查询词典 stress accent

First of all,we tested the germination and water uptake rate of 47 species typical xerophil seeds grow up in north China from 20 families,38 genuses under sufficient water and different Grads water stress by high-molecular-weight polyethylene glycol(PEG6000).The results show that Xerophil seeds from the same habitat exhibited similar patterns in response to water stress.Xerophil seeds from arid community were stronger in germination and imbibition than that from other two communities under serious water stress,whereas Xerophil seeds from humid community were sensitive to any degree of water stress.Namely,the seeds live in arid habitat possessed high germination and quickly water uptake in sufficient water or any degree of water stress,but the others grow up in humid habitat shown significant difference which germination and water uptake well under sufficient water but inhibited even if slight water stress.

首先，我们通过对20个科，38属，47种旱生植物种子在水分充足和不同梯度的干旱处理(聚乙二醇PEG6000)条件下的萌发率及吸水率实验发现，当水分胁迫强烈时，分布于干旱沙漠地区的植物种子其吸水率和萌发率都高于半干旱和湿润地区的植物群落，相反，湿润地区植物种子的吸水率和萌发率对任何的水分胁迫都表现出敏感的响应趋势，也就是说，生境恶劣的植物种子在较强的干旱胁迫下，仍然保持了较高较快的萌发率及吸水率，水分充足与水分缺乏时无显著差异，而生境相对较好的植物种子在水分充足情况下萌发与吸水良好，但在干旱胁迫时则受到明显抑制，水分充足与水分缺乏时差异显著。

Using FEM, the coupled action of thermal stress and crustal stress has been taken into account. The regularities of distribution of the horizontal displacement of surface of slope and the shear stress of junction plane between shotcrete and rock are discussed too. According to the analysis, under the combined action of thermal stress and crustal stress, top and foot of slope are liable to be destructed. Ordinary, the destructional form of the top is tensile failure and the bottom is shear failure. There are some time effect of displacement and stress in the surface of slope and distribution of temperature in slope, which agrees with actual measured rules.

采用有限元的方法，考虑地应力与温度应力的耦合作用，分析了在一定的边界温度作用下不同时刻边坡喷层面的水平位移，以及喷层与岩层结合面处的剪应力的分布规律；指出在温度应力与地应力的共同作用下，喷混凝土边坡坡顶与坡脚均为容易发生破坏的地方，通常坡顶的破坏型式为拉张破坏而坡脚则为剪切破坏；边坡内的温度分布、边坡表面的位移与应力的变化均存在一定的时间效应，这一规律与实测规律比较吻合。

The results show that the influences of duration and amplitude of stress wave on spallation process of rock under stress wave loading are important; and stress wave with different waveforms is characteristic of different stress values and different stress loading ratios during the same period of time, which brings about the comprehensive effect when difform stress wave is loaded to medium.

通过对不同应力波延续时间、不同应力波峰值和不同应力波波形下应力波诱发层裂过程的数值分析，对应力波反射诱发层裂的规律和机制进行探讨。

Incurrent research, aiming at the rupture problem engendered in the shooting process of acertain 5.56mm automatic rifle, the strain and stress distributions on the cartridge caseunder the action of axial pull have been analyzed. Based on the theories of elastic-plasticmechanics and contact mechanics, a mathematic and physical model of the cartridge-caseand chamber system has been set up; and based on the platform of the general softwarepackage APDL of ANSYS for finite element analysis, a parameterized model of thecartridge-case and chamber system has also been established. The method for nonlinearFEA has been adopted to analyze the stress distribution on the entire cartridge-case andchamber system, and the method of contact element has been employed to investigate thecontact stress between the cartridge case and chamber, and then the influences of frictioncoefficient and locking space on the static and dynamic stress and strain response of thecartridge case and chamber to the action of power gas have also been discussed. On thebasis of a lot of numerical tests, a kind of element Plane13, which is concentrated incoupled computation of heat and construction, has been used finally to simulate thetransient response of the cartridge-case and chamber system to the power gas. Throughloading the temporary thermal characteristics of explosive gas in the procedure of emulate, the corresponding transient thermal stress distributed on the entire system under thecombined load of transient thermal stress and transient pressure has been obtained. Owingto these comprehensive considerations, the numerical results obtained in this paperrepresent the actual situations comparatively exactly.

