查询词典 fault current

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。

Based on varying process of generator terminal parameters after excitation fault, shortages of excitation protective principle of static stability boundary and asynchronous impedance boundary are analyzed. It proposed that excitation fault research relates to large-disturbance stability. Because dynamic power-angle character of generator after excitation fault is non-sinusoidal, there are differences between dynamic power-angle character and static state power-angle character. So it isn't ideal to protective operation result based on small-disturbance stability and static stability boundary criterion. At the same time, it proposed that asynchronous boundary impedance criterion is a constant reactive power circle moving adown j Xd′. It can ensure complete loss-of-excitation generator measuring impedance enter into the circle, but can't ensure the other condition measuring impedance including impossible losing synchronism enter. So loss-of-excitation protection would be maloperation when system voltage drops short and recovers or generator rejects load.③Based on stability principle, it puts forward setting conditions and calculation method of generator loss-of-excitation protection by direct measuring power-angle.

以励磁故障后发电机端的相关参数的变化为基础，通过对以静稳定边界和异步阻抗边界作判据的两类三种现行励磁保护在原理上存在的缺陷分析，发现：励磁故障是一个大干扰稳定性问题，励磁故障后的发电机的动态功角特性与静态功角特性有很大的差异，已远非正弦曲线，因此基于小干扰稳定性原理、以静稳定边界作判据的保护必然动作不理想；异步边界阻抗判据是一个下移j Xd′的等无功阻抗圆，它可以保证完全失磁后的发电机测量阻抗能进入该阻抗圆，但不能保证完全失磁之外的其它状态不会进入该阻抗圆，因此在系统电压短时下降或发电机突然甩负荷等情况下可能启动该保护使之误动。

The sealing properties of fault are not only related to tectonic stress, but also to strike and dip angle of fault, depth, lithology of each fault wall, and fluid pressure.

断层的开启与封闭，不仅与构造应力直接相关，而且与断层的走向、倾角、深度、两盘岩性及流体压力直接相关。

Usually, distribution networks operate in arborescence mode, so in the simulation of fault analysis the impact of faulty switch element on system reliability is apportioned to failure consequences of adjacent sections that connect to switch, and then an equivalent analytical model considering switch fault is proposed. Thus, not having to conduct the reliability analysis of switch element singly, the impact of switch element fault on system reliability can be calculated. Applying the proposed algorithm in RBTS-BDS6 system, RBTS-BUS4 system and actual medium-voltage distribution network to conduct reliability assessment, the results show that the proposed algorithm is superior in speed and possesses efficiency and engineering practicality.

配电网常具有树状运行特点，在故障解析模拟时，将开关元件故障对系统可靠性的影响分摊到连接开关的相邻分块的故障后果中，进而提出计及开关故障的可靠性等值解析模型，不需单独进行开关元件故障的可靠性分析即可计算其对系统可靠性的影响，应用该算法对RBTS-BUS6和RBTS-BUS4系统及实际中压配电网进行了可靠性评估，结果表明该算法有较明显的速度优势，具有高效性和工程实用性。

This thesis is mainly focus on the fault forecast problem of compressor, that is, on the basis of the relationship of the gathering correlative parameters of compressor (such as compressive stress of exit or entrance、temperature、oscillation of axletree、the quantity of leaking gas and so on), concluding the possible reason of the fault, taking effective measures to avoid economic lost from shutting down of the fault of equipments.

本论文研究的主要内容是压缩机的故障预测问题，即根据采集到的压缩机的相关参数（如：出/入口压力、温度、轴承振动、泄漏气量等）之间的关联关系推断出可能的故障原因，采取有效措施，避免因设备故障停车造成的经济损失。

The results indicated that the formation of fault basin constrained by magnetic crystalline basement. The more complex of the crustal tectonic, the greater the difference mechanical strength between crust media, the smaller thermal water release less, the easier bred major earthquake.6. Mapped the new quaternary tectonic map of four fault basin based on the data of shallow seismic profiles, drilling, and the redrawn fault system divided by the potential data processing, etc.

研究结果表明断陷盆地的形成受磁性结晶基底的制约；地壳结构越复杂，地壳介质之间的力学强度差异越大，热水点年释放量越小，就越容易孕育和发生大的地震。6、利用浅层地震剖面、钻井等资料，并参考重磁划分的断裂系，新编制了山西四个断陷盆地的第四系构造图。

Foods high in this vitamin include oily fish such as salmon, tuna and, and fish liver oils.

维生素D含量高的食物包括诸如大麻哈鱼、金枪鱼和鲭鱼之类的油鱼以及鱼肝油。

We need you to cosign our public letter demanding that press intimidation cease immediately, and that all charges be dropped.

我们需要您cosign我们的公共信，要求记者立即停止恐吓，并要求所有收费下降。