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On Catastrophe and Cavitation for SphericalCavity

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Communications in Nonlinear Science and Numerical Simulation 1999年第4期4卷 249-254页

作者： Ming JIN Kefu HUANG Jike WU(department of Mechanics and Engineering Science, peking university,{2.,china) department of Mechanics and Engineering Science Peking University Beijing 100871 China

IntroductionInrecelltyears,theresearchesoncavitationandcatastropheofacavitysu***therwithbifllrcationtheory... 详细信息

IntroductionInrecelltyears,theresearchesoncavitationandcatastropheofacavitysu***therwithbifllrcationtheory...

关键词： nonlinearity bifurcation Hooke material

Enantioselective Addition of Diethylzinc to Benzaldehyde by Catalysts of Chiral Heterocyclic Ligands

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chinese Chemical Letters 1999年第9期10卷 717-718页

作者： Yan HE Yue Lan LI Ye Di GUAN(department of Chemistry, peking university,{2.) peking Univ Dept Chem Beijing 100871 Peoples R China

Several kinds of chiral heterocyclic ligands without hydroxyl group have been synthesized and used as catalysts for the asymmetric addition of diethylzinc to benzaldehyde. These ligands promoted the formation of (S)-1... 详细信息

关键词： chiral heterocyclic ligands hydroxyl group asymmetric catalysis enantioselectivity

Development of tourism resources and environment conservation in china: with special reference to Taishan Mountain

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Journal of Environmental Sciences 1991年第3期3卷 99-104页

作者： Liu Jihandepartment of Geography,peking {2.,beijing 100871,china

By analyzing the cases in Taishan Mountain, Shandong Province and other tourist sites in china, this paper pointed out the problems in tourism management, such as resources damage, environment pollution, which are the result of tourism development, and are obstacles to the development. The paper also gave suggestion and practical ways to preserve tourism resources and environment.

关键词： tourism resources environment conservation Taishan Mountain tourism development.

Deprotection of t-Butyldimethylsiloxy (TBDMS) Protecting Group with Catalytic Copper (II) Chloride Dihydrate

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chinese Chemical Letters 2000年第9期11卷 753-756页

作者： Zhong Ping TAN Lin WANG Jian Bo WANG department of Chemistry, peking university,{2. peking Univ Dept Chem Beijing 100871 Peoples R China

t-Butyldimethylsilyl (TBDMS) ether can be cleaved upon refluxing in acetone/H2. (95 : 5) in the presence of a catalytic amount of copper (II) chloride dihydrate (5 mmol %).

关键词： TBDMS ether deprotection copper (II) chloride dihydrate

On the boundary value problem for harmonic maps of the Poincaré disc

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chinese Science Bulletin 1997年第24期42卷 2025-2045页

作者： LI Zhongdepartment of Mathematics, peking university,{2., china department of Mathematics Peking University Beijing China

The boundary value problem for harmonic maps of the Poincare disc is discussed. The emphasis is on the non-smoothness of the given boundary values in the problem. Let T . be a subspace of the universal Teichmüller space, defined as a set of normalized quasisymmetric homeomorphisms h of the unit circle S onto itself where h admits a quasiconformal extension to the unit disc D with a complex dilatation μ satisfyingwhere ρ(z)|dz|2.is the Poincare metric of D. Let B . be a Banach space consisting of holomorphic quadratic differentials φ in D with normsIt is shown that for any given quasisymmetric homeomorphism h : S1→S1∈ T . , there is a unique quasiconformal harmonic map of D with respect to the Poincare metric whose boundary corresponding is h and the Hopf differential of such a harmonic map belongs to B .

关键词： Harmonic maps quasiconfomial mappings universal Teichmüller spaces.

