裂纹

The results show that the heterogeneous characteristic has a great effect on the rock failure,the more the homogeneousness,the fewer the crack branches and the more concentrated acoustic emissions.

结果表明：材料的非均质性对其破坏有重要的影响，均质度越高，破坏过程中的分支裂纹越少，声发射也越集中。

There are not distinct difference of healing results between the direct hot-press healing and pre-heated treatment before hot-press healing.

与单纯高温愈合处理(1000℃循环热处理10 h)的实验结果相比，塑性形变可大大缩短裂纹愈合所需要的热处理时间。

Partial HA cracks,which has not been recovered by hot-press treatment,present the spherical cap-shaped with the length of about 4 μm～8 μm.

采用热压愈合的实验方法，对碳钢氢腐蚀裂纹的愈合行为进行研究。

The main results of the investigation are as following:(1) Some important criteria for the design of multi-layer structure are acquired: the ratio of the layer thickness to the contact diameter should be controlled to a value about 0.8; increasing the number of the gradient layers and elasticity modulus of the top layer would benefit to the yield strength and the stress status at the interface.（2）By means of molecular dynamics simulations for a indentation and sliding process, it is discovered that dislocations of 45 direction to the surface occur in the surfaces layer, which is correspond to the direction of the plastic flows observed in the macroscopic continuous medium. The irreversible deformation caused by the dislocation and the atom piles at the surface are responsible for the irreversibility of the force response. They are also the main factors for the friction generation. The temperature and the indentation velocity have significant effects on the deformation behaviors of the material of the surface layer. The yield strength would increase obviously if the indentation velocity is greater than 10 m/s.（3）A method to evaluate the fracture toughness of coating by estimating the crack-density functionβof a Wicker''s indentation was proposed. Meanwhile a new surface treatment technology was developed using non-equilibrium plasma.（4）A MD-FE hybrid method and corresponding software was developed to analysis the tribological behaviors for multiplayer system.

研究主要内容和结果有：（1）得到指导梯度膜设计的几个准则：控制膜层厚度与接触半径比在0.8左右为宜；适当增加梯度层层数和顶层弹性模量，有利于提高抗屈服能力和改善界面处的应力状态；（2）通过对嵌入和滑动摩擦过程的分子动力学模拟，发现表层产生一个与宏观连续介质的塑性流动方向观测一致的45 方向位错；位错造成的不可逆变形和表面的原子堆积，是力的响应不可逆性的原因，也是构成摩擦力的主要因素；温度和嵌入速度对材料变形特性有显著的影响，当嵌入速度大于10 m/s时，屈服强度明显增加；（3）提出压痕裂纹密度系数β半定量判定膜层断裂韧性的方法；并开发出表面强化新工艺；（4）开发出分析表面摩擦学特性的MD-FE复合模拟方法和相应模拟软件。

The stress corrosion cracking experiments were conducted using SUS 304 L stainless steel WOL samples in 3.0% NaOH solution by mass fraction at 280℃in order to study the anti-stress corrosion performance of PD-201 hydrogenator made of SUS 304 L stainless steel of purified terephthalic acidplant during alkaline washing without stopping production.

通过用SUS304L不锈钢制作的楔形张开加载预裂纹试样，在280℃、质量分数为3.0%的NaOH溶液的条件下进行应力腐蚀试验，以模拟对苯二甲酸装置的加氢反应器PD-201不停车碱洗工作过程中SUS304L不锈钢在该介质环境下的抗应力腐蚀性能。

The shear moduli in two directions were assumed to vary in terms with hyperbolic function .

假设剪切模量沿着梯度方向都按双曲函数变化，采用积分变换-对偶积分方程方法，求得了裂纹尖端应力场和应力强度因子，并研究了材料不均匀参数对应力强度因子的影响。

The deformation mechanism is mainly the single-slip and cross-ship, the fracture mechanism is mainly the congregation of transgranular micro-hole, and large uniform deformation occurred before tough fracture, and therefore, the ability of plastic deformation and the mechanical properties of the material were remarkably improved. These fully indicate that the new melt-treatment developed in this work is an effective and advanced technique, and further testify that the improvement of metallurgical quality of the material is the key to enhance its mechanical properties, especially its plastic deformation performance. The results of tensile and compression tests at elevated temperature also indicate that the suitable hot-working temperature range is 400～450℃. 4. A steady-state plastic flow exists during the plastic deformation of the aluminum sheet used for pressure can at elevated temperature. A hyperbolic sine relationship can be satisfied between the steady-state flow stress and strain rate by introducing an Arrhenius term which involves some thermal activation parameters, i.

压力罐用铝材中的主要冶金缺陷为Al〓O〓夹杂物、气孔及富Fe杂质相；高效熔体处理显著改善了材料的冶金缺陷的存在形态，使含杂量明显减少、夹杂物尺寸变细小且分布均匀，富Fe杂质相变为细小、分布均匀的团球状或短棒状的复杂化合物，同时也明显细化了结晶组织；此外，由于高效熔体处理有效地减少了材料中裂纹萌生源数量，因而改变了材料的塑性变形微观过程及断裂方式，主要以单滑移和交滑移进行塑性变形，断裂方式为穿晶微孔聚集型，韧性断裂前产生了大量的均匀变形，不易出现变形失稳，从而显著提高了罐用铝材的塑变能力和力学性能。

The improvement of the frictional resistance is mainly due to the effect of carbon on residual austenite and the morphology of carbides, and an appropriate amount of residual austenite is helpful to improve the impact toughness and hardness of matrix; The spherical VC can hinder the initiation and propagation of crack and improve the frictional resistance.

碳含量对耐磨性的影响主要是通过对基体残余奥氏体量和碳化物形态表现出来的，适量的残余奥氏体使基体具有较好的冲击韧度及硬度；形态较为固整的VC颗粒，对裂纹的萌生及扩展起阻碍作用，从而使材料的耐磨性提高。

Weld with trailing impactive rolling is a new technique to reduce the residual stress and distortion and prevent hot cracking of thin-walled structure.

随焊冲击碾压是一种控制薄壁结构焊接应力变形、防止热裂纹的新方法。

A new technology is put forward which uses weld with trailing impactive rolling to control the welding stress and distortion of thin component and to prevent welding hot cracking.

提出了随焊冲击碾压控制薄壁构件焊接应力变形、防止焊接热裂纹的新方法，其原理为：通过前后冲击碾压轮，分别对焊后尚处于高温状态的焊趾和焊缝区金属施加一定频率的冲击碾压力

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。