在材料科学领域，弹性能(英文:resilience) 是一材料弹性变形时吸收的能量, 一旦除去应力则可以释放相等的能量。实际上较常用的参数是弹性能模数，定义为一材料从未受应力至受降伏应力每单位体积吸收的应变能，可视为弹性变形内每单位体积能量吸收最大量。

在单轴向拉伸试验，弹性能模数正是应力-应变曲线至降伏点下的面积，可由积分求得。

其中  是 弹性能模数，是 降伏点对应的应变， 是 降伏强度， 是 杨氏模数。

弹性能模数 (U_r) 的单位等同于应力、应变两者单位的乘积。弹性能模数之SI单位为焦耳每立方公尺 (J·m) 。

In ecology, resilience is the capacity of an ecosystem to respond to a perturbation or disturbance by resisting damage and recovering quickly. Such perturbations and disturbances can include stochastic events such as fires, flooding, windstorms, insect population explosions, and human activities such as deforestation, fracking of the ground for oil extraction, pesticide sprayed in soil, and the introduction of exotic plant or animal species. Disturbances of sufficient magnitude or duration can profoundly affect an ecosystem and may force an ecosystem to reach a threshold beyond which a different regime of processes and structures predominates. Human activities that adversely affect ecosystem resilience such as reduction of biodiversity, exploitation of natural resources, pollution, land-use, and anthropogenic climate change are increasingly causing regime shifts in ecosystems, often to less desirable and degraded conditions. Interdisciplinary discourse on resilience now includes consideration of the interactions of humans and ecosystems via socio-ecological systems, and the need for shift from the maximum sustainable yield paradigm to environmental resource management which aims to build ecological resilience through "resilience analysis, adaptive resource management, and adaptive governance".