If injecting an invariable alternating current into patient ' s brain from all directions , and detect the distribution of voltage on the brain ' s surface which reflect the brain ' s internal information about impedance , then use computer to analyze the distribution of voltage detected by sensors , so that localizes the position and constructs an image for the brain edema and haematoma 将一个小的交变电流从大脑不同的方向注入，就会在大脑表面产生不同的电位分布，通过检测大脑表面的电位分布，用计算机来对这些分布的电位进行分析、计算、定位和重建水肿血肿的图像。
The simulated results indicate that the non - uniformity is further intensified due to the bitumen sand base ; soil resistivity in the position where auxiliary anodes are placed has significant effect on potential distribution ; there is a buried depth of anode for optimal potential distribution under different geological conditions 结果表明：罐底沥青砂基础会加大电位分布的不均匀性；阳极理深处的土壤电阻率时整个罐底的电位均有显著影响；在不同地质条件下进行深井阳极保护时，存在一个使电位分布效果最佳的阳极埋深点。
On the ground of educative theory , this paper exposits connotation and characteristic of project - based learning and why we should also enforce project - based learning in high school . as far as substance of project - based learning and objective circumstance what it should have are concerned , it points out the practical ability . at last , based on that university physics education has relatively longer cycle , it proposes stage pattern for enforce project - based learning and give two concrete cases , which discuss capacitance of confocal oval - shaped stylar capacitor and potential distribution of charged conductor of surface being uniparted hyperboloid 本文在具体的教育理论指导下，阐述了研究性学习的内涵及特点；在大学物理中实施研究性学习的意义；以及就研究性学习的实质和所需具备的客观条件而言，论述了研究性学习在高校中实施的可行性；并根据大学物理教育具有周期性相对较长和专业循序渐进的特点，提出了研究性学习的阶段性模式，并给出了具体的实例，利用保角变换法讨论了共焦椭圆柱形电容器电容及单叶双曲面带电导体的电位分布。
It creates the model of layer soil by using the cdegs software , analyses the resistance error which is measured by traditional three - poles way , measures the grounding grids resistance and soil resistance rate of hejin power plant , creates the electromagnetic model of layer soil and grounding grids model of hejin power plant , calculates the step voltage > touch voltage n voltage distribution of earth surface in fault of hejin power plant . in the end , it compares the measuring value and calculating value of grounding grids resistance in hejin power plant 本文利用cdegs软件建立分层土壤接地模型，对传统三极法测量接地电阻误差进行分析；对河津电厂接地网接地电阻和土壤电阻率进行测量；建立河津电厂分层土壤电磁模型和接地网模型；计算河津电厂接地网电阻和事故状态下跨步电压、接触电压和地表电位分布；最后对河津电厂接地网电阻实测值与计算值进行比较分析。
