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Molecular dynamics simulation of mechanical properties of TATB/fluorine-polymer PBXs along different surfaces

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science china Chemistry 2005年第6期48卷 504-510页

作者： XIAO Jijun1, HUANG Yucheng1, HU Yingjie1,2.& XIAO Heming1 1. department of Chemistry, nanjing {2. of science and Technology, nanjing 2.0094, china 2. department of Chemistry, nanjing Xiaozhuang College, nanjing 2.0017, china Correspondence should be addressed to Xiao Heming (email: xiao@***) 1. department of Chemistry Nanjing University of Science and Technology 210094 Nanjing China 2. department of Chemistry Nanjing Xiaozhuang College 210017 Nanjing China

The mechanical properties of PBXs composed of the well-known insensitive explo-sive TATB (1,3,5-Triamino-2.4,6-trinitrobenzene) crystal and four kinds of typical fluo-rine-polymers, i.e. poly (vinylidene difluoride) (PVDF), polychlorotrifluoroethylene (PCTFE), fluo-rine rubber (F2.11) and fluorine resin (F2.14) individually, have been simulated by molecular dy-namics (MD) method. The results show that the mechanical properties of TATB can be effectively improved by blending with a small amount of fluorine-polymers. Different mechanical properties of PBXs are obtained by putting fluorine-polymer binders parallel to different crystalline surfaces. The whole effect of improving mechanical properties is found to be (010)?(100)>(001).

关键词： TATB, polymer bonded explosives, mechanical properties, molecular dynamics.

Cartesian closedness of categories of completely distributive lattices

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Chinese science Bulletin 1998年第24期43卷 2059-2063页

作者： ZHANG Dexue 1 and YANG Zhongqiang 2.1. department of Mathematics, Sichuan university, Chengdu 610064,{2. 2. department of Mathematics, Shaanxi Normal university, Xi’an 710062.{2. department of Mathematics Sichuan University Chengdu China department of Mathematics Shaanxi Normal University Xi’an China

The category of completely distributive lattices with Scott continuous functions is cartesian closed. Neither the category of completely distributive lattices with arbitrary union preserving mappings nor the category ... 详细信息

关键词： completely distributive lattice continuous lattice cartesian closedness.

A new heuristic algorithm for the circular packing problem with equilibrium constraints

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science china(Information sciences) 2011年第8期54卷 1572-1584页

作者： LIU JingFa 1,2.LI Gang 3 & GENG HuanTong 1 1 School of computer and Software,nanjing {2. of Information science & Technology,nanjing 2.0044,china 2.Network Information Center,nanjing {2. of Information science & Technology, nanjing 2.0044,china 3 School of Mathematics and Physics,nanjing {2. of Information science & Technology,nanjing 2.0044,china 1. School of computer and Software Nanjing University of Information Science & Technology Nanjing 210044 China2. Network Information Center Nanjing University of Information Science & Technology Nanjing 210044 China3. School of Mathematics and Physics Nanjing University of Information Science & Technology Nanjing 210044 China

The circular packing problem with equilibrium constraints is an optimization problem about simplified satellite module layout design.A heuristic algorithm based on tabu search is put forward for solving this *** algorithm begins from a random initial configuration and applies the gradient method with an adaptive step length to search for the minimum energy *** jump out of the local minima and avoid the search doing repeated work,the algorithm adopts the strategy of tabu *** the process of tabu search,we improve the traditional neighboring solutions,tabu objects and the acceptance criteria of the current solution *** test two sets of benchmarks consisting of 11 representative instances from the current *** numerical results show that the proposed algorithm breaks the records in seven out of 11 instances,and obtains the optimal solutions for the other four instances.

关键词： equilibrium constraints packing problem heuristic algorithm tabu search layout optimization

The optimization of DNA encodings based on GA/SA algorithms

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Progress in Natural science:Materials International 2007年第6期17卷 739-744页

作者： Wang Wei1, Zheng Xuedong2. Zhang Qiang1 and Xu Jin2.1. Liaoning Key Laboratory of Intelligent Information Processing, Dalian university, Dalian 11662., china 2. {2. of Control science and Engineering, Huazhong university of science and Technology, Wuhan 430074, china) [a]Liaoning Key Laboratory of Intelligent Information Processing Dalian University Dalian China [b]department of Control science and Engineering Huazhong Univerisity of Science and Technology Wuhn China

The design of DNA sequence plays an important role in improving the reliability of DNA computation. Proper constrained terms that DNA sequence should satisfy are selected, and then the evaluation formulas of each DNA individual corresponding to the selected constrained terms are proposed. The heuristic improved genetic algorithm (GA)/simulated annealing (SA) algorithm is presented to solve the multi-objective optimize problem, and the DNA sequence design system is developed. Furthermore, an example is illustrated to show the efficiency of our method given here.

关键词： DNA encoding multi-objective optimize GA/SA algorithms

Molecular dynamics simulation of thermal stability of nanocrystalline vanadium

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science china(Technological sciences) 2006年第4期49卷 400-407页

作者： WEI Mingzhi1, XIAO Shifang1, YUAN Xiaojian2.& HU Wangyu1,2.1. Material science and Engineering College, Hunan university, Changsha 410082.{2. 2. department of Applied Physics, Hunan university, Changsha 410082.{2. Material science Engineering College Hunan University Changsha 410082 China department of Applied Physics Hunan University Changsha 410082 China

The microstructure and thermal stability of nanocrystalline vanadium with an average grain size ranging from 2.86 to 7.50 nm are calculated by means of the analytic embedded-atom method and molecular dynamics. The grain boundary and nanocrystal- line grain atoms are differentiated by the common neighbor analysis method. The results indicate that the fraction of grain boundary increases with the grain size decreasing, and the mean energy of atoms is higher than that of coarse crystals. The thermal-stable tem- peratures of nanocrystalline vanadium are determined from the evolution of atomic energy, fraction of grain boundary and radial distribution function. It is shown that the stable tem- perature decreases obviously with the grain size decreasing. In addition the reasons which cause the grain growth of nanocrystalline vanadium are discussed.

