全文获取类型
收费全文 | 90575篇 |
免费 | 1221篇 |
国内免费 | 1099篇 |
专业分类
安全科学 | 3744篇 |
废物处理 | 3315篇 |
环保管理 | 13934篇 |
综合类 | 21043篇 |
基础理论 | 26228篇 |
环境理论 | 71篇 |
污染及防治 | 14955篇 |
评价与监测 | 5447篇 |
社会与环境 | 3611篇 |
灾害及防治 | 547篇 |
出版年
2022年 | 792篇 |
2021年 | 802篇 |
2020年 | 646篇 |
2019年 | 859篇 |
2018年 | 1126篇 |
2017年 | 1152篇 |
2016年 | 2165篇 |
2015年 | 1827篇 |
2014年 | 2583篇 |
2013年 | 9235篇 |
2012年 | 2210篇 |
2011年 | 2451篇 |
2010年 | 3244篇 |
2009年 | 3397篇 |
2008年 | 2029篇 |
2007年 | 1875篇 |
2006年 | 2300篇 |
2005年 | 2275篇 |
2004年 | 2600篇 |
2003年 | 2427篇 |
2002年 | 1976篇 |
2001年 | 2287篇 |
2000年 | 2023篇 |
1999年 | 1495篇 |
1998年 | 1363篇 |
1997年 | 1352篇 |
1996年 | 1479篇 |
1995年 | 1573篇 |
1994年 | 1459篇 |
1993年 | 1326篇 |
1992年 | 1305篇 |
1991年 | 1283篇 |
1990年 | 1226篇 |
1989年 | 1198篇 |
1988年 | 1042篇 |
1987年 | 985篇 |
1986年 | 988篇 |
1985年 | 1061篇 |
1984年 | 1161篇 |
1983年 | 1166篇 |
1982年 | 1170篇 |
1981年 | 1100篇 |
1980年 | 942篇 |
1979年 | 932篇 |
1978年 | 819篇 |
1977年 | 721篇 |
1976年 | 643篇 |
1975年 | 604篇 |
1973年 | 638篇 |
1972年 | 640篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Catastrophic disasters like earthquake and flood cause widespread destruction and financial devastation. This has brought disaster management into limelight making it a burgeoning academic research field. The remarkable rise of ICT (Information and Communication Technology) has instigated the scientific world to incorporate these technologies in disaster management. This study presents scientometric analysis to identify the status quo of research on the management of various disasters and role of ICT in it. This paper uses bibliographic data retrieved from Scopus for the observation period from 2011 to 2018. We provide extensive insights into growth of publications, citation pattern and their connectedness with other subject disciplines. Furthermore, we identify most productive and influential countries, institutes and journals. Our study analyses co-occurrence of keywords using Visualization of Similarities (VOS) Viewer. This structured overview will enhance the understanding of this field leading to more focussed and purposeful research. 相似文献
32.
Maheswari C. Ramya A. S. Priya B. Meenakshi Sudhahar S. Prabhu Raj B. Lokesh B. Ramani G. 《Journal of Material Cycles and Waste Management》2021,23(6):2255-2265
Journal of Material Cycles and Waste Management - The present research work focused on fabricating Biodegradable Plate (BD plate) composed of rice husk ash, bagasse and corn starch which is... 相似文献
33.
34.
Quantitative methods have been applied to the study of floristic structure and diversity in Samarskaya Luka. The results show that Samarskaya Luka is a floristically heterogeneous area in which six elementary floras can be distinguished. This area has been assessed as a floristically autonomous formation, and its floristic representativeness was estimated. 相似文献
35.
Abstract: Introduction of artificial light into wildlife habitat represents a rapidly expanding form of human encroachment, particularly in coastal systems. Light pollution alters the behavior of sea turtles during nesting; therefore, long-wavelength lights—low-pressure sodium vapor and bug lights—that minimize impacts on turtles are required for beach lighting in Florida (U.S.A.). We investigated the effects of these two kinds of lights on the foraging behavior of Santa Rosa beach mice ( Peromyscus polionotus leucocephalus ). We compared patch use and giving-up densities of mice for experimental food patches established along a gradient of artificial light in the field. Mice exploited fewer food patches near both types of artificial light than in areas with little light and harvested fewer seeds within patches near bug lights. Our results show that artificial light affects the behavior of terrestrial species in coastal areas and that light pollution deserves greater consideration in conservation planning. 相似文献
36.
Chad L. Hewitt Marnie L. Campbell Ronald E. Thresher Richard B. Martin Sue Boyd Brian F. Cohen David R. Currie Martin F. Gomon Michael J. Keough John A. Lewis Matthew M. Lockett Nicole Mays Matthew A. McArthur Tim D. O'Hara Gary C. B. Poore D. Jeff Ross Melissa J. Storey Jeanette E. Watson Robin S. Wilson 《Marine Biology》2004,144(1):183-202
Port Phillip Bay (PPB) is a large (1,930 km2), temperate embayment in southern Victoria, Australia. Extensive bay-wide surveys of PPB have occurred since 1840. In 1995/1996 the Commonwealth Scientific and Industrial Research Organization (CSIRO) Centre for Research on Introduced Marine Pests (CRIMP) undertook an intensive evaluation of the region with the aims of developing a comprehensive species list of native and introduced biota and contrasting previous bay-wide assessments with a current field survey in order to detect new incursions and discern alterations to native communities. Two methods were used to meet these aims: a re-evaluation of regional museum collections and published research in PPB to identify and determine the timing of introductions; and field surveys for benthic (infauna, epifauna and encrusting) organisms between September 1995 to March 1996. One hundred and sixty introduced (99) and cryptogenic (61) species were identified representing over 13% of the recorded species of PPB. As expected, the majority of these are concentrated around the shipping ports of Geelong and Melbourne. Invasions within PPB appear to be increasing, possibly due to an increase in modern shipping traffic and an increase in aquaculture (historically associated with incidental introductions); however the records of extensive biological surveys suggest that this may, in part, be an artefact of sampling effort. In contrast to Northern Hemisphere studies, PPB (and Southern Hemisphere introductions in general) have significantly different suites of successfully invading taxa. PPB is presented as one of the most invaded marine ecosystems in the Southern Hemisphere.Communicated by M.S. Johnson, Crawley 相似文献
37.
F. Pricope Ştefănescu G. Tiţescu I. Cărăuş D. Ureche 《Environmental Chemistry Letters》2003,1(2):149-151
During the artificial reproduction of salmonides, the fecundity can be increased either by improving the viability of spermatozoa,
or by extending the time period during which a roe micropile remains open, thus allowing its fecundation. Practically, this
can be achieved by the use of some fertilising techniques suitable for fish species. Here, we show that the reproduction of
rainbow trout in a 1:1 solution of deuterium-depleted water and distilled water led to a significant increase in survival
of roes during their embryonic development. Moreover, the addition of glucose and fructose into the deuterium-depleted fertilising
solutions led to a further increase in roe survival during embryonic development. The increase in survival is mainly explained
by an increase in the motility of spermatozoa. 相似文献
38.
Large Estimates of Minimum Viable Population Sizes 总被引:2,自引:0,他引:2
39.
40.