对比系数

In the paper, the friction coefficient of the friction pairs of Al2O3 matrix ceramic/45# steel during sliding experiments were studied, and the worn trace's micrographs of Al2O3 matrix ceramic were observed and analyzed, and the wear mechanism of Al2O3 matrix ceramic in dry friction and oil Iubrication were analyzed.

摘 要：本文对Al2O3基陶瓷材料/45#钢摩擦副的摩擦系数与45#钢/45#钢的摩擦系数作了对比滑动摩擦试验研究，观测分析了Al2O3基陶瓷材料磨痕形貌，并就干摩擦，油润滑状态下Al2O3基陶瓷材料的磨损机理进行了分析。

Compared with the conventional analytic methods, the author studies the feasibility that the elastic bearing model is used to simulate the boundary constraint condition of the enrockment.

引入弹性边界模型，对比传统分析中对边界约束的处理，研究用弹性边界来模拟堆石体边界约束条件的可行性；选用规则典型的坝体，研究面板堆石坝的面板及堆石体的应力应变规律，特别是周边缝的变形规律；分别讨论了岸坡坡比、坝前水深、坝高、河床底宽等几何参数对弹簧系数取值的影响，确定弹簧系数的取值范围，给出了可用于实际工程计算的最佳取值范围；以松山面板堆石坝作为工程实例，验证弹性边界模型的实用性，并为工程建设提供了一定的参考。

From the different view of the high building foundation and large volume concrete of the hydrotechnic structure,ANSYS finite element software was applied to the numerical simulation of the temperature field.

文章分析了水化热系数对大体积混凝土温度场的影响，从高层建筑基础与水工结构大体积混凝土的不同点角度出发，运用ANSYS有限元软件对其温度场进行了数值模拟，通过与实测数据的对比，确定了高层建筑基础大体积混凝土水化系数较适宜的取值范围。

In this paper,the condition that gas flow through wood in the pattern of linear flux wasdetermined from the theories of thermodynamics and fluid mechanics.The expression of flow-resistor of tracheids is reduced with the continuity equation and the equation of motion indifferential form.The flow-resistor network is constructed by means of the theory ofpercolation.The equivalent flow-resistor was evaluated by utilizing the real spacerenormalization approach.

本文根据针叶材管胞的解剖结构，运用孔隙介质流体力学的理论，导出了管胞关于气体渗透流阻的数学表达式；继而根据管胞纹孔在三个纹理方向上的连接特性，利用管胞流阻建立了一个描述针叶材三个纹理方向气体渗透性的三维流阻网络；然后运用实空间重整化变换的方法，求解试件流阻网络三个纹理方向的等效流阻，并由此计算试件相应的气体渗透系数；最后用我国南方常见的人工林马尾松木材试件进行渗透系数实际测量，与理论计算结果进行对比分析，以验证三维流阻网络及其理论的准确性。

The results show that phosphate amine salt and phosphonic amine salt additives have much better extreme pressure properties than the conventional S, P, and/or Cl containing additives.

结果显示：2种磷和膦酸胺盐极压抗磨添加剂的承载能力优于常用的含硫添加剂；其摩擦系数处于0.05～0.06之间，大大低于对比添加剂的摩擦系数。

In this study, based on the Rnl, extinction coefficient k, transition coefficient of canopy layer stomatic resistance K', aerodynamics resistance ra and rc calculated with the data of Rn, LAI, rsi, the daily transpiration variation of Picea purpurea, Larix principisrupprechtii, Hippophae rhamnoides ,Betula platyphylla and Populus cathayana were studied in Datong County, Qinghai Province. Comparing with the practical transpiration variation measured by Li1600 Steady Porometer, the relative error of this model was less than ±15%, and the results were stabilized and tested by precision analysis.

本研究通过对Rn、LAI、rsi的实地观测，确定了林冠截流净辐射、消光系数、冠层阻力转换系数、空气动力学阻力和冠层整体气孔阻力，对青海大通地区紫果云杉、华北落叶松、沙棘、白桦和青杨的日蒸腾过程进行了模拟，与用快速称重法订正的Li1600稳态气孔仪实测蒸腾结果对比，模拟的相对误差在±15%以内；模型敏感性分析发现，温度、LAI以及rsi是决定模拟结果的主要参数，模型对各参数变化反应不敏感。

After that, the thesis will introduce an improved EZW algorithm based on scalariform quantization. The new algorithm can fix some redundancy treating in reorganizing the symbol for wavelet coefficients. Finally, we will draw some conclusion after some experiments by comparing the two methods.

同时，从阶梯量化后系数符号的变化规律，提出进一步优化算法，提高图像的压缩比；最后利用对比实验的方法，先对比阶梯量化与传统EZW在性能上的差别，然后再比较新的改进算法是否进一步提高了压缩比。

The analysis and theoretical calculation are studied about the use of heat strips black-coated on two sides for facilitating low temperature mode in a thermal vacuum test.

文章对加热笼双面涂黑漆对热真空试验低温工况实现的作用进行了研究分析和理论计算，并对覆盖系数、加热笼对试件的角系数以及内热源不同的情况进行了对比计算。

The design ideas of the economy analysis program for a ship with high block coefficient and some mathematical models such as that for estimating the light weight of a ship and the shipbuilding cost, for the type depth as well as for predicting the ship speed are given.

文中简述了大方形系数船型经济论证程序的设计思想，给出了数学模型，并作了大方形系数船型与G型2万吨级散货船、秦申线3.5万吨级浅吃水运煤船的经济性对比及敏感性分析。

The whole process includes the analysis, design and implementation of the OOFEM for the acoustic characteristics of underwater anechoic coating.

本文通过对比声波在分层介质材料中传播的吸声系数和透射系数的解析解，验证了自编OOFEM软件的准确性。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