速度函数

Combining NA samples the EB estimation with convergence rates is also obtained; Thirdly, for one-parameter exponential distribution family, we give the parameters' EB estimator that is admissible and asymptotically optimal with convergence rates. Finally, Bayesian and hierarchical Bayesian approaches are applied to analyze the reliability performances for series system with cold standby units and the numerical simulation results show that multiple Bayes estimator is superior to Bayes estimator.

其次，针对一类双边截断分布族，在非对称linex损失下构造了经验Bayes决策函数，建立了它的收敛速度，给出了渐近最优的证明；并结合NA样本研究了参数的经验Bayes估计及其收敛速度；接着给出了指数族参数的经验Bayes估计，证明了它是渐近最优的，也是可容许的，同时也获得了该EB估计的收敛速度；最后，运用Bayes与多层Bayes方法研究了具有冷贮备部件串联系统的可靠性指标的估计，并给出了数值模拟结果，结果表明多层Bayes估计优于Bayes估计。

The discrete velocity ordinate method in the kinetic theory of gases is developed and applied to discretize the correspo

借助非定常时间分裂法和无波动无自由参数的NND耗散格式，建立直接求解微观分子速度分布函数的有限差分数值格式；研究并发展可用于离散速度坐标点选取和离散速度空间宏观取矩的高斯─埃尔米特无穷积分方法、等均间隔的牛顿─柯斯复合积分法、以勒让德多项式的根为积分结点的高斯─勒让德数值积分法，并应用于不同马赫数绕流模拟；通过对不同流域一维激波管问题、二维圆柱绕流问题和三维球体绕流的计算研究，并将计算结果与其他途径得到的研究结果诸如DSMC模拟值、N-S解及有关实验数据进行比较分析，创建了一套能有效模拟稀薄流到连续流不同流域气体流动问题简化的统一数值算法研究框架

In this article, the wave of cutting speed is described as the deviation of mean square and the maximum deviation of speed during the working stroke.

本文用工作行程中速度的平均平方偏差及最大速度差来描述刀具速度波动，并以此为评价函数，采用多目标优化设计方法，确定牛头刨的主传动拉杆尺寸。

Summary In this paper, a brief history review of works on the theory of electromagnetic flowmeters is given. A method named'Alternative iteraction method for approaching real boundaries'is presented to solve Laplace's equation with mixed boundary conditions in electromagnetic flowmeters. The orthogonal expansion is used to analyze weight vectors and flow distribition effects on the sensitivity of the flowmeters.

本文在总结和分析了前人在电磁流量计变送器方面的理论研究成果后，首次提出了"交替迭代逼近边界"的方法求解电磁流量计理论研究中遇到的Laplace方程的混合边界条件问题；采用正交函数展开的方法研究权函数以及被测流体速度分布不规则对仪表输出的影响；采用保角变换的方法首次求解出电磁流量计偏心环域上的权函数。

First,we proposes the acceleration of Monte Carlo EM Algorithm,which is based on Monte Carlo EM Algorithm and Newton-Raphson algorithm,to improve the convergence rate;Second,the it is shown that the accelerated EM algorithm we proposed has quadratic convergence rate in a neighborhood of the posterior mode;Finally,its excellent performance in convergence rate is illustrated by a classical example.

受Monte Carlo EM算法与EM加速算法启发，本文构造了一种新的EM算法，称为Monte Carlo EM加速算法；证明了该算法在似然函数/后验分布的众数的附近确实具有二次收敛速度，改进了Monte Carlo EM算法的收敛速度；并通过一个数值例子的计算结果说明了该算法的优良性，它兼具实现简单及收敛速度快的特点。

The stability problem leads to an ordinary differen-tial equation containing three parameters representing partialderivatives of a phase function.

一个非定常流动的稳定性问题被归结为求解三个未知函数为参数的微分方程的特征值，其三个参数分别是非线性扰动波的相函数的导数及圆盘运动速度的函数。

In the upper bound approach, the velocity of each node are seen as unknown quantity, with the conditions of flow rule, velocity discontinuity, velocity boundary, the energy work equation considered, then the strength safety coefficient of slope, and the corresponding kinematically admissible velocity field are obtained.

在上限法中，以结点速度为未知量，根据单元塑性流动约束条件、速度不连续约束条件、速度边界约束条件，以及由外功功率与内功功率相等条件得到的目标函数，求得了强度储备系数的上限值及相应的机动容许位移场。

In order to contribute to analyse and compute easily setback moving devices on the projectile fuzes,and to make the fuze devisers be able to get the approximate acceleration curves with a few parameters such as tube length and muzzle velocity of the guns,the displacement-time curve and velocity-time curve of gun interior ballistic are fitted with the Logistic models,then the formula of projectile acceleration curves in bore are gotten by the derivation of the formula of fitting velocity-time curve.

为了便于炮弹引信后坐运动机构的分析和计算，能使引信工作者只根据身管长度和炮口速度等少量参数就能获得弹丸膛内加速度近似曲线，运用Logistic函数拟合火炮内弹道的位移－时间曲线和速度－时间曲线，再对拟合得到的速度－时间曲线求导便得到了弹丸膛内加速度近似曲线。

Through inversing receiver function of 34 seismic stations, we obtain S wave velocity structures beneath the stations.

利用71个远震的波形资料，用接收函数方法提取了布设在长白山—镜泊湖火山区的34个宽频带流动数字地震台站的接收函数，通过对接收函数反演，获得了台站下方的S波速度结构。

This paper firstly analyses the limitations of traditional potential field methods in dynamic environment,and based on this analysis,the traditional potential field is improved by introducing the concept of velocity potential field .

分析了传统势场法在动态环境下的不足，并在此基础上引入了速度势场的概念，改进了传统的势场函数，推导出新的引力函数和斥力函数。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。