应力

Bending and torsion of monosymmetric I-section thin-walled curvedbeams with large displacement were studied in detail.The accurate expressions ofwarping displacement,normal stress,shear stress were given as well asgeneralized stress-strain relation.

对薄壁曲梁的有限位移理论进行了详尽的分析，得出了有限位移理论中单轴对称工形截面曲梁的翘曲位移、正应力、剪应力以及广义应力—应变关系的的精确表达。

The influences of mean stress, multiaxial stress and yield stress on the fatigue crack growth rate and the threshold value are analyzed.

分析了平均应力、多轴应力和材料屈服应力等对疲劳裂纹扩展速率和门槛值的影响。

This paper gives the distribution of the Peynolds stresses, which shows that the flow near the wall at the exit is obviously nonisotropic and the maximal turbulence intensity is enough high to impact on the matching of the intake and the engine. The unsteady characteristics of the flow evince that the flow doesn't separate obviously.

出口截面上雷诺应力分布表明：该进气道出口流场主流方向的紊流强度较大，最大值已达8%以上，这给进／发匹配造成影响；正雷诺应力和剪切应力沿径向和周向的分布特点则说明进气道出口核心流区域流动基本是各向同性的，然而在近壁区却表现为明显的各向异性。

When the glancing—tilt method is used, the linearity of 2θ—sin〓Ψ can be remarkedly improved.

X射线应力测定的sin〓Ψ法在测定PCVD TiN的残余应力时，2θ—sin〓Ψ发生严重弯曲，如果沿用线性拟合求斜率的方法计算残余应力，误差必然很大。

It is well known that the large lattice mismatch (16%) and thermal expansion coefficient mismatch between GaN and sapphire substrate are the main origins of TDs. By new growing technique of LEO, we acquired high quality GaN films almost free of TDs. The stress characteristics in GaN films with MLTB growing technique is dependent on growing systems and conditions, and the changes of stress and dislocation density are rightabout; Combining buffer layers of high temperature and low temperature is first developed to growing GaN films with low dislocation density, and the mechanism of lowering TDs density is that the first buffer layer of high temperature can make nuclear in second buffer layer of low temperature bigger. This technique also can restrain yellow luminescence effectively.

众所周知，晶格失配和热应力失配是GaN异质外延中位错产生的主要原因；为此，我们对几种降低缺陷的MOCVD外延生长方法进行了新的尝试，其中尝试了侧向外延生长技术，得到了低位错密度（小于10〓/cm〓）、高质量的GaN外延层；尝试多低温缓冲层法，发现材料中的应力特性与生长系统和生长条件有关，材料中的应力与位错密度按相反方向变化；首次尝试高低温联合缓冲层法，材料中高温缓冲层可以使随后的低温缓冲层中成核颗粒增大，从而导致随后高温GaN外延膜中位错密度降低，并且能够有效地抑制黄光峰。

The result indicated that the stress cracking resistance properties of polymer alloy were greatly improved comparing to pure HDPE, and there was a strong relationship between spherulitic structure, mechanical properties and stress resistant properties.

结果表明，共混体系耐应力开裂性能比纯HDPE有很大提高，而且应力开裂性能与材料的强度和球晶形态密切相关，强度较大且球晶小而不规则者，其耐环境应力开裂性能较好。

OBJECTIVE: To establish continuous passive motion models following repairing acute rupture of supraspinatus tendon, to observe the effect of CPM on histological changes of tendon-bone, and to explore the role of CPM in the postoperative rehabilitation following acute rotator cuff injury .

目的：通过建立兔冈上肌腱急性断裂术后被动应力刺激训练实验动物模型，观察被动应力刺激对其腱-骨界面组织学变化的影响，探讨被动应力刺激在肩袖损伤术后康复中的作用。

The results show that the weaken of crack directors has a little influence on stress release and little influence on stress distribution when the crack directors is uncracked. Once it cracked, the tension stress in the arch dam will reduce greatly.

实例计算结果表明：在诱导缝未开裂时，其削弱程度对坝体应力的释放程度有很小的差别，而对坝体应力分布规律几乎没有影响；一旦诱导缝开裂，则坝体中的拉应力大为降低。

Results of the computation under the same welding temperature field show that the longitudinal residual stresses in the weld are as high as the yield strength of the plate in the strength and TEC evenmatched joints, lower than the yield strength of the plate in the strength evenmatched and TEC undermatched joints. It also has something to do with the strain hardening exponent of the weld metal in the strength evenmatched and TEC overmatched joints.

计算结果表明：等强等胀匹配的焊缝区纵向残余拉应力水平高达母材的屈服强度，等强低胀匹配的焊缝区纵向残余应力水平低于母材屈服强度，等强高胀匹配的焊缝区纵向残余应力水平还与焊缝应变硬化指数有关。

The applicability of this constitutive model is evaluated with the simulations of material tests conducted by Sasaki et al., includes (1)Uniaxially constant strain amplitude cyclic test,(2)Fast in tension/Slow in compression constant strain amplitude cyclic test,(3)Slow-fast-slow constant strain amplitude cyclic test,(4)Cyclic strain with tensile hold time test. Simulations based on this constitutive model have a good agreement with (1),(2) and (3), proofs that it can describe the cyclic stress-strain behavior of 60Sn/40Pb solder very well.

为验证本模式之能力，本文选择Sasaki等人之实验为对象，分别对60Sn/40Pb焊锡在(1)定应变振幅之循环单轴负荷实验、(2)拉伸快/压缩慢之定应变振幅循环负荷实验、(3)慢-快-慢之定应变振幅循环负荷实验、(4)拉伸应力保持之循环应变实验下的材料行为进行模拟，由(1)、(2)及(3)之结果证明本模式对60Sn/40Pb焊锡循环应力-应变整体行为具有理想的描述能力，并对循环塑性应变范围与应力范围之值有准确的预估。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。