首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   183篇
  免费   16篇
  国内免费   61篇
安全科学   7篇
废物处理   13篇
环保管理   11篇
综合类   119篇
基础理论   43篇
污染及防治   47篇
评价与监测   3篇
社会与环境   8篇
灾害及防治   9篇
  2024年   1篇
  2023年   2篇
  2022年   10篇
  2021年   5篇
  2020年   8篇
  2019年   13篇
  2018年   11篇
  2017年   11篇
  2016年   13篇
  2015年   10篇
  2014年   11篇
  2013年   17篇
  2012年   22篇
  2011年   26篇
  2010年   16篇
  2009年   4篇
  2008年   4篇
  2007年   10篇
  2006年   11篇
  2005年   6篇
  2004年   6篇
  2003年   4篇
  2002年   2篇
  2001年   3篇
  2000年   1篇
  1999年   3篇
  1998年   4篇
  1997年   3篇
  1996年   4篇
  1995年   3篇
  1994年   5篇
  1993年   6篇
  1992年   4篇
  1979年   1篇
排序方式: 共有260条查询结果,搜索用时 31 毫秒
121.
百菌清污染土壤生物修复研究进展   总被引:1,自引:0,他引:1  
针对百菌清具有在土壤中药效稳定、不易分解、代谢周期长、长期大量施加导致土壤严重污染等特点和问题,简要介绍了百菌清的毒性作用机制。总结了降解土壤中百菌清的物理法、化学法和生物法的原理及优缺点。重点阐述了生物修复百菌清污染土壤的主要降解菌株及其效果、降解途径以及降解产物及其毒性,分析了土壤性质、微生物种类、温度、土壤含水率等因素对百菌清降解效果的影响。指出今后的研究重点应为降解中间产物的毒性分析及其进一步的降解与转化问题,而复合菌制剂或多酶复合体系可实现百菌清的彻底降解和无害化。  相似文献   
122.
采用线-筒式脉冲电晕反应器对四氯乙烯去除效果进行了研究.结果表明,四氯乙烯去除率随电压的增大而增大.在氮气中加入氧气,四氯乙烯降解效果低于纯氮气下的降解效果.四氯乙烯在氮气下的主要气相产物为Cl_2和少量的CCl_4.当氧气加入后,四氯乙烯主要降解为CO_2、CO、COCl_2、O_3和C_2Cl_4O.为了去除有害中间产物,在反应器中加入Ca(OH)_2固体吸收剂,这明显提高了有害中间产物的去除,存在水汽及含Ca(OH)_2固体吸收剂时并未检测到COCl_2、O_3和有害中间产物C_2Cl_4O,但水汽不利于四氯乙烯去除.  相似文献   
123.
Changes in metal concentrations in the litter of Potamogeton crispus were monitored during a consecutive 40-day in situ decomposition experiment using the litterbag method.The accumulation index was calculated and used to indicate the changes in the metals in litter.The results showed that the concentrations of Al,Cd,Cr,Fe,Mn,and Pb in litter increased significantly during the decomposition,while Cu and Zn concentrations decreased dramatically.Significant positive correlations were found between the concentrations of Al,Cr,Fe,and Mn and between Cu and Zn.Moreover,Cu and Zn both negatively correlated with Al and Fe.The remaining dry mass was negatively correlated with Al and Fe concentrations but positively correlated with Cu and Zn concentrations.Generally the accumulation index values of metals other than Al were less than one,indicating that the litter of P.crispus acted as a source of metals to the surrounding water body.Al was the only metal that showed continuous net accumulation in litter.The net accumulation of Fe and Mn in litter during the last 10 days of the experiment may indicate the precipitation of Feand Mn-oxides.It was estimated that 160 g/m~2(dry weight)P.crispus was decomposed in40 days.This was equivalent to releasing the following amounts of metals:0.01 mg Cd,0.03 mg Cr,0.71 mg Cu,0.55 mg Mn,0.02 mg Pb and 13.8 mg Zn into surrounding water,and accumulating 149 mg Al and 11 mg Fe,in a 1 m~2 area.  相似文献   
124.
