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101.
针对果蝇优化算法易陷入早熟收敛、收敛速度慢、寻优精度低的缺点,提出一种基于极坐标编码的果蝇优化算法.为提高果蝇优化算法的寻优精度,采用极坐标编码的形式,以增加单个母体寻优空间表示方法的多样性,并使种群中的个体,在围绕个体的整个超球体内随机搜索,使个体的搜索范围更加广泛.在迭代寻优过程中,根据适应度值和概率调整极角,逐渐降低观测结果的不确定性.通过9个基准测试函数,对基于极坐标编码的果蝇优化算法进行仿真实验,结果表明了算法在收敛性和稳定性方面,优于其它5个优化算法,测试结果验证了极坐标编码方法的有效性和可行性. 相似文献
102.
《Physics and Chemistry of Liquids》2012,50(1):51-58
Abstract A general proof is given that the classical second virial coefficient satisfies the requirement for the non-existence of a termination point of any locus of Cv extrema. This validity criterion is applied to some proposed forms for the second virial coefficient. The order of the termination temperatures is verified for a fairly general intermolecular potential. In particular a proof is given that TF lies between TC and TA. Also the hard-core limit of the ratio TD/TA(~2) is examined briefly. 相似文献
103.
The influence of lattice structure on the dynamic performance of metal hollow sphere agglomerates 总被引:1,自引:0,他引:1
This paper addresses the dynamic performances of partially bonded or unbonded metallic hollow sphere structure (MHSS). Under the condition that the densities of MHSS are the same, three morphologies, that is, simple cubic (SC), body-centered cubic (BCC) and face-centered cubic (FCC) are investigated to see the topological effect of lattice structure on the dynamic performance of MHS agglomerates. 相似文献
104.
105.
A procedure for predicting thermodynamic, dynamic, and rheological properties of polymerically stabilized colloidal dispersions
in good solvents by mapping onto an effective hard sphere dispersion is investigated and evaluated for its range of applicability.
Configurational pressures and energies, calculted by Monte Carlo simulations, are used to assess the model's accuracy for
predicting thermodynamic data. Similarly, long-time self-diffusivities, calculated by equilibrium Brownian Dynamic simulations,
are used to assess the model's feasibility for predicting dynamic properties. Finally, zero shear viscosities are calculated
by the method of hydrodynamic preaveraging and compared to rheological measurements. The various testing methods demonstrate
the effectiveness of the procedure and suggest the model's range of applicability.
Received: 13 March 2000 Accepted: 28 June 2000 相似文献
106.
The problem of two‐dimensional tracer advection on the sphere is extremely important in modeling of geophysical fluids and has been tackled using a variety of approaches. A class of popular approaches for tracer advection include ‘incremental remap’ or cell‐integrated semi‐Lagrangian‐type schemes. These schemes achieve high‐order accuracy without the need for multistage integration in time, are capable of large time steps, and tend to be more efficient than other high‐order transport schemes when applied to a large number of tracers over a single velocity field. In this paper, the simplified flux‐form implementation of the Conservative Semi‐LAgrangian Multi‐tracer scheme (CSLAM) is reformulated using quadratic curves to approximate the upstream flux volumes and Gaussian quadrature for integrating the edge flux. The high‐order treatment of edge fluxes is motivated because of poor accuracy of the CSLAM scheme in the presence of strong nonlinear shear, such as one might observe in the midlatitudes near an atmospheric jet. Without the quadratic treatment of upstream edges, we observe at most second‐order accuracy under convergence of grid resolution, which is returned to third‐order accuracy under the improved treatment. A shallow‐water barotropic instability also reveals clear evidence of grid imprinting without the quadratic correction. Consequently, these tests reveal a problem that might arise in tracer transport near nonlinearly sheared regions of the real atmosphere, particularly near cubed‐sphere panel edges. Although CSLAM is used as the foundation for this analysis, the conclusions of this paper are applicable to the general class of incremental remap schemes. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
107.
We use the BBGKY hierarchy and the mass, momentum, and intrinsic energy conservation laws, which are consequences of this hierarchy, to obtain the hydrodynamic equations for multicomponent systems and the diffusion equations. We formulate several restrictions on the thermodynamic equations for irreversible processes. 相似文献
108.
E. Peuvrel D. Siegert P. Navard G. H. Meeten 《Journal of Polymer Science.Polymer Physics》1992,30(8):865-869
The Rayleigh-Gans-Debye approximation is used to investigate the small-angle, cross-polarized light scattering by a sphere of radius a, birefringence Δμ and relative index μ. If θmax is the polar scattering angle of the intensity maxima, the quantity Ûmax = 4πa/λ × sin (θmax/2) behaves in two different ways according to the signs of Δμ and μ ? 1. When Δμ > 0, μ > 1 or Δμ < 0, μ < 1, then Ûmax varies from 2.8 to 4.1 as Δμ increases from zero. If Δμ < 0, μ > 1 or Δμ > 0, μ < 1, then Ûmax goes from 2.8 to about 6, thereafter decreasing to 4.1. Another interesting result is that the value of Ûmax for a highly briefringent sphere is 4.1 only for large diameters. It decreases to 4.0 when the diameter decreases. 相似文献
109.
本文分析了强激光作用下铝合金靶表面反射率的时间变化规律。利用转镜调Q钕玻璃激光器和积分球装置对铝LY12的表面激光反射率动态变化规律进行了测量,得到了功率密度在10 ̄6~10 ̄9W/cm ̄2范围内的相应结果。同时,从金属近自由电子模型-Drude理论出发,对金属铝的电导率与温度变化关系进行了数值模拟,亦得到了相应的反射率变化规律,实验结果与数值模拟结果基本符合。当激光功率密度更同时(10 ̄11~10 ̄15W/cm ̄2),由等离子体模型和局部热力学平衡(LTE)理论,得到了反射率随温度变化的数值模拟结果,与国外的实验结果符合得较好。 相似文献
110.
给出了用LMTO-ASA方法计算的共价晶体β-SiC的电子结构和物态方程。其压缩比σ=1.0~2.5。我们在维格纳-赛兹原胞中放入两个空球来模拟原子球的密堆积效果。结果表明,对于开结构体系晶体物性的计算,本方法也是适用的。 相似文献