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481.
地震灾害综合应急能力评估研究 总被引:5,自引:1,他引:4
汶川大地震在给我国带来巨大的悲痛和损失的同时,也检验了我国政府的突发事件应急能力。此次抗震救灾凸显出我国地震灾害应急能力存在的一些不足。建立“突发事件综合应急能力评估指标体系”的目的是为了评估政府的突发事件应急能力,以评促建。地震灾害由于其不同于其它突发事件的特性,其应急管理也有其特定的内容。现以地震灾害特征为标准,选取13个省市为样本,套用已有评估指标体系,分析和评估我国地震灾害应急能力。研究认为,我国应加强地震灾害应急能力建设,同时认为已有评估指标体系能满足使用要求。 相似文献
482.
Aerobic degradation of methyl tert-butyl ether by a Proteobacteria strain in a closed culture system 总被引:4,自引:0,他引:4
The contamination of methyl ten-butyl ether (MTBE) in underground waters has become a widely concerned problem all over the world. In this study, a novel dosed culture system with oxygen supplied by H2O2 was introduced for MTBE aerobic biodegradation. After 7 d, almost all MTBE was degraded by a pure culture, a member of β-Proteobacteria named as PMI, in a closed system with oxygen supply, while only 40% MTBE was degraded in one without oxygen supply. Dissolved oxygen (DO) levels of the broth in closed systems respectively with and without H2O2 were about 5-6 and 4 mg/L. Higher DO may improve the activity of monooxygemase, which is the key enzyme of metabolic pathway from MTBE to tert-butyl alcohol and finally to CO2, and may result in the increase of the degrading activity of PM1 cell. The purge and trap GC-MS result of the broth in closed systems showed that tea-butyl alcohol, isopronol and acetone were the main intermediate products. 相似文献
483.
WU Yu-qiong WANG Chong-gang WANG Yun ZHAO Yang CHEN Yi-xin ZUO Zheng-hong 《环境科学学报(英文版)》2007,19(9):1129-1135
It has been reported that there is an interaction between Benzo[a]pyrene (BaP), a widespread carcinogenic polycyclic aromatic hydrocarbon, and tributyltin (TBT), an organometal used as an antifouling biocide. This study was therefore designed to examine the potential in vivo influence of BaP, TBT and their mixture on splenic antioxidant defense systems of Sebastiscus marmoratus. The fish were exposed to water containing environmentally relevant concentrations of BaP, TBT and their mixture. Spleens were collected for biochemical analysis after exposure for 7, 25, 50 d and after recovery for 7, 20 d. Cotreatment with BaP and TBT for 7 d potentiated the induction of glutathione peroxidase (GPx) activity by BaP or TBT alone. The cotreatment for 25 and 50 d resulted in inhibition of GPx activity, which was similar to the effect of TBT. Splenic glutathione S-transferase (GST) activities were significantly elevated in S. marmoratus exposed to BaP starting from 7 d and remained high up to 25 d. However, no further activity change was found with prolonged exposure. Cotreatment of BaP and TBT primarily inhibited the GST activity, which was similar to the effect of TBT. Cotreatment with BaP and TBT for 25 or 50 d potentiated the depletion of GSH (glutathione) by BaP or TBT alone. MDA (malondialdehyde) contents in spleen of S. marmoratus were not significantly altered compared with the control during the test period. Spleen, as an immune organ, is sensitive to exposure of BaP or TBT. It should have an effective mechanism to counteract oxidative damage. Antioxidative defense systems in spleen of S. marmoratus should be considered as potential biomarkers. Short-term exposure of BaP or TBT could result in induction of antioxidant defense system. A significant decrease of these indices, such as GSH, GST, GPx might indicate more severe contamination. 相似文献
484.
Thermodynamics and kinetics of cadmium adsorption onto
oxidized granular activated carbon 总被引:3,自引:0,他引:3
Cadmium sorption behavior of granular activated carbon oxidized with nitric acid was systematically studied by sets of the equilibrium and time-based experiments under various conditions.The cadmium adsorption capacity of oxidized granular activated carbon enlarged with an increase in pH,and reduced with an increase in ionic strength.Experimental data were evaluated to find out kinetic characteristics.Adsorption processes were found to follow pseudo-second order rate equation.Adsorption isotherms correlate well with the Langmuir isotherm model and the maximum sorption capacity of cadmium evaluated is 51.02μmol/g.Thermodynamic parameters were calculated based on Van't Hoff equation.Equilibrium constant Kd was evaluated from Freundlich isotherm model constants,Langmnir isotherm model constants,and isotherms,respectively.The average change of standard adsorption heatΔH~0 was -25.29 kJ/mol.NegativeΔH~0 andΔG~0 values indicate the adsorption process for cadmium onto the studied activated carbon is exothermic and spontaneous.The standard entropyΔS~0 was also negative,which suggests a decrease in the freedom of the system. 相似文献
485.
