Tree VOC 疑似原文 求确认

mavis77

疑似原文，和jj描述很像
The chemical reactions taking place just above a northern Michigan forest hint that trees there and elsewhere may be emitting highly reactive gases that scientists haven't yet identified or directly detected.

Many plants release large quantities of volatile organic compounds (VOCs). Some of those substances destroy ground-level ozone, says William H. Brune of Pennsylvania State University in State College. In another type of reaction, VOCs combine with hydroxyl radicals and other atmospheric constituents to produce the aerosol particles in haze (SN: 12/7/02, p. 360).

In the Michigan experiments, which took place within equipment mounted on a tower about 10 meters above 20-m-high treetops, Brune and his colleagues found that the concentration of hydroxyl radicals added to air samples during the experiments dropped much faster than the team could account for by the measured concentrations of 42 known VOCs and other atmospheric gases.

Several lines of evidence suggest that the hydroxyl radicals disappeared when they reacted with unknown VOCs, the researchers suggest in the April 30 Science. For example, concentrations of hydroxyl added to air samples during tests dropped at the same rate, regardless of whether prevailing winds were bringing clean air from Canada or polluted air from urban areas. Therefore, the phantom VOCs probably hadn't been produped by human activity, says Brune.

Also, the air samples' effect on hydroxyl during the tests varied according to the prevailing temperature. Other scientists have found that atmospheric concentrations of known tree-emitted VOCs, such as isoprene and terpenes, vary similarly. Because the anomalous effects occurred both day and night, the phantom VOCs probably aren't related to isoprene, which is emitted by vegetation only during daylight hours.

So far, chemical analyses of air samples haven't turned up any candidates for the unidentified gases. "We're not sure what these compounds are, but they're definitely there," says Brune.

The new research is "beautiful confirmation" of the notion that trees emit more types of highly reactive VOCs than are generally acknowledged, says Allen H. Goldstein, an atmospheric chemist at the University of California, Berkeley. His previous studies of the amounts of ozone absorbed by trees in a California pine forest also suggest the presence of unidentified VOCs. He proposes that they're related to terpenes.

Brune and his colleagues' arguments are "reasonably compelling," agrees Roger Atkinson of the University of California, Riverside. The work gives scientists a new group of atmospheric chemicals to look for, he says. The new data suggest that atmospheric concentrations of the purported VOCs above forests are about 1 part in 2 billion.
[版本1] by qishi1218
九月二十四阅读机经
第 60 页 2011-10-4
tree 会释放VOC, 这篇生词比较多..不长, 2/3 屏..因为最后篇,看的有点赶
p1:说plant 会释放种东西叫VOC, 能吸收h..辐射还是射线神马 的, 是XX in haze(后面关于
haze 有个问题..但是lz 当时不知道haze 神马意思,就悲剧了= =+).但是现在有说, 貌似tree
还能释放某种东西,也是能吸收这个的..
p2:科学家们就做了个实验, 取了点空气,弄了那个h..辐射/射线神马的在里面,发现这个辐射
的下降速度比现已知道的要快.所以认为的确存在某种还不知道的东西也能吸收这个. 然后
出现了个高亮"the anomaly"说明 blabla....失忆了= =
题目:1. haze 那边一个题,说有个地方存在haz...(应该是haze 变形的一个词), 哪个措施来解
决这个问题是最无效的..选项不记得了= =
2. 高亮的"anomaly"的作用

V1 by bigeyes8600 720
就说树能 exhale 一种VOD 吧。。VO 什么反正。中间提到了VOD 和other 什么，blabla 的都
不太懂，对不起各位啊。然后还出来undefined VOD。后来说一个实验，把这个VOD 和other
chemical resource 放在树的top 那块，然后它就减少的特别快，就证明了有undefined VOD
的影响。后来又说其实啥那个实验的空气是从工业城市吹过来的还是从别的地吹过来不影响
VOD 的量。。

小情歌璇

顶！！

小情歌璇

楼主在给标题标注【考古】呗，这样大家方便看到~~

imfred

我昨天考到了，确实很像，但是考试的文章比这个更详细一些，而且最后两段昨天应该没有看到。还有就是我不确定那个anomalous是不是在那里。LZ好厉害

zhenglintp

nice！

coloryao

加注【考古】吧，容易被整理JJ的同学看到

jasmine0229

mark之

NOOOOOB

mark

小鱼你可以

谢谢分享