最小值

Statistic analysis result shows that the time step is the most important influence factor of simulation precision, and there is relation between simulation error and the setup value of restitution coefficient which the greater the setup value is, the less the simulation error is. Although there is no effect to the total contact time in the course of collision, the value of the time step decides the total contact step, and there is a logarithmic linear correlativity between them.

统计分析结果表明：计算时步是影响模拟精度最重要的因素；模拟误差还同恢复系数的设定值有关，设定值越大，模拟误差就越小；计算时步的大小虽然对碰撞过程的总接触时间影响不大，但是却决定了碰撞过程的总接触时步数，二者之间存在对数线性相关关系

In addition, some modifications on several computational methods are also presented. Using LMTO method the electronic structure of several systems are studied, and some results are obtained. They are: The ideal Nb (100) surface has three surface states, the multi-layer relaxed surface has two surface states. The surface energy of the ideal surface is higher than that of the relaxed surface, that means that the multi-layer relaxed surface is more stable than the former one, which supports the LEED results. The mono-layer relaxed Ag (111) surface is the most stable one among several" stable surface models"presented by several researchers. The surface energy of Ag (111) surface is higher than that of surface Ag (001), which supports some experimental results such as different reaction rate at different surface orientations for the same material. The surafce states of Si (111) surface not only locate near the Fermi level, but also in the valence band, which agrees well with Cohen's conclusion. Si (111)-H is an effective model for analysing the surface states and H adsorbed on the back surface is a good method for improving the convincingness of the results obtained on thinner slab models. The surface stability depends on three different kinds of MoSi〓(001) surfaces, the surface with mono-layer Si is the most stable one, and the surface with Mo at the first layer is the most unstable one among them. These are consistant with the Kemoda's experimental results. The valence bands of clean or K adsorbed CdTe (111) surface agrees well with the synchrotron radiation studies. The surface of CdTe (111) consists of four kinds of surface models which show different surface electronic structures and different surface structure stabilities. The conclusion agrees well with Wu's experimental work. The different absorbed alkali metals on the CdTe (111) surface give different adsorption characteristics which have relations not only with the valence electrons, but also with the core ones of the alkali metals. The electonic structures of Si-C alloys are different from that of Si-Ge alloys, and the energy band gaps of Si-C alloys do not increase linearly with Carbon concentration, our conclusion supports Alexander's results, but conflicts with Soref's one.

现分述如下： LMTO方法及其应用方面：1）通过对Nb（100）表面电子态分析发现清洁理想表面有三个表面态，多层弛豫表面有两个表面态；表面能大小说明多层弛豫表面更稳定，支持了LEED结果。2）通过对采用不同方法获得的几种不同Ag（111）表面稳定结构的表面能计算分析，给出了单层弛豫表面为Ag（111）表面的最稳定结构；从Ag（111）单层弛豫表面和Ag（001）表面的表面能比较，发现了Ag（001）表面表面能要比Ag（111）小的，表明了同种物质不同表面取向将表现出不同物理、化学性质，这是与实验中得出的结论是吻合的，3）通过对Si（111）表面态分析，不仅发现了Si（111）表面不仅具有居于费米能级附近的悬挂键所对应的表面态，而且还有很多表面态位于价带能量范围内，与Cohen等结果一致，H饱和slab模型背表面相当于增加了slab层的厚度，是一有效的变相增加slab层厚的方法，弛豫表面较清洁理想表面价带谱们低能端的少许移动，预示着总能降低，说明弛豫表面较清洁理想表面稳定。4）MoSi〓具有三种表面，从费米能级上态密度值大小得到单层Si表面最稳定，Mo原子为表层原子的表面最不稳定，双层Si原子表面居中的结论，这与Kemoda等人实验结果是一致的。5）通过对CdTe（111）表面表面电子态、表面结构稳定性及表面H、碱金属吸附的电子结构系列研究，不仅得出了CdTe（111）清洁及碱金属K吸附价带谱与同步辐射光电子谱相吻合的结果，而且发现了CdTe（111）表面具有四类不同原子近邻特征，表现出四类不同的表面结构及电子结构特征：不同表面态分布、不同的表面结构稳定性（表层原子与次层原子成三键有一悬挂键的表面要比表层原子与次层原子成一键有三悬挂键稳定（与Wu等人实验结果一致））、不同的H吸附特性。

SSRs are very suitable for research on genetic diversity and phylogenetic relationship since they are more reliable, co-dominant in heritance large number of alleles per locus, and abundance in genomes.

对椰子SSR反应体系进行了优化，确立了最适宜的体系：在20μL反应体系中，Mg2+、引物和dNTP的最适浓度分别为2.5mmol/L、0.3μmol/L、0.2mmol/L；TaqDNA聚合的最佳使用量为1U，模板DNA应加入50ng，引物最佳退火温度比每对引物Tm值较小者小2-3℃。

The soil cutting experiment indicates that the interior friction angle and the shear intensity of soil is reduced;and the maximum principal stress is decreased due to the vibration load;it induces the decrease of digging resistance.

