一级毛片免费不卡在线视频,国产日批视频免费在线观看,菠萝菠萝蜜在线视频免费视频,欧美日韩亚洲无线码在线观看,久久精品这里精品,国产成人综合手机在线播放,色噜噜狠狠狠综合曰曰曰,琪琪视频

Simulating the transfer and fate of

時(shí)間:2023-04-27 14:48:04 天文地理論文 我要投稿
  • 相關(guān)推薦

Simulating the transfer and fate of hexachlorocyclohexane in recent 50 years in Beijing, China

Taking Beijing as a study area, a dynamic fugacity model was used to simulate the transfer and fate of technical HCHs according to the physic-chemical properties of the studying environment and HCH isomers. Dynamic changes of the transfer fluxes and concentrations of HCH isomers during 1952―2003 were simulated and the model results suggest good agreement between the calculated and measured concentrations of HCH isomers. During 1952―1983, the average input and output amount of HCHs through agricultural application and degradation are 130 t and 150 t respectively. The dominant transfer processes of HCHs in the study area are air-soil deposition, soil erosion and soil-air diffusion, transfer fluxes of these processes are 80 t·a-1, 16 t·a-1 and 11 t·a-1, which account for 92% of total transfer fluxes of HCHs isomers. There were approximately 253t HCHs in all environmental compartments of the study area during this period and 97% of which existed in soil compartment. Air and water advection became the dominant input sources of HCHs after 1984 when the application of technical HCHs was prohibited, concentration of HCHs quickly descended to a quite low level in several years. Total amount of HCHs isomers remaining in the study area environment now is less than 5% that before 1983, and this percentage may descend to 0.5% after 20 years by prediction.

作 者: CAO Hongying LIANG Tao TAO Shu   作者單位: CAO Hongying,LIANG Tao(Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China)

TAO Shu(Laboratory for Earth Surface Processes, Peking University, Beijing 100871, China) 

刊 名: 中國科學(xué)D輯(英文版)  SCI 英文刊名: SCIENCE IN CHINA (EARTH SCIENCES)  年,卷(期): 2005 48(12)  分類號(hào): P5  關(guān)鍵詞: fugacity model   hexachlorocyclohexane   compartment   transfer flux   fate