全文获取类型
收费全文 | 5430篇 |
免费 | 568篇 |
国内免费 | 2541篇 |
专业分类
安全科学 | 365篇 |
废物处理 | 262篇 |
环保管理 | 845篇 |
综合类 | 4323篇 |
基础理论 | 850篇 |
污染及防治 | 1276篇 |
评价与监测 | 330篇 |
社会与环境 | 232篇 |
灾害及防治 | 56篇 |
出版年
2024年 | 12篇 |
2023年 | 73篇 |
2022年 | 167篇 |
2021年 | 199篇 |
2020年 | 196篇 |
2019年 | 244篇 |
2018年 | 252篇 |
2017年 | 253篇 |
2016年 | 338篇 |
2015年 | 322篇 |
2014年 | 433篇 |
2013年 | 531篇 |
2012年 | 556篇 |
2011年 | 579篇 |
2010年 | 424篇 |
2009年 | 569篇 |
2008年 | 361篇 |
2007年 | 438篇 |
2006年 | 398篇 |
2005年 | 363篇 |
2004年 | 259篇 |
2003年 | 239篇 |
2002年 | 209篇 |
2001年 | 190篇 |
2000年 | 199篇 |
1999年 | 131篇 |
1998年 | 96篇 |
1997年 | 88篇 |
1996年 | 80篇 |
1995年 | 88篇 |
1994年 | 53篇 |
1993年 | 41篇 |
1992年 | 36篇 |
1991年 | 15篇 |
1990年 | 17篇 |
1989年 | 5篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 6篇 |
1985年 | 10篇 |
1984年 | 11篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有8539条查询结果,搜索用时 625 毫秒
61.
62.
介绍了回收磺酸盐生产工艺 ,对其装置的产品成本进行了测算 ,并对盈亏平衡及其敏感性进行了分析 ,进而确定了主要经济指标。 相似文献
63.
64.
Stickler syndrome is an autosomal dominant disorder of the connective tissue which includes ocular and systemic manifestations. We report on a large kindred in which we were able to demonstrate very tight linkage between the disease and the type II collagen gene (COL2A1) (LOD score 3·91 at θ=0). In a family in which the father and one of his daughters were severely affected, DNA analysis from a chorionic villus sample demonstrated that the fetus possessed the normal allele of COL2A1. Thereafter a normal child was born. 相似文献
65.
Dr. C. Dawn DeLozier-Blanchet Eric Engel Philippe Extermann Béatrice Pastori 《黑龙江环境通报》1988,8(4):281-286
Cytogenetic study of chorionic villi sampled because of advanced maternal age revealed, after overnight culture, an apparently non-mosaic trisomy 7. Amniocentesis showed exclusively normal mitoses, and the pregnancy continued normally. One hundred mitoses from cord blood of the normal newborn revealed a non-mosaic 46,XX complement. No cells with a proven trisomy 7 were found in cultures from either of two biopsies of the morphologically normal placenta, but the peripheral biopsy showed in multiple cultures an abnormal clone: 47,XX, + 20,-2,-21, + t(2;21)(p13;q22). To our knowledge, this is the first case of non-mosaic trisomy 7 detected on CVS which has had follow-up studies of amniotic fluid, cord blood, and term placenta. 相似文献
66.
IntroductionItiswidelyrecognizedthatthephysicochemicalprofileoforganicchemicalslargelydeterminestheirdistributionbetweenenvironmentalmedia .Fortheenvironmentalbehaviorsoforganiccontaminants,watersolubility(SW)andoctanol waterpartitioncoefficient(KOW)aretremendouslyimportant.Octanol waterpartitioncoefficienthasbeenwidelyrelatedtobiochemicaland orbiologicalactivityinquantitativestructure activityrelationships(QSARs) (Leo ,1 971 ) .Watersolubilitycorrespondstothedispersiontendencyandtothereca… 相似文献
67.
68.
IntroductionTheuseofchemicals,includingpesticides,hasbecomeanintegralandeconomicallyessentialpartofmodernagriculture.Pesticide?.. 相似文献
69.
A baseline for a project consists of estimates of annual emissions of greenhouse gases (GHG) for a given time period without implementing the project. A general three-step process for determining the baseline is suggested. The emission reduction of the project is given by the difference between the baseline and the monitored annual emissions. A preferred method, direct measurement of the emission reduction, is possible for some types of projects. Methods for estimating the annual baseline emissions are not necessary for the latter category, and a definition of this project category is suggested. IPCC Guidelines for National GHG Inventories categorise the emission sources so that only direct emissions from consumption of fuel and feedstock are calculated. There are thus no emission factors for indirect emissions (e.g. electricity consumption or km transported) or emission factors that depend on technology only, independent of consumption of fuel and feedstock. Technology-dependent emission factors may thus need to be developed for estimating indirect emissions and multi-project baselines. Consistency should be sought with the IPCC Guidelines when estimating annual baseline emissions and in monitoring project emissions to ensure comparability with the National Inventories. 相似文献
70.