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Kumada chain-growth polycondensation as a universal method for synthesis of well-defined conjugated polymers

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Science China Chemistry 2010年第8期53卷 1620-1633页

作者： GENG YanHou1,HUANG Li1,2.WU ShuPeng1,2.& WANG FoSong1 1State Key laboratory of Polymer Physics and Chemistry Changchun institute of {2. Chemistry,{2. academy of sciences,Changchun 13002.,China 2.raduate University of chinese academy of sciences,beijing 100049,China 1. State Key laboratory of Polymer Physics and Chemistry Changchun institute of applied Chemistry Chinese Academy of Sciences Changchun 130022 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Kumada chain-growth polycondensation (KCGP) is a novel method for the synthesis of well-defined conjugated *** the Ni-catalyst can transfer in an intramolecular process to the propagating chain end,the polymerization follows chain-growth *** this newly developed method,various conjugated polymers,such as polythiophenes,poly(p-phenylene) (PPP),polypyrrole (PPy),and polyfluorene with controlled molecular weights and relatively narrow polydispersities (PDIs),have been ***,the polymerizations for poly(3-alkylthiophene)s (P3ATs),PPP,and PPy exhibited quasi-living characteristics,which allows preparing polymer brushes,fully-conjugated block copolymers,and macroinitiators and macro-reactants for the synthesis of rod-coil block *** the current review,the progress in this new area is summarized.

关键词： chain growth polycondensation conjugated polymers Kumada reaction block copolymers polymer brush

A three-dimensional variational ocean data assimilation system:Scheme and preliminary results

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Science China Earth sciences 2006年第11期49卷 1212-1222页

作者： ZHU Jiang1,2. ZHOU Guangqing1, YAN Changxiang1, FU Weiwei1 & YOU Xiaobao1,3 1. International Center for Climate and Environment sciences, institute of Atmospheric Physics,{2., beijing 10002., China 2. Jiangsu Key laboratory of Meteorological Disaster, Nanjing University of Information Science and Technology, Nanjing 2.0044, China 3. beijing institute of applied Meteorology, beijing 10002., China 1. International Center for Climate and Environment sciences Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Jiangsu Key laboratory of Meteorological Disaster Nanjing University of Information Science and Technology Nanjing 210044 China 3. beijing institute of {2. Meteorology Beijing 100029 China

A new 3DVAR-based Ocean Variational Analysis System (OVALS) is developed. OVALS is capable of assimilating in situ sea water temperature and salinity observations and satellite altimetry data. As a component of OVALS, a new variational scheme is proposed to assimilate the sea surface height data. This scheme considers both the vertical correlation of background errors and the nonlinear temperature-salinity relationship which is derived from the generalization of the linear balance constraints to the nonlinear in the 3DVAR. By this scheme, the model temperature and salinity fields are directly adjusted from the altimetry data. Additionally, OVALS can assimilate the temperature and salinity profiles from the ARGO floats which have been implemented in recent years and some temperature and salinity data such as from expendable bathythermograph, moored ocean buoys, etc. A 2.-year assimilation experiment is carried out by using OVALS and the Tropical Pacific circulation model. The results show that the assimilation system may effectively improve the estimations of temperature and salinity by assimilating all kinds of observations. Moreover, the root mean square errors of temperature and salinity in the upper depth less than 42. m reach 0.63℃ and 0.34 psu.

关键词： data assimilation, 3DVAR, sea surface height, ARGO floats.

REMARK ON UNIQUE CONTINUATION OF SOLUTIONS TO THE STOKES AND THE NAVIER-STOKES EQUATIONS

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Acta Mathematica Scientia 2005年第4期25卷 594-598页

作者： Jin Kim Tu 常谦顺 Tuinstitute of mathematics Academy of Sciences of DPR of Korea Pyonyang DPR of Korea institute of applied {2. Academy of Mathematics and System SciencesChinese Academy of Sciences Beijing 100080 China

New simple proofs of unique continuation of solutions for the Stokes equation and Navier-Stokes equations is presented under weaker conditions.

关键词： Stokes equation Navier-Stokes equation

FINDING THE STRICTLY LOCAL AND ε-GLOBAL MINIMIZERS OF CONCAVE MINIMIZATION WITH LINEAR CONSTRAINTS

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Journal of Computational mathematics 1997年第4期15卷 327-334页

作者： Patrice Marcotte (Centre de Recherche sur Les Transports, Universit de Montr al, Queb c, Canada)Shi-quan Wu (probability laboratory,{2.,{2.,beijing, China) Centre de Recherche Sur Les Transports Université de Montréal Que. Canada probability laboratory Institute of Applied Mathematics Chinese Academy of Sciences Beijing China

This paper considers the concave minimization problem with linear constrailits,proposes a technique which may avoid the unsuitable Karush-Kuhn-Tucker poiats,then combines this technique with nank-Wolfe method and simplex method to form a pivoting method which can determine a strictly local minimizer of the problem in a finite number of iterations. Basing on strictly local minimizers, a new cutting plane method is proposed. Under some mild conditions, the new cutting plane method is proved to be finitely terminated at an θ-global minimizer of the problem.

