Runge–Kutta discontinuous Galerkin method using WENO limiters II: Unstructured meshes

In [J. Qiu, C.-W. Shu, Runge–Kutta discontinuous Galerkin method using WENO limiters, SIAM Journal on Scientific Computing 26 (2005) 907–929], Qiu and Shu investigated using weighted essentially non-oscillatory (WENO) finite volume methodology as limiters for the Runge–Kutta discontinuous Galerkin (RKDG) methods for solving nonlinear hyperbolic conservation law systems on structured meshes. In this continuation paper, we extend the method to solve two-dimensional problems on unstructured meshes, with the goal of obtaining a robust and high order limiting procedure to simultaneously obtain uniform high order accuracy and sharp, nonoscillatory shock transition for RKDG methods. Numerical results are provided to illustrate the behavior of this procedure.     

Photoemission intensity oscillations in the valence bands of C70 film

We have measured and analyzed the photoemission spectra (PES) of a C₇₀ film in the photon energy region from 13.4 eV to 98.4 eV. The photoelectron intensities of two C 2p π-derived features (denoted by A and B) oscillate regularly in the whole energy region with some fine structures below ∼30 eV. To obtain the detailed information of the oscillations, we have developed a sophisticated but practical procedure for intensity calculation. The procedure consists of two core concepts. The first is ascribing the PES features to their corresponding molecular orbitals with the help of density functional calculations. The second is a background subtraction algorithm. With this procedure, we obtained the oscillating behavior for individual features (A and B), which is by and large consistent with the predictions based on the spherical symmetric approximation although C₇₀ has the ellipsoidal shape. Owing to the solid state effect, the oscillating amplitudes of the A/B intensity ratios are smaller than those of gas phase C₇₀, but an orbital shift reported recently was not observed on our sample. The oscillating curve of a deeper feature, which consists of both σ and π states, are also reported.     

The method of matrices conjoint multiplication for the problem of circular arc corrugated diaphragm

The circular are corrugated diaphragins are taken in this paper and structures of several sections of the ring shells and a central cireular plale I matrices and link matrices are derived by using Prof. Chuen Hei-zang’s general the ring shell[1] and perturbation theory of the circular thin plates. Throngh the meined of matrices conjoint multiplication, the linear exact solution and nonlinear soluaen are obtained. The resutts agree with that of the experiments presented by W. A. Wildhack..     

The lattice polarizability of PbI2

We have measured the far-i.r. reflectivity spectrum of the layer crystal PbI₂ for the in-plane polarization. A strong reststrahlen band is observed, with TO and LO phonon frequencies located at 52 and 108 cm^?1. The large lattice contribution accounts for three-quarters of the low-frequency dielectric constant of 26. The deduced infrared effective charge and electronic polarizability of PbI₂ indicates that the intralayer bonding is closely related to the chemical bonding in the IV–VI rocksalt-structure crystals.     

校园网络数据资源分层访问策略

分析了校园ＭＩＳ及数据资源的特征,针对校园信息资源范围广、关联复杂的状况,提出了数据资源统一访问策略——分层访问．数据访问分为七层,各层完成数据访问独立性的特定功能,使不同的访问软件能透明访问全部数据资源．为保证传统应用能基于网络计算访问统一数据资源,又提出了“数据访问管道”和数据库访问服务器的技术．文章分析了以应用服务器为基础的Ｎ－Ｔｉｅｒｓ计算的弊端,设计了“虚拟应用服务器”ＷＵＶ－ＡＰＰＳ,将数据访问对象构造成数据对象组件．     

Oscillations of nonlinear partial difference systems

This paper studies the following two-dimensional nonlinear partial difference systems

     

利用模拟退火算法进行油井流入动态研究

油井流入动态是油井举升优化设计的基础 ,目前国内外研究油井流入动态的方法有多种 ,但是各有其不足和局限性 .为此利用模拟退火方法进行油井流入动态方法研究 .与以往的近似算法相比 ,该方法不需要将单相流和多相流分开讨论 ,且无任何假设条件 ,适用范围广 ;通过实例 ,把模拟退火的预测的产量结果与利用 Vogel方程所预测的产量结果进行比较和误差分析 ,结果表明 ,该算法的误差是非常小的 .因此 ,利用该算法研究油井流入动态非常可行 .     

Low energy asymptotics for Schrödinger operators with slowly decreasing potentials

Low energy behavior of Schrödinger operators with potentials which decay slowly at infinity is studied. It is shown that if the potential is positive then the zero energy is very regular and the resolvent is smooth near 0. This implies rapid local decay for the solutions of the Schrödinger equation. On the other hand, if the potential is negative then the resolvent has discontinuity at zero energy. Thus one cannot expect local decay faster than ordert ^–1 ast.     

关于建立新型激励机制与综合应用激励手段的研究

本文从西方激励理论与我国企业现状出发．探索了建立适合改革中的企业管理体制的新型激励机制之路，指出新型激励机制中多种激励手段应有机地综合运用．首先对西方激励理论进行了分析．而后对“人”在管理中的地位进行了探讨．在分析我国激励机制中现存缺陷后．提出了从组织结构、企业文化、领导行为多个方面进行变革以建立新型激励机制的建议．     

关于物质激励与精神激励基础与结合研究

从激励的心理学理论基础出发进行分析；对需求、动机、行为等及其相互影响在激励实践中的作用进行了总结。精神激励和物质激励是两种主要的激励模式．它们都是从实践中来经过否定之否定而发展起来的．现代激励理论对两种激励基本上接受，但对两种激励的评价及侧重又各有不同．我国现行激励机制存在一些问题，尤以平均主义为甚．精神激励与物质激励的有机结合．是激励模式发展的未来．