全文获取类型
收费全文 | 659篇 |
免费 | 50篇 |
国内免费 | 10篇 |
专业分类
安全科学 | 43篇 |
废物处理 | 6篇 |
环保管理 | 144篇 |
综合类 | 183篇 |
基础理论 | 29篇 |
污染及防治 | 57篇 |
评价与监测 | 240篇 |
社会与环境 | 11篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 5篇 |
2022年 | 13篇 |
2021年 | 11篇 |
2020年 | 29篇 |
2019年 | 7篇 |
2018年 | 4篇 |
2017年 | 16篇 |
2016年 | 16篇 |
2015年 | 17篇 |
2014年 | 34篇 |
2013年 | 30篇 |
2012年 | 26篇 |
2011年 | 56篇 |
2010年 | 24篇 |
2009年 | 36篇 |
2008年 | 42篇 |
2007年 | 48篇 |
2006年 | 34篇 |
2005年 | 24篇 |
2004年 | 25篇 |
2003年 | 24篇 |
2002年 | 16篇 |
2001年 | 32篇 |
2000年 | 21篇 |
1999年 | 17篇 |
1998年 | 22篇 |
1997年 | 9篇 |
1996年 | 13篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 14篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有719条查询结果,搜索用时 31 毫秒
671.
Alexis Knight Satyendra P. Bhavsar Brian A. Branfireun Peter Drouin Ram Prasha Steve Petro Moustapha Oke 《环境科学学报(英文版)》2019,31(6):137-145
The use of biopsy plugs to sample fish muscle tissue for mercury analyses is a viable alternative to lethal sampling; however, the practice has yet to be widely implemented in routine monitoring due to concerns about variability of mercury concentrations in fish muscle tissues. Here we examine distribution of mercury in fillets of four fish species (Walleye, Northern Pike, Smallmouth Bass and Lake Trout), suitability of left/right side of fillet for biopsy sampling, and appropriateness of re-using a biopsy punch. The results showed that average mercury concentrations in left and right fillets of fish are similar. Mercury concentrations in biopsy plug samples, taken from the anterior dorsal area of the fish fillet, were statistically equivalent to the mercury concentrations in homogenized fillets. There was no discernible cross contamination between samples when a biopsy punch was reused after washing in hot soapy water, and as such, biopsy punches can be recycled during sampling to reduce the sampling cost. If a tissue mass collected from a specific site on the fillet is insufficient, then we suggest sampling corresponding locations on the other fillet rather than sampling two adjacent sites on one fillet to obtain more tissue. The results presented here can improve the accuracy of fillet biopsy plug sampling, minimize fish mortality for mercury monitoring, and reduce labor and material costs in monitoring programs. 相似文献
672.
Jixian Cui Jianlei Lang Tian Chen Shushuai Mao Shuiyuan Cheng Zhanshan Wang Nianliang Cheng 《环境科学学报(英文版)》2019,31(7):225-237
In this study, an analysis framework based on the regular monitoring data was proposed for investigating the annual/inter-annual air quality variation and the contributions from different factors(i.e., seasons, pollution periods and airflow directions), through a case study in Beijing from 2013 to 2016. The results showed that the annual mean concentrations(MC) of PM_(2.5), SO_2, NO_2 and CO had decreased with annual mean ratios of 7.5%, 28.6%, 4.6%and 15.5% from 2013 to 2016, respectively. Among seasons, the MC in winter contributed the largest fractions(25.8%~46.4%) to the annual MC, and the change of MC in summer contributed most to the inter-annual MC variation(IMCV) of PM_(2.5) and NO2. For different pollution periods, gradually increase of frequency of S-1(PM_(2.5), 0~ 75 μg/m~3) made S-1 become the largest contributor(28.8%) to the MC of PM_(2.5) in 2016, it had a negative contribution(-13.1%) to the IMCV of PM_(2.5); obvious decreases of frequencies of heavily polluted and severely polluted dominated(44.7% and 39.5%) the IMCV of PM_(2.5). For different airflow directions, the MC of pollutants under the south airflow had the most significant decrease(22.5%~62.5%), and those decrease contributed most to the IMCV of PM_(2.5)(143.3%),SO2(72.0%), NO_2(55.5%) and CO(190.3%); the west airflow had negative influences to the IMCV of PM_(2.5), NO_2 and CO. The framework is helpful for further analysis and utilization of the large amounts of monitoring data; and the analysis results can provide scientific supports for the formulation or adjustment of further air pollution mitigation policy. 相似文献
673.
