查询词典 convection current

Based on symmetrical analysis theory, the stator current of motor is decompounded into positive-sequence current, negative sequence current and zero-sequence current to distinguish the running state and fault type of the motor according to their magnitude of current. The technology of INTEL80C196KB MCU is applied to design and fulfill a new kind of micro-processor protective device for asynchronous motor.

根据对称分量分析原理，将电动机定子电流分解成正序、负序和零序分量，依据各种序量的大小，判别电动机运行状态和各种故障类型；采用INTEL80C196KB单片机技术，实现了一种新型的异步电动机综合保护装置。

Utilizing the sample data within 5ms after fault initiation and extending the date windows from 5ms to 10ms, the approximate current formula can be extracted from fault current or inrush current using least square fitting method. According to the curvature and convex-concave characteristic of the fitting curve, inrush current and fault current of power transformers can be distinguished.

该方法利用初始5ms内差电流的数据（5ms数据窗），将其拓展为长10ms的数据窗，然后通过最小二乘算法拟合差电流波形得到其近似表达式，再根据拟合曲线在各点处的曲率和凸凹特性来区分变压器励磁涌流和内部故障。

Circular electric current is a classical physical model. The researches on the magnetic field distribution characteristics of the circular current are helpful for the further study on magnetic characteristics of magnetic dielectric. The ellipse electric current is a typical physical model of ring-like electric current. The researches on the magnetic field distribution of it make us obtain more understandings of magnetic problem of ring-like electric current.

圆电流是一个经典的物理模型，对圆电流磁场分布特性的研究有助于进一步研究磁介质的磁性特征；而椭圆形电流又是环形电流中一个典型的物理模型，对椭圆形电流磁场分布情况的研究，将让我们进一步认识环形电流的磁场问题。

Since Al〓Ga〓In〓P possesses larger valence band difference to GaAs and wider energy gap, minor carrier reverse injection from base and space charge region recombination in the emitter are effectively suppressed in Al〓Ga〓 In〓P/GaAs HBT. Under most circumstances, quasi-neutral base recombination current dominates the base current, and its ratio to collector current varies little with collector current and temperature, thus greatly stabilizes the current gain.

Al〓Ga〓〓In〓P/GaAs HBT由于异质结的△Ev较大，发射区禁带较宽，有力地抑制了基区少子反向注入流和发射区空间电荷区复合电流；在大多数情况下，基极电流以准中性基区复合电流为主，其与集电极电流的比值随集电极电流和温度的变化极小，稳定了电流增益。

The relationships between welding pool width, wire extension and welding parameters including welding current duty ratio, base current, peak current, welding speed and wire-feeding speed were studied. Through large numbers of welding experiments, aluminum alloy pulsed MIG welding dynamic process were identified by the curve fitting method, and the mathematical models between welding current duty ratio, base current, welding speed, wire-feeding speed and wire extension were obtained, succeeding the model between the above parameters and weld pool width.

介绍了铝合金MIG焊焊接电流占空比、基值电流、峰值电流、焊接速度、送丝速度对熔宽的影响规律，并在其基础上，通过平板堆焊试验研究了这些参数对焊接干伸长的影响规律；在铝合金机器人脉冲MIG焊平板堆焊过程各焊接参数与正面熔宽之间的传递函数的基础上，采用铝合金平板堆焊阶跃试验，利用曲线拟合法辨识了铝合金机器人脉冲MIG焊动态过程传递函数，建立了焊接电流占空比、基值电流、焊接速度、送丝速度与焊接干伸长之间的对象数学模型。

When the system starts, the speed outer ring saturats non-functional, the current inner ring plays a major role to regulate the starting current to maintain the maximum so that the speed linear change, to reach a given value; when it operates steadily, the speed negative feedback from the outer ring plays a major role ,to let the speed changes with the given speed voltage , at the same time the current inner ring regulates the armature current of motor adjustment to balance the load current.

