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Sample records for b2 b3 approximation

  1. Quantising the B=2 and B=3 Skyrmion systems

    International Nuclear Information System (INIS)

    We examine the quantisation of a collective Hamiltonian for the two-baryon system derived by us in a previous paper. We show that by increasing the sophistication of the approximations we can obtain a bound state - or a resonance - not too far removed from the threshold with the quantum numbers of the deuteron. The energy of this state is shown to depend very sensitively on the parameters of the model. Subsequently we construct part of a collective Hamiltonian for the three-baryon system. Large-amplitude quantum fluctuations play an important role in the intrinsic wave function of the ground state, changing its symmetry from tetrahedral to cubic. Apart from the tetrahedron describing the minimum of the potential, we identify a ''doughnut'' and a ''pretzel'' as the most important saddle points in the potential energy surface. We show that it is likely that inclusion of fluctuations through these saddle points leads to an energy close to the triton's value. (orig.)

  2. Short syntheses of enantiopure calystegine B-2, B-3, and B-4

    DEFF Research Database (Denmark)

    Skaanderup, Philip Robert; Madsen, Robert

    2001-01-01

    Calystegine B-2 B-3, and B-4 have been prepared in 5 steps from the benzyl protected methyl 6-iodoglycopyranosides of glucose, galactose and mannose, respectively, by using a zinc-mediated domino reaction followed by ring-closing olefin metathesis as the key steps.......Calystegine B-2 B-3, and B-4 have been prepared in 5 steps from the benzyl protected methyl 6-iodoglycopyranosides of glucose, galactose and mannose, respectively, by using a zinc-mediated domino reaction followed by ring-closing olefin metathesis as the key steps....

  3. Neuregulin-1-mediated ErbB2-ErbB3 signalling protects human trophoblasts against apoptosis to preserve differentiation.

    Science.gov (United States)

    Fock, Valerie; Plessl, Kerstin; Draxler, Peter; Otti, Gerlinde Regina; Fiala, Christian; Knöfler, Martin; Pollheimer, Jürgen

    2015-12-01

    During placentation, foetal trophoblasts invade deeply into maternal tissue to establish a foeto-maternal circulation. We have previously shown that extravillous trophoblast (EVT) lineage cells express ErbB2 and ErbB3, of which the potential as an oncogenic unit is well established. However, a physiological function of this receptor combination in humans remains a puzzling question. Here, we demonstrate neuregulin 1 (NRG1) expression and secretion by human decidual stromal cells. Stimulation of human primary trophoblasts with exogenous NRG1 induced phosphorylation of ErbB2, ErbB3 and related downstream effectors. Co-immunoprecipitation experiments confirmed the formation of ErbB2-ErbB3 dimers upon ligand engagement. Along this line, receptor knockdown and ErbB3 neutralization strongly diminished NRG1-dependent activation of the signalling complex. Functional studies revealed that NRG1 promotes EVT formation in placental explant cultures. Although, in the presence of NRG1, basal and camptothecin-induced trophoblast apoptosis was significantly repressed, this effect was abolished upon ErbB3 inhibition. Notably, camptothecin provoked a strong reduction of trophoblast cell column size, whereas NRG1-treated explants were refractory to the compound. Taken together, our findings newly identify a physiological function of the NRG1-ErbB2-ErbB3 axis in trophoblast survival during human placental development. PMID:26490994

  4. Bridging η2 -BO in B2(BO)3(-) and B3(BO)3(-) clusters: boronyl analogs of boranes.

    Science.gov (United States)

    Zhai, Hua-Jin; Guo, Jin-Chang; Li, Si-Dian; Wang, Lai-Sheng

    2011-10-01

    Anion photoelectron spectroscopy and theoretical calculations are combined to probe the structures and chemical bonding of two boron-rich oxide clusters, B(5)O(3)(-) and B(6)O(3)(-), which are shown to be appropriately formulated as B(2)(BO)(3)(-) and B(3)(BO)(3)(-), respectively. The anion clusters are found to each possess a bridging η(2)-BO group, as well as two terminal BO groups and are analogs of B(2)H(3)(-) and B(3)H(3)(-). This finding advances the boronyl chemistry and helps establish the isolobal analogy between boron-rich oxide clusters and boranes. PMID:21954002

  5. Volatile magnesium octahydrotriborate complexes as potential CVD precursors to MgB2. Synthesis and characterization of Mg(B3H8)2 and its etherates.

    Science.gov (United States)

    Kim, Do Young; Yang, Yu; Abelson, John R; Girolami, Gregory S

    2007-10-29

    The solid-state reaction of MgBr2 and NaB3H8 at 20 degrees C, followed by sublimation at 80 degrees C and 0.05 Torr, affords Mg(B3H8)2 as a white solid. Similar reactions with MgBr2(Et2O) and MgBr2(Me2O)1.5 afford the crystalline ether adducts Mg(B3H8)2(Et2O)2 and Mg(B3H8)2(Me2O)2, respectively. In contrast, reactions of MgBr2 with NaB3H8, the presence of excess solvent result in the formation of nonvolatile, probably ionic, magnesium compounds of the type [MgLx][B3H8]2. The adducts Mg(B3H8)2(Et2O)2 and Mg(B3H8)2(Me2O)2 are the first crystallographically characterized magnesium complexes of the B3H8- ligand; in both structures, the magnesium center adopts a distorted cis-octahedral geometry with two bidentate B3H8 groups and two Et2O ligands. Owing to their volatility, Mg(B3H8)2(Et2O)2 and Mg(B3H8)2(Me2O)2 are potential precursors for the deposition of MgB2 thin films, although preliminary efforts to employ them as chemical vapor deposition sources produce boron-rich MgBx films instead, with x approximately 7. Finally, the synthesis and structure of Cp2Mg(thf) are described: this mono-thf adduct of Cp2Mg bears two eta5-Cp groups, unlike other Lewis base adducts of Cp2Mg, which contain one eta5-Cp group and one eta1- or eta2-Cp group.

  6. Fracturas del cuello quirúrgico del húmero (B2-B3). Tratamiento quirúrgico.

    OpenAIRE

    Arenas Planelles, Antonio; D'Arrigo, A.; Arenas Miquélez, A.; Garbayo Marturet, Antonio Jesús

    2013-01-01

    Se presentan 36 casos de fractura de húmero proximal tipos B2 y B3 tratados quirúrgicamente mediante osteosíntesis con clavo proximal (4 casos) o placa bloqueada (29 casos) o utilizando una hemiartroplastia de hombro (3 casos). Los resultados fueron buenos en la mayor parte de los pacientes, con un dolor medio de 11,97/15 en la cotación cifrada de Constant, una fuerza de 13,42/25 puntos y una movilidad de 24,33/40 puntos. Las complicaciones más importantes fueron el conflicto subacromial (10 ...

  7. Neuregulin-1-mediated ErbB2–ErbB3 signalling protects human trophoblasts against apoptosis to preserve differentiation

    Science.gov (United States)

    Fock, Valerie; Plessl, Kerstin; Draxler, Peter; Otti, Gerlinde Regina; Fiala, Christian; Knöfler, Martin; Pollheimer, Jürgen

    2015-01-01

    ABSTRACT During placentation, foetal trophoblasts invade deeply into maternal tissue to establish a foeto–maternal circulation. We have previously shown that extravillous trophoblast (EVT) lineage cells express ErbB2 and ErbB3, of which the potential as an oncogenic unit is well established. However, a physiological function of this receptor combination in humans remains a puzzling question. Here, we demonstrate neuregulin 1 (NRG1) expression and secretion by human decidual stromal cells. Stimulation of human primary trophoblasts with exogenous NRG1 induced phosphorylation of ErbB2, ErbB3 and related downstream effectors. Co-immunoprecipitation experiments confirmed the formation of ErbB2–ErbB3 dimers upon ligand engagement. Along this line, receptor knockdown and ErbB3 neutralization strongly diminished NRG1-dependent activation of the signalling complex. Functional studies revealed that NRG1 promotes EVT formation in placental explant cultures. Although, in the presence of NRG1, basal and camptothecin-induced trophoblast apoptosis was significantly repressed, this effect was abolished upon ErbB3 inhibition. Notably, camptothecin provoked a strong reduction of trophoblast cell column size, whereas NRG1-treated explants were refractory to the compound. Taken together, our findings newly identify a physiological function of the NRG1–ErbB2–ErbB3 axis in trophoblast survival during human placental development. PMID:26490994

  8. Simulation of homology models for the extracellular domains (ECD) of ErbB3, ErbB4 and the ErbB2-ErbB3 complex in their active conformations.

    Science.gov (United States)

    Franco-Gonzalez, Juan Felipe; Ramos, Javier; Cruz, Victor L; Martínez-Salazar, Javier

    2013-02-01

    Epidermal growth factor receptors (EGFR) are associated with a number of biological processes and are becoming increasingly recognized as important therapeutic targets against cancer. In this work, we provide models based on homology for the extracellular domains (ECD) of ErbB3 and ErbB4 in their active conformations, including a Heregulin ligand, followed by further refinement of the models by molecular dynamics simulations at atomistic scale. We compare the results with a model built for ErbB2 based on crystallographic information and analyze the common features observed among members of the family, namely, the periscope movement of the dimerization arm and the hinge displacement of domain IV. Finally, we refine a model for the interaction of the ECDs corresponding to a ErbB2-ErbB3 heterodimer, which is widely recognized to have a high impact in cancer development.

  9. The Wyckoff positional order and polyhedral intergrowth in the M3B2- and M5B3-type boride precipitated in the Ni-based superalloys

    Science.gov (United States)

    Hu, X. B.; Zhu, Y. L.; Sheng, N. C.; Ma, X. L.

    2014-12-01

    Ni-based single superalloys play a crucial role in the hottest parts of jet engines. However, due to the complex geometry and macro-segregation during the solidification process, the cast defect such as stray grains is inevitable. Therefore, the transient liquid phase (TLP) bonding which can join several small single crystalline castings together is gradually believed to be an effective method for improving the yields of production of the complex components. The melting point depressant element B is always added into the interlayer filler material. Consequently, borides including the M3B2 and M5B3 phase usually precipitate during the TLP bonding process. So a comprehensive knowledge of the fine structural characteristics of the borides is very critical for an accurate evaluation of the TLP bonding process. In this work, by means of the aberration-corrected transmission electron microscopy, we show, at an atomic scale, the Wyckoff positional order phenomenon of the metal atoms in the unit cell of M3B2- and M5B3-type boride. Meanwhile, the defect along the (001) plane of the above two types of boride are determined to be the polyhedral intergrowth with complex configurations.

  10. Simultaneous determination of fumonisins B1, B2 and B3 contaminants in maize by ultra high-performance liquid chromatography tandem mass spectrometry

    International Nuclear Information System (INIS)

    The present work developed an analytical method for simultaneous determination of fumonisins B1, B2 and B3 residues in maize by ultra high-performance liquid chromatography combined with electrospray ionization triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) under the multiple reaction monitoring (MRM) mode, and especially focused on the optimization of extraction, clean-up, UHPLC separation and MS/MS parameters. The method involves addition of fumonisins isotope internal standards, extraction with a mixture of acetonitrile and water and clean-up with solid-phase extraction (SPE) cartridges before UHPLC-MS/MS analysis. A single-laboratory method validation was conducted by testing three different spiking levels for repeatability and recovery according to International Union of Pure and Applied Chemistry (IUPAC) guidelines. The LOQ of FB1, FB2 and FB3 were 1.50, 1.65 and 0.4 μg kg-1, respectively, which were lower than the criteria of EU, USA and other countries regarding minimum residue limits of fumonisins in foods including baby foods and feedstuffs. Recoveries of three fumonisins ranged from 80.9% to 97.0% with RSD values of 2.4-11.1%.The advantages of this method include simple pretreatment, rapid determination and high sensitivity, and it fulfills the requirements for food analysis with respect to minimum residue limits of fumonisins in various countries.

  11. Synthesis, characterization, thermal and antimicrobial studies of diabetic drug models: Complexes of vanadyl(II) sulfate with ascorbic acid (vitamin C), riboflavin (vitamin B2) and nicotinamide (vitamin B3)

    Science.gov (United States)

    Refat, Moamen S.

    2010-04-01

    The oxovanadium(II) complexes of the different vitamins like ascorbic acid (vitamin C; Vit. C), riboflavin (vitamin B2; Vit. B2) and nicotinamide (vitamin B3; Vit. B3) were synthesized and characterized by elemental analysis, molar conductance, IR, electronic, magnetic measurements, thermal studies, XRD and SEM. Conductance measurements indicated that the vanadyl(II) complexes of Vit. B2 and Vit. B3 are 1:2 electrolytes except for [VO(Vit. C) 2(H 2O) 2] complex is non-electrolyte. IR data show that Vit. B2 is bidentate ligand against azomethine nitrogen of pyrazine ring and C dbnd O of pyrimidine-2,4-dione but Vit. B3 and Vit. C acts as a monodentate ligand through pyridine nitrogen and hydroxo oxygen of furan ring, respectively. Electronic spectral measurements indicated that all VO(II) complexes have a square-pyramidal geometry. Magnetic measurements for the new vanadyl(II) complexes are in a good agreement with the proposed formula. Thermal analyses (TG/DSC) of the studied complexes show that the decomposition process takes place in more than two steps. XRD refer that VO(II) complexes have an amorphous behavior. The surface morphology of the complexes was studied by SEM. The antimicrobial activities of the ligands and its complexes indicate that the vanadyl(II) complexes possess high antibacterial and antifungal activities towards the bacterial species and the fungal species than start ligands.

  12. High-pressure synthesis, long-term stability of single crystals of diboron trioxide, B2O3, and an empirical electronic polarizability of [3]B3+

    Science.gov (United States)

    Burianek, Manfred; Birkenstock, Johannes; Mair, Philipp; Kahlenberg, Volker; Medenbach, Olaf; Shannon, Robert D.; Fischer, Reinhard X.

    2016-07-01

    Single crystals of B2O3 are needed for the precise determination of the refractive indices used to calculate the electronic polarizability α of 3-coordinated boron. The α(B) values in turn are used to predict mean refractive indices of borate minerals. Since the contribution of boron to the total polarizability of a mineral is very low, the synthetic compound B2O3 represents an ideal model system because of its high molar content of boron. Millimeter-sized crystals were synthesized at 1 GPa in a piston-cylinder apparatus. The samples were heated above the liquidus (800 °C), subsequently cooled at 15 °C/h to 500 °C and finally quenched. The refractive indices were determined by the immersion method using a microrefractometer spindle stage. The refractive indices n o = 1.653 (3) and n e = 1.632 (3) correspond to a total polarizability for B2O3 of α = 4.877 Å3. These values were used to determine the electronic polarizability of boron of α(B) = 0.16 Å3. Although the surface of the B2O3 crystals was coated with a hydrous film immediately after being exposed to air, its bulk crystallinity is retained for a period of at least 2 months.

  13. Fate of the fusarium mycotoxins fumonisins B1, B2 and B3, deoxynivalenol and zearalenone in maize flour and maize grits during extrusion cooking.

    OpenAIRE

    Scudamore, Keith; Guy, Robin C, E; Kelleher, Brian; MacDonald, Susan

    2008-01-01

    Abstract Extrusion technology is used widely to manufacture a range of breakfast cereals and snacks for human consumption and animal feeds. Deoxynivalenol (DON) and zearalenone (ZON) in cereals and cereal products and fumonisins B1 and B2 (FB1 and FB2) in maize are controlled in the European Community by legislation with the objective of minimising consumer exposure to these mycotoxins. Relatively few studies have examined the losses of fusarium mycotoxins during processing. The be...

  14. Simultaneous Determination of Total Vitamins B1, B2, B3, and B6 in Infant Formula and Related Nutritionals by Enzymatic Digestion and LC-MS/MS: Single-Laboratory Validation, First Action 2015.14.

    Science.gov (United States)

    Salvati, Louis M; McClure, Sean C; Reddy, Todime M; Cellar, Nicholas A

    2016-05-01

    This method provides simultaneous determination of total vitamins B1, B2, B3, and B6 in infant formula and related nutritionals (adult and infant). The method was given First Action for vitamins B1, B2, and B6, but not B3, during the AOAC Annual Meeting in September 2015. The method uses acid phosphatase to dephosphorylate the phosphorylated vitamin forms. It then measures thiamine (vitamin B1); riboflavin (vitamin B2); nicotinamide and nicotinic acid (vitamin B3); and pyridoxine, pyridoxal, and pyridoxamine (vitamin B6) from digested sample extract by liquid chromatography-tandem mass spectrometry. A single-laboratory validation was performed on 14 matrixes provided by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) to demonstrate method effectiveness. The method met requirements of the AOAC SPIFAN Standard Method Performance Requirement for each of the three vitamins, including average over-spike recovery of 99.6 ± 3.5%, average repeatability of 1.5 ± 0.8% relative standard deviation, and average intermediate precision of 3.9 ± 1.3% relative standard deviation. PMID:27297842

  15. HPLC Analysis of Water-Soluble Vitamins (B2, B3, B6, B12, and C and Fat-Soluble Vitamins (E, K, D, A, and β-Carotene of Okra (Abelmoschus esculentus

    Directory of Open Access Journals (Sweden)

    Rokayya Sami

    2014-01-01

    Full Text Available Okra is consumed as a vegetable by populations in Africa and Asia and particularly in Egypt. In this study, we investigated some nutritional components of okra grown in four different geographical locations of Egypt. A comparative analysis of water-soluble vitamins (B2, B3, B6, B12, and C and fat-soluble vitamins (E, K, D, A, and β-carotene in okra pods was carried out. Results of principal component analysis (PCA showed three clusters of varieties. The first cluster included the Dakahlia (D and Kafr El-Sheikh (K varieties. The second and the third clusters separated out the Suez (S and Mansoura (M varieties independently. The S pod showed the highest contents of vitamins B6 (49.81 μg/100 g and E (1.47 mg/100 g but contained the lowest contents of vitamins B3 (1.42 μg/100 g and B12 (undetected. The K pod showed the lowest vitamin C content (11.60 mg/100 g. The M pod showed the highest contents of vitamins B3 (22.70 μg/100 g, B12 (91.20 μg/100 g, C (27.14 mg/100 g, and K (0.21 mg/100 g. The D pod showed the lowest contents of vitamins E (0.15 mg/100 g, K (0.05 mg/100 g, and B6 (11.50 μg/100 g. These findings could help develop meal planning at the community level by incorporating okra varieties with high vitamin content.

  16. Measurement of the $\\chi_b(3P)$ mass and of the relative rate of $\\chi_{b1}(1P)$ and $\\chi_{b2}(1P)$ production

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; van den Brand, Johannes; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Busetto, Giovanni; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cojocariu, Lucian; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Gavrilov, Gennadii; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Lespinasse, Mickael; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lu, Haiting; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Roa Romero, Diego; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wu, Suzhi; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2014-01-01

    The production of $\\chi_b$ mesons in proton-proton collisions is studied using a data sample collected by the LHCb detector, at centre-of-mass energies of $\\sqrt{s}=7$ and $8$ TeV and corresponding to an integrated luminosity of 3.0 fb$^{-1}$. The $\\chi_b$ mesons are identified through their decays to $\\Upsilon(1S)\\gamma$ and $\\Upsilon(2S)\\gamma$ using photons that converted to $e^+e^-$ pairs in the detector. The $\\chi_b(3P)$ meson mass, and the relative prompt production rate of $\\chi_{b1}(1P)$ and $\\chi_{b2}(1P)$ mesons as a function of the $\\Upsilon(1S)$ transverse momentum in the $\\chi_b$ rapidity range 2.0< $y$<4.5, are measured. Assuming a mass splitting between the $\\chi_{b1}(3P)$ and the $\\chi_{b2}(3P)$ states of 10.5 MeV/$c^2$, the mass of the $\\chi_{b1}(3P)$ meson is \\begin{equation*} m(\\chi_{b1}(3P))= 10515.7^{+2.2}_{-3.9}(stat) ^{+1.5}_{-2.1}(syst) MeV/c^2. \\end{equation*}

  17. Infectious genotype 1a, 1b, 2a, 2b, 3a, 5a, 6a and 7a hepatitis C virus lacking the hypervariable region 1 (HVR1)

    DEFF Research Database (Denmark)

    2014-01-01

    The present inventors used the previously developed H77/JFH 1.sub.T27OOC,A4O8OT (1a/2a), J4/JFH .sub.1T2996C,A4827T,.DELTA.HVRI (1b/2a), J6/JFH .sub.1.DELTA.HVRI (2a/2a), J8/JFH 1.sub..DELTA.HVRI (2b/2a), S52/JFH 1.sub.T27i8G,.tau.7i6oc (3a/2a), SA13/JFH 1.sub.C34O5G,A3696G (5a/2a) and HK6a/JFH 1T.......sub.1389c,A1590G (6a/2a) constructs for the deletion of Hypervariable Region 1 (HVR1) to construct viable, JFH 1 (genotype 2a) based, genomes. The present inventors serially passaged the viruses in cell culture obtaining relatively high HCV RNA titers and infectivity titers. Sequence analysis...

  18. A new sample preparation and separation combination for precise, accurate, rapid, and simultaneous determination of vitamins B1, B2, B3, B5, B6, B7, and B9 in infant formula and related nutritionals by LC-MS/MS.

    Science.gov (United States)

    Cellar, Nicholas A; McClure, Sean C; Salvati, Louis M; Reddy, Todime M

    2016-08-31

    An improved method was developed for simultaneous determination of the fortified forms of thiamine (B1), riboflavin (B2), nicotinamide and nicotinic acid (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), and folic acid (B9) in infant formulas and related nutritionals. The method employed a simple, effective, and rapid sample preparation followed by liquid chromatography tandem mass spectrometry (LC-MS/MS). It improved upon previous methodologies by offering facile and rugged sample preparation with improved chromatographic conditions, which culminated in a highly accurate and precise method for water-soluble vitamin determination in a wide range of formulas. The method was validated over six days in ten unique matrices with two analysts and on instruments in two different labs. Intermediate precision averaged 3.4 ± 2.6% relative standard deviation and over-spike recovery averaged 100.2 ± 2.4% (n = 160). Due to refinements in sample preparation, the method had high sample throughput capacity. PMID:27506358

  19. ErbB3/HER3 intracellular domain is competent to bind ATP and catalyze autophosphorylation

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Fumin; Telesco, Shannon E.; Liu, Yingting; Radhakrishnan, Ravi; Lemmon, Mark A. (UPENN); (UPENN-MED)

    2010-06-21

    ErbB3/HER3 is one of four members of the human epidermal growth factor receptor (EGFR/HER) or ErbB receptor tyrosine kinase family. ErbB3 binds neuregulins via its extracellular region and signals primarily by heterodimerizing with ErbB2/HER2/Neu. A recently appreciated role for ErbB3 in resistance of tumor cells to EGFR/ErbB2-targeted therapeutics has made it a focus of attention. However, efforts to inactivate ErbB3 therapeutically in parallel with other ErbB receptors are challenging because its intracellular kinase domain is thought to be an inactive pseudokinase that lacks several key conserved (and catalytically important) residues - including the catalytic base aspartate. We report here that, despite these sequence alterations, ErbB3 retains sufficient kinase activity to robustly trans-autophosphorylate its intracellular region - although it is substantially less active than EGFR and does not phosphorylate exogenous peptides. The ErbB3 kinase domain binds ATP with a K{sub d} of approximately 1.1 {micro}M. We describe a crystal structure of ErbB3 kinase bound to an ATP analogue, which resembles the inactive EGFR and ErbB4 kinase domains (but with a shortened {alpha}C-helix). Whereas mutations that destabilize this configuration activate EGFR and ErbB4 (and promote EGFR-dependent lung cancers), a similar mutation conversely inactivates ErbB3. Using quantum mechanics/molecular mechanics simulations, we delineate a reaction pathway for ErbB3-catalyzed phosphoryl transfer that does not require the conserved catalytic base and can be catalyzed by the 'inactive-like'configuration observed crystallographically. These findings suggest that ErbB3 kinase activity within receptor dimers may be crucial for signaling and could represent an important therapeutic target.

  20. B2B marketing

    OpenAIRE

    Pospíšilová, Lucie

    2010-01-01

    The main goal of this bachelor thesis is to apply theoretical knowledge in B2B marketing to the example of marketing processes in a particular company, to evaluate the current situation of its activities with regard to B2B principles and to suggest relevant recommendations. The theoretical part focuses on specific characteristics of B2B marketing, describes its differences from marketing on consumer markets, deals with buying behaviour of organizations and specifies particular features of mar...

  1. The Convergence of (i1i),(b2,1k0) and (i1i).(b3,1k0)%(i1i)*(b12k0)及(i1i)*(b31k0)在π*V(1)中的收敛性

    Institute of Scientific and Technical Information of China (English)

    白建侠

    2009-01-01

    对连通有限型谱X,y,存在Adams谱序列{Es,tr,dr},满足(1)dr:Es,t,r→Es+r,t+r-1,r是谱序列的微分, (2)Es,t,2≌Exts,t,A(H*X,H*y),(3)收敛到[∑t-sY,X].当X分别是球谱S,Moore谱M,Toda-smith谱V(1)时,(πt-X)p分别是S,M,V(1)的稳定同伦群.利用Adams 谱序列,证明了(i1i)*(62,1k0)及(i1i)*(b3,1k0)是永久循环但不是边缘,因此收敛到π*V(1)中的非零元,其中P为奇索数,q=2p-2.

  2. Lattice dynamical and thermodynamical properties of ReB2, RuB2, and OsB2 compounds in the ReB2 structure

    Institute of Scientific and Technical Information of China (English)

    E. Deligoz; K. Colakoglu; Y. O. Ciftci

    2012-01-01

    Structural and lattice dynamical properties of ReB2,RuB2,and OsB2 in the ReB2 structure are studied in the framework of density functional theory within the generalized gradient approximation.The present results show that these compounds are dynamically stable for the considered structure.The temperature-dependent behaviors of thermodynamical properties such as internal energy,free energy,entropy,and heat capacity are also preented. The obtained results are in good agreement with the available experimental and theoretical data.

  3. B2(BO)6 0/- and B 2(BS) 6 0/- doubly bridged structures containing BO or BS as ligands.

    Science.gov (United States)

    Li, Da-Zhi; Li, Si-Dian

    2014-09-01

    The investigation on the geometrical and electronic properties of B(2)(BO)(6) (0/-) and B(2)(BS)(6) (0/-) has been performed by density functional theory (DFT) using the B3LYP and BP86 methods. The chemical bonding in B(2)A(6) (A = H, BO, and BS) series is elucidated through the recently developed adaptive natural density partitioning (AdNDP). D(2h) B(2)(BO)(6) and B(2)(BS)(6) were found to possess two bridging η (2)-BO or η (2)-BS groups, as well as four terminal BO or BS groups that are analogs of diborane B(2)H(6). D(2)h B(2)(BO)(6) (-) and B(2)(BS)(6) (-) with two bridging η (2)-BO or η (2)-BS groups which are more stable than their corresponding D(3d) structures. The binding energy of B(2)(BO)(6) and B(2)(BS)(6) with respect to B(2)(BO)(6) (D2h) → 2B(BO)(3) (D(3h)) and B(2)(BS)(6)(D(2h)) → 2B(BS)(3) (D(3h)) are estimated to be (△)E = 19.8 and 40.6 kcal mol(-1) at CCSD(T)//B3LYP level, respectively. This finding advances the boronyl chemistry and helps establish the isolobal analogy between boron-rich oxide clusters and boranes. PMID:25159274

  4. Structural optimization and physical properties of TcB3 and MoB3 at high-pressure: First-principles

    Science.gov (United States)

    Ying, Chun; Bai, Xiaowan; Du, Yungang; Zhao, Erjun; Lin, Lin; Hou, Qingyu

    2016-06-01

    The thermodynamic, mechanical and dynamic properties of TcB3 and MoB3 are systematically investigated at high-pressure by first-principles within density functional theory (DFT). The calculated formation enthalpies are negative for TcB3 with considered structures under the pressure range from 0 to 100 GPa. Triboride hP4-TcB3 (i.e., TcB3 in hP4-OsB3 type structure) has the lowest formation enthalpy of -1.44 eV under ambient condition. The largest shear modulus of 240 GPa and smallest Poisson’s ratio of 0.20 for oP16-TcB3 are comparable to those of 267 GPa and 0.15 for ReB2. The calculated elastic constants show that MB3 (M=Tc and Mo) are mechanically stable at ambient conditions, except for mP8-MoB3. The estimated high hardness of 33.4 and 33.1 GPa for oP16-TcB3 and hP4-TcB3, respectively, are reported for the first time. The calculated lattice parameters for MoB3 are in good agreement with the previously theoretical and experimental studies. Below 13 GPa, hP16-MoB3 and hR24-MoB3 are thermodynamically more favorable than MoB3 in other structures. A pressure-induced phase transition is predicted at 13 GPa from hP16-MoB3 and hR24-MoB3 to hP4-MoB3. Above 13 GPa, hP4-MoB3 becomes the thermodynamically most stable phase among MoB3 in considered structures. All compounds with considered structures are metallic, and the electronic structures of MB3 are governed by a strong hybridization between M-4d and B-2p states. The strong and directional covalent bonding between M-4d and B-2p as well as the strong interlayer interactions of boron layers are correlated to the high hardness of 38.0 and 38.4 GPa for hP16-MoB3 and hR24-MoB3, respectively.

  5. Niacin and niacinamide (Vitamin B3)

    Science.gov (United States)

    Niacin and niacinamide are forms of Vitamin B3. Vitamin B3 is found in many foods including yeast, meat, fish, milk, eggs, green vegetables, beans, and cereal grains. Niacin and niacinamide are also found in many vitamin B complex ...

  6. 7 CFR 15b.3 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Definitions. 15b.3 Section 15b.3 Agriculture Office of... RECEIVING FEDERAL FINANCIAL ASSISTANCE General Provisions § 15b.3 Definitions. As used in this part, the...; epilepsy; muscular dystrophy; multiple sclerosis, cancer; heart disease; diabetes; mental...

  7. Thermal stability of hexagonal OsB2

    Science.gov (United States)

    Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; Cullen, David A.; Andrew Payzant, E.

    2014-11-01

    The synthesis of novel hexagonal ReB2-type OsB2 ceramic powder was performed by high energy ball milling of elemental Os and B powders. Two different sources of B powder have been used for this mechanochemical synthesis. One B powder consisted of a mixture of amorphous and crystalline phases and a mixture of 10B and 11B isotopes with a fine particle size, while another B powder was a purely crystalline (rhombohedral) material consisting of enriched 11B isotope with coarse particle size. The same Os powder was used for the synthesis in both cases. It was established that, in the first case, the hexagonal OsB2 phase was the main product of synthesis with a small quantity of Os2B3 phase present after synthesis as an intermediate product. In the second case, where coarse crystalline 11B powder was used as a raw material, only Os2B3 boride was synthesized mechanochemically. The thermal stability of hexagonal OsB2 powder was studied by heating under argon up to 876 °C and cooling in vacuo down to -225 °C. During the heating, the sacrificial reaction 2OsB2+3O2→2Os+2B2O3 took place due to presence of O2/water vapor molecules in the heating chamber, resulting in the oxidation of B atoms and formation of B2O3 and precipitation of Os metal out of the OsB2 lattice. As a result of such phase changes during heating, the lattice parameters of hexagonal OsB2 changed significantly. The shrinkage of the a lattice parameter was recorded in 276-426 °C temperature range upon heating, which was attributed to the removal of B atoms from the OsB2 lattice due to oxidation followed by the precipitation of Os atoms and formation of Os metal. While significant structural changes occurred upon heating due to presence of O2, the hexagonal OsB2 ceramic demonstrated good phase stability upon cooling in vacuo with linear shrinkage of the lattice parameters and no phase changes detected during cooling.

  8. 15 CFR 8b.3 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Definitions. 8b.3 Section 8b.3... Definitions. As used in this part, the term: (a) The Act means the Rehabilitation Act of 1973, Pub. L. 93-112... hearing impairments, cerebral palsy, epilepsy, muscular dystrophy, multiple sclerosis, cancer,...

  9. The cloning of cyclin B3 and its gene expression during hormonally induced spermatogenesis in the teleost, Anguilla japonica

    International Nuclear Information System (INIS)

    We cloned cyclin B1, B2, and B3 cDNAs from the eel testis. Northern blot analysis indicated that these cyclin B mRNAs were expressed and increased from day 3 onward after the hormonal induction of spermatogenesis, and that cyclin B3 was most dominantly expressed during spermatogenesis. In situ hybridization showed that cyclin B1 and B2 were present from the spermatogonium stage to the spermatocyte stage. On the other hand, cyclin B3 mRNA was present only in spermatogonia. Although mouse cyclin B3 is expressed specifically in the early meiotic prophase, these results indicate that eel cyclin B3 expression is limited during spermatogenesis to spermatogonia, but is not present in spermatocytes. These facts together suggest that eel cyclin B3 is specifically involved in spermatogonial proliferation (mitosis), but not in meiosis

  10. In vivo knockdown of ErbB3 in mice inhibits Schwann cell precursor migration.

    Science.gov (United States)

    Torii, Tomohiro; Miyamoto, Yuki; Takada, Shuji; Tsumura, Hideki; Arai, Miyuki; Nakamura, Kazuaki; Ohbuchi, Katsuya; Yamamoto, Masahiro; Tanoue, Akito; Yamauchi, Junji

    2014-09-26

    The myelin sheath insulates neuronal axons and markedly increases the nerve conduction velocity. In the peripheral nervous system (PNS), Schwann cell precursors migrate along embryonic neuronal axons to their final destinations, where they eventually wrap around individual axons to form the myelin sheath after birth. ErbB2 and ErbB3 tyrosine kinase receptors form a heterodimer and are extensively expressed in Schwann lineage cells. ErbB2/3 is thought to be one of the primary regulators controlling the entire Schwann cell development. ErbB3 is the bona fide Schwann cell receptor for the neuronal ligand neuregulin-1. Although ErbB2/3 is well known to regulate both Schwann cell precursor migration and myelination by Schwann cells in fishes, it still remains unclear whether in mammals, ErbB2/3 actually regulates Schwann cell precursor migration. Here, we show that knockdown of ErbB3 using a Schwann cell-specific promoter in mice causes delayed migration of Schwann cell precursors. In contrast, littermate control mice display normal migration. Similar results are seen in an in vitro migration assay using reaggregated Schwann cell precursors. Also, ErbB3 knockdown in mice reduces myelin thickness in sciatic nerves, consistent with the established role of ErbB3 in myelination. Thus, ErbB3 plays a key role in migration, as well as in myelination, in mouse Schwann lineage cells, presenting a genetically conservative role of ErbB3 in Schwann cell precursor migration. PMID:25204498

  11. A Dual Role of erbB2 in Myelination and in Expansion of the Schwann Cell Precursor Pool

    OpenAIRE

    Garratt, A.N.; Voiculescu, O.; Topilko, P.; Charnay, P; Birchmeier, C.

    2000-01-01

    Neuregulin-1 provides an important axonally derived signal for the survival and growth of developing Schwann cells, which is transmitted by the ErbB2/ErbB3 receptor tyrosine kinases. Null mutations of the neuregulin-1, erbB2, or erbB3 mouse genes cause severe deficits in early Schwann cell development. Here, we employ Cre-loxP technology to introduce erbB2 mutations late in Schwann cell development, using a Krox20-cre allele. Cre-mediated erbB2 ablation occurs perinatally in peripheral nerves...

  12. Marketing Optimization for B2B Market

    OpenAIRE

    Kaynova Tatyana V.

    2012-01-01

    The article presents market definition B2B, the necessity to optimize marketing B2B market, provides a system for B2B-marketing and developed stages of its formation. On this basis it was identified key factors of customer loyalty and are the stages of development of loyalty programs for customers market B2B.

  13. 32 CFR 242b.3 - Notice.

    Science.gov (United States)

    2010-07-01

    ... SCIENCES § 242b.3 Notice. (a) Notice of all meetings of the Board shall be sent by the Secretary to each...-four hours before the meeting, shall be sufficient notice of any meeting. The recital by the Secretary...) Public announcement of meetings shall conform to the Public Meeting Procedures of the Board of...

  14. IAU 2015 Resolution B2 on Recommended Zero Points for the Absolute and Apparent Bolometric Magnitude Scales

    CERN Document Server

    Mamajek, E E; Prsa, A; Harmanec, P; Asplund, M; Bennett, P D; Capitaine, N; Christensen-Dalsgaard, J; Depagne, E; Folkner, W M; Haberreiter, M; Hekker, S; Hilton, J L; Kostov, V; Laskar, J; Kutz, D W; Mason, B D; Milone, E F; Montgomery, M M; Richards, M T; Schou, J; Stewart, S G

    2015-01-01

    The XXIXth IAU General Assembly in Honolulu adopted IAU 2015 Resolution B2 on recommended zero points for the absolute and apparent bolometric magnitude scales. The resolution was proposed by the IAU Inter-Division A-G Working Group on Nominal Units for Stellar and Planetary Astronomy after consulting with a broad spectrum of researchers from the astronomical community. Resolution B2 resolves the long-standing absence of an internationally-adopted zero point for the absolute and apparent bolometric magnitude scales. Resolution B2 defines the zero point of the absolute bolometric magnitude scale such that a radiation source with $M_{\\rm Bol}$ = 0 has luminosity L$_{\\circ}$ = 3.0128e28 W. The zero point of the apparent bolometric magnitude scale ($m_{\\rm Bol}$ = 0) corresponds to irradiance $f_{\\circ}$ = 2.518021002e-8 W/m$^2$. The zero points were chosen so that the nominal solar luminosity (3.828e26 W) adopted by IAU 2015 Resolution B3 corresponds approximately to $M_{\\rm Bol}$(Sun) = 4.74, the value most com...

  15. Five new anthocyanins, ternatins A3, B4, B3, B2, and D2, from Clitoria ternatea flowers.

    Science.gov (United States)

    Terahara, N; Oda, M; Matsui, T; Osajima, Y; Saito, N; Toki, K; Honda, T

    1996-02-01

    Five new ternatins 1-5 have been isolated from Clitoria ternatea flowers, and the structures have been determined by chemical and spectroscopic methods as delphinidin 3-malonylG having 3'-GCG-5'-GCG, 3'-GCG-5'-GC, 3'-GCGCG-5'-GC, 3'-GCGC-5'-GCG, and 3'-GCGC-5'-GC side chains, respectively, in which G is D-glucose and C is p-coumaric acid. Pigment 1 had symmetric 3',5'-side chains. Compounds 3 and 4 are structural isomers. These ternatins were shown to form an intramolecular stacking between the aglycon ring and the 3',5'-side chains in solution. PMID:8991946

  16. 38 CFR 18b.2 - Reviewing authority.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Reviewing authority. 18b.2 Section 18b.2 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED... Rules § 18b.2 Reviewing authority. The term reviewing authority means the Secretary of Veterans...

  17. 216-B-3 expansion ponds closure plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA.

  18. 216-B-3 expansion ponds closure plan

    International Nuclear Information System (INIS)

    This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA

  19. Superconductivity in dense MgB2 wires.

    Science.gov (United States)

    Canfield, P C; Finnemore, D K; Bud'ko, S L; Ostenson, J E; Lapertot, G; Cunningham, C E; Petrovic, C

    2001-03-12

    MgB2 becomes superconducting just below 40 K. Whereas porous polycrystalline samples of MgB2 can be synthesized from boron powders, in this Letter we demonstrate that dense wires of MgB2 can be prepared by exposing boron filaments to Mg vapor. The resulting wires have a diameter of 160 microm, are better than 80% dense, and manifest the full chi = -1/4pi shielding in the superconducting state. Temperature-dependent resistivity measurements indicate that MgB2 is a highly conducting metal in the normal state with rho(40 K) = 0.38 microOmega cm. By using this value, an electronic mean-free path, l approximately 600 A can be estimated, indicating that MgB2 wires are well within the clean limit. Tc, Hc2(T), and Jc data indicate that MgB2 manifests comparable or better superconducting properties in dense wire form than it manifests as a sintered pellet.

  20. The Mysterious Ways of ErbB2/HER2 Trafficking

    OpenAIRE

    Vibeke Bertelsen; Espen Stang

    2014-01-01

    The EGFR- or ErbB-family of receptor tyrosine kinases consists of EGFR/ErbB1, ErbB2/HER2, ErbB3/HER3 and ErbB4/HER4. Receptor activation and downstream signaling are generally initiated upon ligand-induced receptor homo- or heterodimerization at the plasma membrane, and endocytosis and intracellular membrane transport are crucial for regulation of the signaling outcome. Among the receptors, ErbB2 is special in several ways. Unlike the others, ErbB2 has no known ligand, but is still the favore...

  1. Dendrite crystal morphology evolution mechanism of β-BaB2O4 crystal

    Institute of Scientific and Technical Information of China (English)

    HE ChongJun; ZHONG WeiZhuo; LIU YouWen

    2009-01-01

    Existence of [B3-O6]3- hexagonal ring growth unit in melt solution of β-BaB2O4 crystal was proved by the results of high temperature Raman measurements. A morphology evolution process of β-BaB2O4 crys-tal was observed by a high temperature in-situ observation device. The crystal morphology varied with the supersaturation of growth melt solution. The mechanism of β-BaB2O4 crystal morphology evolution was analyzed through the growth unit model.

  2. Dendrite crystal morphology evolution mechanism of β-BaB2O4 crystal

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Existence of [B3-O6]3- hexagonal ring growth unit in melt solution of β-BaB2O4 crystal was proved by the results of high temperature Raman measurements.A morphology evolution process of β-BaB2O4 crys-tal was observed by a high temperature in-situ observation device.The crystal morphology varied with the supersaturation of growth melt solution.The mechanism of β-BaB2O4 crystal morphology evolution was analyzed through the growth unit model.

  3. Controlled indole-3-acetaldoxime production through ethanol-induced expression of CYP79B2

    DEFF Research Database (Denmark)

    Mikkelsen, M.D.; Fuller, V.L.; Hansen, Bjarne Gram;

    2009-01-01

    Indole-3-acetaldoxime (IAOx) is a key branching point between primary and secondary metabolism. IAOx serves as an intermediate in the biosynthesis of indole glucosinolates (I-GLSs), camalexin and the plant hormone indole-3-acetic acid (IAA). The cytochrome P450s CYP79B2 and CYP79B3 catalyze the c...

  4. Sintering of TiB2 ceramics

    Directory of Open Access Journals (Sweden)

    M. Swiatek

    2007-11-01

    Full Text Available Purpose: Titanium diborides (TiB2 ceramic is particularly interesting because it exhibits high elastic modulus and hardness as well as high thermal conductivity. The interest in TiB2 ceramic increased enormously due to these properties but applications seem to be limited due to difficulties during densification process. In the experiment the TiB2 compacts was obtained using HP-HT method. The aim of this study is to work out and optimize the sintering densification process of TiB2 ceramics.Design/methodology/approach: The high temperature-high pressure (HT-HP Bridgman type apparatus was used for densification method of TiB2 powder. Ceramics were sintered at pressure of 7.2 ± 0.2 GPa and temperature at 1500-2300ºC ± 50ºC. The duration of sintering was 60 seconds. In order to investigate the structure changes, the optical and scanning electron microscope was used. Mechanical properties were determined by Vickers hardness. Young modulus measurements were carried out using ultrasonic method.Findings: The TiB2 ceramics was obtained without using sintering agents. The properties and structure of TiB2 ceramics strongly depend on conditions of sintering process. The application of the temperature of 1500ºC±50ºC and pressure of 7.2 ± 0.2 GPa and time of 60 seconds permits to obtain the TiB2 ceramics without cracks.Practical implications: The TiB2 ceramic might be used for production of composites. From a practical position it is important to optimize the sintering densification of TiB2 ceramic.Originality/value: The TiB2 ceramics were formed using HP-HT technique without the use of additives. This method of sintering for TiB2 ceramics is original one.T7

  5. Distrontium lithium beryllium triborate, Sr2LiBeB3O8

    Directory of Open Access Journals (Sweden)

    Ning Ye

    2012-05-01

    Full Text Available Single crystals of distrontium lithium beryllium triborate, Sr2LiBeB3O8, were obtained by spontaneous nucleation from a high-temperature melt. In the Sr2Li[BeB3O8] structure, [BeB2O7]6− rings, made up from one BeO4 tetrahedron and two BO3 triangles, are connected to each other by [BO3] triangles to form the smallest repeat unit {[BeB3O8]8−} and then form chains along the b axis. The Sr2+ cations are seven- or eight-coordinated and Li+ cations are tetra-coordinated and lie between the chains.

  6. 12 CFR 264b.2 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Definitions. 264b.2 Section 264b.2 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM RULES... such. (c) Gift means a tangible or intangible present (other than a decoration) tendered by,...

  7. Regulation of ErbB2 localization and function in breast cancer cells by ERM proteins

    Science.gov (United States)

    Asp, Nagham; Kvalvaag, Audun; Sandvig, Kirsten; Pust, Sascha

    2016-01-01

    The ERM protein family is implicated in processes such as signal transduction, protein trafficking, cell proliferation and migration. Consequently, dysregulation of ERM proteins has been described to correlate with carcinogenesis of different cancer types. However, the underlying mechanisms are poorly understood. Here, we demonstrate a novel functional interaction between ERM proteins and the ErbB2 receptor tyrosine kinase in breast cancer cells. We show that the ERM proteins ezrin and radixin are associated with ErbB2 receptors at the plasma membrane, and depletion or functional inhibition of ERM proteins destabilizes the interaction of ErbB2 with ErbB3, Hsp90 and Ebp50. Accompanied by the dissociation of this protein complex, binding of ErbB2 to the ubiquitin-ligase c-Cbl is increased, and ErbB2 becomes dephosphorylated, ubiquitinated and internalized. Furthermore, signaling via Akt- and Erk-mediated pathways is impaired upon ERM inhibition. Finally, interference with ERM functionality leads to receptor degradation and reduced cellular levels of ErbB2 and ErbB3 receptors in breast cancer cells. PMID:27029001

  8. Diophantine approximations

    CERN Document Server

    Niven, Ivan

    2008-01-01

    This self-contained treatment originated as a series of lectures delivered to the Mathematical Association of America. It covers basic results on homogeneous approximation of real numbers; the analogue for complex numbers; basic results for nonhomogeneous approximation in the real case; the analogue for complex numbers; and fundamental properties of the multiples of an irrational number, for both the fractional and integral parts.The author refrains from the use of continuous fractions and includes basic results in the complex case, a feature often neglected in favor of the real number discuss

  9. 26 CFR 48.4216(b)-3 - Constructive sale price; special rule for arm's-length sales.

    Science.gov (United States)

    2010-04-01

    ...) Definitions. For purposes of section 4216(b)(2) and this section: (1) Actual sale price. “Actual sale price... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Constructive sale price; special rule for arm's... Provisions Applicable to Manufacturers Taxes § 48.4216(b)-3 Constructive sale price; special rule for...

  10. Approximation Techniques

    OpenAIRE

    2006-01-01

    This interactive tutorial presents the following concepts of Approximation Techniques: Methods of Weighted Residual (MWR), Weak Formulatioin, Piecewise Continuous Function, Galerkin Finite Element FormulationExplanations especially for mathematical statements are provided using mouseover the highlight equations. ME4613 Finite Element Methods

  11. THE REINFORCING MECHANISM OF TiB2 IN TiB2/A357 COMPOSITE

    Institute of Scientific and Technical Information of China (English)

    B. Yu; Y.J. Zhang; Z.X. Zhao; F.X. Zhao; Q.K. Cai; C.S. Liu

    2003-01-01

    Mechanical properties were tested for in situ TiB2/A357 composite fabricated by LSM (mixed salts reaction) method. Microstructures of as cast and plastic deformed TiB2/A357 were investigated. The results show that there is a low misfit between (200)A1 and (101)TiB2 with [011]Al // [101]TiB2. There is a change from fully dendritic structure of the α-Al of A357 to a rosette-type structure of TiB2/A357. Significant increases in proof stress and Young's modulus can be obtained at low TiB2 additions. There exist dislocation loops around neighboring TiB2 particles with about 0. 1ηm in diameter and dislocation multiplication near TiB2 particles.

  12. Hotelzon's B2B content marketing plan

    OpenAIRE

    Nguyen, Trang

    2015-01-01

    This thesis follows a research-based structure. The objective of this research was to help the case company Hotelzon develop a practical business-to-business (B2B) content marketing plan to engage new customers. The research topic came up when the case company named Hotelzon started expanding its business to many other countries. Therefore, attracting new prospects has become a critical issue to B2B corporates in this online world and constantly changing business environment. The first pa...

  13. Structural, electronic and magnetic properties of MnB2

    Indian Academy of Sciences (India)

    R Masrour; E K Hlil; M Hamedoun; A Benyoussef; O Mounkachi; H El Moussaoui

    2015-08-01

    The self-consistent ab-initio calculations, based on density functional theory approach and using the full potential linear augmented plane wave method, are performed to investigate both electronic and magnetic properties of the MnB2 compounds. Polarized spin and spin–orbit coupling are included in calculations within the framework of the ferromagnetic state between two adjacent Mn atoms. Magnetic moment considered to lie along the (001) axes are computed. The antiferromagnetic and ferromagnetic energies of MnB2 systems are obtained. Obtained data from ab-initio calculations are used as input for the high-temperature series expansions (HTSEs) calculations to compute other magnetic parameters. The exchange interactions between the magnetic atoms Mn–Mn in MnB2 are established by using the mean field theory. The HTSEs of the magnetic susceptibility with the magnetic moments in MnB2 (Mn) through Ising model is given. The critical temperature C (K) is obtained by HTSEs applied to the magnetic susceptibility series combined with the Padé approximant method. The critical exponent associated with the magnetic susceptibility is deduced as well.

  14. Growth and study of LuNi2B2C single crystals

    International Nuclear Information System (INIS)

    Rare earth-nickel-borocarbides have attracted much interest in the last years because the compounds show the interplay of superconductivity and magnetic ordering. LuNi2B2C can be considered as non-magnetic reference system of such magnetic borocarbides as HoNi2B2C in which superconducting and antiferromagnetic ordering temperatures, Tc and TN, are similar. So far, LuNi2B2C crystals were only prepared by a flux method. For growing larger crystals we used an optical floating zone (FZ) technique, which already was successful in crystal growth of other RNi2B2C (R = Y,Tb,Ho,Tm,Er) compounds. In the case of LuNi2B2C, the primary crystallization field is far from the stoichiometric composition, and adjacent to the properitectic LuB2C2 phase field an extended region of LuNiBC occurs. Systematic studies of polycrystalline samples revealed that samples with nominal compositions LuNi5B3.5C and LuNi5B3C0.5 are free of the properitectic LuB2C2 and LuNiBC phases. Thus in the FZ crystal growth experiments we used a molten zone which corresponds to these compositions. From the grown LuNi2B2C rods single crystalline pieces have been prepared to investigate Fermi surface peculiarities by magneto-resistance measurements and to study the electronic band structure

  15. MgB2 superconducting whiskers synthesized by using the hybrid physical-chemical vapor deposition.

    Science.gov (United States)

    Wang, Yazhou; Zhuang, Chenggang; Gao, Jingyun; Shan, Xudong; Zhang, Jingmin; Liao, Zhimin; Xu, Hongjun; Yu, Dapeng; Feng, Qingrong

    2009-02-25

    In this work, MgB(2) whiskers were fabricated on a copper substrate by using the hybrid physical-chemical vapor deposition, which was one of the most effective ways to make high quality pure MgB(2) films, with the possible growth mechanism discussed. The whiskers are hexagonal and conelike and grow along the [0001] direction with a single-crystal structure. The onset transition temperature is approximately 39 K, which is among the best in the published nanostructure MgB(2) papers. Fabrication of nanoscale MgB(2) whiskers provides the fundamental understanding of the effect of dimensionality and size on superconductivity.

  16. Approximate Representations and Approximate Homomorphisms

    CERN Document Server

    Moore, Cristopher

    2010-01-01

    Approximate algebraic structures play a defining role in arithmetic combinatorics and have found remarkable applications to basic questions in number theory and pseudorandomness. Here we study approximate representations of finite groups: functions f:G -> U_d such that Pr[f(xy) = f(x) f(y)] is large, or more generally Exp_{x,y} ||f(xy) - f(x)f(y)||^2$ is small, where x and y are uniformly random elements of the group G and U_d denotes the unitary group of degree d. We bound these quantities in terms of the ratio d / d_min where d_min is the dimension of the smallest nontrivial representation of G. As an application, we bound the extent to which a function f : G -> H can be an approximate homomorphism where H is another finite group. We show that if H's representations are significantly smaller than G's, no such f can be much more homomorphic than a random function. We interpret these results as showing that if G is quasirandom, that is, if d_min is large, then G cannot be embedded in a small number of dimensi...

  17. Approximate Likelihood

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Most physics results at the LHC end in a likelihood ratio test. This includes discovery and exclusion for searches as well as mass, cross-section, and coupling measurements. The use of Machine Learning (multivariate) algorithms in HEP is mainly restricted to searches, which can be reduced to classification between two fixed distributions: signal vs. background. I will show how we can extend the use of ML classifiers to distributions parameterized by physical quantities like masses and couplings as well as nuisance parameters associated to systematic uncertainties. This allows for one to approximate the likelihood ratio while still using a high dimensional feature vector for the data. Both the MEM and ABC approaches mentioned above aim to provide inference on model parameters (like cross-sections, masses, couplings, etc.). ABC is fundamentally tied Bayesian inference and focuses on the “likelihood free” setting where only a simulator is available and one cannot directly compute the likelihood for the dat...

