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Deformation Twinning in Nanocrystalline Ni during Cryogenic Rolling

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Chinese Physics Letters 2006年第2期23卷 420-422页

作者：冯秀艳程志英周佳武晓雷王自强洪友士 State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Heijing 100080 Department of Materials Science Engineering Tsinghua University Heijing 100084

Deformation twinning is evidenced by transmission electron microscopy examinations in electrodeposited nanocrystalline （nc） Ni with mean grain size 25nm upon cryogenic rolling. Two twinning mechanisms are confirmed to operate in nc grains, i.e. heterogeneous formation via emission of partial dislocations from the grain boundary and homogeneous nucleation through dynamic overlapping of stacking faults, with the former being determined as the most proficient. Deformation twinning in nc Ni may be well interpreted in terms of molecular dynamics simulation based on generalized planar fault energy curves.

关键词： MOLECULAR-DYNAMICS SIMULATION MECHANICAL-PROPERTIES PLASTIC-DEFORMATION METALS AL COPPER NICKEL TWINS SLIP

PHYSIOLOGY OF WOODY PLANT UNDER SALT CONDITION

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Journal of Northeast Forestry University 1996年第1期7卷 1-6页

作者：马焕成 Expermental Center of Forestry Biology Beijing Forestry University Heijing China

Some advances in researches on the physiology of woody plants under salt condition are reviewed. The salt tolerant woody plants can be divided into two main groups. glycophytes and halophyes. They have different mechanisms for maintaining normal metabolism under salt condition. Halophytes usually are salt accumulators and glycophytes are salt excludors. However,the criteria for salt exclusion is not always coear. Although salt responses of different types of woody plants ard not the same some major changes are identilied identilied in net photosynthesis rate and in *** mechamsms are proved to be related to the salt resitance of woody plants(1) Regulation of ion intake;(2) avoidance of toxicity; (3) maintaining meinbrane mtegrity and (4) ion compartmentation. Currently,conventional plant breeding and bioteclogy are both used to improve salt tolerance of woody plant.

关键词： woody plant salt resistance salt response

Roles of computational auditory model in automatic speech recognition

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Progress in Natural Science:Materials International 2000年第12期 9-18页

作者：迟惠生吴玺宏 China heijing 100871 Peking University Slate Key Laboratory of Machine Perception

The development of computational auditory modeling in the last 30 years is reviewed, and its development in the coming years is predicted.

关键词： computational auditory model speech signal processing automatic speech recognition.

Polarographic immunoassay coupled with catalysis of non-radioactive multiple iodine label

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Science China Chemistry 1997年第5期40卷 457-463页

作者：宋俊峰白亚丽过玮贾晓琳 Institute of Electroanalytical Chemistry Northwest UniversityXi an 710069China Aerospace Central Hospital Heijing 100039China

A now polarographic immunoassay was developed In this assay,human serum albumin (HSA) as the model antigen was covalently labeled with organic compound erythrosin B(EB) containing four non-radioactive iodides through Ⅰ step chemical reaction The labeling procedure is simple and the conditions needed are *** molar labeling ratio of KB HSA was 12 Ⅰ The content of iodine in the conjugate obtained by the proposed procedure is ninth higher than that by the other existing methods.A heterogeneous competitive immunoassay was established by compling the catalysis of the conjugate to substrate As(Ⅲ)-Ce(Ⅳ) reaction with the linear-sweep polarographic detec-tion of As(Ⅲ) amount HSA can be determined in the HSA concentration range from 1 to 200μg/mL,with the de-tection hum of 0 66μg/ml.

关键词： HSA erythrosin B immunoassay catalysis linear-sweep polarography

An explicit criterion to determine the number of roots in an interval of a polynomial

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Progress in Natural Science:Materials International 2000年第12期 19-32页

作者：杨路夏壁灿 Chengdu 610041 Chengdu Institute of Computer Applications China Chinese Academy of Sciences heijing 100871 Peking University School of Mathematical Sciences

The negative root discriminant sequence (n.r.d.) for a given polynomial with general symbolic coefficients is a set of explicit expressions in terms of the coefficients that are sufficient for determining the number of distinel negative/positive roots and thus can be used to determine the number of mots in an interval of the given polynomial. Some interesting properties related to n.r.d. are studied.

