查询词典 mathematical constant

In order to prepare low dielectric constant glass powder, we use SiO2, boracic acid etc as raw material to prepare glass powder. The result of testing is: its dielectric constant is about 4.0, and it is suit for our experiment.

作为低介常数的玻璃粉料，采用SiO2、硼酸等为原料，通过熔融、研磨制得了玻璃粉料，其介电常数约为4.0，介质损耗为10×10－4。

Cable reel motor torque constant tension which has the characteristics When the load increases in the motor output shaft speed will automatically come down, volume Rao assured when cable tension unchanged. Rao nature of this excellent performance closely integrated with the Volume; Cage used motor hysteresis coupling increases in size, functionality, easy installation, the constant tension similar characteristics, we can under the conditions required output torque. They can pull the cable external circumstances, hysteresis coupling protect cables; using torque motor controller to increase frequency hysteresis couplings Surge part because of the cable reel SCR converter using a new technology operation, smoothing adjustments to the motor terminal voltage, thereby ensuring that the output torque of the motor unchanged. so that the cable can smooth the road with the truck

其中力矩电机电缆卷筒具有恒张力的特点，当负载增加时电机的输出轴转速能自动随之降低，保证电缆卷饶时张力不变，这个优越的性能与卷饶性紧密结合；采用笼型电机加磁滞式联轴器具有体积小，功能全，安装维护方便，近似恒张力等特点，既可以根据工况需要输出力矩，又可以在电缆受外力拉住的情况下，通过磁滞式联轴器保护电缆；而采用力矩控制器加变频电机加磁滞式联轴节的电缆卷筒因其调压部分采用可控硅变流新技术，可以平滑地对电机的端电压进行调节，从而保证了力矩随负载的变化而改变，使电缆能平稳的跟大车的行进。

In a constant electric field, a charged particle experiences constant acceleration.

在恒定电场中，带电粒子得到恒定的加速度。

Researches show that the drive force characteristics of the electric tractor drive system based on series DC motor is close the ideal characteristics, the curves are concave, low speed with constant power, and high speed with constant torque; the electric tractor has large working speed under different shifts, but the extensive coincidence speed shows that the variable ratio of the gear is unreasonable; the maximum climbable gradient of this electric tractor is more than 30%, and does not need frequent shift when working for its extensive climbable gradient; there are many influence factors of continuous working time, which the more obvious factors are working speed and working load, the working time increases with the increase of the working speed and working load.2. Simulation researches on the drive characteristic of the electric tractor.

研究结果表明：基于串励直流电动机(来源：ABC21论文网www.abclunwen.com)的电动拖拉机电驱动系统的驱动力特性场接近理想驱动力特性场，其各挡下的驱动力特性是一组下凹的曲线，低速恒转矩，高速恒功率；同一行驶速度下所对应高挡驱动力大于低挡驱动力，这是由电机的调速特性决定的；电动拖拉机各个挡位下具有较广的稳定作业速度范围，但是各个挡位之间速度重合的范围较多，说明所用变速箱变速比与电动机匹配不合理；电动拖拉机最大爬坡度达到30%以上，并且各挡爬坡度变化范围较广，作业过程中不需要频繁换挡；影响电动拖拉机连续作业时间的因素较多，其中作业行驶速度和作业负荷影响最为明显，作业负荷越大，连续作业时间就越短，作业速度越快，连续作业时间就越短。2、电动拖拉机驱动特性仿真研究。

A constant current/constant voltage and double closed-loop control system, which is composed of TL494, is developed in this paper.

开发了一种用TL494构成的恒流恒压双闭环控制系统。

Therefore, if we have a way of holding emitter current constant through a transistor, the transistor will work to regulate collector current at a constant value.

于是，只要我们能让晶体管的发射极电流保持恒定，它就能保持发射极电流为恒定值。

Company is mainly engaged in automation and control products (string-based industrial data acquisition and control interface cards, serial 8 ~ 24 Road multifunction relay controller, I / V conversion module, etc.), monitoring equipment (Intelligent Comptroller General Instrument, etc.), constant current , constant-voltage products, the surface of school non-destructive testing products (indicator magnetic properties, metal defect diagnosis module, a new generation of intelligent digital display module) and the metal magnetic memory testing product development, sales and after-sale repair Service.

公司主要从事自动化控制产品（串型接口工业数据采集控制卡、串行8路~24路多功能继电器控制器、I/V转换模块等），监控设备，恒流、恒压产品，表面学无损检测产品（磁特性指示仪、金属缺陷诊断模块、新一代智能数字显示模块）以及金属磁记忆检测产品的研发、销售和售后维修服务。

The first process is to optimize the geometric parameters of the press, on the assumption that the servomotor rotates at a constant angular velocity equal to that of the constant velocity motor. The second process is to optimize the displacement trajectory of the servomotor based on the results of the first process while keeping the geometric parameter unchangeable.

然后，建立了混合驱动压力机的优化设计模型，并将优化分为两步：第一步，假定伺服电机角速度与常规电机相同的条件下，优化设计出压力机的尺寸参数；第二步，在第一步优化结果的基础上，使机构的尺寸参数不变，优化设计伺服输入运动规律。

Constant Angular Velocity mode and Constant Linear Velocity mode are integrated to build a single spindle motor control module to incorporate with long-seek servo. CAV mode and CLV mode are performed to show its feasibility. The experiment results showed that the pick-up-head can perform arbitrarily track-jump command, quite well.

此外，在主轴马达伺服部分，提出以跨轨旗标讯号来决定使用『碰-碰』控制法则让主轴马达转速变化的执行时间，也将主轴马达伺服中的等角速度控制模组与等线速度控制模组整合成功，形成单一的主轴马达控制模组，使与长寻轨伺服结合而更易於操作，让不论内、外寻轨的任意跨轨命令皆可以达成定线速度或是等角速度的控制目标。

One constant in any field during the digital age is that change is constant.

一个不断在任何领域在数字化时代是变化是永恒的。

Although translator has turned from being a crystal ball by which the original culture can unrestrainedly penetrate to another crystal ball by which the target culture can freely traverse, the translator's personal embodiment, in the process of cognitive act, are still absent in translation studies. Translators are still subjects without body or simply disembodied subjects.

译者虽然由原语文化可以自由穿透的玻璃球变成了译语文化可以自由穿越的玻璃球，但译者认知过程中的个体体验在翻译研究中依然缺席，译者依然仅仅是一个没有躯体体验的主体。

Chillingly, he claimed our technology is 'not nearly as sophisticated' as theirs and "had they been hostile", he warned 'we would be been gone by now'.

令人毛骨悚然的，他声称我们的技术是'并不那么复杂，像他们一样，和"如果他们敌意"，他警告说，'我们将现在已经过去了。