全文获取类型
收费全文 | 4124篇 |
免费 | 33篇 |
国内免费 | 13篇 |
专业分类
安全科学 | 43篇 |
废物处理 | 264篇 |
环保管理 | 245篇 |
综合类 | 674篇 |
基础理论 | 848篇 |
环境理论 | 5篇 |
污染及防治 | 1459篇 |
评价与监测 | 383篇 |
社会与环境 | 241篇 |
灾害及防治 | 8篇 |
出版年
2023年 | 44篇 |
2022年 | 127篇 |
2021年 | 125篇 |
2020年 | 47篇 |
2019年 | 50篇 |
2018年 | 149篇 |
2017年 | 105篇 |
2016年 | 204篇 |
2015年 | 109篇 |
2014年 | 228篇 |
2013年 | 390篇 |
2012年 | 246篇 |
2011年 | 244篇 |
2010年 | 187篇 |
2009年 | 142篇 |
2008年 | 234篇 |
2007年 | 240篇 |
2006年 | 215篇 |
2005年 | 144篇 |
2004年 | 119篇 |
2003年 | 108篇 |
2002年 | 92篇 |
2001年 | 64篇 |
2000年 | 46篇 |
1999年 | 37篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1996年 | 11篇 |
1995年 | 25篇 |
1994年 | 28篇 |
1993年 | 20篇 |
1992年 | 9篇 |
1991年 | 10篇 |
1990年 | 12篇 |
1989年 | 11篇 |
1985年 | 7篇 |
1967年 | 7篇 |
1966年 | 12篇 |
1965年 | 17篇 |
1964年 | 28篇 |
1963年 | 13篇 |
1962年 | 17篇 |
1961年 | 11篇 |
1960年 | 12篇 |
1959年 | 28篇 |
1958年 | 26篇 |
1957年 | 19篇 |
1956年 | 15篇 |
1955年 | 19篇 |
1954年 | 8篇 |
排序方式: 共有4170条查询结果,搜索用时 718 毫秒
841.
Asare Michael O. Száková Jiřina Tlustoš Pavel 《Environmental science and pollution research international》2023,30(5):11378-11398
Environmental Science and Pollution Research - The study used scattered literature to summarize the effects of excess Cd, As, and Pb from contaminated soils on plant secondary metabolites/bioactive... 相似文献
842.
David A. Wiedenfeld Allison C. Alberts Ariadne Angulo Elizabeth L. Bennett Onnie Byers Topiltzin Contreras-MacBeath Gláucia Drummond Gustavo A. B. da Fonseca Claude Gascon Ian Harrison Nicolas Heard Axel Hochkirch William Konstant Penny F. Langhammer Olivier Langrand Frederic Launay Daniel J. Lebbin Susan Lieberman Barney Long Zhi Lu Michael Maunder Russell A. Mittermeier Sanjay Molur Razan Khalifa al Mubarak Michael J. Parr Jonah Ratsimbazafy Anders G. J. Rhodin Anthony B. Rylands Jim Sanderson Wes Sechrest Pritpal Soorae Jatna Supriatna Amy Upgren Jean-Christophe Vié Li Zhang 《Conservation biology》2021,35(5):1388-1395
Some conservation prioritization methods are based on the assumption that conservation needs overwhelm current resources and not all species can be conserved; therefore, a conservation triage scheme (i.e., when the system is overwhelmed, species should be divided into three groups based on likelihood of survival, and efforts should be focused on those species in the group with the best survival prospects and reduced or denied to those in the group with no survival prospects and to those in the group not needing special efforts for their conservation) is necessary to guide resource allocation. We argue that this decision-making strategy is not appropriate because resources are not as limited as often assumed, and it is not evident that there are species that cannot be conserved. Small population size alone, for example, does not doom a species to extinction; plants, reptiles, birds, and mammals offer examples. Although resources dedicated to conserving all threatened species are insufficient at present, the world's economic resources are vast, and greater resources could be dedicated toward species conservation. The political framework for species conservation has improved, with initiatives such as the UN Sustainable Development Goals and other international agreements, funding mechanisms such as The Global Environment Facility, and the rise of many nongovernmental organizations with nimble, rapid-response small grants programs. For a prioritization system to allow no extinctions, zero extinctions must be an explicit goal of the system. Extinction is not inevitable, and should not be acceptable. A goal of no human-induced extinctions is imperative given the irreversibility of species loss. 相似文献
843.
