A projection method for solving incompressible viscous flows on domains with moving boundaries

In this paper, a projection method is presented for solving the flow problems in domains with moving boundaries. In order to track the movement of the domain boundaries, arbitrary‐Lagrangian–Eulerian (ALE) co‐ordinates are used. The unsteady incompressible Navier–Stokes equations on the ALE co‐ordinates are solved by using a projection method developed in this paper. This projection method is based on the Bell's Godunov‐projection method. However, substantial changes are made so that this algorithm is capable of solving the ALE form of incompressible Navier–Stokes equations. Multi‐block structured grids are used to discretize the flow domains. The grid velocity is not explicitly computed; instead the volume change is used to account for the effect of grid movement. A new method is also proposed to compute the freestream capturing metrics so that the geometric conservation law (GCL) can be satisfied exactly in this algorithm. This projection method is also parallelized so that the state of the art high performance computers can be used to match the computation cost associated with the moving grid calculations. Several test cases are solved to verify the performance of this moving‐grid projection method. Copyright © 2004 John Wiley Sons, Ltd.     

Point-to-Periodic and Periodic-to-Periodic Connections

In this work we consider computing and continuing connecting orbits in parameter dependent dynamical systems. We give details of algorithms for computing connections between equilibria and periodic orbits, and between periodic orbits. The theoretical foundation for these techniques is given by the seminal work of Beyn in 1994, “On well-posed problems for connecting orbits in dynamical systems”, where a numerical technique is also proposed. Our algorithms consist of splitting the computation of the connection from that of the periodic orbit(s). To set up appropriate boundary conditions, we follow the algorithmic approach used by Demmel, Dieci, and Friedman, for the case of connecting orbits between equilibria, and we construct and exploit the smooth block Schur decomposition of the monodromy matrices associated to the periodic orbits. Numerical examples illustrate the performance of the algorithms. This revised version was published online in July 2006 with corrections to the Cover Date.     

Codimension-one minimal projections onto Haar subspaces

Let H_n be an n-dimensional Haar subspace of and let H_n−1 be a Haar subspace of H_n of dimension n−1. In this note we show (Theorem 6) that if the norm of a minimal projection from H_n onto H_n−1 is greater than 1, then this projection is an interpolating projection. This is a surprising result in comparison with Cheney and Morris (J. Reine Angew. Math. 270 (1974) 61 (see also (Lecture Notes in Mathematics, Vol. 1449, Springer, Berlin, Heilderberg, New York, 1990, Corollary III.2.12, p. 104) which shows that there is no interpolating minimal projection from C[a,b] onto the space of polynomials of degree n, (n2). Moreover, this minimal projection is unique (Theorem 9). In particular, Theorem 6 holds for polynomial spaces, generalizing a result of Prophet [(J. Approx. Theory 85 (1996) 27), Theorem 2.1].     

Computational experience with general equilibrium problems

We report on computational experience with an implementation of three algorithms for the general economic equilibrium problem. As a result we get that the projection algorithm for variational inequalities increases the size of solvable models by a factor of 5–10 in comparison with the classical homotopy method. As a third approach we implemented a simulated annealing heuristic which might be suitable to estimate equilibria for very large models.Supported by the German Research Association (Deutsche Forschungsgemeinschaft, SFB 303).     

无自旋混杂的耦簇理论

本文用APCCSD(T)，自旋投影方法消除CCSD中的自旋混杂，自旋投影算符^P用自旋湮灭算符^As 1和^As 2的乘积近似表出，提高了计算精度。     

辣根过氧化物酶反应的化学动力学分析

用辣根过氧化物酶来处理废水中的苯酚和氯酚为许多人所关注。采用停流快速混合技术，利用快速扫描紫外可见分光光度计得到辣根过氧化物酶催化过氧化氢氧化苯酚聚合过程的瞬态光谱数据。对此测量数据矩阵用正交投影及遗传算法解析后，确定体系中产生紫外吸收的物种数，及辣根过氧化物酶中间体形式的纯光谱信息，进而解出反应过程中各组分的动力学曲线。     

Three-dimensional structural features and the toxicity of aminobenzenes and phenols

There are many organic pollutants in the environment, such as polychlorinated biphenyl, polycyclic aromatic hydrocarbons, dichlorodiphenyl-trichloroethane (DDT), and polychlorinated naphthalene. These organic pollutants are persistent,liposoluble and easily cumulated in organism; consequently, the potential toxicity will be high. Risk assessment of industrial chemicals is currently carried out using scanty experimental data, because many of these chemicals have very little or no test data. S…     

Rapid biomass analysis

New, rapid, and inexpensive methods that monitor the chemical composition of corn stover and corn stover-derived samples are a key element to enabling the commercialization of processes that convert stover to fuels and chemicals. These new techniques combine near infrared (NIR) spectroscopy and projection to latent structures (PLS) multivariate analysis to allow the compositional analysis of hundreds of samples in 1 d at a cost of about $10 each. The new NIR/PLS rapid analysis methods can also be used to support a variety of research projects that would have been too costly to pursue by traditional methods.     

多组分光谱相关色谱及其在中药色谱指纺图谱分析中的应用

基于正交投影理论和相关色谱方法提出多组分光色谱方法提出多组分光谱相关 色谱。为克服联用色谱仪器的不等性噪声影响，采用目标组分投影前后的光谱夹角 余弦判据，判断不同的中药色谱指纹图谱的相关组分色谱峰簇。该方法为中药指纹 图谱的数据处理、合理评价以及中药谱效学的基本理论研究提供一种实用的工具。