值分布

Therefore,the numerical algorithm of normal distribution function in continuous space is improved,so that the difficulty of the discretization of question difficulty and the difficul...

本文对连续的正态分布函数计算方法进行了改进，解决了试题难度的离散化和试题数量为整型值造成的试题难度正态分分配困难问题。

If the Landweber method and pre-iteration method were convergent, the residue sequence would be monotone decreasing. By analyzing the convergence, the fact is demonstrated that for the severe ill-conditioned matrix of sensitivity coefficient, because of the limitation of the precision of the computer, the residue sequence is not monotone decreasing; thereby the reconstruction images diverge from the true distribution of the conductivity. So the generalized inverse method with threshold is established and the selection way of the regularization parameter is presented, by which the better images are reconstructed.

Landweber法和预迭代法收敛，则其残差序列单调递减，通过对它们的收敛性进行分析，证实对于病态性严重的灵敏度系数矩阵，由于受计算精度的限制，迭代过程中的残差序列不再单调递减，从而导致重建图象偏离实际电导率分布，因此作者建立了带阈值的广义逆算法，提出了规则化参数选择方法，获得了较好的图象重建质量。

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。

The distributed phase shifters consist of a coplanar waveguide transmission line loaded periodically with MEMS capacitors,which provide variable phase shift through voltage control of the MEMS capacitors.

通过在共平面波导上周期性地分布微机械电容，外加电压驱动改变电容值，可实现级联式MEMS移相器。

Corbicula fluminea (Müller 1774) was bred in the laboratory and two shell samples (shell height, A=13 mm, B=9 mm) were selected to determine the carbon isotopic composition of the increment shells (aragonite, CaCO3) and the host water. The results indicate that the carbon isotopic compositions of the two shells increased as the δ^13 C values of the host water increased from -5.24‰ to 1.41‰, showing the influence of δ^13C values on the shell carbon isotopes.δ^13C value ranges from -4.76% to -2.09% and δ^13 C from -8.49% to -2.89%. The δ^13 C values of shells A and B are both more negative than the predicted equilibrium ones, indicating that the shell had used the metabolic CO2 rich in 12C during their growth process.

对双壳类河蚬进行了室内养殖，并选取两个壳体样品（壳高，A=13 mm， B=9 mm），测定其生长部分壳体和生长期间水体碳同位素，研究表明，随着水体碳同位素的升高（δ^13C由－5.24‰升至1.41‰），两壳体碳同位素也随之升高，表明水体对壳体碳同位素的影响；δ^13CA分布范围为－4.76‰~-2.09‰，δ^13CB为－8.49‰~-2.89‰，壳体A和B碳同位素均比预测平衡值偏负，表明壳体在形成过程中利用了新陈代谢产生的富集12C的CO2。

In this paper the influence for critical value of the different distributed phase randomized to the data obtained in dynamic analysis is studied.

研究了在动态分析中不同分布的相位随机临界值对获取数据的影响。

On study of technology adoption timing and innovation diffusion, we get the firm's optimal threshold of technology adoption under the uncertainties about both the time of the arrival and efficiency of improvement of technologies, and give the relevant cumulative probability distribution function regarding adopting technology timing.

在采纳时机及创新扩散研究方面，在新技术的到达时间和提高效率都不确定的情况下，得到了企业最优的技术采纳的投资门槛值，并给出了企业采用时机的累积概率分布函数。

It transforms the image based on the cumulative distribution function of histogram. However, there is a caveat to over-enhance the contrast when the auto-generated transform curve is too sharp due to some high peaks in the histogram.

但是当直方图的分布函数中某一个值特别大的时候，则会使产生的转换函数斜率过大，换句话说就是使影像过度增强，这会使输出影像太亮，清晰度反而下降。

Methods BNP results from 103 patients and 44 healthy people were collected. Cumulative frequency distribution form with Excel was made. Best coordinate was established and the area under curve calculated.

方法］将103例患者和44例正常人BNP结果用Execl软件作累积频数分布表，然后以灵敏度为纵坐标，以1-特异性为横坐标，建立ROC曲线评价系统，确定最佳诊断分界值，计算ROC曲线下面积。

With SLGallery it is possible to plot graphs and find values for probability density, cumulative distribution, survival and Hazard functions.

与slgallery是有可能的阴谋图并找到值的概率密度，累积分布，生存和危险的职能。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。