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排序方式: 共有1422条查询结果,搜索用时 15 毫秒
921.
922.
南水北调中线工程与汉江中下游地区农业的持续发展 总被引:7,自引:4,他引:7
南水北调中线工程是指从汉江的丹江口水库引水供给华北地区,同时考虑鄂,豫两省汉江唐白河流域和淮河流域的需水要求的战略性工程,是调整水资源的空白布局,解决我国北方缺水问题的紧迫任务。汉江中下游地区是湖北省的粮仓和重要的产业基地,是汉江流域经济发展的中心。由于调水的影响,汉江丹江口以下的流量及季节性分配将发生变化,航运,水质,农业灌溉,工业生产以及城市发展等将受到不同程度的影响,直接关系到汉江中下游地区 相似文献
923.
Abstract Strategic environmental assessment (SEA) in China has developed rapidly since it was introduced into China in the 1990s. Chinese government promulgated the Environmental Impact Assessment Law of China (hereinafter referred to as the EIA Law) in 2002. In this law, it is stipulated clearly that regional and sector plans should be assessed. Through investigating materials and analyzing literatures, this article analyses the practical and academic study achievements of SEA in China that have been achieved since the EIA Law was implemented, probes into the current situation of the main level of SEA in China—plan EIA, then summarizes the development characteristics, and eventually, puts forward the development trends of SEA in China. The research conclusions can offer the foundations for comprehending systematically the progress of SEA in China. 相似文献
924.
925.
Ang Li Rui Cai Di Cui Tian Qiu Changlong Pang Jixian Yang Fang M Nanqi Ren 《环境科学学报(英文版)》2013,25(11):2281-2290
Carbamazepine is frequently detected in waters and hardly eliminated during conventional wastewater treatment processes due to its complicated chemical structure and resistance to biodegradation. A carbamazepine-degrading bacterium named CBZ-4 was isolated at a low temperature (10℃) from activated sludge in a municipal wastewater treatment plant. Strain CBZ-4, which can use carbamazepine as its sole source of carbon and energy, was identified as Pseudomonas sp. by the 16S rRNA gene sequence. The composition and percentage of fatty acids, which can reveal the cold-adaptation mechanism of strain CBZ-4, were determined. Strain CBZ-4 can effectively degrade carbamazepine at optimal conditions: pH 7.0, 10℃, 150 r/min rotation speed, and 13% inoculation volume. The average removal rate of carbamazepine was 46.6% after 144 hr of incubation. The biodegradation kinetics of carbamazepine by CBZ-4 was fitted via the Monod model. Vmax and Ks were found to be 0.0094 hr^-1 and 32.5 mg/L, respectively. 相似文献
926.
以中原城市群强市-新乡市为例,介绍城市环境噪声的声源构成主要以工业噪声和社会生活噪声为主。随着城镇化规模的扩大,近年来的噪声监测值总体呈下降趋势,但道路交通噪声和社会生活噪声有增高趋势。结合声环境质量现状,提出了合理规划功能区布局、加强声环境管理、利用城市绿地降低噪声、提高单体建筑规划设计水平等改善对策措施。 相似文献
927.
城市污泥毒性有机物对草履虫综合毒性研究 总被引:1,自引:0,他引:1
本文以好氧发酵处理前、后城市污泥中毒性有机物提取液为实验液,以草履虫为实验动物进行了综合毒性研究。结果表明:好氧发酵前的实验液对草履虫的半致死浓度为5593mg/l,发酵后的实验液对草履虫的半致死浓度为56053mg/l。 相似文献
928.
929.
Ximing Cai 《Journal of the American Water Resources Association》2005,41(3):679-692
ABSTRACT: This paper examines irrigation water supply deficit and associated risk indicators due to random climate events and potential effects on irrigated food production during the period 1996 to 2025 for seven river basins in the USA, China, and India. An integrated water and food model with global scope is applied for the analysis. The global climate regime during 1961 to 1990 is used to generate 30 climatic scenarios for the time period 1996 to 2025, and these scenarios are applied to the model in order to characterize the randomness of precipitation, runoff, and evapotranspiration, which affects both irrigation water supply and demand. The risk with random climate events is represented by reliability, variability, and vulnerability from different perspectives. Regarding irrigation water supply, Colorado will bear an increasingly unstable situation although the average water supply relative to the demand will maintain at a relatively high level; selected basins in China and India indicate that significantly lower levels of reliability and more deleterious affects from drought can be expected, but under a less variable condition due to assumed water storage increase. From 1996 to 2025, the effects of water deficits on irrigated food production are characterized with a nonlinear phenomenon and food production loss will be more sensitive to irrigation water supply deficit in the future. Future work following this paper needs to consider the impact of global climate change and the water quality of the irrigation return flow and result verification by local studies. 相似文献
930.
二氧化钛光催化降解处理染料废水 总被引:34,自引:1,他引:34
研究了TiO2的添加量,粒径大小,作用时间对3种染料废水脱色率的影响及TiO2薄膜对染料废水的处理效果。对于汽巴克染绿和直接大红染料溶液,适宜的TiO2添加量均为5g/L,紫外灯照射60min,其脱色率大于85%。对于阳离子红染料溶液,适宜的TiO2添加量为3g/L,其脱色率为83.5%。粒径小的TiO2作用效果优于粒径大的效果。在室温和适宜的TiO2添加量的条件下,随照射时间的延长,太阳光的光催化降解效果渐渐接近于紫外光的光催化降解效果。将TiO2薄膜固定在陶瓷睛上,有利于TiO2的重复使用。 相似文献