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Energy dispersion of complex non-isolated vortices

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Chinese science Bulletin 2011年第25期56卷 2713-2717页

作者： LUO ZheXian 1,2 1 Key Laboratory of Meteorological Disaster of Ministry of Education, nanjing univ.rsity of Information science and technology, nanjing 210044, china 2 Wuxi research center of Environmental science and technology, Wuxi 214031, china Key Laboratory of Meteorological Disaster of Ministry of Education Nanjing University of Information Science and Technology Wuxi research center of Environmental science and technology

Energy dispersion is a fundamental scientific problem in the study of natural disasters such as typhoons, heavy rain and earthquakes. The problem has been addressed by both multi-discipline research and forecast studies. The dynamics of isolated circular vortex energy dispersion have been solved. However, the disastrous results of typhoons and heavy rain often occur due to non-isolated circular vortices, the dynamics of which are explored in this paper. The energy dispersion characteristics of non-isolated vortices with complex structural patterns are examined using a linearized nondivergent barotropical vorticity equation model. In the initial field, a tropical cyclone (TC) vortex and a meso-scale vortex coexist, forming a complex structural pattern. An analytic solution based on a Fourier transform and simulations using a two-dimensional model show the following. (1) A wave train of TC-G-D may be created by the energy dispersion where the line connecting the three member centers of the wave train is parallel to the x axis in the case of an initial TC vortex without a meso-scale vortex. (2) A wave train of TC-G-D may also be created by energy dispersion. However, the line connecting the three member centers of the wave train would no longer be parallel to the x axis. Instead, they would form a triangle in the presence of the initial TC vortex with the meso-scale vortex. (3) There is a nonlinear relationship between the initial intensity of the meso-scale vortex and the base angle of the triangle. These results have the potential to be applied in the field of typhoon forecasting.

关键词：能量色散非隔离式旋涡非线性关系中尺度涡台风预报结构模式傅立叶变换

Numerical simulations of self-propelled swimming of 3D bionic fish school

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science china(Technological sciences) 2009年第3期52卷 658-669页

作者： WU ChuiJie1 & WANG Liang2 1 State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian univ.rsity of technology, Dalian 116024, china 2 research center for fluid dynamics, People’s Liberation Army univ.rsity of science and technology, nanjing 211101, china State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian 116024 China research center for fluid dynamics People’s Liberation Army University of Science and Technology Nanjing 211101 China

Numerical simulations of self-propelled swimming of a three dimensional bionic fish and fish school in a viscous fluid are carried out. This is done with the assistance of a parallel software package produced for 3D moving boundary problems. This computational fluid dynamics package combines the adaptive multi-grid finite volume method, the immersed boundary method and VOF (volume of fluid) method. By using the package results of the self-propelled swimming of a 3D bionic fish and fish school in a vis- cous fluid are obtained. With comparison to the existing experimental measurements of living fishes, the predicted structure of vortical wakes is in good agreement with the measurements.

关键词： adaptive multi-grid immersed boundary method self-propelled swimming fish school 3D bionic fish

A relative local variational principle for topological pressure

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science china Mathematics 2010年第6期53卷 1491-1506页

作者： MA XianFeng1,CHEN ErCai2,3,& ZHANG AiHua2,4 1Department of Mathematics,East china univ.rsity of science and technology,Shanghai 200237,china 2school of Mathematics and Computer science,nanjing Normal univ.rsity,nanjing 210097,china 3center of Nonlinear science,nanjing univ.rsity,nanjing 210093,china 4College of Mathematics and Physics,nanjing univ.rsity of Posts and Telecommunications,nanjing 210046,china 1. Department of Mathematics East China University of Science and Technology Shanghai 200237 China2. School of Mathematics and Computer Science Nanjing Normal University Nanjing 210097 China3. Center of Nonlinear Science Nanjing University Nanjing 210093 China4. College of Mathematics and Physics Nanjing University of Posts and Telecommunications Nanjing 210046 China

We define the relative local topological pressure for any given factor map and open cover,and prove the relative local variational principle of this *** precisely,for a given factor map π:(X,T)→(Y,S) between two topological dynamical systems,an open cover U of X,a continuous,real-valued function f on X and an S-invariant measure ν on Y,we show that the corresponding relative local pressure P(T,f,U,y) satisfies sup μ∈M(X,T){ hμ(T,U|Y)+∫X f(x)dμ(x) :πμ=ν}=∫Y P(T,f,U,y)dν(y),where M(X,T) denotes the family of all T-invariant measures on ***,the supremum can be attained by a T-invariant measure.

