全文获取类型
收费全文 | 2874篇 |
免费 | 17篇 |
国内免费 | 33篇 |
专业分类
安全科学 | 83篇 |
废物处理 | 140篇 |
环保管理 | 275篇 |
综合类 | 552篇 |
基础理论 | 569篇 |
环境理论 | 2篇 |
污染及防治 | 858篇 |
评价与监测 | 242篇 |
社会与环境 | 183篇 |
灾害及防治 | 20篇 |
出版年
2023年 | 26篇 |
2022年 | 86篇 |
2021年 | 104篇 |
2020年 | 53篇 |
2019年 | 42篇 |
2018年 | 98篇 |
2017年 | 101篇 |
2016年 | 121篇 |
2015年 | 70篇 |
2014年 | 114篇 |
2013年 | 224篇 |
2012年 | 125篇 |
2011年 | 162篇 |
2010年 | 114篇 |
2009年 | 110篇 |
2008年 | 127篇 |
2007年 | 113篇 |
2006年 | 76篇 |
2005年 | 116篇 |
2004年 | 157篇 |
2003年 | 154篇 |
2002年 | 98篇 |
2001年 | 76篇 |
2000年 | 33篇 |
1999年 | 33篇 |
1998年 | 15篇 |
1997年 | 28篇 |
1996年 | 16篇 |
1995年 | 33篇 |
1994年 | 19篇 |
1993年 | 17篇 |
1992年 | 20篇 |
1991年 | 24篇 |
1990年 | 12篇 |
1989年 | 18篇 |
1988年 | 6篇 |
1987年 | 12篇 |
1986年 | 11篇 |
1985年 | 14篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1982年 | 7篇 |
1981年 | 13篇 |
1979年 | 18篇 |
1977年 | 7篇 |
1970年 | 3篇 |
1966年 | 3篇 |
1964年 | 4篇 |
1961年 | 3篇 |
1924年 | 4篇 |
排序方式: 共有2924条查询结果,搜索用时 15 毫秒
31.
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
32.
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
33.
Reverse phase HPLC of radioactive globin chains has been compared to classical carboxy methyl cellulose chromatography for the prenatal diagnosis of β thalassaemia. The two methods correlated highly (r = 0.97 p < 0.0005) and provided an identical diagnosis for 40 fetal blood samples of fetuses homozygous or heterozygous for β thalassaemia. The HPLC procedure was much faster and required fewer biochemical steps (no globin preparation). It was at least as accurate and more sensitive than the classical chromatography. A single column can be used for 150 analyses and is always ready to be used. Last but not least it is much less expensive than CMC chromatography. 相似文献
34.
35.
36.
37.
38.
39.
Frances R. Sweetman Kenneth M. Gibson Lawrence Sweetman Ph.D William L. Nyhan Homer Chin William Swartz Oliver W. Jones 《黑龙江环境通报》1986,6(3):187-194
We have documented the presence of five mitochondrial enzymes in samples of chorionic villus tissue and measured the levels of activity. Three of the enzymes catalyse biotindependent reactions. These are propionyl-CoA carboxylase, 3-methylcrotonyl-CoA carboxylase and pyruvate carboxylase. the other enzymes. 4-aminobutyric acid aminotransferase and succinic semialdehyde dehydrogenase, are involved inthe degradation of the central inhibitory neurotransmitter GABA. Distinct diseases in whichthere is deficiency of each of these enzymes have been documented in man. Significant levels of activity were observed for all five enzymes in chorionic villus tissue. This methodology should permit early prenatal diagnosis of deficiencies of these enzymes by chorionic villus biopsy in the first trimester. 相似文献
40.
We report relatively high citrulline concentration in amniotic fluid of a citrullinemic fetus suggesting that prenatal detection of this condition could be done on this basis in conjunction with a direct or an indirect determination of argininosuccinate synthetase activity in amniotic fluid cells. 相似文献