本文针对某5.56mm自动步枪在工作中出现断壳的问题，分析了弹壳在轴向拉力作用下的应力应变；基于弹塑性力学及接触理论，建立了弹壳弹膛系统的数学、物理学模型，在通用有限元ANSYS软件的参数化建模工具APDL平台上，建立了弹壳弹膛系统的参数化模型；采用非线性有限元法计算了弹壳弹膛系统的整体应力，引入接触单元法分析弹壳和弹膛的接触压力，探讨了在不同的摩擦系数和不同的闭锁间隙对弹壳弹膛静、动态响应的影响；本文进行了大量的尝试，最后确定采用热、结构耦合单元Plane13，在计算中加载了火药气体的温度历程，成功的获得了弹壳弹膛系统在瞬态的热载荷和瞬态的压力载荷同时作用下弹壳弹膛系统的热应力数值解，考虑因素全面，比较真实的反映了弹壳弹膛系统在火药气体压力和热载荷下作用的情况。

In this paper, the 3-D finite element relocating mesh method is used to calculate the temperature field and the thermal creep stress field of spillway dam and mid level outlet dam in certain roller compacted concrete gravity dam, sensitivity analysis have been down with different parameters, such as placing temperature, the location of cooling pipe, cooling temperature, time for water supply, ascended-layer of concrete, intermissive time and different placing time, and the commendatory construction scheme have been put forward in such analysis; according by the test result on the two scheme of concrete aggregate combination (basalt as coarse aggregate and limestone as fine aggregate, basalt as coarse aggregate and basalt as fine aggregate), simulation analysis on temperature field and thermal creep stress field of the commendatory construction scheme have been down, and analysis have also been down on temperature field and thermal stress field of the two different aggregate combination, the result indicates that the spillway dam and mid level outlet dam which adopted these two aggregate combination can both satisfy the require of design crack resistance in concrete, furthermore limestone as fine is better than basalt as fine aggregate; the effect of summer water storage and winter water storage on the temperature field and thermal stress field have been analyzed, comparing with winter water storage, in summer water storage scheme the maximum tensile stress at abnormal concrete in upstream fill is decreased by 0.1～0.3MPa and there are no evidence change of the maximum tensile stress at other parts, which indicate that summer water storage is avail for the crack resistance of upstream fill; according to the simulation calculating result and comparing temperature simulation calculating results and temperature controlling measures of some similarity projects both completed and construction, synthesis appraise have been carried to the design temperature controlling measures of dam, and the temperature controlling measures of this project have been brought forward, all these have great reference value on the design of temperature controlling measures and the optimization of the construction scheme.

本文采用三维有限元浮动网格法仿真计算程序，对某碾压混凝土重力坝的溢流坝段和中孔坝段分别进行了三维有限元温度场和温度徐变应力仿真计算分析，对浇筑温度、冷却水管的布置方式、冷却水温、通水时间、浇筑升程和间歇时间、不同开始浇筑日期等参数进行了敏感性分析，在此基础上提出了推荐的施工方案；根据两种骨料方案(玄武岩粗骨料+灰岩细骨料方案；玄武岩粗骨料+玄武岩细骨料方案)的混凝土性能试验研究成果，对推荐的施工方案进行了温度场和温度徐变应力仿真计算，并对比分析了两种不同骨料情况下的温度场和温度应力，结果表明溢流坝段及中孔坝段采用上述两种骨料均能满足混凝土的抗裂设计要求，且灰岩细骨料优于玄武岩细骨料；计算分析了夏季蓄水和冬季蓄水对坝体温度场和温度应力的影响，夏季蓄水方案与冬季蓄水方案相比，坝体上游变态混凝土区域最大拉应力小0.1～0.3MPa，其他部位最大拉应力无明显变化，夏季蓄水对坝体上游面混凝土的抗裂有利；根据仿真计算成果并通过比较国内一些已建和在建的类似工程的温度仿真计算成果及采取的温控措施，对大坝的设计温控措施进行了综合评价，并提出了该工程的温控措施，对温控设计和优化施工方案具有重要参考价值。

