全文获取类型
收费全文 | 39762篇 |
免费 | 418篇 |
国内免费 | 316篇 |
专业分类
安全科学 | 1298篇 |
废物处理 | 1842篇 |
环保管理 | 5278篇 |
综合类 | 6258篇 |
基础理论 | 10365篇 |
环境理论 | 15篇 |
污染及防治 | 9889篇 |
评价与监测 | 2759篇 |
社会与环境 | 2540篇 |
灾害及防治 | 252篇 |
出版年
2023年 | 195篇 |
2022年 | 368篇 |
2021年 | 430篇 |
2020年 | 272篇 |
2019年 | 344篇 |
2018年 | 612篇 |
2017年 | 620篇 |
2016年 | 958篇 |
2015年 | 721篇 |
2014年 | 1108篇 |
2013年 | 3258篇 |
2012年 | 1350篇 |
2011年 | 1803篇 |
2010年 | 1450篇 |
2009年 | 1541篇 |
2008年 | 1826篇 |
2007年 | 1782篇 |
2006年 | 1603篇 |
2005年 | 1414篇 |
2004年 | 1313篇 |
2003年 | 1266篇 |
2002年 | 1207篇 |
2001年 | 1440篇 |
2000年 | 1013篇 |
1999年 | 640篇 |
1998年 | 457篇 |
1997年 | 505篇 |
1996年 | 510篇 |
1995年 | 603篇 |
1994年 | 532篇 |
1993年 | 474篇 |
1992年 | 471篇 |
1991年 | 473篇 |
1990年 | 458篇 |
1989年 | 438篇 |
1988年 | 382篇 |
1987年 | 329篇 |
1986年 | 343篇 |
1985年 | 319篇 |
1984年 | 353篇 |
1983年 | 344篇 |
1982年 | 356篇 |
1981年 | 306篇 |
1980年 | 238篇 |
1979年 | 274篇 |
1978年 | 216篇 |
1977年 | 195篇 |
1975年 | 195篇 |
1973年 | 222篇 |
1972年 | 191篇 |
排序方式: 共有10000条查询结果,搜索用时 207 毫秒
21.
22.
Jorge Alberto Vieira Costa Bárbara Catarina Bastos Freitas Camila Gonzales Cruz Jéssica Silveira Michele Greque Morais 《Journal of environmental science and health. Part. B》2019,54(5):366-375
The loss of yields from agricultural production due to the presence of pests has been treated over the years with synthetic pesticides, but the use of these substances negatively affects the environment and presents health risks for consumers and animals. The development of agroecological systems using biopesticides represents a safe alternative that contributes to the reduction of agrochemical use and sustainable agriculture. Microalgae are able to biosynthesize a number of metabolites with potential biopesticidal action and can be considered potential biological agents for the control of harmful organisms to soils and plants. The present work aims to provide a critical perspective on the consequences of using synthetic pesticides, offering as an alternative the biopesticides obtained from microalgal biomass, which can be used together with the implementation of environmentally friendly agricultural systems. 相似文献
23.
es Ruiz de Arcaute Celeste Ossana Natalia A. Pérez-Iglesias Juan Manuel Soloneski Sonia Larramendy Marcelo L. 《Environmental science and pollution research international》2019,26(20):20485-20498
Environmental Science and Pollution Research - Pesticides might increase the production of reactive oxygen species (ROS). Dicamba (DIC) and 2,4-dichlorophenoxyacetic acid (2,4-D) are auxinic... 相似文献
24.
