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691.
To analysze the dynamic degradation and final residues of acephate and its metabolite methamidophos, field-experiments with pakchoi (Brassica campestris L.) in open field and greenhouse were carried out in Beijing, China in 2004 and 2005. The degradation dynamics and final residues were determined by gas chromatography (GC) equipped with a pulsed flame photometric detector and GC coupled to mass spectrometry (MS)/MS after acephate was applied on open field and green house pakchoi (B. campestris L.). The dynamic degradation results showed that the half-lives of acephate and methamidophos in open field pakchoi were 1.36 days with dynamic degradation equation C t ?=?133.01e???0.5107t , and 2.86 days with C t ?=?6.5753e???0.2422t , respectively. While the half-lives of acephate and methamidophos in the greenhouse were 1.07 days with C t ?=?59.134e???0.4353t and 0.79 days with C t ?=?0.2703e???0.2595t , respectively. The final residue analysis demonstrated that >50% of total methamidophos were resulted from the degradation of acephate 7 and 18 days after it was applied on the greenhouse pakchoi, respectively. While in the open-field pakchoi, >90% of total methamidophos was found to be the metabolite of acephate.  相似文献   
692.
To understand electromagnetic radiation field strength and its influencing factors of certain 110-kV high-voltage lines in one urban area of Chongqing by measuring 110-kV high-voltage line’s electromagnetic radiation level. According to the methodology as determined by the National Hygienic Standards, we selected certain adjacent residential buildings, high-voltage lines along a specific street and selected different distances around its vertical projection point as monitoring points. The levels of electromagnetic radiations were measured respectively. In this investigation within the frequency of 5–1,000 Hz both the electric field strength and magnetic field strength of each monitoring sites were lower than the public exposure standards as determined by the International Commission on Non-Ionizing Radiation Protection. However, the electrical field strength on the roof adjacent to the high-voltage lines was significantly higher than that as measured on the other floors in the same buildings (p < 0.05). The electromagnetic radiation measurements of different monitoring points, under the same high-voltage lines, showed the location which is nearer the high-voltage line maintain a consistently higher level of radiation than the more distant locations (p < 0.05). Electromagnetic radiation generated by high-voltage lines decreases proportionally to the distance from the lines. The buildings can to some extent shield (or absorb) the electric fields generated by high-voltage lines nearby. The electromagnetic radiation intensity near high-voltage lines may be mitigated or intensified by the manner in which the high-voltage lines are set up, and it merits attention for the potential impact on human health.  相似文献   
693.
长江河源区大气环境考察报告   总被引:1,自引:0,他引:1  
1997年7、8月间,中华环保基金会组织“97’长江河源生态考察”活动,考察活动覆盖了长江河源区广大地区,取得圆满成功。将实地考察所获得的第一手数据汇总,对大气主要污染物,如TSP、SO2、NOx、CO和O2在源区大气中的分布作了一定探讨,对今后大气环境发展趋势作了初步的分析,并提出了相关建议  相似文献   
694.
In the last 10 yr, Beijing has made a great effort to improve its air quality. However, it is still suffering from regional coarse particulate matter (PM10) pollution that could be a challenge to the promise of clean air during the 2008 Olympics. To provide scientific guidance on regional air pollution control, the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality Model (CMAQ) air quality modeling system was used to investigate the contributions of emission sources outside the Beijing area to pollution levels in Beijing. The contributions to the PM10 concentrations in Beijing were assessed for the following sources: power plants, industry, domestic sources, transportation, agriculture, and biomass open burning. In January, it is estimated that on average 22% of the PM10 concentrations can be attributed to outside sources, of which domestic and industrial sources contributed 37 and 31%, respectively. In August, as much as 40% of the PM10 concentrations came from regional sources, of which approximately 41% came from industry and 31% from power plants. However, the synchronous analysis of the hourly concentrations, regional contributions, and wind vectors indicates that in the heaviest pollution periods the local emission sources play a more important role. The implications are that long-term control strategies should be based on regional-scale collaborations, and that emission abatement of local sources may be more effective in lowering the PM10 concentration levels on the heavy pollution days. Better air quality can be attained during the Olympics by placing effective emission controls on the local sources in Beijing and by controlling emissions from industry and power plants in the surrounding regions.  相似文献   
695.
樊星  樊迎春  李炜  符茂飞 《灾害学》2008,23(1):108-112
以地震安全图实时制作与动态查询公共系统开发的必要性与可行性为例,阐述了社会对“自然灾害与安全信息民用产品”的需求,以及它对提高减灾实效、推动灾害与信息科学发展水平的作用。同时介绍了海口市地震安全图实时制作与动态查询公共系统的功能、制作方法和社会用户群体的分析。  相似文献   
696.
