第一时刻：指某个事件或行动发生的最初的瞬间。
the sum of the values of a random variable divided by the number of values
同义词： arithmetic mean / expectation / expected value
一次矩
一阶矩
一阶距-引用次数：1
静力矩
一阶力矩
...nction )的方法可以对上式进行求解，并可以进一步描述溶剂化电子空间分布函数最基本的两个参数：分布函数的一阶矩(First moment)和二阶矩..
式中,为图中右侧所示截面之斜线部分面积对中性轴的一次矩(first moment),I为整个截面对中性轴的面积二次矩.
... first law of thermodynamics热力学第一定律 first moment静力矩 first moment of the surface静力表面矩 ...
... first moment of area 一次面积矩 first moment 静矩 First Motor Man 一级机工 ...
静力矩；[数]一阶矩；一次矩
From the first moment he got on the set, he wanted to be a director too.
从踏进摄影棚的第一刻起，他就也想成为一名导演。
In the first moment of fear, he called, indeed, as loud as he could—"You impudent little blackguard!"
在他害怕那一刻，用最大的声音喊道：“你这个无礼的小坏蛋！”
This is the first moment, right now, "thus sang the uncouth swain."
这是第一次，“粗鄙的青年人吟唱着
So we're only looking at a snapshot of that very first moment in time.
VOA : standard.2010.06.30
Today. So this is the first class, the first moment of shopping that you guys are going to!
所以这是第一节课,这是你们上的第一节试听课
关于食物的心理学、生物学和政治学课程节选 : 耶鲁公开课
This is the first moment that the poet John Milton is actually speaking in his own voice, and he's speaking directly to us.
这是第一次诗人弥尔顿,在以本尊的声音做着叙述，并且是在直接的向我们叙述。
弥尔顿课程节选 : 耶鲁公开课
Woodstock is described as a moment when the news media first recognized music and entertainment as a cultural and commercial force.
VOA : special.2009.08.10
There was silence for a moment. Then the first man spoke again.
VOA : special.2009.01.01
It might mark the very first moment that someone has used Twitter to communicate something useful.
We must be ready for the 21st century from its very first moment, by solving the "Y2K" computer problem.
But it was a high ball into the box that created the first moment of real danger after 25 minutes.