  18. Diophantine approximation

    CERN Document Server

    Schmidt, Wolfgang M

    1980-01-01

    "In 1970, at the U. of Colorado, the author delivered a course of lectures on his famous generalization, then just established, relating to Roth's theorem on rational approxi- mations to algebraic numbers. The present volume is an ex- panded and up-dated version of the original mimeographed notes on the course. As an introduction to the author's own remarkable achievements relating to the Thue-Siegel-Roth theory, the text can hardly be bettered and the tract can already be regarded as a classic in its field."(Bull.LMS) "Schmidt's work on approximations by algebraic numbers belongs to the deepest and most satisfactory parts of number theory. These notes give the best accessible way to learn the subject. ... this book is highly recommended." (Mededelingen van het Wiskundig Genootschap)

  19. EGF receptor inhibitors increase ErbB3 mRNA and protein levels in breast cancer cells

    DEFF Research Database (Denmark)

    Grøvdal, Lene Melsæther; Kim, Jiyoung; Holst, Mikkel Roland;

    2012-01-01

    that, when inhibiting the epidermal growth factor receptor (EGFR) with the tyrosine kinase inhibitor gefitinib, increased activation of ErbB3 via MET, or by re-localization of ErbB3 mediates cell survival. Here we show further evidence that members of the ErbB receptor family facilitate resistance......The potential benefits of drugs directly targeting the ErbB receptors for cancer therapy have led to an extensive development within this field. However, the clinical effects of ErbB receptor-targeting drugs in cancer treatment are limited due to a high frequency of resistance. It has been reported...... to EGFR inhibitor treatment in ErbB2 overexpressing breast cancer cells. We found that gefitinib treatment increased ErbB3 expression, both at protein and mRNA levels. ErbB3 expression was upregulated not only by gefitinib but also by a panel of different EGFR inhibitors, suggesting that inhibition...

  20. ErbB2 resembles an autoinhibited invertebrate epidermal growth factor receptor

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado, Diego; Klein, Daryl E.; Lemmon, Mark A.; (UPENN-MED)

    2009-09-25

    The orphan receptor tyrosine kinase ErbB2 (also known as HER2 or Neu) transforms cells when overexpressed, and it is an important therapeutic target in human cancer. Structural studies have suggested that the oncogenic (and ligand-independent) signalling properties of ErbB2 result from the absence of a key intramolecular 'tether' in the extracellular region that autoinhibits other human ErbB receptors, including the epidermal growth factor (EGF) receptor. Although ErbB2 is unique among the four human ErbB receptors, here we show that it is the closest structural relative of the single EGF receptor family member in Drosophila melanogaster (dEGFR). Genetic and biochemical data show that dEGFR is tightly regulated by growth factor ligands, yet a crystal structure shows that it, too, lacks the intramolecular tether seen in human EGFR, ErbB3 and ErbB4. Instead, a distinct set of autoinhibitory interdomain interactions hold unliganded dEGFR in an inactive state. All of these interactions are maintained (and even extended) in ErbB2, arguing against the suggestion that ErbB2 lacks autoinhibition. We therefore suggest that normal and pathogenic ErbB2 signalling may be regulated by ligands in the same way as dEGFR. Our findings have important implications for ErbB2 regulation in human cancer, and for developing therapeutic approaches that target novel aspects of this orphan receptor.

  1. Superconductivity in MgB2

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In January of 2001 the superconductivity of the compound MgB2 with a critical temperature Tc of up to 39 K was discovered. This Tc is the highest in all intermetallic compound and alloy superconductors. MgB2 has a simple structure and its manufacturing capital cost is lower, therefore it could become a practical superconductor in the future. The recent progress is reviewed here which covers the progress in electronic structure, high Tc mechanism, superconducting parameters (Debye temperature, specific heat coefficient of electron, critical fields, coherent length, penetration depth, energy gap, critical current and relaxation rate of flux). Moreover the issue on power transmission is discussed.

  2. Improved critical current density of MgB2--carbon nanotubes composite.

    Science.gov (United States)

    Shekhar, Chandra; Giri, Rajiv; Malik, S K; Srivastav, O N

    2007-06-01

    In the present study, we report a systematic study of doping/admixing of carbon nanotubes (CNTs) in different concentrations in MgB2. The composite material corresponding to MgB2-x at.% CNTs (35 at.% > or = x > or = 0 at.%) have been prepared by solid-state reaction at ambient pressure. All the samples in the present investigation have been subjected to structural/microstructural characterization employing XRD, Scanning electron microscopic (SEM), and Transmission electron microscopic (TEM) techniques. The magnetization measurements were performed by Physical property measurement system (PPMS) and electrical transport measurements have been done by the four-probe technique. The microstructural investigations reveal the formation of MgB2-carbon nanotube composites. A CNT connecting the MgB2 grains may enhance critical current density due to its size (approximately 5-20 nm diameter) compatible with coherence length of MgB2 (approximately 5-6 nm) and ballistic transport current carrying capability along the tube axis. The transport critical current density (Jct) of MgB2 samples with varying CNTs concentration have been found to vary significantly e.g., Jct of the MgB2 sample with 10 at.% CNT addition is approximately 2.3 x 10(3) A/cm2 and its value for MgB2 sample without CNT addition is approximately 7.2 x 102 A/cm2 at 20 K. In order to study the flux pinning effect of CNTs doping/ admixing in MgB2, the evaluation of intragrain critical current density (JJ) has been carried out through magnetic measurements on the fine powdered version of the as synthesized samples. The optimum result on Jc is obtained for 10 at.% CNTs admixed MgB2 sample at 5 K, the Jc reaches approximately 5.2 x 10(6) A/cm2 in self field, -1.6 x 10(6) A/cm2 at 1 T, approximately 2.9 x 10(5) A/cm2 at 2.6 T, and approximately 3.9 x 10(4) A/cm2 at 4 T. The high value of intragrain Jc in 10 at.% CNTs admixed MgB2 superconductor has been attributed to the incorporation of CNTs into the crystal matrix of

  3. B2B Pioneer A Millionaire Maker

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    China should soon see its largest group of instant millionaires after Jack Ma,Chief Executive Officer and Chairman of Alibaba Group,announced on July 27 that the China’s preeminent e-commerce company has initiated the listing of its B2B unit alibaba.com

  4. B2-Eirene modelling of ASDEX Upgrade

    Science.gov (United States)

    Coster, D. P.; Schneider, R.; Neuhauser, J.; Bosch, H.-S.; Wunderlich, R.; Fuchs, C.; Mast, F.; Kallenbach, A.; Dux, R.; Becker, G.; Braams, B. J.; Reiter, D.; ASDEX Upgrade Team

    1997-02-01

    The extension of the computational region of the coupled fluid plasma, Monte-Carlo neutrals code, B2-Eirene, to the plasma center is discussed. The simulation of completely detached H-mode plasma is presented, as is the modelling of He and Ne compression.

  5. B2B制胜之道

    Institute of Scientific and Technical Information of China (English)

    但华香

    2000-01-01

    在E-commerce初露头角的时候,精明的投资者就暗暗盯上了B2B,他们说“电子是壳,商务是核”,并且从那一刻起,现实而理智。于是,人们渐渐熟悉了E-commerce,人们看到了B2B的力量,看到了它的威慑力、穿透力和感召力。因为,B2B不说大话,只谈生意。新生意,旧生意 B2B(Business to Business E-commerce)市场之所以不断升温,不仅因为“商务”内核以“电子”的形式来表达时,能给商人们带来畅快的效率和便利,更因为它给企业带来的营业额和利润的潜能远远高于针对最终消费者的电

  6. On Heavy Carbon Doping of MgB$_2$

    OpenAIRE

    Kasinathan, Deepa; Lee, K. -W.; PICKETT, W.E.

    2004-01-01

    Heavy carbon doping of MgB$_2$ is studied by first principles electronic structure studies of two types, an ordered supercell (Mg(B$_{1-x}$C$_{x}$)$_{2}$,x=0.0833) and also the coherent potential approximation method that incorporates effects of B-C disorder. For the ordered model, the twofold degenerate $\\sigma$-bands that are the basis of the high temperature superconductivity are split by 60 meV (i.e.7 meV/%C) and the $\\sigma$ Fermi cylinders contain 0.070 holes/cell, compared to 0.11 for ...

  7. Habit and formation mechanism of β-BaB2O4 crystal

    Institute of Scientific and Technical Information of China (English)

    仲维卓; 洪慧聪; 路治平; 赵天德; 华素坤; 唐鼎元; 赵庆兰

    1995-01-01

    The relationship between the orientation of structure unit [B3O6]3- anion ring and the morphology of β-BaBO4 crystal has been studied on the basis of crystallography. According to the results measured from the solution structure of Na2O-B2O3 system, the structure of the growth unit of β-BaB2O4 crystal and the incorporation discipline of the growth unit on the faces and facets of the crystal are proposed. The formation mechanism and crystallization habit of the β-BaB2O4 are discussed. The dimensions of the growth unit vary with the physicochemistry conditions of the crystal growth. Moreover, the incorporation rates of the growth units with different dimensions on the faces and facets are also changed This is the major reason of the diver-sity of the crystal morphology

  8. Electronic structure of MgB2

    Indian Academy of Sciences (India)

    P Modak; R S Rao; B K Godwal; S K Sikka

    2002-05-01

    Results of ab initio electronic structure calculations on the compound MgB2 using the FPLAPW method employing GGA for the exchange-correlation energy are presented. Total energy minimization enables us to estimate the equilibrium volume, / ratio and the bulk modulus, all of which are in excellent agreement with experiment. We obtain the mass enhancement parameter by using our calculated (F) and the experimental specific heat data. The c is found to be 24.7 K.

  9. Thermodynamic properties of vitamin B2

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Temperature dependence of heat capacity of vitamin B2 has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B2 have been determined for the range from T → 0 to 322 K. • The energy of combustion of the riboflavin has been measured at 298.15 K. • The enthalpy of combustion ΔcH° and the thermodynamic parameters ΔfH°, ΔfS°, ΔfG° have been calculated. - Abstract: In the present work temperature dependence of heat capacity of vitamin B2 (riboflavin) has been measured for the first time in the range from 6 to 322 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B2, namely, the heat capacity, enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and Gibbs function G°(T) − H°(0) have been determined for the range from T → 0 to 322 K. The value of the fractal dimension D in the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. In a calorimeter with a static bomb and an isothermal shield, the energy of combustion of the riboflavin has been measured at 298.15 K. The enthalpy of combustion ΔcH° and the thermodynamic parameters ΔfH°, ΔfS°, ΔfG° and of reaction of formation of the riboflavin from simple substances at T = 298.15 K and p = 0.1 MPa have been calculated

  10. Characterization of MgB2 Superconducting Hot Electron Bolometers

    Science.gov (United States)

    Cunnane, D.; Kawamura, J. H.; Wolak, M. A.; Acharya, N.; Tan, T.; Xi, X. X.; Karasik, B. S.

    2014-01-01

    Hot-Electron Bolometer (HEB) mixers have proven to be the best tool for high-resolution spectroscopy at the Terahertz frequencies. However, the current state of the art NbN mixers suffer from a small intermediate frequency (IF) bandwidth as well as a low operating temperature. MgB2 is a promising material for HEB mixer technology in view of its high critical temperature and fast thermal relaxation allowing for a large IF bandwidth. In this work, we have fabricated and characterized thin-film (approximately 15 nanometers) MgB2-based spiral antenna-coupled HEB mixers on SiC substrate. We achieved the IF bandwidth greater than 8 gigahertz at 25 degrees Kelvin and the device noise temperature less than 4000 degrees Kelvin at 9 degrees Kelvin using a 600 gigahertz source. Using temperature dependencies of the radiation power dissipated in the device we have identified the optical loss in the integrated microantenna responsible as a cause of the limited sensitivity of the current mixer devices. From the analysis of the current-voltage (IV) characteristics, we have derived the effective thermal conductance of the mixer device and estimated the required local oscillator power in an optimized device to be approximately 1 microwatts.

  11. 26 CFR 48.4161(b)-3 - Use considered sale.

    Science.gov (United States)

    2010-04-01

    ....4161(b)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES MANUFACTURERS AND RETAILERS EXCISE TAXES Sporting Goods § 48.4161(b)-3 Use considered sale. For provisions relating to the tax on use of taxable articles by the manufacturer, producer,...

  12. High-average-power femtosecond pulse generation in the blue using BiB3O6

    Science.gov (United States)

    Ghotbi, M.; Ebrahim-Zadeh, M.; Majchrowski, A.; Michalski, E.; Kityk, I. V.

    2004-11-01

    Efficient generation of tunable femtosecond pulses in the blue is reported in the nonlinear crystal BiB3O6. By use of fundamental pulses from a mode-locked Ti:sapphire laser at 76 MHz, single-pass second-harmonic average powers of as much as 830 mW have been generated at 50% conversion efficiency, and a tunable range of 375-435 nm in the blue is demonstrated. Temporal measurements using cross correlation of the fundamental and second-harmonic pulses in a 100-µm-thick ß-BaB2O4 crystal result in blue pulse durations of 220 fs for 130-fs fundamental pulses. Direct experimental comparison with ß-BaB2O4 confirms the superior performance BiB3O6 for second-harmonic generation of femtosecond pulses.

  13. Anti-ErbB-2 monoclonal antibodies and ErbB-2-directed vaccines.

    Science.gov (United States)

    Yip, Yum L; Ward, Robyn L

    2002-01-01

    The tumour antigen ErbB-2 belongs to the epidermal growth factor receptor family. Numerous studies have shown that ErbB-2 is overexpressed in many cancers and it is prognostically important in a subset of malignancies. It is well recognised that this receptor has many characteristics that make it an excellent target for tumour-specific immunotherapy. One anti-ErbB-2 monoclonal antibody, Herceptin or TrastuzuMab, has already shown clinical efficacy for the treatment of metastatic breast cancer. However, despite this success, it is still currently unclear how monoclonal antibodies inhibit tumour growth in vivo. This review will summarise the biological activities of a range of anti-ErbB-2 Mabs, as well as their possible mechanisms of action. In addition, as an active mode of immunotherapy, the current vaccine strategies for inducing or enhancing ErbB-2-specific immunity will also be discussed. It is anticipated that a better understanding of the activities of anti-ErbB-2 Mabs will aid in the development of both passive and active immunotherapies against this important receptor. PMID:11807621

  14. Metabolic products of microorganisms. 249. Tetracenomycins B3 and D3, key intermediates of the elloramycin and tetracenomycin C biosynthesis.

    Science.gov (United States)

    Rohr, J; Eick, S; Zeeck, A; Reuschenbach, P; Zähner, H; Fiedler, H P

    1988-08-01

    Tetracenomycins B3 and D3, besides tetracenomycin D (D1), were produced by a blocked mutant of the elloramycin producer Streptomyces olivaceus TU 2353. The compounds were isolated as red powders, and their structures were elucidated by comparing their physicochemical data with those of the known tetracenomycins A2, B1, B2, D and E. Tetracenomycin B3 (2), the main compound, and tetracenomycin D (3) were antibiotically inactive against Gram-positive and Gram-negative bacteria, whereas tetracenomycin D3 (1) showed a moderate activity against Bacillus subtilis and Arthrobacter aurescens. Tetracenomycin B3 (2) is the key intermediate where the biosynthesis of the elloramycins branches off from the line leading to tetracenomycin C (5) as the final product of the tetracenomycin biosynthesis branch.

  15. 维生素B2

    Institute of Scientific and Technical Information of China (English)

    郭红卫

    2007-01-01

    维生素B2又称核黄素(riboflavin)。最初人们于19世纪后期认识到,在天然乳清中存在着一种可溶于水的能产生黄色荧光的物质,可预防皮肤炎症。1933年由几个科研小组将其分离出来,并命名为核黄素,意指其来源于卵黄素、肝黄素和尿黄素。

  16. Ambient temperature cured TiB2 cathode coating for aluminum electrolysis

    Institute of Scientific and Technical Information of China (English)

    赖延清; 李庆余; 杨建红; 李劼

    2003-01-01

    The concept of ambient temperature curable TiB2 cathode coating was put forward, and the ambient temperature curable TiB2 cathode coating was prepared successfully. Differing from the previous TiB2 cathode coating solidified approximately at 200 ℃,the ambient temperature curable TiB2 cathode coating can be solidified at room temperature, so the heating equipment is not necessary, which simplifies the preparation process and facilitates the industrial application of TiB2 cathode coating. Many kinds of resin and curing agent were investigated. On the above-mentioned basis, the ambient temperature curable TiB2 cathode coating was prepared with furan resin 5 500 mixed with complex resins B as carbon binder and DXG1 as curing agent in 24 h. The results show that the properties of prepared coating are excellent, the electrical resistivity is 29.8 μΩ*m, the compressive strength is 33.6 MPa, which are all better than the relevant properties of partially graphitized cathode carbon block for aluminum electrolysis prescribed by the GB 8744-88. SEM morphologies show that the section morphology of the TiB2 coating is unaltered during the electrolysis test, the TiB2 coating can be used in aluminum electrolysis industry to save energy and prolong the life of aluminum electrolysis cell.

  17. Electronic states of BP, BP +, BP -, B 2P 2, B2P2- and B2P2+

    Science.gov (United States)

    Linguerri, Roberto; Komiha, Najia; Oswald, Rainer; Mitrushchenkov, Alexander; Rosmus, Pavel

    2008-05-01

    Using augmented sextuple zeta basis sets and internally contracted multireference configuration interaction (MRCI) wavefunctions, potential energy, electric dipole and transition moments have been computed for the X 3Π, a 1Σ +, b 1Π and A 3Σ - states of BP, X 2Σ + and A 2Π states of BP - and X 4Σ - and A 4Π states of BP +. From these data spectroscopic constants, radiative transition probabilities and photoelectron spectra of BP - and BP have been evaluated. The non-vanishing spin-orbit coupling elements between the four low lying triplet and singlet states of the neutral BP have also been calculated from MRCI wavefunctions. The treatment of the corresponding perturbations in the manifold of dense rovibrational states in the three lowest states would require a precise knowledge of the electronic excitation energies. Our best singlet-triplet separations (X-a) are calculated to be 2412 cm -1 (MRCI) and 2482 cm -1 (restricted coupled cluster with perturbative triples (RCCSD(T))) with an estimated error bound of about ±200 cm -1. All three states have long radiative lifetimes with cascading among the rovibrational levels of different states. The ionization energy IE e of BP is calculated to be 9.22 eV (MRCI) and 9.48 eV (RCCSD(T)), the electron affinity EA e 2.51 eV (MRCI) and 2.74 eV (RCCSD(T)). The photoelectron spectra of BP and BP - have been obtained from the Franck-Condon factors of the MRCI potentials. For the UV spectroscopy the dipole allowed radiative transition probabilities are given for A 3Σ - ↔ X 3Π, b 1Π ↔ a 1Σ + of BP, A 2Π ↔ X 2Σ + of BP - and A 4Π ↔ X 4Σ - of BP +. The ionization energy IE e of B 2P 2 of 8.71 eV and the electron affinity EA e of 2.34 eV have been calculated by the RCCSD(T)/aVQZ approach. Also the harmonic vibrational wavenumbers for the electronic ground states of the ions B2P2+ and B2P2- are given.

  18. Rare bile duct anomaly: B3 duct draining to gallbladder

    Directory of Open Access Journals (Sweden)

    Seung Eun Lee

    2016-01-01

    Full Text Available A 10-year-old girl presented with recurrent right upper abdominal pain and dyspepsia. Magnetic resonance cholangiopancreatography revealed a dilated common channel of intrahepatic bile duct of segment 3 (B3 and segment 4 (B4 drained into the gallbladder directly. The patient underwent laparoscopic cholecystectomy and Roux-en Y hepaticojejunostomy (B3-jejunostomy. Among the anatomical variability of the biliary system, the cholecystohepatic ducts are controversial in existence and incidence. We report a very rare variant of a cholecystohepatic duct in which the B3 duct drained into gallbladder directly and to the best of our knowledge this is the first report.

  19. To be or not B2B?

    CERN Document Server

    Symons, L J

    2001-01-01

    La question du commerce électronique interentreprises par le web (Business to Business, B2B) est posée actuellement par les grands groupes industriels impliqués dans le commerce mondial. Les prévisions sont imposantes, le B2B atteindra le C.A. de 3000 milliards de dollars en 2003. Les conditions d'accès, la façon de procéder des deux organisateurs (ARIBA et COMMERCE ONE) des plus grandes places de marchés actuelles, sont décrites. La base de l'énorme pyramide est le catalogue électronique multilingue UNSPSC (United Nations Standard Products and Services Classification) et l'organisation ECCMA (Electronic Commerce Code Management Association) qui gère le développement des UNSPSC codes en 8 langues. Dans ce contexte, l'auteur (re)-déclare qu'un des efforts principaux à fournir par le CERN est la création de son propre catalogue électronique. Dans la Division ST, une aide partielle à ce vaste programme pourrait être apportée par la normalisation des codes et désignations des pièces de maint...

  20. Whole Genome and Transcriptome Sequencing of a B3 Thymoma

    OpenAIRE

    Iacopo Petrini; Arun Rajan; Trung Pham; Donna Voeller; Sean Davis; James Gao; Yisong Wang; Giuseppe Giaccone

    2013-01-01

    Molecular pathology of thymomas is poorly understood. Genomic aberrations are frequently identified in tumors but no extensive sequencing has been reported in thymomas. Here we present the first comprehensive view of a B3 thymoma at whole genome and transcriptome levels. A 55-year-old Caucasian female underwent complete resection of a stage IVA B3 thymoma. RNA and DNA were extracted from a snap frozen tumor sample with a fraction of cancer cells over 80%. We performed array comparative genomi...

  1. Coxsackievirus B3 infection and its mutation in Keshan disease

    Institute of Scientific and Technical Information of China (English)

    Li-Qun Ren; Xiang-Jun Li; Guang-Sheng Li; Zhi-Tao Zhao; Bo Sun; Fei Sun

    2004-01-01

    AIM: To investigate coxsackievirus B3 infection and its gene mutation in Keshan disease.METHODS: The expression of Coxsackievirus B3 RNA was detected in autopsy specimens of acute (12 cases), sub-acute(27 cases) and chronic (15 cases) Keshan disease by in situ hybridization. In sub-acute Keshan disease specimens, 3 cases with positive result by in situ hybridization were selected RT-PCR analysis. The DNA segments were then sequenced.RESULTS: Coxsackievirus B3 RNA was detected in the cytoplasm of myocardiocyte. The positive rate was 83% in acute, 67% in sub-acute and 80% in chronic Keshan disease.In the conservative region of Coxsackievirus B3 genome,there was a mutation in 234 (C-T) compared to the noncardiovirulent strain, CVB3/0.CONCLUSION: Coxsackievirus B3 RNA can survive and replicate in heart muscle of Keshan disease, which may play an important role in the occurrence of Keshan disease. The possible mechanism of occurrence of Keshan disease is associated with point a mutation in Coxsackievirus B3 genome.

  2. 18 CFR Appendix I to Subpart F of... - Procedures for Compliance With the Endangered Species Act of 1973 Under § 157.206(b)(3)(i)

    Science.gov (United States)

    2010-04-01

    ... CFR 402.02. The certificate holder shall be deemed in compliance with § 157.206(b)(2)(vi) of the... appropriate) as determined pursuant to 50 CFR 402.01 for the purpose of initiating informal consultations. 2... Compliance With the Endangered Species Act of 1973 Under § 157.206(b)(3)(i) I Appendix I to Subpart F...

  3. Coherent phonon decay and the boron isotope effect for MgB2.

    Science.gov (United States)

    Alarco, Jose A; Talbot, Peter C; Mackinnon, Ian D R

    2014-12-14

    Ab initio DFT calculations for the phonon dispersion (PD) and the phonon density of states (PDOS) of the two isotopic forms ((10)B and (11)B) of MgB2 demonstrate that use of a reduced symmetry super-lattice provides an improved approximation to the dynamical, phonon-distorted P6/mmm crystal structure. Construction of phonon frequency plots using calculated values for these isotopic forms gives linear trends with integer multiples of a base frequency that change in slope in a manner consistent with the isotope effect (IE). Spectral parameters inferred from this method are similar to that determined experimentally for the pure isotopic forms of MgB2. Comparison with AlB2 demonstrates that a coherent phonon decay down to acoustic modes is not possible for this metal. Coherent acoustic phonon decay may be an important contributor to superconductivity for MgB2.

  4. Neutron diffraction studies of magnetic ordering in superconducting ErNi2B2C and TmNi2B2C in an applied magnetic field

    DEFF Research Database (Denmark)

    Toft, Katrine Nørgaard

    The field-induced magnetic structures of ErNi2B2C and TmNi2B2C in are especially interesting because the field suppresses the superconducting order parameter and therefore the magnetic properties can be studied while varying the strength ofsuperconductivity. ErNi2B2C: For magnetic fields along all...... three symmetry directions, the observed magnetic structures have a period corresponding to the Fermi surface nesting structure. The phase diagrams present all the observed magnetic structures.Two results remain unresolved: 1. When applying the magnetic field along [010], the minority domain (QNB = (0,Q......,0) with moments perpendicular to the field) shows no signs of hysteresis. I expected it to be a meta-stable state, which would be graduallysuppressed by a magnetic field, and when decreasing the field it would not reappear until some small field of approximately 0.1 T. 2. When the field is applied...

  5. Component Based System Framework for Dynamic B2B Interaction

    OpenAIRE

    Hu jinmin, H.J.; Grefen, P.W.P.J.

    2002-01-01

    Business-to-business (B2B) collaboration is becoming a pivotal way to bring today's enterprises to success in the dynamically changing, e-business environment. Though many business-to-business protocols are developed to support B2B interaction, none are generally accepted. A B2B system should support different B2B protocols dynamically to enable interaction between diverse enterprises. This paper proposes a framework for dynamic B2B interaction. A B2B transaction is divided into the interacti...

  6. Some Considerations on B2B in China%对我国B2B的一些思考

    Institute of Scientific and Technical Information of China (English)

    王进; 和金生

    2001-01-01

    B2B的现状入手,指出中国非常需要B2B;从B2B企业的内部环境对B2B出现的问题加以分析,并提出了相关对策,最后对B2B给予了展望。%Based on the analysis of the present situation of B2B,it indicates the requirement of B2B in China. Then,it analyses the questions in the implementation of B2B in enterprises and puts forward some countermeasures. Finally,the prospect of B2B development is given.

  7. 75 FR 23574 - Airworthiness Directives; CFM International, S.A. CFM56-5B1/P, -5B2/P, -5B3/P, -5B3/P1, -5B4/P...

    Science.gov (United States)

    2010-05-04

    ... INFORMATION: The FAA proposed to amend 14 CFR part 39 by superseding AD 2009-01-01, Amendment 39-15779 (73 FR... (74 FR 67834). That action proposed to require continuous monitoring of EGT margin deterioration... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) Will not have a...

  8. Buck-Buck- Boost Regulatr (B3R)

    Science.gov (United States)

    Mourra, Olivier; Fernandez, Arturo; Landstroem, Sven; Tonicello, Ferdinando

    2011-10-01

    In a satellite, the main function of a Power Conditioning Unit (PCU) is to manage the energy coming from several power sources (usually solar arrays and battery) and to deliver it continuously to the users in an appropriate form during the overall mission. The objective of this paper is to present an electronic switching DC-DC converter called Buck-Buck-Boost Regulator (B3R) that could be used as a modular and recurrent solution in a PCU for regulated or un- regulated 28Vsatellite power bus classes. The power conversion stages of the B3R topology are first described. Then theoretical equations and practical tests illustrate how the converter operates in term of power conversion, control loops performances and efficiency. The paper finally provides some examples of single point failure tolerant implementation using the B3R.

  9. A promising birefringent crystal Ba2Na3(B3O6)2F

    Science.gov (United States)

    Wang, Xing; Xia, Mingjun; Li, R. K.

    2014-12-01

    Bulk crystals of Ba2Na3(B3O6)2F (BNBF) have been successfully grown by top-seeded solution growth (TSSG) technique. Its transmittance spectra show a wide transparency range from 186 nm to 3000 nm. The refractive indices in 13 wavelengths were measured with high accuracy and the Sellmeier equations were obtained, which demonstrated that the title crystal displayed a birefringence (Δn = 0.1030 at 588 nm) comparable to that of the commercial birefringent crystal α-BBO (the high temperature form of BaB2O4). A prototype Glan-Taylor polarizer made of BNBF prisms was fabricated, which showed high transparency and large optical extinction ratio similar to the commercial polarizer made of α-BBO. In addition, BNBF crystal is less moisture sensitive than that of α-BBO, thus BNBF can be a potential new birefringent crystal.

  10. Effect of hydrostatic pressure on the structural, elastic and electronic properties of (B3) boron phosphide

    Indian Academy of Sciences (India)

    Salah Daoud; Kamel Loucif; Nadhira Bloud; Noudjoud Lebgaa; Laarbi Belagraa

    2012-07-01

    In this paper we present the results obtained from first-principles calculations of the effect of hydrostatic pressure on the strucural, elastic and electronic properties of (B3) boron phosphide, using the pseudopotential plane-wave method (PP-PW) based on density functional theory within the Teter and Pade exchange-correlation functional form of the local density approximation (LDA). The lattice parameter, molecular and crystal densities, near-neighbour distances, independent elastic constant, bulk modulus, shear modulus, anisotropy factor and energy bandgaps of (B3) BP under high pressure are presented. The results showed a phase transition pressure from the zinc blende to rock-salt phase at around 1.56 Mbar, which is in good agreement with the theoretical data reported in the literature.

  11. 26 CFR 1.663(b)-2 - Election.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Election. 1.663(b)-2 Section 1.663(b)-2 Internal... TAXES Estates and Trusts Which May Accumulate Income Or Which Distribute Corpus § 1.663(b)-2 Election. (a) Manner and time of election; irrevocability—(1) When return is required to be filed. If a...

  12. Component Based System Framework for Dynamic B2B Interaction

    NARCIS (Netherlands)

    Hu jinmin, H.J.; Grefen, P.W.P.J.

    2002-01-01

    Business-to-business (B2B) collaboration is becoming a pivotal way to bring today's enterprises to success in the dynamically changing, e-business environment. Though many business-to-business protocols are developed to support B2B interaction, none are generally accepted. A B2B system should suppor

  13. TRUST IN B2B E-MARKETPLACES

    Directory of Open Access Journals (Sweden)

    SEBASTIAN KOT

    2011-01-01

    Full Text Available The paper presents background of B2B exchanges and review of their forms and functionalities. The benefits and fails reasons are noticed. European enterprises interest in B2B trade is next aspect of consideration. Finally, the trust barriers of B2B exchanges are presented.

  14. 32 CFR 242b.2 - Meetings of the Board.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Meetings of the Board. 242b.2 Section 242b.2... THE HEALTH SCIENCES § 242b.2 Meetings of the Board. (a) Regular meetings. (1) The Board shall hold at... determined by the Board, meetings shall be held at the offices of the University, 4301 Jones Bridge...

  15. MgB2 tunnel junctions and SQUIDs

    NARCIS (Netherlands)

    Brinkman, A.; Rowell, J.M.

    2007-01-01

    Recent advances in the realization and understanding of MgB2 tunnel junctions and SQUIDs are surveyed. High quality MgB2 junctions with suitable tunnel barriers have been realized based on both oriented and epitaxial thin MgB2 films. Multiband transport properties, such as the existence of two energ

  16. Electronic Commerce in Tourism in China: B2B or B2C?

    Science.gov (United States)

    Li, Hongxiu; Suomi, Reima

    E-commerce has significantly changed the distribution channels of travel products in the world including China. Online channels are growing important in travel service distribution. In China tourism industry has been developed rapidly with the economic development, more and more international travel service providers are trying to expand their Chinese market through the Internet. This paper sheds lights on the e-commerce development models in China for international travel service providers. It explores the current e-tourism in China from the three different participants in the value chain in tourism industry - consumer, travel agent and travel service provider. The paper also identifies the barriers in B2C arena in international outbound travel market, and discusses the possible approaches for international travel service providers to develop their e-commerce in the huge Chinese market. The results in this study reveal that international travel service providers should focus on B2B model to expand their electronic market in China. B2C development in tourism largely depends on the change of Chinese customers' behavior and the change of international tourism regulations. The findings of the study are expected to assist international travel service providers to understand current e-tourism in China and to support their planning for future e-commerce development in China.

  17. Diophantine approximation and badly approximable sets

    DEFF Research Database (Denmark)

    Kristensen, S.; Thorn, R.; Velani, S.

    2006-01-01

    . The classical set Bad of `badly approximable' numbers in the theory of Diophantine approximation falls within our framework as do the sets Bad(i,j) of simultaneously badly approximable numbers. Under various natural conditions we prove that the badly approximable subsets of Omega have full Hausdorff dimension....... Applications of our general framework include those from number theory (classical, complex, p-adic and formal power series) and dynamical systems (iterated function schemes, rational maps and Kleinian groups)....

  18. Design of 3B3 beamline control system

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Both structure and design of the control system in BSRF-3B3 beamline, are discussed and the subsystems are described. The LabVIEW software has advantages on data collecting and real time inspecting. In the process of data collecting, some methods are taken to solve the problems that may be met.

  19. 75 FR 79988 - Airworthiness Directives; Eurocopter France Model AS350B, B1, B2, B3, BA, and EC130 B4 Helicopters

    Science.gov (United States)

    2010-12-21

    ... ] Belleville springs (cup springs) and the self-locking nut, and aligning the shaft damping system of the APC... require disassembling the damping system, replacing the cup springs and self-locking nut, and reassembling... ASBs that one nut (P/N 150SG1071, $36.12) and two springs (P/N 150SG1093, $29.14 each) are required...

  20. 76 FR 28637 - Airworthiness Directives; Eurocopter France Model AS350B, B1, B2, B3, BA, and EC130 B4 Helicopters

    Science.gov (United States)

    2011-05-18

    ... United States. These ASBs specify disassembly of the damping system, replacing the Belleville springs (cup springs) and the self-locking nut, and aligning the shaft damping system of the APC starter.... That NPRM was published in the Federal Register on December 21, 2010 (75 FR 79988). That NPRM...

  1. 20 CFR Appendix B to Part 718 - Standards for Administration and Interpretation of Pulmonary Function Tests. Tables B1, B2, B3...

    Science.gov (United States)

    2010-04-01

    ... the entire maximum inspiration and the entire maximum forced expiration. The instrument shall, in... instructed to expire completely, momentarily hold his breath, place the mouthpiece in his mouth and close the.... Inspiration and expiration shall be checked visually for reproducibility. The effort shall be...

  2. Transposable B2 SINE elements can provide mobile RNA polymerase II promoters.

    Science.gov (United States)

    Ferrigno, O; Virolle, T; Djabari, Z; Ortonne, J P; White, R J; Aberdam, D

    2001-05-01

    Short interspersed elements (SINEs) are highly abundant components of mammalian genomes that are propagated by retrotransposition. SINEs are recognized as a causal agent of human disease and must also have had a profound influence in shaping eukaryotic genomes. The B2 SINE family constitutes approximately 0.7% of total mouse genomic DNA (ref. 2) and is also found at low abundance in humans. It resembles the Alu family in several respects, such as its mechanism of propagation. B2 SINEs are derived from tRNA and are transcribed by RNA polymerase (pol) III to generate short transcripts that are not translated. We find here, however, that one B2 SINE also carries an active pol II promoter located outside the tRNA region. Indeed, a B2 element is responsible for the production of a mouse Lama3 transcript. The B2 pol II promoters can be bound and stimulated by the transcription factor USF (for upstream stimulatory factor), as shown by transient transfection experiments. Moreover, this pol II activity does not preclude the pol III transcription necessary for retrotransposition. Dispersal of B2 SINEs by retrotransposition may therefore have provided numerous opportunities for creating regulated pol II transcription at novel genomic sites. This mechanism may have allowed the evolution of new transcription units and new genes. PMID:11326281

  3. Theoretical Calculations for Structural, Elastic and Thermodynamic Properties of MgB2 under High Pressure

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    We have investigated the structural and elastic properties of MgB2 under high pressures using the fullpotential linearized muffin-tin orbital (FP-LMTO) scheme within the generalized gradient approximation correction (GGA) in the frame of density functional theory. The calculated pressure dependence of the normalized volume is in excellent agreement with the experimental results. At the same time the elastic constants and acoustic anisotropy as a function of applied pressure are presented. Through the quasi-harmonic Debye model, we also investigate the thermodynamic properties of MgB2.

  4. Low-Temperature Synthesis of Superconducting Nanocrystalline MgB2

    Directory of Open Access Journals (Sweden)

    Jun Lu

    2010-01-01

    Full Text Available Magnesium diboride (MgB2 is considered a promising material for practical application in superconducting devices, with a transition temperature near 40 K. In the present paper, nanocrystalline MgB2 with an average particle size of approximately 70 nm is synthesized by reacting LiBH4 with MgH2 at temperatures as low as 450°C. This synthesis approach successfully bypasses the usage of either elemental boron or toxic diborane gas. The superconductivity of the nanostructures is confirmed by magnetization measurements, showing a superconducting critical temperature of 38.7 K.

  5. Mechanical properties and microstructure of TiB2 ceramic influenced by ZrB2 additive

    Institute of Scientific and Technical Information of China (English)

    王皓; 傅正义; 辜萍; 王为民; 袁润章

    2002-01-01

    Since some transition metal diborides have the same crystal structure with TiB2, which can react with TiB2 to form solid solution by adequate technique. With ZrB2 used as additive, the TiB2-ZrB2 solid solution was prepared by hot pressing. The effects of additive content on mechanical properties of composite were investigated. The microstructure analyzing were employed by EPMA, SEM and TEM. It is shown that TiB2 can partly form solid solution with ZrB2 and redound to gain uniform grains, which h results in the increase of mechanical properties.

  6. A research on B2B modes%B2B电子商务模式研究

    Institute of Scientific and Technical Information of China (English)

    黎梅

    2001-01-01

    21世纪是电子商务时代,在对最具潜力的B2B电子商务模式的网站调查基础上,对B2B电子商务的模式进行了详细分类和分析,为我国的B2B电子商务经营者制订切实可行的发展策略和营销策略提供了参考和借鉴.从目前情况和长远趋势来看,在B2B电子商务的4种模式中,其中企业B2B网站、B2B交易场、垂直型的B2B网站在中国将有很好的发展趋势.

  7. Potassium zinc borate, KZnB3O6

    Directory of Open Access Journals (Sweden)

    Yang Wu

    2010-05-01

    Full Text Available The title compound, KZnB3O6 contains a remarkable [B6O12]6− group (overline{1} symmetry formed by two rings linked by edge-sharing BO4 tetrahedra, a feature that has only been observed previously under high pressure conditions. These borate groups are connected through distorted ZnO4 tetrahedra in edge-shared pairs (overline{1} symmetry, forming a three-dimensional network whose cavities are filled by K+ cations.

  8. Potassium zinc borate, KZnB(3)O(6).

    Science.gov (United States)

    Wu, Yang; Yao, Ji-Yong; Zhang, Jian-Xiu; Fu, Pei-Zhen; Wu, Yi-Cheng

    2010-01-01

    The title compound, KZnB(3)O(6) contains a remarkable [B(6)O(12)](6-) group ( symmetry) formed by two rings linked by edge-sharing BO(4) tetra-hedra, a feature that has only been observed previously under high pressure conditions. These borate groups are connected through distorted ZnO(4) tetra-hedra in edge-shared pairs ( symmetry), forming a three-dimensional network whose cavities are filled by K(+) cations. PMID:21578991

  9. Anisotropy of superconducting MgB2 as seen in electron spin resonance and magnetization data.

    Science.gov (United States)

    Simon, F; Jánossy, A; Fehér, T; Murányi, F; Garaj, S; Forró, L; Petrovic, C; Bud'ko, S L; Lapertot, G; Kogan, V G; Canfield, P C

    2001-07-23

    We observed the conduction electron spin resonance (CESR) in fine powders of MgB2 both in the superconducting and normal states. The Pauli susceptibility is chi(s) = 2.0 x 10(-5) emu/mole in the temperature range of 450 to 600 K. The spin relaxation rate has an anomalous temperature dependence. The CESR measured below T(c) at several frequencies suggests that MgB2 is a strongly anisotropic superconductor with the upper critical field, H(c2), ranging between 2 and 16 T. The high-field reversible magnetization data of a randomly oriented powder sample are well described assuming that MgB2 is an anisotropic superconductor with H(ab)(c2)/H(c)(c2) approximately 6-9.

  10. Organizational patterns for knowledge capture in B2B engagements

    OpenAIRE

    Niwe, Moses

    2010-01-01

    The purpose of this research is to present a means of knowledge capture in form of patterns that are solutions to reoccurring problems for business-to-business (B2B) organizations. Using empirical data, we examine the processes involved in the B2B engagement and capture valuable solutions as best practices. The collection of patterns forms a pattern language for B2B engagements that addresses operational, communication and collaboration areas of the B2B environment. The thesis is organized in...

  11. Boron isotope effect in superconducting MgB2.

    Science.gov (United States)

    Bud'ko, S L; Lapertot, G; Petrovic, C; Cunningham, C E; Anderson, N; Canfield, P C

    2001-02-26

    We report the preparation method of and boron isotope effect for MgB2, a new binary intermetallic superconductor with a remarkably high superconducting transition temperature T(c)(10B) = 40.2 K. Measurements of both temperature dependent magnetization and specific heat reveal a 1.0 K shift in T(c) between Mg11B2 and Mg10B2. Whereas such a high transition temperature might imply exotic coupling mechanisms, the boron isotope effect in MgB2 is consistent with the material being a phonon-mediated BCS superconductor.

  12. Thermoelastic properties of ScB2, TiB2, YB4 and HoB4

    DEFF Research Database (Denmark)

    Waskowska, A.; Gerward, L.; Staun Olsen, J.;

    2011-01-01

    High-pressure X-ray diffraction in ScB2, TiB2, YB4 and HoB4 powders and single crystals has been studied using synchrotron radiation as well as conventional X-rays. The experimental results are supported by calculations using density functional theory. ScB2, YB4 and HoB4 are hard materials (bulk ...

  13. Whole genome and transcriptome sequencing of a B3 thymoma.

    Directory of Open Access Journals (Sweden)

    Iacopo Petrini

    Full Text Available Molecular pathology of thymomas is poorly understood. Genomic aberrations are frequently identified in tumors but no extensive sequencing has been reported in thymomas. Here we present the first comprehensive view of a B3 thymoma at whole genome and transcriptome levels. A 55-year-old Caucasian female underwent complete resection of a stage IVA B3 thymoma. RNA and DNA were extracted from a snap frozen tumor sample with a fraction of cancer cells over 80%. We performed array comparative genomic hybridization using Agilent platform, transcriptome sequencing using HiSeq 2000 (Illumina and whole genome sequencing using Complete Genomics Inc platform. Whole genome sequencing determined, in tumor and normal, the sequence of both alleles in more than 95% of the reference genome (NCBI Build 37. Copy number (CN aberrations were comparable with those previously described for B3 thymomas, with CN gain of chromosome 1q, 5, 7 and X and CN loss of 3p, 6, 11q42.2-qter and q13. One translocation t(11;X was identified by whole genome sequencing and confirmed by PCR and Sanger sequencing. Ten single nucleotide variations (SNVs and 2 insertion/deletions (INDELs were identified; these mutations resulted in non-synonymous amino acid changes or affected splicing sites. The lack of common cancer-associated mutations in this patient suggests that thymomas may evolve through mechanisms distinctive from other tumor types, and supports the rationale for additional high-throughput sequencing screens to better understand the somatic genetic architecture of thymoma.

  14. HER2/ErbB2 Receptor Signaling in Rat and Human Prolactinoma Cells: Strategy for Targeted Prolactinoma Therapy

    OpenAIRE

    Fukuoka, Hidenori; Cooper, Odelia; MIZUTANI, JUN; Tong, Yunguang; Ren, Song-Guang; Bannykh, Serguei; Melmed, Shlomo

    2010-01-01

    Dopamine agonist resistance or intolerance is encountered in approximately 20% of prolactinoma patients. Because human epidermal growth factor receptor 2 (HER2)/ErbB2 is overexpressed in prolactinomas and ErbB receptor ligands regulate prolactin (PRL) gene expression, we tested the role of HER2/ErbB2 in prolactinoma hormone regulation and adenoma cell proliferation to assess the rationale for targeting this receptor for prolactinoma therapy. As we showed prolactinoma HER2 overexpression, we g...

  15. From E2g to other modes: effects of pressure on electron-phonon interaction in MgB2.

    Science.gov (United States)

    Singh, Prabhakar P

    2006-12-15

    We study the effects of pressure on the electron-phonon interaction in MgB2 using density-functional-based methods. Our results show that the superconductivity in MgB2 vanishes by 100 GPa, and then reappears at higher pressures. In particular, we find a superconducting transition temperature Tc approximately 2 K for mu*=0.1 at a pressure of 137 GPa.

  16. 26 CFR 1.403(b)-2 - Definitions.

    Science.gov (United States)

    2010-04-01

    ...) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.403(b)-2 Definitions. (a) Application... 1450(b) of the Small Business Job Protection Act of 1996 (110 Stat. 1755, 1814) for special rules... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Definitions. 1.403(b)-2 Section...

  17. Removal of oxide contamination from TiB2 powders

    International Nuclear Information System (INIS)

    Commerical TiB2 powders from the carbothermic process are invariably contaminated with oxygen. Contamination is usually caused by surface oxidation during grinding or comminution. Surface oxide contamination, which commonly occurs in fine TiB2 powders and affects their properties, can be removed by treatment with BCl3(g) at 6500C

  18. 26 CFR 48.4161(b)-2 - Meaning of terms.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Meaning of terms. 48.4161(b)-2 Section 48.4161(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS... with a string and used for the propelling of arrows in the sport of archery (target shooting), or...

  19. Multiband model for tunneling in MgB2 junctions

    NARCIS (Netherlands)

    Brinkman, A.; Golubov, A.A.; Rogalla, H.; Dolgov, O.V.; Kortus, J.; Kong, Y.; Jepsen, O.; Andersen, O.K.

    2002-01-01

    A theoretical model for quasiparticle and Josephson tunneling in multiband superconductors is developed and applied to MgB2-based junctions. The gap functions in different bands in MgB2 are obtained from an extended Eliashberg formalism, using the results of band structure calculations. The temperat

  20. EXTREMAL VECTORS FOR VERMA TYPE REPRESENTATION OF B2

    Directory of Open Access Journals (Sweden)

    Čestmír Burdík

    2013-10-01

    Full Text Available Starting from the Verma modules of the algebra B2 we explicitly construct factor representations of the algebra B2 which are connected with the unitary representation of the group SO(3, 2. We find a full set of extremal vectors for representations of this kind. So we can explicitly resolve the problem of the irreducibility of these representations.

  1. ORM-based semantics of B2B transactions.

    NARCIS (Netherlands)

    Balsters, H.; van Blommestein, F.; Meersman, R; Herrero, P; Dillon, T

    2009-01-01

    After widespread implementation of Enterprise Resource Planning and Personal Information Management, the next wave in the application of ICT is headed towards business to business (B2B) communication. B2B has a number of specific aspects, one of them being negotiation. This aspect has been largely n

  2. Anisotropies of the lower and upper critical fields in MgB2 single crystals.

    Science.gov (United States)

    Lyard, L; Szabó, P; Klein, T; Marcus, J; Marcenat, C; Kim, K H; Kang, B W; Lee, H S; Lee, S I

    2004-02-01

    The temperature dependence of the upper (H(c2)) and lower (H(c1)) critical fields has been deduced from Hall probe magnetization measurements of high quality MgB2 single crystals along the two main crystallographic directions. We show that Gamma(H(c2))=H(c2 axially ab)/H(c2 axially c) and Gamma(H(c1))=H(c1 axially c)/H(c1 axially ab) differ significantly at low temperature (being approximately 5 and approximately 1, respectively) and have opposite temperature dependencies. We suggest that MgB2 can be described by a single field dependent anisotropy parameter gamma(H) (=lambda(c)/lambda(ab)=xi(ab)/xi(c)) that increases from Gamma(H(c1)) at low field to Gamma(H(c2)) at high field.

  3. 为了B2C的聚会

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    2006年12月8日“第一届中国B2C发展大会”在北京举行,在这个为了B2C的聚会中,业界人士、专家学者就中国B2C的现状畅所欲言,其中B2C经营模式、产品的创新、网上支付的应用情况、B2C网站的互动性.存在在的法律问题等消费者关注的问题成为讨论的热点。

  4. Evidence for two-band superconductivity from break-junction tunneling on MgB2.

    Science.gov (United States)

    Schmidt, H; Zasadzinski, J F; Gray, K E; Hinks, D G

    2002-03-25

    Superconductor-insulator-superconductor tunnel junctions have been fabricated on MgB2 that display Josephson and quasiparticle currents. These junctions exhibit a gap magnitude, Delta approximately 2.5 meV, that is considerably smaller than the BCS value, but which clearly and reproducibly closes near the bulk T(c). In conjunction with fits of the conductance spectra, these results are interpreted as direct evidence of two-band superconductivity.

  5. First-Principles Calculations of Elastic Constants of Superconducting MgB2

    Institute of Scientific and Technical Information of China (English)

    GUO Hua-Zhong; CHEN Xiang-Rong; ZHU Jun; CAI Ling-Cang; GAO Jie

    2005-01-01

    @@ The five independent elastic constants of superconducting MgB2 are obtained using the first-principles plane wave method with the new relativistic analytic pseudopotential of the Hartwigsen-Goedecker-Hutter (HGH) scheme in the frame of local density approximation. The dependences of bulk modulus on temperature and pressure are also obtained. It is suggested that the HGH-type pseudopotentials are successful in investigating the ground-state mechanical properties of any solids.

  6. Optimal Belief Approximation

    CERN Document Server

    Leike, Reimar H

    2016-01-01

    In Bayesian statistics probability distributions express beliefs. However, for many problems the beliefs cannot be computed analytically and approximations of beliefs are needed. We seek a ranking function that quantifies how "embarrassing" it is to communicate a given approximation. We show that there is only one ranking under the requirements that (1) the best ranked approximation is the non-approximated belief and (2) that the ranking judges approximations only by their predictions for actual outcomes. We find that this ranking is equivalent to the Kullback-Leibler divergence that is frequently used in the literature. However, there seems to be confusion about the correct order in which its functional arguments, the approximated and non-approximated beliefs, should be used. We hope that our elementary derivation settles the apparent confusion. We show for example that when approximating beliefs with Gaussian distributions the optimal approximation is given by moment matching. This is in contrast to many su...

  7. l/f Noise in the Superconducting Transition of a MgB2 Thin Film

    Science.gov (United States)

    Lakew, B.; Aslam, S.; Jones, H.; Stevenson, T.; Cao, N.

    2010-01-01

    The noise voltage spectral density in the superconducting transition of a MgB2 thin film on a SiN-coated Si thick substrate was measured over the frequency range 1 Hz-to-1 KHz. Using established bolometer noise theory the theoretical noise components due to Johnson, 1/f(excess) and phonon noise are modeled to the measured data. It is shown that for the case of a MgB2 thin film in the vicinity of the mid-point of transition, coupled to a heat sink via a fairly high thermal conductance (approximately equal to 10(sup -1) W/K)) that the measured noise voltage spectrum is 1/f limited and exhibits lit dependence with a varying between 0.3 and 0.5 in the measured frequency range. At a video frame rate frequency of 30 Hz the measured noise voltage density in the film is approximately equal to 61 nV /the square root of HZ, using this value an upper limit of electrical NEP approximately equal to 0.67pW / the square root of Hz is implied for a practical MgB2 bolometer operating at 36.1 K.

  8. A ridge of recent massive star formation between Sgr B2M and Sgr B2N

    CERN Document Server

    De Vicente, P; Neri, R; Colom, P

    2000-01-01

    We present single dish and interferometric maps of several rotational transitions of HC3N vibrationally excited levels towards Sgr B2. The single dish maps show, for the first time, new four bright clumps (Sgr B2R1 to B2R4) in the ridge connecting the main cores Sgr B2M and Sgr B2N, and a low brightness extended region to the west of the ridge (Sgr B2W). The physical properties and the kinematics of all hot cores have been derived from the HC3N* lines. Our high angular resolution images show that the Sgr B2N hot core breaks in two different hot cores, Sgr B2N1 and N2, with different radial velocities and separated by 2 arcsec in declination. We find that the excitation of the HC3N* emission in all hot cores can be represented by a single temperature and that the linewidth of the HC3N* rotational lines arising from different vibrational levels systematically decreases as the energy of the vibrational level increases. The systematic trend in the linewidth is likely related to the increase of the velocity as the...

  9. Preparation of MgB2 Superconducting Materials%MgB2超导材料的制备

    Institute of Scientific and Technical Information of China (English)

    王醒东

    2014-01-01

    二硼化镁(MgB2)是重要的超导材料,在超导磁体等领域有着潜在的应用.本文介绍了MgB2超导块材、带材及薄膜,重点介绍了制备MgB2超导带材的粉末套管法以及制备MgB2超导薄膜的电子束蒸发法、共蒸发法和溅射法,指出了MgB2超导材料未来的发展方向.

  10. Fuzzy Approximating Spaces

    OpenAIRE

    Bin Qin

    2014-01-01

    Relationships between fuzzy relations and fuzzy topologies are deeply researched. The concept of fuzzy approximating spaces is introduced and decision conditions that a fuzzy topological space is a fuzzy approximating space are obtained.

  11. Approximate flavor symmetries

    CERN Document Server

    Rasin, A

    1994-01-01

    We discuss the idea of approximate flavor symmetries. Relations between approximate flavor symmetries and natural flavor conservation and democracy models is explored. Implications for neutrino physics are also discussed.

