriptorium Estoniae

    Eberhart, Kristi

    2007-01-01

    Von Krahli Teatri kolmest lavastusest: "Erki ja Tiina" (lavastaja Mart Kangro, tantsivad Erki Laur ja Tiina Tauraite), "Faust" (J. W. Goethe ainetel tekst ja lavastus Taavi Eelmaa, muusika ja laulud Chalice, osades Jarek Kasar ja Rein Pakk), "Hamletid" (William Shakespeare'i ainetel kontseptsiooni, lavastuse, koreograafia, kujunduse, valguse autor Sasha Pepeljajev, video- ja helikunstnik Taavet Jansen. Esitaja Juhan Ulfsak)

  20. Drei neue Chelonarium-Arten von Sumatra

    NARCIS (Netherlands)

    Reitter, Edm.

    1886-01-01

    Die Arten dieser Gattung kommen vorherschend in Central- und Süd-Amerika vor, doch sind in neuerer Zeit auch drei Arten: Ch. orientale Reitt. 1), conspersum Reitt. 2) und adspersum Chevrl.3) von den grossen Sunda-Inseln und Malakka bekannt geworden, zu denen nun weitere 3 Arten treten, die ich nachf

  1. Ueber eine Anomalie von Acromitus flagellatus (Stiasny)

    NARCIS (Netherlands)

    Stiasny, G.

    1934-01-01

    Bei erneuter Durchsicht des reichhaltigen Materiales von Acromitus flagellatus (Stiasny) in der Scyphomedusen-Sammlung des Rijksmuseum van Natuurlijke Historie in Leiden (vergl. meine Mitteilungen daruber, 1920, Uebersichtstabelle III und 1921, p. 131/136) fand ich ein Exemplar, das eine

  2. Ueber zwei neue Vogelarten von Java

    NARCIS (Netherlands)

    Finsch, O.

    1902-01-01

    Die beiden nachstehend beschriebenen Vögel wurden mir von Herrn Max Bartels als muthmasslich neu zugesandt. Die genaue Untersuchung hat dies bestätigt. Ich freue mich daher eine der Arten zu Ehren des Entdeckers benennen zu können. Seit einigen Jahren als Leiter der Plantage Pangerango bei Pasir Dat

  3. Active Von Willebrand Factor, thrombocytopenia and thrombosis

    NARCIS (Netherlands)

    Hulstein, J.J.J.

    2006-01-01

    Platelets and von Willebrand factor (VWF) are unable to interact in circulation. To induce an interaction, a conversion of VWF to a platelet-binding conformation is required. At higher shear stresses, the first step in thrombus formation is binding of VWF to the subendothelium. This results in expos

  4. The von Bertalanffy growth model for horticulture

    NARCIS (Netherlands)

    Tijskens, L.M.M.; Schouten, R.E.; Unuk, T.; Šumak, D.

    2017-01-01

    Traditionally, crop load and fruit yield from previous seasons are used as indicators for prediction of fruit size. Disregarding the inevitable biological variation between fruit, von Bertalanffy (1938) described the growth, expressed as length, of virtually any living organism. The model is here

  5. Von Kalifornien nach Taxham / Katri Soe

    Index Scriptorium Estoniae

    Soe, Katri, 1971-

    2005-01-01

    Neljas osa magistritööst "Von Kalifornien nach Taxham: Formen und Strukturen der Kommunikation in Peter Handkes Romanen "Der kurze Brief zum langen Abschied" und "In einer dunklen Nacht ging ich aus meinem stillen Haus"" (Tartu, 2000. Juhendaja: Claus Sommerhage)

  6. Ueber eine Anomalie von Acromitus flagellatus (Stiasny)

    NARCIS (Netherlands)

    Stiasny, G.

    1934-01-01

    Bei erneuter Durchsicht des reichhaltigen Materiales von Acromitus flagellatus (Stiasny) in der Scyphomedusen-Sammlung des Rijksmuseum van Natuurlijke Historie in Leiden (vergl. meine Mitteilungen daruber, 1920, Uebersichtstabelle III und 1921, p. 131/136) fand ich ein Exemplar, das eine bemerkenswe

  7. Zustandsschätzung von aktiven Fahrwerkregelsystemen

    NARCIS (Netherlands)

    Leenen, R.; Maurice, J.P.

    2010-01-01

    Eine Weiterentwicklung von Fahrdynamikregelung, Überroll- und Seitenaufprallschutz sowie Pre-Crash-Funktionen und Kollisionsminderung verspricht TNO. Mit einem System zur Beobachtung des aktuellen Fahrzeugzustands (Vehicle State Estimator – VSE) bietet der niederländische Zulieferer ein zentrales Mo

  8. Ueberreste vorweltlicher Proboscidier von Java und Banka

    NARCIS (Netherlands)

    Martin, K.

    1884-01-01

    Junghuhn führte in seinem Werke über Java nur einen einzigen Wirbelthierrest, Carcharias megalodon, an (7, IV, pag. 97); es war ihm nicht gelungen bei seinem ersten Aufenthalte auf der Insel Reste von Säugethieren zu finden, so eifrig er auch darnach in den Höhlen des Tertiaergebirges suchte (7, IV,

  9. Entendendo a entropia de von Neumann

    OpenAIRE

    Maziero, Jonas

    2015-01-01

    Revisamos os postulados da mecânica quântica necessários para discutir a entropia de von Neumann, que é introduzida como uma generalização da entropia de Shannon e propomos um jogo simples que facilita o entendimento do seu significado físico.

  10. Das Haarkleid eines Fetus von Schimpanse

    NARCIS (Netherlands)

    Bolk, L.

    1919-01-01

    In seiner ausführlichen Arbeit über die Richtung der Haare bei den Affenembryonen nebst allgemeinen Erörterungen über die Ursachen der Haarrichtungen, hat Schwalbe eine Fülle von Tatsachen und eine wertvolle kritische Betrachtung über das Problem der Haarrichtungen geliefert. Leider war der Autor ni

  11. Preparation, Biological Evaluation and Dosimetry Studies of 175Yb-Bis-Phosphonates for Palliative Treatment of Bone Pain

    Directory of Open Access Journals (Sweden)

    Ashraf Fakhari

    2015-10-01

    Full Text Available Objective: Optimized production and quality control of ytterbium-175 (Yb-175 labeled pamidronate and alendronate complexes as efficient agents for bone pain palliation has been presented. Methods: Yb-175 labeled pamidronate and alendronate (175Yb-PMD and 175Yb-ALN complexes were prepared successfully at optimized conditions with acceptable radiochemical purity, stability and significant hydroxyapatite absorption. The biodistribution of complexes were evaluated up to 48 h, which demonstrated significant bone uptake ratios for 175Yb-PAM at all-time intervals. It was also detected that 175Yb-PAM mostly washed out and excreted through the kidneys. Results: The performance of 175Yb-PAM in an animal model was better or comparable to other 175Yb-bone seeking complexes previously reported. Conclusion: Based on calculations, the total body dose for 175Yb-ALN is 40% higher as compared to 175Yb-PAM (especially kidneys indicating that 175Yb-PAM is probably a safer agent than 175Yb-ALN.

  12. Enhanced exciton emission from ZnO nano-phosphor induced by Yb3+ ions

    CSIR Research Space (South Africa)

    Kabongo, GL

    2014-01-01

    Full Text Available In this work, the sol–gel method was used to prepare Ytterbium (Yb(sup3+)) doped ZnO nano-phosphors with different concentrations of Yb(sup3+) ions. Their structural, morphological, photoluminescence, electronic states and the chemical composition...

  13. Magnetocaloric effect in In doped YbMnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Sattibabu, Bhumireddi, E-mail: bsb.satti@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Department of Electronics and Physics, Institute of Science, GITAM University, Visakhapatnam 530045 (India); Bhatnagar, A.K., E-mail: anilb42@gmail.com [School of Physics, University of Hyderabad, Hyderabad 500046 (India); Vinod, K.; Mani, Awadhesh [Condensed Matter Physics Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2017-06-01

    Magnetic and magnetocaloric (MCE) properties of Yb{sub 0.9}In{sub 0.1}MnO{sub 3} and Yb{sub 0.8}In{sub 0.2}MnO{sub 3} polycrystalline samples are presented in this paper. Isothermal magnetization measurements reveal a field induced magnetic transition. Magnetic entropy change of 2.34±0.35 J/mole-K for Yb{sub 0.9}In{sub 0.1}MnO{sub 3} and 2.64±0.38 J/mole-K for Yb{sub 0.8}In{sub 0.2}MnO{sub 3} field change ΔH =10 KOe is observed around the ferromagnetic ordering temperature of Yb{sup 3+}. Values of relative cooling power for the same field change are found to be 38.03±9 J /mol, and 40.90±10 J/mol for Yb{sub 0.9}In{sub 0.1}MnO{sub 3} and Yb{sub 0.8}In{sub 0.2}MnO{sub 3}, respectively. These values suggest In doped YbMnO{sub 3} may be a potential candidate for magnetic refrigerant at low temperatures.

  14. Yb~(3+)/Er~(3+)-Codoped Tungsten-Tellurite Glasses for Broadband Optical Amplifier

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Emission spectra and fluorescence lifetime of Er3+ in Yb3+/Er3+-codoped tungsten-tellurite glasses were measured. Effects of Yb3+concentration on 1.5μm emission intensity and bandwidth of Er3+ were investigated and a FWHM of 81 nm was demonstrated.

  15. Local Laser Cooling of Yb:YLF to 110 K

    Science.gov (United States)

    2011-09-01

    Mansoor Sheik-Bahae1 1Department of Physics and Astronomy, University of New Mexico ,1919 Lomas Blvd. NE MSC074220, Albuquerque, NM 87131, USA 2DNEST...Pringsheim, “Zwei bemerkungen uber den unterschied von lumineszenz- und temperaturstrahlung,” Z. Phys. 57(11-12), 739–746 (1929). 2. M. Sheik-Bahae and

  16. Near-infrared emission of Yb3+ through energy transfer from ZnO to Yb3+ in glass ceramic containing ZnO nanocrystals.

    Science.gov (United States)

    Luo, Qun; Qiao, Xvsheng; Fan, Xianping; Zhang, Xianghua

    2011-08-01

    Yb(3+)-doped glass and glass ceramic containing ZnO nanocrystals were prepared by the melting-quenching method and subsequent heat treatment. Intense near-IR emission around 1000 nm that originated from the transition of Yb(3+):(2)F(5/2)→(2)F(7/2) was generated as a result of energy transfer from oxygen interstitials in ZnO nanocrystals to Yb(3+) with energy transfer efficiency of about 10%. The quantum yield for the near-IR emission of Yb(3+) under the excitation of 390 nm was about 16.7%. These materials have potential application in achieving high-efficiency Si solar cells via spectrum modification.

  17. Thermodynamic description of the Al-Cu-Yb ternary system supported by first-principles calculations

    Directory of Open Access Journals (Sweden)

    Huang G.

    2016-01-01

    Full Text Available Phase relationships of the ternary Al-Cu-Yb system have been assessed using a combination of CALPHAD method and first principles calculations. A self-consistent thermodynamic parameter was established based on the experimental and theoretical information. Most of the binary intermetallic phases, except Al3Yb, Al2Yb, Cu2Yb and Cu5Yb, were assumed to be zero solubility in the ternary system. Based on the experimental data, eight ternary intermetallic compounds were taken into consideration in this system. Among them, three were treated as line compounds with large homogeneity ranges for Al and Cu. The others were treated as stoichiometric compounds. The calculated phase diagrams were in agreement with available experimental and theoretical data.

  18. Enhancement of Tb-Yb quantum cutting emission by inverse opal photonic crystals

    Science.gov (United States)

    Wang, Qi; Qiu, Jianbei; Song, Zhiguo; Yang, Zhengwen; Yin, Zhaoyi; Zhou, Dacheng; Wang, Siqin

    2016-04-01

    Yb3+, Tb3+ co-doped YPO4 inverse opal photonic crystal was prepared directly by sol-gel technique in combination with self-assembly method. With the influence of the photonic band gap, quantum cutting emission of Tb3+, Yb3+ was investigated in photonic crystals by photoluminescence and fluorescence lifetime. The result clearly shows that, when the spontaneous emission of donor Tb3+ is inhibited by photonic band gap, Tb3+-Yb3+ quantum cutting quantum efficiency from Tb3+ to Yb3+ could be enhanced from 131.2% to 140.5%. The mechanisms for the influence of the photonic band gap on quantum cutting process of Tb3+ and Yb3+ are discussed. We believe that the present work will be valuable for the foundational study of quantum cutting energy transfer process and application of quantum cutting optical devices in spectral modification materials for silicon solar cells.

  19. Synthesis and Downconversion Emission Property of Yb2O3:Eu3+ Nanosheets and Nanotubes

    Directory of Open Access Journals (Sweden)

    Chao Qian

    2013-01-01

    Full Text Available Ytterbium oxide (Yb2O3 nanocrystals with different Eu3+ (1%, 2%, 5%, and 10% doped concentrations were synthesized by a facile hydrothermal method, subsequently by calcination at 700°C. The crystal phase, size, and morphology of prepared samples were characterized by X-ray diffraction (XRD and transmission electron microscopy (TEM. The results show that the as-prepared Yb2O3 nanocrystals with sheet- and tube-like shape have cubic phase structure. The Eu3+ doped Yb2O3 nanocrystals were revealed to have good down conversion (DC property and intensity of the DC luminescence can be modified by Eu3+ contents. In our experiment the 1% Eu3+ doped Yb2O3 nanocrystals showed the strongest DC luminescence among the obtained Yb2O3 nanocrystals.

  20. Noncoding RNAs that associate with YB-1 alter proliferation in prostate cancer cells.

    Science.gov (United States)

    Liu, Teresa T; Arango-Argoty, Gustavo; Li, Zhihua; Lin, Yuefeng; Kim, Sang Woo; Dueck, Anne; Ozsolak, Fatih; Monaghan, A Paula; Meister, Gunter; DeFranco, Donald B; John, Bino

    2015-06-01

    The highly conserved, multifunctional YB-1 is a powerful breast cancer prognostic indicator. We report on a pervasive role for YB-1 in which it associates with thousands of nonpolyadenylated short RNAs (shyRNAs) that are further processed into small RNAs (smyRNAs). Many of these RNAs have previously been identified as functional noncoding RNAs (http://www.johnlab.org/YB1). We identified a novel, abundant, 3'-modified short RNA antisense to Dicer1 (Shad1) that colocalizes with YB-1 to P-bodies and stress granules. The expression of Shad1 was shown to correlate with that of YB-1 and whose inhibition leads to an increase in cell proliferation. Additionally, Shad1 influences the expression of additional prognostic markers of cancer progression such as DLX2 and IGFBP2. We propose that the examination of these noncoding RNAs could lead to better understanding of prostate cancer progression.

  1. Passive Q-switching of Yb bulk lasers by a graphene saturable absorber

    Science.gov (United States)

    Loiko, P. A.; Serres, J. M.; Mateos, X.; Liu, J.; Zhang, H.; Yasukevich, A. S.; Yumashev, K. V.; Petrov, V.; Griebner, U.; Aguiló, M.; Díaz, F.

    2016-04-01

    Compact Yb:KLu(WO4)2 and Yb:LuVO4 lasers diode-pumped at 978 nm are passively Q-switched by a single-layer graphene saturable absorber. The Yb:KLu(WO4)2 laser generated 165 ns/0.49 μJ pulses at 1030 nm with 170 mW average output power and 12 % slope efficiency. With the Yb:LuVO4 laser, 152 ns/0.83 μJ pulses were achieved. The output power reached 300 mW at 1024 nm, and the slope efficiency was 10 %. Laser operation in a plano-plano cavity is achieved with both crystals with thermal lensing playing a key role in their performance. A model describing graphene Q-switched Yb lasers is developed. Our results indicate the potential of graphene for passive Q-switching of ~1 μm bulk lasers.

  2. Poly(ADP-ribosyl)ation as a new posttranslational modification of YB-1.

    Science.gov (United States)

    Alemasova, Elizaveta E; Pestryakov, Pavel E; Sukhanova, Maria V; Kretov, Dmitry A; Moor, Nina A; Curmi, Patrick A; Ovchinnikov, Lev P; Lavrik, Olga I

    2015-12-01

    Multifunctional Y-box binding protein 1 (YB-1) is actively studied as one of the components of cellular response to genotoxic stress. However, the precise role of YB-1 in the process of DNA repair is still obscure. In the present work we report for the first time new posttranslational modification of YB-1 - poly(ADP-ribosyl)ation, catalyzed by one of the main regulatory enzymes of DNA repair - poly(ADP-ribose)polymerase 1 (PARP1) in the presence of model DNA substrate carrying multiple DNA lesions. Therefore, poly(ADP-ribosyl)ation of YB-1 catalyzed with PARP1, can be stimulated by damaged DNA. The observed property of YB-1 underlines its ability to participate in the DNA repair by its involvement in the regulatory cascades of DNA repair.

  3. Spectroscopic and thermal characterizations of Yb:LaF3 single crystal

    Science.gov (United States)

    Hong, Jiaqi; Zhang, Lianhan; Hang, Yin; Xu, Min

    2016-10-01

    A Yb3+ doped LaF3 laser crystal was detailed investigated by both spectroscopic and thermal measurements. A peak absorption at 974 nm with FWHM broader than 60 nm makes the crystal suitable to InGaAs LDs. Fluorescence spectrum and calculated spectroscopic parameters show potential of Yb:LaF3 crystal to laser operations around 1009 nm. A relatively long fluorescence lifetime of 2.92 ms was detected for Yb3+:2F5/2 manifold. The thermal diffusivity and specific heat capacity in the range of 300-575 K were studied to calculate the thermal conductivity of Yb:LaF3. The results indicate that the Yb:LaF3 crystal is a good candidate for diode-pumped ∼1 μm solid-state laser applications.

  4. Infrared Luminescence of Yb3+-Doped Ions in Floride Glasses (ZBLAN)%Yb3+离子在氟化物玻璃中的红外光谱性质

    Institute of Scientific and Technical Information of China (English)

    张军杰; 李毛和; 胡和方

    1999-01-01

    根据测得的Yb3+离子在氟锆酸盐玻璃(ZBLAN)中的吸收光谱和荧光光谱, 分析了Yb3+离子在氟锆酸盐玻璃中的吸收特性和发光特性; 计算了Yb3+离子的发射截面σe, 讨论了Yb3+离子的再吸收效应; 增加Yb3+离子掺杂浓度不会发生浓度淬灭效应.

  5. Thermoelectric nanocrystalline YbCoSb laser prepared layers

    Energy Technology Data Exchange (ETDEWEB)

    Jelinek, Miroslav; Kocourek, Tomas; Remsa, Jan [Institute of Physics, ASCR v.v.i., Prague (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, Kladno (Czech Republic); Zeipl, Radek [Institute of Physics, ASCR v.v.i., Prague (Czech Republic); Navratil, Jiri [Institute of Macromolecular Chemistry, ASCR v.v.i., Prague (Czech Republic)

    2016-03-15

    Filled thermoelectric Yb{sub x}Co{sub 4}Sb{sub 12} layers were prepared by pulsed laser deposition method. The Yb{sub 0.19}Co{sub 4}Sb{sub 12} target was fabricated by hot pressing. Various deposition conditions were tested: target - substrate distance d{sub T-S} (4 or 6 cm), ambient argon pressure (from 0.5 to 13 Pa), laser repetition rate (from 3 to 10 Hz), substrate temperature (from 250 to 400 C) and laser fluence (in region from 0.8 to 5 J cm{sup -2}). Film roughness was determined by mechanical profilometer and by AFM. For d{sub T-S} = 4 cm we observed a deficit of Yb and surplus of Co. Sb was transferred from target to film roughly stoichiometrically (as measured by EDX). Films created at 0.8 J cm{sup -2} exhibited generally poor stoichiometry and mechanical properties. Optimal conditions and stoichiometric transport were found for d{sub T-S} = 6 cm and 13 Pa of Ar. XRD shows that the films were nanocrystalline with CoSb{sub 3} structure. Grain size was in the range of ∝ 50-80 nm. Temperature dependence of Seebeck coefficient and power factor was measured. Thermoelectric efficiency ZT ∝ 0.04-0.05 was measured at room temperature using Harman method. In dependence on layers quality, we calculated thermal conductivity λ ∝ 0.4-1.3 W K{sup -1} m{sup -1}. (orig.)

  6. In-Situ Growth of Yb2O3 Layer for Sublimation Suppression for Yb14MnSb11 Thermoelectric Material for Space Power Applications

    Science.gov (United States)

    Nesbitt, James A.; Opila, Elizabeth J.; Nathal, Michael V.

    2012-01-01

    The compound Yb14MnSb11 is a p-type thermoelectric material of interest to the National Aeronautics and Space Administration (NASA) as a candidate replacement for the state-of-the-art Si-Ge used in current radioisotope thermoelectric generators (RTGs). Ideally, the hot end of this leg would operate at 1000 C in the vacuum of space. Although Yb14MnSb11 shows the potential to double the value of the thermoelectric figure of merit (zT) over that of Si-Ge at 1000 C, it suffers from a high sublimation rate at elevated temperatures and would require a coating in order to survive the required RTG lifetime of 14 years. The purpose of the present work is to measure the sublimation rate of Yb14MnSb11 and to investigate sublimation suppression for this material. This paper reports on the sublimation rate of Yb14MnSb11 at 1000 C (approximately 3 x 10(exp -3) grams per square centimeter hour) and efforts to reduce the sublimation rate with an in situ grown Yb2O3 layer. Despite the success in forming thin, dense, continuous, and adherent oxide scales on Yb14MnSb11, the scales did not prove to be sublimation barriers.

  7. Doença de von Willebrand e anestesia Enfermedad de von Willebrand y anestesia Von Willebrand's disease and anesthesia

    OpenAIRE

    Fabiano Timbó Barbosa; Rafael Martins da Cunha; Luciano Timbó Barbosa

    2007-01-01

    JUSTIFICATIVA E OBJETIVOS: A doença de von Willebrand ocorre devido à mutação no cromossomo 12 e é caracterizada por deficiência qualitativa ou quantitativa do fator de von Willebrand. A diversidade de mutações leva ao aparecimento das mais variadas manifestações clínicas possibilitando a divisão dos pacientes em vários tipos e subtipos clínicos. A coagulopatia se manifesta basicamente através da disfunção plaquetária associada à diminuição dos níveis séricos do fator VIII coagulante. O objet...

  8. Cooperative emission in ion implanted Yb:YAG waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, G V; Desirena, H; De la Rosa, E [Centro de Investigaciones en Optica, Loma del Bosque 115, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Flores-Romero, E; Rickards, J; Trejo-Luna, R [Instituto de Fisica, UNAM, Apartado Postal 20364, 01000 Mexico, D. F. (Mexico); Marquez, H, E-mail: gvvazquez@cio.mx [Departamento de Optica, CICESE, Km 107 Carr. Tijuana-Ensenada, 22860 Ensenada, B. C. (Mexico)

    2011-01-01

    In this work, we report the analysis of spectroscopic properties of waveguides fabricated by ion implantation in YAG doped with Yb{sup 3+} ions. Three emission bands were detected in the blue, green and red regions under 970-nm excitation. The strong blue-green emission can be explained by a cooperative process between ytterbium ion pairs, leading to emission centered at 514 nm. The additional blue bands as well as green and red emission bands are attributed to the presence of Tm{sup 3+} and Er{sup 3+} traces. The results include absorption and emission curves as well as decay time rates.

  9. Yb integrates piRNA intermediates and processing factors into perinuclear bodies to enhance piRISC assembly.

    Science.gov (United States)

    Murota, Yukiko; Ishizu, Hirotsugu; Nakagawa, Shinichi; Iwasaki, Yuka W; Shibata, Shinsuke; Kamatani, Miharu K; Saito, Kuniaki; Okano, Hideyuki; Siomi, Haruhiko; Siomi, Mikiko C

    2014-07-10

    PIWI-interacting RNAs (piRNAs) direct Piwi to repress transposons and maintain genome integrity in Drosophila ovarian somatic cells. piRNA maturation and association with Piwi occur at perinuclear Yb bodies, the centers of piRNA biogenesis. Here, we show that piRNA intermediates arising from the piRNA cluster flamenco (flam) localize to perinuclear foci adjacent to Yb bodies, termed Flam bodies. RNAi-based screening of piRNA factors revealed that Flam body formation depends on Yb, the core component of Yb bodies, while Piwi and another Yb body component, Armitage, are dispensable for formation. Abolishing the RNA-binding activity of Yb disrupts both Flam bodies and Yb bodies. Yb directly binds flam, but not transcripts from neighboring protein-coding genes. Thus, Yb integrates piRNA intermediates and piRNA processing factors selectively into Flam bodies and Yb bodies, respectively. We suggest that Yb is a key upstream factor in the cytoplasmic phase of the piRNA pathway in ovarian somatic cells. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Yb Integrates piRNA Intermediates and Processing Factors into Perinuclear Bodies to Enhance piRISC Assembly

    Directory of Open Access Journals (Sweden)

    Yukiko Murota

    2014-07-01

    Full Text Available PIWI-interacting RNAs (piRNAs direct Piwi to repress transposons and maintain genome integrity in Drosophila ovarian somatic cells. piRNA maturation and association with Piwi occur at perinuclear Yb bodies, the centers of piRNA biogenesis. Here, we show that piRNA intermediates arising from the piRNA cluster flamenco (flam localize to perinuclear foci adjacent to Yb bodies, termed Flam bodies. RNAi-based screening of piRNA factors revealed that Flam body formation depends on Yb, the core component of Yb bodies, while Piwi and another Yb body component, Armitage, are dispensable for formation. Abolishing the RNA-binding activity of Yb disrupts both Flam bodies and Yb bodies. Yb directly binds flam, but not transcripts from neighboring protein-coding genes. Thus, Yb integrates piRNA intermediates and piRNA processing factors selectively into Flam bodies and Yb bodies, respectively. We suggest that Yb is a key upstream factor in the cytoplasmic phase of the piRNA pathway in ovarian somatic cells.

  11. Wir zeigen andere Bilder von Frauen ...

    Directory of Open Access Journals (Sweden)

    Bettina Rulofs

    2010-03-01

    Full Text Available Der vorliegende Beitrag beleuchtet die Bedeutung der Geschlechterordnung im Prozess der sportmedialen Kommunikation. Im Kern geht es um die Frage, inwiefern im Prozess der medialen Vermittlung von Sport traditionelle Geschlechterstereotype aufrechterhalten werden oder Möglichkeiten der Irritation solcher Stereotype bestehen. Dazu werden verschiedene Ebenen des massenmedialen Kommunikationsprozesses in den Blick genommen: die Medienprodukte, die Öffentlichkeitsarbeit und Selbst-Präsentation der Sportler/innen, die Medienrezeption und die Herstellungsprozesse von Medien in den Sportredaktionen. This article illustrates the relevance of gender in processes of sports media communication. The question in focus is in what way traditional gender stereotypes are perpetuated in the process of media communication in sport and how such stereotypes can be irritated. Therefore different levels of mass media communication are considered: the media products, the public relations of athletes and the presentation of themselves as athletes, the media-reception and the production processes in sport departments of media institutions.

  12. Von Neumann's Quantization of General Relativity

    CERN Document Server

    Arbuzov, A B; Cirilo-Lombardo, D J; Nazmitdinov, R G; Han, Nguyen Suan; Pavlov, A E; Pervushin, V N; Zakharov, A F

    2015-01-01

    Von Neumann's procedure is applied for quantization of General Relativity. We quantize the initial data of dynamical variables at the Planck epoch, where the Hubble parameter coincides with the Planck mass. These initial data are defined via the Fock simplex in the tangent Minkowskian space-time, the Dirac conformal interval. The Einstein cosmological principle is applied for the average of the spatial metric determinant logarithm over the spatial volume of the visible Universe. We derive the splitting of the general coordinate transformations into the diffeomorphisms (as the object of the second Noether theorem) and the initial data transformations (as objects of the first Noether theorem). Following von Neumann, we suppose that the vacuum state is a quantum ensemble. The vacuum state is degenerated with respect to quantum numbers of non-vacuum states with the distribution function that yields the Casimir effect in gravidynamics in analogy to the one in electrodynamics. The generation functional of the pertu...

  13. Integrales Lernen in und von Organisationen

    Directory of Open Access Journals (Sweden)

    Wendelin Kupers

    2006-06-01

    Full Text Available Bezogen auf das integrale Models von Ken Wilber untersucht der Beitrag die Bedeutung des Lernens in und von Organisationen. Nach einer Darstellung der Relevanz und des Grundverständnisses des Lernens im Organisationskontext, werden integrale Dimensionen des Lernens dargestellt. Im Einzelnen werden die verschiedenen Sphären eines inneren-subjektiven und äusseren-„objektiven“ Lernens des Einzelnen als auch ein gemeinschaftliches Lernen und Lernen im System auf der kollektiven Ebene dargestellt sowie deren interrelationaler Zusammenhang diskutiert. Schließlich beschreibt der Beitrag noch integrale Lernprozesse sowie integrale Gestaltungsfelder zur Förderung des Lernens in den verschiedenen Bereichen. Abschließend spricht der Artikel noch Schwierigkeiten und Probleme an sowie nimmt im Fazit ein perspektivischen Ausblick vor.

  14. NOTIZ USER EIN GNETUM VON BORNEO

    Directory of Open Access Journals (Sweden)

    Fr. Markgraf

    2015-11-01

    Full Text Available Diese Varietat, die ich friiher nach unvollstandigem Material zu G. diminutum gerechnet habe, besitzt in beiden Geschlechtern verzweigte Blutenstande. Dieses Merkmal kommt in der Gruppe mit sitzenden Fruch-ten (Subsection Sessiles nur bei G. leptostachyum, vor, zu dem auch die Friichte der neuen Varietat gut passen. Sie ist eine Nebelwaldpflanze grosserer Hohen und hat bei reduzierten Massen der Blatter und Bliitenstande die schmalen, kurzen mannlichen Katzchen der Tieflands-Varietat leptostachyum mit den kurzgliedrigen, grossfriichtigen weiblichen Bluten-standen der Tieflands-Varietat robustum vereinigt. In Indochina und Siam lebt eine zweite Berg-Varietat — entsprechend der weiteren Ent-fernung vom Aquator in etwas geringeren Hohen die umgekehrt die dicken mannlichen Katzchen von der Varietat robustum mit den lang-gliedrigen weiblichen Bliitenstanden von der Varietat leptostachyum vereinigt. In beiden Fallen sind die Verkiirzungs- und Verlangerungs-Tenden-zen bei den Berg-Varietaten starker als bei denen des Tieflandes.

  15. Evolution equations of von Karman type

    CERN Document Server

    Cherrier, Pascal

    2015-01-01

    In these notes we consider two kinds of nonlinear evolution problems of von Karman type on Euclidean spaces of arbitrary even dimension. Each of these problems consists of a system that results from the coupling of two highly nonlinear partial differential equations, one hyperbolic or parabolic and the other elliptic. These systems take their name from a formal analogy with the von Karman equations in the theory of elasticity in two dimensional space. We establish local (respectively global) results for strong (resp., weak) solutions of these problems and corresponding well-posedness results in the Hadamard sense. Results are found by obtaining regularity estimates on solutions which are limits of a suitable Galerkin approximation scheme. The book is intended as a pedagogical introduction to a number of meaningful application of classical methods in nonlinear Partial Differential Equations of Evolution. The material is self-contained and most proofs are given in full detail. The interested reader will gain a ...

  16. Influence of Yb-Doped Nanoporous TiO2 Films on Photovoltaic Performance of Dye-Sensitized Solar Cells

    Institute of Scientific and Technical Information of China (English)

    XU Wei-Wei; DAI Song-Yuan; HU Lin-Hua; LIANG Lin-Yun; WANG Kong-Jia

    2006-01-01

    @@ Yb-doped TiO2 pastes with different Yb/TiO2 weight ratios are prepared in the sol-gel process to obtain dyesensitized solar cells (DSCs). The nanocrystalline size of Yb-TiO2 becomes smaller and the lattice parameters change. Lattice distortion is observed and dark current is detected. It is found that a part of Yb existing as insulating oxide Yb2Oa state acts as barrier layers at the electrode-electrolyte interface to suppress charge recombination. A Yb-doped TiO2 electrode applied in DSCs leads to a higher open-circuit voltage and a higher fill factor. How the Yb-doped TiO2 films affect the photovoltaic response of DSCs is discussed.

  17. Structural and optical studies of Yb3+, Er3+ and Er3+/Yb3+ co-doped phosphate glasses

    Institute of Scientific and Technical Information of China (English)

    S.Hraiech; M.Ferid; Y.Guyot; G.Boulon

    2013-01-01

    Phosphate glass samples with various Yb2O3 and Er2O3 contents were synthesized by the conventional melt quenching technique and characterized by X-ray diffraction,IR absorption spectroscopy and Raman scattering spectroscopy.The absorption,emission spectra and fluorescence decay studies were carried out both at low and room temperatures.Results showed the existence of several sites occupied by the rare earth ions in the phosphate glass.Up-conversion and cooperative fluorescence were also discussed.

  18. Metabolisierung von Lebensmittelinhaltsstoffen im simulierten Verdauungsmodell

    OpenAIRE

    Hageböck, Martin

    2013-01-01

    Mit Hilfe eines in vitro Modells, basierend auf 4 hintereinander geschalteten Bioreaktoren, war es möglich, komplexe Vorgänge der Verdauung modellhaft nachzustellen. Somit konnte die stufenweise Metabolisierung von ausgewählten Lebensmittelinhaltsstoffen unter definierten physikochemischen, enzymatischen und mikrobiellen Bedingungen der einzelnen Verdauungsstufen verfolgt werden. Beim Einsatz der polyphenolischen Reinsubstanzen wurden zunächst charakteristische Abbaureaktionen wie Hydrolyse v...

  19. La Medea de Lars von Trier

    Directory of Open Access Journals (Sweden)

    Iratxe Fresneda Delgado

    2013-04-01

    Full Text Available El presente artículo analiza el modo en el que Lars von Trier recrea para el cine el estereotipo de Medea. Mediante el análisis fílmico de la película y apoyándose en los estudios culturales, el texto se interroga acerca de la importancia y el poder potencial del cine a la hora recuperar el antiguo mito y demostrar su vigencia. El análisis amplía horizontes para la compresión de los mecanismos que articulan el entramado de significados de la película, donde Von Trier aporta una nueva visión del arquetipo de Medea uniéndola, a la tradición pictórica del Romanticismo. Una influencia que habita en las posteriores obras del director danés, donde el paisaje, la naturaleza, se erige en elemento catalizador de las pulsiones humanas, en su cómplice y testigo.This paper explores the way that Lars von Trier’s film recreates the stereotype of Medea. Using film analysis and based on cultural studies the article asks about the importance and potential power of cinema to recover the ancient myth and show their effects. The analysis expands horizons for the understanding of the mechanisms that link the network of meanings of the film, where the author offers a new vision of Medea's archetype attaching it to the pictorial tradition tied to the Romanticism. An influence that can be seen in the later works of Lars von Trier, where the landscape, the nature, stands as a catalyst of human drives, as his accomplice and witness.

  20. Diskretfrequente Synthese von Nachhall-Prozessen

    OpenAIRE

    Boesnecker, Robert

    2008-01-01

    Die Arbeit verfolgt einen neuartigen Ansatz zur digitalen Nachhallsynthese. Es wird dabei von folgender Beobachtung ausgegangen: Ruft man in ein Klavier, dessen Saiten unbedämpft sind, so antwortet das Instrument mit einem aus diskreten Einzeltönen bestehenden Nachklang, der ähnlich wie ein raumakustischer Nachhall klingt. Verbreitert man bei einer diskretfrequenten Synthese nun die spektrale Breite eines jeden "Klaviertons" auf einen schmalbandigen Bandpass, so dass nicht 12 Töne, sondern 12...

  1. Von Medien, Übertragungen und Automaten

    Directory of Open Access Journals (Sweden)

    Alessandro Barberi

    2013-12-01

    Full Text Available Im Zuge der Debatten zum Medialen Habitus wurde vielfach betont, dass die >Theorie der Praxispraxeologischen Medientheorie< des Medialen Habitus avant la lettre gesprochen werden kann. Dieser Artikel untersucht – ausgehend von den Debatten zur "Medienkompetenz" – wie Bourdieu Sprache, Sprechen und Diskurs, sowie Akteure, Felder und Habitus als Medien begreift und betont dabei die Nützlichkeit der Bourdieuschen Bildungssoziologie im Rahmen einer sozialwissenschaftlichen Grundlegung der Medienpädagogik.

  2. Bettina von Zwehl: Made up Love Song

    OpenAIRE

    Brown, Camilla

    2012-01-01

    This article considers an exhibition of work made whilst the artist Bettina von Zwehl was on a residency at the Victoria and Albert Museum London. Influenced by their miniature collection she made a new series of work and for the first time made one longer series of work with the same person. This essay considers how this development evolved from the artist's previous practice over a period of 10 years.

  3. Herstellung von Chitosan und einige Anwendungen

    Science.gov (United States)

    Struszczyk, Marcin Henryk

    2001-05-01

    1. Die Deacetylierung von crabshell - Chitosan führte gleichzeitig zu einem drastischen Abfall der mittleren viscosimetrischen Molmasse ( Mv), insbesondere wenn die Temperatur und die Konzentration an NaOH erhöht werden. Diese Parameter beeinflussten jedoch nicht den Grad der Deacetylierung (DD). Wichtig ist jedoch die Quelle des Ausgangsmaterials: Chitin aus Pandalus borealis ist ein guter Rohstoff für die Herstellung von Chitosan mit niedrigem DD und gleichzeitig hoher mittlerer Mv, während Krill-Chitin (Euphausia superba) ein gutes Ausgangsmaterial zur Herstellung von Chitosan mit hohem DD und niedrigem Mv ist. Chitosan, das aus Insekten (Calliphora erythrocephala), unter milden Bedingungen (Temperatur: 100°C, NaOH-Konzentration: 40 %, Zeit: 1-2h ) hergestellt wurde, hatte die gleichen Eigenschaften hinsichtlich DD und Mv wie das aus Krill hergestellte Chitosan. Der Bedarf an Zeit, Energie und NaOH ist für die Herstellung von Insekten-Chitosan geringer als für crabshell-Chitosan vergleichbare Resultaten für DD und Mv. 2. Chitosan wurde durch den Schimmelpilz Aspergillus fumigatus zu Chitooligomeren fermentiert. Die Ausbeute beträgt 25%. Die Chitooligomere wurden mit Hilfe von HPLC und MALDI-TOF-Massenspektrmetrie identifiziert. Die Fermentationsmischung fördert die Immunität von Pflanzen gegen Bakterien und Virusinfektion. Die Zunahme der Immunität schwankt jedoch je nach System Pflanze-Pathogen. Die Fermentation von Chitosan durch Aspergillus fumigatus könnte eine schnelle und billige Methode zur Herstellung von Chitooligomeren mit guter Reinheit und Ausbeute sein. Eine partiell aufgereinigte Fermentationsmischung dieser Art könnte in der Landwirtschaft als Pathogeninhibitor genutzt werden. Durch kontrollierte Fermentation, die Chitooligomere in definierter Zusammensetzung (d.h. definierter Verteilung des Depolymerisationsgrades) liefert, könnte man zu Mischungen kommen, die für die jeweilige Anwendung eine optimale Bioaktivität besitzen. 3

  4. Optimierung von Mehrkörpersystemen

    OpenAIRE

    Theis, Winfried; Räbiger, Klaus

    2009-01-01

    Auf Grund der ständig steigenden Anforderungen während der Entwicklung neuartiger Produkte ist es oftmals schwierig einen optimalen Entwurf zu finden. Die vorliegende Arbeit soll deshalb einen Einblick in die Welt der mathematischen Optimierung geben und anhand von ausgewählten Beispielen aus der Mehrkörperdynamik die nötigen Schritte einer Optimierungsrechnung genauer erklären. Spezielle Aufmerksamkeit wird hierbei der Ermittlung der Bewegungsgleichungen, der Formulierung der Optimierungsauf...

  5. β-YbAlB4: a critical vortex metal

    Science.gov (United States)

    Ramires, Aline; Coleman, Piers; Tsvelik, Alexei

    2012-02-01

    β-YbAlB4 is the first Yb based heavy fermion superconductor and has a non Fermi Liquid behavior in the normal state that develops without external tuning by pressure or doping, making it intrinsically quantum critical [1]. Application of a magnetic field is found to drive the development of a Fermi Liquid in which the Fermi temperature is determined by the Zeeman energy [2]. Here we present a theory for the intrinsic quantum criticality in which the main ingredient is an anisotropic hybridization matrix with line nodes in momentum space that carry a vorticity and resemble topological defects. Our theory predicts that the application of a field induces a novel Lifshitz transition, in which a quasi-two dimensional Fermi Liquid with density of states N^*(B) 1/√B nucleates around the line node in momentum space. We also discuss how the vortex metal picture can account for the ESR anomalies observed in this system [3]. 0.3truein [1] S. Nakatsuji et al., Nature Phys. 4, 603 (2008). [2] Y. Matsumoto et al., Science 21, 316 (2011). [3] L. M. Holanda et al., Phys Rev. Lett. 107, 026402 (2011).

