summationn.总结；加法；总和；有代表性的整体Summation Function和函数summation notation总和记号summation by parts分部求和summation exponent叠加指数summation metering求和测量法summation amplifier加法放大器, 求和放大器summation flowmeter总流量计summation of losses损耗求和summation potential和电位,累积电位summation frequency[电] 总和频率