THE ERRORS ESTIMATION OF THE CHEBYSHEV SPECTRAL－DIFFERENCE METHOD FOR TWO－DIMENSIONAL VORTICITY EQUATION

ＴＨＥ　ＥＲＲＯＲＳ　ＥＳＴＩＭＡＴＩＯＮ　ＯＦ　ＴＨＥ　ＣＨＥＢＹＳＨＥＶ　ＳＰＥＣＴＲＡＬ－ＤＩＦＦＥＲＥＮＣＥ　ＭＥＴＨＯＤ　ＦＯＲ　ＴＷＯ－ＤＩＭＥＮＳＩＯＮＡＬ　ＶＯＲＴＩＣＩＴＹ　ＥＱＵＡＴＩＯＮＴＨＥＥＲＲＯＲＳＥＳＴＩＭＡＴＩＯＮＯＦ...     

Precise lattice parameter measurements in CsCl-Br solid solutions between room temperature and 90°K by powder x-ray diffraction

Solid solutions of CsCl-Br in five different concentrations were prepared in sealed quartz tubes by heating the mixture to 1123°K for 6–8 hr and quenching to room temperature. X-ray diffractograms were taken at eight different temperatures between room temperature and 90°K for these solid solutions using the YPC50NM powder diffractometer and a continuous flow cryostat. The observed lattice parameters for each sample at each temperature obtained from the powder diffractograms were then extrapolated to give the true lattice parameters using the least square method with Nelson-Riley extrapolation scheme. The values of the true lattice parameters at each concentration and at each temperature were tabulated and the results discussed. It is shown that the lattice parameters vs temperature for some concentrations exhibit an anomalous behaviour. Contribution No. 691     

Gas kinetic algorithm for flows in Poiseuille-like microchannels using Boltzmann model equation

~~Gas kinetic algorithm for flows in Poiseuille-like microchannels using Boltzmann model equation1. Feynman, R., There's plenty of room at the bottom, Journal of Microelectromechanical Systems, 1992, 1: 60 -66. 2. Piekos, E. S., Breuer, K. S., Numerical modeling of micromechanical devices using the direct simulation Monte Carlo method, Transactions of the ASME, Journal of Fluids Engineering, 1996, 118: 464-469. 3. Beskok, A., Karniadakis, G. E., Trimmer, W., Rarefaction and …     

用自适应流线网格计算定常超声速流场

提出一个用自适应流线网格计算定常超声速流场的数值方法。Friedrichs-Lax格式推广到任意四边形网格,在迭代过程中得到速度场后,从流线方程计算流线的位置,最后算出由本方法得到高分辨率结果     

利用地铁隧道风能发电的设计与研究

当今世界,随着社会发展,能源是经济之本,是人类生活的依存。本项目对地铁隧道风力发电展开研究,从了解地铁隧道风能的特征入手,通过理论分析结合实验验证,制作实体模型辅助研究,做出初步可行性分析,认定方案可行,然后提出有效利用地铁风力发电的创新设计方案,其中包括羽状风叶、差速装置和机械蓄能装置,并以此为基础设计了整套地铁隧道风力发电设计。该设计是对室内环境风力发电的率先探索,通过研究可得出：利用地铁隧道风力发电设计是一种新的能源利用形式,并有一定应用前景。     

Synchronization of impulsively coupled complex networks

We investigate the synchronization of complex networks,which are impulsively coupled only at discrete instants.Based on the comparison theory of impulsive differential systems,a distributed impulsive control scheme is proposed for complex dynamical networks to achieve synchronization.The proposed scheme not only takes into account the influence of all nodes to network synchronization,which depends on the weight of each node in the network,but also provides us with a flexible method to select the synchronized state of the network.In addition,it is unnecessary for the impulsive coupling matrix to be symmetrical.Finally,the proposed control scheme is applied to a chaotic Lorenz network and Chua’s circuit network.Numerical simulations are used to illustrate the validity of this control scheme.     

Si团簇的结构特性研究

采用由 M.Menon等人的非正交紧束缚模型,结合遗传算法和分子动力学方法,对n=2～20的中小尺寸Si团簇的结构进行了优化,计算了束缚能Eb、平均配位数CN,团簇的裂化能Efrag,总能的二阶差分Δ2E,最高占据分子轨道(HOMO)和最低未占据分子轨道(LUMO)的能隙Eg, 结合Mullikon集居数分析研究了电子特性,得出了随着团簇尺寸的增加,团簇的构型发生了近球形-长椭球形-近球形的转变、n=4,7,10等团簇具有较强稳定性、团簇中原子之间共价键性结合占支配地位等主要结论.所得的主要结论与已有的从头计算和实验结果相一致.     

126Cs的高自旋态能级结构

利用融合蒸发反应¹¹⁶Cd(¹⁴N,4n)¹²⁶Cs布居了¹²⁶Cs的高自旋态.观测到了100多条新的γ跃迁和相应的能级,建立了双奇核¹²⁶Cs由9个转动带构成的能级纲图.尝试性地指定了大部分能级的自旋和宇称以及各转动带的Nilsson单粒子组态.极大地丰富了已有的实验结果.     

On representations of affine Kac-Moody groups and related loop groups

We demonstrate a one to one correspondence between the irreducible projective representations of an affine Kac-Moody group and those of the related loop group, which leads to the results that every non-trivial representation of an affine Kac-Moody group must have its degree greater than or equal to the rank of the group and that the equivalence appears if and only if the group is of type for some . Moreover the characteristics of the base fields for the non-trivial representations are found being always zero.

     

SYMPLECTIC SCHEMES FOR NONAUTONOMOUS HAMILTONIAN SYSTEM

ＳＹＭＰＬＥＣＴＩＣＳＣＨＥＭＥＳＦＯＲＮＯＮＡＵＴＯＮＯＭＯＵＳ　ＨＡＭＩＬＴＯＮＩＡＮ　ＳＹＳＴＥＭＱＩＮＭＥＮＧＺＨＡＯ（秦孟兆）（ＩｎｓｔｉｔａｔｅｏｆＣｏｍｐｕｔａｔｉｏｎａｌＭａｔｈｅｍａｔｉｃｓａｎｄＳｃｉｅｎｔｉｆｉｃ－Ｅｎｇｉｎｅｅ...