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Explicit analytical solutions of the anisotropic Brinkman model for the natural convection in porous media(Ⅱ)

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Science china(Physics,Mechanics & Astronomy) 2005年第4期48卷 422-430页

作者： cai ruixian1, {2. chenhua1, 2.& ZHANG Na1 1. institute of engineering thermophysics, chinese academy of Sciences, Beijing 100080, china 2. Graduate School, chinese academy of Sciences, Beijing 100080, china 1. institute of engineering {2. Chinese Academy of Sciences 100080 Beijing China 2. Graduate School Chinese Academy of Sciences 10080 Beijing China

Some algebraically explicit analytical solutions are derived for the anisotropic Brinkman model―an improved Darcy model―describing the natural convection in porous media. Besides their important theoretical meaning (for example, in analyzing the non-Darcy and anisotropic effects on the convection), such analytical solutions can be the benchmark solutions that can promote the development of computational heat and mass transfer. Some solutions considering the anisotropic effect of permeability have been given previously by the authors, and this paper gives solutions including the anisotropic effect of thermal conductivity and the effect of heat sources.

关键词： explicit analytical solution, porous medium, natural convection, Brinkman model, anisotropic.

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 {2. ruixian ( {4. of engineering thermophysics, chinese academy of Sciences, Beijing 100080, china Graduate School, chinese academy of Sciences, Beijing 100080, china) [a]institute of engineering {2. 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

Fundamental study of CO_2.control technologies and policies in china

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Science china(Technological Sciences) 2008年第7期51卷 857-870页

作者： JIN HongGuang1, ZHANG XiLiang2. GAO Lin1, YUE Li2. HE JianKun2.& cai {4. 1 {2. of engineering thermophysics, chinese academy of Sciences, Beijing 100080, china 2.{2. of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084. china 1. institute of engineering {2. Chinese Academy of Sciences Beijing 100080 China 2. institute of Nuclear and New Energy Technology Tsinghua University Beijing 100084 China

The technical roadmap and policies for CO2.mitigation suitable for china are a common center of attention in the fields of energy, environment, and management science in the country. Emphasizing interaction between technical research and policy research, this work discovers the potential breakthrough in the integrated field. The technical difficulties of recovering CO2.are pointed out, the mechanism of combining CO2.recovery with energy conversion is investigated, and the basic principle for integrating an environmental-friendly energy system is discussed. Moreover, the formulation of a new energy system that can recover CO2.with very low or even zero energy penalty is proposed, while the assessment methodology and model system for the technical roadmap of CO2.emission control are developed. Finally, a new technical roadmap constructing an energy network suitable for china is proposed, which may provide a new way for the development of sustainable energy and environment technologies.

关键词： CO2 capture and storage technical roadmap energy policy

Explicit analytical solutions fof transport equations considering non-Fourier and non-Fick effects in porous media

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Progress in Natural Science:Materials International 2005年第6期 545-549页

作者： gou chenhua 1,2., {2. {4.* and ZHANG Na1(1. institute of engineering thermophysics, chinese academy of Sciences, Beijing 100080, china 2. Graduate School, chinese academy of Sciences, Beijing 100080, china)

Based on the method of separation variables with addition developed in recent years, new methods of separation variables are proposed, and two algebraically explicit analytical solutions to the general partial differential equation set of non-Fourier and non-Fick heat and mass transfer in porous media drying are derived. The physical meaning of these solutions is simple and clear, and they are valuable for computational heat and mass transfer as benchmark solutions.

关键词： non-Fourier effects non-Fick effects porous media heat and mass transfer analytical solution.

An analytical solution of non-Fourier Chen-Holmes bioheat transfer equation

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chinese Science Bulletin 2005年第23期50卷 2791-2792页

作者： gou chenhua {2. ruixian institute of engineering {2. Chinese Academy of Sciences Beijing 100080 China Graduate School Chinese Academy of Sciences Beijing 100080China

An algebraically explicit analytical solution with heat wave effect is derived for the non-Fourier bioheat transfer Chen-Holmes model. Besides its important theoreti-cal meaning (for example, to expand the understanding of heat wave phenomena in living tissues), this analytical solu-tion is also valuable as the benchmark solution to check the numerical calculation and to develop various numerical computational approaches.

