Global Witness says trends in the number and average size of oil discoveries has been in decline since 1965.

VOA: standard.2009.10.20

We'll then take a turn to talking about the periodic table, we'll look at a bunch of periodic trends, including ionization energy, electron affinity, electronegativity and atomic radius.

然后我们再开始讲元素周期表，我们会看到很多周期性规律，比如电离能，电子亲和能，电负性以及原子半径。

麻省理工公开课 - 化学原理课程节选

And there's a lot we can explain by talking about what we see in the periodic table in terms of what different trends are in grouping different elements in different spots within the periodic table.

我们可以解释很多,通过讨论元素,周期表中的内容,按照各种不同的规律,将周期表中不同位置的元素分组归类。

麻省理工公开课 - 化学原理课程节选

These trends are reported in a special issue of the Journal of the American Medical Association, entirely devoted to cancer research.

VOA: standard.2010.03.25

They warn us of dangerous trends. They point out potent evils.

他们为我们警告对危险倾向，指出潜在的邪恶。

耶鲁公开课 - 1945年后的美国小说课程节选

Forest Trends sought to prevent those conflicts by commissioning an international law firm to look into the rights of one tribe,the Surui.

VOA: standard.2009.12.17

So this, in fact, is going to be our last principle that we're going to talk about in terms of periodic trends.

实际上，这将是,我们要讨论的最后一个,周期性规律。

麻省理工公开课 - 化学原理课程节选

That makes it hard to get a good sense of trends.

VOA: standard.2009.04.28

But you actually need to keep a few caveats in mind as you do this, which is the fact that trends predict a lot of chemical properties, but they can't predict everything in terms of biological properties.

不过在你使用的过程中,需要牢记一些注意事项,那就是元素周期律可以预言很多化学性质，但是不能预言一切性质,比如生物学性质。

麻省理工公开课 - 化学原理课程节选

It also says there are generally positive trends on economic development, the rule of law, the provision of government services and Iraq's effort to expand its regional diplomatic contacts.

VOA: standard.2009.03.31

All right. So that is an anti-example of using periodic trends.

好的，这是一个关于使用元素周期律的反例。

麻省理工公开课 - 化学原理课程节选

And the glitch that doesn't make sense just through periodic trends, is that it turns out that the ionization energy of boron is actually less than the ionization energy up beryllium.

仅仅考虑周期性规律,是无法理解这个问题的，这里显示硼的电离能,实际上比铍的要小。

麻省理工公开课 - 化学原理课程节选

So, again, this is one of the more straightforward trends.

再说一遍，这是一个更简单直接的规律。

麻省理工公开课 - 化学原理课程节选