查询词典 conduction current

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 solve the application problem of conduction heating machining, this project investigates some problems, such as dynamic characteristics of heating power, features of circuit current and voltage, arc discharge states and so on. It also studies control characteristics of Uni-phase or Tri-phase Direct Current Power Supply and Inverse Switch Power Supply. A High Frequency Inverse Switch Commutate Power Supply is developed.

为了解决导电加热切削的应用问题，从加热电源的动态性能和回路的电流、电压特性及电弧放电状态等方面进行研究，分析比较了单、三相交直流电源和逆变开关电源的特点和控制特性，研制了高频逆变开关整流电源。

Maxwell's equations group in fact was already found in the basic experimental laws of electromagnetic phenomena, as well as a single magnetic pole does not exist on the facts and the integrated displacement current assumptions, using an international system of units, these equations can be written as: DivDW =ρ or DW =ρ(1) kiDivBq = 0 or Bq = 0 (2) kiCurlEBq =- Zt or × EqkZ =- BqZt (3) ZCurlHDWDW = jE Zt, or × HW = jE Zkt (4) Z-type in the Curl, and Div were vector operator curl and divergence, Micro-k points for the Hamiltonian operator, in the rectangular coordinate system,= iZZEkx jEy kqz, iE, jE, kq along Zx, y, z-axis unit vector, a vector for any AW are × AW = CurlAW, kAW = DivAW; DW for the electric displacement, Bq for the magnetic induction intensity, Eq, and HW, respectively i field and electric field strength, jY for the conduction current density,ρ the charge density for free.

麦克斯韦方程组实际上是当时已发现的电磁现象的基本实验定律以及单个磁极不存在的事实和位移电流假设的综合，采用国际单位制，这些方程式可写成：DivDW＝ρ或DW＝ρ（1）kiDivBq＝0或Bq＝0（2）kiCurlEBq＝－Zt或×EqkZ＝－BqZt（3）ZCurlHDWDW＝jE＋Zt或×HW＝jE＋Zkt（4）Z式中Curl和Div分别为矢量算符旋度和散度，为哈密顿微k分算符，在直角坐标系中，＝iZZEkx＋jEy＋kqz，iE，jE，kq是沿Zx、y、z轴的单位矢量，对任一矢量AW有×AW＝CurlAW，kAW＝DivAW；DW为电位移，Bq为磁感应强度，Eq和HW分别为电i场和磁场强度，jY为传导电流密度，ρ为自由电荷密度。

LED or photo aging components: the core of IC optical mouse has a constant internal integrated circuit, the LED constant current of about 50mA, the general use of the mouse high-grade intermittent sampling technique, sent intermittent conduction current is the (sampling frequency of about 5KHz), can be in the same power under the premise of testing to enhance the power LED, the high detection sensitivity.

1发光管或光敏元件老化：光电鼠标的核心IC内部集成有一个恒流电路，将发光管的工作电流恒定在约50mA，高档鼠标一般采用间歇采样技术，送出的电流是间歇导通的(采样频率约5KHz)，可以在同样功耗的前提下提高检测时发光管的功率，故检测灵敏度高。

Measurements of the forward I-V characteristics of these diodes have shown that thermionic emission current is the dominant current conduction mechanism for these Schottky contacts.

对研制的器件特性进行了比较分析，I-V特性测量说明Pt／6H-SiC肖特基二极管有较好的整流特性，热电子发射是其主要的输运机理，理想因子为1.23，肖特基势垒高度为1.03eV，开启电压约为0.5V。

The thermionic emission and tunneling current dominate the conduction process at higher Xc. However, if the film has low Xc, which means lager barrier width, the tunneling current can be neglected.

首次运用二维结构渗流模型计算了微晶硅薄膜结构对电导率的影响，从理论上解释了造成微晶硅薄膜输运各向异性的主要因素是薄膜中晶粒的柱状生长。

"What makes these different from conventional electronic networks," he said,"is that instead of thinking in terms of a conduction current, one should think in terms of the displacement current, which indeed can 'flow' in free space and in dielectric materials."

他解释道：&之所以会产生这些与传统电子网络不同的概念，原因是我们不是从传导电流的角度而是从位移电流的角度进行考虑的，位移电流确实可以在自由空间和在电介质材料中流动。&

For the device of this structure significant decrease of the fluctuation in both the emission current and the PS diode conduction current and the spike noise are also obtained.

这种结构的PS二极管工作电流和发射电流的波动性被明显减弱，器件稳定性得到提高。

"Second Life is remarkably easy to work with, and is very popular,"

"第二次生命是显着容易的工作，并且很受欢迎，"

For example, we usually assume that materials are homogeneous and isotropic and free of internal defects or flaws.

为了得到适合有限元分析的模型，我们必须经过如图2所示的简化步骤。