微裂纹

The germination, expansion and reciprocity of the crack inside the material embody on the crystal bound of the material. So, in this study we can change the bourgeon and extend condition of the tiny crack inside the material by design and control the crystal interface structure effectively and provide new research approach for the design and manufacture of the machinability ceramic.

由于材料的破坏和加工都决定于材料内部微裂纹生成的难易程度和扩展程度，而材料内部裂纹的萌发、扩展和相互作用集中表现在材料的晶界和相界面上；因此，本研究通过有效的设计和控制界面结构，改变材料内部微裂纹的萌生和扩展条件，为可加工陶瓷的设计和制备提供新的研究途径。

The parallel or series assumption cannot be applicable to the synthesis mode of stress and strain for complexus theory of geomaterials damage.

狭义上，可认为损伤力学是利用宏观理论分析与解决在宏观裂纹出现以前微观缺陷、微裂纹、微空穴的

According to the stress-strain complete process curve, the total volumetric strains and crack induced 1 volumetric strains is adopted as damage parameters for analyzing the five phases during the crack growth (crack closure , linear elastic, stable crack growth, unstable crack growth and post failure).

通过压缩试验获得的脆性岩石的全应力应变曲线，利用体积变量和裂纹体积变量等损伤变量分析得出裂纹发展的五个阶段即：压密、弹性、微裂纹稳定扩展、裂纹非稳定扩展和峰后失稳等。

The breakage of particle is because of the development of the microcrack, which is caused by particle impact velocity and generalized size strength.

颗粒气流冲击破坏是由于其内部微裂纹的产生和繁衍所致，而微裂纹的产生和繁衍是其冲击速度和广义尺寸强度直接作用的结果。

These T-stress effects depend on the sign and the magnitude of the T-stress as well as on the geometry of the microcrack arrangement.

当考虑T应力影响时，各向异性材料中的微裂纹对主裂纹的屏蔽效应比相同情况下各向同性材料中的微裂纹屏蔽效应更显著。

By use of the concept of domain of microcrack growth the damaged status of micocrack in rock can be described accurately and the problem about damage development of rock under any complicated loading pathes can be solved.

采用微裂纹扩展域的概念，准确地描述了岩石中微裂纹的损伤状态，解决了任意复杂加载路径下的岩石损伤演化问题。

At last, through the analysis of the T-stress, it is concluded that the T-stress plays an important role for the oriented microcrack cases. It is necessary to consider the effect of the T-stress in determining the shielding or amplification effect of the oriented microcracks.

最后，本文采用离散模型研究了各向异性材料主微裂纹干涉问题中T应力对主裂尖应力强度因子的影响：T应力对主裂尖应力强度因子的影响是不能被忽视的，这种影响不但与微裂纹的几何分布有关，而且还与T应力的大小和符号有关。

When heat load flux increases to 3MW/m2, there are microcracks on surface in several micrometers depth.Microcracks complect to a reticulation along the tungsten grain boundaries.

热流密度为3MW/m2时，表面无宏观裂纹，试样表层几个微米内出现微裂纹，微裂纹沿钨晶粒边界交织成网状分布。

During SCC of type 310 austenitic stainless steel in MgCl〓 solution at 115℃, corrosion process can enhance dislocation emission, multiplication and motion. Stress corrosion microcrack nucleates in the dislocation free zone or at the tip of the crack when the corrosion-enhanced dislocation emission and motion develop to the critical condition.

本文所得主要结论如下： 1.310不锈钢在沸腾MgCl〓溶液中SCC时，腐蚀过程能促进位错的发射、增殖和运动，当其达到临界条件时，SCC微裂纹就会在无位错区中不连续形核或从原裂纹顶端连续形核；由于介质的作用，纳米级微裂纹并不钝化成空洞和缺口，而是解理扩展。

The ionic space charge in the micro-voids of water tree will produce a period vibration by AC voltage stimulating. Under superposition voltage, the vibration can impel the ion penetrating into the tiny crackle between micro-voids of water tree and lead to a change in the conductivity of water tree. With this the ultra-low frequency spatial current signal of the water tree would be emerged in detecting circuit. The polarization and depolarization of the polar end-group of the PE formed in water tree developing will also contribute to this special signal.

本文分析认为，水树枝中的离子型空间电荷在几种电压共同作用下会发生周期性振动，这种振动会促使水树枝中的导电离子在较低的叠加电压激励下进入连接水树枝微孔的微裂纹，微裂纹导通不仅导致水树枝的电导发生变化，而且在检测回路中会有水树枝老化超低频特征信号电流产生。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。