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Recrystallization Texture and Microstructure of Metal Substrate for Y123 Coated Superconductor

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Journal of Rare Earths 2003年第4期21卷 450-452页

作者：刘慧舟史锴杨坚袁冠森 Superconductivity Research Center

The cube textured pure Ni and non magnetic Cu Ni tapes were obtained by rolling and recrystallization, and these tapes are suitable as substrates of the second generation high temperature superconducting tape. The texture of tapes was studied using Orientation Distribution Function (ODF) and φ scans. The results indicate that sharp cube texture of Cu 0 70 Ni 0.30 and pure Ni was formed at 1000 ℃ and that of Cu 0 85 Ni 0.15 was formed at 900 ℃. The intensities of cube texture differ from each other. Uniform equiaxial crystallites are formed in all the tapes and the size of Cu 0.85 Ni 0.15 is larger than that of Cu 0.70 Ni 0.30 and pure Ni. Annealing twin is formed in Cu 0.85 Ni 0.15 and Cu 0.70 Ni 0.30 .

关键词： metal materials high temperature superconductor cube texture substrate twin rare earths

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类铍氧离子X射线及EUV光谱理论模拟

天文学报 2005年第2期46卷 151-157页

作者：梁雅琼仲佳勇中国科学院物理研究所北京100080 中国科学院国家天文台北京100012

根据非局域热动平衡状态下谱线形成理论,利用相对论多组态原子程序软件包FAC模拟了类铍氧离子的X射线及EUV光谱.分析了间接过程对类铍氧离子X射线及EUV光谱形成的影响.在典型天体等离子体密度(ne=1010/立方厘米)情况下,采用了3种模型,... 详细信息

根据非局域热动平衡状态下谱线形成理论,利用相对论多组态原子程序软件包FAC模拟了类铍氧离子的X射线及EUV光谱.分析了间接过程对类铍氧离子X射线及EUV光谱形成的影响.在典型天体等离子体密度(ne=1010/立方厘米)情况下,采用了3种模型,在不同温度下模拟X射线及EUV光谱形成过程,分析比较了间接过程对谱线形成的贡献,并给出了它们的速率系数,得出了在谱线形成过程中,间接过程具有非常重要的作用.

关键词：类铍氧离子 X射线 EUV光谱速率系数碰撞辐射模型复合系数

Superconductivity of(R_(0.4)Pr_(0.6))_(0.5)Ca_(0.5)Ba_(2)Cu_(3)O_(7-δ)(R=La,Pr,Nd,Sm,Eu,gd and Y)Prepared Under High Pressure

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Chinese Physics Letters 2001年第5期18卷 684-686页

作者： XIONg Han CHE guang-Can YAO Yu-Shu NI Yong-Ming LIU Zhen-Xing JIA Shun-Lian DONg Cheng ZHAO Zhong-Xian National Laboratory for Superconductivity Institute of Physics and Centre for Condensed Matter PhysicsChinese Academy of SciencesBeijing 100080

The nearly single phase(R_(0.4)Pr_(0.6))_(0.5)Ca_(0.5)Ba_(2)Cu_(3)O_(7-δ)compounds(R=La,Pr,Nd,Sm,Eu,gd and Y)with Tc about 100 K were prepared under high pressure and high temperature using the cubic anvil *** Tc is much higher than that of the traditional R-123 superconductors without doping Ca on the rare-earth *** various rare earths with different ionic radius,the(R_(0.4)Pr_(0.6))_(0.5)Ca_(0.5)Ba_(2)Cu_(3)O_(7-δ)compounds have almost the same critical *** is different from the result of the ion-size effect of rare-earth ions in R1-xPrxBa2Cu3O7-δ*** results show that Pr has the same properties as other rare earths in the 123-phase compounds due to the doping of Ca.

