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791.
The United States Department of Energy is developing the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico for the disposal of transuranic wastes generated by defense programs. Because changes in climate during the next 10,000 years (10 ka) may affect performance of the repository, an understanding of long-term climate variability is essential for evaluating regulatory compliance. Fluctuations in global climate corresponding to glaciation and deglaciation of the northern hemisphere have been regular in both frequency and amplitude for at least 780 ka. Coolest and wettest conditions in the past have occurred at the WIPP during glacial maxima, when the North American ice sheet reached its southern limit roughly 1200 km north of the WIPP and deflected the jet stream southward. Average precipitation in southeastern New Mexico during the last glacial maximum 22-18 ka before present (BP) was approximately twice that of the present. Driest conditions (precipitation approximately 90% of present) occurred 6.5-4.5 ka BP, after the ice sheet had retreated to its present location. Wet periods of unknown duration have occurred since the retreat of the ice sheet, but none have exceeded glacial conditions. Global climate models suggest that anthropogenic climate changes (i.e., warming caused by an increased greenhouse effect) will not result in an increase in precipitation at the WIPP. The climate of the last glacial maximum is therefore suitable for use as a cooler and wetter limit for variability during the next 10 ka.  相似文献   
792.
ABSTRACT: Water quality in the Brazos River of Texas is seriously degraded by natural salt pollution. Two thousand tons/day of total dissolved solids emanate from brine springs and seeps in the Upper Brazos River drainage. Approximately 45 percent of the total salt load comes from a relatively small flow in the Dove Creek area. The companion paper demonstrates that a system of wells pumping brine at a constant rate of about 2 cfs from the near surface aquifer should eliminate the brine springs in this area. In this paper, injection into deep brine aquifers is shown to be a feasible brine disposal alternative. Four brine aquifers were determined from the literature to be possible injection zones. Accurate net aquifer thickness maps were generated in a 23 by 14 mile area centered on the Dove Creek area for three of the aquifers from an interpretation of 41 well logs. Constant injection for a project life of 100 years was simulated using the SWIFT/486 software. Modeling suggests that one well would be sufficient to inject the entire disposal volume into either the Strawn or Ellenburger Formation.  相似文献   
793.
Goal, Scope and Background Sewage sludge produced in wastewater treatment contains large amounts of organic matter and nutrients and could, therefore, be suitable as fertiliser. However, with the sludge, besides heavy metals and pathogenic bacteria, a variety of organic contaminants can be added to agricultural fields. Whether the organic contaminants from the sludge can have adverse effects on human health and wildlife if these compounds enter the food chain or groundwater still remains a point of controversial discussion. Main Features This paper presents an overview on the present situation in Europe and a summary of some recent results on the possible uptake of organic contaminants by crops after addition to agricultural fields by sewage sludge. Results Greenhouse experiments and field trials were performed to study the degradation and uptake of organic micro-contaminants in sludge-amended agricultural soil in crops, such as barley and carrots grown in agricultural soil amended with anaerobically-treated sewage sludge from a wastewater treatment plant, but studies hitherto have revealed no immediate risks. Common sludge contaminants such as linear alkylbenzene sulphonates (LAS), nonylphenol ethoxylates (NPE), polycyclic aromatic hydrocarbons (PAH), bis(diethylhexyl) phthalate (DEHP), showed neither accumulation in soil nor uptake in plants. Discussion It is assumed that the annual amount of sewage sludge produced in Europe will increase in the future, mainly due to larger amounts of high quality drinking water needed by an increasing population and due to increasing demands for cleaner sewage water. Application of sewage sludge to agricultural soils is sustainable and economical due to nutrient cycling and disposal of sewage sludge. However, this solution also involves risks with respect to the occurrence of organic contaminants and other potentially harmful contents such as pathogens and heavy metals present in the sludge. There have been concerns that organic contaminants may accumulate in the soil, be taken up by plants and thereby transferred to humans via the food chain. Results obtained so far revealed, however, no immediate risk of accumulation of common organic sludge contaminants in soil or uptake in plants when applying sewage sludge to agricultural soil. With very high dosages of sewage sludge, there may be a risk for accumulation of very apolar contaminants, such as DEHP, to the soil. Conclusions Any conclusions on the safe use of sewage sludge in agriculture have to be drawn carefully, as the studies performed until now have been limited. Further studies are required, and before final statements can be drawn, it is imminent to study a larger variety of common crops and the effect sewage sludge application may have on a possible accumulation of organic contaminants in the crops. Furthermore, a larger variety of organic contaminants need to be studied and special focus should be given to contaminants newly introduced into the environment. Besides investigating possible plant uptake of organic contaminants, the fate of these compounds in soil after sludge application need to be monitored too. Here, special attention has to begiven to studies on degradation and the formation of degradation products, to weathering and to leaching effects on groundwater, to the application of different crops on the same field (crop rotation), to the use of full-width tillage and strip tillage, and to long term application of sewage sludge on the soil. Recommendations and Perspectives There are environmental, political as well as economical incentives to increase the agricultural application of sludge. However, such usage should be performed with care as there are also ways in which sludge fertilisation could harm the environment and human health. Recently, a new European COST Action (859) has been established covering the field of food safety and improved food quality. Part of the Action is dealing with the application of sewage sludge in agriculture. Before any political and economical measures can be taken, the pros and cons have to be sufficiently investigated on a scientific level first. ESS-Submission Editor: Prof. Elena Maestri (elena.maestri@unipr.it)  相似文献   
794.
