全文获取类型
收费全文 | 67922篇 |
免费 | 628篇 |
国内免费 | 694篇 |
专业分类
安全科学 | 1788篇 |
废物处理 | 3140篇 |
环保管理 | 8753篇 |
综合类 | 11411篇 |
基础理论 | 18399篇 |
环境理论 | 41篇 |
污染及防治 | 16525篇 |
评价与监测 | 4628篇 |
社会与环境 | 4181篇 |
灾害及防治 | 378篇 |
出版年
2022年 | 487篇 |
2021年 | 502篇 |
2020年 | 379篇 |
2019年 | 499篇 |
2018年 | 2143篇 |
2017年 | 2041篇 |
2016年 | 2299篇 |
2015年 | 1131篇 |
2014年 | 1486篇 |
2013年 | 4586篇 |
2012年 | 2227篇 |
2011年 | 3686篇 |
2010年 | 2715篇 |
2009年 | 2641篇 |
2008年 | 3304篇 |
2007年 | 3658篇 |
2006年 | 2363篇 |
2005年 | 2005篇 |
2004年 | 1973篇 |
2003年 | 2034篇 |
2002年 | 1917篇 |
2001年 | 2320篇 |
2000年 | 1592篇 |
1999年 | 1028篇 |
1998年 | 775篇 |
1997年 | 778篇 |
1996年 | 801篇 |
1995年 | 889篇 |
1994年 | 863篇 |
1993年 | 744篇 |
1992年 | 743篇 |
1991年 | 723篇 |
1990年 | 760篇 |
1989年 | 715篇 |
1988年 | 652篇 |
1987年 | 571篇 |
1986年 | 506篇 |
1985年 | 562篇 |
1984年 | 595篇 |
1983年 | 589篇 |
1982年 | 594篇 |
1981年 | 525篇 |
1980年 | 443篇 |
1979年 | 480篇 |
1978年 | 432篇 |
1977年 | 349篇 |
1976年 | 351篇 |
1975年 | 361篇 |
1974年 | 335篇 |
1972年 | 344篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
R L Jat Pramod Jha M L Dotaniya B L Lakaria I Rashmi B P Meena A O Shirale A L Meena 《Environmental monitoring and assessment》2018,190(7):439
Selection of appropriate residue application method is essential for better use of biomass for soil and environmental health improvement. A laboratory incubation experiment was conducted for 75 days to investigate C and N mineralization of residues of soybean (Glycine max L.), chickpea (Cicer arietinum L.), maize (Zea mays L.), and wheat (Triticum aestivum L.) placed on the soil surface and incorporated into the soil. The residue of soybean and chickpea had a greater decomposition rate than that of maize and wheat, despite of their placements. Higher rate of decomposition of the residue of soybean and chickpea was recorded when it was kept on the soil surface while soil incorporation of residue of wheat and maize resulted in faster decomposition. Therefore, these findings could be used as guidelines for management of crop residue application in farmland to improve soil and environmental quality. 相似文献
52.
Vanessa Santana Vieira Santos Karen Magalhães Arantes Ester Luiza Gonçalves Carlos Fernando Campos Edimar Olegário de Campos Júnior Antônio Marcos Machado de Oliveira Boscolli Barbosa Pereira 《Environmental monitoring and assessment》2018,190(5):303
Phyllanthus niruri is a plant that is used to prevent calcium oxalate crystallisation and to block the stone formation in urolithiasis. Contaminants in the environment can be readily taken up by medicinal plants due to their ability to absorb chemicals into their tissues. If contaminated plants are ingested, they have the potential to negatively affect human and environmental health. The aim of this study was to assess contamination in the soil and the medicinal plant P. niruri by cadmium (Cd) in ceramic industrial areas of Monte Carmelo, Brazil. Soil samples and plant samples (divided in root, shoot and leaves) were collected from a contaminated monitoring site and from a rural area (which was used as a reference site for comparative purposes). The Cd concentrations of the samples were analysed with an atomic absorption spectrometer. P. niruri was found to be sensitive to soil contamination by Cd that was attributed to ceramic industrial emissions. The results revealed that Cd bioaccumulation in the roots and shoots of P. niruri was associated with a significant increase (p?<?0.05) in the concentration of active lignan compounds (phyllanthin and hypophyllanthin) in the leaves. The identification of high concentrations of Cd and active lignan compounds suggests a risk of contamination of the site and the risk of a high dose of Cd to people exposed at the site. 相似文献
53.
Kåre Hendriksen Birgitte Hoffmann 《Environmental science and pollution research international》2018,25(33):32964-32974
A good water supply and wastewater management is essential for a local sustainable community development. This is emphasized in the new global goals of the UN Sustainable Development, where the sixth objective is to: “Ensure availability and sustainable management of water and sanitation for all” (United Nations 2015). This obviously raises the question of how this can be achieved considering the very different conditions and cultures around the globe. This article presents the Greenlandic context and elucidates the current Greenland water supply system and wastewater management system from a socio-technical approach, focusing on the geographic, climatic and cultural challenges. The article identifies a diverse set of system constellations in different parts of Greenland and concludes with a discussion of health and quality of life implications. 相似文献
54.
