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Physical aging in Zr_(4..75)Ti_(8.25)Cu_(7.5)Ni_(10)Be_(27.5) typical bulk metallic glass manifested as enthalpy relaxation

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Science China(Physics,Mechanics & Astronomy) 2008年第4期51卷 356-364页

作者： WEN Ping,ZHAO ZuoFeng & WANG WeiHua institute of Physics,chinese academy of {3.,{4. 100080,China institute of Physics Chinese Academy of Sciences Beijing China

Enthalpy recovery is not only an important characteristic of physical aging of glass,but also a good tool to investigate the physical aging. Using differential scanning calorimeter (DSC),the enthalpy recovery of Zr4..75Ti8.25Cu7.5Ni10Be27.5 bulk metallic glass (BMG) was studied. The typical characteristics of enthalpy recovery of glass including the sub-Tg peak and ‘overshot’ were found in BMG. The evolution of the sub-Tg peak and ‘overshot’ were described by the free volume theory and Hodge’s model,respectively. It was found that the former failed to describe the enthalpy recovery in the BMG,while the latter could give a qualitative explanation. In com-bination with the dynamics in the BMG,the origin of the enthalpy recovery in the BMG was discussed. The results show that BMGs are an ideal material to investi-gate the physical aging. The further understanding of physical aging of BMGs is useful to clarify the nature of glass and improve the application and device of new types of BMGs.

关键词： bulk metallic glass enthalpy recovery physical aging

Asymptotic behavior of the divergence on loop spaces over a compact Riemannian manifold

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chinese Science Bulletin 1998年第4期43卷 272-274页

作者： LI Xiangdong Probability Laboratory, institute of Applied Mathematics, chinese academy of sciences, beijing 100080, China Probability Laboratory Institute of Applied Mathematics Chinese Academy of Sciences Beijing China

The asymptotic behavior of the divergence on loop space is studied over a compact Riemannian manifold via quasi_sure analysis. A Sobolev estimate plays a crucial role.

关键词： divergence exponential integrability Sobolev estimate.

SYNTHESIS OF POLY(ETHYLENE TEREPHTHALATE)-POLYCAPROLACTONE BLOCK COPOLYMER BY DIRECT COPOLYMERIZATION

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chinese Journal of Polymer Science 1999年第3期17卷 231-235页

作者： Shen-guo Wang Kai Tang institute of Chemistry, chinese academy of sciences, beijing 100080, China 中科院化学所北京 100080 中科院化学所北京

Po ly(ethylene terephthalate)-polycaprolactone block copolymer (PCL-b-PET) is a polyester with improved biodegradability. In the present paper, a new direct copolymerization method of epsilon-caprolactone (epsilon-CL) and bishydroxyethylene terephthalate (BHET) in the presence of Ti(OBu)(4. was proposed for the synthesis of PCL-b-PET. The PCL-b-PET copolymer was characterized by IR, GPC and H-1-NMR techniques, and the effects of synthesis conditions, such as temperature, reaction time and concentration of catalyst on the copolymerization were discussed.

关键词： poly(ethylene terephthalate)-polycaprolactone block copolymer direct copolymerization biodegradable polymer

Linear relationship between the interdecadal and interannual variabilities of North China rainfall in rainy season

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chinese Science Bulletin 2003年第10期48卷 1040-1044页

作者： LU Riyu institute of Atmospheric Physics, chinese academy of sciences, beijing 100080, China institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100080 China

Interdecadal and interannual timescales are dominant in the North China rainfall in rainy season (July and August). On the interdecadal timescale, the North China rainfall exhibited an abrupt decrease at the end of 1970s. In this study, we examined the effect of this abrupt rainfall decrease on the association between rainfall and circulation on the interannual timescale, and found that the interdecadal variation does not change the physical mechanism responsible for the interannual variation of North China rainfall. There is a linear relationship between the interdecadal and interannual variabilities of North China rainfall in rainy season.

