系指(23±2)℃的室温.
遗憾的是，一秒钟的标准定义依赖于原子在绝对零度的条件，而实际的时钟需要在室温下运行，室温条件下电子壳层膨胀了。
Unfortunately, the standard definition of a second relies on what the atom does at a temperature of absolute zero. Real clocks need to run at room temperature, where the shell of electrons puffs up.
在室温和压强(常压)下，装满氢的75升(大约20加仑)标准燃料箱只能驱动一辆氢动力汽车行使大约1公里。
Filling a typical fuel tank of 75 litres-about 20 American gallons-with hydrogen at room temperature and pressure will take a hydrogen-powered car only about a kilometre or so.
冷镦钢是一种在室温条件下，利用金属塑性成型工艺，生产互换性较高的标准件用钢。
Cold forge steel is a kind of special use of steel which can be used to produce the standard part in the room temperature.
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