全文获取类型
收费全文 | 915篇 |
免费 | 16篇 |
国内免费 | 10篇 |
专业分类
安全科学 | 82篇 |
废物处理 | 30篇 |
环保管理 | 203篇 |
综合类 | 166篇 |
基础理论 | 195篇 |
环境理论 | 1篇 |
污染及防治 | 168篇 |
评价与监测 | 52篇 |
社会与环境 | 34篇 |
灾害及防治 | 10篇 |
出版年
2023年 | 7篇 |
2022年 | 3篇 |
2021年 | 8篇 |
2020年 | 17篇 |
2019年 | 13篇 |
2018年 | 21篇 |
2017年 | 19篇 |
2016年 | 39篇 |
2015年 | 24篇 |
2014年 | 27篇 |
2013年 | 95篇 |
2012年 | 41篇 |
2011年 | 63篇 |
2010年 | 37篇 |
2009年 | 45篇 |
2008年 | 50篇 |
2007年 | 45篇 |
2006年 | 52篇 |
2005年 | 23篇 |
2004年 | 27篇 |
2003年 | 29篇 |
2002年 | 24篇 |
2001年 | 17篇 |
2000年 | 17篇 |
1999年 | 15篇 |
1998年 | 3篇 |
1997年 | 6篇 |
1996年 | 13篇 |
1995年 | 7篇 |
1994年 | 13篇 |
1993年 | 9篇 |
1992年 | 9篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 12篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 15篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1980年 | 3篇 |
1978年 | 4篇 |
1975年 | 3篇 |
1970年 | 2篇 |
1966年 | 2篇 |
1963年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有941条查询结果,搜索用时 671 毫秒
881.
882.
883.
Marguerite Miguet Julien Thevenon Vincent Laugel Mathilde Lefebvre Aurélie Bourchany Jean-Baptiste Rivière Yannis Duffourd Elise Schaefer Maria Cristina Antal Rosalie Abida Anne-Sophie Weingertner Valérie Kremer Pierre Vabres Fanny Morice-Picard Marie Gonzales Dan Lipsker Sylvie Fraitag Jean-Louis Mandel Jamel Chelly Hélène Dollfus Laurence Faivre Christel Thauvin-Robinet Nadège Calmels Salima El Chehadeh 《黑龙江环境通报》2016,36(13):1276-1279
884.
Objective
Women with high body mass index (BMI) tend to have reduced fetal fraction (FF) during cell-free DNA-based noninvasive prenatal screening (NIPS), causing test failure rates up to 24.3% and prompting guidelines that recommend aneuploidy screening other than NIPS for patients with significant obesity. Because alternatives to NIPS are only preferable if they perform better, we compared the respective sensitivities at different BMI levels of traditional aneuploidy screening and a customized whole-genome sequencing NIPS.Method
The relationship between FF, aneuploidy, and BMI was quantified from 58 105 patients screened with a customized NIPS that does not fail samples because of low FF alone. Expected analytical sensitivity as a function of aneuploidy and BMI (eg, trisomy 18 sensitivity when BMI = 35) was determined by scaling the BMI- and aneuploidy-specific FF distribution by the FF- and aneuploidy-specific sensitivity calculated from empirically informed simulations.Results
Across all classes of obesity and assuming zero FF-related test failures, analytical sensitivity for the investigated NIPS exceeded that of traditional aneuploidy screening for trisomies 13, 18, and 21.Conclusion
Relative to traditional aneuploidy screening, a customized NIPS with high accuracy at low FF and a low test-failure rate is a superior screening option for women with high BMI. 相似文献885.
886.
887.
888.
889.
The investigation was carried out from 62°N to 73°N and from 14°E to 11°W in the Norwegian Sea during 19 June-12 July 1997. Regional differences in the phase of the seasonal development of the plankton community were evident, most pronounced across the Arctic front. In the Coastal and eastern Atlantic domains, post-bloom conditions prevailed, characterised by low chlorophyll a (chl a) levels and a phytoplankton assemblage dominated by coccolithophorids and small flagellates. During the study period, egg production rates of Calanus finmarchicus were low (<10 eggs female-1 day-1), older copepodite stages dominated, and the seasonal descent to deeper waters had started. In the Arctic domain, bloom conditions were evident by high chl a levels and a high abundance of large diatoms. Egg production rates were higher (a maximum of 29 eggs female-1 day-1), but the dominance of stages CI-CIII indicated that considerable spawning had already occurred prior to the spring bloom. The seasonal descent had barely started. Both invertebrate and fish predators were most abundant in the Coastal and eastern Atlantic domains, with abundance strongly decreasing north-westwards. No tight relationship between total abundance of invertebrate or fish predators and that of C. finmarchicus was apparent. However, a weak, but significant, relationship between abundance of young stages of chaetognaths and Euchaeta spp. versus young stages of C. finmarchicus was found, indicating that these invertebrate predators develop parallel to the development of the new cohort of C. finmarchicus. In early summer, C. finmarchicus had reached overwintering stages, and had started to accumulate in deeper waters in areas with the highest abundance of horizontally migratory planktivorous fish. 相似文献
890.
Employee turnover is a major concern because of its cost to organizations. Although theory supports the influence of nonwork factors on turnover, our understanding of the degree to which nonwork factors relate to actual turnover behavior is not well developed. Using a sample of 5505 U.S. Army officers, we assessed the extent to which spouse career support related to reduced turnover four years later through work interfering with family (WIF) and job satisfaction as mechanisms. Results revealed that spouse career support decreased the odds of turnover, and WIF and job satisfaction sequentially mediated this relationship, with lower WIF and higher job satisfaction reducing the odds of turnover. Practical implications of using family support systems as retention interventions are discussed. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献