关键词： pressure conditional entropy relative local variational principle

基流对热对流涡旋结构影响的实验结果初步分析

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物理学报 2002年第9期51卷 2057-2062页

作者：林上金解放军理工大学南京211101

用实验室模拟方法研究了径向温度梯度对热对流涡旋的影响 ,结果表明 ,径向温度梯度所引起的基流使热对流涡旋的对称性结构被破坏 ,使涡旋变成非对称结构 ,并使涡旋向基流下游偏移 ,其强度随基流的加强而减弱 ,直至消失 .热对流涡旋越强... 详细信息

用实验室模拟方法研究了径向温度梯度对热对流涡旋的影响 ,结果表明 ,径向温度梯度所引起的基流使热对流涡旋的对称性结构被破坏 ,使涡旋变成非对称结构 ,并使涡旋向基流下游偏移 ,其强度随基流的加强而减弱 ,直至消失 .热对流涡旋越强其对称性结构越稳定。

关键词：转盘实验基流热对流涡旋径向温度梯度对称性结构天然系统

Study on rare earth/alkaline earth oxide-doped CeO_2 solid electrolyte

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Rare Metals 2007年第4期26卷 311-316页

作者： YAN Kai ZHEN Qiang Song Xiwen school of Materials science and Engineering Shanghai University Shanghai 200072 China research center of Nanoscience and Nanotechnology Shanghai Univeesity Shanghai 200444 China school of Materials science and Engineering Inner Mongolia University of Science and Technology B aotou 014010 China

Five types of rare earth/alkaline earth oxide-doped CeO2 superfine-powders were synthesized by a low-temperature combustion technique. The relevant solid electrolyte materials were also sintered by pressureless sintering at different temperatures. The results of X-ray diffraction and transmission electron microscopy showed that the grain size of the powders was approximately 20-30 nm, and rare earth/alkaline earth oxides were completely dissolved into ceria-based solid solution with fluorite structure. The electrical conductivities of the SmzO3-CeO2 system were measured by the ac impedance technique in air at temperatures ranging from 513-900℃. The results indicated that the ionic conductivities of Srno.2oCe0.8Ol.875 solid electrolyte increase with increasing sintering temperature, and the relationship between the conductivities and measuring temperature obeys the An＇henius equation. Then the SmzO3-CeO2 material was further doped with other rare earth/alkaline earth oxide, and the conductivities improve with the effective index.

关键词： doped ceria rare earth/alkaline earth oxide solid electrolyte conductivity effective index

Representations of Real and Complex Stability Radii of 2-Dimensional LinearSystems

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International Journal of Minerals,Metallurgy and Materials 1999年第4期13卷 299-301页

作者： Lequan Min1.2 Ning Song1(l Applied science school, univ.rsity of science and technology’ Beijing, Beijing 100083, china2 china center of Advanced science and technology, Beijing 100080, china) univ Sci & Technol Beijing Appl Sci Sch Beijing 100083 Peoples R China china Ctr Adv Sci & Technol Beijing 100080 Peoples R China

Rigorous proofs are given for the representations of real and complex stability' radii of 2-dimensional linear systems. This representations can be used to analyze the robustness of a nominal 2-dimensional linear system under pelturbation of the system parameters, in particular testing the effect of numerical algorithms which are used to calculate the real stability radii of higher dimensional piecewise-linear systems.

关键词： linear systems robustness stability radii

Adsorption of surfactants onto acrylic ester resins with different pore size distribution

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science china Chemistry 2006年第5期49卷 445-453页

作者： YANG Weiben1,2,3,LI Aimin1,3,CAI Jianguo1,3,MENG Guanhua1,3 & ZHANG Quanxing1,3 1. State Key Laboratory of Pollution Control and Resource Reuse,school of the Environment,nanjing univ.rsity,nanjing 210093,china 2. nanjing College of Chemical technology,nanjing 210048,china 3. Jiangsu Engineering & technology research center for Organic Toxicant Control and Resource Reuse,nanjing 210038,china 1. State Key Laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University Nanjing 210093 China 2. nanjing College of Chemical technology Nanjing 210048 China 3. Jiangsu Engineering & technology research center for Organic Toxicant Control and Resource Reuse Nanjing 210038 China

