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941.
Jin Y. Fan Jin J. Geng Hong Q. Ren Xiao R. Wang Chao Han 《Journal of environmental science and health. Part. B》2013,48(10):844-850
Roundup® is a glyphosate-based herbicide containing a mixture of surfactants. This paper evaluates the toxic effects of Roundup® and its main constituents on the goldfish, Carassius auratus, after 7 days exposure. Fish were exposed to 0.16, 0.032 and 0.0064 mg/L of Roundup® [containing 41% isopropylamine salt of glyphosate (G.I.S) and 18% polyoxyethylene amine (POEA)], G.I.S, and POEA. Their livers were taken for determining reactive oxygen species (ROS), superoxide dismutase (SOD) activity, malondialdehye (MDA) content and acetylcholinesterase (AChE) activity. Hydroxyl radical (·OH) could be induced by exposing Roundup® at a rate of 43%–111%, G.I.S at 90%–124% and POEA at142%–157%. A decreased SOD activity was observed in fish exposed to G.I.S and POEA. The contents of MDA significantly increased when exposed to Roundup® at all concentrations, 0.16 mg/L G.I.S and 0.032 mg/L POEA. The exposure led to an inhibition of AChE in livers overall during the experimental periods. POEA was more toxic than Roundup® or G.I.S during this experiment. AChE and ·OH are supposed to be sensitive biomarkers of the exposure of Roundup® and its main constituents to C. auratus. 相似文献
942.
安全文化是随着社会的繁荣、城乡的发展及科技进步,从工业文明、社会文化衍生而来。本文从国内外事故灾害频发的特点出发,探讨国内提出安全防灾文化建设的概念,并着重分析了拓展安全防灾文化建设的大思路。 相似文献
943.
地质灾害管理信息系统 总被引:7,自引:1,他引:6
在地质灾害普查、勘查、防治、社会经济状况、统计信息等资料的基础上,设计出为决策提供服务的地质灾害管理信息系统,以便对地质灾害进行科学管理 相似文献
944.
Yuliang Zhou Dong Zhang Ping Zhou Zhaoli Wang Pan Yang Juliang Jin Yi Cui Shaowei Ning 《Journal of the American Water Resources Association》2023,59(3):571-583
In univariate frequency analysis, the return period of an event has a one-to-one correspondence with its characteristic value, and the response of the hydraulic structure to hydrological load expressed by the hydrological event is monotonic. Thus, the design criteria of the hydraulic structure can be equivalently represented by the return period of the hydrological event, and consequently, design event-based design parameters evaluated have been widely used in practical engineering. However, the monotonic correspondence between the return period of the hydrological event and the response of the hydraulic structure does not exist in the multivariate context, and hydrological load with a larger joint return period does not always produce a more unsafe response. Misunderstandings of concepts of return periods of hydrological event, and estimation of hydrological design events usually take place in multivariate frequency analysis. This study theoretically derives the relations between different types of joint return periods, joint return period and its marginal return periods, the occurrence of bivariate extreme events and their return periods, and then the theoretical framework is tested. Results from the case contribute to the understanding of bivariate return periods of hydrological event, and the results demonstrate that design criteria cannot be equivalently represented by joint return periods of hydrological load, and design parameters of the hydraulic structure should not be determined by multivariate hydrological design events. 相似文献
945.
通过对代表性山区河流电厂的取水工程安全实例分析 ,根据取水方式不同 ,建议应采取的措施分为 :直接在天然河道上布置取水构筑物时 ,取水头部上下端加设三角形挡沙板 ,取水口上游设导沙丁坝 ,抬高取水头高程和进水底槛高程 ,并且可考虑设置两套取水系统 ,枯水期直接利用河道取水头取水 ,洪水期从移动式泵车取水 ;在河道上设置拦河低坝取水时 ,必须设置配套取水防沙设施 ,如排沙闸或冲沙闸 ,进水闸前设导沙坝 ,冲刷闸前设导沙坎 ,泄洪闸前设冲沙廊道和导流堤 ,还可在河道上设置潜水丁坝等。 相似文献
946.
光催化法降解有机废水的显著性研究 总被引:2,自引:1,他引:2
本文采用紫外光照射并加入催化剂的方法,对有机废水一阳离子艳红染料(5GN)进行了光催化降解的研究。从实际应用出发,实验得出了影响阳离子艳红染料降解的各因素的最佳取值及影响显著性次序。 相似文献
947.
Viruses from contaminant sources can be transported through porous media to drinking water wells. The objective of this study was to investigate inactivation and sorption of viruses during saturated and unsaturated transport in different soils. Bacteriophages phiX174 and MS-2, and Br- tracer in a phosphate-buffered saline solution were introduced into saturated and unsaturated soil columns as a step function under constant flow rate and hydraulic conditions. Results showed that significantly greater virus removal occurred in the unsaturated columns than in the saturated columns in the two soils containing high metal oxides content. However, the increase in virus retention under unsaturated conditions was not significant in two other soils having high phosphorus and calcium contents and high pH, and in another soil with high organic matter content. The results imply that the extent of water content effect on inactivation and sorption of viruses can range from significant to minimal depending on the properties of the transport medium. We found that the presence of in situ metal oxides was a significant factor responsible for virus sorption and inactivation. Therefore, soils with high metal oxides content may have the potential to be used as hydrological barriers in preventing microbial contamination in the subsurface environments. We also found that the water content effect on virus removal and inactivation strongly depended on solid properties of the testing medium. 相似文献
948.
949.
中国城市综合减灾体系建设及其系统思考 总被引:3,自引:0,他引:3
从中国城市减灾现状分析入手,重点剖析城市减灾的可持续发展问题,并探讨了城市社会经济可持续发展中如何确立防灾减灾的地位.进而用系统科学思路研究城市综合减灾的体系建设问题,从一定意义上较为科学地解决了跨世纪的中国城市可持续发展的关键问题. 相似文献
950.
推导了落尘的沉积模型,提出了落尘聚集体、落尘凝结体的概念。通过对落尘颗粒间四种主要内聚力以及气流浮力的量级分析,指出矿井条件下抑制落尘颗粒二次飞扬的前提是使尘粒得到充分的湿润,并进行了两种集合体的二次飞扬试验 相似文献