  6. Synthesis and characterization of (Ba,Yb doped ceria nanopowders

    Directory of Open Access Journals (Sweden)

    Branko Matović

    2011-06-01

    Full Text Available Nanometric size (Ba, Yb doped ceria powders with fluorite-type structure were obtained by applying selfpropagating room temperature methods. Tailored composition was: Ce0.95−xBa0.05YbxO2−δ with fixed amount of Ba − 0.05 and varying Yb content “x” from 0.05 to 0.2. Powder properties such as crystallite and particle size and lattice parameters have been studied. Röntgen diffraction analyses (XRD were used to characterize the samples at room temperature. Also, high temperature treatment (up to 1550°C was used to follow stability of solid solutions. The mean diameters of the nanocrystals are determined from the full width at half maxima (FWHM of the XRD peaks. It was found that average diameter of crystallites is less than 3 nm. WilliamsonHall plots were used to separate the effect of the size and strain in the nanocrystals.

  7. Katheterablation von Vorhofflimmern - Neue Technologien und Strategien

    Directory of Open Access Journals (Sweden)

    Rolf S

    2011-01-01

    Full Text Available Die Katheterablation von symptomatischem Vorhofflimmern hat sich zu einem Therapieverfahren mit reproduzierbaren Erfolgsraten und überschaubarem Risiko bei selektierten Patientenkollektiven entwickelt. Hinsichtlich der Effektivität ist sie der Antiarrhythmika-Therapie schon heute überlegen. Die Verfahrenstechnik wird stetig weiterentwickelt, um die langfristige Erfolgsrate zu erhöhen, die Rate an Re-Interventionen zu reduzieren, die Komplikationsraten zu senken, die Prozedur selber zu vereinfachen und die Prozedurzeit zu verkürzen. Beispiele für solche Neuerungen sind die zielorientierte CT-Integration in elektro-anatomische Mappingsysteme, die optimierte Schaffung und Validierung linearer Läsionen mit der Pace-and-Ablate-Strategie, der effizientere Energietransfer ins Gewebe durch Verwendung steuerbarer transseptaler Schleusen und Berücksichtigung des elektrischen Kontaktes, sowie die strategische Planung von Linienkonzepten bei atrialen Makro-Reentry-Tachykardien durch Erstellung farbkodierter Entrainment- Maps. Diese Behandlungsinnovationen haben sich als wirkungsvoll erwiesen und in den vergangenen Jahren Einzug in den klinischen Alltag der Katheterablation von Vorhofflimmern im Herzzentrum Leipzig gefunde

  8. (Gd,Yb,Tb)PO4 up-conversion nanocrystals for bimodal luminescence-MR imaging

    Science.gov (United States)

    Debasu, Mengistie L.; Ananias, Duarte; Pinho, Sonia L. C.; Geraldes, Carlos F. G. C.; Carlos, Luís D.; Rocha, João

    2012-07-01

    Up-conversion (Gd,Yb,Tb)PO4 materials and their potential for bimodal imaging have received little attention in the literature. Herein, we report the first study on the up-conversion emission of (Gd,Yb,Tb)PO4 nanocrystals synthesized via a hydrothermal method at 150 °C. These materials exhibit ultraviolet, blue and green up-conversion emissions upon excitation with a 980 nm continuous wave laser diode. The intensity of the blue-emission band at 479 nm, ascribed to the cooperative up-conversion emission of a pair of excited Yb3+ ions, depends on the Yb3+/Tb3+ concentration ratio, calcination temperature and particle size. Strong green up-conversion emission of Tb3+ is observed at 543 nm for the 5D4 --> 7F5 transition. Relaxometry measurements reveal that the nanocrystals are efficient T2-weighted (negative) contrast agents which, combined with visible-light emission generated by infrared excitation, affords them considerable potential for being used in bimodal, photoluminescence-magnetic resonance, imaging.Up-conversion (Gd,Yb,Tb)PO4 materials and their potential for bimodal imaging have received little attention in the literature. Herein, we report the first study on the up-conversion emission of (Gd,Yb,Tb)PO4 nanocrystals synthesized via a hydrothermal method at 150 °C. These materials exhibit ultraviolet, blue and green up-conversion emissions upon excitation with a 980 nm continuous wave laser diode. The intensity of the blue-emission band at 479 nm, ascribed to the cooperative up-conversion emission of a pair of excited Yb3+ ions, depends on the Yb3+/Tb3+ concentration ratio, calcination temperature and particle size. Strong green up-conversion emission of Tb3+ is observed at 543 nm for the 5D4 --> 7F5 transition. Relaxometry measurements reveal that the nanocrystals are efficient T2-weighted (negative) contrast agents which, combined with visible-light emission generated by infrared excitation, affords them considerable potential for being used in bimodal

  9. A Mössbauer investigation of orthorhombic phase YbMnO3

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, G. A., E-mail: G.Stewart@adfa.edu.au; Salama, H. A. [UNSW Canberra at the Australian Defence Force Academy, School of Physical, Environmental and Mathematical Sciences (Australia); Voyer, C. J.; Ryan, D. H. [McGill University, Centre for Physics of Materials and Department of Physics (Canada); Scott, D.; O’Neill, H. StC. [The Australian National University, Research School of Earth Sciences (Australia)

    2015-04-15

    {sup 170}Yb- and {sup 57}Fe-Mössbauer spectra are reported for orthorhombic phase manganites YbMnO{sub 3} and Yb({sup 57}Fe{sub 0.005}Mn{sub 0.995})O{sub 3}, respectively. Point charge model estimates of the electric field gradient agree well with experimental {sup 57}Fe-Mössbauer results in terms of both sign and magnitude of the electric quadrupole interaction strength, and the orientation of the magnetic hyperfine field is consistent with an E-type antiferromagnetic order where Mn moments are aligned along the a-axis (Pnma notation). The {sup 170}Yb-Mössbauer spectra exhibit pure quadrupole splitting down to 1.8 K, contradicting an earlier report that the Yb sub-lattice orders in it own right at T{sub Yb} ≈ 4 K. Nevertheless, there is a slight increase in line broadening with decreasing temperature, probably due to the weak magnetic exchange field arising out of the ordered Mn sub-lattice. The small variation with temperature of the quadrupole interaction strength suggests that the Yb{sup 3+} electronic ground state is a well-isolated Kramers doublet.

  10. Synthesis, crystal structure, and properties of the nitridosilicates SrYbSi{sub 4}N{sub 7} and BaYbSi{sub 4}N{sub 7}; Synthese, Kristallstruktur und Eigenschaften der Nitridosilicate SrYbSi{sub 4}N{sub 7} und BaYbSi{sub 4}N{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Huppertz, H. [Bayreuth Univ. (Germany). Lehrstuhl fuer Anorganische Chemie I; Schnick, W. [Bayreuth Univ. (Germany). Lehrstuhl fuer Anorganische Chemie I

    1997-02-01

    Pure SrYbSi{sub 4}N{sub 7} and BaYbSi{sub 4}N{sub 7} were obtained by reaction of silicon diimide with metallic strontium/barium and ytterbium. The reactions have been carried out under nitrogen atmosphere in a high-frequency furnace at 1650 C, SrYbSi{sub 4}N{sub 7} (P6{sub 3}mc, a = 598.80(3), c = 974.99(9) pm, Z = 2, R1 = 0.023, wR2 = 0.038) and BaYbSi{sub 4}N{sub 7} (P6{sub 3}mc, a = 603.07(2), c = 981.98(4) pm, Z = 2, R1 = 0.021, wR2 = 0.048) are isotypic and contain M{sup 2+} ions (M = Sr, Ba), Yb{sup 3+} ions, as well as a three-dimensional covalent network structure of corner-sharing SiN{sub 4} tetrahedra. SrYbSi{sub 4}N{sub 7} and BaYbSi{sub 4}N{sub 7} are the first compounds with one central nitrogen connecting four silicon. These N{sup [4]} bridges significantly extend the spectrum of possible linkages in Si-N network structures. (orig.)

  11. Growth and Characteristic of YbAl3(BO3)4 Crystal

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    YbAl3(BO3)4 crystal of good optical quality was grown by the flux method. The structure of YbAl3(BO3)4 crystal was determined by single-crystal X-ray diffraction. The experiment shows that YbAl3(BO3)4 belongs to the double borates with a trigonal structure. The space group is R32 and its unit cell constants were measured to be a=0.92965 nm, c=0.72129 nm, V=0.53673 nm3, Z=3. The transmittance spectra were measured. The cut-off of YbAl3(BO3)4 crystal is 216 nm, and there are two absorption peaks located at 940 and 975 nm from 190 nm to 2600 nm. The thermal properties of YbAl3(BO3)4 crystal were studied for the first time. The average thermal expansion coefficients were determined to be 2×10-6/℃, 9.5×10-6/℃ along a- and c- direction. The specific heat of YbAl3(BO3)4 crystal was measured to be 0.6695 J·(g·℃)-1 at room temperature. All results indicate that the YbAl3(BO3)4 crystal is an excellent stoichioimetric laser material.

  12. Syntheses and Structural Researches of Yb3+ Complexes with Nitrilotriacetic Acids--Nine-coordinate K3[Yb(nta)2(H2O)]·5H2O and Eight-coordinate Na3[Yb(nta)2]·6H2O Complexes

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Yb3+ complexes with two nitrilotriacetic acid molecules were prepared and their compositions were determined as K3[Yb(nta)2(H2O)]*5H2O and Na3[Yb(nta)2]*6H2O by elemental analyses. Their structures were characterized by single-crystal X-ray diffraction analyses. In complex K3[Yb(nta)2(H2O)]*5H2O, the YbN2O7 part forms a nine-coordinate monocapped square antiprismatic structure. In complex Na3[Yb(nta)2]*6H2O, the YbN2O6 part forms an eight-coordinate square antiprismatic structure. It can be seen that the outer cations (K+ and Na+) greatly affect the coordination number and coordinate structure from these results.

  13. Yb-doped ZnSe nanoparticles: synthesis, physical properties and photocatalytic activity.

    Science.gov (United States)

    Khataee, A R; Hosseini, M; Hanifehpour, Y; Safarpour, M; Joo, S W

    2014-09-01

    In this study, Yb-doped ZnSe nanoparticles were synthesized by co-reduction method at 150 degrees C and pH = 12 for 24 h. The obtained materials were characterized by X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Powder XRD patterns indicated that the Yb(x)Zn(1-x)Se crystals (x = 0.00-0.10) are isostructural with ZnSe. SEM and TEM images confirmed doping of Yb3+ into the lattice of ZnSe nanoparticles. The UV-Vis diffuse reflectance characteristics of the Yb-doped ZnSe samples were quite similar to that of the undoped sample and showed a strong photoabsorption at visible light range. The electrical conductivity of Yb-doped ZnSe nanomaterials was higher than pure ZnSe at room temperature, and increased with temperature. The photocatalytic activity of synthesized nanoparticles was investigated by the degradation of Orange II solution under visible light irradiation. It was observed that the color removal efficiency of Yb-doped ZnSe catalyst was much higher than that of pure ZnSe (26.28 and 77.10% after 120 min of treatment for ZnSe and Yb(0.06)Zn(0.94)Se, respectively). The results demonstrated the good photocatalytic ability of synthesized nanoparticles under visible light. Also, it was revealed that the decolorization efficiency of Orange II over Yb-doped ZnSe increased with increasing Yb loading up to 6 mol% and then decreased.

  14. Influences of Yb substitution on the intergrain connections and flux pinning properties of Bi-2212 superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shengnan, E-mail: snzhang@c-nin.com [Superconducting Materials Research Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China); Li, Chengshan; Hao, Qingbin [Superconducting Materials Research Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China); Lu, Tianni [Superconducting Materials Research Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China); College of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Zhang, Pingxiang [Superconducting Materials Research Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China)

    2015-04-15

    Highlights: • Optimization of intergrain connections has been obtained by Yb doping. • Changes of the grain boundary structures after doping have been observed by HRTEM. • Flux pinning mechanism change with Yb doping has been analyzed and explained. • Improved critical current density has been obtained by proper amount of Yb doping. - Abstract: Polycrystalline bulks Bi{sub 2}Sr{sub 2−x}Yb{sub x}CaCu{sub 2.0}O{sub 8+δ} (Bi-2212) with Yb doping content of x = 0, 0.01, 0.02 and 0.05) were fabricated by solid state sintering process. Bi-2212 precursor powders were synthesized by modified co-precipitation process, and Yb{sub 2}O{sub 3} powders were added into the precursor powders during the calcination process as dopants. The influences of Yb substitution on the lattice parameter, microstructure and related superconducting properties were systematically investigated. The amorphous components within the grain boundaries were observed with HRTEM, which contributed to the formation of weak links. Therefore, both the decreasing number of porosity and better crystallized grain boundary structure after Yb doping obviously enhanced the intergrain connections. Meanwhile, doping of Yb ions into Bi-2212 matrix also contributed to the enhancement of point pining, thus lead to the improvement of in-field critical current density. Based on the enhancements of both intergrain connections and flux pinning properties, improvement of critical current density was obtained with the optimal doping content of x = 0.02.

  15. Engagement und Beanspruchung von Lehrpersonen in der Phase des Berufseintritts

    OpenAIRE

    Affolter-Huber, Benita Barbara

    2017-01-01

    Die Dissertation untersucht die Entstehung von Engagement und Beanspruchung von Lehrpersonen am Übergang von der Ausbildung in den Beruf. Das Job Demands-Resources Modell wird durch die Lern- und Vermeidungsleistungszielorientierung, die allgemeine Selbstwirksamkeits- sowie die Lehrerselbstwirksamkeitserwartung, die Extraversion und den Neurotizismus ergänzt und empirisch mittels Pfadanalysen geprüft. Aus den Befunden geht hervor, dass das Engagement und die Beanspruchung durch unterschiedlic...

  16. Studien zur Kinetik der Fehlfaltung un Aggregation von Proteinen

    OpenAIRE

    Modler, Andreas Johannes

    2003-01-01

    Diese Arbeit befasst sich mit der Kinetik der Fehlfaltung und Aggregation von Proteinen. Anhand dreier Beispiele, der Phosphoglyceratkinase (PGK) aus Hefe, einer Variante von Barstar und des Prion-Proteins des Syrischen Hamsters (SHaPrP(90-232)) wurde insbesondere die Kinetik der Bildung von Amyloidfibrillen und deren kinetischer Vorläuferstrukturen mittels dynamischer und statischer Lichtstreuung, Circulardichroismus, Infrarotspektroskopie, Elektronenmikroskopie und teilweise analytischer Ch...

  17. From regular modules to von Neumann regular rings via coordinatization

    Directory of Open Access Journals (Sweden)

    Leonard Daus

    2014-07-01

    Full Text Available In this paper we establish a very close link (in terms of von Neu- mann's coordinatization between regular modules introduced by Zel- manowitz, on one hand, and von Neumann regular rings, on the other hand: we prove that the lattice L^{fg}(M of all finitely generated submodules of a finitely generated regular module M, over an arbitrary ring, can be coordinatized as the lattice of all principal right ideals of some von Neumann regular ring S.

  18. Thomas-Fermi-von Weizsaecker theory of atoms and molecules

    Energy Technology Data Exchange (ETDEWEB)

    Benguria, R.; Brezis, H.; Lieb, E.H.

    1981-11-02

    We place the Thomas-Fermi-von Weizsaecker model of atoms on a firm mathematical footing. We prove existence and uniqueness of solutions of the Thomas-Fermi-von Weizsaecker equation as well as the fact that they minimize the Thomas-Fermi-von Weizsaecker energy functional. Moreover, we prove the existence of bindings for two very dissimilar atoms in the frame of this model.

  19. Portrait of Dr. Von Braun with Walt Disney, 1954.

    Science.gov (United States)

    1954-01-01

    Marshall Center Director Dr. Wernher Von Braun is pictured with Walt Disney during a visit to the Marshall Space Flight Center in 1954. In the 1950s, Dr. Von Braun while working in California on the Saturn project, also worked with Disney studios as a technical director in making three films about Space Exploration for television. Disney's tour of Marshall in 1965 was Von Braun's hope for a renewed public interest in the future of the Space Program at NASA.

  20. Saage tuttavaks : Elisabeth ja Karl von Hoerschelmann / Mai Levin

    Index Scriptorium Estoniae

    Levin, Mai, 1942-

    2004-01-01

    Kuraator M. Levin kuni 10. X 2004 Adamson-Ericu muuseumis avatud näitusest "Tuntud ja tundmatud Elisabeth von Rosendorff-Hoerschelmann ja Karl von Hoerschelmann". Enamik töid on kunstnike laste Konstantin Hoerschelmanni ja Anna Röder-Hoerschelmanni omand. Elisabeth Rosendorff (1898-1984) sündis Virumaal Maidlas eesti perekonnas, Karl von Hoerschelmann (1899-1951) Sevastoopolis saksa perekonnas

  1. Saage tuttavaks : Elisabeth ja Karl von Hoerschelmann / Mai Levin

    Index Scriptorium Estoniae

    Levin, Mai, 1942-

    2004-01-01

    Kuraator M. Levin kuni 10. X 2004 Adamson-Ericu muuseumis avatud näitusest "Tuntud ja tundmatud Elisabeth von Rosendorff-Hoerschelmann ja Karl von Hoerschelmann". Enamik töid on kunstnike laste Konstantin Hoerschelmanni ja Anna Röder-Hoerschelmanni omand. Elisabeth Rosendorff (1898-1984) sündis Virumaal Maidlas eesti perekonnas, Karl von Hoerschelmann (1899-1951) Sevastoopolis saksa perekonnas

  2. Sicherheitskriterien bei der Auswahl von ERP-Systemen

    OpenAIRE

    Wollersheim, Jan;Konstantinidis, Christos;Krcmar, Helmut

    2014-01-01

    Bei Auswahl und Anpassung von Software as a Service (SaaS) basierten ERP-Systemen (SaaS-ERP) kann auf bew?hrte und erprobte Kriterien zur?ckgegriffen werden. Dieser Beitrag strukturiert exemplarisch ausgew?hlte Sicherheits- und Risiko-Kriterien (S&R-Kriterien) anhand von f?nf Perspektiven. Dabei wird zuerst die Auswahl und im Folgenden die Anpassung von SaaS basierten ERP-Systemen betrachtet.

  3. Preiswettbewerb im deutschen Lebensmitteleinzelhandel: Empirische Analysen anhand von Scannerdaten

    OpenAIRE

    Hoffmann, Angela

    2012-01-01

    Der deutsche Lebensmitteinzelhandel ist durch eine hohe Konzentration und einen intensiven Preiswettbewerb gekennzeichnet. Ziel dieser Arbeit ist es, die Preissetzung von Discountern, Super- und Verbrauchermärkten unter Beachtung von Sonderangeboten und den daraus resultierenden Preiswettbewerb zu analysieren. Vier empirische Studien anhand von Scannerdaten werden durchgeführt. Es zeigt sich, dass das Ausmaß der Preissynchronisation bei Milchprodukten im deutschen Handel deutlich größer i...

  4. Synthesis and spectroscopic characterization of Yb3+ in Ca1-XYbXF2+X crystals

    Science.gov (United States)

    Ito, M.; Goutaudier, C.; Guyot, Y.; Lebbou, K.; Fukuda, T.; Boulon, G.

    2004-11-01

    Ca1-XYbXF2+X crystals were grown by two different methods: simple melting under CF{4} atmosphere and laser heated pedestal growth (LHPG) method under Ar atmosphere. Spectroscopic characterization has been carried out to separate different crystallographic site in Ca1-XYbXF2+X crystals and to identify Stark's levels of Yb3+ transitions. Experimental decay time dependence of Yb3+ concentration was analyzed by using concentration gradient fiber in order to understand concentration quenching mechanisms. Energy transfer to unexpected rare earth impurities observed by up-conversion emission spectra in visible region under IR Yb3+ ion pumping seems to be an efficient process.

  5. Optical properties of Yb{sup 3+}-doped phosphate laser glasses

    Energy Technology Data Exchange (ETDEWEB)

    Venkatramu, V. [Department of Physics, Yogi Vemana University, Kadapa 516 003 (India); Vijaya, R. [Department of Physics, Sri Venkateswara University, Tirupati 517 502, Andhra Pradesh (India); Leon-Luis, S.F. [MALTA Consolider Team, Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, E-38200 San Cristobal de La Laguna, Santa Cruz de Tenerife (Spain); Babu, P. [Department of Physics, Govt. Degree and P.G. College, Wanaparthy 509 103 (India); Jayasankar, C.K., E-mail: ckjaya@yahoo.com [Department of Physics, Sri Venkateswara University, Tirupati 517 502, Andhra Pradesh (India); Lavin, V. [MALTA Consolider Team, Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, E-38200 San Cristobal de La Laguna, Santa Cruz de Tenerife (Spain); Instituto Universitario de Estudios Avanzados en Atomica, Molecular y Fotonica (IUdEA), Universidad de La Laguna, E-38200 San Cristobal de La Laguna, Santa Cruz de Tenerife (Spain); Dhareshwar, L.J. [Laser and Neutron Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2011-04-21

    Graphical abstract: Display Omitted Research highlights: > The optical properties of Yb{sup 3+}-doped phosphate glasses exhibit better laser performance parameters. > The OH{sup -} concentration in glasses increases with increase of Yb{sub 2}O{sub 3} concentration. > The quenching of lifetime is purely diffusion limited at lower Yb{sub 2}O{sub 3} concentration. > The lifetime of {sup 2}F{sub 5/2} is proportional to inter-ionic distance between Yb{sup 3+} ions. - Abstract: Ytterbium-doped phosphate glasses have been prepared and studied their spectroscopic properties through absorption, emission and Fourier transform infrared (FTIR) spectral studies and time-resolved luminescence decay curves. The absorption cross-section has been found to vary with the variation of Yb{sub 2}O{sub 3} concentration. The results of the FTIR spectra show that the OH{sup -} content is increasing with increase of the Yb{sub 2}O{sub 3} concentration in these glasses. The decay curves of the {sup 2}F{sub 5/2} level of Yb{sup 3+} ions exhibit a single exponential nature for all the concentrations. The lifetimes of the {sup 2}F{sub 5/2} level of Yb{sup 3+} ions decreases from 1.04 to 0.27 ms when the Yb{sub 2}O{sub 3} concentration is increased from 0.1 to 6.0 mol%. The quenching of lifetimes has been found to vary directly with the inter-ionic distance between the Yb{sup 3+} ions. The concentration quenching of the lifetime has been analyzed using different energy transfer processes and no evidence of cooperative luminescence of Yb{sup 3+} ions has been found in these glasses, which reveals that the present glasses are useful for photonic device applications. The laser performance properties have also been evaluated for these glasses and compared with those of other reported Yb{sup 3+}-doped glass systems.

  6. Modeling of Yb3+-sensitized Er3+-doped silica waveguide amplifiers

    DEFF Research Database (Denmark)

    Lester, Christian; Bjarklev, Anders Overgaard; Rasmussen, Thomas

    1995-01-01

    A model for Yb3+-sensitized Er3+-doped silica waveguide amplifiers is described and numerically investigated in the small-signal regime. The amplified spontaneous emission in the ytterbium-band and the quenching process between excited erbium ions are included in the model. For pump wavelengths...... between 860 and 995 nm, the amplified spontaneous emission in the ytterbium-band is found to reduce both the gain and the optimum length of the amplifier significantly. The achievable gain of the Yb3+-sensitized amplifier is found to be higher than in an Er3+-doped silica waveguide without Yb 3+ (18 d...

  7. Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses

    Science.gov (United States)

    Rathod, K. D.; Singh, P. K.; Natarajan, Vasant

    2014-09-01

    We demonstrate generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman Slower. They are then subjected to a pair of molasses beams inclined at $45^\\circ$ with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate selective deflection of the bosonic isotope $^{174}$Yb, and the fermionic isotope $^{171}$Yb. Using a transient measurement after the molasses beams are turned on, we find a longitudinal temperature of 41 mK.

  8. Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses

    Indian Academy of Sciences (India)

    K D Rathod; P K Singh; Vasant Natarajan

    2014-09-01

    We demonstrate the generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman slower. They are then subjected to a pair of molasses beams inclined at 45° with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate the selective deflection of the bosonic isotope 174Yb and the fermionic isotope 171Yb. Using a transient measurement after the molasses beams are turned on, we find a longitudinal temperature of 41 mK.

  9. Yb-doped yttria-alumino-silicate nano-particles based optical fibers: Fabrication and characterization

    Science.gov (United States)

    Paul, M. C.; Pal, M.; Kir'yanov, A. V.; Das, S.; Bhadra, S. K.; Barmenkov, Yu. O.; Martinez-Gamez, A. A.; Lucio-Martínez, J. L.

    2012-04-01

    An efficient method to fabricate transparent glass ceramic fibers containing in-situ grown Yb 3+ doped oxide nano-particles based on yttria-alumino-silicate glass is presented. These large-mode area Yb 3+ doped fibers having a core diameter around 25.0 μm were drawn by a proper control over the involved process parameters; by this, the size of nano-particles was maintained within 5-10 nm. The main spectroscopic and laser properties of the fabricated fibers along with the nano-structuration results are reported. These results reveal that the developed method offers new scopes for the contemporary Yb 3+ fiber based devices.

  10. Laser Cooling Using Anti-Stokes Fluorescencein Yb3+-Doped Fluorozirconate Glasses

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The fluorozirconate glasses ZBLANP( ZrF4-BaF2-LaF3-AlF3-NaF-PbF2) doped with different Yb3+ concentration were prepared. The Raman spectra and absorption spectra are measured to substantiate the existence of phonon-assisted emission. After analyzing the normalized absorption spectra of samples with different Yb3+-doped concentration, we calculated the maximum cooling effect in the 3 wt% Yb3+-doped sample pumped at 1 012.5 nm. The corresponding cooling capability is about -4.09 ℃/W and the cooling efficiency reaches 1.76%.

  11. Investigation of the Spin Hamiltonian Parameters of Yb3+ in CaWO4 Crystal

    Science.gov (United States)

    Dong, Hui-Ning; Wu, Shao-Yi

    2004-12-01

    In this paper, the spin Hamiltonian parameters g factors g∥ and g⊥ of Yb3+ and hyperfine structure constants A∥ and A⊥ of 171Yb3+ and 173Yb3+ in CaWO4 crystal are calculated from the two-order perturbation formulae. In these formulae, the contributions of the covalence effects, the admixture between J =7/2 and J =5/2 states as well as the second-order perturbation are included. The needed crystal parameters are obtained from the superposition model and the local structure of the studied system. The calculated results are in reasonable agreement with the observed values. The results are discussed.

  12. YbNiAl{sub 2}: A new Yb-based antiferromagnet with a field-induced ferromagnetic order

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, D.P., E-mail: rojasd@unican.e [Departamento CITIMAC, Av de los Castros S/N, Santander 39005 (Spain); Rodriguez Fernandez, J.; Espeso, J.I.; Gomez Sal, J.C. [Departamento CITIMAC, Av de los Castros S/N, Santander 39005 (Spain)

    2009-10-15

    We report measurements on the thermal and magnetic properties in the temperature range 2-300 K for the YbNiAl{sub 2} compound which crystallizes in the orthorhombic MgCuAl{sub 2}-type structure (space group Cmcm). At zero magnetic field, AC-magnetic susceptibility data show a peak in the real component consistent with an antiferromagnetic order below T{sub N}=4.8K. A field-induced ferromagnetic order is observed from the zero field cooled and field cooled curves of DC-magnetic susceptibility at different magnetic fields with a transition to a ferromagnetic state between 9 and 10 kOe. It is further confirmed by the isothermal magnetization curves as a function of the magnetic field at several temperatures, showing two metamagnetic transitions at H{sub 1}=8kOe and H{sub 2}=9.3kOe. The results are compared to those reported for other Yb-Ni-Al compounds.

  13. Solares Recyceln von Aluminium in einem direkt bestrahlten Drehrohrofen

    OpenAIRE

    Neises-von Puttkamer, Martina; Roeb, Martin; Beyer, T.; Reinhold, Jan Philipp; Willsch, Christian; Thelen, Martin; Raeder, Christian; Oliveira,Lamark de; TESCARI, Stefania; Breuer, Stefan; Sattler, Christian

    2016-01-01

    Das Aufschmelzen von Metallen ist ein energieintensiver Prozess, da hier hohe Temperaturen benötigt werden. Konventionell wird diese Energie mit fossilen Energieträgern zur Verfügung gestellt. Mit einem solaren Schmelzverfahren von Metallen können der Ausstoß von CO2 und die Energiekosten der Gießereien erheblich gesenkt werden. Insbesondere Länder mit hoher direkter Solarstrahlung wie Südafrika, können ein solches Verfahren zum Schmelzen und Wiederverwerten von Metallschrott einsetzten. ...

  14. Synthesis and thermoelectric properties of rare earth Yb-doped Ba{sub 8−x}Yb{sub x}Si{sub 30}Ga{sub 16} clathrates

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lihua, E-mail: lhliu@ustb.edu.cn [University of Science and Technology Beijing, School of Mathematics and Physics, Department of Physics, Beijing 100083 (China); Li, Feng [University of Science and Technology Beijing, School of Mathematics and Physics, Department of Physics, Beijing 100083 (China); Wei, Yuping; Chen, Ning; Bi, Shanli [University of Science and Technology Beijing, School of Materials Science and Engineering, Beijing 100083 (China); Qiu, Hongmei [University of Science and Technology Beijing, School of Mathematics and Physics, Department of Physics, Beijing 100083 (China); Cao, Guohui [University of Science and Technology Beijing, School of Materials Science and Engineering, Beijing 100083 (China); Li, Yang [University of Science and Technology Beijing, School of Mathematics and Physics, Department of Physics, Beijing 100083 (China); University of Puerto Rico at Mayaguez, Department of Engineering Science and Materials, Mayaguez, PR 00681-9044 (United States)

    2014-03-05

    Highlights: • Samples with the chemical formula Ba8−{sub x}Yb{sub x}Si{sub 30}Ga{sub 16} (x = 0, 0.5, 0.7, 1 and 1.5) were prepared. • Some Yb atoms enter the clathrate lattice to replace Ba, while other Yb atoms are oxidized as Yb{sub 2}O{sub 3}. • The thermal conductivity decreases with Yb-doping. • Thermoelectric figure of merit ZT significantly increased. -- Abstract: The potential thermoelectric and magnetic application of clathrate materials with rare-earth doping is the focus of much of the recent research activity in the synthetic material physics and chemistry. A series of clathrate samples with the chemical formula Ba{sub 8−x}Yb{sub x}Si{sub 30}Ga{sub 16} (x = 0, 0.5, 0.7, 1 and 1.5) were prepared by combining arc melting, ball milling and spark plasma sintering (SPS) techniques. X-ray diffraction and scanning electronic microscopy combined with energy-dispersive X-ray spectroscopy (EDS) analysis showed the dominant phase to be the type-I clathrate. Whereas, X-ray structural refinement and EDS analysis indicated that some Yb atoms enter the clathrate lattice to replace Ba at 2a sites, while other Yb atoms are oxidized as Yb{sub 2}O{sub 3} precipitated around grain boundaries. The solid solubility of Yb into clathrate lattice yielded x ∼ 0.3. Comparative analysis between Yb-doped and Yb-free clathrates showed that the thermal conductivity decreases with Yb-doping. Consequently, thermoelectric figure of merit ZT significantly increased.

  15. Zielgerechte Logistikkonzepte in Betrachtung von LNG- Umschlageplätzen unter Berücksichtigung von Industrie 4.0

    OpenAIRE

    Jenne, Christian; Noche, Bernd

    2016-01-01

    Logistikkonzepte in der Spedition und Transportgewerbe spielen heutzutage eine immer wichtigere Rolle, um Lohnnebenkosten so niedrig wie möglich zu halten. Gerade in der Spedition entsteht ein Zusammenspiel aus zeitnaher Lieferung von Konsumgütern und Optimierung der Lagerhaltungskosten bei dem die modulare Integration von Logistik, Informationstechnischen Systemen und vernetzter Kommunikation eine ganz spezifische Rolle hat. Anbindung von der Industrie zum Kunden wird dadurch immer mehr vers...

  16. WIE PREISSENSIBEL REAGIEREN DEUTSCHE VERBRAUCHER? AKTUELLE SCHÄTZUNGEN VON PREIS- UND AUSGABENELASTIZITÄTEN AUF DER BASIS VON HAUSHALTSPANELDATEN

    OpenAIRE

    2012-01-01

    Der Beitrag untersucht das Nachfrageverhalten der deutschen Privathaushalte anhand von Daten zweier Haushaltspanels der Gesellschaft für Konsumforschung. Es wird ein Almost Ideal Demand System (AIDS) mit 13 Lebensmittelgruppen für den Zeitraum von 2004 bis 2008 geschätzt. Der Fokus der Analyse liegt auf den geschätzten Eigenpreis- und Ausga-benelastizitäten und deren Einordnung in die Literatur. Mit Ausnahme von Kaffee und Eiern zeigt sich die Nachfrage in allen Lebensmittelgruppen, darunter ...

  17. Produktion von pharmakologischen Sekundärmetabolite - Am Beispiel von mikrobiellen β-Lactam-Antibiotika und pflanzlichen Triterpenen

    OpenAIRE

    Ludwig, Benjamin

    2015-01-01

    Durch das Entstehen von neuen Infektionskrankheiten und das Auftreten von Resistenzen können bisher verwendete Medikamente ihren pharmazeutischen Nutzen verlieren. Daher ist eine konstante Weiterentwicklung von bioaktiven Pharmazeutika lebensrettend. Viele pflanzli-che und mikrobielle Sekundärmetabolite besitzen gesundheitsfördernde Wirkungen und kön-nen als Ressourcen für die Entwicklung neuer Arzneimittel herangezogen werden. Da Pflan-zen und Mikroorganismen ein sehr umfangreiches Repertoir...

  18. Assoziation des arteriellen Sauerstoffpartialdrucks mit dem Auftreten von Erythroblasten im peripheren Blut von Patienten einer chirurgischen Intensivstation

    OpenAIRE

    Kuert, Sandra

    2012-01-01

    Erythroblasten (EBL) treten im peripheren Blut eines gesunden Erwachsenen gewöhnlich nicht auf. Studien zeigten, dass das Auftreten von EBL bei hospitalisierten Patienten auf ein erhöhtes Mortalitätsrisiko hinweist. Die zugrundeliegenden Mechanismen sind bisher unbekannt. Es ergaben sich Hinweise, dass EBL bei Zuständen von Hypoxie und Inflammation auftreten. Die vorliegende Studie untersucht den Einfluss des arteriellen Sauerstoffpartialdruckes (pO2) auf das Auftreten von EBL ...

  19. Production and spectroscopy of ultracold YbRb{sup *} molecules

    Energy Technology Data Exchange (ETDEWEB)

    Nemitz, Nils

    2008-11-15

    This thesis describes the formation of electronically excited but translationally cold molecules formed from rubidium atoms and two isotopes of ytterbium ({sup 176}Yb and {sup 174}Yb) by means of photoassociation. The experiments were performed in a combined MOT with 10{sup 9} rubidium atoms and 2.10{sup 6} ytterbium atoms at temperatures of less than 1 mK. Photoassociation lines were found by trap loss spectroscopy throughout a wavelength range of 2 nm near the 795 nm D1 transition in rubidium. The majority of lines belong to two vibrational series in the excited YbRb{sup *} molecule, converging on a system of a ground state ytterbium atom and an excited rubidium atom. The strong variation of line strength between different vibrational lines is explained through the Franck-Condon principle. An improved version of the Leroy-Bernstein equation was used to extract the leading dispersion coefficient of the potential from the vibrational progression. Most of the observed lines show a resolved rotational structure as expected from a basic quantum mechanical model. The series terminates with the third or forth rotational component due to the ground state centrifugal barrier.The measured rotational constants agree very well with calculations based on the C{sub 6} coefficient. The discovery of a splitting of the rotational components into subcomponents indicates an uncommon angular momentum coupling described by Hund's case. Variations in the depth of the subcomponents indicates a similar splitting in the ground state, with the energies of the substates based on the alignment of the rubidium atom's magnetic dipole moment relative to the angular momentum carried by an approaching ytterbium atom. This creates an additional ground state barrier, partially suppressing some of the subcomponents. Using a rate equation model developed for this purpose, a maximum formation rate of 2.5.10{sup 6} molecules per second was calculated over the volume of the entire trap. The

  20. Philologie im Horizont der Geschichtlichkeit von Sprache und Text: zum Tagungsband von Wulf Oesterreicher und Maria Selig

    Directory of Open Access Journals (Sweden)

    Olaf Müller

    2016-03-01

    Full Text Available Wulf Oesterreicher und Maria Selig, Hrsg., Geschichtlichkeit von Sprache und Text: Philologien – Disziplingenese – Wissenschaftshistoriographie (Paderborn: Wilhelm Fink, 2014, 332 S.

  1. Optical and magnetic properties of Yb ion-doped cobalt-based ZnO nanoparticles for DMS applications

    Indian Academy of Sciences (India)

    T Thangeeswari; M Priya; J Velmurugan; N Padmanathan

    2015-09-01

    Well-crystalline structured ZnO nanoparticles with cobalt (Co) and ytterbium (Yb) multiple ions doping were successfully synthesized by the chemical precipitation technique. The structures, optical and magnetic properties of the samples were analysed with X-ray diffraction (XRD), UV–visible spectroscopy and magnetic measurements, respectively. In the XRD pattern of the pure ZnO and Yb co-doped samples, the formation of highly crystalline phase of pure ZnO was observed even at high Yb concentration. UV–vis spectra show a strong UV absorbance for all the samples with different absorbance maxima. Magnetic characterizations have shown that the sample with 1% Yb co-doped ZnO: Co nanoparticles exhibited a clear ferromagnetic (FM) behaviour at room temperature. The X-ray photoelectron spectral peaks for Yb 4f ions reveal Yb occupation of both Yb3+ as well as Yb2+ states. Hence, it can be confirmed that a clear FM behaviour at room temperature was exhibited by an imbalanced valence state of Yb that strongly interacted with the Co2+. When compared to the Co-doped ZnO, Yb co-doped ZnO exhibits a clear ferromagnetism at room temperature with high coercivity due to the contribution of both 3d and 4f exchange interaction with the host matrix.

  2. YB-1 expression promotes epithelial-to-mesenchymal transition in prostate cancer that is inhibited by a small molecule fisetin

    Science.gov (United States)

    Khan, Mohammad Imran; Adhami, Vaqar Mustafa; Lall, Rahul Kumar; Sechi, Mario; Joshi, Dinesh C.; Haidar, Omar M.; Syed, Deeba Nadeem; Siddiqui, Imtiaz Ahmad; Chiu, Shing-Yan; Mukhtar, Hasan

    2014-01-01

    Epithelial-to-mesenchymal transition (EMT) plays an important role in prostate cancer (PCa) metastasis. The transcription/translation regulatory Y-box binding protein-1 (YB-1) is known to be associated with cancer metastasis. We observed that YB-1 expression increased with tumor grade and showed an inverse relationship with E-cadherin in a human PCa tissue array. Forced YB-1 expression induced a mesenchymal morphology that was associated with down regulation of epithelial markers. Silencing of YB-1 reversed mesenchymal features and decreased cell proliferation, migration and invasion in PCa cells. YB-1 is activated directly via Akt mediated phosphorylation at Ser102 within the cold shock domain (CSD). We next identified fisetin as an inhibitor of YB-1 activation. Computational docking and molecular dynamics suggested that fisetin binds on the residues from β1 - β4 strands of CSD, hindering Akt's interaction with YB-1. Calculated free binding energy ranged from −11.9845 to −9.6273 kcal/mol. Plasmon Surface Resonance studies showed that fisetin binds to YB-1 with an affinity of approximately 35 μM, with both slow association and dissociation. Fisetin also inhibited EGF induced YB-1 phosphorylation and markers of EMT both in vitro and in vivo. Collectively our data suggest that YB-1 induces EMT in PCa and identify fisetin as an inhibitor of its activation. PMID:24770864

  3. Tolerance and removal of chromium(Ⅵ) by Bacillus sp. strain YB-1 isolated from electroplating sludge

    Institute of Scientific and Technical Information of China (English)

    LIU Yun-guo; FENG Bao-ying; FAN Ting; ZHOU Hai-zhou; LI Xin

    2008-01-01

    Four chromium(Ⅵ)-resistant bacteria named YB-1, YB-2, YB-3 and YB-4 were isolated from Cr-electroplating sludge. YB-1 and YB-2 were identified as a member of Bacillus sp. based on morphology and Biolog Microstation System. The strain of YB-1 was selected to test for its resistance and ability to remove Cr(Ⅵ) from aqueous solution. The results indicate that YB-1 exhibits high MIC value which can almost reach 140 mg/L and the growth of YB-1 in liquid medium containing 60 mg/L Cr(Ⅵ) is affected especially in the late exponential phase and stationary phase. Furthermore, the potential of living and freeze-dried YB-1 biomass to remove Cr(Ⅵ) was studied in different pH, biosorbent dose, contact time and initial concentration using the batch method. At the optimal conditions, living and freeze-dried biomass are capable of absorbing 34.5 mg/g and 17.8 mg/g chromium(Ⅵ) at initial concentration of 60 mg/L, respectively. The adsorption data were fitted to Langmuir isotherm model for these two sorbents. Kinetic studies show that the rates of sorption all follow the pseudo-second order kinetics.