The localization of 1-cohomology of transitive Lie algebroids

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Science china Mathematics 2006年第2期49卷 277-288页

作者： CHEN Zhuo & LIU Zhangju department of Mathematics, Capital Normal university, {2. 100037, china School of Mathematical Science, peking university, beijing 100871, china 1. department of Mathematics Capital Normal University Beijing 100037 China 2. School of Mathematical Science Peking University Beijing 100871 China

For a transitive Lie algebroid A on a connected manifold M and its representation on a vector bundle F, we define a morphism of cohomology groups rk: Hk(A,F) → Hk(Lx,Fx), called the localization map, where Lx is the adjoint algebra at x ∈ M. The main result in this paper is that if M is simply connected, or H (LX,FX) is trivial, then T is injective. This means that the Lie algebroid 1-cohomology is totally determined by the 1-cohomology of its adjoint Lie algebra in the above two cases.

关键词： transitive Lie algebroid representation cohomology localization.

Integrative inversion of land surface component temperature

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Science china Earth Sciences 2005年第11期48卷 2011-2019页

作者： FAN Wenjie1 & XU Xiru1,2.1. Institute of Remote Sensing and Geographical Information System, peking university, beijing 100871,{2.a 2. Center of Remote Sensing and GIS of beijing Normal university, beijing 100875,{2.a 1. Institute of Remote Sensing and Geographical Information System Peking University 100871 Beijing China 2. Center of Remote Sensing and GIS of beijing Normal university 100875 Beijing China

In this paper, the row winter wheat was selected as the example to study the com-ponent temperature inversion method of land surface target in detail. The result showed that the structural pattern of row crop can affect the inversion precision of component temperature evi-dently. Choosing appropriate structural pattern of row crop can improve the inversion precision significantly. The iterative method combining inverse matrix was a stable method that was fit for inversing component temperature of land surface target. The result of simulation and field ex-periment showed that the integrative method could remarkably improve the inversion accuracy of the lighted soil surface temperature and the top layer canopy temperature, and enhance inver-sion stability of components temperature. Just two parameters were sufficient for accurate at-mospheric correction of multi-angle and multi-spectral thermal infrared data: atmospheric trans-mittance and the atmospheric upwelling radiance. If the atmospheric parameters and component temperature can be inversed synchronously, the really and truly accurate atmospheric correction can be achieved. The validation using ATSRII data showed that the method was useful.

关键词： components temperature, inverse pattern, atmospheric correction

Improvement of Selectivity with Boric Acid in Separating Phenolic Acids by Capillary Zone Electrophoresis

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chinese Chemical Letters 1998年第1期9卷 87-91页

作者： Hong LONG Ai Jin HUANG Yi Liang SUN(department of Chemistry, peking university,{2.) peking Univ Dept Chem Beijing 100871 Peoples R China

It was shown that in capillary electrophoresis (CE) the addition of boric acid as a complexing agent in phosphate buffer can modulate the separation selectivity of phenolic acids.

关键词： capillary electrophoresis boric acid separation phenolic acid

SYNTHESIS AND BIOTECHNOLOGICAL APPLICATIONS OF VINYL POLYMERINORGANIC HYBRID AND MESOPOROUS MATERIALS

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chinese Journal of Polymer Science 2000年第1期18卷 1-7页

作者： Yen Wei Kun-yuan Qiu department of Chemistry, Drexel university, Philadelphia, Pennsylvania 19104, USA department of Polymer Science and Engineering, peking university, beijing 100871, china Drexel Univ Dept Chem Philadelphia PA 19104 USA peking Univ Dept Polymer Sci & Engn Beijing 100871 Peoples R China

We describe the sol-gel synthesis of a new family of organic-inorganic hybrid materials, in which various vinyl polymers are covalently bonded to and uniformly distributed in inorganic oxide matrices. The materials can be tailored to have both good toughness and hardness while maintaining excellent optical transparency. Doping the sol-gel metal oxides with optically active compounds such as D-glucose results in new optical rotatory composite materials. Removal of the dopant compounds from the composites affords mesoporous oxide materials; which represents a new, nonsurfactant-templated route to mesoporous molecular sieves. We have successfully immobilized a series of enzymes and other bioactive agents in mesoporous materials. Catalytical activities of the enzyme encapsulated in mesoporous materials were found to be much higher than those encapsulated in microporous materials.

关键词： vinyl polymer-inorganic hybrid materials mesoporous materials sol-gel process biotech-nological applications