离散晶格的正族、负族及其Hamilton结构

构造了一个新的等谱问题，利用相容性条件，推导出离散晶格方程的正族和负族。再利用迹恒等式，建立其Hamilton 结构。获得的离散方程族的达布变换、双线性化、对称、守恒率及其精确解也值得进一步研究。     

新疆淡水藻类研究乌鲁木齐南山八一林场鼓藻属再报

报道了新疆乌鲁木齐南山八一林场鼓藻属８种，２变种，其中７种，２变种以为新疆维吾乐自治区新记录，这些结果是对１９９１年６～７月所采集的２０号标本经鉴定后获得的。     

Linear error-block codes

A linear error-block code is a natural generalization of the classical error-correcting code and has applications in experimental design, high-dimensional numerical integration and cryptography. This article formulates the concept of a linear error-block code and derives basic results for this kind of code by direct analogy to the classical case. Some problems for further research are raised.     

一些特殊类型广义Bent函数的不存在性

本文利用分圆域中的素理想分解特性和一些特殊的不定方程的解性质,得到一些特殊类型的广义Bent函数的不存在性结果。     

横向风对自然通风干式冷却塔空气流场影响的模型实验研究

本文通过模型实验手段研究了横向风对自然通风干式冷却塔空气流场的影响问题。研究揭示了产生影响的主要原因，并提出了有效的改进建议     

矩形截面管内电流变液的流动

基于伽辽金方法，导出了矩形截面直管内泊肃叶流动的一阶和二阶近似解．在此基础上，研究了电流变单链的变形问题，并得到了描述它形状的多项式函数．     

Features of the supercritical transition in the wake of a circular cylinder

The features of the wake behind a uniform circular cylinder atRe=200, which is just beyond the critical Reynolds number of 3-D transition, are investigated in detail by direct numerical simulations by solving 3-D incompressible Navier-Stokes equations using mixed spectral-spectral-element method. The high-order splitting algorithm based on the mixed stiffly stable scheme is employed in the time discretization. Due to the nonlinear evolution of the secondary instability of the wake, the spanwise modes with different wavelengths emerge. The spanwise characteristic length determines the transition features and global properties of the wake. The existence of the spanwise phase difference of the primary vortices shedding is confirmed by Fourier analysis of the time series of the spanwise vorticity and attributed to the dominant spanwise mode. The spatial energy distributions of various modes and the velocity profiles in the near wake are obtained. The numerical results indicate that the near wake is in 3-D quasi-periodic laminar state with transitional behaviors at this supercritical Reynolds number. The project supported by the State Key Fundamental Research Project of “Large Scale Scientific Computation Research” (G199903281)     

Laminar flow of micropolar fluid in rectangular microchannels

Compared with the classic flow on macroscale, flows in microchannels have some new phenomena such as the friction increase and the flow rate reduction. Papautsky and co-workers explained these phenomena by using a micropolar fluid model where the effects of micro-rotation of fluid molecules were taken into account. But both the curl of velocity vector and the curl of micro-rotation gyration vector were given incorrectly in the Cartesian coordinates and then the micro-rotation gyration vector had only one component in the z-direction. Besides, the gradient term of the divergence of micro-rotation gyration vector was missed improperly in the angular moment equation. In this paper, the governing equations for laminar flows of micropolar fluid in rectangular microchannels are reconstructed. The numerical results of velocity profiles and micro-rotation gyrations are obtained by a procedure based on the Chebyshev collocation method. The micropolar effects on velocity and micro-rotation gyration are discussed in detail.The project was supported by the National Natural Science Foundation of China (10472054). The English text was polished by Boyi Wang.