Anaerobic tapered fluidized bed reactor for starch wastewater treatment and
modeling using multilayer perceptron neural network 总被引:1,自引:0,他引:1
Anaerobic treatability of synthetic sago wastewater was investigated in a laboratory anaerobic tapered fluidized bed reactor(ATFBR) with a mesoporous granular activated carbon(GAC)as a support material.The experimental protocol was defined to examine the effect of the maximum organic loading rate(OLR),hydraulic retention time(HRT),the efficiency of the reactor and to report on its steady- state performance.The reactor was subjected to a steady-state operation over a range of OLR up to 85.44 kg COD/(m~3.d).The COD removal efficiency was found to be 92% in the reactor while the biogas produced in the digester reached 25.38 m~3/(m~3·d) of the reactor. With the increase of OLR from 83.7 kg COD/(m~3.d),the COD removal efficiency decreased.Also an artificial neural network(ANN) model using multilayer perceptron(MLP)has been developed for a system of two input variable and five output dependent variables. For the training of the input-output data,the experimental values obtained have been used.The output parameters predicted have been found to be much closer to the corresponding experimental ones and the model was validated for 30% of the untrained data.The mean square error(MSE)was found to be only 0.0146. 相似文献
486.
环境经济系统整合模型的研究将环境的、经济的、社会的因素整合在可持续发展框架中.模拟、分析经济系统与环境系统之闻的相互作用和反馈关系。本文在分析环境经济系统整合模型构建的背景、理论与方法的基础上.设计了环境经济系统整合模型开发的技术路线.提出了环境经济系统整合模型的主要内容。 相似文献
487.
三峡库区坡耕地利用与水土保持种植制 总被引:15,自引:3,他引:15
三峡库区耕地资源十分有限,且坡耕地占有相当大的比重,陡坡地多,在不良的耕作方式下肥力低下,水土流失十分严重在分析三峡库区自然条件与坡耕地资源特点的基础上,讨论了坡耕地种植制度与土壤侵蚀的关系,提出通过合理搭配作物种类进行多熟制间套作,一年生农作物与多年生经饲作物间作及农作物与木本植物等高间作等手段来建立坡耕地水土保持种植制,从而达到减轻土 蚀之目的。 相似文献
488.
随着上海经济的快速发展,一些大型海洋工程在上海海域纷纷兴建,造成了生境破碎化、生物多样性的破坏等一系列的生态损害。在分析海洋工程可能造成生态损害的同时,以上海长江口隧桥工程为例,选择2007年春季和秋季的2次生态调查数据进行研究。架桥阶段结束后,综合分析了春季与秋季的调查数据,发现各项指标均有偏向于不利的趋势。基于结构功能指标体系评价法,并利用层次分析法研究后得出上海长江口隧桥工程附近海域的综合健康指数分别为2043和2166。根据CHI≤3的情况下判断,该海域的生态健康状况属于不健康接近亚健康状态,表明河口生态系统自然属性发生明显改变,生物多样性及生态系统结构发生了一定程度的变化,主要生态服务功能出现退化或丧失。针对遭遇海洋工程破坏的生境,需要进行更多、更长时间的人工干预,并提出有效的生态保护和修复对策。 相似文献
489.
饮用水安全是最大的民生工程,也是自然资源管理研究的热点。基于实地调研、部门访谈和制度条文的梳理与分析,以苏州市太湖水源地为例研究湖泊型水源地管理体制。研究表明:我国水源地管理由国家、省、市、县的法律法规、规章和规范性文件构成相对完善的制度体系,具有水资源和水环境分割管理、流域管理和行政区管理交错的制度特征,初步具备了综合管理的架构;水源保护缺乏流域管治的思维,农村面源污染治理制度支撑不足;在管理手段上以命令控制型手段为主,经济激励与公众参与不足。建立水源地综合管理协调机制,完善经济激励手段,推进公众参与,实施水源地管理共同责任机制将有利于提高水源地管理效率 相似文献
490.
河流综合水质评价方法比较研究 总被引:42,自引:0,他引:42
为探讨综合水质评价结论的科学合理性,对典型的7种河流综合水质评价方法,包括单因子评价法、污染指数法、模糊评价法、灰色系统评价法、层次分析法、人工神经网络法、水质标识指数法,在归类分析其特性的基础上,针对代表性的评价样本,进行了综合水质评价比较研究。主要结论为:①单因子评价法以最差水质指标所属类别作为综合水质类别,评价结论表现为过保护;②污染指数法能够直观判断综合水质是否达到功能区目标,但是不能判断综合水质类别;③对模糊数学法、灰色系统评价法、层次分析法、BP人工神经网络法和水质标识指数法等5种典型评价方法,当综合水质为Ⅰ~Ⅴ类水情形时,这几种方法评价结论基本一致,证明这5种典型评价方法对Ⅰ~Ⅴ类水的评价结论具有科学合理性;④当综合水质为劣Ⅴ类水时,模糊数学法、灰色系统评价法、层次分析法、BP人工神经网络法的评价结论偏保守,而水质标识指数法解决了劣Ⅴ类水质的连续性描述问题,能够对劣Ⅴ类水进行科学合理评价,并对Ⅰ~Ⅴ类水、劣Ⅴ类水不黑臭、劣Ⅴ类水黑臭进行全面、科学合理的定性与定量评价. 相似文献