局域电荷体系的电势  

Electric Potential Caused by Local Electric Charges

作　　者：余利华[1] 

机构地区：[1]武汉理工大学理学院,武汉430063

出　　处：《武汉理工大学学报（交通科学与工程版）》2012年第3期645-647,651,共4页Journal of Wuhan University of Technology（Transportation Science & Engineering）

摘　　要：探讨了分布在小区域v内的连续电荷体系在远场所产生的电势,可表为一组位于原点的各级多极子在远场产生的电势的叠加,而连续分布电荷体系可用位于原点的各级多极子代替.In the presence of PbO catalyst, synthesis of methyl carbamate（MC） from methanol and urea was discussed. The synthetic products were characterized by melting point determination, IR, 1HNMR and GC-MS. The effects of molar ratios of methanol to urea, reaction temperature, catalyst dosage, reaction time on the reaction were studied. Under the optimum reaction conditions, the yield of MC reached 61.80% and Selectivity of MC is 98%.

关 键 词：局域电荷 多极子 屯势 电场 

分 类 号：O442[理学—电磁学]