极

Because the carbonyl in its structure is with strongly absorb-electron effect, so it is a kind of non-proton polarity solvent with high boiling point, high flash point and low melting point, use conveniently for many processing operation such as filtration, distillation, solvent extraction, and so on; it is with very low toxicity, so the harm to human body is inappreciable, and reduce the environment pollution; due to its very strong dissolvability, it can dissolve organic matter, inorganic matter, resin, polymer, etc., and activate all kinds of reagent, mix to dissolve the other high boiling point solvents; it is with very good stability, it is stable under the hot strong alkali and acidity condition, it is with water-resistance and light, oxygen stability.

246℃ m.p：—20℃闪点121℃ flash point： 121℃分子式：C6H12N2O molecular formula： C6H12N2O 分子量128.18 molecular weight： 128.18 二、DMPU的化学性质 Chemical character of DMPU 其结构中由于羰基具有强烈的吸电子效应，因而它是一种非质子的极性溶剂，具有高沸点、高闪点、低熔点，在过滤、蒸馏、溶剂萃取等工艺操作中使用方便；毒性极低，对人体危害微不足道，也减少了对环境的污染；由于它具有极强的溶解性，能溶解有机物、无机物、树脂、聚合物等，并对各种试剂具有活化性质，还能与其它高沸点溶剂混溶；具有极好的稳定性，在热的强碱和酸性条件下都很稳定，还具有耐水性及对光、氧的稳定性。

In the experiment, a powder pressedboard whose concentration of W, Mo, Co was 35%, 20%, 45% seperately was regarded as a source pole. Under the hollow cathode effection of incordinate voltage, the Ar atom was ionized to Ar+. Then the source pole and the specimen one were cleaned by a great amount of Ar+. Their temperature was increased to about 1100℃.

利用不等电位空心阴极放电效应，真空条件下被电离的Ar~+离子同时轰击源极和工件极，源极上的合金元素被溅射出来，在强烈的电场作用下，吸附到受轰击而得到清洁的工件表面上。

A sufficient and necessary condition of an isothermal surface being a minimal surface is obtained.

除平面外没有其它二次多项式极小曲面，Enneper曲面是目前微分几何文献中唯一出现的三次参数多项式极小曲面，还没有出现高次多项式极小曲面的例子。

The equivalent definition of the minimal strong component is given, and it discusses the relation between the standard form and the minimal strong component in the paper. Consequently, the theory is proved that the periodicity of a fuzzy matrix is the least common multiple of periodicity of its minimal strong component.

给出了极小强支的等价定义，讨论了模糊矩阵的标准型与极小强支关系，从而得到了模糊矩阵周期是极小强支周期的最小公倍数的定理。

In this thesis, the metal-oxide-semiconductor tunneling diodes were utilized as light emitting diodes based on that the tunneling gate current recombines with accumulated majority carriers and results in radiative luminescence.

本论文中，我们利用金氧半穿隧二极体中穿隧闸极电流与累积的多数载子结合发光的特性来制作发光二极体。

Selecting corresponding rolling force model, the paper make an experiment and studies on cold rolled paper-thin strip processing characteristics of sixteen-roll rolling machine based on cold-rolled theory aand forms corresponding rolling model, tension model and moment calculation model .And comes to a conclusion that distortion force and press utmost have a large effect on rolling force and paper-thin strip shape, primarily presenting paper-thin strip rolling subarea theory that rolling force decreases corresponding to the thick decrease of strip but increases rapidly when to a certain thick.

结合带钢冷轧基本理论，选用适当的轧制压力模型，针对十六辊轧机轧制极薄带钢时的工艺特点进行了实验和分析，建立了相应的张力模型及辊系传动力矩模型；并得出变形抗力及压靠对轧制极薄带钢时的轧制力和板形有很大的影响，初步提出了当带厚较大时，为保持板形良好，随着轧件厚度的减少，轧制压力相应降低，当轧制到一定厚度时，轧制压力随着带厚的减少急剧增加的极薄带轧制分区理论。

In chapter 2, we define a new operator—the minimal operator on martingale space, it's well known that the maximal operator controls where given martingale f is large, intuitively, we say that the minimal operator controls where a martingale is small.

第二章引入了鞅空间上极小算子mf的概念，众所周知，极大算子可以控制一个"较大"的鞅，那么形象地说，极小算子就是用来控制那些"较小"的鞅，因此，在研究关于极小算子的加权不等式时，很自然地要估计诸如〓，log mf等算子的值。

However, for hill-climbing strategies to be guaranteed to find the global optimum the optimality landscape must be unimodal. Moreover, research has demonstrated that multiple maxima exist under the maximum likelihood principle. Therefore, hill climbing based evolutionary tree reconstruction methods often return local optima.

但是由于进化树的似然函数通常含有多个局部极优解，而爬山算法没有逃离局部极优的能力，因此基于爬山算法的进化树构建算法很容易陷入局部极优。

This paper begin with a review of curves and surfces modeling, then we discuss the parametric polynomial minimal surface. This is followed by a discussion of the representations of catenoids and helicoids. Next, we discuss the numeric approximations to the minimal surfaces with piecewise polygons and B-Spline surfaces.

全文安排如下首先，我们简要回顾曲面造型历史和发展现状在第二和第三章，讨论参数多项式极小曲面；在第四章讨论悬链面和螺旋面的表示；在第五章讨论极小曲面的分片线性逼近；在第六章讨论极小曲面的B-样条逼近；最后，我们对全文做简单的总结。

The expectation value of atom dipole moment is always zero, but the fluctuation of dipole moment is a constant and not zero during the atomic spontaneous emission.

在原子的自发辐射过程中，其偶极矩的期待值总是零，但偶极矩的涨落恒等于一个不为零的常量，因此原子的自发辐射是由真空起伏导致偶极矩的涨落引起的。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。