全文获取类型
收费全文 | 34195篇 |
免费 | 332篇 |
国内免费 | 334篇 |
专业分类
安全科学 | 961篇 |
废物处理 | 1513篇 |
环保管理 | 4455篇 |
综合类 | 4593篇 |
基础理论 | 9075篇 |
环境理论 | 8篇 |
污染及防治 | 9490篇 |
评价与监测 | 2482篇 |
社会与环境 | 2049篇 |
灾害及防治 | 235篇 |
出版年
2022年 | 305篇 |
2021年 | 339篇 |
2020年 | 218篇 |
2019年 | 291篇 |
2018年 | 521篇 |
2017年 | 506篇 |
2016年 | 816篇 |
2015年 | 615篇 |
2014年 | 932篇 |
2013年 | 2943篇 |
2012年 | 1121篇 |
2011年 | 1461篇 |
2010年 | 1238篇 |
2009年 | 1307篇 |
2008年 | 1506篇 |
2007年 | 1634篇 |
2006年 | 1439篇 |
2005年 | 1198篇 |
2004年 | 1205篇 |
2003年 | 1169篇 |
2002年 | 1125篇 |
2001年 | 1455篇 |
2000年 | 1033篇 |
1999年 | 617篇 |
1998年 | 458篇 |
1997年 | 428篇 |
1996年 | 498篇 |
1995年 | 475篇 |
1994年 | 452篇 |
1993年 | 415篇 |
1992年 | 388篇 |
1991年 | 358篇 |
1990年 | 372篇 |
1989年 | 371篇 |
1988年 | 346篇 |
1987年 | 297篇 |
1986年 | 245篇 |
1985年 | 264篇 |
1984年 | 317篇 |
1983年 | 303篇 |
1982年 | 323篇 |
1981年 | 276篇 |
1980年 | 240篇 |
1979年 | 283篇 |
1978年 | 211篇 |
1977年 | 188篇 |
1976年 | 173篇 |
1975年 | 169篇 |
1973年 | 161篇 |
1972年 | 160篇 |
排序方式: 共有10000条查询结果,搜索用时 99 毫秒
381.
382.
Chemical synapses are highly specialized cell–cell junctions designed for efficient signaling between nerve cells. Distinct
cytoskeletal matrices are assembled at either side of the synaptic junction. The presynaptic cytomatrix at the active zone
(CAZ) defines and organizes the site of neurotransmitter release from presynaptic nerve terminals. The postsynaptic density
(PSD) tethers neurotransmitter receptors and the postsynaptic signal transduction machinery. Recent progress in the identification
and characterization of novel CAZ and PSD components has revealed new insights into the molecular organization and assembly
mechanisms of the synaptic neurotransmission apparatus. On the presynaptic side, Bassoon and Piccolo, two related giant proteins,
are crucially involved in scaffolding the CAZ. On the postsynaptic side, two families of multi-domain adaptor proteins, the
MAGuKs (membrane-associated guanylate kinase homologs) and the ProSAP (proline-rich synapse-associated protein, also termed
Shank) family members are thought to be major organizing molecules of the PSD. 相似文献
383.
Yuen Tannirandorn Umberto Nicolini Peter C. Nicolaidis Nicholas M. Fisk Sabaratnam Arulkumaran Charles H. Rodeck 《黑龙江环境通报》1990,10(3):189-193
Twelve second-trimester fetuses with cystic hygroma underwent fetal blood sampling for rapid karyotyping, haematologic evaluation, and blood gas analysis. An abnormal karyotype was found in seven cases: monosomy X in five, trisomy 21 in one, and trisomy 13 in the other. Eight often fetuses undergoing blood gas analysis showed hypoxaemia, five of which were growth-retarded. Nine pregnancies were terminated. Of the remaining three, only one fetus survived the perinatal period. 相似文献
384.
385.
386.
387.
388.
John S. Rinehart 《Die Naturwissenschaften》1976,63(5):218-223
389.
The Science of Nature - 相似文献
390.
This paper describes a method for determining reductions of SO2 emissions from coal- and oil-fired power stations, oil refineries and large industrial units in the UK taking into account their pollution potential. The method is based on the use of two gridded data sets: critical loads, which represent the sensitivity of the environment to acid deposition and modelled estimates of total (wet + dry) sulphur deposition for 646 point sources within the UK. An iterative method is used to identify and subsequently reduce emissions from point sources that contribute most to areas of critical loads exceedance. This paper demonstrates how the method may be used to determine an optimal allocation of emissions across the UK which yields the maximum amount of environmental protection per unit of emission.The paper then goes on to consider the changes that will have to take place within the UK power generation industry in order to meet the revised EC Large Combustion Plant Directive which comes into force on 1 January 2008. Particular emphasis is placed upon proposed emissions trading schemes and the environmental implications of allowing trading between stations with high and low pollution potentials. The paper concludes by suggesting that the emissions trading process should take into account the pollution potential of each source, irrespective of whether the proposed emission is within the plant's agreed emission limit. An approach based entirely on minimizing environmental damage rather than one which takes cost into account, as in current integrated assessment modelling, could provide an interesting approach across the rest of Europe. 相似文献