全文获取类型
收费全文 | 6609篇 |
免费 | 48篇 |
国内免费 | 32篇 |
专业分类
安全科学 | 139篇 |
废物处理 | 273篇 |
环保管理 | 561篇 |
综合类 | 981篇 |
基础理论 | 1379篇 |
环境理论 | 3篇 |
污染及防治 | 1614篇 |
评价与监测 | 543篇 |
社会与环境 | 1167篇 |
灾害及防治 | 29篇 |
出版年
2022年 | 69篇 |
2021年 | 87篇 |
2020年 | 41篇 |
2019年 | 57篇 |
2018年 | 121篇 |
2017年 | 140篇 |
2016年 | 170篇 |
2015年 | 110篇 |
2014年 | 224篇 |
2013年 | 540篇 |
2012年 | 245篇 |
2011年 | 290篇 |
2010年 | 232篇 |
2009年 | 267篇 |
2008年 | 317篇 |
2007年 | 352篇 |
2006年 | 279篇 |
2005年 | 268篇 |
2004年 | 247篇 |
2003年 | 227篇 |
2002年 | 212篇 |
2001年 | 247篇 |
2000年 | 199篇 |
1999年 | 90篇 |
1998年 | 67篇 |
1997年 | 74篇 |
1996年 | 61篇 |
1995年 | 81篇 |
1994年 | 66篇 |
1993年 | 56篇 |
1992年 | 57篇 |
1991年 | 59篇 |
1990年 | 71篇 |
1989年 | 54篇 |
1988年 | 42篇 |
1987年 | 38篇 |
1986年 | 46篇 |
1985年 | 46篇 |
1984年 | 51篇 |
1983年 | 36篇 |
1982年 | 46篇 |
1981年 | 36篇 |
1980年 | 44篇 |
1979年 | 44篇 |
1975年 | 30篇 |
1974年 | 30篇 |
1973年 | 33篇 |
1972年 | 39篇 |
1971年 | 30篇 |
1969年 | 31篇 |
排序方式: 共有6689条查询结果,搜索用时 421 毫秒
651.
652.
653.
After the Aznalcóllar mining spill (25th April 1998), considerable social concern arose amongst the inhabitants of the SW Iberian Peninsula concerning the consumption of local seafood. Squilla mantis was collected in four regions of the Gulf of Cádiz with a dual objective: to analyze the heavy metal levels for human consumption and as part of biomonitoring program. Heavy metal concentrations (Fe, Mn, Zn, Cu, Cd and Pb) were analyzed in soft tissues and cuticle. The highest values were found in the soft tissues for zinc, copper and cadmium and in the cuticle for iron, manganese and lead. The mean copper concentration in the soft tissue, corresponding to the edible part, was 27.1 microg x g(-1) wet weight. Approximately 80% of stations showed values higher than 20 microg x g(-1) wet weight of copper, the Spanish legal limit for the concentration of this metal in the crustacean for human consumption. For Zn and Cu no significant differences were found between regions, probably related with the capacity for regulation of S. mantis. The highest values found for copper in the Gulf of Cádiz compared to other areas is likely to be related with contamination from terrestrial mining activities (copper and pyrites) in the region, dating back to the times of Tartessians and Romans, rather than the effects of mining spill which was shown not to create any significant increases in heavy metal concentrations of organisms of the Guadalquivir River or the adjacent coastal area. 相似文献
654.
655.
P. Herzsprung K. Friese R. Frömmichen J. Göttlicher M. Koschorreck W. V. Tümpling Jr. K. Wendt-Potthoff 《Water, Air, & Soil Pollution: Focus》2002,2(3):123-140
In the past five years, enclosures have beeninstalled in an acidic mining lake in Lusatia to investigate insitu remediation processes. They were treated with straw, withstraw and Carbokalk, or with Carbokalk alone, where Carbokalkis a by-product of the sugar industry (solid precipitate ofnon-sugars after lime clarification of extracted sugar beetjuice). Sediment samples were taken as cores to get informationabout the behaviour of organic and inorganic components insediment pore-water with depth. Vertical distributions of pH,soluble reactive phosphate, nitrate, ammonium, silica,aluminium, iron, manganese, calcium, magnesium, sodium,potassium, sulphate, and DOC were measured. The resultingprofiles, each consisting of 15 data points at differentdepths, were compared by cluster analysis. The similarities ofsediment cores from different treated enclosures relating toprofiles of chemical components were discussed. Increasedconcentrations of potassium and sulphate were found in pore-water after substrate treatment. The data imply dissolution ofpotassium iron sulphate hydroxide minerals (jarosite) after anincrease of pH caused by dissolution of lime and by sulphatereducing processes which were stimulated by organic substrateaddition. 相似文献
656.