  4. X-ray Excitation Triggers Ytterbium Anomalous Emission in CaF 2 :Yb but Not in SrF 2 :Yb

    Energy Technology Data Exchange (ETDEWEB)

    Hughes-Currie, Rosa B.; Ivanovskikh, Konstantin V.; Wells, Jon-Paul R.; Reid, Michael F.; Gordon, Robert A.; Seijo, Luis; Barandiarán, Zoila

    2017-02-27

    Materials that luminesce after excitation with ionizing radiation are extensively applied in physics, medicine, security, and industry. Lanthanide dopants are known to trigger crystal scintillation through their fast d–f emissions; the same is true for other important applications as lasers or phosphors for lighting. However, this ability can be seriously compromised by unwanted anomalous emissions often found with the most common lanthanide activators. We report high-resolution X-ray-excited optical (IR to UV) luminescence spectra of CaF2:Yb and SrF2:Yb samples excited at 8949 eV and 80 K. Ionizing radiation excites the known anomalous emission of ytterbium in the CaF2 host but not in the SrF2 host. Wave function-based ab initio calculations of host-to-dopant electron transfer and Yb2+/Yb3+ intervalence charge transfer explain the difference. The model also explains the lack of anomalous emission in Yb-doped SrF2 excited by VUV radiation.

  5. X-ray Excitation Triggers Ytterbium Anomalous Emission in CaF2:Yb but Not in SrF2:Yb.

    Science.gov (United States)

    Hughes-Currie, Rosa B; Ivanovskikh, Konstantin V; Wells, Jon-Paul R; Reid, Michael F; Gordon, Robert A; Seijo, Luis; Barandiarán, Zoila

    2017-02-27

    Materials that luminesce after excitation with ionizing radiation are extensively applied in physics, medicine, security, and industry. Lanthanide dopants are known to trigger crystal scintillation through their fast d-f emissions; the same is true for other important applications as lasers or phosphors for lighting. However, this ability can be seriously compromised by unwanted anomalous emissions often found with the most common lanthanide activators. We report high-resolution X-ray-excited optical (IR to UV) luminescence spectra of CaF2:Yb and SrF2:Yb samples excited at 8949 eV and 80 K. Ionizing radiation excites the known anomalous emission of ytterbium in the CaF2 host but not in the SrF2 host. Wave function-based ab initio calculations of host-to-dopant electron transfer and Yb(2+)/Yb(3+) intervalence charge transfer explain the difference. The model also explains the lack of anomalous emission in Yb-doped SrF2 excited by VUV radiation.

  6. Unterschiedliche beta-blockierende Wirkungen von Carvedilol, Metoprolol und Bisoprolol

    Directory of Open Access Journals (Sweden)

    Stoschitzky K

    2001-01-01

    Full Text Available Metoprolol und Bisoprolol sind beta1-selektive Beta-Blocker, Carvedilol ist ein nicht-selektiver Beta-Blocker mit zusätzlicher alpha1-blockierender Wirkung. Wir verglichen die Wirkungen von klinisch empfohlenen Dosen von Carvedilol (25, 50 und 100 mg, Metoprolol (50, 100 und 200 mg und Bisoprolol (2,5, 5 und 10 mg mit Placebo in einer randomisierten, überkreuzten, placebokontrollierten Doppelblind-Studie an 12 gesunden männlichen Freiwilligen. Zwei Stunden (Bisoprolol: drei Stunden nach oraler Applikation der jeweiligen Substanzen wurden arterieller Blutdruck und Herzfrequenz in Ruhe, nach 10 Minuten Belastung und nach weiteren 15 Minuten Erholung gemessen. Verglichen mit Placebo führten ansteigende Dosen von Metoprolol und Bisoprolol in Ruhe zu ansteigenden Wirkungen auf die Herzfrequenz (jeweils -13 %, -15 % und -18 % während ansteigende Dosen von Carvedilol abfallende Wirkungen zeigten (-13 %, -7 % und -3 %. Die Herzfrequenz unter Belastung wurde von Metoprolol (-21 %, -25 % und -24 %, Bisoprolol (-17 %, -21 % und -25 % und Carvedilol gesenkt (-16 %, -16 % und -18 %, die Wirkung von Metoprolol erschien dabei etwas ausgeprägter als jene von Carvedilol. Der systolische Blutdruck wurde sowohl von Metoprolol (-9 %, -16 %, -16 % unter Belastung und -7 %, -7 %, -9 % nach 15 min Erholung, Bisoprolol (-8 %, -12 %, -15 % unter Belastung als auch von Carvedilol (-7 %, -17 %, -20 % unter Belastung und -8 %, -11 %, -14 % nach 15 min Erholung deutlich gesenkt. Auf den diastolischen Blutdruck zeigten die Substanzen (mit Ausnahme von 50 und 100 mg Carvedilol in Ruhe jedoch keine signifikanten Wirkungen. Wir schließen aus unseren Ergebnissen, daß klinisch empfohlene Dosen von Carvedilol bei gesunden Freiwilligen klinisch relevante beta-blockierende Wirkungen nur unter Belastung zeigen, während die von Carvedilol bewirkte Beta-Blockade in Ruhe bestenfalls als schwach zu bezeichnen ist. Auf der anderen Seite zeigen Metoprolol und Bisoprolol sowohl in

  7. Von den Liven von Oesel / August Ludwig Schlözer

    Index Scriptorium Estoniae

    Schlözer, August Ludwig

    2008-01-01

    Avaldatud Eberhard Winkleri initsiatiivil A. L. Schlözeri teose põhjal: Gesammelte Nachrichten von den Ueberresten der Liven, in Livland und Kurland. (1770), mis moodustab osa teosest: Schlözer, August Ludwig. M. Johann Joseph Haigold's Beylagen zum Neuveränderten Russland. Zweiter Theil. Riga und Leipzig, 1770

  8. Ööklubi Club von Überlingen = Club von Überlingen

    Index Scriptorium Estoniae

    2008-01-01

    Ööklubi Club von Überlingen (Madara 22A, Tallinn) sisekujundusest. Sisearhitekt: Taavi Aunre (Boom.ee OÜ). Taavi Aunrest, tema tähtsamad tööd. I-II korruse plaan, 11 värv. vaadet, foto T. Aunrest

  9. Aino Lepik von Wiren / Aino Lepik von Wiren ; interv. Kadi Alatalu

    Index Scriptorium Estoniae

    Lepik von Wirén, Aino, 1961-

    2007-01-01

    Heinrich Marga eksiilvalitsuse (20.06.1990-7.10.1992) kohtuminister Aino Lepik von Wiren pagulaslapse elust Rootsis, haridusest ja elukutse valikust, tööst eksiilvalitsuses, tööleasumisest Eestisse 1992. aastal, seadusandlikust tegevusest ning aluse panekust välismaalaste- ja kodakondsuspoliitikale, naiste võimalustest poliitilisse tippu tõusmiseks, kodu- ja väliseestlaste vastandamisest

  10. Von den Liven von Oesel / August Ludwig Schlözer

    Index Scriptorium Estoniae

    Schlözer, August Ludwig

    2008-01-01

    Avaldatud Eberhard Winkleri initsiatiivil A. L. Schlözeri teose põhjal: Gesammelte Nachrichten von den Ueberresten der Liven, in Livland und Kurland. (1770), mis moodustab osa teosest: Schlözer, August Ludwig. M. Johann Joseph Haigold's Beylagen zum Neuveränderten Russland. Zweiter Theil. Riga und Leipzig, 1770

  11. Ytterbium Doped Gadolinium Oxide (Gd2O3:Yb3+ Phosphor: Topology, Morphology, and Luminescence Behaviour

    Directory of Open Access Journals (Sweden)

    Raunak Kumar Tamrakar

    2014-01-01

    Full Text Available Gd2O3:Yb3+ phosphor has been synthesized by the solid state reaction method with boric acid used as a flux. The resulting Gd2O3:Yb3+ phosphor was characterized by X-ray diffraction (XRD technique, Fourier transmission infrared spectroscopy (FTIR, scanning electron microscope (SEM and transmission electron microscope (TEM, and photoluminescence and thermoluminescence. The results of the XRD show that obtained Gd2O3:Yb3+ phosphor has a cubic structure. The average crystallite sizes could be calculated as 42.9 nm, confirmed by the TEM results. The study suggested that Yb3+ doped phosphors are potential luminescence material for IR laser diode pumping.

  12. Microcalorimetric Study of the Action of Yb3+ ion on the Growth of Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    侯安新; 薛智; 刘义; 屈松生

    2003-01-01

    A microcalorimetric method was used to evaluate the action of Yb3+ ions onthe growth metabolism of Staphylococcus aureus.The power-time curves of the growth metabolism of Staphylo.coccus aureus and the action of Yb3+ ions were obtained by us-ing stopped-flow method at 37 ℃. For evaluation of the action,the growth rate constants ( k1 and k2) for the log phase 1, log phase 2, and the total heat effect (Qtotal) for Staphylococcus aureus were determined. The results show that Yb3+ ions at low concentrations have the stimnlatory effect on Staphylococcus au-reus and that Yb3+ions at higher concentration could inhibit its growth.

  13. Combining Yb and Li: Rapid Quantum Degenerate Gas Production and Interacting Mixtures

    Science.gov (United States)

    Green, Alaina; Roy, Richard; Bowler, Ryan; Gupta, Subhadeep

    2016-05-01

    We detail a readily adaptable method for optimizing evaporative cooling efficiency in optical dipole traps (ODTs), reducing the production time of quantum degenerate gases. Utilizing the time-averaged 'painting' potential of a rapidly moving laser beam, we dynamically shape the trap over the course of evaporation to produce 174 Yb Bose-Einstein condensates of (0.5-1.0) × 105 atoms in (1.6-1.8) seconds. We also report on interaction studies in the quantum degenerate Bose-Fermi 174 Yb-6 Li mixture in the BEC-BCS crossover. Additionally, we present work on photoassociation spectroscopy on 6 Li-Yb mixtures and the production of YbLi* molecules in a dual magneto-optical trap, a first step toward coherent production of ultracold 2 Σ molecules.

  14. Synthesis and properties of Yb:Sc2O3 transparent ceramics

    Institute of Scientific and Technical Information of China (English)

    JIANG Benxue; HU Chen; LI Jiang; KOU Huamin; SHI Yun; LIU Wenbin; PAN Yubai

    2011-01-01

    Yb:Sc2O3 transparent ceramics were fabricated by solid-state reaction and vacuum sintering method.CaO was added as sintering aids by a high energy ball milling.Transparent nearly-fully dense samples were obtained after 1840 ℃ sintering.Using transmitted-light microscope we get the grain sizes are more than 1 00 μm.Using spectrophotometer we get the absorption coefficient centered at 975 nm was 2.65 cm-1.The phosphorescence spectra showed that the line-widths (FWHM) at 975 and 1041 nm were about 4 and 10 nm and the lifetime of Yb ions in Sc2O3 transparent ceramics was about 883 μs.According to the absorption and fluorescence band centers of Yb:Sc2O3 transparent ceramics,the level scheme of Yb3+ ions in Sc2O3 ceramics could be gotten.

  15. Data of evolutionary structure change: 1ATGA-2H5YB [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1ATGA-2H5YB 1ATG 2H5Y A B ---ELKVVTATNFLGTLEQLAGQFAKQTGHAVVISSGSS...>QTAPVTVFAAASLKESMDEAATAYEKATGTPVRVSYAASSALARQIEQGAPADVFLSADLEWMDYLQQHGLVLPAQRHNL...HHHH - 0 1ATG... A 1ATGA KVLAG--NGWRH 1ATG A 1ATGA DKL

  16. The recombination channels of luminescence excitation in YAG:Yb single crystalline films

    Energy Technology Data Exchange (ETDEWEB)

    Zakharko, Ya.M. [Faculty of Electronics, Ivan Franko National University of Lviv, 107 Tarnavskogo str., Lviv 79017 (Ukraine)], E-mail: zakharko@electronics.wups.lviv.ua; Luchechko, A.P. [Faculty of Electronics, Ivan Franko National University of Lviv, 107 Tarnavskogo str., Lviv 79017 (Ukraine); Ubizskii, S.B. [Lviv Polytechnic National University, 12, Bandera srt., Lviv 79013 (Ukraine); Syvorotka, I.I. [Scientific Research Company ' Carat' , 202, Stryjska str., Lviv 79031 (Ukraine); Martynyuk, N.V. [Lviv Polytechnic National University, 12, Bandera srt., Lviv 79013 (Ukraine); Syvorotka, I.M. [Scientific Research Company ' Carat' , 202, Stryjska str., Lviv 79031 (Ukraine)

    2007-04-15

    Absorption and emission spectra, luminescence decay kinetics and thermostimulated luminescence of X-ray irradiated YAG:Yb single crystalline films were studied. Two emission bands peaked at 420 and 488 nm have been detected in the investigated films. The strong thermal quenching of luminescence band at 488 nm was observed above 160 K. The influence of growth conditions and annealing in air on the lifetime of Yb{sup 3+} ion excited state in the IR spectral region have been revealed. The recombination mechanisms of the f-f transition at Yb{sup 3+} ion excitation, as well as the mechanism of lifetime shortening for the excited Yb{sup 3+} luminescence have been discussed.

  17. Yb:YAG ceramic-based laser driver for Inertial Fusion Energy (IFE)

    Science.gov (United States)

    Vetrovec, John; Copeland, Drew A.; Litt, Amardeep S.

    2016-03-01

    We report on a new class of laser amplifiers for inertial confinement fusion (ICF) drivers based on a Yb:YAG ceramic disk in an edge-pumped configuration and cooled by a high-velocity gas flow. The Yb lasant offers very high efficiency and low waste heat. The ceramic host material has a thermal conductivity nearly 15-times higher than the traditionally used glass and it is producible in sizes suitable for a typical 10- to 20-kJ driver beam line. The combination of high lasant efficiency, low waste heat, edge-pumping, and excellent thermal conductivity of the host, enable operation at 10 to 20 Hz at over 20% wall plug efficiency while being comparably smaller and less costly than recently considered face-pumped alternative drivers using Nd:glass, Yb:S-FAP, and cryogenic Yb:YAG. Scalability of the laser driver over a broad range of sizes is presented.

  18. Alumina Paste Layer as a Sublimation Suppression Barrier for Yb14MnSb11

    Science.gov (United States)

    Paik, Jong-Ah; Caillat, Thierry

    2010-01-01

    Sublimation is a major cause of degradation of thermoelectric power generation systems. Most thermoelectric materials tend to have peak values at the temperature where sublimation occurs. A sublimation barrier is needed that is stable at operating temperatures, inert against thermoelectric materials, and able to withstand thermal cycling stress. A porous alumina paste layer is suitable as a sublimation barrier for Yb14MnSb11. It can accommodate stress generated by the thermal expansion discrepancy between the suppression layer and thermoelectric materials. Sublimation suppression is achieved by filling pores naturally with YbO2, a natural byproduct of sublimation. YbO2 generated during the sublimation of Yb14MnSb11 fills the porous structure of the alumina paste, causing sublimation to decrease with time as the pores become filled.

  19. Laser induced broad band anti-Stokes white emission from LiYbF4 nanocrystals

    Institute of Scientific and Technical Information of China (English)

    L. Marciniak; R. Tomala; M. Stefanski; D. Hreniak; W. Strek

    2016-01-01

    Spectroscopic properties of tetragonal LiYbF4 nanocrystals under high dense NIR excitation at vacuum condition were in-vestigated. White, broad band emission covering whole visible part of the spectrum from LiYbF4 nanocrystals was observed. Its in-tensity strongly depended on the excitation power, excitation wavelength and ambient pressure. Temperature of the nanocrystals un-der 975 nm excitation was determined as a function of excitation power. Strong photo-induced current was observed from LiYbF4 pallet. The emission kinetic was analyzed. The mechanism of the anti-Stokes white emission was discussed in terms of the la-ser-induced charge transfer emission from Yb2+ states.

  20. Photoluminescence of an Yb3+/Al3+-codoped microstructured optical fibre

    Institute of Scientific and Technical Information of China (English)

    Xia Chang-Ming; Zhou Gui-Yao; Han Ying; Hou Lan-Tian

    2011-01-01

    An Yb3+/Al3+-codoped microstructured optical fibre is prepared based on photonic crystal fibre technology.The characteristic spectra of preforms and fibres are experimentally investigated.The results show that under a 971 nm excitation,besides the known infrared fluorescence luminescence around 1050 nm,a blue luminescence peak at 486 nm is obtained.Moreover,an unexpected emission peak at 730 nm is also observed.The photoluminescence mechanism of an Yb3+/Al3+-codoped microstructured optical fibre is discussed.The emission peak at 486 nm is attributed to the cooperative upconversion resulting from pairs of Yb3+ions,and the emission peak around 730 nm is ascribed to the stimulated Raman scattering because of nonlinear effects of microstructured optical fibre.The Yb3+/Al3+-codoped microstructured optical fibre is promising for varieties of applications from laser printing and optical recording to cancer treatments,such as photodynamic therapy.

  1. Up-Conversion Emission of Er3+ Ions in Yb3+ Sensitized Oxide Crystals

    Institute of Scientific and Technical Information of China (English)

    Wang Jun; Ruan Yongfeng; Lin Junyi; Liu Jian; Huang Boxian

    2004-01-01

    Most of the up-conversion lasers operated at room temperature are realized with heavy metal fluorides, In this paper the Judd-Ofelt parameters Ωλ ( λ = 2,4,6 ) were calculated for Er3+ ions in Yb3 + sensitized LiNbO3 and YVO4 crystals at room temperature, together with the radiative transition probabilities, non-radiative transition probabilities and resonant transition probabilities of Er3+ ions. Taking into account the energy transfer from Yb3 + to Er3 +, the rate equations are given for Er3 + ions. We obtained from a solution of the rate equations that Yb3 + sensitized YVO4 crystal is more efficient than Yb3 + sensitized LiNbO3 crystal in the up-conversion of 550 nm of Er3+ emission, which is consistent with our observation.

  2. Anisotropic intermediate valence in Yb2M3Ga9 (M = Rh, Ir)

    Energy Technology Data Exchange (ETDEWEB)

    Christianson, A.D.; Lawrence, J.M.; Lobos, A.M.; Aligia, A.A.; Bauer, E.D.; Moreno, N.O.; Booth, C.H.; Goremychkin, E.A.; Sarrao, J.L.; Thompson, J.D.; Batista, C.D.; Trouw, F.R.; Hehlen, M.P.

    2005-04-26

    The intermediate valence compounds Yb{sub 2}M{sub 3}Ga{sub 9} (M = Rh, Ir) exhibit an anisotropic magnetic susceptibility. We report measurements of the temperature dependence of the 4f occupation number, n{sub f}(T), for Yb{sub 2}M{sub 3}Ga{sub 9} as well as the magnetic inelastic neutron scattering spectrum S{sub mag}({Delta}E) at 12 and 300 K for Yb{sub 2}Rh{sub 3}Ga{sub 9}. Both n{sub f}(T) and S{sub mag}({Delta}E) were calculated for the Anderson impurity model with crystal field terms within an approach based on the non-crossing approximation. These results corroborate the importance of crystal field effects in these materials; they also suggest that Anderson lattice effects are important to the physics of Yb{sub 2}M{sub 3}Ga{sub 9}.

  3. High energy single frequency Yb:YAG crystalline fiber waveguide master oscillator power amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall objective is to demonstrate the concept of Yb:YAG crystalline fiber MOPA laser and investigation the technical feasibility toward 50 mJ single frequency...

  4. Study on Band Structure of YbB6 and Analysis of Its Optical Conductivity Spectrum

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The electronic structure of YbB6 crystal was studied by means of density functional (GGA+U) method.The calculations were performed by FLAPW method.The high accurate band structure was achieved.The correlation between the feature of the band structure and the Yb-B6 bonding in YbB6 was analyzed.On this basis, some optical constants of YbB6 such as reflectivity, dielectric function, optical conductivity, and energy-loss function were calculated.The results are in good agreement with the experiments.The real part of the optical conductivity spectrum and the energy-loss function spectrum were analyzed in detail.The assignments of the spectra were carried out to correlate the spectral peaks with the interband electronic transitions, which justify the reasonable part of previous empirical assignments and renew the missed or incorrect ones.

  5. CW fountain of laser-cooled Yb atoms

    CERN Document Server

    Rathod, K D; Natarajan, Vasant

    2013-01-01

    We demonstrate launching of laser-cooled Yb atoms in a continuous atomic fountain. The continuous fountain has significant advantages over the more common pulsed fountain, which was also demonstrated by us recently. The fountain is formed in the following steps---(i) Atoms from a thermal beam are first Zeeman slowed to a small final velocity, (ii) the slowed atoms are captured in a two-dimensional magneto-optic trap (2D-MOT), and (iii) atoms are launched {\\em continuously} in the vertical direction using two sets of moving-molasses beams, inclined at $\\pm 15^\\circ$ to the vertical. The cooling transition used is the strongly-allowed ${^1S}_0 \\rightarrow {^1P}_1$ transition at 399 nm. We capture about $7 \\times 10^6$ atoms in the 2D-MOT, and then launch them with a vertical velocity of 13 m/s at a longitudinal temperature of 125(6) mK.

  6. Spectroscopic properties and laser operation of Yb3+ : SGYB crystal

    Science.gov (United States)

    Xia, Houping; Ma, Qian; Xu, Qiang; Zhao, Lei

    2017-03-01

    A Sr3Yb0.1Gd0.2Y0.7) single crystal was grown by the Czochralski method. The crystal was evaluated by absorption, emission, and luminescence decay measurements. The relevant absorption and emission cross-sections as well as fluorescence lifetimes were calculated and compared. Studies showed that the existence of Gd3+ can lead to greater structural disorder and broaden the spectra of the crystal. Diode-pumped laser action of this crystal is demonstrated for the first time, and the best output power of 1.8 W with a slope efficiency of 75.8% was obtained. Dual-wavelength and three-wavelength oscillations were observed. Thus, this crystal is suitable for use as tunable or ultrashort laser mediums.

  7. Trapped 173Yb Fermi gas across an orbital Feshbach resonance

    Science.gov (United States)

    Iskin, M.

    2017-01-01

    Starting with the two-band description of an orbital Feshbach resonance, we study superfluid properties of a trapped 173Yb Fermi gas under the assumptions of a local-density approximation for the trapping potential and a mean-field approximation for the intraband Cooper pairings. In particular, we investigate the competition and interplay between the pair-breaking effect that is caused by the interband detuning energy, and the pair-breaking and thermal-broadening effects that are simultaneously caused by the temperature. We predict several experimental signatures that are directly caused by this interplay including a spatial separation of superfluid and normal phases within the trap, and could play decisive roles in probing two-band superfluidity in these systems.

  8. Graphene Q-switched Yb:KYW planar waveguide laser

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Wan; Young Choi, Sun; Jun Ahn, Kwang; Yeom, Dong-Il, E-mail: diyeom@ajou.ac.kr, E-mail: rotermun@ajou.ac.kr; Rotermund, Fabian, E-mail: diyeom@ajou.ac.kr, E-mail: rotermun@ajou.ac.kr [Department of Energy Systems Research and Department of Physics, Ajou University, 443-749 Suwon (Korea, Republic of); Aravazhi, Shanmugam; Pollnau, Markus [Integrated Optical Micro Systems Groups, MESA+ Institute of Nanotechnology, University of Twente, 7500 AE Enschede (Netherlands); Griebner, Uwe; Petrov, Valentin [Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin (Germany); Bae, Sukang [Soft Innovative Materials Research Center, Korea Institute of Science and Technology, Jeonbuk 565-905 (Korea, Republic of)

    2015-01-15

    A diode-pumped Yb:KYW planar waveguide laser, single-mode Q-switched by evanescent-field interaction with graphene, is demonstrated for the first time. Few-layer graphene grown by chemical vapor deposition is transferred onto the top of a guiding layer, which initiates stable Q-switched operation in a 2.4-cm-long waveguide laser operating near 1027 nm. Average output powers up to 34 mW and pulse durations as short as 349 ns are achieved. The measured output beam profile, clearly exhibiting a single mode, agrees well with the theoretically calculated mode intensity distribution inside the waveguide. As the pump power is increased, the repetition rate and pulse energy increase from 191 to 607 kHz and from 7.4 to 58.6 nJ, respectively, whereas the pulse duration decreases from 2.09 μs to 349 ns.

  9. Graphene Q-switched Yb:KYW planar waveguide laser

    Directory of Open Access Journals (Sweden)

    Jun Wan Kim

    2015-01-01

    Full Text Available A diode-pumped Yb:KYW planar waveguide laser, single-mode Q-switched by evanescent-field interaction with graphene, is demonstrated for the first time. Few-layer graphene grown by chemical vapor deposition is transferred onto the top of a guiding layer, which initiates stable Q-switched operation in a 2.4-cm-long waveguide laser operating near 1027 nm. Average output powers up to 34 mW and pulse durations as short as 349 ns are achieved. The measured output beam profile, clearly exhibiting a single mode, agrees well with the theoretically calculated mode intensity distribution inside the waveguide. As the pump power is increased, the repetition rate and pulse energy increase from 191 to 607 kHz and from 7.4 to 58.6 nJ, respectively, whereas the pulse duration decreases from 2.09 μs to 349 ns.

  10. Mode instability in a Yb-doped stretched core fiber

    Science.gov (United States)

    Xia, N.; Yoo, S.

    2017-02-01

    In this work we present the theoretical study of transverse mode instability (TMI) in ytterbium (Yb)-doped rectangular core fibers with different core aspect ratios using the fast Fourier transform (FFT) beam propagation method (BPM). As expected, the rectangular core fiber with larger aspect ratio (AR.) offers more efficient heat dissipation than a circular core fiber. However, it is found that the rectangular core fiber does not benefit from the better heat dissipation to suppress the TMI when compared to the circular core counterpart. The temperature building in the rectangular core fiber decreases by up to 24.6% with a 10:1 aspect ratio core, while threshold pump power drops by up to 38.3% when compared with a circular core fiber with the same core area. Our study reveals that a smaller effective refractive index difference between modes and a weaker gain saturation effect compensate the thermal advantage from more efficient heat dissipation.

  11. High-average-power diode-pumped Yb: YAG lasers

    Energy Technology Data Exchange (ETDEWEB)

    Avizonis, P V; Beach, R; Bibeau, C M; Emanuel, M A; Harris, D G; Honea, E C; Monroe, R S; Payne, S A; Skidmore, J A; Sutton, S B

    1999-10-01

    A scaleable diode end-pumping technology for high-average-power slab and rod lasers has been under development for the past several years at Lawrence Livermore National Laboratory (LLNL). This technology has particular application to high average power Yb:YAG lasers that utilize a rod configured gain element. Previously, this rod configured approach has achieved average output powers in a single 5 cm long by 2 mm diameter Yb:YAG rod of 430 W cw and 280 W q-switched. High beam quality (M{sup 2} = 2.4) q-switched operation has also been demonstrated at over 180 W of average output power. More recently, using a dual rod configuration consisting of two, 5 cm long by 2 mm diameter laser rods with birefringence compensation, we have achieved 1080 W of cw output with an M{sup 2} value of 13.5 at an optical-to-optical conversion efficiency of 27.5%. With the same dual rod laser operated in a q-switched mode, we have also demonstrated 532 W of average power with an M{sup 2} < 2.5 at 17% optical-to-optical conversion efficiency. These q-switched results were obtained at a 10 kHz repetition rate and resulted in 77 nsec pulse durations. These improved levels of operational performance have been achieved as a result of technology advancements made in several areas that will be covered in this manuscript. These enhancements to our architecture include: (1) Hollow lens ducts that enable the use of advanced cavity architectures permitting birefringence compensation and the ability to run in large aperture-filling near-diffraction-limited modes. (2) Compound laser rods with flanged-nonabsorbing-endcaps fabricated by diffusion bonding. (3) Techniques for suppressing amplified spontaneous emission (ASE) and parasitics in the polished barrel rods.

  12. Enhanced 1G 4 emission in NaLaF 4: Pr 3+, Yb 3+ and charge transfer in NaLaF 4: Ce 3+, Yb 3+ studied by fourier transform luminescence spectroscopy

    Science.gov (United States)

    van der Kolk, E.; Ten Kate, O. M.; Wiegman, J. W.; Biner, D.; Krämer, K. W.

    2011-05-01

    A high resolution luminescence study of NaLaF 4: 1%Pr 3+, 5%Yb 3+ and NaLaF 4: 1%Ce 3+, 5%Yb 3+ in the UV to NIR spectral range using a InGaAs detector and a fourier transform interferometer is reported. Although the Pr 3+( 3P 0 → 1G 4), Yb 3+( 2F 7/2 → 2F 5/2) energy transfer step takes place, significant Pr 3+1G 4 emission around 993, 1330 and 1850 nm is observed. No experimental proof for the second energy transfer step in the down-conversion process between Pr 3+ and Yb 3+ can be given. In the case of NaLaF 4: Ce 3+, Yb 3+ it is concluded that the observed Yb 3+ emission upon Ce 3+ 5d excitation is the result of a charge transfer process instead of down-conversion.

  13. Die Felsfassadengräber von Kyrene

    OpenAIRE

    Greve, Anika

    2006-01-01

    Die griechische Kolonie Kyrene wurde im letzten Drittel des 7. Jhs. v. Chr. einige Kilometer vom Mittelmeer entfernt im libyschen Innenland gegründet. Die Siedler waren dorische Griechen aus Thera im Süden der Kykladen. Nicht nur die erhaltenen innerstädtischen Gebäude zeugen von einem einstigen Wohlstand, auch die Nekropole nahm im Laufe der Zeit gewaltige Ausmaße mit aufwendig gestalteten Grabanlagen an, die sich rund um die urbane Bebauung entlang der Ausfallstraßen ausbreitete. Viele Ruhe...

  14. Authentifizierung von Bio-Milch im Labor

    OpenAIRE

    2008-01-01

    In Deutschland ist die Nachfrage nach Bio-Lebensmitteln in den letzten Jahren stetig gestiegen. So erhöhte sich der Absatz von Bio-Trinkmilch in 2007 im Vergleich zum Vorjahr erneut kräftig um 34 Prozent (ZMP, Bonn) und der Bio-Anteil beträgt inzwischen bei Frischmilch knapp elf Prozent. Aufgrund sporadisch resultierender Lieferengpässe bei Bio-Milch sowie der vorhandenen Handelspreisdifferenz besteht zunehmend ein potenzielles Risiko der Falschdeklaration konventionell erzeugter Milch als Bi...

  15. Key contributors: Ernst von Glasersfeld's radical constructivism

    Science.gov (United States)

    Tobin, Kenneth

    2007-07-01

    This article reviews the significance of the contributions of Ernst von Glasersfeld to research in science education, especially through his theoretical contributions on radical constructivism. As a field shaper, Glasersfeld's subversive ideas catalyzed debate in the science education community and fuelled transformation of many facets including research methods, ways of thinking about teaching and learning, curriculum, and science teacher education. Perturbations emanating from the debates on constructivism forged new pathways that led to the development and use of many of the sociocultural frameworks employed by authors in Cultural Studies of Science Education.

  16. Synthese und Applikation von magnetisch verformbaren Hydrogelkompositen

    OpenAIRE

    Bolle, Jens

    2011-01-01

    Als „intelligent“ bezeichnete Materialien sind in der Lage, mit steuerbaren Form- oder Eigenschaftsänderungen auf Zielreize zu reagieren, ohne dafür einen zusätzlichen Sensor zu benötigen. Man bezeichnet sie daher auch als Sensor-Aktor-Systeme. Da sie ohne äußere Sensorsysteme auskommen, können diese Werkstoffe als kleine, einfach anwendbare und preisgünstige Bauteile für eine Vielzahl von Applikationen dienen. Ihre Entwicklung gestattet sowohl die fortschreitende Miniaturisierung tech-nische...

  17. Paramagnetic spin relaxation in Cs/sub 2/NaYbCl/sub 6/

    Energy Technology Data Exchange (ETDEWEB)

    Dunlap, B.D. (Argonne National Lab., IL); Shenoy, G.K.; Dattagupta, S.; Asch, L.

    1977-01-01

    Theoretical line shapes are obtained for Mossbauer spectra in the presence of paramagnetic relaxation effects which do not involve the ''white noise'' approximation. The results are applied to the data for /sup 170/Yb in Cs/sub 2/NaYbCl/sub 6/ to give values for the rms dipolar field and the spin correlation time in this material.

  18. SYNTHESES AND STRUCTURES OF AGLNS2 (LN=SM-YB) COMPOUNDS

    NARCIS (Netherlands)

    VANDERLEE, A; VANDEBELT, R; WIEGERS, GA

    1992-01-01

    The ternary compounds AgLnS2 (Ln = Sm-Yb) have been synthesized and characterized. It has been found, in accordance with a previous study, that all compounds, except AgYbS2, are monoclinic with a almost-equal-to b almost-equal-to 7.7 angstrom, c almost-equal-to 12 angstrom and 90-degrees

  19. Optimizing Yb concentration of fiber amplifiers in the presence of transverse modal instabilities and photodarkening

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper

    2016-01-01

    The Yb concentration of double-clad optical fiber amplifiers is numerically optimized with respect to maximizing the transverse modal instability threshold in the presence of absorption arising from photodarkening. The pump cladding area is scaled with the Yb concentration to approximately maintain...... the pump absorption in operation. It is found that approximate analytical expressions can predict the optimized concentration levels found in numerical simulations with sufficient accuracy to be useful in fiber design. (C) 2016 Optical Society of America...

  20. Synthesis and physical properties of oxygen adsorbed YbFe2As2

    Science.gov (United States)

    Santhosh Raj, S.; Ghosh, Nilotpal; Navamathavan, R.

    2017-08-01

    We had synthesized a new compound YbFe2As2 using heating technique followed by the furnace cooling process. YbFe2As2 had been synthesized in polycrystalline form. The presence of adsorbed oxygen was confirmed on the surfaces of grown YbFe2As2 by EDAX analysis. Hence the sample had been named as YbFe2As2:O2. This new compound YbFe2As2:O2 had shown paramagnetic behaviour when magnetization (M) versus temperature (T) was measured using superconducting quantum interference device (SQUID) at constant magnetic field (H  =  795.77  ×  103 A m-1). A sharp slope change around 140 K was noticed during magnetization (M) versus temperature (T) at H  =  (795.77  ×  101 A m-1) which is the SDW transition temperature for the well-studied parent compound BaFe2As2. Result of M versus H measurements for YbFe2As2:O2 at 2 and 200 K had revealed that the saturation point could not been achieved at H  =  (557.04  ×  104 A m-1). The detailed magnetic studies on YbFe2As2:O2 exhibited that the co-existence of both strong antiferromagnetic as well as a weak ferromagnetic behaviour. Temperature versus resistivity measurement showed metallic behaviour along with a transition at around 13 K. Influence of anti-ferromagnetic spin fluctuation in the normal state transport property of YbFe2As2:O2 had been found.

  1. Detailed characterization of a highly Yb-doped double-clad fiber

    Science.gov (United States)

    Vallés, J. A.; Berdejo, V.; Martín, J. C.; Cases, R.; Álvarez, J. M.; Rebolledo, M. Á.

    2016-12-01

    A characterization method based on the careful measurement of the characteristic parameters and fluorescence emission spectra of a highly Yb-doped double-clad fiber is presented. The method is successfully checked by numerically fitting experimental results of a ring laser based on highly doped double-clad Yb-doped silica fibers with different dopant concentrations, fiber lengths and ring-laser output-coupler rates.

  2. Guided mode gain competition in Yb-doped rod-type photonic crystal fibers

    DEFF Research Database (Denmark)

    Poli, Federica; Passaro, Davide; Cucinotta, Annamaria

    2009-01-01

    The gain competition among the guided modes in Yb-doped rod-type photonic crystal fibers with a low refractive index core is investigated with a spatial model to demonstrate the fiber effective single-mode behaviour.......The gain competition among the guided modes in Yb-doped rod-type photonic crystal fibers with a low refractive index core is investigated with a spatial model to demonstrate the fiber effective single-mode behaviour....

  3. Von Krahli Teater hakkab koolitama näitlejaid

    Index Scriptorium Estoniae

    2007-01-01

    Von Krahli Teater hakkab osalema järgmisel sügisel TÜ Viljandi Kultuuriakadeemia teatrikunsti erialale õppima asuvate tudengite koolitamises. Tudengeid hakkavad juhendama Von Krahli juht Peeter Jalakas, näitlejad Taavi Eelmaa ja Juhan Ulfsak, vene tantsija ja koreograaf Sasha Pepeljajev ning soome lavastaja Kristian Smeds

  4. On the miscellaneous aspects of von Willebrand factor

    NARCIS (Netherlands)

    Groeneveld, Dafna Jordana

    2015-01-01

    Von Willebrand disease is the most common inherited bleeding disorder and is characterized by reduced plasma von Willebrand factor (VWF) levels or functionally abnormal VWF. VWF is best known for its three classical hemostatic functions: (i) as a carrier protein for coagulation factor VIII, (ii)

  5. von Willebrand disease and aging : an evolving phenotype

    NARCIS (Netherlands)

    Sanders, Y. V.; Giezenaar, M. A.; Laros-van Gorkom, B. A. P.; Meijer, K.; van der Bom, J. G.; Cnossen, M. H.; Nijziel, M. R.; Ypma, P. F.; Fijnvandraat, K.; Eikenboom, J.; Mauser-Bunschoten, E. P.; Leebeek, F. W. G.

    2014-01-01

    Background: Because the number of elderly von Willebrand disease (VWD) patients is increasing, the pathophysiology of aging in VWD has become increasingly relevant. Objectives: To assess age-related changes in von Willebrand factor (VWF) and factor VIII (FVIII) levels and to compare age-related diff

  6. Von Krahli teatris etenduvad Tõnu Kõrvitsa kammerooperid / Esme Kassak

    Index Scriptorium Estoniae

    Kassak, Esme

    2006-01-01

    20. apr. esietenduvad Von Krahli Teatris Peeter Jalaka lavastuses Tõnu Kõrvitsa uued kammerooperid "Tuleaed" ja "Mu luiged, mu mõtted", mille aluseks on luuletaja Marie Heibergi saatus. Libretode autor on Maarja Kangro. Kammerooperid tulevad lavale Von Krahli Teatri ja Nargen Opera koostöös. Esitavad Kädy Plaas, Helen Lokuta, Nargen Opera koor ja Tallinna Kammerorkester, dirigent Tõnu Kaljuste

  7. Von Krahli teater mängib Kõrvitsa kammeroopereid

    Index Scriptorium Estoniae

    2006-01-01

    20. apr. esietenduvad Von Krahli Teatris Peeter Jalaka lavastuses Tõnu Kõrvitsa uued kammerooperid "Tuleaed" ja "Mu luiged, mu mõtted", mille aluseks on luuletaja Marie Heibergi saatus. Libretode autor on Maarja Kangro. Kammerooperid tulevad lavale Von Krahli Teatri ja Nargen Opera koostöös. Esitavad Kädy Plaas, Helen Lokuta, Nargen Opera koor ja Tallinna Kammerorkester, dirigent Tõnu Kaljuste

  8. Von Krahli teatris etenduvad Tõnu Kõrvitsa kammerooperid / Esme Kassak

    Index Scriptorium Estoniae

    Kassak, Esme

    2006-01-01

    20. apr. esietenduvad Von Krahli Teatris Peeter Jalaka lavastuses Tõnu Kõrvitsa uued kammerooperid "Tuleaed" ja "Mu luiged, mu mõtted", mille aluseks on luuletaja Marie Heibergi saatus. Libretode autor on Maarja Kangro. Kammerooperid tulevad lavale Von Krahli Teatri ja Nargen Opera koostöös. Esitavad Kädy Plaas, Helen Lokuta, Nargen Opera koor ja Tallinna Kammerorkester, dirigent Tõnu Kaljuste

  9. Victor or Villain? Wernher von Braun and the Space Race

    Science.gov (United States)

    O'Brien, Jason L.; Sears, Christine E.

    2011-01-01

    Set during the Cold War and space race, this historical role-play focuses on Wernher von Braun's involvement in and culpability for the use of slave laborers to produce V-2 rockets for Nazi Germany. Students will grapple with two central questions. Should von Braun have been allowed to emigrate to the United States given his affiliation with the…

  10. Die baltischen Kapitulationen von 1710 : Kontext, Wirkungen, Interpretationen / Marten Seppel

    Index Scriptorium Estoniae

    Seppel, Marten, 1979-

    2015-01-01

    Arvustus: Die baltischen Kapitulationen von 1710 : Kontext, Wirkungen, Interpretationen, hrsg. von Karsten Brüggemann, Mati Laur und Pärtel Piirimäe, Queleln und Studien zur baltischen Geschichte, Bd 23 (Köln u.a: Böhlau Verlag, 2014)

  11. Von Krahli teater mängib Kõrvitsa kammeroopereid

    Index Scriptorium Estoniae

    2006-01-01

    20. apr. esietenduvad Von Krahli Teatris Peeter Jalaka lavastuses Tõnu Kõrvitsa uued kammerooperid "Tuleaed" ja "Mu luiged, mu mõtted", mille aluseks on luuletaja Marie Heibergi saatus. Libretode autor on Maarja Kangro. Kammerooperid tulevad lavale Von Krahli Teatri ja Nargen Opera koostöös. Esitavad Kädy Plaas, Helen Lokuta, Nargen Opera koor ja Tallinna Kammerorkester, dirigent Tõnu Kaljuste

  12. Diurnal variation of von Willebrand factor in plasma

    DEFF Research Database (Denmark)

    Timm, Annette; Fahrenkrug, Jan; Jørgensen, Henrik L;

    2014-01-01

    BACKGROUND: Quantitation of von Willebrand factor (VWF) in plasma is a central element in assessing von Willebrand disease (VWD). VWF activity is known to vary, which has partly been ascribed to biological and preanalytical variation. However, a possible diurnal expression of VWF has not been tho...