关键词： real root polynomial discriminant sequence negative root discriminant sequence.

Paleornithology of China: A general review

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Chinese Science Bulletin 1999年第23期44卷 2113-2116页

作者： HOU Lianhai and ZHOU Zhonghe Institute of Vertebrate Paleontology and Paleoantfiropology, Chinese Academy of Sciences , heijing 100044, China Natural History Museum and Department of Ecology and Kvolut ionary Kiology , University of Kansas , Lawrence , KS 66045 , USA Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Heijing China Natural History Museum and Department of Ecology and and Evolutionary Biology University of Kansas Lawrence USA

Study of fossil birds in China was first conducted by western scholars in last century, and extensive study of Cenozoic birds by Chinese scholars since the 1970s. However, it is the finding of Mesozoic birds, mostly from northeast China since the 1990s, that has become the focus and highlight of paleornithology of China. Enantiornithine birds from the Late Jurassic-Early Cretaceous of China provide the most complete record of the early evolution of this

关键词： Mesozoic brids origin of brids origin of avian flight.

Bubble Behavior and Heat Transfer of Nucleate Pool Boiling on Micro-Pin-Finned Surface in Microgravity

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Chinese Physics Letters 2011年第1期28卷 160-163页

作者： WEI Jin-Jia XUE Yan-Fang ZHAO Jian-Fu LI Jing State Key Laboratory of Multiphase Flow in Power Engineering Xi 'an Jiaotong University Xi'an 710049 Key Laboratory of Microgravity (National Microgravity Laboratory)/CAS Institute of Mechanics Chinese Academy of Sciences Heijing 100190

Nucleate pool boiling on micro-pin-finned surface structure is proposed for efficiently cooling electronic compo- nents with high heat flux in microgravity, and was verified by experiments performed utilizing the drop tower Beijing. Micro-pin-fins with tile dimensions of 50 × （30 μm2 （thickness × height） and the space of 50 μm were fabricated on the chip surface by the dry etching technique. FC-72 was used as the working fluid. Nucleate pool boiling of FC-72 on a smooth surface was also tested for comparison. Unlike much obvious deterioration of heat transfer of nucleate pool boiling on the smooth surface in microgravity, constant heater surface temperature of nucleate pool boiling for the micro-pin-finned surface was observed, even though a large coalesced bubble completely covered the surface under microgravity condition. The performance of high efficient heat transfer on micro-pin-finned surface is independent of the gravity, which stems from the sufficient supply of fresh liquid to the heater surface due to the capillary forces.

关键词： Fluid dynamics Surfaces, interfaces and thin films

Saltation in wind blown sand

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Science China Mathematics 1998年第6期41卷 629-637页

作者：朱久江匡震邦邹学勇刘玉章 1. Institute of Mechanics Chinese Academy of Sciences 100080 Heijing China 2. Shanghai Jiaotong University 200240 Shanghai China 3. Institute of Desert Chinese Academy of Sciences 730000 Lnzhou China

The Boltzmann equation of the sand particle velocity distribution function in wind-blown sand two-phase flow is established based on the motion equation of single particle in air. And then, the generalized balance law of particle property in single phase granular flow is extended to gas-particle two-phase flow. The velocity distribution function of panicle phase is expanded into an infinite series by means of Grad’s method and the Gauss distribution is used to replace Maxwell distribution. In the case of truncation at the third-order terms, a closed third-order moment dynamical equation system is constructed. The theory is further simplified according to the measurement results obtained by stroboscopic photography in wind tunnel tests.

关键词： sallation blown sand turbulent boundary flow

Exceptional symmetric classical domains Ⅰ

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Progress in Natural Science:Materials International 1999年第5期 11-20页

作者：许以超 China Chinese Academy of Sciences heijing 100080 Institute of Mathematics

A new proof for the classification and realization of symmetric bounded domains is given, which does not use the classification result of real Riemannian symmetric spaces by K. Cart an. It is proved that any symmetric... 详细信息

关键词： Siegel domains symmetric spaces.