某极低放废物处理场地下水中Sr迁移形式热力学分析   总被引:3,自引:0,他引:3  
将化学热力学平衡分析模式与地球化学条件相结合,形成Sr元素水文地球化学迁移形式热力学分析方法体系.计算出某特定场址地下水中Sr的化学形态和迁移形式.结果表明,Sr2 迁移形式占总量的99.38%,SrHCO3 形式占0.55%,SrCO03占0.019%.  相似文献   
795.
应用地球化学工程学修复水、气、土壤污染的研究进展   总被引:2,自引:0,他引:2  
本文简要介绍了地球化学工程学的基本概念、主要环境技术及尺度 ,综述了地球化学工程学在水、大气、土壤污染修复中的研究进展。  相似文献   
796.
稠油废水及油性废渣处理技术   总被引:1,自引:0,他引:1  
克拉玛依油田的稠油废水及油性废渣的有效治理,一直是困扰油田的技术难题。为了解决这一难题,利用专效化学药剂使废水内含的油性杂质产生中和、破乳、架桥、絮凝等反应形成絮凝胶体,通过机组的加压、加气、混匀、旋流、释放、气浮、分离、阻截等物理作用,加速药剂与杂质的反应过程,将其从水体中分离出来,达到净化水质的目的。对油性废渣,加入还原剂在室温以上进行充分搅拌,产生还原反应,分离成原油和铝(铁)离子水溶液。该项技术经过三年多的实践与探索,在机组性能、运行费用、作业条件等方面,取得了满意的效果,特别是油渣回收处理不仅消除了二次污染,填补了国内技术空白,而且具有明显的环境效益与经济效益。  相似文献   
797.
油田采出水处理技术现状及展望   总被引:16,自引:1,他引:15  
综述了国内油田水处理技术的发展现状,并在广泛调研分析的基础上指出了当前油田采出水处理技术中所存在的问题,指明了今后油田采出水处理技术的发展趋势。  相似文献   
798.
环境污染应急处置技术的CBR-MADM两步筛选法模型   总被引:2,自引:0,他引:2  
突发环境污染事件进行应急处置时,需要在历史案例库和处置技术库的基础上通过筛选模型筛选出最适宜的应急处置技术.其中筛选的效率和准确性是构建技术筛选模型的首要因素,目前尚无较为满意的解决方案.本文结合案例推理技术(CBR)和模糊多属性群决策模型(MADM)的优势,建立了环境污染应急处置技术的CBR-MADM两步筛选法模型:第1步,先利用基于熵权G1法的CBR推理从案例库中匹配案例,再从相似度最高的几个案例中提取应急处置技术作为备选技术;第2步,利用MADM对备选技术进行筛选和决策.CBR-MADM两步筛选法既充分利用了历史处置经验,又极大地提高了应急处置技术的筛选速度和效率.将该方法应用于2012年底山西长治浊漳河苯胺泄漏污染事件中,成功筛选出“投加混凝剂-活性炭坝拦截”技术,同实际情况吻合,验证了其适用性和可行性.  相似文献   
799.
我国城市固体废物处理情况及温室气体减排启示   总被引:2,自引:1,他引:1       下载免费PDF全文
对我国城市固体废物(MSW)清运量、无害化处理量、卫生填埋量和场所、焚烧量和堆肥量的变化进行了趋势分析、相关性分析以及时空分布分析;并且对联合国气候变化框架公约(UNFCCC)官方网站公布的《京都议定书》中附件1国家温室气体的排放数据进行了统计分析. 结果表明:我国城市固体废物清运量和卫生填埋量很大并逐年增加;城市固体废物卫生填埋处理厌氧消化产生的温室气体随着填埋量以及标准卫生填埋场所的变化而变化;从发达国家各领域的温室气体排放情况来看,废物领域的减排潜力很大,尤其是城市固体废物卫生填埋处理,这对我国开展城市固体废物卫生填埋处理温室气体减排有一定启示.   相似文献   
800.
一种高效的油水分离器   总被引:3,自引:0,他引:3  
研制并开发了一种高效的污水除油设备,此设备采用斜通道纹板作为油水分离构件。由于构件内液流流动的特殊形态,提供了频繁的油滴之间碰撞聚结和油滴在波纹板上粘附聚结机会,因而具有较高的分离效率,并已在多处油田及炼油厂得到成功应用。  相似文献   
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