您要查找的是不是：
- A long tapered rod with a leather tip used to strike the cue ball in billiards and pool. 球杆在桌球戏和落袋台球戏中用来击球的细杆，其带有皮包头的一头逐渐变细
- This paper introduces a modified Gibbs wave equation, and considers the effect of connection on commingling rod string. 本文对吉布斯波动方程做了一些修正，考虑了接箍对混合杆柱的影响，推导出新的方程。
- The recommendation about anti-dropout of rod string in Zhoucheng Oilfield is also prese... 文章还提出了洲城油田下步工作建议。
- Stabilization and antifriction of the rod string in horizontal hole are of great importance. 水平井用杆式泵采油时,抽油杆柱的扶正和减摩是一个重要的研究课题。
- The rod string dynamics model including the influences of rod-fluid-tubing viscous friction and rod-tubing Coulomb friction is developed. 在建立定向井有杆抽油系统的预测数学模型时 ,计入了杆液管粘性摩擦和定向井井斜造成的杆管库仑摩擦 ,同时考虑了实际泵况对系统的影响。
- The new device uses a rotary mechanism similar to ball joint to eliminate the unscrewing torque caused by the reciprocating motion of the rod string. 这种装置采用类似球形关节的旋转机构，消除了抽油杆柱上下往复运动产生的倒扣扭矩；
- A three-dimensional dynamic simulation model of rod string in actual borehole was established based on the characteristics of actual well track and system dynamics theory. 根据实际井眼轨迹的特征及系统动力学理论建立了抽油杆柱在实际井眼中的动态仿真模型。
- The forces on the rod string in slant stralght holes is different for that in stheight holes, therefore the calculationof the antishock sboke is different. 斜直井中抽油杆柱受力状况不同于直井，故其防冲距的计算也不同于直井。斜宜并检泵作业碰泵时，抽油杆柱由于重力作用在油管内呈螺旋状弯曲。
- According to the calculating equations of the friction load on the rod string on the upstroke and downstroke, the friction load increases remarkably with the increa... 孤东油田八区部分见聚油井摩擦载荷的计算值与实测值的实例对比表明,二者的数值差距很小,表明计算方法可行。
- When using the mechanical recovery method with sucker rod pump in directional and horizontal wells,it needed install to centralizer on sucker rod string. 在定向井、水平井中使用有杆泵机械采油方法时,需要在抽油杆柱上安装扶正器。
- In contrast to conventional centralizers screwed on sucker rod, new-type centralizers have several advantages of simple structure,ease use, less cost and any positions spaced on the rod string. 它相对接头连接式抽油杆扶正器具有结构简单、成本低、易于安装使用,能够根据生产需要布置在抽油杆柱任意位置的特点。
- In the light of the frequent breaking of the rod string in a surface driven screw pump well, the force condition of the string in the well is analyzed by means of the elastoplasticity theory. 针对井口驱动螺杆泵抽油杆柱断脱频繁的问题，应用弹塑性理论分析了抽油杆柱在井中的受力状况。
- The causes of abrasion of sucker rod string and tubing string aie analyzed, and it is indicated that the effective measure for preventing the abrasion is using sucker rod centralizers. 分析了油管和抽油杆产生偏磨的原因，指出防止油管和抽油杆偏磨的有效措施是采用抽油杆扶正器。
- Partial abrasion of rod string in screw pump well which is surface driven is the main reason that restricts its application, but the prevention method used presently cant solve the problem radically. 地面驱动螺杆泵井抽油杆的偏磨是制约螺杆泵应用的主要原因,目前采用的防治方法不能从根本上解决该问题。
- The dynamic strength of rod string and the mount position of centralizer were calculated，according to the acquired deformation of rod string and its impact contact force with tube in the time domain. 根据求得的时域内抽油杆柱受力变形值以及与油管柱碰撞接触力，计算了抽油杆柱动强度和扶正器安放位置。
- I need a piece of string to tie this parcel up. 我需要一根细绳把这包裹扎起来。
- The organization tapered off in about a year. 这个组织在一年左右的时间里逐步停止了活动。
- With this diagram, we can judge whether the rod string meets the strength demand or not in any combination of multistage rods. 该图版可以判断任何三级抽油杆长度组合能否满足抽油杆柱强度要求,也就是直接进行强度校核;
- The economic boom tapered off in the 1970s. 经济繁荣在七十年代慢慢消失了。
