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| 1 | Entransy dissipation minimization for liquid-solid phase change processes显示文摘The liquid-solid phase change process of a simple one-dimensional slab is studied in this paper.By taking entransy dissipation minimization as optimization objective,the optimal external reservoir temperature profiles are derived by using optimal control theory under the condition of a fixed freezing or melting time.The entransy dissipation corresponding to the optimal heat exchange strategies of minimum entransy dissipation is 8/9 of that corresponding to constant reservoir temperature operations,which is independent of all system parameters.The obtained results for entransy dissipation minimization are also compared with those obtained for the optimal heat exchange strategies of minimum entropy generation and constant reservoir temperature operations by numerical examples.The obtained results can provide some theoretical guidelines for the choice of optimal cooling or heating strategy in practical liquid-solid phase change processes. | XIA ShaoJun,CHEN LinGen & SUN FengRui Postgraduate School,Naval University of Engineering,Wuhan 430033,China | 2010 | Science China(Technological Sciences)2010，53，4： | 41 |
| 2 | “Volume-Point” heat conduction constructal optimization with entransy dissipation minimization objective based on rectangular element显示文摘By taking equivalent thermal resistance, which reflects the average heat conduc- tion effect and is defined based on entransy dissipation, as optimization objective, the 'volume to point' constructal problem of how to discharge the heat generated in a fixed volume to a heat sink on the border through relatively high conductive link is re-analyzed and re-optimized in this paper. The constructal shape of the control volume with the best average heat conduction effect is deduced. For the elemental area and the first order construct assembly, when the thermal current density in the high conductive link is linear with the length, the optimized shapes of assemble based on the minimization of entransy dissipation are the same as those based on minimization of maximum temperature difference, and the mean tem- perature difference is 2/3 of the maximum temperature difference. For the second and higher order construct assemblies, the thermal current densities in the high conductive link are not linear with the length, and the optimized shapes of assem- ble based on the minimization of entransy dissipation are different from those based on minimization of maximum temperature difference. For the same parame- ters, the constructs based on minimization of entransy dissipation and the con- structs based on minimization of maximum temperature difference are compared, and the results show that the constructs based on entransy dissipation can de- crease the mean temperature difference better than the constructs based on mini- mization of maximum temperature difference. But with the increase of the number of the order, the mean temperature difference does not always decrease, and there exist some fluctuations. Because the idea of entransy describes the heat transfer ability more suitably, all of the heat conduction constructal problems may be re-optimized based on it. | WEI ShuHuan, CHEN LinGen & SUN FengRui Postgraduate School, Naval University of Engineering, Wuhan 430033, China | 2008 | Science China(Technological Sciences)2008，51，8： | 47 |
| 3 | Constructal optimization for geometry of cavity by taking entransy dissipation minimization as objective显示文摘The entransy dissipation extremum principle provides new warranty and criterion for optimization of heat transfer.For two cases(body with heat generation and body heated externally)of a solid conducting wall with an open cavity,a dimensionless equivalent thermal resistance based on entransy dissipation definition was taken as the optimization objective to optimize the model constructal ge- ometry.Numerical results validated the necessity and feasibility of the presented method.Comparisons of the numerical results based on minimization of dimensionless maximum thermal resistance and minimization of dimensionless equivalent thermal resistance,respectively,showed that there was no obvious difference between the two results when the volume fractionΦoccupied by cavity was small, but the difference between the two results increased with the increases ofΦand the body aspect ratio H/L for any model.The optimal cavities for bodies heated externally were more slender than those for bodies with heat generation.Heat origin had obvious effect on the global performance of heat transfer. The entransy dissipation of body heated externally increased 2―3 times than that of body with heat generation,indicating that the global performance of heat transfer weakened.The method presented herein provides some guidelines for some relevant thermal design problems. | XIE ZhiHui CHEN LinGen SUN FengRui | 2009 | Science China(Technological Sciences)2009，52，12： | 37 |
| 4 | 微网主从控制模式下的稳定性分析显示文摘主要研究主从控制模式下微网独立运行时的稳定性问题。基于离散时间状态方程的微网数学模型,通过特征值理论分析和PSCAD仿真结果验证,发现当主电源电压环比例增益、从电源数量或负荷等参数发生变化时,系统特征矩阵中一对高频共轭复特征值会到达z域单位圆外,导致系统不稳定,交流母线电压和各分布式电源输出电流中出现高频振荡分量。提出在主电源电压环电压反馈通道中加入基于二阶通用积分环节的带通滤波器,能有效改善系统的稳定性,保证系统稳定运行。 | 李霞林 郭力 王成山 | 2014 | 电工技术学报2014，29，2： | 37 |