In this study, a series of acrylic ester resins with different pore size distribution were prepared successfully by varying the type and the amount of pore-forming agents. In order to inves-tigate the adsorption behavior and mechanism of surfactants on acrylic ester resins, three kinds of surfactants were utilized as adsorbates that were sodium 6-dodecyl benzenesulfonate (6-NaDBS), sodium 1-dodecyl benzene sulfonate (1-NaDBS) and sodium 1-dodecyl sulfonate, respectively. It was observed that the surface area was available in a particular pore size and an appropriate pore size of resins appeared to be more important for the adsorption of surfactants. As compared to commercial acrylic ester resins XAD-7 and HP2MG, 50# and 38# resins exhibited more excellent adsorption properties toward 1-NaDBS and 6-NaDBS. The experimental equilibrium data were fitted to the Langmuir, and double-Langmuir models. Two models provided very good fittings for all resins over the temperature range studied. The investigation indicated that electrostatic attraction and hydrogen bond between resins and surfactants were the main forces and had an obvious effect on adsorption proc-ess.

关键词： acrylic ester resin, surfactant, adsorption, pore size distribution, isotherm.

Significance of stress on mobilization of ore-forming materials

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Chinese science Bulletin 1999年第S2期44卷 139-141页

作者： MA Rui and JIANG Qigang research center of Metamorphic dynamics of Changchun univ.rsity of science and technology, Changchun 130061, china research center of Metamorphic dynamics Changchun University of Science and Technology Changchun 130061 China

METALLOGENIC processes represent migration and concentration of useful elements, which are controlled by a number of factors. Among varied geological factors, stress is very improtant. Stress could not only causethe fracture and deformation, but also is closely related to the mobilization and migration of ore-formingmaterials, especially for hydrothermal deposits. Varied experiments have been carried out to showthe above phenomenon. The sample is carbonaceous slate collected from the Taiyangding Group of the Nuo ’ ergai area,Sichuan Province. The rock is fresh, creckless, containing 40×10-9 of gold and high content of organiccarbon. Under a microscope, it is black. A group of state cleavage is observed, fine quartz and uniformily distributed carbonaceous materials. The quartz is<0.01 mm in diametre. Using high temperature

关键词： stress mobilization ore-formmg material.

P2P traffic optimization

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science china(Information sciences) 2012年第7期55卷 1475-1492页

作者： ZHANG GuoQiang 1,2 ,TANG MingDong 3 ,CHENG SuQi 2,4 ,ZHANG GuoQing 2 ,SONG HaiBin 5 ,CAO JiGuang 6 & YANG Jing 7 1 school of Computer science and technology,nanjing Normal univ.rsity,nanjing 210046,china 2 Institute of Computing technology,Chinese Academy of sciences,Beijing 100190,china 3 school of Computer science and Engineering,Hunan univ.rsity of science and technology,Xiangtan 411201,china 4 Graduate univ.rsity of Chinese Academy of sciences,Beijing 100190,china 5 nanjing R&D center,Huawei Technologies,nanjing 210012,china 6 china Academy of Telecommunication research of MIIT,Beijing 100191,china 7 china Mobile research Institute,Beijing 100053,china 1. school of Computer science and technology Nanjing Normal University Nanjing 210046 China2. Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China3. School of Computer Science and Engineering Hunan University of Science and Technology Xiangtan 411201 China4. Graduate University of Chinese Academy of Sciences Beijing 100190 China5. Nanjing R&D Center Huawei Technologies Nanjing 210012 China6. China Academy of Telecommunication Research of MIIT Beijing 100191 China7. China Mobile Research Institute Beijing 100053 China

Peer-to-peer (P2P) based content distribution systems have emerged as the main form for content distribution on the Internet,which can greatly reduce the distribution cost of content providers and improve the overall system ***,the mismatch between the overlay and underlay networks causes large volume of redundant traffic,which intensifies the tension between P2P content providers and ***,how to efficiently use network resources to reduce the traffic burden on the ISPs is crucial for the sustainable development of P2P *** paper surveys the state-of-art P2P traffic optimization technologies from three perspectives:P2P cache,locality-awareness and data *** details,comparison between these technologies and their applicabilities are presented,followed by a discussion of the issues that remain to be addressed and the direction of future content distribution research.

关键词： P2P traffic localization P2P traffic optimization P2P cache locality-awareness network coding content-centric network