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Microstructure of Pd_(77.5)Au_6Si_(16.5) Alloy Droplet Solidified in a Drop Tube Process

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Journal of Materials Science & Technology 1996年第5期12卷 385-388页

作者： Liling SUN Qi WU Liwei SUN and Wenkui WANG (institute of Physics, chinese academy of sciences, Beijing {2.,{3.) institute of Physics Chinese Academy of Sciences Beijing 100080 China

The microstructure development of Pd77.5Au6Si16.5 alloy droplet solidified in a drop tube process was studied. It was found that two distinct microstructures, i.e. (Pd,Au)3.i primary phase and Pd+(Pd,Au)3.i eutectic can be obtained when the droplet diameter is within the range between 2.3.0.4 mm. The morpologies of the (Pd,Au)3.i developed from dendrite trunk-like with single branching only into dendrite cluster-like with ternary branching with the decrease of the droplet diameter. When the droplet diameter is about 0.2. mm, the primary phase (Pd,Au)3.i almost disappears and the microstructure mainly shows Pd+(Pd,Au)3.i eutectic. The morphology of the eutectic transforms from fiber-like to plate-like with the decrease of the droplet diameter in the range between 2.3.0.2. mm. When the droplet diameter is about 0.19 mm, the microstructure is only the single phase of Pd solid solution

关键词： Microstructure of Pd Au6Si Alloy Droplet Solidified in a Drop Tube Process

The species diversity of fusulinaceans and high-frequency sea-level changes in the Carboniferous-Permian boundary section at Xikou, Zhen'an County,Shaanxi Province, china

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Science china Earth sciences 2006年第7期49卷 673-683页

作者： ZHANG Haijun1, WANG Xunlian2. DING Lin1, XIA Guoying3.& WANG Lei2.1. institute of Tibetan Plateau Research,{2., Beijing 100085, china 2. Faculty of Earth {3. and Mineral Resources, china University of Geo{3., Beijing 100083. china 3. Tianjin institute of Geology and Mineral Resources, Tianjin 3.0170, china 1. institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China 2. Faculty of Earth sciences and Mineral Resources China University of Geosciences Beijing 100083 China 3. Tianjin institute of Geology and Mineral Resources Tianjin 300170 China

The study on the interrelation between sea-level changes and biodiversity with its evolu-tion has great significance for understanding the impact of global changes on organic evolution and exploring the inherent laws of life-environment coevolution in geological history. In this paper, the stratigraphic distribution of fusulinacean fauna in the Carboniferous-Permian boundary section at Xikou, Zhen’an County, Shaanxi Province, is analyzed quantitatively, and the relationship between the species diversity of fusulinaceans and relative sea-level changes is discussed. As a whole, the spe-cies numbers of fusulinacean fauna experience a rapid increase and an obvious decline in Xikou, Zhen’an County, from the Late Carboniferous to the Early Permian. There is a significant increase in species diversity around the Carboniferous-Permian boundary, which is one of the biggest bio-events of the fusulinacean fauna, and represents the radiation of Pseudoschwagerininae subfamily in the studied area. Integrated fusulinacean species diversity into sequence stratigraphic framework, de-tailed study suggests that the species diversity of the fusulinaceans is closely related to its relative stratigraphic location, and is essentially controlled by the sea-level changes, especially by the high-frequency sea-level changes. Generally, the species diversity of fusulinaceans is low, and the number of first and last appearance datum is small in the lower unit of high-frequency depositional cycle formed during the quick rise of the sea level; whereas the species diversity of fusulinaceans is high, and the number of first and last appearance datum is large in the upper unit of high-frequency cycle formed during the slow fall of the sea level. Within the third-order depositional sequence, the species diversity of the fusulinaceans at the first flooding surfaces and the maximum flooding surfaces is low, and it increases upward. The fusulinacean species diversity is low within the transgressive syst

关键词： fusulinaceans, species diversity, high-frequency cyclothem, sequence stratigraphy, sea-level changes, Carboniferous-Permian boundary, Zhen'an, Shaanxi.

