二维小波变换理论在地震信号去噪中的应用

针对地震信号随机干扰和规则干扰的特点，运用二维小波变换的理论，设计了相应的变换域去噪滤波器。理论记录和实际野外记录试算表明，二维小波变换具有较强的信噪分离作用。只要运用得当就能取得满意的效果。     

相变区等温处理对V-N钢轧后组织的影响

研究轧后等温处理工艺对微合金V—N钢γ→α相变组织的影响。对含氮量不同的两种低碳V钢进行了模拟轧制和控轧冷却，接着于650～700℃进行了等温处理，使发生γ-α相变。用光学显微镜和透射电子显微镜(TEM)观察和比较了钢中的显微组织转变特点。结果表明，随等温温度的降低及保温时间的延长，铁素体的转变量增加；增加钢中的氮含量，能明显促进轧后显微组织中铁素体的生成，有利于细化晶粒。     

Identification and Validation of a Discrete Element Model for Concrete

The use of a three-dimensional discrete element method (DEM) is proposed to study concrete structures submitted to dynamic loading. The aim of this paper is to validate the model first in the quasistatic domain, and second in dynamic compression, at the sample scale. A particular growing technique is used to set a densely packed assembly of arbitrarily sized spherical particles interacting together, representing concrete. An important difference from classical DEMs where only contact interactions are considered, is the use of an interaction range. First, the correct identification of parameters of the DEM model to simulate elastic and nonlinear deformation including damage and rupture is made through quasistatic uniaxial compression and tension tests. The influence of the packing is shown. The model produces a quantitative match of strength and deformation characteristics of concrete in terms of Young’s modulus, Poisson’s coefficient, and compressive and tensile strengths. Then, its validity is extended through dynamic tests. The simulations exhibit complex macroscopic behaviors of concrete, such as strain softening, fractures that arise from extensive microcracking throughout the assembly, and strain rate dependency.     

A functional correspondence between call-by-need evaluators and lazy abstract machines

We bridge the gap between compositional evaluators and abstract machines for the lambda-calculus, using closure conversion, transformation into continuation-passing style, and defunctionalization of continuations. This article is a followup of our article at PPDP 2003, where we consider call by name and call by value. Here, however, we consider call by need.We derive a lazy abstract machine from an ordinary call-by-need evaluator that threads a heap of updatable cells. In this resulting abstract machine, the continuation fragment for updating a heap cell naturally appears as an ‘update marker’, an implementation technique that was invented for the Three Instruction Machine and subsequently used to construct lazy variants of Krivine's abstract machine. Tuning the evaluator leads to other implementation techniques such as unboxed values. The correctness of the resulting abstract machines is a corollary of the correctness of the original evaluators and of the program transformations used in the derivation.     

考虑风电接入和气电转换的综合能源系统日前区间优化

针对气电综合能源系统优化调度中未充分挖掘可调度因素、未充分考虑风电预测误差不确定性的现状,研究含风电的气电综合能源系统日前区间优化调度方法。首先,基于区间数学对风电出力的不确定性进行区间描述,综合考虑抽水蓄能、气电双向转换以及需求响应等资源和技术,并用区间数学表示优化目标和优化约束,构建含高比例风电的气电综合能源系统日前优化模型,综合优化系统的经济性、环保性。然后,基于区间序关系和可能度的方法将区间优化模型转化为确定性优化模型,继而采用Jaya算法进行求解,保证求解的高效性和解空间的可行性。最后,进行算例分析,仿真结果验证了综合利用抽水蓄能、气电双向转换以及需求响应等要素对系统进行区间优化,能取得优化效果上的优势,并能为系统调度人员提供风电不确定度对系统优化影响的信息。     

RTK测量若干问题探析

RTK测量是目前应用最广泛的GNSS测量模式。分析研究了RTK测量的坐标转换、基准站的架设点选择、基准站已知坐标的输入等问题。此研究对RTK测量工作具有一定的参考和指导作用。     

Simulation of X-ray pulsar signals with multiphysical properties

In view of the few and discontinuous X-ray pulsar data, based on the physical properties of the X-ray pulsar real data from the Rossi X-ray Timing Explorer (RXTE) spacecraft, this paper adopts the fast iterative method and the 10 μs time transformation model, simulates the X-ray pulsar signals which have the periodic property, spectral property, and the background noise property as well as a variety of delay effects. We design and implement simulation software which can simulate the X-ray pulsar signals with multi-physical properties. The results of comparing the real data and simulation data in the same situation show that the simulation noises and the actual noises have the same distribution, that the period stability of the simulated X-ray pulsar data agrees with the real data, with the error of only 0.43％, in different energy levels, that the simulated data's integrated profile and the real data's standard profile are highly correlated with the Pearson correlation coefficient of 0.99, and that under the 10μs time transformation model, the time conversion accuracy of the simulation data can reach 10^-7s, the error between the simulation and the real data being just only 10^-7s, which meets the time transformation accuracy. Therefore, the proposed method can realize the high-fidelity simulations and generate the continuous pulsar signal with many physical properties.     

用仿射对应求4点椭圆的方法及应用

本文是应用仿射对应原理,以椭圆曲线上4个点及其中心,求作椭圆的方法。以及用此方法解决某些一般形式的二次曲面中的一些几何作图问题。     

随机振动离散分析方法的实用化处理

通过作者前文[2]的讨论,我们得到了随机振动离散分析方法的一个具有无条件稳定性和高精确度的递推公式—β递推格式。但由于在这个递推格式中存在一个增广矩阵求逆的问题,这就给它在实际应用中带来了一定的困难。本文通过等效变换,成功地克服了这一困难,避免了这个增广矩阵求逆,并完全应用了原动力体系质量阵、阻尼阵和刚度阵的对称、带状等特点,大大减少了计算所需的内存和工作量,从而使该方法很实用。     

用CR－39固体径迹探测器测定重带电粒子的Bragg峰位

采用ＣＲ－３９固体径迹探测器，根据辐射损伤密度沿粒子的径迹分布规律，测定了经３、４ｃｍ空气降能和φ１ｍｍ孔准直的α粒子（５．１５ＭｅＶ）的Ｂｒａｇｇ峰位。对于通过３ｃｍ空气后能量降至～１２ＭｅＶ的α粒子，在ＣＲ－３９中的Ｂｒａｇｇ峰位大约在７μｍ深度处，理论计算值在６．１４μｍ，实验值与理论值符合得较好。