  13. Entwicklung eines amperometrischen Biosensors zur Erfassung von Polyphenolen

    OpenAIRE

    2013-01-01

    In der durchgeführten Arbeit wurden neue Immobilisierungsstrategien zur Etablierung eines amperometrischen Biosensors, welcher Polyphenole erfasst, untersucht. Ziel war es eine „Handheld-Unit“ unter Verwendung einer Dickschichtelektrode (Thick-Film Technology, TFT) zu entwickeln. Zur Erfassung von Polyphenolen wurde das Enzym Laccase ausgewählt, welche die Oxidation von Phenolen zu Chinonen katalysiert. Dabei wurden in dieser Arbe...

  14. Von Stryk : halb oli nii aadlikel kui talupoegadel / Margus Haav

    Index Scriptorium Estoniae

    Haav, Margus, 1969-

    2007-01-01

    Rets. rmt.: Stryk, Wolf Dietmar von. Morsel-Podrigel, das Stammhaus der familie von Stryk in Livland/Estland 1562-1919-2003. : die Geschichte eines Gutes im Wandel der Zeiten der Jahrhunderte bis zur Gegenwart. Viljandi : W. Stryk, 2006. Artikkel ilmunud ka: Valgamaalane, 3. märts 2007, lk 4

  15. Erfahrungen an der Schnittstelle von Medienarbeit und Praxisforschung

    Directory of Open Access Journals (Sweden)

    Peter Holzwarth

    2007-11-01

    Full Text Available Der Beitrag reflektiert die Verbindung von praktischer Medienarbeit und Forschung am Beispiel eines internationalen EU-Forschungsprojekts zum Thema Medien und Migration. Neben didaktischen Prinzipien und Konzepten für die aktive Medienarbeit im Forschungskontext geht es um die Kooperation von medienpädagogischer Begleitung (MB und wissenschaftlicher Begleitung (WB sowie um deren spezifische Kompetenzen.

  16. Possible undercompensation effect in the Kondo insulator (Yb,Tm)B12

    Science.gov (United States)

    Alekseev, P. A.; Nemkovski, K. S.; Mignot, J.-M.; Clementyev, E. S.; Ivanov, A. S.; Rols, S.; Bewley, R. I.; Filipov, V. B.; Shitsevalova, N. Yu.

    2014-03-01

    The effects of Tm substitution on the dynamical magnetic response of Yb1-xTmxB12 (x=0, 0.08, 0.15, and 0.75) and Lu0.92Tm0.08B12 compounds have been studied using time-of-flight inelastic neutron scattering. Major changes were observed in the spectral structure and temperature evolution of the Yb contribution to the inelastic response for a rather low content of magnetic Tm ions. A sizable influence of the RB12 host (YbB12, as compared to LuB12 or pure TmB12) on the crystal-field splitting of the Tm3+ ion is also reported. The results point to a specific effect of impurities carrying a magnetic moment (Tm, as compared to Lu or Zr) in a Kondo insulator, which is thought to reflect the "undercompensation" of Yb magnetic moments, originally Kondo screened in pure YbB12. A parallel is made with the strong effect of Tm substitution on the temperature dependence of the Seebeck coefficient in Yb1-xTmxB12, which was reported previously.

  17. Near-Infrared Quantum Cutting in Yb3+ Doped SrMoO4 Phosphors.

    Science.gov (United States)

    Luo, Xiaobing; Shen, Jun; Huang, He; Xu, Lu; Wang, Zhixiang; Chen, Yang; Li, Li

    2016-04-01

    Efficient near-infrared (NIR) quantum cutting (QC) has been demonstrated in Yb3+ doped SrMoO4 phosphors synthesized by the high-temperature solid-state reaction method. The obtained SrMoO4:Yb3+ phosphors were characterized by X-ray diffraction (XRD), diffuse reflectance spectra, photoluminescence (PL) spectra and decay lifetime to understand the observed near-infrared quantum cutting phenomena. The XRD results show that all the prepared phosphors can be readily indexed to the pure tetragonal phase of SrMoO4 and exhibit good crystallinity. The experimental results showed that the strong visible molybdate (MoO2-(4)) emission around 493 nm and near-infrared (NIR) emission around 1000 nm from Yb3+(2F(5/2)-->2F(7/2)) of SrMoO4:Yb3+ phosphors were observed under ultraviolet (290 nm) excitation. The Yb + concentration dependence of luminescent properties and lifetimes of both the visible and NIR emissions have also been investigated. The quenching concentration of Yb3+ ions approaches as high as 10 mol%. The cooperative energy transfer (CET) mechanism was also discussed in detail. The broadband NIR QC phosphors may possibly have potential application in enhancing the conversion efficiency of solar cells.

  18. Stability of cluster glass state in nano order sized YbFe2O4 powders

    Science.gov (United States)

    Kobayashi, H.; Fujiwara, K.; Kobayashi, N.; Ogawa, T.; Sakai, M.; Tsujimoto, M.; Seri, O.; Mori, S.; Ikeda, N.

    2017-04-01

    Slow magnetic relaxation and the Fe ion stoichiometry were investigated in spin and charge frustrated system YbFe2O4. DC susceptibility, AC susceptibility, aging process and electron diffraction observation were carried out on nano order sized YbFe2O4 single-phase powders with the Fe/Yb=2.00, 2.02, and 2.04 ratios. The variation of the cluster glass behavior was studied in relation between the magnetic relaxation and the various chemical compositions. With the increase of the Fe/Yb ratios, the magnetic coherence length increased and the magnetic aging time goes slow down. The observed critical slowing down of the glassy fluctuation is interpreted by the development of the spin cluster size. This indicates that the spin glass like property of this material arises from the competition between various sized magnetic domains having ferrimagnetic moments. Additionally, electron diffraction experiments showed that the increase of Fe/Yb ratios from Fe/Yb=2.00 enhances the development of the charge ordering coherence in triangular lattice. This study shows that the measurement of magnetic fluctuation for nano order sized particles gives the essential information about the spin cluster fluctuation in RFe2O4.

  19. Lanthanide near infrared imaging in living cells with Yb3+ nano metal organic frameworks.

    Science.gov (United States)

    Foucault-Collet, Alexandra; Gogick, Kristy A; White, Kiley A; Villette, Sandrine; Pallier, Agnès; Collet, Guillaume; Kieda, Claudine; Li, Tao; Geib, Steven J; Rosi, Nathaniel L; Petoud, Stéphane

    2013-10-22

    We have created unique near-infrared (NIR)-emitting nanoscale metal-organic frameworks (nano-MOFs) incorporating a high density of Yb(3+) lanthanide cations and sensitizers derived from phenylene. We establish here that these nano-MOFs can be incorporated into living cells for NIR imaging. Specifically, we introduce bulk and nano-Yb-phenylenevinylenedicarboxylate-3 (nano-Yb-PVDC-3), a unique MOF based on a PVDC sensitizer-ligand and Yb(3+) NIR-emitting lanthanide cations. This material has been structurally characterized, its stability in various media has been assessed, and its luminescent properties have been studied. We demonstrate that it is stable in certain specific biological media, does not photobleach, and has an IC50 of 100 μg/mL, which is sufficient to allow live cell imaging. Confocal microscopy and inductively coupled plasma measurements reveal that nano-Yb-PVDC-3 can be internalized by cells with a cytoplasmic localization. Despite its relatively low quantum yield, nano-Yb-PVDC-3 emits a sufficient number of photons per unit volume to serve as a NIR-emitting reporter for imaging living HeLa and NIH 3T3 cells. NIR microscopy allows for highly efficient discrimination between the nano-MOF emission signal and the cellular autofluorescence arising from biological material. This work represents a demonstration of the possibility of using NIR lanthanide emission for biological imaging applications in living cells with single-photon excitation.

  20. Forward to cryogenic temperature: laser cooling of Yb: LuLiF crystal

    Science.gov (United States)

    Zhong, Biao; Luo, Hao; Lei, Yongqing; Shi, Yanling; Yin, Jianping

    2017-06-01

    The high quality Yb-doped fluoride crystals have broad prospects for optical refrigeration. We have laser cooled the Yb:LuLiF crystal to a temperature below the limit of current thermoelectric coolers ( 180 K). The 5% Yb:LuLiF crystal sample has a geometry of 2 mm×2 mm×5 mm and was supported by two fibers of 200 μm in diameter. They were placed in a 2×10-4 Pa vacuum chamber with an environment temperature of 294.5 K. The 1019 nm CW laser of power 38.7 W was adopted to irradiate the sample. The temperature of the sample was measured utilizing the DLT methods. After 20 minutes of laser irradiation, the 5% Yb:LuLiF crystal sample was cooled down to 182.4 K. By further optimizing experimental conditions and increasing the doped Yb concentration, the Yb:LuLiF crystal might be optically cooled below the cryogenic temperature of 123K in the near future.

  1. Thermoelectric and magnetic properties of Yb{sub 2}MgSi{sub 2} prepared by spark plasma sintering method

    Energy Technology Data Exchange (ETDEWEB)

    Kubouchi, M.; Hayashi, K.; Miyazaki, Y. [Tohoku University, Department of Applied Physics, Graduate School of Engineering, Sendai (Japan)

    2016-08-15

    An intermediate-valence compound, Yb{sub 2}MgSi{sub 2}, has been prepared using a spark plasma sintering method. The magnetic susceptibility and thermoelectric properties of Yb{sub 2}MgSi{sub 2} are measured in the temperature range from 5 to 300 K. From the magnetic susceptibility results, Yb valence of the Yb{sub 2}MgSi{sub 2} is evaluated. As compared with YbAl{sub 3}, which is one of the promising thermoelectric materials that can be used at low temperatures, Yb{sub 2}MgSi{sub 2} exhibits a lower absolute value of Seebeck coefficient, higher electrical resistivity, and lower thermal conductivity over the measured temperature range. A maximum dimensionless figure of merit, ZT, of 0.0018 is achieved at around 200 K. (orig.)

  2. Co-precipitation synthesis and upconversion luminescence properties of ZrO2:Yb3+-Ho3+

    Indian Academy of Sciences (India)

    Jinsheng Liao; Shaohua Liu; Liling Nie; Suijun Liu; Junxiang Fu

    2015-12-01

    ZrO2:Yb3+-Ho3+ phosphors with different Yb3+ doping concentration have been prepared by coprecipitation method. X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence spectra were used to characterize the properties of ZrO2:Yb3+-Ho3+ phosphors. Different phases of ZrO2 can be obtained by changing the concentration of Yb3+. Under the 980 nm excitation, the sample gives a set of light: strong green (539 nm), weak red (670 nm) and near-infrared (760 nm). The upconversion luminescence is based on two-photon absorption by the energy transfer from the donor (Yb3+) to the acceptor (Ho3+). All the results indicate that ZrO2:Yb3+-Ho3+ phosphors could be a promising biological labelling material.

  3. Auf den Schultern von Riesen und Zwergen Einsteins unvollendete Revolution

    CERN Document Server

    Renn, Jürgen

    2006-01-01

    Dies ist die Geschichte von Einsteins unvollendeter Revolution, einer tiefgreifenden Veränderung unserer Begriffe von Raum, Zeit, Materie und Strahlung. Diese Revolution begann in Einsteins Wunderjahr 1905, wurde durch seine allgemeine Relativitätstheorie aus dem Jahre 1915 fortgesetzt und wirkt in den heutigen Versuchen der Wissenschaft, die Entstehung und das Schicksal des Universums zu verstehen, weiter. Vor dem Hintergrund einer historischen Theorie des wissenschaftlichen Fortschritts wird Einsteins bis heute nicht abgeschlossene Revolution als das Ergebnis einer langfristigen Entwicklung des Wissens verständlich. Anhand der spannenden Geschichte von Einsteins Entdeckungen wird nachvollziehbar, warum große Denker wie Einstein weiter gesehen haben als ihre Vorgänger. Sie standen nicht nur auf den Schultern von Riesen, also den wissenschaftlichen Leistungen einzelner großer Vorgänger wie Newton, sondern auch auf den Schultern von "Zwergen", dem wissenschaftlichen Wissen, dem technischen Wissen, und d...

  4. Welding of Thermomechanically Rolled Steel by Yb:YAG Disk Laser / Spawanie Stali Walcowanej Termomechanicznie Laserem Dyskowym Yb:YAG

    Directory of Open Access Journals (Sweden)

    Lisiecki A.

    2015-12-01

    Full Text Available Autogenous laser welding of 5.0 mm thick butt joints of thermomechanically rolled steel S700MC was investigated. The Yb:YAG disk laser TruDisk 3302 emitted at 1.03 μm was used for the trials of autogenous welding. The effect of laser welding parameters and thus thermal conditions of welding on weld shape, microstructure of weld metal and heat affected zone (HAZ, tensile strength, bending angle, impact toughness and microhardness profile was determined. Studies have shown that it is advantageous to provide a high welding speed and low heat input. High cooling rate of weld metal and HAZ leads to the formation of a favorable structure characterized by a large proportion of fine-grained acicular ferrite and provides high mechanical properties of butt joints.

  5. Study of chromites YbMIICr2O5,5 (MII - Mg, Ca, Sr, Ba by X-ray diffraction

    Directory of Open Access Journals (Sweden)

    B. Kasenov

    2012-03-01

    Full Text Available Compounds of composition YbMeMnFeO5,5 (Me – Mg, Ca, Sr, Ba are synthesized from Yb2O3, , Cr2O3 and MgCO3, CaCO3, SrCO3, BaCO3 by solid phase method. X-ray powder diffraction showed that the compound YbMgCr2O5,5, YbCaCr2O5,5, YbSrCr2O5,5, YbBaCr2O5,5 crystallizes in the tetragonal crystal system.

  6. Femtosecond pulses at 50-W average power from an Yb:YAG planar waveguide amplifier seeded by an Yb:KYW oscillator.

    Science.gov (United States)

    Leburn, Christopher G; Ramírez-Corral, Cristtel Y; Thomson, Ian J; Hall, Denis R; Baker, Howard J; Reid, Derryck T

    2012-07-30

    We report the demonstration of a high-power single-side-pumped Yb:YAG planar waveguide amplifier seeded by an Yb:KYW femtosecond laser. Five passes through the amplifier yielded 700-fs pulses with average powers of 50 W at 1030 nm. A numerical simulation of the amplifier implied values for the laser transition saturation intensity, the small-signal intensity gain coefficient and the gain bandwidth of 10.0 kW cm(-2), 1.6 cm(-1), and 3.7 nm respectively, and identified gain-narrowing as the dominant pulse-shaping mechanism.

  7. Heterogeneous mixed valence in YbPd sub 3 S sub 4 : evidence from sup 1 sup 7 sup 0 Yb Moessbauer and x-ray L sub I sub I sub I -edge absorption measurements

    CERN Document Server

    Bonville, P; Alleno, E; Takahashi, F; Matsuoka, E; Ishikawa, M

    2003-01-01

    The intermetallic bronze YbPd sub 3 S sub 4 is shown to be a heterogeneous mixed-valence system, by means of sup 1 sup 7 sup 0 Yb Moessbauer spectroscopy and x-ray L sub I sub I sub I -edge absorption and magnetic measurements. Two valence states coexist in this compound: Yb sup 3 sup + and close-to-divalent Yb. The trivalent fraction (about 50%) undergoes a transition to magnetic ordering at about 2 K, with the GAMMA sub 7 doublet as the ground crystal field state. The possibility of charge (or valence) ordering is discussed. (letter to the editor)

  8. Suitability of tracers; Eignung von Tracern

    Energy Technology Data Exchange (ETDEWEB)

    Klotz, D. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany). Inst. fuer Hydrologie

    1999-02-01

    Hydrological tracer techniques are a means of making statements on the direction and speed of underground water. One of the simpler tasks is to find out whether there is hydrological communication between two given points. This requires a determination of the direction of flow, which places less exacting demands on the properties of the tracer than does the task of determining the flow velocity of underground water. Tracer methods can serve to infer from flow velocity the distance (flow) velocity, which is defined as the ratio between the distance between two points located in flow direction and the actual time it takes water to flow from one to the other. [Deutsch] Mit Hilfe der hydrologischen Markierungstechniken koennen Aussagen ueber die Richtung und die Geschwindigkeit von Bewegungen des unterirdischen Wassers gemacht werden. Der einfachere Fall liegt vor, wenn festgestellt werden soll, ob zwischen zwei Punkten eine hydrologische Verbindung besteht. Bei dieser Fliessrichtungsbestimmung sind die Forderungen an die Eigenschaften der einzusetzenden Tracer geringer als bei der Bestimmung der Geschwindigkeit des unterirdischen Wassers. Von den Geschwindigkeiten des unterirdischen Wassers ist die Abstands-(Fliess)geschwindigkeit, die definiert ist durch das Verhaeltnis aus dem Abstand und der wahren Fliesszeit zwischen zwei in Bewegungsrichtung gelegenen Punkten, durch Tracermethoden zu bestimmen. (orig.)

  9. Guy von Dardel 1919-2009

    CERN Multimedia

    2009-01-01

    Guy von Dardel, a well-known figure at CERN and in the international particle physics community, passed away on 28 August. Guy von Dardel came to CERN when it was founded in 1954 and was a full-time staff member until 1964, performing several experiments and working on technical developments. These included the first measurement of the neutral pion’s life-time. Called to Lund University in 1964, he became professor there in 1965 and director of the 1.2 GeV electron accelerator. In the late 1960s, he performed an experiment at CERN’s PS that measured the decays of the Λ. Then, in the early 1970s, he involved the Lund group in a series of experiments at the Intersecting Storage Rings (ISR), where he measured the production of various types of particles. In particular, he participated in a series of experiments that observed the production of a high abundance of particles with large transverse momenta. This required an explanation...

  10. Approximate von Neumann entropy for directed graphs.

    Science.gov (United States)

    Ye, Cheng; Wilson, Richard C; Comin, César H; Costa, Luciano da F; Hancock, Edwin R

    2014-05-01

    In this paper, we develop an entropy measure for assessing the structural complexity of directed graphs. Although there are many existing alternative measures for quantifying the structural properties of undirected graphs, there are relatively few corresponding measures for directed graphs. To fill this gap in the literature, we explore an alternative technique that is applicable to directed graphs. We commence by using Chung's generalization of the Laplacian of a directed graph to extend the computation of von Neumann entropy from undirected to directed graphs. We provide a simplified form of the entropy which can be expressed in terms of simple node in-degree and out-degree statistics. Moreover, we find approximate forms of the von Neumann entropy that apply to both weakly and strongly directed graphs, and that can be used to characterize network structure. We illustrate the usefulness of these simplified entropy forms defined in this paper on both artificial and real-world data sets, including structures from protein databases and high energy physics theory citation networks.

  11. Kontextualisierung von Queer Theory Contextualizing Queer Theory

    Directory of Open Access Journals (Sweden)

    Anna Voigt

    2008-03-01

    Full Text Available Christine M. Klapeer legt in diesem Einführungsband dar, aus welchen politischen und theoretischen Kontexten heraus sich ‚queer‘ zu einem Begriff mit besonderem politischem und theoretischem Gehalt entwickelt hat. Wesentlich zielt sie dabei auf eine kritische Kontextualisierung von „queer theory”. Die Autorin geht zunächst auf das Gay Liberation Movement ein, grenzt die Queer Theory vom Poststrukturalismus, von feministischen Theorien und den Lesbian and Gay Studies ab, beleuchtet Eckpunkte queeren Denkens und zeichnet schließlich die Entwicklungen in Österreich sowohl politisch-rechtlich als auch bewegungsgeschichtlich und in der Wissenschaftslandschaft nach.Christine M. Klapeer’s introductory volume demonstrates the manner in which ‘queer’ grew out of various political and theoretical contexts to become a term with special political and theoretical content. She focuses primarily on a critical contextualization of “queer theory.” The author begins by approaching the Gay Liberation Movement and then distinguishes Queer Theory from poststructuralism, from feminist theories, and from Lesbian and Gay Studies. She continues on to illuminate the key aspects of queer thought and concludes by sketching the development in Austria in terms of politics and the law, the history of movements, and within the landscape of knowledge.

  12. Integrales Lernen in und von Organisationen

    Directory of Open Access Journals (Sweden)

    Wendelin Küpers

    2006-06-01

    Full Text Available Bezogen auf das integrale Models von Ken Wilber untersucht der Beitrag die Bedeutung des Lernens in und von Organisationen. Nach einer Darstellung der Relevanz und des Grundverständnisses des Lernens im Organisationskontext, werden integrale Dimensionen des Lernens dargestellt. Im Einzelnen werden die verschiedenen Sphären eines inneren-subjektiven und äusseren-„objektiven“ Lernens des Einzelnen als auch ein gemeinschaftliches Lernen und Lernen im System auf der kollektiven Ebene dargestellt sowie deren interrelationaler Zusammenhang diskutiert. Schließlich beschreibt der Beitrag noch integrale Lernprozesse sowie integrale Gestaltungsfelder zur Förderung des Lernens in den verschiedenen Bereichen. Abschließend spricht der Artikel noch Schwierigkeiten und Probleme an sowie nimmt im Fazit ein perspektivischen Ausblick vor. Abstract: Related to the integral model of Ken Wilber, this paper investigates the role of learning in and of organisations. After describing the relevance and basic understanding of learning in the context of organisations, integral dimensions of learning will be outlined. In particular learning in the sphere of an inner-subjective and exterior-objective learning of the individual and a communal learning and learning within a system on the collective level as well as its interrelations will be discussed. Afterwards integral learning processes and various measurements for enhancing integral learning in the different sphere will be discussed. Finally, difficulties and problems will be addressed and in conclusion some perspectives and implications are presented.

  13. Katheterablation von supraventrikulären Tachykardien

    Directory of Open Access Journals (Sweden)

    Strohmer S

    2011-01-01

    Full Text Available Supraventrikuläre Tachykardien (SVT spielen in der klinischen Praxis aufgrund ihrer Häufigkeit und Symptomatik eine große Rolle. Obwohl diese Arrhythmien im Allgemeinen nicht lebensbedrohlich sind, führen sie aufgrund ihres unvorhersehbaren Auftretens zu einer beträchtlichen Unsicherheit und Einschränkung der Lebensqualität. Die elektrophysiologische Untersuchung inklusive Katheterablation hat sich in den vergangenen 20 Jahren als kurative und sichere Erstlinientherapie für Patienten mit hochsymptomatischen bzw. wiederholten Anfällen etabliert. Heutzutage liegen die Erfolgsraten für die Radiofrequenzablation der regulären SVT über 95 % bei einer sehr niedrigen Rezidivrate von weniger als 5 %. Eine antiarrhythmische Therapie für das Langzeitmanagement ist aufgrund der geringen Effektivität und Gefahr von ernsthaften Nebenwirkungen weitgehend obsolet und nur in Ausnahmefällen erforderlich. Der folgende Artikel gibt eine aktuelle Übersicht über die häufigsten rhythmischen Schmalkomplextachykardien, die verschiedenen Mechanismen und moderne nicht-pharmakologische Therapieansätze.

  14. Die Krakauer Kirche von Karmeliten und Karmelitaninnen

    Directory of Open Access Journals (Sweden)

    Józef Szymon Wronski

    2004-12-01

    Full Text Available 1. Die Klosterkirche der unbeschuhten Karmelitinnen Zum Heiligen Josef. Ein glücklicher Auftakt und somit die charakteristische Einführung in das 20. Jh. für den Kirchenbau von Krakau war die Errichtung der Karmeliterinnen St. Josephs-Kirche an der Lobzowska-Straße 40, in der die Architekten (Tadeusz Stryjeński (1849-1943 - Projektant der Kirche und Franciszek Mączyński (1874-1947 - Ausführer des Bauprojektes mit eigenen Verbesserungen die historisch- eklektizistischen Formen d.h. die mittelalterlichen Formen vor allem des sog. Übergangsstils vereinfachten. Die Kirche, die in den Jahren 1903-1905 errichtet wurde, steht inmitten vom Baukomplex des Klosters, dessen Grundriss das Quadrat ist49. Der Kirchenbau ist ein dem Gesamtbau des Klosters eingefügter Längsraum. Hinter dem Chor liegt das Oratorium des Konvents. Das Material Backstein (mit Verwendung von Stein erinnert an die Baukunst eines der besten Architekten jener Zeit, nämlich Teodor Talowskis (1857-1910, der viele Kirchen in Südpolen, aber auch viele Bürgerhäuser nicht nur in Krakau im ausgehenden 19. Jh. baute. Die Architektur der Karmeliterinnen St. Josephs-Kirche ist immer noch im Malerischen begriffen. Aber die Vereinfachung der historischen Formen führt zu ihrer „Beruhigung” und dadurch zur Wuchtigkeit des Ausdrucks. Bemerkenswert ist die in dieser Zeit (in der Anlage noch seltene ausgewogene Proportionierung des Baukörpers. Das methodische Prinzip jener Zeit ist der Kontrast. Im Kontrast zu den gedrungenen und wuchtigen Formen des Baukörpers stehen z.B. die sich verjüngenden obeliskenförmigen und pylonenartigen Türmchen, die nicht nur die Eingangsfassade der Kirche flankieren, sondern auch an den Ecken des Querhauses der Kirche stehen. Die ingravierten weißen Steine an der Fassade in der Zahl von Zehn erinnern an das Gebot des Karmelterinnenordens: Bete täglich den Rosenkranz und sind zugleich ein Vanitativmotiv. 2. Die Klosterkirche der unbeschuhten

  15. Rethinking the diagnosis of von Willebrand disease.

    Science.gov (United States)

    Favaloro, Emmanuel J

    2011-01-01

    von Willebrand disease (VWD) is the most common inherited bleeding disorder and arises from deficiencies and/or defects in the plasma protein von Willebrand factor (VWF). VWD is classified into 6 different types, with type 1 identified as a (partial) quantitative deficiency of VWF, type 3 defined by a (virtual) total deficiency of VWF, and type 2 identifying four separate types (2A, 2B, 2M, 2N) characterised by qualitative defects. The classification is based on phenotypic assays including FVIII, VWF:Ag and VWF activity, typically by ristocetin cofactor (VWF:RCo), but also increasingly by collagen binding (VWF:CB). Phenotypic testing may be supplemented by multimer analysis, RIPA, and VWF:FVIII binding. Although genetic analysis is not required to diagnose VWD or to define a classification type, it may be useful in discrete situations. The current review briefly covers this diagnostic process, with a focus on newer approaches, including extended test panels and the use of data from desmopressin challenges as a diagnostic tool. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. [Heinz von zur Mühlen. Das Bürgertum Fordert Blut. Ein Bolschewistiches Flugblatt von 1918] / Paul Kaegbein

    Index Scriptorium Estoniae

    Kaegbein, Paul

    2007-01-01

    Arvustus: Heinz von zur Mühlen. Das Bürgertum Fordert Blut. Ein Bolschewistiches Flugblatt von 1918. In : Ostseeprovinzen, baltische Staaten und das Nationale. Münster : LIT, 2005, lk. 403-414. 1918. aastast pärit lendlehest, mille käekirja järgi otsustades on kirjutanud Viktor Kingissepp

  17. [Heinz von zur Mühlen. Das Bürgertum Fordert Blut. Ein Bolschewistiches Flugblatt von 1918] / Paul Kaegbein

    Index Scriptorium Estoniae

    Kaegbein, Paul

    2007-01-01

    Arvustus: Heinz von zur Mühlen. Das Bürgertum Fordert Blut. Ein Bolschewistiches Flugblatt von 1918. In : Ostseeprovinzen, baltische Staaten und das Nationale. Münster : LIT, 2005, lk. 403-414. 1918. aastast pärit lendlehest, mille käekirja järgi otsustades on kirjutanud Viktor Kingissepp

  18. Microstructure investigations of Yb- and Bi-doped Mg2Si prepared from metal hydrides for thermoelectric applications

    Energy Technology Data Exchange (ETDEWEB)

    Janka, Oliver; Zaikina, Julia V.; Bux, Sabah K.; Tabatabaifar, Hosna; Yang, Hao; Browning, Nigel D.; Kauzlarich, Susan M.

    2017-01-01

    Within the field of thermoelectric materials for energy conversion magnesium silicide, Mg2Si, is an outstanding candidate due to its low density, abundant constituents and low toxicity. However electronic and thermal tuning of the material is a required necessity to improve its Figure of Merit, zT. Doping of Yb via reactive YbH2 into the structure is performed with the goal of reducing the thermal conductivity. Hydrogen is released as a by-product at high temperatures allowing for facile incorporation of Yb into the structure. We report on the properties of Yb-and Bi-doped Mg2Si prepared with MgH2 and YbH2 with the focus on the synthetic conditions, and samples' microstructure, investigated by various electron microscopy techniques. Yb is found in the form of both Yb3Si5 inclusions and Yb dopant segregated at the grain boundary substituting for Mg. The addition of 1 at% Yb concentration reduced the thermal conductivity, providing a value of 30 mW/cm K at 800 K. In order to adjust carrier concentration, the sample is additionally doped with Bi. The impact of the microstructure on the transport properties of the obtained material is studied. Idealy, the reduction of the thermal conductivity is achieved by doping with Yb and the electronic transport is adjusted by doping with Bi. Large grain microstructure facilitates the electronic transport. However, the synthetic conditions that provide the optimized microstructure for electrical transport do not facilitate the additional Yb dopant incorporation. Therefore, the Yb and Bi containing sample with the optimized microstructure provides a zT=0.46 at 800 K.

  19. Microstructure investigations of Yb- and Bi-doped Mg2Si prepared from metal hydrides for thermoelectric applications

    Science.gov (United States)

    Janka, Oliver; Zaikina, Julia V.; Bux, Sabah K.; Tabatabaifar, Hosna; Yang, Hao; Browning, Nigel D.; Kauzlarich, Susan M.

    2017-01-01

    Within the field of thermoelectric materials for energy conversion magnesium silicide, Mg2Si, is an outstanding candidate due to its low density, abundant constituents and low toxicity. However electronic and thermal tuning of the material is a required necessity to improve its Figure of Merit, zT. Doping of Yb via reactive YbH2 into the structure is performed with the goal of reducing the thermal conductivity. Hydrogen is released as a by-product at high temperatures allowing for facile incorporation of Yb into the structure. We report on the properties of Yb- and Bi-doped Mg2Si prepared with MgH2 and YbH2 with the focus on the synthetic conditions, and samples' microstructure, investigated by various electron microscopy techniques. Yb is found in the form of both Yb3Si5 inclusions and Yb dopant segregated at the grain boundary substituting for Mg. The addition of 1 at% Yb concentration reduced the thermal conductivity, providing a value of 30 mW/cm K at 800 K. In order to adjust carrier concentration, the sample is additionally doped with Bi. The impact of the microstructure on the transport properties of the obtained material is studied. Idealy, the reduction of the thermal conductivity is achieved by doping with Yb and the electronic transport is adjusted by doping with Bi. Large grain microstructure facilitates the electronic transport. However, the synthetic conditions that provide the optimized microstructure for electrical transport do not facilitate the additional Yb dopant incorporation. Therefore, the Yb and Bi containing sample with the optimized microstructure provides a zT=0.46 at 800 K.

  20. Alexander von Humboldt in Daniel Kehlmanns Welt

    Directory of Open Access Journals (Sweden)

    Ottmar Ette

    2012-12-01

    Full Text Available Zusammenfassung Wie stark sich im Verlauf des zurückliegenden Vierteljahrhunderts der Bekanntheitsgrad Alexander von Humboldts in der deutschsprachigen Öffentlichkeit verändert hat, zeigen nicht nur Fernsehumfragen zu den berühmtesten Deutschen, in denen Alexander von Humboldt mittlerweile figuriert, oder Fernsehserien, die über aktuelle Expeditionen berichten und auf Humboldts Namen zurückgreifen. Am deutlichsten vielleicht belegt dies der enorme Erfolg von Daniel Kehlmanns Roman Die Vermessung der Welt, der ohne die zuvor skizzierte Entwicklung nicht denkbar gewesen wäre. Es ist vor diesem Hintergrund nicht nur reizvoll, sondern aufschlußreich, sich mit dem großen Erfolg dieses kleinen Romans zu beschäftigen. Worum geht es in Die Vermessung der Welt? Und wie läßt sich das „Phänomen Kehlmann“ aus etwas größerer Distanz erklären? Abstract In the last 25 years, Alexander von Humboldt‘s popularity has radically changed in the german-speaking public opinion. Proof of this are not only television surveys about the most famous germans - in which Alexander von Humboldt now regularly figures - or television series about contemporary expeditions, which constantly refer to Humboldt‘s name; perhaps what most clearly verifies this change is the great success of Daniel Kehlmann‘s novel Die Vermessung der Welt. Without the recent developments outlined above, this novel‘s degree of impact would have been unimaginable. To study the great success of this text against this backdrop is not only attractive, but also revealing. What is Die Vermessung der Welt really about? And how can we explain the „Kehlmann phenomenon“ from a greater distance? Resumen La popularidad de Alejandro de Humboldt ha cambiado profundamente dentro del último cuarto de siglo en la opinión pública de habla alemana. Prueba de esto son no sólo las encuestas televisivas sobre los alemanes más famosos, dentro de las cuales figura en estos momentos Alejandro

  1. Ludwig Leichhardt und Alexander von Humboldt

    Directory of Open Access Journals (Sweden)

    Aliya-Katarina Südfels

    2012-10-01

    Full Text Available Zusammenfassung Im Juli des Jahres 1841 kommt es zu einem Treffen zwischen zwei Männern, das zunächst belanglos erscheint, sich aber Jahre später als wichtige historische Begebenheit herausstellen wird. In seinem Pariser Büro empfängt der 71jährige Naturforscher Alexander von Humboldt den jungen Preußen Ludwig Leichhardt. Der angehende Naturwissenschaftler erhofft sich Zuspruch und Empfehlung des berühmten Alexander von Humboldts. Die Unterredung ist kurz und verläuft für Leichhardt ergebnislos. Es wird das einzige Treffen der beiden Naturwissenschaftler bleiben. Aus heutiger Sicht unverständlich, da Ludwig Leichhardt und Alexander von Humboldt mehr verband, als ihre Leidenschaft für die Naturwissenschaften. Viel zu wenig ist sich bis jetzt den biographischen Analogien und den vergleichbaren geographischen Leistungen der beiden Preußen gewidmet worden. Abstract During July 1841 a meeting between two men takes place, which seems to have been extraneous, but turns out to be a significant historical incident. 71 year old natural scientist Alexander von Humboldt welcomes young Ludwig Leichhardt from Prussia in his office in Paris. The prospective young scientist expects help and references from famous Alexander von Humboldt. The conversation is short and ends from Leichhardt’s point of view without results. Unfortunately this is going to be the only meeting between the two scientists even though the two Prussians have more in common than their passion for the natural sciences. Way too seldomly have biographical analogy and geographical productivity of the two men been compared. Résumé En juillet 1841 une rencontre entre deux hommes a lieu, qui au premier abord semble sans importance, mais qui des années plus tard est considéré comme un événement historique majeur. Dans son bureau parisien, le naturaliste Alexandre de Humboldt, alors âgé de 71 ans, reçoit le jeune Prussien Ludwig Leichhardt. Le jeune scientifique en devenir

  2. Preparation and up-conversion luminescence properties of LaOBr:Yb3+/Er3+ nanofibers via electrospinning.

    Science.gov (United States)

    Ma, Wenwen; Yu, Wensheng; Dong, Xiangting; Wang, Jinxian; Liu, Guixia

    2014-11-01

    LaOBr:Yb(3+)/Er(3+) nanofibers were synthesized for the first time by calcinating electrospun PVP/[La(NO3)3 + Er(NO3)3 + Yb(NO3)3 + NH4 Br] composites. The morphology and properties of the final products were investigated in detail using scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), X-ray diffractometry (XRD) and fluorescence spectroscopy. The results indicate that LaOBr:Yb(3+)/Er(3+) nanofibers are tetragonal in structure with a space group of P4/nmm. The diameter of LaOBr:Yb(3+)/Er(3+) nanofibers is ~ 147 nm. Under the excitation of a 980-nm diode laser, LaOBr:Yb(3+)/Er(3+) nanofibers emit strong green and red up-conversion emission centering at 519, 541 and 667 nm, ascribed to the (2)H11/2, (4)S3/2 → (4) I(15/2) and (4)F9/2 → (4)I(15/2) energy-level transitions of Er(3+) ions, respectively. The up-conversion luminescent mechanism of LaOBr:Yb(3+)/Er(3+) nanofibers is advanced. Moreover, near-infrared emission of LaOBr:Yb(3+)/Er(3+) nanofibers is obtained under the excitation of a 532-nm laser. The formation mechanism of LaOBr:Yb(3+)/Er(3+) nanofibers is proposed. LaOBr:Yb(3+)/Er(3+) nanofibers could be important up-conversion luminescent materials.

  3. Electronic structure of YbNiX{sub 3} (X =Si, Ge) studied by hard X-ray photoemission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Hitoshi; Shimada, Kenya; Namatame, Hirofumi [Hiroshima Synchrotron Radiation Center, Hiroshima University, Kagamiyama 2-313, Higashi-Hiroshima 739-0046 (Japan); Utsumi, Yuki [Max-Planck Institute for Chemical Physics of Solids, 01187 Dresden (Germany); Kodama, Junichi; Nagata, Heisuke [Graduate School of Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 (Japan); Avila, Marcos A.; Ribeiro, Raquel A. [Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Santo Andre - SP, 09210-580 (Brazil); Umeo, Kazunori [Cryogenics and Instrumental Analysis Division, N-BARD, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Takabatake, Toshiro [Department of Quantum Matter, AdSM, Hiroshima University, Higashi-Hiroshima 739-8530 (Japan); Institute for Advanced Materials Research, Hiroshima University, Higashi-Hiroshima 739-8530 (Japan); Mimura, Kojiro; Motonami, Satoru; Anzai, Hiroaki [Graduate School of Engineering, Osaka Prefecture University, Sakai 599-8531 (Japan); Ueda, Shigenori [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148 (Japan); Taniguchi, Masaki [Hiroshima Synchrotron Radiation Center, Hiroshima University, Kagamiyama 2-313, Higashi-Hiroshima 739-0046 (Japan); Graduate School of Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 (Japan)

    2015-06-15

    lectronic structure of the Kondo lattices YbNiX{sub 3} (X =Si, Ge) has been investigated by means of hard x-ray photoemission spectroscopy (HAXPES) with hν = 5.95 keV. From the Yb 3d HAXPES spectra, the Yb valence in YbNiSi{sub 3} is estimated to be ∝ 2.92, which is almost temperature-independent. On the other hand, the valence in YbNiGe{sub 3} is estimated to be 2.48 at 300 K, showing significant valence fluctuation, and gradually decreases to 2.41 at 20 K on cooling. The Ni 2p{sub 3/2} and Yb{sup 3+} 4f peaks exhibit opposite energy shifts amounting to ∝ 0.6 eV between YbNiSi{sub 3} and YbNiGe{sub 3}. We propose a simple model for the electronic structure of YbNiX{sub 3} based on the HAXPES results. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Yb9+xCuMg4-x (x = 0.034): A κ-Phase Formed by Lanthanoids.

    Science.gov (United States)

    De Negri, Serena; Romaka, Vitaliy; Solokha, Pavlo; Saccone, Adriana; Giester, Gerald; Michor, Herwig; Rogl, Peter F

    2016-08-15

    Atom order in the crystal structures of Yb2Cu2-xMg (x = 0.17; Mo2FeB2-type; P4/mbm; a = 0.75592(2) nm; c = 0.40282(1) nm) and Yb9+xCuMg4-x (x = 0.034; Hf9Mo4B-type; P63/mmc; a = 1.0169(5) nm; c = 1.0290(5) nm) was determined from powder and X-ray single-crystal counter data analyses supported by electron probe microanalyses. Among the group of the so-called κ-phases, Yb9+xCuMg4-x is the first representative formed by a lanthanoid element. The structure of this κ-phase can be viewed as a typical network of corner-connected empty Yb6-octahedra, which encompass Yb6Mg6-icosahedra (filled by a mix of Mg/Yb atoms) and Yb6-trigonal prisms centered by Cu atoms to complete the three-dimensional metal framework. From another point of view, the same structure is considered as built from infinite polyicosahedral columns of Yb9Mg4 composition with Cu atoms located in trigonal prismatic interstices, highlighting similarities with other Yb-rich Yb-Cu-Mg phases. Density functional theory (DFT) calculations classify Yb9CuMg4 as a polar intermetallic. Metallic-like behavior is inferred from the Sommerfeld constant, γ = 49.2 mJ/mol·K(2), derived from the electronic density of states, calculated at the Fermi level. DFT integration of the f-density of states indicates almost completely filled f-states, revealing 13.6 and 13.7 electrons in the valence band for Yb1 and Yb2 atoms, respectively, close to the Yb(2+) ground state ((1)S0) for both Yb atoms. Magnetic susceptibility data recorded on the same compound are consistent with a nonmagnetic divalent Yb(2+) state. Temperature-dependent heat capacity data display a metallic behavior characterized by a small Sommerfeld constant γ = 64.8 mJ/mol·K(2) and a rather low Debye temperature ΘD = 140 K as typical for soft materials.

