Two kinds of methods particularly suitable to shape optimization, semi-analytic method and local difference method, are proposed to calculate the first-order derivatives of magnetic flux density with respect to the design variables on the basis of solving sensitivity equations of the magnetic vector potential. 在用直接法求解矢量磁位灵敏度方程的基础上,给出适合形状优化的磁通密度灵敏度分析的两种方法&半解析法和局部差分法。
This article points out the difference between the direction of gradient and the direction of magnetic field in the MRI system, gives the equations of the magnetic lines in the gradient magnetic field and the scalar magnetic potential function, and describes the method of computing it. 本文指出了核磁共振成象仪中,梯度方向与磁场方向的区别,给出了梯度磁场中的磁力线方程,标量磁势函数和计算它的方法。