全文获取类型
收费全文 | 24098篇 |
免费 | 230篇 |
国内免费 | 201篇 |
专业分类
安全科学 | 677篇 |
废物处理 | 1047篇 |
环保管理 | 3108篇 |
综合类 | 3373篇 |
基础理论 | 6284篇 |
环境理论 | 9篇 |
污染及防治 | 6718篇 |
评价与监测 | 1598篇 |
社会与环境 | 1563篇 |
灾害及防治 | 152篇 |
出版年
2023年 | 132篇 |
2022年 | 213篇 |
2021年 | 227篇 |
2020年 | 145篇 |
2019年 | 197篇 |
2018年 | 342篇 |
2017年 | 353篇 |
2016年 | 530篇 |
2015年 | 432篇 |
2014年 | 669篇 |
2013年 | 1985篇 |
2012年 | 801篇 |
2011年 | 1073篇 |
2010年 | 847篇 |
2009年 | 970篇 |
2008年 | 1094篇 |
2007年 | 1171篇 |
2006年 | 1028篇 |
2005年 | 871篇 |
2004年 | 875篇 |
2003年 | 855篇 |
2002年 | 811篇 |
2001年 | 992篇 |
2000年 | 710篇 |
1999年 | 413篇 |
1998年 | 280篇 |
1997年 | 283篇 |
1996年 | 326篇 |
1995年 | 332篇 |
1994年 | 330篇 |
1993年 | 285篇 |
1992年 | 270篇 |
1991年 | 251篇 |
1990年 | 273篇 |
1989年 | 240篇 |
1988年 | 238篇 |
1987年 | 220篇 |
1986年 | 212篇 |
1985年 | 184篇 |
1984年 | 220篇 |
1983年 | 222篇 |
1982年 | 217篇 |
1981年 | 197篇 |
1980年 | 165篇 |
1979年 | 192篇 |
1978年 | 137篇 |
1977年 | 132篇 |
1976年 | 118篇 |
1973年 | 120篇 |
1972年 | 126篇 |
排序方式: 共有10000条查询结果,搜索用时 500 毫秒
301.
302.
R. G. Tiessen A. M. W. van Elsacker-Niele Chr. Vermeij-Keers D. Oepkes J. van Roosmalen M. C. B. Gorsira 《黑龙江环境通报》1994,14(3):173-176
A fetus with multiple structural defects was seen at prenatal ultrasound examination. After termination of the pregnancy a bilateral cleft lip, alveolus, and palate; micrognathia; and webbed joints were seen. Fetal tissues showed indications of infection, intranuclear inclusion bodies, chronic stress, haemolysis, arterial wall damage, and profuse haemorrhage. Parvovirus B19 DNA was detected in fetal tissues by dot hybridization after polymerase chain reaction. The possibility of parvovirus B19 infection leading to congenital malformations is discussed. 相似文献
303.
Ruth E. Alcock Ruth Boumphrey Heath M. Malcolm Daniel Osborn Kevin C. Jones 《Ambio-人类环境杂志》2002,31(3):202-206
1977~1998年间,在苏格兰西部的艾尔萨克雷格对收集到的塘鹅蛋中的多氯联苯(PCB)同类物进行了回顾性分析.对一些年份所收集的塘鹅蛋中每年选择8~10个对其PCB同类物浓度范围分别进行了分析.所有的同类物在几年之内浓度都降在低,但不同的同类物降解速率不同. 相似文献
304.
Duodenal stenosis associated with oesophageal atresia was diagnosed by ultrasound at 12 weeks' gestation. The diagnosis was made by recognition of a double bubble sign which was more pronounced when a vaginal transducer was used. Post-abortion autopsy confirmed the diagnosis. Oesophageal and duodenal obstruction in this case had no effect on the amount of amniotic fluid or the alpha-fetoprotein concentration since swallowing and subsequent utilization of amniotic fluid do not occur before 12 weeks of gestation. 相似文献
305.
306.
307.
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
308.
C. Sheinbaum I. Jauregui L. Rodríguez V. 《Mitigation and Adaptation Strategies for Global Change》1998,2(4):359-372
An analysis of the impacts on Mexican energy demand and associated carbon dioxide (CO2) emissions in the year 2005 due to efficient lighting in the commercial and residential sectors and cogeneration in the industrial sector is presented. Estimation of CO2 abatement costs and an incremental cost curve for CO2 mitigation options are considered. These technologies are cost effective opportunities, and together are projected to reduce CO2 emissions in 2005 by nearly 13 percent. Implementation of efficient lighting is already part of the demand side management (DSM) programs of the Mexican state-owned utility. However, there are important barriers that may hinder the implementation of large scale cogeneration plants. 相似文献
309.
I. Shagina H. L. Dadali V. P. Sitnikov V. V. Pugachev N. A. Malygina O. V. Evgrafov 《黑龙江环境通报》1995,15(1):27-34
Ninety-two families with spinal muscular atrophy (SMA) applied for genetic counselling and further prenatal diagnosis. To minimize expenses, only one tightly linked informative marker was determined in the course of preliminary examination, and non-radioactive allele detection was preferably used. Four prenatal diagnoses of SMA type I, four of SMA type II, and one of SMA type III were made. This trial programme shows the considerable requirements, importance, and potential effectiveness of prenatal prediction of SMA in Russia. 相似文献
310.
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