查询词典 dynamic friction

The friction characteristics of polyurethane for the friction liner of hoisting were studied. It was found that the dynamic friction coefficient of polyurethane increases with sliding velocity in the range of 0.01 to 0.4 mm/s and decreases beyond 0.4 mm/s.

本文研究了聚氨酯弹性体摩擦衬垫材料的摩擦特性，发现聚氨酯弹性体材料的动摩擦系数是和滑动速度有关的，在0.01～0.4mm/s的速度范围内，速度提高摩擦系数上升，在更高的速度下摩擦系数还会下降。

Because of the small difference between the static friction coefficient and the dynamic friction coefficient of DF-5S slide, it avoids the squirming phenomenon in the restarting-up process efficiently and lowers the severe wear in the restarting-up process.

由于DF-5S铜基镶嵌滑块的动静摩擦系数的差值小，有效地避免了启动过程中的蠕动爬行现象的发生，降低了启动过程中的剧烈磨损。

The field of machinery industry of the friction coefficient of PTFE small, the static coefficient of friction lower than the dynamic friction coefficient, can be used for low-speed high-load areas, such as in construction, chemical, bridges and other structures to resolve cases arising from thermal expansion and vibration of the stretching problem.

机械工业领域聚四氟乙烯的的摩擦系数小，其静摩擦系数低于动摩擦系数，可用于低速高负荷领域，如在土建、化工、桥梁等结构件中可解决热膨胀和震动引起的伸缩问题。

My main production TSF Academy Soft Machine Tool belt and matching adhesive used primarily for machine tool guideways, abrasion resistance, static and dynamic friction coefficient of the difference small, not crawling, positioning accuracy, and has enough anti-aging and physical properties of mechanical is to improve the machining precision, extended service life Guide the best choice, the products applicable to all types of machinery and equipment manufacturing friction vice and maintenance.

我院主要生产TSF机床导轨软带与配套使用的胶粘剂，主要用于机床导轨，抗磨损，静动磨擦系数差值小，不爬行，定位准确，并具有耐老化和足够的机械物理性能，是提高机床加工精度，，延长导轨副使用寿命的最好选择，本产品适用于各类机械设备磨擦副的制造与维修。

The friction performances of carbon face were investigated with an inertia friction tester. The torque curve of carbon face was ideal, the coefficient of static friction was lower than that of dynamic in 0.28 MPa, the friction coefficient of static and dynamic decreased with the braking pressure increasing. To the fiber face, the coefficient of dynamic friction of carbon face was more stable in cycle braking process, the wear rate was lower, and it was efficient to protect the couple plate not to be worn.

结果表明：碳质层的摩擦力矩在制动初期上升较快，中间过渡区平稳，尾部翘起较小；在制动压力小于0.28 MPa时静摩擦系数小于动摩擦系数，且动、静摩擦系数均随制动压力增加而减小；相对纤维层而言，采用碳质层摩擦时摩擦力矩曲线形态更好，连续制动时摩擦系数波动较小，磨损率低且能够有效保护偶件，是1种静/动摩擦系数比较低且适用于高载荷工况条件下使用的摩擦材料。

By making use of multi-points backward pressure of one dry gas well, this paper introduces how to confirm dynamic friction coefficient of downhole tubing at the exact moment through stable testing material, gives the productivity and the corresponding bottom hole pressure by using productivity equation, calculates wellhead pressure in combination with dynamic friction coefficient of tubing, establishes the correct wellhead outflow performance equation for this well, draws out wellhead outflow performance curve and discusses how wellhead outflow performance equation or wellhead outflow performance curve changes with the decrease of formation pressure or the change of wellhead outflow performance curve.

借助1口干气井的多点回压法试井资料，介绍了如何利用气井稳定试井资料，确定该气井此时此刻井下油管动态摩阻系数；利用产能方程给出产量和对应的井底压力，结合油管动态摩阻系数计算井口压力，建立该井准确的井口流出动态方程并编绘井口流出动态曲线；讨论了随着地层压力递减和井下油管动态摩阻系数变化规律，井口流出动态方程或井口流出动态曲线的变化规律。

It is difficult to measure the static friction coefficient of the material like polyurethane. The state of friction under very low velocity with small sliding distance is a special state between static and dynamic friction. This state of friction can be called initial stages'friction.

聚氨酯弹性体材料的静摩擦系数是比较难以确定的，本文建议把滑动量较小而滑动速度又很低的这一时期的摩擦称为"初期摩擦"，它是界于静摩擦与动摩擦之间的一种特殊的摩擦状态。

Therefore, the torque required to open the gate valve required torque than the closure of large, in addition, for a pair of contact between the sealing surface, the Non Rising Stem Resilient Seated Gate Valves coefficient of static friction between them than the dynamic friction coefficient, to make them from the static state generate the relative movement is required to exert greater force to overcome the static friction; due to temperature changes, so that the sealing surface pressure between the larger, need to overcome the static friction force also will be bigger, so that when you open the valve on the stem nut on the sometimes increase the torque exerted a lot.

所以，开启闸阀所需的力矩比关闭闸阀所需的力矩大，此外，对于一对互相接触的密封面来说，它们之间的静摩擦系数也比动摩擦系数大，要使它们从静止状态产生相对运动，需施加较大的力以克服静摩擦力；由于温度变化，使密封面间的压力变大，需要克服的静摩擦力也随之变大，从而使开启闸阀时，对阀杆螺母上施加的力矩有时会增大很多。" Moment analysis of valve operation "是由中国闸阀网提供的国际阀门新闻，译文仅供参考。另外，中国闸阀网还提供相关产品搜索：闸阀型号、闸阀价格、闸阀技术、闸阀新闻、闸阀生产商等。

In order to analyze the result caused by the frictional dynamic character in servo system,and test the validity of various friction compensation methods,a simulation scheme for dynamic friction model is required.

为了深入分析摩擦力动态特性在高精度的伺服系统控制中造成的影响，检验摩擦补偿方法对动态摩擦的补偿效果，需要建立一个有效的动态仿真摩擦模型。

At present, although finite element methods is a kind of effective measures in analyzing metal plastically forming problems with friction, dynamic friction in the process of metal forming is substituted with static friction and constant frictional force as one of independent constraint conditions is transposed to equivalent node-load or FEM unit is divided into contact unit and inner unit in numerous studys and applications, so that it result in relative bad accuracy and awkward operation. These defects mostly attribute to the fact that FEM bases on the variational equality principles, however frictional constraint will actually result in variational inequality energy functional.

目前，应用于分析金属塑性成形的有限元法是一种有效的处理摩擦效应的定量计算方法，但是许多应用和研究是用常摩擦来代替金属塑性成形过程中的动态摩擦；把常摩擦力作为单独的约束条件移置到等效结点载荷上或把有限元单元划分成接触单元和内单元，这些将导致解的精度相对不高及实际操作不方便等一系列问题，产生这些不足的重要原因之一在于它的理论基础是变分等式原理。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。