全文获取类型
收费全文 | 5681篇 |
免费 | 450篇 |
国内免费 | 2041篇 |
专业分类
安全科学 | 516篇 |
废物处理 | 235篇 |
环保管理 | 471篇 |
综合类 | 3752篇 |
基础理论 | 940篇 |
环境理论 | 1篇 |
污染及防治 | 1399篇 |
评价与监测 | 338篇 |
社会与环境 | 309篇 |
灾害及防治 | 211篇 |
出版年
2024年 | 36篇 |
2023年 | 113篇 |
2022年 | 347篇 |
2021年 | 299篇 |
2020年 | 331篇 |
2019年 | 227篇 |
2018年 | 246篇 |
2017年 | 284篇 |
2016年 | 298篇 |
2015年 | 364篇 |
2014年 | 399篇 |
2013年 | 558篇 |
2012年 | 527篇 |
2011年 | 577篇 |
2010年 | 463篇 |
2009年 | 429篇 |
2008年 | 389篇 |
2007年 | 386篇 |
2006年 | 313篇 |
2005年 | 195篇 |
2004年 | 172篇 |
2003年 | 181篇 |
2002年 | 158篇 |
2001年 | 140篇 |
2000年 | 142篇 |
1999年 | 106篇 |
1998年 | 86篇 |
1997年 | 82篇 |
1996年 | 74篇 |
1995年 | 55篇 |
1994年 | 55篇 |
1993年 | 44篇 |
1992年 | 27篇 |
1991年 | 12篇 |
1990年 | 14篇 |
1989年 | 10篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1972年 | 2篇 |
1918年 | 1篇 |
1917年 | 1篇 |
1916年 | 1篇 |
排序方式: 共有8172条查询结果,搜索用时 390 毫秒
391.
392.
393.
394.
395.
396.
397.
基于2008—2012年污染源环境统计数据,采用Spearman秩相关系数法等分析南水北调中线陕西水源区污废水及污染物年排放总量变化趋势,借助ArcGIS空间分析功能表征水源区污染源排放的空间分布特征。结果表明:2008—2012年水源区污废水和NH_3-N年排放总量呈显著上升趋势,COD、As、Pb、Cd、Cr和Hg年排放总量呈抛物线型变化,总体上COD、Pb、Cd年排放总量增加,As、Cr和Hg年排放总量降低。水源区污废水及污染物排放量空间差异明显,污废水、COD和NH_3-N排放涉及流域所有区县,其排放量从干流到流域边缘呈现较明显的梯度变化,即位于流域中心或地级市行政中心的区县排放量明显高于位于流域边缘的区县;As、Pb、Cd、Cr和Hg排放量呈现明显的区域分布,主要分布在勉县等8个区县。 相似文献
398.
调查分析蔷薇河非点源废水排放情况,结合相关统计资料,核算出蔷薇河非点源废水污染物的排放量。结论表明,农田回归水污染是蔷薇河水体非点源污染的主要因素。 相似文献
399.
Qiang Huang Jianzhong Song Ying Zhong Ping’an Peng Weilin Huang 《Environmental monitoring and assessment》2014,186(1):247-256
Organochlorine pesticides (OCPs) have variously been phased out in agricultural activities, but they are still widely detected in air, water, and soil systems due to their recalcitrant nature in the environment. The purposes of this study were to assess potential OCP pollution via dry and wet deposition over the fast developing Pearl River Delta area with 41,700 km2, where the main effort has been focused on emerging pollutants such as petroleum hydrocarbons and PM2.5. We quantified both the dry and wet deposition fluxes of 19 OCPs including dichlorodiphenyltrichloroethanes (DDTs), endosulfans (Endos), and hexachlorocyclohexanes (HCHs). The results showed that each year about 67.4, 42.0, 15.0, and 8.07 kg of total OCPs, DDTs, Endos, and HCHs were returned to the ground, among which 11.7, 10.4, 0.84, and 0.16 kg were in the dry deposition forms. The large spatial variations in OCP deposition fluxes indicated that OCP pollution in the air is mainly influenced on local scales because evaporation from local soil is likely the major source of the phased out OCPs. Source analysis indicated that DDTs may be still in use as antifouling agent and/or dicofol, but Endos and HCHs were mainly derived from the residual of historical usage. The study suggests that the historical OCP pollutants are persistent at high levels in this area and should not be overlooked, while we tackle emerging pollutants. 相似文献
400.
Distribution,sources, and ecological risk assessment of SVOCs in surface sediments from Guan River Estuary,China 总被引:1,自引:0,他引:1
Xinran He Xiaojuan Song Yong Pang Yiping Li Binlin Chen Zhihua Feng 《Environmental monitoring and assessment》2014,186(7):4001-4012
The contamination of semi-volatile organic compounds (SVOCs) in the surface sediments of the Guan River Estuary, China was fully investigated. Total concentrations of 56 species of SVOCs ranged from 132 to 274 ng/g with an average of 186 ng/g (dry weight). Polycyclic aromatic hydrocarbon (PAH) concentrations were positively correlated with clay content and negatively correlated with sediment grain size. Source identification indicated that PAHs originated mainly from pyrolytic sources. However, intense ship traffic in the estuary may provide sources of petrogenic PAHs. Organochlorine pesticides (OCPs) mainly originated from direct input of dichlorodiphenyltrichloroethanes (DDTs) during some industrial processes. The SVOC concentrations were also compared with International Sediments Quality Guidelines and Sediments Quality Criteria, and the results indicated that negative biological impacts may originate from high concentrations of FLO, p,p′-DDE, and total DDTs. 相似文献