全文获取类型
收费全文 | 4291篇 |
免费 | 70篇 |
国内免费 | 199篇 |
专业分类
安全科学 | 78篇 |
废物处理 | 99篇 |
环保管理 | 554篇 |
综合类 | 1010篇 |
基础理论 | 2012篇 |
污染及防治 | 356篇 |
评价与监测 | 119篇 |
社会与环境 | 222篇 |
灾害及防治 | 110篇 |
出版年
2021年 | 1篇 |
2018年 | 114篇 |
2017年 | 116篇 |
2016年 | 207篇 |
2015年 | 43篇 |
2014年 | 13篇 |
2013年 | 23篇 |
2012年 | 239篇 |
2011年 | 283篇 |
2010年 | 95篇 |
2009年 | 43篇 |
2008年 | 22篇 |
2007年 | 41篇 |
2006年 | 42篇 |
2005年 | 593篇 |
2004年 | 1009篇 |
2003年 | 819篇 |
2002年 | 123篇 |
2001年 | 62篇 |
2000年 | 55篇 |
1999年 | 95篇 |
1998年 | 59篇 |
1997年 | 132篇 |
1996年 | 41篇 |
1995年 | 35篇 |
1994年 | 37篇 |
1993年 | 72篇 |
1992年 | 58篇 |
1991年 | 51篇 |
1990年 | 6篇 |
1989年 | 16篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1974年 | 1篇 |
1916年 | 1篇 |
排序方式: 共有4560条查询结果,搜索用时 765 毫秒
201.
综述了2009年我国机动车污染防治行业的发展环境及市场特点、主要(骨干)企业发展情况,分析了2009年行业发展中存在的主要问题,提出了解决对策和建议,并对行业的发展进行了展望。 相似文献
202.
中国环境保护产业协会循环经济专业委员会 《中国环保产业》2010,(8):7-10
概述了2009年我国循环经济发展状况,以及国家颁布的相关法规、政策和指导性文件,分析了钢铁、有色金属、煤炭、水泥、电力、造纸等行业利用新技术发展循环经济取得的成效,指出了国内循环经济行业发展中存在的主要问题,提出了解决对策及建议。 相似文献
203.
204.
Naser?A.?Anjum Iqbal?AhmadEmail author Mónica?Válega Etelvina?Figueira Armando?C.?Duarte Eduarda?Pereira 《Environmental science and pollution research international》2013,20(6):3910-3922
Efficient and sustainable management of rapidly mounting environmental issues has been the focus of current intensive research. The present study aimed to investigate the impact of plant phenological development stage variation on mercury (Hg) tolerance, accumulation, and allocation in two salt marsh macrophytes Triglochin maritima and Scirpus maritimus prevalent in historically Hg-contaminated Ria de Aveiro coastal lagoon (Portugal). Both plant samples and the sediments vegetated by monospecific stands of T. maritima and S. maritimus were collected from reference (R) and sites with moderate (M) and high (H) Hg contamination in Laranjo bay within Ria de Aveiro lagoon. Hg tolerance, uptake, and allocation in T. maritima and S. maritimus, physico-chemical traits (pH, redox potential, and organic matter content) and Hg concentrations in sediments vegetated by these species were impacted differentially by phenological development stages variation irrespective of the Hg contamination level. In T. maritima, Hg concentration increased with increase in Hg contamination gradient where root displayed significantly higher Hg followed by rhizome and leaf maximally at H. However, in S. maritimus, the highest Hg concentration was perceptible in rhizome followed by root maximally at M. Between the two studied plant species, S. maritimus displayed higher Hg tolerance index (depicted by higher plant dry mass allocated to reproductive stage) and higher available Hg at M (during all growth stages) and H (during senescent stage) when compared to T. maritimus. Both plant species proved to be Hg excluder (low root/rhizome–leaf Hg translocation). Additionally, T. maritima also acted as Hg stabilizer while, S. maritimus as Hg accumulator. It can be inferred from the study that (a) the plant phenological development stage variations significantly influenced plant Hg sensitivity by impacting sediment chemistry, plant growth (in terms of plant dry mass), Hg accumulation, and its subsequent allocation capacity, contingent to Hg contamination gradient; (b) S. maritimus accumulated higher Hg but restricted its translocation to above-ground part using exclusion process at both M and H due to its accelerated growth during Hg-tolerant reproductive/metabolically active phenological development stage greater than its counterpart T. maritima; and (c) the studied salt marsh plants although hailed from the same C3 and monocot group did not necessarily display similar phenotypic plasticity and behavior towards Hg-contaminated scenario during their life cycle. 相似文献
205.
Liu X Sun L Yuan D Yin L Chen J Liu Y Liu C Liang Y Lin F 《Environmental science and pollution research international》2011,18(8):1324-1332
Background and purpose
More and more coal-fired power plants equipped with seawater flue gas desulfurization systems have been built in coastal areas. They release large amount of mercury (Hg)-containing waste seawater into the adjacent seas. However, very limited impact studies have been carried out. Our research targeted the distribution of Hg in the seawater, sediment, biota, and atmosphere, and its environmental transportation. 相似文献206.