  5. First-principles study of electronic, elastic, and optical properties of Yb:CaF{sub 2} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Yuan-Yuan; Li, Zhi-Guo; Chen, Xiang-Rong [Sichuan Univ., Chengdu (China). Inst. of Atomic and Molecular Physics; Cheng, Yan [Sichuan Univ., Chengdu (China). Inst. of Atomic and Molecular Physics; Sichuan Univ., Chengdu (China). Key Lab. of High Energy Density Physics and Technology of Ministry of Education; Ji, Guang-Fu [Chinese Academy of Engineering Physics, Mianyang (China). National Key Lab. for Shock Wave and Detonation Physics Research

    2015-07-01

    The electronic structure, elastic, and optical properties of CaF{sub 2} and Yb-doped CaF{sub 2} are investigated by the first-principles calculations. The obtained lattice parameters, band structure, density of state, elastic constants, and imaginary part of dielectric function ε{sub 2} for CaF{sub 2} agree well with the experimental and other theoretical results. A good comparison of the properties is made between CaF{sub 2} and Yb:CaF{sub 2}, and it is found that: firstly, Yb doping leads to the crystal structure distortion of CaF{sub 2} and reduction of the elastic constants. Secondly, an impurity band is found at the top of valence band in the band structure of Yb:CaF{sub 2} and contributes to the bandgap narrowing. Thirdly, the peaks at about 26 eV in the optical curves disappear after Yb doping, and the remaining two peaks shift towards the longer-wavelength side, with the peak intensities drop down, indicating that Yb doping makes the ultraviolet transmittance of the system improve and the range of light in the UV region widen. Furthermore, Yb doping induces new peaks in the optical curves, which may be caused by 4f electron transitions of Yb atom. Finally, the transmittance of the doped system increases when the Yb-doped proportion decreases.

  6. Phases in the Al-Yb-Zn system between 25 and 50 at% ytterbium

    Science.gov (United States)

    Mazzone, Donata; Manfrinetti, Pietro; Fornasini, Maria L.

    2009-09-01

    Phases YbZn 1-xAl x, YbZn 2-xAl x and YbZn 3-xAl x were studied by electron microprobe analysis and X-ray single crystal and powder methods. The compound YbZn 0.8Al 0.2 crystallizes with the CsCl-type, a=3.635(2) Å. Four phases were investigated by single crystal X-ray diffraction: YbZn 0.996(6)Al 1.004(6), MgNi 2-type, P6 3/ mmc, a=5.573(1), c=18.051(3) Å, Z=8, w R2=0.040 and YbZn 0.88(3)Al 1.12(3), MgCu 2-type, Fd3¯m, a=7.860(2) Å, Z=8, w R2=0.060, both showing mixed Zn/Al occupancy; YbZn 2.50(1)Al 0.50(1), CeNi 3-type, P6 3/ mmc, a=5.496(1), c=17.336(2) Å, Z=6, w R2=0.036 and YbZn 1.92(2)Al 1.08(2), PuNi 3- or NbBe 3-type, R3¯m, a=5.499(1), c=26.134(5) Å, Z=9, w R2=0.053, where the zinc atoms are ordered in the CaCu 5 segment, while share the sites with aluminium in the Laves phase segment. In the pseudobinary section YbZn 2-xAl x four structures occur in sequence with increasing the electron concentration: CeCu 2 or KHg 2 ( x=0-0.3), MgZn 2 ( x=0.33-0.54), MgNi 2 ( x=0.68-1.01) and MgCu 2 ( x=1.12-2). This sequence agrees with the results of first-principles calculations, already reported in the literature for other similar series. In the YbZn 3-xAl x section CeNi 3-type compounds occur with x=0.40-0.88 followed by PuNi 3-type compounds with x=0.92-1.10. The stability ranges of these phases are related to the valence electron concentration.

  7. Construction of four low-dimensional NIR-luminescence-tunable Yb(III) complexes.

    Science.gov (United States)

    Zheng, Zhi-Peng; Zhang, Xiu-Xia; Li, Teng; Yang, Jian; Wei, Lei-Ming; Zhang, Li-Guo; Lin, Xiao-Ming; Cai, Yue-Peng

    2014-10-07

    Four low-dimensional ytterbium(iii)-organic compounds through hydrothermal reactions of quinoline-2,3-dicarboxylic acid (2,3-H2qldc) and oxalic acid (H2ox) with Yb2O3, namely, [Yb(2,3-qldc)(ox)1/2(H2O)3·(H2O)4]n (1), [Yb(2,3-qldc)(ox)1/2(H2O)2·(H2O)2]n (2), [Yb(2,3-Hqldc)(ox)(H2O)2·(H2O)]n (3) and [Yb(2,3-Hqldc)(ox)(H2O)·(H2O)2]n (4), were first synthesized and characterized by elemental analysis (EA), infrared spectroscopy (IR), thermogravimetric analysis (TG), and single-crystal X-ray diffraction. When the reactant ratio of 2,3-H2qldc : H2ox : Yb2O3 is 2 : 1 : 1, 1-D chain-like complex 1 with three coordinated water molecules around the Yb(iii) ion was obtained in mixed solvents of H2O and CH3OH (v : v = 10 : 1) at 70 °C, and with the increase of temperature to 100 °C, the same reactants gave 2-D 6(3) topological layer-like complex 2 with two coordinated water molecules in the coordination sphere of the Yb(iii) ion. However, when the reactant ratio was changed to 1 : 1 : 1, two 2-D 6(3) topological layer-like complexes 3 (70 °C) and 4 (100 °C) were obtained at different temperatures, in which the coordination water molecules in 3 and 4 are two and one, respectively. Obviously, these results reveal that the reaction temperature and reactant ratios play critical roles in the structural direction of these low-dimensional compounds. Interestingly, with the gradual loss of coordination water molecules to the Yb(iii) ion, the near infrared (NIR) emission of four Yb(iii)-based compounds 1-4 can be gradually strengthened with increasing order of 1 complexes have tunable near infrared luminescence.

  8. Photocatalytic Water Splitting for Hydrogen Production with Novel M2YbSbO7 (M = In, Gd, Y by Using Visible Light Photoenergy

    Directory of Open Access Journals (Sweden)

    Jingfei Luan

    2012-01-01

    Full Text Available Novel photocatalysts M2YbSbO7 (M=In, Gd, Y were synthesized by solid state reaction method for the first time. A comparative study on the structural and photocatalytic properties of M2YbSbO7 M2YbSbO7 (M=In, Gd, Y was reported. The results showed that In2YbSbO7, Gd2YbSbO7, and Y2YbSbO7 crystallized with the pyrochlore-type structure, cubic crystal system and space group Fd3m. For the photocatalytic water splitting reaction, H2 or O2 evolution was observed from pure water with In2YbSbO7, Gd2YbSbO7, or Y2YbSbO7 as the photocatalyst under visible light irradiation. (wavelength>420 nm. Moreover, under visible light irradiation (>420 nm, H2 and O2 were also evolved by using In2YbSbO7, Gd2YbSbO7, or Y2YbSbO7 as catalyst from CH3OH/H2O and AgNO3/H2O solutions respectively. The In2YbSbO7 photocatalyst showed the highest activity compared with Gd2YbSbO7 or Y2YbSbO7. At the same time, The Y2YbSbO7 photocatalyst showed higher activity compared with Gd2YbSbO7. The photocatalytic activities were further improved under visible light irradiation with In2YbSbO7, Gd2YbSbO7, or Y2YbSbO7 being loaded by Pt, NiO, or RuO2. The effect of Pt was better than that of NiO or RuO2 for improving the photocatalytic activity of In2YbSbO7, Gd2YbSbO7, or Y2YbSbO7.

  9. Neurochirurgische Therapie von atypischen neuropathischen Gesichtsschmerzen und Clusterkopfschmerz mit Darstellung von Kernaspekten neurochirurgischer Schmerztherapie

    Directory of Open Access Journals (Sweden)

    Eisner W

    2016-01-01

    Full Text Available Die primäre Behandlung von Schmerzen jeglicher Art erfolgt pharmakologisch, physikalisch-medizinisch oder verhaltenstherapeutisch. Wenn diese konservativen Therapiemaßnahmen versagen, geraten Therapeuten und Patienten schnell in große Not; Alternativmethoden werden herangezogen. Solange geholfen wird und eine Schmerzerleichterung erkennbar ist, ist nichts dagegen einzuwenden. Versagen auch diese Methoden, sucht der Patient erneut Spezialisten auf, denen die schwere Aufgabe zukommt, dem Patienten weitere therapeutische Möglichkeiten zu ermöglichen oder ihn seinem Schicksal zu überlassen.br Die vorliegende Arbeit über atypische Gesichtsschmerzen möchte über neurochirurgische Behandlungsmöglichkeiten informieren. Die Komplexität dieser Erkrankungen benötigt die Interdisziplinarität von Neurologen, Schmerztherapeuten sowie Psychologen und nicht Beisätze wie „Vorsicht, Chirurgen, die schneiden überall rein und dann erst …“.

  10. Preparation of Yb-substituted α-Ni(OH){sub 2} and its physicochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qingsheng; Zhu, Yanjuan, E-mail: yanjuanzhu007@126.com; Han, Quanyong; Zhao, Rudong; Zhuang, Yihuan; Liu, Yonglin; Zhang, Shujie; Miao, Chengcheng

    2014-01-25

    Highlights: • Yb substituted α-nickel hydroxide was prepared by ultrasonic-assisted precipitation. • The electrode for 1.44 wt.% Yb has the highest capacity of 295.1 mAh/g at 0.2 C. • EDS spectrum was tested to show that Yb distributing in the lattice of α-Ni(OH){sub 2} uniformly. • The FWHM of peaks were marked to show the directional growth of the crystallite. -- Abstract: Nano-sized Yb-substituted α-Ni(OH){sub 2} was synthesized by ultrasonic-assisted precipitation, using nickel sulfate as nickel source and Yb(NO{sub 3}){sub 3}⋅5H{sub 2}O as doping material. The crystal structure, morphology, and particle size distribution of the sample were characterized with X-ray diffraction (XRD), infrared spectroscopy, transmission electron microscope (TEM), scanning electron microscope (SEM), high resolution transmission electron microscopy (HRTEM), and laser particle size analyzer (PSD). The results indicate that the samples are anisotropic polycrystalline α-Ni(OH){sub 2} with particle size of 50–200 nm, and the particle size increases with Yb-doping. The synthesized samples were tested in Ni-MH battery. The specific capacity increases initially and then decreases with increasing Yb-doping ratio with the maximum discharge capacity of 295.1 mAh/g at 0.2 C, which is 60 mAh/g higher than the micro-sized spherical nickel electrode. At the same time, the prepared material has lower charging voltage, higher discharge voltage plateau, and better cycle performance.

  11. Photoluminescence characterization of porous YAG: Yb{sup 3+}–Er{sup 3+} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Desirena, H., E-mail: hagdes@cio.mx [Centro de Investigaciones en Óptica, A. P. 1-948, León 37150, Guanajuato (Mexico); Diaz-Torres, L.A. [Centro de Investigaciones en Óptica, A. P. 1-948, León 37150, Guanajuato (Mexico); Rodríguez, R.A. [Centro Universitario de Los Lagos, Universidad de Guadalajara, Lagos de Moreno, Jalisco (Mexico); Meza, O. [Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado Postal J-48, Centro Historico 72570, Puebla (Mexico); Salas, P. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Apartado Postal 1-1010, Querétaro 76000, Querétaro México (Mexico); Angeles-Chávez, C. [Instituto Mexicano del Petróleo, Ciudad México, D.F. 07730, México (Mexico); Tobar, E.H.; Castañeda-Contreras, J. [Centro Universitario de Los Lagos, Universidad de Guadalajara, Lagos de Moreno, Jalisco (Mexico); De la Rosa, E., E-mail: elder@cio.mx [Centro de Investigaciones en Óptica, A. P. 1-948, León 37150, Guanajuato (Mexico)

    2014-09-15

    Yb{sup 3+}/Er{sup 3+} codoped yttrium aluminium garnet (YAG) porous nanocrystals were prepared by glycolate method assisted with poly-vinyl alcohol (PVA) and urea. The typical cubic structure for YAG was confirmed from XRD with crystallite average size of ∼40 nm, calculated from Scherrer formula and corroborated by TEM. Strong green and red upconversion emissions are observed readily with the naked eyes, and the color coordinates were obtained from emission spectra. A theoretical model to calculate CIE coordinate as a function of donor (Yb{sup 3+}) and acceptors (Er{sup 3+}) concentration is proposed. The eye-safe near infrared emitted signal and fluorescence lifetime were also measured and results show lifetime as large as 8.5 ms. The maximum energy transfer efficiency from Yb{sup 3+} to Er{sup 3+} was 72% for 20 mol% of Yb{sub 2}O{sub 3}. The proposed mechanisms for signal emitted are explained in terms of direct and energy back transfer processes, and cross relaxation. - Highlights: • Strong upconversion emission were observed in YAG:Er{sup 3+}–Yb{sup 3+} samples. • Color emission can be tuned from green to red by choosing properly the Yb{sup 3+} concentration. • The experimental colour coordinates match very well with the proposed theoretical model. • Cross relaxation and energy back transfer are mainly responsible for the red emission. • Fluorescence lifetime of {sup 4}I{sub 13/2} level increase with the Yb{sup 3+} concentration.

  12. Evolution of magnetic properties and exchange interactions in Ru doped YbCrO3

    Science.gov (United States)

    Dalal, Biswajit; Sarkar, Babusona; Ashok, Vishal Dev; De, S. K.

    2016-10-01

    Magnetic properties of YbCr1-x Ru x O3 as a function of temperature and magnetic field have been investigated to explore the intriguing magnetic phenomena in rare-earth orthochromites. A quantitative analysis of x-ray photoelectron spectroscopy confirms the mixed valence state (Yb3+ and Yb2+) of Yb ions for the highest doped sample. Field-cooled magnetization reveals a broad peak around 75 K and then becomes zero at about 20-24 K, due to the antiparallel coupling between Cr3+ and Yb3+ moments. An increase of the Ru4+ ion concentration leads to a slight increase of compensation temperature T comp from 20 to 24 K, but the Néel temperature remains constant. A larger value of the magnetic moment of Yb ions gives rise to negative magnetization at low temperature. An external magnetic field significantly modifies the temperature dependent magnetization. Simulation of temperature dependent magnetization data, below T N, based on the three (two) magnetic sub-lattice model predicts stronger intra-sublattice exchange interaction than that of inter-sublattice. Thermal hysteresis and Arrot plots suggest first order magnetic phase transition. Random substitution of Ru4+ ion reduces the magnetic relaxation time. Weak ferromagnetic component in canted antiferromagnetic system and negative internal magnetic field cause zero-field-cooled exchange bias effect. Large magnetocrystalline anisotropy associated with Ru creates high coercivity in the Ru doped sample. A maximum value of magnetocaloric effect is found around the antiferromagnetic ordering of Yb3+ ions. Antiferromagnetic transition at about 120 K and temperature induced magnetization reversal lead to normal and inverse magnetocaloric effects in the same material.

  13. Energy transfer and luminescence studies of Pr 3+ , Yb 3+ co-doped lead borate glass

    Science.gov (United States)

    Wen, Hongli; Tanner, Peter A.

    2011-09-01

    Lead borate glass samples doped with the tripositive lanthanide ions Pr 3+ and Yb 3+ were synthesized by the conventional melting-quenching method. The luminescence properties and energy transfer process from Pr 3+ to Yb 3+ were investigated. Upon ultraviolet excitation, the room temperature luminescence decay curve of a sample containing only a low concentration of Pr 3+ exhibited monoexponential decay from 1D 2 with the lifetime 37 μs, without emission from 3P 0. The room temperature Pr 3+ emission intensity decreased with the increase of Yb 3+ mole ratio in the glass. Under the excitation of 454.5 nm at 10 K, a broad red emission band centered at 605 nm, and an NIR emission band at 995 nm were observed in the co-doped lead borate glass, originating from Pr 3+ and Yb 3+ ions, respectively. The decay curves of the 1D 2 emission from Pr 3+ with addition of Yb 3+ in lead borate glass show non-monoexponential character, and are best described by a stretched exponential function. The average 1D 2 decay time decreases considerably with the addition of Yb 3+ in the glass. Decay curve fitting using a modified Inokuti-Hirayama expression indicates dipole-dipole energy transfer from Pr 3+ to Yb 3+, which is consistent with the expected cross-relaxation scheme. There is a good agreement of the estimated overall energy transfer efficiency obtained from the integrals under the normalized decay curves, or from the lifetimes fitted by the stretched exponential function, or from the average decay times.

  14. Charakterisierung von Mutanten im Lösungsmittelstoffwechsel von Clostridium acetobutylicum

    OpenAIRE

    Hönicke, Daniel

    2015-01-01

    Im Rahmen dieser Arbeit wurden insgesamt neun durch ClosTron-basierte Mutagenese erhaltene Insertionsmutanten von C. acetobutylicum ATCC 824 einer umfangreichen Charakterisierung unterzogen. Für alle im Batch-Fermentationsmaßstab und/oder in kontinuierlicher Kultur fermentierten Stämme erfolgte eine globale Analyse des Transkriptoms unter Verwendung der DNA-Microarray-Technologie. Für eine Analyse des Acetat- und Aceton-Stoffwechsels wurden Stämme mit einer inaktivierten Phosphotransacetyl...

  15. Update: SPECT in der Diagnostik von Parkinson-Syndromen

    Directory of Open Access Journals (Sweden)

    Pirker W

    2015-01-01

    Full Text Available Die Diagnose des Morbus Parkinson fußt primär auf Anamnese und klinischer Untersuchung. Die Abgrenzung von milden Bewegungsstörungen bei ansonsten gesunden älteren Personen, von medikamenteninduzierten und vaskulären Parkinson-Syndromen sowie von Tremor-Syndromen kann jedoch schwierig sein. Die Differenzierung zwischen M. Parkinson und atypischen Parkinson-Erkrankungen wie der Multisystematrophie (MSA und der progressiven supranukleären Paralyse (PSP ist im Frühstadium häufig unmöglich und kann auch in fortgeschrittenen Stadien Probleme bereiten. Die SPECT-Untersuchung mit Dopamin-Transporter- (DAT- Liganden wie 123I-FP-CIT erlaubt mit wenigen Ausnahmen bereits im Frühstadium eine Dokumentation der dopaminergen Degeneration beim M. Parkinson und atypischen Parkinson- Erkrankungen und damit meist eine Abgrenzung von nichtdegenerativen Parkinson- und Tremor-Syndromen. Sie kann die einzelnen degenerativen Parkinson-Syndrome jedoch nicht voneinander unterscheiden. Die Untersuchung postsynaptischer Dopamin- D2-Rezeptoren mit der 123I-IBZM-SPECT kann zur Differenzierung von M. Parkinson und MSA bzw. PSP beitragen. Neueren Untersuchungen zufolge dürften die Untersuchung des zerebralen Glukosemetabolismus mittels 18F-FDG-PET sowie moderne MRT-basierte Methoden in dieser Fragestellung jedoch eine höhere Sensitivität und Spezifität haben. Während Medikamente die diagnostische Aussagekraft von DAT-SPECT-Untersuchungen selten beeinflussen, kann das Ergebnis der IBZM-SPECT sowohl durch dopaminerge Substanzen als auch durch Dopaminantagonisten stark verfälscht werden. Die richtige Interpretation von SPECT-Daten setzt darüber hinaus die Kenntnis der individuellen strukturellen bildgebenden Befunde voraus. Eine MRT- oder CCTUntersuchung sollte zum Ausschluss von läsionellen Parkinson-Syndromen und zur Dokumentation von Kopathologien immer Bestandteil der Parkinson-Abklärung sein.

  16. Pressure-induced magnetic transition exceeding 30 K in the Yb-based heavy-fermion β -YbAlB4

    Science.gov (United States)

    Tomita, Takahiro; Kuga, Kentaro; Uwatoko, Yoshiya; Nakatsuji, Satoru

    2016-12-01

    Measurements of the electric resistivity ρ (T ) under pressure up to 8 GPa were performed on high-quality single crystals of the Yb-based heavy-fermion system β -YbAlB4 in the temperature range 2 resistivity data, we observed pressure-induced magnetic ordering above the critical pressure Pc˜2 GPa. The clear difference in the phase diagram under pressure using two types of pressure media indicates that the transition temperature may be further enhanced under application of uniaxial pressure. With pressure, this phase-transition temperature TM is enhanced, reaching 32 K at 8 GPa, which is the highest transition temperature so far recorded for the Yb-based heavy-fermion compounds. The power-law exponent α in ρ =ρ0+A Tα below TM gradually changes from 3/2 to 5/2 with increasing pressure from 2 to 8 GPa. In contrast, the resistivity exhibits a T -linear behavior in the temperature range 2 ≤T ≤20 K and is insensitive to pressure below Pc. In this pressure regime, the magnetization is also nearly independent of pressure and shows no anomaly above 2 K. Our results indicate that a quantum critical point for β -YbAlB4 is also located near Pc in addition to the strange metal region near the ambient pressure.

  17. Informationssuchverhalten als Grundlage für die Gestaltung von Veranstaltungen zum Erwerb von Informationskompetenz

    Directory of Open Access Journals (Sweden)

    Martin Wollschläger-Tigges

    2015-09-01

    Full Text Available Für die Gestaltung bibliothekarischer Veranstaltungen zum Erwerb von Informationskompetenz stellen die bisherigen Ergebnisse und Befunde der Forschung zum Informationssuchverhalten eine wertvolle Grundlage dar, indem bestimmte und v.a. typische Verhaltensmuster, Routinen und Präferenzen im Umgang mit Informationsressourcen und Informationen in konzeptionelle und inhaltliche Anpassungen von IK- Veranstaltungen eingebracht und eingesetzt werden. Das Informationssuchverhalten untersucht sowohl individuelle als auch kollektive Informationsprozesse und Faktoren, die diese maßgeblich beeinflussen. Hierzu werden der gesamte Informationsprozess oder einzelne Abschnitte untersucht, die den Information Need, Seeking und Using (INSU-Prozess bilden. Die Befunde der einzelnen INSU-Prozesses-Einheiten zeigen, dass Faktoren wie Informationsbedarf, Informationsart und -form sowie die Einbindung in übergeordnete Arbeitsprozesse wesentlichen Einfluss auf das Informationssuchverhalten haben. Des Weiteren konnte die ISB-Forschung eine Klassifizierung von Benutzergruppen entwickeln und z.B. Fast Surfers, Broad Scanners und Deep Divers charakterisieren bzw. auch das Bouncing oder Flicking Behavior beschreiben. Hinzu kommen mehrere Modelle, die Informationssuchverhalten und Informationsverhalten in bestimmten Situationen nachbilden und darstellen können.

  18. Valence bond and von Neumann entanglement entropy in Heisenberg ladders.

    Science.gov (United States)

    Kallin, Ann B; González, Iván; Hastings, Matthew B; Melko, Roger G

    2009-09-11

    We present a direct comparison of the recently proposed valence bond entanglement entropy and the von Neumann entanglement entropy on spin-1/2 Heisenberg systems using quantum Monte Carlo and density-matrix renormalization group simulations. For one-dimensional chains we show that the valence bond entropy can be either less or greater than the von Neumann entropy; hence, it cannot provide a bound on the latter. On ladder geometries, simulations with up to seven legs are sufficient to indicate that the von Neumann entropy in two dimensions obeys an area law, even though the valence bond entanglement entropy has a multiplicative logarithmic correction.

  19. A von Bertalanffy growth model with a seasonally varying coefficient

    Science.gov (United States)

    Cloern, James E.; Nichols, Frederic H.

    1978-01-01

    The von Bertalanffy model of body growth is inappropriate for organisms whose growth is restricted to a seasonal period because it assumes that growth rate is invariant with time. Incorporation of a time-varying coefficient significantly improves the capability of the von Bertalanffy equation to describe changing body size of both the bivalve mollusc Macoma balthicain San Francisco Bay and the flathead sole, Hippoglossoides elassodon, in Washington state. This simple modification of the von Bertalanffy model should offer improved predictions of body growth for a variety of other aquatic animals.

  20. Bioaktivitäten von Wertstoffen aus Saccharomyces Hefen

    OpenAIRE

    Jährig, Silke Christiane

    2007-01-01

    In der vorliegenden Arbeit wurden die antioxidative Aktivität sowie die immunmodulierende Kapazität von Zellwänden und Zellwandbestandteilen der Bierhefe Saccharomyces cerevisiae untersucht. Die Zellwände von Saccharomyces-Hefen bestehen aus (1→3),(1→6)-β-D-Glucan, Mannanen, Proteinen und Lipiden. Als potentieller Immunmodulator ist vor allem das (1→3),(1→6)-β-D-Glucan von Interesse. Vor kurzem konnte für dieses Glucan zusätzlich eine antioxidative Wirkung nachgewiesen werden [KOGAN et al., 2...

  1. Emotionales Erleben von Lehrkräften beim Unterrichten

    OpenAIRE

    Frenzel, Anne C.; Götz, Thomas

    2007-01-01

    Ziel dieser Studie war es, das Ausmaß an Variabilität des Erlebens von Freude, Angst und Ärger bei Lehrkräften zu ermitteln, das auf ihre Persönlichkeit, das Unterrichtsfach (hier: Mathematik vs. Physik) und die jeweils unterrichtete Klasse zurückzuführen ist. Zudem wurde der Einfluss von Person- und Kontextmerkmalen auf das emotionale Erleben beim Unterrichten untersucht. 59 Gymnasiallehrkräfte (9 weiblich) gaben anhand von einem Fragebogen sowie einem Tagebuch Auskunft über ihre Unterrichts...

  2. Über die Ethoxylierung von Octanol im Mikrostrukturreaktor

    OpenAIRE

    2015-01-01

    Die basisch katalysierte ringöffnende Polymerisation von Ethylenoxid mit Octanol (Ethoxylierung) wurde in einem kontinuierlich betriebenen Mikrostrukturreaktor untersucht. Es wurde die Kinetik dieser Reaktion unter intensivierten Bedingungen ermittelt. Die Reaktion wurde homogen in der Flüssigphase durchgeführt, bei Drücken bis 100 bar und Temperaturen im Bereich von 130 °C bis 240 °C. Für die Propagationsreaktion eine Aktivierungsenergie von 73 kJ/mol gefunden. Es wurde gezeigt, dass die Pro...

  3. Modernisation of ventilation systems; Modernisierung von Lueftungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Richter, W. [Technische Univ. Dresden (Germany). Inst. fuer Thermodynamik und Technische Gebaeudeausruestung

    1997-12-31

    When redeveloping buildings it is common to use window constructions with air-tight rabbets which obviate the inflow of fresh air almost entirely. This leads to the well-known structural-physics and hygienic consequences. As an added effect, the distinctly enhanced thermal insulation results in changes in dynamic heat loss. The paper focuses on the issues of how to safeguard the inflow of fresh air, and the heating capacity of radiators. (MSK) [Deutsch] Da die bei Gebaeudesanierungen eingesetzten fugendichten Fensterkonstruktionen die Nachstroemmoeglichkeiten fuer die Zuluft fast ganz unterbinden, fuehrt das zu den bekannten bauphysikalischen und hygienischen Konsequenzen. Dazu kommen veraenderte dynamische Waermverlustverhaeltnisse aufgrund der deutlich verbesserten Waermedaemmung. Im Folgenden wird schwerpunktmaessig auf die Probleme Zuluftsicherung und Waermeleistung von Heizkoerpern eingegangen.

  4. Wirksame Alternativen zur Behandlung von klimakterischen Beschwerden

    Directory of Open Access Journals (Sweden)

    Stute P

    2011-01-01

    Full Text Available Vasomotorische Beschwerden (VMS werden von 75 % der postmenopausalen Frauen angegeben. Neben der konventionellen Hormontherapie stehen verschiedene Behandlungsmöglichkeiten aus dem Bereich der Alternativ- und Komplementärmedizin (CAM zur Verfügung. Soja Isoflavone und Traubensilberkerze können bei jüngeren peri- und frühen postmenopausalen Frauen mit leichten bis moderaten VMS hilfreich sein. Die Studienlage zur CMA ist jedoch insgesamt unzureichend. In Zukunft wäre es wünschenswert, nicht nur das Wirkungsvermögen, sondern auch die Effizienz einer Behandlung in randomisiert-kontrollierten Studien zu untersuchen. Hierfür bietet sich die ICF Klassifikation der WHO an.

  5. Hermann von Helmholtz and the empiricist vision.

    Science.gov (United States)

    Turner, R S

    1977-01-01

    The philosophical convictions of Hermann von Helmholtz and the empiricist psychology he developed have been extensively discussed in historical literature. This literature has not usually emphasized the tacti assumptions about human physiology that underlaid these convictions nor the way in which Helmholtz's epistemology served as a methodological directive in his research. Helmholtz assumed nerve transmission between sense organs and the mind to be a passive process. Distortion in stimulus patterns occurs physically in the sense organs, which can therefore be treated through mechanical analogies. Stimuli become converted to the perceptions of consciousness through mental processes that are essentially analogous to conscious, inductive inference and that are therefore susceptible, in principle, to introspective investigation. This view of mental function reflected Helmholtz's intellectual debt to German idealism, especially to the philosophical views of J.G. Fichte.

  6. Effects of Sc and Y substitution on the structure and thermoelectric properties of Yb14MnSb11

    Science.gov (United States)

    Grebenkemper, Jason H.; Klemenz, Sebastian; Albert, Barbara; Bux, Sabah K.; Kauzlarich, Susan M.

    2016-10-01

    Yb14MnSb11 is the most efficient bulk p-type thermoelectric material for high temperature applications. Materials with Y and Sc substitutions in Yb14MnSb11 were made both in Sn-flux and by ball milling. These small 3+ rare earth (RE) cations were introduced with the goal of providing chemical pressure on the structure. The RE3+ cation is smaller than Yb2+ and also donates one additional electron to this p-type semiconductor. In Yb14-xRExMnSb11 (RE = Sc, Y) the maximum x was about 0.5. X-ray diffraction experiments on the single crystals obtained from Sn-flux showed that Sc preferentially substitutes for Yb(1) and Yb(3), and decreases the size of the unit cell by about 0.3%. Y substitutes on all Yb sites and increases the size of the unit cell by about 0.2%. Samples with Yb14-xRExMnSb11 (x~0.3) were prepared via powder metallurgy and spark plasma sintering for transport and thermal conductivity measurements. Electron microprobe of the Sc-substituted sample showed small regions (≤1 μ m) containing greater amounts of Sc, and X-ray powder diffraction of the ball milled Sc sample could be fitted as phase pure Yb14-xScxMnSb11. Y-substituted samples showed larger regions of excess Y in electron microprobe, and small amounts of Yb4Sb3 in X-ray powder diffraction. The Sc sample has slightly reduced carrier concentration over optimized Yb14MnSb11, while the Y samples have even lower carrier concentrations. These carrier concentrations lead to comparable resistivity to Yb14MnSb11 in the Sc-substituted material, and higher resistivities in the Y-substituted material. All materials had similar Seebeck coefficients that slightly exceed Yb14MnSb11 at high temperatures, with the Sc-substituted sample having the highest despite having a higher carrier concentration. Sc-substituted samples also had a slightly higher thermal conductivity over the Y-substituted samples, which had comparable thermal conductivity to Yb14MnSb11. The zT values of the Sc and Y substituted samples are

  7. [Study on Spectral Characteristics of Two Kinds of Home-Made Novel Yb-Doped Fluoride Laser Crystals].

    Science.gov (United States)

    Xu, Wen-bin; Chai, Lu; Shi, Jun-kai; Song, You-jian; Hu, Ming-lie; Wang, Qing-yue; Su, Liang-bi; Jiang, Da-peng; Xu, Jun

    2015-09-01

    Yb-doped fluoride crystals are of important another Yb-doped laser materials besides Yb-doped oxide, which are becoming one of interests for developing tunable lasers and ultrafast lasers. In this paper, the systematic and contrastive experiments of the optical spectral characteristics are presented for two types of home-made novel Yb-doped fluoride laser crystals, namely, Yb-doped CaF2-SrF2 mixed crystal and co-doped Yb, Y:CaF2 single crystal. The fluorescent features of Yb-doped CaF2-SrF2 mixed crystal and co-doped Yb, Y:CaF2 single crystal are apparently different by the fluorescence experiment. The physical mechanism of these fluorescence spectra were analyzed and proposed. The influence of doping concentrations of active Yb(3+) ions or co-doping Y ions on the absorption of Yb-doped CaF2-SrF2 mixed crystal and co-doped Yb, Y:CaF2 single crystal was experimentally investigated, and the optimal values of doping concentrations of active Yb(3+) ions or co-doping Y ions in the two types of fluoride laser crystals were obtained. Continuous-wave laser operation for the two novel fluoride laser crystals has been achieved in three-mirror-folded resonator using a laser diode as the pump source. Therein, the laser operation for the co-doped Yb, Y:CaF2 crystal is demonstrated for the first time. For the two types of fluoride laser crystals (four samples), the input-output power relational curves, the optical slope efficiencies and the laser spectra were demonstrated by the laser experiments. By comparisons between the two types of fluoride laser crystals in the absorbability, fluorescence and laser spectra, laser threshold and slope efficiency of the continuous-wave laser operation, the results show that the best one of the four samples in spectral and laser characteristics is co-doped 3at%Yb, 6at% Y:CaF2 single crystal, which has an expected potential in the application. The research results provide available references for improving further laser performance of Yb

  8. Energy transfer in Tb3+,Yb3+ codoped Lu2O3 near-infrared downconversion nanophosphors

    Institute of Scientific and Technical Information of China (English)

    LI Li; WEI Xiantao; CHEN Yonghu; GUO Changxin; YIN Min

    2012-01-01

    Tb3+ and Yb3+ codoped Lu2O3 nanophosphors were synthesized by the reverse-strike co-precipitation method.The obtained Lu2O3:Tb3+,Yb3+ nanophosphors were characterized by X-ray diffraction (XRD) and photoluminescence (PL) spectra.The XRD results showed that all the prepared nanophosphors could be readily indexed to pure cubic phase of Lu2O3 and indicated good crystallinity.The Tb3+→Yb3+ energy transfer mechanisms in the UV-blue region in Lu2O3 nanophosphors were investigated.The experimental results showed that the strong visible emission around 543 nm from Tb3+ (5D4→7F5) and near-infrared (NIR) emission around 973 nm from Yb3+ (2F5/2→2F7/2) of LuzO3:Tb3+,Yb3+ nanophosphors were observed under ultraviolet light excitation,respectively.Tb3+ could be effectively excited up to its 4f75d1 state and relaxed down to the 5D4 level,from which the energy was transferred cooperatively to two neighboring Yb3+.The Yb3+concentration dependent luminescent properties and lifetimes of both the visible and NIR emissions were also studied.The lifetime of the visible emission decreased with the increase of Yb3+ concentration,verifying the efficient energy transfer from the Tb3+to the Yb3+.Cooperative energy transfer (CET) from Tb3+ to Yb3+ was discussed as a possible mechanism for the near-infrared emission.When doped concentrations were 1 mol.% Tb3+ and 2 mol.% Yb3+,the intensity of NIR emission was the strongest.

  9. Hepatische Effekte von Wachstumshormon auf den Glukosestoffwechsel

    Directory of Open Access Journals (Sweden)

    Rufinatscha K

    2015-01-01

    Full Text Available Untherapierter Wachstumshormonmangel im Erwachsenenalter (AGHD ist mit viszeraler Adipositas, Dyslipidämie, Insulinresistenz und Fettleber verbunden. Interessanterweise finden sich viele der AGHD-Merkmale auch bei Patienten mit metabolischem Syndrom. Die nichtalkoholische Fettlebererkrankung (NAFLD gilt als hepatische Manifestation des metabolischen Syndroms. In einigen Studien wurden bei Patienten mit NAFLD verminderte Konzentrationen von zirkulierendem IGF-1, dessen Synthese zu einem großen Teil durch Wachstumshormon (GH reguliert wird, beschrieben. Mäuse, welche eine hepatische Wachstumshormondefizienz aufweisen, zeigen zahlreiche phänotypische Charakteristika des metabolischen Syndroms, unter anderen auch eine Fettlebererkrankung. Dies legt einen Zusammenhang zwischen dem Wachstumshormon und der Entstehung einer NAFLD nahe. Ziel unserer Studie ist es, in einem Zellkulturmodell die Effekte des Wachstumshormons auf den intrazellulären Glukosestoffwechsel näher zu untersuchen. Im Detail sollen Auswirkungen einer verminderten Wachstumshormonrezeptorexpression auf den Insulinsignaltransduktionsweg, den Glykogengehalt und auf Schlüsselenzyme der Glukoneogenese untersucht werden. Präliminäre Daten zeigen, dass eine verminderte Wachstumshormonrezeptorexpression mit intrazellulären Veränderungen des hepatischen Glukosestoffwechsels verbunden ist. Die verminderte Insulinsensitivität könnte auf Alterationen im Insulinsignaltransduktionsweg und Änderungen der Glukoneogenese zurückzuführen sein. Diese präliminären Daten weisen darauf hin, dass Wachstumshormon einen direkten Einfluss auf den Glukosestoffwechsel in der Leber hat. Zudem legen sie nahe, dass Veränderungen im Wachstumshormonstoffwechsel einen wichtigen pathophysiologischen Mechanismus in der Entstehung der Fettlebererkrankung bei Patienten mit metabolischem Syndrom darstellen könnten. Der folgende Artikel soll einen kurzen Überblick über die Effekte von Wachstumshormon

  10. Thermodynamic properties of multiferroic Mg doped YbMnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Sattibabu, Bhumireddi, E-mail: bsb.satti@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Bhatnagar, A.K., E-mail: anilb42@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); School of Physics, University of Hyderabad, Hyderabad 500046 (India); Samatham, S. Shanmukharao; Singh, D. [Low Temperature Laboratory, UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001, M.P. (India); Rayaprol, S. [UGC-DAE Consortium for Scientific Research, Mumbai Centre, BARC Campus, Mumbai 400085 (India); Das, D. [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Siruguri, V. [UGC-DAE Consortium for Scientific Research, Mumbai Centre, BARC Campus, Mumbai 400085 (India); Ganesan, V. [Low Temperature Laboratory, UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001, M.P. (India)

    2015-09-25

    Highlights: • Specific heat data shows that T{sub N} increases for Mg doped YbMnO{sub 3} from 83 K to 86 K. • Yb{sub 1−x}Mg{sub x}MnO{sub 3} (x = 0.0 and 0.05) shows multiple magnetic transitions. • RCP are found to be 26.1 J/mol and 27.2 J/mol for YbMnO{sub 3} and Yb{sub 0.95}Mg{sub 0.05}MnO{sub 3}. - Abstract: Calorimetric studies of polycrystalline samples Yb{sub 1−x}Mg{sub x}MnO{sub 3} with x = 0.0 and 0.05 are reported. It is revealed that the Mg doping raises the antiferromagnetic ordering temperature, T{sub N,} from 83 K for x = 0.0 to 86 K for x = 0.05. A ferromagnetic ordering is also observed around 3 K. The broad feature in the specific heat data just above ferromagnetic ordering, is attributed to the Schottky anomaly. The estimated effective molecular fields from the Schottky analysis are H{sub mf} = 3.0 and 3.5 T for YbMnO{sub 3} and Yb{sub 0.95}Mg{sub 0.05}MnO{sub 3}, respectively. High temperature shift of Schottky anomaly with Mg doping indicates increase in effective molecular field of Mn at the Yb 4b site. The data supports that the idea that although molecular field is mainly responsible for the Schottky anomaly in Yb{sub 1−x}Mg{sub x}MnO{sub 3} and Mn{sup 3+} spin ordering also affects it. Magnetic part of the specific heat is obtained by subtracting the lattice contribution estimated using two Debye temperatures. The magnetic entropy change (ΔS{sub mag}) for pure and doped samples are 2.0 J mol{sup −1} K{sup −1} and 2.1 J mol{sup −1} K{sup −1} respectively, while the relative cooling power (RCP) calculate 26.1 J/mol, 27.2 J/mol for a field change of 10 T.

  11. Facile synthesis of NaYF4:Yb, Ln/NaYF4:Yb core/shell upconversion nanoparticles via successive ion layer adsorption and one-pot reaction technique

    NARCIS (Netherlands)

    Zeng, Q.; Xue, B.; Zhang, Y.; Wang, D.; Liu, X.; Tu, L.; Zhao, H.; Kong, X.; Zhang, H.

