the SI unit of work or energy, equal to the work done by a force of one newton when its point of application moves one metre in the direction of action of the force, equivalent to one 3,600th of a watt-hour.
焦耳（功和能量的国际公制单位）。
James Prescott (1818—89), English physicist. Joule established that all forms of energy were basically the same and interchangeable—the first law of thermodynamics. The Joule-Thomson effect, discovered with William Thomson, later Lord Kelvin, in 1852, led to the development of the refrigerator and to the science of cryogenics. Joule also measured and described the heating effects of an electric current passing through a resistance.
焦耳，詹姆斯· 普雷斯科特（１８１８—１８８９，英国物理学家；焦耳为热力学第一定律奠定了基础，即能量的所有形式都是基本相同并可互相转换的，１８５２年他与威廉·汤姆逊，即后来的开尔文勋爵，一起发现的焦耳－汤姆逊效应，导致冰箱的研制和低温学的开创；焦耳还测量并描述了电流通过电阻时产生的热效应）。
"late 19th cent.: named after J. P.