  12. Approximate iterative algorithms

    CERN Document Server

    Almudevar, Anthony Louis

    2014-01-01

    Iterative algorithms often rely on approximate evaluation techniques, which may include statistical estimation, computer simulation or functional approximation. This volume presents methods for the study of approximate iterative algorithms, providing tools for the derivation of error bounds and convergence rates, and for the optimal design of such algorithms. Techniques of functional analysis are used to derive analytical relationships between approximation methods and convergence properties for general classes of algorithms. This work provides the necessary background in functional analysis a

  13. Effects of hypervitaminosis of vitamin B3 on silkworm biology

    Indian Academy of Sciences (India)

    Kayvan Etebari; Leila Matindoost

    2004-12-01

    A high-dose of vitamin B3 in silkworm diet interrupts larval feeding and normal growth. High mortality of larvae occurs during molting and they cannot complete this process normally. Also the larvae exhibit nicotinamide hypervitaminosis symptoms such as immobility, dyspepsia, darkening of the skin, inability to excrete normally, exerting brownish fluid from anus and swelling of rectal muscles. Maximum larval weights in 1, 2 and 3 g/l treatments were 2.9, 1.6 and 1.2 g respectively, while maximum larval weight in the control was 5.6 g. Larval stage compared to control had increased 18, 26 and 31 days respectively. The concentration increase of uric acid in haemolymph demonstrates the hyperuricemia, while other measured biochemical compounds show significant decrease; sodium and potassium did not change significantly.

  14. Digitaalisen markkinoinnin suunnitelma b2b-yritykselle

    OpenAIRE

    Harhakoski, Oskari

    2011-01-01

    Työ käsittelee digitaalisen markkinoinnin suunnitelman tekemistä b2b-yritykselle. Tavoitteena oli kilpailuedun hankkiminen sosiaalisen median tehokkaalla hyödyntämisellä mark-kinoinnissa. Konkreettisemmin yritys halusi lisää näkyvyyttä ja myyntiä. Suunnitelman laatimisessa hyödynnettiin POST-menetelmää. Erityistä huomiota kiinnitettiin b2b-markkinoinnin eroihin b2c-markkinointiin verrattuna. Myös yrityksen toimiminen Suomen markkinoilla huomioitiin. Lisäksi analysoitiin kilpailijoita asia...

  15. B2B营销的权威

    Institute of Scientific and Technical Information of China (English)

    陈荣

    2006-01-01

    现在很流行的一个词就是B2B营销,那么到底什么叫B2B营销呢?雷·赖特所著的《组织间营销》(英文全名Business—to—Business Marketing:AStep-by-Step Guide)可以回答你的问题,它可谓是全面了解B2B营销所涉及的各个层面的权威书籍。

  16. Ultrasonic Properties of the MgB2 Superconductor

    Institute of Scientific and Technical Information of China (English)

    YU Ri-Cheng; JIN Chang-Qing; LI Shao-Chun; WANG Ru-Ju; LI Feng-Ying; LIU Zhen-Xing; ZHU Jia-Lin

    2001-01-01

    The sound velocities of longitudinal and shear waves are measured on a polycrystalline MgB2 superconductor with Tc of 39 K. The specimen used in the experiments is pressed and heated using the MgB2 powder. The elastic moduli, Debye temperature and specific heat at room temperature are obtained based on sound velocity data. The results indicate that the velocities are much higher than those in the usual materials, while elastic constants remain reasonably soft, which may be due to the high transition temperature of the MgB2 superconductor.

  17. Fine-Filament MgB2 Superconductor Wire

    Science.gov (United States)

    Cantu, Sherrie

    2015-01-01

    Hyper Tech Research, Inc., has developed fine-filament magnesium diboride (MgB2) superconductor wire for motors and generators used in turboelectric aircraft propulsion systems. In Phase I of the project, Hyper Tech demonstrated that MgB2 multifilament wires (MgB2 rotor coil packs for a superconducting generator. The ultimate goal is to enable low-cost, round, lightweight, low-AC-loss superconductors for motor and generator stator coils operating at 25 K in next-generation turboelectric aircraft propulsion systems.

  18. Planar B3S2H3(-) and B3S2H3 clusters with a five-membered B3S2 ring: boron-sulfur hydride analogues of cyclopentadiene.

    Science.gov (United States)

    Li, Da-Zhi; Li, Rui; Zhang, Li-Juan; Ou, Ting; Zhai, Hua-Jin

    2016-08-21

    Boron clusters can serve as inorganic analogues of hydrocarbons or polycyclic aromatic hydrocarbons (PAHs). We present herein, based upon global searches and electronic structural calculations at the B3LYP and CCSD(T) levels, the global-minimum structures of two boron-sulfur hydride clusters: C2v B3S2H3(-) (1, (2)B1) and C2v B3S2H3 (2, (1)A1). Both species are perfectly planar and feature a five-membered B3S2 ring as the structural core, with three H atoms attached terminally to the B sites. Chemical bonding analysis shows that C2v B3S2H3(-) (1) has a delocalized 5π system within a heteroatomic B3S2 ring, analogous to the π bonding in cyclopentadiene, D5h C5H5. The corresponding closed-shell C2v B3S2H3(2-) (3, (1)A1) dianion is only a local minimum. At the single-point CCSD(T) level, it is 5.7 kcal mol(-1) above the chain-like C1 ((1)A) open structure. This situation is in contrast to the cyclopentadienyl anion, C5H5(-), a prototypical aromatic hydrocarbon with a π sextet. The C2v B3S2H3 (2) neutral cluster is readily obtained upon removal of one π electron from C2v B3S2H3(-) (1). The anion photoelectron spectrum of C2v B3S2H3(-) (1) and the infrared absorption spectrum of C2v B3S2H3 (2) are predicted. The C2v B3S2H3(-) (1) species can be stabilized in sandwich-type C2h [(B3S2H3)2Fe](2-) and salt C2h [(B3S2H3)2Fe]Li2 complexes. An intriguing difference is observed between the pattern of π sextet in C2v B3S2H3(2-) (3) dianion and that in cyclopentadienyl anion. The present work also sheds light on the mechanism of structural evolution in the B3S2H3(0/-/2-) series with charge states. PMID:27424889

  19. Characterization of LiB(3)O(5) crystal for second-harmonic generation.

    Science.gov (United States)

    Xie, F; Wu, B; You, G; Chen, C

    1991-08-15

    We present second-harmonic generation characteristics of LiB(3)O(5) (LBO) crystal with different phase-matching lengths and comparison with those of beta-BaB(2)O(4) crystal. A computer program of the numerical interaction method was adopted to make the theoretical calculation of second-harmonic generation conversion efficiencies of LBO with different phase-matching lengths and power densities of the fundamental beam of a Nd:YAG laser, and the calculated result was compared with the experimental one. It is seen from the calculated and experimental results that for certain power densities of the fundamental laser beam, so long as the length of the LBO crystal is selected appropriately, a high energy conversion efficiency could be obtained. For example, an optimal external energy conversion efficiency of LBO crystal of more than 70% has been attained for several 100-MW/cm(2) fundamental laser beams. Experiments also showed that the crystal could be used under high power densities without any damage to the surface and the interior. PMID:19776930

  20. Approximation of distributed delays

    CERN Document Server

    Lu, Hao; Eberard, Damien; Simon, Jean-Pierre

    2010-01-01

    We address in this paper the approximation problem of distributed delays. Such elements are convolution operators with kernel having bounded support, and appear in the control of time-delay systems. From the rich literature on this topic, we propose a general methodology to achieve such an approximation. For this, we enclose the approximation problem in the graph topology, and work with the norm defined over the convolution Banach algebra. The class of rational approximates is described, and a constructive approximation is proposed. Analysis in time and frequency domains is provided. This methodology is illustrated on the stabilization control problem, for which simulations results show the effectiveness of the proposed methodology.

  1. Thermal shock resistance of ZrB2 and ZrB2-30% SiC

    International Nuclear Information System (INIS)

    Thermal shock of high density (>99% relative density) zirconium diboride (ZrB2) and zirconium diboride containing 30 vol.% silicon carbide (SiC) was studied. Calculations based on thermal shock theory indicated that ZrB2-30 vol.% SiC should have greater thermal shock resistance than ZrB2 due to its higher fracture strength. Water quench tests revealed essentially the same critical thermal shock values for both materials (ΔTcrit = ∼400 deg. C). A finite element model was used to estimate the temperatures and stresses in both ceramics during quench testing. The model predicted that maximum thermal stresses during the experimental quench test exceeded the strength of ZrB2 (568 MPa) but not ZrB2-30 vol.% SiC (863 MPa). The lower than predicted thermal shock resistance of ZrB2-SiC was attributed to the non-uniform cooling between the ZrB2 matrix grains and the SiC particulate phase

  2. Structural stability and electrical properties of AlB2-type MnB2 under high pressure

    International Nuclear Information System (INIS)

    The structural stability and electrical properties of AlB2-type MnB2 were studied based on high pressure angle-dispersive x-ray diffraction, in situ electrical resistivity measured in a diamond anvil cell (DAC) and first-principles calculations under high pressure. The x-ray diffraction results show that the structure of AlB2-type MnB2 remains stable up to 42.6 GPa. From the equation of state of MnB2, we obtained a bulk modulus value of 169.9±3.7 GPa with a fixed pressure derivative of 4, which indicates that AlB2-type MnB2 is a hard and incompressible material. The electrical resistance undergoes a transition at about 19.3 GPa, which can be explained by a transition of manganese 3d electrons from localization to delocalization under high pressure. (condensed matter: structural, mechanical, and thermal properties)

  3. Sparse approximation with bases

    CERN Document Server

    2015-01-01

    This book systematically presents recent fundamental results on greedy approximation with respect to bases. Motivated by numerous applications, the last decade has seen great successes in studying nonlinear sparse approximation. Recent findings have established that greedy-type algorithms are suitable methods of nonlinear approximation in both sparse approximation with respect to bases and sparse approximation with respect to redundant systems. These insights, combined with some previous fundamental results, form the basis for constructing the theory of greedy approximation. Taking into account the theoretical and practical demand for this kind of theory, the book systematically elaborates a theoretical framework for greedy approximation and its applications.  The book addresses the needs of researchers working in numerical mathematics, harmonic analysis, and functional analysis. It quickly takes the reader from classical results to the latest frontier, but is written at the level of a graduate course and do...

  4. Photoelectron spectroscopy of boron-gold alloy clusters and boron boronyl clusters: B3Au(n)(-) and B3(BO)n(-) (n = 1, 2).

    Science.gov (United States)

    Chen, Qiang; Bai, Hui; Zhai, Hua-Jin; Li, Si-Dian; Wang, Lai-Sheng

    2013-07-28

    Photoelectron spectroscopy and density-functional theory are combined to study the structures and chemical bonding in boron-gold alloy clusters and boron boronyl clusters: B3Au(n)(-) and B3(BO)n(-) (n = 1, 2). Vibrationally resolved photoelectron spectra are obtained for all four species and the B-Au and B-BO clusters exhibit similar spectral patterns, with the latter species having higher electron binding energies. The electron affinities of B3Au, B3Au2, B3(BO), and B3(BO)2 are determined to be 2.29 ± 0.02, 3.17 ± 0.03, 2.71 ± 0.02, and 4.44 ± 0.02 eV, respectively. The anion and neutral clusters turn out to be isostructural and isovalent to the B3H(n)(-)∕B3H(n) (n = 1, 2) species, which are similar in bonding owing to the fact that Au, BO, and H are monovalent σ ligands. All B3Au(n)(-) and B3(BO)n(-) (n = 1, 2) clusters are aromatic with 2π electrons. The current results provide new examples for the Au∕H and BO∕H isolobal analogy and enrich the chemistry of boronyl and gold. PMID:23901981

  5. B2B“风口”渐近

    Institute of Scientific and Technical Information of China (English)

    杨宁

    2014-01-01

    经过十多年的发展,B2B业务在2014年有一种“风口”的感觉。经过十多年的发展,B2B在2014年有一种“风口”的感觉。2009-2013年,B2B交易额和市场收入差异非常大:包括阿里巴巴、慧聪网等总收入不到200亿元,而中国B2B市场的交易规模在7万~8万亿之间。

  6. Bending strain tolerance of MgB2 superconducting wires

    Science.gov (United States)

    Kováč, P.; Hušek, I.; Melišek, T.; Kulich, M.; Kopera, L.

    2016-04-01

    This work describes the strain tolerance of MgB2 superconductors subjected to variable bending stresses. Bending of MgB2 wire was done at room temperature in different modes: (i) direct bending of straight annealed samples to variable diameters and by (ii) indirect bending by straightening of bent and annealed samples. I c-bending strain characteristics of samples made by in situ PIT and by the internal magnesium diffusion (IMD) process were measured at 4.2 K. The results show a good agreement between the direct and indirect bending mode, which allows easier estimation of limits important for the winding process of MgB2 superconductors with brittle filaments. A comparison of MgB2 wires made by in situ PIT and IMD processes showed improved strain tolerance for IMD due to better grain connectivity the low annealing temperature, which does not appear to reduce the mechanical strength of sheath material.

  7. Preparation of MgB2 superconducting tapes using electrophoresis

    Science.gov (United States)

    Xu, J. D.; Wang, S. F.; Zhou, Y. B.; Zhou, Y. L.; Chen, Z. H.; Cui, D. F.; Lu, H. B.; He, M.; Dai, S. Y.; Yang, G. Z.

    2002-08-01

    Superconducting MgB2/Ta tapes with a critical temperature of 34 K have been prepared successfully by ex situ annealing of electrophoresis-grown boron in the presence of Mg vapour at 920 °C. Scanning electron microscopy was used to examine the surface morphology of the MgB2/Ta tapes, and well-formed MgB2 crystals with sizes up to 2 μm were observed. The x-ray diffraction patterns showed randomly orientated growth of MgB2 phase in the tapes. Estimates using hysteresis loops and the Bean model give a value of 6.8 × 105 A cm-2 for the critical current density.

  8. Scope of Internal Marketing in B2B Companies

    OpenAIRE

    Nigam, Niharika

    2007-01-01

    Abstract Previous studies have focused on "internal marketing" from services marketing perspective. There is, therefore, a great dearth of in-depth research on its application to other business types. This research attempts to find the scope of internal marketing in B2B companies. The purpose of this research is to closely examine the elements, their linkage, tools and applications of Internal marketing when applied to B2B settings. Internal marketing, the application of marketing managem...

  9. TiB2 ceramic and DLC Multilayered PVD coatings

    OpenAIRE

    Santos da Silva Cruz, Ricardo Manuel

    2007-01-01

    Titanium diboride (TiB2) has been investigated as a potential candidate for several industrial applications, such as: cutting tools, electric devices, wear parts and many more fields of application. The main drawback of TiB2 is its brittle nature, which has limited its range of applications. Diamond-like Carbon (DLC) has been used in industrial applications, mainly for wear resistant parts. However, the application of DLC films has been limited by the level of internal stres...

  10. B2B emarketplace announcements and shareholder wealth

    OpenAIRE

    Andrew H. Chen; Siems, Thomas F.

    2001-01-01

    In the business-to-business (B2B) sector, new supply-chain models within electronic marketplaces (eMarketplaces) offer firms significantly lower procurement costs, increased operating efficiencies, and expanded market opportunities. Using event-study methodology to look at the period July 1999-March 2000, Andrew Chen and Thomas Siems find that investors reacted favorably to B2B eMarketplace announcements, with slightly higher abnormal returns associated with vertical than with horizontal eMar...

  11. Preparation and characterization of MgB2 superconductor

    Indian Academy of Sciences (India)

    Shashwati Sen; D K Aswal; Ajay Singh; T V Chandrasekhar Rao; K P Muthe; J C Vyas; L C Gupta; S K Gupta; V C Sahni

    2002-05-01

    The MgB2 superconductor, synthesized using solid-state and liquid-phase sintering methods, have been characterized for various properties. The upper critical field, irreversibility line and critical current density have been determined using magnetization data. The current–voltage characteristics recorded under an applied magnetic field revealed the existence of vortex glass transition. The surface analysis using X-ray photoelectron spectroscopy shows that MgB2 is sensitive to atmospheric degradation.

  12. POLICY CONCERNS FOR ONLINE B2B EXCHANGES

    OpenAIRE

    Hooker, Neal H.; Rha, Jong-Youn; Ernst, Stanley C.; Widdows, Richard

    2002-01-01

    Policy concerns arise as e-business activities become increasingly common. This paper discusses important elements of such concerns, particularly the pro- and anti-competitive assessment of online business-to-business (B2B) exchanges. The definition of markets, the role of quality management and communication, and join purchasing implications within such environments are related to food distribution systems. Other online business-to-consumer (B2C) and consumer-to-business (C2B) policy concern...

  13. B2B品牌的隐形价值

    Institute of Scientific and Technical Information of China (English)

    詹姆斯·格雷戈里; 唐纳德·塞克斯顿

    2007-01-01

    @@ 消费品营销人员满脑子想着品牌资产(brand equity),他们也理应如 此.B2B公司如能效法,将是明智之举.我们对450多家公司进行了16年的量化研究,结果表明B2B品牌蕴藏着数十亿美元的价值.

  14. Il B2B e il paradigma dei costi di transazione (B2B and the Transaction Costs Paradigm

    Directory of Open Access Journals (Sweden)

    Pierluigi Sabbatini

    2001-06-01

    Full Text Available Business to Business (B2B Internet commerce causes a significant contraction of transaction costs. According to the Coase paradigm, we would thus expect a deverticalization of the industry and broader scope for anonymous market mechanisms. In reality, such expectations are not fully borne out by the facts. When the industrial structure is concentrated the B2Bgenerally loses its independence, and is owned by the firms which most contribute to its development, e.g. the ones able to bring the liquidity to it. The B2B governance mechanism established by these firms gives hierarchical mechanisms a role which they do not usually play in extensive, anonymous markets.

  15. Phonon dispersion and electron-phonon coupling in MgB2 and AlB2.

    Science.gov (United States)

    Bohnen, K P; Heid, R; Renker, B

    2001-06-18

    We present a first principles investigation of the lattice dynamics and electron-phonon coupling of the superconductor MgB2 and the isostructural AlB2 within the framework of density functional perturbation theory using a mixed-basis pseudopotential method. Complete phonon dispersion curves and Eliashberg functions alpha2F are calculated for both systems. The main differences are related to high frequency in-plane boron vibrations, which are strongly softened in MgB2 and exhibit an exceptionally strong electron-phonon coupling. We also report on Raman measurements, which support the theoretical findings. Implications for the superconducting transition temperature are briefly discussed.

  16. Neutron diffraction studies of magnetic ordering in superconducting ErNi2B2C and TmNi2B2C in an applied magnetic field

    International Nuclear Information System (INIS)

    The field-induced magnetic structures of ErNi2B2C and TmNi2B2C in are especially interesting because the field suppresses the superconducting order parameter and therefore the magnetic properties can be studied while varying the strength of superconductivity. ErNi2B2C: For magnetic fields along all three symmetry directions, the observed magnetic structures have a period corresponding to the Fermi surface nesting structure. The phase diagrams present all the observed magnetic structures. Two results remain unresolved: 1. When applying the magnetic field along [010], the minority domain (QNB = (0,Q,0) with moments perpendicular to the field) shows no signs of hysteresis. I expected it to be a meta-stable state, which would be gradually suppressed by a magnetic field, and when decreasing the field it would not reappear until some small field of approximately 0.1 T. 2. When the field is applied along [110], the magnetic structure rotates a small angle of 0.5 degrees away from the symmetry direction. TmNi2B2C: A magnetic field applied in the [100] direction suppresses the zero field magnetic structure QF = (0.094,0.094,0) (TN = 1.6 K), in favor of the Fermi surface nesting structure QN = (0.483,0,0). The appearance of the QN phase was initially believed to be caused by the suppression of superconductivity. This suppression should make it favorable to create a magnetic order with a Q-vector determined by the maximum in the magnetic susceptibility at the Fermi surface nesting vector QN. The phase diagram for the magnetic structures is presented, however several properties of the QN magnetic structure cannot be explained within any known models. Quadrupolar ordering is suggested as a possible candidate for explaining these features of the QN structure. (au)

  17. Studies of the influence of vitamin B1, B2 and B3 on the interaction between lysionotin and BSA%维生素B1、B2B3对石吊兰素与BSA结合作用的影响

    Institute of Scientific and Technical Information of China (English)

    张国文; 胡玉婷

    2014-01-01

    在模拟人体生理条件下,联合应用紫外-可见光谱法、荧光光谱法以及圆二色谱(CD)技术,研究了3种B族维生素(VB1、VB2、VB3)分别对石吊兰素与牛血清白蛋白(BSA)结合作用的影响.计算了3种维生素分别存在下石吊兰素-BSA体系的猝灭常数(k)、结合常数(K)、结合位点数(n)和结合距离(r)等参数,探讨了3种维生素对石吊兰素-BSA相互作用可能的影响方式.结果显示:VB1、VB2、VB3的加入使得石吊兰素-BSA体系的k和K增大,n基本不变,r稍有减小,表明VB1、VB2、VB3均能够增加石吊兰素-BSA体系的稳定性.VB1使得BSA-石吊兰素体系的主要作用力类型从以氢键和范德华力为主转变为以疏水作用力为主,而VB2、VB3的存在没有改变BSA-石吊兰素体系的主要作用力.CD分析结果表明:3种B族维生素的加入均能使BSA的α-螺旋含量有所增加.推断VB1、VB2、VB3与BSA的结合导致了BSA分子构象变化是维生素影响BSA-石吊兰素结合的主要方式.

  18. Myocilin mediates myelination in the peripheral nervous system through ErbB2/3 signaling.

    Science.gov (United States)

    Kwon, Heung Sun; Johnson, Thomas V; Joe, Myung Kuk; Abu-Asab, Mones; Zhang, Jun; Chan, Chi Chao; Tomarev, Stanislav I

    2013-09-13

    The glaucoma-associated gene, myocilin, is expressed in ocular and non-ocular tissues including the peripheral nervous system, but its functions in these tissues remain poorly understood. We demonstrate that in sciatic nerve, myocilin is expressed in Schwann cells with high concentrations at the nodes of Ranvier. There, myocilin interacts with gliomedin, neurofascin, and NrCAM, which are essential for node formation and function. Treatment of isolated dorsal root ganglion cultures with myocilin stimulates clustering of the nodal proteins neurofascin and sodium channel Nav1.2. Sciatic nerves of myocilin null mice express reduced levels of several myelin-associated and basal membrane proteins compared with those of wild-type littermates. They also demonstrate reduced myelin sheath thickness and partial disorganization of the nodes. Myocilin signaling through ErbB2/3 receptors may contribute to these observed effects. Myocilin binds to ErbB2/ErbB3, activates these receptors, and affects the downstream PI3K-AKT signaling pathway. These data implicate a role for myocilin in the development and/or maintenance of myelination and nodes of Ranvier in sciatic nerve. PMID:23897819

  19. Ab initio investigation of the electronic and geometric structure of magnesium diboride, MgB2.

    Science.gov (United States)

    Tzeli, Demeter; Mavridis, Aristides

    2005-12-01

    Employing multireference variational (MRCI) and coupled cluster (CC) methods combined with quadruple-zeta quality correlation-consistent basis set, we have studied 36 states of the magnesium diboride (MgB(2)) molecule as well as 17 states of the experimentally unknown diatomic MgB. For all states of MgB(2), we report geometries, atomization energies, and dipole moments, while for the first 5 states, potential energy profiles have been also constructed. The ground state is formally of (1)A(1) V-shaped symmetry with an atomization energy of 108.1(109) kcal/mol at the MRCI(MRCI + Davidson correction) level. The first excited state ((3)B(1)) is less than 1 kcal/mol above the X(1)A(1) state, with the next state of linear Mg-B-B geometry (b(3)Sigma(-)) located 10 kcal/mol higher. In all states, bent or linear, the bonding is complicated and unconventional because of the extraordinary bonding agility of the boron atom(s).

  20. Mechanical Spectroscopy of MgB2 Containing Sic / Spektroskopia Mechaniczna MgB2 Zawierającego Sic

    Directory of Open Access Journals (Sweden)

    Silva M.R.

    2015-12-01

    Full Text Available The compound magnesium diboride (MgB2 has been well-known since the 1950s; however, its superconducting properties were unknown. Intrinsic characteristics of MgB2 make this material a promising candidate for technological applications, although the low value of the irreversibility field and the decrease in critical current density with the increase in the magnetic field considerably reduce its utility. The present work aimed to study the effect of carbon-based doping on anelastic properties of MgB2 as measured by mechanical spectroscopy. The samples were prepared by using the powder-intube method. The samples were made with 5, 7.5, and 10 wt.% of silicon carbide (SiC. The results reveal complex mechanical loss spectra caused by the interaction between point defects and surface defects in the crystalline lattice of MgB2.

  1. AN OPTIMAL FUZZY APPROXIMATOR

    Institute of Scientific and Technical Information of China (English)

    YueShihong; ZhangKecun

    2002-01-01

    In a dot product space with the reproducing kernel (r. k. S. ) ,a fuzzy system with the estimation approximation errors is proposed ,which overcomes the defect that the existing fuzzy control system is difficult to estimate the errors of approximation for a desired function,and keeps the characteristics of fuzzy system as an inference approach. The structure of the new fuzzy approximator benefits a course got by other means.

  2. Approximation techniques for engineers

    CERN Document Server

    Komzsik, Louis

    2006-01-01

    Presenting numerous examples, algorithms, and industrial applications, Approximation Techniques for Engineers is your complete guide to the major techniques used in modern engineering practice. Whether you need approximations for discrete data of continuous functions, or you''re looking for approximate solutions to engineering problems, everything you need is nestled between the covers of this book. Now you can benefit from Louis Komzsik''s years of industrial experience to gain a working knowledge of a vast array of approximation techniques through this complete and self-contained resource.

  3. Coxsackievirus B3-induced apoptosis and Caspase-3

    Institute of Scientific and Technical Information of China (English)

    JIAN PING YUAN; WEI ZHAO; HONG TAO WANG; KAI YU WU; TAO LI; XIAO KUI GUO; SHAN QING TONG

    2003-01-01

    Cell death can be classified into two categories: apoptosis and necrosis. Apoptotic pathway can beeither caspase-dependent or caspase-independent. Caspase-independent cytopathic effect (CPE) has beendescribed. In order to evaluate the pattern of HeLa cell death induced by Coxsackievirus B3 (CVB3)and whether apoptosis involves caspase activation, we co-cultivated HeLa cells with CVB3 and detectedthe cytopathic changes, the alteration of mRNA and protein expression of caspase-3 gene plus caspase-3activity, as well as analyzing DNA fragmentation before and after caspase-3 activity inhibition. Accordingto the results, we propose that CVB3 may induce apoptosis and necrosis in HeLa cells, the latter appearingmuch earlier. Caspase-3 is activated at the levels of both transcription and translation, and procaspase-3 isproteolytically cleaved, thus leading to the continuous increasing of both caspase-3 precursor protein and itssubunit. However, besides CPE, apoptosis induced by CVB3 is not a direct consequence of the activationof caspase-3, or caspase-3 is not the only effector molecule in apoptotic cell death, for caspase-3 inhibitorcan not decrease DNA fragmentation. Some other biochemical mechanisms may participate in the process,whose role weakens the effect of inhibiting caspase-3 activity.

  4. Assessment of G3(MP2)//B3 theory including a pseudopotential for molecules containing first-, second-, and third-row representative elements

    International Nuclear Information System (INIS)

    G3(MP2)//B3 theory was modified to incorporate compact effective potential (CEP) pseudopotentials, providing a theoretical alternative referred to as G3(MP2)//B3-CEP for calculations involving first-, second-, and third-row representative elements. The G3/05 test set was used as a standard to evaluate the accuracy of the calculated properties. G3(MP2)//B3-CEP theory was applied to the study of 247 standard enthalpies of formation, 104 ionization energies, 63 electron affinities, 10 proton affinities, and 22 atomization energies, comprising 446 experimental energies. The mean absolute deviations compared with the experimental data for all thermochemical results presented an accuracy of 1.4 kcal mol−1 for G3(MP2)//B3 and 1.6 kcal mol−1 for G3(MP2)//B3-CEP. Approximately 75% and 70% of the calculated properties are found with accuracy between ±2 kcal mol−1 for G3(MP2)//B3 and G3(MP2)//B3-CEP, respectively. Considering a confidence interval of 95%, the results may oscillate between ±4.2 kcal mol−1 and ±4.6 kcal mol−1, respectively. The overall statistical behavior indicates that the calculations using pseudopotential present similar behavior with the all-electron theory. Of equal importance to the accuracy is the CPU time, which was reduced by between 10% and 40%

  5. Non-resonant microwave absorption studies of superconducting MgB2 and MgB2 + MgO

    Indian Academy of Sciences (India)

    Janhavi P Joshi; Subhasis Sarangi; A K Sood; Dilip Pal; S V Bhat

    2002-02-01

    Non-resonant microwave absorption (NRMA) studies of superconducting MgB2 and a sample containing ∼ 10% by weight of MgO in MgB2 are reported. The NRMA results indicate near absence of intergranular weak links in the pure MgB2 sample. A linear temperature dependence of the lower critical field c1 is observed indicating a non- wave superconductivity. However, the phase reversal of the NRMA signal which could suggest wave symmetry is also not observed. In the MgB2 + MgO sample, much larger low field dependent absorption is observed indicating the presence of intergranular weak links. The hysteretic behavior of NRMA is compared and contrasted in the two samples. In the pure MgB2 sample, a large hysteresis is observed between the forward and the reverse scans of the magnetic field indicating strong pinning of flux lines. This hysteresis saturates a few degrees below c while in the MgB2 + MgO sample, a much slower increase of hysteresis with decreasing temperature is observed, a signature of weaker pinning.

  6. Mechanical-thermal synthesis of NbB2 powder from Mg/B2O3/Nb powder mixture

    International Nuclear Information System (INIS)

    Three different approaches were used for the synthesis of niobium boride using a stoichiometric ratio of Mg-B2O3-Nb powder mixture: (i) thermal ignition, (ii) mechanochemical and (iii) a combined mechanical and thermal activation process. Phase transformation analysis and structural evaluation were carried out by means of differential thermal analysis techniques, X-ray diffractometry, scanning electron microscopy and transmission electron microscopy. During the thermal synthesis, the reaction between Mg and B2O3 partially occurred (liquid state reaction). The desired final phase (NbB2) was poorly obtained. Phase analysis revealed that the NbB2 phase was synthesized after 10 h of high energy ball milling. A pre-milling treatment of the powder mixture up to 2 h significantly reduced the reactions temperature (580 C). Consequently, NbB2 was prepared simultaneously involving magnesiothermic reduction of B2O3 and reaction between elemental of Nb and boron. Mg3(BO3)2, as major by-product, was formed in noticeable amounts during the thermal process, while its quantity significantly decreased during mechanochemical synthesis and completely eliminated by using the combined mechanical and thermal synthesis.

  7. Kinetic energy release in CO fragmentation by electron loss and capture collisions of fast B''2''+ ions

    International Nuclear Information System (INIS)

    Ionization and fragmentation of CO molecules have been investigated in charge-changing collisions of B''2''+ ions at v = 1.69 a.u.. Fragment ions from CO were measured by using a momentum 3D imaging technique in coincidence with outgoing projectile charge states. We deduced the kinetic energy release (KER) associated with charge-changing collisions of B''2''+ to B''3''+, B''1''+ and B''0''+. The KER spectra in the fragmentation to C''+ and O''+ ions are found to be different to some extent for these loss and capture collisions. It is concluded that the electron loss collision populates the intact CO molecule to highly excited states of (CO)''2''+''1 more effectively than electron capture collisions, resulting from different effective impact parameters associated with loss and capture collisions.

  8. Dislocation Core Structure and Peierls Stress of B2-Based AlSc in {110} Plane

    Science.gov (United States)

    Li, S. R.; Wu, X. Z.; Zhang, T.; Tian, Y. X.; Yan, Z. X.; Zhu, H. Z.

    2016-10-01

    The core structure and Peierls stress of , , and dislocations in {110} plane of B2-based AlSc (B2-AlSc) have been investigated using improved dislocation equations combined with the generalized stacking fault (GSF) energy. The truncated approximation method is utilized to construct the dissociated and undissociated dislocations in AlSc, then the effects of dislocation angles on the elastic strain energy and misfit energy are presented. Specifically, with increasing dislocation angle, the misfit energy, elastic strain energy, and total energy, and their corresponding stresses, decrease on the {110} and {110} slip systems. However, for {110} dislocation, all energies and corresponding stresses exhibit the relationship 0° > 54.7° > 35.3° > 90°. The misfit energy is always smaller than the elastic strain energy, even by one or two orders of magnitude, and their phases are always opposite.

  9. Kinematics of the SgrB2(N-LMH) Molecular Core

    Science.gov (United States)

    Hollis, J. M.; Pedelty, J. A.; Boboltz, D. A.; Liu, S.-Y.; Snyder, L. E.; Palmer, Patrick; Lovas, F. J.; Jewell, P. R.

    2003-01-01

    Ethyl cyanide (CH3CH2CN) emission and absorption have been imaged with the Very Large Array (VLA) toward SgrB2(N-LMH) by means of the 5(sub 15)-4(sub 14) rotational transition at 43.5 GHz (lambda approx. 7 mm). The 1.5" x 1.4" VLA beam shows two principal sources of ethyl cyanide emission: an unresolved source approx. 5" north of the LMH that is kinematically consistent with simple expansion, contraction, or small-scale turbulence, and the resolved LMH core source itself that shows kinematics indicating an edge-on rotating disk that extends 23" (approx. 0.1 pc) in the approximate east-west direction. A search for the 7(sub 07)-6(sub 06) rotational transition of the amino acid glycine (NH2CH2COOH) at 43.7 GHz toward SgrB2(N-LMH) gave negative results.

  10. Ab initio investigation of collective charge excitations in MgB2.

    Science.gov (United States)

    Ku, Wei; Pickett, W E; Scalettar, R T; Eguiluz, A G

    2002-02-01

    A sharp collective charge excitation is predicted in MgB2 at approximately 2.5 eV for q perpendicular to the boron layers, based on an all-electron analysis of the dynamical density response within time-dependent density functional theory. This novel excitation, consisting of coherent charge fluctuation between Mg and B sheets, induces an abrupt plasma edge in the experimentally observable reflectivity. The existence of this mode reflects the unique electronic structure of MgB2 that is also responsible for strong electron-phonon coupling. By contrast, the acoustic plasmon, recently suggested to explain the high T(c), is not realized when realistic transition strengths are incorporated.

  11. Optical properties of c-axis oriented superconducting MgB2 films.

    Science.gov (United States)

    Tu, J J; Carr, G L; Perebeinos, V; Homes, C C; Strongin, M; Allen, P B; Kang, W N; Choi, E M; Kim, H J; Lee, S I

    2001-12-31

    Temperature dependent optical conductivities and dc resistivity of c-axis oriented superconducting (T(c) = 39.6 K) MgB2 films (approximately 450 nm) have been measured. The normal state ab-plane optical conductivities can be described by the Drude model with a temperature independent Drude plasma frequency of omega(p,D) = 13 600+/-100 cm(-1) or 1.68+/-0.01 eV. The normal state resistivity is fitted by the Bloch-Grüneisen formula with an electron-phonon coupling constant lambda(tr) = 0.13+/-0.02. The optical conductivity spectra below T(c) of these films suggest that MgB2 is a multigap superconductor.

  12. Expectation Consistent Approximate Inference

    DEFF Research Database (Denmark)

    Opper, Manfred; Winther, Ole

    2005-01-01

    We propose a novel framework for approximations to intractable probabilistic models which is based on a free energy formulation. The approximation can be understood from replacing an average over the original intractable distribution with a tractable one. It requires two tractable probability dis...

  13. The compressibility of high purity YbB2.

    Science.gov (United States)

    Kalkan, B; Suzer, S; Ozdas, E

    2012-08-29

    The compressibility and phase stability of Y bB(2) are investigated under high pressure using high-resolution synchrotron x-ray diffraction in a diamond anvil cell. The bulk modules of high purity Y bB(2) is obtained as ∼182 GPa using the Birch-Murnaghan equation of state. The patterns measured up to 20 GPa and the pressure dependence of normalized lattice parameters, a/a(0) and c/c(0), reveal that the compressibility of Y bB(2) is low and fairly isotropic, and this material can be classified as a hard material. X-ray photoemission studies demonstrate that Yb in Y bB(2) has a mostly trivalent valence state at room temperature. Moreover, sample preparation details provide a new insight into the high purity synthesis of Y bB(2) at ambient pressure and moderate temperatures. The presented structural and compressibility results are in agreement with the available theoretical and experimental data on binary rare-earth borides and can serve as a reliable reference for future studies. PMID:22850355

  14. Ordered cones and approximation

    CERN Document Server

    Keimel, Klaus

    1992-01-01

    This book presents a unified approach to Korovkin-type approximation theorems. It includes classical material on the approximation of real-valuedfunctions as well as recent and new results on set-valued functions and stochastic processes, and on weighted approximation. The results are notonly of qualitative nature, but include quantitative bounds on the order of approximation. The book is addressed to researchers in functional analysis and approximation theory as well as to those that want to applythese methods in other fields. It is largely self- contained, but the readershould have a solid background in abstract functional analysis. The unified approach is based on a new notion of locally convex ordered cones that are not embeddable in vector spaces but allow Hahn-Banach type separation and extension theorems. This concept seems to be of independent interest.

  15. Approximate Modified Policy Iteration

    CERN Document Server

    Scherrer, Bruno; Ghavamzadeh, Mohammad; Geist, Matthieu

    2012-01-01

    Modified policy iteration (MPI) is a dynamic programming (DP) algorithm that contains the two celebrated policy and value iteration methods. Despite its generality, MPI has not been thoroughly studied, especially its approximation form which is used when the state and/or action spaces are large or infinite. In this paper, we propose three approximate MPI (AMPI) algorithms that are extensions of the well-known approximate DP algorithms: fitted-value iteration, fitted-Q iteration, and classification-based policy iteration. We provide an error propagation analysis for AMPI that unifies those for approximate policy and value iteration. We also provide a finite-sample analysis for the classification-based implementation of AMPI (CBMPI), which is more general (and somehow contains) than the analysis of the other presented AMPI algorithms. An interesting observation is that the MPI's parameter allows us to control the balance of errors (in value function approximation and in estimating the greedy policy) in the fina...

  16. Data of evolutionary structure change: 3EK2B-3FNFB [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 6833343506 EVID> 3 3FNF EVID> 4 3FNF B 3FNF...EVID>EVID> 5 3FNF...3EK2B-3FNFB 3EK2 3FNF B B MGFLDGKRILLTGLLSNRSIAYGIAKACKREGAELAFTY...VGDRFKDRITEFAAEFGSE-LVFPCDVADDAQIDALFASLKTHWD---SLDGLVHSIGFAPREAIAG-DFLDGLTRENFRIAHDISAYSFPALAKAALPMLSDDASLL

  17. Expanding Interprofessional EHR Data in i2b2.

    Science.gov (United States)

    Westra, Bonnie L; Christie, Beverly; Johnson, Steven G; Pruinelli, Lisiane; LaFlamme, Anne; Park, Jung In; Sherman, Suzan G; Byrne, Matthew D; Ranallo, Piper; Speedie, Stuart

    2016-01-01

    Emerging issues of team-based care, precision medicine, and big data science underscore the need for health information technology (HIT) tools for integrating complex data in consistent ways to achieve the triple aims of improving patient outcomes, patient experience, and cost reductions. The purpose of this study was to demonstrate the feasibility of creating a hierarchical flowsheet ontology in i2b2 using data-derived information models and determine the underlying informatics and technical issues. This study is the first of its kind to use information models that aggregate team-based care across time, disciplines, and settings into 14 information models that were integrated into i2b2 in a hierarchical model. In the process of successfully creating a hierarchical ontology for flowsheet data in i2b2, we uncovered a variety of informatics and technical issues described in this paper. PMID:27570680

  18. EBSD analysis of MgB2 bulk superconductors

    Science.gov (United States)

    Koblischka-Veneva, A.; Koblischka, M. R.; Schmauch, J.; Inoue, K.; Muralidhar, M.; Berger, K.; Noudem, J.

    2016-04-01

    The grain orientation, the texture and the grain boundary misorientations are important parameters for the understanding of the magnetic properties of the bulk MgB2 samples intended for super-magnet applications. Such data can be provided by electron backscatter diffraction (EBSD) analysis. However, as the grain size (GS) of the MgB2 bulks is preferably in the 100-200 nm range, the common EBSD technique working in reflection operates properly only on highly dense samples. In order to achieve a reasonably good Kikuchi pattern quality on all samples, we apply here the newly developed transmission EBSD (t-EBSD) technique to several bulk MgB2 samples. This method requires the preparation of TEM slices by means of focused ion-beam milling, which are then analyzed within the SEM, operating with a specific sample holder. We present several EBSD mappings of samples prepared with different techniques and at various reaction temperatures.

  19. MgB2 superconducting wires basics and applications

    CERN Document Server

    2016-01-01

    The compendium gives a complete overview of the properties of MgB2 (Magnesium Diboride), a superconducting compound with a transition temperature of Tc = 39K, from the fundamental properties to the fabrication of multifilamentary wires and to the presentation of various applications. Written by eminent researchers in the field, this indispensable volume not only discusses superconducting properties of MgB2 compounds, but also describes known preparation methods of thin films and of bulk samples obtained under high pressure methods. A unique selling point of the book is the detailed coverage of various applications based on MgB2, starting with MRI magnets and high current cables, cooled by Helium (He) vapor. High current cables cooled by liquid hydrogen are also highlighted as an interesting alternative due to the shrinking He reserves on earth. Other pertinent subjects comprise permanent magnets, ultrafine wires for space applications and wind generator projects.

  20. 26 CFR 48.4061(b)-3 - Rebuilt, reconditioned, or repaired parts or accessories.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Rebuilt, reconditioned, or repaired parts or accessories. 48.4061(b)-3 Section 48.4061(b)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE..., Tires, Tubes, Tread Rubber, and Taxable Fuel Automotive and Related Items § 48.4061(b)-3...

  1. B2C支付的三大瓶颈

    Institute of Scientific and Technical Information of China (English)

    顾卓

    2007-01-01

    尽管B2C电子支付正在如火如荼地发展,但仍然存在着这样或那样的问题,这些问题已经影响到了B2C业务的发展。作为以满足市场需求而生的第三方支付厂商们,也需要因时做出改变,以满足现在的支付需求。

  2. Isostructural Transition of MgB2 Under High Pressure

    Institute of Scientific and Technical Information of China (English)

    SUN Li-Ling; WU Qi; ZHAN Zai-Ji; WANG Wen-Kui; WANG Wen-Kui; T.Kikegawa

    2001-01-01

    The high-pressure behaviour of the superconductor MgB2 with a hexagonal structure has been investigated by the in situ synchrotron radiation x-ray diffraction method under pressures up to 42.2 GPa in a diamond anvil cell. An abrupt decrease of about 7% in the unit cell volume of this material occurs in the pressure range of 26.3-30.2 GPa. A split of the Raman spectrum was also observed. The jump of the compression curve and Raman spectrum are ascribed to an isostructural transition in MgB2 at a pressure of 30.2 GPa.

  3. Customized E-Learning for B2B Companies

    Directory of Open Access Journals (Sweden)

    Tim Thomasma

    2014-06-01

    Full Text Available Business-to-Business (B2B companies have customers that are primarily other corporations. These companies have unique problems in workplace training. They must train their customers and their customers’ employees. A B2B company may operate with only a few dozen employees, but they may need to help thousands of customers learn how to make best use of their product or service. Discussions with industry executives suggest an ideal training solution might include a number of features that are reviewed in this paper.

  4. Superconducting properties of MgB2 from first principles.

    Science.gov (United States)

    Floris, A; Profeta, G; Lathiotakis, N N; Lüders, M; Marques, M A L; Franchini, C; Gross, E K U; Continenza, A; Massidda, S

    2005-01-28

    Solid MgB(2) has rather interesting and technologically important properties, such as a very high superconducting transition temperature. Focusing on this compound, we report the first nontrivial application of a novel density-functional-type theory for superconductors, recently proposed by the authors. Without invoking any adjustable parameters, we obtain the transition temperature, the gaps, and the specific heat of MgB(2) in very good agreement with experiment. Moreover, our calculations show how the Coulomb interaction acts differently on sigma and pi states, thereby stabilizing the observed superconducting phase.

  5. Superconductivity of metallic boron in MgB2.

    Science.gov (United States)

    Kortus, J; Mazin, I I; Belashchenko, K D; Antropov, V P; Boyer, L L

    2001-05-14

    Boron in MgB2 forms stacks of honeycomb layers with magnesium as a space filler. Band structure calculations indicate that Mg is substantially ionized, and the bands at the Fermi level derive mainly from B orbitals. Strong bonding with an ionic component and considerable metallic density of states yield a sizable electron-phonon coupling. Together with high phonon frequencies, which we estimate via zone-center frozen phonon calculations to be between 300 and 700 cm(-1), this produces a high critical temperature, consistent with recent experiments. Thus MgB2 can be viewed as an analog of the long sought, but still hypothetical, superconducting metallic hydrogen.

  6. Risk Analysis and Consumer Protection in B2C Transactions

    Institute of Scientific and Technical Information of China (English)

    YANG Jian-zheng; SHI Qi-liang; Gary Millar; Ruhul A. Sarker

    2005-01-01

    Recent studies have shown that the perceived lack of security is a major obstacle to the wider acceptance of e-commerce. To overcome this barrier, businesses need to implement comprehensive consumer protection systems that protect consumers during every stage of the purchasing process. This paper used the consumer behaviour model as the basis for analysing risks in Bussiness-to-Consumer (B2C) transactions. Four categories of risks were identified: information, agreement, payment and delivery risk. By combining these risk categories with the three dimensions of management, technology and legislation, a comprehensive B2C consumer protection framework is developed.

  7. 拟南芥B3转录因子基因超家族%Research progress of Arabidopsis B3 transcription factor gene superfamily

    Institute of Scientific and Technical Information of China (English)

    罗光宇; 叶玲飞; 陈信波

    2013-01-01

    B3类转录因子基因组成了植物所特有的B3基因超家族,按照其结构和功能的特征可将其进一步分为LAV(LEAFY COTYLEDON2 [LEC2]-ABSCISIC ACID INSENSITIVE3 [ABI3]-VAL)、RF(AUXINRESPONSE FACTOR)、RAV(RELATED TO ABI3 and VPl)和REM(REPRODUCTIVE MERISTEM)等4个家族.B3基因超家族主要存在于裸子植物、苔藓和绿藻类植物中,并在植物逆境胁迫响应和生长发育过程中起着极其重要的作用.目前已在拟南芥中发现了118个B3类转录因子,本文综述了拟南芥中B3转录因子基因超家族的系统发育和功能鉴定方面的研究进展.%The B3 transcription factor genes form a plant-specific B3 gene superfamily and can be further classified into four families:LAV (LEAFY COTYLEDON2 [LEC2]-ABSCISIC ACID INSENSITIVE3 [ABI3]-VAL),ARF (AUXIN RESPONSE FACTOR),RAV (RELATED TO ABI3 and VP1) and REM (REPRODUCTIVE MERISTEM) family.The B3 transcription factor genes exist mainly in gymnosperms,mosses and green algae and play extremely important roles in plant stress responses and plant growth and development.In Arabidopsis,118 B3 superfamily transcription factor genes have been identified.This review aims to overview the research progress of the phylogenetical and functional characterization of the B3 gene superfamily in Arabidopsis.

  8. The Karlqvist approximation revisited

    OpenAIRE

    Tannous, C.

    2015-01-01

    The Karlqvist approximation signaling the historical beginning of magnetic recording head theory is reviewed and compared to various approaches progressing from Green, Fourier, Conformal mapping that obeys the Sommerfeld edge condition at angular points and leads to exact results.

  9. Approximations in Inspection Planning

    DEFF Research Database (Denmark)

    Engelund, S.; Sørensen, John Dalsgaard; Faber, M. H.;

    2000-01-01

    Planning of inspections of civil engineering structures may be performed within the framework of Bayesian decision analysis. The effort involved in a full Bayesian decision analysis is relatively large. Therefore, the actual inspection planning is usually performed using a number of approximations....... One of the more important of these approximations is the assumption that all inspections will reveal no defects. Using this approximation the optimal inspection plan may be determined on the basis of conditional probabilities, i.e. the probability of failure given no defects have been found...... by the inspection. In this paper the quality of this approximation is investigated. The inspection planning is formulated both as a full Bayesian decision problem and on the basis of the assumption that the inspection will reveal no defects....

  10. Approximation of irrationals

    Directory of Open Access Journals (Sweden)

    Malvina Baica

    1985-01-01

    Full Text Available The author uses a new modification of Jacobi-Perron Algorithm which holds for complex fields of any degree (abbr. ACF, and defines it as Generalized Euclidean Algorithm (abbr. GEA to approximate irrationals.

  11. Approximation Behooves Calibration

    DEFF Research Database (Denmark)

    da Silva Ribeiro, André Manuel; Poulsen, Rolf

    2013-01-01

    Calibration based on an expansion approximation for option prices in the Heston stochastic volatility model gives stable, accurate, and fast results for S&P500-index option data over the period 2005–2009.......Calibration based on an expansion approximation for option prices in the Heston stochastic volatility model gives stable, accurate, and fast results for S&P500-index option data over the period 2005–2009....

  12. Approximation and Computation

    CERN Document Server

    Gautschi, Walter; Rassias, Themistocles M

    2011-01-01

    Approximation theory and numerical analysis are central to the creation of accurate computer simulations and mathematical models. Research in these areas can influence the computational techniques used in a variety of mathematical and computational sciences. This collection of contributed chapters, dedicated to renowned mathematician Gradimir V. Milovanovia, represent the recent work of experts in the fields of approximation theory and numerical analysis. These invited contributions describe new trends in these important areas of research including theoretic developments, new computational alg

  13. Il B2B e il paradigma dei costi di transazione (B2B and the Transaction Costs Paradigm

    Directory of Open Access Journals (Sweden)

    Pierluigi Sabbatini

    2012-04-01

    Full Text Available Business to Business (B2B Internet commerce causes a significant contraction of transaction costs. According to the Coase paradigm, we would thus expect a deverticalization of the industry and broader scope for anonymous market mechanisms. In reality, such expectations are not fully borne out by the facts. When the industrial structure is concentrated the B2Bgenerally loses its independence, and is owned by the firms which most contribute to its development, e.g. the ones able to bring the liquidity to it. The B2B governance mechanism established by these firms gives hierarchical mechanisms a role which they do not usually play in extensive, anonymous markets.         JEL Codes: D23, L86Keywords: Cost, Transaction Costs, Transactions

  14. Supporting B2B Business Documents in XML Web Services

    Institute of Scientific and Technical Information of China (English)

    KIM Hyoungdo

    2004-01-01

    While XML web services become recognized as a solution to business-to-business transactions, there are many problems that should be solved. For example, it is not easy to manipulate business documents of existing standards such as RosettaNet and UN/EDIFACT EDI, traditionally regarded as an important resource for managing B2B relationships. As a starting point for the complete implementation of B2B web services, this paper deals with how to support B2B business documents in XML web services. In the first phase, basic requirements for driving XML web services by business documents are introduced. As a solution, this paper presents how to express B2B business documents in WSDL, a core standard for XML web services. This kind of approach facilitates the reuse of existing business documents and enhances interoperability between implemented web services. Furthermore, it suggests how to link with other conceptual modeling frameworks such as ebXML/UMM, built on a rich heritage of electronic business experience.

  15. Marketing-sales interface configurations in B2B firms

    NARCIS (Netherlands)

    Biemans, Wim G.; Brencic, Maja Makovec; Malshe, Avinash; Makovec Brenciv, M.

    2010-01-01

    As the body of knowledge on marketing-sales interface expands, there is a greater need to investigate the specific aspects of marketing-sales configurations in B2B firms. Using a qualitative methodology and interview data collected from over 100 sales and marketing professionals from the US, The Net

  16. Itinerant magnetism in CeRh3B2

    DEFF Research Database (Denmark)

    Eriksson, Olle; Johansson, Börje; Brooks, M. S. S.;

    1989-01-01

    Spin-polarized energy-band calculations, including spin-orbit coupling in the band Hamiltonian, have been performed on CeRh3B2. Good agreement is obtained between theory and experiment concerning the magnetic moment. It is also found that the magnetic moment varies strongly with volume and from...

  17. Erratum: Ultrasonic Properties of the MgB2 Superconductor

    Institute of Scientific and Technical Information of China (English)

    李绍春; 王汝菊; 李凤英; 刘振兴; 朱嘉林; 禹日成; 靳常青

    2001-01-01

    The last sentence in the abstract should be: "The results indicate that the velocities are much higher than those in the usual materials while elastic constants remain reasonably soft, which is considered to be one of the reasons for the high transition temperature of the MgB2 superconductor".

  18. Multiband model for penetration depth in MgB2

    NARCIS (Netherlands)

    Golubov, A.A.; Brinkman, A.; Dolgov, O.V.; Kortus, J.; Jepsen, O.

    2002-01-01

    The results of first-principles calculations of the electronic structure and the electron-phonon interaction in MgB2 are used to study theoretically the temperature dependence and anisotropy of the magnetic-field penetration depth. The effects of impurity scattering are essential for a proper descri

  19. 29 CFR 2520.104b-2 - Summary plan description.

    Science.gov (United States)

    2010-07-01

    ... section 102 or 29 CFR 2520.102-3 would have been reflected in the most recently distributed summary plan... section 102 or 29 CFR 2520.102-3 would have been reflected in the most recently distributed summary plan... 29 Labor 9 2010-07-01 2010-07-01 false Summary plan description. 2520.104b-2 Section...