关键词：线性关系中国北部降雨量大气环流

Numerical Calculation of a Standing Soliton

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Communications in Nonlinear Science and Numerical Simulation 1999年第3期4卷 3-5页

作者： Xianchu ZHOU and Yi RUI(LNM institute of Mechanics, chinese academy of sciences, beijing 100080, China) LNM institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

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关键词： standing soliton cubic Schrodinger equation numerical simulation

Flow Instability and Its Control in Compression Systems

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Journal of Thermal Science 2003年第1期12卷 1-9页

作者： Jingyi Cheninstitute of Engineering Thermophysics, chinese academy of sciences, beijing 100080, China institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China

This paper reviews the development in the research of flow instability and its control over the recent ten or more years. This development was largely stimulated by the novel idea of active control of the aerodynamic instability in compressors. Three topics are covered in the paper, which appeared as the major themes towards the goal of stability enhancement. The first topic is the pre-stall behavior of rotating stall, which plays a vital role in designing the control scheme and discovering the convenient route to find the causal factors of flow disturbances potentially leading to stall. The second topic is the mechanism of blade passage flow during stall and its inception, which is the basic knowledge needed to manipulate the blade design for the stability improvement and eventually to predict the unsteady performance of the compressor system. The third topic is the recent trend of the control strategy based on the learning of active vs. passive methods. To introduce to the discussion of these topics, a brief description of the history of the recent development is given at the beginning of the paper. In discussing each topic, future works are also highlighted to enhance the further development of this long-standing problem in turbomachinery research and application.

关键词： compressors rotating stall pre-stall active/passive control wavelet.

REACTIONS OF PYRITE IN CATALYTICAL OXIDATION ACID LEACHING SYSTEM

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中国有色金属学会会刊：英文版 1995年第2期5卷 43-48页

作者： Xia, Guangxiang Tu, Taozhi Yang, Hanlin Shi, Wei(institute of Chemical Metallurgy, chinese academy of sciences, beijing 100080) chinese Acad of sciences Beijing China

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关键词： catalytic oxidation acidic leaching pyrite oxidation pretreatment

Quasi-Homeomorphisms and Measures of Finite Energy Integrals of Generalized Dirichlet Forms

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Acta Mathematica Sinica,English Series 2000年第2期16卷 325-336页

作者： Wei Sun institute of Applied Mathematics,chinese academy of {3.,{4.,100080,P.R.China institute of Applied Mathematics Chinese Academy of Sciences Beijing 100080 P. R. China

We introduce the quasi-homeomorphisms of generalized Dirichlet forms and prove that any quasi-regular generalized Dirichlet form is quasi-homeomorphic to a semi-regular generalized Dirichlet form. Moreover. we apply this quasi-homeomorphism method to study the measures of finite energy integrals of generalized Dirichlet forms. We show that any 1-coexcessive function which is dominated by a function in is associated with a measure of finite energy integral. Consequently, we prove that a Borel set B is-exceptional if and only if μ(B)=0 for any measure μ of finite energy integral.

关键词： Generalized Dirichlet form Quasi-homeomorphism Measure of finite energy integral

Geochemical characteristics of rare earth elements in Wuhan section of the Yangtze River

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Journal of Environmental sciences 1995年第1期7卷 44-51页

作者： Wang Lijun Zhang Shen Zhang Chaosheng(institute of Geography,chinese academy of {3.,{4. 100101,China)Li Xiuxia(institute of High Energy Physics,chinese academy of {3.,{4. 100080,China) Inst of Geog Chinese Academy of Sciences Beijing China China

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ＧｅｏｃｈｅｍｉｃａｌｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓｉｎＷｕｈａｎｓｅｃｔｉｏｎｏｆｔｈｅＹａｎｇｔｚｅＲｉｖｅｒＷａｎｇＬｉｊｕｎ；ＺｈａｎｇＳｈｅｎ；ＺｈａｎｇＣｈａｏｓｈｅｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＧｅｏ...

关键词： geochemical characteristics rare earth elements Yangtze River