全文获取类型
收费全文 | 481篇 |
免费 | 18篇 |
国内免费 | 168篇 |
专业分类
安全科学 | 38篇 |
废物处理 | 32篇 |
环保管理 | 66篇 |
综合类 | 237篇 |
基础理论 | 87篇 |
污染及防治 | 153篇 |
评价与监测 | 19篇 |
社会与环境 | 13篇 |
灾害及防治 | 22篇 |
出版年
2023年 | 7篇 |
2022年 | 32篇 |
2021年 | 24篇 |
2020年 | 14篇 |
2019年 | 22篇 |
2018年 | 15篇 |
2017年 | 25篇 |
2016年 | 20篇 |
2015年 | 32篇 |
2014年 | 33篇 |
2013年 | 52篇 |
2012年 | 50篇 |
2011年 | 50篇 |
2010年 | 33篇 |
2009年 | 26篇 |
2008年 | 32篇 |
2007年 | 27篇 |
2006年 | 41篇 |
2005年 | 8篇 |
2004年 | 14篇 |
2003年 | 11篇 |
2002年 | 11篇 |
2001年 | 9篇 |
2000年 | 13篇 |
1999年 | 12篇 |
1998年 | 5篇 |
1997年 | 10篇 |
1996年 | 11篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有667条查询结果,搜索用时 296 毫秒
441.
Atmospheric mixing ratios of carbonyl sulfide (COS) in Beijing were intensively measured from March 2011 to June 2013. COS mixing ratios exhibited distinct seasonal variation, with a maximum average value of 849 ± 477 pptv in winter and a minimal value of 372 ± 115 pptv in summer. The seasonal variation of COS was mainly ascribed to the combined effects of vegetation uptake and anthropogenic emissions. Two types of significant linear correlations (R2 > 0.66) were found between COS and CO during the periods from May to June and from October to March, with slopes (ΔCOS/ΔCO) of 0.72 and 0.14 pptv/ppbv, respectively. Based on the emission ratios of COS/CO from various sources, the dominant anthropogenic sources of COS in Beijing were found to be vehicle tire wear in summer and coal burning in winter. The total anthropogenic emission of COS in Beijing was roughly estimated as 0.53 ± 0.02 Gg/year based on the local CO emission inventory and the ΔCOS/ΔCO ratios. 相似文献
442.
Ye Cheng Chenglong Zhang Yuanyuan Zhang Hongxing Zhang Xu Sun Yujing Mu 《环境科学学报(英文版)》2015,28(2):163-170
Atmospheric mixing ratios of carbonyl sulfide(COS) in Beijing were intensively measured from March 2011 to June 2013. COS mixing ratios exhibited distinct seasonal variation, with a maximum average value of 849 ± 477 pptv in winter and a minimal value of 372 ± 115 pptv in summer. The seasonal variation of COS was mainly ascribed to the combined effects of vegetation uptake and anthropogenic emissions. Two types of significant linear correlations(R2 0.66) were found between COS and CO during the periods from May to June and from October to March, with slopes(ΔCOS/ΔCO) of 0.72 and 0.14 pptv/ppbv, respectively. Based on the emission ratios of COS/CO from various sources, the dominant anthropogenic sources of COS in Beijing were found to be vehicle tire wear in summer and coal burning in winter. The total anthropogenic emission of COS in Beijing was roughly estimated as 0.53 ± 0.02 Gg/year based on the local CO emission inventory and the ΔCOS/ΔCO ratios. 相似文献
443.
Periann P. Russell Susan M. Gale Breda Muñoz John R. Dorney Matthew J. Rubino 《Journal of the American Water Resources Association》2015,51(1):226-239
Headwater streams are the primary sources of water in a drainage network and serve as a critical hydrologic link between the surrounding landscape and larger, downstream surface waters. Many states, including North Carolina, regulate activity in and near headwater streams for the protection of water quality and aquatic resources. A fundamental tool for regulatory management is an accurate representation of streams on a map. Limited resources preclude field mapping every headwater stream and its origin across a large region. It is more practical to develop a model for headwater streams based on a sample of field data that can then be extrapolated to a larger area of interest. The North Carolina Division of Water Quality has developed a cost‐effective method for modeling and mapping the location, length, and flow classification (intermittent and perennial) of headwater streams. We used a multiple logistic regression approach that combined field data and terrain derivatives for watersheds located in the Triassic Basins ecoregion. Field data were collected using a standard methodology for identifying headwater streams and origins. Terrain derivatives were generated from digital elevation models interpolated from bare‐earth Light Detection and Range data. Model accuracies greater than 80% were achieved in classifying stream presence and absence, stream length and perennial stream length, but were not as consistent in predicting intermittent stream length. 相似文献
444.