844.
Reproduction patterns of four Antarctic octocorals in the Weddell Sea: an inter-specific,shape, and latitudinal comparison 总被引:1,自引:1,他引:0
C. Orejas J. M. Gili P. J. López-González C. Hasemann W. E. Arntz 《Marine Biology》2007,150(4):551-563
The reproductive patterns of four Antarctic gorgonian species have been investigated. Two of them, Dasystenella acanthina and Thouarella sp., present the bottle-brush-shape type; the other two, Fannyella rossii and Fannyella spinosa, are fan-shaped. Two different reproductive patterns have been observed in D. acanthina and Thouarella sp., which point to two size classes in the frequency distribution of oocytes. This feature indicates a reproduction cycle
with overlapping generations, being each of them of more than one year, probably with seasonal spawning. F. rossii and F. spinosa show only one size class of oocytes, which could point towards an annual reproductive cycle. The presence of larvae in the
gastrovascular cavities in both Fanyella species and Thoaurella sp. is a sign of a possible larvae release during austral summer. The number of oocytes per polyp ranges from 1.1 ± 0.10
SE to 1.5 ± 0.06 SE, and the size ranges from 50 to 1200 μm. The number of spermatic cysts ranges from 2.6 ± 0.19 SE to 5.0 ± 0.21SE,
and their sizes range from 50 to 800 μm. These values are comparable to the reproductive trends and features found in gorgonians
from other latitudes, which correspond in some cases with similar morphotypes. These coincident strategies could be related
to morphological similarities rather than with latitude or water temperature. The results of this study indicate that octocoral
morphology may play a crucial role in determining the reproductive output of these organisms. 相似文献
845.
846.
847.
Leonardo Lavanderos M. Eugenia Pozo Carlos Pattillo Hernán Miranda 《Environmental monitoring and assessment》1990,14(1):9-22
Spatial heterogeneity of the Rapel reservoir surface waters is analyzed through Landsat images. The image digital counts are used with the aim or developing an aprioristic quantitative sample design.Natural horizontal stratification of the Rapel Reservoir (Central Chile) is produced mainly by suspended solids. The spatial heterogeneity conditions of the reservoir for the Spring 86-Summer 87 period were determined by qualitative analysis and image processing of the MSS Landsat, bands 1 and 3. The space-time variations of the different observed strata obtained with multitemporal image analysis.A random stratified sample design (r.s.s.d) was developed, based on the digital counts statistical analysis. Strata population size as well as the average, variance and sampling size of the digital counts were obtained by the r.s.s.d method.Stratification determined by analysis of satellite images were later correlated with ground data. Though the stratification of the reservoir is constant over time, the shape and size of the strata varys. 相似文献
848.
The second and third steps of wastewater treatment in the tanning industry generate sludges that are rich in salts, organic matter and suspended solids. Since these are formally catalogued as industrial wastes by environmental legislation, they cannot be disposed of directly but need a final treatment. One of the problems with these wastes is their high water content, which has to be reduced. In the particular case of the concentrated streams from the secondary and tertiary treatment steps, the sludges are first concentrated by evaporation, and the evaporated water is used in other parts of the plant. This study, which preceded evaporator design, analysed the evaporation process (laboratory scale) of a saline residue produced in the reverse osmosis step of the treatment of tanning wastewaters by the company Aquagest Levante, S.A. in Lorca (Murcia, Spain), to ascertain its behaviour in the evaporation process and the evolution of its physical properties. The study served to determine the exact mineralogy and ionic composition as well as the characteristics of the waste in question. This information was used in the last step of the design of the evaporation equipment. 相似文献
849.
A Barba S Navarro M A Cámara 《Journal of environmental science and health. Part. B》1988,23(4):331-341
The Survan (a mixture of the insecticides chlorfenvinphos and cypermethrin) persistence in lemon citrus fruits, verna variety, is studied. In all the cases, residues of both compounds have been detected in the juices of the fruits treated. When the mixture of the insecticides is used at a concentration of 0.20%, the levels of chlorfenvinphos after 14 days is not higher than 0.14 ppm; however, when it is used at a 0.15% concentration, this value is overpassed in all the samples. The residues of the cypermethrin component are not higher than 0.35 ppm throughout the whole experiment. 相似文献
850.