Ecosystems thus involve the circulation, transformation, and accumulation of energy and matter through the medium of living things and their activities.
因此，生态系统以生物及其活动作为媒介，涉及能量和物质的循环、转化和积累。
By use of rate equations, we have analyzed the effect ot laser wavelength radiation in pump light source on excited state population accumulation of laser medium and laser threshold.
本文用速率方程分析了泵浦光源中激光波长辐射对激光介质激发态粒子数积累和激光器阀值的影响情况。
Because of the continuous energy accumulation of stress concentration units, hardening process of medium emerges.
应力集中单元由于能量的不断积累，介质出现硬化过程。
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