全文获取类型
收费全文 | 5476篇 |
免费 | 27篇 |
国内免费 | 25篇 |
专业分类
安全科学 | 131篇 |
废物处理 | 296篇 |
环保管理 | 433篇 |
综合类 | 828篇 |
基础理论 | 1356篇 |
环境理论 | 1篇 |
污染及防治 | 1351篇 |
评价与监测 | 396篇 |
社会与环境 | 709篇 |
灾害及防治 | 27篇 |
出版年
2023年 | 42篇 |
2022年 | 76篇 |
2021年 | 59篇 |
2020年 | 29篇 |
2019年 | 42篇 |
2018年 | 75篇 |
2017年 | 90篇 |
2016年 | 110篇 |
2015年 | 70篇 |
2014年 | 146篇 |
2013年 | 416篇 |
2012年 | 167篇 |
2011年 | 241篇 |
2010年 | 214篇 |
2009年 | 219篇 |
2008年 | 253篇 |
2007年 | 250篇 |
2006年 | 240篇 |
2005年 | 207篇 |
2004年 | 187篇 |
2003年 | 214篇 |
2002年 | 175篇 |
2001年 | 254篇 |
2000年 | 161篇 |
1999年 | 101篇 |
1998年 | 41篇 |
1997年 | 58篇 |
1996年 | 53篇 |
1995年 | 60篇 |
1994年 | 64篇 |
1993年 | 59篇 |
1992年 | 58篇 |
1991年 | 61篇 |
1990年 | 66篇 |
1989年 | 52篇 |
1988年 | 57篇 |
1987年 | 54篇 |
1986年 | 55篇 |
1985年 | 41篇 |
1984年 | 47篇 |
1983年 | 47篇 |
1982年 | 48篇 |
1980年 | 30篇 |
1979年 | 32篇 |
1978年 | 29篇 |
1977年 | 28篇 |
1976年 | 28篇 |
1974年 | 31篇 |
1973年 | 30篇 |
1972年 | 27篇 |
排序方式: 共有5528条查询结果,搜索用时 203 毫秒
561.
562.
563.
A. Camacho R. Devesa I. Serrano S. Blázquez L. Matia 《Journal of environmental radioactivity》2010,101(12):1048-1054
A study is presented on the distribution of 234U, 238U, 235U isotopes in surface water of the Llobregat river basin (Northeast Spain), from 2001 to 2006. Sixty-six superficial water samples were collected at 16 points distributed throughout the Llobregat river basin. Uranium isotopes were measured by alpha spectrometry (PIPS detectors). The test procedure was validated according to the quality requirements of the ISO17025 standard. The activity concentration for the total dissolved uranium ranges from 20 to 261 mBq L−1. The highest concentrations of uranium were detected in an area with formations of sedimentary rock, limestone and lignite. A high degree of radioactive disequilibrium was noted among the uranium isotopes. The 234U/238U activity ratio varied between 1.1 and 1.9 and the waters with the lowest uranium activity registered the highest level of 234U/238U activity ratio. Correlations between uranium activity in the tested water and chemical and physical characteristics of the aquifer were found. 相似文献
564.
565.
Non-invasive prenatal screening (NIPS) has revolutionized the approach to prenatal fetal aneuploidy screening. Many commercial providers now offer analyses for sub-chromosomal copy number variations (CNVs). Here, we review the use of NIPS in the context of screening for microdeletions and microduplications, issues surrounding the choice of disorders tested for, and the advantages and disadvantages associated with the inclusion of microdeletions to current NIPS. Several studies have claimed benefits; however, we suggest that microdeletions have not demonstrated a low enough false positive rate to be deemed practical or ethically acceptable, especially considering their low positive predictive values. Because a positive NIPS result should be confirmed using diagnostic techniques, and false positive rates are as high as 90% for some microdeletions, diagnostic testing seems preferable when the goal is to maximize the detection of microdeletion or microduplication syndromes. 相似文献
566.
This paper details the development of, and perceived role and effectiveness of an innovative intervention designed to ultimately improve the safety of a group of community care (CC) nurses while driving. Recruiting participants from an Australian CC nursing car fleet, qualitative responses from a series of open-ended questions were obtained from drivers (n = 36), supervisors (n = 22), and managers (n = 6). The findings supported the effectiveness of the intervention in reducing self-reported speeding and promoting greater insight into one’s behaviour on the road. This research has important practical implications in that it highlights the value of developing an intervention based on a sound theoretical framework and which is aligned with the needs and beliefs of personnel within a particular organisation. 相似文献
567.
Bushra Waheed Faisal I. Khan Brian Veitch Kelly Hawboldt 《Journal of Cleaner Production》2011,19(6-7):720-732
Evaluation of sustainability in various facets of life is gaining increasing importance. Traditionally, different multi-criteria decision-making methods have been used for sustainability assessment. “Sustainability” can be a qualitative concept, and as such several researchers have attempted fuzzy logic for the quantitative assessment of sustainability. This paper outlines a new evaluation model based on fuzzy multi-criteria decision-making. The model is tested for sustainability assessment of higher education institutions (HEIs). It is based on a driving force–pressure–state–exposure–effect–action (DPSEEA) framework and is called uncertainty-based DPSEEA-Sustainability index Model (uD-SiM). The uD-SiM is a causality-based model in which the sustainability index is an outcome of nonlinear impacts of sustainability indicators in different stages of DPSEEA. The percent contribution of driving forces on the sustainability index of HEI is investigated using sensitivity analysis. The study reveals that education in sustainability and global and local research trends are the major driving forces for achieving sustainability in HEI, followed by financial and economic growth rate, social equity, energy requirements rate, and institutional enhancement, in descending order. The results of uD-SiM were found to be more realistic and rational than our earlier proposed approach, D-SiM. 相似文献
568.
Kovacevic R. Teodorovic I. Kaisarevic S. Planojevic I. Fa S. Dakic V. Pogrmic K. Virijevic S. 《Environmental science and pollution research international》2009,16(1):130-131
Environmental Science and Pollution Research - 相似文献
569.
570.