日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

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: 国产精品美女www | 91亚洲国产成人精品一区二区三 | 久久伊人影视 | 亚洲国产日韩在线 | 日韩视频久久 | 青青草原亚洲 | 在线观看av的网站 | 三级中文字幕 | 日韩经典一区 | 国产哺乳奶水91在线播放 | 91视频a| 午夜精品91| 国产精品国产精品国产 | 在线观看免费黄色 | 337p粉嫩色噜噜噜大肥臀 | 狠狠爱夜夜 | 亚洲天堂久久久 | 超碰av在线 | 97国产在线视频 | 亚洲高清中文字幕 | 久久四虎| 日韩美在线 | 免费观看黄色网 | 欧美在线一级 | 尤物网站在线 | 欧美一级久久 | 免费观看av | 久久久亚洲天堂 | 欧洲一区二区在线 | 插吧插吧综合网 | 日日网站| 成年人午夜视频 | 日韩免费高清视频 | 超碰97在线免费观看 | 午夜看片福利 | 亚洲高清免费 | 一级免费片 | 成人午夜网 | 日韩精品久久久久久 | 综合国产在线 | 成人免费网站在线观看 |