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Lattice Boltzmann model for the perfect gas flows with near-vacuum region

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Communications in Nonlinear Science and Numerical Simulation 2000年第2期5卷 58-63页

作者： Guangwu YAN and Li YUAN (LSEC, institute of Computational Mathematics, academy of Mathematics and System sciences,chinese academy of sciences, beijing 100080, china Department of Mathermatics, Jilin university, changchun 130023, china) LSEC Institute of Computational Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China Department of Mathematics Jilin University Changchun 130023 China

It is known that the standard lattice Boltzmann method has near-vacuum limit,i. e., when the density is near zero, this method is invalid. In this letter, we propose a shople lattice Boltzmann model for one-dimensional fiows. It possesses the ability of simulating near vacuum area by setting a limitation of the relaxation factor. Thus, the model overcomes the disadvantage of non-physical pressure and the density. The numerical examples show these results are satisfactory.

关键词： lattice Boltzmann method perfect gas near-vacuum region Roe’s tests

Thermal behavior and phase behavior in blends of liquid crystalline poly(aryl ether ketone) and poly(aryl ether ether ketone) containing thioether units

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Science china chemistry 2012年第4期55卷 612-617页

作者： LI Ye1, CHEN Jian2, LIU XinCai1 & YANG DeCai2 1Alan G. MacDiarmid institute, Jilin university, changchun 130012, china 2State Key Laboratory of Polymer Physics and chemistry changchun institute of applied chemistry, chinese academy of sciences, changchun 130022, china Alan G. MacDiarmid institute Jilin University Changchun China State Key Laboratory of Polymer Physics and chemistry changchun institute of applied chemistry Chinese Academy of Sciences Changchun China

Thermal behavior and phase behavior in blends of liquid crystalline poly(aryl ether ketone) with lateral methoxy groups (M-PAEK) and poly(aryl ether ether ketone) containing thioether units (S-PEEK) have been investigated by differential scanning calorimetry (DSC) and polarized light microscopy (PLM) techniques. The results indicate that the composition of the blends has great effect on the phase behavior and morphology. Thin films of pure M-PAEK and S-PEEK crystallized from the melts exhibit typical mosaic and spherulitic structures, respectively. For the blends with higher M-PAEK contents (> 50%), an unusual ring-banded spherulite with structural discontinuity is formed. The bright core and rings of the ring-banded spherulites under PLM are composed of M-PAEK phase, while the dark rings consist mainly of S-PEEK phase. For the 50:50 M-PAEK/S-PEEK blend, the ring-banded spherulites and S-PEEK spherulites coexist, which implies that a partial phase separation between the two components takes place in the melting state. In S-PEEK-rich blends, a volume-filled spherulite is produced. In addition, the effect of isothermal crystallization temperature on the phase behavior, especially the ring-banded spherulite formation in the blends, is discussed.

关键词： liquid crystalline poly(aryl ether ketone) – poly(aryl ether ether ketone) containing thioether units – phase behavior – rhythmically grown ring banded spherulite

Digital forestry research in china

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Science china(Technological sciences) 2006年第z1期49卷 1-8页

作者： TANG Shouzheng, TANG Una, Guofan Shao & DAI Limin Research institute of Resource Information Techniques, chinese academy of Forestry, beijing 100091, china institute of applied Ecology, chinese academy of sciences, Shenyang 110016, china Departmet of Forestry and Natural Resources, Purdue university, West Lafayette, IN 47907, USA graduate university, chinese academy of sciences, beijing 100101, china Research institute of Resource Information Techniques Chinese Academy of Forestry Beijing 100091 China

Digital Forestry as a concept was developed after the Digital Earth program. The chinese scientists were not only among the pioneers who first proposed the concept of Digital Forestry, but also contributed a lot to the development of Digital Forestry. Digital Forestry is a digital framework to maintain forest planting, management, using, and protect. The synergetic use of computationally-intensive quantitative methods together with information technologies is the most important foundation for the development of Digital Forestry. Under this situation, the experience of Digital Forestry development in china is relatively rich. A number of academicians, scholars, and professional administrators were involved in discussing the Digital Forestry Construction Scheme. The Project of Digital Forestry Practicability approved by the State Forestry Administration is a major instance in developing Digital Forestry standard and key techniques. By introducing a case study of Digital Forestry, this paper reviews the concept of Digital Forestry, the way turning traditional forestry into Digital Forestry, and the future development of Digital Forestry.

关键词： Digital Forest, Digital Earth, Digital Forestry standard, Digital Forestry techniques.