苏筠  伍国凤  朱莉  周夏  付丽佳 《灾害学》2008,23(2):19-23
研究公众自然灾害知觉中的不安全因素,有助于开展有针对性的减灾宣教活动、构建社会预防文化。通过问卷方式,调查了北京5所高校大学生的自然灾害知觉现状及特征。统计分析显示,大学生自然灾害知觉中存在不安全心理特性,主要表现在:对自身灾害知识和经验存在过高估计的乐观偏差;在灾害预期中表现出悲观的心理噪声效应;面对自然灾害多数出现消极情绪,其应急行为倾向呈负距平状态;防灾减灾过程中对政府行为依赖性、服从性高。在此基础上,提出了通过普及正确防灾知识、完善心理防御机制、强化能动意识等重塑大学生灾害知觉、调适灾害行为的建议。  相似文献   
697.
强磁粉协同作用预处理垃圾渗滤液   总被引:1,自引:0,他引:1  
研究了强磁粉(Fe3O4)与无机混凝剂Al2(SO4)3在垃圾渗滤液处理中的协同作用。结果表明:Fe3O4与Al2(SO4)3复合使用混凝效果优于单纯使用Al2(SO4)3的混凝效果。当Al2(SO4)32.0g/L,磁粉(Fe3O4)1.6g/L,搅拌强度150r/min,pH值3.0,沉降时间5min时,可使渗滤液的COD去除率达70%,混凝时的胶粒沉降速率明显加快。  相似文献   
698.
This article examines the sustainability of the Grain for Green Project in the Wolong Nature Reserve. Pertinent data were collected through a questionnaire survey and a spatial analysis of reforested lands. The study results identified four critical issues that may influence the sustainability of the project in the study area. The first issue is concerned with the project’s impacts on local sustenance. Because local grain consumption depends greatly on compensation awarded by the project, the potential for sustainability of the project is compromised. The second issue is that the project causes negative effects on local incomes in the Wolong Nature Reserve, which may undermine local economic prospects. The third issue is that the project failed to deliver suitable habitat for the giant panda, although two of the suitability requirements that deal with landform features were met. Lastly, the project neglects great differences among geographical areas in the country, providing the same compensation and length of compensation period to all participants. Appropriate compensation mechanisms should be established and adapted to local economic, environmental, and social conditions. In managing nature reserves and moving toward sustainability, ensuring all aspects of local socioeconomic and ecological/environmental issues are properly addressed is a real challenge. Based on our study, some recommendations for improving sustainability of the project are given.  相似文献   
699.
高浓度酚降解菌的选育及其降酚性能   总被引:13,自引:0,他引:13  
吕荣湖  付强 《环境科学》2005,26(5):147-147-151
以苯酚为唯一碳源,对活性污泥进行筛选及驯化,得到能降解高酚浓度的优势降酚菌.该混合菌在15h内将1700mg/L浓度的酚完全降解,同时使COD降至102.9mg/L,降解率达到96.9%.经分离纯化,得到4种不同的单一菌株,并对各菌株的菌属进行了初步鉴定.同时,还考察了初始酚浓度、菌投加量、温度、pH等因素对降酚菌降解COD和酚的影响.混合菌的降酚效果要优于所分离出的4种单菌株.  相似文献   
700.
典型电子垃圾拆解区大气中多溴联苯醚的污染   总被引:3,自引:4,他引:3  
分别在典型电子垃圾拆解区(E)和其上风向参考点(S)采集了大气颗粒相和气相样品.以研究该区域大气中PBDEs的浓度水平、污染特征和气/固分布特点.分析过程中运用气相色谱.质谱联用仪,负化学离子源(GC-NCI-MS)检测了11种PBDEs结果表明,电子垃圾拆解造成r比较严蘑的PBDEs污染,三溴-十溴联苯醚的浓度范围为51.1~2 685 pg.m-3,(平均值830Pg.m-3),而对照区由于制衣行业的影响也造成了一定程度的PBDEs污染,三溴~十溴联苯醚的浓度范围为1.00-98.9Pg.m-3(平均值28.7 Pg.m-3).在气/固分布的研究中发现,不同的PBDEs在气相和颗粒相的分布比例相差很大,从低溴至高溴PBDEs在气相中的比例呈降低趋势,而在颗粒相中的比例呈上升趋势.电子垃圾拆解区以五溴.联苯醚污染为主,占∑11PBDEs总量的54.3%;而十溴-联苯醚污染次之,占∑11PBDEs总最的23.8%,该污染特征进一步证实了该地区电子垃圾的来源,不仅来自亚洲国家,而且还来自欧美等国家.  相似文献   
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