全文获取类型
收费全文 | 91095篇 |
免费 | 1217篇 |
国内免费 | 1084篇 |
专业分类
安全科学 | 3755篇 |
废物处理 | 3322篇 |
环保管理 | 14071篇 |
综合类 | 21125篇 |
基础理论 | 26405篇 |
环境理论 | 73篇 |
污染及防治 | 15069篇 |
评价与监测 | 5448篇 |
社会与环境 | 3576篇 |
灾害及防治 | 552篇 |
出版年
2022年 | 800篇 |
2021年 | 794篇 |
2020年 | 647篇 |
2019年 | 860篇 |
2018年 | 1118篇 |
2017年 | 1159篇 |
2016年 | 2158篇 |
2015年 | 1833篇 |
2014年 | 2565篇 |
2013年 | 9232篇 |
2012年 | 2213篇 |
2011年 | 2470篇 |
2010年 | 3267篇 |
2009年 | 3394篇 |
2008年 | 2024篇 |
2007年 | 1873篇 |
2006年 | 2305篇 |
2005年 | 2287篇 |
2004年 | 2584篇 |
2003年 | 2431篇 |
2002年 | 2005篇 |
2001年 | 2302篇 |
2000年 | 2020篇 |
1999年 | 1499篇 |
1998年 | 1371篇 |
1997年 | 1362篇 |
1996年 | 1490篇 |
1995年 | 1588篇 |
1994年 | 1475篇 |
1993年 | 1342篇 |
1992年 | 1323篇 |
1991年 | 1295篇 |
1990年 | 1251篇 |
1989年 | 1226篇 |
1988年 | 1059篇 |
1987年 | 991篇 |
1986年 | 991篇 |
1985年 | 1071篇 |
1984年 | 1166篇 |
1983年 | 1171篇 |
1982年 | 1177篇 |
1981年 | 1107篇 |
1980年 | 944篇 |
1979年 | 933篇 |
1978年 | 827篇 |
1977年 | 717篇 |
1976年 | 651篇 |
1975年 | 626篇 |
1973年 | 658篇 |
1972年 | 655篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
Impacts of Changes in Precipitation Amount and Distribution on Water Resources Studied Using a Model Rainwater Harvesting System 下载免费PDF全文
Behzad Asadieh Nir Y. Krakauer 《Journal of the American Water Resources Association》2016,52(6):1450-1471
Water supply reliability is expected to be affected by both precipitation amount and distribution changes under recent and future climate change. We compare historical (1951‐2010) changes in annual‐mean and annual‐maximum daily precipitation in the global set of station observations from Global Historical Climatology Network and climate models from the Inter‐Sectoral Impact Model Intercomparison Project (ISI‐MIP), and develop the study to 2011‐2099 for model projections under high radiative forcing scenario (RCP8.5). We develop a simple rainwater harvesting system (RWHS) model and drive it with observational and modeled precipitation. We study the changes in mean and maximum precipitation along with changes in the reliability of the model RWHS as tools to assess the impact of changes in precipitation amount and distribution on reliability of precipitation‐fed water supplies. Results show faster increase in observed maximum precipitation (10.14% per K global warming) than mean precipitation (7.64% per K), and increased reliability of the model RWHS driven by observed precipitation by an average of 0.2% per decade. The ISI‐MIP models show even faster increase in maximum precipitation compared to mean precipitation. However, they imply decreases in mean reliability, for an average 0.15% per decade. Compared to observations, climate models underestimate the increasing trends in mean and maximum precipitation and show the opposite direction of change in reliability of a model water supply system. 相似文献
952.
Eric D. Carter 《Local Environment》2016,21(1):3-23
This paper presents the results of ethnographic research conducted with several environmental justice (EJ) organisations in Latino communities of Los Angeles, California. Traditional EJ politics revolves around research and advocacy to reduce discriminatory environmental exposures, risks, and impacts. However, I argue that in recent years there has been a qualitative change in EJ politics, characterised by four main elements: (1) a move away from the reaction to urban environmental “bads” (e.g. polluting industries) in the city towards a focus on the production of nature in the city; (2) strategies that are less dependent on the legal, bureaucratic, and technical “regulatory route”; (3) the formation of a distinctive “Latino environmental ethic” that offers a more complex consideration of the place of race in EJ organising; and (4) a spatial organisation of EJ politics that moves away from hyperlocal, vertical organisation towards diversified city-wide networks that include EJ organisations, mainstream environmental groups, nonprofits, foundations, and entrepreneurs. This shift in EJ movement politics is shaped by broader political-economic changes, including the shift from post-Fordist to neoliberal and now green economy models of urban development; the influence of neoliberal multiculturalism in urban politics; and the increasingly prominent role of Latinos in city, state, and national politics. New spaces of Latino EJ also reflect the ambitions of Los Angeles as a global city, with urban growth increasingly framed in an international discourse of sustainability that combines quality of life, environmental, and economic development rationales. 相似文献
953.