Research on Nanometer Technique and Low-Work-Loss Sensor

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稀有金属材料与工程 2006年第S3期 110-112页

作者： Lan Wang~1 Yayan Liu~1 Yifei Yang~(1,2) Jingwen He~1 (1.changchun institute of applied chemistry,chinese academy of sciences,changchun 130022,china) (2.graduate School of chinese academy of sciences,beijing 100080,china)

The preparation process of the CO gas sensor used at normal temperature is *** electric conductance of this type of sensor evolved oscillation from regularly when the sensor is exposed to low level CO *** gas sensing mechanism was investigated by its crystalline *** mechanism of information sensing,which was the concurrence of the grain boundary barrier control and the crystal surface control,is discussed.

关键词： nanometer technique low-work-loss sensor

Estimation of forest volumes by integrating Landsat TM imagery and forest inventory data

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Science china(Technological sciences) 2006年第z1期49卷 54-62页

作者： GU Huiyan, DAI Limin, WU Gang, XU Dong, WANG Shunzhong &WANG Hui institute of applied Ecology, chinese academy of sciences, Shenyang 110016, china School of Forestry, Northeast Forestry university, Harbin 150040, china State Key Lab of Systems Ecology, Research Center for Eco-Environmental sciences, chinese academy of sciences, beijing 100085, china graduate university of chinese academy of sciences, beijing 100039, china institute of applied Ecology Chinese Academy of Sciences School of Forestry Northeast Forestry University State Key Lab of Systems Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences

Accurate information about forest volumes is essential for forest management planning. The survey interval of the Forest Resource Inventory of china (FRIC) is too long to meet the demand for timely decision-making required for forest protection, management, and utilization. Analysis of satellite imagery provides good potential for more frequent reporting of forest parameters. In this study, we describe an application of the k-nearest neighbors (kNN) method to Landsat TM imagery for improving estimation of forest volumes. Several spectral features were tested and compared in forest volume estimations, including normalized difference vegetation index, environmental vegetation index, and the combination of the spectral features. The combined index resulted in the most accurate volume estimations. The kNN estimator and the combined index were then used in forest volume estimation. The estimation error (RMSE) of the total volume was44.2%, much lower than those for Larix forest (the RMSE was 51.7%) and those for the Korean pine and broadleaved forests (the estimation errors were over 71.7% and 88.19%,respectively). This preliminary study demonstrates the potential of forest volume estimations with remote sensing data to provide useful information for forest management if only limited ground information is available.

关键词： forest inventory, landsat TM, k-nearest neighbors, spectral extraction.

Systematic study of the transfer of amino acids across the water/1,2-dichloroethane interface facilitated by dibenzo-18-crown-6

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Science china chemistry 2004年第1期47卷 24-33页

作者： CHEN Yong, YUAN Yi, ZHANG Meiqin, LI Fei, SUN Peng, GAO Zhao & SHAO YuanhuaState Key Laboratory of Electroanalytical chemistry, changchun institute of applied chemistry, chinese academy of sciences, changchun 130022, china College of chemistry and Molecular Engineering, Peking university, beijing 100871, china Lab. of Electroanalytical Chem. Changchun Inst. of Appl. Chem. Chinese Acad. of Sci. Changchun 130022 China Coll. of Chem. and Molecular Eng. Peking Univ. Beijing 100871 China

Facilitated ion transfer reactions of 20 amino acids with dibenzo-18-crown-6 (DB18C6) at the water/1,2-dichloroethane (W/DCE) interfaces supported at the tips of micro- and nano-pipets were investigated systematically using cyclic voltammetry. It was found that there were only 10 amino acids, that is, Leu, Val, lie, Phe, Trp, Met, Ala, Gly, Cys, Gin (in brief), whose protonated forms as cations can give well-defined facilitated ion transfer voltammograms within the potential window, and the reaction pathway was proven to be consistent with the transfer by interfacial complexation/dissociation (TIC/TID) mechanisms. The association constants of DB 18C6 with different amino acids in the DCE (β0), and the kinetic parameters of reaction were evaluated based on the steady-state voltammetry of micro- or nano-pipets, respectively. The experimental results demonstrated that the selectivity of complexation of protonated amino acid by DB18C6 compared with that of alkali metal cations was low, which can be attributed to the vicinal effect arising from steric hindrance introduced by their side group and the steric bulk effect by lipophilic stabilization. Moreover, the association constants and the standard rate constants for different amino acids showed good correlations with their hydrophobicity (π), except Gly and Met, which inferred that the selectivity of such heterogeneous complex reaction for different amino acids with DB18C6, was not only affected by discrimination in binding these ions to the crown ether macro-cycle, but also significantly modified by the ion transfer Gibbs energy which was closely related to the structure of the transferred ions, protonated amino acids.