Ye Zi Wang Bin Mu Ge Zhou Yun Qiu Weihong Yang Shijie Wang Xing Zhang Zhuang Chen Weihong 《Environmental science and pollution research international》2021,28(46):65140-65149
Environmental Science and Pollution Research - Fine particulate matter (PM2.5) is still the primary air pollutant in most Chinese cities and its adverse effects on lung function have been widely... 相似文献
445.
446.
Microalgae as a main feedstock has attracted much attention in recent years but is still not economically feasible due to high algal culture cost. The objective of this study was to develop a comprehensive eco-friendly technology for cultivating microalgae Platymonas subcordiformis using aquaculture wastewater as growth medium for biomass and biofuel production. Platymonas subcordiformis was grown in pretreated flounder aquaculture wastewaters taken from different stages. Each of wastewater contained different levels of nutrients. The biomass yield of microalgae and associated nitrogen and phosphorous removal were investigated. The results showed that algal cell density increased 8.9 times than the initial level. Platymonas subcordiformis removed nitrogen and phosphorus from wastewater with an average removal efficiency of 87%–95% for nitrogen and 98%–99% for phosphorus. It was feasible to couple the removal of nitrogen and phosphorus from wastewater to algal biomass and biofuel production. However, further studies are required to make this technologies economically viable for algae biofuel production. 相似文献
447.
在对高等师范院校环境教育的现状及存在问题进行全面分析的基础上,提出了环境教育课程化的基本方式,包括开设环境教育的系列课程和加强实践性环境教育活动.对高等师范院校非环境类专业环境教育的课程化问题提出一些看法和建议:高等师范院校非环境类专业的环境教育应强化学生的职前培训,实施环境教育的课程化,建立完善的课程体系并采用多种课程教育模式,加强社会实践活动,将传统的师范教育课程体系改为更为广泛的多种课程体系.同时还要注重环境教育师资培养、加强学生的环保法律法规教育、创建绿色校园环境. 相似文献
448.
慕常强 《安全.健康和环境》2011,11(8):19-21,24
介绍了采用真空辅助液压潜油泵接卸铁路槽车石脑油的卸车工艺系统在安全环保方面存在的问题,提出了安全控制措施方案及控制系统,并对控制系统的实施效果进行了分析。 相似文献
449.
猪粪废水处理中养份含量与能量流通变化规律研究 总被引:3,自引:0,他引:3
本文研究了集约化猪场粪便废水处理过程中养份含量与能量流通变化规律。结果表明:猪粪废水经综合处理后养份的利用与回收达50—96%,有机碳的利用与回收达53.1%,能量的利用与回收达61.2%。其中,输入土壤生态系统的养份可达原粪养份总量的50—96%,有机碳可达28.1%,能量可达原粪总能量的42.2%。 相似文献
450.
Tischa A. Muñoz-Erickson Bernardo Aguilar-González Matthew R. R. Loeser Thomas D. Sisk 《Environmental management》2010,45(1):132-144
As collaborative groups gain popularity as an alternative means for addressing conflict over management of public lands, the
need for methods to evaluate their effectiveness in achieving ecological and social goals increases. However, frameworks that
examine both effectiveness of the collaborative process and its outcomes are poorly developed or altogether lacking. This
paper presents and evaluates the utility of the holistic ecosystem health indicator (HEHI), a framework that integrates multiple
ecological and socioeconomic criteria to evaluate management effectiveness of collaborative processes. Through the development
and application of the HEHI to a collaborative in northern Arizona, the Diablo Trust, we present the opportunities and challenges
in using this framework to evaluate the ecological and social outcomes of collaborative adaptive management. Baseline results
from the first application of the HEHI are presented as an illustration of its potential as a co-adaptive management tool.
We discuss lessons learned from the process of selecting indicators and potential issues to their long-term implementation.
Finally, we provide recommendations for applying this framework to monitoring and adaptive management in the context of collaborative
management. 相似文献