  20. Investigation of TaC–TaB2 ceramic composites

    Indian Academy of Sciences (India)

    Behzad Mehdikhani; Gholam Hossein Borhani; Saeed Reza Bakhshi; Hamid Reza Baharvandi

    2016-02-01

    The TaC–TaB2 composition was sintered by spark plasma (SPS) at 1900–2100°C and applied pressure of 30 MPa. TaC and 2–3 wt% B4C were used as starting powders. Densification process, phase evolution, microstructure and the mechanical properties of the composites were investigated. The results indicated that the TaC–TaB2 composition could be SPS to 97% of theoretical density in 10 min at 2100°C. Addition of B4C leads to an increase in the density sample from 76 to 97%. B4C nano-powder resists grain growth even at high temperature 2100°C. The formation of TaB2/carbon at TaC grain boundaries helps in pinning the grain boundary and inhibiting grain growth. The phase formation was associated with carbon and boron diffusion from the starting particles B4C to form TaB2 phases. TaC grain sizes decreased with increase in B4C concentration. Samples with 2.0 wt% B4C composition had highest flexure strength up to 520 MPa. The effect of B4C addition on hardness measured by microhardness has been studied. Hardness of samples containing 3.0 wt% B4C was 16.99 GPa.

  1. Superconductivity in MgB2: Clean or Dirty?

    NARCIS (Netherlands)

    Mazin, I.I.; Andersen, O.K.; Jepsen, O.; Dolgov, O.V.; Kortus, J.; Golubov, A.A.; Kuz'menko, A.B.; Marel, van der D.

    2002-01-01

    A large number of experimental facts and theoretical arguments favor a two-gap model for superconductivity in MgB2. However, this model predicts strong suppression of the critical temperature by interband impurity scattering and, presumably, a strong correlation between the critical temperature and

  2. Effect of Al on the NiAl-Type B2 Precipitates in Ferritic Superalloys

    Science.gov (United States)

    Huang, Shenyan; Ghosh, Gautam; Li, Xin; Ilavsky, Jan; Teng, Zhenke; Liaw, Peter K.

    2012-10-01

    Ultra-small-angle X-ray scattering (USAXS) is employed to quantify the average size, interparticle spacing, and volume fraction of the primary B2 precipitates in Fe-based superalloys with varying Al concentration. The results are analyzed with a model incorporating polydispersity and interference effects and verified by transmission electron microscopy (TEM) characterizations. As the Al amount increases from 4 to 10 mass pct, there is an approximately 40 pct decrease in the average interparticle spacing and ~30 pct reduction in the average particle diameter.

  3. Reinvestigation on the phase transition of a LiB3O5 crystal near its melting point

    Science.gov (United States)

    Wan, S. M.; Zheng, G. M.; Feng, D. X.; Yao, Y. N.; Zhao, Y.; You, J. L.; Hu, Z. G.

    2016-02-01

    Raman spectroscopy has been applied to investigate in-situ the phase transition of a LBO (LiB3O5) crystal near its melting point in order to explain the discrepancies between the experimental results observed in the LBO crystal growth process and the predicted results obtained from the Li2O-B2O3 phase diagram. When the LBO crystal begins to melt, it first decomposes to the kinetic products Li2B4O7 and B2O3; then the Li2B4O7 reacts with the undecomposed LBO to form the thermodynamic product Li3B7O12. On the basis of these results, a set of models have been proposed to describe the structural transformations present in the phase transition. Additionally, our experimental result indicates that Li3B7O12 is stable/metastable at room temperature. Its Raman spectrum has been calculated by the density functional theory method for identification of the Li3B7O12 crystalline phase in a mixture. The result shows that Li3B7O12 has three strong characteristic Raman peaks located around 595, 775 and 1040 cm-1.

  4. Transport and superconducting properties of RNi2B2C (R=Y,nLu) single crystals

    Science.gov (United States)

    Rathnayaka, K. D. D.; Bhatnagar, A. K.; Parasiris, A.; Naugle, D. G.; Canfield, P. C.; Cho, B. K.

    1997-04-01

    The in-plane resistivity, in-plane absolute thermopower, and upper critical field measurements are reported for single-crystal samples of YNi2B2C and LuNi2B2C superconductors. The in-plane resistivity shows metallic behavior and varies approximately linearly with temperature near room temperature (RT) but shows nearly quadratic behavior in temperature at low temperatures. The YNi2B2C and LuNi2B2C single-crystal samples exhibit large transverse magnetoresistance (~6-8 % at 45 kOe) in the ab plane. The absolute thermopower S(T) is negative from RT to the superconducting transition temperature Tc. Its magnitude at RT is a few times of the value for a typical good metal. S(T) is approximately linear in temperature between ~150 K and RT. Extrapolation to T=0 gives large intercepts (few μV/K) for both samples suggesting the presence of a much larger 'knee' than would be expected from electron-phonon interaction renormalization effects. The upper critical fields for H parallel and perpendicular to the c axis and the superconducting parameters derived from it do not show any anisotropy for the YNi2B2C single-crystal samples in agreement with magnetization and torque magnetometry measurements, but a small anisotropy is observed for the LuNi2B2C single crystals. The analysis shows that these are moderately strong-coupling type-II superconductors (similar to the A-15 compounds) with a value of the electron-phonon coupling parameter λ(0) approximately equal to 1.2 for YNi2B2C and 1.0 for LuNi2B2C, the Ginzburg-Landau coherence length ξ(0) approximately equal to 70 Å, and Hc2(0)~60-70 kOe. The temperature dependence of the upper critical field shows a positive curvature near Tc in disagreement with the Werthamer, Helfand, Hohenberg, and Maki (WHHM) theory but in agreement with a recent solution of the Gor'kov equation using a basis formed by Landau levels (Bahcall); however, the data show a severe disagreement between the observed low-temperature behavior of Hc2(T) and that

  5. Specific heat of single crystal MgB2: a two-band superconductor with two different anisotropies.

    Science.gov (United States)

    Bouquet, F; Wang, Y; Sheikin, I; Plackowski, T; Junod, A; Lee, S; Tajima, S

    2002-12-16

    Heat-capacity measurements of a 39 microg MgB2 single crystal in fields up to 14 T and below 3 K allow the determination of the low-temperature linear term of the specific heat, its field dependence, and its anisotropy. Our results are compatible with two-band superconductivity, the band carrying the smaller gap being isotropic, that carrying the larger gap having an anisotropy of approximately 5. Three different upper critical fields are thus needed to describe the superconducting state of MgB2.

  6. Diophantine approximations on fractals

    CERN Document Server

    Einsiedler, Manfred; Shapira, Uri

    2009-01-01

    We exploit dynamical properties of diagonal actions to derive results in Diophantine approximations. In particular, we prove that the continued fraction expansion of almost any point on the middle third Cantor set (with respect to the natural measure) contains all finite patterns (hence is well approximable). Similarly, we show that for a variety of fractals in [0,1]^2, possessing some symmetry, almost any point is not Dirichlet improvable (hence is well approximable) and has property C (after Cassels). We then settle by similar methods a conjecture of M. Boshernitzan saying that there are no irrational numbers x in the unit interval such that the continued fraction expansions of {nx mod1 : n is a natural number} are uniformly eventually bounded.

  7. Evaluating surface energy budgets simulated by SiB3 at three different climate-ecosystem tower sites%SiB3对不同下垫面的模拟试验与验证

    Institute of Scientific and Technical Information of China (English)

    蒋玲梅; 卢立新; 邢伟坡; 张立新; Ian Baker; 张庚军; 左菁颖

    2011-01-01

    首先介绍简单生物圈模式版本3( Simple Biosphere Model 3,SiB3)相比SiB2的改进之处以及相应的参数化方案.为了检验SiB3模式能否模拟不同下垫面的地气之间水分和能量交换,本文在全球选择3个代表高、中、低纬度的典型实验站点(青藏高原安多站点、亚马逊流域的Km34站点和美国中西部的WLEF站点),利用SiB3进行模拟分析和实验验证.研究结果表明,SiB3能够较好地模拟出不同下垫面的地表感热通量、潜热通量和净辐射通量随时间的变化率以及变化趋势,模式模拟值和测量值的相关系数达到0.80左右.但与实测相比,SiB3模拟的感热通量值仍偏高.在安多站点,模式模拟的地表土壤水分比较干燥,且模拟的地表温度较测量值偏高.%In this paper, three climate - ecosystem representative sites have been selected to run SiB3 to evaluate its performance, including Anduo on Tibetan Plateau, Km34 flux tower site in Amazon Basin, and WLEF tower in midwest of United States. Among these three sites, Anduo has a typical arid and semi-arid climate with high-plain grassland, Km34 tower site is in tropical rainforest, and WLEF tower site has temperate continental climate with mixed forest. Our work demonstrates that the net radiations, sensible heat fluxes, latent heat fluxes, and land-surface skin temperatures are reasonably simulated especially for Tibetan Plateau and Amazon, where the correlations between modeled and observed values are generally above 0. 80. The simulated sensible heat fluxes have persistent positive biases of 40. 1 73. 9 and 53. 5 w/ m2, compared to the measurements at all three sites. At Anduo site, the simulated soil moisture is too dry, and SiB3 has some difficulties in reproducing the observed soil water variations with depth.

  8. Orbital Interaction and Electron Density Transfer in PdII([9]aneB2AL2 Complexes: Theoretical Approaches

    Directory of Open Access Journals (Sweden)

    Jong Keun Park

    2013-10-01

    Full Text Available The geometric structures of Pd-complexes {Pd([9]aneB2AL2 and Pd([9]aneBABL2 where A = P, S; B = N; L = PH3, P(CH33, Cl−}, their selective orbital interaction towards equatorial or axial (soft A…Pd coordination of macrocyclic [9]aneB2A tridentate to PdL2, and electron density transfer from the electron-rich trans L-ligand to the low-lying unfilled a1g(5s-orbital of PdL2 were investigated using B3P86/lanl2DZ for Pd and 6-311+G** for other atoms. The pentacoordinate endo-[Pd([9]aneB2A(L-donor2]2+ complex with an axial (soft A--Pd quasi-bond was optimized for stability. The fifth (soft A--Pd quasi-bond between the σ-donor of soft A and the partially unfilled a1g(5s-orbital of PdL2 was formed. The pentacoordinate endo-Pd([9]aneB2A(L-donor2]2+ complex has been found to be more stable than the corresponding tetracoordinate endo-Pd complexes. Except for the endo-Pd pentacoordinates, the tetracoordinate Pd([9]aneBABL2 complex with one equatorial (soft A-Pd bond is found to be more stable than the Pd([9]aneB2AL2 isomer without the equatorial (A-Pd bond. In particular, the geometric configuration of endo-[Pd([9]anePNP(L-donor2]2+ could not be optimized.

  9. Semisynthesis of S-desoxybrevetoxin-B2 and brevetoxin-B2, and assessment of their acute toxicities.

    Science.gov (United States)

    Selwood, Andrew I; Ginkel, Roel van; Wilkins, Alistair L; Munday, Rex; Ramsdell, John S; Jensen, Dwayne J; Cooney, Janine M; Miles, Christopher O

    2008-04-01

    Brevetoxins are neurotoxins associated with blooms of marine algae such as Karenia brevis and can accumulate in the marine food chain, causing intoxication of marine animals and people consuming seafood. Brevetoxin-B2 ( 5) is a toxic metabolite produced in shellfish exposed to algae that contain brevetoxin-B ( 1). S-Desoxybrevetoxin-B2 ( 4) has been proposed as a cometabolite produced during this transformation, and while LC-MS analyses suggest its presence in shellfish, it has not yet been isolated and characterized. Studies on these materials are severely constrained by the difficulty of obtaining and purifying them from natural sources. We have developed a convenient one-pot conversion of commercially available brevetoxin-B ( 1) into S-desoxybrevetoxin-B2 ( 4), and a simple method for converting 4 into brevetoxin-B2 ( 5). Full NMR and mass-spectral characterization of 4 and 5 confirmed their structures and showed that the ratio of diastereoisomers in the synthetic 4 and 5 was similar to that observed in naturally contaminated shellfish. The LD 50 values for 4, 5, and dihydrobrevetoxin-B ( 6) by ip injection in mice were 211, 400, and 250 microg/kg, respectively. The methodology for synthesis of brevetoxin metabolites should greatly facilitate toxicological, biochemical and immunochemical studies of these substances, as well as the production of analytical standards. PMID:18335998

  10. Strongly bound metastable states of B2 + 2

    Science.gov (United States)

    Bruna, Pablo J.; Wright, James S.

    1990-08-01

    The stabilities of about 25 electronic states of B2+2 have been investigated using a multireference CI (MRD-CI) method and an AO basis set composed of 6s4p2d contracted Gaussian species per atom, including semidiffuse functions relevant for an adequate description of charge transfer interactions. The ground state X1∑+g (σ2gσ2u) is repulsive, as expected by its electronic configuration with a zero bond order. In spite of this and the doubly-positive charge, many excited states are found to be metastable, four of them (11∏g, 11∏u, 13∑-g, and 11Δg ) having potential wells from 1.52 eV (11∏u) to 2.83 eV (13∑-g). Relative to the ground state configuration, the metastable states arise from the excitations σu→σg(3∑+u), σu→πu(3,1∏g), σ2u→σgπu(3,1∏u), and σ2u→π2u(3∑-g, 1Δg, 1∑+g); they are analogous to those states showing deep local minima in B2 and B+2. Differences in stabilities among quasibound states can be explained on the basis of the asymptotic ΔE's between repulsive channels B++B+ and appropriate higher-lying limits (states) B+B2+ of bonding character; another important factor governing stability is the actual bonding character of the electronic configurations assigned to each state. The vertical double-ionization potential B2B2+2(π2u→∞) between both ground states is 27.97 eV, the repulsive X1∑+g dication state being created with 8.37 eV excess energy relative to B++B+. Doubly-ionized states with a chance of being detected because of their long lifetimes against predissociation are those showing a strongly quasibound character, such as (with the vertical double ionization potential in eV given in parentheses): 11∏g(σuπu→∞; 30.29); 11∏u(σ2uπu→σg∞; 31.30); 13∑-g(σ2u→∞; 31.33), and 11Δg(σ2u→∞; 31.95).

  11. Elastic and piezoelectric properties, sound velocity and Debye temperature of (B3) boron–bismuth compound under pressure

    Indian Academy of Sciences (India)

    S Daoud; N Bioud; N Lebgaa

    2013-11-01

    Pseudopotential plane-wave method (PP–PW) based on density functional theory (DFT) and density functional perturbation theory (DFPT) within the Teter and Pade exchangecorrelation functional form of the local spin density approximation (LSDA) is applied to study the effect of pressure on the elastic and piezoelectric properties of the (B3) boron–bismuth compound. The phase transition, the independent elastic stiffness constants, the bulk modulus, the direct and converse piezoelectric coefficients, the longitudinal, transverse, and average sound velocities, and finally the Debye temperature under pressure are studied. The results obtained are generally lower than the available theoretical data (experimental data are not available) reported in the literature.

  12. Approximate and Incomplete Factorizations

    NARCIS (Netherlands)

    Chan, T.F.; Vorst, H.A. van der

    2001-01-01

    In this chapter, we give a brief overview of a particular class of preconditioners known as incomplete factorizations. They can be thought of as approximating the exact LU factorization of a given matrix A (e.g. computed via Gaussian elimination) by disallowing certain ll-ins. As opposed to other PD

  13. Prestack wavefield approximations

    KAUST Repository

    Alkhalifah, Tariq

    2013-09-01

    The double-square-root (DSR) relation offers a platform to perform prestack imaging using an extended single wavefield that honors the geometrical configuration between sources, receivers, and the image point, or in other words, prestack wavefields. Extrapolating such wavefields, nevertheless, suffers from limitations. Chief among them is the singularity associated with horizontally propagating waves. I have devised highly accurate approximations free of such singularities which are highly accurate. Specifically, I use Padé expansions with denominators given by a power series that is an order lower than that of the numerator, and thus, introduce a free variable to balance the series order and normalize the singularity. For the higher-order Padé approximation, the errors are negligible. Additional simplifications, like recasting the DSR formula as a function of scattering angle, allow for a singularity free form that is useful for constant-angle-gather imaging. A dynamic form of this DSR formula can be supported by kinematic evaluations of the scattering angle to provide efficient prestack wavefield construction. Applying a similar approximation to the dip angle yields an efficient 1D wave equation with the scattering and dip angles extracted from, for example, DSR ray tracing. Application to the complex Marmousi data set demonstrates that these approximations, although they may provide less than optimal results, allow for efficient and flexible implementations. © 2013 Society of Exploration Geophysicists.

  14. The Zeldovich approximation

    CERN Document Server

    White, Martin

    2014-01-01

    This year marks the 100th anniversary of the birth of Yakov Zel'dovich. Amongst his many legacies is the Zel'dovich approximation for the growth of large-scale structure, which remains one of the most successful and insightful analytic models of structure formation. We use the Zel'dovich approximation to compute the two-point function of the matter and biased tracers, and compare to the results of N-body simulations and other Lagrangian perturbation theories. We show that Lagrangian perturbation theories converge well and that the Zel'dovich approximation provides a good fit to the N-body results except for the quadrupole moment of the halo correlation function. We extend the calculation of halo bias to 3rd order and also consider non-local biasing schemes, none of which remove the discrepancy. We argue that a part of the discrepancy owes to an incorrect prediction of inter-halo velocity correlations. We use the Zel'dovich approximation to compute the ingredients of the Gaussian streaming model and show that ...

  15. Approximating The DCM

    DEFF Research Database (Denmark)

    Madsen, Rasmus Elsborg

    2005-01-01

    The Dirichlet compound multinomial (DCM), which has recently been shown to be well suited for modeling for word burstiness in documents, is here investigated. A number of conceptual explanations that account for these recent results, are provided. An exponential family approximation of the DCM that...

  16. IAU 2015 Resolution B2 on Recommended Zero Points for the Absolute and Apparent Bolometric Magnitude Scales

    DEFF Research Database (Denmark)

    Mamajek, E. E.; Torres, G.; Prsa, A.;

    2015-01-01

    such that a radiation source with $M_{\\rm Bol}$ = 0 has luminosity L$_{\\circ}$ = 3.0128e28 W. The zero point of the apparent bolometric magnitude scale ($m_{\\rm Bol}$ = 0) corresponds to irradiance $f_{\\circ}$ = 2.518021002e-8 W/m$^2$. The zero points were chosen so that the nominal solar luminosity (3.828e26 W......) adopted by IAU 2015 Resolution B3 corresponds approximately to $M_{\\rm Bol}$(Sun) = 4.74, the value most commonly adopted in recent literature. The nominal total solar irradiance (1361 W/m$^2$) adopted in IAU 2015 Resolution B3 corresponds approximately to apparent bolometric magnitude $m_{\\rm bol...

  17. Implications of reflectance measurements on the mechanism for superconductivity in MgB2.

    Science.gov (United States)

    Marsiglio, F

    2001-12-10

    Recent optical studies in c-axis oriented superconducting MgB2 films indicate that the electron-phonon coupling is weak. We reinforce this conclusion by examining the raw reflectance data; its frequency dependence is incompatible with strong electron-phonon scattering. This is further strengthened by analysis of the real part of the conductivity, and by the temperature dependence of the effective Drude scattering rate. Using a realistic electron-phonon spectral shape, we find lambda(tr) approximately 0.15. To the extent that lambda(tr) approximately lambda, this disagrees sharply with model calculations, and is far too low to provide the means for T(c) = 39 K. A simple model is constructed with coupling to a high frequency excitation, which is consistent with both the low frequency optical data and the high T(c).

  18. Temperature and field dependence of the anisotropy of MgB2.

    Science.gov (United States)

    Angst, M; Puzniak, R; Wisniewski, A; Jun, J; Kazakov, S M; Karpinski, J; Roos, J; Keller, H

    2002-04-22

    The anisotropy gamma of the superconducting state of high quality single crystals of MgB2 was determined, using torque magnetometry with two different methods. The anisotropy of the upper critical field was found to be temperature dependent, decreasing from gamma approximately 6 at 15 K to 2.8 at 35 K. Reversible torque data near T(c) reveal a field dependent anisotropy, increasing nearly linearly from gamma approximately equal to 2 in zero field to 3.7 in 10 kOe. The unusual temperature dependence is a true bulk property and can be explained by nonlocal effects of anisotropic pairing and/or the k--> dependence of the effective mass tensor.

  19. Oxidation of ZrB2-SiC

    Science.gov (United States)

    Opila, Elizabeth J.; Halbig, Michael C.

    2001-01-01

    In this paper the oxidation behavior of ZrB2-20 vol% SiC is examined. Samples were exposed in stagnant air in a zirconia furnace (Deltech, Inc.) at temperatures of 1327, 1627, and 1927 C for ten ten-minute cycles. Samples were removed from the furnace after one, five, and ten cycles. Oxidized material was characterized by mass change when possible, x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Oxidation kinetics, oxide scale development, and matrix recession were monitored as a function of time and temperature. Oxidation and recession rates of ZrB2 - 20 vol% SiC were adequately modeled by parabolic kinetics. Oxidation rates of this material are rapid, allowing only very short-term application in air or other high oxygen partial pressure environments.

  20. Structured Crowdsourcing: A B2B Innovation Roadmap

    DEFF Research Database (Denmark)

    Edgeman, Rick; Engell, Toke; Jensen, Nik Grewy;

    Crowdsourcing is an increasingly popular source of both ideas and funding. Crowdsourcing in a B2B context is less well understood and, as such, much of our discussion will highlight business-to-business crowdsourcing. More generally discussion will address crowdsourcing relative to innovation...... from crowd-sourcing efforts. The roadmap emphasizes on early stages in the overall innovation management activity that is related to development and specification of the task to be crowdsourced, the identification of the crowd, the creation of the environment to connect the crowdsourcer, the task...... and the crowd, motivation of the crowd, and actual activities in reaching the crowd. Managing the input from the crowd is regarded as a later stage in the overall innovation management but also as a focal point in the arguments for improving B2B crowdsourcing. In crowd selection processes this paper aims...

  1. Substitution Effects on MgB2 Superconductivity

    Institute of Scientific and Technical Information of China (English)

    DONG Rui-Xin; LIU Juan; YAN Xun-Ling; ZHAO Yuan; YANG Bing; YI Lin

    2008-01-01

    With the help of supercell method, the first-principle calculations were performed for the study of doping crystal Mg1-xAlxB2 and Mg(B1-yCy)2. Analyzing the variations of the charge distribution and the partial densities of states, we found that the compounds with doping A1 to MgB2 compound and/or replacing boron by carbon exhibit new covalent bond effects and unexpected electronic properties, related to superconductivity. The study of the density of states indicates that superconductivity decreases with the increase of AI fraction and carbon concentration. There exists a transition of superconductor to non-superconductor with the change of AI doping fraction. The substitution of boron by carbon results in the decrease of the transition temperature since the decrease of the electron concentration and the lattice constant. The theoretical predictions agree with experimental observations.

  2. Applying conceptual design to B2B sales negotiations

    DEFF Research Database (Denmark)

    Illi, Mikko; Ylirisku, Salu

    , service, configuration and customisation of the products in their company as well as to develop an apposite understanding of the key values and characteristics of the client organisation. Based on a design-ethnographical study of real sales practice in lift truck business the paper draws parallels between......This paper addresses the challenge of perceiving B2B sales negotiation in a manner that would open up new possibilities for the improvement of the practice. B2B sales agents work under high pressure in developing relevant and appealing proposals when negotiating for a deal with a customer. The key...... sales agent’s work practice and collaborative conceptual design work, i.e. innovation design work. This perception provides a means to understand the value that the use of conceptual design tools could possibly provide for sales negotiation work. We also use the notion of boundary object to elaborate...

  3. Permanent magnet with MgB2 bulk superconductor

    Science.gov (United States)

    Yamamoto, Akiyasu; Ishihara, Atsushi; Tomita, Masaru; Kishio, Kohji

    2014-07-01

    Superconductors with persistent zero-resistance currents serve as permanent magnets for high-field applications requiring a strong and stable magnetic field, such as magnetic resonance imaging. The recent global helium shortage has quickened research into high-temperature superconductors (HTSs)—materials that can be used without conventional liquid-helium cooling to 4.2 K. Herein, we demonstrate that 40-K-class metallic HTS magnesium diboride (MgB2) makes an excellent permanent bulk magnet, maintaining 3 T at 20 K for 1 week with an extremely high stability (cryocoolers, making MgB2 bulks promising for the next generation of Tesla-class permanent-magnet applications.

  4. High-resolution photoemission study of MgB2.

    Science.gov (United States)

    Takahashi, T; Sato, T; Souma, S; Muranaka, T; Akimitsu, J

    2001-05-21

    We have performed high-resolution photoemission spectroscopy on MgB2 and observed opening of a superconducting gap with a narrow coherent peak. We found that the superconducting gap is s like with the gap value ( Delta) of 4.5+/-0.3 meV at 15 K. The temperature dependence (15-40 K) of the gap value follows well the BCS form, suggesting that 2Delta/k(B)T(c) at T = 0 is about 3. No pseudogap behavior is observed in the normal state. The present results strongly suggest that MgB2 is categorized into a phonon-mediated BCS superconductor in the weak-coupling regime.

  5. Heterostructures of Bi-4334 and MgB2 superconductors

    Science.gov (United States)

    Padmavathi, M.; Singh, R.

    2016-05-01

    We report the studies on hetero structures of Bi-4334 and MgB2 superconductors. The two superconductors were arranged in the form of bulk multilayers using hydraulic pressure system. X-ray diffraction pattern and dc magnetization studies confirm the presence of both superconducting phases in this try-layer hetero structured sample. The d.c magnetization shows the superconducting onset at 77K and 39K for Bi-4334 and MgB2 phases respectively. Critical current density (Jc) is calculated from hysteresis loop of the sample in both in-plane field and out of plane field configurations. Inverted anisotropy in Jc is observed due to enhancement of ab-plane properties because of multilayer growth process. Morphology of the samples at surface and interface of two superconducting layers is discussed in view of Field emission scanning electron microscopy.

  6. Evidence for two superconducting gaps in MgB2.

    Science.gov (United States)

    Chen, X K; Konstantinovic, M J; Irwin, J C; Lawrie, D D; Franck, J P

    2001-10-01

    We have measured the Raman spectra of polycrystalline MgB2 from 25 to 1200 cm(-1). A superconductivity-induced redistribution in the electronic Raman continuum was observed. Two pair-breaking peaks appear in the spectra, suggesting the presence of two superconducting gaps. The measured spectra were analyzed using a quasi-two-dimensional model in which two s-wave superconducting gaps open on two sheets of Fermi surface. For the gap values we have obtained Delta(1) = 22 cm(-1) ( 2.7 meV) and Delta(2) = 50 cm(-1) ( 6.2 meV). Our results suggest that a conventional phonon-mediated pairing mechanism occurs in the planar boron sigma bands and is responsible for the superconductivity of MgB2.

  7. Performance and Applications of L1B2 Ultrasonic Motors

    OpenAIRE

    Gal Peled; Roman Yasinov; Nir Karasikov

    2016-01-01

    Piezoelectric ultrasonic motors offer important advantages for motion applications where high speed is coupled with high precision. The advances made in the recent decades in the field of ultrasonic motor based motion solutions allow the construction of complete motion platforms in the fields of semiconductors, aerospace and electro-optics. Among the various motor designs, the L1B2 motor type has been successful in industrial applications, offering high precision, effective control and operat...

  8. Social media usage: an investigation of B2B salespeople

    OpenAIRE

    Roberta J. Schultz; Charles H. Schwepker, Jr; David J. Good

    2012-01-01

    A great deal has been written recently in the practitioner press about the strategic importance and usage of social media. However, as practitioners only release limited information about the internal advantages such a tool provides, research in this emerging field remains extremely limited about its usage in the sales area. In this context, the purpose of this paper is to propose and empirically assess a model of social media usage among business-to-business (B2B) salespeople. A survey of 27...

  9. Content Marketing vs. Traditional Advertising for B2B Companies

    OpenAIRE

    Anthony, Lorena

    2015-01-01

    This thesis follows a traditional research-based structure. The thesis focuses around content marketing and traditional advertising for B2B companies. The thesis was pro-duced for a company called INS and aims at showing that, in present times, content marketing is more valuable than traditional advertising. The first part of the thesis covers different views and theories on both content market-ing and traditional advertising, from definitions, types, roles and stages to planning and mea...

  10. STRUCTURE ANALYSIS OF NEW SUPERCONDUCTOR MgB2

    Institute of Scientific and Technical Information of China (English)

    HE LUN-HUA; YAN QI-WEI; ZHANG PAN-LIN; HU GUI-QING

    2001-01-01

    The superconductivity of a sintered pellet of the newly discovered MgB2 superconductor has been studied with magnetic measurements and its crystal structure was analysed using the Rietveld method of powder X-ray patterns. It has hexagonal symmetry (S.G. P6/mmm) with unit cell lattice parameters a=0.308136(14)nm and c=0.351782(17)nm.

  11. Superconductivity in MgB2 irradiated with energetic protons

    Science.gov (United States)

    Sandu, Viorel; Craciun, Liviu; Ionescu, Alina Marinela; Aldica, Gheorghe; Miu, Lucica; Kuncser, Andrei

    2016-09-01

    A series of MgB2 samples were irradiated with protons of 11.3 and 13.2 MeV. Magnetization data shows an insignificant reduction of the critical temperatures but a continuous decrease of the Meissner fraction with increasing fluence or energy. All samples show a consistent improvement of the critical current density compared to the virgin sample and an increase of the pinning energy at high fields as resulted from relaxation data.

  12. CO and its Isotopomers Observation towards Sgr B2

    Indian Academy of Sciences (India)

    L. L. Sun; J. S. Zhang; D. R. Lu; J. J. Qiu

    2014-09-01

    We present our observations toward Sgr B2 region in = 1−0 lines of 12CO, 13CO, C18O and C17O using 13.7-m Delingha millimeter telescope with newly installed 9-beam SIS superconducting receiver. From the integrated line intensity, we derive the abundance ratio of C18O/C17O with a mean value of 3.11 ± 0.10, which is consistent with the previous results.

  13. Agent-based services for B2B electronic commerce

    Science.gov (United States)

    Fong, Elizabeth; Ivezic, Nenad; Rhodes, Tom; Peng, Yun

    2000-12-01

    The potential of agent-based systems has not been realized yet, in part, because of the lack of understanding of how the agent technology supports industrial needs and emerging standards. The area of business-to-business electronic commerce (b2b e-commerce) is one of the most rapidly developing sectors of industry with huge impact on manufacturing practices. In this paper, we investigate the current state of agent technology and the feasibility of applying agent-based computing to b2b e-commerce in the circuit board manufacturing sector. We identify critical tasks and opportunities in the b2b e-commerce area where agent-based services can best be deployed. We describe an implemented agent-based prototype system to facilitate the bidding process for printed circuit board manufacturing and assembly. These activities are taking place within the Internet Commerce for Manufacturing (ICM) project, the NIST- sponsored project working with industry to create an environment where small manufacturers of mechanical and electronic components may participate competitively in virtual enterprises that manufacture printed circuit assemblies.

  14. Biotechnological production of vitamin B2-enriched bread and pasta.

    Science.gov (United States)

    Capozzi, Vittorio; Menga, Valeria; Digesu, Anna Maria; De Vita, Pasquale; van Sinderen, Douwe; Cattivelli, Luigi; Fares, Clara; Spano, Giuseppe

    2011-07-27

    Lactic acid bacteria (LAB) were obtained from durum wheat flour samples and screened for roseoflavin-resistant variants to isolate natural riboflavin-overproducing strains. Two riboflavin-overproducing strains of Lactobacillus plantarum isolated as described above were used for the preparation of bread (by means of sourdough fermentation) and pasta (using a prefermentation step) to enhance their vitamin B2 content. Pasta was produced from a monovarietal semolina obtained from the durum wheat cultivar PR22D89 and, for experimental purposes, from a commercial remilled semolina. Several samples were collected during the pasta-making process (dough, extruded, dried, and cooked pasta) and tested for their riboflavin content by a high-performance liquid chromatography method. The applied approaches resulted in a considerable increase of vitamin B2 content (about 2- and 3-fold increases in pasta and bread, respectively), thus representing a convenient and efficient food-grade biotechnological application for the production of vitamin B2-enriched bread and pasta. This methodology may be extended to a wide range of cereal-based foods, feed, and beverages. Additionally, this work exemplifies the production of a functional food by a novel biotechnological exploitation of LAB in pasta-making.

  15. Modernization of B-2 Data, Video, and Control Systems Infrastructure

    Science.gov (United States)

    Cmar, Mark D.; Maloney, Christian T.; Butala, Vishal D.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Spacecraft Propulsion Research Facility, commonly referred to as B-2, is NASA s third largest thermal-vacuum facility with propellant systems capability. B-2 has completed a modernization effort of its facility legacy data, video and control systems infrastructure to accommodate modern integrated testing and Information Technology (IT) Security requirements. Integrated systems tests have been conducted to demonstrate the new data, video and control systems functionality and capability. Discrete analog signal conditioners have been replaced by new programmable, signal processing hardware that is integrated with the data system. This integration supports automated calibration and verification of the analog subsystem. Modern measurement systems analysis (MSA) tools are being developed to help verify system health and measurement integrity. Legacy hard wired digital data systems have been replaced by distributed Fibre Channel (FC) network connected digitizers where high speed sampling rates have increased to 256,000 samples per second. Several analog video cameras have been replaced by digital image and storage systems. Hard-wired analog control systems have been replaced by Programmable Logic Controllers (PLC), fiber optic networks (FON) infrastructure and human machine interface (HMI) operator screens. New modern IT Security procedures and schemes have been employed to control data access and process control flows. Due to the nature of testing possible at B-2, flexibility and configurability of systems has been central to the architecture during modernization.

  16. Fabrication and characterization of an MgB2 bolometer

    International Nuclear Information System (INIS)

    In this work, we present the experimental results obtained in the fabrication and characterization of a superconducting MgB2 bolometer. The device was made from an MgB2 meander-like structure suspended on a 500 nm thick SiN membrane. The MgB2 meander line was 50 μm wide and 7.6 mm long and it was defined by optical lithography and dry etching. The SiN membrane had an area of 1.3 mm x 1.3 mm and it was obtained by a silicon micromachining technique. The electrical and thermal properties of the device were measured at low temperature in a closed-cycle cryocooler. The resulting Tc of the meander was unchanged with respect to the unprocessed film and the transport properties, measured in voltage-biased mode, indicated a value for Jc of the order of 105 A cm-2 at 27 K. The logarithmic sensitivity of the bolometer turned out to be higher than 150. The study of the thermal properties of the bolometer on the membrane showed a thermal conductance of the order 10-5 W K-1 at a working temperature of 32 K. The bolometer, irradiated by a chopped laser beam, showed a cut-off frequency of 94 Hz. The maximum experimental responsivity was estimated to be 2.3 x 103 V W-1

  17. Molecular dynamics study of the ternary compound Li3AlB2O6

    Institute of Scientific and Technical Information of China (English)

    Zhang Hong; Wu Hai-Ying; Chen Yu-Yu; Cheng Xin-Lu

    2006-01-01

    A new compound with the same chemical composition as LisAlB2O6 but with a different x-ray powder diffraction pattern as reported before was synthesized and studied experimentally by M. He, Chen X L et al (J. Solid State Chem. 163, 369 (2002)), but there lacks first principles study on the structure of it. Using conjugant gradient (CG) molecule dynamics (MD) simulation with a full relaxation of the atomic positions and of the shape and size of the cell, the structure of LisAlB2O6 is studied from first principles. For the density functional, the local density approximation (LDA) and the generalized gradient approximation (GGA) forms are used respectively. Both the LDA and GGA results support the experimental structure of M. He et al. The result of MD simulation using GGA agrees with the experimental result much better. The energy bands are also studied, the band gap given by LDA and GGA are 5.65 eV, 5.34eV, respectively.

  18. High critical current density and enhanced irreversibility field in superconducting MgB2 thin films.

    Science.gov (United States)

    Eom, C B; Lee, M K; Choi, J H; Belenky, L J; Song, X; Cooley, L D; Naus, M T; Patnaik, S; Jiang, J; Rikel, M; Polyanskii, A; Gurevich, A; Cai, X Y; Bu, S D; Babcock, S E; Hellstrom, E E; Larbalestier, D C; Rogado, N; Regan, K A; Hayward, M A; He, T; Slusky, J S; Inumaru, K; Haas, M K; Cava, R J

    2001-05-31

    The discovery of superconductivity at 39 K in magnesium diboride offers the possibility of a new class of low-cost, high-performance superconducting materials for magnets and electronic applications. This compound has twice the transition temperature of Nb3Sn and four times that of Nb-Ti alloy, and the vital prerequisite of strongly linked current flow has already been demonstrated. One possible drawback, however, is that the magnetic field at which superconductivity is destroyed is modest. Furthermore, the field which limits the range of practical applications-the irreversibility field H*(T)-is approximately 7 T at liquid helium temperature (4.2 K), significantly lower than about 10 T for Nb-Ti (ref. 6) and approximately 20 T for Nb3Sn (ref. 7). Here we show that MgB2 thin films that are alloyed with oxygen can exhibit a much steeper temperature dependence of H*(T) than is observed in bulk materials, yielding an H* value at 4.2 K greater than 14 T. In addition, very high critical current densities at 4.2 K are achieved: 1 MA cm-2 at 1 T and 105 A cm-2 at 10 T. These results demonstrate that MgB2 has potential for high-field superconducting applications.

  19. B2C电子商务网站设计%Design of B2 C E-commerce Website

    Institute of Scientific and Technical Information of China (English)

    董慧; 王海洋; 谢静

    2014-01-01

    With the development of information technology, E-commerce is springing up. As the mainstream of E-commerce, B2C(Business to Consumer) has occupied a considerable market share in global online-shopping trade. In order to provide a more user-friendly B2C E-commerce website and enhance the interests of enterprises, it is essential to make a detailed demand a-nalysis and design. Therefore, the essay analyses the demand of a B2C E-commerce website through the perspective of customers, the inner enterprises and the network marketing, divides each function module as well as analyses the business flow and data flow. Based on the demand analysis, the whole design of the system focuses on the relational database design process of user, shopping cart and goods. In combination with the search engine optimization, it is more conducive to explore potential customer. Furthermore, it plays a guiding role in the website maintenance and development in the long run.%随着信息化的发展,电子商务蓬勃兴起。 B2C(Business to Consumer)作为当今主流电子商务,已在全球网络购物交易额中占据相当大的市场份额。为了提高B2 C电子商务网站的用户体验和企业的收益,详细的需求分析和设计是必不可少的。本文从客户、企业内部和网络营销3个方面对B2 C电子商务网站进行需求分析,划分各个功能模块,分析业务流和数据流。根据需求给出系统整体设计,并重点叙述以用户、购物车、商品的关系为例的数据库设计过程。结合搜索引擎优化思想,更有利于发掘潜在用户,并为后期的网站维护和发展起了导向作用。

  20. Benchmarking the starting points of the GW approximation for molecules

    International Nuclear Information System (INIS)

    The GW approximation is nowadays being used to obtain accurate quasiparticle energies of atoms and molecules. In practice, the GW approximation is generally evaluated perturbatively, based on a prior self-consistent calculation within a simpler approximation. The final result thus depends on the choice of the self-consistent mean-field chosen as a starting point. Using a recently developed GW code based on Gaussian basis functions, we benchmark a wide range of starting points for perturbative GW, including Hartree-Fock, LDA, PBE, PBE0, B3LYP, HSE06, BH and HLYP, CAM-B3LYP, and tuned CAM-B3LYP. In the evaluation of the ionization energy, the hybrid functionals are clearly superior results starting points when compared to Hartree-Fock, to LDA, or to the semi local approximations. Furthermore, among the hybrid functionals, the ones with the highest proportion of exact-exchange usually perform best. Finally, the reliability of the frozen-core approximation, that allows for a considerable speedup of the calculations, is demonstrated. (authors)

  1. Activation of macrophages by an exopolysaccharide isolated from Antarctic Psychrobacter sp. B-3

    Science.gov (United States)

    Yu, Leiye; Sun, Guojie; Wei, Jingfang; Wang, Yingze; Du, Chao; Li, Jiang

    2016-09-01

    An exopolysaccharide (EPS) was isolated and purified from an Antarctic psychrophilic bacterium B-3, identified as Psychrobacter sp., and the activation of RAW264.7 cells by B-3 EPS was investigated. The results show that B-3 EPS, over a certain concentration range, promoted cell viability, nitric oxide production, tumor necrosis factor (TNF)α secretion, and phagocytic ability. Furthermore, TAK-242, an inhibitor of the toll-like receptor 4 (TLR4) significantly reduced nitric oxide production by these cells after stimulation with B-3 EPS. Moreover, B-3 EPS induced p65 phosphorylation and IκBα degradation in these cells. In conclusion, B-3 EPS might have activated RAW264.7 cells by combining with TLR4 on cell surface and triggering activation of NF-κB signaling pathways, implying that this EPS could activate macrophages and regulate initial immune response.

  2. Prestack traveltime approximations

    KAUST Repository

    Alkhalifah, Tariq Ali

    2011-01-01

    Most prestack traveltime relations we tend work with are based on homogeneous (or semi-homogenous, possibly effective) media approximations. This includes the multi-focusing or double square-root (DSR) and the common reflection stack (CRS) equations. Using the DSR equation, I analyze the associated eikonal form in the general source-receiver domain. Like its wave-equation counterpart, it suffers from a critical singularity for horizontally traveling waves. As a result, I derive expansion based solutions of this eikonal based on polynomial expansions in terms of the reflection and dip angles in a generally inhomogenous background medium. These approximate solutions are free of singularities and can be used to estimate travetimes for small to moderate offsets (or reflection angles) in a generally inhomogeneous medium. A Marmousi example demonstrates the usefulness of the approach. © 2011 Society of Exploration Geophysicists.

  3. Order-Disorder Transition and Phase Separation in the MgB2 Metallic Sublattice Induced by Al Doping.

    Science.gov (United States)

    Brutti, S; Gigli, G

    2009-07-14

    MgB2 is a superconductor constituted by alternating Mg and B planar layers: doping of both the sublattices has been observed experimentally to destroy the outstanding superconductive properties of this simple material. In this study we present the investigation by first principles methods at atomistic scale of the phase separation induced by aluminum doping in the MgB2 lattice. The calculations were performed by Density Functional Theory in generalized gradient approximation and pseudopotentials. Orthorhombic oP36 supercells derived by the primitive hR3 MgB2 cell were built in order to simulate the aluminum-magnesium substitution in the 0-50% composition range. The computational results explained the occurrence of a phase separation in the Mg1-xAlxB2 system. The miscibility gap is predicted to be induced by an order-disorder transition in the metallic sublattice at high Al concentration. Indeed at 1000 K aluminum substitution takes place on random Mg sites for concentration up to 17% of the total metallic sites, whereas at Al content larger than 31% the substitution is energetically more favorable on alternated metallic layers (Mg undoped planes alternate with Mg-Al layers). The formation of this Al-rich phase lead at 50% doping to the formation of the double omega Mg1/2Al1/2B2 ordered lattice. From 17 to 31% the two phases, the disordered Mg1-xAlxB2 (x MgB2 occurs in parallel with the collapse of the superconductive properties of the material.

  4. City centres in the internet age : Exploring the implications of b2c e-commerce for retailing at city centres in the Netherlands

    OpenAIRE

    Weltevreden, J.W.J.

    2006-01-01

    The rapid development of Internet use and b2c e-commerce led to many speculations about the impacts of ICT on society. In the Netherlands, there is a growing concern about the implications of b2c e-commerce for city centre retailing. Therefore, this dissertation has empirically investigated the implications of b2c e-commerce for retailing at city centres in the Netherlands. Approximately 1,000 city centre retailers and 3,200 internet users have been interviewed. So far, the large majority (ar...

  5. Approximate option pricing

    Energy Technology Data Exchange (ETDEWEB)

    Chalasani, P.; Saias, I. [Los Alamos National Lab., NM (United States); Jha, S. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    1996-04-08

    As increasingly large volumes of sophisticated options (called derivative securities) are traded in world financial markets, determining a fair price for these options has become an important and difficult computational problem. Many valuation codes use the binomial pricing model, in which the stock price is driven by a random walk. In this model, the value of an n-period option on a stock is the expected time-discounted value of the future cash flow on an n-period stock price path. Path-dependent options are particularly difficult to value since the future cash flow depends on the entire stock price path rather than on just the final stock price. Currently such options are approximately priced by Monte carlo methods with error bounds that hold only with high probability and which are reduced by increasing the number of simulation runs. In this paper the authors show that pricing an arbitrary path-dependent option is {number_sign}-P hard. They show that certain types f path-dependent options can be valued exactly in polynomial time. Asian options are path-dependent options that are particularly hard to price, and for these they design deterministic polynomial-time approximate algorithms. They show that the value of a perpetual American put option (which can be computed in constant time) is in many cases a good approximation to the value of an otherwise identical n-period American put option. In contrast to Monte Carlo methods, the algorithms have guaranteed error bounds that are polynormally small (and in some cases exponentially small) in the maturity n. For the error analysis they derive large-deviation results for random walks that may be of independent interest.

  6. Approximations to Euler's constant

    International Nuclear Information System (INIS)

    We study a problem of finding good approximations to Euler's constant γ=lim→∞ Sn, where Sn = Σk=Ln (1)/k-log(n+1), by linear forms in logarithms and harmonic numbers. In 1995, C. Elsner showed that slow convergence of the sequence Sn can be significantly improved if Sn is replaced by linear combinations of Sn with integer coefficients. In this paper, considering more general linear transformations of the sequence Sn we establish new accelerating convergence formulae for γ. Our estimates sharpen and generalize recent Elsner's, Rivoal's and author's results. (author)

  7. Finite elements and approximation

    CERN Document Server

    Zienkiewicz, O C

    2006-01-01

    A powerful tool for the approximate solution of differential equations, the finite element is extensively used in industry and research. This book offers students of engineering and physics a comprehensive view of the principles involved, with numerous illustrative examples and exercises.Starting with continuum boundary value problems and the need for numerical discretization, the text examines finite difference methods, weighted residual methods in the context of continuous trial functions, and piecewise defined trial functions and the finite element method. Additional topics include higher o

  8. Electric-quadrupole interaction at 181Hf/181Ta in Hf doped MgB2 and HfB2: a perturbed angular correlation study

    International Nuclear Information System (INIS)

    Hyperfine interaction of the 181Hf/181Ta is studied in HfB2 and Hf doped MgB2 by perturbed angular correlation spectroscopy. Nuclear quadrupole constants and attenuation factors were extracted from the data. Quadrupole coupling constant shows that Hf goes to three inequivalent sites in MgB2. There is sign of HfB2 formation at high temperature. (author)

  9. Neon ion Irradiation studies on MgB2 Superconductor

    OpenAIRE

    Talapatra, A.; Bandyopadhyay, S K; Sen, Pintu; P. Barat

    2004-01-01

    160 MeV Neon ion irradiation has been carried out on MgB2 polycrystalline pellets at various doses. There has not been any significant change in Tc except at the highest dose of 1x10^15 ions/cm^2. Increase in resistivity has been noticed. Resistivity data has been fitted with Bloch-Gruneisen function and the values of Debye temperature, residual resistivity and temperature coefficient of resistivity have been extracted for irradiated as well as unirradiated samples. The increase in the resist...

  10. Strategic Insights from Mystery Shopping in B2B Relationships

    DEFF Research Database (Denmark)

    Mattsson, Jan

    2012-01-01

    guideline covering the themes of map, smoke and mirror as metaphors) has been extended to comprise a larger group of engineers and may be taken up in a company-wide way. The experiment was deemed effective in developing both a procedure for mystery shopping and a new way to train the consultants.......This paper describes how mystery shopping can be used to gain valuable strategic input in B2B service relationships. We account for a longitudinal case study framed as a natural experiment (duration 18 months) in a Swedish group of consultancy companies offering a wide selection of industrial...

  11. Superconductivity in MgB2: clean or dirty?

    Science.gov (United States)

    Mazin, I I; Andersen, O K; Jepsen, O; Dolgov, O V; Kortus, J; Golubov, A A; Kuz'menko, A B; Van Der Marel, D

    2002-09-01

    A large number of experimental facts and theoretical arguments favor a two-gap model for superconductivity in MgB2. However, this model predicts strong suppression of the critical temperature by interband impurity scattering and, presumably, a strong correlation between the critical temperature and the residual resistivity. No such correlation has been observed. We argue that this fact can be understood if the band disparity of the electronic structure is taken into account, not only in the superconducting state, but also in normal transport.

  12. Microwave absorption studies of MgB2 superconductor

    Indian Academy of Sciences (India)

    M K Bhide; R M Kadam; M D Sastry; Ajay Singh; Shashwati Sen; Manmeet Kaur; D K Aswal; S K Gupta; V C Sahni

    2002-05-01

    Microwave absorption studies have been carried out on MgB2 superconductor using a standard X-band EPR spectrometer. The modulated low-field microwave absorption signals recorded for polycrystalline (grain size ∼ 10m) samples suggested the absence of weak-link character. The field dependent direct microwave absorption has been found to obey a $\\sqrt{H}$ dependence with two different slopes, which indicated a transition from strongly pinned lattice to flux flow regime.

  13. Phonon dispersion and lifetimes in MgB2.

    Science.gov (United States)

    Shukla, Abhay; Calandra, Matteo; D'Astuto, Matteo; Lazzeri, Michele; Mauri, Francesco; Bellin, Christophe; Krisch, Michael; Karpinski, J; Kazakov, S M; Jun, J; Daghero, D; Parlinski, K

    2003-03-01

    We measure phonon dispersion and linewidth in a single crystal of MgB2 along the Gamma-A, Gamma-M, and A-L directions using inelastic x-ray scattering. We use density functional theory to compute the effect of both electron-phonon coupling and anharmonicity on the linewidth, obtaining excellent agreement with experiment. Anomalous broadening of the E(2g) phonon mode is found all along Gamma-A. The dominant contribution to the linewidth is always the electron-phonon coupling.

  14. Two-band superconductivity in MgB2.

    Science.gov (United States)

    Iavarone, M; Karapetrov, G; Koshelev, A E; Kwok, W K; Crabtree, G W; Hinks, D G; Kang, W N; Choi, Eun-Mi; Kim, Hyun Jung; Kim, Hyeong-Jin; Lee, S I

    2002-10-28

    The study of the anisotropic superconductor MgB2 using a combination of scanning tunneling microscopy and spectroscopy reveals two distinct energy gaps at Delta(1)=2.3 meV and Delta(2)=7.1 meV at 4.2 K. Different spectral weights of the partial superconducting density of states are a reflection of different tunneling directions in this multiband system. Temperature evolution of the tunneling spectra follows the BCS scenario [Phys. Rev. Lett. 3, 552 (1959)

  15. Correlation of needle core biopsy with excision histology in screen-detected B3 lesions: the Merrion Breast Screening Unit experience.

    LENUS (Irish Health Repository)

    Hayes, B D

    2012-02-01

    AIMS: Needle core biopsy (NCB) is a widely-used technique for non-operative evaluation of screen-detected breast lesions. Although most NCBs are B2 (benign) or B5 (malignant), some fall into the B3 category of "uncertain malignant potential". This study aims to categorise the lesions prompting a B3 NCB in the Merrion Breast Screening Unit, and establish the incidence of malignancy on subsequent excision biopsy. METHODS: Patients attending the Merrion Breast Screening Unit in Dublin between 2000 and 2008 who had a B3 NCB were identified. The NCB pathology reports were reviewed and the diagnosis correlated with excision histology; the latter was classified as benign, atypical or malignant. Lesion-specific positive predictive values (PPVs) for malignancy were derived. RESULTS: 141 patients with a B3 NCB were identified. The most frequent lesions on NCB were radial scar (RS; n = 57), atypical intraductal epithelial proliferation (AIDEP; n = 25) and papillary lesion (n = 24). The final diagnosis was malignant in 22 patients (16%), atypical in 40 (28%) and benign in 79 (56%). Two of the patients with a malignant diagnosis had invasive carcinoma. The lesion-specific PPVs were: lobular neoplasia 50%, AIDEP 32%, columnar cell lesion with atypia 12.5%, RS 12.3%, papillary lesion 8.3%, suspected phyllodes tumour 7.7%, and spindle cell lesion 0%. Atypia on RS NCB predicted an atypical or malignant excision diagnosis, but atypia on papillary lesion NCB did not. CONCLUSIONS: One-sixth of B3 NCBs in this series proved to be malignant on excision. The PPV for malignancy varied according to lesion type.

  16. The Compact Approximation Property does not imply the Approximation Property

    OpenAIRE

    Willis, George A.

    1992-01-01

    It is shown how to construct, given a Banach space which does not have the approximation property, another Banach space which does not have the approximation property but which does have the compact approximation property.

  17. 22 CFR 9b.3 - Press correspondents employed by foreign media organizations.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Press correspondents employed by foreign media organizations. 9b.3 Section 9b.3 Foreign Relations DEPARTMENT OF STATE GENERAL REGULATIONS GOVERNING DEPARTMENT... media organizations must: (a) Present to the Office of Press Relations, Department of State,...

  18. Preparation of highly preferred orientation TiB2 coatings

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper focuses on the preparation of titanium diboride (TiB2) coatings on the graphite substrate by continuous current plating (CCP) and pulse current plating (PIC) electrochemical techniques in fluoride electrolytes (LiF-NaF-KF)containing K2TiF6 and KBF4 as the electrochemically-active components at 700℃. Thick leveled and uniform coatings were obtained and were composed of relatively pure TiB2. The effect of the experimental parameters on the microstructure of the coatings was studied. The results showed the electrodeposition with PIC produced coatings with better quality, when compared with those obtained by CCP, under the conditions of the current density i = 0.6 A/cm2, frequency = 100 Hz, and ton/toff = 4/1. XRD analysis indicated that the preferred orientation of coatings is (110) plane, which is in accordance with the prediction of the two-dimensional crystal nuclei theory. The effect of a ratio of ton/toff and frequency on the crystal size, texture coefficient and microstress was also investigated.