    2013-01-01

    The facile one-pot synthesis of NaYF4:Yb, Ln/NaYF4:Yb core/shell (CS) upconversion nanoparticles (UCNPs) was firstly developed through the successive ion layer adsorption and reaction (SILAR) technique, which represents an attractive alternative to conventional synthesis utilizing the chloride of Ln

  12. The contribution of valence unstable ytterbium states into kinetic properties of YbNi{sub 2-x}Ge{sub 2+x} and YbCu{sub 2-x}Si{sub 2+x}

    Energy Technology Data Exchange (ETDEWEB)

    Kuzhel, B.C. [Department of Physics, Ivan Franko National University of Lviv, 50 Dragomanow Str., 79005, Lviv (Ukraine)]. E-mail: kuzhelb@org.lviv.net; Shcherba, I.D. [Department of Physics, Ivan Franko National University of Lviv, 50 Dragomanow Str., 79005, Lviv (Ukraine); Institute of Techniques, Academy of Pedagogy, Podchorozych 2, 30-084, Krakow (Poland); Kravchenko, I.I. [Department of Physics, University of Florida, P.O. Box 118440, Gainesville, FL 32611 (United States)]. E-mail: kravch@phys.ufl.edu

    2006-11-30

    The intermetalic YbNi{sub 2-x}Ge{sub 2+x} (-0.25>=x>=0.25) and YbCu{sub 2-x}Si{sub 2+x} (-0.20>=x>=0.20) alloy systems (CeGa{sub 2}Al{sub 2} -type crystal structure) were studied by measuring X-ray absorption and diffraction at room temperatures as well as electrical resistivity and thermopower in the 4.2-300K temperature range. The temperature dependence of the contribution of valence unstable Yb ions to the total electrical resistance has been analyzed. The qualitative estimation of this contribution has been performed by utilizing the following equation:{delta}{rho}{sub Yb}(T)={rho}{sub exp}(T)-{rho}{sub YbCu{sub 2}Ge{sub 2}}(T)-{delta}{rho}{sub 4.2K},where {delta}{rho}{sub YbCu{sub 2}Ge{sub 2}}(T) is the temperature dependence of YbCu{sub 2}Ge{sub 2} electrical resistance, {delta}{rho}{sub 4.2}={rho}{sub 4.2}(exp)-{rho}{sub 4.2}(YbCu{sub 2}Ge{sub 2})

  13. Yb:CaF2 thin-disk laser.

    Science.gov (United States)

    Wentsch, Katrin Sarah; Weichelt, Birgit; Günster, Stefan; Druon, Frederic; Georges, Patrick; Abdou Ahmed, Marwan; Graf, Thomas

    2014-01-27

    We present Ytterbium-doped CaF2 as a laser active material with good prospects for high-power operation in thin-disk laser configuration owing to its favorable thermal properties. Thanks to its broad emission bandwidth the material is also suitable for the generation of ultra-short pulses. The properties of the crystal as well as the challenges related to the coating, polishing, mounting and handling processes which are essential to achieve high power laser oscillation in thin-disk configuration are discussed. A wavelength tunability of 92 nm is demonstrated, which confirms the potential of Yb:CaF2 for the generation of ultra-short pulses. An output power of 250 W with an optical efficiency of η opt = 47% was measured in CW multimode thin-disk laser operation with a pump spot diameter of 3.6 mm. Using a smaller pump spot diameter of 1 mm the fundamental mode output power was 13 W with an optical efficiency of η opt = 34%.

  14. Study of Yb isotopes with the coherent state formalism

    Science.gov (United States)

    Inci, I.

    2016-08-01

    Coherent state approach (CSA) is applied to the interacting boson model (IBM) in the rotational region. States of the N particle system are built up in a most general form as a function of the shape parameters β and γ. The parameter χ occurring in the quadrupole operator which determines the degree of the γ-softness is taken to be varying with the boson number. The excitation energy equations are formed by using the moment of inertia of a rotating system which is obtained from the solution of the cranking problem. For each isotope, the deformation parameter is found by minimizing the ground state energy equation. The results are used to fit the experimental excitation energy spectrum and the electric quadrupole transition ratios of Yb isotopes. It is found that CSA works well to predict the energy of the states up to L = 10. But the predictions about the electric quadrupole transitions are nearly 1.5 times greater than the experimental data.

  15. Single-shot spectroscopy of broadband Yb fiber laser

    Science.gov (United States)

    Suzuki, Masayuki; Yoneya, Shin; Kuroda, Hiroto

    2017-02-01

    We have experimentally reported on a real-time single-shot spectroscopy of a broadband Yb-doped fiber (YDF) laser which based on a nonlinear polarization evolution by using a time-stretched dispersive Fourier transformation technique. We have measured an 8000 consecutive single-shot spectra of mode locking and noise-like pulse (NLP), because our developed broadband YDF oscillator can individually operate the mode locking and NLP by controlling a pump LD power and angle of waveplates. A shot-to-shot spectral fluctuation was observed in NLP. For the investigation of pulse formation dynamics, we have measured the spectral evolution in an initial fluctuations of mode locked broadband YDF laser at an intracavity dispersion of 1500 and 6200 fs2 for the first time. In both case, a build-up time between cw and steady-state mode locking was estimated to be 50 us, the dynamics of spectral evolution between cw and mode locking, however, was completely different. A shot-to-shot strong spectral fluctuation, as can be seen in NLP spectra, was observed in the initial timescale of 20 us at the intracavity dispersion of 1500 fs2. These new findings would impact on understanding the birth of the broadband spectral formation in fiber laser oscillator.

  16. Luminescent properties of the ZnSe:Yb crystals in the visible spectral range

    Energy Technology Data Exchange (ETDEWEB)

    Radevici, I., E-mail: ivarad@utu.fi [Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Faculty of Physics and Engineering, Moldova State University, Mateevici str. 60, MD-2009, Chisinau, Republic of Moldova (Moldova, Republic of); Sushkevich, K. [Faculty of Physics and Engineering, Moldova State University, Mateevici str. 60, MD-2009, Chisinau, Republic of Moldova (Moldova, Republic of); Sirkeli, V. [Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Faculty of Physics and Engineering, Moldova State University, Mateevici str. 60, MD-2009, Chisinau, Republic of Moldova (Moldova, Republic of); Huhtinen, H. [Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Nedeoglo, D. [Faculty of Physics and Engineering, Moldova State University, Mateevici str. 60, MD-2009, Chisinau, Republic of Moldova (Moldova, Republic of); Paturi, P. [Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland)

    2013-11-15

    Luminescent properties of the ytterbium doped zinc selenide crystals with various concentrations of the doping impurity in 0.03–8 at % range within the temperature interval from 6 K to 300 K were studied. It was shown that ytterbium does not form any proper photoluminescence (PL) bands in the visible spectral range, but it has significant influence on the crystals luminescent properties by changing their defect composition. An attempt to determine ytterbium ion surroundings in the crystal lattice was made based on the obtained experimental results. An assumption about simultaneous compensation of donor and acceptor defects as a result of doping annealing in Zn+X at % Yb melt was made. -- Highlights: • ZnSe:Yb crystals with Yb concentration within 0.03–8 at% range were obtained • Temperature and concentration dependences of ZnSe:Yb PL properties were studied • Ytterbium impurity contribution to formation of the PL bans was determined • A model explaining Yb interaction with native and extrinsic defects was proposed.

  17. Bulk and surface electron transport in topological insulator candidate YbB{sub 6-δ}

    Energy Technology Data Exchange (ETDEWEB)

    Glushkov, Vladimir V.; Demishev, Sergey V.; Sluchanko, Nikolay E. [Prokhorov General Physics Institute of RAS, Vavilov str. 38, 119991, Moscow (Russian Federation); Moscow Institute of Physics and Technology, Institutskii per. 9, 141700, Dolgoprudny, Moscow Region (Russian Federation); Bozhko, Alexey D.; Bogach, Alexey V.; Semeno, Alexey V.; Voronov, Valeriy V. [Prokhorov General Physics Institute of RAS, Vavilov str. 38, 119991, Moscow (Russian Federation); Dukhnenko, Anatoliy V.; Filipov, Volodimir B.; Shitsevalova, Natalya Yu. [Frantsevich Institute for Problems of Materials Science NAS, Krzhyzhanovsky str. 3, 03680, Kiev (Ukraine); Kondrin, Mikhail V. [Vereshchagin Institute of High Pressure Physics of RAS, 142190, Troitsk, Moscow (Russian Federation); Kuznetsov, Alexey V.; Sannikov, Ilia I. [National Research Nuclear University ' ' MEPhI' ' , Kashirskoe Shosse 31, 115409, Moscow (Russian Federation)

    2016-04-15

    We report the study of transport and magnetic properties of the YbB{sub 6-δ}single crystals grown by inductive zone melting. A strong disparity in the low temperature resistivity, Seebeck and Hall coefficients is established for the samples with the different level of boron deficiency. The effective parameters of the charge transport in YbB{sub 6-δ} are shown to depend on the concentration of intrinsic defects, which is estimated to range from 0.09% to 0.6%. The pronounced variation of Hall mobility μ{sub H} found for bulk holes is induced by the decrease of transport relaxation time from τ ∼ 7.7 fs for YbB{sub 5.994} to τ ∼ 2.2 fs for YbB{sub 5.96}. An extra contribution to conductivity from electrons with μ{sub H}∼ -1000 cm{sup 2} V{sup -1} s{sup -1} and the very low concentration n /n{sub Yb}∼ 10{sup -6} discovered below 20 K for all the single crystals under investigation is suggested to arise from the surface electron states appeared in the inversion layer due to the band bending. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Synthesis and optoelectrical properties of ABO{sub 2} (A = Li, Na; B = Y, Yb)

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Ying; Natsume, Yuuki; Sawaguchi, Naoya; Sasaki, Makoto, E-mail: sasaki@mmm.muroran-it.ac.jp [Muroran Institute of Technology (Japan)

    2011-10-29

    The transparent electrically conductive composite materials ABO{sub 2} (A = Li, Na; B = Y, Yb) were synthesized under high temperature solid-state reactions from A{sub 2}O and B{sub 2}O{sub 3}. The synthesized compounds have been investigated by Rietveld analysis, giving the crystal (monoclinic, c12/c1, a = 611.6 pm) for LiYO2, (monoclinic, p121/c1, a = 999 pm) for NaYO{sub 2}, (trigonal, R3-bar m, a = 335.2 pm) for NaYbO{sub 2}, (tetragonal, I4{sub 1}/amd, a = 438.6 pm) for LiYbO{sub 2}. Optical properties of the four compounds were studied by UV-vis spectral measurements, results show each of the compounds has an optical band gap more than 3.3 eV which is the standard for transparent property. Electrical conductivities of the four compounds have been studied by two probe direct current electrical conductivity measurements. The results show with increasing heating temperature, an obvious increase in electrical conductivity was observed for each compound. Also, the crystal energy band structure of each compound has been studied by using density functional theory code CASTEP. The results show the solid-state compounds of NaYO{sub 2}, NaYbO{sub 2} and LiYbO{sub 2} are semiconductors with direct band gaps, LiYO{sub 2} is a semiconductor with an indirect band gap.

  19. Highly-efficient multi-watt Yb:CaLnAlO4 microchip lasers

    Science.gov (United States)

    Loiko, Pavel; Serres, Josep Maria; Mateos, Xavier; Xu, Xiaodong; Xu, Jun; Yumashev, Konstantin; Griebner, Uwe; Petrov, Valentin; Aguiló, Magdalena; Díaz, Francesc; Major, Arkady

    2017-02-01

    Tetragonal rare-earth calcium aluminates, CaLnAlO4 where Ln = Gd or Y (CALGO and CALYO, respectively), are attractive laser crystal hosts due to their locally disordered structure and high thermal conductivity. In the present work, we report on highly-efficient power-scalable microchip lasers based on 8 at.% Yb:CALGO and 3 at.% Yb:CALYO crystals grown by the Czochralski method. Pumped by an InGaAs laser diode at 978 nm, the 6 mm-long Yb:CALGO microchip laser generated 7.79 W at 1057-1065 nm with a slope efficiency of η = 84% (with respect to the absorbed pump power) and an optical-to-optical efficiency of ηopt = 49%. The 3 mm-long Yb:CALYO microchip laser generated 5.06 W at 1048-1056 nm corresponding to η = 91% and ηopt = 32%. Both lasers produced linearly polarized output (σ- polarization) with an almost circular beam profile and beam quality factors M2 x,y <1.1. The output performance of the developed lasers was modeled yielding a loss coefficient as low as 0.004-0.007 cm-1. The results indicate that the Yb3+- doped calcium aluminates are very promising candidates for high-peak-power passively Q-switched microchip lasers.

  20. Superconductivity in Yb-doped BaFe{sub 2}As{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.C. [Department of Physics, National Chung Cheng University, Ming-Hsiung, Chia-Yi 62199, Taiwan, ROC (China); Lee, W.H., E-mail: phywhl@ccu.edu.tw [Department of Physics, National Chung Cheng University, Ming-Hsiung, Chia-Yi 62199, Taiwan, ROC (China); Lan, M.D. [Department of Physics, National Chung Hsing University, Taichung, Taiwan, ROC (China)

    2015-02-15

    Highlights: • Single crystal of (Ba{sub 1−x}Yb{sub x})Fe{sub 2}As{sub 2} (x = 0–0.2) has been grown. • The grown crystals have pure tetragonal ThCr{sub 2}Si{sub 2}-type structure. • (Ba{sub 1−x}Yb{sub x})Fe{sub 2}As{sub 2} (0.05 ≦ x ≦ 0.15) showed a T{sub c,onset} 18–20 K. - Abstract: We report the discovery of superconductivity in Yb-doped BaFe{sub 2}As{sub 2}. Single-crystal specimens of (Ba{sub 1−x}Yb{sub x})Fe{sub 2}As{sub 2} (x = 0–0.2) were grown by using FeAs flux and a slow-cooling method. The superconducting transition temperature for the crystals was determined by dc magnetic susceptibility measurements with a commercial SQUID magnetometer. A clear phase transition from paramagnetic to perfect diamagnetic state was observed around 18–20 K for the samples with nominal composition (Ba{sub 1−x}Yb{sub x})Fe{sub 2}As{sub 2} (0.05 ≦ x ≦ 0.15)

  1. The influence of critical current density of Bi-2212 superconductors by defects after Yb-doping

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Tianni [State key Laboratory for Mechanical Behavior of Materials of Xi' an Jiaotong University, Xi' an 710014 (China); SMRC, Northwest Institute for Nonferrous Metal Research, Xi' an 710016 (China); Zhang, Cuiping [SMRC, Northwest Institute for Nonferrous Metal Research, Xi' an 710016 (China); Guo, Shengwu [State key Laboratory for Mechanical Behavior of Materials of Xi' an Jiaotong University, Xi' an 710014 (China); Wu, Yifang [State key Laboratory for Mechanical Behavior of Materials of Xi' an Jiaotong University, Xi' an 710014 (China); SMRC, Northwest Institute for Nonferrous Metal Research, Xi' an 710016 (China); Li, Chengshan, E-mail: csli368@126.com [SMRC, Northwest Institute for Nonferrous Metal Research, Xi' an 710016 (China); Zhou, Lian [State key Laboratory for Mechanical Behavior of Materials of Xi' an Jiaotong University, Xi' an 710014 (China); SMRC, Northwest Institute for Nonferrous Metal Research, Xi' an 710016 (China)

    2015-12-15

    Highlights: • Ca substituting Yb element in Bi-2212 single crystal. • The critical current density of this sample is the highest without the optimal Tc value. • The Cu–O{sub 2} and Ca–O layers in pure and doping samples are observed using HRTEM. • The optimal defect density is calculated. - Abstract: Bi{sub 2}Sr{sub 2}Ca{sub 1−x}Yb{sub x}Cu{sub 2}O{sub 8+δ} (Bi-2212) single crystals with x = 0.000, 0.005, 0.010 and 0.020 have been prepared by self-flux method. The influences of Yb doping on the formation of the dislocations in the lattice structures, as well as the related current carrying capability are investigated. Due to the SQUID measurement and the Bean model calculation, the maximum critical current density (Jc) is obtained when the Yb doping content is x = 0.010, though the Tc and the carrier concentration are not in the optimal region. Based on the HRTEM analyses of the Ca–O and Cu–O{sub 2} layers, the optimal dislocation density in the Cu–O{sub 2} layers is deduced according to the number of the dislocations per unit area. Besides, the sizes of the dislocations also prove the effectiveness of Yb substitution on the enhancement of the current carrying capability in Bi-2212 single crystals.

  2. Von Krahli Teater viis Helsingisse kaks menulavastust / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2003-01-01

    Von Krahli Teater esineb 29. nov. Helsingis "Baltic Circle" festivalil lavastustega "Luikede järv" ja "Taksojuhid". Tutvustatakse lühidalt ka paari olulisemat soome lavastust ("Puksiirabi" ja "Hamlet"), mis tulevad festivalil esitamisele

  3. CFD-Simulation von Mehrkomponentenadsorption in einem Festbett

    OpenAIRE

    2016-01-01

    von Clemens Gößnitzer Arbeit an der Bibliothek noch nicht eingelangt - Daten nicht geprueft Abweichender Titel nach Übersetzung der Verfasserin/des Verfassers Technische Universität Wien, Univ., Diplomarbeit, 2016

  4. Spurensuche einer Rezeptionsgeschichte Alexander von Humboldt und Johann Gottfried Herder

    National Research Council Canada - National Science Library

    Bernhard Hunger

    2009-01-01

    Article in German, Abstracts in English, German and Spanish.Alexander von Humboldt's work displays traces of Johann Gottfried Herder which are as multifaceted as the references to the latter are scarce...

  5. Von Krahli Teatri lavastus pääses tippfestivalile

    Index Scriptorium Estoniae

    1999-01-01

    Von Krahli Teatri uuendatud lavastus "Eesti mängud. Pulm" esietendub festivalil Theater Der Welt Berliinis. Peeter Jalaka multimeediaetendus Eesti ajaloost ja traditsioonidest osaleb ka suveteatrite festivalil Hamburgis, seejärel antakse kuus etendust Amsterdamis

  6. Magnus Georg von Paucker (1787-1855) / Eckhard Spring

    Index Scriptorium Estoniae

    Spring, Eckhard

    2013-01-01

    Eestis sündinud ja Tartu Ülikoolis õppinud silmapaistvast baltisaksa teadlasest ja tema lapselapsest Alexandrine Pauckerist. 23. novembril 2012 Jelgavas/Mitaus toimunud Magnus Georg von Pauckerile pühendatud teaduskonverentsist

  7. Von Krahli Teatri lavastus pääses tippfestivalile

    Index Scriptorium Estoniae

    1999-01-01

    Von Krahli Teatri uuendatud lavastus "Eesti mängud. Pulm" esietendub festivalil Theater Der Welt Berliinis. Peeter Jalaka multimeediaetendus Eesti ajaloost ja traditsioonidest osaleb ka suveteatrite festivalil Hamburgis, seejärel antakse kuus etendust Amsterdamis

  8. Study on the electronic structure and the optical performance of YB6 by the first-principles calculations

    Directory of Open Access Journals (Sweden)

    Lihua Xiao

    2011-06-01

    Full Text Available The electronic structure and the optical performance of YB6 were investigated by first-principles calculations within the framework of density functional theory. It was found that the calculated results are in agreement with the relevant experimental data. Our theoretical studies showed that YB6 is a promising solar radiation shielding material for windows.

  9. Ultra-high, broadband gain in a lattice-engineered, Yb-doped double tungstate channel waveguide

    NARCIS (Netherlands)

    Geskus, D.; Aravazhi, S.; Bernhardi, E.H.; Agazzi, L.; García-Blanco, S.M.; Pollnau, M.

    2012-01-01

    150 dB/cm gain over 55 nm wavelength range between 977-1032 nm is obtained in a 47.5% Yb-doped potassium double tungstate waveguide amplifier. The dependence of luminescence lifetime and gain on Yb concentration is investigated.

  10. Nash y von Neumann: mundos posibles y juegos de lenguaje

    Directory of Open Access Journals (Sweden)

    Salazar , Boris

    2004-06-01

    Full Text Available Este ensayo emplea las nociones de juego de lenguaje y de equivalencia entre juegos para examinar la decisión de John Nash de no jugar el juego coalicional que propuso John von Neumann. El argumento central es que Nash concibió una clase de mundos posibles incompatible con la de von Neumann, y que en el origen de esa divergencia estarían sus distintas nociones de racionalidad.

  11. Kooperation mit der Industrie bei der Ausbildung von Softwareingenieuren

    OpenAIRE

    2010-01-01

    Vor allem in Regionen, in denen der Personalbedarf der Unternehmen nicht durch Absolventen gedeckt werden kann, sollte sich die Hochschulausbildung auch an den Anforderungen der Industrie orientieren. In diesem Beitrag werden diese Anforderungen für Softwareingenieure für den Standort Görlitz spezifiziert und es werden Kooperationsmöglichkeiten von Hochschule und lokalen Unternehmen aufgezeigt. Dabei wird auf die praxisorientierte Ausbildung, auf die Übernahme von Ausbildungsverantwortung dur...

  12. Hans von Hattingberg (1879-1944) Leben und Werk

    OpenAIRE

    Keifenheim, Katharina Eva

    2011-01-01

    Hans von Hattingberg, geboren am 18.11.1879 in Wien, wird heute vor allem mit dem Deutschen Institut für Psychologische Forschung und Psychotherapie („Göring-Institut“) in Verbindung gebracht, wo er sich mit der „Neuen Deutschen Seelenheilkunde“ und der Erarbeitung von „Thesen zur Neurosenlehre“ befasste. Interessanterweise war Hattingberg bis 1932 eher eine Randfigur in der Psychotherapeutenszene und galt vielen als unbelehrbarer Querulant. Viele seiner Arbeiten wurden nie veröffentlicht, u...

  13. Numerical Analysis Of Buckling Of Von Mises Planar Truss

    Directory of Open Access Journals (Sweden)

    Kalina Martin

    2015-12-01

    Full Text Available A computational algorithm of a discrete model of von Mises planar steel truss is presented. The structure deformation is evaluated by seeking the minimal potential energy. The critical force invented by mathematical solution was compared with solution by computer algorithm. Symmetric and asymmetric effects of initial shape of geometric imperfection of axis of struts are used in model. The shapes of buckling of von Mises planar truss of selected vertical displacement of top joint are shown.

  14. Wie vergleichbar sind Ergebnisse von Rechtschreib-und Lesetests?

    OpenAIRE

    Steinhauser, Susanne

    2006-01-01

    Eine umschriebene Lese-Rechtschreibstörung (ICD-10: F81) ist durch eine Diskrepanz zwischen den allgemeinen kognitiven Fähigkeiten eines Kindes und dessen Lese-Rechtschreibleistungen gekennzeichnet. Für die Diagnostik steht eine Vielzahl von Lese- und Rechtschreibtests zur Verfügung. In der Studie wurde untersucht, ob die Diagnosestellung von der Wahl des Testverfahrens abhängt. Es wurden Kinder mit mehreren Rechtschreib- und Lesetests untersucht. Die allgemeinen kognitiven Fähigkeiten wur...

  15. Modellbasierte Merkmalsplanung zur objektbezogenen laserscannerbasierten Navigation von Fahrzeugen

    OpenAIRE

    Stahn, Roland

    2010-01-01

    In dieser Dissertation wird ein neues System zur modellbasierten Merkmalsplanung für die objektbezogene laserscannerbasierte Navigation von Fahrzeugen vorgestellt. Die robuste Orientierung und Bewegung in natürlichen Umgebungen ist eine zentrale Problemstellung der mobilen Robotik. Die präzise Navigation relativ zu Objekten der Umgebung bildet ein Teilgebiet, welches speziell für die Realisierung von zukünftigen Assistenz- und Autonomiefunktionen bei Fahrzeugen, fahrerlosen Transportsystemen ...

  16. Untersuchungen zum enzymatisch-physikalischen Aufschluss von Apfeltrester

    OpenAIRE

    Schalow,Sebastian

    2009-01-01

    Apfeltrester fallen in großen Mengen als Reststoffe bei der industriellen Fruchtsaftproduktion an. Neben der Pektinherstellung können Apfeltrester u. a. für die Alkoholerzeugung genutzt werden. Im Gegensatz zur Produktion von technischem Alkohol werden bei der Trinkalkoholherstellung jedoch höhere Anforderungen an die chemische Zusammensetzung und die sensorischen Eigenschaften der erzeugten Destillate gestellt. Apfeltrester besitzen eine Trockensubstanz von ca. 25 %, die sich zum größten Tei...

  17. Geschlechterstereotype - Qualifikationsbarrieren von Frauen in der Fußballtrainerausbildung?

    OpenAIRE

    Weigelt-Schlesinger, Yvonne

    2007-01-01

    Eines der letzten fast vollständig männlichen dominierten Reservoirs des Sports ist der Trainerbereich. Vor dem Hintergrund dieser Einsicht setzt sich die Arbeit mit der Frage auseinander, weshalb Frauen erst gar keine Ausbildung zur Trainerin beginnen oder die begonnene Ausbildung wieder abbrechen. Dabei interessiert insbesondere die Bedeutung von Geschlechtsstereotypen bei der Ausgrenzung von Frauen aus oder der Benachteiligung während der Trainerausbildung. So fragt die Autorin danach,...

  18. Identifizierung und Charakterisierung eines Sdr-Proteins von Staphylococcus saprophyticus

    OpenAIRE

    Sakinç, Türkân

    2001-01-01

    Gegenstand der vorliegenden Arbeit war es, das Oberflächenprotein Ssp zu klonieren und zu charakterisieren. Stattdessen wurde ein neues Zellwand-assoziertes Protein, das SdrI, ein MSCRAMM, kloniert. Dies sollte zur Klärung der Uropathogenität von Staphylococcus saprophyticus weiterhelfen. Die Voraussetzungen zur Untersuchung der Funktion des SdrI Protein von Staphylococcus saprophyticus wurde durch die Konstruktion einer isogenen Mutante geschaffen. Die Bedeutung der SdrI-Protein ...

  19. Green up-converted luminescence in (Er3+-Yb3+) co-doped LiNbO3 crystals

    Science.gov (United States)

    Stoffel, M.; Rinnert, H.; Kokanyan, E.; Demirkhanyan, G.; Demirkhanyan, H.; Aillerie, M.

    2016-07-01

    Er3+ doped and (Er3+-Yb3+) co-doped LiNbO3 (LN) crystals grown by the Czochralski method are investigated by photoluminescence spectroscopy. Green up-converted luminescence is observed in Er3+ doped LN crystals under 980 nm excitation. This is explained by an energy transfer between two neighboring Er3+ ions. In (Er3+, Yb3+) co-doped LN crystals, the intensity of the green up-converted luminescence can be further enhanced suggesting that Yb3+ ions also contribute to the up-conversion process. Time resolved photoluminescence measurements clearly demonstrate that an efficient energy transfer occurs between Yb3+ and Er3+ ions. A theoretical model taking into account the contribution of both Er3+-Er3+ pairs and Yb3+-Er3+ pairs is able to describe correctly the decay of the up-converted luminescence.

  20. Near Infrared Photoluminescence from Yb,Al Co-implanted SiO2 Films on Silicon

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian-Guo; WANG Xiao-Xin; CHENG Bu-Wen; YU Jin-Zhong; WANG Qi-Ming

    2006-01-01

    @@ Intense room-temperature near infrared (NIR) photoluminescence (980 nm and 1032nm) is observed from Yb, Al co-implanted SiO2 films on silicon. The optical transitions occur between the 2F5/2 and 2F7/2 levels of Yb3+ in SiO2. The additional Al-implantation into SiO2 films can effectively improve the concentration quenching effect of Yb3+ in SiO2. Photoluminescence excitation spectroscopy shows that the NIR photoluminescence is due to the non-radiative energy transfer from Al-implantation-induced non-bridging oxygen hole defects in SiO2 to Yb3+ in the Yb-related luminescent complexes. It is believed that the defect-mediated luminescence of rare-earth ions in SiO2 is very effective.

  1. Politische Bildung im Kontext von Regierung, Unterricht und Zucht

    Directory of Open Access Journals (Sweden)

    Thomas Rucker

    2014-02-01

    Full Text Available Johann Friedrich Herbart (1776-1841 gilt als der Begründer der wissenschaftlichen Pädagogik. In diesem Beitrag wird zu zeigen versucht, dass Herbart die Unterstützung politischer Bildung als eine Aufgabe von Regierung, Unterricht und Zucht bestimmt und in seinem Werk wichtige „Bausteine“ für eine Theorie der politischen Bildung unter den Bedingungen von Erziehung vorlegt hat. Nach Herbart ist das politische Selbst- und Weltverhältnis auf Sachverhalte bezogen, die nicht nur die Lebensführung einzelner Menschen, sondern die Lebensführung einer Mehrzahl von Menschen betreffen. Nicht das Zusammenleben von Menschen generell ist jedoch Orientierungsgesichtspunkt des politischen Selbst- und Weltverhältnisses, sondern nur das problematisch gewordene Zusammenleben. Politik ergibt sich nach Herbart aus einem Konflikt hinsichtlich der Frage, wie das Zusammenleben von Menschen geregelt sein sollte. Während die Regierung lediglich mittelbar einen Beitrag zur politischen Bildung leistet, indem sie die Voraussetzungen für Unterricht und Zucht bereitstellt, fungieren die beiden zuletzt genannten Formen von Erziehung als die eigentlichen Medien, in denen die politische Bildung im Sinne Herbarts ihren Ort hat.

  2. Suppression of nonlinear phonon relaxation in Yb:YAG thin disk via zero phonon line pumping.

    Science.gov (United States)

    Smrž, Martin; Miura, Taisuke; Chyla, Michal; Nagisetty, Siva; Novák, Ondřej; Endo, Akira; Mocek, Tomáš

    2014-08-15

    A quantitative comparison of conventional absorption line (940 nm) pumping and zero phonon line (ZPL) (969 nm) pumping of a Yb:YAG thin disk laser is reported. Characteristics of an output beam profile, surface temperature, and deformation of a thin disk under the different pump wavelengths are evaluated. We found that a nonlinear phonon relaxation (NPR) of the excited state in Yb:YAG, which induces nonlinear temperature rise and large aspheric deformation, did not appear in the case of a ZPL pumped Yb:YAG thin disk. This means that the advantage of ZPL pumping is not only the reduction of quantum defect but also the suppression of NPR. The latter effect is more important for high power lasers.

  3. High-energy, ceramic-disk Yb:LuAG laser amplifier.

    Science.gov (United States)

    Siebold, M; Loeser, M; Roeser, F; Seltmann, M; Harzendorf, G; Tsybin, I; Linke, S; Banerjee, S; Mason, P D; Phillips, P J; Ertel, K; Collier, J C; Schramm, U

    2012-09-24

    We report the first short-pulse amplification results to several hundred millijoule energies in ceramic Yb:LuAG. We have demonstrated ns-pulse output from a diode-pumped Yb:LuAG amplifier at a maximum energy of 580 mJ and a peak optical-to-optical efficiency of 28% at 550 mJ. In cavity dumped operation of a nanosecond oscillator we obtained 1 mJ at up to 100 Hz repetition rate. A gain bandwidth of 5.4 nm was achieved at room temperature by measuring the small-signal single-pass gain. Furthermore, we compared our results with Yb:YAG within the same amplifier system.

  4. Ion-exchanged waveguide lasers in Er3+/Yb3+ codoped silicate glass.

    Science.gov (United States)

    Peters, P M; Funk, D S; Peskin, A P; Veasey, D L; Sanford, N A; Houde-Walter, S N; Hayden, J S

    1999-11-20

    We investigated an Er(3+)/Yb(3+) codoped silicate glass as a host material for waveguide lasers operating near 1.5 microm. Spectroscopic properties of the glass are reported. Waveguide lasers were fabricated by K(+)-ion exchange from a nitrate melt. The waveguides support a single transverse mode at 1.5 microm. An investigation of the laser performance as a function of the Yb:Er ratio was performed, indicating an optimal ratio of approximately 5:1. Slope efficiencies of as great as 6.5% and output powers as high as 19.6 mW at 1.54 microm were realized. The experimental results are compared with a waveguide laser model that is used to extract the Er(3+) upconversion coefficients and the Yb(3+)-Er(3+) cross-relaxation coefficients. The results indicate the possibility of obtaining high-performance waveguide lasers from a durable silicate host glass.

  5. Observation of hyperfine interaction in photoassociation spectra of ultracold RbYb

    Science.gov (United States)

    Bruni, C.; Görlitz, A.

    2016-08-01

    We report on the creation of ultracold heteronuclear and electronically excited Rb*Yb molecules in a hybrid conservative trap by photoassociation of ultracold 87Rb and 176Yb. The molecules are formed below the Rb5 p 1(1/2 2P)+Yb6 s 2(S10) dissociation limit and the resonances are detected using trap-loss spectroscopy. By addressing vibrational levels with binding energies down to EB=-h ×2.2 THz , we study the change in hyperfine coupling of the diatomic molecule as a function of internuclear separation. We observe a decreasing hyperfine splitting for more tightly bound excited molecular states where the hyperfine splitting is reduced by more than 30 % compared to the atomic value for 87Rb.

  6. Comparison of different fiber amplifiers in Yb-doped fiber femtosecond optical frequency combs

    Science.gov (United States)

    Liu, H.; Cao, S.; Lin, B.; Fang, Z.

    2016-12-01

    Recently, Yb-doped fiber femtosecond optical frequency combs (Yb-FOFCs) have obtained high repetition rates and high power outputs, and the wavelengths can cover the visible region by using a photonic crystal fiber to broaden the spectrum. In this paper, f0 (carrier-envelope offset frequency) with a signal-to-noise ratio (SNR) of 40 dB is generated in an Yb-FOFC by adopting a scheme which includes the three processes of amplifying, broadening the spectrum and detecting f0, and optimizing the system parameters. The effects of two types of amplifiers which employ direct optical pulse amplification and self-similar amplification, respectively, on the output parameters of the amplifiers, minimal output power of the octave spectrum meeting f0 detection requirements, and the SNR of f0 are compared and analyzed in detail.

  7. Magneto-optical spectroscopy of Yb{sup 3+} ions in huntite structure

    Energy Technology Data Exchange (ETDEWEB)

    Sukhachev, A.L. [L.V. Kirensky Institute of Physics, Siberian Branch Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Malakhovskii, A.V., E-mail: malakha@iph.krasn.r [L.V. Kirensky Institute of Physics, Siberian Branch Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Edelman, I.S.; Zabluda, V.N.; Temerov, V.L.; Makievskii, I.Ya. [L.V. Kirensky Institute of Physics, Siberian Branch Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation)

    2010-01-15

    We report the first measurements of magnetic circular dichroism (MCD) and magneto-optical activity (ratio of zero moments of MCD and absorption bands) of Yb{sup 3+} ion in the trigonal single crystals Yb{sub x}Tm{sub 1-x}Al{sub 3}(BO{sub 3}){sub 4} as a function of temperature in the range of 100-293 K. Magneto-optical activity follows the Curie-Weiss law with the Weiss constant theta=-55 K for Yb{sub 0.1}Tm{sub 0.9}Al{sub 3}(BO{sub 3}){sub 4} crystal. The value and origin of the magneto-optical activity is theoretically analyzed.

  8. Synthesis, characterization and DFT calculations of electronic and optical properties of YbPO4

    Science.gov (United States)

    Khadraoui, Z.; Horchani-Naifer, K.; Ferhi, M.; Ferid, M.

    2015-08-01

    YbPO4 crystals were synthesized by solid-state reaction and characterized by X-ray diffraction, infrared and Raman spectroscopies. The electronic structure and optical properties of YbPO4 such as the energy band structures, density of states and chemical bonds were calculated with the Density Functional Theory (DFT) for the first time. We present a combination of the GGA and the LDA + U approaches in order to obtain appropriate results due to the strong Coulomb repulsion between the highly localized 4f electrons of rare earth atoms. The linear photon-energy-dependent dielectric functions, conductivity and some optical constants such as refractive index, reflectivity and absorption coefficients were determined. The calculated total and partial densities of states indicate that the top of valance band is built upon O-2p states with P-3p states via σ (P-O) interactions, and the conduction bands mostly originate from Yb-5d states.

  9. Efficient Yb laser fibers with low photodarkening by optimization of the core composition.

    Science.gov (United States)

    Jetschke, Sylvia; Unger, Sonja; Schwuchow, Anka; Leich, Martin; Kirchhof, Johannes

    2008-09-29

    We report on photodarkening (PD) investigations at Yb doped fibers with specific variation of the concentrations of the codopants aluminum and phosphorus, measured during cladding pumping at 915 nm. A core composition with equal content of Al and P is most promising to achieve Yb fibers with low PD, high laser efficiency and low numerical aperture of the laser core despite of high codoping. A laser output power of more than 100 W was demonstrated on such a fiber with a slope efficiency of 72%. The correlation of the PD loss with the NIR-excited cooperative luminescence encourages the supposition that cooperative energy transfer from excited Yb(3+) ions to the atomic defect precursors in the core glass enables the formation of color centers in the pump-induced PD process.

  10. Efficient ultraviolet-blue to near-infrared downconversion in Bi-Dy-Yb-doped zeolites

    Science.gov (United States)

    Bai, Zhenhua; Fujii, Minoru; Hasegawa, Takashi; Imakita, Kenji; Mizuhata, Minoru; Hayashi, Shinji

    2011-11-01

    Ultraviolet-blue to near-infrared (NIR) downconversion is investigated for the Dy3+-Yb3+ couple in zeolites by steady-state and time-resolved photoluminescence (PL) spectra, and PL excitation spectra. Upon excitation of the 4F9/2 level of Dy3+, NIR quantum cutting could occur through a two-step energy transfer from one Dy3+ ion to two neighbouring Yb3+ ions via an intermediate level. The energy transfer efficiency from the 4F9/2 level is estimated to be 42%, and the intrinsic PL quantum efficiency of Yb3+ emission reaches 54%. The findings may have potential application in enhancing the energy efficiency of silicon-based solar cells.

  11. Boiling effect in liquid nitrogen directly cooled Yb³⁺:YAG laser.

    Science.gov (United States)

    Sakurai, Toshimitsu; Chosrowjan, Haik; Furuse, Hiroaki; Taniguchi, Seiji; Kitamura, Toshiyuki; Fujita, Masayuki; Ishii, Shinya; Izawa, Yasukazu

    2016-02-20

    Liquid nitrogen (LN2) behavior on the surface of excited Yb(3+):YAG is investigated using fluorometry. From the time-resolved temperature variations and integrated fluorescence spectra intensity on this directly cooled Yb(3+):YAG surface, we observe a phase transition of LN2 from nucleate boiling to film boiling. As a result of this pool boiling, good beam quality should occur when the temperature and heat flux at an excited surface of Yb(3+):YAG are below 95 K and 15.8  W/cm2, respectively. That is, the LN2 should remain in a steady state of nucleate boiling to produce good beam quality using pool boiling.

  12. Experimental study on all Yb-doped photonic crystal fiber laser

    Science.gov (United States)

    Fu, Jian; Hou, Zhiyun; Zhou, Guiyao; Zhao, Jingde; Zhang, Wei; Xia, Changming; Cang, Xuelong; Liu, Jiantao

    2017-02-01

    In this paper, we demonstrated an experiment of the all Yb-doped photonic crystal fiber laser using free space optical paths method. The experimental setup of all Yb-doped photonic crystal fiber laser is composed of the seed laser and the amplifier. The laser gain medium of the seed laser and the amplifier are the same Yb-doped photonic crystal fibers that are fabricated by non-chemical vapor deposition (Non-CVD) technology. The seed laser cavity is a Fabry-Perot cavity. The amplifier is pumped by back-end method. They are coupled each other by lens and dichroic mirrors on the optical table. The experimental results have a good reference value for the photonic crystal fiber laser research in the future.

  13. Cooperative energy transfer in Tm3+ and Yb3+ co-doped phosphate glasses

    Institute of Scientific and Technical Information of China (English)

    XU Bo; YANG Bin; ZHANG Yuepin; XIA Haiping; WANG Jinhao

    2013-01-01

    An efficient near-infrared (NIR) quantum cutting (QC) in Tm3+ and Yb3+ co-doped phosphate glasses was demonstrated,which involved the emission of two NIR photons from an absorbed visible photon via a cooperative energy transfer (CET) from Tm3+to Yb3+ ions.Judd-Ofelt (J-O) theory was used to calculate the intensity parameters (Ω2,Ω4,Ω6),the radiative transition rates (Ar),and radiative transition lifetime (τrad) of Tm3+.Based on Inokuti-Hirayama's model,the energy transfer processes were studied and results indicated that the energy transfer of the electric dipole-dipole (Edd) was dominant in this system.Quantum efficiency related to Yb3+concentration was calculated,and the maximum QE efficiency reached 169.8%.

  14. Intense upconversion fluorescence in Tm 3+/Yb3+ codoped alumina lead borate glasses

    Science.gov (United States)

    Krishna Murthy Goud, K.; Shekhar Reddy, M. Chandra; Appa Rao, B.

    2016-09-01

    The Tm3+/Yb3+ codoped alumina lead borate glasses were prepared by the conventional melt quenching technique. Optical absorption and FTIR spectra were recorded. The upconversion fluorescence spectra exhibited weak blue (480 nm) and intense red (660 nm) emissions due to 1G4 → 3H6 and 1G4 → 3H4 transitions, respectively. The results concluded that both emissions are due to three photon absorption process. It has been observed that in the upconversion efficiency increases with the increase in the concentration of Yb3+ ions. The strong red upconversion fluorescence indicate that Tm3+/Yb3+ codoped alumina lead borate glasses can be used as potential host material for upconversion lasers.

