全文获取类型
收费全文 | 30441篇 |
免费 | 719篇 |
国内免费 | 5561篇 |
专业分类
安全科学 | 1242篇 |
废物处理 | 1574篇 |
环保管理 | 3014篇 |
综合类 | 11735篇 |
基础理论 | 6190篇 |
环境理论 | 8篇 |
污染及防治 | 9250篇 |
评价与监测 | 1548篇 |
社会与环境 | 1498篇 |
灾害及防治 | 662篇 |
出版年
2023年 | 269篇 |
2022年 | 780篇 |
2021年 | 662篇 |
2020年 | 471篇 |
2019年 | 525篇 |
2018年 | 723篇 |
2017年 | 844篇 |
2016年 | 983篇 |
2015年 | 1083篇 |
2014年 | 1509篇 |
2013年 | 2687篇 |
2012年 | 1652篇 |
2011年 | 1941篇 |
2010年 | 1420篇 |
2009年 | 1493篇 |
2008年 | 1634篇 |
2007年 | 1585篇 |
2006年 | 1420篇 |
2005年 | 1102篇 |
2004年 | 935篇 |
2003年 | 1059篇 |
2002年 | 965篇 |
2001年 | 1019篇 |
2000年 | 816篇 |
1999年 | 764篇 |
1998年 | 605篇 |
1997年 | 554篇 |
1996年 | 551篇 |
1995年 | 514篇 |
1994年 | 462篇 |
1993年 | 400篇 |
1992年 | 345篇 |
1991年 | 292篇 |
1990年 | 265篇 |
1989年 | 222篇 |
1988年 | 214篇 |
1987年 | 184篇 |
1986年 | 178篇 |
1985年 | 161篇 |
1984年 | 184篇 |
1983年 | 185篇 |
1982年 | 183篇 |
1981年 | 156篇 |
1980年 | 133篇 |
1979年 | 125篇 |
1978年 | 137篇 |
1977年 | 116篇 |
1976年 | 105篇 |
1975年 | 109篇 |
1974年 | 120篇 |
排序方式: 共有10000条查询结果,搜索用时 214 毫秒
1.
Russian Journal of Ecology - The dynamics of the species richness, breeding density, and structure of the community of birds occupying nest-boxes upon a 50-fold reduction of atmospheric emissions... 相似文献
2.
Uptake and concentration of heavy metals in dominant mangrove species from Hainan Island,South China
Wang Junguang Wang Peng Zhao Zhizhong Huo Yanru 《Environmental geochemistry and health》2021,43(4):1703-1714
Environmental Geochemistry and Health - By investigating three dominant mangrove species, namely Aegiceras corniculatum, Kandelia candel, Ceriops tagal and their rhizosediment in Mangrove wetlands... 相似文献
3.
Wang Chunbo Cai Qijia Li Yang Tian Cuicui Wu Xingqiang Huang Yuhong Xiao Bangding 《Environmental science and pollution research international》2021,28(31):42082-42092
Environmental Science and Pollution Research - A mechanical harvesting technology based on coupling flocculation with a rotary drum filter (RDF, 35-μm) was applied to remove cyanobacterial... 相似文献
4.
Li Ying Rong Yanyu Ahmad Umme Marium Wang Xiaotong Zuo Jian Mao Guozhu 《Environmental science and pollution research international》2021,28(34):46196-46214
Environmental Science and Pollution Research - Buildings account for nearly 2/5ths of global energy expenditure. Due to this figure, the 90s witnessed the rise of green buildings (GBs) that were... 相似文献
5.
Yang Nian Chen Lei Wang Wenzhuo Shen Zhenyao 《Environmental science and pollution research international》2021,28(37):51356-51368
Environmental Science and Pollution Research - At present, the contradiction between survival and ecology necessitates the integration of crop planting, chemical fertilizer application, and... 相似文献
6.
Zhu Rong Wang Shixin Srinivasakannan C. Li Shiwei Yin Shaohua Zhang Libo Jiang Xiaobin Zhou Guoli Zhang Ning 《Environmental Chemistry Letters》2023,21(3):1611-1626
Environmental Chemistry Letters - The demand for lithium is growing rapidly with the increase in electric vehicles, batteries and electronic equipments. Lithium can be extracted from brines, yet... 相似文献
7.
Günter Gunkel Florian Selge Jonas Keitel Debora Lima Silvana Calado Maria Sobral Maricela Rodriguez Elena Matta Reinhard Hinkelmann Peter Casper Michael Hupfer 《Regional Environmental Change》2018,18(7):1913-1925
Reservoirs have a wide variety of uses that have led to frequent conflicts over ecological conservation and contamination, especially as land management has intensified. Oligotrophication must be implemented in numerous tropical reservoirs that experience advanced eutrophication to maintain aquatic ecosystem functions. To quantify impacts on ecosystem functions and to develop an adaptive management policy, multiple studies have been conducted on the Itaparica Reservoir, São Francisco River, in the semi-arid north-eastern region of Brazil. Here, we add to that existing body of knowledge through investigating how nutrient accumulation is affected by water exchange between the main river flow and Icó-Mandantes Bay. Operational water-level fluctuations in the reservoir create large desiccated littoral areas that release high amounts of nutrients when they are rewetted. In particular, water-level variation promotes proliferation of Egeria densa, a noxious weed, thus elevating trophic levels of the Itaparica Reservoir and Icó-Mandantes Bay. Analysis with a P efficiency model determined 25 μg P L?1 to be the critical concentration and further indicated that the critical load in both bodies of water have been exceeded. Moreover, intensive fish aquaculture using net cages has led to further overtaxing of the reservoir. We conclude that an effective ecological reservoir management policy must involve oligotrophication, harvesting of noxious water weeds for use as soil amendment in agriculture or biogas production, “blue” aquaculture, and limiting hydroelectric power production based on current water availability. 相似文献
8.
