机翼大攻角下失速颤振的气动弹性研究

本文采用流固耦合的数值方法研究了机翼在0°～50°攻角下的颤振。计算结果表明,随着来流攻角α0的增大,机翼的固有频率对颤振的影响越来越大,颤振由线性的强迫振动逐渐发展成为非线性的自激振动,而当α0增加到一定程度以后,大尺度分离流交替地从机翼头部和尾部产生,机翼和流场会发生共振,引起机翼的失速颤振。     

增湿活化反应器内喷水脱硫试验研究

本文介绍在热态脱硫试验台上进行的生石灰和消石灰的喷水活化脱硫试验,研究了Ca/S比、饱和温距、入口烟气SO2浓度、烟气速度及水喷嘴雾化风对脱硫效率和钙利用率的影响规律,对两种脱硫剂的脱硫活性进行了比较,并对喷水增湿提高脱硫效率的机理进行了分析。研究表明,喷水增湿使两种脱硫剂的活性都有明显提高,生石灰具有价格优势。     

基于MATLAB(SIMULINK)的电弧炉电极调节系统FUZZY-PD控制器的仿真

介绍了采用MATLAB V5.2提供的模糊逻辑工具箱来设计研究电孤纺电极调节系统中的模糊－－PD控制器，讨论了在SIMULINK环境下模糊－PD控制器的参数自调速原理、结构、建立模糊控制规则库和模糊推论方法，并给出仿真结果与结论。     

基于同步辐射加速器的康普顿背散射γ射线源(Ⅰ)产生MeV量级γ光子的数值计算

提出在筹建的上海同步辐射装置上建造一条MeV量级γ射线束及应用站,采用μm波长的红外(或远红外)激光与储存环中3.5GeV电子束进行康普顿背散射,从而获得能区为1—25MeV的康普顿背散射γ光子束,该光子束具有高强度、高极化度(线和圆极化)、准单色、方向性好的优点,可以广泛地应用于核物理和核天体物理基础研究及相关的应用研究领域.介绍了康普顿背散射的基本原理,并结合储存环参数给出了光子束性能的数值计算结果.     

Algorithms for flattened Gaussian beams passing through apertured and unapertured paraxial ABCD optical systems

The propagation property of flattened Gaussian beams (FGBs) is studied based on the Collins formula, and analytical propagation equations for FGBs with and without an aperture are derived. It is shown that the closed-form expressions for the FGB of order N passing through paraxial ABCD optical systems without an aperture can be written as the combinations of Confluent Hyper-geometric Functions, and that the analytical equations for the FGB of order N passing through apertured paraxial ABCD optical systems may involve Error Functions. The proposed algorithms for the considered beams can save computing time, provide intuitive physical insights, and help to design optical systems. Our results are confirmed and illustrated with numerical examples.     

Convergence analysis of a modified inexact implicit method for general mixed monotone variational inequalities

We consider a useful modification of the inexact implicit method with a variable parameter in Wang et al. J Optim Theory 111: 431–443 (2001) for generalized mixed monotone variational inequalities. One of the contributions of the proposed method in this paper is that the restrictions imposed on the variable parameter are weaker than the ones in Wang et al. J Optim Theory 111: 431–443 (2001). Another contribution is that we establish a sufficient and necessary condition for the convergence of the proposed method to a solution of the general mixed monotone variational inequality.     

一个线性约束优化问题的广义梯度投影法

本文对线性约束优化问题提出了一个新的广义梯度投影法，该算法采用了非精确线性搜索，并在每次迭代运算中结合了广义投影矩阵和变尺度方法的思想确定其搜索方向．在通常的假设条件下，证明了该算法的整体收敛性和超线性收敛速度．     

Hamiltonian N2‐locally connected claw‐free graphs

A graph G is N₂‐locally connected if for every vertex ν in G, the edges not incident with ν but having at least one end adjacent to ν in G induce a connected graph. In 1990, Ryjá?ek conjectured that every 3‐connected N₂‐locally connected claw‐free graph is Hamiltonian. This conjecture is proved in this note. © 2004 Wiley Periodicals, Inc. J Graph Theory 48: 142–146, 2005