| 5 | Analyses of hot and humid weather in Beijing city in summer and its dynamical identification显示文摘The circulation, hygrothermal property and moisture transport character of typical hot and humid weather were analyzed in Beijing areas from July 30 to August 4, 2002. It was pointed out that, under the control of subtropical anticyclone which stretches to the west and north, downdraft suppresses the lifting of lower-troposphere moisture, which makes moisture keep in the lower troposphere. That is the direct reason causing hot and humid weather. Considering the non-uniformity saturated character in real atmosphere, generalized moist potential vorticity (GMPV) equation is derived by the introduction of generalized moist potential temperature concept. The analysis of GMPV shows that negative GMPV anomaly occurs in the lower troposphere. It has indicative sense to hot and humid weather. Thus, the GMPV anomaly can be utilized to identify this kind of weather and to make a short-term prediction. | GAO Shouting ZHOU Yushu LEI Ting SUN Jianhua | 2005 | Science China Earth Sciences2005，48，z2： | 30 |
| 6 | Constructal optimization of discrete and continuous-variable cross-section conducting path based on entransy dissipation rate minimization显示文摘Using constructal entransy dissipation rate minimization method based on discrete variable cross-section conducting path,constructal optimizations of elemental area with variable cross-section conducting path are performed,and the results are compared with the optimization results of elemental area with the constant cross-section conducting path.The comparison shows that the minimum mean temperature difference based on elemental area with variable cross-section conducting path increases and approaches a constant as the assembly's order increases,but the minimum mean temperature difference based on elemental area with constant cross-section conducting path decreases and approaches a constant as the assembly's order increases.The difference between them is caused by the different dimensionless mean temperature difference of the first order assembly.A universal constructal optimization method by self similar organization to improve heat transfer ability and its corresponding rule are proposed.With the constructal optimization method by self similar organization based on entransy dissipation rate minimization objective,the mean temperature difference approaches a constant as the assembly's order increases. | WEI ShuHuan,CHEN LinGen & SUN FengRui Postgraduate School,Naval University of Engineering,Wuhan 430033,China | 2010 | Science China(Technological Sciences)2010，53，6： | 27 |
| 7 | Constructal entransy dissipation rate and flow-resistance minimizations for cooling channels显示文摘Based on constructal theory,a construct of a volume that generates heat at every point and is cooled by the coolant in the constant or tapered channel is optimized by minimizing entransy dissipation rate and flow resistance.The optimal constructs of the rectangular elements with dimensionless mean thermal resistance minimization as well as the first-,secondand thirdorder assemblies with dimensionless global flow resistance minimizations are obtained respectively.The results show that both the mean temperature difference and the limiting temperature difference of rectangular elements based on EDR (entransy dissipation rate) and MTD (maximum temperature difference) minimizations respectively are almost equal.Comparing heat transfer performances from the two optimization procedures,the dimensionless global flow resistance is decreased more for the former procedure when the assembly’s order is high.It may create great superiority for constructal optimization to combine the entransy dissipation extreme principle with heat convection. | XIAO QingHua,CHEN LinGen & SUN FengRui Postgraduate School,Naval University of Engineering,Wuhan 430033,China | 2010 | Science China(Technological Sciences)2010，53，9： | 27 |
| 8 | A new algorithm of edge detection for color image: Generalized fuzzy operator显示文摘The definition of the generalized fuzzy set is presented for the first time, and a generalized fuzzy operator is proposed to transform a generalized fuzzy set into a normal fuzzy set. The algorithm theory of the operator, as the newest method of the edge detection of a 2-D image, is successfully established. Many experiments haw proved that the algorithm is simpler, more rapid and more precise in location than other edge detection methods. And a schedule of the concrete performance has been given additionally about the edge detection of color images. | 陈武凡 鲁贤庆 陈建军 吴国雄 | 1995 | Science China Mathematics1995，38，10： | 28 |
| 9 | Improvement of tree-like network constructal method for heat conduction optimization显示文摘The analysis of the “tree-like network” construct method has been repeated. The high effective conduction channel distribution has been optimized again, without the premise that the new order assembly construct must be assembled by the optimized last order construct. It is proved that the “tree-like network” construct method is faultiness. A more optimal construct is obtained, and when the thermal conductivity and the proportion of the two heat conduction materials are constant, the limit of the minimum heat resistance is derived. All these conclusions can be used to guide the engineering application. | WU Wenjun CHEN Lingen SUN Fengrui | 2006 | Science China(Technological Sciences)2006，49，3： | 25 |