为了解全氟辛烷磺酸盐(perfluorooctane sulfonate, PFOS)暴露对半滑舌鳎(Cynoglossus semilaevis)免疫功能的影响,在实验室条件下,运用RT-PCR方法分析了PFOS暴露对半滑舌鳎热休克蛋白hsp70、hsp90、C型凝集素(c-type lectin)和细胞色素c氧化酶(cytochrome c oxidase, cox)等4种免疫相关基因表达水平的影响。实验测定了上述4种基因在半滑舌鳎肝、鳃、肠及肌肉4种不同组织中随时间(0、24 h、48 h、96 h和7 d)的表达变化情况。结果表明,在4种组织中,hsp70基因的表达与对照相比为上调,其中,肝组织hsp70基因的表达量显著高于其他各组织,且表达高峰值的出现也早于其他各组织;hsp90基因在肝和鳃组织中表达量随时间不同而波动,在肠组织中表达上调,在肌肉中表达显著下调;c-type lectin基因表达量与对照组相比表达显著下调或无明显差异;cox基因在肝组织和肠组织中表达下调,在鳃和肌肉中表达上调。上述研究结果表明,PFOS能引起免疫相关基因的表达变化,对半滑舌鳎具有潜在的免疫毒性。肝组织中各免疫基因对PFOS胁迫的响应高于其他组织。本研究可为阐明全氟辛烷磺酸盐对半滑舌鳎的免疫毒性提供基础数据。 相似文献
9.
Ling R. Zeng Li H. Shi Xin G. Meng J. Xu Gui F. Jia T. Gui 《Journal of environmental science and health. Part. B》2019,54(4):317-325
This study evaluated the hydrolysis and photolysis kinetics of pyraclostrobin in an aqueous solution using ultra-high-performance liquid chromatography–photodiode array detection and identified the resulting metabolites of pyraclostrobin by hydrolysis and photolysis in paddy water using high-resolution mass spectrometry coupled with liquid chromatography. The effect of solution pH, metal ions and surfactants on the hydrolysis of pyraclostrobin was explored. The hydrolysis half-lives of pyraclostrobin were 23.1–115.5?days and were stable in buffer solution at pH 5.0. The degradation rate of pyraclostrobin in an aqueous solution under sunlight was slower than that under UV photolysis reaction. The half-lives of pyraclostrobin in a buffer solution at pH 5.0, 7.0, 9.0 and in paddy water were less than 12?h under the two light irradiation types. The metabolites of the two processes were identified and compared to further understand the mechanisms underlying hydrolysis and photolysis of pyraclostrobin in natural water. The extracted ions obtained from paddy water were automatically annotated by Compound Discoverer software with manual confirmation of their fragments. Two metabolites were detected and identified in the pyraclostrobin hydrolysis, whereas three metabolites were detected and identified in the photolysis in paddy water. 相似文献
10.
Ecologically relevant traits of organisms in an assemblage determine an ecosystem's functional fingerprint (i.e., the shape, size, and position of multidimensional trait space). Quantifying changes in functional fingerprints can therefore provide information about the effects of diversity loss or gain through time on ecosystem condition and is a promising approach to monitoring ecological integrity. This, however, is seldom possible owing to limitations in historical surveys and a lack of data on organismal traits, particularly in diverse tropical regions. Using data from detailed bird surveys from 4 periods across more than a century, and morphological and ecological traits of 233 species, we quantified changes in the avian functional fingerprint of a tropical montane forest in the Andes of Colombia. We found that 78% of the variation in functional space, regardless of period, was described by 3 major axes summarizing body size, dispersal ability (indexed by wing shape), and habitat breadth. Changes in species composition significantly altered the functional fingerprint of the assemblage and functional richness and dispersion decreased 35–60%. Owing to species extirpations and to novel additions to the assemblage, functional space decreased over time, but at least 11% of its volume in the 2010s extended to areas of functional space that were unoccupied in the 1910s. The assemblage now includes fewer large-sized species, more species with greater dispersal ability, and fewer habitat specialists. Extirpated species had high functional uniqueness and distinctiveness, resulting in large reductions in functional richness and dispersion after their loss, which implies important consequences for ecosystem integrity. Conservation efforts aimed at maintaining ecosystem function must move beyond seeking to sustain species numbers to designing complementary strategies for the maintenance of ecological function by identifying and conserving species with traits conferring high vulnerability such as large body size, poor dispersal ability, and greater habitat specialization. Article impact statement: Changes in functional fingerprints provide a means to quantify the integrity of ecological assemblages affected by diversity loss or gain. 相似文献