关键词： micro-/nano-pipet, water/1,2-dichloroethane interface, facilitated ion transfer, cyclic voltammetry, amino acid.

Effect of strontium substitution on the activity of La_(2-x)Sr_xNiO_4(x=0.0-1.2)in NO decomposition

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Science china chemistry 2007年第1期50卷 41-46页

作者： ZHU JunJiang 1 ,YANG XiangGuang 2 ,XU XueLian 3 &WEI KeMei 1 1 National Research Center of Chemical Fertilizer Catalysts,Fuzhou university,Fuzhou 350002,china 2 changchun institute of applied chemistry,chinese academy of sciences,changchun 130022,china 3College of chemistry&Chemical Engineering,Fuzhou university,Fuzhou 350002,china National Research Center of Chemical Fertilizer Catalysts Fuzhou University Fuzhou China changchun institute of applied chemistry Chinese Academy of Sciences Changchun China College of chemistry & Chemical Engineering Fuzhou University Fuzhou China

The aim of this work is to study the effect of Sr substitution on the redox properties and catalytic ac- tivity of La2-xSrxNiO4(x=0.0-1.2)for NO *** suggest that the x=0.6 sample shows the highest *** characterization(TPD,TPR,etc.)of samples indicates that the x=0.6 sample possesses suitable abilities in both oxidation and reduction,which facilitates the proceeding of oxygen desorption and NO *** temperature below 700℃,the oxygen desorption is difficult, and is the rate-determining step of NO *** the increase of reaction temperature(T> 700℃),the oxygen desorption is favorable and,the active adsorption of NO on the active site(NO+Vo+ Ni2+→NO^--Ni3+)turns out to be the rate-determining *** existence of oxygen vacancy is the prerequisite condition for NO decomposition,but its quantity does not relate much to the activity.

关键词： NO decomposition La2-xSrxNiO4 TPD TPR oxygen vacancy

A shortest path algorithm for moving objects in spatial network databases

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Progress in Natural Science:Materials International 2008年第7期18卷 893-899页

作者： Xiaolan Yin a,b,*, Zhiming Ding c, Jing Li a a Technology Center of Software Engineering, institute of Software, chinese academy of Science, P.O. Box 8718, beijing 100080, china b graduate university, chinese academy of sciences, beijing 100049, china c Technology Center of Basic Software, institute of Software, chinese academy of sciences, beijing 100080, china Technology Center of Software Engineering Institute of Software Chinese Academy of Science P.O. Box 8718 Beijing 100080 China graduate university Chinese Academy of Sciences Beijing 100049 China Technology Center of Basic Software Institute of Software Chinese Academy of Sciences Beijing 100080 China

One of the most important kinds of queries in Spatial Network Databases (SNDB) to support location-based services (LBS) is the shortest path query. Given an object in a network, e.g. a location of a car on a road network, and a set of objects of interests, e.g. hotels, gas station, and car, the shortest path query returns the shortest path from the query object to interested objects. The studies of shortest path query have two kinds of ways, online processing and preprocessing. The studies of preprocessing suppose that the interest objects are static. This paper proposes a shortest path algorithm with a set of index structures to support the situation of moving objects. This algorithm can transform a dynamic problem to a static problem. In this paper we focus on road networks. However, our algorithms do not use any domain specific information, and therefore can be applied to any network. This algorithm’s complexity is O(klog2i), and traditional Dijkstra’s complexity is O((i + k)2).

关键词： Moving object Spatial network databases Shortest path index Shortest path

Lattice Boltzmann solver of Rossler equation

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Communications in Nonlinear Science and Numerical Simulation 2000年第2期5卷 64-68页

作者： Guangwu YAN and Li RUAN (LSEC institute of Computational Mathematics, academy of Mathematics and System sciences, chinese academy of sciences, beijing 100080, china Department of Mathematics, Jilin university, changchun 130023, china) LSEC Institute of Computational Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China Department of Mathematics Jilin University Changchun 130023 China

We proposed a lattice Boltzmann model for the Rossler equation. Using a method of multiscales in the lattice Boltzmann model, we get the ditheion reaction as a special case. If the diffusion effect disappeared, we can obtain the lattice Boltzmann solution of the Rossler equation on the mesescopic scale. The numericale results show the method can be used to simulate Rossler equation.

关键词： lattice Boltzmann method multiscale technique Rossler equation