关键词： temperature. rare (0)

Bacterial community in sediment from the Western Pacific "Warm Pool" and its relationship to environment

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Science China Earth Sciences 2005年第2期48卷 282-290页

作者： ZENg Runying ZHAO Jing ZHANg Rui LIN Nianwei Key Laboratory of Marine Biotechnology Third Institute of OceanographyState Oceanic AdministrationXiamen361005China Key Laboratory of Marine BiotechnologyThird Institute of OceanographyState Oceanic AdministrationXiamen361005China Key Laboratory of Marine BiotechnologyThird Institute of OceanographyState Oceanic AdministrationXiamen361005China Key Laboratory of Marine BiotechnologyThird Institute of OceanographyState Oceanic AdministrationXiamen361005China

Total DNAs were extracted from different sections of deep sea sediment core sample collected from the Western Pacific "Warm Pool". The bacterial 16S ribosomal DNA (rDNA) clone libraries were constructed and analyzed by PCR-restriction fragment length polymorphism (RFLP) and DNA sequencing. The bacterial communities in these samples and their relationship to environment were analyzed consequently. The results indicated that among eight main bacterial groups found in these sediments, members of the γ-Proteobacteria were most abundant in each section of sediment core sample and the genus Colwellia belonging to γ-Proteobacteria was dominant in this area. Members of the α-Proteobacteria were found commonly existing in these samples, while members belonging to β-Proteobacteria were seldom detected. The diversity of bacterial communities from different sections of sediment core sample was δ- and ε-Proteo- bacteria and the bacterial group including genera Cytopahga, Flexibacteria and Bacteroides (CFB group). These bacteria all were inversely proportional to the depth of sediment. Phylogenetic analysis showed that there were 18%-30% and 15%-25% of total bacterial communities related to methane and sulfur metabolism respectively in each section of core sample, implicating that the metabolism of sulfur and methane played an important role in the substance and energy cycles of the Western Pacific "Warm Pool".

关键词： Western Pacific "Warm Pool", sediment, microbial diversity, carbon cycle, sulfur cycle.

Superconductivity of Nd_(1.85)Ce_(0.15)CuO_(4-y) by Electrochemical Oxidation

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Chinese Physics Letters 2000年第8期17卷 601-602页

作者： CHEN Ling CHE gUANg-CAN LI Hong DONg Cheng ZHOU Fang Huang Yu-zhen ZHAO Zhong-Xian National Laboratory for Superconductivity Institute of PhysicsChinese Academy of SciencesBeijing 100080 National Laboratory for Solid State Ionics Institute of PhysicsChinese Academy of SciencesBeijing 100080

Superconductivity of n-type superconductor Nd_(1.85)Ce_(0.15)CuO_(4-y)(NCCO)by electrochemical oxidation is re ported for the first time and the cyclic voltammogram curve for NCCO as working electrode is *** vestigations indicate that after oxidation,superconductivity of NCCO is improved:Tc is raised from 20 K up to 26 K,the superconducting volume fraction is increased *** valence electronic states of oxygen and copper in NCCO are studied by x-ray photoelectron *** is found that the Cu-2_(ps/2)peak shifts to the higher binding energy side about 0.4 e V,which indicates that the valence-state of copper ions is risen up after *** results imply that hole-carriers exist in n-type superconductor.

关键词： spectroscopy. copper Oxidation

A Study of the Energy Sources of Herbig-Haro Objects

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Chinese Journal of Astronomy and Astrophysics 2002年第1期2卷 33-42页

作者： Jing－Wen Yue－FangWu 等 DepartmentofAstronomy CAS－PKUJointBeijingAstrophysicsCenterPekingUniversityBeijing100871

We make a statistical study of the energy sources of high-velocity phenomena, Herbig-Haro (HH) objects. IRAS counterparts of HH objects are identified. Their colors, brightness, geometric relation to the RH objects and SED are analysed. The sources are found to be concentrated in a band-shaped region in the IRAS color-color diagram. We suggest an explanation of thick surrounding material for this distribution. We propose a new method for identifying the energy sources based on color arid brightness. This method is applied to more than 200 HR objects whose energy sources are still unknown. Finally, a group of very young stellar object candidates which have similar properties to the RH energy sources is picked out. Their large-scale distribution is discussed.

