ITO粉的Rietveld全谱图拟合定量相分析

对ITO粉样品用Rietveld全谱图拟合法进行了定量相分析，该样品由立方晶型的In2O3和少量的四方晶系的SnO2所组成。In2O3和SnO2质量百分含量分别为94．23％和5．77％。结果表明，用Rietveld法进行了定量相分析是非常有效和准确的。     

The perturbation method and the extended finite element method. An application to fracture mechanics problems

The extended finite element method has been successful in the numerical simulation of fracture mechanics problems. With this methodology, different to the conventional finite element method, discretization of the domain with a mesh adapted to the geometry of the discontinuity is not required. On the other hand, in traditional fracture mechanics all variables have been considered to be deterministic (uniquely defined by a given numerical value). However, the uncertainty associated with these variables (external loads, geometry and material properties, among others) it is well known. This paper presents a novel application of the perturbation method along with the extended finite element method to treat these uncertainties. The methodology has been implemented in a commercial software and results are compared with those obtained by means of a Monte Carlo simulation.     

新型横向磁场电机的标量磁位三维磁场分析与参数计算

提出了一种新型横向磁场电机（TFM），定子采用E型铁心，可以大大降低加工难度和制造成本。但是，该电机磁路复杂，需采用三维场场进行分析。在三维有限元磁场中，如果对电流区域进行适当处理，采用标量磁位进行分析，与采用矢量磁位相比，可大大提高计算速度。对电流区域在三维磁场计算中的处理方法进行了推导，根据所推导的原理编制三维有限元软件，利用该软件对样机磁场进行计算。试验结果表明了该方法的正确性。     

有限差分法计算HF分子的振动能级和光谱

本文用有限差分法计算了HF分子的振动能级并且把计算的结果用切比雪夫法进行拟合得到了HF的光谱项,将所得结果与黄整等人的用时域有限差分法计算所的结果和实验值进行了比较。     

基于MATLAB的分段卷积计算

线性卷积要求两个输入序列具有持续时间,但在实际应用中,可能遇到输入序列具有无限持续时间的情况。在这种情况下,分段卷积是一种有效的解决方案。文章讨论了计算分段卷积的两种方法。仿真试验表明,分段卷积方法正确且高效。     

时间最优开关控制的非线性规划方法

提出单输入非线性时间最优开关控制的非线性规划算法．针对不同的开关控制划分未知时间段，以时间段为变量建立与最优控制等价的非线性规划模型．构造每个未知时间段的等分龙格库塔格式，该格式不但不增加未知变量，而且可构造出不含导数的非线性规划算法．利用龙格库塔格式的收敛性和非线性规划的一阶最优性条件证明该方法的收敛性．最后以实例验证该算法．     

Analysis of singular stress fields at multi‐material corners under thermal loading

The scaled boundary finite‐element method is extended to the modelling of thermal stresses. The particular solution for the non‐homogeneous term caused by thermal loading is expressed as integrals in the radial direction, which are evaluated analytically for temperature changes varying as power functions of the radial coordinate. When applied to model a multi‐material corner, only the boundary of the problem domain is discretized. The boundary conditions on the straight material interfaces and the side‐faces forming the corner are satisfied analytically without discretization. The stress field is expressed semi‐analytically as a series solution. The stress distribution along the radial direction, including both the real and complex power singularity and the power‐logarithmic singularity, is represented analytically. The stress intensity factors are determined directly from their definitions in stresses. No knowledge on asymptotic expansions is required. Numerical examples are calculated to evaluate the accuracy of the scaled boundary finite‐element method. Copyright © 2005 John Wiley & Sons, Ltd.     

The generalized Riemann problem method for the shallow water equations with bottom topography

This paper extends the generalized Riemann problem method (GRP) to the system of shallow water equations with bottom topography. The main contribution is that the generalized Riemann problem method (J. Comput. Phys. 1984; 55 (1):1–32) is used to evaluate the midpoint values of solutions at each cell interface so that the bottom topography effect is included in numerical fluxes, and at the same step the source term is discretized with an interface method in which only mid‐point values are plugged in. This scheme is well balanced between the flux gradient and bottom topography when incorporating the surface gradient method (SGM) (J. Comput. Phys. 2001; 168 (1):1–25) into data reconstruction step, and it is also suitable for both steady and unsteady flow simulations. We illustrate the accuracy of this scheme by several 1‐D and 2‐D numerical experiments. Copyright © 2005 John Wiley & Sons, Ltd.     

矿业软件在矿产储量评价中的应用

矿产储量评价的基本内容是建立矿床地质模型进行品位估计和储量分类分级．地质控制条件限制是矿床建模的重要手段。地质统计学方法是矿块品位估计以及储量分级等的有效方法．国内的应用实例表明。国际先进矿业软件是矿产储量评价的先进工具，应用矿业软件进行矿产储量评价是市场经济的需要。