查询词典 compressive stress

The influence of free surface on tunnels is discussed.The influence of blasting vibration on fresh concrete lining is studied. The finite element method is employed to analyze the spatial distribution of temperature and thermal stress of fresh concrete lining, the wave function expansion method is used to study the interaction of blasting seismic wave and the circular tunnel with lining, thenthe safe PPV of fresh concrete lining with different age is decided by taking into account the thermal stress of concrete lining. Using the conformal mapping method, the influence of blasting vibration on the arch tunnel with lining is studied and the safe PPV of concrete lining is deduced under different incident angle.

研究了爆破振动对新浇混凝土衬砌的影响，采用有限元法求出了圆形洞室新浇混凝土衬砌内温度和温度应力在空间上的分布及其随时间的变化，采用波函数展开法求解了爆破地震波与有衬砌圆形洞室的相互作用，获得了考虑新浇混凝土衬砌内温度应力前提下不同龄期的新浇混凝土衬砌的安全振速；利用保角变换研究了爆破振动对直墙拱形有衬砌隧洞的影响，得到了爆破地震波以不同角度入射时混凝土衬砌的安全振速。

The results show that the flow stress decreases with increasing deforming temperature and increases with increasing strain rate. The flow stress of the alloy during hot compression deformation can be described by constitutive equation in hyperbolic sine function with a hot deformation activation energy of 196.27 kJ/mol. Partial recystallization takes place in the alloys deformed at a high temperature or at a low strain rate, and large number of dislocations and subgrains are observed in the alloy. The elongated grains observed in the samples coarsen with increasing temperature and decreasing strain rate. Correspondingly, the subgrain size increases and the dislocation density decreases. The main soften mechanism of the alloy transforms from dynamic recovery to dynamic recrystallization.

结果表明：Al-Cu-Mg-Ag耐热铝合金在热压缩变形中的流变应力随着温度的升高而减小，随着应变速率的增大而增大；该合金的热压缩变形流变应力行为可用双曲正弦形式的本构方程来描述，其变形激活能为196.27kJ/mol；在变形温度较高或应变速率较低的合金中发生部分再结晶，并且在合金组织中存在大量的位错和亚晶；随着温度的升高和应变速率的降低，合金中拉长的晶粒发生粗化，亚晶尺寸增大，位错密度减小，合金的主要软化机制逐步由动态回复转变为动态再结晶。

It is found, fitted with data, that the Singh-Mitchell model has a higher precise in the stress level between 20% and 80%, and the deformation modulus and viscosity coefficient of Kelvin model all vary with stress level.

与试验数据拟合发现：Singh-Mitchell经验模型对应力水平为20%~80％时具有较高的拟合精度；Kelvin模型中的变形模量和粘滞系数均不为常数。

A rapid, efficient protocol to detect the toxicity of Cu2+ stress using wheat coleoptile, which is simple, uniformal in structure and sensitive, was established. By using this model, the mechanism of Cu2+ stress leading to the inhibition of cell elongation was also studied.

本文以小麦为材料，研究不同浓度Cu2+对小麦种子萌发和幼苗生长的影响及机理；利用小麦胚芽鞘结构简单、反应敏感的特点，探索建立小麦胚芽鞘快速检测铜离子毒害模式，并利用此模式研究了铜离子胁迫对细胞伸长抑制作用的机理。

The inhibition of coleoptile elongation is alleviated when exogenous auxin was added to the medium under the low concentrations of Cu2+ stress. However, under high concentrations of Cu2+ stress, as the toxicity is so much, exogenous auxin is not available any further.

小麦胚芽鞘的生长只表现为细胞的伸长，原理为生长素作用的结果，外加生长素，发现生长素缓解了重金属铜对胚芽鞘伸长作用的抑制，而在高浓度时，由于毒害太大，所以无效。

At 28℃～68℃, the isochromatic line of optic colophony lens of thermal stress was determined, and the interference fringe patterns were obtained at different temperatures and main stress differences.

从28℃～68℃的温度范围内，实验获得了树脂镜头的热应力等色线和不同温度、静置情况下的树脂镜头的热应力等色线干涉条纹的图像。

It suggested that under static status, the nasal septum, nasal columella and the lateral feet of nasal alar were the most concentrated areas of stress distribution. They are key mechanical parts of deformed nasal.3.2 Nasal displacement load analysis of patients with unilateral cleft lip and nasal alar collapse Deformed nasal displacement load three-dimensional finite element analysis showed that if the ipsilateral and contralateral nasal parts obtain similar geometry, the positions around nasal columella in ipsilateral nostril were the most stress concentrated region, next parts were the nasal septum and the lateral nasal alar.

提示静态状态下，鼻中隔、鼻小柱和两侧鼻翼外侧角是应力分布最集中部位，也是畸形鼻部的关键力学部位。3.2单侧唇裂鼻翼塌陷畸形患者的鼻部位移载荷形变后力学分析单侧唇裂鼻畸形患者的位移载荷三维有限元分析表明，畸形鼻部的患侧要获得和健侧近似的几何形态，其患侧鼻孔近鼻小柱周围应力分布最为集中，其次为鼻中隔和患侧鼻翼外方。

It is shown that the mechanical properties including Young's modulus, tensile strength, critical strain and stress under buckling can be enhanced with the decreasing of intershell spacing. The shear strength can be enhanced by 2-3 orders of magnitude when the intershell spacing is reduced to 20%, which is also dependent on commensuration. Zigzag-type carbon nanotubes have higher shear strength. The axial stress in tubes when the load transferring from outmost tube to inner tube is observed as well.

研究了单壁纳米管束横截面的六方化失稳现象，给出各种管径的面内压力－应变关系曲线；每条曲线都给出一个明显的拐点而且有很强的非线性；线弹性模量与参考构形有关，也受管直径的影响；分析了管束横截面的晶格不稳定性特征，表明晶格的缺陷能够明显的减小临界值；模拟了在不同应变下纳米管束对静水压的反应，发现不同压力下的截面形态不同，在很高压力下相邻管之间会形成化学键。

Weak equilibrium condition, orthogonality condition and energy compatibility condition are used to construct high performance elements. An ideal approach is to suppose that stress satisfy these conditions simultaneously, such as the stress mode of CH (0-1) in 2-D case.

弱平衡、正交性和能量协调条件是构造高性能杂交元的三种手段，三个条件同时满足是一种理想的应力设计方案，四边形单元CH(0-l)的应力是这种理想方案的一个代表。

To increase component of grinding force ratio can increase principal stress extreme values in grinding stress field.

根据工程陶瓷材料的珩磨加工特征，分析了陶瓷材料珩磨加工机理。

Researches reveal that students who suffer from corporal punishment tend to resort to violence in their future life.

研究表明遭受过肉体惩罚的孩子倾向于在他们今后的人生中使用暴力。

Total sugar of sarcocarp and chlorophyll of pericarp increased firstly, and then decreased afterward along with altitude; Titratable acidity, ascorbicacid and anthocyanin of pericarp were increased along with altitude; The content of protein increased firstly and decreased afterward along with altitude; Carotenoid of pericarp were decreased along with altitude.

果肉总糖和果皮叶绿素含量随海拔高度升高先升高后降低；可滴定酸、维生素C和果皮花青苷含量均随海拔升高而升高；蛋白质在1720m处最大，1420m处最小；果皮类胡萝卜素随海拔升高而降低。