单亦初
,
张维冰
,
SEIDEL-MORGENSTERN Andreas
,
赵瑞环
,
张玉奎
色谱
doi:10.3321/j.issn:1000-8713.2006.02.004
计算机辅助高效液相色谱(HPLC)分离条件优化可以低成本、快速地得到优化的分离条,因而已较为广泛地用于复杂样品的分离分析.基于移动重叠分离图方法,又发展了一种新型的多台阶梯度分离条件的优化方法可调移动重叠分离图法.该方法通过预测不同流动相条件下各组分的保留时间、峰宽和分离度,绘制出对于样品中各组分的重叠分离区域图.在对当前台阶流动相组成进行优化的同时,考虑其对后面一到两个台阶上流出组分保留的影响,实时地重新绘制对于后面台阶上流出组分的重叠分离区域图.通过观察当前台阶流动相条件对当前台阶和后面台阶上流出组分分离的影响,综合考虑样品中所有组分的分离情况,找到更接近全局最优的分离条件.通过扫描的方法对优化得到的分离条件进行微调,能够进一步提高分离效果.采用文献数据对可调移动重叠分离图法的应用加以说明,在二元流动相体系下,证明了该方法在HPLC方法建立方面的优越性.
关键词:
高效液相色谱
,
分离条件优化
,
可调移动重叠分离图
Physics Letters A
Two-dimension spring square network model involving the nearest and second neighbour bonds is studied by numerical simulation with Gauss-Seidel iteration for brittle fracture Mode 1. The material-dependent parameter, G(0)/G, is introduced in this simulation, G and G(0) are the parameters related to the elastic moduli of the nearest and second neighbour, bonds, respectively. Brittle fracture of materials with different G(0)/G are simulated under the same quenched disorder. The fractal dimension of crack fluctuates with G(0)/G. It seems that it is impossible for different materials to have a universal fractal dimension of crack in brittle fracture. However, it is possible to have different so-called universal fractal dimensions. (C) 2003 Elsevier Science B.V All rights reserved.
关键词:
fracture;crack;fractal dimension;scanning-tunneling-microscopy;surfaces;roughness;geometry;metals;model
Chinese Physics Letters
A new porous media model with correlated sites-bonds has been constructed. Taking into account both the pore and throat geometries, the viscous fingering (VF) in porous media has been investigated by using the standard over-relaxed Gauss-Seidel scheme. The simulation results show that the VF's structure varies with the correlation parameter epsilon and the viscous ratio M. The sweep efficiency epsilon decreases along with the increase of the correlation parameter E and the lattice size R-1s. The surface fractal D-s gradually increases as the correlation parameter epsilon increases, whatever the viscous ratio M is. Also, D-s gradually increases as M increases whatever epsilon is. This means that not only the viscosity ratio but also the topology and the geometry of the porous media have a strong effect on the displacement process, the VF's structure, the sweep efficiency and the surface pattern.
关键词:
porous-media;computer-simulations;fractal nature;2-phase flow;percolation;displacement;ratio
Physica a-Statistical Mechanics and Its Applications
Two-dimensional spring square network model involving the nearest and second neighbour bonds is studied by numerical simulation with Gauss-Seidel iteration for brittle fracture Mode I. The material-dependent parameter, G(0)/G(1) is introduced in this simulation, and G and G(0) are the parameters related to the elastic moduli of the nearest and second neighbour bonds, respectively. Brittle fracture of the same material with different quenched disorders is simulated. Fractal dimension of crack fluctuates with quenched disorder. It seems that it is impossible to have a universal fractal dimension of crack in brittle fracture for the same material with different quenched disorders. However, it is possible to have different so-called universal fractal dimensions in some cases. (C) 2003 Published by Elsevier B.V.
关键词:
disorder;fracture;crack;fractal dimension;scanning-tunneling-microscopy;surfaces;breakdown;lattices;metals
卢义
,
袁新
工程热物理学报
基于通量重构形式的高阶算法,在保持间断Galerkin算法局部重构特性和非结构网格中任意高阶精度优点的同时,其计算量大大减小,且具有形式简单、灵活性高等特点。使用显式Runge-Kutta法,隐式非线性LU-SGS法,以及使用无矩阵预处理的广义极小残值法（generalized minimal residual,GMRES）进行求解,并使用p型多重网格在低阶次上光顺低频误差以加快求解。一至四阶精度结果显示使用p型多重网格对显式Runge-Kutta求解以及LU-SGS均具有明显的加速效果,而基于无矩阵预处理的GMRES解法具有更好的稳定性和更快的求解速度。本文提出的基于Gauss-Seidel迭代的无矩阵预处理方法,具有高效和稳定的特征,存储量大大小于ILU预处理。
关键词:
通量修正
,
p型多重网格
,
GMRES
,
无矩阵预处理
Chinese Physics
We have constructed a porous media model in which there are percolation clusters with varying percolation probability P and correlated site-bonds. Taking into account both the pore and the throat geometry, the viscous fingering (VF) in porous media has been investigated by using the standard over-relaxed Gauss-Seidel scheme. The simulation results show that the VF structure varies with the correlation parameter epsilon, the viscosity ratio M and the percolation probability P. The smaller the correlation parameter e, the greater the deviation of the normalized size distribution of the invaded throat N-inv(r) from the truncated Rayleigh distribution. For a larger viscosity ratio M, the VF pattern looks like a diffusion-limited-aggregation structure in percolation clusters. The fractal dimension D increases with the increase of the percolation probability P and the correlation parameter epsilon. The velocity distribution f (alpha) of VF in percolation clusters is of a parabola-like curve. The tail of the distribution (large alpha) is longer for a larger correlation parameter epsilon. For a smaller epsilon, the distribution is very sharp. The sweep efficiency E decreases along with the decrease of the correlation parameter e and the increase of the network size L-nz. E has a minimum as L increases up to the maximum no matter what the values of P, M and epsilon. The E similar to L-nz curve has a frozen zone and an active zone. The geometry and the topology of the porous media have strong effects on the displacement processes and the structure of VF.
关键词:
correlation parameter;fractal dimension;sweep efficiency;scaling;function;diffusion-limited-aggregation;viscous fingers;percolation;displacement;simulations;growth;ratio