A quasi-local mass for 2.spheres with negative Gauss curvature

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Science china Mathematics 2008年第9期51卷 1644-1650页

作者： ZHANG Xiao institute of Mathematics, academy of Mathematics and Systems Science,{2., Beijing {3., china 1. institute of Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

We extend our previous definition of quasi-local mass to 2.spheres whose Gauss curvature is negative, and prove its positivity.

关键词： general relativity quasi-local mass positivity 53.2. 53.50 83.60

Accuracy of Multivariable Refinable Functions and Two-Scale Similarity Transform

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Acta Mathematica Sinica,English Series 2000年第2期16卷 271-276页

作者： Qiuhui Sheng Silong Peng institute of Mathematics,academy of Mathematics and Systems {2.,{3. academy of {2.,Beijing 100080,P.R.china institute of Mathematics Academy of Mathematics and Systems Sciences Chinese Academy of Sciences Beijing 100080 P. R. China

In this paper,we prove that if two multiresolutions satisfy a relation,then they have the same accuracy in the multivariate FSI case.

关键词： Accuracy Symbol function Two-scale similarity transform

SILICA-SUPPORTED NICKEL AND ZIRCONIUM CATALYSTS FOR BRANCHED POLYETHYLENE

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chinese Journal of Polymer Science 2003年第4期21卷 453-458页

作者：孙文华 State Key Laboratory of Engineering Plastics The Center for Molecular sciences institute of Chemistry {2. {3. of sciences Beijing 100080 china chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Engn Plast Beijing 100080 Peoples R China

8-Aminoquinoline nickel dichloride and bis(cyclopentadienyl)zirconium dichloride (Cp_2.rCl_2. were supportedsimultaneously on silica to produce branched polyethylene successfully by combined polymerization. The supportedpolymerization results showed that the molecular weight of polyethylene increased while the molecular weight distributionbecame wider and the molecular chains of oligomers remaning in the final solution became shorter as compared to theoligomers obtained in polymerization processes with pure 8-aminoquinoline nickel dichloride catalysis, as well as theCp_2.rCl_2.and nickel combination system. With decreasing amount of Ni catalyst in the supported catalyst, the molecular chains of oligomers in the resulting solution became shorter, while α-olefin selectivity increased.

关键词： 8-Aminoquinoline nickel dichloride, Cp_2.rCl_2 Silica supported catalysts Branched polyethylene

Parentage determination of an isolated Yangtze finless porpoise population Neophocaena phocaenoides asiaeorientalis in the Yangtze Tian-e-Zhou Baiji National Natural Reserve based on molecular data

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Progress in Natural Science:Materials International 2005年第2期15卷 54-61页

作者： XIA Junhong 1,2. ZHENG Jinsong 1,2. XU Limei 1,2.and WANG Ding1*(1. institute of Hydrobiology, chinese academy of sciences, Wuhan 4{2.072. china 2. Graduate School of the chinese academy of sciences, Beijing 1000{2., china) institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China. Graduate School of the chinese academy of sciences Beijing 100039 China

Reproductive behaviors are poorly known for the Yangtze finless porpoise Neophocaena phocaenoides asiaeorientalis. In this study, the parentage of an isolated Yangtze finless porpoise population inhabiting the Yangtze Tian-e-Zhou Baiji National Natural Reserve is determined by analysis of microsatellite loci and mitochondrial DNA (mtDNA) control region sequences, and the porpoise's reproductive behaviors are studied. Overall 4 full parentage assignments and additional 3.single parentage assignments were determined for the population of 2.0}individuals. The analysis shows that their estimated reproductive cycle is shorter than that reported previously and there probably exists an overlapping between gestation and lactation period. The study also shows that the female does not show fidelity to a particular male for breeding and vice versa, the oldest males did not monopolize mating and the dominance rank could not be so strict for the porpoise society. Moreover, the porpoise's mating pattern and relatedness among candidate parents are discussed here. These results provide important information for making guidelines of management and conservation for this protected population.