关键词： NLP GLOBAL MINIMIZERS OF CONCAVE MINIMIZATION WITH LINEAR CONSTRAINTS Pro PI FINDING THE STRICTLY LOCAL AND

Effect of upward ion on field-aligned currents in the near-earth magnetotail

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Science China(Physics,Mechanics & Astronomy) 2007年第5期50卷 673-680页

作者： ZHANG LingQian1, LIU ZhenXing1, MA ZhiWei2. SHEN Chao1, ZHOU XuZhi3 & ZHANG XianGuo3 1 Center for Space and applied Research, chinese academy of sciences,{2., China 2.institute of Plasma Physics, chinese academy of sciences, Hefei 2.0031, China 3 School of Earth and Space Science, Peking University, beijing 100871, China 1. Center for Space and applied Research Chinese Academy of Sciences Beijing 100080 China 2. institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 China 3. School of Earth and Space Science Peking University Beijing 100871 China

A 3-dimensional resistive MHD simulation was carried out to study the effect of the upward ions on the field-aligned currents (FACs) in the near-earth magnetotail. The simulation results show that the up-flow ions originating from the nightside auroral oval would drift into the center plasma sheet along the magnetic field lines in the plasma sheet boundary, and have an important effect on the field-aligned currents. The main conclusions include that: 1) the upward-ions mainly affect the field- aligned currents in the near-earth magnetotail (inside 15 Re); 2. the generated FACs in the near-earth region have two types, i.e., Region 1 FAC in the high-latitude and Region 2.FAC in the low-latitude; 3) FACs increase with the enhancement of the upward ion flux; 4) with the same flux of the upward ions, FACs enhance with the increase of the velocity of the up-flow ions; 5) the intensification of FACs is also closely related with the latitude of the upward ions, and the ions from the closed field line region generate larger FACs; 6) the generation of FACs is closely related with By created by the upward ions.

关键词： up-flow ions, near-earth magnetotail, field-aligned current

One-dimensional unsteady general solution for Wang bioheat transfer equation with heat source proportional to temperature

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Progress in Natural Science:Materials International 2006年第7期16卷 766-768页

作者： GOU Chenhua and CAI Ruixian ( institute of Engineering Thermophysics, chinese academy of sciences,{2., China Graduate School, chinese academy of sciences,{2., China) [a]institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China [b]Graduate School Chinese Academy of Sciences Beijing China

An analytical general solution is derived for the non-Fourier Wang bioheat transfer model with special internal heat production. It is valuable for finding the special solutions with specified conditions and for expanding the understanding of the non-Fourier heat conduction phenomena in living tissues, for example, the controversial temperature fluctuation effects. This analytical solution can also be used as the benchmark solution to check the numerical calculations and to develop various numerical computational approaches. Because there is an arbitrary function in the expression of internal heat production, this solution can actually be applied to many types of internal heat production distributions.

关键词： bioheat transfer model non-fourier effect analytical solution

Quasi-likelihood estimation of average treatment effects based on model information

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Science China mathematics 2007年第1期50卷 1-12页

作者： Zhi-hua SUN academy of mathematics and Systems Science, {2. academy of Science, beijing 100080, China 1. academy of mathematics and Systems Science Chinese Academy of Science Beijing 100080 China

In this paper, the estimation of average treatment effects is considered when we have the model information of the conditional mean and conditional variance for the responses given the covariates. The quasi-likelihood method adapted to treatment effects data is developed to estimate the parameters in the conditional mean and conditional variance models. Based on the model information, we define three estimators by imputation, regression and inverse probability weighted methods. All the estimators are shown asymptotically normal. Our simulation results show that by using the model information, the substantial efficiency gains are obtained which are comparable with the existing estimators.

关键词： average treatment effects inverse probability weighted quasi-likelihood unconfounded assignment treatment model information 62.18

Nonlinear analysis on the coupling process of electromagnetic vibrator and earth

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Science China Earth sciences 2005年第8期48卷 1175-1182页

作者： CHEN Zubin1,2. TENG Jiwen2. LIN Jun1, ZHANG Linhang1 & JIANG Zhongjin1 1. institute of Intelligent Instrument & Measurement Control Technology, Jilin University, Changchun 13002., China 2. institute of Geology & Geophysics,{2., beijing 10002., China 1. institute of Intelligent Instrument & Measurement Control Technology Jilin University 130026 Changchun China 2. institute of Geology & Geophysics Chinese Academy of Sciences 100029 Beijing China

The linear model based on the hydraulic pressure vibrator has been no longer adaptable to the electromagnetic vibrator. In order to realize the effective transmission of the limited energy from the vibrator to the ground, it is important to study the coupling model of the electromagnetic vibrator and the earth. In this paper, a nonlinear restore term was introduced to the coupling model because of the existence of a large amount of harmonics in the vibrator baseplate. The nonlinear vibration analysis was applied to the model by the multiscale method. In the course of energy transmission from the vibrator to the ground, ultraharmonic resonance was used to explain the generation of harmonics. An improved scheme was advanced to select the cross correlation reference signal in the vibrator seismic exploration. Good application results were obtained in field experiments.

关键词： vibrator, coupling model, electromagnetic, nonlinear vibration.

Effects of gravity waves on the distributions of O_3 and OH in the mesopause region

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chinese Science Bulletin 2001年第15期46卷 1265-1268页

作者： XU Jiyao & MA Ruipinglaboratory for Space Weather, Center for Space Science and applied Research,{2.,{2., China laboratory of Numeric Study of Heliospheric Physics,{2.,{2., China laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China laboratory of Numeric Study of Heliospheric Physics Chinese Academy of Sciences Beijing China

A dynamical-photochemical model of atmospheric gravity waves is used to study the influences of gravity waves on distributions of atmospheric minor species through transportation and photochemical reactions. We mainly study the effect of gravity waves on the distributions of atmospheric trace gases through the nonlinear photochemical reactions. O3 and OH are taken as examples in this note. The calculations indicate that the effect of gravity waves on the distributions of atmospheric trace gases is mainly through the nonlinear photochemical reactions in the mesopause region. The contribution of the nonlinear photochemical reaction caused by gravity waves can exceed the nonlinear transportation and the eddy diffusion.

关键词： gravity wave photochemical reaction coupling between photochemistry and dynamics.