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   1388篇
  免费   88篇
  国内免费   248篇
安全科学   90篇
废物处理   159篇
环保管理   316篇
综合类   636篇
基础理论   202篇
污染及防治   151篇
评价与监测   37篇
社会与环境   39篇
灾害及防治   94篇
  2024年   2篇
  2023年   11篇
  2022年   31篇
  2021年   39篇
  2020年   41篇
  2019年   25篇
  2018年   45篇
  2017年   48篇
  2016年   48篇
  2015年   51篇
  2014年   125篇
  2013年   119篇
  2012年   87篇
  2011年   111篇
  2010年   69篇
  2009年   84篇
  2008年   68篇
  2007年   94篇
  2006年   85篇
  2005年   62篇
  2004年   47篇
  2003年   56篇
  2002年   58篇
  2001年   44篇
  2000年   46篇
  1999年   35篇
  1998年   23篇
  1997年   25篇
  1996年   31篇
  1995年   25篇
  1994年   10篇
  1993年   9篇
  1992年   6篇
  1991年   8篇
  1990年   4篇
  1989年   2篇
  1988年   3篇
  1987年   5篇
  1986年   6篇
  1985年   3篇
  1984年   9篇
  1983年   5篇
  1982年   5篇
  1981年   1篇
  1980年   4篇
  1979年   5篇
  1978年   2篇
  1977年   1篇
  1975年   1篇
排序方式: 共有1724条查询结果,搜索用时 734 毫秒
971.
以制药废水实验了50 m3螺旋式厌氧反应器(SPAC反应器)的稳定性。采用Augmented Dickey-Fuller(ADF)单位根检验表明,螺旋式反应器具有良好的启动和运行稳定性。负荷冲击实验显示,SPAC反应器具有较好的耐浓度冲击能力和耐水力冲击能力,所能耐受的最大浓度冲击强度大于60 000 (mg·h)/L(进水浓度提升2倍),所能耐受的最大水力冲击强度为300(m3·h)/d(进水流量提升50%)。SPAC反应器还具备受扰恢复能力。在反应液pH低于5.74,出水浓度、COD去除率和容积COD去除速率(VRR)分别为3 500 mg/L、22.30%和2.52 kg/(m3·d)的工况下,经过30 d恢复,出水浓度、COD去除率和VRR的恢复程度达到80%~90%。  相似文献   
972.
废弃油基钻井液提取柴油剩余废弃物无害化处理研究   总被引:1,自引:0,他引:1  
针对废弃油基钻井液中柴油回收过程产生的泥渣、废水、废白土和酸碱废渣具有高色度、高pH、高COD和高石油类的特点,通过优化实验得出了一步法无害化处理废弃混合物的最佳固化配方:水泥和粉煤灰加量分别为12.5%,激活剂SG加量1.5%,促凝剂LSL加量1.5%,石灰加量1%。在最佳固化配方下,固化体浸出液的各主要污染指标都符合《污水综合排放标准》(GB 8978-1996)一级标准,固化成本约100元/m3,与分别处理废渣、废液相比,其处理成本可降低约20%。  相似文献   
973.
制肥工业废水中氨氮浓度高,难以直接进行生化反应,采用鸟粪石沉淀法可有效去除并回收氨氮。利用中试反应器回收某制肥工业废水中的氨氮,采用氯化镁与氧化镁作为联用镁源,通过考察不同进料方式、搅拌速度、停留时间等因素的影响,确定了鸟粪石法回收氨氮的最佳工况:采用间歇进水、固体投加镁源的投料方式,搅拌速度300 r/min,停留时间2 h。最佳条件下,氨氮去除率达到93.5%,磷残余率小于0.3%,生成的鸟粪石纯度可达85.6%,砷和铅的质量分数分别为0.0036和0.0008,符合肥料中重金属限值(GB/T 23349-2009),其他重金属均未检出。因此,回收产品有很好的利用价值。经济分析表明磷源是此方法处理成本较高的主要原因。  相似文献   
974.
Acadia National Park was one of the 14 sites included in the Park Research and Intensive Monitoring of Ecosystems network (PRIMENet). For eight years the EPA monitored ultraviolet (UV) radiation at this site, with the National Park Service (NPS) sponsoring a total climate and air monitoring station. Under the auspices of PRIMENet, research projects were initiated that investigated the effects of UV on amphibians, determined watershed mass balances, and developed a model of deposition along an elevational gradient. The monitoring data and research results have been used by park management to protect vegetation and water resources from ozone and deposition. These data are now being used to develop a “vital signs” monitoring program under the NPS’ Inventory and Monitoring Program. These data sets have been used in regional, national and international programs to protect human health and resources from air pollution. Public outreach has been accomplished through web site resources and via the Schoodic Education and Research Center.  相似文献   
975.