该系统起动时，转速外环饱和不起作用，电流内环起主要作用，调节起动电流保持最大值，使转速线性变化，迅速达到给定值；稳态运行时，转速负反馈外环起主要作用，使转速随转速给定电压的变化而变化，电流内环跟随转速外环调节电机的电枢电流以平衡负载电流。

The main research work of this dissertation is as follows: Based on the chemical reaction engineering theory and the nitrobenzene electroreduction mechanism, the plate and frame electrolyzer was designed and applied to the process of electroreduction nitrobenzene to p-aminophenol. This dissertation measured the residence time distribution data of the electrolyzer by means of the pulse response method and studied the rule of flow pattern along with the current capacity change. Under different conditions ,this dissertation studied the cyclic voltammetry properties of nitrobenzene on different electrodes by means of the dynamic cyclic voltammetry method and the electrode materials applied to the NB electroreduction have been selected primarily.Baseed on the results of cyclic voltammetry tests, this dissertation used p-electrode systems to measure the steady-state- polarization curves of nitrobenzene on different electrodes in H-type diaphragm cell, and obtained each primary factor s influence rule and the exchange current density value of each electrode.And then on the basis of the conclusions of fundamental researchs upword, the effects of influence factors on the the yield of p-aminophenol and the current efficiency,such as electrode material, current density, quantity of electricity circulated, nitrobenzene concentration . sulpuric acid concentration and so on, have been studied in detail in the systems of hign temperature , strong acidity and oxygen-poorthrough a series of electrolysis experiments in this paper.After all using Pb as anode Monel metal as cathode Dupont Nafion 417 cation-exchange membrane as membrane, this dissertation obtained the optimum technological condition: reaction temperature about 85C, current density 500A m-2, sulphuric acid concentration 20%wt.

论文的主要研究工作为：运用化学反应工程理论，结合硝基苯的电还原机理，设计出用于硝基苯直接电还原合成对氨基苯酚实验的板框式电解槽，并利用脉冲响应法测定了该板框式电解槽的停留时间分布数据，研究了流型随流量变化的规律；通过动态循环伏安法研究了硝基苯在不同电极上、不同条件下的循环伏安特性，初步评选出了用于硝基苯电还原的电极材料；结合循环伏安的测定结果，在H型隔膜电解槽中采用三电极体系测定了硝基苯在不同电极上、不同条件下的稳态极化曲线，得到了各主要因素的影响规律及硝基苯在各个电极上电还原的交换电流密度数值；在基础研究结论指导下，采用板框式电解槽，在高温、强酸、贫氧系统中，进行了一系列的电解实验，分别考察了电极材料、电流密度、通电量、硝基苯浓度、硫酸浓度等因素对收率及电流效率的影响，最终选择以蒙乃尔合金电极作为阴极、铅合金为阳极、Dupont Nofion 417阳离子交换膜为隔膜，得到由硝基苯直接电还原制对氨基苯酚的最佳电解工艺条件：反应温度85℃，电流密度500A·m~(-2)，硫酸浓度20％wt。

In order to improve the accurate of measurement, the artifacts, such as eddy current, thermal convection, background gradient must be considered both experimentally and methodologically.

我们把多自旋回波和双向梯度场技术相结合，用来抑制这些干扰，并在生物样品的自扩散系数测定中的进行了应用。

Lower and upper valves 25 and 26, respectively, provide a natural convection current whereby cooler ambient air is drawn into the passageway and the solar heated moisture-laden air in the passageway is passed to the environment outside the container.

上，下阀门， 25日和26日，分别提供一个自然对流电流，让清凉的空气是卷入通道和太阳能发热的水分-拉登的空气通道，是通过对环境以外的货柜。

From thanks in the work which the spirit convection current hands down from generation to generation, we may see Xie Lingyun not only are the remarkable poet, also is an important tax family and prose master, his prose poems creation also has the characteristic very much.

从谢灵运流传下来的作品中，我们可以看出谢灵运不但是卓越的诗人，也是一位重要的赋家和散文大师，他的辞赋创作也是很有特色的。

Listen,point and check your answers.

听，指出并且检查你的答案。

Warming needle is one of effective treatment methods for knee arthralgia aggravated by cold,and it is simple,safety,so it should be developed in clinical acupuncture and moxibustion extensively.

但以本院科针灸门诊在2005年1月—2006年6月期间共收治膝痛患者100余例，经过临床的诊断后，其中施以温针治疗的48例，疗效显著，报道如下。1临床资料本组病例48