  19. USING UML SCENARIOS IN B2B SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. Jakimi

    2010-05-01

    Full Text Available Scenarios has become a popular technique for requirements elicitation and specification building. Since scenarios capture only partial descriptions of the system behavior, an approach for scenario composition and/or integration is needed to produce more complete specifications. The Unified Modeling Language (UML, which has become a standard notation for object-oriented modeling, provides a suitable framework for scenario acquisition using Use Case diagrams and Sequence or Collaboration diagrams. In this paper, we suggest an algorithmic and tool support for composing and integrating scenarios that are represented in form of sequence diagrams. We suggest four operators (;: sequential operator, ||: concurrent operator, ?: conditional operator and  * :iteration operator to compose a set of scenarios that describe a use case of a given system. In this paper, we suggest also to apply the scenario approach to B2B systems (Business to Business. We propose to develop B2B systems as a three activities process deriving formal specifications and code skeletons from UML scenarios. Activities of this proposed process are generally automatic and are supported by a set of developed algorithms and tools.

  20. Low-noise THz MgB2 Josephson mixer

    Science.gov (United States)

    Cunnane, Daniel; Kawamura, Jonathan H.; Acharya, Narendra; Wolak, Matthäus A.; Xi, X. X.; Karasik, Boris S.

    2016-09-01

    The potential applications for high frequency operation of the Josephson effect in MgB2 include THz mixers, direct detectors, and digital circuits. Here we report on MgB2 weak links which exhibit the Josephson behavior up to almost 2 THz and using them for low-noise heterodyne detection of THz radiation. The devices are made from epitaxial film grown in the c-axis direction by the hybrid physical-chemical vapor deposition method. The current in the junctions travels parallel to the surface of the film, thus making possible a large contribution of the quasi-two-dimensional σ-gap in transport across the weak link. These devices are connected to a planar spiral antenna with a dielectric substrate lens to facilitate coupling to free-space radiation for use as a detector. The IcRn product of the junction is 5.25 mV, giving confirmation of a large gap parameter. The sensitivity of the mixer was measured from 0.6 THz to 1.9 THz. At a bath temperature of over 20 K, a mixer noise temperature less than 2000 K (DSB) was measured near 0.6 THz.

  1. Multilayer MgB2 superconducting quantum interference filter magnetometers

    Science.gov (United States)

    Galan, Elias; Melbourne, Thomas; Davidson, Bruce A.; Xi, X. X.; Chen, Ke

    2016-04-01

    We report two types of all-MgB2 superconductive quantum interference filter (SQIF) magnetometers that can measure absolute magnetic fields with high sensitivity. In one configuration, the SQIFs were made of 20 multilayer nonplanar all-MgB2 superconducting quantum interference devices (SQUIDs) connected in parallel with loop areas ranging in size from 0.4 to 3.6 μm2. These devices are sensitive to magnetic fields parallel to the substrate and show a single antipeak from 3 to 16 K with a maximum transfer function of ˜16 V/T at 3 K and a field noise of ˜110 pT/Hz1/2 above 100 Hz at 10 K. In a second configuration, the SQIFs were made with 16 planar SQUIDs connected in parallel with loop areas ranging in size from 4 μm2 to 25 μm2 and are sensitive to the magnetic fields perpendicular to the substrate. The planar SQIF shows a single antipeak from 10 to 22 K with a maximum transfer function of 7800 V/T at 10 K and a field noise of ˜70 pT/Hz1/2 above 100 Hz at 20 K.

  2. NuSTAR Detection of the Blazar B2 1023+25 at Redshift 5.3

    Science.gov (United States)

    Sbarrato, T.; Tagliaferri, G.; Ghisellini, G.; Perri, M.; Puccetti, S.; Balokovic, M.; Nardini, M.; Stern, D.; Boggs, S. E.; Brandt, W. N.; Christensen, F. E.; Giommi, P.; Greiner, J.; Hailey, C. J.; Harrison, F. A.; Hovatta, T.; Madejski, G. M.; Rau, A.; Schady, P.; Sudilovsky, V.; Urry, C. M.; Zhang, William W.

    2013-01-01

    B2 1023+25 is an extremely radio-loud quasar at zeta = 5.3 that was first identified as a likely high-redshift blazar candidate in the SDSS+FIRST quasar catalog. Here, we use the Nuclear Spectroscopic Telescope Array (NuSTAR) to investigate its non-thermal jet emission, whose high-energy component we detected in the hard X-ray energy band. The X-ray flux is approximately 5.5 × 10 (exp -14) erg cm(exp -2) s(exp -1) (5-10 keV) and the photon spectral index is Gamma(x) approx. =1.3-1.6. Modeling the full spectral energy distribution, we find that the jet is oriented close to the line of sight, with a viewing angle of approximately 3deg, and has significant Doppler boosting, with a large bulk Lorentz factor approximately 13, which confirms the identification of B2 1023+25 as a blazar. B2 1023+25 is the first object at redshift larger than 5 detected by NuSTAR, demonstrating the ability of NuSTAR to investigate the early X-ray universe and to study extremely active supermassive black holes located at very high redshift.

  3. The Microwave Sintering Technology and Its Application in the Synthesis of ZrB2

    Institute of Scientific and Technical Information of China (English)

    HE Zhiyong; LI Lin; PENG Xiaoyan

    2005-01-01

    The principles and features of microwave sintering, the application in refractories and synthesis methods of ZrB2 are reviewed. The synthesis results of ZrB2 by thermit deoxidate method show that production price of ZrB2 can be effectively lowered through microwave synthesis. It will expand the application of ZrB2 in refractories.

  4. Getting started with Oracle SOA B2B Integration a hands-on tutorial

    CERN Document Server

    Bhatia, Krishnaprem; Perlovsky, Alan

    2013-01-01

    This hands on tutorial gives you the best possible start you could hope for with Oracle B2B. Learn using real life scenarios and examples to give you a solid footing of B2B.This book is for B2B architects, consultants and developers who would like to design and develop B2B integrations using Oracle B2B. This book assumes no prior knowledge of Oracle B2B and explains all concepts from scratch using illustrations, real world examples and step-by-step instructions. The book covers enough depth and details to be useful for both beginner and advanced B2B users.

  5. Sulla razionalità delle 3-varietà di Fano con B_2 almeno 2

    Directory of Open Access Journals (Sweden)

    Alberto Alzati

    1992-05-01

    Full Text Available Complex, smooth, projective Fano varieties were classified by Iskovskih when B2 =1 (B2 is the second Betti number and by Mori and Mukai when B2  is at least 2. When B2 =1 it is known if such varieties are rational (unirational or not; in this paper we solve this problem when B2  greater or equal 2.

  6. Cross section of the impact single ionization of B2+ by H+

    Institute of Scientific and Technical Information of China (English)

    Ye Dan-Dan; Qi Yue-Ying; Hu Ya-Hua; Ning Li-Na

    2013-01-01

    The ionization process of B2+ by H+ impact is studied using the continuum-distorted-wave eikonal-initial-state (CDW-EIS) method and the modified free electron peak approximation (M-FEPA),respectively.Total,single-,and doubledifferential cross sections from ls and 2s orbitals are presented for the energy range from 10 keV/u to 10 MeV/u.Comparison between the results from the two methods demonstrates that the total and single-differential cross sections for the high-energy incident projectile case can be well evaluated using the simple M-FEPA model.Moreover,the M-FEPA model reproduces the essential features of the binary-encounter (BE) bump in the double-differential cross sections.Thus,the BE ionization mechanism is discussed in detail by adopting the M-FEPA model.In particular,the double-and single-differential cross sections from the 2s orbital show a high-energy hip,which is different from those from the 1 s orbital.Based on Ref.[1],the Compton profiles of B2+ for ls and 2s orbitals are given,and the hips in DDCS and SDCS from the 2s orbital are explained.

  7. Interacting boson approximation

    International Nuclear Information System (INIS)

    Lectures notes on the Interacting Boson Approximation are given. Topics include: angular momentum tensors; properties of T/sub i//sup (n)/ matrices; T/sub i//sup (n)/ matrices as Clebsch-Gordan coefficients; construction of higher rank tensors; normalization: trace of products of two s-rank tensors; completeness relation; algebra of U(N); eigenvalue of the quadratic Casimir operator for U(3); general result for U(N); angular momentum content of U(3) representation; p-Boson model; Hamiltonian; quadrupole transitions; S,P Boson model; expectation value of dipole operator; S-D model: U(6); quadratic Casimir operator; an O(5) subgroup; an O(6) subgroup; properties of O(5) representations; quadratic Casimir operator; quadratic Casimir operator for U(6); decomposition via SU(5) chain; a special O(3) decomposition of SU(3); useful identities; a useful property of D/sub αβγ/(α,β,γ = 4-8) as coupling coefficients; explicit construction of T/sub x//sup (2)/ and d/sub αβγ/; D-coefficients; eigenstates of T3; and summary of T = 2 states

  8. Prestack traveltime approximations

    KAUST Repository

    Alkhalifah, Tariq Ali

    2012-05-01

    Many of the explicit prestack traveltime relations used in practice are based on homogeneous (or semi-homogenous, possibly effective) media approximations. This includes the multifocusing, based on the double square-root (DSR) equation, and the common reflection stack (CRS) approaches. Using the DSR equation, I constructed the associated eikonal form in the general source-receiver domain. Like its wave-equation counterpart, it suffers from a critical singularity for horizontally traveling waves. As a result, I recasted the eikonal in terms of the reflection angle, and thus, derived expansion based solutions of this eikonal in terms of the difference between the source and receiver velocities in a generally inhomogenous background medium. The zero-order term solution, corresponding to ignoring the lateral velocity variation in estimating the prestack part, is free of singularities and can be used to estimate traveltimes for small to moderate offsets (or reflection angles) in a generally inhomogeneous medium. The higher-order terms include limitations for horizontally traveling waves, however, we can readily enforce stability constraints to avoid such singularities. In fact, another expansion over reflection angle can help us avoid these singularities by requiring the source and receiver velocities to be different. On the other hand, expansions in terms of reflection angles result in singularity free equations. For a homogenous background medium, as a test, the solutions are reasonably accurate to large reflection and dip angles. A Marmousi example demonstrated the usefulness and versatility of the formulation. © 2012 Society of Exploration Geophysicists.

  9. Semantic ETL into i2b2 with Eureka!

    Science.gov (United States)

    Post, Andrew R; Krc, Tahsin; Rathod, Himanshu; Agravat, Sanjay; Mansour, Michel; Torian, William; Saltz, Joel H

    2013-01-01

    Clinical phenotyping is an emerging research information systems capability. Research uses of electronic health record (EHR) data may require the ability to identify clinical co-morbidities and complications. Such phenotypes may not be represented directly as discrete data elements, but rather as frequency, sequential and temporal patterns in billing and clinical data. These patterns' complexity suggests the need for a robust yet flexible extract, transform and load (ETL) process that can compute them. This capability should be accessible to investigators with limited ability to engage an IT department in data management. We have developed such a system, Eureka! Clinical Analytics. It extracts data from an Excel spreadsheet, computes a broad set of phenotypes of common interest, and loads both raw and computed data into an i2b2 project. A web-based user interface allows executing and monitoring ETL processes. Eureka! is deployed at our institution and is available for deployment in the cloud. PMID:24303265

  10. Vortex lattice transitions in YNi2B2C

    Indian Academy of Sciences (India)

    S J Levett; C D Dewhurst; D McK Paul

    2002-05-01

    We have performed extensive small-angle neutron scattering (SANS) diffraction studies of the vortex lattice in single crystal YNi2B2C for $B||c$. High-resolution SANS, combined with a field-oscillation vortex lattice preparation technique, allows us to separate Bragg scattered intensities from two orthogonal domains and accurately determine the unit cell angle, . The data suggest that upon increasing field there is a finite transition width where both low- and high-field distorted hexagonal vortex lattice phases, mutually rotated by 45°, coexist. The smooth variation of diffracted intensity from each phase through the transition corresponds to a redistribution of populations between the two types of domains.

  11. Enhanced MgB2 Superconductivity Under High Pressure

    Institute of Scientific and Technical Information of China (English)

    刘振兴; 靳常青; 游江洋; 李绍春; 朱嘉林; 禹日成; 李风英; 苏少奎

    2002-01-01

    We report on in situ high-pressure studies up to 1.0 GPa on the MgB2 superconductor which was high-pressure synthesized. The as-prepared sample is of high quality in terms of sharp superconducting transition (Tc) at 39K from the magnetic measurements. The in situ high-pressure measurements were carried out using a Be-Cu piston-cylinder-type instrument with mixed oil as the pressure transmitting medium which warrants a quasihydrostatic pressure environment at low temperature. The superconducting transitions were measured using the electrical conductance method. It is found that Tc increases by more than 1 K with pressure in the low-pressure range, before the Tc value decreases with the further increase of the pressure.

  12. Relationship Quality as Predictor of B2B Customer Loyalty

    Directory of Open Access Journals (Sweden)

    Shaimaa S. B. Ahmed Doma

    2013-02-01

    Full Text Available Relationship marketing has become extremely important recently due to the fierce competition in today's marketplace. Companies are required to build long-term profitable relationship with customers and to achieve customer loyalty. Also, switching behaviors frequently occur among most of targeted customers. Fewer studies, however, discuss the effects of relationship quality efforts on customer loyalty. Therefore, this study is aimed to investigate the impact of relationship quality on customer loyalty in B2B context in the Egyptian shipping services sector. Building on prior research, we propose relationship quality as a higher construct comprising trust, commitment and satisfaction. An analytical model is developed as a guideline to test the relationships between relationship quality dimensions and customer loyalty.

  13. Matchmaking Framework for B2B E-Marketplaces

    Directory of Open Access Journals (Sweden)

    Fekete ZOLTAN ALPAR

    2010-01-01

    Full Text Available In the recent years trading on the Internet become more popular. Online businesses gradually replace more and more from the conventional business. Much commercial information is exchanged on the internet, especially using the e-marketplaces. The demand and supply matching process becomes complex and difficult on last twenty years since the e-marketplaces play an important role in business management. Companies can achieve significant cost reduction by using e-marketplaces in their trade activities and by using matchmaking systems on finding the corresponding supply for their demand and vice versa. In the literature were proposed many approaches for matchmaking. In this paper we present a conceptual framework of matchmaking in B2B e-marketplaces environment.

  14. Scanning tunneling spectroscopy in MgB2.

    Science.gov (United States)

    Karapetrov, G; Iavarone, M; Kwok, W K; Crabtree, G W; Hinks, D G

    2001-05-01

    We present scanning tunneling microscopy measurements of the surface of superconducting MgB2 with a critical temperature of 39 K. In zero magnetic field the conductance spectra can be analyzed in terms of the standard BCS theory with a smearing parameter gamma. The value of the superconducting gap is 5 meV at 4.2 K, with no experimentally significant variation across the surface of the sample. The temperature dependence of the gap follows the BCS form, fully consistent with phonon-mediated superconductivity in this novel superconductor. The application of a magnetic field induces strong pair breaking as seen in the conductance spectra in fields up to 6 T.

  15. Evolution of the B3 DNA binding superfamily: new insights into REM family gene diversification.

    Directory of Open Access Journals (Sweden)

    Elisson A C Romanel

    Full Text Available BACKGROUND: The B3 DNA binding domain includes five families: auxin response factor (ARF, abscisic acid-insensitive3 (ABI3, high level expression of sugar inducible (HSI, related to ABI3/VP1 (RAV and reproductive meristem (REM. The release of the complete genomes of the angiosperm eudicots Arabidopsis thaliana and Populus trichocarpa, the monocot Orysa sativa, the bryophyte Physcomitrella patens,the green algae Chlamydomonas reinhardtii and Volvox carteri and the red algae Cyanidioschyzon melorae provided an exceptional opportunity to study the evolution of this superfamily. METHODOLOGY: In order to better understand the origin and the diversification of B3 domains in plants, we combined comparative phylogenetic analysis with exon/intron structure and duplication events. In addition, we investigated the conservation and divergence of the B3 domain during the origin and evolution of each family. CONCLUSIONS: Our data indicate that showed that the B3 containing genes have undergone extensive duplication events, and that the REM family B3 domain has a highly diverged DNA binding. Our results also indicate that the founding member of the B3 gene family is likely to be similar to the ABI3/HSI genes found in C. reinhardtii and V. carteri. Among the B3 families, ABI3, HSI, RAV and ARF are most structurally conserved, whereas the REM family has experienced a rapid divergence. These results are discussed in light of their functional and evolutionary roles in plant development.

  16. Antibody-mediated neutralization of myelin-associated EphrinB3 accelerates CNS remyelination.

    Science.gov (United States)

    Syed, Yasir A; Zhao, Chao; Mahad, Don; Möbius, Wiebke; Altmann, Friedrich; Foss, Franziska; Sentürk, Aycan; Acker-Palmer, Amparo; Lubec, Gert; Lilley, Kathryn; Franklin, Robin J M; Nave, Klaus-A; Kotter, Mark R N

    2016-02-01

    Remyelination in multiple sclerosis (MS) lesions often remains incomplete despite the presence of oligodendrocyte progenitor cells (OPCs). Amongst other factors, successful remyelination depends on the phagocytic clearance of myelin debris. However, the proteins in myelin debris that act as potent and selective inhibitors on OPC differentiation and inhibit CNS remyelination remain unknown. Here, we identify the transmembrane signalling protein EphrinB3 as important mediator of this inhibition, using a protein analytical approach in combination with a primary rodent OPC assay. In the presence of EphrinB3, OPCs fail to differentiate. In a rat model of remyelination, infusion of EphrinB3 inhibits remyelination. In contrast, masking EphrinB3 epitopes using antibodies promotes remyelination. Finally, we identify EphrinB3 in MS lesions and demonstrate that MS lesion extracts inhibit OPC differentiation while antibody-mediated masking of EphrinB3 epitopes promotes it. Our findings suggest that EphrinB3 could be a target for therapies aiming at promoting remyelination in demyelinating disease. PMID:26687980

  17. Performance and Applications of L1B2 Ultrasonic Motors

    Directory of Open Access Journals (Sweden)

    Gal Peled

    2016-06-01

    Full Text Available Piezoelectric ultrasonic motors offer important advantages for motion applications where high speed is coupled with high precision. The advances made in the recent decades in the field of ultrasonic motor based motion solutions allow the construction of complete motion platforms in the fields of semiconductors, aerospace and electro-optics. Among the various motor designs, the L1B2 motor type has been successful in industrial applications, offering high precision, effective control and operational robustness. This paper reviews the design of high precision motion solutions based on L1B2 ultrasonic motors—from the basic motor structure to the complete motion solution architecture, including motor drive and control, material considerations and performance envelope. The performance is demonstrated, via constructed motion stages, to exhibit fast move and settle, a repeatability window of tens of nanometers, lifetime into the tens of millions of operational cycles, and compatibility with clean room and aerospace environments. Example stages and modules for semiconductor, aerospace, electro-optical and biomedical applications are presented. The described semiconductor and aerospace solutions are powered by Nanomotion HR type motors, driven by a sine wave up to 80 V/mm rms, having a driving frequency of 39.6 kHz, providing a maximum force up to 4 N per driving element (at 5 W power consumption per element and a maximum linear velocity above 300 mm/s. The described electro-optical modules are powered by small Nanomotion Edge motors driven by voltages up to 11 V AC, providing stall forces up to 0.35 N (power consumption up to 0.75 W and maximum linear velocity above 200 mm/s.

  18. B3-lesions of the breast and cancer risk - an analysis of mammography screening patients

    Science.gov (United States)

    HOFFMANN, OLIVER; STAMATIS, GESINA ATHINA; BITTNER, ANN-KATHRIN; ARNOLD, GEORG; SCHNABEL, ROLF; KRÜGER, KARLGEORG; KIMMIG, RAINER; HEUBNER, MARTIN

    2016-01-01

    The use of mammography screening, followed by needle core biopsy (NCB), is associated with an increasing amount of invasive procedures. A considerable amount of specimens must be classified as lesions with uncertain malignant potential (B3-lesion). In these cases, an open biopsy is indicated for further diagnosis. We evaluated patients with B3-lesions to determine the risk of malignancy corresponding to the histopathological NCB results and the type of radiological lesion identified. A total of 95 patients participating in the German mammography screening program with a B3-lesion following NCB (104 B3-lesions in total) were included in our analysis. We analyzed the correlation between the initial histopathological findings from the NCB specimen and cancer risk. We further analyzed the correlations of malignant results with the type of mammographic lesion. In 23 cases (22%), histopathological examination following excision revealed a malignant lesion, including invasive and in situ carcinoma. The positive predictive value of the subgroups of B3-lesions ranged between 0.11 and 0.31; the B3-lesion associated with the highest cancer risk was the atypical ductal hyperplasia; however, no significant difference was observed between the B3-lesion subgroups (P=0.309) regarding the risk of malignancy. Comparing the different types of mammographic findings, such as radiological mass or microcalcifications, there was no significant difference in the risk for malignancy (P=0.379). The different types of B3-lesions did not exhibit differences in the risk for malignancy, and the morphological type of mammographic lesion does not appear to be correlated with cancer risk; therefore, our results underline the need for open biopsy in patients with B3-lesions following NCB. PMID:27123266

  19. Modeling the Magnetosphere of the B2Vp star sigma Ori E

    CERN Document Server

    Oksala, M E; Townsend, R H D; Kochukhov, O; Owocki, S

    2010-01-01

    This paper presents results obtained from Stokes I and V spectra of the B2Vp star sigma Ori E, observed by both the Narval and ESPaDOnS spectropolarimeters. Using Least- Squares Deconvolution, we investigate the longitudinal magnetic field at the current epoch, including period analysis exploiting current and historical data. sigma Ori E is the prototypical helium-strong star that has been shown to harbor a strong magnetic field, as well as a magnetosphere, consisting of two clouds of plasma forced by magnetic and centrifugal forces to co-rotate with the star on its 1.19 day period. The Rigidly Rotating Magnetosphere (RRM) model of Townsend & Owocki (2005) approximately reproduces the observed variations in longitudinal field strength, photometric brightness, Halpha emission, and various other observables. There are, however, small discrepancies between the observations and model in the photometric light curve, which we propose arise from inhomogeneous chemical abundances on the star's surface. Using Magn...

  20. Disorder trapping during crystallization of the B2-ordered NiAl compound.

    Science.gov (United States)

    Zheng, X Q; Yang, Y; Gao, Y F; Hoyt, J J; Asta, M; Sun, D Y

    2012-04-01

    Using molecular dynamics simulations, disorder trapping associated with solidification is studied for the (100), (110), and (111) growth directions in the B2 NiAl ordered alloy compound. At the high interface velocities studied we observe pronounced disorder and defect trapping, i.e., the formation of antisite defects and vacancies in the crystal at higher than equilibrium concentrations upon rapid solidification. The vacancies are located primarily on the Ni sublattice and the majority of antisite defects are Ni atoms on the Al sublattice, while the concentration of Al on the Ni sublattice is negligibly small. The defect concentration is found to increase in an approximately linear relationship with increasing the interface velocity. Further there is no significant anisotropy in the defect concentrations for different interface orientations. Our results suggest that the currently available models of disorder trapping should be extended to include both antisite defects and vacancies. PMID:22680482

  1. Flux pinning mechanism and Hc2-anisotropy in melanin doped bulk MgB2

    Science.gov (United States)

    Shahabuddin Shah, M.; Shahabuddin, Mohammed; Alzayed, Nasser S.; Parakkandy, Jafar M.

    2014-06-01

    Flux pinning mechanism in melanin doped MgB2 superconductor has been studied using a scaling law proposed by Dew-Hughes and another method proposed by Eisterer. Our experimental data could be fitted very closely by the aforementioned scaling law. The fitting parameters, the positions of peaks bpeak and k = bpeak/bn confirm a grain-boundary pinning in the 10% melanin doped sample, while the undoped sample consists of mixed pinning. Furthermore, percolation theory was utilized under grain-boundary approximation to investigate the role of Hc2-anisotropy in the critical current density, and its dependence on applied field as well as temperature. The Hc2-anisotropy decreases with melanin doping resulting in the increase of Jc in high field. There is suppression of flux pinning maximum due to melanin doping, which is found to be the main reason for the degradation of low-field Jc.

  2. Crystal structure and magnetism of Fe2(OH)[B2O4(OH)

    DEFF Research Database (Denmark)

    Kurayoshi, Yotaro; Hara, Shigeo; Sato, Hirohiko;

    2014-01-01

    The structure and magnetism of Fe2(OH)[B2O4(OH)] are reported. Powder x-ray diffraction reveals a characteristic structure containing two crystallographically independent zigzag-ladder chains of magnetic Fe2+ ions. Magnetization measurements reveal a phase transition at 85 K, below which a weak...... spontaneous magnetization (approximate to 0.15 μB/Fe) appears. Below 85 K, magnetization increases with decreasing temperature down to 70 K, below which it decreases and approaches a constant value at low temperature. The Mossbauer spectrum at room temperature is composed of two paramagnetic doublets...... corresponding to the two crystallographic Fe2+ sites. Below 85 K, each doublet undergoes further splitting because of the magnetic hyperfine fields. The temperature dependence of the hyperfine field is qualitatively different for the two distinguishable Fe2+ sites. This is responsible for the anomalous...

  3. Magnetic phase diagram of ErNi2B2C

    DEFF Research Database (Denmark)

    Jensen, A.; Toft, K.N.; Abrahamsen, A.B.;

    2004-01-01

    The magnetic phase diagram of the superconductor ErNi2B2C (T-c = 11 K and T-N = 6 K) has been studied by neutron diffraction as a function of temperature and magnetic field applied along the symmetry directions [010], [110] and [001] of the tetragonal crystal structure. A series of commensurate...... magnetic structures, consistent with a transversely polarized spin-density wave with modulation vectors Q = n/ma* (0.55 less than or equal to n/m ... an analysis of bulk magnetization and zero-field neutron diffraction data. The model accounts for most of the observed features but fails to explain the occurrence of a small component Qdelta approximate to -0.005b* observed close to H-c2 when the field is applied along [110]. (C) 2004 Elsevier B.V. All...

  4. Far-infrared optical conductivity gap in superconducting MgB2 films.

    Science.gov (United States)

    Kaindl, Robert A; Carnahan, Marc A; Orenstein, Joseph; Chemla, Daniel S; Christen, Hans M; Zhai, Hong-Ying; Paranthaman, Mariappan; Lowndes, Doug H

    2002-01-14

    We report the first study of the optical conductivity of MgB2 covering the range of its lowest-energy superconducting gap. Terahertz time-domain spectroscopy is utilized to determine the complex, frequency-dependent conductivity sigma(omega) of thin films. The imaginary part reveals an inductive response due to the emergence of the superconducting condensate. The real part exhibits a strong depletion of oscillator strength near 5 meV resulting from the opening of a superconducting energy gap. The gap ratio of 2Delta0/k(B)TC approximately 1.9 is well below the weak-coupling value, pointing to complex behavior in this novel superconductor.

  5. de Haas-van Alphen effect in single crystal MgB2.

    Science.gov (United States)

    Yelland, E A; Cooper, J R; Carrington, A; Hussey, N E; Meeson, P J; Lee, S; Yamamoto, A; Tajima, S

    2002-05-27

    We report observations of quantum oscillations in single crystals of the high temperature superconductor MgB2. Three de Haas-van Alphen frequencies are clearly resolved. Comparison with band structure calculations strongly suggests that two of these come from a single warped Fermi surface tube along the c direction, and that the third arises from cylindrical sections of an in-plane honeycomb network. The measured values of the effective mass range from (0.44-0.68)m(e). By comparing these to calculated band masses, we find that the electron-phonon coupling strength lambda is a factor of approximately 3 larger for the c-axis tube orbits than for the in-plane network orbit, in accord with recent microscopic calculations.

  6. Physical properties of ferroelectric superlattice A3/B3 system in electric field

    Institute of Scientific and Technical Information of China (English)

    Jiang Wei; Lo Veng-Cheong; Bai Bao-Dong

    2005-01-01

    Based on the differential operator technique, a transverse Ising model (TIM) in the effective-field theory is developed to study the physical properties of a ferroelectric superlattice A3/B3 system. The effects of an external electric field on the polarization, susceptibility and pyroelectric coefficient of the ferroelectric superlattice A3/B3 system are discussed in detail. The susceptibility of the ferroelectric superlattice A3/B3 system decreases with the increase of the electric field, implying that the polarization is weak.

  7. Bond deformation paths and electronic instabilities of ultraincompressible transition metal diborides: Case study of OsB2 and IrB2

    Science.gov (United States)

    Zhang, R. F.; Legut, D.; Wen, X. D.; Veprek, S.; Rajan, K.; Lookman, T.; Mao, H. K.; Zhao, Y. S.

    2014-09-01

    The energetically most stable orthorhombic structure of OsB2 and IrB2 is dynamically stable for OsB2 but unstable for IrB2. Both diborides have substantially lower shear strength in their easy slip systems than their metal counterparts. This is attributed to an easy sliding facilitated by out-of-plane weakening of metallic Os-Os bonds in OsB2 and by an in-plane bond splitting instability in IrB2. A much higher shear resistance of Os-B and B-B bonds than Os-Os ones is found, suggesting that the strengthened Os-B and B-B bonds are responsible for hardness enhancement in OsB2. In contrast, an in-plane electronic instability in IrB2 limits its strength. The electronic structure of deformed diborides suggests that the electronic instabilities of 5d orbitals are their origin of different bond deformation paths. Neither IrB2 nor OsB2 can be intrinsically superhard.

  8. Effect of TiB2 content on resistance to sodium penetration of TiB2/C cathode composites for aluminium electrolysis

    Institute of Scientific and Technical Information of China (English)

    李劼; 方静; 李庆余; 赖延清

    2004-01-01

    TiB2/C cathode composites with various contents of TiB2 were prepared and their characterizations were observed and compared. The expansion of samples due to sodium and bath penetration was tested with a modified laboratory Rapoport apparatus and the appearances of the cut sections of specimens after electrolysis were studied.The results show that the mass of TiB2/C cathode composites with mass fraction of TiB2 less than 70 % appreciably increases, but that of the composites with mass fraction of TiB2 more than 70% decreases slightly after being baked.The resistance to sodium and bath penetration of TiB2/C cathode composites increases with the increase of TiB2 content, especially in the composites with high TiB2 content. TiB2/C cathode composites have high resistance to the penetration of sodium and bath as well as good wettability by molten aluminum, and keep integrality and have little change of appearance after electrolysis, which indicates that TiB2/C cathode composites can be used as inert wettable cathode for aluminum electrolysis.

  9. The conserved nhaAR operon is drastically divergent between B2 and non-B2 Escherichia coli and is involved in extra-intestinal virulence.

    Directory of Open Access Journals (Sweden)

    Mathilde Lescat

    Full Text Available The Escherichia coli species is divided in phylogenetic groups that differ in their virulence and commensal distribution. Strains belonging to the B2 group are involved in extra-intestinal pathologies but also appear to be more prevalent as commensals among human occidental populations. To investigate the genetic specificities of B2 sub-group, we used 128 sequenced genomes and identified genes of the core genome that showed marked difference between B2 and non-B2 genomes. We focused on the gene and its surrounding region with the strongest divergence between B2 and non-B2, the antiporter gene nhaA. This gene is part of the nhaAR operon, which is in the core genome but flanked by mobile regions, and is involved in growth at high pH and high sodium concentrations. Consistently, we found that a panel of non-B2 strains grew faster than B2 at high pH and high sodium concentrations. However, we could not identify differences in expression of the nhaAR operon using fluorescence reporter plasmids. Furthermore, the operon deletion had no differential impact between B2 and non-B2 strains, and did not result in a fitness modification in a murine model of gut colonization. Nevertheless, sequence analysis and experiments in a murine model of septicemia revealed that recombination in nhaA among B2 strains was observed in strains with low virulence. Finally, nhaA and nhaAR operon deletions drastically decreased virulence in one B2 strain. This effect of nhaAR deletion appeared to be stronger than deletion of all pathogenicity islands. Thus, a population genetic approach allowed us to identify an operon in the core genome without strong effect in commensalism but with an important role in extra-intestinal virulence, a landmark of the B2 strains.

  10. Photo-activated psoralen binds the ErbB2 catalytic kinase domain, blocking ErbB2 signaling and triggering tumor cell apoptosis.

    Directory of Open Access Journals (Sweden)

    Wenle Xia

    Full Text Available Photo-activation of psoralen with UVA irradiation, referred to as PUVA, is used in the treatment of proliferative skin disorders. The anti-proliferative effects of PUVA have been largely attributed to psoralen intercalation of DNA, which upon UV treatment, triggers the formation of interstrand DNA crosslinks (ICL that inhibit transcription and DNA replication. Here, we show that PUVA exerts antitumor effects in models of human breast cancer that overexpress the ErbB2 receptor tyrosine kinase oncogene, through a new mechanism. Independent of ICL formation, the antitumor effects of PUVA in ErbB2+ breast cancer models can instead be mediated through inhibition of ErbB2 activation and signaling. Using a mass spectroscopy-based approach, we show for the first time that photo-activated 8MOP (8-methoxypsoralen interacts with the ErbB2 catalytic autokinase domain. Furthermore, PUVA can reverse therapeutic resistance to lapatinib and other ErbB2 targeted therapies, including resistance mediated via expression of a phosphorylated, truncated form of ErbB2 (p85(ErbB2 that is preferentially expressed in tumor cell nuclei. Current ErbB2 targeted therapies, small molecule kinase inhibitors or antibodies, do not block the phosphorylated, activated state of p85(ErbB2. Here we show that PUVA reduced p85(ErbB2 phosphorylation leading to tumor cell apoptosis. Thus, in addition to its effects on DNA and the formation of ICL, PUVA represents a novel ErbB2 targeted therapy for the treatment of ErbB2+ breast cancers, including those that have developed resistance to other ErbB2 targeted therapies.

  11. Study of the Isothermal Oxidation Process and Phase Transformations in B2-(Ni,PtAl/RENE-N5 System

    Directory of Open Access Journals (Sweden)

    Luis Alberto Cáceres-Díaz

    2016-09-01

    Full Text Available Changes in composition, crystal structure and phase transformations of B2-(Ni,PtAl coatings upon isothermal oxidation experiments (natural and scale free oxidation at 1100 °C, as a function of time beyond their martensitic transformation, are reported. Specifically, the analysis of lattice parameter and composition are performed to identify changes in the B2-(Ni,PtAl phase upon the chemically-driven L10-(Ni,PtAl and L12-(Ni,Pt3Al transformations. The B2-(Ni,PtAl phase was found to disorder and transform the martensite during the heat treatments for both oxidation experiments at approximately 36.3 and 40.9 at. % of Al, 47.7 and 42.9 at. % of Ni, 6.2 and 8.5 at. % of Pt, 4.2 and 2.9 at. % of Cr and 4.4 and 3.8 at. % of Co. The lattice constant and the long-range order parameter of the B2-(Ni,PtAl phase decreased linearly as a function of the elemental content irrespective of the nature of the oxidation experiments.

  12. Microstructure and properties of TiB2-TiB reinforced titanium matrix composite coating by laser cladding

    Science.gov (United States)

    Lin, Yinghua; Yao, Jianhua; Lei, Yongping; Fu, Hanguang; Wang, Liang

    2016-11-01

    TiB2 particle and TiB short fiber reinforced titanium matrix composite coatings were prepared utilizing in situ synthesized technique by laser cladding on the surface of Ti6Al4V alloy. Through the experiment, it was found that the surface of the single-track coatings appeared in the depression, but it can be improved by laser track overlapping. With the increase of laser power density, the amount of TiB short fiber was increased, and the distribution of TiB2 and TiB became more uniform from the top to bottom. The micro-hardness of TiB2/TiB coating showed a gradient decreasing trend, and the average micro-hardness of the coatings was two-fold higher than that of the substrate. Due to the strengthening effect of TiB2 particle and TiB short fiber, the wear volume loss of the center of the coating was approximately 30% less than that of the Ti-6Al-4V substrate, and the wear mechanism of the coating was mild fatigue particle detachment.

  13. Cardiac-specific over-expression of epidermal growth factor receptor 2 (ErbB2 induces pro-survival pathways and hypertrophic cardiomyopathy in mice.

    Directory of Open Access Journals (Sweden)

    Polina Sysa-Shah

    Full Text Available BACKGROUND: Emerging evidence shows that ErbB2 signaling has a critical role in cardiomyocyte physiology, based mainly on findings that blocking ErbB2 for cancer therapy is toxic to cardiac cells. However, consequences of high levels of ErbB2 activity in the heart have not been previously explored. METHODOLOGY/PRINCIPAL FINDINGS: We investigated consequences of cardiac-restricted over-expression of ErbB2 in two novel lines of transgenic mice. Both lines develop striking concentric cardiac hypertrophy, without heart failure or decreased life span. ErbB2 transgenic mice display electrocardiographic characteristics similar to those found in patients with Hypertrophic Cardiomyopathy, with susceptibility to adrenergic-induced arrhythmias. The hypertrophic hearts, which are 2-3 times larger than those of control littermates, express increased atrial natriuretic peptide and β-myosin heavy chain mRNA, consistent with a hypertrophic phenotype. Cardiomyocytes in these hearts are significantly larger than wild type cardiomyocytes, with enlarged nuclei and distinctive myocardial disarray. Interestingly, the over-expression of ErbB2 induces a concurrent up-regulation of multiple proteins associated with this signaling pathway, including EGFR, ErbB3, ErbB4, PI3K subunits p110 and p85, bcl-2 and multiple protective heat shock proteins. Additionally, ErbB2 up-regulation leads to an anti-apoptotic shift in the ratio of bcl-xS/xL in the heart. Finally, ErbB2 over-expression results in increased activation of the translation machinery involving S6, 4E-BP1 and eIF4E. The dependence of this hypertrophic phenotype on ErbB family signaling is confirmed by reduction in heart mass and cardiomyocyte size, and inactivation of pro-hypertrophic signaling in transgenic animals treated with the ErbB1/2 inhibitor, lapatinib. CONCLUSIONS/SIGNIFICANCE: These studies are the first to demonstrate that increased ErbB2 over-expression in the heart can activate protective signaling

  14. Operators of Approximations and Approximate Power Set Spaces

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xian-yong; MO Zhi-wen; SHU Lan

    2004-01-01

    Boundary inner and outer operators are introduced; and union, intersection, complement operators of approximations are redefined. The approximation operators have a good property of maintaining union, intersection, complement operators, so the rough set theory has been enriched from the operator-oriented and set-oriented views. Approximate power set spaces are defined, and it is proved that the approximation operators are epimorphisms from power set space to approximate power set spaces. Some basic properties of approximate power set space are got by epimorphisms in contrast to power set space.

  15. B2B E- Commercial Exchange Platform Based on RosettaNet%基于RosettaNet的B2B电子商务交换平台

    Institute of Scientific and Technical Information of China (English)

    钟山; 许炜

    2005-01-01

    B2B hub是简化Busines-to-Business(B2B)交换的一个中介体.通过B2B网关,管理不同贸易伙伴间消息交换的通信及安全问题,通过管理系统和数据转换引擎实现购买流程中,买卖双方的匹配.HUB架构中的核心部分是B2B集成服务器,它实现了RosettaNet以及其他B2B协议.因此,hub是一个在B2B集成服务器上的特殊应用.

  16. Ionization potential optimized double-hybrid density functional approximations.

    Science.gov (United States)

    Margraf, Johannes T; Verma, Prakash; Bartlett, Rodney J

    2016-09-14

    Double-hybrid density functional approximations (DH-DFAs) provide an accurate description of the electronic structure of molecules by semiempirically mixing density functional and wavefunction theory. In this paper, we investigate the properties of the potential used in such approximations. By using the optimized effective potential approach, the consistent Kohn-Sham (KS) potential for a double-hybrid functional (including the second-order perturbational contribution) can be generated. This potential is shown to provide an improved description of orbital energies as vertical ionization potentials (IPs), relative to the perturbation-free KS potential typically used. Based on this observation, we suggest that DH-DFAs should be constructed in such a way that the potential provides accurate orbital energies. As a proof of principle, the B2-PLYP functional is reparameterized to obtain the IP-optimized B2IP-PLYP functional, using a small set of vertical IPs and atomization energies as reference data. This functional is shown to outperform B2-PLYP in a wide range of benchmarks and is en par with the related B2GP-PLYP. In particular, it is shown to be the most reliable choice in electronically difficult and multireference cases. PMID:27634250

  17. B2C电子商务中的信息抽取技术%Information Extraction Techniques Applied to B2C E-Commerce

    Institute of Scientific and Technical Information of China (English)

    于琨; 蔡智; 糜仲春; 蔡庆生

    2002-01-01

    After stepping out the valley of net economy, B2C e-commerce is about to come into a climax of develop-ment. Information extraction techniques are going to be one of the most important factors to promote B2C e-com-merce. In this paper, we present a review on the recent progress of information extraction techniques applied to B2Ce-commerce. The characteristics of each technique are also appraised.

  18. Experiences and Future Expectations towards Online Courses--An Empirical Study of the B2C-and B2B-Segments

    Science.gov (United States)

    Krämer, Andreas; Böhrs, Sandra

    2016-01-01

    This article explores the future potential for the development of online courses. The findings are based on an empirical study with 3 sample groups: (1) B2C segment in Germany, (2) B2C segment in the United States, and (3) B2B segment (international). In the first step the status quo of the use of e-learning in general and online courses in…

  19. Study on electronic commerce pattern of B2B in China%中国B2B电子商务模式研究

    Institute of Scientific and Technical Information of China (English)

    罗新方

    2008-01-01

    介绍了中国B2B的现状及五大发展趋势,指出了阻碍B2B企业发展的症结所在--模式选择不当,战略分析不清,盲目追从,缺乏创新.提出了几条适合中国B2B企业发展的创新途径.

  20. Protective role of miR-23b-3p in kainic acid-induced seizure.

    Science.gov (United States)

    Zhan, Lianbo; Yao, Yi; Fu, Huajun; Li, Zhenghui; Wang, Fengpeng; Zhang, Xiaobin; He, Wencan; Zheng, Weihong; Zhang, Yunwu; Zheng, Honghua

    2016-07-01

    Dysregulation of microRNAs has been proposed to contribute toward epilepsy. The miRNA miR-23b-3p has been found to protect against neuronal apoptosis and the production of reactive oxygen species. In this study, we assessed the potential role of miR-23b-3p in the kainic acid (KA)-induced seizure model. We found that miR-23b-3p levels were significantly decreased in the brain cortex of mice and in cultured mouse primary neurons treated with KA. Importantly, supplement of miR-23b-3p agomir by an intacerebroventricular injection alleviated seizure behaviors and abnormal cortical electroencephalogram recordings in KA-treated mice. Together, these results indicate that miR-23b-3p plays a crucial role in suppressing seizure formation in experimental models of epilepsy and that miR-23b-3p supplement may be a potential anabolic strategy for ameliorating seizure. PMID:27232518

  1. State Environmental Policy Act (SEPA) Environmental Checklist Form 216-B-3 Expansion Ponds Closure Plan

    International Nuclear Information System (INIS)

    The 216-B-3 Expansion Ponds Closure Plan (Revision 1) consists of a Part A Dangerous Waste Permit Application and a Resource Conservation and Recovery Act Closure Plan. An explanation of the Part A submitted with this document is provided at the beginning of the Part A Section. The closure plan consists of nine chapters and five appendices. The 216-B-3 Pond System consists of a series of four earthen, unlined, interconnected ponds and the 216-B-3-3 Ditch that receive waste water from various 200 East Area operating facilities. These four ponds, collectively. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the 216-B-3-3 Ditch. Water discharged to the 216-8-3-3 Ditch flows directly into the 216-B-3 Pond. In the past, waste water discharges to B Pond and the 216-B-3-3 Ditch contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the nonradioactive dangerous portion of mixed waste is regulated under RCRA. Mixed waste also may be considered a hazardous substance under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) when considering remediation of waste sites

  2. Crystal Growth of CsB3O5 from NaF Flux

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Nonlinear optical CsB3O5 single crystals have been grown successfully using NaF as a flux. The primary CsB3O5-NaF quasi-binary system has been investigated by X-ray diffraction and differential thermal analysis. There is a single eutectic point, and the eutectic composition corresponds to 40mol% NaF with the temperature of 690.5 ℃ in CsB3O5-NaF system. Volatility of the CsB3O5-NaF system along the liquidus has been measured, and the volatiles of the solution were collected and detected by XRD method. Growth of CsB3Os crystals was carried out by different composition of NaF in CsB3O5-NaF system, and the growth parameters were discussed. Simultaneously, the properties of grown crystals from NaF flux were characterized by transmission spectrum and scanning electron microscopy.

  3. Customer Behavior Analysis under B2C Environment%B2C环境下的客户行为分析

    Institute of Scientific and Technical Information of China (English)

    牛文博

    2012-01-01

    Taking the background of B2C e-commerce transactions, this paper starts from the objective of customer behavior analysis, proposes the process of customer behavior analysis based on B2C e-commerce environment, analyzes the customer's consumer psychology and behavior under B2C environment, and points out the customer retention strategy. This paper has a reference to B2C website.%本文以B2C电子商务交易过程为背景,从客户行为分析的目标出发,提出了基于B2C电子商务环境下的客户行为分析过程,并对B2C环境下的客户消费心理和行为进行了分析,提出了B2C环境下的客户保留策略,这对B2C网站具有借鉴意义.

  4. Study on Logistics Distribution Centers for B2C Online Shopping%B2C网购物流配送中心研究

    Institute of Scientific and Technical Information of China (English)

    侯凌燕; 尹军琪

    2011-01-01

    分析了我国B2C网购物流配送的现状,对其特点和难点作了分析,并提出了相应的B2C网购物流配送中心设计解决方案.%The paper analyzes the current status of the logistics and distribution operations for B2C online shopping in China, analyzes its characteristics and existing issues, and puts forth solutions for the design of logistics and distribution centers for B2C online shopping.

  5. Discussion on B2B electronic commerce pattern%B2B电子商务模式的探讨

    Institute of Scientific and Technical Information of China (English)

    陈昌

    2007-01-01

    针对B2B模式将成为未来电子商务发展的主流,文章先从价值链角度分析了B2B电子商务模式对价值链上游的冲击,然后概括性地总结了目前主要的3种B2B电子商务模式,最后用"SWOT"战略评估方法分析了基于供应链管理的区域型B2B电子商务新模式.

  6. Scheme to prepare the MgB2 superconducting multilayer films%MgB2超导多层膜的制备方案

    Institute of Scientific and Technical Information of China (English)

    罗子江; 杨健; 王继红

    2007-01-01

    简要叙述了MgB2的发展和制备历史,通过对不同衬底材料上MgB2的反应情况的总结概括以及对不同衬底材料和MgB2的晶体结构和晶格常量的比较,提出一种MgB2超导多层膜的制备方案.

  7. Electronic structure and superconductivity of MgB2

    Indian Academy of Sciences (India)

    D M Gaitonde; P Modak; R S Rao; B K Godwal

    2003-01-01

    Results of ab initio electronic structure calculations on the compound, MgB2, using the FPLAPW method employing GGA for the exchange–correlation energy are presented. Total energy minimization enables us to estimate the equilibrium volume, / ratio and the bulk modulus, all of which are in excellent agreement with experiment. We obtain the mass enhancement parameter by using our calculated, $D(E_F)$ and the experimental specific heat data. The $T_c$ is found to be 37 K. We use a parametrized description of the calculated band structure to obtain the = 0 K values of the London penetration depth and the superconducting coherence length. The penetration depth calculated by us is too small and the coherence length too large as compared to the experimentally determined values of these quantities. This indicates the limitations of a theory that relies only on electronic structure calculations in describing the superconducting state in this material and implies that impurity effects as well as mass renormalization effects need to be included.

  8. Effects of neutron irradiation on polycrystalline Mg11B2

    International Nuclear Information System (INIS)

    We studied the influence of the disorder introduced in polycrystalline MgB2 samples by neutron irradiation. To circumvent self-shielding effects due to the strong interaction between thermal neutrons and 10B we employed isotopically enriched 11B which contains 40 times less 10B than natural B. The comparison of electrical and structural properties of different series of samples irradiated in different neutron sources, also using Cd shields, allowed us to conclude that, despite the low 10B content, the main damage mechanisms are caused by thermal neutrons, whereas fast neutrons play a minor role. Irradiation leads to an improvement in both upper critical field and critical current density for an exposure level in the range 1-2x1018 cm-2. With increasing fluence the superconducting properties are depressed. An in-depth analysis of the critical field and current density behavior has been carried out to identify what scattering and pinning mechanisms come into play. Finally, the correlation between some characteristic lengths and the transition widths is analyzed

  9. Herschel observations of deuterated water towards Sgr B2(M)

    CERN Document Server

    Comito, Claudia; Rolffs, Rainer; Lis, D C; Belloche, A; Bergin, E A; Phillips, T G; Bell, T A; Crockett, N R; Wang, S; Blake, G A; Caux, E; Ceccarelli, C; Cernicharo, J; Daniel, F; Dubernet, M -L; Emprechtinger, M; Encrenaz, P; Gerin, M; Giesen, T F; Goicoechea, J R; Goldsmith, P F; Gupta, H; Herbst, E; Joblin, C; Johnstone, D; Langer, W D; Latter, W D; Lord, S D; Maret, S; Martin, P G; Melnick, G J; Menten, K M; Morris, P; Mueller, H S P; Murphy, J A; Neufeld, D A; Ossenkopf, V; Pearson, J C; Perault, M; Plume, R; Qin, S -L; Schlemmer, S; Stutzki, J; Trappe, N; van der Tak, F F S; Vastel, C; Yorke, H W; Yu, S; Olberg, M; Szczerba, R; Larsson, B; Liseau, R; Lin, R H; Samoska, L A; Schlecht, E

    2010-01-01

    Observations of HDO are an important complement for studies of water, because they give strong constraints on the formation processes -- grain surfaces versus energetic process in the gas phase, e.g. in shocks. The HIFI observations of multiple transitions of HDO in Sgr~B2(M) presented here allow the determination of the HDO abundance throughout the envelope, which has not been possible before with ground-based observations only. The abundance structure has been modeled with the spherical Monte Carlo radiative transfer code RATRAN, which also takes radiative pumping by continuum emission from dust into account. The modeling reveals that the abundance of HDO rises steeply with temperature from a low abundance ($2.5\\times 10^{-11}$) in the outer envelope at temperatures below 100~K through a medium abundance ($1.5\\times 10^{-9}$) in the inner envelope/outer core, at temperatures between 100 and 200~K, and finally a high abundance ($3.5\\times 10^{-9}$) at temperatures above 200~K in the hot core.

  10. Lightweight MgB2 superconducting 10 MW wind generator

    Science.gov (United States)

    Marino, I.; Pujana, A.; Sarmiento, G.; Sanz, S.; Merino, J. M.; Tropeano, M.; Sun, J.; Canosa, T.

    2016-02-01

    The offshore wind market demands a higher power rate and more reliable turbines in order to optimize capital and operational costs. The state-of-the-art shows that both geared and direct-drive conventional generators are difficult to scale up to 10 MW and beyond due to their huge size and weight. Superconducting direct-drive wind generators are considered a promising solution to achieve lighter weight machines. This work presents an innovative 10 MW 8.1 rpm direct-drive partial superconducting generator using MgB2 wire for the field coils. It has a warm iron rotor configuration with the superconducting coils working at 20 K while the rotor core and the armature are at ambient temperature. A cooling system based on cryocoolers installed in the rotor extracts the heat from the superconducting coils by conduction. The generator's main parameters are compared against a permanent magnet reference machine, showing a significant weight and size reduction. The 10 MW superconducting generator concept will be experimentally validated with a small-scale magnetic machine, which has innovative components such as superconducting coils, modular cryostats and cooling systems, and will have similar size and characteristics as the 10 MW generator.

  11. Phonon linewidths in YNi2B2C

    Indian Academy of Sciences (India)

    L Pintschovius; F Weber; W Reichardt; A Kreyssig; R Heid; D Reznik; O Stockert; K Hradil

    2008-10-01

    Phonons in a metal interact with conduction electrons which give rise to a finite linewidth. In the normal state, this leads to a Lorentzian shape of the phonon line. Density functional theory is able to predict the phonon linewidths as a function of wave vector for each branch of the phonon dispersion. An experimental verification of such predictions is feasible only for compounds with very strong electron–phonon coupling. YN2B2C was chosen as a test example because it is a conventional superconductor with a fairly high c (15.2 K). Inelastic neutron scattering experiments did largely confirm the theoretical predictions. Moreover, they revealed a strong temperature dependence of the linewidths of some phonons with particularly strong electron–phonon coupling which can as yet only qualitatively be accounted for by theory. For such phonons, marked changes of the phonon frequencies and linewidths were observed from room temperature down to 15 K. Further changes were observed on entering into the superconducting state. These changes can, however, not be described simply by a change of the phonon linewidth.

  12. Approximation algorithms and hardness of approximation for knapsack problems

    NARCIS (Netherlands)

    Buhrman, H.; Loff, B.; Torenvliet, L.

    2012-01-01

    We show various hardness of approximation algorithms for knapsack and related problems; in particular we will show that unless the Exponential-Time Hypothesis is false, then subset-sum cannot be approximated any better than with an FPTAS. We also give a simple new algorithm for approximating knapsac

  13. New ternary tantalum borides containing boron dumbbells: Experimental and theoretical studies of Ta2OsB2 and TaRuB

    Science.gov (United States)

    Mbarki, Mohammed; Touzani, Rachid St.; Rehorn, Christian W. G.; Gladisch, Fabian C.; Fokwa, Boniface P. T.

