Singularity-free expression of magnetic field of cuboid under undulating terrain

Most of the current computing methods used to determine the magnetic field of a uniformly magnetized cuboid assume that the observation point is located in the upper half space without a source. However, such methods may generate analytical singularities for conditions of undulating terrain. Based on basic geomagnetic field theories, in this study an improved magnetic field expression is derived using an integration method of variable substitution, and all singularity problems for the entire space without a source are discussed and solved. This integration process is simpler than that of previous methods, and final integral results with a more uniform form. AT at all points in the source-flee space can be calculated without requiring coordinate transformation; thus forward modeling is also simplified. Corresponding model tests indicate that the new magnetic field expression is more correct because there is no analytical singularity and can be used with undulating terrain.

杭嘉湖地区近现代粮仓建筑遗产研究

首先对杭嘉湖地区近现代粮仓概况进行论述,并从时间、空间、类型、文保等级等四方面界定案例样本的调查范畴,据此筛选案例样本,建立了"杭嘉湖地区近现代粮仓建筑遗产名录";在此基础上,对案例样本的空间分布进行分析。进而,基于该地区近现代粮仓建筑遗产的分类,结合典型案例,分别对房式仓、立筒仓、土圆仓和组合型粮仓的建筑形体特征进行解析。结合案例调研,分析了该地区近现代粮仓建筑遗产保护与再利用的现状。最后,提出杭嘉湖地区近现代粮仓建筑遗产保护与再利用的对策思路。