在尺寸上

This project studies the scale-dependent deformation behavior of the metal matrix composite, the void nucleation and void growth mechanisms at the micron/submicron scale. The main results are:(1) In prophase, growth and coalescence of the void embedded in the graded matrix are analyzed in detailed;(2) Based on the infinite solid model containing a micro-void, coupling effects of the void shape and the void size on the void growth are studied carefully, the results show that it seems to exist a critical equivalent void radius, which is associated with the material length. When radius of a microvoid is close to or smaller than the critical void radius, the micro-void growth rate is essentially eliminated;(3) The coupling effects of the particle shape and size on the mesoscopic stress fields within the particle and matrix are also investigated by introducing the conception of inclusion/matrix interfacial energy. The results show that the stress concentration factors within the particle and on the matrix/particle interface are also strongly size-dependent,so the void nucleation mechanism is size-dependent.(4) By employing a specific orthogonal curve coordinate frame and a 'kernel function' conception, a 'unified method'solving the spheriodal and spherical void problems is suggested; by this unified method, size-dependent plastic potentials of the porous materials containing the spheriodal or spherical voids are obtained, which extend the traditional Gurson model for the spherical void and GLD model for the spheriodal voids to the micron scale.(5) Based on the RVE model containing the spheriodal or spherical particles, the influences of the particle shape and size on the size-dependent mechanical behavior of metal matrix composite are studied.

中文摘要：本项目对金属基复合材料在微细观尺度下的尺度相关变形行为、孔洞形核及长大的机理和模型进行了研究，取得了如下主要结果：1）在前期研究中，探讨了基体的梯度分布对孔洞长大和聚合的影响；2）基于含孔洞的无限大体模型，探讨了孔洞形状和孔洞尺寸对其长大的耦合作用，结果表明：可能存在一个与材料特征长度相关的临界孔洞尺寸，当椭球孔洞的等效半径小于临界孔洞半径时，孔洞的长大受到明显抑制；3）通过引入基体/夹杂界面能的概念，分析了夹杂尺寸、夹杂形状对材料细观应力场的耦合影响，结果表明：颗粒内部和界面上的应力集中因子强烈地依赖于夹杂的尺寸和形状，因此，孔洞的形核机理是尺寸相关的；4）采用一种特殊的正交曲线坐标系和引入"核函数"的概念，"统一"地得到了含椭球和球形孔洞的材料的尺寸相关塑性势，它将传统的Gurson球形孔洞模型和GLD椭球孔洞模型推广到微尺度范围；5）基于含椭球和球形夹杂的体胞模型，初步研究了夹杂形状、夹杂尺寸对金属基复合材料尺寸相关力学行为的影响。

Similarly, if the strong shear, which could suppress all the scattering in the quiescent two phase region, stopped, the follow-up phase separation also displayed characteristics of anisotropism and relaxation, In this dissertation, the transposed"butterfly'and"streakpattern were observed for the first time within the shear-history-influenced phase separation, which is found closely relevant to the anisotropical relaxation behavior of macromolecules. 5. The phase separation kinetics of PS/PVME under oscillatory shear was further studied on the base of that done under simple shear. It is found that, under specific temperature and strain amplitude, the occurrence of phase separation is strongly contingent on oscillatory frequency and only intermediate frequency could effectively induce phase separation; If all considered oscillatory shear could stimulate phase separation, a fixed frequency can maintain specific most probable phase size and higher frequency yields smaller phase, which makes a higher elasticity but weaker stress relaxation; Furthermore, higher frequency can produces stronger compulsory oscillation on the MPPS but won't change the mean of the MPPS. Under given frequency and strain amplitude, the phase separation kinetics dramatically depends on the phase angle of oscillation and the phase separation corresponding to different phase angle follows different dynamical process.

在简单剪切场下相分离动力学研究的基础上进一步对振动剪切场下PS／PVME的相分离动力力学进行了尝试性的研究，发现：在一定温度和振幅条件下，相分离的发生强烈的依赖于振动频率，只有中等频率的振动剪切才能有效地促进相分离的发生；在都能使相分离发生的前提下，一定频率的剪切能够使体系维持一定的最可几相尺寸，较高频率的剪切导致体系形成的相区尺寸较小，因而体系的弹性效应较强而应力松弛效应较弱；同时，更高频率的剪切对最可几相尺寸的强迫振动效应越强，但不会使最可几相尺寸的平均值发生改变；在一定的振幅和频率条件下，相分离的动力学过程会强烈地依赖于相位角，不同相位角对应的相分离遵循不同的动力学过程但机理一样。

As the same section is concerned, near the bottom the maximum value of frequency appear within 1mm of bubble size, towards the water face this value tend to decrease, yet the corresponding size turns to increase; in the same time, the frequency is concentrated near the bottom and deconcentrated near the water face; under the experiment condition, the maximum frequency of the total section approximately appear at 0.5mm size; mean bubble size access 0 at bottom and increase acceleratively towards water face where tend to be infinite; total number increase during developing of aeration, and become steady when reach wholly developed area; on the same section, the total number in unit time tend to increase at first and decrease then, along the water depth.

对于同一断面，靠近槽底的测点气泡个数分布最大值出现在气泡尺寸小于1mm的范围内，朝水面方向各测点气泡个数分布最大值呈减小趋势，而其对应尺寸则呈现变大趋势；在靠近槽底，个数分布表现得比较集中，而在水面附近气泡个数分布曲线表现得低而平缓；实验条件下，整个断面上的气泡个数分布的最大值大体上出现在尺寸为0.5mm的地方；气泡平均尺寸在槽底处接近于0而朝水面方向迅速增大，且越接近掺气水流的水面，增加速度越快，最终趋于无穷大；气泡总数在掺气发展区内是沿程增加的，当掺气水流发展到一定程度后气泡总数就基本保持不变了；在同一断面上，各测点单位时间内的气泡总数随高度呈现出先增加后减小的趋势。

When I'm making intricate cardboard dioramas or free standing larger pieces I have to focus on the functionality of the piece – display wise. Very simply, does it stand up?

当我在硬纸板上创作的时候，要考虑到它的尺寸大小，以及展示的时候，所遇到的繁琐细节，有一些简单的想法，必须要先问问自己，例如：「它可以站立吗？

Suppose that the two hydrants are exactly alike in shape, but they differ in size.

假设两个消防栓，正好在形状上相似，但不同尺寸。

Check the drawings and their dimensions to compare it on spot. Mark the line with pencil for any extra and grind or cut with grinder or jig saw.

核对现场实际和图纸标准尺寸，如有多余就用铅笔在台面上划好线，用穿梭机或者角磨机切割。

The objective is to supplement the analytical model of mechanism moving reliability taking account of kinematics joint gap focusing on high velocity motion mechanism.

实际机构的运动规律是由构成机构的各构件的几何形状和尺寸、质量、材料性能及作用在机构上的驱动力和工作阻力等因素决定的。

Use tape to measure the dimensions of the upper and lower jointers and use this dimension to mark the positioning line on the door panels.

然后把固定门板的上下两个配件插入米箱箱体的相应孔位里面，分别用卷尺测量米箱上下插件的尺寸并据此在门板上划好定位线。

Bead size in a range from several nanometers to hundreds of micrometers are commercially available.

尺寸范围从几纳米到几百微米的珠粒在市场上都有存在。

A bow fairlead should measure at least 600 by 450 mm and be placed on the centre line.

艏导缆孔的尺寸应至少为600 x 450毫米，并安装在中心线上。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了