磁场

The theory of accretion disks are important for many astrophysical phenomena, including Quasars, active galatic nucleic, X-ray binary stars, and young stellar objects. The most important branch of accretion djsk theory is the stability properties of djsks. It is widely considered that the luminosity variations of various astronomical objects are associated with the instability of accretion disk. The viscosity plays an important role in the accretion disk theory, and magnetic field exists commonly in astronomical phenomena. A more realistic analysis of the stabihty of the accretion disk should include both the radjal and azimuthal perturbations because of the strong shear of viscous flow.In this paper, according to the luminosity Variations of Various astronomical objects, we study the radial-azimuthal instability of an isothermal with magnetic field. We find that the radial and azimuthal fields B〓,B〓 are mainly responsible for enhancing the instability of the magneto-acoustic modes and non-axisymmetric modes,and that pulsational oscillations are larger in the radial than in the Z direction. The model may be useful in explaining the periodic light variation of FU orionis and. T Tauri stars.

在许多天体物理现象中，例如活动星系核，X-射线双星和年青的恒星理论中，吸积盘理论起着重要的作用，而吸积盘理论中的一个重要分支是吸积盘的不稳定性理论，普遍认为活动天体的周期，准周期光变现象与吸积盘的不稳定性有关，在吸积盘理论中，粘滞起着重要的作用，而磁场是天体物理中普遍存在的现象，对于几何薄吸积盘不稳定性分析，由于强剪切流的缘故，应该包括径向和环向扰动两个方面，本文结合天体物理中的各种周期，准周期光变现象，研究了含磁场的等温薄吸积盘的径向-环向振荡不稳定性，结果表明：磁场的径向和环向分量对磁声模和非轴对称模的不稳定性的增加起着主要的作用，且径向振荡大于轴向振荡，所得结果有利于解释FU Orionis和T Tauri Stars的周期光变现象。

On the two sides of the north pole two auxiliary magnets make the terrestrial globe run automatically at average speed by rotating the magnetic field generator.

当距离变小时，控制器自动减弱磁场，当距离变大时，控制器自动增强磁场，从而保证地球仪与控制器有一定距离，在北极两侧有两个辅助磁铁，通过旋转磁场发生器使地球仪匀速自转。

In order to explore the effect on DNA synthesis and DNA double-strand breaks by magnetic field, We chose a relatively simple uniform magnetic field, study the affect on DNA synthesis and DNA double-strand breaks by such magnetic field, conclused that this impact related to magnetic field strength.

为了研究磁场对DNA的合成速度和DNA双链断裂的影响，我们选择比较简单的均匀磁场，从理论上探讨了此种磁场对DNA合成速度和DNA断链的影响，得到其合成速度改变和双链断裂程度与磁场强度大小有关。

As to concrete treating method, the thesis adds the components in third dimension to the original 2D MHD code, and inward flows are embedded along the side of the current sheet, through changes of certain flow's scale, its distance to the current sheet, the viscosity coefficient and the resistivity in the plasma, the magnetic field figure, the velocity vector figure and the density distribution figure with different situations would be showed and observed, the reconnection growth rate figure is to be presented also, and the physical explanation involved will be made consequently.

在具体的处理方法上，文章在原有二维MHD流体理论基础上加入第三方向的分量，并且在电流片两侧加入入流扰动，通过改变其大小，距离电流片的位置，等离子体中的粘滞系数和等离子体电阻率，从而观察不同扰动情况下磁场重联的磁场位形、流场位形或者密度分布，绘制出磁场重联增长率在不同入流扰动下的图像，并分析其中的物理过程。

Firstly, a scalar and vector potential analysis models of tooth-layer magnetic field in a two-degree-of-freedom motor is developed, which is the same as standard hybrid step motor. By applying the finite element method, the distribution of the tooth-layer magnetic field is studied in detail. It provides an effective means for further calculation of performance and parameters of the motor.

