均匀磁场

With experience gained from the Finite Element method, a quasi-linear model based on the Magnetic Equivalent Circuit method has been used to obtain the static torque of the motor. Three types of magnetic tubes are employed in the model, and through the exchange principle of magnetic lines of force and magnetic equipotential line, the tube in which the flux distribution is non-uniform is applied to the model.

通过分析电机二维磁场分布和考虑电机特殊的电磁结构，提出了用三种磁通管单元来近似磁场分布，并借用磁力线和等磁位线互换的方法，将磁力线分布不均匀的磁通管引入到分析模型中，有效的处理了平动式啮合电动机中的磁场分布不均匀和磁路局部饱和，使分析模型得到简化并兼顾了求解精度。

Permanent magnet can provide for a maximum intensity of the magnetic field around Tesla, Helmholtz coils and solenoids can provide alternating magnetic field or relatively uniform magnetic field, and solenoids can also be used to provide strength for the solenoid around 10 Tesla.

其中永磁铁能够提供强度最大为1特斯拉左右的静磁场，亥姆霍兹线圈和螺线管可提供交变磁场或相对均匀的磁场，也可用螺线管提供强度为10特斯拉左右的超强静磁场，电磁铁则可产生强度为几百毫特斯拉或特斯拉级的静磁场。

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。

Based on the analysis of displacement of the electron in transverse magnetic field ,computation of magnetic field of Helmholtz coil and the analysis of uniform scope of magnetic field,the expression of the electron displacement with magnetic field intensity in intensitive uniform magnetic field is modified by the authors.

为了衡量电子在横向磁场下的偏移量的实验中所测数据的优劣性，分析了电子在横向磁场下的偏移原理，，通过亥姆霍兹线圈全空间磁场的计算和磁场均匀性范围的分析；修正了电子在匀强磁场中偏移距离与磁感应强度的关系式，得到了电子在磁场中的偏移距离与产生匀强磁场的电流以及磁场大小的偏差率之间的关系以及成立的条件。

In this paper,surface line-charge method was taken to calculate the magnetic distribution in a 160kA large prebake anode aluminum reduction cell in Guizhou Aluminum Smelter.

应用表面磁荷法对贵州铝厂 16 0kA大型预焙阳极铝电解槽的磁场进行了计算，通过对电流分布均匀情况下和考虑了实际电流分布情况下的电解槽磁场的比较，可以看出，阳极和阴极电流分布对铝电解槽磁场分布具有绝对的影响，只有在考虑了阳极和阴极电流实际分布的情况下，才能准确地计算出铝电解槽的实际磁场分布。

A non-singular single integral mathematical model is adopted to calculate the external intermittent and alternative longitudinal magnetic field acquired by single axisymmetrical and cylindrical hollow coil t which is coaxial to electrode and excitated by a revisable pulsed current of square wave t in austenitic stainless steel GTA welding.

针对奥氏体不锈钢外加纵向磁场的气体保护钨极电弧焊接时，与电极同轴的单个轴对称空心圆柱线圈在双向脉冲矩形励磁电流作用下产生的间歇交变纵向磁场，采用无暇点单积分磁场的数学模型，对＊TAW焊接外加间歇交变纵向磁场进行了数值计算，该方法具有模型简单、计算速度快和精度高等优点并讨论了该间隙交变纵向磁场的分布、磁场的均匀性及其纵向分量与径向分量的比率等规律及其对焊接行为的影响，认为横磁分量将削弱GTAW外加纵向磁场的有利作用，影响磁控电弧的焊接质量

Shim current calculationWhen shim coils are excited by appropriate current, they can generate correcting magnetic field to compensate the imaging magnetic field unhomogeneity. Based on the indirect calculation method, we proposed a novel iterative optimization algorithm to calculate shim current. Because there is a direct proportion relationship between FID signal and magnetic field homogeneity, we use the intensity of FID signal as feedback information to the calculation. Shim current can be worked out in less than 3 minutes. This satisfied the requirement that active shimming should be performed in real time.

5匀场电流计算对匀场线圈施加适当的电流后才能产生校正磁场消除成像磁场的非均匀分量，本文在匀场电流间接计算方法的基础上，利用磁共振成像原理中磁场均匀性与系统FID信号强度成正比的关系提出了一种电流迭代优化算法，将系统FID信号强度的变化作为反馈信息，能够快速计算出匀场电流对成像磁场进行补偿校正，平均耗时不到三分钟，满足磁共振成像系统对有源匀场的实时性要求。

Compared to other means,using Hore component to measure the displacement of object has some advantages including smaller transient response,better dynamic properties,non-contact and higher accuracy of measurement. However,the magnetic field produced by common magnet can keep the gradient unchanged only in a small area.

然而，一般磁场只可能在极小的范围内保持均匀梯度，若要求在大范围内保持均匀梯度，其磁场结构复杂、体积庞大，在很大程度上限制了霍尔元件测量位移的应用。

Base on the magnetic performance of gas, the moment of rotation of a dumbbell is derived when it is in a nonuniform magnetic field. A design of the measuring cell is proposed, a rotary resistance for the dumbbell ball is implemented by a silver-coated erosion approach, and the techinque requirements are analyzed for the nonuniform gradient magnetic field.

从气体磁性推导出了哑铃球在非均匀梯度磁场中受到的转动力矩公式，给出测量池系统的设计方案，采用镀银刻蚀方案实现哑铃球系统的转动阻尼，分析了非均匀梯度磁场系统的技术要求。

Saddle shaped AMF can produce a radial expanding force, which has more effective effect on resisting the pinch effect of self-generated azimuthal magnetic field of arc current. This effect of saddle shaped AMF can keep vacuum arc in diffuse mode under much higher current. So the limiting current interruption capacity of vacuum interrupter can be enhanced.

为了进一步提高纵向磁场对真空电弧的控制作用，本文提出在真空灭弧室的触头间引入从触头中心向边缘逐渐增强的非均匀纵向磁场，马鞍形纵向磁场会对真空电弧产生一个径向扩张力，而纵向磁场分布的合理设计可以使这一扩张力进一步抑制真空电弧自生环向磁场对电弧的箍缩作用，从而使真空电弧在更大的电流时仍能保持在扩散态，使真空灭弧室的极限电流开断能力得以提高。

Plunder melds and run with this jewel!

掠夺melds和运行与此宝石！

My dream is to be a crazy growing tree and extend at the edge between the city and the forest.

此刻，也许正是在通往天国的路上，我体验着这白色的晕旋。