G. Grasa V. Navarro O. Rubio J. A. Pea J. Santamaria 《Journal of Loss Prevention in the Process Industries》2002,15(6):525-530
Opinion polls were conducted to assess the level of risk perceived by the citizens in communities of different sizes where chemical industries were present. The aim of the study was to relate the risk perceived to variables such as the nature of risks, the specific information received regarding the industrial activity and the economic impact of this activity in the community. 相似文献
657.
Kellie B. Vach Joseph M. Eilers Mary V. Santelmann 《Journal of the American Water Resources Association》2002,38(3):773-787
ABSTRACT: Simulated water quality resulting from three alternative future land‐use scenarios for two agricultural watersheds in central Iowa was compared to water quality under current and historic land use/land cover to explore both the potential water quality impact of perpetuating current trends and potential benefits of major changes in agricultural practices in the U.S. Corn Belt. The Soil Water Assessment Tool (SWAT) was applied to evaluate the effect of management practices on surface water discharge and annual loads of sediment and nitrate in these watersheds. The agricultural practices comprising Scenario 1, which assumes perpetuation of current trends (conversion to conservation tillage, increase in farm size and land in production, use of currently‐employed Best Management Practices (BMPs)) result in simulated increased export of nitrate and decreased export of sediment relative to the present. However, simulations indicate that the substantial changes in agricultural practices envisioned in Scenarios 2 and 3 (conversion to conservation tillage, strip intercropping, rotational grazing, conservation set‐asides and greatly extended use of best management practices (BMPs) such as riparian buffers, engineered wetlands, grassed waterways, filter strips and field borders) could potentially reduce current loadings of sediment by 37 to 67 percent and nutrients by 54 to 75 percent. Results from the study indicate that major improvements in water quality in these agricultural watersheds could be achieved if such environmentally‐targeted agricultural practices were employed. Traditional approaches to water quality improvement through application of traditional BMPs will result in little or no change in nutrient export and minor decreases in sediment export from Corn Belt watersheds. 相似文献
658.
Robert V. Sobczak Thomas C. Cambareri 《Journal of the American Water Resources Association》2002,38(3):747-757
ABSTRACT: An inverse‐simulation approach is used to determine optimal strategies for developing public water‐supply systems in a shallow, coastal aquifer on the outermost arm of the Cape Cod peninsula in Massachusetts. Typically a forward simulation (or “trial and error”) approach is used to find best pumping strategies, but the chances of finding success with this tact diminish as the number of potential options grows large. Well locations and pumping rates are optimized with respect to: (1) providing sufficient water to areas of water‐quality impairment, (2) minimizing impacts to nearby surface waters, (3) preventing saltwater contamination due to overpumping, and (4) minimizing financial cost of well development. Potential well sites and water‐supply scenarios are separated into “politically‐based” and “resource‐based” categories to gain insight into the degree that pre‐existing political boundaries hinder best management practices. The approach provides a promising tool in transboundary water‐resources settings because it allows stakeholders to find solutions that best meet everyone's goals, as opposed to pursuing options that will create conflict, or are less than optimal. 相似文献
659.
This article describes regulatory issues and emission control equipment for air toxics applications. A brief history of air quality legislation is provided, illustrating the difficulty government has had in implementing air quality statutes; this has contributed to the complexity of air quality regulations. Evaluation methodologies are described for three different emission control technologies: thermal oxidation, catalytic oxidation, and adsorption. Brief case histories are provided that describe the pitfalls and benefits associated with each technology. The benefits of integrating health risk assessment into an air quality program are also discussed. 相似文献
660.
Robert N. Havis Carlos V. Alonso John G. King Russell F. Thurow 《Journal of the American Water Resources Association》1993,29(3):435-444
ABSTRACT: A simulation model [Salmonid Spawning Analysis Model (SSAM)] was developed as a management tool to evaluate the relative impacts of stream sediment load and water temperature on salmonid egg survival. The model is useful for estimating acceptable sediment loads to spawning habitat that may result from upland development, such as logging and agriculture. Software in common use in the USA were adapted for use in gravel bedded rivers and linked to simulate water temperature (the USFWS Instream Water Temperature, SNTEMP model) and water and sediment routing (the USAE Scour and Deposition in Rivers and Reservoirs, HEC-6 model, version 3.2). These models drive the redd (spawning nest) model (the USDA-ABS Sediment Intrusion Dissolved Oxygen SIDO model) which simulates sediment intrusion and dissolved oxygen concentration in the redd environment. The SSAM model predictions of dissolved oxygen and water temperature compared favorably with field data from artificial redds containing hatchery chinook salmon eggs. 相似文献