关键词： nanocrystalline, embedded-atom method, molecular dynamics, thermal stability.

High resolution stalagmite δ18O records over the past 1000 years from Dongge Cave in Guizhou

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science Bulletin 2005年第10期50卷 1003-1008页

作者： HE Yaoqi1, WANG Yongjin1, KONG Xinggong1 & CHENG Hai2. 1. College of Geography science, nanjing Normal {2., nanjing 2.0097, china 2. department of Geology and Geophysics, Minnesota {2., Mineapolis MN 55455, USA College of Geography science Nanjing Normal University Nanjing 210097 China

Based on MC-ICP-MS U-series dating and stable O-isotope analysis results, a 4―5 years resolution monsoon record over the past 1000 years has been estab- lished for two stalagmites from Dongge Cave, Guizhou. The high resolution oxygen isotope record serves as a proxy for variations in rainfall of Asian southwest monsoon over the Yunnan-Guizhou Plateau. A close relation of the δ 18O record with the ?14C record from tree rings largely reflects impact of centennial-scale solar activity on the monsoon climate changes. The conspicuous decrease in the δ 18O value at AD 172. indicates an abrupt increase in monsoon rainfall, sug- gesting that an atmospheric-oceanic couple over the tropical Indian Ocean plays an important role in rapid increase of the Northern Hemisphere temperature over the last century.

关键词： cave stalagmite oxygen isotope southwest monsoon solar activity Guizhou.

Terrain classification based on adaptive weights with airborne LiDAR data for mining area

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中国有色金属学会会刊：英文版 2011年第S3期21卷 648-653页

作者： LI Hui-ying1, WANG Zhi2. SUN Ya-feng1, LI Wen-hui1 1. College of computer science and Technology, Jilin {2., Changchun 130012. china 2. College of Resources and Civil Engineering, Northeastern {2., Shenyang 110004, china [a] College of computer science and Technology Jilin University Changchun 130012 China [b] College of Resources and Civil Engineering Northeastern University Shenyang 110004 China

The fast high-efficiency inspection for mining subsidence of mine area is a reliable way for forecasting accident and evaluating losing expense. In order to monitor mining subsidence of exploitation mine efficiently, LiDAR data were used and a novel strip division method was brought forward based on separating-treatment theory, which divided the mass of discrete three-dimensional point cloud data into a series of parallel strips and reduced the dimension in each strip. Polynomial fitting algorithm based on the adaptive weights, which located in the range of the strip, was used for classification complex terrain data of mine-area. The results show that LiDAR datamation can be greatly reduced. In the mean time, the time spending for calculation is shortened, and computational complexity is simplified. Therefore, high-efficiency terrain classification of LiDAR point cloud method can be great beneficial to monitoring environment of mine area.

关键词： mining subsidence airborne LiDAR strip division adaptive weights

Non-isothermal Melt Crystallization Kinetics of Anhydrite-Filled Polypropylene Composites

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Journal of Wuhan university of Technology(Materials science) 2010年第1期25卷 12-19页

作者：王少会 department of Chemistry and Chemical Engineering East China JiaoTong University

The non-isothermal crystallization kinetics of polypropylene （PP）, PP/anhydrite composites were investigated by differential scanning calorimetry （DSC） with various cooling rates. The Avrami analysis modified by Jeziorny and a method developed by Mo were employed to describe the non-isothermal crystallization process of these samples. The difference in the exponent n between PP and PP/anhydrite composites indicated that non-isothermal kinetic crystallization corresponded to tri-dimensional growth with heterogeneous nucleation. The values of half-time, Zc and F（T） showed that the crystallization rate increased with the increasing of cooling rates for PP and PP/anhydrite composites, but the crystallization rate of PP/anhydrite composites was faster than that of PP at a given cooling rate. The method developed by Ozawa did not describe the non-isothermal crystallization process of PP very well. Moreover, the method proposed by Kissinger was used to evaluate the activation energy of the mentioned samples. The result showed that the activation energy of PP/anhydrite was greatly larger than that of PP.

关键词： polypropylene anhydrite composites non-isothermal crystallization kinetics

Lipschitz classes on local fields

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science china Mathematics 2007年第7期50卷 1005-1014页

作者： Wei-yi SU~(1+) Guo-xiang CHEN~2.1 department of Mathematics,nanjing {2.,nanjing 2.0093,china 2.department of Mathematics,nanjing Audit {2.,nanjing 2.1815,china 1. department of Mathematics Nanjing University Nanjing 210093 China 2. department of Mathematics Nanjing Audit University Nanjing 211815 China

The Lipschitz class Lipαon a local field K is defined in this note,and the equivalent relationship between the Lipschitz class Lipαand the Holder type space C~α(K)is ***,those important characteristics on the Euclidean space R^n and the local field K are compared,so that one may interpret the essential differences between the analyses on R^n and ***,the Cantor type fractal functionθ(x)is showed in the Lipschitz class Lip(m,K),m＜(ln 2.ln 3).

关键词： local field Holder type space Lipschitz class Cantor type fractal function 11F85 46F05 43A2. 2.A80 2.A78