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   2227篇
  免费   137篇
  国内免费   386篇
安全科学   124篇
废物处理   18篇
环保管理   313篇
综合类   1218篇
基础理论   270篇
环境理论   6篇
污染及防治   102篇
评价与监测   98篇
社会与环境   341篇
灾害及防治   260篇
  2024年   5篇
  2023年   36篇
  2022年   65篇
  2021年   98篇
  2020年   85篇
  2019年   99篇
  2018年   88篇
  2017年   97篇
  2016年   97篇
  2015年   69篇
  2014年   101篇
  2013年   164篇
  2012年   158篇
  2011年   163篇
  2010年   92篇
  2009年   103篇
  2008年   116篇
  2007年   139篇
  2006年   120篇
  2005年   114篇
  2004年   101篇
  2003年   81篇
  2002年   76篇
  2001年   86篇
  2000年   82篇
  1999年   64篇
  1998年   45篇
  1997年   37篇
  1996年   35篇
  1995年   34篇
  1994年   27篇
  1993年   16篇
  1992年   18篇
  1991年   13篇
  1990年   12篇
  1989年   4篇
  1988年   3篇
  1987年   1篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
排序方式: 共有2750条查询结果,搜索用时 15 毫秒
991.
2006年11-12月国内环境事件   总被引:22,自引:22,他引:0  
简要统计了2006年11-12月国内发生的各种环境事件57起,包括污染事件35起,地震7起,山体滑坡和泥石流3起,旱灾5起,以及其他自然灾害7起.对污染事件和自然灾害进行了讨论.  相似文献   
992.
概述了1994-2006年国内外对我国农村室内空气污染干预的研究成果,从中总结了改炉改灶、健康教育与行为干预、开发和使用清洁能源、社会动员等4项干预措施.其中,使用改良炉灶和清洁能源可直接而有效地改善室内空气质量; 健康教育、行为干预与社会动员通过帮助人们改变不良的生活方式达到改善室内空气质量的目的,这些措施在我国农村室内空气污染干预中取得了很好的效果.建议结合我国各地实际,采用综合干预措施控制农村室内空气污染.  相似文献   
993.
2007年3-4月国内环境事件   总被引:23,自引:23,他引:0  
简要统计了2007年3-4月国内发生的各种环境事件90起,包括沙尘天气17起,污染事件26起,地震11起,山体滑坡和泥石流11起,旱灾5起,以及其他自然灾害20起.对自然灾害进行了讨论.  相似文献   
994.
胡佶  张传松  王修林  王江涛 《环境科学》2007,28(7):1442-1448
应用实验室培养法现场研究了3~5月东海硅藻赤潮发生前后10个站位的营养盐在沉积物-海水界面的交换,并应用连续函数拟合法计算了营养盐的界面交换速率.结果显示,NO-3-N在赤潮前向沉积物中汇聚[-1.33~-0.68 mmol/(m2·d)],赤潮后却基本由沉积物向海水中释放[-0.69~0.82 mmol/(m2·d)].NH+4-N在赤潮前后大都从沉积物中释放[-0.65~1.46 mmol/(m2·d)],赤潮后释放速率小于赤潮前.NO-2-N赤潮前后除Zc17站外都向沉积物中汇聚[-0.09~0.05 mmol/(m2·d)],赤潮后汇聚速率稍高.SiO2-3-Si在所有站位都由沉积物向海水释放[0.85~9.23 mmol/(m2·d)],其赤潮后速率高于赤潮前.PO3-4-P在赤潮前向沉积物中汇聚[-0.06~-0.01 mmol/(m2·d)],在赤潮后却由沉积物向海水中释放[0~1.26 mmol/(m2·d)].NO-3-N和PO3-4-P向东海近海沉积物的汇聚在春季不利于硅藻赤潮的暴发,但其在硅藻赤潮暴发后从沉积物的大量释放为后面紧接的大面积甲藻赤潮的暴发提供了重要的营养物质补充.  相似文献   
995.
Soil microbes play a major role in ecological processes and are closely associated with the aboveground plant community.In order to understand the effects of vegetation type on the characteristics of soil microbial communities,the soil microbial communities were assessed by plate counts,phospholipid fatty acid (PLFA) and Biolog microplate techniques in five plant communities,i.e.,soybean field (SF),artificial turf (AT),artificial shrub (AS),natural shrub (NS),and maize field (MF) in Jinan,Shandong Province,North China.The results showed that plant diversity had little discernible effect on microbial biomass but a positive impact on the evenness of utilized substrates in Biolog microplate.Legumes could significantly enhance the number of cultural microorganisms,microbial biomass,and community catabolic diversity.Except for SF dominated by legumes,the biomass of fungi and the catabolic diversity of microbial community were higher in less disturbed soil beneath NS than in frequently disturbed soils beneath the other vegetation types.These results confirmed that high number of plant species,legumes,and natural vegetation types tend to support soil microbial communities with higher function.The present study also found a significant correlation between the number of cultured bacteria and catabolic diversity of the bacterial community.Different research methods led to varied results in this study.The combination of several approaches is recommended for accurately describing the characteristics of microbial communities in many respects.  相似文献   
996.
