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Tectonic Units and Their Fundamental Characteristics on the Northern Margin of the Alxa Block

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Acta Geologica Sinica(English Edition) 1993年第4期67卷 373-385页

作者： Wu Tairan geology department, china university of Geosciences, beijing and He Guoqi geology department, peking university Jiang Minxi geology department China University of Geosciences Beijing China

The northern margin of the Alxa block is the junction of a tectonic units. Four first-order tectonic units are distinguished: 1. the Yagan structural zone characteristic of an immature island arc; 2. the Zhusileng-Hangwula structural zone, which was a passive continental margin in the Early Palaeozoic and was transformed into an active continental margin in the Late Palaeozoic;3. the Shalazha structural zone characteristic of a mature island arc; 4. the Nuru-Langshan structural zone, which was a Proterozoic orogenic belt and later evolved into an extensional transtional crust in the Palaeozoic. The above-mentioned tectonic units differ remarkably in sedimentary formations, magmatic rock associations, metamorphism and geochemistry and are bounded by faults between one another.

关键词： Alxa structural zone boundary rock association

The effect of discharge conditions of ICP etching reactor on plasma parameters

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Acta Mechanica Sinica 2009年第6期25卷 769-776页

作者： Yijia Lu Yaosong Chen Yiran An LTCS, College of Engineering, peking university,100871 beijing, china LTCS College of Engineering Peking University Beijing China

This study investigated the inductively coupled plasma etching reactor and RF coils developed by North Microelectronic Corporation. Full three dimensional simulations were made at different discharge conditions. The simulations examined and compared the distribution and non-uniformity of several plasma parameters at a fixed position upon the wafer at different pressures and coil currents. These parameters included electron density, electron temperature and power deposition. The results demonstrate that the electron density, power deposition and uniformity increase with either higher pressure or stronger coil currents, while the electron temperature decreases at this condition. Coil number increase can reduce the non-uniformity of parameters in the spatial distribution. The linear relationship between power deposition and electron density does not always exist. The comparison between simulation results and experiment results is also presented in the paper.

关键词： Inductively coupled plasma. Electron densityElectron temperature ~ Power deposition - RF coils

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 university 美国北京大学高分子科学与工程系北京

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

New discrete element models for elastoplastic problems

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Acta Mechanica Sinica 2009年第5期25卷 629-637页

作者： Ming Cheng Weifu Liu Kaixin Liu LTCS and department of Mechanics and Aerospace Engineering,College of Engineering, peking university, 100871 beijing, china LTCS and department of Mechanics and Aerospace Engineering College of Engineering Peking University Beijing China

The discrete element method （DEM） has attractive features for problems with severe damages, but lack of theoretical basis for continua behavior especially for nonlinear behavior has seriously restricted its application. The present study proposes a new approach to developing the DEM as a general and robust technique for modeling the elastoplastic behavior of solid materials. New types of connective links between elements are proposed, the interelement parameters are theoretically determined based on the principle of energy equivalence and a yield criterion and a flow rule for DEM are given for describing nonlinear behavior of materials. Moreover, a numerical scheme, which can be applied to modeling the behavior of a continuum as well as the transformation from a continuum to a discontinuum, is obtained by introducing a fracture criterion and a contact model into the DEM. The elastoplastic stress wave propagations and the tensile failure process of a steel plate are simulated, and the numerical results agree well with those obtained from the finite element method （FEM） and corresponding experiment, and thus the accuracy and efficiency of the DEM scheme are demonstrated.

关键词： DEM Continuum Plasticity Fracture

Structural pattern of eastern Himalayan syntaxis in Namjagbarwa and its formation process

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Science china Earth Sciences 2004年第2期47卷 138-150页

作者： ZHANG Jinjiang, Jl Jianqing, ZHONG Dalai, DING Lin & HE Shundong1. department of geology, peking university, beijing 100871, china 2. Institute of geology and Geophysics, Chinese Academy of Sciences, beijing 100029, china Correspondence should be addressed to Zhang Jinjiang (email: zhjj@***) department of geology Peking University Beijing China Institute of geology and Geophysics Chinese Academy of Sciences Beijing China

The structural pattern of the eastern Himalayan syntaxis in Namjagbarwa consists of two series of structures with different styles. One series compiles the earlier ductile contractional and lateral-slip deformation system, formed by nearly north-south shortening within the syntaxis, left-lateral and right-lateral slipping along its western and eastern boundaries respectively. They were possibly produced by the indentation of the Indian continent into Asian continent after India-Asia collision. The peak deformation-metamorphic ages in these structures are 62-60 Ma, ~23 Ma and ~13 Ma. The other series is composed of ductile-brittle normal faults distributing concentrically and dipping toward the outsides of Namjagbarwa Peak. They were probably the collapse structures caused by rapid uplift in a later time and the beginning ages for the normal faulting are about 7.3-6.3 Ma. Keywords Namjagbarwa - eastern Himalayan syntaxis (EHS) - structural pattern - formation process - structural chronology

关键词： Namjagbarwa, eastern Himalayan syntaxis (EHS), structural pattern, formation process, structural chronology.