为处理稀土分离排放的高浓度NH4 -N废水,采用模拟废水研究了在不同条件下减压蒸馏回收氯化铵对馏出液中NH4 -N浓度变化影响.发现真空度、不同浓度范围及溶液pH对馏出液中NH4 -N浓度有显著影响,在真空度为0.07MPa,溶液pH为3~4条件下蒸馏,可使馏出液中NH4 -N浓度<15 mg/L.实际废水验证试验表明,废水经气浮除油、氨水中和、适量重金属沉淀剂DTCR去除重金属及活性炭吸附微量重金属及油类物质等预处理后,减压蒸馏可获得较高品质氯化铵产品,经分析达到工业级合格产品,馏出液可作为自来水回用于生产.对废水处理成本和收益进行了估算,发现每处理1 m3废水可获得67.1元的经济收入,实现较高的经济效益和生态环境效益.  相似文献   
976.
An iron oxide solid sponge H2S adsorbent works by reacting H2S and turning ferric oxide into ferric sulfide. The ferric sulfide will be converted back into ferric oxide and elemental sulfur when contacting oxygen or air. This study investigates the leaching of elemental sulfur from the solid sponge using anhydrous liquid ammonia as solvent. The leaching treatment expectedly results in effective regeneration of the adsorbent, which is able to lead to a sulfur removal and recovery process suitable for handling the small and mid-sized sulfur production cases, i.e., those less than 10 ton/day sulfur. The leaching does not significantly impair the physical properties, including the adsorbent pellet strength. The adsorption–regeneration (or leaching) cycle could be repeated at least three times. The cumulative sulfur loading can achieve as high as 50% (w/w), three times greater than that in the one-time use. The wash-off in leaching and the spent adsorbent can be made into slurry that is to be injected into underground formations such as depleted oil wells. It is anticipated that this underground injection is safer and more efficient than acid gas injection.  相似文献   
977.
鸟粪石沉淀法回收污泥处理构筑物中氮磷的研究进展   总被引:1,自引:0,他引:1  
陈轶  员建  苑宏英 《四川环境》2008,27(5):89-92
污水处理厂氮磷的处理和回收已经成为必然。而污泥处理构筑物中氮磷的释放则进一步要求对其中释放的氮磷进行回收。本文介绍了国内外对鸟粪石形成条件、外加镁源以及各种利用鸟粪石沉淀法进行污泥处理构筑物中氮磷回收的研究现状,并对其在污泥处理构筑物氮磷回收中存在的问题进行了论述。  相似文献   
978.
Green R  Bates LK  Smyth A 《Disasters》2007,31(4):311-335
In the aftermath of Hurricane Katrina, a rapid succession of plans put forward a host of recovery options for the Upper and Lower Ninth Ward in New Orleans. Much of the debate focused on catastrophic damage to residential structures and discussions of the capacity of low-income residents to repair their neighbourhoods. This article examines impediments to the current recovery process of the Upper and Lower Ninth Ward, reporting results of an October 2006 survey of 3,211 plots for structural damage, flood damage and post-storm recovery. By examining recovery one year after Hurricane Katrina, and by doing so in the light of flood and structural damage, it is possible to identify impediments to recovery that may disproportionately affect these neighbourhoods. This paper concludes with a discussion of how pre- and post-disaster inequalities have slowed recovery in the Lower Ninth Ward and of the implications this has for post-disaster recovery planning there and elsewhere.  相似文献   
979.
Flynn DT 《Disasters》2007,31(4):508-515
A major flood in 1997 forced the evacuation of Grand Forks, North Dakota and caused damage of USD 1 billion. Despite this recent disaster there is only marginal evidence of an increase in disaster recovery planning by businesses that experienced the flood. This finding is consistent with the results of other business-related disaster research. Statistical tests of survey results from 2003 indicate that there is a significantly higher rate of disaster recovery planning in businesses started since the 1997 flood than in businesses started before the flood and still in business. Such an outcome indicates a need for public policy actions emphasizing the importance of disaster planning. Improved disaster planning is an aid to business recovery and the results demonstrate the need for more widespread efforts to improve disaster recovery planning on the part of smaller businesses, even in areas that have recently experienced disasters.  相似文献   
980.
大气氟污染治理技术   总被引:7,自引:0,他引:7  
氟化物是当今重要的大气污染物之一,其毒性超过二氧化硫。文章概要叙述我国近年工业废气的氟排放和治理状况。面对日益严峻的污染形势,提请企业界加以关注和治理。文中着重介绍几种常用的技术装备和工艺流程。  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