    2016-10-01

    The new ternary transition metal-rich borides Ta2OsB2 and TaRuB have been successfully synthesized by arc-melting the elements in a water-cooled crucible under an argon atmosphere. The crystal structures of both compounds were solved by single-crystal X-ray diffraction and their metal compositions were confirmed by EDX analysis. It was found that Ta2OsB2 and TaRuB crystallize in the tetragonal Nb2OsB2 (space group P4/mnc, no. 128) and the orthorhombic NbRuB (space group Pmma, no. 51) structure types with lattice parameters a=5.878(2) Å, c=6.857(2) Å and a=10.806(2) Å, b=3.196(1) Å, c=6.312(2) Å, respectively. Furthermore, crystallographic, electronic and bonding characteristics have been studied by density functional theory (DFT). Electronic structure relaxation has confirmed the crystallographic parameters while COHP bonding analysis indicates that B2-dummbells are the strongest bonds in both compounds. Moreover, the formation of osmium dumbbells in Ta2OsB2 through a Peierls distortion along the c-axis, is found to be the origin of superstructure formation. Magnetic susceptibility measurements reveal that the two phases are Pauli paramagnets, thus confirming the theoretical DOS prediction of metallic character. Also hints of superconductivity are found in the two phases, however lack of single phase samples has prevented confirmation. Furthermore, the thermodynamic stability of the two modifications of AMB (A=Nb, Ta; M =Ru, Os) are studied using DFT, as new possible phases containing either B4- or B2-units are predicted, the former being the most thermodynamically stable modification.

  14. NF-κB2 mutation targets survival, proliferation and differentiation pathways in the pathogenesis of plasma cell tumors

    Directory of Open Access Journals (Sweden)

    McCarthy Brian A

    2012-05-01

    Full Text Available Abstract Background Abnormal NF-κB2 activation has been implicated in the pathogenesis of multiple myeloma, a cancer of plasma cells. However, a causal role for aberrant NF-κB2 signaling in the development of plasma cell tumors has not been established. Also unclear is the molecular mechanism that drives the tumorigenic process. We investigated these questions by using a transgenic mouse model with lymphocyte-targeted expression of p80HT, a lymphoma-associated NF-κB2 mutant, and human multiple myeloma cell lines. Methods We conducted a detailed histopathological characterization of lymphomas developed in p80HT transgenic mice and microarray gene expression profiling of p80HT B cells with the goal of identifying genes that drive plasma cell tumor development. We further verified the significance of our findings in human multiple myeloma cell lines. Results Approximately 40% of p80HT mice showed elevated levels of monoclonal immunoglobulin (M-protein in the serum and developed plasma cell tumors. Some of these mice displayed key features of human multiple myeloma with accumulation of plasma cells in the bone marrow, osteolytic bone lesions and/or diffuse osteoporosis. Gene expression profiling of B cells from M-protein-positive p80HT mice revealed aberrant expression of genes known to be important in the pathogenesis of multiple myeloma, including cyclin D1, cyclin D2, Blimp1, survivin, IL-10 and IL-15. In vitro assays demonstrated a critical role of Stat3, a key downstream component of IL-10 signaling, in the survival of human multiple myeloma cells. Conclusions These findings provide a mouse model for human multiple myeloma with aberrant NF-κB2 activation and suggest a molecular mechanism for NF-κB2 signaling in the pathogenesis of plasma cell tumors by coordinated regulation of plasma cell generation, proliferation and survival.

  15. NF-κB2 mutation targets survival, proliferation and differentiation pathways in the pathogenesis of plasma cell tumors

    International Nuclear Information System (INIS)

    Abnormal NF-κB2 activation has been implicated in the pathogenesis of multiple myeloma, a cancer of plasma cells. However, a causal role for aberrant NF-κB2 signaling in the development of plasma cell tumors has not been established. Also unclear is the molecular mechanism that drives the tumorigenic process. We investigated these questions by using a transgenic mouse model with lymphocyte-targeted expression of p80HT, a lymphoma-associated NF-κB2 mutant, and human multiple myeloma cell lines. We conducted a detailed histopathological characterization of lymphomas developed in p80HT transgenic mice and microarray gene expression profiling of p80HT B cells with the goal of identifying genes that drive plasma cell tumor development. We further verified the significance of our findings in human multiple myeloma cell lines. Approximately 40% of p80HT mice showed elevated levels of monoclonal immunoglobulin (M-protein) in the serum and developed plasma cell tumors. Some of these mice displayed key features of human multiple myeloma with accumulation of plasma cells in the bone marrow, osteolytic bone lesions and/or diffuse osteoporosis. Gene expression profiling of B cells from M-protein-positive p80HT mice revealed aberrant expression of genes known to be important in the pathogenesis of multiple myeloma, including cyclin D1, cyclin D2, Blimp1, survivin, IL-10 and IL-15. In vitro assays demonstrated a critical role of Stat3, a key downstream component of IL-10 signaling, in the survival of human multiple myeloma cells. These findings provide a mouse model for human multiple myeloma with aberrant NF-κB2 activation and suggest a molecular mechanism for NF-κB2 signaling in the pathogenesis of plasma cell tumors by coordinated regulation of plasma cell generation, proliferation and survival

  16. 新型B2B2C电子商务模式在促进鲜活农产品物流信息管理中的应用研究%Application of New B2B2C E-Commerce Model in Promoting Logistics Information Management of Fresh Agricultural Products

    Institute of Scientific and Technical Information of China (English)

    杨浩雄; 张梦楠

    2012-01-01

    B2B2C e-commerce model of fresh agricultural products circulating was proposed in this paper, and also the function and advantages of the system were analyzed. The building and using of B2B2C e-commerce model would accelerate the fresh agricultural products circulating in the logistics operation of fresh agricultural products, and would gain the most profit with minimum consumption.%提出了鲜活农产品流通的B2B2C电子商务模式,分析了该模式的系统功能及优势.在鲜活农产品物流运作过程中构建并运用电子商务B2B2C模式,有利于加快鲜活农产品流通,以最小的消耗获得最大的收益.

  17. Data of evolutionary structure change: 1B2KA-2EQLA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1B2KA-2EQLA 1B2K 2EQL A A KVFGRCELAAAMKRHGLDNYRGYSLGNWVCAAKFESNFN...SKCELAHKLKAQEMDGFGGYSLANWVCMAEYESNFNTRAFNGKNANGSSDYGLFQLNNKWWCKDN-KRSSSNACNIMCSKLLDENIDDDISCAKRVVRDPKGMSAWKA...6 2EQL A 2EQL... 1 2EQL A 2EQL

  18. ErbB3 mRNA leukocyte levels as a biomarker for major depressive disorder

    Directory of Open Access Journals (Sweden)

    Milanesi Elena

    2012-09-01

    Full Text Available Abstract Background In recent years, the identification of peripheral biomarkers that are associated with psychiatric diseases, such as Major Depressive Disorder (MDD, has become relevant because these biomarkers may improve the efficiency of the differential diagnosis process and indicate targets for new antidepressant drugs. Two recent candidate genes, ErbB3 and Fgfr1, are growth factors whose mRNA levels have been found to be altered in the leukocytes of patients that are affected by bipolar disorder in a depressive state. On this basis, the aim of the study was to determine if ErbB3 and Fgfr1 mRNA levels could be a biomarkers of MDD. Methods We measured by Real Time PCR ErbB3 and Fgfr1 mRNA expression levels in leukocytes of MDD patients compared with controls. Successively, to assess whether ErbB3 mRNA levels were influenced by previous antidepressant treatment we stratified our patients sample in two cohorts, comparing drug-naive versus drug-free patients. Moreover, we evaluated the levels of the transcript in MDD patients after 12 weeks of antidepressant treatment, and in prefrontal cortex of rats stressed and treated with an antidepressant drug of the same class. Results These results showed that ErbB3 but not Fgfr1 mRNA levels were reduced in leukocytes of MDD patients compared to healthy subjects. Furthermore, ErbB3 levels were not affected by antidepressant treatment in either human or animal models Conclusions Our data suggest that ErbB3 might be considered as a biomarker for MDD and that its deficit may underlie the pathopsysiology of the disease and is not a consequence of treatment. Moreover the study supports the usefulness of leukocytes as a peripheral system for identifying biomarkers in psychiatric diseases.

  19. Beyond the exchange--the future of B2B.

    Science.gov (United States)

    Wise, R; Morrison, D

    2000-01-01

    Using the Internet to facilitate business-to-business commerce promises many benefits, such as dramatic cost reductions and greater access to buyers and sellers. Yet little is known about how B2B e-commerce will evolve. The authors argue that changes in the financial services industry over the past two decades provide important clues. Exchanges, they say, are not the primary source of value in information-intensive markets; value tends to accumulate among a diverse group of specialists that focus on such tasks as packaging, standard setting, arbitrage, and information management. Because scale and liquidity are vitally important to efficient trading, today's exchanges will consolidate into a relatively small set of mega-exchanges. Originators will handle the origination and aggregation of complex transactions before sending them on to mega-exchanges for execution. E-speculators, seeking to capitalize on an abundance of market information, will tend to concentrate where relatively standardized products can be transferred easily among a large group of buyers. In many markets, a handful of independent solution providers with well-known brand names and solid reputations will thrive alongside mega-exchanges. Sell-side asset exchanges will create the networks and provide the tools to allow suppliers to trade orders among themselves, sometimes after initial transactions with customers are made on the mega-exchanges. For many companies, traditional skills in such areas as product development, manufacturing, and marketing may become relatively less important, while the ability to understand and capitalize on market dynamics may become considerably more important. PMID:11184979

  20. Approximation by planar elastic curves

    DEFF Research Database (Denmark)

    Brander, David; Gravesen, Jens; Nørbjerg, Toke Bjerge

    2015-01-01

    We give an algorithm for approximating a given plane curve segment by a planar elastic curve. The method depends on an analytic representation of the space of elastic curve segments, together with a geometric method for obtaining a good initial guess for the approximating curve. A gradient......-driven optimization is then used to find the approximating elastic curve....

  1. Approximate sine-Gordon solitons

    Energy Technology Data Exchange (ETDEWEB)

    Stratopoulos, G.N. (Dept. of Mathematical Sciences, Durham Univ. (United Kingdom)); Zakrzewski, W.J. (Dept. of Mathematical Sciences, Durham Univ. (United Kingdom))

    1993-08-01

    We look at the recently proposed scheme of approximating a sine-Gordon soliton by an expression derived from two dimensional instantons. We point out that the scheme of Sutcliffe in which he uses two dimensional instantons can be generalised to higher dimensions and that these generalisations produce even better approximations than the original approximation. We also comment on generalisations to other models. (orig.)

  2. CCD SURFACE PHOTOMETRY OF THE LOW-LUMINOSITY RADIO GALAXIES CONTAINING RADIO JETS B-2-0034+25 AND B-2-0206+35

    NARCIS (Netherlands)

    GONZALEZSERRANO, JI; PEREZFOURNON, [No Value

    1991-01-01

    We present broad-band CCD imaging of the radio galaxies B2 0034+25 and B2 0206+36. Both galaxies are of low radio power and contain radio jets at the arcsec scale. The galaxies have close companions and the optical morphology suggests that they are interacting. The surface photometry method and its

  3. 17 CFR 240.13b2-1 - Falsification of accounting records.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Falsification of accounting records. 240.13b2-1 Section 240.13b2-1 Commodity and Securities Exchanges SECURITIES AND EXCHANGE... Required Reports § 240.13b2-1 Falsification of accounting records. No person shall directly or...

  4. Vortex phase diagram studies in the weakly pinned single crystals of YNi2B2C and LuNi2B2C

    Indian Academy of Sciences (India)

    D Jaiswal-Nagar; D Pal; M R Eskildsen; P C Canfield; H Takeya; S Ramakrishnan; A K Grover

    2006-01-01

    We present a study of magnetization measurements performed on the single crystals of YNi2B2C and LuNi2B2C. For both the compounds, we find flux jumps in magnetisation values in the respective field regions, where the structural transitions in the flux line lattice symmetry have been reported in these systems via the small angle neutron scattering experiments. The magnetisation hysteresis loops and the AC susceptibility measurements show pronounced peak effect as well as second magnetisation peak anomaly for both YNi2B2C and LuNi2B2C. Based on these results, a vortex phase diagram has been constructed for YNi2B2C for $H \\Arrowvert c$ depicting different glassy phases of the vortex matter.

  5. Doping effects of ZrC and ZrB2 in the powder-in-tube processed MgB2 tapes

    Institute of Scientific and Technical Information of China (English)

    MA Yanwei

    2006-01-01

    We have investigated the effects of ZrC and ZrB2 doping on the superconducting properties of the powder-in-tube processed MgB2/Fe tapes. Samples were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM/EDX), transport and magnetic measurements. We confirmed the following quite different roles of ZrC and ZrB2 in MgB2.ZrC doping was found to decrease the transport critical current density (Jc) at 4.2 K, while the critical temperature (Tc) kept constant. In contrast, the Jc values in magnetic fields were enhanced greatly by the ZrB2 addition, which resulted in a decrease in Tc by only 0.5 K. The reason for different effects of two dopants is also discussed.

  6. Exact constants in approximation theory

    CERN Document Server

    Korneichuk, N

    1991-01-01

    This book is intended as a self-contained introduction for non-specialists, or as a reference work for experts, to the particular area of approximation theory that is concerned with exact constants. The results apply mainly to extremal problems in approximation theory, which in turn are closely related to numerical analysis and optimization. The book encompasses a wide range of questions and problems: best approximation by polynomials and splines; linear approximation methods, such as spline-approximation; optimal reconstruction of functions and linear functionals. Many of the results are base

  7. Analysis of the Role of Social Media in B2B Marketing for Startups

    OpenAIRE

    Fomicheva, Yekaterina

    2015-01-01

    Social media is a new, yet very prominent concept in present marketing communication. It has been growing steadily and became popular among marketers both in business-to-customer (B2C) and business-to-business (B2B). However, there has been more research done on how to apply and utilize social media in the B2C scenario and there are fewer explanations about B2B cases. Therefore, it was interesting to do research and analysis on how B2B companies operate, what are the factors influencing socia...

  8. Effect of Nano Scale Fe Doping on Superconducting Properties of MgB2

    OpenAIRE

    S. X. Dou; Soltanian, S.; Zhao, Y.; Getin, E.; Chen, Z.; Horvat, J.

    2004-01-01

    Iron is an important sheath material for fabrication of MgB2 wires. However, the effect of Fe doping on the superconducting properties of MgB2 remains controversial. In this work, we present results of nano-scale Fe particle doping in to MgB2. The Fe doping experiments were performed using both bulk and thin film form. It was found that Fe doping did not affect the lattice parameters of MgB2, as evidenced by the lack of change in the XRD peak positions for MgB2. Because of the high reactivity...

  9. ErbB2 signaling at the crossing between heart failure and cancer

    OpenAIRE

    Vermeulen, Zarha; Segers, Vincent F.M.; De Keulenaer, Gilles W.

    2016-01-01

    The dual role of ErbB2 (or HER-2) in tumor growth and in physiological adaptive reactions of the heart positions ErbB2 at the intersection between cancer and chronic heart failure. Accordingly, ErbB2-targeted inhibitory therapy of cancer may lead to ventricular dysfunction, and activation of ErbB2 for heart failure therapy may induce malignancy. The molecular processes leading to the activation of ErbB2 in tumors and cardiac cells are, however, fundamentally different from each other. Thus, i...

  10. B2B电子商务网站分类新探索

    Institute of Scientific and Technical Information of China (English)

    谢启燕

    2010-01-01

    B2B电子商务是电子商务的主流,发展前景可观.B2B电子商务网站每年呈快速增长趋势,要研究B2B电子商务网的发展规律和发展方向,我们应将从更深的维度和不同的角度来分类和分析B2B电子商务网站.由此文章分析了三种B2B电子商务网站新分类.

  11. Distorted Wave Effects of the 1b3g Orbital in Ethylene

    Institute of Scientific and Technical Information of China (English)

    邓景康; 李桂琴; 黄建东; 王芳; 宁传刚; 卢杰; 何垚; 王晓东; 张亦安; 高虹; 王岩; 郑延友

    2002-01-01

    We study the unexpected distorted wave effects of the 1b3g orbital in ethylene using a high resolution binary (e, 2e) electron momentum spectrometer, at an impact energy of 800 eV plus the binding energy (8 - 22 eV) with symmetric non-coplanar kinematics. The experimental momentum profile of the 1bag orbital is obtained and compared with the data previously measured at an impact energy of 1200eV plus the binding energy. Also, the experimental momentum profles of the 1b3g orbital are compared with the theoretical momentum distributions calculated by using Hartree-Fock and density functional theory methods. The experimental momentum profiles of the 1b3g orbital of ethylene at different impact energies show that the cross section of the orbital below the momentum p~l a.u. is higher for lower impact energies.

  12. The biaxial nonlinear crystal BiB3O6 as a polarization entangled photon source using non-collinear type-II parametric down-conversion

    CERN Document Server

    Halevy, A; Dovrat, L; Eisenberg, H S; Becker, P; Bohatý, L

    2011-01-01

    We describe the full characterization of the biaxial nonlinear crystal BiB3O6 (BiBO) as a polarization entangled photon source using non-collinear type-II parametric down-conversion. We consider the relevant parameters for crystal design, such as cutting angles, polarization of the photons, effective nonlinearity, spatial and temporal walk-offs, crystal thickness and the effect of the pump laser bandwidth. Experimental results showing entanglement generation with high rates and a comparison to the well investigated beta-BaB2O4 (BBO) crystal are presented as well. Changing the down-conversion crystal of a polarization entangled photon source from BBO to BiBO enhances the generation rate as if the pump power was increased by more than three times. Such an improvement is currently required for the generation of multiphoton entangled states.

  13. 17 CFR 275.203(b)(3)-1 - Definition of “client” of an investment adviser.

    Science.gov (United States)

    2010-04-01

    ... generally to the public as an investment adviser, within the meaning of section 203(b)(3) of the Act (15 U.S... than the United States, and is regulated as a public investment company under the laws of the country... investment adviser. 275.203(b)(3)-1 Section 275.203(b)(3)-1 Commodity and Securities Exchanges SECURITIES...

  14. A Photoelectron Spectroscopy and ab initio Study of B3- and B4- Anions and Their Neutrals

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Hua-Jin; Wang, Lai S.; Alexandrova, A N.; Boldyrev, Alexander I.; Zakrzewski, V G.

    2003-11-06

    The two smallest boron clusters (B3 and B4) in their neutral and anionic forms were studied by photoelectron spectroscopy and ab initio calculations. Vibrationally resolved photoelectron spectra were observed for B3- at three photon energies (355, 266, and 193 nm) and the electron affinity of B3 was measured to be+0.02 eV.

  15. Structure and microtribological characteristics of laser-arc deposited TiB2 thin film

    Institute of Scientific and Technical Information of China (English)

    CAO Xiankun; SHAO Tianmin; WEN Shizhu; QING Tao; QI Feng

    2004-01-01

    TiB2 thin film was deposited by laser-arc deposition method on the surface of single crystalline silicon. The morphology, composition, structure and microtribological properties of the film were studied by using XPS, XRD and atomic force/friction force microscope (AFM/FFM). The results show that TiB2 (100) preferred growth on the Si(100)substrate, TiB2(001) preferred growth on the Si(111) substrate. The TiB2 thin film was composed of TiB2 and a small amount of TiO2. The friction coefficient of TiB2 film on substrates Si (100) and Si(111) in microtribological process were 0.087 and 0.073,respectively. TiB2 thin film displayed distinct ability of anti-scratch and wear-resistance.

  16. Fracturas del radio distal tipo B3. Tratamiento quirúrgico.

    OpenAIRE

    Arenas Planelles, Antonio; Ortega Arruti, J.A.; Corchuelo Maíllo, C.; Arenas Miquélez, A.; Ortega Sáez, M. (Marta)

    2007-01-01

    Se presentan 67 casos de fractura de radio distal tipo B3 tratadas en nuestro Servicio. Se utilizó como método de osteosíntesis una placa palmar en 30 casos, agujas de Kirschner en 19 casos, fijadores externos en 17 y fijador externo + agujas en 1 caso. Los mejores resultados se obtuvieron en el grupo de casos tratados con placa palmar (90 % de resultados satisfactorios). A total of 67 cases of B3 type fracture of the distal radius treated in our Department are presented. A volar plate ...

  17. MOLECULAR DYNAMICS STUDY OF INTERACTIONS OF POLYMYXIN B3 AND ITS ALA-MUTANTS WITH LIPOPOLYSACCHARIDE

    Directory of Open Access Journals (Sweden)

    Lisnyak Yu. V.

    2015-12-01

    Full Text Available Introduction. Emergence of nosocomial bacterial pathogens (especially Gram-negative bacteria with multiple resistance against almost all available antibiotics is a growing medical problem. No novel drugs targeting multidrug-resistant Gram-negative bacteria have been developed in recent years. In this context, there has been greatly renewed interest to cyclic lipodecapeptides polymyxins. Polymyxins exhibit rapid bactericidal activity, they are specific and highly potent against Gramnegative bacteria, but have potential nephrotoxic side effects. So polymyxins are attractive lead compounds to develop analogues with improved microbiological, pharmacological and toxicological properties. A detailed knowledge of the molecular mechanisms of polymyxin interactions with its cell targets is a prerequisite for the purposeful improvement of its therapeutic properties. The primary cell target of a polymyxin is a lipopolysaccharide (LPS in the outer membrane of Gram-negative bacteria. The binding site of polymyxin on LPS has been supposed to be Kdo2-lipid A fragment. Methods. For all molecular modeling and molecular dynamics simulation experiments the YASARA suite of programs was used. Complex of antimicrobial peptide polymyxin В3 (PmB3 with Kdo2-lipid A portion of E. coli lipopolysaccharide was constructed by rigid docking with flexible side chains of the peptide. By alanine scanning of polymyxin В3 bound to LPS followed by simulated annealing minimization of the complexes in explicit water environment, the molecular aspects of PmB3-LPS binding have been studied by 20 ns molecular dynamics simulations at 298 K and pH 7.0. The AMBER03 force field was used with a 1.05 nm force cutoff. To treat long range electrostatic interactions the Particle Mesh Ewald algorithm was used. Results. Ala-mutations of polymyxin’s residues Dab1, Dab3, Dab5, Dab8 and Dab9 in the PmB3-LPS complex caused sustained structural changes resulting in the notable loss in stability of

  18. Thermal conductivity of A1B3C26 ternary compounds and their solid solutions

    International Nuclear Information System (INIS)

    Thermal conductivity of ternary compounds A1B3C26 and solid solutions CuGaxIn1-xS2, CuGaxIn1-xSe2, CuInS2xSe2(1-x), was studied by the absolute and relative methods in the temperature range of 300-550 K. Interrelation between thermal conductivity and tetragonal distortion of the ternary compounds A1B3C26 was established. It is shown that concentrational dependence of thermal conductivity for the solid solutions has the minimum near equimolar compositions

  19. Evidence for strong-coupling s-wave superconductivity in MgB2: (11)B NMR Study.

    Science.gov (United States)

    Kotegawa, H; Ishida, K; Kitaoka, Y; Muranaka, T; Akimitsu, J

    2001-09-17

    We have investigated a gap structure in a newly discovered superconductor, MgB2, through measurement of the (11)B nuclear spin-lattice relaxation rate, (11)(1/T(1)). (11)(1/T(1)) is proportional to the temperature (T) in the normal state, and decreases exponentially in the superconducting (SC) state, revealing a tiny coherence peak just below T(c). The T dependence of 1/T(1) in the SC state can be accounted for by an s-wave SC model with a large gap size of 2Delta/k(B)T(c) approximately 5 which suggests it is in a strong-coupling regime.

  20. BPO4@B2O3 and (BPO4@B2O3):Eu3+: The novel single-emitting-component phosphors for near UV-white LEDs

    Science.gov (United States)

    Cao, Xiyu; Liu, Wei; Jiang, Yu; Cao, Lixin; Su, Ge; Gao, Rongjie

    2016-08-01

    Nowadays much effort has been devoted to exploring novel luminescent materials with low-cost, high stability and excellent luminescent properties. In this paper, a new kind of luminescent material BPO4@B2O3 was prepared by using a facile method. The as-obtained samples contain numerous BPO4 nanoparticles enclosed by amorphous and crystalline B2O3 homogeneously, which exhibits a broad emission band ranging from 380 to 700 nm under near-UV irradiation. More importantly, it is worth noting that the BPO4@B2O3 phosphor exhibits the excellent thermal quenching property, which endows it with a promising prospect as phosphors for high power white LEDs. To further promote its application as white light phosphors, Eu3+ ions were doped into the BPO4@B2O3 samples and prepared the (BPO4@B2O3):Eu3+ phosphors with chromaticity coordinates (0.3022, 0.3122). The corresponding packaging of LEDs indicates that both BPO4@B2O3 and (BPO4@B2O3):Eu3+ can be considered as the promising phosphors for WLEDs.

  1. Secretion of SerpinB2 from endothelial cells activated with inflammatory stimuli

    Energy Technology Data Exchange (ETDEWEB)

    Boncela, Joanna; Przygodzka, Patrycja [Institute of Medical Biology, Polish Academy of Sciences, Lodz (Poland); Wyroba, Elzbieta [Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw (Poland); Papiewska-Pajak, Izabela [Department of Molecular and Medical Biophysics, Medical University of Lodz (Poland); Cierniewski, Czeslaw S., E-mail: czeslaw.cierniewski@umed.lodz.pl [Institute of Medical Biology, Polish Academy of Sciences, Lodz (Poland); Department of Molecular and Medical Biophysics, Medical University of Lodz (Poland)

    2013-05-01

    Due to the lack of an N-terminal signal peptide, SerpinB2 (plasminogen activator inhibitor type 2) accumulates in cells and only a small percentage of it is secreted. The extracellular concentration of SerpinB2 significantly increases during inflammation. In the present study we investigated the mechanism with which SerpinB2 can be secreted from endothelial cells activated with LPS. We evaluated the intracellular distribution of SerpinB2 by double immunogold labeling followed by a high resolution electron microscopy analysis. We found that SerpinB2 gathers in the vesicular structures and in the endothelial cell periphery. These vesicles stained positive for the trans-Golgi network marker TGN46, which is consistent with their formation by the endoplasmatic reticulum (ER) and Golgi-dependent pathways. SerpinB2 was delivered to the plasma membrane, apparently together with TGN46 in the same vesicles, which after fusion with the membranes released cargo. Secretion of SerpinB2 was partially inhibited by brefeldin A. The secreted SerpinB2 was predominantly in its nonglycosylated 43 kDa form as evaluated by Western immunoblotting. Our data suggest that increased expression of SerpinB2 by an inflammatory stimulus is sufficient to generate structures that resemble secretory vesicles. These vesicles may represent the mechanism by which high local concentrations of SerpinB2 are released at inflammation sites from endothelial cells. - Highlights: ► LPS stimulates generation of secretory vesicles containing SerpinB2. ► SerpinB2 concentrates in TGN46 positive vesicles close to the plasma membrane. ► Brefeldin A inhibits secretion of SerpinB2. ► The secreted SerpinB2 was predominantly in its nonglycosylated 43 kDa.

  2. Approximate solutions for the skyrmion

    CERN Document Server

    Ponciano, J A; Fanchiotti, H; Canal-Garcia, C A

    2001-01-01

    We reconsider the Euler-Lagrange equation for the Skyrme model in the hedgehog ansatz and study the analytical properties of the solitonic solution. In view of the lack of a closed form solution to the problem, we work on approximate analytical solutions. We show that Pade approximants are well suited to continue analytically the asymptotic representation obtained in terms of a power series expansion near the origin, obtaining explicit approximate solutions for the Skyrme equations. We improve the approximations by applying the 2-point Pade approximant procedure whereby the exact behaviour at spatial infinity is incorporated. An even better convergence to the exact solution is obtained by introducing a modified form for the approximants. The new representations share the same analytical properties with the exact solution at both small and large values of the radial variable r.

  3. BDD Minimization for Approximate Computing

    OpenAIRE

    Soeken, Mathias; Grosse, Daniel; Chandrasekharan, Arun; Drechsler, Rolf

    2016-01-01

    We present Approximate BDD Minimization (ABM) as a problem that has application in approximate computing. Given a BDD representation of a multi-output Boolean function, ABM asks whether there exists another function that has a smaller BDD representation but meets a threshold w.r.t. an error metric. We present operators to derive approximated functions and present algorithms to exactly compute the error metrics directly on the BDD representation. An experimental evaluation demonstrates the app...

  4. Factors Required for the Uridylylation of the Foot-and-Mouth Disease Virus 3B1, 3B2, and 3B3 Peptides by the RNA-Dependent RNA Polymerase (3Dpol) In Vitro

    OpenAIRE

    Nayak, Arabinda; Goodfellow, Ian G.; Belsham, Graham J.

    2005-01-01

    The 5′ terminus of picornavirus genomic RNA is covalently linked to the virus-encoded peptide 3B (VPg). Foot-and-mouth disease virus (FMDV) is unique in encoding and using 3 distinct forms of this peptide. These peptides each act as primers for RNA synthesis by the virus-encoded RNA polymerase 3Dpol. To act as the primer for positive-strand RNA synthesis, the 3B peptides have to be uridylylated to form VPgpU(pU). For certain picornaviruses, it has been shown that this reaction is achieved by ...

  5. B2C电子商务存在的问题与对策%B2C e-commerce existing problems and countermeasures

    Institute of Scientific and Technical Information of China (English)

    高艳

    2014-01-01

    B2C电子商务是企业与消费者之间的电子商务模式,使用Intemet为技术支撑,为消费者提供服务.本文对B2C模式的电子商务类型进行了评述,分析了我国目前B2C电子商务存在的问题,同时为解决这些问题提出了相应的对策.

  6. A report on how foreign trade enterprises use B2B platform%外贸B2B平台使用调查

    Institute of Scientific and Technical Information of China (English)

    李冠艺

    2010-01-01

    @@ 为帮助外贸企业更好地选择外贸B2B平台所提供的服务,用好外贸B2B平台,提高使用效果,2010年5月,我们针对全国的外贸企业进行了网络抽样调查,根据调查结果形成此外贸B2B平台使用调查报告.

  7. B2C电子商务市场的逆向物流分析%Analysis on Reverse Logistic in B2C Electronic Commerce Market

    Institute of Scientific and Technical Information of China (English)

    刘田; 牟援朝

    2006-01-01

    讨论B2C电子商务市场中的逆向物流问题,以期能够在人们研究逆向物流这一问题之时,与当前的电子商务市场加以结合.从逆向物流的定义谈起,结合B2C电子商务市场的特点,分析了如何进行B2C电子商务市场中逆向物流的管理.

  8. The magnetic field of the B3V star 16 Pegasi

    NARCIS (Netherlands)

    H.F. Henrichs; C. Neiner; R.S. Schnerr; E. Verdugo; A. Alecian; C. Catala; F. Cochard; J. Gutiérrez; A.L. Huat; J. Silvester; O. Thizy

    2008-01-01

    The slowly pulsating B3V star 16 Pegasi was discovered by Hubrig et al. (2006) to be magnetic, based on low-resolution spectropolarimetric observations with FORS1 at the VLT. We have confirmed the presence of a magnetic field with new measurements with the spectropolarimeters Narval at TBL, France a

  9. 2D numerical comparison of trailing edge flaps - UpWind WP1B3

    DEFF Research Database (Denmark)

    Buhl, Thomas; Andersen, Peter Bjørn; Barlas, T.K.

    This report covers the investigations and comparisons of trailing edge flaps carried out by Delft and Risø. The work is a part of the W1B3 work package of the UpWind EU-project. This report covers only 2D test cases with simple control of the trailing edge flap with the objective of keeping CL co...

  10. Data of evolutionary structure change: 1DR8B-3DMSA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1DR8B-3DMSA 1DR8 3DMS B A --------------------------MKVAVLPGDGIGP...D>3DMS A 3DMSA AVEKAYGGKKKIH ...entryChain> 3DMS A 3DMSA TKVYGPDV...90 SER CA 526 3DMS A 3DMSA...ine>PHE CA 324 3DMS A 3DMSA

  11. Design, synthesis and biological activity of some novel benzimidazole derivatives against Coxsackie virus B3

    Institute of Scientific and Technical Information of China (English)

    Zhong Lv Zhang; Zhi Jie Sun; Fei Xue; Xian Jin Luo; Nai Yun Xiu; Li Teng; Zong Gen Peng

    2009-01-01

    A series of novel benzirnidazole derivatives was synthesized and their anti-Coxsackie virus B3 (CVB3) activity was evaluated in VERO cells. Compounds 9 and 10 exhibited better inhibitory activity than those of ribavirin (RBV) with IC50 values of 5.30 and 1.06 μg/mL, respectively.

  12. 17 CFR 270.24b-3 - Sales literature deemed filed.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Sales literature deemed filed... (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.24b-3 Sales literature deemed filed. Any advertisement, pamphlet, circular, form letter or other sales literature addressed to or...

  13. Unidirectional thermal expansion in KZnB3O6: role of alkali metals.

    Science.gov (United States)

    Lou, Yanfang; Li, Dandan; Li, Zhilin; Zhang, Han; Jin, Shifeng; Chen, Xiaolong

    2015-12-14

    The driving force of the unidirectional thermal expansion in KZnB3O6 has been studied experimentally and theoretically. Our results show that the low-energy vibrational modes of alkali metals play a crucial role in this unusual thermal behavior. PMID:26515521

  14. DFT (B3LYP COMPUTATIONAL STUDY ON THE MECHANISMS OF FORMATION OF SOME SEMICARBAZONES

    Directory of Open Access Journals (Sweden)

    Abdulfatai Siaka

    2016-06-01

    Full Text Available Thermodynamic and kinetic mechanisms of forming six semicarbazones have been investigated computationally by DFT B3LYP method. All the reactions proceed via two transitions and include two consecutive steps: bimolecular and unimolecular. The computed transition steps have varying equilibrium constants values, enthalpy of activation and Gibbs energy of activation, depending on the semicarbazone involved.

  15. Probable transmission of coxsackie B3 virus from human to chimpanzee, Denmark

    DEFF Research Database (Denmark)

    Nielsen, Sandra Cathrine Abel; Mourier, Tobias; Baandrup, Ulrik;

    2012-01-01

    In 2010, a chimpanzee died at Copenhagen Zoo following an outbreak of respiratory disease among chimpanzees in the zoo. Identification of coxsackie B3 virus, a common human pathogen, as the causative agent, and its severe manifestation, raise questions about pathogenicity and transmissibility among...... humans and other primates....

  16. Thermodynamic properties and low-temperature X-ray diffraction of vitamin B3

    International Nuclear Information System (INIS)

    Highlights: • Temperature dependence of heat capacity of vitamin B3 has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B3 have been determined for the range from T → 0 to 346 K. • The thermodynamic analysis of reactions involving nicotinic acid was made. • The low-temperature X-ray diffraction was used for the determination of coefficients of thermal expansion. - Abstract: In the present work temperature dependence of heat capacity of vitamin B3 (nicotinic acid) has been measured for the first time in the range from 5 to 346 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B3, namely, the heat capacity, enthalpy H°(T) – H°(0), entropy S°(T) – S°(0) and Gibbs function G°(T) – H°(0) have been determined for the range from T → 0 to 343 K. The value of the fractal dimension D in the function of multifractal generalization of Debye’s theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. The thermodynamic parameters ΔfS°, ΔfG° at T = 298.15 K and p = 0.1 MPa have been calculated. The thermodynamic analysis of reactions involving nicotinic acid was made. The low-temperature X-ray diffraction was used for the determination of coefficients of thermal expansion

  17. Data of evolutionary structure change: 3EK2B-3FNFD [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available rmsd> 3.226280927658081 EVID> 4 3FNF...3EK2B-3FNFD 3EK2 3FNF B D MGFLDGKRILLTGLLSNRSIAYGIAKACKREGAELAFTY...VGDRFKDRITEFAAEFGSE-LVFPCDVADDAQIDALFASLKTHWD---SLDGLVHSIGFAPREAIAG-DFLDGLTRENFRIAHDISAYSFPALAKAALPMLSDDASLL.../ss_2> EVID> 0 3EK2 3FNF D 3FNFD

  18. Secretion of SerpinB2 from endothelial cells activated with inflammatory stimuli.

    Science.gov (United States)

    Boncela, Joanna; Przygodzka, Patrycja; Wyroba, Elzbieta; Papiewska-Pajak, Izabela; Cierniewski, Czeslaw S

    2013-05-01

    Due to the lack of an N-terminal signal peptide, SerpinB2 (plasminogen activator inhibitor type 2) accumulates in cells and only a small percentage of it is secreted. The extracellular concentration of SerpinB2 significantly increases during inflammation. In the present study we investigated the mechanism with which SerpinB2 can be secreted from endothelial cells activated with LPS. We evaluated the intracellular distribution of SerpinB2 by double immunogold labeling followed by a high resolution electron microscopy analysis. We found that SerpinB2 gathers in the vesicular structures and in the endothelial cell periphery. These vesicles stained positive for the trans-Golgi network marker TGN46, which is consistent with their formation by the endoplasmatic reticulum (ER) and Golgi-dependent pathways. SerpinB2 was delivered to the plasma membrane, apparently together with TGN46 in the same vesicles, which after fusion with the membranes released cargo. Secretion of SerpinB2 was partially inhibited by brefeldin A. The secreted SerpinB2 was predominantly in its nonglycosylated 43kDa form as evaluated by Western immunoblotting. Our data suggest that increased expression of SerpinB2 by an inflammatory stimulus is sufficient to generate structures that resemble secretory vesicles. These vesicles may represent the mechanism by which high local concentrations of SerpinB2 are released at inflammation sites from endothelial cells.

  19. Preparation and Microstructure of Porous ZrB2 Ceramics Using Reactive Spark Plasma Sintering Method

    Institute of Scientific and Technical Information of China (English)

    YUAN Huiping; LI Junguo; SHEN Qiang; ZHANG Lianmeng

    2015-01-01

    Zirconium oxide (ZrO2) and boron carbide (B4C) were added to ZrB2 raw powders to prepare ZrB2 porous ceramics by reactive spark plasma sintering (RSPS). The reactions between ZrO2 and B4C which produce ZrB2 and gas (such as CO and B2O3) result in pore formation. X-Ray Diffraction results indicated that the products phase was ZrB2 and the reaction was completed after the RSPS process. The porosity could be controlled by changing the ratio of synthesized ZrB2 to raw ZrB2 powders. The porosity of porous ceramics with 20 wt% and 40 wt% synthsized ZrB2 are 0.185 and 0.222, respectivly. And dense ZrB2-SiC ceramic with a porosity of 0.057 was prepared under the same conditions for comparison. The pores were homogeneously distributed within the microstructure of the porous ceramics. The results indicate a promising method for preparing porous ZrB2-based ceramics.

  20. ErbB2 signaling at the crossing between heart failure and cancer.

    Science.gov (United States)

    Vermeulen, Zarha; Segers, Vincent F M; De Keulenaer, Gilles W

    2016-11-01

    The dual role of ErbB2 (or HER-2) in tumor growth and in physiological adaptive reactions of the heart positions ErbB2 at the intersection between cancer and chronic heart failure. Accordingly, ErbB2-targeted inhibitory therapy of cancer may lead to ventricular dysfunction, and activation of ErbB2 for heart failure therapy may induce malignancy. The molecular processes leading to the activation of ErbB2 in tumors and cardiac cells are, however, fundamentally different from each other. Thus, it must be feasible to design drugs that specifically target either physiological or malignant ErbB2 signaling, to activate ErbB2 signaling in heart failure with no increased risk for cancer, and to inhibit ErbB2 signaling in cancer with no increased risk for heart failure. In this review, we present a state-of-the-art on how ErbB2 is regulated in physiological conditions and in tumor cells and how this knowledge translates into smart drug design. This leads to a new generation of drugs interfering with ErbB2 in a unique way tailored for a specific clinical goal. These exciting developments at the crossing between cancer and heart failure are an elegant example of interdisciplinary collaborations between clinicians, physiologists, pharmacologists, and molecular biologists. PMID:27596216

  1. Role of Erbin in ErbB2-dependent breast tumor growth.

    Science.gov (United States)

    Tao, Yanmei; Shen, Chengyong; Luo, Shiwen; Traoré, Wilfried; Marchetto, Sylvie; Santoni, Marie-Josée; Xu, Linlin; Wu, Biao; Shi, Chao; Mei, Jinghong; Bates, Ryan; Liu, Xihui; Zhao, Kai; Xiong, Wen-Cheng; Borg, Jean-Paul; Mei, Lin

    2014-10-21

    ErbB2 (v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2), a receptor tyrosine kinase of the ErbB family, is overexpressed in around 25% of breast cancers. In addition to forming a heterodimer with other ErbB receptors in response to ligand stimulation, ErbB2 can be activated in a ligand-independent manner. We report here that Erbin, an ErbB2-interacting protein that was thought to act as an antitumor factor, is specifically expressed in mammary luminal epithelial cells and facilitates ErbB2-dependent proliferation of breast cancer cells and tumorigenesis in MMTV-neu transgenic mice. Disruption of their interaction decreases ErbB2-dependent proliferation, and deletion of the PDZ domain in Erbin hinders ErbB2-dependent tumor development in MMTV-neu mice. Mechanistically, Erbin forms a complex with ErbB2, promotes its interaction with the chaperon protein HSP90, and thus prevents its degradation. Finally, ErbB2 and Erbin expression correlates in human breast tumor tissues. Together, these observations establish Erbin as an ErbB2 regulator for breast tumor formation and progression.

  2. Thermoluminescence kinetic parameters of different amount La-doped ZnB2O4

    International Nuclear Information System (INIS)

    The kinetic parameters of 1%, 2%, 3% and 4% La-doped ZnB2O4 phosphors (i.e. ZnB2O4:0.01La, ZnB2O4:0.02La, ZnB2O4:0.03La and ZnB2O4:0.04La) synthesized by nitric acid method have been calculated. Thermoluminescence (TL) glow curves of ZnB2O4:La phosphors after beta-irradiation showed a very well defined main peak having the maximum temperature at around 200 °C and a shoulder peak at around 315 °C with a constant heating rate of 5 °C/s. The kinetic parameters of ZnB2O4:La phosphors TL glow peaks (i.e. order of kinetics (b), activation energies (Ea) and frequency factors (s)) have been determined and evaluated by Computerized Glow Curve Deconvolution (CGCD), and Peak Shape (PS) methods using the glow curve data. From the results, it can conclude that the values of Ea obtained with these methods for ZnB2O4:La phosphors are consistent with each other, but the s values differ considerably. - Highlights: • Calculation of TL kinetic parameters for La-doped ZnB2O4. • La-doped ZnB2O4 was synthesized by nitric acid method. • Well defined main peak at about 200 °C

  3. Ephrin B2 is involved in Porphyromonas gingivalis infection-enhanced adhesion of THP-1 to human umbilical vein endothelial cells%肝配蛋白B2在牙龈卟啉单胞菌诱导单核细胞黏附人脐静脉内皮细胞中的作用

    Institute of Scientific and Technical Information of China (English)

    张彩霞; 宋洁; 徐杨; 吴娟; 孙卫斌; 李宽钰

    2014-01-01

    Objective To investigate the mechanisms of Porphyromonas gingivalis(Pg) infection-mediated enhancement of adhesion between monocytes THP-1 and human umbilical vein endothelial cells(HUVEC) by detecting the effect of erythropoietin producing hepatomocellular receptor interacting protein B2(Ephrin B2) and its receptors on the adhesion.Methods PgATCC33277 was cultured in an anaerobic jar,and THP-1 cells were infected with various concentrations of Pg at multiplicity of infection(MOI) of 1:100 for 8 and 24 h,respectively.The expression of Ephrin B2 receptor of THP-1 cells was detected.After removal of the free Pg,THP-1 cells were cocultured with HUVEC(overexpress of EphrinB2 or not) for 24 h to detect the expression of Ephrin B2 of HUVEC cells after additional cultivation for 23 h.Results The adhesion of THP-1 cells post infection by Pg to HUVEC was enhanced.The mRNA levels of Ephrin B2 receptors,including EphB3(5.169±0.152,P=0.005),EphB4(11.040± 1.195,P=0.001),and EphA4(4.976± 0.122,P=0.001) expressed by THP-1,and Ephrin B2(8.938±0.962,P=0.008) expressed by HUVEC were significantly elevated 24 h post infection of Pg.Over expression of Ephrin B2 in HUVEC promoted the adhesion of THP-1 to HUVEC.Conclusions Ephrin B2 and its receptors are involved in Pg infection mediated enhancement of the adhesion of THP-1 to HUVEC cells,suggesting that Ephrin B2 participates in the development of atherosclerosis.%目的 检测肝配蛋白B2 (erythropoietin producing hepatomocellular receptor interacting protein B2,Ephrin B2)及其受体在单核细胞THP-1黏附人脐静脉内皮细胞(human umbilical vein endothelial cell,HUVEC)中的作用,揭示牙龈卟啉单胞菌(Porphyromonas gingivalis,Pg)感染增强THP-1黏附HUVEC的分子机制.方法 应用厌氧罐培养Pg,以感染复数1∶100感染人单核细胞株THP-1,感染8和24 h后,收集部分样品分别用于检测THP-1细胞Ephrin B2及其受体表达水平的变化;其余样品与转染空载体或过表达Ephrin B2

  4. Nonlinear approximation with redundant dictionaries

    DEFF Research Database (Denmark)

    Borup, Lasse; Nielsen, M.; Gribonval, R.

    2005-01-01

    In this paper we study nonlinear approximation and data representation with redundant function dictionaries. In particular, approximation with redundant wavelet bi-frame systems is studied in detail. Several results for orthonormal wavelets are generalized to the redundant case. In general...

  5. Approximate Inference in Probabilistic Models

    DEFF Research Database (Denmark)

    Opper, Manfred; Winther, Ole

    2004-01-01

    We present a framework for approximate inference in probabilistic data models which is based on free energies. The free energy is constructed from two approximating distributions which encode different aspects of the intractable model. Consistency between distributions is required on a chosen set...

  6. The Logic of Approximate Dependence

    OpenAIRE

    Väänänen, Jouko

    2014-01-01

    We extend the treatment of functional dependence, the basic concept of dependence logic, to include the possibility of dependence with a limited number of exceptions. We call this approximate dependence. The main result of the paper is a Completeness Theorem for approximate dependence atoms. We point out some problematic features of this which suggests that we should consider multi-teams, not just teams.

  7. Beyond the random phase approximation

    DEFF Research Database (Denmark)

    Olsen, Thomas; Thygesen, Kristian S.

    2013-01-01

    We assess the performance of a recently proposed renormalized adiabatic local density approximation (rALDA) for ab initio calculations of electronic correlation energies in solids and molecules. The method is an extension of the random phase approximation (RPA) derived from time-dependent density...

  8. Analysis on the Confidence Crisis in B2C%B2C电子商务模式下的信任危机研究

    Institute of Scientific and Technical Information of China (English)

    方芳

    2011-01-01

    阐述了电子商务信任所涉及的相关概念,以B2C电子商务模式为前提,讨论了目前该模式下存在的信任危机,分析了信任危机的产生原因,期望能够为解决B2C电子商务中的信任危机提供帮助。%Some relevant concepts of E-commerce confidence were described in this paper,and based on the B2C E-commerce,the confidence crisis under the mode was discussed and the causes were analyzed,in order to offer help to solve the confidence crisis in B2C E-commerce.

  9. B2C Consumer Protection in Electronic Commerce Research%B2C电子商务中消费者权益保护研究

    Institute of Scientific and Technical Information of China (English)

    陆勇

    2012-01-01

    随着商家对顾客(Business-to-Customer,B2C)的电子商务井喷式发展,在交易过程中处于弱势地位的消费者权益屡遭侵害,保护消费者权益是稳定B2C电子商务发展的基础.文章通过对国内B2C主要交易平台消费者投诉数据的实证分析,提出B2C电子商务中消费者权益的构成情况,指出每一个权益的侵害成因、表现形式和保障基础,并提出了权益保护的具体措施.

  10. B2C E-commerce Distribution Service Capacity Evaluation%B2C电子商务配送服务能力评价研究

    Institute of Scientific and Technical Information of China (English)

    王玲玉; 赵启兰

    2011-01-01

    在深入研究B2C电子商务环境下新型配送特征基础上,构建适用于B2C电子商务环境的配送服务能力评价指标体系,并用层次分析法进行了评价模型的建立,以期为B2C电子商务企业构建物流服务竞争力提供一定参考.%In this paper, the additional requirements placed upon distribution services by the B2C e-commerce environment are explored and a compatible distribution service capacity evaluation index system is established using analytic hierarchy process.

  11. 关于B2B服务品牌忠诚度的研究%A research on brand loyalty of B2B service

    Institute of Scientific and Technical Information of China (English)

    孔令明; 耿禧则

    2012-01-01

    The research on brand loyalty has been confined to the product brand in the past. This paper applied brand loyalty theory to B2B service brand. Through empirical research, this paper reflected the effect of the brand recognition and brand image to action loyalty and attitude loyalty, and put forward some suggestions for the B2B service brand management%对于品牌忠诚度的研究,过去一直局限于产品品牌上。本文将品牌忠诚度理论运用于B2B服务品牌,通过实证调查,研究品牌认知度与品牌形象对态度忠诚度和行动忠诚度的影响作用,并据此为B2B服务品牌的成功管理提出建议。

  12. Observation of b2 symmetry vibrational levels of the SO2 C̃ (1)B2 state: Vibrational level staggering, Coriolis interactions, and rotation-vibration constants.

    Science.gov (United States)

    Park, G Barratt; Jiang, Jun; Saladrigas, Catherine A; Field, Robert W

    2016-04-14

    The C̃ (1)B2 state of SO2 has a double-minimum potential in the antisymmetric stretch coordinate, such that the minimum energy geometry has nonequivalent SO bond lengths. However, low-lying levels with odd quanta of antisymmetric stretch (b2 vibrational symmetry) have not previously been observed because transitions into these levels from the zero-point level of the X̃ state are vibronically forbidden. We use IR-UV double resonance to observe the b2 vibrational levels of the C̃ state below 1600 cm(-1) of vibrational excitation. This enables a direct characterization of the vibrational level staggering that results from the double-minimum potential. In addition, it allows us to deperturb the strong c-axis Coriolis interactions between levels of a1 and b2 vibrational symmetry and to determine accurately the vibrational dependence of the rotational constants in the distorted C̃ electronic state.

  13. Development and Application of Interatomic Potentials for Ultra High Temperature Ceramics (UHTC): ZrB2 and HfB2

    Science.gov (United States)

    Lawson, John W.; Daw, Murray; Bauschlicher

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 are characterized by high melting point, good strength, and reasonable oxidation resistance. These materials are of interest for use as sharp leading edges for hypersonic vehicles among other applications. Progress in computational modeling of UHTCs has been limited in part due to the absence of suitable interatomic potentials. We present a Tersoff style parameterization of such potentials for ZrB2 and HfB2 appropriate for atomistic simulations. Parameters are fit to data generated from ab initio calculations. The accuracy of the potentials is assessed against further ab initio data. As a first non ]trivial application, molecular dynamics simulations are performed to evaluate the thermal conductivity of single crystals and the thermal resistance of high symmetry grain boundaries.

  14. Growth of MgB2 Thin Films by Chemical Vapour Deposition Using B2H6 as a boron Source

    Institute of Scientific and Technical Information of China (English)

    王淑芳; 朱亚彬; 刘震; 周岳亮; 张芹; 陈正豪; 吕惠宾; 杨国桢

    2003-01-01

    Superconducting MgB2 thin films were grown on single crystal Al2O3 (0001) by chemical vapour deposition using B2H6 as a boron source. MgB2 film was then accomplished by annealing the boron precursor films in the presence of high-purity magnesium bulk at 890℃ in vacuum. The as-grown MgB2 films are smooth and c-axis-oriented.The films exhibit a zero-resistance transition of about 38K with a narrow transition width of 0.2 K. Magnetic hysteresis measurements yield the critical current density of 1.9 × 107 A/cm2 at 10 K in zero field.

  15. Observation of b2 symmetry vibrational levels of the SO2 C ˜ 1B2 state: Vibrational level staggering, Coriolis interactions, and rotation-vibration constants

    Science.gov (United States)

    Park, G. Barratt; Jiang, Jun; Saladrigas, Catherine A.; Field, Robert W.

    2016-04-01

    The C ˜ 1B2 state of SO2 has a double-minimum potential in the antisymmetric stretch coordinate, such that the minimum energy geometry has nonequivalent SO bond lengths. However, low-lying levels with odd quanta of antisymmetric stretch (b2 vibrational symmetry) have not previously been observed because transitions into these levels from the zero-point level of the X ˜ state are vibronically forbidden. We use IR-UV double resonance to observe the b2 vibrational levels of the C ˜ state below 1600 cm-1 of vibrational excitation. This enables a direct characterization of the vibrational level staggering that results from the double-minimum potential. In addition, it allows us to deperturb the strong c-axis Coriolis interactions between levels of a1 and b2 vibrational symmetry and to determine accurately the vibrational dependence of the rotational constants in the distorted C ˜ electronic state.

  16. Reserch and Progress in MgB2 Matrix Superconductive Material%MgB2基超导材料研究进展

    Institute of Scientific and Technical Information of China (English)

    黄勇; 刘心宇; 曾中明

    2003-01-01

    2001年1月发现MgB2基超导体具有39K的临界转变温度。是迄今为止转变温度最高的非铜氧化物超导体。国内外对MgB2基超导材料进行了广泛而又深入的研究,本文简述了近期对MgB2基超导材料的研究进展,介绍了近期主要有关MgB2基超导材料电子结构研究和应用开发的工作。着重叙述了关于基超导机制的研究。

  17. Approximate circuits for increased reliability

    Energy Technology Data Exchange (ETDEWEB)

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-12-22

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  18. Approximate circuits for increased reliability

    Energy Technology Data Exchange (ETDEWEB)

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-08-18

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  19. N-variable rational approximants

    International Nuclear Information System (INIS)

    ''Desirable properties'' of a two-variable generalization of Pade approximants are laid down. The ''Chisholm approximants'' are defined and are shown to obey nearly all of these properties; the alternative ways of completing a unique definition are discussed, and the ''prong structure'' of the defining equations is elucidated. Several generalizations and variants of Chisholm approximants are described: N-variable diagonal, 2-variable simple off-diagonal, N-variable simple and general off-diagonal, and rotationally covariant 2-variable approximants. All of the 2-variable approximants are capable of representing singularities of functions of two variables, and of analytically continuing beyond the polycylinder of convergence of the double series. 8 figures

  20. Caenorhabditis elegans cyclin B3 is required for multiple mitotic processes including alleviation of a spindle checkpoint-dependent block in anaphase chromosome segregation.