  15. Buffer-gas loaded magneto-optical traps for Yb, Tm, Er and Ho

    CERN Document Server

    Hemmerling, Boerge; Chae, Eunmi; Ravi, Aakash; Doyle, John M

    2013-01-01

    Direct loading of magneto-optical traps from a very slow cryogenic buffer-gas beam of lanthanides is achieved and studied, without the need for laser slowing. A collisionally cooled cryogenic atomic source with average forward velocity of 60-70 m/s and a width of ~70 m/s allows for loading without additional dissipation, unlike oven or supersonic sources. The lanthanides Yb, Tm, Er, and Ho are trapped. Despite the He buffer-gas background, we observe a maximum lifetime of about 80 ms (with Yb). We further show that the addition of a single-frequency slowing laser increases the number of trapped Yb atoms by an order of magnitude, yielding a total of 4.0(2) x 10^8. We study decay to metastable states in all species and report decay rates. Extension of this approach to MOTs of molecules is discussed.

  16. High-efficiency broadband anti-Stokes emission from Yb3+-doped bulk crystals.

    Science.gov (United States)

    Zhu, Siqi; Wang, Chunhao; Li, Zhen; Jiang, Wei; Wang, Yichuan; Yin, Hao; Wu, Lidan; Chen, Zhenqiang; Zhang, Ge

    2016-05-15

    We investigate the broadband anti-Stokes emission (BASE) from Yb3+-doped crystals with a laser diode (LD) pumping at 940 nm. Our experiment reveals that Yb3+-doped crystals with random cracks are able to generate bright BASE at room temperature and atmospheric pressure. By examining the various characteristics of the crystals and the emitted light, we supply a theory for interpreting the underlying physics for this variety of BASE. In particular, we take into consideration the effects of energy migration, avalanche process, and charge-transfer luminescence. This represents the first time, to the best of our knowledge, that BASE was obtained from Yb3+-doped bulk crystals with a high optical-optical efficiency.

  17. Design of large-core single-mode Yb3+-doped photonic crystal fiber

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xing-tao; ZHENG Yi; LIU Xiao-xu; ZHOU Gui-yao; LIU Zhao-lun; HOU Lan-tian

    2012-01-01

    The effective index of the cladding fundamental space-filing mode in photonic crystal fiber (PCF) is simulated by the effective index method.The variation of the effective index with the structure parameters of the fiber is achieved.For thefirst thne,the relations of the V parameter ofYb3+-doped PCF with the refractive index of core and the structure parameters of the fiber are provided.The single-mode characteristics of large-core yb3+-doped photonic crystal fibers with 7 and 19 missing air holes in the core are analyzed.The large-core single-mode Yb3+-doped photonic crystal fibers with core diameters of 50 μm,100 μm and 150 μm are designed.The results provide theory instruction for the design and fabrication of fiber.

  18. Cr and Yb markers determination in animal feces by energy dispersive X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Eduardo de; Senicato, Luis A; Nascimento Filho, Virgilio F. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear (LIN)]. E-mail: edualm@usp.br; Gomide, Catarina A. [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Dept. de Zootecnia]. E-mail: cbgomide@usp.br

    2007-07-01

    Chromium and Ytterbium elements are utilized in animal nutritional studies as markers. This paper describes an analytical method for Cr and Yb determination in solid buffalo feces sample using standard addition method and energy dispersive X-ray spectrometry (EDXRF) technique. One gram dried sample was pressed manually in an XRF sample cup with Mylar film (6.3 {mu}m thickness) in the bottom. The experimental conditions were: Mo target X-ray tube with Zr filter, operated at 25 kV/10 mA, and 500 s of acquisition time. The limits of detection for Cr and Yb were 16.6 and 11.4 mg/kg, respectively. This methodology has showed appropriated for simultaneous Cr and Yb determination as marker in animal feces. (author)

  19. Minimization of temperature for laser cooling of Yb-ion-doped crystals.

    Science.gov (United States)

    Ivanov, Andrei; Rozhdestvensky, Yuriy; Perlin, Evgeniy

    2016-10-01

    In this paper, quantum mechanical calculations of cooling characteristics for the Yb3+:  YLF system with use of the vibronic model of laser cooling are presented. Dynamics of the laser cooling process for the seven-level system of an Yb ion is described by the density-matrix formalism. Dependences of the cooling characteristics on the pump intensity are obtained for various temperatures and absorption coefficients of impurity ions. It is shown that the pump intensity, at which the net cooling power has a maximum, depends on temperature. Thus, choosing the intensities, which correspond to the net cooling power maximum over the entire temperature range, we achieve a lower sample temperature at a shorter time than in the case of using a constant intensity throughout the cooling process. Calculations are performed for the parameters of the Yb3+:YLF system.

  20. Prophylaxis escalation in severe von Willebrand disease: A prospective study from the von Willebrand Disease Prophylaxis Network

    NARCIS (Netherlands)

    T.C. Abshire (Thomas Calvin); J. Cox-Gill; C.L. Kempton; F.W.G. Leebeek (Frank); M. Carcao (M.); P. Kouides (P.); S. Donfield (S.); E. Berntorp

    2015-01-01

    textabstractBackground: Treatment of mucosal bleeding (epistaxis, gastrointestinal bleeding, and menorrhagia) and joint bleeding remains problematic in clinically severe von Willebrand disease (VWD). Patients are often unresponsive to treatment (e.g. desmopressin or antifibrinolytic therapy) and may

  1. Electronic Resource Management System. Vernetzung von Lizenzinformationen

    Directory of Open Access Journals (Sweden)

    Michaela Selbach

    2014-12-01

    Full Text Available In den letzten zehn Jahren spielen elektronische Ressourcen im Bereich der Erwerbung eine zunehmend wichtige Rolle: Eindeutig lässt sich hier ein Wandel in den Bibliotheken (fort vom reinen Printbestand zu immer größeren E-Only-Beständen feststellen. Die stetig wachsende Menge an E-Ressourcen und deren Heterogenität stellt Bibliotheken vor die Herausforderung, die E-Ressourcen effizient zu verwalten. Nicht nur Bibliotheken, sondern auch verhandlungsführende Institutionen von Konsortial- und Allianzlizenzen benötigen ein geeignetes Instrument zur Verwaltung von Lizenzinformationen, welches den komplexen Anforderungen moderner E-Ressourcen gerecht wird. Die Deutsche Forschungsgemeinschaft (DFG unterstützt ein Projekt des Hochschulbibliothekszentrums des Landes Nordrhein-Westfalen (hbz, der Universitätsbibliothek Freiburg, der Verbundzentrale des Gemeinsamen Bibliotheksverbundes (GBV und der Universitätsbibliothek Frankfurt, in dem ein bundesweit verfügbares Electronic Ressource Managementsystem (ERMS aufgebaut werden soll. Ein solches ERMS soll auf Basis einer zentralen Knowledge Base eine einheitliche Nutzung von Daten zur Lizenzverwaltung elektronischer Ressourcen auf lokaler, regionaler und nationaler Ebene ermöglichen. Statistische Auswertungen, Rechteverwaltung für alle angeschlossenen Bibliotheken, kooperative Datenpflege sowie ein über standardisierte Schnittstellen geführter Datenaustausch stehen bei der Erarbeitung der Anforderungen ebenso im Fokus wie die Entwicklung eines Daten- und Funktionsmodells. In the last few years the importance of electronic resources in library acquisitions has increased significantly. There has been a shift from mere print holdings to both e- and print combinations and even e-only subscriptions. This shift poses a double challenge for libraries: On the one hand they have to provide their e-resource collections to library users in an appealing way, on the other hand they have to manage these

  2. Influence of O2 exposure on the interaction between CH4 and amorphous AlYB14

    Science.gov (United States)

    Hunold, Oliver; Wiesing, Martin; de los Arcos, Teresa; Music, Denis; Grundmeier, Guido; Schneider, Jochen M.

    2017-01-01

    The influence of surface oxidation on the interaction between CH4 and amorphous AlYB14 (a-AlYB14) has been studied theoretically by using density functional theory and experimentally by ultra-high vacuum atomic force microscopy (UHV-AFM). CH4 mimics the -CH3 termination and aliphatic subunits of a polymer chain. Low-energy ion scattering measurements of magnetron sputtered thin films suggest that the bonding at the surfaces of pristine a-AlYB14 and O2 exposed a-AlYB14 (O2//a-AlYB14) is metal-boron and metal-oxygen dominated, respectively. Based on the ab initio calculations the adsorption energies of CH4 on a-AlYB14 and O2//a-AlYB14 decreases from -0.07 to -0.30 eV, respectively. This trend is consistent with experimental data obtained by colloidal probe UHV-AFM studies with a polyethylene sphere, where larger adhesion forces for the O2 exposed surface as compared to the pristine a-AlYB14 surface were measured. No charge transfer takes place between CH4 and the pristine as well as the O2 exposed a-AlYB14. Oxygen chemisorption induces changes in surface bonding. States at the Fermi level are depleted upon oxidation, hence the surface bonding becomes more semiconducting causing a charge redistribution within the adsorbed CH4 molecule. Hence, these data serve as proof of concept for exploring the effect of O2 exposure on the interaction between aliphatic polymers and a-AlYB14 using a correlative experimental and theoretical research approach.

  3. Structural characterization and EXAFS wavelet analysis of Yb doped ZnO by wet chemistry route

    Energy Technology Data Exchange (ETDEWEB)

    Otal, Eugenio H., E-mail: eugenio.otal@citedef.gob.ar [Division of Porous Materials, UNIDEF, CITEDEF, CONICET, S.J.B de la Salle 4397, Villa Martelli (B1603ALO), Buenos Aires (Argentina); Laboratory for Materials Science and Technology, FRSC-UTN, Av. Inmigrantes 555, Río Gallegos 9400 (Argentina); Sileo, Elsa [INQUIMAE, Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina); Aguirre, Myriam H. [Dept. of Physics Condensed Matter, University of Zaragoza (Spain); Laboratory of Advanced Microscopy (LMA), Institute of Nanoscience of Aragón (INA), University of Zaragoza (Spain); Fabregas, Ismael O. [Division of Porous Materials, UNIDEF, CITEDEF, CONICET, S.J.B de la Salle 4397, Villa Martelli (B1603ALO), Buenos Aires (Argentina); Kim, Manuela [Division of Porous Materials, UNIDEF, CITEDEF, CONICET, S.J.B de la Salle 4397, Villa Martelli (B1603ALO), Buenos Aires (Argentina); Laboratory for Materials Science and Technology, FRSC-UTN, Av. Inmigrantes 555, Río Gallegos 9400 (Argentina)

    2015-02-15

    Highlights: • Optical and electrical properties of ZnO are influenced by lanthanide doping. • Optical and electrical properties of ZnO are influenced by lanthanide positioning. • Yb is incorporated in the O{sub h} sites of the wurtzite structure. • There is not Yb{sub 2}O{sub 3} clustering or segregation for treatments below 800 °C. - Abstract: Lanthanide doped ZnO are interesting materials for optical and electrical applications. The wide band gap of this semiconductor makes it transparent in the visible range (E{sub gap} = 3.2 eV), allowing a sharp emission from intra shell transition from the lanthanides. From the electrical side, ZnO is a widely used material in varistors and its electrical properties can be tailored by the inclusion of lanthanides. Both applications are influenced by the location of the lanthanides, grain boundaries or lattice inclusion. Yb doped ZnO samples obtained by wet chemistry route were annealed at different temperatures and characterized by Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Rietveld refinement of XRD data, and X-ray Absorption Fine Structure (XAFS). These techniques allowed to follow the changes occurred in the matrix and the Yb environment. The use of the Cauchy continuous wavelet transform allowed identifying a second coordination shell composed of Zn atoms, supporting the observations from XRD Rietveld refinement and XAFS fittings. The information obtained confirmed the incorporation of Yb in O{sub h} sites of the wurtzite structure without Yb{sub 2}O{sub 3} clustering in the lattice.

  4. Modeling the absorption spectra of Er3+ and Yb3+ in a phosphate glass

    Science.gov (United States)

    Gruber, John B.; Sardar, Dhiraj K.; Zandi, Bahram; Hutchinson, J. Andrew; Trussell, C. Ward

    2003-10-01

    Absorption spectra of Er3+ and Yb3+ ions, codopants in a phosphate glass, are reported at 8 K and at wavelengths between 350 and 1600 nm. Detailed structure appearing in the spectra, associated with individual multiplet states, 2S+1LJ, of Er3+(4f11) and Yb3+(4f13) is interpreted using a ligand-field coordination sphere model to characterize the microscopic environment surrounding the rare earth ions in multiple sites. Inhomogeneous broadening of the spectra is likely due to different configurations of PO4 tetrahedra clustered about a caged rare earth ion in the amorphous host. Similarity between the Er3+ spectrum in the glass and in the spectrum of single-crystal LiErP4O12, where Er3+ occupies sites of C2 symmetry, suggests that an averaged site symmetry of C2 is a reasonable approximation for Er3+ and Yb3+ ions in the phosphate glass. Calculated splitting of multiplet states by the ligand-field cluster model are compared with energy levels derived from the observed absorption peaks and well-defined shoulders. Inhomogeneous broadening of the spectra limit the precision in establishing the energy of the multiplet splittings, but the analysis is useful for modeling studies of the Er:Yb:phosphate glass as an eye-safe laser (1.53 μm). The splitting of the Yb3+(4f13)2FJ states is determined using parameters obtained from the Er3+ set by means of the three-parameter theory. No adjustments were made to the Yb3+ parameters that predict multiplet splittings in reasonable agreement with experimental data.

  5. Anisotropic magnetic properties and magnetic structure of YbPdSi

    Science.gov (United States)

    Tsujii, Naohito; Keller, Lukas; Dönni, Andreas; Kitazawa, Hideaki

    2016-08-01

    YbPdSi with orthorhombic crystal structure (space group Pmmn) exhibits a magnetic transition at {{T}\\text{m}}=8 K, below which a ferromagnetic moment develops with an enhanced electronic specific-heat coefficient γ ˜ 200 mJ K-2 mol-1. We have investigated the magnetization, electrical resistivity, and specific heat of YbPdSi using single crystalline samples as functions of temperature and magnetic field. It has been found that the ferromagnetic moment points to the c-direction, although the magnetic moments have an Ising-like anisotropy along the b-direction above the magnetic-transition temperature. Field dependence of the magnetization and electrical resistivity shows a metamagnetic-like transition at {{H}\\text{m}}=0.3 T when field is applied along the b-axis below T  =  3 K, suggesting the existence of an antiferromagnetic component along this direction. The magnetic structure has been investigated by neutron diffraction using powder samples. The magnetic unit cell is identical to the crystal unit cell. The Rietveld fitting has revealed that Yb at the 2a and 2b positions exhibit a collinear ferromagnetic order along the c-axis, whereas Yb at the 4e position undergoes a non-collinear order, involving the ferromagnetic moment along the c-axis and an antiferromagnetic component along the b-axis. The ferromagnetic moments determined by the neutron diffraction are 0.26, 1.3, and 0.15 {μ\\text{B}} for Yb at the 4e, 2b, and 2a sites, respectively. The reduced moments for the 4e and the 2a sites suggest that the Kondo screening effect is important in YbPdSi.

  6. Entwicklung von molekularen Sonden für die sichere Identifizierung von Hefen der Gattungen Brettanomyces, Dekkera

    OpenAIRE

    Röder, Christoph

    2007-01-01

    Hefen der Gattungen Brettanomyces/Dekkera sind in der Produktion von fermentierten Getränken, insbesondere in der Bier-, Sekt- und Weinherstellung bekannt. Sie können als Schädlingshefen insbesondere durch die Bildung von charakteristischen Sekundärmetaboliten zu einer negativen geschmacklichen Veränderung des Getränks führen. Aufgrund ihres langsamen Wachstums werden diese Hefen bei Routineanalysen mit konventionellen Kultivierungsmethoden leicht übersehen. Ein schneller und eindeutiger N...

  7. Von Roll RCP method - first experiences; Von Roll RCP - Verfahren. Erste Erfahrungen

    Energy Technology Data Exchange (ETDEWEB)

    Capitaine, P.; Engweiler, J. [Roll Umwelttechnik AG, Zuerich (Switzerland)

    1998-09-01

    The RCP method was designed as a residue-optimised alternative to the thermally optimised grate firing of residual wastes. Its technical realisation and development to market maturity took no more than 5 years. In the first process stage the waste is converted to high-carbon pyrolysis charcoal and high-rank gas in the absence of oxygen. In the second stage these substances are oxidised by addition of oxygen. The resulting temperature causes the non-combustible constituents of the slag to melt. In a third, optional, stage this molten slag can be liberated of (heavy) metals to such an extent that it can subsequently be used directly as additive for grinding. Further exhaust gas treatment is facilitated by the use of a circulatory fluidised-bed secondary combustion chamber. Despite the reduced flue gas volume and resultant higher pollutant concentrations in the crude gas, overall emissions are lower than in conventional plants. [Deutsch] Das reststoffoptimierte RCP Verfahren ist als Alternative zur thermisch optimierten Rostverbrennung von Restabfaellen konzipiert. In nur fuenf Jahren wurde das Verfahren technisch umgesetzt und zur Marktreife entwickelt. In einer ersten Stufe des Verfahrens wird der Abfall unter Luftabschluss in einen kohlenstoffreichen Pyrolysekoks und eine heizwertreiches Gas umgesetzt. Im zweiten Schritt werden diese Stoffe unter Zugabe von Sauerstoff oxidiert. Dabei treten Temperaturen auf, bei denen die nichtbrennbaren Bestandteile der Schlacke schmelzen. Optional wird diese Schmelzschlacke in einem dritten Schritt derart von (Schwer-) Metallen befreit, dass sie anschliessend direkt als Zement-Zumahlstoff eingesetzt werden kann. Die Nutzung der zirkulierenden Wirbelschicht - Nachbrennkammer zur Abgasbehandlung vereinfacht die weitergehende Abgasbehandlung. Trotz verringertem Rauchgasvolumen und damit hoeheren Schadstoffkonzentrationen im Rohgas werden die Gesamtemissionen gegenueber konventionellen Anlagen verringert. (orig./SR)

  8. Electron Spin-Lattice Relaxation of doped Yb3+ ions in YBa2Cu3Ox

    OpenAIRE

    2005-01-01

    The electron spin-lattice relaxation (SLR) times T1 of Yb3+‡ ions were measured from the temperature dependence of electron spin resonance linewidth in Y0.99Yb0.01Ba2Cu3Ox with different oxygen contents. Raman relaxation processes dominate the electron SLR. Derived from the temperature dependence of the SLR rate, the Debye temperature (Td) increases with the critical temperature Tc and oxygen content x. Keywords: EPR; ESR; Electron spin-lattice relaxation; Debye temperature; Critical tem...

  9. Purification of precursors of Yb3+-doped YLF crystals by solvent extraction and electrochemical processing

    Science.gov (United States)

    Boncher, William L.; Judge, Elizabeth; Sansinena, Jose-Maria; Dirmyer, Matthew R.; Hehlen, Markus P.

    2015-03-01

    Optical refrigeration by laser irradiation of YLiF4:Yb3+ (YLF:Yb) crystals has been shown to be strongly deteriorated by impurities, which absorb energy at the laser wavelength, and relax non-radiatively, negating cooling produced from anti-Stokes fluorescence. We aim to increase the efficiency of optical refrigeration through materials purification. We start with the purest sources commercially available and process them in a cleanroom environment. Our method proceeds through electrochemical purification, separating out the transition metal impurities by their redox potentials, and can be scaled up to produce the amounts of material needed for crystal growth.

  10. Yb3+ sensitized Tm3+ upconversion in tellurite lead oxide glass.

    Science.gov (United States)

    Mohanty, Deepak Kumar; Rai, Vineet Kumar; Dwivedi, Y

    2012-04-01

    Triply ionized thulium/thulium--ytterbium doped/codoped TeO2-Pb3O4 (TPO) glasses have been fabricated by classical quenching method. The upconversion emission spectra in the Tm3+/Tm3+-Yb3+ doped/codoped glasses upon excitation with a diode laser lasing at ∼980 nm has been studied. Effect of the addition of the Yb3+ on the upconversion emission intensity in the visible and near infrared regions of the Tm3+ doped in TPO glass has been studied and the processes involved explored.

  11. Magic mode switching in Yb:CaGdAlO4 laser under high pump power.

    Science.gov (United States)

    Druon, Frédéric; Olivier, Mickaël; Jaffrès, Anaël; Loiseau, Pascal; Aubry, Nicolas; DidierJean, Julien; Balembois, François; Viana, Bruno; Georges, Patrick

    2013-10-15

    We present unique spatial-mode switching in a cw Yb:CALGO laser when pumped at a multihundred-watts power level. It permits us to automatically stabilize to a TEM(00) mode from a highly spatial multimode regime. This stabilization is achievable thanks to polarization-mode switching allowed by the particular spectroscopic and thermal properties of Yb:CALGO crystal. This atypical and unexpected behavior is studied in detail in this Letter and explained by analysis of the thermo-optical coefficients for CALGO.

  12. Optical properties and residual stress of YbF3 thin films deposited at different temperatures.

    Science.gov (United States)

    Wang, Ying; Zhang, Yue-guang; Chen, Wei-lan; Shen, Wei-dong; Liu, Xu; Gu, Pei-fu

    2008-05-01

    The influence of deposition temperature on the optical properties, microstructure, and residual stress of YbF(3) films, deposited by electron-beam evaporation, has been investigated. The increased refractive indices and surface roughness of YbF(3) films indicate that the film density and columnar structure size increase with deposition temperature. At the same time, higher packing density reduces absorption of moisture. The residual stress is related to deposition temperature and to substrate. For the samples deposited on BK7, the residual stress mainly comes from intrinsic stress, however, for those on fused silica, thermal stress is the dominant factor of total residual stress.

  13. Near infrared emission of TbAG:Ce3+,Yb3+ phosphor for solar cell applications

    Science.gov (United States)

    Meshram, N. D.; Yadav, P. J.; Pathak, A. A.; Joshi, C. P.; Moharil, S. V.

    2016-05-01

    Luminescent materials doped with rare earth ions are used for many devices such as optical amplifiers in telecommunication, phosphors for white light emitting diodes (LEDs), displays, and so on. Recently, they also have attracted a great interest for photovoltaic applications to improve solar cell efficiency by modifying solar spectrum. Crystal silicon (c-Si) solar cells most effectively convert photons of energy close to the semiconductor band gap. The mis-match between the incident solar spectrum and the spectral response of solar cells is one of the main reasons to limit the cell efficiency. The efficiency limit of the c-Si has been estimated to be 29% by Shockley and Queisser. However, this limit is estimated to be improved up to 38.4% by modifying the solar spectrum by a quantum cutting (down converting) phosphor which converts one photon of high energy into two photons of lower energy. The phenomenon such as the quantum cutting or the down conversion of rare earth ions have been investigated since Dexter reported the possibility of a luminescent quantum yield greater than unity in 1957. In the past, the quantum cutting from a vacuum ultraviolet photon to visible photons for Pr3+, Gd3+,Gd3+-Eu3+, and Er3+-Tb3+ had been studied. Recently, a new quantum cutting phenomenon from visible photon shorter than 500 nm to two infrared photons for Tb3+-Yb3+, Pr3+-Yb3+, and Tm3+-Yb3+ has been reported. The Yb3+ ion is suitable as an acceptor and emitter because luminescent quantum efficiency of Yb3+ is close to 100% and the energy of the only excited level of Yb3+ (1.2 eV) is roughly in accordance with the band gap of Si (1.1 eV). In addition, the Ce3+-doped Tb3Al5O12 (TbAG), used as a phosphor for white LED, has broad absorption bands in the range of 300-500 nm due to strong ligand field and high luminescent quantum efficiency. Therefore, the Ce3+ ions in the TbAG can be suitable as an excellent sensitizing donor for down conversion materials of Si solar cells. In this

  14. Yb3+-Doped Double-Clad Fibre Laser Based on Fibre Bragg Grating

    Institute of Scientific and Technical Information of China (English)

    范万德; 付圣贵; 张强; 宁鼎; 李丽君; 王志; 袁树忠; 董孝义

    2003-01-01

    A novel Yb3+-doped double-clad fibre laser based on a double-clad fibre Bragg grating is presented. The fibre Bragg grating, as the output mirror, has been formed in Yb3+-doped double-clad fibre with the phase-mask method. When the input pump power is 2.8 W, the maximum laser output power is 570mW, with < 0.2 nm in line-width at the wavelength of 1.058μm, over 40dB signal-to-noise ratio and 24% slope efficiency.

  15. Sol-gel silica films embedding NIR- emitting Yb-quinolinolate complexes

    Energy Technology Data Exchange (ETDEWEB)

    Figus, Cristiana, E-mail: cristiana.figus@dsf.unica.it; Quochi, Francesco, E-mail: cristiana.figus@dsf.unica.it; Piana, Giacomo; Saba, Michele; Mura, Andrea; Bongiovanni, Giovanni [Dipartimento di Fisica, University of Cagliari, SS 554 Bivio per Sestu, I-09042, Monserrato-Cagliari (Italy); Artizzu, Flavia [Dipartimento di Fisica, University of Cagliari and Dipartimento di Scienze Chimiche e Geologiche, University of Cagliari, SS 554 Bivio per Sestu, I-09042, Monserrato-Cagliari (Italy); Mercuri, Maria Laura; Serpe, Angela; Deplano, Paola [Dipartimento di Scienze Chimiche e Geologiche, University of Cagliari, SS 554 Bivio per Sestu, I-09042, Monserrato-Cagliari (Italy)

    2014-10-21

    Sol-gel silica thin films embedding an ytterbium quinolinolato complex (YbClQ{sub 4}) have been obtained using different alkoxides. Homogeneous, crack- and defect-free thin films of optical quality have been successfully deposited on glass substrate by dip-coating. The silica thin films have been characterized by time-resolved photoluminescence. The luminescence properties of the YbClQ{sub 4} are preserved in silica films prepared through an optimized sol-gel approach. The excited state lifetime of the lanthanide is comparable to those observed in bulk and longer than the corresponding ones in solution.

  16. Sol-gel silica films embedding NIR- emitting Yb-quinolinolate complexes

    Science.gov (United States)

    Figus, Cristiana; Quochi, Francesco; Artizzu, Flavia; Piana, Giacomo; Saba, Michele; Mercuri, Maria Laura; Serpe, Angela; Deplano, Paola; Mura, Andrea; Bongiovanni, Giovanni

    2014-10-01

    Sol-gel silica thin films embedding an ytterbium quinolinolato complex (YbClQ4) have been obtained using different alkoxides. Homogeneous, crack- and defect-free thin films of optical quality have been successfully deposited on glass substrate by dip-coating. The silica thin films have been characterized by time-resolved photoluminescence. The luminescence properties of the YbClQ4 are preserved in silica films prepared through an optimized sol-gel approach. The excited state lifetime of the lanthanide is comparable to those observed in bulk and longer than the corresponding ones in solution.

  17. Preparation, characterization and optical properties of ZrO2:Er3+, Yb3+ nanomaterials

    Science.gov (United States)

    Thu Huong, Tran; Thanh Huong, Nguyen; Thi Kieu Giang, Lam; Anh, Tran Kim; Lojkowski, Witold; Minh, Le Quoc

    2009-09-01

    Luminescent nanomaterials from lanthanide are one of most promising materials for applications in medical diagnostics. In this paper, we present for the first time the ZrO2 nanomaterials with capsule like nanostructure with the sizes of 150 nm in length and 50 nm in width. These nanocapsule like ZrO2 doped with Er3+, Yb3+ ions were prepared by soft template methods. Morphological characterization of nano - ZrO2:Er3+, Yb3+ was performed by using FESEM, X-ray diffraction, micro Raman. Up conversion luminescence and photoluminescence have been also studied with IR-laser excitation at 940 nm and UV excitation at 365 nm.

  18. Exploring strategies for the production of ultracold RbYb molecules in conservative traps

    Energy Technology Data Exchange (ETDEWEB)

    Bruni, Cristian

    2015-07-14

    Within the scope of this thesis, the production of ultracold molecules at a temperature of a few μK with various isotopes of rubidium (Rb) and ytterbium (Yb) was examined by means of photoassociation spectroscopy and magnetic Feshbach resonances in combined conservative traps. The long-term goal of this experiment is the production of ultracold RbYb molecules in the rovibronic ground state. It was possible to produce electronically excited {sup 87}Rb {sup 176}Yb molecules in a novel hybrid trap (HT) at a combined temperature of 1.7 μK by means of 1-photon photoassociation close to the Rb D1 line at 795 nm. This HT takes advantage of the different magnetic properties of Rb and Yb and allows for independent trapping and manipulation of the atomic species. It combines an Ioffe-Pritchard type magnetic trap for Rb and a near-resonant optical dipole trap for Yb. The excited molecular {sup 2}Π{sub 1/2} state could be characterized further extending previous works in a combined MOT and vibrational levels reaching binding energies up to E{sub b}=-h x 2.2 THz could be assigned by trap-loss spectroscopy. Almost every detected vibrational state consists of two resonances that could be assigned to the molecular analogue of the hyperfine structure of {sup 87}Rb. An important experimental observation is a decrease in hyperfine splitting with increasing binding energy of a vibrational level. For the deepest found vibrational state the hyperfine splitting amounts only 70 % of the atomic value (817 MHz) which emphasizes a gradual passage from weakly to tightly bound molecules. Furthermore, detailed attempts were undertaken to induce magnetic Feshbach resonances in {sup 85}Rb and different Yb isotopes, especially {sup 171}Yb in a crossed optical dipole trap at 1064 nm at temperatures of 10 μK. For this purpose, a homogeneous magnetic field was applied and scanned in small steps over the range of 495 G ∼ 640 G. Unfortunately, our efforts were without success. Additionally, well

  19. Nachhaltigkeit von E-Learning-Innovationen: Von der Pionierphase zur nachhaltigen Implementierung

    Directory of Open Access Journals (Sweden)

    Sabine Seufert

    2003-11-01

    Full Text Available In den letzten Jahren wurden an den meisten Hochschulen im In- und Ausland E-Learning-Projekte in die Wege geleitet. Nach den Projekt- und Impulsprogrammen folgen die Konsolidierungsphasen. Schon während der Projektphasen zeigen sich Problemgruppen, die darauf verweisen, dass E-Learning nicht «nur» eine Angelegenheit der Pädagogik und Didaktik ist. Der erste Teil des Aufsatzes benennt einzelne dieser Problemfelder. Der zweite Teil zeigt auf, dass E-Learning die Hochschulen als Ganzes betrifft, und unterbreitet ein Rahmenkonzept, in dem gezeigt wird, wie die benannten Probleme bei der Implementierung von E-Learning vermieden werden können.

  20. Diskriminierung in der 'longue durée' : von der Notwendigkeit der Kontextualisierung von Strukturproblemen

    OpenAIRE

    2006-01-01

    "Diskriminierung auf der Grundlage von Rasse, Ethnie, Geschlecht, Herkunft, körperlicher Verfassung oder Bildungsniveau ist ein Kennzeichen der westlichen Moderne. Das für moderne Nationalstaaten charakteristische Gewaltmonopol übte nicht nur eine Schutzfunktion in Bezug auf das Leben und Eigentum der Staatsbürger aus, sondern verfügte darüber hinaus über die Definitionsmacht, die Kriterien der Zugehörigkeit zur nationalen Gemeinschaft festlegte und dabei Gewalt gegenüber Nicht-Staatsbürgern ...

  1. Sympathetic cooling of ytterbium with rubidium; Sympathetische Kuehlung von Ytterbium mit Rubidium

    Energy Technology Data Exchange (ETDEWEB)

    Tassy, S.

    2007-12-14

    Within the scope of this thesis, a mixture of ultracold ytterbium and rubidium atoms was experimentally realized and investigated. For these experiments, a novel trap geometry was developed which allows simultaneous trapping and cooling of diamagnetic and paramagnetic atomic species. The main focus was put on the investigation of the interspecies scattering properties, where sympathetic cooling of ytterbium through elastic collisions with rubidium could be demonstrated. In addition, the interspecies scattering length could be determined. In the current configuration the combined trap allows the preparation of up to 2.10{sup 5} atoms of {sup 170}Yb, {sup 171}Yb, {sup 172}Yb, {sup 174}Yb or {sup 176}Yb at a temperature of 40..60 {mu}K and a density in the range of 10{sup 12} cm{sup -3}, and of about 10{sup 7} {sup 87}Rb atoms at a temperature of 25 {mu}K and a density in the range of 5.10{sup 11} cm{sup -3}. Detailed studies of the thermalization of bosonic {sup 170}Yb, {sup 172}Yb, {sup 174}Yb and {sup 176}Yb and of fermionic {sup 171}Yb each with {sup 87}Rb were performed under varying experimental conditions. The deduced total scattering cross section was clearly found to increase with higher mass of the ytterbium isotope. In general, a mass scaling of the scattering properties is in agreement with theoretical models and former experimental work. With the assumption of pure s-wave scattering, which is approximately fulfilled for the given experimental parameters, the interspecies scattering length could be derived from the measured thermalization data and was found to be (in units of the Bohr radius a{sub 0}): {sup 170}Yb-{sup 87}Rb:(18{sup +12}{sub -4})a{sub 0}, {sup 171}Yb-{sup 87}Rb:(25{sup +14}{sub -7})a{sub 0}, {sup 172}Yb-{sup 87}Rb:(33{sup +23}{sub -7})a{sub 0}, {sup 174}Yb-{sup 87}Rb:(83{sup +89}{sub -25})a{sub 0}, {sup 176}Yb-{sup 87}Rb:(127{sup +245}{sub -45})a{sub 0}. (orig./HSI)

  2. Entstehungsbedingungen von Übergängen von der Schule in den Beruf aus qualitativer und quantitativer Perspektive

    Directory of Open Access Journals (Sweden)

    Nora Gaupp

    2013-03-01

    Full Text Available Methodenintegration wird in den Sozialwissenschaften mit dem Argument sich ergänzender Erkenntnismöglichkeiten häufig gefordert. Die vorliegende Analyse zu Übergangswegen von der Schule in Ausbildung und Arbeit von Jugendlichen mit Hauptschulbildung beruht auf Daten einer quantitativen Panelstudie und einer qualitativen Ergänzungsstudie. Aus quantitativer und qualitativer Perspektive wird jeweils ein Einzelfall betrachtet sowie im Rahmen einer Modellbildung eine Verallgemeinerung auf Aggregatebene vorgenommen. Über ein logistisches Regressionsmodell wird die Bedeutung von zentralen individuellen, sozialen und strukturellen Merkmalen wie Schulleistungen, beruflichen Plänen, individuellen Problembelastungen, Migrationshintergrund und Arbeitslosigkeit der Eltern sowie regionaler Arbeitsmarktsituation für den Verlauf von Übergangswegen (Direkteinstieg in Ausbildung, Umweg in Ausbildung über schulische oder berufsvorbereitende Zwischenschritte, fortgesetzter mehrjähriger Schulbesuch und prekäre Wege in Ausbildungslosigkeit untersucht. Über das qualitative Paradigma konnten vier für den Verlauf von Übergängen zentrale Dimensionen identifiziert werden: Agency, Motivation, kritische biografische Ereignisse und soziale Interaktionen. Der Schritt der Modellbildung integriert die vier Erfahrungsebenen und zeigt ihre Bedeutung für Übergänge von der Schule in den Beruf. Die Diskussion fragt nach Möglichkeiten und Grenzen der Erkenntnisentwicklung der beiden Forschungszugänge. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1302126

  3. Richard von Volkmann: surgeon and Renaissance man.

    Science.gov (United States)

    Willy, Christian; Schneider, Peter; Engelhardt, Michael; Hargens, Alan R; Mubarak, Scott J

    2008-02-01

    Richard von Volkmann (1830-1889), one of the most important surgeons of the 19(th) century, is regarded as one of the fathers of orthopaedic surgery. He was a contemporary of Langenbeck, Esmarch, Lister, Billroth, Kocher, and Trendelenburg. He was head of the Department of Surgery at the University of Halle, Germany (1867-1889). His popularity attracted doctors and patients from all over the world. He was the lead physician for the German military during two wars. From this experience, he compared the mortality of civilian and war injuries and investigated the general poor hygienic conditions in civilian hospitals. This led him to introduce the "antiseptic technique" to Germany that was developed by Lister. His powers of observation and creativity led him to findings and achievements that to this day bear his name: Volkmann's contracture and the Hueter-Volkmann law. Additionally, he was a gifted writer; he published not only scientific literature but also books of children's fairy tales and poems under the pen name of Richard Leander, assuring him a permanent place in the world of literature as well as orthopaedics.

  4. Geschichte der Natur bei Alexander von Humboldt

    Directory of Open Access Journals (Sweden)

    Christian Helmreich

    2009-05-01

    Full Text Available Article in German, Abstracts in English, German and French.This article analyses the importance of an historical view of nature in the works of Alexander von Humboldt. In several of his first writings, Humboldt seems to outline the importance of what one may call history of nature. But even before his famous American travel, his position changed and he became reluctant to accept the seriousness of historical enquiry in the area of natural sciences: if we want to reconstruct the past state of nature, we cannot rely on empirical proofs; and history of nature is therefore necessarily based on uncertain hypotheses. Humboldt kept his sceptical attitude in the first decades of the 19th century, despite the positive results of the palaeontological researches of his scientific colleagues. However, he gradually convinced himself of the scientific interest of historical investigations in the natural sciences. The Cosmos paradoxally displays two apparently conflicting points of view: in his methodological remarks, Humboldt maintains that precise accounts of the past state of nature are out of reach of human knowledge, yet elsewhere in the same Cosmos he gives broad and rather vivid descriptions of the eventful history of nature.

  5. Modellbasierte Steuerung, Regelung und Diagnose von Brennstoffzellenantrieben

    Science.gov (United States)

    Bußhardt, Joachim; Baaser, Bernhard; Formanski, Volker; Schäfer, Sascha; Sinsel, Stefan

    Steigende Bevölkerungszahlen und damit zunehmender Energiebedarf stellen eine große Herausforderung für Menschheit und Umwelt dar. Mit steigendem Wohlstand ist auch ein stärkeres Bedürfnis nach Mobilität und damit ein höherer Energieverbrauch verbunden. Die derzeitigen enormen Steigerungen des Bruttoinlandsproduktes in China und Indien - zwei Ländern, die zusammen mehr als ein Drittel der Weltbevölkerung stellen - lassen auch zukünftig ungebrochene Steigerungen des Weltenergieverbrauches erwarten. Dies gilt für alle Bereiche, besonders aber für den Verkehrssektor. Letzterer stellt mit seinem signifikanten Anteil am Energieverbrauch sowie den damit einhergehenden Emissionen und seinem hohen Wachstumspotenzial ein besonderes Handlungsfeld dar. Insbesondere wegen der in diesem Sektor zu erwartenden ansteigenden CO2-Emissionen stehen Effizienzverbesserungen und die Entwicklung alternativer Antriebe im Vordergrund. Dabei spielt die Brennstoffzelle als Fahrzeugantrieb eine entscheidende Rolle, da sie einen hohen Systemwirkungsgrad mit fehlenden CO2- und Schadstoffemissionen verbindet. Wegen der hohen Komplexität sind dabei moderne Steuerungs-, Regelungs- und Diagnoseverfahren von besonderer Bedeutung, auf die in diesem Beitrag näher eingegangen wird. Neben einigen grundlegenden Konzepten wird an Hand zweier Beispiele das Potenzial modellgestützter Methoden aufgezeigt.

  6. Zur Struktur und Funktion von Synonymen

    Directory of Open Access Journals (Sweden)

    Marina Zorman

    1998-12-01

    Full Text Available Der Artikel behandelt die Synonyme im Licht der funktionell-strukturellen Sprachtheorie Coserius. 1 Die Wahl der theoretischen Grundsätze wurde durch die Festellung diktiert, daß die bisherigen Erkenntnisse über die Synonymie widersprüchlich sind und daß auch schon über alle Feststellungen berechtigte Einsprüche erhoben wurden. Deshalb wird in dieser Arbeit auf der genannten theoretischen Grundlage, die verschiedene Gesichtspunkte des Problems verbindet, anstatt sie zu trennen (s. Punkt 2, ein Modell für die Analyse von Synonymen vorgestellt (3, das die klassischen Schwächen der Semantikforschung (zu geringe Menge tatsächlicher Daten, Subjektivität und Introspektion durch eine empirische Untersuchung in einem Textkorpus zu ersetzen versucht. In die Analyse sind drei Inhaltsebenen einbezogen (Bezeichnung, Bedeutung und Sinn und ihnen sind jeweils entsprechende Untersuchungsmethoden zugeordnet. Im Sinne des Modells wurden in der Arbeit Zorman 1997 zwei slowenische Synonympaare (kuverta - ovojnica und borba - boj analysiert, die als Beispiele reiner (und totaler Synonymie gelten können. Die Analyse wird aus Platzgründen an dieser Stelle nicht detailliert dargestellt,2 veranschaulicht werden nur ihre Tragweite und die Ergebnisse (4. Im letzten Teil (5 werden die Leistungen der vorgeschlagenen Methode bewertet und einige Annahmen dargestellt, die der weiteren Erforschung der Synonyme dienen könnten. Die objektive Behandlung der Synonymie unter unterschiedlichen Gesichtspunkten scheint einige Dogmen über Synonyme in Frage zu  stellen.

