When male and female (M&F) or tongue and groove (T&G) type flanges are specified, the nozzle flange facing of the vessel shall be of female or groove type.

如指定使用外螺纹及内螺纹或榫面及槽面法兰，容器设备口法兰端面应为凹槽型。

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Phase difference between the e. m. f. of an alternator taken as a reference and that of another alternator or that of an infinite bus.

作为参考的交流电机电动势与另一台交流电机或无限大母线电动势之间的相角差。

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The dependence of the refractive index of optical fiberes on composition, temperature, warelength, M F D and drawing tension (or drawing temperature) as well as attenuation is described.

叙述光纤折射率与组成、温度、波长、模场直径和拉丝张力 （拉丝温度 ）以及衰减等因素的相互依赖关系。

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"Actually my first name is Charles. When I was in the military they would always assume that somebody had mis-keyed the M versus the F and would house me with a male roommate or such."

VOA: special.2009.07.06

But F-Commerce as a trend on par with, or even within striking distance of m-commerce this holiday season?

FORBES: M-Commerce Rocked the Holiday Season. Still No Word About F-Commerce