“LIVING”/CONTROLLED RADICAL POLYMERIZATION OF ETHYL METHYLACRYLATE WITH 2,2’-AZOBISISOBUTYRONITRILE/FERRIC CHLORIDE/TRIPHENYLPHOSPHINE INITIATION SYSTEM

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Chinese Journal of Polymer Science 2000年第2期18卷 149-153页

作者： Xiao-ping Chen Kun-yuan Qiu department of Polymer Science and Engineering, College of Chemistry, peking university, beijing 100871, china 北京大学北京

'Living'/controlled radical polymerization of ethyl methacrylate (EMA) was carried out with a 2,2'-azobisisobutyronitrile (AIBN)/ferric chloride (FeCl_3)/triphenylphosphine (PPh_3) initiation system at 85℃. Thc numberaverage molecular weight (M_n) increases linearly with monomer conversion and the rate of polymerization is first order withrespect to monomer concentration. The M_w of PEMA ranges from 3900 to 17600 and the polydispersity indices are quitenarrow (1.09～1.22). The conversion can reach up to～100% and M_w of the polymers obtained is close to that designed. Thepolymerization mechanism belongs to the reverse atom transfer radical polymerization (ATRP). The polymer was end-functionalized by chlorine atom, which acts as a macroinitiator to proceed extension polymerization in the presence ofCuBr/bipy catalyst system via an ATRP process. The presence of ω-chlorine in the PEMA obtained was identified by ~1H-NMR spectrum.

关键词： 'Living'/controlled radical polymerization Reverse ATRP Ethyl methacrylate AIBN/FeCl_3/PPh_3 Bulk polymerization

A　CONVENIENT　METHOD　FOR　SYNTHESIZING　AND　CHARACTERIZATION　OF　（Z）－ALKENOLS　AND　THEIR　ACETATES

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Chinese Chemical Letters 1995年第11期6卷 943-944页

作者： Gu YUAN(department of Chemistry,peking university, beijing 100871) beijing Univ Dept Chem Beijing 100871 Peoples R China

All double bond positional isomers of (Z)-dodecenol, (Z)-tetradecenol, (Z)hexadecenol and their acetates were synthesized by the Wittig reaction and the coupling reaction, and a novel procedure for the identification ...

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Burial Metamorphism of the Ordos Basin in Northern Shaanxi

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Acta Geologica Sinica(English Edition) 1993年第2期67卷 181-193,248-249页

作者： Zhang Lifei department of geology, peking university, beijing department of geology Peking University Beijing

Burial metamorphism has been found in the Ordos basin of northern Shaanxi. On the basis of a rather intensive study of burial metamorphism of sandstone, it has been shown that the evolution from diagenesis to metamorphism involves four stages: cementation of clay minerals, regrowth of pressolved quartz and feldspar, cementation of carbonates and formation of laumontite. On that basis it has been put forward that the laumontite is formed by burial metamorphism of clay and carbonate minerals. According to the thermodynamic data of minerals, the conditions under which laumontite is formed are T<250℃ and X_(CO_2)<0.17. High-resolution SEM and TEM studies of clay minerals in mudstone show that there occur a mixed layer assemblage of bertherine and illite/chlorite and transformation from bertherine to chlorite. On that basis coupled by the X-ray diffraction analysis the author suggests the following transformation of clay minerals during burial metamorphism: the earliest smectite-kaolinite assemblage changes into the bertherine-illite mixture with increasing depth, then into the illite/chlorite mixed layer assemblage and finally into dispersed individual illite and chlorite. The reaction of the transformation is:smectite+kaolinite+K^+=illite+chlorite+quartz According to the study of the oxygen isotope thermometry of the coexisting illitequartz pair, the temperature of the above transformation is lower than 180℃.

关键词： laumontite clay minerals burial metamorphism Ordos basin

Raising approximation order of refinable vector by increasing multiplicity

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Science china Mathematics 2006年第1期49卷 86-97页

作者： YANG Shouzhi & PENG Lizhong department of Mathematics, Shantou university, Shantou 515063, china LMAM, School of Mathematical Sciences, peking university, beijing 100871, china department of Mathematics Shantou University Shantou China LMAM School of Mathematical Sciences Peking University Beijing China

An algorithm is presented for raising an approximation order of any given orthogonal multiscaling function with the dilation factor a. Let φ(x) = [φ1(x),φ2(x),…,φr(x)]T be an orthogonal multiscaling function with the dilation factor a and the approximation order m. We can construct a new orthogonal multiscaling function φnew(x) = [ φT(x). f3r+1(x),φr+2(x),…,φr+s(x)}T with the approximation order m + L(L ∈ Z+). In other words, we raise the approximation order of multiscaling function φ(x) by increasing its multiplicity. In addition, we discuss an especial setting. That is, if given an orthogonal multiscaling function φ(x) = [φ1 (x), φ2(x), …, φr(x)]T is symmetric, then the new orthogonal multiscaling function φnew(x) not only raise the approximation order but also preserve symmetry. Finally, some examples are given.

关键词： orthogonal, multiscaling functions, approximation order, symmetry.