关键词： star: formation - ISM: Herbig-Haro objects - stars: pre-main- sequence

Extracting Local Schema from Semistructured Data Based on graph-Oriented Semantic Model

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Journal of Computer Science & Technology 2001年第6期16卷 560-566页

作者：王腾蛟唐世渭杨冬青刘云峰林斌 Department of Computer Science and Technology Peking University Beijing P.R. China National Laboratory on Machine Perception Peking University Beijing P.R. China

Many modern applications (e-commerce, digital library, etc.) require inte- grated access to various information sources (from traditional RDBMS to semistructured Web repositories). Extracting schema from semistructured data is a prerequisite to integrate hetero- geneous information sources. The traditional method that extracts global schema may require time (and space) to increase exponentially with the number of objects and edges in the source. A new method is presented in this paper, which is about extracting local schema. In this method, the algorithm controls the scale of extracting schema within the 'schema diameter' by examining the semantic distance of the target set and using the Hash class and its path distance operation. This method is very efficient for restraining schema from expanding. The prototype validates the new approach.

关键词： information integration data model semistructured data extracting schema

Coexistence of Ferromagnetism and Superconductivity in EuSr_(2)Ru_(1-x)Nb_(x)Cu_(2)O_(8)

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Chinese Physics Letters 2001年第7期18卷 963-966页

作者： FANg Ming-Bao FANg Ming-Hu XU Zheng JIAO Zheng-Kuan Department of Materials Science and Technology Tongji UniversityShanghai 200092 Department of Physics Zhejiang UniversityHangzhou 310027

The structural,magnetic and transport properties of EuSr_(2)Ru_(1-x)Nb_(x)Cu_(2)O_(8)(x=0,0.1,0.2 and 0.5)samples have been investigated by means of x-ray diffraction,magnetization and resistance *** is found that the EuSr_(2)Ru_(1-x)Nb_(x)Cu_(2)O_(8) compound exhibits a ferromagnetic order of the Ru moments below the Curie temperature 130.19 K,and becomes superconducting at a much lower critical temperature of 10 *** experimental observation that partial substitution of Nb for Ru in this system results in the decrease of the Curie temperature further supports the idea that the ferromagnetic order involves only Ru moments in this *** suggest that the decrease of the superconducting critical temperature Tc due to the partial substitution of Nb for Ru originates from the decrease of the carrier concentration in the CuO_(2) plane because of Nb existing always in the Nb5+valance state while Ru is in a mixted valance state between Ru4+and Ru5+.The coexistence of ferromagnetism and superconductivity is also discussed.

关键词： resistance ferromagnetic (x)

Information from the Kinematics of F and g Stars in the Solar Neighborhood

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Chinese Journal of Astronomy and Astrophysics 2002年第5期2卷 419-428页

作者： Yu-Qin Chen, gang Zhao and Jian-Rong ShiNational Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

We have calculated the orbital parameters for 90 stars in Chen et al. and updated the kinematic data for stars in Edvardsson et al. by using the accurate Hipparcos parallaxes and proper motions, and recalculated the α-element abundances in Edvardsson et al. in a way consistent with Chen et al. The two sets of data are combined in a study of stellar populations and characteristics of F & g stars in the solar neighborhood. We confirm the result of Chen et al. that a distinguishable group of stars may belong to the thick disk rather than the thin disk. The ages for the stars are determined using the theoretical isochrones of VandenBerg et al. The age-metallicity relation is investigated for different subgroups according to distance from the sun and galactic orbital parameters. It is found that a mixing of stars with different orbital parameters significantly affect the age-metallicity relation for the disk. Stars with orbits confined to the solar circle all have metallicities [Fe/H] > -0.3 irrespective of their distances from the sun or from the galactic plane.

关键词： stars: kinematics - galaxy: evolution - galaxy: solar neighborhood