关键词： Chen-Holmes方程生物热传递模型非傅立叶效应解析解

Explicit analytical solutions of axisymmetric laminar natural convection along vertical tubes

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Progress in Natural Science:Materials International 2005年第3期 66-69页

作者： cai ruixian ˇˇ ,ZHANG Na and {2. chenhua ({4. of engineering thermophysics,chinese academy of Sciences,Beijing100080,china) institute of engineering {2. Chinese Academy of Sciences Beijing 100080 China

There are many natural convection processes in various fields,and it is still valuable to investigate the fluid dynamics and heat transfer of natural *** analytical solutions are meaningful in both theoretical investigation and practical ***-cially,they can be used as the benchmark solutions to check the numerical solutions and to develop numerical differencing schemes,grid generation methods and so *** explicit analytical solutions of axisymmetric steady laminar natural convection along a vertical tube with porous wall and between two vertical concentric tubes are derived for better understanding of the flow and heat transfer as well as promot-ing the computational fluid dynamics and computational heat transfer.

关键词： analytical solution natural convection laminar flow boundary layer vertical cylindrical tube.

Algebraically explicit analytical solutions of unsteady conduction with variable thermal properties in cylindrical coordinate

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Progress in Natural Science:Materials International 2004年第4期 28-35页

作者： cai ruixian and ZHANG Na({2. of engineering {4., chinese academy of Sciences, Beijing 100080, china) institute of engineering {2. Chinese Academy of SciencesBeijing 100080China

The analytical solutions of unsteady heat conduction with variable thermal properties (thermal conductivity, density and specific heat are functions of temperature or coordinates) are meaningful in theory. In addition, they are very useful to the computational heat conduction to check the numerical solutions and to develop numerical schemes, grid generation methods and so forth. Such solutions in rectangular coordinates have been derived by the authors. Some other solutions for 1-D and 2.D axisymmetrical heat conduction in cylindrical coordinates are given in this paper to promote the heat conduction theory and to develop the relative computational heat conduction.

关键词： analytical solution heat conduction nonlinear variable thermal property cylindrical coordinates.

Electronic and Optical Properties of Rock-Salt A1N under High Pressure via First-Principles Analysis

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Communications in Theoretical Physics 2008年第10期50卷 990-994页

作者： ZHANG Wei CHEN Xiang-Rong cai Ling-Cang gou Qing-Quan institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China International Centre for Materials Physics Chinese Academy of Sciences Shenyang 110016 China Laboratory for Shock Wave and Detonation Physics Research Institute of Fluid Physics Chinese Academy of Engineering Physics Mianyang 621900 China

Electronic and optical properties of rock-salt AIN under high pressure are investigated by first-principlesmethod based on the plane-wave basis *** of band structures suggests that the rock-salt AIN has an indirectgap of 4.53 eV,which is in good agreement with other *** investigating the effects of pressure on the energygap,the different movement of conduction band at X point below and above 2..5 GPa is *** opticalproperties including dielectric function,absorption,reflectivity,and refractive index are also calculated and *** found that the rock-salt AIN is transparent from the partially ultra-violet to the visible light area and hardly does thetransparence affected by the ***,the curve of optical spectrum will shift to high energy area (blueshift) with increasing pressure.

关键词： semiconductors electronic band structure optical properties density functional theory

基于复频散曲线特征的周期结构高铁路基减振研究

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岩土工程学报 2021年第12期43卷 2169-2179页

作者：唐豪陈晓斌唐孟雄蔡德钩王业顺中南大学土木工程学院湖南长沙410075 北京城建设计发展集团股份有限公司深圳分公司广东深圳518000 重载铁路工程结构教育部重点实验室湖南长沙410075 广州市建筑集团有限公司广东广州510440 中国铁道科学研究院北京100081

目前对周期排桩衰减域的研究只停留在频散曲线分析阶段,只有少数学者利用二维复频散曲线来研究周期排桩衰减域,而频散曲线只能得到衰减域的范围,复频散曲线能得到振动波在衰减域内的衰减程度。利用COMSOL PDE模块求解三维模型的复频散曲... 详细信息

目前对周期排桩衰减域的研究只停留在频散曲线分析阶段,只有少数学者利用二维复频散曲线来研究周期排桩衰减域,而频散曲线只能得到衰减域的范围,复频散曲线能得到振动波在衰减域内的衰减程度。利用COMSOL PDE模块求解三维模型的复频散曲线,通过对排桩排布形式和不同桩身材料的影响进行分析得到:三角形排布的排桩衰减域范围最广且减振效果最好;当桩身材料为混凝土或钢时,能产生高频衰减域,而使用两组元桩时可以产生低频衰减域,但两组元桩和混凝土桩的减振程度比钢桩小。最后,通过建立有限尺度的周期排桩频域响应模型验证了复频散曲线计算的正确性,同时对高铁荷载引起的地基振动特征频率0~50Hz,提出针对不同频率减振的4.类型桩和1种组合桩,结果说明组合桩能结合4.类型排桩产生衰减域频率分布的特点,且减振效果较好。

关键词：周期排桩复频散曲线三维模型高铁隔振