全文获取类型
收费全文 | 31760篇 |
免费 | 392篇 |
国内免费 | 267篇 |
专业分类
安全科学 | 1095篇 |
废物处理 | 1531篇 |
环保管理 | 4586篇 |
综合类 | 4687篇 |
基础理论 | 8199篇 |
环境理论 | 9篇 |
污染及防治 | 7757篇 |
评价与监测 | 2236篇 |
社会与环境 | 2105篇 |
灾害及防治 | 214篇 |
出版年
2023年 | 137篇 |
2022年 | 274篇 |
2021年 | 341篇 |
2020年 | 207篇 |
2019年 | 268篇 |
2018年 | 475篇 |
2017年 | 493篇 |
2016年 | 767篇 |
2015年 | 571篇 |
2014年 | 897篇 |
2013年 | 2675篇 |
2012年 | 1104篇 |
2011年 | 1447篇 |
2010年 | 1195篇 |
2009年 | 1237篇 |
2008年 | 1527篇 |
2007年 | 1434篇 |
2006年 | 1307篇 |
2005年 | 1157篇 |
2004年 | 1091篇 |
2003年 | 1058篇 |
2002年 | 990篇 |
2001年 | 1134篇 |
2000年 | 807篇 |
1999年 | 503篇 |
1998年 | 397篇 |
1997年 | 403篇 |
1996年 | 426篇 |
1995年 | 502篇 |
1994年 | 415篇 |
1993年 | 372篇 |
1992年 | 399篇 |
1991年 | 363篇 |
1990年 | 345篇 |
1989年 | 333篇 |
1988年 | 312篇 |
1987年 | 254篇 |
1986年 | 263篇 |
1985年 | 265篇 |
1984年 | 285篇 |
1983年 | 274篇 |
1982年 | 293篇 |
1981年 | 249篇 |
1980年 | 196篇 |
1979年 | 199篇 |
1978年 | 182篇 |
1977年 | 141篇 |
1975年 | 141篇 |
1973年 | 170篇 |
1972年 | 150篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
471.
B. Sikkema-Raddatz R. H. Sijmons M. B. Tan-Sindhunata A. Y. Van Der Veen R. Brunsting B. De Vries J. R. Beekhuis D. J. Bekedam B. Van Aken B. De Jong 《黑龙江环境通报》1995,15(5):467-473
We report two cases of apparently balanced complex de novo chromosomal rearrangements (BCCR) detected prenatally at 17 weeks and 10 weeks of gestation, respectively. Chromosomes were studied using GTG-banding and fluorescent in situ hybridization (FISH). In one case four chromosomes and in the other case three chromosomes were involved in the rearrangements. One of the pregnancies was terminated and no external or internal abnormalities were detected at autopsy. The other pregnancy continued to term. Level III ultrasound examination showed no abnormalities. The child is now 3 years old and has neither congenital anomalies nor evidence of delayed psychomotor development. 相似文献
472.
Frans J. Los MD PhD Diane Van Opstal Martin P. Schol Johannes L. J. Gaillard Helen Brandenburg Ans M. W. Van Den Ouweland Peter A. In 'T Veld 《黑龙江环境通报》1995,15(12):1155-1159
A prenatally detected case of a rare mosaic tetrasomy 12p/trisomy 12p is reported, presenting as the well-known accessory isochromosome 12p and a supernumerary single 12p marker in 17/24 and 6/24 clones of cultured amniotic fluid cells, respectively. The chromosomal nature of both marker chromosomes was investigated in cultured amniotic fluid cells by fluorescent in situ hybridization with various probes: the 12-centromeric probes pa12H8 and D12Z3, a whole chromosome 12 paint, and the chromosome 12p-specific paint M28. DNA analysis revealed a maternal origin of the extra 12p material. After counselling, the parents requested termination of pregnancy. Inspection and autopsy of the fetus revealed many of the dysmorphisms and internal structural abnormalities of the Pallister–Killian syndrome. 相似文献
473.
Yves Dumez Marc Dommergues Marie-Claire Gubler Victor Bunduki Francoise Narcy Martine Lemerrer Laurent Mandelbrot Richard Berkowitz 《黑龙江环境通报》1994,14(2):141-144
A case of Meckel—Gruber syndrome was diagnosed by embryoscopy at 10 menstrual weeks, allowing for early termination of pregnancy. Post-mortem examination confirmed the presence of polydactyly and bilateral cystic lesions of the mesonephros and metanephros. Both the forming nephrons and the collecting ducts were involved in the formation of renal cysts. 相似文献
474.
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
475.
Dr. Linda A. Cannizzaro Barbara K. Hecht Helen A. Bixenman Stephen Pazdziorko Robert Tamis Frederick Hecht 《黑龙江环境通报》1988,8(4):297-301
We report herein a de novo unbalanced chromosome translocation in a fetus resulting from in vitro fertilization technology. Prenatal diagnostic analysis of an amniotic fluid revealed a 46,XX,4p+ karyotype. The origin of the extra material on the short arm of chromosome 4 could not be identified by a variety of banding techniques. However, examination of fetal parts did reveal some dysmorphic features. 相似文献
476.
477.
A Framework for Monitoring and Evaluating Carbon Mitigation by Farm Forestry Projects: Example of a Demonstration Project in Chiapas,Mexico 总被引:1,自引:0,他引:1
De Jong Ben H.J. Tipper Richard Taylor John 《Mitigation and Adaptation Strategies for Global Change》1997,2(2-3):231-246
Mitigation and Adaptation Strategies for Global Change - In Mexico an estimated 4.5 × 106ha are available for farm forestry, while up to 6.1 × 106 ha could be saved from deforestation by... 相似文献
478.
479.
480.