全文获取类型
收费全文 | 2912篇 |
免费 | 72篇 |
国内免费 | 31篇 |
专业分类
安全科学 | 150篇 |
废物处理 | 113篇 |
环保管理 | 787篇 |
综合类 | 282篇 |
基础理论 | 692篇 |
环境理论 | 3篇 |
污染及防治 | 686篇 |
评价与监测 | 174篇 |
社会与环境 | 109篇 |
灾害及防治 | 19篇 |
出版年
2023年 | 16篇 |
2022年 | 22篇 |
2021年 | 32篇 |
2020年 | 32篇 |
2019年 | 38篇 |
2018年 | 57篇 |
2017年 | 57篇 |
2016年 | 98篇 |
2015年 | 64篇 |
2014年 | 68篇 |
2013年 | 305篇 |
2012年 | 110篇 |
2011年 | 168篇 |
2010年 | 125篇 |
2009年 | 137篇 |
2008年 | 145篇 |
2007年 | 151篇 |
2006年 | 134篇 |
2005年 | 78篇 |
2004年 | 110篇 |
2003年 | 103篇 |
2002年 | 89篇 |
2001年 | 58篇 |
2000年 | 42篇 |
1999年 | 46篇 |
1998年 | 41篇 |
1997年 | 40篇 |
1996年 | 45篇 |
1995年 | 55篇 |
1994年 | 43篇 |
1993年 | 42篇 |
1992年 | 26篇 |
1991年 | 33篇 |
1990年 | 35篇 |
1989年 | 24篇 |
1988年 | 30篇 |
1987年 | 25篇 |
1986年 | 37篇 |
1985年 | 21篇 |
1984年 | 35篇 |
1983年 | 28篇 |
1982年 | 30篇 |
1981年 | 30篇 |
1980年 | 18篇 |
1979年 | 18篇 |
1978年 | 12篇 |
1977年 | 10篇 |
1976年 | 9篇 |
1974年 | 8篇 |
1972年 | 10篇 |
排序方式: 共有3015条查询结果,搜索用时 250 毫秒
761.
Jacob A. Canick Glenn E. Palomaki Edward M. Kloza Geralyn M. Lambert-Messerlian James E. Haddow 《黑龙江环境通报》2013,33(7):667-674
Maternal plasma contains circulating cell-free DNA fragments originating from both the mother and the placenta. The proportion derived from the placenta is known as the fetal fraction. When measured between 10 and 20 gestational weeks, the average fetal fraction in the maternal plasma is 10% to 15% but can range from under 3% to over 30%. Screening performance using next-generation sequencing of circulating cell-free DNA is better with increasing fetal fraction and, generally, samples whose values are less than 3% or 4% are unsuitable. Three examples of the clinical impact of fetal fraction are discussed. First, the distribution of test results for Down syndrome pregnancies improves as fetal fraction increases, and this can be exploited in reporting patient results. Second, the strongest factor associated with fetal fraction is maternal weight; the false negative rate and rate of low fetal fractions are highest for women with high maternal weights. Third, in a mosaic, the degree of mosaicism will impact the performance of the test because it will reduce the effective fetal fraction. By understanding these aspects of the role of fetal fraction in maternal plasma DNA testing for aneuploidy, we can better appreciate the power and the limitations of this impressive new methodology. © 2013 John Wiley & Sons, Ltd. 相似文献
762.
763.
Walker David I. Cross Lisa J. Stapleton Tina A. Jenkins Connaire L. Lees David N. Lowther James A. 《Food and environmental virology》2019,11(3):229-237
Food and Environmental Virology - Human noroviruses are the leading cause of viral gastroenteritis. In the absence of a practical culture technique for routine analysis of infectious noroviruses,... 相似文献
764.
Carrier screening tests reproductive couples for their risk of having children affected by serious monogenic conditions. Carrier screening has historically been offered for certain conditions in high-risk populations. However, more recent evidence has shown that offering carrier screening to all patients, regardless of their ethnicity, more effectively and equitably identifies at-risk couples. Coupled with technology that enables screening for a nearly unlimited number of conditions, this expanded carrier screening (ECS) approach is now supported by professional society guidelines. Despite recent recommendations by the American College of Medical Genetics and Genomics to screen all patients who are pregnant or considering pregnancy for 113 conditions, questions remain about what conditions should be included on a core ECS panel. Here, we briefly review the history of carrier screening and guidelines on criteria for panel design. We then suggest which of these criteria are most critical, as well as thresholds to identify which conditions meet these criteria. Based on these interpretations, we recommend a core panel of 64 conditions that would identify the vast majority of at-risk couples. Widespread adoption of a core panel such as this would result in a marked improvement in the number of patients currently receiving comprehensive carrier screening. 相似文献
765.
766.
Heather Elizabeth Braid Jonathan Deeds Stacey Lea DeGrasse John James Wilson Josephine Osborne Robert Harland Hanner 《Marine Biology》2012,159(1):25-31
In fall of 2009, several mass strandings of Humboldt squid (Dosidicus gigas) occurred on Vancouver Island (49°7′60N 125°54′0W). Morphological dissections coupled with DNA barcoding of stomach contents
revealed Sardinops sagax (Pacific sardine) and Clupea pallasii (Pacific herring) as their primary prey. Plastic nurdles, fishing line, bull kelp, eelgrass, and a guillemot feather were
also discovered. The primary prey, Pacific sardines and Pacific herring, are known to bioaccumulate paralytic shellfish toxins
(PSTs); additionally, both PSTs and domoic acid (DA) have been implicated in other mass strandings. Therefore, stomach contents,
and other tissues when possible, were tested for PSTs and DA. Testing revealed DA concentrations below regulatory guidance
levels for human consumption, yet PSTs were well in excess. Though we cannot conclude that PSTs were the definitive cause
of the strandings, our findings are the first report of PSTs in D. gigas. 相似文献
767.
768.
Nicolas Gruchy Eleonore Blondeel Nathalie Le Meur Géraldine Joly-Hélas Pascal Chambon Marianne Till Martine Herbaux Adeline Vigouroux-Castera Aurélie Coussement James Lespinasse Florence Amblard Mélanie Jimenez Pocquet Camille Lebel-Roy Frédérique Carré-Pigeon Elisabeth Flori Francine Mugneret Sylvie Jaillard Catherine Yardin Radu Harbuz Marie-Agnès Collonge-Rame Philippe Vago Mylène Valduga Nathalie Leporrier François Vialard 《黑龙江环境通报》2016,36(6):523-529
769.
770.
Eliza Kluckow Jane Halliday Alice Poulton Anthea Lindquist Briohny Hutchinson Michael Bethune Leonard Bonacquisto Fabricio Da Silva Costa Lucy Gugasyan James Harraway Amanda Howden Abhijit Kulkarni Nicole Martin Richard McCoy Melody Menezes Debbie Nisbet Ricardo Palma-Dias Mark D. Pertile Zeffie Poulakis Lisa Hui 《黑龙江环境通报》2019,39(13):1254-1261