The Centers for Disease Control says HEPA filters are effective in clearing the air of many particles that cause disease.

VOA: special.2009.07.14

z So, this is what we find the actual z effective is for an electron in the helium atom.

所以这就是我们得到了实际有效的,对于一个氦原子的电子。

麻省理工公开课 - 化学原理课程节选

So we're going to feel a higher z effective in the case of the ion compared to the neutral atom.

因此，我们在离子中,会比在中性原子中感受到更高的有效核电量。

麻省理工公开课 - 化学原理课程节选

The study in Benin found that solar-powered pumps are effective in supplying water, especially during the long dry season.

VOA: special.2010.01.11

This is more well-established question of nurture, in terms of moving away from the way we normally teach to what is clearly more effective way.

这更是一种,培养方法问题，从我们平常的教学方法,转移到,明确的更有效的方法。

麻省理工公开课 - 媒体、教育、市场课程节选

So far it has proven effective at preventing the disease in half of those vaccinated which is more than ever before.

VOA: special.2009.12.07

In other words, only if we really are sure that the historicist act of reading is effective and works, if I know the meaning of a text. Well, fine.

换言之，要是我们确定,阅读这个历史主义行为是有效的，有用的，如果我知道文本的意思，那么，很好。

耶鲁公开课 - 文学理论导论课程节选

The vaccine has already proven effective at preventing the disease in half of those vaccinated which is more than ever before.

VOA: special.2009.12.22

One can stop spread of disease through a community without being 100% effective in each person who gets the vaccine.

疫苗能够遏制疾病在整个社区中传播,虽然对于每个人来说它并非百分之百有效

耶鲁公开课 - 生物医学工程探索课程节选

In the United States, the Armed Forces Radiobiology Research Institute is looking for more-effective treatments for radiation exposure.

VOA: special.2011.03.30

But in England, the tradition of freedom and government bound by law was already strong enough to produce effective resistance.

但是在英国,自由传统和法制政府,使得自由得以很好的保护

耶鲁公开课 - 古希腊历史简介课程节选

"If I felt that I could have been increasingly effective in that job, I suppose I would have continued to do it.

VOA: special.2010.05.09

Similarly,I believe that if we wish to prevent drug abuse in teenagers who grow up in a neighborhood that puts them at risk, the effective prevention is not remedial.

同样，如果我们要防止,青少年受不良的社会环境影响,而滥用药物的情况，但预防的效果不佳。

哈佛公开课 - 幸福课课程节选

He says there is clear evidence of the kinds of policies and programming interventions that can be most effective in combating the problem.

VOA: special.2010.05.17

Germany was very effective in these-- they had advanced bureaucracy, a good postal service, and they had a network of post offices all over the country-- every little town had a post office.

德国人处理此事非常有效-,他们推进了行政机制和邮政服务，出现了全国范围的邮局网-,每个小镇都有一所邮局。

耶鲁公开课 - 金融市场课程节选

And it sank,too. The Confederacy also developed very effective underwater explosive devices for use in the harbors.

VOA: special.2009.09.10

He said Southerners are "Proud, brave, honorable by its" The South is "Proud, brave, honorable by its lights, courteous, personally generous, loyal, swift to act, often too swift, but signally effective, sometimes terrible in its actions.

他写道南方,"因自豪勇敢而可敬",南方人,"因自豪勇敢而可敬,他们彬彬有礼,对人慷慨,他们忠诚,行动迅速,常常过于迅速,但他们效率显著,有时甚至不择手段

耶鲁公开课 - 美国内战与重建课程节选

He says the study shows that, in theory,white roofs could be effective in reducing urban heat.

VOA: special.2010.03.02

Now we're doing the same for IT, using standards, taking things that are in what's this big bucket known as services and really encapsulating them in the form of services and products, but in a much more cost-effective way, using standards.

现在对于整个信息技术行业我们也采取这种方法，使用标准,通过服务,注入产品和服务，通过标准，提高成本效率。

斯坦福公开课 - 戴尔CEO-Michael.Dell谈创业和发展课程节选

But recent findings suggested that tPA may be effective in saving brain tissue even if three to four and a half hours have passed.

VOA: special.2009.09.22

If we have a higher z effective, it's pulled in tighter, we have to put in more energy in order to eject an electron, so it turns out that that's why case 2 is actually the lowest energy that we need to put in.

而如果有效核电量更高，原子核的束缚也就更紧，我们不得不输入更多的能量来打出一个电子，这就是第二种情况,所需要输入的,能量更少的原因。

麻省理工公开课 - 化学原理课程节选

Scientist Ian Wilson at the Scripps Research Institute in California says the antibodies proved highly effective in laboratory mice exposed to deadly levels of virus.

VOA: special.2009.03.04

As a lot of research, especially in physics education, shows that this kind of pedagogy is more effective.

因为很多研究表明，尤其是一些物理教学领域的，这种教学方法,会更有效。

麻省理工公开课 - 媒体、教育、市场课程节选

But recent findings have suggested that tPA may be effective in saving brain tissue even if three to four and a half hours have passed.

VOA: special.2009.08.12

So again, when we check these, what we want to see is that our z effective falls in between the two extreme cases that we could envision for shielding.

所以当我们再一次检查这些时，我们想看到的是,有效电荷量处于两种极端案例中,这两种极端案例。

麻省理工公开课 - 化学原理课程节选

And again, Americans all around the country took note of this quiet,serious man who did such effective work in so many different kinds of situations.

VOA: special.2011.02.10

I think the smallpox vaccine we made now would probably be better, more effective, and safer than the vaccines we made in the '50s.

我相信若我们现在制造天花疫苗,应该会比五十年代的更有效更安全

耶鲁公开课 - 生物医学工程探索课程节选

In another study, the vaccine was effective in reducing clinical malaria by thirty-five percent.

VOA: special.2010.04.20

Part of the reason why I'm endorsing this market stability regulator is that there's no way we can set up a system that is both very effective in allocating resources and that is also very stable.

我赞成市场稳定性监控者,的部分原因是,没有方法建立一个,既能完全有效配置资源有非常稳定,的系统。

耶鲁公开课 - 金融市场课程节选

Not only are we taking away an electron here, but we're also going to decrease shielding, so the electrons that are already in there are going to feel a higher z effective and will be pulling and the atom will be getting smaller.

这不只是因为我们拿走了一个电子，还因为我们这样做会减小屏蔽效应，这样留下的电子,将会感受到更大的有效核电量,也就会感受到更强的吸引力，使得原子变得更小。

麻省理工公开课 - 化学原理课程节选