全文获取类型
收费全文 | 2119篇 |
免费 | 74篇 |
国内免费 | 76篇 |
专业分类
安全科学 | 126篇 |
废物处理 | 4篇 |
环保管理 | 64篇 |
综合类 | 1775篇 |
基础理论 | 201篇 |
污染及防治 | 13篇 |
评价与监测 | 18篇 |
社会与环境 | 28篇 |
灾害及防治 | 40篇 |
出版年
2024年 | 1篇 |
2023年 | 12篇 |
2022年 | 20篇 |
2021年 | 34篇 |
2020年 | 24篇 |
2019年 | 17篇 |
2018年 | 12篇 |
2017年 | 12篇 |
2016年 | 21篇 |
2015年 | 25篇 |
2014年 | 26篇 |
2013年 | 36篇 |
2012年 | 44篇 |
2011年 | 108篇 |
2010年 | 91篇 |
2009年 | 78篇 |
2008年 | 88篇 |
2007年 | 114篇 |
2006年 | 132篇 |
2005年 | 113篇 |
2004年 | 119篇 |
2003年 | 104篇 |
2002年 | 118篇 |
2001年 | 92篇 |
2000年 | 36篇 |
1999年 | 13篇 |
1998年 | 9篇 |
1997年 | 11篇 |
1996年 | 6篇 |
1995年 | 90篇 |
1994年 | 80篇 |
1993年 | 73篇 |
1992年 | 62篇 |
1991年 | 59篇 |
1990年 | 55篇 |
1989年 | 63篇 |
1988年 | 47篇 |
1987年 | 50篇 |
1986年 | 30篇 |
1985年 | 42篇 |
1984年 | 44篇 |
1983年 | 21篇 |
1982年 | 21篇 |
1981年 | 16篇 |
排序方式: 共有2269条查询结果,搜索用时 203 毫秒
891.
Stefano Regis Mirella Filocamo Raffaella Mazzotti Roberto Cusano Fabio Corsolini Gloria Bonuccelli Marina Stroppiano Rosanna Gatti 《黑龙江环境通报》2001,21(8):668-671
A prenatal diagnosis of Pelizaeus-Merzbacher disease (PMD) resulting from proteolipid protein gene (PLP) duplication was performed by a quantitative fluorescent multiplex PCR method. PLP gene copy number was determined in the proband, the pregnant mother, the male fetus and two aunts. Small amounts of genomic DNA extracted from peripheral blood and from chorionic villi were used. The fetus, in common with the proband, was identified as PMD-affected being a carrier of the PLP gene duplication, inherited from the mother, while the two aunts were non-carriers. The data obtained were confirmed by segregation analysis of a PLP-associated dinucleotide-repeat polymorphism amplified by the same multiplex PCR. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
892.
893.
894.
895.
896.
B. Loeys L. Nuytinck P. Van Acker S. Walraedt M. Bonduelle K. Sermon B. Hamel A. Sanchez L. Messiaen A. De Paepe 《黑龙江环境通报》2002,22(1):22-28
Marfan syndrome (MFS) is an autosomal dominant disorder with a prevalence of 2–3 per 10 000 individuals. Symptoms range from skeletal overgrowth, cutaneous striae to ectopia lentis and aortic dilatation leading to dissection. Prenatal diagnosis was until recently mainly performed in familial cases by linkage analysis. However, mutation detection has become available with thorough screening methods. The phenotypic variability observed in MFS makes reproductive options difficult, as molecular diagnosis cannot predict clinical severity of the disease. Data are presented on 15 prenatal and/or preimplantation genetic diagnoses (PGD) in nine families, originating from Belgium, the Netherlands, Spain and France. In four families data from linkage analysis were used, whereas in five other families the causative FBN1 mutation was characterised. Four PGD cycles in two couples led to one ongoing pregnancy. In addition, two amniocenteses and nine chorionic villus (CV) samplings were performed. In five pregnancies an affected fetus was diagnosed. In one of them, the couple chose to continue the pregnancy and an affected child was born, whereas the other four couples decided to terminate the pregnancy. It is expected that the greater availability of mutation testing of the FBN1 gene will increase requests for prenatal diagnosis. PGD appears to be an acceptable alternative for couples facing ethical reproductive dilemmas. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
897.
898.
899.
900.