useful energy

基本解釋

Getting useful energy from formate is now the simplest way known for any life form to get its fuel, though it relies on the absence of oxygen.
從甲酸鹽中獲取所需的能量是目前最簡單的維持生命方式，雖然它依賴于無氧的環(huán)境。
To generate useful energy, plants have evolved very sophisticated "nano-machinery" which operates with light as its energy source and gives a perfect quantum yield of 100%.
為了產生有效能，植物進化出了異常精密的“納米機器”，它以光為能量來源，光能轉化率達到了完美的100％。
The building of a real-life version of "Maxwell's demon" – which can turn information into useful energy – might mean that future nanomachines can be powered purely by information.
建造“麥斯威爾妖”的現實生活版本——它可以把信息轉變?yōu)橛杏玫哪芰俊馕吨磥淼暮廖⒓売嬎銠C可能純粹地依靠信息來作為動力。

So, in this class we'll be talking about energy a lot, and it's often useful to draw some sort of energy diagram to visualize the differences in energy that we're discussing.
所以，這堂課我們會討論很多,關于能量的問題，討論時，畫能級圖來使能量差別,形象化常常是很有用的。
麻省理工公開課 - 化學原理課程節(jié)選
Now these quantities were useful because you could relate them. The slope of changes, with respect to volume or temperature of the energy with respect to quantities that you understood, that you could measure.
去得到這些量,這些量很有用，而且你們已經知道了，怎么把它們相互聯系起來,像這種比例形式的量，能量比上溫度或體,或其它你們懂的可以測量量。
麻省理工公開課 - 熱力學與動力學課程節(jié)選

Think of nuclear fission: it generates useful energy but if it runs out of control you get a cataclysmic explosion.
ECONOMIST: Why Germany seems not to want a quick fix for the euro crisis
Dr Kanatzidis argues that wherever heat is generated as part of power generation, thermoelectric devices could help extract more useful energy.
ECONOMIST: Thermoelectrics