| 10 | Representation of the constitutive equation of viscoelastic materials by the generalized fractional element networks and its generalized solutions显示文摘The generalized fractional element networks are presented in this paper. In order to extend the structure of the model solutions to the generalized function space and make it contain more physical meanings, the restriction on the parameters of the fractional element proposed by Schiessel et al. is eliminated and a 'compatibility equation' is added. The discretization method for solving the inverse Laplace transform is used and developed. The generalized solutions of the model equations are given. At the same time the generalized fractional element network--Zener and Poyinting-Thomson models are discussed in detail. It is shown that all the results obtained previously about the models of single parameter with fractional order and the classical models with integer order can be contained as the special cases of the results of this paper. | 徐明瑜 谭文长 | 2003 | Science China(Physics,Mechanics & Astronomy)2003，46，2： | 25 |
| 11 | A generalized variational principle and theoretical model for magnetoelastic interaction of ferromagnetic bodies显示文摘The quantitative analysis shows that no theoretical model for 3-d magnetoelastic bodies, in literatures to date, can commonly simulate two kinds of distinct experimental phenomena on magnetoelastic interaction of ferromagnetic structures. This makes it difficult to effectively discribe the magnetoelastic mechanical behavior of structures with complex geometry, such as shells. Therefore, it is a key step for simulating magnetoelastic mechanical characteristics of structures with complex geometry to establish a 3-d model which also can commonly characterize the two distinct experimental phenomena. A theoretical model for three dimension magnetizable elastic bodies, which is commonly suitable for the two kinds of experimental phenomena on magnetoelastic interaction of ferromagnetic plates, is presented by the variational principle for the total energy functional of the coupling system of the 3-d ferromagnetic bodies. It is found that for the case of linear isotropic magnetic materials, the magnetic | 周又和 郑晓静 | 1999 | Science China Mathematics1999，42，6： | 26 |
| 12 | Lie bialgebras of generalized Witt type显示文摘In this paper, all Lie bialgebra structures on the Lie algebras of generalized Witt type are considered. It is proved that, for any Lie algebra W of generalized Witt type, all Lie bialgebras on W are the coboundary triangular Lie bialgebras. As a by-product, it is also proved that the first cohomology group H1(W, W (x) W) is trivial. | SONG Guang’ai & SU Yucai College of Mathematics and Information Science, Shandong Institute of Business and Technology, Yantai 264005, China Department of Mathematics, University of Science and Technology of China, Hefei 230026, China Department of Mathematics, Shanghai Jiaotong University, Shanghai 200240, China | 2006 | Science China Mathematics2006，49，4： | 22 |
| 13 | GENERALIZED H-KKM TYPE THEOREMS IN H-METRIC SPACES WITH APPLICATIONS显示文摘The new notions of H-metric spaces and generalized H-KKM mappings were introduced. Some generalized H-KKM type theorems for generalized H-KKM mappings with finitely metrically compactly closed values and finitely metrically compactly open values were established in H-metric spaces. These theorems generalize recent results of Khamsi and Yuan. As applications, some Ky Fan type matching theorems for finitely metrically compactly open covers and finitely metrically compactly closed covers, fixed point theorems and minimax inequality are obtained in H-metric spaces. These results generalize a number of known results in recent literature. | DING Xie-ping(丁协平) XIA Fu-quan(夏福全) | 2001 | Applied Mathematics and Mechanics(English Edition)2001，22，10： | 23 |
| 14 | Rank theorems of operators between Banach spaces显示文摘Let E and F be Banach spaces, and B( E, F) all of bounded linear operators on E into F. Let T0 ∈ B( E, F) with an outer inverse T0# ∈ B( F, E). Then a characteristic condition of S= (I + T0# ( T- T0))-1 T0# with T∈ B( E, F) and || T0# ( T- T0) || < 1, being a generalized inverse of T, is presented, and hence, a rank theorem of operators on E into F is established (which generalizes the rank theorem of matrices to Banach spaces). Consequently, an improved finite rank theorem and a new rank theorem are deduced. These results will be very useful to nonlinear functional analysis. | MA JipuDepartment of Mathematics, Nanjing University, Nanjing 210093, China | 2000 | Science China Mathematics2000，43，1： | 22 |
| 15 | 结合GLWT和LBP提取纹理特征的图像分割显示文摘提出一种提取图像纹理特征的新方法:结合广义局部沃尔什变换(GLWT)和局部二值模式(LBP)。首先说明广义局部沃尔什变换的定义,然后计算并分析广义局部沃尔什变换系数,并选取识别性能较好的2阶矩作为纹理特征。结合LBP空间纹理特征和灰度特征,然后根据纹理特征采用模糊C均值算法对像素进行聚类。实验结果表明,结合广义局部沃尔什变换和LBP的纹理特征具有更好的鉴别性能,且计算简单。 | 詹曙 胡德凤 蒋建国 | 2014 | 电子测量与仪器学报2014，28，2： | 23 |
