久久亚洲国产成人影院-久久亚洲国产的中文-久久亚洲国产高清-久久亚洲国产精品-亚洲图片偷拍自拍-亚洲图色视频

US EUROPE AFRICA ASIA 中文
Business / Green China

Beijing-area air better than before

By Cheng Yingqi (China Daily) Updated: 2014-03-03 03:54

The pollution that hit Hebei province, Beijing and Tianjin in the past week was less severe than last year's incident, monitoring results revealed.

From Feb 20 to 26, Beijing, Tianjin and Hebei were shrouded in smog.

However, environment-monitoring results of the Chinese Academy of Sciences showed that the average concentration of PM2.5 — fine particulate matter with a diameter less than 2.5 microns that can lodge in the lungs — was 11 percent less than it was when smog hit the region in spring 2013, and the peak concentration decreased by 16.4 percent.

"The concentration of pollutants in the smog decreased by 20 to 30 percent in general over the last year," said Wang Yuesi, a researcher from the Institute of Atmospheric Physics under the Chinese Academy of Sciences.

Wang was speaking on Saturday at a forum in Beijing held by the Chinese Academy of Sciences, which discussed the cause of the smog.

The institute monitored the concentration of PM2.5 and other pollutants across the country, with 23 monitoring stations in North China. The comparison was based on data collected in January and February this year and January 2013, when severe pollution lasted nearly a month in North China.

Both of these smog events had similar climatic conditions, Wang said.

"The monitoring results show that the emergency measures taken to cope with air pollution were effective. But the effect may not be so obvious to the general public because the PM2.5 concentration still caused a deterioration in visibility," he said.

Visibility in the smog was 2 kilometers, while Wang said the visibility will not be improved unless the PM2.5 concentration falls to less than 100 micrograms per cubic meter. In February, it was 230 mg per cubic meter.

Beijing's contingency plan includes forcing nearby plants to cut their production.

However, Wang said that only long-term solutions will end the pollution.

"The major PM2.5 source comes from coal power stations," he said. "The overall area of Beijing, Tianjin and Hebei accounts for some 0.05 percent of the world, while this region consumes 11 percent of its coal, so you don't have to use your imagination to understand why we are suffering from air pollution. We are living inside a huge chimney."

He Hong, a researcher at the Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, said: "Our research shows that 'second particles' contribute around 60 percent to the formation of PM2.5 in Beijing and Tianjin."

Second particles are pollutants generated by chemical reactions between different pollutants released into the atmosphere.

"As a result, reducing the emissions of oxynitride and oxysulfide from coal fuel and vehicles is necessary," He said.

However, due to the complex chemical reactions, scientists are not sure about the exact contributing factors of smog. To understand better, the Chinese Academy of Sciences will apply for construction in 2016 of a "smog chamber" to simulate pollution conditions.

Hot Topics

Editor's Picks
...
主站蜘蛛池模板: 日韩在线 | 中文 | 久久在线免费观看视频 | 亚洲美女视频网 | 欧美亚洲国产激情一区二区 | 99在线视频精品费观看视 | 国产女人成人精品视频 | 大片国产片日本观看免费视频 | 欧美理论大片清免费观看 | 亚洲欧美日韩在线一区 | 日本成人在线看 | 欧美日韩精品免费一区二区三区 | 国产成人女人视频在线观看 | 男女扒开双腿猛进入爽爽视频 | 香蕉依依精品视频在线播放 | 暖暖视频日韩欧美在线观看 | 日本特黄特色 | 五月天激激婷婷大综合蜜芽 | 国产日产欧产精品精品推荐在线 | 91久久精品一区二区三区 | 日本一级做人免费视频 | 亚洲天堂区| 欧美一区二区在线 | 真人一级毛片免费完整视 | 亚洲国产一区二区三区综合片 | 午夜成人免费影院 | 欧洲亚洲一区二区三区 | 精品视频一区二区三区 | 女人十八一级毛片 | 一本色道久久综合 | 日韩黄色一级毛片 | 一本本久综合久久爱 | 亚洲国产精品久久卡一 | 亚洲高清免费在线观看 | 伊人久热这里只有精品视频99 | 国产色视频在线观看免费 | 日韩欧美高清在线 | 欧美日韩一区二区综合 | 国产成人麻豆精品 | 在线高清一级欧美精品 | 国产成人aa在线视频 | 一级毛片在线不卡直接观看 |