Through designing of composition and structure of the bioactive graded coating,innerstress and its distribution in the coating were analyzed and calculated, the resultsshowed that when composition distribution coefficient n was 1.5, a reasonable stressdistribution could be got, that was at the beginning of deposition the suspension containingrichly BG granules was used so that a rich BG granules layer, a good transitional layerbetween BG layer at the bottom and the coating could be obtained at the titanium alloy side,the bottom of the coating; the stress value near the interface and surface and its character,pressure stress or tensile stress, were decided by the character of its composition itself.Changing composition distribution coefficient n could only change the variation tendency ofstress in the coating, but did not change the stress distribution rule in the coating. Thethinner the coating is, the sharper stress variation in the coating is, which does not mean thatthicker coating is better because the thicker the coating is, the little the permitteddeformation of coating is, so the coating thickness should be thinner, for example, about50μm for bending applications, but for applications only bearing pure shear stress, such asroot of tooth implant, the coating can be thicker little, for instance, about 80～100μm. The study on electrification characteristic and electrophoresis deposition of HAand BG granules in aqueous and non-aqueous solution system found that EPD almost didn'toccur in aqueous solution system. However, because HA granules take position charges inabsolute alcohol, a homogeneous EPD be carried out on the cathode titanium alloy slice, but taking negative charge in absolute alcohol the BG granules not be deposited on the cathode. A guided HA crystallizing, 100～300nm, on surface of the BG granules be realized by metathetical reaction, which cover BG granules with HA microcrystals and make the covered BG granules taking position charges in absolute alcohol, sequentially realize the EPCD of the BG and HA granules on the cathode, so it is feasible to make a titanium alloy/BG/HA bioactive graded coating by making use of EPCD technology. The corrosion experiment of rich boron bioglass coating and plasma spray coating showed that split phase, rich boron and rich silicon phase, occurred during its preparation. In basic medium the corrosion behavior of 〓 BG coating showed uniformity corrosion, the corrosion mostly occurred at rich boron phase area, therefore batch formula design of BGshould avoid the occurring of split phase. The corrosion appearance of plasma spray coatingappeared a non-uniform corrosion, mostly occurred at the edge of the laminated HA moltendrops, and emerged an accelerated corrosion tendency, which will easyly lead to corrosioncrackles extending to the interface and the happening of osmotic interfacial corrosion, thatmay be one of the major reasons leading to the coating cracking-off in the later period. Thetesting results of thermal expansion coefficient of 〓 and 〓BG showed the thermalexpansion coefficient of 〓 BG matched with that of titanium alloy better, and 〓 BG couldsinter with titanium alloy into densification enamel layer at low temperature (720℃).

将Ti6Al4V合金在1000℃下进行真空热处理会降低其力学性能，且合金内的V元素会向表面富集，因此，钛合金真空热处理和表面涂层的烧结温度不能过高，即应低于其相转变点；通过对生物活性梯度涂层的组成和结构的设计，分析和计算了梯度涂层内的应力大小和分布，结果表明：对于本研究，当成分分布系数n=1.5时，可以获得较合理的涂层力学性能，即在沉积开始时，采用富含BG颗粒的悬浮液，以便在钛合金侧获得同底层BG有良好过渡的富BG涂层；梯度涂层界面和表面的应力大小、性质由材料组成本身的性质决定，改变成分分布系数，只能改变涂层内应力变化的趋势；涂层的厚薄不影响涂层内的应力分布规律，但涂层越薄，涂层内的应力变化越快，但这并不意味着涂层越厚越好，因为涂层越厚，涂层允许的变形越小，对于应用于弯曲受力部位的涂层而言，涂层应薄一点为好(50μm)；而对于仅纯受剪切应力的部位，如牙根种植体，涂层可适当加厚(80～100μm)；通过对HA和BG颗粒在水溶液体系和非水溶液体系中的带电特性和电泳沉积的研究发现，它们在水溶液体系中很难发生电沉积；在无水乙醇溶液中，HA颗粒带正电，可在阴极钛合金片上发生均匀的电泳沉积，而BG颗粒则带负电荷；利用复分解反应法，可以制得100～300nm的HA，通过诱导HA在BG颗粒表面结晶，可对BG颗粒进行表面包覆，获得了被HA包覆的BG颗粒，改变了BG颗粒表面的带电特性，使BG和HA颗粒在无水乙醇中均带上正电荷，从而实现了HA和BG颗粒在阴极上的共沉积。

As showed in Fig.1, the diagrammed stress of short time endurance test forAs showed in Fig.1, the diagrammed stress of short time endurance test for500 hours at 565℃on welded-joint of T91-F12 is 240MPa. Considering the℃on welded-joint of T91-F12 is 240MPa. Considering thedispersity of±20％, stress of check test for 500 hours is 192MPa. The result±20％, stress of check test for 500 hours is 192MPa. The resultof short time endurance test for 500 hours at 565of short time endurance test for 500 hours at 565℃on T91-X20CrMoV121℃on T91-X20CrMoV121welded-joints is showed in Tab.5. The result shows that the short timewelded-joints is showed in Tab.5. The result shows that the short timeendurance stress of weldedendurance stress of welded-joints with two procedures at 565℃for 500 hours-joints with two procedures at 565℃for 500 hoursboth above 192MPa, and meet the requirement.both above 192MPa, and meet the requirement.