  7. Eine Frau in der Kultur, die Kultur einer Frau: Caroline von Humboldt. A woman in the culture, the culture of a woman: Caroline von Humboldt

    Directory of Open Access Journals (Sweden)

    Elžbieta M. Kowalska

    2008-01-01

    Full Text Available The subject of this presentation is Wilhelm von Humboldt’s wife, Alexander von Humboldt’s sisterin-law, a close female friend of Lotte Schiller and of her sister, Caroline von Wolzogen, held in high regard by Goethe, admired by Schiller, the former Fräulein von Dacheröden from Erfurt, the future Caroline von Humboldt. She was the ancestress of one of the most respected and best German noble families, a mother of eight children, an intellectually gifted woman, in which the German ideals of femininity were fulfilled, who knew to lead the salons and to talk about arts and literature.

  8. Synthesis and Upconversion Luminescence of LaF3: Yb3+, Er3+/SiO2 Core/Shell Microcrystals

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    LaF3: Yb3+, Er3+ microcrystals were synthesized by a hydrothermal method, and then, the LaF3: Yb3+, Er3+ microcrystals were coated with silica. Phase identification of LaF3: Yb3+, Er3+ and LaF3: Yb3+, Er3+/SiO2 was performed via XRD. The TEM image showed that the size of LaF3: Yb3+, Er3+ was 150 nm and LaF3: Yb3+, Er3+/SiO2 presented clearly a core/shell structure with 20 nm shell thickness. The upconversion spectra of LaF3: Yb3+, Er3+ and LaF3: Yb3+, Er3+/SiO2 in solid state and in ethanol were studied with a 980 nm diode laser as the excitation source. The upconversion spectra showed that the silica shell had little effect on the properties of fluorescence of the LaF3: Yb3+, Er3+ microcrystals. At the same time, the green luminescence photo of LaF3: Yb3+, Er3+/SiO2 in the PBS buffer was obtained, which indicated that the LaF3: Yb3+, Er3+/SiO2 could be used in biological applications.

  9. Microscopic evidence for significant ionic disorder in the Yb sup 3 sup + -chain in Yb sub 4 (As sub 1 sub - sub x P sub x) sub 3 : sup 3 sup 1 P NMR studies

    CERN Document Server

    Tanida, H; Aoki, H; Ochiai, A

    2003-01-01

    We report unambiguous microscopic evidence from sup 3 sup 1 P NMR under H sub e sub x sub t approx = 7.3 T for significant ionic disorder in the Yb sup 3 sup + chain in Yb sub 4 (As sub 1 sub - sub x P sub x) sub 3 (x=0.05 and 0.40), which have similar characteristic chi(T) and C sub p (T, H sub e sub x sub t) behavior to the antiferromagnetic quantum spin chain (AFQSC) system Yb sub 4 As sub 3. Our conclusion is based on the observations only below the charge-ordering transition at T sub 0 approx = 292 K of clear structures in the spectrum, which can be fitted well by the superpositions of almost equally spaced five Gaussian components. Since perfect ordering of Yb sup 3 sup + in the chain sites would lead to a single-line spectrum also below T sub 0 , the structures should be ascribed to significant ionic disorder in the Yb sup 3 sup + chain and resulting distribution of local configurations of Yb sup 3 sup + in the eight nearest-neighboring Yb sites around sup 3 sup 1 P. Quantitative comparisons with a sim...

  10. Effect of the concentration of the dopants (Er3 +, Yb3 + and Zn2 +) and temperature on the upconversion emission behavior of Er3 +/Yb3 + co-doped SrAl2O4 phosphor

    Science.gov (United States)

    Choudhary, Ajay Kumar; Dwivedi, A.; Bahadur, A.; Rai, S. B.

    2017-10-01

    Er3 +/Yb3 + co-doped SrAl2O4 (SRA: Er3 +, Yb3 +) phosphor has been synthesized by high temperature solid state reaction technique. The pure phase formation has been confirmed by X-ray diffraction (XRD) measurements. The surface morphology is studied by scanning electron microscopy (SEM) technique. The FTIR measurements give the information of vibrational bands arising due to sample. The intense UC emission from SRA: Er3 +, Yb3 + phosphor has been monitored on excitation with 980 nm diode laser. The SRA: Er3 +, Yb3 + samples prepared at 1473 K show a dominant green emission. On the other hand it shows dominant red emission when the sample is heated to 1623 K. Variation of concentration of Er3 + and Yb3 + ions in SRA: Er3 +, Yb3 + phosphor suggests two possible mechanisms involved in UC emission process viz. cross relaxation (CR) process and energy back transfer (EBT) process, respectively. The cross relaxation mechanism seems to play a major role. The UC emission efficiency is enhanced several times on co-doping of Zn2 + ion replacing Al3 + or Sr2 + in SRA: Er3 +, Yb3 + phosphor sample. The color of the UC emission can be tuned from green to red region by varying the concentration of zinc.

  11. [Determination of von Willebrand factor multimers in Mexican population].

    Science.gov (United States)

    Hernández-Zamora, Edgar; Zavala-Hernández, Cesar; Viveros-Sandoval, Martha Eva; Ochoa-Rico, Angeles; Martínez-Murillo, Carlos; Reyes-Maldonado, Elba

    2014-01-01

    Antecedentes: la enfermedad de von Willebrand es un padecimiento hereditario en el que la estructura, función y concentración del factor de von Willebrand están alteradas y, en consecuencia, también la interacción plaqueta-factor de von Willebrand-endotelio. En México no hay registros epidemiológicos de la enfermedad, sólo se han efectuado algunos estudios aislados desde el punto de vista clínico y hematológico. Material y métodos: estudio retrospectivo efectuado en 155 mexicanos mestizos, 75 de ellos con diagnóstico presuntivo de enfermedad de von Willebrand, 15 con sospecha de hemofilia A y 65 donadores sanos (testigos). Se realizaron pruebas: básicas de coagulación, especiales y de clasificación: análisis de la composición multimérica. Resultados: 15 pacientes se diagnosticaron con hemofilia A; de los 75 sujetos con sospecha de enfermedad de von Willebrand se diagnosticaron 50 de la manera siguiente: tipo 1 (62%), tipo 2 (22%) [subtipos: 2A (14%), 2B (2%) y 2N (6%)] y tipo 3 (16%). Conclusión: el análisis de los multímeros del factor de von Willebrand es un método que cumple con las características adecuadas para el diagnóstico de la enfermedad de von Willebrand, por lo que es necesario implementar esta metodología para su estudio y mejorar su diagnóstico específico.

  12. Change in thermoluminescence behaviour of cubic Gd2O3:Yb3+ phosphors with successive increase in Yb3+ ion concentrations

    Science.gov (United States)

    Tamrakar, Raunak Kumar; Bisen, D. P.; Upadhyay, Kanchan

    2017-01-01

    Nanocrystalline Yb3+ doped Gd2O3 phosphors were synthesized by solid state reaction method (SSRM), and effect of Yb3+ concentrations (1 mol% to 7 mol%) on thermoluminescence properties were studied. The XRD technique shows the cubic structure of prepared phosphor for different concentrations of Yb3+. No phase change was found due to the dopant concentration. The crystal size was calculated by Scherer's formula, which is found in 20-60 nm range. The same was also confirmed from the field emission gun scanning electron microscopy (FEGSEM) image, which shows the formation of nanospheres having diameter 20-60 nm range. They are found to be quite uniform in shapes and sizes. Functional group analysis was studied by Fourier transform infrared spectroscopy (FTIR) techniques and the elemental analysis of prepared phosphor was studied by energy dispersive X-ray spectroscopic (EDX) analysis. The samples were irradiated with UV and gamma radiation for the doses varying from 5 to 30 min for UV and 0.5 kGy to 2 kGy for gamma respectively and their thermoluminescence (TL) characteristics have been studied. The effect of heating rate (3-7 °C s-1) and effect of Yb3+ concentration in TL glow curve have been studied. The TL glow curve of nanophosphor shows a peak at around 130 °C for UV and at 247 °C for gamma irradiation respectively. The TL response of the sample irradiated with different gamma doses shows a linear behaviour from 0.5 kGy to 2 kGy and become sublinear behaviour in the range of 5-25 min UV exposure before it saturates with further increase in the dose. Simple glow curve structure, easy method of synthesis and the linear dose response make the nanocrystalline phosphor a good candidate for radiation dosimetry, especially for the estimation of high doses of gamma rays where the nanocrystalline phosphors generally saturated.

  13. Some Physicochemical Properties of Yb14MnSb11 and Its Solid Solutions with Gadolinium Yb14-xGdxMnSb11 Type

    Directory of Open Access Journals (Sweden)

    Abdusalyamova Makhsuda

    2016-01-01

    Full Text Available Data on structure, melting temperatures, density, thermal dilatation, kinetic of oxidation of Yb14MnSb11 and its solid solutions with gadolinium are presented in this article. All solid solutions are isostructural with Zintlcompound Ca14AlSb11 and crystallizes in tetragonal structure. Investigations melting temperatures, thermal dilatation, oxidation have shown that GdincorporatenearGd≈ 0.5 and increased melting point and thermal dilatation.

  14. Some Physicochemical Properties of Yb14MnSb11 and Its Solid Solutions with Gadolinium Yb14-xGdxMnSb11 Type

    OpenAIRE

    Abdusalyamova Makhsuda; Vasilyeva Inga

    2016-01-01

    Data on structure, melting temperatures, density, thermal dilatation, kinetic of oxidation of Yb14MnSb11 and its solid solutions with gadolinium are presented in this article. All solid solutions are isostructural with Zintlcompound Ca14AlSb11 and crystallizes in tetragonal structure. Investigations melting temperatures, thermal dilatation, oxidation have shown that GdincorporatenearGd≈ 0.5 and increased melting point and thermal dilatation.

  15. Dually functioned core-shell NaYF4:Er(3+)/Yb(3+)@NaYF4:Tm(3+)/Yb(3+) nanoparticles as nano-calorifiers and nano-thermometers for advanced photothermal therapy.

    Science.gov (United States)

    Zhang, Yanqiu; Chen, Baojiu; Xu, Sai; Li, Xiangping; Zhang, Jinsu; Sun, Jiashi; Zheng, Hui; Tong, Lili; Sui, Guozhu; Zhong, Hua; Xia, Haiping; Hua, Ruinian

    2017-09-19

    To realize photothermal therapy (PTT) of cancer/tumor both the photothermal conversion and temperature detection are required. Usually, the temperature detection in PTT needs complicated instruments, and the therapy process is out of temperature control in the present investigations. In this work, we attempt to develop a novel material for achieving both the photothermal conversion and temperature sensing and control at the same time. To this end, a core-shell structure with NaYF4:Er(3+)/Yb(3+) core for temperature detection and NaYF4:Tm(3+)/Yb(3+) shell for photothermal conversion was designed and prepared. The crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Furthermore, the temperature sensing properties for the NaYF4:Er(3+)/Yb(3+) and core-shell NaYF4:Er(3+)/Yb(3+)@NaYF4:Tm(3+)/Yb(3+) nanoparticles were studied. It was found that the temperature sensing performance of the core-shell nanoparticles did not become worse due to coating of NaYF4:Tm(3+)/Yb(3+) shell. The photothermal conversion behaviors were examined in cyclohexane solution based on the temperature response, the NaYF4:Er(3+)/Yb(3+)@NaYF4:Tm(3+)/Yb(3+) core-shell nanoparticles exhibited more effective photothermal conversion than that of NaYF4:Er(3+)/Yb(3+) nanoparticles, and a net temperature increment of about 7 °C was achieved by using the core-shell nanoparticles.

  16. Mid-infrared luminescence and energy transfer of Tm3+ in silicate glasses by codoping with Yb3+ ions

    Science.gov (United States)

    Cao, Ruijie; Lu, Yu; Tian, Ying; Huang, Feifei; Guo, Yanyan; Xu, Shiqing; Zhang, Junjie

    2017-09-01

    A kind of novel silicate glasses doped with Tm3+ sensitized by Yb3+ were prepared by conventional melt quenching method. The optical properties of the synthesized glasses were theoretically and experimentally investigated. Based on the absorption spectra and the Judd-Ofelt theory, the J-O intensity parameters (Ωt), radiative transition probability (400.4 s-1), fluorescence lifetime (4.99 ms) and absorption and emission cross sections (σe = 2.51 × 10-20 cm2) were calculated. According to fluorescence spectra, the 1.8 μm emission of Tm3+ could be greatly enhanced by adding proper amount of Yb3+ under the excitation of 980 nm and the optimized concentration ratio of Tm3+ and Yb3+ was found to be 1:3 in the present silicate glass system. Besides, the energy transfer mechanism between Yb3+ and Tm3+ were thoroughly discussed. With the assistance of Yb3+, the lifetime of Tm3+ from 0.54 ms increased to 1.42 ms. The energy transfer efficiency from Yb3+ to Tm3+ could reach 90.94%, and the energy transfer coefficient was 5.43 × 10-41 cm6/s. The content of OH- was measured. The above results showed that Tm3+/Yb3+ co-doping could be expected to a promising way to achieve high efficient 2 μm lasing pumped by a 980 nm LD.

  17. Synthesis, Structural Characterization, and Emission Properties of NaYF4:Er3+/Yb3+ Upconversion Nanoluminophores

    Science.gov (United States)

    Giang, Lam Thi Kieu; Marciniak, Lukasz; Hreniak, Dariusz; Anh, Tran Kim; Minh, Le Quoc

    2016-10-01

    We propose a new method to prepare Er3+/Yb3+-codoped β-NaYF4 upconversion nanoluminophores, allowing creation of single-crystalline-phase β-NaYF4: Er3+/Yb3+ with concentrations up to 20 mol.% through a hydrothermal process. Using hexagonal-phase Y(OH)3 precursors with different nanostructures (nanosheets, nanorods, nanotubes, etc.), one can obtain many types of one-dimensional nano-NaYF4:Er3+/Yb3+ materials and significantly improve the multiphase phenomenon, which is a common challenge facing many research groups that use a hydrothermal process for synthesis of NaYF4 compounds. Upon near-infrared laser excitation at 976 nm, the obtained β-NaYF4:Er3+/Yb3+ nanorods emit in green (2H11/2, 4S3/2 → 4I15/2) and red (4F9/2 → 4I15/2) spectral regions with high intensity. Moreover, it is shown that one can change the luminescence integrated intensity ratio between the red and green emissions by varying the concentration and components of Er3+ and Yb3+ in the NaYF4 host material. Comparative studies on the luminescence kinetics of the NaYF4:Er3+/Yb3+ nanoluminophores were also conducted to explain the influence of Yb3+ ion on the upconversion processes.

  18. Magnetic and thermoelectric properties of a heterogeneous mixed-valence system, Yb sub 2 Pt sub 3 Sn sub 5

    CERN Document Server

    Muro, Y; Kim, M S; Takabatake, T; Godart, C; Rogl, P

    2003-01-01

    We have studied the valence states and thermoelectric properties of Yb sub 2 T sub 3 Sn sub 5 (T=Pt and Pd) with two inequivalent Yb sites. For Yb sub 2 Pt sub 3 Sn sub 5 , the 4 f-hole occupation number n sub f is estimated to be 0.4 at 300 K from the magnetic susceptibility and L sub I sub I sub I -edge absorption spectrum. Intermediate-valence behaviors manifest themselves in a largely negative value of the paramagnetic Curie temperature, -216 K, a broad peak at 300 K in the magnetic part of the resistivity, and a large minimum in the thermopower, -38 mu V/K at 60 K. The specific heat shows no transition down to 0.6 K. These results are explained by a model in which Yb ions in one site are divalent and those in the other site are in a valence fluctuating state with a Kondo temperature of 200 K. Thus, Yb sub 2 Pt sub 3 Sn sub 5 is a rare example of the heterogeneous mixed-valence system. An isostructural compound Yb sub 2 Pd sub 3 Sn sub 5 has a larger unit-cell volume by 2.4%, which allows the Yb ions in b...

  19. Energy transfer mechanism in Yb{sup 3+}:Er{sup 3+}-ZBLAN: macro- and micro-parameters

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Z. E-mail: zmengjp@yahoo.co.jp; Nagamatsu, K.; Higashihata, M.; Nakata, Y.; Okada, T. E-mail: okada@ees.kyushu-u.ac.jp; Kubota, Y.; Nishimura, N.; Teshima, T.; Buddhudu, S

    2004-04-01

    Dynamics of forward energy transfer and backward energy transfer processes in fluorozirconate glass doubly doped with Yb{sup 3+} and Er{sup 3+} have been explained by 'rate equation' and 'fluorescence transfer function' models. From the rate equation analysis, macroscopic energy transfer parameters, the cross-relaxation coefficients, were determined to be 1.36x10{sup -17} and 3.38x10{sup -17} s{sup -1} cm{sup 3} for the forward energy transfer (Yb{sup 3+}{yields}Er{sup 3+}) and the backward transfer (Er{sup 3+}{yields}Yb{sup 3+}), respectively. Based on the fluorescence 'transfer-function' model, the kinetics of the energy transfer processes between Yb{sup 3+} and Er{sup 3+} ions has been analyzed, and the microscopic energy transfer parameters of the Yb:Er-codoped system, the critical radii, were derived as 13.0 and 18.0 A for the donor-acceptor (Yb{sup 3+}{yields}Er{sup 3+}) and the acceptor-donor (Er{sup 3+}{yields}Yb{sup 3+}), respectively. The 1.55 {mu}m band emission property of the rare-earth-codoped fluoride glass systems has been discussed.

  20. Diode Pumped Yb:YAG Thin Disk Laser Achieves 16 W CW Output%二极管泵浦Yb:YAG Thin Disk激光器获得16W连续激光输出

    Institute of Scientific and Technical Information of China (English)

    李超; 徐震; 李俊林; 吴念乐; 李师群; 姚广涛; 张绍光

    2002-01-01

    近年来,Yb:YAG激光研究已被视为发展高效、高功率二极管泵浦固体激光器的一个主要方向.本文简要分析了Yb:YAG作为增益介质优于Nd:YAG的性质,阐述了Thin Disk激光器的原理,并介绍了我们在国内首次获得16 W连续激光(波长1030 nm)输出的二极管泵浦Yb:YAGThin Disk激光器装置及数据.

  1. Chromaticity modulation of upconversion luminescence in CaSnO{sub 3}:Yb{sup 3+}, Er{sup 3+}, Li{sup +} phosphors through Yb{sup 3+} concentration, pumping power and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Tao, E-mail: tpang@126.com; Lu, Wenhui; Shen, Wujian

    2016-12-01

    CaSnO{sub 3}:Yb{sup 3+}, Er{sup 3+}, Li{sup +} upconverting phosphors are synthesized by a simple solid state method. The doping concentration of Li{sup +} ions is optimized by comparatively studying upconversion luminescence of samples with various Li{sup +} content. The effects of Yb{sup 3+} concentration, pumping power and temperature on chromaticity of upconversion luminescence in CaSnO{sub 3}:Yb{sup 3+}, Er{sup 3+}, Li{sup +} phosphors are investigated, the related mechanisms are discussed and the abilities to modulate chromaticity are evaluated.

  2. Síntese de ZnAl2O4: Yb:Er por reação de combustão Synthesis of ZnAl2O4: Yb:Er by combustion reaction

    Directory of Open Access Journals (Sweden)

    J. F. Silva

    2006-09-01

    Full Text Available Aluminato de zinco dopado com os íons terras raras itérbio e érbio nas proporções 2:1, 3:1, 4:1, e 5:1 mol de Yb:Er foi sintetizado por reação de combustão. O efeito da dopagem simultânea Yb:Er na estrutura e na morfologia do aluminato de zinco foi investigado. Os pós foram sintetizados com base nos conceitos da química dos propelentes e então caracterizados por difração de raios X, análise granulométrica, adsorção de nitrogênio (método BET e microscopia eletrônica de varredura. Os resultados mostraram a formação da fase cristalina majoritária de ZnAl2O4:Yb:Er e traços das fases secundárias ZnO e Yb2O3 e que o aumento da relação Yb:Er favoreceu o aumento das fases secundárias. Todas as composições apresentaram morfologia formada por aglomerados moles constituídos por partículas finas. A área superficial aumentou em função da elevação da proporção Yb:Er.Zinc aluminate doped with ytterbium and erbium in the proportions 2:1, 3:1, 4:1, and 5:1 mol of Yb:Er were synthesized by combustion reaction. The effect of the Yb:Er in the structure and morphology of the zinc aluminate was investigated. The powders were synthesized on the basis of the propellants chemistry concepts and characterized by X-ray diffraction, nitrogen adsorption (BET method and scanning electron microscopy. The results show the formation of the ZnAl2O4:Yb:Er as majority crystalline phase and traces of ZnO and Yb2O3 as secondary phases, and that the increase of the Yb:Er proportion favored the increase of the content of secondary phases. All the compositions presented morphology formed by soft agglomerates of fine particles. The surface area increases with increasing Yb:Er proportion.

  3. Locally Compact Quantum Groups. A von Neumann Algebra Approach

    Science.gov (United States)

    Van Daele, Alfons

    2014-08-01

    In this paper, we give an alternative approach to the theory of locally compact quantum groups, as developed by Kustermans and Vaes. We start with a von Neumann algebra and a comultiplication on this von Neumann algebra. We assume that there exist faithful left and right Haar weights. Then we develop the theory within this von Neumann algebra setting. In [Math. Scand. 92 (2003), 68-92] locally compact quantum groups are also studied in the von Neumann algebraic context. This approach is independent of the original C^*-algebraic approach in the sense that the earlier results are not used. However, this paper is not really independent because for many proofs, the reader is referred to the original paper where the C^*-version is developed. In this paper, we give a completely self-contained approach. Moreover, at various points, we do things differently. We have a different treatment of the antipode. It is similar to the original treatment in [Ann. Sci. & #201;cole Norm. Sup. (4) 33 (2000), 837-934]. But together with the fact that we work in the von Neumann algebra framework, it allows us to use an idea from [Rev. Roumaine Math. Pures Appl. 21 (1976), 1411-1449] to obtain the uniqueness of the Haar weights in an early stage. We take advantage of this fact when deriving the other main results in the theory. We also give a slightly different approach to duality. Finally, we collect, in a systematic way, several important formulas. In an appendix, we indicate very briefly how the C^*-approach and the von Neumann algebra approach eventually yield the same objects. The passage from the von Neumann algebra setting to the C^*-algebra setting is more or less standard. For the other direction, we use a new method. It is based on the observation that the Haar weights on the C^*-algebra extend to weights on the double dual with central support and that all these supports are the same. Of course, we get the von Neumann algebra by cutting down the double dual with this unique

  4. Downconversion in Pr{sup 3+}–Yb{sup 3+} co-doped ZBLA fluoride glasses

    Energy Technology Data Exchange (ETDEWEB)

    Maalej, O. [Institut des Molécules et Matériaux du Mans, UMR CNRS 6283, Université du Maine, Av. O. Messiaen, 72085 Le Mans cedex 09 (France); Laboratoire de Chimie Inorganique, Université de Sfax, Faculté des Sciences de Sfax, BP 1171, 3000 Sfax (Tunisia); Boulard, B., E-mail: brigitte.boulard@univ-lemans.fr [Institut des Molécules et Matériaux du Mans, UMR CNRS 6283, Université du Maine, Av. O. Messiaen, 72085 Le Mans cedex 09 (France); Dieudonné, B. [Institut des Molécules et Matériaux du Mans, UMR CNRS 6283, Université du Maine, Av. O. Messiaen, 72085 Le Mans cedex 09 (France); Ferrari, M. [Institute of Photonics and Nanotechnology (CNR), CSMFO Lab., Via alla Cascata 56/C Povo, 38123 Trento (Italy); Dammak, M. [Laboratoire de Physique Appliquée, Groupe des Matériaux Luminescents, Université de Sfax, Faculté des Sciences de Sfax, BP 1171, 3000 Sfax (Tunisia); Dammak, M. [Laboratoire de Chimie Inorganique, Université de Sfax, Faculté des Sciences de Sfax, BP 1171, 3000 Sfax (Tunisia)

    2015-05-15

    Fluorozirconate ZBLA glasses with molar composition 57ZrF{sub 4}–34BaF{sub 2}–5LaF{sub 3}–4AlF{sub 3}–0.5PrF{sub 3}–xYbF{sub 3} (from x=0 to 10) were synthesized to evaluate the rate of the conversion of visible photons into infrared photons. The emission spectra in the near infrared (NIR) at 950–1100 nm and the luminescence decays in the visible and NIR indicate an energy transfer from Pr{sup 3+} to Yb{sup 3+} upon blue excitation of Pr{sup 3+} at 440 nm. The energy transfer efficiency increases with Yb{sup 3+} concentration to reach 86% with 0.5Pr{sup 3+}–10Yb{sup 3+} co-doping (in mol%). However, the quenching of the Yb{sup 3+} emission strongly reduces the efficiency of the downconversion process: the decay time values decrease from 600 µs (x=0.5 mol%) to 85 µs (x=10 mol%). - Highlights: • We synthesized 0.5Pr{sup 3+}–xYb{sup 3+} co-doped ZBLA glasses (from x=0 to 10 mol %). • Photoluminescence of Yb{sup 3+} was observed at 980 nm under blue excitation. • Time resolved measurements have been performed in the visible and near infrared. • Energy transfer efficiency from Pr{sup 3+} to Yb{sup 3+} reaches 86% in 0.5 Pr{sup 3+}–10Yb{sup 3+} glass.

  5. Entwicklungsperspektiven von Social Software und dem Web 2.0

    Science.gov (United States)

    Raabe, Alexander

    Der Artikel beschäftigt sich zunächst mit dem derzeitigen und zukünftigen Einsatz von Social Software in Unternehmen. Nach dem großen Erfolg von Social Software im Web beginnen viele Unternehmen eigene Social Software-Initiativen zu entwickeln. Der Artikel zeigt die derzeit wahrgenommenen Einsatzmöglichkeiten von Social Software im Unternehmen auf, erörtert Erfolgsfaktoren für die Einführung und präsentiert mögliche Wege für die Zukunft. Nach der Diskussion des Spezialfalles Social Software in Unternehmen werden anschließend die globalen Trends und Zukunftsperspektiven des Web 2.0 in ihren technischen, wirtschaftlichen und sozialen Dimensionen dargestellt. Wie aus den besprochenen Haupttrends hervorgeht, wird die Masse an digital im Web verfügbaren Informationen stetig weiterwachsen. So stellt sich die Frage, wie es in Zukunft möglich sein wird, die Qualität der Informationssuche und der Wissensgenerierung zu verbessern. Mit dem Einsatz von semantischen Technologien im Web wird hier eine revolutionäre Möglichkeit geboten, Informationen zu filtern und intelligente, gewissermaßen verstehende" Anwendungen zu entwerfen. Auf dem Weg zu einem intelligenten Web werden sich das Semantic Web und Social Software annähern: Anwendungen wie Semantic Wikis, Semantic Weblogs, lightweight Semantic Web-Sprachen wie Microformats oder auch kommerzielle Angebote wie Freebase von Metaweb werden die ersten Vorzeichen einer dritten Generation des Webs sein.

  6. Acquired von Willebrand syndrome: A rare disorder of heterogeneous etiology

    Directory of Open Access Journals (Sweden)

    P Kasatkar

    2013-01-01

    Full Text Available Context: Acquired von Willebrand syndrome (AVWS is a rare bleeding disorder that mimics the inherited form of von Willebrand disease (VWD in terms of laboratory findings and clinical presentation. Aims: To study the etiology of acquired VWD. Settings and Design: The patients referred from various hospitals in and out of Mumbai were included in the study. Materials and Methods: Six patients with AVWS diagnosed at this center over the last 10 years were analyzed against 171 patients with inherited VWD. The differential diagnosis of AVWS was made based on reduced levels of von Willebrand antigen and von Willebrand ristocetin cofactor, decrease in ristocetin induced platelet aggregation, absence of correction in mixing studies with no prior history of bleeding problems and a negative family history for bleeding disorders. Results: In three patients, the disease was associated with systematic lupus erythematosus, out of which one was also associated with Kikuchi lymphadenitis and second with autoimmune hemolytic anemia. Fourth case was associated with hypothyroidism and fifth was a case of dermatitis and vitiligo. The last patient was a case of hemophilia A with Burkitts lymphoma, who developed autoantibodies to von Willebrand factor. Except two patients, all other patients responded to immune suppressive therapy with corticosteroids, while the patient with hypothyroidism responded to oral thyroxine. Conclusion: AVWS is a rare condition and may often be missed or diagnosed as inherited disease associated with heterogeneous disease conditions.

  7. Thermodynamic modeling of the Eu–Te and Te–Yb systems

    Energy Technology Data Exchange (ETDEWEB)

    Ghamri, H., E-mail: ghamri.houda@hotmail.fr; Djaballah, Y.; Belgacem-Bouzida, A.

    2015-09-15

    Highlights: • The Eu–Te and Te–Yb binary systems were not previously thermodynamically assessed. • The Eu–Te and Te–Yb systems were assessed by using the CALPHAD technique. • A coherent set of thermodynamic parameters was obtained for both systems. • An agreement between the calculated results and experimental data was obtained for both systems. - Abstract: In this work, thermodynamic assessments of the Eu–Te and Te–Yb binary systems were carried out by using the CALculation of PHase Diagrams (CALPHAD) method based on the available experimental data including thermodynamic properties and phase equilibria. Reasonable models were constructed for all the phases of the two systems. The liquid phases were described by the substitutional solution model with the Redlich–Kister polynomial. The three intermetallic compounds, Eu{sub 4}Te{sub 7}, Eu{sub 3}Te{sub 7} and TeYb in the two systems, were treated as stoichiometric phases, while the non-stoichiometric phase (EuTe), which has an homogeneity range, was treated by a two-sublattice model following the schema: (Eu,Te){sub 0.5}(Te){sub 0.5}. A consistent set of thermodynamic parameters leading to reasonable agreement between the calculated results and experimental data was obtained.

  8. YellowupconversionluminescenceinHo3+/Yb3+co-dopedGd2Mo3O9phosphor

    Institute of Scientific and Technical Information of China (English)

    孙家跃; 薛兵; 孙广超; 崔殿鹏

    2013-01-01

    The strong yellow upconversion (UC) light emission was observed in Ho3+/Yb3+co-doped Gd2Mo3O9 phosphor under the excitation of 980 nm diode laser. The phosphors were synthesized by the traditional solid-state reaction method. The structures of the samples were characterized by X-ray diffraction (XRD). Under 980 nm excitation, Ho3+/Yb3+co-doped Gd2Mo3O9 exhibited strong yellow UC emission based on the green emission near 541 nm generated by 5F4,5S2→5I8 transition and the strong red emission around 660 nm generated by 5F5→5I8 transition, which assigned to the intra-4f transitions of Ho3+ions. The doping concentrations of Ho3+and Yb3+were determined to be 0.01 mol Ho3+and 0.2 mol Yb3+for the strongest yellow emission. Then the dependence of UC emis-sion intensity on excitation power density showed that the green and red UC emissions were involved in two-photon process. The possible UC mechanisms for the strong yellow emission were also investigated. The result indicated that this material was a promis-ing candidate for the application in the yellow display field.

  9. Near-infrared quantum cutting in Yb3+ ion doped strontium vanadate

    Science.gov (United States)

    Sawala, N. S.; Bajaj, N. S.; Omanwar, S. K.

    2016-05-01

    The materials Sr3-x(VO4)2:xYb were successfully synthesized by co-precipitation method varying the concentration of Yb3+ ions from 0 to 0.06 mol. It was characterize by powder X-ray powder diffraction (XRD) and surface morphology was studied by scanning electronic microscope (SEM). The photoluminescence (PL) properties were studied by spectrophotometers in near infra red (NIR) and ultra violet visible (UV-VIS) region. The Yb3+ ion doped tristrontium vanadate (Sr3(VO4)2) phosphors that can convert a photon of UV region (349 nm) into photons of NIR region (978, 996 and 1026 nm). Hence this phosphor could be used as a quantum cutting (QC) luminescent convertor in front of crystalline silicon solar cell (c-Si) panels to reduce thermalization loss due to spectral mismatch of the solar cells. The theoretical value of quantum efficiency (QE) was calculated from steady time decay measurement and the maximum efficiency approached up to 144.43%. The Sr(3-x) (VO4)2:xYb can be potentiality used for betterment of photovoltaic (PV) technology.

  10. Layered Yb:YAG ceramics produced by two different methods: processing, characterization, and comparison

    Science.gov (United States)

    Hostaša, Jan; Biasini, Valentina; Piancastelli, Andreana; Vannini, Matteo; Toci, Guido

    2016-08-01

    Yb:YAG ceramic solid-state laser gain media have been of growing interest for high-repetition rate and high-power lasers during the last few years. A great advantage of ceramic technology compared with that of single crystals is the flexibility of shaping methods allowing the production of near-net-shape components with a well-defined internal structure. A favorable dopant distribution can enhance laser efficiency by mitigating thermal effects. The presented work reports on Yb:YAG transparent ceramics composed of layers with different Yb doping produced by two different shaping methods: dry pressing of spray-dried powders and tape casting, all sintered under high vacuum. The selected geometry of materials was based on numerical simulations. Optical quality of produced ceramics was characterized and discussed in connection with the microstructure and laser emission results. Output power of nearly 7 W and slope efficiency of 58.1% were obtained in quasi-continuous wave regime from bilayered 0% to 10% Yb:YAG. In the case of multilayered materials, higher scattering losses were observed. The comparison of the two processing methods highlighted that the tape-cast materials provided higher optical uniformity and the diffusion zone between the single layers with different dopant content was about 150 μm compared to about 250 μm in samples produced by pressing of powders.

  11. Nanocrystal formation and photoluminescence in the Yb3+/Er3+ codoped phosphosilicate glasses

    DEFF Research Database (Denmark)

    Liu, S.J.; Fu, G.Z.; Shan, Z.T.

    2014-01-01

    In the paper we show that the Yb3+/Er3+ codoped transparent nanocrystal containing phosphosilicate glasses can be obtained by the melt-quenching devitrification approach. We find that the type of alkali oxides has a strong impact on the crystallization in phosphosilicate melts during cooling. The...

  12. Novel rib structures in Yb-doped KY(WO4)2 for laser applications

    NARCIS (Netherlands)

    Gardillou, F.; Borca, C.N.; Romanyuk, Y.E.; Hibert, C.; Salathé, R.P.; Pollnau, Markus

    2006-01-01

    We report for the first time, on the fabrication of flexible refractive-index-contrast rib waveguides based on Yb-doped $KY(WO_4)_2$ epilayers. These results pave the way for integrated optical circuits in this promising material.

  13. Yb-doped Gd2O2CO3: Structure, microstructure, thermal and magnetic behaviour

    Science.gov (United States)

    Artini, Cristina; Locardi, Federico; Pani, Marcella; Nelli, Ilaria; Caglieris, Federico; Masini, Roberto; Plaisier, Jasper Rikkert; Costa, Giorgio Andrea

    2017-04-01

    Structural and microstructural features, as well as thermal and magnetic properties of Yb-doped Gd2O2CO3, were investigated with the aim to clarify the location and the oxidation state of Yb within the structure, and its role in driving the extent of the (Gd1-xYbx)2O2CO3 solid solution. Yb is found in the 3+ oxidation state and it enters the structure only at the rare earth atomic site; the solubility limit results to be located in the close vicinity of x=0.25, and thermal analyses reveal a linear decrease of the decomposition temperature with increasing the Yb amount, in agreement with literature data. The structural analysis allows to exclude long-range clusterization of Yb and Gd, since both rare earths randomly distribute over the 4f atomic position, but relying on the results of the microstructural analysis, the presence of compositional inhomogenities at the local scale cannot be excluded. Not all the structural forms are documented for the pure rare earth dioxycarbonates [1]; in particular, while form I exists for each lanthanide ion, form II is stable only for the largest ones (from La to Dy); moreover, even if II-Ho2O2CO3 (rHo3+ CN8=1.015 Å [6]) is not reported to be stable, the existence of II-Y2O2CO3 (rY3+ CN8=1.019 Å [6]) has been claimed [7]. Based on the described evidence, the stability of hexagonal Yb-doped Gd2O2CO3 is not expected along the whole compositional range. As a general remark, not all the rare earth mixed dioxycarbonates exist: (Ce, Gd)2O2CO3, for instance, could not be obtained at any composition [8]; moreover, all the structural forms can be observed only in some mixed systems, such as for example (Gd, Nd)2O2CO3, by varying temperature and tuning the composition [9]. Rare earth dioxycarbonates are studied mainly for their CO2 sensing properties [10,11], and for their emission when properly doped with a luminescent lanthanide ion [12-17]. Recently, a study of this research group [18] revealed in Gd2O2CO3:4% Yb a phenomenon of

  14. Dimensional evolution of spin correlations in the magnetic pyrochlore Yb2Ti2O7

    DEFF Research Database (Denmark)

    Ross, K.A.; Yaraskavitch, L.R.; Laver, Mark

    2011-01-01

    The pyrochlore material Yb2Ti2O7 displays unexpected quasi-two-dimensional (2D) magnetic correlations within a cubic lattice environment at low temperatures, before entering an exotic disordered ground state below T=265 mK. We report neutron scattering measurements of the thermal evolution of the 2...

  15. Large magnetocaloric effect and adiabatic demagnetization refrigeration with YbPt2Sn.

    Science.gov (United States)

    Jang, Dongjin; Gruner, Thomas; Steppke, Alexander; Mitsumoto, Keisuke; Geibel, Christoph; Brando, Manuel

    2015-10-23

    Adiabatic demagnetization is currently gaining strong interest in searching for alternatives to (3)He-based refrigeration techniques for achieving temperatures below 2 K. The main reasons for that are the recent shortage and high price of the rare helium isotope (3)He. Here we report the discovery of a large magnetocaloric effect in the intermetallic compound YbPt2Sn, which allows adiabatic demagnetization cooling from 2 K down to 0.2 K. We demonstrate this with a home-made refrigerator. Other materials, for example, paramagnetic salts, are commonly used for the same purpose but none of them is metallic, a severe limitation for low-temperature applications. YbPt2Sn is a good metal with an extremely rare weak magnetic coupling between the Yb atoms, which prevents them from ordering above 0.25 K, leaving enough entropy free for use in adiabatic demagnetization cooling. The large volumetric entropy capacity of YbPt2Sn guarantees also a good cooling power.

  16. Er3+/Yb3+ Codoped Phosphate Glass for Ion-Exchanged Planar Waveguide Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Shilong Zhao; Baoyu Chen; Zhuping Liu; Lili Hu

    2003-01-01

    A novel Er3+/Yb3+ codoped phosphate glass was developed, which exhibited good chemical durability in molten salts and excellent spectroscopic properties. Preliminary results of ion exchange at different time and temperature, and with varying melt concentrations indicated that WM4 glass was suitable for ion-exchange experiments and there was no deterioration of surface quality.

  17. Er~(3+)/Yb~(3+) Codoped Phosphate Glass for Ion-Exchanged Planar Waveguide Amplifiers

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel Er3+/Yb3+ codoped phosphate glass was developed, which exhibited good chemical durability in molten salts and excellent spectroscopic properties. Preliminary results of ion exchange at different time and temperature, and with varying melt concentrations indicated that WM4 glass was suitable for ion-exchange experiments and there was no deterioration of surface quality.

  18. Blue cooperative emission in Yb3+ - doped GeO2 - PbO glasses

    Directory of Open Access Journals (Sweden)

    Vanessa Duarte Del Cacho

    2006-03-01

    Full Text Available Investigation of the blue cooperative luminescence in a binary composition of GeO2-PbO glasses with different Yb3+ concentrations is reported. High refractive index (1.96 and large transmission window (0.4 up to 5.0 µm are characteristics of this vitreous system. Luminescence and lifetime measurements in the visible and near infrared regions were performed to investigate the spectroscopic characteristics of the glasses. Visible emission around 507 nm was detected in all samples. The visible emission intensity increases with the Yb2O3 content at least up to 2.0 wt. (%, that represents the maximum Yb2O3 concentration possible for this glass system. The visible lifetimes are about half of their respective near infrared ones, and the blue luminescence comes from a cooperative process. A rate equation was used to describe the behavior of the cooperative emission intensity as a function of Yb2O3 concentration; a good agreement with the calculated and measured cooperative luminescence was achieved.

  19. 30W, 1178nm Yb-doped photonic bandgap fiber amplifier

    DEFF Research Database (Denmark)

    Shirakawa, Akira; Maruyama, Hiroki; Ueda, Ken-ichi

    2009-01-01

    High-power, high-efficiency ytterbium-doped solid-core photonic-bandgap fiber amplification at the long-wavelength edge of the Yb gain band is reported. Amplified-spontaneous-emission-free, 30W nonpolarized and 25W linearly-polarized 1178nm outputs have been achieved with

  20. Ytterbium can relax slowly too: a field-induced Yb2 single-molecule magnet.

    Science.gov (United States)

    Lin, Po-Heng; Sun, Wen-Bin; Tian, Yong-Mei; Yan, Peng-Fei; Ungur, Liviu; Chibotaru, Liviu F; Murugesu, Muralee

    2012-10-28

    An unusual dinuclear Yb(2) complex isolated using a mixed ligand strategy leads to field-induced SMM behaviour. Low magnetic axiality and a large tunnelling gap lead to significant quantum tunnelling of the magnetisation, which was reduced under an applied static optimum field of 1600 Oe.