The magazine also holds a yearly skyscraper competition for the best ideas for redefining the role of skyscrapers.

VOA: special.2010.03.31

So in terms of the carbon hydrogen bond, it's a sigma bond, - because we define it -- any time we are bonding to an atom, we have to keep redefining our bond axis to whatever two atoms we're talking about.

对于碳氢键，它是sigma键，因为我们定义它-,任何时候我们有原子成键，我们要重新定义键轴方向,为我们所讨论的两个原子方向。

麻省理工公开课 - 化学原理课程节选

And so redefining then the temperature scale to the Kelvin scale, where t in degrees Kelvin is equal to t in degree Celsius, plus 273.15.

以K为单位的温度,是以℃为单位的温度,加上273。15度。

麻省理工公开课 - 热力学与动力学课程节选