压下

The structure-acoustic coupled models of Santana2000 are built both with and without absorption material, and ANSYS finite element analysis software is used to calculate interior acoustic pressure due to panels vibration under specific frequency, then the acoustic contribution of panel is evaluated.

以桑塔那2000型轿车为实例建立无吸声材料和有吸声材料的结构-声学模型，使用ANSYS有限元分析软件计算车身板件在给定频率下振动引起的车内声压，进而求得板件的声学贡献。

The different distribution of initial acoustic pressure was given.

分析比较了超宽带微波与单一频率微波入射下，初始声压分布的不同。

This research shall be obtain that ocean-sand motor shall have more compressive strength early, but later strength shall descend, by means of non-standard sand mixing sample is quite obvious. By means of 50% ocean-sand substitutes for river-sand to mix fine aggregate compressive strength early shall be risen 20%~30%; Adds slag to ocean-sand or a half of river-sand and ocean-sand to make motor test sample, Compressive strength、bending strength and tensile strength shall be according to slag additament, by means of. slag add itament substitutes for cement 40%~60% is most. But slag be able to substitute for cement is too enough, 1ater strength shall be descent.

由本研究可得知海砂拌和的水泥砂浆，其早期抗压强度较高，而晚期强度则有下降的趋势，其中以非标准砂拌和效果最为明显；若以50%海砂替代河砂做为拌和细骨材，其早期抗压强度约上升20%~30%；添加炉石於海砂或河砂、海砂各半的水泥砂浆，其抗压、抗弯及抗拉强度，会随著炉石添加量增加而增加，其中以40%~60%炉石替代量为最佳，但是炉石替代量过高，晚期强度会下降；在相同水灰比状况下以海砂拌和水泥砂浆做比较，以非标准砂拌和有较高的抗压强度，其强度约比标准砂高10%左右。

The main factors affecting the soil-structure interface behaviors were found experimentally and theoretically, including: 1 the thickness of the interface that is five to six times the average grain size of the soil; 2 the aeolotropy of interface, which is responsible for anisotropic response of the stress-strain response of the interface; 3 two physical states, including crashing and compression of the soil near the structure surface, which govern the stress-strain response of the interface strongly; 4 two shear deformation components due to sliding and constraint of the structure surface relative to the soil respectively, which forms the deformation of the interface; 5 the volumetric strain due to dilatancy, which is found to be composed of a reversible dilatancy component and an irreversible dilatancy component. 4. A unified constitutive model of the interface, based on new elasto-plasticity damage theory, was developed. It was confirmed to be effective for the conditions considering monotonic and cyclic shearing, coupling effect of shear and volumetric strains, evolution of physical state, micro-structure aeolotropy of the soil and the resulting aeolotropy of the interface as well as the three normal boundary conditions stated above. 5. 2D and 3D finite element formulations of the present model were derived and incorporated into the FEM codes. They were applied to the evaluation of practical engineering problems with different typical interfaces between soil and structure. The new model was shown to be reasonable and effective.

确定了粗粒土与结构接触面厚度约为5～6倍的平均粒径，首次揭示了接触面的细观结构异向性以及由此所引起的宏观剪切异向性，发现了在单调和往返剪切荷载作用下土颗粒破碎和剪切压密两种物态变化机制共同支配着接触面力学性质的变化，通过细观分析证实了接触面的变形可分解为一般同时发生的土与结构交界面上的滑移变形以及结构面位移约束范围之内土体本身的剪切变形两部分，观测到接触面受剪时表现出明显的相对法向位移，并可分解为可逆性和不可逆性两个分量；(4)建立了第一个能够统一地描述单调与往返剪切特性、剪应变与体应变耦合特性、细观结构和宏观剪切异向性以及土颗粒破碎等物态变化特性的土与结构接触面弹塑性损伤本构数学模型，并采用多种法向边界条件复杂加载路径的试验成果验证了新模型的合理性和有效性；(5)提出了新模型的二、三维有限元格式并结合实际边值问题进行了应用计算分析，比较了不同接触面本构模型对计算结果的影响，证实了新模型及其有限元格式不仅能够合理地描述土与结构接触面的主要力学特性，还能够较好地反映土体与结构物在接触面处的滑移、脱开等不连续现象。

In this paper, a measuring device has been developed and used to measure the tire contact pressure distribution of light vehicle with different tires of different tread pattern and different age, air pressure and different tire load.

利用自主开发的轮胎接地压力测试仪，进行了轻型货车不同花纹和不同使用年限轮胎，在不同轮胎胎压和不同负荷作用下，轮胎的接地压力分布规律测量。

So in this paper based on the characteristics and the optimum state theory of the vehicle, some kinds of control schemes are compared and discussed, and the fuzzy PID control scheme is adopted at last. The relation between air-cushion pressure and fan rotational speed on the optimum driving state is studied. The cushion pressure is used as controlled variable and the fan revolution is used as regulated variable. And transducer and fan motor are actuators.Based on the structure and operating properties of half-tracked air-cushion vehicle, the control system scheme and structure are presented. A control scheme using the self-tuning PID fuzzy logical controller is adopted. Fuzzy rules are set up and some researches have been done for fuzzy tuning method. At the same time the real-time measurement scheme by computer control is proposed, and electric circuits are designed. In the control system of half-tracked air-cushion vehicle cushion pressure P〓 is used as controlled variable and the fan speed n〓 as regulated variable.

因此本文以半履带式气垫车的特性和最佳工作状态理论为指导，通过对各种控制方法的比较与探讨，提出采用模糊PID控制方案，并且研究了在最佳工作状态下垫压及风机转速的关系，提出气垫压力作为控制参数，变频器和风机电机为执行机构，风机转速为调节量；主要进行了自整定模糊PID控制器的设计，研究了自整定PID模糊控制器的实现方法，编制了模糊控制规则，制定了模糊控制参数查询表，并分析了影响自整定模糊控制器相关的影响因素，确定了模糊控制表；为了实现半履带式气垫车的自动控制，还提出了计算机模糊控制系统的原理与结构，设计了相应的测量电路与控制软件。

The cardiovascular functional state of aircrew or astronaut can be evaluated by this physiological metho...

下身负压这种生理应激方法，可以用来评价飞行员或航天员的心血管功能。

Experimental results show that,when calcined gypsum and calcined alunite were added by 5% alone or synchronously,the setting time of cement decreases remarkably and 3d compressive strength at different temperatures increases remarkably.

试验结果表明，烧石膏和烧明矾石单掺和复合双掺的掺入量为5%时，水泥的凝结时间明显缩短，3d耐压强度在各温度下均有显著提高。

When the optical fiber polishes, the motor leads the polishing disc to do revolving and swinging motion through vertical eccentric shaft by two synchronizations rotary motion with the ambulacrum.

光纤抛光时，电机经同步带带动两个同步旋转运动的立式偏心轴从而带动抛光盘作旋摆运动，光纤端面在外力的作用下紧压在抛光盘上，依靠光纤端面与贴在抛光盘上的固着磨料磨具之间的摩擦从而达到对光纤端面的抛光作用。

The influence of handling, salinity, temperature, parasitism, and gender on the immune responses reactie oxygen species (ROS production and coelomic amoebocyte concentration of the starfish Asterias rubens was inestigated in experimental conditions.

在实验室条件下研究了海星Asterias rubens对不同选择压、盐度、温度、寄生和性别的免疫反应即活性氧和体腔阿米细胞浓度。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。