依据图1，对T91－F12 焊接接头 565℃温度下的短时持久性能 500 小时考核试验依据图1，对T91－F12 焊接接头 565℃温度下的短时持久性能 500 小时考核试验的图示应力值应为 240MPa，按照持久强度试验数据的±20％的分散度，取 500的图示应力值应为 240MPa，按照持久强度试验数据的±20％的分散度，取 500小时考核试验应力值为 192MPa.T91－X20CrMoV121 焊接接头 565℃、500 小时小时考核试验应力值为 192MPa.T91－X20CrMoV121 焊接接头 565℃、500 小时短时持久考核试验试验结果见表5 ，试验结果表明，两种工艺条件下的焊接接头短时持久考核试验试验结果见表5 ，试验结果表明，两种工艺条件下的焊接接头565℃温度下的短时持久性能，500 小时的持久断裂应力均高于 192MPa，结果符565℃温度下的短时持久性能，500 小时的持久断裂应力均高于 192MPa，结果符合要求。

The results of these analysis show that the initial stress of steel stiffened girder has a significant impact on maximum vertical displacement, maximum tensile stress of pavement surface and maximum shear stress of binding course; the deformation of steel stiffened girder has a significant impact on shear stress of binding course; heavy-vehicle load can increase each control index rapidly; the horizontal force of vehicle load has a significant impact on longitudinal tensile stress of pavement surface and longitudinal shear stress of binding course.

分析结果表明钢加劲梁初始应力对铺装层表面最大竖向位移、铺装层表面最大拉应力与粘结层最大剪应力均有显著影响；钢加劲梁变形对粘结层剪应力影响显著；重车荷载将使各控制指标均急剧增加；车辆荷载的水平力则对铺装层表面纵向拉应力与粘结层纵向剪应力影响显著。

Alone cold stress, simulated 2 km hypoxia stress (4 hours/day, continuation for 2 days)+ cold, 2 km hypoxia stress, 2 km hypoxia stress + restraint stress and alone restraint stress all significantly decreased rats body weight gain.

与各自的单独应激相比较，冷应激+5km低氧(4小时／天，连续2天)的复合应激，束缚应激+5km低氧的复合应激显著地抑制了大鼠体重的增重。

The measurement results show that the general characteristics of the present crustal stress field of the project area are as follows: the horizontal principal stress is the maximum principal stress, and the preferred orientation of the maximum horizontal principal stress is NW-WNW, the maximum principal stress of surrounding rocks of the plant buildings and high-pressure branch tunnel area is generally 14.5±0.5 MPa and the minimum principal stress is 9±0.5 MPa; the dead oad-bearing capacity of surrounding rocks is 10—14 MPa; and the surrounding rocks are essentially impermeable at high pressures of 8—10 MPa.

测量结果表明，工程区现今地壳应力场的总体特征为：水平主应力为最大主应力，最大水平主应力的优势方向为NW-NWW向；厂房和高压岔管区围岩的最大主应力值一般为14.5±0.5MPa，最小主应力值一般为9±0.5MPa；围岩自身的抗载强度一般为10～14MPa；在8～10MPa高压力作用下围岩基本不透水。

The work of this paper is as follows: 1. Looking back the progressing history of the linear motor, introducing the features of the elevator driven by linear induction motor, radicating the topic of this paper "the digital frequency variable control of the elevator bi-side direct driven by linear induction motor". The research of this paper covers the conventional VVVF control, space vector based VVVF control, vector control and DTC.

本文主要开展了以下几个方面的工作： 1 回顾了直线电机发展历史，电机的驱动技术演变，特别是针对直线电机的驱动，简要介绍了直线感应电机驱动电梯的优点和不同结构类型，对传统的v／f控制，基于空间矢量法的v／f控制，矢量控制，和基于电压空间矢量的直接转矩控制进行了比较，确立了本课题的研究主题：直线感应电机双边直推式驱动电梯的全数字变频控制。

The article combines with the treatment of a superficial civil air defense work to introduce how the grouting method to improve the performance of the backfill soil.

文章从治理漂浮人防工事的角度提出了注浆技术在改善回填土性质方面的应用，并详细阐述了注浆技术的施工流程。