首先，对两自由度电机产生转矩的关键部分——齿层区域的磁场进行了细致深入的分析，提出了齿层磁场的标量位和向量位分析模型，并通过有限元的数值计算，对各种情况下齿层磁场的分布规律从微观上进行了形象的分析和研究，为完整电机的进一步计算提供了有力的工具。

The results show that,(1) the ion acceleration and energization mainly occur in the middle of dipolarization at distance of -12 R to -8 R,(2) the ion acceleration and energization along the direction perpendicular to magnetic field are faster than along parallel direction,(3) variations of speed and energy for lighter ion are faster than that of heavier ion,(4) the higher the initial energyis, the faster the ion acceleration is, and the more energy is obtained by the ions.

主要结果为：(1)离子的加速及能量变化主要发生在磁场偶极化过程的中期，对应的地心距离位於-12R到-8R之间；(2)垂直於磁场方向上离子加速及能量变化较快，平行方向上较慢；(3)轻离子较重离子加速及能量变化快，磁场偶极化终结，3种离子的能量均可增加200倍左右；(4)初始能量较高时，离子加速及能量变化较快，离子最终获得的能量较大。

The results show that,(1) the ion acceleration and energization mainly occur in the middle of dipolarization at distance of -12 RE to -8 RE,(2) the ion acceleration and energization along the direction perpendicular to magnetic field are faster than along parallel directi on,(3) variations of speed and energy for lighter ion are faster than that o f heavier ion,(4) the higher the initial energyis,the faster the ion accelerati on is, and the more energy is obtained by the ions.

主要结果为：(1)离子的加速及能量变化主要发生在磁场偶极化过程的中期，对应的地心距离位于-12RE到-8RE之间；(2)垂直于磁场方向上离子加速及能量变化较快，平行方向上较慢；(3)轻离子较重离子加速及能量变化快，磁场偶极化终结，3种离子的能量均可增加200倍左右；(4)初始能量较高时，离子加速及能量变化较快，离子最终获得的能量较大。

According to the neural cable model, this dissertation deduced a stable solution. Based on the lead model, the vibratory equation of electriferous lead in a static magnetic field is set up under the condition of coupling magneto-acoustic field. It is verified that the vibration in bio-tissue is proportional to with the product of the magnitude of the magnetic field, the current amplitude and the sinusoid of angle between them.

根据神经的电缆模型，论文导出直流稳态解；基于导线模型，根据洛仑兹方程和细弦上的波动方程，论文建立了磁声耦合条件下带电导线在磁场中的振动方程，导出生物组织中的振动与磁场的大小、电流的大小和磁场与电流角度的正弦值乘积成正比。

When placing the semiconductor carrying current in the magnetic field axial to the current direction, the semiconductor will generate transverse galvanomagnetic phenomenon, namely generate electromotive force in the direction axial to the magnetic field and current, which is Hall Effect.

把载有电流的半导体放在垂直于电流方向的磁场中时，半导体会产生横向磁场电现象，即：在垂直于磁场和电流的方向产生电动势，这就是霍尔效应。

Methods From pregnancy to parturition, we used different magnetic dosage to expose pregnant rats. 10 weeks later, we measured liver and kidney function of filial generation rats and metabolic biochemical indexes of glucide, fat, protein and nucleic acid, then changes of these indexes were analyzed to estimate the magnetic hazard.

方法］用恒定磁场(0.4T)每日0.5、1、2h暴磁处理SD受孕母鼠至仔鼠出生，仔鼠继续饲养至10周，检测仔鼠的肝功能、肾功能以及糖类、脂类、蛋白质、核酸代谢的相关生化指标，据此分析磁场对大鼠生理有无影响，判断磁场是否对大鼠有害。

What are your goals and strategies for growth?

你的成长目标和策略是什么？

And unto the angel of the church in Sardis write; These things saith he that hath the seven irits of God, and the seven star I know thy works, that thou hast a name that thou livest, and art dead.

3：1 你要写信给撒狄教会的使者，说，那有神的七灵和七星的，说，我知道你的行为，按名你是活的，其实是死的。