Environmental Science and Pollution Research - Hepatocellular carcinoma (HCC), a common type of human malignancies, leads to increasing incidence and fairly high mortality. An increasing number of...  相似文献   
125.
针对各省市冰箱报废量统计数据缺失问题,研究了趋势外推法和市场供给模型测算我国各省市冰箱报废量的可行性,预测了我国31个省市2011—2017年冰箱报废量,以及东、中、西部地区冰箱1999—2017年冰箱报废量。研究结果表明:各省市冰箱报废量预测结果误差小于10%;2011—2017年各省市冰箱报废量逐年上升;东部和中、西部地区分别于2011,2013年进入冰箱报废量直线增长阶段。  相似文献   
126.
长期以来,重大工业事故的不断发生促进了过程安全技术的发展与应用.如1974年英国的FLIXBOROUGH环己烷氧化过程的爆炸、1984年墨西哥LPG爆炸、1984年印度BHOPAL MIC泄漏事故、1988年SHELL NORCO炼油厂爆炸以及2005年BP德克萨斯州炼油厂火灾爆炸事故.  相似文献   
127.
Lucina pectinata is a large tropical Lucinidae which is characterized by abundant tissue hemoglobin in its deep-red gills. In the present paper, hemoglobin is described as being located in cytoplasmic dark patches of the bacteriocytes together with a cystine-rich protein. Large microbodies contain a non-hemoglobin heme-compound which is identified with a previously described non-protein-bound hematin; however, it has not been established whether this heme is involved in a sulphur-oxidizing system or represents a catabolic by-product of hemoglobin. Electron-lucent vesicles are associated with the basal microbodies but their function is, so far, unknown. In addition, the bacteriocytes have been observed to have direct contact with sea water, modulated by large intercalary cells which overlap the bacteriocytes on their margin. Such relationships between bacteriocytes and intercalary cells, as well as their cytological features, are different from those observed in lucinid species inhabiting sea-grass beds, but very similar to those observed in Calyptogena magnifica. From the congruence between the shallow-water Lucinidae L. pectinata, inhabiting mangrove swamps, and the deep-sea Vesicomyidae C. magnifica, found at hydrothermal vents, we conclude that such features are likely to be adaptative to high-sulphide environments, notwithstanding the phylogenetic distance.  相似文献   
128.
洱海表层沉积物中磷形态分布及pH、DO影响的分析   总被引:1,自引:0,他引:1  
研究了洱海代表性区域表层沉积物中总磷分布及不同形态磷赋存特征,探讨了pH值及溶解氧对沉积物中总磷和各形态磷赋存状态的影响。结果表明洱海表层沉积物中总磷和不同形态磷分布不均,总磷含量湖心高于湖口,湖心区域闭蓄态磷(BD-P和Al-P)和生物有效态磷占总磷的比例较高,更容易受pH和DO的影响,碱性和厌氧条件会增加洱海湖心底泥中磷的潜在释放能力。  相似文献   
129.
The development of everthing follows its own law, which does not change at people’s own sweet will. Therefore, we must study the development of things so as to grasp the essence of things in their deep meanings, explore the direction of their de- velopment, and make them better serve the people. As a part of the thought of sustainable development, city environment art will be of active significance to the perfection of the thought and will also be the concrete embodiment of the synthetic index of economic development. Such a thesis, starting from the macroscopic angle, and relying on the leading thought of sustainable development, takes hold of the development trend of city environment art, and explores the various problems that have arisen in city environment in the process of city management by combining thoughts on city planning, so as to guide urban harmonious development theoretically. The present paper expounds on the views comprehensively and, through the synthetic analysis on city planning, city environment, art esthetics and the thought of sustainable development, makes a detailed analysis of the effects of the present rapid city development on city environment.  相似文献   
130.
介绍了5家国外大型石油化工企业环境管理的特点和先进性,分析了其环境指标体系的构成,对国内企业的环境指标体系建设具有参考和借鉴意义。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号