M. Kansanga P. Andersen D. Kpienbaareh S. Mason-Renton K. Atuoye Y. Sano 《国际发展与全球生态学杂志》2019,26(1):11-24
Following the renewed effort at achieving a new green revolution for Africa, emphasis has been placed on modernizing smallholder agriculture through the deployment of improved inputs especially mechanized technologies. In Ghana, the government has in the last decade emphasized the provision of subsidized mechanized ploughing services to farmers alongside a rapidly growing private sector tractor service market. While mechanized technology adoption rates have increased rapidly, the deployment of these technologies has been without critical analysis of the impacts on production patterns and local agrarian systems. This paper examines the distributional impacts of agriculture mechanization on cropping patterns and farm sizes of smallholder farmers in northern Ghana using Geographic Information Systems (GIS) techniques, and semi-structured interviews with smallholder farmers (n=60). Specifically, comparative analysis of the field sizes and cropping patterns of participant farmers prior to and after the adoption of mechanized technologies was conducted. In-depth interviews were used to contextualize the experiences of smallholder farmers toward understanding how mechanization may be impacting traditional agriculture. Our findings reveal a mechanization paradox in which farm sizes are expanding, while cropping patterns are shifting away from traditional staple crops (pearl millet and sorghum bicolor) to market-oriented crops (maize, rice and groundnuts). This transition we argue, has adverse implications on the cultural dimension of food security, the organization of social life, and climate change adaptation. We recommend a retooling of the current agricultural policy focus to ensure context sensitivity for a more robust battle against food insecurity. 相似文献
55.
Radi Abeer M. Abdel Azeem Naglaa M. EL-Nahass EL-Shaymaa 《Environmental science and pollution research international》2021,28(5):5158-5167
Environmental Science and Pollution Research - Zinc is an essential nutritional trace mineral required for growth and health. The aim of the current work is to compare the effects of bulk zinc... 相似文献
56.
Although studies on environmental conflicts have engaged with the subject of violence, a multidimensional approach has been lacking. Using data from 95 environmental conflicts in Central America, we show how different forms of violence appear and overlap. We focus on direct, structural, cultural, slow, and ecological forms of violence. Results suggest that the common understanding of violence in environmental conflicts as a direct event in time and space is only the tip of the iceberg and that violence can reach not only environmental defenders, but also communities, nature, and the sustainability of their relations. 相似文献
57.
Anna Zubrowska Ewa Piorkowska Joanna Bojda 《Journal of Polymers and the Environment》2018,26(1):145-151
Blending of polylactide (PLA) with low stereoregularity and polyhedral oligomeric silsesquioxane grafted with arms of poly(ethylene glycol) methyl ether, acting as a plasticizer, allowed us previously to obtain a novel stable elastomeric-like material. The present contribution focuses on the properties of semi-crystalline PLA plasticized with this compound. Melt blends of PLA with 5–15 wt% of the plasticizer, were compression molded, quenched and annealed, which enabled cold-crystallization. The glass transition temperature of the blends and their drawability depended on their crystallinity and plasticizer content. The best ductility was reached at the plasticizer content of 15 wt%; the achieved strain at break was 6.5 (650%) and 1.3 (130%), for the quenched and annealed material, respectively. The latter value exceeded 20 times the strain at break of neat crystalline PLA. The tensile toughness of the annealed 15 wt% blend was 12 times larger than that of crystalline PLA. Moreover, annealing of 15 wt% blend improved its yield strength by 40%. Despite the two peaks of the loss modulus, indicating the two glass transitions in this blend, no heterogeneities were found by scanning electron microscopy, indicating that the plasticizer enriched phase formed instead of distinct inclusions of the plasticizer. 相似文献
58.
Lorena A. Latini María M. Indaco María B. Aguiar Liliana B. Monza María E. Parolo Carlos F. Melideo 《Journal of environmental science and health. Part. B》2018,53(7):469-475
Chlorpyrifos (O, O-diethyl O-3,5,6-trichloropyridin-2-yl phosphorothioate) and carbaryl (1-naphthyl methylcarbamate) are often applied concurrently as insecticides in food production. The aim of this study was to research their migration behavior in a real environment. We researched the leaching of both pesticides by setting up field lysimeters on a farm with the typical soil used in fruit production today. In order to analyze the variables involved in this process, we performed complementary adsorption studies, we performed complementary adsorption studies using batches and undisturbed soil laboratory columns for both compounds. The results for pesticide transport through the lysimeters showed that less than 1% of chlorpyrifos was recovered in the leachates, while almost 17% was recovered for carbaryl. Having completed the experiment in undisturbed laboratory columns, soil analysis showed that chlorpyrifos mainly remained in the first 5 cm, while carbaryl moved down to the lower sections. These results can be explained in view of the sorption coefficient values (KD) obtained in horizons A and B for chlorpyrifos (393 and 184 L kg?1) and carbaryl (3.1 and 4.2 L kg?1), respectively. By integrating the results obtained in the different approaches, we were able to characterize the percolation modes of these pesticides in the soil matrix, thus contributing to the sustainable use of resources. 相似文献
59.
Cassava starch waste hydrolysates (CSWHs) with different degrees of polymerisation, i.e., CSWHs-1, CSWHs-2 and CSWHs-3, were prepared through the hydrolysis of cassava starch waste with thermostable a-amylase from Thermococcus sp. HJ21. The prepared CSWHs were then used as a carbon source for curdlan production with Alcaligenes faecalis ATCC 31749. The amount of curdlan produced and the glucosyltransferase activity during curdlan synthesis increased more obviously when CSWHs-2 was used as the carbon source than when glucose was used. Using both carbon sources, the maximum curdlan production was observed at day 5, and the maximum glucosyltransferase activity was observed at day 4. Glucosyltransferase activity decreased thereafter, and biomass continued to increase until the end of the experiment (day 6). Results indicated that the enhanced curdlan production with CSWHs as the carbon source was highly correlated with glucosyltransferase activity. 相似文献
60.