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   342篇
  免费   29篇
  国内免费   102篇
安全科学   37篇
废物处理   28篇
环保管理   17篇
综合类   203篇
基础理论   69篇
污染及防治   70篇
评价与监测   28篇
社会与环境   13篇
灾害及防治   8篇
  2024年   4篇
  2023年   3篇
  2022年   24篇
  2021年   21篇
  2020年   28篇
  2019年   11篇
  2018年   14篇
  2017年   18篇
  2016年   12篇
  2015年   12篇
  2014年   17篇
  2013年   23篇
  2012年   23篇
  2011年   32篇
  2010年   28篇
  2009年   27篇
  2008年   31篇
  2007年   17篇
  2006年   12篇
  2005年   11篇
  2004年   13篇
  2003年   8篇
  2002年   15篇
  2001年   18篇
  2000年   13篇
  1999年   10篇
  1998年   6篇
  1997年   4篇
  1996年   9篇
  1995年   3篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1988年   1篇
  1987年   1篇
排序方式: 共有473条查询结果,搜索用时 281 毫秒
31.
2014年12月29—30日,青岛市发生了一次空气污染过程,利用环境一号卫星CCD遥感影像数据和实测PM_(2.5)浓度数据,分析了该过程前后5 d的实测PM_(2.5)浓度与环境一号卫星CCD遥感影像的DN值之间的相关性,分别按日期和区域建立了反演模型。结果表明,按日期拟合反演模型相关系数为0.02~0.51,按区域拟合反演模型相关系数为0.01~0.80,总体来说,区域拟合结果较好。  相似文献   
32.
Polycyclic aromatic hydrocarbons (PAHs) were measured in surface sediments and dated core sediments from the Nansi Lake of China to investigate the spatial and temporal distribution characteristics. The concentrations of 16 kinds priority PAH compounds were determined by GC-MS method. And 210Pb isotope dating method was used to determine the chronological age of the sediment as well as the deposition rate. The results indicated that the total PAHs concentration ranges in surface and core sediment samples were 160 ~32,600 and 137 ~ 693 ng/g (dry wt.), respectively. The sediment rate and the average mass sedimentation were calculated to be 0.330 cm·year???1 and 0.237 g·cm???2·yr???1 and the sediment time of the collected core sample ranged from 1899 to 2000. The peak of PAH concentrations came at recent years. The source analysis showed PAHs mainly came from the contamination of low temperature pyrogenic processes, such as coal combustion. The PAHs concentrations were lower than ERL and LEL values for most collected samples. However, in several surface sediment samples especially in estuary sites, the PAHs concentrations were not only higher than ERL and LEL values, but also higher than ERM values.  相似文献   
33.
Automobiles usually contain toxic substances, such as lubricants, acid solutions and coolants. Therefore, inappropriate handling of end-of-life vehicles (ELVs) will result in environmental pollution. ELV parts, which include metallic and non-metallic substances, are increasingly gaining recycling value due to the recent global shortage of raw materials. Hence, the establishment of a proper recycling system for ELVs will not only reduce the impact on the environment during the recycling process, but it will also facilitate the effective reuse of recycled resources. Prior to 1994, the recycling of ELVs in Taiwan was performed by related operators in the industry. Since the publishing of the “End-of-life vehicle recycling guidelines” under the authority of the Waste Disposal Act by the Environmental Protection Administration (EPA) in 1994, the recycling of ELVs in Taiwan has gradually become systematic. Subsequently, the Recycling Fund Management Board (RFMB) of the EPA was established in 1998 to collect a Collection–Disposal–Treatment Fee (recycling fee) from responsible enterprises for recycling and related tasks. Since then, the recycling channels, processing equipment, and techniques for ELVs in Taiwan have gradually become established. This paper reviews the establishment of the ELV recycling system, analyzes the current system and its performance, and provides some recommendations for future development. The reduction of auto shredder residue (ASR) is a key factor in maximizing the resource recovery rate and recycling efficiency. The RFMB needs to provide strong economic incentives to further increase the recycling rate and to encourage the automobile industry to design and market greener cars.  相似文献   
34.
介绍了污水自动监测系统的基本组成及相对于传统采样监测的优势,并就系统在企业中的应用实例和取得的明显效果进行综述。  相似文献   
35.
A two-stage UASB reactor was employed to remove sulfate from acrylic fiber manufacturing wastewater. Mesophilic operation (35±0.5℃) was performed with hydraulic retention time (HRT) varied between 28 and 40 hr. Mixed liquor suspended solids (MLSS) in the reactor was maintained about 8000 mg/L. The results indicated that sulfate removal was enhanced with increasing the ratio of COD/SO42-. At low COD/SO42-, the growth of the sulfate-reducing bacteria (SRB) was carbon-limited. The optimal sulfate removal efficiencies were 75% when the HRT was no less than 38 hr. Sulfidogenesis mainly happened in the sulfate-reducing stage, while methanogenesis in the methane-producing stage. Microbes in sulfate-reducing stage performed granulation better than that in methane-producing stage. Higher extracellular polymeric substances (EPS) content in sulfate-reducing stage helped to adhere and connect the flocculent sludge particles together. SRB accounted for about 31% both in sulfate-reducing stage and methane-producing stage at COD/SO42- ratio of 0.5, while it dropped dramatically from 34% in sulfate-reducing stage to 10% in methane-producing stage corresponding to the COD/SO42- ratio of 4.7. SRB and MPA were predominant in sulfate-reducing stage and methane-producing stage respectively.  相似文献   
36.