Qu W  Bi X  Sheng G  Lu S  Fu J  Yuan J  Li L 《Environment international》2007,33(8):1029-1034
Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants. The aim of the present study was to evaluate the PBDE serum levels in residents from an electronic waste dismantling region, residents living within 50 km of the dismantling region, and a referent group with no occupational PBDE exposure. Fourteen PBDE congeners including BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, BDE-196, BDE-197, BDE-203, BDE-206, BDE-207, BDE-208 and BDE-209 were quantified in these three groups by gas chromatography-negative chemical ionization (NCI) mass spectrometry in selected ion monitoring (SIM) mode. We found that the levels of all PBDE congeners in serum of residents from electronic waste dismantling region were significantly higher than those in the two other groups. The referents showed the lowest PBDE levels. Concentrations of congeners with a high number of bromine substituents, i.e., hepta- to decaBDEs in occupational exposure workers were 11-20 times higher than those in the referent group. BDE-209 was the dominant congener. The highest concentration of BDE-209 was observed among the electronic waste dismantling workers, and it was 3436 ng g(-1) lipid weight (ng g(-1) l.w.), which is the highest concentration of BDE-209 in humans worldwide. Some higher brominated PBDE congeners such as BDE-197, BDE-207 and BDE-208 also showed elevated concentrations in dismantling workers. This study confirms that BDE-209 is released to the environment and can bioaccumulate in the blood of electronic waste dismantling workers, and extensive occupational exposure to PBDEs leads to elevated concentrations of all PBDE congeners in serum.  相似文献   
997.
中国生物质燃烧大气污染物排放清单   总被引:49,自引:12,他引:37  
根据2000-2007年各省市生物质燃烧消耗量和排放因子,估算了中国大陆生物质燃烧所导致的NOx、SO2、CO、CO2、CH4、NMHC、PM、BC排放量,并给出了分省区、分生物质类型的排放清单.研究表明,2007年中国生物质燃烧排放的NOx、SO2、CO、CO2、CH4、NMHC、PM和BC排放量分别为109万t,1...  相似文献   
998.
Persistent organochlorine compounds, including hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and polychlorinated biphenyls (PCBs) were analyzed in surface water and sediments from Baiyangdian Lake, North China. Total concentrations of HCHs, DDTs and PCBs in surface water were in the range of 3.13-10.60, 4.05-20.59 and 19.46-131.62 ng/L, respectively, and total concentrations of HCHs, DDTs and PCBs in sediments were 1.75-5.70, 0.91-6.48 and 5.96-29.61 ng/g dry weight, respectively. Among the groups of HCHs (sum of α-HCH, β-HCH, γ-HCH and δ-HCH) and DDTs (sum of DDT, DDD and DDE), the predominance of β-HCH, DDE and DDD in water and sediment samples was clearly observed. This observation suggested that β-HCH was resistant to biodegradation and the DDTs had been transformed to its metabolites, DDE and DDD. For PCBs, penta-, hexa- and hepta-chlorinated congeners were the most abundant compounds in the both phases. Furthermore, the partitioning of chlorinated compounds between sediment and water was investigated to understand their transport and fates in aquatic ecosystems. The results indicated that average logs of organic carbon-normalized sediment-water partition coefficients (logKoc') for OCPs varied between 3.20 and 5.53, and for PCBs, logKoc' values ranged from 3.19 to 5.57. The observed logKoc' was lower than their equilibrium logKoc predicted from linear model, which may be attributed to the solubility enhancement effect of colloidal matter in water phase and the disequilibrium between sediment and water.  相似文献   
999.
Two ornithogenic sediment cores, which have a time span of 1000 years and are influenced by red-footed booby (Sula sula), were collected from Dongdao Islands, South China Sea. The determined mercury concentrations of the two cores show similar and substantial fluctuations during the past millennium, and the fluctuations are most likely caused by the changes in mercury level of the ocean environment and in anthropogenic Hg emission. For the past 500 years, the mercury concentration in the red-footed booby excrement has a striking association with global anthropogenic mercury emission. The mercury concentration increased rapidly after AD 1600 in corresponding to beginning of the unparalleled gold and silver mining in South Central America that left a large volume of anthropogenic mercury pollution. Since the Industrial Revolution, the mercury level has increased at a fast pace, very likely caused by modern coal combustion, chlor-alkali and oil refining industries. The comparison of mercury profiles from different places on earth suggested that anthropogenic mercury pollution after the Industrial Revolution is more severe in Northern Hemisphere than in Antarctica.  相似文献   
1000.
针对当前研究中忽略化石能源地生态承载力的不足,从土地碳吸收功能的角度将生态足迹法与净初级生产力相结合,根据构建的化石能源地生态承载力模型,对东北地区进行了实证研究.结果表明,2004-2008年,东北地区化石能源地生态承载力的区域性差异显著,辽宁最低、吉林居中、黑龙江最高;三省人均化石能源地生态承载力均呈缓慢下降趋势,...  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