| 16 | Constructal optimization of a vertical insulating wall based on a complex objective combining heat flow and strength显示文摘For a vertical insulating wall,a product function of heat flow and strength with power weight is introduced as the complex optimization objective to compromise between insulating performance and mechanical performance.Under the global constraints of fixed external dimensions and safety requirements,the constructal optimization of the wall is carried out by taking the complex function maximization as the objective.It is shown that the maximum of the complex-objective function and its corresponding optimal internal structure design under a certain environmental condition can be obtained by allowing the internal structure of the wall to vary(evolve)freely.The validity,effectivity and applicability of the complex function are proved by the results and the power weight parameter in the range from 0.4 to 4 can compromise between the requirements of insulating and strength simultaneously and preferably.The constructal optimization with coequal attention to heat flow and strength and the corresponding results are discussed in detail.The optimal structure design and the corresponding performance analyses under various environmental conditions of application are presented.When the change of environment is greater and the total Rayleigh number is bigger,the insulating wall with large number of cavities should be employed.When the total Rayleigh number is small,the better performance can be obtained by reasonably employing the insulating wall with small number of cavities.The complex function has better selfadaptability,and the results in the recent literature are special cases of this paper. | XIE ZhiHui,CHEN LinGen &SUN FengRui Postgraduate School,Naval University of Engineering,Wuhan 430033,China | 2010 | Science China(Technological Sciences)2010，53，8： | 21 |
| 17 | Seismogram Synthesis in Multi-layered Half-space Part Ⅰ. Theoretical Formulations显示文摘In the past two decades numerous studies were made to develop and improve the theory and practical computation techniques of synthesizing theoretical seismograms for the model of multi-layered half-space. Today, synthesizing theoretical seismograms in multi-layered half-space is an important tool for understanding the structure of the Earth’s interior as well as the seismic source process from well-recorded seismograms data. As part of a review of the state-of-the-art, in this article I shall present a systematic and self-contained theory of elastic waves in multi-layered half-space media based on the developments in the past two decades. | Chen XiaofeiDepartment of Geophysics, Peking University, Beijing 100871, China | 1999 | Earthquake Research in China1999，13，2： | 21 |
| 18 | Constructal optimization of twice Y-shaped assemblies of fins by taking maximum thermal resistance minimization as objective显示文摘In this paper,constructal optimization of the twice Y-shaped assemblies of fins with six freedom degrees (characteristic parameters of geometry) is performed by employing finite element method and taking dimensionless maximum thermal resistance as a performance index,and the heat transfer performance of the twice Y-shaped assemblies of fins under various conditions with different freedom degrees are analyzed. The results show that the twice assemblies can improve the heat transfer performance of Y-shaped fin remarkably,and the minimum maximum thermal resistance of the twice Y-shaped assemblies of fins decreases by 36.37% compared with that of once Y-shaped assembly of fins. It is also proved again that the larger the number of freedom degrees for evolving is,the more perfect the system performance is. The effects of different characteristic parameters of geometry on the performance of the twice Y-shaped assemblies of fins are different,one should pay different attention to these parameters in practical engineering designs. The effects of two angles on the maximum thermal resistance are larger,but the optima of the two angles are robust. The effects of two height ratios on the maximum thermal resistance are more remarkable than those of two thickness ratios. | XIE ZhiHui, CHEN LinGen & SUN FengRui Postgraduate School, Naval University of Engineering, Wuhan 430033, China | 2010 | Science China(Technological Sciences)2010，53，10： | 21 |
| 19 | A CLASS OF SINGULARLY PERTURBED GENERALIZED BOUNDARY VALUE PROBLEMS FOR QUASI-LINEAR ELLIPTIC EQUATION OF HIGHER ORDER显示文摘The singularly perturbed generalized boundary value problems for the quasi_linear elliptic equation of higher order are considered. Under suitable conditions,the existence, uniqueness and asymptotic behavior of the generalized solution for the Dirichlet problems are studied. | MO Jia-qi(莫嘉琪) OUYANG Cheng(欧阳成) | 2001 | Applied Mathematics and Mechanics(English Edition)2001，22，3： | 19 |
| 20 | Dense coding scheme using superpositions of Bell-states and its NMR implementation显示文摘Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR)quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system. | ZHANG Jingfu, XIE Jingyi, DENG Zhiwei & LU Zhiheng Key Laboratory for Quantum Information and Measurements, Department of Physics, Tsinghua University, Beijing 100084, China Center for Quantum Information, Tsinghua University, Beijing 100084, China Department of Materials Science and Engineering, Beijing Normal University, Beijing 100875, China Testing and Analytical Center, Beijing Normal University, Beijing 100875, China Department of Physics, Beijing Normal University, Beijing 100875, China | 2005 | Science China(Physics,Mechanics & Astronomy)2005，48，1： | 18 |
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