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Large Eddy Simulation of New Vortex Generator Enhancing Heat Exchange of Solar Energy

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湖南大学学报（自然科学版） 2009年第S1期36卷 186-192页

作者： WEN Juan,YANG Li,QI Cheng-ying(department of Thermal Power Engineering,Hebei university of Technology,Tianjin 300401,china) department of Thermal Power Engineering Hebei University of Technology Tianjin 300401 China

This paper put forward a new-type vortex generator enhancing heat exchange of solar air-drier and air-heater on the gas side,and investigated the mechanism of heat transfer enhancement and drag reduction by the influence of vortex generators on the coherent structure of turbulent boundary *** flow and heat transfer characteristics of rectangle channel with bevel-cut half-elliptical column vortex generators were obtained using large eddy simulation(LES)and the hydromechanics software *** instantaneous properties of velocity,temperature and pressure in channel were *** coherent structure of turbulent boundary layer flow was showed,and the characteristic of vortex induced by inclined-cut semi-ellipse vortex generator and its influence on turbulent coherent structure were *** the effect mechanism of turbulent coherent structure on flow field,pressure field and temperature field was *** on the results,the heat transfer coefficient and drag reduction of the new vortex generator with different pitch angles were ***,the coherent effects of the increased wall heat transfer and the decreased skin friction do not satisfy the Reynolds *** turbulent coherent structure can be controlled through the geometry of the vortex generator,so the heat transfer and drag reduction can also be *** we can seek suitable form of vortex generator and structure parameters,in order to achieve the enhanced heat transfer and flow of drag reduction in the solar air-heater and solar air-drier.

关键词： large eddy simulation vortex generator bevel-cut half-elliptical column coherent structure heat transfer enhancement

A NEW SYNERGIST FOR INTUMESCENT FLAME RETARDANT POLYPROPYLENE

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Chinese Journal of Polymer Science 2002年第4期20卷 377-380页

作者： Qiang Wu Bao-jun Qu State Key Laboratory of Fire Science and department of Polymer Science and Engineering university of Science and Technology of china, Hefei 230026 china Univ Sci & Technol china State Key Lab Fire Sci Hefei 230026 Peoples R China Univ Sci & Technol china Dept Polymer Sci & Engn Hefei 230026 Peoples R China

The synergistic effects of silicotungstic acid (SiW12) as a catalyst in the phosphorus-nitrogen compounds AM-based intumescent flame-retardant (IFR) polypropylene (PP) were studied using the limiting oxygen index (LOI), the UL-94 test, thermogravimetric analysis (TGA), real time Fourier transform infrared (FTIR), laser Raman spectroscopy (LRS). The LOI data show that SiW12 added to PP/IFR systems has a synergistic FR effect with an IFR additive named AM. The TGA data show that SiW12 apparently increases the thermal stability of the PP/IFR systems at high temperature (T > 500degreesC). The FTIR results provide the positive evidence that IFR can improve the thermal stability of PP and SiW12 can induce a higher rate of formation of phosphoric acid and its derivatives. The LRS measurements provide useful information on the carbonaceous microstructures. In short, a suitable amount of SiW12 (1.5 wt%) exerts synergistic effects with the IFR by increasing the LOI value and the thermal stability at high temperature and promoting the formation of charred structures on the burning PP surface.

关键词： silicotungistic acid synergistic effect intumescent flame retardant polypropylene

Analysis of Environmental and Socio-economic Determinants Affecting Population Longevity Level at County Level in china

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Chinese Journal of Population,Resources and Environment 2005年第1期3卷 36-41页

作者： Lu Jiehua , Wang Hongbo 1 2 & Pan Yi 1 1. Institute of Population Research, Peking university, Beijing 100871, china 2. department of Sociology, university of California at Los Angeles, Los Angeles, USA. Institute of Population Research Peking University Beijing 100871 China department of Sociology University of California at Los Angeles Los Angeles United States

Based on the current literature, this paper is mainly intended to test whether environmental factors and socio-economic factors will have direct effect on the longevity at county level in china in order to determine the major determinants affecting local longevity level. Using the multi-regression model, we find the result that factors such as temperature, climate, longitude, type of soils, as well as type of agricultural food production play a major role in shaping the longevity at county level, and that socio- economic factors like infant mortality and gross death rate also have some direct impact on longevity, but the degree of impact is not as strong as the above environmental factors.

