压下

In addition, some experience formulas for them are regressed. The third chapter establishes a unified S-N curve equation to calculate multi-axial fatigue ultimate strength of concrete considering both the effect of confinement and minimum/maximum stress ratio, based on the triaxial fatigue test data in this paper and the test results under uniaxial and biaxial fatigue loading in previous literatures. Moreover, the consistency of calculating condition fatigue ultimate strength with fatigue life distribution and initial ultimate strength distribution is analyzed.

第二章简要地介绍了本文三轴疲劳试验装置，进行了两向等侧压约束下混凝土立方体试件三轴受压等幅和变幅疲劳试验，分析了三轴受压疲劳破坏机理，给出了相应的疲劳破坏试验判断标准；得到了混凝土在两向侧压约束下单级和多级受压疲劳的变形发展规律，包括最大纵向应变、残余应变、最大纵向应变率和疲劳变形模量等随循环次数的发展规律以及疲劳损伤的演变规律，并给出了相应的经验公式。

METHODS: Sixty Sprague-Dawley male rats were randomly divided into four groups(n = 15), four methods were designed on rats models of sciatic nerve compression. There were simple decompression as group A, internal neurolysis after decompression as group B, lemithason(0.5 mg/kg) injected in the epineurium after decompression as group C, and lemithason(0.5 mg/kg) injected around the epineurium after decompression and internal neurolysis as group D.

在大鼠坐骨神经卡压模型基础上，将60只SD成年雄性大鼠随机等分为四组。A组：仅去除卡压；B组：去除卡压后切开神经外膜；C组：去除卡压后神经外膜下周围注射利美达松(0.5mg/kg)；D组：去除卡压后切开神经外膜，然后在神经周围注射利美达松(0.5mg/kg)。

In the spiral pipe heat exchanger exports terminal, the ammonia steam temperature has been heated up 85 ℃--95 ℃, by now, the ammonia steam had the 45kg-55kg/cm2 ammonia steam pressure, sent in the ammonia steam turbine through the constant temperature pipeline, impelled ammonia steam turbine revolving, led the generator electricity generation;After the ammonia steam makes the merit release energy, the temperature drop, the returns ammonia storage tank, passes through again adjusts the press pump to press into the spiral pipe-type heat exchangers to carry on the next circulation;Including the ammonia steam turbine entire ammonia steam road is becomes the independent closed cycle system, is isolates completely with the outside air;The ammonia steam only plays the carryhome and the shift energy role, in the electricity generation process does not consume the actuating medium, the stored energy carrier water also is only gets up the carryhome and the shift energy function,The waterway also is from becomes the independent closed cycle system, in the electricity generation process also the needless water consumption, through the actuating medium ammonia steam and the stored energy carrier water unceasing shuttle service, transforms through the heat interchanger the solar energy as the actuating medium ammonia steam heat energy and the kinetic energy,With the aid of the ammonia steam turbine heat - machine transformation function and the generator machine - electricity transformation function, has realized the solar energy hot - electricity entire conversion process, transforms continuously the solar energy into the electrical energy, power supply for foreign;The low temperature generating system must solve three big technical keys:One, the anticorrosion (has actuating medium has strong corrosiveness), two is Explosion-proof (Some actuating medium Can have the detonation with the air mix when divulging, controls warm malfunction, elevates temperature suddenly also can have detonation), three is guards against the revolution axis divulging

以太阳能低温发电系统为例，低温发电方法是这样进行的：以水作为储能载体的太阳能采集器将太阳能采集起来，将水温提升至85℃--98℃；用氨作为工作介质储于氨储罐及氨汽路中；采用螺旋管型热交换器；用调压泵将氨储罐中的氨汽压入螺旋管型热交换器的螺旋管内，用调压泵将携带太阳能的85℃--98℃的储能载体热水压入螺旋管型热交换器的螺旋管外壁空间进行循环式热交换，在热交换器的螺旋管出口端，氨汽温度已被加热到85℃--95℃，这时，氨汽具有45kg—55kg/cm2的氨汽压力，通过恒温管道送入氨汽轮机，推动氨汽轮机旋转，带动发电机发电；氨汽作功释放能量后，温度下降，返回氨储罐，再经调压泵压入螺旋管型热交换器进行下一次循环；包括氨汽轮机在内的整个氨汽汽路是自成独立的封闭循环系统，与外界空气是完全隔绝的；氨汽只起携带和转移能量的作用，发电过程中并不消耗工作介质，储能载体水也是只起携带和转移能量的作用，水路也是自成独立的封闭循环系统，发电过程中也不消耗水，通过工作介质氨汽和储能载体水的不断循环运行，通过热交换器将太阳能转化为工作介质氨汽的热能和动能，借助氨汽轮机的热—机转化功能和发电机的机—电转化功能，实现了太阳能的整个热—电转化过程，将太阳能源源不断地转变为电能，对外供电；低温发电系统要解决的三大技术关键：一是防腐（有的工作介质具有较强的腐蚀性）、二是防爆（有的介质泄漏与空气混合会产生爆炸，控温失灵，急剧升温也会产生爆炸）、三是防轴漏（汽轮机是动态旋转体，必须解决工作介质的防轴漏问题）。

The boundary conditions and the latent heat of heat transfer system have been treated by heat-enthalpy method.