The World Bank used the Consumer Price Index (CPI) to calculate changes in the world poverty level (measured in U.S. dollars)
prior to 1982. In 1983, the U.S. Bureau of Labor Statistics (BLS) replaced the CPI with several indices including CPI-W which
was then adopted by the World Bank. This caused the inflated rate of the U.S. dollars and the percentage of the world population
in poverty to be dramatically underestimated. This new incorrect procedure gives 25% (1.5 million) below the poverty line
in 2005, while the more appropriate procedure (described herein) gives 52% (3.3 million in 2005). The rapid rise of the poverty
line (using the preferable CPI) starting in 1987 occurred at nearly the same time as the peak in per capita annual cereal
production. 相似文献
207.
Minakshi?Sultania Deepak?SrivastavaEmail author 《Journal of Polymers and the Environment》2011,19(4):950-956
Diglycidyl ether of bisphenol—A (DGEBA)—based epoxy resin was blended in the ratio of 3:1 (weight basis) with cycloaliphatic
epoxy (CAE) resin. The prepared blend sample was further blended with different weight percentages of carboxyl-terminated
butadiene acrylonitrile copolymer (CTBN) ranging between 0 and 25 wt% with an interval of 5 wt% and cured with stiochiometric
amounts of 4, 4’- diamino diphenyl sulphone (DDS) cure agent. Structural changes during blending were studied by Fourier-transform
infra-red (FTIR) spectroscopic analysis. The kinetic parameters, viz., order of decomposition reaction (n), activation energy (E), pre-exponential factor (Z) and rate decomposition constant (k), for the decomposition of the samples were calculated by applying Coats-Redfern equation over thermogravimetric (TG) data.
The degradation of each sample followed second-order degradation kinetics, which was calculated by Coats-Redfern equation
using best-fit analysis. This was further confirmed by linear regression analysis. The validity of data was checked by t-test
statistical analysis. Further, the blend sample had higher initial degradation temperature and activation energy than its
respective pure epoxy resin indicating that the CTBN acted as thermal stabilizer for epoxy resin which improved the thermal
stability. 相似文献
208.
Miyun County,located in the northeast of Chinese capital Beijing,was underwent remarkable variations in land use in recent years.This paper aimed to detect changes in land use of Miyun from 1997 to 2005,and to qualify the response of ecosystem to LUCC based on ecosystem services valuation.With two-periods TM images,we got land use change data,and then ecosystem services values were calculated using ecosystem services valuation coefficients proposed by Chinese scholar Xie Gaodi.Results showed that water area,farm land and unused land decreased while residential land,forest land,grassland and orchard land increased during the study period.The loss of ESV was RMB 206 million and the main reason was the decrease of water area and farm land area.As for spatial variation,there were most dramatically land use change and ESV decline in reservoir ecological protection region.The coefficient sensitivity analysis indicates that valuation coefficients used in the study are suitable and results are reasonable.The driving forces of ESV loss were rapid population growth and economic development.More work should be done to make eco-environment stay healthy. 相似文献
209.
Yang Yuwen Yang Wenya .Research Center for Circular Economy Nankai University Tianjin China; . 《中国人口.资源与环境(英文版)》2011,(4):77-81
The aim of this study is to examine the relationship between environment and personal well-being using a sample of 562 urban employees from three cities in Liaoning province in the People’s Republic of China.In contrast to previous studies,this study controlled positive affectivity (PA),negative affectivity (NA),job satisfaction and Big Five personality traits.In addition,the research variables of personal well-being index (PWI),positive affectivity,negative affectivity,job satisfaction,Big Five,and environmental satisfaction are measured with multi-item scales.The research finds that environmental satisfaction is positively related to personal well-being,suggesting that improvement of the natural surroundings in the cities can improve people’s well-being. 相似文献
210.
Qiu Ling Fang Chuanglin Shen Yuming Liu Xiaoli .Institution of Geographic Sciences Natural Resources Research Chinese Academy of Sciences Beijing China; 《中国人口.资源与环境(英文版)》2011,(4):82-89
The five central cities-Beijing,Tianjin,Shanghai,Guangzhou and Shenzhen-of the three most important strategic regions in China,namely Beijing-Tianjin-Hebei metropolitan region,the Yangtze River Delta and the Pearl River Delta,are taken as a comparative analysis on urban producer services’ competitiveness,especially focusing on the comparative advantages and disadvantages of producer services in Beijing.Firstly,based on an integrated indicator system including one objective hierarchy,four standard hierarchies and 35 indicator hierarchies,the study applies factor analysis model and analytic hierarchy process model reformed by entropy technology to measure the comprehensive competitiveness of producer services in the above five cities.Secondly,Beijing has comparative advantages of capital resource,industrial base,scientific research resource and market scale,since it takes the first place of the five cities in the comprehensive competitiveness of producer services,the competitiveness of industrial development,business environment and living environment,only inferior to Shanghai in the competitiveness of talent capital.Thirdly,Beijing has comparative disadvantages in the level of producer services development,urban innovation capability and living environment.Finally,five proposals are put forth to enhance the competitiveness of producer services in Beijing,namely perfecting the system of laws and statutes,supporting the development of industry association,implementing scientific development planning,introducing preferential fiscal and taxation policies and strengthening human capital reserve. 相似文献