关键词： longevity socio-economic factors environmental factors

A Heuristic Algorithm for the Two-Machine Flowshop Group Scheduling Problem

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Journal of Systems Engineering and Electronics 2002年第4期13卷 8-16页

作者： Wang Xiuli & Wu Tihua department of Automation, Shanghai Jiaotong university, Shanghai 200030, P.R. china department of Automation Shanghai Jiaotong University Shanghai 200030 P. R. China

This paper presents the two-machine flowshop group scheduling problem with the optimal objective of maximum lateness. A dominance rule within group and a dominance rule between groups are established. These dominance rules along with a previously established dominance rule are used to develop a heuristic algorithm. Experimental results are given and analyzed.

关键词： Group scheduling Flowshop Heuristic algorithm.

同方期刊数据库

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Cbase查询优化的重写机制及其实现

计算机工程与应用 2002年第22期38卷 192-194,238页

作者：邓支益毛宇光江国华南京航空航天大学计算机科学研究所南京210016 南京大学软件新技术国家重点实验室南京210093

Cbase是南京大学计算机系与南大谷元石油软件研究所有限公司研制的新一代商用关系数据库管理系统。为了提高查询效率,作者开发了Cbase数据库的查询优化器。文章详细论述了Cbase查询优化器中重写模块的设计思想与实现技术,并讨论了基于... 详细信息

Cbase是南京大学计算机系与南大谷元石油软件研究所有限公司研制的新一代商用关系数据库管理系统。为了提高查询效率,作者开发了Cbase数据库的查询优化器。文章详细论述了Cbase查询优化器中重写模块的设计思想与实现技术,并讨论了基于执行引擎特点引入的一组基于等价谓词的简单语句的重写规则。测试结果表明,所设计的重写器能够显著提高系统的查询效率。

关键词：关系数据库管理系统 Cbase 查询优化器重写模块等价谓词查询图

Oroclinal bending and block rotations in South china since the Mesozoic——Geological and paleomagnetic evidence

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Chinese Science Bulletin 1997年第2期42卷 132-136页

作者： LI Zhengxiang, FANG Dajun, Christopher McA. Powell and LOU Gang1. department of Geology and Geophysics, The university of Western Australia, Nedlands WA 6907, Australia 2. department of Earth Sciences, Zhejiang university, Hangzhou 310027, china department of Geology and Geophysics The University of Western Australia Nedlands Australia department of Earth Sciences Zhejiang University Hangzhou China

THE South china Block exhibits a complex structural pattern in its Neoproterozoic-Mesozoic sedimentary cover. The lack of knowledge about the formation of this pattern hinders our understanding of the regional tectonic evolution and paleogeography, and the reconstruction of Phanerozoic apparent polar wander path(s). In this note we present a synthesis based on a paleomagnetic and tectonic analysis, which suggests that (i) the structural pattern over

关键词： Mesozoic paleomagnetism block rotation.

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天体力学的几个热点问题

天文学进展 2001年第2期19卷 279-281页

作者：刘林季江徽王昌彬南京大学天文系南京210093 中国科学院紫金山天文台南京210008

阐述当今天体力学前沿课题中的几个热点问题：近地小行星与地球的交会及其动力演化，航天器定轨新手段中的星－星跟踪自主定轨方法以及星际探测中的轨道力学问题．

关键词：天体力学小行星航天器定轨地球轨道力学

Self-organized evolving scale-free network model with coupled local correlations and node state multifractality

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Self-organized evolving scale-free network model with couple...

Numerical simulation of two-dimensional interface breakup

第三届全国复杂动态网络学术论坛

作者： Chen-Ping Zhu, Tao Zhou Hui-Jie Yang, Shi-Jie Xiong, Li Wang, Zhi-Ming Gu, Da-Ning Shi, Bing-Hong Wang College of Sciences, nanjing university of Aeronautics and Astronautics, nanjing, 210016, china department of Theoretical Physics & Nonlinear Science Center, university of Science and Technology of china, Hefei, 230026, china department of Physics & National Laboratory of Microstructures, nanjing, 210093, china

Background Separate kinds of research on complex networks: topological models /processes on networks Actually there should be 3 kinds of cases: 1. Topological connections varies slowly, node dynamics proceed quickly;2. Opposite to case 1;3. Topological/ node state update in the same pace To make clear which kind of process occurs in a practical system would be the key problem in the research

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Progress in Natural Science:Materials International 2006年第5期16卷 554-558页

作者： CAI Yong,MA Dongjun, SUN Dejun and YIN Xieyuan (department of Modern Mechanics, university of Science and Technology of china, Hefei 230027, china) [a]department of Modern Mechanics University of Science and Technology of China Hefie China

The nonlinear evolution of the two-dimensional mixing layer flow of two immiscible fluids separated by the interface with surface tension is simulated numerically. The volume of the fluid method is used to capture the motion of the interface. A parametric study is conducted to investigate the effects of Weber number, Reynolds number, and the density ratio, etc. on the breaking process.

关键词： interface surface tension volume of fluid