    Directory of Open Access Journals (Sweden)

    Gary M R Deyter

    2010-11-01

    Full Text Available The master regulators of the cell cycle are cyclin-dependent kinases (Cdks, which influence the function of a myriad of proteins via phosphorylation. Mitotic Cdk1 is activated by A-type, as well as B1- and B2-type, cyclins. However, the role of a third, conserved cyclin B family member, cyclin B3, is less well defined. Here, we show that Caenorhabditis elegans CYB-3 has essential and distinct functions from cyclin B1 and B2 in the early embryo. CYB-3 is required for the timely execution of a number of cell cycle events including completion of the MII meiotic division of the oocyte nucleus, pronuclear migration, centrosome maturation, mitotic chromosome condensation and congression, and, most strikingly, progression through the metaphase-to-anaphase transition. Our experiments reveal that the extended metaphase delay in CYB-3-depleted embryos is dependent on an intact spindle assembly checkpoint (SAC and results in salient defects in the architecture of holocentric metaphase chromosomes. Furthermore, genetically increasing or decreasing dynein activity results in the respective suppression or enhancement of CYB-3-dependent defects in cell cycle progression. Altogether, these data reveal that CYB-3 plays a unique, essential role in the cell cycle including promoting mitotic dynein functionality and alleviation of a SAC-dependent block in anaphase chromosome segregation.

  1. Synthesis and crystal structure of Cu2NiO(B2O5) and Cu2MgO(B2O5)

    International Nuclear Information System (INIS)

    A transport reaction synthesis technique has been used to prepare single crystals of two pyroborate compounds having the formulas Cu2NiO(B2O5) and Cu2MgO(B2O5). The two compounds are isostructural and crystallize in the monoclinic space group P21/c. Cu2NiO(B2O5): a=3.2003(10), b=14.775(3), c=9.097(3), β=93.28(4), V=429.4(2) A3, Z=4; and Cu2MgO(B2O5): a=3.2401(6), b=14.790(2), c=9.147(2), β=94.88(2), V=436.7(2) A3, Z=4. The structures of Cu2NiO(B2O5) and Cu2MgO(B2O5) were, respectively, refined from 804 and 1000 independent reflections to the final residuals R1=0.0366, wR2=0.0911 and R1=0.0231, wR2=0.0644. Both compounds exhibit a chevron-like structure built up of ribbons, made of edge-connected copper and nickel-oxygen polyhedra, running along the (1 0 0) direction. These ribbons are connected from one another via oxygen atoms and the cohesion of the three-dimensional network is ensured by [B2O5] entities. Cu in part occupies the position for Ni or Mg, so that the compounds actually are solid solution compounds. Ni or Mg atoms are octahedrally coordinated by oxygen, while the two pure Cu sites show [4] and [4+1] coordination, for Cu(1) and Cu(2), respectively. The ELNES B-K edge spectra for the two compounds support that the borate group present is [B2O5

  2. B2B电子商务协作模型研究%Research on B2B Electronic Business Collaboration Model

    Institute of Scientific and Technical Information of China (English)

    李双庆; 程代杰; 何玲

    2003-01-01

    B2B is an important application form in electronic business, it provides the methods to do business activities through Internet among companies. But the heterogeneous of the information systems between companies makes it difficult in interoperating between them. In this paper, a B2B electronic business collaboration model is proposed, solving the collaboration between heterogeneous business systems by defining the business irformation ontology and describing the hierarchy in business collaboration process.

  3. Overlapping B2B and Family Business Marketing : A Study about Family and B2B Firms Exhibiting at Bilsport Performance and Custom Motor Show

    OpenAIRE

    Kervaire Orellana, Brian André; DeLeon, Eber Andres

    2009-01-01

    Background: Family Businesses’ way of doing marketing has similarities with B2B marketing. Usuallyfamily firms focus on what they have traditionally done well and diversify in related areas using their knowledge of how to perform in certain markets with certain customers and by offering certain productsand services. In order to do this, it is important for family firms, as for firms operating in B2Bmarkets, to create and keep good relationships with their stakeholders, so that at the end thei...

  4. Research on B2C Buying Online Mode%基于B2C的网络团购模式研究

    Institute of Scientific and Technical Information of China (English)

    王晓燕

    2011-01-01

    Purchasing online trade is seen more and more frequently in our country since the beginning of 21st century, and a large quantity of B2C websites for purchasing online have appeared. The factors influencing purchasing online are bargaining space, buyer expectation, competitive situation and so on. All of these factors play a decisive role for B2C purchasing online mode. Summing up the development of various purchasing online modes, eight B2C purchasing online modes can be divided from the three latitudes of sponsors, diversity of products and the number of buyers.%我国从21世纪以来网络团购交易越来越频繁,出现了大批的B2C网络团购网站。影响网络团购的因素有议价空间、买方预期、竞争状况等,这些因素对于B2C网络团购模式都有决定性的作用,总结多种团购模式发现,较为稳定的八种B2C网络团购模式都可从发起者、产品的多样性及卖家数量三个维度来进行划分。

  5. Lattice Thermal Conductivity of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2 from Atomistic Simulations

    Science.gov (United States)

    Lawson, John W.; Daw, Murray S.; Bauschlicher, Charles W.

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 have a number of properties that make them attractive for applications in extreme environments. One such property is their high thermal conductivity. Computational modeling of these materials will facilitate understanding of fundamental mechanisms, elucidate structure-property relationships, and ultimately accelerate the materials design cycle. Progress in computational modeling of UHTCs however has been limited in part due to the absence of suitable interatomic potentials. Recently, we developed Tersoff style parameterizations of such potentials for both ZrB2 and HfB2 appropriate for atomistic simulations. As an application, Green-Kubo molecular dynamics simulations were performed to evaluate the lattice thermal conductivity for single crystals of ZrB2 and HfB2. The atomic mass difference in these binary compounds leads to oscillations in the time correlation function of the heat current, in contrast to the more typical monotonic decay seen in monoatomic materials such as Silicon, for example. Results at room temperature and at elevated temperatures will be reported.

  6. Study of TiB2 Ceramics via SHS/PHIP%SHS/PHIP法合成TiB2陶瓷的研究

    Institute of Scientific and Technical Information of China (English)

    徐强; 张幸红; 曲伟; 韩杰才

    2002-01-01

    采用自蔓延高温合成结合准热等静压(SHS/PHIP)工艺制备了TiB2陶瓷材料,并进行了X射线衍射(XRD)、扫描电镜(SEM)、力学性能等实验研究.XRD结果表明反应生成了高纯度的TiB2,没有其他相生成,这与热力学计算结果相吻合.材料SEM分析发现,TiB2陶瓷颗粒形貌为近等轴状,尺寸细小且较均匀,在TiB2陶瓷颗粒间还存在"烧结颈",由于SHS反应所产生的高温,造成了TiB2陶瓷颗粒表面的圆化.合成产物的致密度较低,气孔主要存在于TiB2陶瓷颗粒交界处,较低的致密性导致了材料具有较低的硬度、弯曲强度和断裂韧性等力学性能.

  7. Research Progress of Doping in MgB2 Superconducting Material%MgB2超导材料掺杂研究进展

    Institute of Scientific and Technical Information of China (English)

    付尧; 张松; 吴燕平; 邓朝勇

    2013-01-01

    元素掺杂可以提升MgB2在磁场中的性能,解决其超导性能在磁场环境下的退化问题,对MgB2超导材料的应用具有重大意义.介绍了元素掺杂MgB2的目的及作用机理,从薄膜、块材、线带材3个方面具体综述了纳米SiC和有机物掺杂MgB2超导体的研究进展,系统总结了烧结温度及有机物掺杂量对MgB2超导体的性能影响,深入分析了有机物掺杂改善MgB2超导性能的微观原因.

  8. Visible absorption spectroscopy of the B 2A1-X 2B2 transition of fluoroformyloxyl radical, FC(O)O

    Science.gov (United States)

    Maricq, M. Matti; Szente, Joseph J.; Li, Z.; Francisco, Joseph S.

    1993-01-01

    We report the visible absorption spectrum of the fluoroformyloxyl radical. The spectrum is assigned to the B 2A1-X 2B2 transition in FC(O)O. The origin of the excitation spectrum is observed at 13 150 cm-1 (760 nm). Extensive progressions in the OCO bending mode of the B state, ν'3 = 610 cm-1, dominate the spectrum. Three other progressions are observed: the OCO wag mode, ν'6 = 840 cm-1; the CF stretching mode, ν'2 = 1110 cm-1; and the asymmetric CO stretching mode, ν'4 = 2820 cm-1. Two series of hot bands also appear in the spectrum. From these bands the frequency of the OCO bending mode, ν`3 = 520 cm-1, is assigned for ground state FC(O)O. The experimental spectrum is compared to the results of ab initio MO calculations. These include second-order Møller-Plesset perturbation theory (UMP2) and quadratic configuration interactions theory with single and double excitations (QCISD) for both the X 2B2 and B 2A1 states. The origin of the B 2A1-X 2B2 transition and the predicted vibrational frequencies are found to be in reasonable agreement with experiment.

  9. NASA Plum Brook's B-2 Test Facility: Thermal Vacuum and Propellant Test Facility

    Science.gov (United States)

    Kudlac, Maureen T.; Weaver, Harold F.; Cmar, Mark D.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Spacecraft Propulsion Research Facility, commonly referred to as B-2, is NASA's third largest thermal vacuum facility. It is the largest designed to store and transfer large quantities of liquid hydrogen and liquid oxygen, and is perfectly suited to support developmental testing of upper stage chemical propulsion systems as well as fully integrated stages. The facility is also capable of providing thermal-vacuum simulation services to support testing of large lightweight structures, Cryogenic Fluid Management (CFM) systems, electric propulsion test programs, and other In-Space propulsion programs. A recently completed integrated system test demonstrated the refurbished thermal vacuum capabilities of the facility. The test used the modernized data acquisition and control system to monitor the facility. The heat sink provided a uniform temperature environment of approximately 77 K. The modernized infrared lamp array produced a nominal heat flux of 1.4 kW/sq m. With the lamp array and heat sink operating simultaneously, the thermal systems produced a heat flux pattern simulating radiation to space on one surface and solar exposure on the other surface.

  10. NASA Plum Brook's B-2 test facility-Thermal vacuum and propellant test facility

    Science.gov (United States)

    Kudlac, Maureen; Weaver, Harold; Cmar, Mark

    2012-06-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Spacecraft Propulsion Research Facility, commonly referred to as B-2, is NASA's third largest thermal vacuum facility. It is the largest designed to store and transfer large quantities of liquid hydrogen and liquid oxygen, and is perfectly suited to support developmental testing of upper stage chemical propulsion systems as well as fully integrated stages. The facility is also capable of providing thermal-vacuum simulation services to support testing of large lightweight structures, Cryogenic Fluid Management (CFM) systems, electric propulsion test programs, and other In-Space propulsion programs. A recently completed integrated system test demonstrated the refurbished thermal vacuum capabilities of the facility. The test used the modernized data acquisition and control system to monitor the facility. The heat sink provided a uniform temperature environment of approximately 77K. The modernized infrared lamp array produced a nominal heat flux of 1.4 kW/m2. With the lamp array and heat sink operating simultaneously, the thermal systems produced a heat flux pattern simulating radiation to space on one surface and solar exposure on the other surface.

  11. Origin of thickness dependent spin reorientation transition of B2 type FeCo alloy films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongyoo [Applied Materials Physics, Department of Materials Science and Engineering, Royal Institute of Technology, SE-10044 Stockholm (Sweden); Hong, Jisang [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2013-12-07

    We have investigated the origin of thickness dependent spin reorientation transition (SRT) of B2 type FeCo alloy using the full potential linearized augmented plane wave method. It has been reported that FeCo alloy films on various substrates show a SRT from perpendicular to in-plane magnetization at an approximate thickness of 15 monolayers (MLs). The enhanced perpendicular magnetic anisotropy in bulk FeCo is attributed to a tetragonal distortion. However, we have found that the tetragonal distortion tends to suppress the magnetocrystalline anisotropy (MCA) energy at increasing film thickness in two-dimensional structure. In contrast, the magnitude of the shape anisotropy energy increases at increasing FeCo film thickness. Interestingly, the shape anisotropy overcomes the MCA and the SRT, from perpendicular anisotropy to in-plane magnetization, which occurs at a thickness of 15 ML. Consequently, we are able to clearly understand the physical mechanism of the thickness dependent SRT in terms of the competing reactions of these two counteracting contributions.

  12. Molecular dynamics simulation of surface segregation in a (110) B2-NiAl thin film.

    Science.gov (United States)

    Levchenko, Elena V; Evteev, Alexander V; Kozubski, Rafal; Belova, Irina V; Murch, Graeme E

    2011-01-21

    Surface segregation in (110) B2-NiAl film approximately 3 nm thick is investigated by using molecular dynamics simulation with a reliable embedded-atom potential. The simulation is performed for the stoichiometric composition at a temperature of 1500 K, just below the melting temperature of the film model. It is found that the (110) surface is structurally stable but develops adatoms, vacancies and antisites. The coverage of an adatom layer is estimated to be ∼0.07 ML (monatomic layers) and it contains on average ∼95% of Al atoms. The top (surface) and second (subsurface) layers of the (110) surface is the most enriched in Ni relative to the bulk composition. These layers contain on average ∼51% of Ni atoms. The Ni fraction in the third and forth layers of the film is estimated as ∼50.5%. The deeper layers have essentially the bulk composition. Vacancies in the film model are found only on the Ni sublattice. The vacancy concentration on the Ni sublattice in the top layer is ∼7.5%. The second layer almost does not contain vacancies. The next layers have essentially the constant bulk vacancy composition which can be estimated as ∼1.3-1.4%. PMID:21079844

  13. Densification and dielectric properties of SrO–Al2O3–B2O3 ceramic bodies

    Indian Academy of Sciences (India)

    Doaa A Abdel Aziz; Shama E Ahmed

    2011-02-01

    The influence of SrO (0.0–5.0 wt%) on partial substitution of alpha alumina (corundum) in ceramic composition (95 Al2O3–5B2O3) have been studied by co-precipitated process and their phase composition, microstructure, microchemistry and microwave dielectric properties were studied. Phase composition was revealed by XRD, while microstructure andmicrochemistry were investigated by electron-probe microanalysis (EPMA). The dielectric properties by means of dielectric constant (r), quality factor ( × ) and temperature coefficient of resonant frequency (f) were measured in the microwave frequency region using a network analyser by the resonance method. The addition of B2O3 and SrO significantly reduced the sintering temperature of alumina ceramic bodies to 1600°C with optimum density (∼ 4 g/cm3) as compared with pure alumina powders recycled from Al dross (3.55 g/cm3 sintered at 1700°C). The sintered ceramic bodies show different ranges for the dielectric properties. Dielectric constant exists between 24 and 29, quality factor ( × ) is ranging between 15,236 and 22,020 GHz with a slight increase than those recorded with commercial alumina (10,000 – 20,000 GHz) and temperature coefficient of resonant frequency (f) in the –69 to –83 ppm/°C range. The addition of SrO up to 5 wt% leads to a maximum (r) value (29) due to relatively higher ionic polarizability of Sr2+ than that of the Al3+ and B3+ ions. On the other hand, changing chemical and phase composition with the formation of platelets of Sr-hexaluminate phase (SrAl12O19) results in maximizing value of ( × ) up to 22,020 GHz at ≈ 8 GHz and large negative charge of (f) to –83 ppm/°C.

  14. The angiotensin II type 1 receptor antagonist Losartan binds and activates bradykinin B2 receptor signaling

    DEFF Research Database (Denmark)

    Bonde, Marie Mi; Olsen, Kristine Boisen; Erikstrup, Niels;

    2011-01-01

    The angiotensin II type 1 receptor (AT1R) blocker (ARB) Losartan has cardioprotective effects during ischemia-reperfusion injury and inhibits reperfusion arrhythmias -effects that go beyond the benefits of lowering blood pressure. The renin-angiotensin and kallikrein-kinin systems are intricately...... connected and some of the cardioprotective effects of Losartan are abolished by blocking the bradykinin B2 receptor (B2R) signaling. In this study, we investigated the ability of six clinically available ARBs to specifically bind and activate the B2R. First, we investigated their ability to activate...... phosphoinositide (PI) hydrolysis in COS-7 cells transiently expressing the B2R. We found that only Losartan activated the B2R, working as a partial agonist compared to the endogenous ligand bradykinin. This effect was blocked by the B2R antagonist HOE 140. A competitive binding analysis revealed that Losartan does...

  15. A new therapeutic antibody masks ErbB2 to its partners.

    Science.gov (United States)

    Badache, Ali; Hynes, Nancy E

    2004-04-01

    In cancer cells, the ErbB2 receptor tyrosine kinase can be activated in two ways: by overexpression or by ligand-mediated stimulation of another ErbB receptor. The ErbB2-targeting antibody trastuzumab (Herceptin) is used for treatment of metastatic breast cancer patients whose tumors overexpress ErbB2. A new structural study in this issue of Cancer Cell reveals how targeting ErbB2 with another antibody, pertuzumab (Omnitarg), prevents ligand-induced dimerization of ErbB2 with the other ErbB receptors. Pertuzumab's novel mode of action might offer additional therapeutic opportunities for treatment of tumors expressing ligand-activated ErbB2. PMID:15093533

  16. B2B电子商务使用的研究综述

    Institute of Scientific and Technical Information of China (English)

    庞远超

    2011-01-01

    B2B电子商务是一种伴随着互联网技术发展起来的新型商务模式.本文从B2B电子商务的概念、B2B电子商务模式、企业对B2B电子商务的使用三个方面对以往研究B2B电子商务的文献进行整理和回顾。并在简要评价的基础上,并对下一步B2B电子商务的研究趋势进行了展望.

  17. Fast creation of dense MgB2 phase in wires made by IMD process

    Science.gov (United States)

    Kováč, P.; Hušek, I.; Melišek, T.; Kopera, L.; Kulich, M.

    2016-10-01

    Single-core MgB2 wires have been made by internal magnesium diffusion (IMD) into boron process. Heat treatments were performed at variable periods (4-90 min) for two adjusted temperatures 635 °C and 650 °C, with an overshoot of ≈20 °C after 5 min. Critical currents of differently treated MgB2/Ti/GlidCop wires have been measured and related with the MgB2 layers. The fast creation MgB2 compound has been observed after 8 min annealing at both temperatures and showing the critical current maxima. The less uniform MgB2 containing cracks was created for longer annealing periods (≥10 min), which resulted in lowered critical currents and worsened thermal stability. The fast creation of dense MgB2 allows it to utilize a continual and short heat treatment process for high current density wires made by IMD.

  18. Improvement of skin wound healing in diabetic mice by kinin B2 receptor blockade.

    Science.gov (United States)

    Desposito, Dorinne; Chollet, Catherine; Taveau, Christopher; Descamps, Vincent; Alhenc-Gelas, François; Roussel, Ronan; Bouby, Nadine; Waeckel, Ludovic

    2016-01-01

    Impaired skin wound healing is a major medical problem in diabetic subjects. Kinins exert a number of vascular and other actions limiting organ damage in ischaemia or diabetes, but their role in skin injury is unknown. We investigated, through pharmacological manipulation of bradykinin B1 and B2 receptors (B1R and B2R respectively), the role of kinins in wound healing in non-diabetic and diabetic mice. Using two mouse models of diabetes (streptozotocin-induced and db/db mice) and non-diabetic mice, we assessed the effect of kinin receptor activation or inhibition by subtype-selective pharmacological agonists (B1R and B2R) and antagonist (B2R) on healing of experimental skin wounds. We also studied effects of agonists and antagonist on keratinocytes and fibroblasts in vitro. Levels of Bdkrb1 (encoding B1R) and Bdkrb2 (encoding B2R) mRNAs increased 1-2-fold in healthy and wounded diabetic skin compared with in non-diabetic skin. Diabetes delayed wound healing. The B1R agonist had no effect on wound healing. In contrast, the B2R agonist impaired wound repair in both non-diabetic and diabetic mice, inducing skin disorganization and epidermis thickening. In vitro, B2R activation unbalanced fibroblast/keratinocyte proliferation and increased keratinocyte migration. These effects were abolished by co-administration of B2R antagonist. Interestingly, in the two mouse models of diabetes, the B2R antagonist administered alone normalized wound healing. This effect was associated with the induction of Ccl2 (encoding monocyte chemoattractant protein 1)/Tnf (encoding tumour necrosis factor α) mRNAs. Thus stimulation of kinin B2 receptor impairs skin wound healing in mice. B2R activation occurs in the diabetic skin and delays wound healing. B2R blockade improves skin wound healing in diabetic mice and is a potential therapeutic approach to diabetic ulcers.

  19. Assay of charge of Mg in MgB2 superconductor

    International Nuclear Information System (INIS)

    XPS studies of polycrystalline MgB2 sample have shown that the charge state of Mg is less than 2(+). We have performed TB-LMTO calculation for average charge of Mg 3s orbital in MgB2 and MgF2. We found that average charge of Mg3s orbital is 0.8 in MgB2 in conformity with XPS result. (author)

  20. A role of nesfatin-1/NucB2 in dehydration-induced anorexia.

    Science.gov (United States)

    Yoshimura, Mitsuhiro; Matsuura, Takanori; Ohkubo, Junichi; Maruyama, Takashi; Ishikura, Toru; Hashimoto, Hirofumi; Kakuma, Tetsuya; Mori, Masatomo; Ueta, Yoichi

    2014-07-15

    Nesfatin-1/NucB2, an anorexigenic molecule, is expressed mainly in the hypothalamus, particularly in the supraoptic nucleus (SON) and the paraventricular nucleus (PVN). Nesfatin-1/NucB2 is also expressed in the subfornical organ (SFO). Because the SON and PVN are involved in body fluid regulation, nesfatin-1/NucB2 may be involved in dehydration-induced anorexia. To clarify the effects of endogenous nesfatin-1/NucB2, we studied changes in nesfatin-1/NucB2 mRNA levels in the SFO, SON, and PVN in adult male Wistar rats after exposure to osmotic stimuli by using in situ hybridization histochemistry. Significant increases in nesfatin-1/NucB2 mRNA levels, ∼2- to 3-fold compared with control, were observed in the SFO, SON, and PVN following water deprivation for 48 h, consumption of 2% NaCl hypertonic saline in drinking water for 5 days, and polyethylene glycol-induced hypovolemia. In addition, nesfatin-1/NucB2 expression was increased in response to water deprivation in a time-dependent manner. These changes in nesfatin-1/NucB2 mRNA expression were positively correlated with plasma sodium concentration, plasma osmolality, and total protein levels in all of the examined nuclei. Immunohistochemistry for nesfatin-1/NucB2 revealed that nesfatin-1/NucB2 protein levels were also increased after 48 h of dehydration and attenuated by 24 h of rehydration. Moreover, intracerebroventricular administration of nesfatin-1/NucB2-neutralizing antibody after 48 h of water deprivation resulted in a significant increase in food intake compared with administration of vehicle alone. These results suggested that nesfatin-1/NucB2 is a crucial peptide in dehydration-induced anorexia.

  1. Preubiquitinated chimeric ErbB2 is constitutively endocytosed and subsequently degraded in lysosomes

    Energy Technology Data Exchange (ETDEWEB)

    Vuong, Tram Thu [Institute of Clinical Medicine, University of Oslo, Rikshospitalet, 0027 Oslo (Norway); Berger, Christian [Department of Pathology, Oslo University Hospital, Rikshospitalet, P.O. Box 4950 Nydalen, 0424 Oslo (Norway); Bertelsen, Vibeke; Rødland, Marianne Skeie [Institute of Clinical Medicine, University of Oslo, Rikshospitalet, 0027 Oslo (Norway); Stang, Espen [Department of Pathology, Oslo University Hospital, Rikshospitalet, P.O. Box 4950 Nydalen, 0424 Oslo (Norway); Madshus, Inger Helene, E-mail: i.h.madshus@medisin.uio.no [Institute of Clinical Medicine, University of Oslo, Rikshospitalet, 0027 Oslo (Norway); Department of Pathology, Oslo University Hospital, Rikshospitalet, P.O. Box 4950 Nydalen, 0424 Oslo (Norway)

    2013-02-01

    The oncoprotein ErbB2 is endocytosis-deficient, probably due to its interaction with Heat shock protein 90. We previously demonstrated that clathrin-dependent endocytosis of ErbB2 is induced upon incubation of cells with Ansamycin derivatives, such as geldanamycin and its derivative 17-AAG. Furthermore, we have previously demonstrated that a preubiquitinated chimeric EGFR (EGFR-Ub{sub 4}) is constitutively endocytosed in a clathrin-dependent manner. We now demonstrate that also an ErbB2-Ub{sub 4} chimera is endocytosed constitutively and clathrin-dependently. Upon expression, the ErbB2-Ub{sub 4} was further ubiquitinated, and by Western blotting, we demonstrated the formation of both Lys48-linked and Lys63-linked polyubiquitin chains. ErbB2-Ub{sub 4} was constitutively internalized and eventually sorted to late endosomes and lysosomes where the fusion protein was degraded. ErbB2-Ub{sub 4} was not cleaved prior to internalization. Interestingly, over-expression of Ubiquitin Interaction Motif-containing dominant negative fragments of the clathrin adaptor proteins epsin1 and Eps15 negatively affected endocytosis of ErbB2. Altogether, this argues that ubiquitination is sufficient to induce clathrin-mediated endocytosis and lysosomal degradation of the otherwise plasma membrane localized ErbB2. Also, it appears that C-terminal cleavage is not required for endocytosis. -- Highlights: ► A chimera containing ErbB2 and a tetra-Ubiquitin chain internalizes constitutively. ► Receptor fragmentation is not required for endocytosis of ErbB2. ► Ubiquitination is sufficient to induce endocytosis and degradation of ErbB2. ► ErbB2-Ub4 is internalized clathrin-dependently.

  2. 聪慧地拓展B2B的空间

    Institute of Scientific and Technical Information of China (English)

    郭凡生

    2007-01-01

    信息阻滞造成的浪费,是B2B(企业间商业机会)的浪费,但也正意味着B2B商务的机会。我相信,哪儿浪费最大,哪儿就能挣到钱,所以慧聪一直在千方百计地拓展B2B。

  3. 建立真正的B2B市场

    Institute of Scientific and Technical Information of China (English)

    GlennRamsdell

    2001-01-01

    两年前,B2B市场几乎还没有出现,人们连这方面的想法也没有。如今,成千上万的人要在网上建立B2B业务,而且几乎每天都有新的B2B交易问世,其中牵涉的不乏全球性大企业。

  4. 关于电子商务B2B分析研究

    Institute of Scientific and Technical Information of China (English)

    陈昊祺

    2012-01-01

      本文结合笔者多年实践工作经验,针对电子商务B2B模式进行详细阐述,首先从B2B模式的含义以及发展现状入手,探讨了B2B各项分类以及功能体现,与大家共同探讨。

  5. The efficiency of Flory approximation

    International Nuclear Information System (INIS)

    The Flory approximation for the self-avoiding chain problem is compared with a conventional perturbation theory expansion. While in perturbation theory each term is averaged over the unperturbed set of configurations, the Flory approximation is equivalent to the perturbation theory with the averaging over the stretched set of configurations. This imposes restrictions on the integration domain in higher order terms and they can be treated self-consistently. The accuracy δν/ν of Flory approximation for self-avoiding chain problems is estimated to be 2-5% for 1 < d < 4. (orig.)

  6. B2C电子商务服务质量评价研究%Research on Evaluation of Service Quality for B2C E-commerce

    Institute of Scientific and Technical Information of China (English)

    施国洪; 施钟贤

    2013-01-01

    After more than ten years of development, China's network shopping has begun to enter the relative mature stage. Because the current B2C mode of the electronic commerce development is particularly rapid and its market share increase year by year, e-commerce will become the core of the future development and the focus of theoretical research. Related research shows that traditional service quality evaluation models represented by SERVQUAL model for e-commerce service quality evaluation are lack of adequate reliability, so the evaluation research for B2C e-commerce service quality has to be further deepened. This article focuses on the current research on B2C e-commerce service quality. The characteristics and existing problems in these studies are summarized and the future development direction of the B2C e-commerce service quality research is pointed out , in order to improve the service quality and provide reference and help for B2C e-commerce enterprises.%经过十余年的发展,中国的网络购物已经开始步入相对成熟的阶段,当前以B2C模式的电子商务发展尤为迅速,市场份额逐年提高,必将成为未来电子商务发展的核心及理论研究的重点。相关研究表明,以SERVQUAL模型为代表的传统服务质量评价模型对于电子商务服务质量的评价缺乏足够的信度,因此对于B2C电子商务服务质量的评价研究也就有待进一步深化。本文对当前涉及B2C电子商务服务质量的相关研究进行了重点介绍,总结了这些研究的特点以及存在的问题,指出了今后B2C电子商务服务质量的研究需要发展的方向,以期为B2C电子商务企业提高服务质量提供借鉴和帮助。

  7. CHARACTERIZATION OF TiB2 COATING ADHERENCE BY A MULTI-PASS SCRATCH TESTING

    OpenAIRE

    YASAR TOTIK; ERSIN ARSLAN; IHSAN EFEOGLU; IRFAN KAYMAZ

    2009-01-01

    TiB2 films deposited using various deposition techniques are used to increase the wear lifetime of industrial components. The performance of TiB2 films is dependent on the coating–substrate adhesion. In this study, the fatigue behavior of TiB2 films was investigated using the multi-mode scratch method. Films of TiB2 were deposited on silicon wafers and AISI M2 steel substrates at different frequencies by pulsed-dc closed field unbalanced magnetron sputtering (CFUBMS). The microstructures of t...

  8. XPS studies of MgB2 superconductor for charge state of Mg

    International Nuclear Information System (INIS)

    X-ray photoelectron spectroscopic (XPS) studies have been carried out on polycrystalline MgB2 pellets. Characteristic Mg-2p and B-Is spectra have been analysed for extracting binding energies. There are evidences of MgB2 and formation of traces of metallic Mg, MgO and B2O3. Binding energy of Mg in MgB2 reveals its charge state to be less than 2(+) indicative of partial and not full charge transfer from Mg to B. (author)

  9. Study of preparation of TiB2 by TiC in Al melts

    International Nuclear Information System (INIS)

    TiB2 particles are prepared by TiC in Al melts and the characteristics of them are studied. It is found that TiC particles are unstable when boron exists in Al melts with high temperature and will transform to TiB2 and Al4C3. Most of the synthesized TiB2 particles are regular hexagonal prisms with submicron size. The diameter of the undersurfaces of these prisms is ranging from 200 nm to 1 μm and the height is ranging from 100 nm to 300 nm. It is considered that controlling the transformation from TiC to TiB2 is an effective method to prepare small and uniform TiB2 particles. - Highlights: ► TiC can easily transform into TiB2 in Al melts. ► TiB2 formed by TiC will grow into regular hexagonal prisms with submicron size. ► Controlling the transformation from TiC to TiB2 is an effective method to prepare small and uniform TiB2 particles.

  10. Antiaging Gene Klotho Regulates Adrenal CYP11B2 Expression and Aldosterone Synthesis.

    Science.gov (United States)

    Zhou, Xiaoli; Chen, Kai; Wang, Yongjun; Schuman, Mariano; Lei, Han; Sun, Zhongjie

    2016-06-01

    Deficiency of the antiaging gene Klotho (KL) induces renal damage and hypertension through unknown mechanisms. In this study, we assessed whether KL regulates expression of CYP11B2, a key rate-limiting enzyme in aldosterone synthesis, in adrenal glands. We found that haplodeficiency of KL(+/-) in mice increased the plasma level of aldosterone by 16 weeks of age, which coincided with spontaneous and persistent elevation of BP. Blockade of aldosterone actions by eplerenone reversed KL deficiency-induced hypertension and attenuated the kidney damage. Protein expression of CYP11B2 was upregulated in adrenal cortex of KL(+/-) mice. KL and CYP11B2 proteins colocalized in adrenal zona glomerulosa cells. Silencing of KL upregulated and overexpression of KL downregulated CYP11B2 expression in human adrenocortical cells. Notably, silencing of KL decreased expression of SF-1, a negative transcription factor of CYP11B2, but increased phosphorylation of ATF2, a positive transcription factor of CYP11B2, which may contribute to upregulation of CYP11B2 expression. Therefore, these results show that KL regulates adrenal CYP11B2 expression. KL deficiency-induced spontaneous hypertension and kidney damage may be partially attributed to the upregulation of CYP11B2 expression and aldosterone synthesis. PMID:26471128

  11. Acid Leaching of SHS Produced MgO/TiB2

    OpenAIRE

    Lok, Jonathan Y.

    2006-01-01

    The stoichiometric Self-propagating High-temperature Synthesis (SHS) thermite reaction involving magnesium oxide (MgO), titanium dioxide (TiO2), and boron oxide (B2O3) forms titanium diboride (TiB2) and MgO as final products. Selective acid leaching is used to remove the MgO leaving high purity TiB2 powder. The SHS method to produce TiB2 is attractive because of the relatively low temperature required to initiate the reaction, fast reaction time, and product purity. This study investigates th...

  12. 关注B2B服务的发展

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    12月7日,飞马旅参与主办的首届中国B2B服务峰会存上海举行。说起来B2B业务大家并不陌生。基本上属于公司间业务基本上都属于这个范畴。B2B服务与B2B一般业务最大的区别在哪儿呢?

  13. B2B企业市场调研的意义

    Institute of Scientific and Technical Information of China (English)

    蔺华

    2013-01-01

    什么是B2B企业?简单来讲,B2B就是企业与企业之间的各类商务活动,不与消费者直接进行的商务活动都可以归为B2B,向企业而非消费者出售产品或服务的企业称为B2B企业,

  14. B2B:登峰造极VS暮气沉沉

    Institute of Scientific and Technical Information of China (English)

    张洁; 顾卓

    2007-01-01

    @@ 说到中国的制造业就不得不说到中国的B2B,说到B2B就不得不说阿里巴巴.这个在马云带领下的B2B网站现在已成为公认的B2B老大,"打着灯笼也找不到竞争对手"的话也并非一时脑热的脱口而出.

  15. 从“雅蜂模式”谈B2B网站联盟

    Institute of Scientific and Technical Information of China (English)

    刘红梅

    2007-01-01

    在今年刚结束的首届“中国B2B联盟大会暨高峰论坛”上,中国首家全英文的国际贸易B2B垂直搜索引擎Yaphon雅蜂网正式宣告“雅蜂B2B网站联盟”成立,本文基于“雅蜂模式”探讨了B2B网站的联盟策略。

  16. Thermal Shock Resistance and Erosion Resistance of TiB2 Multiphase Ceramic Composites

    Institute of Scientific and Technical Information of China (English)

    HE Ping; WANG Weimin; DONG Yanling

    2006-01-01

    The thermal shock resistance and anti-aluminum erosion of TiB2-BN multiphase ceramics com posites were studied. The experimental results show that the TiB2-BN multiphase ceramic possesses a good thermal shock resistance at high temperatures ( 1000,1200,1400,1500 ℃ ), with the increasing in thermal shocking tem perature, the electro-conductivity of TiB2-BN ceramics increases. The metal aluminum has a great influence on the properties of TiB2- BN ceramics and the main reason is that the aluminum reacts seriously with BN. It is suggested that the content of BN should be reduced to the greatest extent.

  17. MgB2材料在超导科学中的研究

    Institute of Scientific and Technical Information of China (English)

    吴尝

    2006-01-01

    2001年,具有39K超导转变温度的MgB2被发现,该发现在科技界引起极大关注.文章就近年来二硼化镁(MgB2)的晶体结构及超导原理,制备温度、压强、过量Mg对MgB2超导电性的影响,MgB2超导体的掺杂效应及制备等方面的研究进展作了阐述.

  18. Isotope Effect on Electron-Phonon Coupling in Multiband Superconductor MgB2

    Science.gov (United States)

    Mou, Daixiang; Taufour, Valentin; Wu, Yun; Huang, Lunan; Bud'Ko, Serguei; Canfield, Paul; Kaminski, Adam

    We systematically investigate the isotope effect of electron-phonon coupling in multi-band superconductor MgB2 by laser based Angle Resolved Photoemission Spectroscopy. The kink structure around 70 meV on two σ bands, which is caused by electron coupling to E2 g phonon mode, is shifted to higher binding energy in Mg10B2 than that in Mg11B2. The measured shifting energy of 3.5 meV is consistent with theoretical calculation based on harmonic phonon in MgB2. Our temperature dependent measurement also indicates the isotope effect of kink structure is not dependent on superconducting transition.

  19. Al-doped MgB2 materials studied using electron paramagnetic resonance and Raman spectroscopy

    Science.gov (United States)

    Bateni, Ali; Erdem, Emre; Repp, Sergej; Weber, Stefan; Somer, Mehmet

    2016-05-01

    Undoped and aluminum (Al) doped magnesium diboride (MgB2) samples were synthesized using a high-temperature solid-state synthesis method. The microscopic defect structures of Al-doped MgB2 samples were systematically investigated using X-ray powder diffraction, Raman spectroscopy, and electron paramagnetic resonance. It was found that Mg-vacancies are responsible for defect-induced peculiarities in MgB2. Above a certain level of Al doping, enhanced conductive properties of MgB2 disappear due to filling of vacancies or trapping of Al in Mg-related vacancy sites.

  20. Supercondcuting properties in MgB2/Fe wires prepared by PIT method

    Institute of Scientific and Technical Information of China (English)

    YAN Guo; FENG Yong; FU Baoquan; LIU Chunfang; JI Ping; ZHANG Pingxiang; ZHOU Lian

    2003-01-01

    The MgB2 formation was analyzed physically and chemically and the MgB2/Fe wires were fabricated by powder in tube (PIT) technology. The microstructureof MgB2 in wires was studied by the scanning electrical microscope (SEM), whichshows a good connection of grains and the size of MgB2 grain is 1-3μm. The results of Jc measured by the standard four probes method show that Jc value reaches 6.1×104 A/cm2 at 20 K in self field.

  1. Superconducting MgB2 flowers: growth mechanism and their superconducting properties

    Science.gov (United States)

    Seong, Won Kyung; Ranot, Mahipal; Lee, Ji Yeong; Yang, Cheol-Woong; Lee, Jae Hak; Oh, Young Hoon; Ahn, Jae-Pyoung; Kang, Won Nam

    2016-04-01

    We report for the first time the growth and the systematic study of the growth mechanism for flower-like MgB2 structures fabricated on the substrates for solid-state electronics by the hybrid physical-chemical vapor deposition (HPCVD) technique. The MgB2 flower has a width of 30 μm and a height of 10 μm. The superconductivity of MgB2 flowers was confirmed by a magnetization measurement, and the transition temperature is 39 K, which is comparable with high-quality bulk samples. The excellent current-carrying capability was demonstrated by MgB2 flowers. To understand the nucleation and growth mechanism of MgB2 flowers a very systematic study was performed by a high-resolution transmission electron microscope (HRTEM) and atom probe (AP) microscopy. The HRTEM revealed that the seed grain of a MgB2 flower has a [101¯0] direction, and the flower is composed of micro-columnar MgB2 grains having pyramidal tips and which are grown along the (0001) plane. A clear understanding of the growth mechanism for MgB2 flowers could lead to the growth of other low-dimensional MgB2 structures for superconducting electronic devices.

  2. Inhibition of ErbB-2 induces TFF3 downregulation in breast cancer cell lines.

    Science.gov (United States)

    Yue, Lu; Xiang, Jinyu; Shen, Zan; Wang, Zhihao; Yao, Yasai; Zhou, Quan; Ding, Aiping; Qiu, Wensheng

    2014-07-01

    ErbB-2 gene plays an important role in carcinoma formation whose overexpression was observed in many types of tumors, including breast cancer. Dysregulation of Trefoil factor 3 (TFF3), which is thought to function in the development and progression of breast cancer, was found to be upregulated in ErbB2-overexpressing breast cancers and cells. However, a putative interaction between ErbB-2 and TFF3 in breast cancer remains unknown. To determine whether TFF3 has an important role in breast tumor, its levels were measured by immunohistochemistry in 130 cases of breast infiltrating duct carcinoma and 30 cases of normal breast tissue with a specific monoclonal antibody raised against human TFF3. Patients who were positive for ErbB-2 also had high expression levels of TFF3 (p TFF3 by real-time polymerase chain reaction and Western blotting, respectively. Compared with the control groups, ErbB-2 mRNA expression was decreased in the Lenti-ShERBB2 infection group, and Western blotting indicated a concordant ErbB-2 protein reduction. On the other hand, TFF3 expression at both mRNA and protein levels was significantly downregulated by ErbB-2 silencing in SK-BR-3. These findings are a proof of the foundation for a certain relationships of ErbB-2 and TFF3, which may serve as novel therapeutic markers of ErbB2-overexpressing breast cancers in the future.

  3. The calculation of active Raman modes of -quartz crystal via density functional theory based on B3LYP Hamiltonian in 6–311+G(2d) basis set

    Indian Academy of Sciences (India)

    M Talebian; E Talebian; A Abdi

    2012-05-01

    We obtained an approximation of the force field of -quartz crystal using a new idea of applying density functional theory [J Purton, R Jones, C R A Catlow and M Leslie, Phys. Chem. Minerals 19, 392 (1993)]. Our calculations were based on B3LYP Hamiltonian [A N Lazarev and A P Mirgorodsky, Phys. Chem. Minerals 18, 231 (1991)] in 6−311+G(2d) basis set for H16Si7O6 cluster and included a unit cell of the lattice. The advantage of our method is the increase in the speed of calculations and the better adaption of simulation results with the experimental data.

  4. Binary nucleation beyond capillarity approximation

    NARCIS (Netherlands)

    Kalikmanov, V.I.

    2010-01-01

    Large discrepancies between binary classical nucleation theory (BCNT) and experiments result from adsorption effects and inability of BCNT, based on the phenomenological capillarity approximation, to treat small clusters. We propose a model aimed at eliminating both of these deficiencies. Adsorption

  5. Approximate Implicitization Using Linear Algebra

    Directory of Open Access Journals (Sweden)

    Oliver J. D. Barrowclough

    2012-01-01

    Full Text Available We consider a family of algorithms for approximate implicitization of rational parametric curves and surfaces. The main approximation tool in all of the approaches is the singular value decomposition, and they are therefore well suited to floating-point implementation in computer-aided geometric design (CAGD systems. We unify the approaches under the names of commonly known polynomial basis functions and consider various theoretical and practical aspects of the algorithms. We offer new methods for a least squares approach to approximate implicitization using orthogonal polynomials, which tend to be faster and more numerically stable than some existing algorithms. We propose several simple propositions relating the properties of the polynomial bases to their implicit approximation properties.

  6. Weighted approximation with varying weight

    CERN Document Server

    Totik, Vilmos

    1994-01-01

    A new construction is given for approximating a logarithmic potential by a discrete one. This yields a new approach to approximation with weighted polynomials of the form w"n"(" "= uppercase)P"n"(" "= uppercase). The new technique settles several open problems, and it leads to a simple proof for the strong asymptotics on some L p(uppercase) extremal problems on the real line with exponential weights, which, for the case p=2, are equivalent to power- type asymptotics for the leading coefficients of the corresponding orthogonal polynomials. The method is also modified toyield (in a sense) uniformly good approximation on the whole support. This allows one to deduce strong asymptotics in some L p(uppercase) extremal problems with varying weights. Applications are given, relating to fast decreasing polynomials, asymptotic behavior of orthogonal polynomials and multipoint Pade approximation. The approach is potential-theoretic, but the text is self-contained.

  7. Approximate maximizers of intricacy functionals

    CERN Document Server

    Buzzi, Jerome

    2009-01-01

    G. Edelman, O. Sporns, and G. Tononi introduced in theoretical biology the neural complexity of a family of random variables. This functional is a special case of intricacy, i.e., an average of the mutual information of subsystems whose weights have good mathematical properties. Moreover, its maximum value grows at a definite speed with the size of the system. In this work, we compute exactly this speed of growth by building "approximate maximizers" subject to an entropy condition. These approximate maximizers work simultaneously for all intricacies. We also establish some properties of arbitrary approximate maximizers, in particular the existence of a threshold in the size of subsystems of approximate maximizers: most smaller subsystems are almost equidistributed, most larger subsystems determine the full system. The main ideas are a random construction of almost maximizers with a high statistical symmetry and the consideration of entropy profiles, i.e., the average entropies of sub-systems of a given size. ...

  8. Reinforcement Learning via AIXI Approximation

    OpenAIRE

    Veness, Joel; Ng, Kee Siong; Hutter, Marcus; Silver, David

    2010-01-01

    This paper introduces a principled approach for the design of a scalable general reinforcement learning agent. This approach is based on a direct approximation of AIXI, a Bayesian optimality notion for general reinforcement learning agents. Previously, it has been unclear whether the theory of AIXI could motivate the design of practical algorithms. We answer this hitherto open question in the affirmative, by providing the first computationally feasible approximation to the AIXI agent. To deve...

  9. Binary nucleation beyond capillarity approximation

    OpenAIRE

    Kalikmanov, V.I.

    2010-01-01

    Large discrepancies between binary classical nucleation theory (BCNT) and experiments result from adsorption effects and inability of BCNT, based on the phenomenological capillarity approximation, to treat small clusters. We propose a model aimed at eliminating both of these deficiencies. Adsorption is taken into account within Gibbsian approximation. Binary clusters are treated by means of statistical-mechanical considerations: tracing out the molecular degrees of freedom of the more volatil...

  10. Geological studies of the COST No. B-3 Well, United States Mid-Atlantic continental slope area

    Science.gov (United States)

    Scholle, Peter A.

    1980-01-01

    The COST No. B-3 well is the first deep stratigraphic test to be drilled on the Continental Slope off the Eastern United States. The well was drilled in 2,686 ft (819 m) of water in the Baltimore Canyon trough area to a total depth of 15,820 ft (4,844 m) below the drill platform. It penetrated a section composed of mudstones, calcareous mudstones, and limestones of generally deep water origin to a depth of about 8.200 ft (2,500 m) below the drill floor. Light-colored, medium- to coarse-grained sandstones with intercalated gray and brown shales, micritic limestones, and minor coal and dolomite predominate from about 8,200 to 12,300 ft (2,500 to 3,750 m). From about 12,300 ft (3,750 m) to the bottom, the section consists of limestones (including oolitic and intraclastic grainstones) with interbedded fine-to medium-grained sandstones, dark-colored fissile shales, and numerous coal seams. Biostratigraphic examination has shown that the section down to approximately 6,000 ft (1,830 m) is Tertiary. The boundary between the Lower and Upper Cretaceous sections is placed between 8,600 and 9,200 ft (2,620 and 2,800 m) by various workers. Placement of the Jurassic-Cretaceous boundary shows an even greater range based on different organisms; it is placed variously between 12,250 and 13,450 ft (3,730 and 5,000 m). The oldest unit penetrated in the well is considered to be Upper Jurassic (Kimmeridgian) by some workers and Middle Jurassic (Callovian) by others. The Lower Cretaceous and Jurassic parts of the section represent nonmarine to shallow-marine shelf sedimentation. Upper Cretaceous and Tertiary units reflect generally deeper water conditions at the B-3 well site and show a general transition from deposition at shelf to slope water depths. Examination of cores, well cuttings, and electric logs indicates that potential hydrocarbon-reservoir units are present throughout the Jurassic and Cretaceous section. Porous and moderately permeable limestones and sandstones have been

  11. IAU 2015 Resolution B3 on Recommended Nominal Conversion Constants for Selected Solar and Planetary Properties

    CERN Document Server

    Mamajek, E E; Torres, G; Harmanec, P; Asplund, M; Bennett, P D; Capitaine, N; Christensen-Dalsgaard, J; Depagne, E; Folkner, W M; Haberreiter, M; Hekker, S; Hilton, J L; Kostov, V; Kurtz, D W; Laskar, J; Mason, B D; Milone, E F; Montgomery, M M; Richards, M T; Schou, J; Stewart, S G

    2015-01-01

    Astronomers commonly quote the properties of celestial objects in units of parameters for the Sun, Jupiter, or the Earth. The resolution presented here was proposed by the IAU Inter-Division Working Group on Nominal Units for Stellar and Planetary Astronomy and passed by the XXIXth IAU General Assembly in Honolulu. IAU 2015 Resolution B3 adopts a set of nominal solar, terrestrial, and jovian conversion constants for stellar and (exo)planetary astronomy which are defined to be exact SI values. While the nominal constants are based on current best estimates (CBEs; which have uncertainties, are not secularly constant, and are updated regularly using new observations), they should be interpreted as standard values and not as CBEs. IAU 2015 Resolution B3 adopts five solar conversion constants (nominal solar radius, nominal total solar irradiance, nominal solar luminosity, nominal solar effective temperature, and nominal solar mass parameter) and six planetary conversion constants (nominal terrestrial equatorial ra...

  12. Thermochemistry of organic reactions in microporous oxides by atomistic simulations: benchmarking against periodic B3LYP.

    Science.gov (United States)

    Bleken, Francesca; Svelle, Stian; Lillerud, Karl Petter; Olsbye, Unni; Arstad, Bjørnar; Swang, Ole

    2010-07-15

    The methylation of ethene by methyl chloride and methanol in the microporous materials SAPO-34 and SSZ-13 has been studied using different periodic atomistic modeling approaches based on density functional theory. The RPBE functional, which earlier has been used successfully in studies of surface reactions on metals, fails to yield a qualitatively correct description of the transition states under study. Employing B3LYP as functional gives results in line with experimental data: (1) Methanol is adsorbed more strongly than methyl chloride to the acid site. (2) The activation energies for the methylation of ethene are slightly lower for SSZ-13. Furthermore, the B3LYP activation energies are lower for methyl chloride than for methanol. PMID:20557090

  13. IAU 2015 Resolution B3 on Recommended Nominal Conversion Constants for Selected Solar and Planetary Properties

    DEFF Research Database (Denmark)

    Mamajek, E. E.; Prsa, A.; Torres, G.;

    2015-01-01

    , are not secularly constant, and are updated regularly using new observations), they should be interpreted as standard values and not as CBEs. IAU 2015 Resolution B3 adopts five solar conversion constants (nominal solar radius, nominal total solar irradiance, nominal solar luminosity, nominal solar effective...... Assembly in Honolulu. IAU 2015 Resolution B3 adopts a set of nominal solar, terrestrial, and jovian conversion constants for stellar and (exo)planetary astronomy which are defined to be exact SI values. While the nominal constants are based on current best estimates (CBEs; which have uncertainties...... temperature, and nominal solar mass parameter) and six planetary conversion constants (nominal terrestrial equatorial radius, nominal terrestrial polar radius, nominal jovian equatorial radius, nominal jovian polar radius, nominal terrestrial mass parameter, and nominal jovian mass parameter)....

  14. Electrospark deposition of Al2O3–TiB2/Ni composite-phase surface coatings on Cu–Cr–Zr alloy electrodes

    Directory of Open Access Journals (Sweden)

    Ping Luo

    2015-03-01

    Full Text Available To improve electrode life during the resistance spot welding of galvanized steel plates, an Al2O3–TiB2 composite coating was synthesized on the surfaces of spot-welding electrodes through an electrospark deposition process. The microstructure, elemental composition, phase structure, and mechanical properties of the coating were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and microhardness testing. It was found that extensive cracking occurred in the monolithic Al2O3–TiB2 coating and at the coating–electrode interface. When the Al2O3–TiB2 coating was deposited on electrodes precoated with Ni, the number of defects decreased significantly. Further, delamination did not occur, and fewer cracks were formed. The average hardness of the multilayered Al2O3–TiB2/Ni coating was approximately 2200 HV and higher than that of the monolithic Al2O3–TiB2 coating (1100 HV.

  15. Twisted inhomogeneous Diophantine approximation and badly approximable sets

    CERN Document Server

    Harrap, Stephen

    2010-01-01

    For any real pair i, j geq 0 with i+j=1 let Bad(i, j) denote the set of (i, j)-badly approximable pairs. That is, Bad(i, j) consists of irrational vectors x:=(x_1, x_2) in R^2 for which there exists a positive constant c(x) such that max {||qx_1||^(-i), ||qx_2||^(-j)} > c(x)/q for all q in N. Building on a result of Kurzweil, a new characterization of the set Bad(i, j) in terms of `well-approximable' vectors in the area of `twisted' inhomogeneous Diophantine approximation is established. In addition, it is shown that Bad^x(i, j), the `twisted' inhomogeneous analogue of Bad(i, j), has full Hausdorff dimension 2 when x is chosen from the set Bad(i, j).

  16. B3 and B9 huts at the Bronze Age settlement of Mursia (Pantelleria)

    OpenAIRE

    Matteo Cantisani

    2015-01-01

    The hut B3 and B9, located on the southwestern edge of Sector B of the prehistoric settlement of Mursia, identify frequent structural changes inside the residential unit. The huts are characterized by architectural components and floor plans typical of the early phase of this part of the settlement and show clear traces of continuous occupation in spite of the architectural rearrangement. The reconstruction of the stratigraphic sequence, the analysis of the formation processes of the material...

  17. Human infections caused by Brevibacterium casei, formerly CDC groups B-1 and B-3.

    OpenAIRE

    Gruner, E; Steigerwalt, A G; Hollis, D G; Weyant, R S; Weaver, R E; Moss, C W; M Daneshvar; J. M. Brown; Brenner, D J

    1994-01-01

    Forty-one clinical strains of CDC coryneform groups B-1 and B-3 were compared biochemically, by analysis of cell wall sugars, amino acids, and cellular fatty acids, and by DNA relatedness to the type strains of Brevibacterium casei, Brevibacterium epidermidis, and Brevibacterium linens. Twenty-two strains were shown to be B. casei, while five other strains formed a phenotypically inseparable genomospecies in the same genus. The remaining isolates were genetically heterogeneous, and most are p...