Phenolic compounds and their derivatives have been found in industrial wastewater, which pose threats to the natural environment. Ordered mesoporous carbon(OMC) has been identified as an ideal adsorbent possessing high specific surface area and large pore volume to alleviate these pollutants. A novel ordered mesoporous carbon was prepared using COK-19 template with the cubic Fm3 m structure for the first time. Ordered mesoporous silica COK-19 was synthesized and reported in 2015. Sucrose as the carbon precursor was impregnated into the mesopores of silica and converted to carbon through carbonization process using sulfuric acid as a catalyst. Ordered mesoporous carbon was obtained after the removal of silica framework using hydrofluoric acid. Boric acid was employed for the preparation of OMCs with tunable pore sizes in the range of 6.9–16.6 nm. Several characterization techniques such as nitrogen adsorption–desorption isotherms, transmission electron microscope(TEM), Fourier transform infrared spectroscopy, Boehm titration and elemental analysis were employed to characterize the OMCs. The pore size analysis and TEM images confirmed that OMC has replicated the mesostructure of the COK-19. Results obtained from adsorption kinetics and isotherms suggest that the Pseudo-second-order model and Langmuir isotherm well described the experimental data.  相似文献   
37.
王勇  许子易  张亚新 《环境科学学报》2019,39(12):4284-4292
城市是中国碳排放的重要来源,而超大城市的碳达峰研究对国内其他城市和全国能否实现碳达峰目标具有重要的现实意义.以北京、上海、广州、深圳、天津和重庆等6个超大城市为研究对象,能源强度为门限变量,建立门限-STIRPAT模型,首先确定6个超大城市碳排放的驱动因素,然后对27种情景下的各城市碳排放达峰进行预测.研究结果表明:①人口、人均GDP和能源强度对各城市碳排放起到正向促进效应,人口的影响效应最大,其次是能源强度,人均GDP对碳排放的影响最小.②能源强度对二氧化碳排放的影响呈阶段性变化特征.③北京、上海和重庆在高能源强度下降率的情景下,已经达峰;天津、除最宽松的高-高-高情景外的广州和深圳会在2030年前实现达峰.如果能源强度以中速率下降,6个城市碳排放不能保证一定能在2030年前达峰.如果能源强度以低速率下降,6个城市均不能在2030年前达峰.本研究有利于明确超大城市碳排放的影响因素,对其他城市尽快实现碳排放达峰具有借鉴意义,为全国实现碳达峰目标提供可行的研究思路.  相似文献   
38.
大连地区水资源可持续利用问题思考   总被引:2,自引:0,他引:2  
从水资源可用的战略高度,从生命之源-水入手,较详细地分析了大连地区水危急资源开发利用问题,从而,较全面地论述了大连地区水资源可持续利用的战略措施。  相似文献   
39.
分离出能高效降解机油的真菌并研究其使用方法.从机械润滑油污染的土中分离出2株真菌,GXUA和GXUB.形态鉴定为曲霉属(Aspergillus)菌.rDNA的ITS序列同源性分析表明,GXUA与A.tubingens,GXUB与A.fumigatus菌株SRRC 43完全同源.根据均匀设计的油-矿质液中的摇床发酵结果,混合菌体对机油的降解效率高于单菌株,最佳发酵条件为25 g菌丝体/L矿质液,pH=5.0,26 ℃.在此条件下,于10 g机油/L矿质液中摇床发酵9 d,其降解效率为95.90%.液-质色谱分析表明,混合菌能降解机油中700~900 Dt的大分子.用两菌株的孢子和其他两种生物材料试制了实验室级的颗粒(直径1 cm)生物制剂.在实验室级水平上,按500粒/m2水面和150粒/kg土用量分别处理具有约2 mm厚油膜的水(自来水和海水)和50 g机油/kg土的土壤,处理后的水和土壤中残余油量符合国家有关环境污染控制标准,添加油酸钠和H2O2能够显著提高降解效率.  相似文献   
40.
海洋油气资源开发技术发展战略研究   总被引:5,自引:0,他引:5  
开辟深水油气勘探开发领域、实现边际油田的高效和经济开发是提高油气后续发展能力。保障油气资源安全的重要途径之一。我国在深水油气勘探开发技术方面基础较薄弱.在“十一五”期间尚不具备开发深水油气的条件。因此“十一五”期间需针对我圈海域特点选择部分关键技术进行重点攻关。实现我国海洋油气开发由近海向深水的技术转移。为实现全海域资源开发提供高技术支撑。本文以海洋油气资源开发技术为对象.从海洋油气资源及其勘探开发状况、国内外技术发展现状和趋势、图象及社会经济需求筹方面进行内外部环境条件分析.提出了我国海洋油气资源技术领域所面临的挑战以及与国际水平的差距。并对制约我国该技术领域和相关油气产业发展的瓶颈技术、国外垄断技术进行了分析.最终提出我国海洋资源开发技术发展的战略目标和战略模式。  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