浮环

El Centro is input, simulation calculations are made on floating-peak tank with circular-ring energy dissipater. The research indicates this control system is effect to apply to decrease earthquake response. History time curves of displacement, absolute acceleration, shearing force and uplift angle are contrasted with and without control. The effect of sets of cirque costing-energy is discussed.

对实际应用的浮顶罐进行了数值仿真计算，所采用的控制体系具有较好的减震效果；对比了储液容器液固耦合质量无控与有控时的位移、绝对加速度和基底剪力和提离转角的时程曲线；探讨了圆环套数对减震效果的影响。

At first, this paper gives the brief introduction of the history and present status of accelerometer and its testing technology, the working principium and math model of the liquid floated pendu-lous accelerometer, and then, decides the binary width pulse force retrim loop as the design proposal of testing system, researches the transfer function of every part in the system emphasizly, analyses the stability of the whole accelerometer testing system from the angle of control theoretics by the open loop transfer function of system, and designed the correcting net, analyses the basal problems such as resolution, sampling restraint, precision and so on, designs the hardware testing circuits such as preamplification, band-pass filter, alternating amplifier, phase sensitive demodulatorn, pulse-width modulation, frequency scale circuit, moment current generator. Finally, using the graphics program language LabV-IEW which is designed for testing field especially by NI accomplishes the solfware design of testing system,realized the testing functions.

首先对加速度计及其测试技术的发展历史和现状，液浮摆式加速度计的工作原理和数学模型等作了简要的介绍，然后确定了以二元调宽脉冲再平衡测试回路为设计方案，并从控制理论的角度进行了分析，着重研究了系统中各部分的传递函数，利用系统开环传递函数分析了系统的稳定性，同时设计了系统的校正网络；分析了二元调宽脉冲再平衡测试回路的分辨率、采样约束以及测试精度等基本问题，并按照系统分析的结果设计了包括前置放大、带通滤波、交流放大、相敏解调、脉宽调制、频标电路以及力矩电流发生器等测试系统各部分硬件电路，验证了电路的正确性，最后按照测试系统的要求，采用了美国NI公司专为测试领域所开发的虚拟仪器工具——LabVIEW作为测试软件开发工具，利用该图形化编程语言完成了测试系统软件部分的设计，实现了测试功能。

All the actuators of the three-axis turntable are brushless torque motors, all the bearings are aerostatic air bearings, so the friction caused by these elements can be neglected. The main source of friction is the metal-to-metal friction on the slip rings. Hence the "Columb+Viscous+Static" friction model is used here for analysis.

由于三轴转台的驱动系统选用的是无刷电机，轴承则采用的是气浮轴承，轴系上的摩擦力已大大降低，三轴转台上的摩擦主要是滑环轴上金属对金属的摩擦，所以文中选用&库仑＋粘滞＋静摩擦&的摩擦模型来进行分析。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了