全文获取类型
收费全文 | 3208篇 |
免费 | 25篇 |
国内免费 | 38篇 |
专业分类
安全科学 | 90篇 |
废物处理 | 174篇 |
环保管理 | 305篇 |
综合类 | 527篇 |
基础理论 | 654篇 |
环境理论 | 2篇 |
污染及防治 | 994篇 |
评价与监测 | 295篇 |
社会与环境 | 202篇 |
灾害及防治 | 28篇 |
出版年
2023年 | 33篇 |
2022年 | 103篇 |
2021年 | 135篇 |
2020年 | 62篇 |
2019年 | 57篇 |
2018年 | 121篇 |
2017年 | 127篇 |
2016年 | 154篇 |
2015年 | 90篇 |
2014年 | 147篇 |
2013年 | 222篇 |
2012年 | 154篇 |
2011年 | 195篇 |
2010年 | 135篇 |
2009年 | 127篇 |
2008年 | 144篇 |
2007年 | 139篇 |
2006年 | 91篇 |
2005年 | 129篇 |
2004年 | 165篇 |
2003年 | 158篇 |
2002年 | 115篇 |
2001年 | 78篇 |
2000年 | 38篇 |
1999年 | 35篇 |
1998年 | 16篇 |
1997年 | 26篇 |
1996年 | 18篇 |
1995年 | 24篇 |
1994年 | 21篇 |
1993年 | 10篇 |
1992年 | 12篇 |
1991年 | 16篇 |
1990年 | 11篇 |
1989年 | 12篇 |
1988年 | 7篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 10篇 |
1984年 | 11篇 |
1983年 | 11篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1979年 | 8篇 |
1970年 | 3篇 |
1966年 | 3篇 |
1965年 | 3篇 |
1964年 | 4篇 |
1963年 | 3篇 |
1961年 | 4篇 |
排序方式: 共有3271条查询结果,搜索用时 15 毫秒
21.
22.
Salomao O. Bandeira Rui Paula e Silva Jose Paula Adriano Macia Lars Hernroth Almeida T. Guissamulo Domingos Z.Bergman 《Ambio-人类环境杂志》2002,31(7):606-609
本文概述了莫桑比克包括渔业在内的海洋生物学研究的发展情况.莫桑比克的海岸线约为3000km,海洋的生物资源在莫桑比克的社会中起着重要的作用,主要是作为人们的蛋白质来源以及收入和出口创汇的来源. 相似文献
23.
The Science of Nature - Because of the sudden rise in primary-energy costs and the rapid inflation of plants which are used for the conversion of primary to secondary energy, the storage of energy,... 相似文献
24.
While true mosaicism occurs in only 0–25 per cent of genetic amniocenteses, nearly 2–5 per cent of amniotic fluid cell cultures contain a second cell line. In the common practice of prenatal diagnosis, an aberrant cell line confined to a single colony is usually disregarded. We present a case of mosaic trisomy 14 which was not detected on initial chromosome analysis. At birth, multiple malformations were apparent. Newborn cytogenetic studies revealed mosaicism [46,XX/46,XX,-14,+i(14q)] with an isochromosome 14 in 37 per cent of lymphocytes. Additional cells from the initial amniotic fluid culture were analysed post-delivery and the isochromosome 14 identified in only one of 12 total colonies. This case illustrates two important lessons in prenatal diagnosis. First, amniotic fluid cell cultures may not accurately reflect the relative distribution of the normal and abnormal cell lines within a mosaic fetus. Second, while it is generally reasonable to disregard mosaicism confined to a single colony, this policy will, on rare occasion, result in diagnostic error. This should be taken into consideration, particularly when dealing with autosomal trisomies potentially compatible with livebirth. 相似文献
25.
26.
Klaassien J. Ganzeveld Annechien van Hagen Martin H. van Agteren Wim de Koning Anton J. M. Schoot Uiterkamp 《Journal of Cleaner Production》1999,7(6):690
Two types of fermented organic waste (trade and industry waste and fruit and vegetable waste) were successfully used as a sole carbon source to produce poly-3-hydroxybutyrate-co-valerate (PHBV) by Ralstonia eutrophus (formerly Alcaligenes eutrophus) via oxygen limitation.The production of PHBV could be optimized by optimizing the oxygen transfer through the fermentor. Thereby, a peak concentration of 1.1 g PHBV per liter cell suspension, 40 w% of cell dry weight, was obtained at an aeration rate of 0.24 mol O2/h·kg biomass. The yield of PHBV on the fatty acid concentration in the organic waste was 0.16 g polymer/g volatile organic matter. The process obtained, compares well with the commercial production process of PHBV based on glucose. 相似文献
27.
Christine Willekes Frans J. M. E. Roumen MD PhD Anne-Marie W. van Elsacker-Niele Harro T. Weiland Christl Vermey-Keers Johan H. J. M. van Krieken Christine E. M. de Die-Smulders Guus J. H. Hamers Gerrie P. M. Vaes-Peters 《黑龙江环境通报》1994,14(3):181-185
In a case of hydrops fetalis, serological examination showed a recent maternal human parvovirus B19 infection. Amniocentesis revealed a unique unbalanced translocation between chromosomes 3 and 11 of the fetus. The mother proved to have a balanced reciprocal translocation between chromosomes 3 and 11. A grossly macerated hydropic male fetus was delivered with a flat nose and low implanted deformed ears. Histopathological examination revealed nuclear inclusion bodies in fetal erythroid cells, confirming human parvovirus B19 infection. Parvovirus B19 DNA was demonstrated by in situ hybridization in the nuclei of heart muscle cells. Our finding of two different disorders in one case illustrates the importance of a complete evaluation of every case of hydrops fetalis, especially concerning counselling on the outcome of future pregnancies. The human parvovirus B19 infection will not recur due to the acquired immunity of the mother, whereas the balanced reciprocal translocation will endanger future pregnancies. 相似文献
28.
We describe a patient with a significantly elevated serum alphafetoprotein (AFP) concentration at 17 weeks of gestation, who showed only a marginally increased amniotic fluid AFP and lacked the second rapidly migrating band of acetylcholinesterase electrophoresis. Ultrasound examination revealed an encephalocele and ventriculomegaly. Autopsy showed that the encephalocele was not covered by skin. 相似文献
29.
30.