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151.
顶空气相色谱法测定土壤中的苯系物   总被引:8,自引:0,他引:8  
利用惠普顶空进样仪作为一种处理土壤样品的手段,自动把待测物送到气相色谱进行分析。研究顶空温度、气液比、平衡时间等条件对测定结果的影响。方法操作简便,灵敏度高。苯的变异系数为1.7%和4.1%,加标回收率为95%-105%,最小检出浓度为2.0μg/kg。  相似文献   
152.
Frequent monitoring and relatively high fines are usually necessary to bring about improvements in environmental quality, but more challenging for many countries with limited human, material, and financial resources is to put them into practice. This paper developed a three-group model of a state-dependent enforcement in a repeated game to improve the policy implementation under limited inspection capacities. A certain number of firms are grouped (group 1, group 2, group 3) for different supervision intensity (e.g., the order of inspection probability corresponding to each group is p 1?<?p 2?<?p 3) based on their environmental performance. The optimal policy parameters, such as inspection probability of each group and the probability that a firm found in compliance is moved to a better reputation group, were obtained as the basis for regulator’s policy making. Numerical simulations indicated that the three-group inspection regime can significantly increase compliance rate as compared with static enforcement with the same monitoring probability. Among the number of firms in each group under steady state conditions, group 2 had the most, group 1 was the second, and group 3 had the smallest. Analysis and prediction of a three-group reputation example provided a good experiment for the model. The results give a practical reference for the policy makers with inspection capacity constraints to achieve higher compliance rate.  相似文献   
153.
根据国内外研究报道,系统地总结了计算毒理学和化合物环境行为模拟在环境科学领域的研究进展,包括二者的概念、理论、研究方法以及在环境研究中的应用;分析了计算毒理学和化合物环境行为模拟在发展中所面临的挑战,并提出对策;展望了计算毒理学和化合物环境行为模拟在环境研究中的发展前景。  相似文献   
154.
建立DPX快速吸附萃取、程序升温(PTV)大体积进样与气相色谱/质谱(GC/MS)联用,SIM模式同时测定水中19种多溴联苯(PBBs)单体的方法。该方法在PBBs质量浓度1~50μg/L范围内线性良好,19种PBBs单体检出限为0.147~0.230μg/L,相对标准偏差为6.61%~10.5%,加标回收率为61.5%~82.6%。  相似文献   
155.
Pig manure (PM) is widely used as an organic fertilizer to increase yields of crops. Excessive application of compost containing relatively great concentrations of copper (Cu) and zinc (Zn) can change soil quality. To clarify the effects of different rates of application and to determine the optimal rate of fertilization, PM containing 1,115 mg Cu kg?1, dry mass (dm) and 1,497 mg Zn kg?1, dm was applied to alkaline soil at rates of 0, 11, 22, 44, 88, and 222 g PM kg?1, dm. Phospholipid fatty acids (PLFAs) were used to assess soil microbial community composition. Application of PM resulted in greater concentrations of total nitrogen (TN), NH4 +-N, NO3 ?-N, total carbon (TC), soil organic matter (SOM) but lesser pH values. Soils with application rates of 88–222 g PM kg?1, dm had concentrations of total and EDTA-extractable Cu and Zn significantly greater than those in soil without PM, and concentrations of T-Cu and T-Zn in these amended soils exceeded maximum limits set by standards in china. Except in the soil with a rate of 11 g PM kg?1, dm, total bacterial and fungal PLFAs were directly proportional to rate of application of PM. Biomasses of bacteria and fungi were significantly greater in soils with application rates of 44–222 g PM kg?1, dm than in the soil without PM. SOM, TC and EDTA-Zn had the most direct influence on soil microbial communities. To improve fertility of soils and maintain quality of soil, rate of application should be 22–44 g PM kg?1 dm, soil containing Cu and Zn.  相似文献   
156.
王佳  张瑛  徐鸣 《干旱环境监测》2010,24(4):222-225
以2005—2009年乌鲁木齐市城市大气降尘数据为依据,对乌鲁木齐市城市自然降尘的浓度水平和变化规律进行了研究,用Arc-GIS绘出乌鲁木齐市城市自然降尘的空间分布图,并分析和探讨了城市降尘与PM10相关性及防治对策。  相似文献   
157.
Low impact development best management practices (LID-BMPs) are considered to be cost-effective measures for mitigating the water quantity and quality impact of urban runoff. Currently, there are many types of LID-BMPs, and each type has its own intrinsic technical and/or economical characteristics and limitations for implementation. The selection of the most appropriate BMP type(s) for a specific installation site is therefore a very important planning step. In the present study, a multi-criteria selection index system (MCIS) for LID-BMP planning was developed. The selection indexes include 12 first-level indices and 26 second-level indices which reflect the specific installation site characteristics pertaining to site suitability, runoff control performance, and economics of implementation. A mechanism for ranking the BMPs was devised. First, each individual second-level index was assigned a numeric value that was based on site characteristics and information on LID-BMPs. The quantified indices were normalized and then integrated to obtain the score for each of the first-level index. The final evaluation scores of each LID-BMP were then calculated based on the scores for the first-level indices. Finally, the appropriate BMP types for a specific installation site were determined according to the rank of the final evaluation scores. In order to facilitate the application of the MCIS BMP ranking system, the computational process has been coded into a software program, BMPSELEC. A case study demonstrating the MCIS methodology, using an LID-BMP implementation planning at a college campus in Foshan, Guangdong Province, is presented.  相似文献   
158.
研究了环境空气中汞浓度的直接测定方法。利用金汞齐富集-便携式测汞仪对环境空气中的汞进行直接测定,具有简便、快捷、不使用化学试剂的优点。经测试,该方法在0~180 ng/m^3范围内具有良好的线性关系,最低检出浓度为5 ng/m^3。  相似文献   
159.
简述了污染源自动监测数据异常诊断系统的概念以及异常数据的来源,以及系统的工作原理和基本功能结构。提出了系统模拟专家分析过程的信息处理工作方式,以期实现污染源自动监测数据质量自动诊断与故障识别。  相似文献   
160.
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