刘铭刚 《安全.健康和环境》2019,19(1):47-53
基于统计学理论提出了一种针对复杂油气井井筒完整性失效贡献因素的量化评价方法并进行了工程应用。通过引入因子载荷矩阵推导了井筒完整性评价的因子分析模型,以最少信息丢失为原则对井筒完整性失效的贡献因素进行了分类、筛选和重要度排名,将井筒完整性失效的贡献因素类别从23类压缩为7类,在保证精度的情况下提高了统计效率。重要度分析表明:"抗剪切失效"对普光T4井筒完整性失效的贡献最大,累计重要度达到了11. 093;而"结构失效"对顶事件普光T4井筒完整性失效的贡献最小,累计重要度为1. 199。研究成果可为复杂油气井井筒的设计、安全评价提供理论和方法支持。 相似文献
674.
675.
676.
Tina L. Cheng Jonathan D. Reichard Jeremy T. H. Coleman Theodore J. Weller Wayne E. Thogmartin Brian E. Reichert Alyssa B. Bennett Hugh G. Broders Joshua Campbell Katherine Etchison Daniel J. Feller Richard Geboy Traci Hemberger Carl Herzog Alan C. Hicks Sandra Houghton Jessica Humber Joseph A. Kath R. Andrew King Susan C. Loeb Ariane Massé Katrina M. Morris Holly Niederriter Gerda Nordquist Roger W. Perry Richard J. Reynolds D. Blake Sasse Michael R. Scafini Richard C. Stark Craig W. Stihler Steven C. Thomas Gregory G. Turner Shevenell Webb Bradford J. Westrich Winifred F. Frick 《Conservation biology》2021,35(5):1586-1597
Assessing the scope and severity of threats is necessary for evaluating impacts on populations to inform conservation planning. Quantitative threat assessment often requires monitoring programs that provide reliable data over relevant spatial and temporal scales, yet such programs can be difficult to justify until there is an apparent stressor. Leveraging efforts of wildlife management agencies to record winter counts of hibernating bats, we collated data for 5 species from over 200 sites across 27 U.S. states and 2 Canadian provinces from 1995 to 2018 to determine the impact of white-nose syndrome (WNS), a deadly disease of hibernating bats. We estimated declines of winter counts of bat colonies at sites where the invasive fungus that causes WNS (Pseudogymnoascus destructans) had been detected to assess the threat impact of WNS. Three species undergoing species status assessment by the U.S. Fish and Wildlife Service (Myotis septentrionalis, Myotis lucifugus, and Perimyotis subflavus) declined by more than 90%, which warrants classifying the severity of the WNS threat as extreme based on criteria used by NatureServe. The scope of the WNS threat as defined by NatureServe criteria was large (36% of Myotis lucifugus range) to pervasive (79% of Myotis septentrionalis range) for these species. Declines for 2 other species (Myotis sodalis and Eptesicus fuscus) were less severe but still qualified as moderate to serious based on NatureServe criteria. Data-sharing across jurisdictions provided a comprehensive evaluation of scope and severity of the threat of WNS and indicated regional differences that can inform response efforts at international, national, and state or provincial jurisdictions. We assessed the threat impact of an emerging infectious disease by uniting monitoring efforts across jurisdictional boundaries and demonstrated the importance of coordinated monitoring programs, such as the North American Bat Monitoring Program (NABat), for data-driven conservation assessments and planning. 相似文献
677.
A Suggestion for an Improved Vegetation Scheme for Local and Global Mapping and Monitoring 总被引:1,自引:0,他引:1
Jonathan M. Adams 《Environmental management》1999,23(1):1-13
The next stage in the process will be to obtain the views of as many people working in as many different fields as possible,
to see whether the proposed scheme suits their needs and how it should be modified. With a few modifications, such a scheme
could easily be appended to an existing land cover classification scheme, such as the FAO system, greatly increasing the usefulness
and accessability of the results of the landcover classification. 相似文献
678.
环保设施竣工验收监测报告书的编制应以为环境管理和企业污染防治服务为宗旨。报告书的内容应具有技术性、可操作性和指导性。报告书应以污染源调查及验收监测分析和环保设施“三同时”执行情况调查和环保设施竣工验收监测分析为核心内容。报告书的结论应明确:主要污染物的排放浓度达标情况,合格率以及主要污染物的排放总量情况;环保设施的“三同时”执行情况,“三同时”执行率以及环保设施运行合格率。 相似文献
679.
为解决家用空调器噪声污染纠纷日益增多的问题,以一居民住宅楼为例,对家用空调噪声影响进行了监测与评价,并提出了防治措施。 相似文献
680.
一般用t检验和方差分析对水质监测中多项指标进行评价分析,有是会得不到确切的结果。应用多元统计分析中HetellinmgT^2检验法进行分析得到了满意结果。以两个年度水质监测5项指标的监测数据为例,同时用t检验和HeltellingT^2检测进行评价分析,结果表明,HetellingT^2检验具有更好的实用性和合理性。 相似文献