The researchers compared cotinine levels to behavioral problems that parents observed in the children during a 2-week period.

VOA: special.2009.01.13

So, for example, we can move to the next periods in the periodic table. When we talk about a period, we're just talking about that principle quantum number, so period 2 means that we're talking about starting with the 2 s orbitals, period 3 starts with, what we're now filling into the 3 s orbitals here.

我们可以移至周期表的下一个周期,当我们讨论一个周期时，我们仅仅讨论,周期3以我们所填充的3s轨道，开始填充所以周期2意味着,我们从2s轨道谈起，周期3以我们所填充的3s轨道开始填充。

麻省理工公开课 - 化学原理课程节选

.. The equity premium is the-- 2.8% this short-term 2.8% is the riskless return, historically, for a period of almost 200 years.

股权溢价就是-,这个短期无风险投资收益率是，是根据近200年的数据得出的。

耶鲁公开课 - 金融市场课程节选

s1 So for the fourth period, now we're into the 4 s 1 3d for potassium here. And what we notice when we get to the third element in 4s2 and the fourth period is 3d that we go 4 s 2 and then we're back to the 3 d's.

对于第四周期到现在我们来到钾的1,然后我们返回到,我们注意到当我们看到第三个元素,第四周期我们来到,然后我们返回到。

麻省理工公开课 - 化学原理课程节选

The price of the two-period bond is 1/2 and the price of the one-period bond is 1/.

所以两年期债券的价格是1/^2,一年期债券的价格则是1/

耶鲁公开课 - 金融市场课程节选

Roger Ibbotson took a look at a larger group of funds -3,500--funds over a ten-year period and found survivorship bias at 2.9% per year and backfill bias at 4.6% per year.

罗杰·伊博森研究了更大的样本组,3500支基金10年间的表现,算出其生存偏差是每年2.9%,回填偏差是每年4.6%

耶鲁公开课 - 金融市场课程节选