从理论上研究了振动掘削岩土的减阻机理，土壤剪切试验结果表明，振动载荷能够使土壤的内摩擦角变小、抗剪强度下降、最大主应力值减小，从而导致挖掘阻力降低；对土壤在静态载荷和振动载荷作用下的失效过程进行了对比仿真实验研究，可知土壤在振动加载的条件下强度显著下降，并提前于相同条件的静态加载而破坏，同时跟踪X方向的载荷发现，振动掘削最大掘削阻力可降低50%。

The main content includes that the accuracy of interpolation operators is creased since defect equations introduce less error: Gauss-Seidel solution can save effectively the computational time, in particular, the CPU-time for the setup phase; Jacobi-relaxation interpolation contributes to efficient and robust algebraic multigrid methods by a simple and purely algebraic mean.

最主要的内容是基于亏量方程引入的误差较小，从而进一步提高插值算子的精度；采用Gauss-Seidel解法有利于节省计算时间，特别是预备阶段的CPU时间；插值的松驰以一种简单的纯代数的方式获得高效且稳健的代数多重网格算法。

The rainstorm process is a complex and stochastic multi-dimensional process.A correlation exists between the maximal annual period-storm and the rainfall duration,with overlooking many factors,the parameterwill not be a constant.Since 1980s,heavy rain and flood of small basins can be calculated by auto-recording rainfall observation system,and 20-year's self-recording rainfall data can improve the calculation accuraey.

暴雨过程是一个复杂的多维随机过程，年最大时段暴雨xt，p与暴雨历时t的暴雨公式属于经验相关关系，忽略了不少影响因素，因此，公式中参数n值不会是稳定不变的。20世纪80年代以后，随着自记雨量观测应用，到目前已经有20多年的资料系列，小流域暴雨设计的计算就可以直接利用时段实测降水资料系列进行计算，设计洪水时，可根据实测雨量时段资料，计算该设计流域的n值，可提高计算精度。

Chapter four studies the chaotic responses in a system consisting of simple pendulum and harmonic oscillator under bounded noise excitation. Firstly, the Melnikov function of the two-degree-of-freedom system under Hamiltonian perturbation is derived. The essential condition of the autonomous system for the probable onset of chaos is obtained, the Poincare maps of the system under small Hamiltonian perturbation and the effect of increasing perturbation on the Poincare maps are studies. Then for the non-autonomous system under damping and harmonic or bounded noise excitation, the largest Lyapunov exponent and Poincare maps are calculated. From the analysis of the largest Lyapunov exponent, the critical criterion for the onset of chaos, and the conclusion that the threshold of bounded noise amplitude for the onset of chaos in the system increases as the intensity parameter of Wiener process increases are obtained. The result from the analysis of Poincare maps is in agreement with that obtained from the Largest Lyapunov exponent. The effect of varying damping coefficient and intensity parameter of Wiener process is also analyzed.

第四章研究了有界噪声激励下的两自由度单摆—谐振子系统的混沌运动，首先推导了该两自由度系统仅在Hamilton扰动下的Melnikov函数，得到该自治系统可能产生混沌的必要条件；研究了该系统在小的Hamilton扰动和增大摄动情形下的Poincare截面；然后对有阻尼、谐和或有界噪声激励下的非自治系统数值计算了其最大Lyapunov指数和Poincare截面；从Lyapunov指数分析得到了这个两自由度系统产生混沌运动的临界条件及产生混沌的临界激励幅值随Wiener过程强度参数值的增大而增大的结论，Poincare截面分析的结果亦符合Lyapunov指数分析的结论；研究了Wiener过程强度参数、阻尼系数变化对Poincare截面的影响。

This experiment adopted organic solvent extraction step by step,following deproteinization,dialyzation,alcohol-precipitation and layer-separation of dextran,to reveal the unknown effective ingredients in pumpkin,which have influence to blood sugar in normal mice or model mice of diabetes mellitus.

为探寻南瓜中对正常及糖尿病模型小鼠血糖有影响的未知有效成分，本实验依次采用有机溶剂分步萃取、除蛋白、透析、乙醇沉淀及葡聚糖柱层析等分离手段，以小白鼠血糖值作为筛选活性成分的指标，在分离的每一阶段对分离所得各个组分进行活性定量评估，并追踪活性最强的部分，最后分离纯化出降血糖活性最强的组分G———南瓜多糖。

A feature extraction method for palmprint image is proposed,the implementation procedure of this method is as follows:firstly,the 2D Gabor wavelet transform coefficient amplitudes are computed at the equispaced discrete positions on the palmprint image,and they are used as original features of the palmprint image;then,the dimension of the Gabor wavelet feature is reduced by principal component analysis;lastly,the optimal discriminant features that are most advantageous for classification are extracted by linear discriminant analysis.

提出了一种提取掌纹图像特征的方法，该方法的实现过程如下：首先，计算掌纹图像上均布离散位置的二维Gabor小波变换系数的幅值，将其作为掌纹图像的原始特征；其次，利用主分量分析实现Gabor小波特征的降维；最后，通过线性判别分析提取最有利于分类的最佳鉴别特征。

After simulation on a multitude of images,eight different thresholding weights applied to as many as eight levels of red-black wavetlet transforms have been proposed.

通过仿真试验，对不同尺度下的阈值提出了一组最多适用到8级红-黑小波变换的阈值权重。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。