  18. Vibrational thermodynamics of Fe90Zr7B3 nanocrystalline alloy from nuclear inelastic scattering

    DEFF Research Database (Denmark)

    Stankov, S.; Miglierini, M.; Chumakov, A. I.;

    2010-01-01

    Recently we determined the iron-partial density of vibrational states (DOS) of nanocrystalline Fe(90)Zr(7)B(3) (Nanoperm), synthesized by crystallization of an amorphous precursor, for various stages of nanocrystallization separating the DOS of the nanograins from that of the interfaces [S. Stank......, vibrational entropy, and lattice specific heat as the material transforms from amorphous, through nanocrystalline, to fully crystallized state. The reported results shed new light on the previously observed anomalies in the vibrational thermodynamics of nanocrystalline materials....

  19. Major Persistent 5′ Terminally Deleted Coxsackievirus B3 Populations in Human Endomyocardial Tissues

    Science.gov (United States)

    Bouin, Alexis; Nguyen, Yohan; Wehbe, Michel; Renois, Fanny; Fornes, Paul; Bani-Sadr, Firouze; Metz, Damien

    2016-01-01

    We performed deep sequencing analysis of the enterovirus 5′ noncoding region in cardiac biopsies from a patient with dilated cardiomyopathy. Results displayed a mix of deleted and full-length coxsackievirus B3, characterized by a low viral RNA load (8.102 copies/μg of nucleic acids) and a low viral RNA positive-sense to RNA negative-sense ratio of 4.8. PMID:27434549

  20. B3A: Prompting Cooperation Among Rational Participants in P2P Bulk File Sharing Environments

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Peer-to-peer (P2P) file sharing systems assume that their users download files in proportion to their sharing. Unfortunately, users are unlikely to do so without an incentive mechanism. Previous solutions to the problem required some types of centralized control, which strays from the spirit of P2P to provide long-term incentives. This paper presents the balance-based bandwidth allocation, B3A, an incentive framework to inspire participants to share files. In the B3A framework, each peer keeps the differences between the amount of data it has received from each peer and the amount it has sent to that one. When receiving simultaneous requests from various peers, the peer prefers to allocate its limited upload bandwidth to those peers with larger differences. Therefore, the downloading bandwidth perceived by a peer is positively related to its contributions to others, consequently stimulating it to share more files. The B3A framework is fully decentralized, scalable, and secure.

  1. Theoretical study of B3-to-B1 phase transition in ZnS

    Science.gov (United States)

    Li, Qiang; Zhang, Rui; Lv, Tianquan; Cao, Qilong

    2016-10-01

    The pressure-induced phase transformation from B3 to B1 structures in ZnS using first-principle projector-augmented wave method is studied. To understand the nature and driving force behind the transition, the interesting properties in both phases, including enthalpy, phonon dispersion curves and elastic constants, are systematically investigated. The results show that the calculated transition pressure is within the range of 16.33 GPa to 19.04 GPa, which is in good agreement with the available experimental and theoretical data. The transition process can be viewed as the appearance and disappearance of very slight lattice distortion accompanied by the movement of Zn and S atoms along the [111] crystallographic axis. The physical driving force of the B3-B1 phase transition is confirmed to be a coupling effect between the mechanical instability of B3 phase under pressure and the softening acoustic phonon mode resulting from the pressure-induced lattice deformation. For B1 phase, it is further predicted that a new phase transition takes place at about 59.9 GPa.

  2. Effects of ZrB2 on substructure and wear properties of laser melted in situ ZrB2p/6061Al composites

    Science.gov (United States)

    Zeng, Yida; Chao, Yuhjin; Luo, Zhen; Cai, Yangchuan; Huang, Yongxian

    2016-03-01

    Aluminum matrix composites reinforced by in situ ZrB2 particles were successfully fabricated from an Al-KBF4-K2ZrF6 system via a direct melt reaction. A laser surface melting strategy is used to improve the surface strength of the in situ ZrB2p/6061Al composite, which includes a series of laser-melted composites with different laser power processed by a 2 kW YAG laser generator. XRD and EDS results demonstrated the existence of ZrB2 nanoparticles in the composite. After laser melting, the penetration depth of the molten pool increases with increasing power density. OM and SEM analysis indicate that the laser melting process yields narrower cellular spacing of the matrix and partly disperses the ZrB2 particle clusters. Compared with laser-melted matrix alloys, the crystal orientations near the melted layers edge of the composite are almost random due to heterogeneous nucleation in the melt and the pinning effect of laser-dispersed ZrB2 nanoparticles at the solidification front. Wear test results show that the laser melted layer performs better at wear resistance than both the substrate and the matrix AA6061 by measuring wear mass loss. Compared with composite samples prepared without laser melting, the wear mass loss of the laser melted composites decreased from 61 to 56 mg under a load of 98 N for 60 min.

  3. Procyanidin B3 prevents articular cartilage degeneration and heterotopic cartilage formation in a mouse surgical osteoarthritis model.

    Directory of Open Access Journals (Sweden)

    Hailati Aini

    Full Text Available Osteoarthritis (OA is a common disease in the elderly due to an imbalance in cartilage degradation and synthesis. Heterotopic ossification (HO occurs when ectopic masses of endochondral bone form within the soft tissues around the joints and is triggered by inflammation of the soft tissues. Procyanidin B3 (B3 is a procyanidin dimer that is widely studied due to its high abundance in the human diet and antioxidant activity. Here, we evaluated the role of B3 isolated from grape seeds in the maintenance of chondrocytes in vitro and in vivo. We observed that B3 inhibited H(2O(2-induced apoptosis in primary chondrocytes, suppressed H(2O(2- or IL-1ß-induced nitric oxide synthase (iNOS production, and prevented IL-1ß-induced suppression of chondrocyte differentiation marker gene expression in primary chondrocytes. Moreover, B3 treatment enhanced the early differentiation of ATDC5 cells. To examine whether B3 prevents cartilage destruction in vivo, OA was surgically induced in C57BL/6J mice followed by oral administration of B3 or vehicle control. Daily oral B3 administration protected articular cartilage from OA and prevented chondrocyte apoptosis in surgically-induced OA joints. Furthermore, B3 administration prevented heterotopic cartilage formation near the surgical region. iNOS protein expression was enhanced in the synovial tissues and the pseudocapsule around the surgical region in OA mice fed a control diet, but was reduced in mice that received B3. Together, these data indicated that in the OA model, B3 prevented OA progression and heterotopic cartilage formation, at least in a part through the suppression of iNOS. These results support the potential therapeutic benefits of B3 for treatment of human OA and heterotopic ossification.

  4. 7 CFR Exhibit B-3 to Subpart B of... - Letter for Notifying Applicants, Lender, Holders and Borrowers of Adverse Decisions Where the...

    Science.gov (United States)

    2010-01-01

    ... Farmer Program Primary Loan Servicing Actions) B Exhibit B-3 to Subpart B of Part 1900 Agriculture... GENERAL Adverse Decisions and Administrative Appeals Pt. 1900, Subpt. B, Exh. B-3 Exhibit B-3 to Subpart...

  5. Cyclin B2 and p53 control proper timing of centrosome separation

    NARCIS (Netherlands)

    Nam, H.J.; Deursen, J.M.A. van

    2014-01-01

    Cyclins B1 and B2 are frequently elevated in human cancers and are associated with tumour aggressiveness and poor clinical outcome; however, whether and how B-type cyclins drive tumorigenesis is unknown. Here we show that cyclin B1 and B2 transgenic mice are highly prone to tumours, including tumour

  6. A Decompositional Approach to Executing Quality Data Model Algorithms on the i2b2 Platform

    Science.gov (United States)

    Mo, Huan; Jiang, Guoqian; Pacheco, Jennifer A.; Kiefer, Richard; Rasmussen, Luke V.; Pathak, Jyotishman; Denny, Joshua C.; Thompson, William K.

    2016-01-01

    The Quality Data Model (QDM) is an established standard for representing electronic clinical quality measures on electronic health record (EHR) repositories. The Informatics for Integrated Biology and the Bedside (i2b2) is a widely used platform for implementing clinical data repositories. However, translation from QDM to i2b2 is challenging, since QDM allows for complex queries beyond the capability of single i2b2 messages. We have developed an approach to decompose complex QDM algorithms into workflows of single i2b2 messages, and execute them on the KNIME data analytics platform. Each workflow operation module is composed of parameter lists, a template for the i2b2 message, an mechanism to create parameter updates, and a web service call to i2b2. The communication between workflow modules relies on passing keys ofi2b2 result sets. As a demonstration of validity, we describe the implementation and execution of a type 2 diabetes mellitus phenotype algorithm against an i2b2 data repository. PMID:27570665

  7. Pair-Breaking Critical Current Density of Two-Band Superconductor MgB2

    Institute of Scientific and Technical Information of China (English)

    I.N. Askerzade

    2005-01-01

    Temperature dependence of the pair-breaking critical current density of MgB2, jd(T), is studied using a two-band Ginzburg-Landau theory. The results are shown to be in good agreement with experimental data for the superconducting magnesium diboride MgB2.

  8. Effects of Hf doping on magnetic properties of MgB2 superconductor

    International Nuclear Information System (INIS)

    Magnetisation and upper critical field measurements of hafnium doped MgB2 are presented. There is an increase in upper critical field and enhancement of critical current density in hafnium doped MgB2. The irreversibility line extracted from Jc shows an upward shift. The enhancement has been more than that by neon ion irradiation. (author)

  9. Formation of MgB2 at ambient temperature with an electrochemical process: a plausible mechanism

    International Nuclear Information System (INIS)

    The binary intermetallic MgB2 superconductor has been synthesized by many research groups. However, the mechanism of its formation is not clearly understood. In this communication, a comprehensive mechanism of the formation of MgB2 from Le Chatelier's principle of equilibrium reaction has been explained both for solid-state reaction and electrodeposition methods. (rapid communication)

  10. 17 CFR 270.24b-2 - Filing copies of sales literature.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Filing copies of sales literature. 270.24b-2 Section 270.24b-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... literature. Copies of material filed with the Commission for the sole purpose of complying with section...

  11. Conceptualizing B2C Businesses as a New Category of Services

    OpenAIRE

    Anil Pandya; Nikhilesh Dholakia

    2005-01-01

    Conceptualizing B2C businesses as an innovative class of technology-infused services yields insights into the factors that may lead to success or failure of such businesses. Drawing from services’ marketing literature and recent thinking on Internet service metrics, this paper presents a framework for analyzing B2C businesses.

  12. EphB2 in the Medial Prefrontal Cortex Regulates Vulnerability to Stress.

    Science.gov (United States)

    Zhang, Ruo-Xi; Han, Ying; Chen, Chen; Xu, Ling-Zhi; Li, Jia-Li; Chen, Na; Sun, Cheng-Yu; Chen, Wen-Hao; Zhu, Wei-Li; Shi, Jie; Lu, Lin

    2016-09-01

    The ephrin B2 (EphB2) receptor is a tyrosine kinase receptor that is associated with synaptic development and maturation. It has recently been implicated in cognitive deficits and anxiety. However, still unknown is the involvement of EphB2 in the vulnerability to stress. In the present study, we observed decreases in EphB2 levels and their downstream molecules in the medial prefrontal cortex (mPFC) but not in the orbitofrontal cortex (OFC) in mice that were susceptible to chronic social defeat stress. The activation of EphB2 receptors with EphrinB1-Fc in the mPFC produced stress-resistant and antidepressant-like behavioral effects in susceptible mice that lasted for at least 10 days. EphB2 receptor knockdown by short-hairpin RNA in the mPFC increased the susceptibility to stress and induced depressive-like behaviors in a subthreshold chronic social defeat stress paradigm. These behavioral effects were associated with changes in the phosphorylation of cofilin and membrane α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) trafficking and the expression of some synaptic proteins in the mPFC. We also found that EphB2 regulated stress-induced spine remodeling in the mPFC. Altogether, these results indicate that EphB2 is a critical regulator of stress vulnerability and might be a potential target for the treatment of depression. PMID:27103064

  13. A Decompositional Approach to Executing Quality Data Model Algorithms on the i2b2 Platform.

    Science.gov (United States)

    Mo, Huan; Jiang, Guoqian; Pacheco, Jennifer A; Kiefer, Richard; Rasmussen, Luke V; Pathak, Jyotishman; Denny, Joshua C; Thompson, William K

    2016-01-01

    The Quality Data Model (QDM) is an established standard for representing electronic clinical quality measures on electronic health record (EHR) repositories. The Informatics for Integrated Biology and the Bedside (i2b2) is a widely used platform for implementing clinical data repositories. However, translation from QDM to i2b2 is challenging, since QDM allows for complex queries beyond the capability of single i2b2 messages. We have developed an approach to decompose complex QDM algorithms into workflows of single i2b2 messages, and execute them on the KNIME data analytics platform. Each workflow operation module is composed of parameter lists, a template for the i2b2 message, an mechanism to create parameter updates, and a web service call to i2b2. The communication between workflow modules relies on passing keys ofi2b2 result sets. As a demonstration of validity, we describe the implementation and execution of a type 2 diabetes mellitus phenotype algorithm against an i2b2 data repository. PMID:27570665

  14. Combustion Synthesis and Densification of NiAl/TiB2 Composites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A suitable combustion synthesis and densification process was designed to fabricate dense NiAl/TiB2 composites from Ni-Al-Ti-B system. Combustion synthesis processing and microstructure characteristics of products were studied in detail.The results show that the amount of TiB2 ceramics has a great influence on the combustion synthesis processing and microstructure; with the increase of the amount of TiB2 ceramics, the combustion temperature and combustion velocity increase rapidly.The volume of synthesized products and the grain size of ceramics particle size are also affected by the amount of TiB2 ceramics.TiB2 ceramics fiber can be produced in this synthesis system.The dense NiAl/TiB2 composites with residual porosity of no more than 1% are fabricated by the combustion synthesis and hot pressing,the mechanical properties of the dense NiAl/TiB2 composites increase with increase of the amount of TiB2 ceramics.

  15. In situ epitaxial MgB2 thin films for superconducting electronics.

    Science.gov (United States)

    Zeng, Xianghui; Pogrebnyakov, Alexej V; Kotcharov, Armen; Jones, James E; Xi, X X; Lysczek, Eric M; Redwing, Joan M; Xu, Shengyong; Li, Qi; Lettieri, James; Schlom, Darrell G; Tian, Wei; Pan, Xiaoqing; Liu, Zi-Kui

    2002-09-01

    The newly discovered 39-K superconductor MgB2 holds great promise for superconducting electronics. Like the conventional superconductor Nb, MgB2 is a phonon-mediated superconductor, with a relatively long coherence length. These properties make the prospect of fabricating reproducible uniform Josephson junctions, the fundamental element of superconducting circuits, much more favourable for MgB2 than for high-temperature superconductors. The higher transition temperature and larger energy gap of MgB2 promise higher operating temperatures and potentially higher speeds than Nb-based integrated circuits. However, success in MgB2 Josephson junctions has been limited because of the lack of an adequate thin-film technology. Because a superconducting integrated circuit uses a multilayer of superconducting, insulating and resistive films, an in situ process in which MgB2 is formed directly on the substrate is desirable. Here we show that this can be achieved by hybrid physical-chemical vapour deposition. The epitaxially grown MgB2 films show a high transition temperature and low resistivity, comparable to the best bulk samples, and their surfaces are smooth. This advance removes a major barrier for superconducting electronics using MgB2.

  16. 22 CFR 9b.2 - Press correspondents employed by United States media organizations.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Press correspondents employed by United States media organizations. 9b.2 Section 9b.2 Foreign Relations DEPARTMENT OF STATE GENERAL REGULATIONS... employed by United States media organizations must: (a) Present to the Office of Press...

  17. Phonon density of states and phonon dispersion of superconducting MgB2

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    For the superconductor MgB2, we have calculated the phonon density of states (DOS), phonon dispersion and Eliashberg function throughout the Brillouin zone (BZ), using an empirical potential model. The calculated values are consistent with the theoretical and experimental values. The calculated results show our empirical potential model is available for MgB2.

  18. Wavelet Sparse Approximate Inverse Preconditioners

    Science.gov (United States)

    Chan, Tony F.; Tang, W.-P.; Wan, W. L.

    1996-01-01

    There is an increasing interest in using sparse approximate inverses as preconditioners for Krylov subspace iterative methods. Recent studies of Grote and Huckle and Chow and Saad also show that sparse approximate inverse preconditioner can be effective for a variety of matrices, e.g. Harwell-Boeing collections. Nonetheless a drawback is that it requires rapid decay of the inverse entries so that sparse approximate inverse is possible. However, for the class of matrices that, come from elliptic PDE problems, this assumption may not necessarily hold. Our main idea is to look for a basis, other than the standard one, such that a sparse representation of the inverse is feasible. A crucial observation is that the kind of matrices we are interested in typically have a piecewise smooth inverse. We exploit this fact, by applying wavelet techniques to construct a better sparse approximate inverse in the wavelet basis. We shall justify theoretically and numerically that our approach is effective for matrices with smooth inverse. We emphasize that in this paper we have only presented the idea of wavelet approximate inverses and demonstrated its potential but have not yet developed a highly refined and efficient algorithm.

  19. The structure of approximate groups

    CERN Document Server

    Breuillard, Emmanuel; Tao, Terence

    2011-01-01

    Let K >= 1 be a parameter. A K-approximate group is a finite set A in a (local) group which contains the identity, is symmetric, and such that A^2 is covered by K left translates of A. The main result of this paper is a qualitative description of approximate groups as being essentially finite-by-nilpotent, answering a conjecture of H. Helfgott and E. Lindenstrauss. This may be viewed as a generalisation of the Freiman-Ruzsa theorem on sets of small doubling in the integers to arbitrary groups. We begin by establishing a correspondence principle between approximate groups and locally compact (local) groups that allows us to recover many results recently established in a fundamental paper of Hrushovski. In particular we establish that approximate groups can be approximately modeled by Lie groups. To prove our main theorem we apply some additional arguments essentially due to Gleason. These arose in the solution of Hilbert's fifth problem in the 1950s. Applications of our main theorem include a finitary refineme...

  20. Relativistic regular approximations revisited: An infinite-order relativistic approximation

    International Nuclear Information System (INIS)

    The concept of the regular approximation is presented as the neglect of the energy dependence of the exact Foldy - Wouthuysen transformation of the Dirac Hamiltonian. Expansion of the normalization terms leads immediately to the zeroth-order regular approximation (ZORA) and first-order regular approximation (FORA) Hamiltonians as the zeroth- and first-order terms of the expansion. The expansion may be taken to infinite order by using an un-normalized Foldy - Wouthuysen transformation, which results in the ZORA Hamiltonian and a non-unit metric. This infinite-order regular approximation, IORA, has eigenvalues which differ from the Dirac eigenvalues by order E3/c4 for a hydrogen-like system, which is a considerable improvement over the ZORA eigenvalues, and similar to the non-variational FORA energies. A further perturbation analysis yields a third-order correction to the IORA energies, TIORA. Results are presented for several systems including the neutral U atom. The IORA eigenvalues for all but the 1s spinor of the neutral system are superior even to the scaled ZORA energies, which are exact for the hydrogenic system. The third-order correction reduces the IORA error for the inner orbitals to a very small fraction of the Dirac eigenvalue. copyright 1999 American Institute of Physics

  1. Optical spectroscopy and decoherence studies of Y b3 + :YAG at 968 nm

    Science.gov (United States)

    Böttger, Thomas; Thiel, C. W.; Cone, R. L.; Sun, Y.; Faraon, A.

    2016-07-01

    The 7/2 2F ↔ 5/2 2F optical transitions of Y b3 + doped into Y3A l5O12 (YAG) were studied for potential quantum information and photonic signal processing applications. Absorption and fluorescence spectroscopy located the energy levels of the ground >7/2 2F and excited 5/2 2F manifolds, allowing inconsistencies between previous assignments of crystal field splittings in the literature to be resolved. These measurements reveal an unusually large splitting between the first and second levels in both the ground and excited multiplets, potentially providing for reduced sensitivity to thermally induced decoherence and spin-lattice relaxation. Spectral hole burning through two-level saturation was observed, determining the excited state lifetime to be 860 μs and resolving ambiguities in previous fluorescence measurements that were caused by the large radiation trapping effects in this material. Optical decoherence measurements using two-pulse photon echoes gave a homogeneous linewidth of 18 kHz for an applied magnetic field of 1 T, narrowing to 5 kHz at 2.5 T. The observed decoherence was described by spectral diffusion attributed to Y b3 +- Y b3 + magnetic dipole interactions. Laser absorption determined an inhomogeneous linewidth of 3.6 GHz for this transition in this 0.05%-doped crystal, which is narrower than for any other rare-earth-ion transition previously studied in the YAG host. The temperature dependence of the transition energy and linewidth of the lowest 7/2 2F to lowest 5/2 2F transition centered at 968.571 nm measured from 4 K to 300 K was well described by phonon scattering at higher temperatures, with an additional anomalous linear temperature-dependent broadening at temperatures below 80 K. Two magnetically inequivalent subgroups of Y b3 + ions were identified when a magnetic field was applied along the axis, as expected for the D2 sites in the cubic symmetry crystal, with ground and excited state effective g -values of gg=3.40 (3.34) and ge=1.04 (2

  2. Downregulation of kinin B1 receptor function by B2 receptor heterodimerization and signaling.

    Science.gov (United States)

    Zhang, Xianming; Brovkovych, Viktor; Zhang, Yongkang; Tan, Fulong; Skidgel, Randal A

    2015-01-01

    Signaling through the G protein-coupled kinin receptors B1 (kB1R) and B2 (kB2R) plays a critical role in inflammatory responses mediated by activation of the kallikrein-kinin system. The kB2R is constitutively expressed and rapidly desensitized in response to agonist whereas kB1R expression is upregulated by inflammatory stimuli and it is resistant to internalization and desensitization. Here we show that the kB1R heterodimerizes with kB2Rs in co-transfected HEK293 cells and natively expressing endothelial cells, resulting in significant internalization and desensitization of the kB1R response in cells pre-treated with kB2R agonist. However, pre-treatment of cells with kB1R agonist did not affect subsequent kB2R responses. Agonists of other G protein-coupled receptors (thrombin, lysophosphatidic acid) had no effect on a subsequent kB1R response. The loss of kB1R response after pretreatment with kB2R agonist was partially reversed with kB2R mutant Y129S, which blocks kB2R signaling without affecting endocytosis, or T342A, which signals like wild type but is not endocytosed. Co-endocytosis of the kB1R with kB2R was dependent on β-arrestin and clathrin-coated pits but not caveolae. The sorting pathway of kB1R and kB2R after endocytosis differed as recycling of kB1R to the cell surface was much slower than that of kB2R. In cytokine-treated human lung microvascular endothelial cells, pre-treatment with kB2R agonist inhibited kB1R-mediated increase in transendothelial electrical resistance (TER) caused by kB1R stimulation (to generate nitric oxide) and blocked the profound drop in TER caused by kB1R activation in the presence of pyrogallol (a superoxide generator). Thus, kB1R function can be downregulated by kB2R co-endocytosis and signaling, suggesting new approaches to control kB1R signaling in pathological conditions. PMID:25289859

  3. MgB2 multifilamentary tapes: microstructure, chemical composition and superconducting properties

    Science.gov (United States)

    Birajdar, B.; Braccini, V.; Tumino, A.; Wenzel, T.; Eibl, O.; Grasso, G.

    2006-09-01

    Multifilamentary Ni-sheathed Cu-stabilized MgB2 tapes with a critical current density of 2.0 × 105 A cm-2 (at 20 K and 1 T) were prepared by a powder in tube technique, using pre-reacted MgB2 powders. The microstructure and chemical composition of the superconducting core and the MgB2-Ni interface were studied using SEM, EPMA and TEM. A quick, reliable and standard-less method of B quantification using SEM-EDX is established for the analysis of MgB2 wires and tapes. Carbon-contamination-free sample preparation was crucial for the analysis of boron. The typical size of MgB2 colonies, i.e. the arrangement of several well connected grains, in the MgB2 filaments was between 1 and 6 µm. The colonies are structurally well connected to each other, although sub-micrometre-sized voids are present. The B to Mg mole fraction ratio in the MgB2 colonies was found to be close to two and the O mole fraction is less than 1 at.%. The typical size of the MgB2 grains in the colonies is about 0.5-1 µm however, numerous grains of size 30-200 nm are also present. MgO precipitates of the size of 15-70 nm were found in the MgB2 grains. Long straight dislocations with a density of 1 × 1010 cm-2 are observed. Non-superconducting layers which appear as oxide layers in SEM and TEM samples were found on the surface of the MgB2 colonies and yield poor connectivity between the colonies. It is expected that these layers yield a significant reduction of the critical current density Jc. A 10 µm wide intermetallic reaction layer of B, Mg and Ni is formed at the MgB2-Ni interface. Reduction of the MgB2 grain size by milling of starting MgB2 powder and elimination of non-superconducting layers around MgB2 colonies could further enhance the critical current density because of improved pinning and connectivity between colonies.

  4. Consideration on Establishing B2C Countryside E-commerce Websites%建设B2C农村电子商务网站的分析

    Institute of Scientific and Technical Information of China (English)

    白东蕊

    2009-01-01

    本文从建设B2C农村电子商务网站的环境分析入手,提出发展农产品市场BtoC电子商务的条件,阐述了发展农产品电子商务的优势和劣势,提出了建设B2C农村电子商务网站应采取的具体措施.通过本文的研究.可以为建设农村B2C电子商务提供一定的可行性方案.

  5. B2B电子集市重构中国流通经济%Reconstruction of China's Retail Industry through B2B Marketplace

    Institute of Scientific and Technical Information of China (English)

    颜艳春

    2001-01-01

    @@ 自2000年4月美国NASDAQ股市狂跌以来,网络股票一直阴雨绵绵.很多DOTCOM公司 将会长期处于高危险的ILMI运行模式中(投资、烧钱、再投资,Invest,Lose Mo ney,Invest).曾几何时,网络股被炒得发烫.今天,从Boo.com公司的破产,I CP、B2C、B2B公司们的纷纷陨落,到B2C的业界翘楚Amazon.com遭到资本市场的棒 喝,曾经牛气冲天的Tom.com网站不得不裁掉近1/4的员工.真是此一时,彼一时 也.

  6. 新型金属间化合物MgB2超导材料%Novel Intermetallic Compound MgB2 Superconductor

    Institute of Scientific and Technical Information of China (English)

    朱祖昌

    2005-01-01

    2000年10月日本科学家发现了新型金属间化合物MgB2超导体,其超导转变温度Tc为39K,在非铜氧化物块状超导体中最高[1],具有广阔应用前景,MgB2的发现立即使其成为当前超导研究的新热点.本文侧重从材料角度论述MgB2的晶体结构、应用上的优点和主要制造方法.

  7. C-erbB-2 expression and benefit from adjuvant chemotherapy and radiotherapy of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Staal, O.; Sullivan, S.; Wingren, S.; Skoog, L.; Rutqvist, L.E.; Nordenskjoeld, B. [Karolinska Sjukhuset, Stockholm (Sweden); Carstensen, J.M. [Linkoeping Univ. (Sweden)

    1995-12-31

    Frozen tissue from primary tumours of 152 premenopausal breast cancer patients, who participated in a trial comparing radiotherapy with adjuvant chemotherapy (cyclophosphamide, methotrexate, 5-fluorouracil, CMF), was analysed for c-erbB-2 protein expression, measured by flow cytometry. The relative risk of distant recurrence or death in the chemotherapy group as compared with the radiotherapy group was 3.0 (95% confidence interval (CI) 1.1-7.8) for patients whose tumours showed high c-erbB-2 levels and 0.87 (95% CI 0.43-1.7) for those with tumours with low levels of c-erbB-2 protein. Patients with highly proliferative tumours that did not overexpress c-erbB-2 benefited most, in terms of survival, from CMF. In addition, we found an increased risk of locoregional recurrence for tumours overexpressing c-erbB-2 when radiotherapy was replaced by chemotherapy. (author).

  8. Consolidation of B4C-TaB2 eutectic composites by spark plasma sintering

    OpenAIRE

    Dmytro Demirskyi

    2015-01-01

    The in situ synthesis/consolidation of B4C-TaB2 eutectic composites by spark plasma sintering (SPS) is reported. The microstructure–property relations were determined for composites with the B4C-TaB2 eutectic composition as functions of TaB2 content, and TaB2-TaB2 interlamellar spacing. A clear maximum in fracture toughness was identified (∼4.5 MPa m1/2) for eutectic composites with interlamellar spacing between 0.9 and 1.1 μm. The composites with the hypereutectic composition of 40 mol.% TaB...

  9. Phase formation in the BaB2O4-BaF2 system

    Science.gov (United States)

    Bekker, T. B.; Fedorov, P. P.; Kokh, A. E.

    2012-07-01

    It is shown that the BaB2O4-BaF2 system is quasi-binary with the following eutectics coordinates: 760°C, 59 mol % BaF2, 41 mol % BaB2O4. Due to the intense pyrohydrolysis during the growth of β-BaB2O4 crystals from the 55.6 mol % BaB2O4-44.4 mol % BaF2 composition, the Ba5B4O11 compound is formed in the system. This process leads to the cocrystallization of the β-BaB2O4 and Ba5B4O11 phases and impedes the formation of high-quality crystals.

  10. Reactivity of carbides in synthesis of MgB 2 bulks

    Science.gov (United States)

    Yamamoto, Akiyasu; Shimoyama, Jun-ichi; Ueda, Shinya; Horii, Shigeru; Kishio, Kohji

    2006-10-01

    The reactivity of various carbides (B4C, Al4C3, SiC, TiC, ZrC, NbC, Mo2C, HfC and WC) with magnesium and boron in synthesis of MgB2 was systematically studied. Decreases in the a-axis length and transition temperature were observed in all the carbide doped MgB2 bulks, reflecting a certain amount of carbon substituted for boron site in MgB2. The reactivity of each carbide estimated by the carbon content in MgB2 was found to be different depending on the chemical stability. Our results suggest that carbon content in MgB2 lattice can be controlled to its optimal doping level by adjusting synthesis conditions and selection of doping reagents.

  11. Mechanical Properties and Microstructure of In Situ TiB2-7055 Composites

    Institute of Scientific and Technical Information of China (English)

    CHEN dong; LE Yong-kang; BAI Liang; MA Nai-heng; LI Xian-feng; WANG Hao-wei

    2006-01-01

    In order to fabricate a kind of high strength particulate reinforced aluminum-matrix composites, the high strength aluminum alloy 7055 was selected as a matrix. Composites reinforced with varying amounts of TiB2 particles were synthesized using the in situ method, and their mechanical properties and microstructure were analyzed. It is found that the in situ TiB2 particles sized from 50 to 400 nm uniformly disperse in the matrix. With the weight fraction of TiB2 particles increasing, the elastic modulus as well as the yield strength and the ultimate tensile strength increase, while the ductility decrease. The improvement of strength could be attributed to good bonding between TiB2 and the matrix, and also the TiB2 particles act as a barrier to dislocation.

  12. A New Method for Preparing Superconducting MgB2 Films from Diborane

    Institute of Scientific and Technical Information of China (English)

    王殿生; 傅兴华; 张正平; 杨健

    2002-01-01

    We report on a new preparation method for magnesium diboride (MgB2) films by chemical vapour deposition(CVD) from diborane (B2H6). It is a two-step ex situ approach, with the precursor boron films grown by CVD from B2H6 at 460°C, followed by a post-annealing process in magnesium (Mg) vapour at 830°C. The prepared MgB2 thin films on Al2O3 polycrystalline substrates have an onset transition temperature of 35K and a zeroresistance temperature of about 24K. Well-crystallized MgB2 grains have clearly been observed in the SEM images and confirmed by x-ray diffraction analysis. The advantages of the proposed method are the feasibility to prepare large-area superconducting films and the compatibility with semiconductor technology.

  13. Possible coexistence of superconductivity and magnetic order in NdPt2B2C

    Indian Academy of Sciences (India)

    S K Dhar; A D Chinchure; E Alleno; C Godart; L C Gupta; R Nagarajan

    2002-05-01

    Coexistence of superconductivity and magnetic order has been one of the exciting aspects of the quaternary borocarbide superconductors. So far, RNi2B2C (R=Tm, Er, Ho and Dy) are the only known magnetic superconductors in this family. Here, we present our resistivity, magnetization and heat capacity studies on NdPt2B2C (nominal composition, NdPt1.5Au0.6B2C and NdPt2.1B2.4C1.2). We find superconductivity in both samples with c,onset∼ 3 K. Bulk magnetic order is found to occur below 1.7 K. We suggest that NdPt2B2C is a possible magnetic superconductor.

  14. Approximating Graphic TSP by Matchings

    CERN Document Server

    Mömke, Tobias

    2011-01-01

    We present a framework for approximating the metric TSP based on a novel use of matchings. Traditionally, matchings have been used to add edges in order to make a given graph Eulerian, whereas our approach also allows for the removal of certain edges leading to a decreased cost. For the TSP on graphic metrics (graph-TSP), the approach yields a 1.461-approximation algorithm with respect to the Held-Karp lower bound. For graph-TSP restricted to a class of graphs that contains degree three bounded and claw-free graphs, we show that the integrality gap of the Held-Karp relaxation matches the conjectured ratio 4/3. The framework allows for generalizations in a natural way and also leads to a 1.586-approximation algorithm for the traveling salesman path problem on graphic metrics where the start and end vertices are prespecified.

  15. Approximation methods in probability theory

    CERN Document Server

    Čekanavičius, Vydas

    2016-01-01

    This book presents a wide range of well-known and less common methods used for estimating the accuracy of probabilistic approximations, including the Esseen type inversion formulas, the Stein method as well as the methods of convolutions and triangle function. Emphasising the correct usage of the methods presented, each step required for the proofs is examined in detail. As a result, this textbook provides valuable tools for proving approximation theorems. While Approximation Methods in Probability Theory will appeal to everyone interested in limit theorems of probability theory, the book is particularly aimed at graduate students who have completed a standard intermediate course in probability theory. Furthermore, experienced researchers wanting to enlarge their toolkit will also find this book useful.

  16. Reinforcement Learning via AIXI Approximation

    CERN Document Server

    Veness, Joel; Hutter, Marcus; Silver, David

    2010-01-01

    This paper introduces a principled approach for the design of a scalable general reinforcement learning agent. This approach is based on a direct approximation of AIXI, a Bayesian optimality notion for general reinforcement learning agents. Previously, it has been unclear whether the theory of AIXI could motivate the design of practical algorithms. We answer this hitherto open question in the affirmative, by providing the first computationally feasible approximation to the AIXI agent. To develop our approximation, we introduce a Monte Carlo Tree Search algorithm along with an agent-specific extension of the Context Tree Weighting algorithm. Empirically, we present a set of encouraging results on a number of stochastic, unknown, and partially observable domains.

  17. Concept Approximation between Fuzzy Ontologies

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Fuzzy ontologies are efficient tools to handle fuzzy and uncertain knowledge on the semantic web; but there are heterogeneity problems when gaining interoperability among different fuzzy ontologies. This paper uses concept approximation between fuzzy ontologies based on instances to solve the heterogeneity problems. It firstly proposes an instance selection technology based on instance clustering and weighting to unify the fuzzy interpretation of different ontologies and reduce the number of instances to increase the efficiency. Then the paper resolves the problem of computing the approximations of concepts into the problem of computing the least upper approximations of atom concepts. It optimizes the search strategies by extending atom concept sets and defining the least upper bounds of concepts to reduce the searching space of the problem. An efficient algorithm for searching the least upper bounds of concept is given.

  18. An Approximation Ratio for Biclustering

    OpenAIRE

    Puolamäki, Kai; Hanhijärvi, Sami; Garriga, Gemma C

    2007-01-01

    The problem of biclustering consists of the simultaneous clustering of rows and columns of a matrix such that each of the submatrices induced by a pair of row and column clusters is as uniform as possible. In this paper we approximate the optimal biclustering by applying one-way clustering algorithms independently on the rows and on the columns of the input matrix. We show that such a solution yields a worst-case approximation ratio of 1+sqrt(2) under L1-norm for 0-1 valued matrices, and of 2...

  19. An Approximation Ratio for Biclustering

    CERN Document Server

    Puolamäki, Kai; Garriga, Gemma C

    2007-01-01

    The problem of biclustering consists of the simultaneous clustering of rows and columns of a matrix such that each of the submatrices induced by a pair of row and column clusters is as uniform as possible. In this paper we approximate the optimal biclustering by applying one-way clustering algorithms independently on the rows and on the columns of the input matrix. We show that such a solution yields a worst-case approximation ratio of 1+sqrt(2) under L1-norm for 0-1 valued matrices, and of 2 under L2-norm for real valued matrices.

  20. On Logistics Mode of Enterprises with B2C E-commerce%B2C电子商务企业的物流模式研究

    Institute of Scientific and Technical Information of China (English)

    刘婵媛; 卢金鹏

    2005-01-01

    分析了B2C电子商务企业物流存在的主要问题,探讨了B2C企业物流管理急需创新的方向,着重阐述了适宜我国电子商务企业的几种物流配送模式.这对我国企业构建高效的、经济合理的、现代化的物流体系有着重要的意义.

  1. Research on e-commerce trust path B2C%B2C电子商务消费者信任路径研究

    Institute of Scientific and Technical Information of China (English)

    山崴

    2013-01-01

    电子商务网站消费者信任缺失问题已经成为阻碍网络时代商务活动的关键因素之一.本文通过对国内外已有研究进行归纳和总结,在分析B2C电子商务消费者信任研究内容的基础上,指出提高B2C电子商务消费者信任的具体路径.

  2. B2C电子商务发展策略研究%Research on B2C E-commerce Development Strategy

    Institute of Scientific and Technical Information of China (English)

    卢智慧

    2012-01-01

    20世纪90年代以来,电子商务得到了快速发展.近年来,我国的B2C电子商务在快速发展的同时,也存在着许多问题.对这些问题,我们必须采取有效措施加以解决,才能加快我国B2C电子商务的发展步伐.

  3. Social Media within a B2B context : A qualitative study about how industrial corporations can use social media to maintain B2B relationships

    OpenAIRE

    Andersén, Sophia; Bengtsson, Annie; Gilén, Sandra

    2014-01-01

    The last thirty years there has been a dramatic change in relationship marketing. The use of computers connected to the Internet at work places has increased over time and social media is widely used in marketing strategies. Social media is a new phenomenon to communicate with each other, it enables market information based on individual consumer’s experiences. Therefore managers are seeking a way to incorporate social media into their strategies, but this is more common within B2C than B2B. ...

  4. Some SEO Skills for Foreign Trade Enterprise' s B2C Website%实用外贸B2C网站SEO优化技巧

    Institute of Scientific and Technical Information of China (English)

    刘庆华

    2012-01-01

    B2C网站是未来外贸企业开展业务的一个方向,而SEO优化是企业B2C网站能否运营成功的基础.列举了一些SEO优化的实用技巧,主要包括:如何选择域名、如何设计网站框架、网站内容如何设计、网站搜索功能如何优化以及如何添加网站的外部链接等.

  5. Study on the Transport Properties of Superconductor MgB2%MgB2超导体输运特性的研究

    Institute of Scientific and Technical Information of China (English)

    王洪涛; 郑素燕

    2003-01-01

    文中对MgB2超导体的制备过程,对其同位素效应、电阻率、Ⅰ-Ⅴ曲线、热电势、电导涨落效应、能隙、霍尔效应、热重-差热分析实验等输运特性进行了较全面的综述,并讨论了在MgB2超导体基础上的元素替代效应.

  6. Tree wavelet approximations with applications

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    [1]Baraniuk, R. G., DeVore, R. A., Kyriazis, G., Yu, X. M., Near best tree approximation, Adv. Comput. Math.,2002, 16: 357-373.[2]Cohen, A., Dahmen, W., Daubechies, I., DeVore, R., Tree approximation and optimal encoding, Appl. Comput.Harmonic Anal., 2001, 11: 192-226.[3]Dahmen, W., Schneider, R., Xu, Y., Nonlinear functionals of wavelet expansions-adaptive reconstruction and fast evaluation, Numer. Math., 2000, 86: 49-101.[4]DeVore, R. A., Nonlinear approximation, Acta Numer., 1998, 7: 51-150.[5]Davis, G., Mallat, S., Avellaneda, M., Adaptive greedy approximations, Const. Approx., 1997, 13: 57-98.[6]DeVore, R. A., Temlyakov, V. N., Some remarks on greedy algorithms, Adv. Comput. Math., 1996, 5: 173-187.[7]Kashin, B. S., Temlyakov, V. N., Best m-term approximations and the entropy of sets in the space L1, Mat.Zametki (in Russian), 1994, 56: 57-86.[8]Temlyakov, V. N., The best m-term approximation and greedy algorithms, Adv. Comput. Math., 1998, 8:249-265.[9]Temlyakov, V. N., Greedy algorithm and m-term trigonometric approximation, Constr. Approx., 1998, 14:569-587.[10]Hutchinson, J. E., Fractals and self similarity, Indiana. Univ. Math. J., 1981, 30: 713-747.[11]Binev, P., Dahmen, W., DeVore, R. A., Petruchev, P., Approximation classes for adaptive methods, Serdica Math.J., 2002, 28: 1001-1026.[12]Gilbarg, D., Trudinger, N. S., Elliptic Partial Differential Equations of Second Order, Berlin: Springer-Verlag,1983.[13]Ciarlet, P. G., The Finite Element Method for Elliptic Problems, New York: North Holland, 1978.[14]Birman, M. S., Solomiak, M. Z., Piecewise polynomial approximation of functions of the class Wαp, Math. Sb.,1967, 73: 295-317.[15]DeVore, R. A., Lorentz, G. G., Constructive Approximation, New York: Springer-Verlag, 1993.[16]DeVore, R. A., Popov, V., Interpolation of Besov spaces, Trans. Amer. Math. Soc., 1988, 305: 397-414.[17]Devore, R., Jawerth, B., Popov, V., Compression of wavelet decompositions, Amer. J. Math., 1992, 114: 737-785.[18]Storozhenko, E

  7. Signatures of spin-glass behaviour in PrIr2B2 and heavy fermion behaviour in PrIr2B2C.

    Science.gov (United States)

    Anupam; Anand, V K; Hossain, Z; Adroja, D T; Geibel, C

    2011-09-21

    The magnetic and transport properties of PrIr(2)B(2) and PrIr(2)B(2)C have been investigated by dc and ac magnetic susceptibility, specific heat, electrical resistivity and magnetoresistance measurements. PrIr(2)B(2) forms in CaRh(2)B(2)-type orthorhombic crystal structure (space group Fddd). At low fields the dc magnetic susceptibility of PrIr(2)B(2) exhibits a sharp anomaly near 46 K which is followed by an abrupt increase below 10 K with a peak at 6 K, and split-up in ZFC and FC data below 46 K. In contrast, the specific heat exhibits only a broad Schottky type hump near 9 K which indicates that there is no long range magnetic order in this compound. The thermo-remanent magnetization is found to decay very slowly with a mean relaxation time τ = 3917 s. An ac magnetic susceptibility measurement also observes two sharp anomalies; the peak positions strongly depend on the frequency and shift towards high temperature with an increase in frequency, obeying the Vogel-Fulcher law as expected for a canonical spin-glass system. The two spin-glass transitions occur at freezing temperatures T(f1) = 36 K and T(f2) = 3.5 K with shifts in the freezing temperatures per decade of frequency δT(f1) = 0.044 and δT(f2) = 0.09. An analysis of the frequency dependence of the transition temperature with critical slowing down, τ(max)/τ(0) = [(T(f)-T(SG))/T(SG)](-zν), gives τ(0) = 10(-7) s and exponent zν = 8, and the Vogel-Fulcher law gives an activation energy of 84 K for T(f1) and 27.5 K for T(f2). While zν = 8 is typical for spin-glass system, the characteristic relaxation time τ(0) = 10(-7) s is very large and comparable to that of superspin-glass systems. An addition of C in PrIr(2)B(2) leads to PrIr(2)B(2)C which forms in LuNi(2)B(2)C-type tetragonal structure (space group I4/mmm) and remains paramagnetic down to 2 K. The specific heat data show a broad Schottky type anomaly, which could be fairly reproduced with CEF analysis which suggests that the ground state is a

  8. Adoption of the B2SAFE EUDAT replication service by the EPOS community

    Science.gov (United States)

    Cacciari, Claudio; Fares, Massimo; Fiameni, Giuseppe; Michelini, Alberto; Danecek, Peter; Wittenburg, Peter

    2014-05-01

    B2SAFE is the EUDAT service for moving and replicating data between sites and storage systems for different purposes. The goal of B2SAFE is to keep the data from a repository safe by replicating it across different geographical and administrative zones according to a set of well-defined policies. It is also a way to store large volumes of data permanently at those sites which are providing powerful on-demand data analysis facilities. In particular, B2SAFE operates on the domain of registered data where data objects are referable via persistent identifiers (PIDs). B2SAFE is more than just copying data because the PIDs must be carefully managed when data objects are moved or replicated. The EUDAT B2SAFE Service offers functionality to replicate datasets across different data centres in a safe and efficient way while maintaining all information required to easily find and query information about the replica locations. The information about the replica locations and other important information is stored in PID records, each managed in separate administrative domains. The B2SAFE Service is implemented as an iRODS module providing a set of iRODS rules or policies to interface with the EPIC handle API and uses the iRODS middleware to replicate datasets from a source data (or community) centre to a destination data centre. The definition of the dataset(s) to replicate is flexible and up to the communities using the B2SAFE service. While the B2SAFE is internally using the EPIC handle API, communities have the choice to use any PID system they prefer to assign PIDs to their digital objects. A reference to one or more EUDAT B2SAFE PIDs is returned by the B2SAFE service when a dataset is replicated. The presentation will introduce the problem space of B2SAFE, presents the achievements that have been made during the last year for enabling communities to make use of the B2SAFE service, demonstrates a EPOS use cases, outlines the commonalities and differences between the policies

  9. Truthful approximations to range voting

    DEFF Research Database (Denmark)

    Filos-Ratsika, Aris; Miltersen, Peter Bro

    We consider the fundamental mechanism design problem of approximate social welfare maximization under general cardinal preferences on a finite number of alternatives and without money. The well-known range voting scheme can be thought of as a non-truthful mechanism for exact social welfare...

  10. Shearlets and Optimally Sparse Approximations

    DEFF Research Database (Denmark)

    Kutyniok, Gitta; Lemvig, Jakob; Lim, Wang-Q

    2012-01-01

    Multivariate functions are typically governed by anisotropic features such as edges in images or shock fronts in solutions of transport-dominated equations. One major goal both for the purpose of compression as well as for an efficient analysis is the provision of optimally sparse approximations...

  11. Approximate Reasoning with Fuzzy Booleans

    NARCIS (Netherlands)

    Broek, van den P.M.; Noppen, J.A.R.

    2004-01-01

    This paper introduces, in analogy to the concept of fuzzy numbers, the concept of fuzzy booleans, and examines approximate reasoning with the compositional rule of inference using fuzzy booleans. It is shown that each set of fuzzy rules is equivalent to a set of fuzzy rules with singleton crisp ante

  12. Analytical Approximations to Galaxy Clustering

    OpenAIRE

    Mo, H. J.

    1997-01-01

    We discuss some recent progress in constructing analytic approximations to the galaxy clustering. We show that successful models can be constructed for the clustering of both dark matter and dark matter haloes. Our understanding of galaxy clustering and galaxy biasing can be greatly enhanced by these models.

  13. Approximation properties of haplotype tagging

    Directory of Open Access Journals (Sweden)

    Dreiseitl Stephan

    2006-01-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs are locations at which the genomic sequences of population members differ. Since these differences are known to follow patterns, disease association studies are facilitated by identifying SNPs that allow the unique identification of such patterns. This process, known as haplotype tagging, is formulated as a combinatorial optimization problem and analyzed in terms of complexity and approximation properties. Results It is shown that the tagging problem is NP-hard but approximable within 1 + ln((n2 - n/2 for n haplotypes but not approximable within (1 - ε ln(n/2 for any ε > 0 unless NP ⊂ DTIME(nlog log n. A simple, very easily implementable algorithm that exhibits the above upper bound on solution quality is presented. This algorithm has running time O((2m - p + 1 ≤ O(m(n2 - n/2 where p ≤ min(n, m for n haplotypes of size m. As we show that the approximation bound is asymptotically tight, the algorithm presented is optimal with respect to this asymptotic bound. Conclusion The haplotype tagging problem is hard, but approachable with a fast, practical, and surprisingly simple algorithm that cannot be significantly improved upon on a single processor machine. Hence, significant improvement in computatational efforts expended can only be expected if the computational effort is distributed and done in parallel.

  14. Ultrafast Approximation for Phylogenetic Bootstrap

    NARCIS (Netherlands)

    Bui Quang Minh, [No Value; Nguyen, Thi; von Haeseler, Arndt

    2013-01-01

    Nonparametric bootstrap has been a widely used tool in phylogenetic analysis to assess the clade support of phylogenetic trees. However, with the rapidly growing amount of data, this task remains a computational bottleneck. Recently, approximation methods such as the RAxML rapid bootstrap (RBS) and

  15. Approximation by Penultimate Stable Laws

    NARCIS (Netherlands)

    L.F.M. de Haan (Laurens); L. Peng (Liang); H. Iglesias Pereira

    1997-01-01

    textabstractIn certain cases partial sums of i.i.d. random variables with finite variance are better approximated by a sequence of stable distributions with indices \\\\alpha_n \\\\to 2 than by a normal distribution. We discuss when this happens and how much the convergence rate can be improved by using

  16. Approximate Reanalysis in Topology Optimization

    DEFF Research Database (Denmark)

    Amir, Oded; Bendsøe, Martin P.; Sigmund, Ole

    2009-01-01

    In the nested approach to structural optimization, most of the computational effort is invested in the solution of the finite element analysis equations. In this study, the integration of an approximate reanalysis procedure into the framework of topology optimization of continuum structures...

  17. Endocytic down-regulation of ErbB2 is stimulated by cleavage of its C-terminus

    DEFF Research Database (Denmark)

    Lerdrup, Mads; Bruun, Silas; Grandal, Michael Vibo;

    2007-01-01

    protein (CFP) to the N- and C-terminus of ErbB2, respectively (YFP-ErbB2-CFP). After geldanamycin stimulation YFP-ErbB2-CFP became cleaved in nonapoptotic cells in a proteasome-dependent manner, and a markedly larger relative amount of cleaved YFP-ErbB2-CFP was observed in early endosomes than in the...

  18. Low Rank Approximation in $G_0W_0$ Approximation

    CERN Document Server

    Shao, Meiyue; Yang, Chao; Liu, Fang; da Jornada, Felipe H; Deslippe, Jack; Louie, Steven G

    2016-01-01

    The single particle energies obtained in a Kohn--Sham density functional theory (DFT) calculation are generally known to be poor approximations to electron excitation energies that are measured in transport, tunneling and spectroscopic experiments such as photo-emission spectroscopy. The correction to these energies can be obtained from the poles of a single particle Green's function derived from a many-body perturbation theory. From a computational perspective, the accuracy and efficiency of such an approach depends on how a self energy term that properly accounts for dynamic screening of electrons is approximated. The $G_0W_0$ approximation is a widely used technique in which the self energy is expressed as the convolution of a non-interacting Green's function ($G_0$) and a screened Coulomb interaction ($W_0$) in the frequency domain. The computational cost associated with such a convolution is high due to the high complexity of evaluating $W_0$ at multiple frequencies. In this paper, we discuss how the cos...

  19. Consolidation of B4C-TaB2 eutectic composites by spark plasma sintering

    Directory of Open Access Journals (Sweden)

    Dmytro Demirskyi

    2015-12-01

    Full Text Available The in situ synthesis/consolidation of B4C-TaB2 eutectic composites by spark plasma sintering (SPS is reported. The microstructure–property relations were determined for composites with the B4C-TaB2 eutectic composition as functions of TaB2 content, and TaB2-TaB2 interlamellar spacing. A clear maximum in fracture toughness was identified (∼4.5 MPa m1/2 for eutectic composites with interlamellar spacing between 0.9 and 1.1 μm. The composites with the hypereutectic composition of 40 mol.% TaB2 obtained by SPS exhibited lower Vickers hardness (25–26 GPa but higher indentation fracture toughness (up to 4.9 MPa m1/2 than eutectic composites with 30–35 mol.% of TaB2.

  20. Identification of novel nuclear localization signal within the ErbB-2 protein

    Institute of Scientific and Technical Information of China (English)

    Qiao Qiao CHEN; Xiao Ying CHEN; Yun Yun JIANG; Jing LIU

    2005-01-01

    ErbB2,a member of the receptor tyrosine kinase family,is frequently over-expressed in breast cancer.Proteolysis of the extracellular domain of ErbB2 results in constitutive activation of ErbB2 kinase.Recent study reported that ErbB2 is found in the nucleus.Here,we showed that ErbB2 is imported into the nucleus through a nuclear localization signal (NLS)-mediated mechanism.The NLS sequence KRRQQKIRKYTMRR (aa655-668) contains three clusters of basic amino acids and it is sufficient to target GFP into the nucleus.However,mutation in any basic amino acid cluster of this NLS sequence significantly affects its nuclear localization.Furthermore,it was found that this NLS is essential for the nuclear localization of ErbB2 since the intracellular domain of Erb2 lacking NLS completely abrogates its nuclear translocation.Taken together,our study identified a novel nuclear localization signal and reveals a novel mechanism underlying ErbB2 nuclear trafficking and localization.