关键词： Yangtze finless porpoise isolated population reproductive behavior parentage

Preparation and Characterization of Ultrafine ZrO_2.Powders from Solvent Extraction of Zr(Ⅳ) with Tri-n-butyl Phosphate in Kerosene from Nitric Acid Solutions

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Journal of Materials Science & Technology 1996年第6期12卷 439-444页

作者： Chuanfang YANG and Jiayong CHEN (institute of Chemical Metallurgy, chinese academy of sciences, Beijing {2.,{3.)(To whom correspondence should be addressed) institute of Chemical Metallurgy Chinese Academy of Sciences Beijing 100080 China

Zr(IV) was extracted by tri-n-butyl phosphate in kerosene from concentrated nitric acid solutions and the formation of the third phase during extraction was experimentally investigated. Zirconia powders were prepared by using the loaded organic phase as the bulk solution precipitated with aqueous ammonia or NaOH solution. The powder prepared was characterized with TEM, XRD,EDAX and TG-DTA. Effects of some conditions on powder preparation were studied and it was shown that nanosized particles could be obtained from this extraction system but conditions should be carefully controlled for powder purity and particle size.

关键词： Zirconia

Study on the atmospheric photochemical reaction of CF_3.radicals using ultraviolet photoelectron and photoionization mass spectrometer

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Science china Chemistry 2008年第4期51卷 316-321页

作者： YAO Li1,2. DU Lin1,2. YIN Shi1,2.& GE MaoFa1 1 Beijing National Laboratory for Molecular sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, institute of Chemistry,{2., Beijing {3., china 2.Graduate University of{2., Beijing {3., china 1. Beijing National Laboratory for Molecular sciences (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China 2. Graduate University of chinese academy of sciences Beijing 100080 China

A study of the atmospheric photochemical reaction of CF3.radical with CO and O2.was performed by using a homemade ultraviolet photoelectron spectrometer-photoionization mass spectrometer (PES- PIMS). The electronic structures and mechanism of ionization and dissociation of CF3.C(O)OOC(O)- OCF3.were investigated. It was indicated that the two bands on the photoelectron spectrum of CF3.C(O)OOC(O)OCF3.are the result of ionization of an electron from a lone pair of oxygen and a fluo- rine lone pair of CF3.group. The outermost electrons reside in the oxygen lone pair. The experimental and theoretical first vertical ionization energy is 13.2. and 13.178 eV, respectively, with the PES and OVGF method. They are in good agreement. The photo ionization and dissociation processes were discussed with the help of theoretical calculations and PES-PIMS experiment. After ionization, the parent ions prefer the dissociation of the C-O bond and giving the fragments CF3.CO+ and CF3.. It demonstrated that the ultraviolet photoelectron and photoionization mass spectrometer could be ap- plied widely in the study of atmospheric photochemical reaction.

关键词： photochemical reaction CF3 radical ultraviolet photoelectron and photoionization mass spectroscopy transient species

Global analysis theory of climate system and its applications

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chinese Science Bulletin 2003年第10期48卷 1034-1039页

作者： LI Jianping1,2.& CHOU Jifan2.3.1. LASG, institute of Atmospheric Physics,{2., Beijing 10002., china 2. Department of Atmospheric {3., Lanzhou University, Lanzhou 73.000, china 3. Training Center for china Meteorological Administration, Beijing 100081, china Department of Atmospheric sciences Lanzhou University Lanzhou 730000 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The idea and main theoretical results of the global analysis theory of climate system are briefly summarized in this paper. A theorem on the global behavior of climate system is given, i.e. there exists a global attractor in the dynamical equations of climate, any state of climate system will be evolved into the global attractor as time increases, indicating the nonlinear adjustment process of climate system to external forcing. The different effects of external forcing, dissipation and nonlinearity on the long-term behavior of solutions are pointed out, and some main applications of the global analysis theory are also introduced. Especially, three applications, the adjustment and evolution processes of climate, the principle of numerical model design and the optimally numerical integration, are discussed.

关键词：整体分析理论气侯体系应用不定性计算法则气侯科学数字模型