Understanding implications of consumer behavior for wildlife farming and sustainable wildlife trade 下载免费PDF全文
A. Nuno J. M. Blumenthal T. J. Austin J. Bothwell G. Ebanks‐Petrie B. J. Godley A. C. Broderick 《Conservation biology》2018,32(2):390-400
Unsustainable wildlife trade affects biodiversity and the livelihoods of communities dependent upon those resources. Wildlife farming has been proposed to promote sustainable trade, but characterizing markets and understanding consumer behavior remain neglected but essential steps in the design and evaluation of such operations. We used sea turtle trade in the Cayman Islands, where turtles have been farm raised for human consumption for almost 50 years, as a case study to explore consumer preferences toward wild‐sourced (illegal) and farmed (legal) products and potential conservation implications. Combining methods innovatively (including indirect questioning and choice experiments), we conducted a nationwide trade assessment through in‐person interviews from September to December 2014. Households were randomly selected using disproportionate stratified sampling, and responses were weighted based on district population size. We approached 597 individuals, of which 37 (6.2%) refused to participate. Although 30% of households had consumed turtle in the previous 12 months, the purchase and consumption of wild products was rare (e.g., 64–742 resident households consumed wild turtle meat [i.e., 0.3–3.5% of households] but represented a large threat to wild turtles in the area due to their reduced populations). Differences among groups of consumers were marked, as identified through choice experiments, and price and source of product played important roles in their decisions. Despite the long‐term practice of farming turtles, 13.5% of consumers showed a strong preference for wild products, which demonstrates the limitations of wildlife farming as a single tool for sustainable wildlife trade. By using a combination of indirect questioning, choice experiments, and sales data to investigate demand for wildlife products, we obtained insights about consumer behavior that can be used to develop conservation‐demand‐focused initiatives. Lack of data from long‐term social–ecological assessments hinders the evaluation of and learning from wildlife farming. This information is key to understanding under which conditions different interventions (e.g., bans, wildlife farming, social marketing) are likely to succeed. 相似文献
25.
Srichandan Suchismita Baliarsingh Sanjiba Kumar Prakash Satya Lotliker Aneesh A. Parida Chandanlal Sahu Kali Charan 《Environmental science and pollution research international》2019,26(12):12025-12041
Environmental Science and Pollution Research - Seasonal distribution of phytoplankton community and size structure was assessed in three different tropical ecosystems of the western Bay of Bengal... 相似文献
26.
Regional Environmental Change - The rapid environmental changes currently underway in many dry regions of the world, and the deep uncertainty about their consequences, underscore a critical... 相似文献
27.
A.?R.?M.?Towfiqul?IslamEmail author Shuanghe?Shen Muhammed?Atikul?Haque Md.?Bodrud-Doza K.?W.?Maw Md.?Ahosan?Habib 《Environment, Development and Sustainability》2018,20(5):1935-1959
Sustainable groundwater quality is a key global concern and has become a major issue of disquiets in most parts of the world including Bangladesh. Hence, the assessment of groundwater quality is an important study to ensure its sustainability for various uses. In this study, a combination of multivariate statistics, geographical information system (GIS) and geochemical approaches was employed to evaluate the groundwater quality and its sustainability in Joypurhat district of Bangladesh. The results showed that the groundwater samples are mainly Ca–Mg–HCO3 type. Principal component analysis (PCA) results revealed that geogenic sources (rock weathering and cation exchange) followed by anthropogenic activities (domestic sewage and agro-chemicals) were the major factors governing the groundwater quality of the study area. Furthermore, the results of PCA are validated using the cluster analysis and correlation matrix analysis. Based on the groundwater quality index (GWQI), it is found that all the groundwater samples belong to excellent to good water quality domains for human consumption, although iron, fluoride and iodide contaminated to the groundwater, which do not pose any significant health hazard according to World Health Organization’s and Bangladesh’s guideline values. The results of irrigation water quality index including sodium adsorption ratio (SAR), permeability index and sodium percentage (Na %) suggested that most of the groundwater samples are good quality water for agricultural uses. The spatial distribution of the measured values of GWQI, SAR, Fe (iron), EC (electrical conductivity) and TH (total hardness) were spatially mapped using the GIS tool in the study area. 相似文献
28.
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
29.
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
30.