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241.
介绍了液相色谱-质谱联用(LC-MS)技术中新型软电离技术大气压光电离法(APPI)的基本原理、鼻子源结构以及电离的影响因素,综述了LC-APPI-MS在环境污染物定性定量分析中的应用. 相似文献
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The ecological water conveyance project (EWCP) in the lower reaches of the Tarim River provided a valuable opportunity to study hydro-ecological processes of desert riparian vegetation. Ecological effects of the EWCP were assessed at large spatial and temporal scales based on 13 years of monitoring data. This study analyzed the trends in hydrological processes and the ecological effects of the EWCP. The EWCP resulted in increased groundwater storage—expressed as a general rise in the groundwater table—and improved soil moisture conditions. The change of water conditions also directly affected vegetative cover and the phenology of herbs, trees, and shrubs. Vegetative cover of herbs was most closely correlated to groundwater depth at the last year-end (R?=?0.81), and trees and shrubs were most closely correlated to annual average groundwater depth (R?=?0.79 and 0.66, respectively). The Normalized Difference Vegetation Index (NDVI) responded to groundwater depth on a 1-year time lag. Although the EWCP improved the NDVI, the study area is still sparsely vegetated. The main limitation of the EWCP is that it can only preserve the survival of existing vegetation, but it does not effectively promote the reproduction and regeneration of natural vegetation. 相似文献
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Brian L. Finlayson Jon Barnett Taoyuan Wei Michael Webber Maotian Li Mark Y. Wang Jing Chen Hao Xu Zhongyuan Chen 《Regional Environmental Change》2013,13(2):329-340
Big cities are often said to have big water problems, and Shanghai is no exception. In this paper, we examine and compare the influence of the major factors that give rise to the risk of water insecurity in Shanghai. There is an extensive and diverse literature on these issues, dealt with in isolation, and here, we provide a synthesis of the literature, together with our own assessments and calculations, to assess what are the risks to Shanghai’s water supply and what is our degree of confidence in this assessment. We describe the systems that supply water to the city, and past and future changes in the systems, including changes in the glaciers that supply some water to the river, changes in climate, changes in land use, the construction of dams, and water diversions. We show how, at the same time as Shanghai is increasing its dependence on the Yangtze river, water diversions and sea level rise are increasing the risk that this water will be too saline to consume at certain times of the year. This analysis suggests that most of the major drivers of the risk to water security in Shanghai are within the power of environmental managers to control. 相似文献
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运用计算流体动力学(CFD)方法,对具有超压防护功能的某化学事故应急救援手术方舱室内气体污染物运动扩散的规律以及对人员安全的影响进行了数值模拟,其研究结果表明:当大气环境中氢氰酸(HCN)浓度为5mg/L时,前10s从常规进风口进入舱室的HCN在滤毒通风装置开启后,随气流运动逐渐向整个舱室扩散,经净化空气的混合稀释作用,绝大部分通过舱体缝隙排出舱室,30min内舱室HCN浓度的总量下降了95.1%,说明超压防护很好地保证了舱室环境的安全性。 相似文献
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矿井通风网络解算可视化软件研究 总被引:1,自引:1,他引:1
采用面向对象编程语言Visual Basic6.0为开发工具,以Access为后台数据库,开发了具有风机优选功能的矿井通风网络解算软件。该软件承袭了Windows系统应用程序界面直观、交互性好的特点,集矿井通风网络解算、自然风压计算、风机自动选型以及经济断面优化等功能于一体,并辅以强大的数据管理系统,为矿山通风设计和管理工作提供了便利工具。 相似文献