Naveen K. Shrivastava Shashikant B. Thombre Kailas L. Wasewar 《International Journal of Green Energy》2016,13(2):213-228
In order to understand the complex transport phenomena in a passive direct methanol fuel cell (DMFC), a theoretical model is essential. The analytical model provides a computationally efficient framework with a clear physical meaning. For this, a non-isothermal, analytical model for the passive DMFC has been developed in this study. The model considers the coupled heat and mass transport along with electrochemical reactions. The model is successfully validated with the experimental data. The model accurately describes the various species transport phenomena including methanol crossover and water crossover, heat transport phenomena, and efficiencies related to the passive DMFC. It suggests that the maximum real efficiency can be achieved by running the cell at low methanol feed concentration and moderate current density. The model also accurately predicts the effect of various operating and geometrical parameters on the cell performance such as methanol feed concentration, surrounding temperature, and polymer electrolyte membrane thickness. The model predictions are in accordance with the findings of the other researchers. The model is rapidly implementable and can be used in real-time simulation and control of the passive DMFC. This comprehensive model can be used for diagnostic purpose as well. 相似文献
954.
G. N. Demirer 《International Journal of Green Energy》2016,13(13):1320-1324
Pistachio processing wastes create significant waste management problems unless properly managed. However, there are not well-established methods to manage the waste generated during the processing of pistachios. Anaerobic digestion can be an attractive option not only for the management of pistachio processing wastes but also producing renewable energy in the form of biogas. This study investigated anaerobic digestibility and biogas production potential of pistachio de-hulling waste from wet de-hulling process. Best to our knowledge, this is the first report on biogas production from pistachio de-hulling waste. The results indicated that (1) anaerobic digestion of pistachio de-hulling wastewater, solid waste, and their mixtures in different ratios is possible with varying levels of performance; (2) 1 L of de-hulling wastewater (chemical oxygen demand concentration of 30 g/L) produced 0.7 L of methane; (3) 1 L of de-hulling wastewater and 20 g of pistachio de-hulling solid waste produced 1.25 L of methane; and (4) 1 g of de-hulling solid waste produced 62.6 mL of methane (or 134 mL of biogas). 相似文献
955.
Protected areas’ role in climate-change mitigation 总被引:1,自引:0,他引:1
956.
Marlene Roellig Laura M. E. Sutcliffe Marek Sammul Henrik von Wehrden Jens Newig Joern Fischer 《Ambio》2016,45(2):185-195
Wood-pastures are associated with high cultural and biodiversity values in Europe. However, due to their relatively low productivity, large areas of wood-pastures have been lost over the last century. In some areas, incentive schemes have been developed to revive wood-pastures. We investigated the effects of one such scheme in western Estonia. We compared the structure of grazed wood-pastures (old and restored) to those of abandoned wood-pastures and ungrazed forest stands to explore the effects of management, and conducted interviews with 24 farmers to investigate their motivations to carry out the management. We found a positive influence of active management on the semi-open structure of wood-pastures. Financial support was vital for management, but personal values related to tradition also played an important role. The interviewees differed widely in their range of motivations, suggesting that other strategies in addition to financial incentives would further improve the management of wood-pastures in the region.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-015-0719-8) contains supplementary material, which is available to authorized users. 相似文献957.
958.
David A. Ross Héctor M. Guzmán Vincent J. Van Hinsberg Catherine Potvin 《Journal of environmental science and health. Part. B》2016,51(10):675-687
Concentrations of eight elements were measured in Chelonia mydas and Lepidochelys olivacea eggs collected along the Pacific coast of Panama. Manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), and mercury (Hg) concentrations were similar to previous reports of these species from around the world, while lead (Pb) was lower than previous reports. Cd posed the highest health risk to people who regularly eat the eggs, with average consumption rates leading to target hazard quotients (THQ) of up to 0.35 ± 0.15. Our conclusions indicate that current turtle egg consumption in isolated, coastal Pacific communities may pose a health concern for young children, and that youth and young adults should limit their consumption of turtle eggs to reduce their total intake of nonessential metals. 相似文献
959.
960.