在这样的充填条件下，虽然金属压铸模的导热性很高，蓄热能力很强，但要求在压铸模型腔内获得形状完整、轮廓清晰、尺寸精度高的铸件，必须得选用合理的模具结构和压铸工艺，而压铸模具的尺寸精度和使用寿命在很大程度上取决于其在压铸过程中热应力和其产生的变形。

As the plastic region expansion on circle plate under extemal pressure is smaller than that under equal internal pressure, it can be qualitatively reckoned that the critical pressure of in-plane instability under external pressure is higher than that under internal pressure with the same axial displacement load.

由于外压增量导致环板内塑性区域扩展的范围小于等值内压的影响，因此可以定性的认为，在同样的轴向压缩量下，波纹管的平面失稳外压临界压力大于内压临界压力。

The rolling wheel of D51 rolling loop machine is fixed with an expansion ring and its axial locating accuracy is high so the processing difficult of rolling wheel is reduced.

D51型辗环机辗压轮系采用涨圈固定，轴向定位精度高，简化了辗压轮的机械加工；下支承轴端圆锥孔后面设有方孔，辗压辊与下支承轴的联接可靠，更换容易，减少了非生产性工作消耗，提高了劳动生产率。

Although paper has to be fed and held down manually, arbitrary hold-down pressure against paper is thus available to avoid the disadvantage resulting from improper hold-down pressure The paper-cutting blade holder is driven by a motor, but it can also be operated by means of a handle to suit the needs of the location where power supply is not yet available.

本机的送纸与压纸需要手动，但压纸时，压力可任意选择，故可避免压纸的压力不适所引起的弊病。刀座切纸是由电动机驱动，但也可用手柄摇动，可适用在无电源的状态下下使用。

It analyzes the effects of the pollution severity and the altitude or atmospheric pressure on the flashover voltage or the flashover gradient. It is shown that FOV is determined by the configuration, and the insul...

结果表明：合成绝缘子的污闪电压与伞裙结构有密切关系；在同样的最短干弧距离下，简单伞形结构的合成绝缘子具有更高的污闪电压和污闪梯度，对于伞形结构复杂的合成绝缘子，虽然其爬电距离提高了，但其污闪电压没有明显提高；高海拔下合成绝缘子的气压影响特征指数n大于瓷和玻璃绝缘子，并受伞裙结构形式、污秽程度的影响，且随着污秽程度增加，n逐渐减小，此外，染污方法和方式对n也有一定影响但不明显。

The results show that:(1)the low-noise source-follower circuit can be effectively used to measure the output of PVDF thin film;(2)the piezoelectric coefficient D33 of the PVDF is very sensitive on temperatures;(3)the value of D33 intensively fluctuate in initial loading stage,this means that a pre-load is needed in practice application to keep a constant piezoelectric coefficient D33 of the PVDF;(4)when the compressive load is imposed on the surface of the PVDF along a incline direction,D33 value is obvious changed with changing incline angle,and(5)the frequency bandwidth of the PVDF thin film is very wide,it is more suitable to measure strike or impact loading at various loading conditions.

结果表明：(1)低噪声源跟随电路可有效测量PVDF 薄膜输出；(2)PVDF压电薄膜的压电系数D33对温度很敏感；(3)D33值在加载初始阶段波动很大，所以实际应用中应给PVDF提供一个预压载荷，以确保有一恒定的压电系数D33；(4)当压载荷沿倾斜方向作用在PVDF 表面时，由于有剪切力作用，D33 值会随着倾斜角的变化发生显著改变；(5)PVDF 薄膜具有很宽的频响，更适用于测定不同载荷条件下的侵彻或冲击等动态载荷。

The lead-less piezoelectric ceramic composition is prepared through sintering at relatively low temperature, say, 1190 deg.c or even lower, and has good piezoelectric characteristic, practical plane electromechanical coupling coefficient kp, high Curie point and no lead and lead compound contained.

本发明的制备工艺能在较低温度下，如1190℃或更低温度下烧结无铅压电陶瓷组合物，使制备的无铅压电陶瓷具有好的压电性、可实用的平面机电耦合系数kp和高的居里温度，制备工艺过程中不含铅或铅的化合物。

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。