电磁场

Southwest Jiaotong University, Chengdu 610031, China;Southwest Institue of Electronic equipment,chengdu 610036,china

西南交通大学电磁场与微波技术研究所，四川成都 6100031；西南电子设备研究所；四川成都 610036

The Integral domain and integral pattern in EMT electromagnetic field.

介绍了EMT电磁场中的积分域和积分形式问题。

In this paper, four examples were given to prove that vector integral methods can be used to calculate several simple problems of electromagnetic fields directly.

电磁学中有些简单问题中的电磁场可以直接使用矢量积分法求解，本文给出了4个例子。

A mathemetical model of magnetic field in electromagnetic separation of inclusions from molten aluminum under rectangle coil and 50Hz current is presented according to the magnetic vector potential integral equation and the basic theory of magnetohydrodynamics. The magnetic field distribution in the gap of coils is simulated by the model and the actual magnetic field distribution also is measured. The experimental results show that the magnetic field distribution in the gap of coils is uniform and is consistemt with the model simulation. The magnetic field designed accord the simulated result is proved suitable in the practice.

摘 要：根据电磁流体力学的基本理论，利用矢量磁位积分，建立了在采用矩形电磁线圈和工频电源的条件下电磁分离铝熔体中夹杂的电磁场数学模型，模拟计算了电磁感应线圈气隙中的磁场分布状态，同时对制做的感应线圈的实际磁场进行了测量模拟计算磁场的分布状态与实际磁场的测量结果基本一致，都表明在电磁感应线圈气隙中磁场分布均匀，可以进行分离铝熔体中的非金属夹杂。

Firstly, by using the vector integral theory and boundary conditions of the electromagnetic filed, the boundary problem of two electromagnetic fields in the upper half space and lower half space is transformed into two vector integral equations just related to the topography interface, i.e.

提出了一种用边界元法计算频率域人工源三维地形电磁场的数值模拟方法。

The results showed that in specifically range the variety of electric current intensity and frequency remarkably affect the magnitude of magnetic field intensity .

结果表明：在特定范围内电流强度及频率的变化能显著影响到磁场强度的大小，电流强度为20 A左右时，电磁场出现磁饱和，增大电流强度，电磁力增值很小。

It is showed that the gap and coupling length between fingers of interdigital capacitors contribute to cut-off frequency of photodetector.

应用时域电磁场三维TLM方法模拟分析了指栅间距和指栅间的耦合长度与光电探测器截止频率的关系。

When an intermediate frequency electromagnetic field of 12 kW with the frequency of 2500Hz, high quality hollow billets can be gained. Horizontal electromagnetic continuous casting of copper tube blanks was proposed.

当施加功率为12kW、频率为2500Hz的中频电磁场时，得到了表面光滑、宏观凝固组织中具有高等轴晶的比率的高质量空心管坯。

The numerical calculation and influencing factors of casing well resistivity logging are studied.The response equation of resistivity logging is established based on the electromagnetic field theory and the distribution characteristics of the electric field in the intermediate zone.

根据电磁场理论和中场区电场分布特点，建立套管井地层电阻率测井测井响应方程，用传输线理论分析了套管井测井数值计算的可行性，分析了水泥环、地层电阻率、套管厚度等因素对测井响应的影响。

The results show that, the distribution of magnetic field and electromagnetic force in the aluminum film on the cathode slope are in symmetry to the long axis of the cell, especially the magnetic force is in the same direction as the gravity force, which is in favor of the aluminum discharging from the cathode slope. The highest fluctuation of aluminum pad surface in the accumulation sump is 0.021 m, which still remains within the safe range, and will not cause interpolar short circuit, so a normal operation process could be maintained with the same bus bar configuration as the current 75 kA aluminum reduction cells.

结果表明：阴极斜坡表面电磁场和电磁力场分布基本呈沿电解槽长轴对称分布，且电磁力与重力方向相同，这有利于阴极表面电磁力向聚铝沟排放，而在电磁力作用下，聚铝沟内铝液波动最大幅度为0.021 m，仍保持在安全范围之内，不会引起两极短路现象的发生，表明在现有75 kA普通预焙槽母线配置方案下，可以维持导流型结构电解槽的正常运行。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。