全文获取类型
收费全文 | 560篇 |
免费 | 3篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 36篇 |
环保管理 | 58篇 |
综合类 | 43篇 |
基础理论 | 134篇 |
污染及防治 | 157篇 |
评价与监测 | 108篇 |
社会与环境 | 26篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 15篇 |
2022年 | 48篇 |
2021年 | 31篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 18篇 |
2017年 | 14篇 |
2016年 | 27篇 |
2015年 | 17篇 |
2014年 | 27篇 |
2013年 | 54篇 |
2012年 | 27篇 |
2011年 | 30篇 |
2010年 | 35篇 |
2009年 | 22篇 |
2008年 | 33篇 |
2007年 | 26篇 |
2006年 | 20篇 |
2005年 | 14篇 |
2004年 | 11篇 |
2003年 | 13篇 |
2002年 | 15篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1964年 | 1篇 |
1961年 | 3篇 |
1960年 | 1篇 |
1958年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有568条查询结果,搜索用时 281 毫秒
501.
Photocatalytic degradation and mineralization of pesticides are studied over TiO(2) supported mesoporous SBA-15 composite system using solar light. TiO(2) is immobilized over SBA-15 by solid sate dispersion method. The catalysts are characterized by XRD, surface area, UV-Vis diffused reflectance spectra, SEM and TEM. The detailed photocatalytic degradation studies are carried out over TiO(2), SBA-15 and different TiO(2) wt% supported SBA-15. The activity evaluation parameters such as catalyst amount, pH, and pollutant initial concentration are studied taking isoproturon as a model compound and established conditions for pesticide degradation. The optimum degradation is achieved over 10 wt% TiO(2)/SBA-15 within 30 min and the reaction is following pseudo-first order kinetics. The isoproturon mineralization is monitored with TOC reduction and it takes around 9h for disappearance. The commercial pesticide solutions containing imidacloprid and phosphamidon are also successfully degraded over these composites with the established conditions. The data indicates that 10 wt% TiO(2)/SBA-15 composite is an effective and highly active system for the pesticide degradations. 相似文献
502.
503.
Application of CCME Water Quality Index to Monitor Water Quality: A Case Study of the Mackenzie River Basin, Canada 总被引:2,自引:0,他引:2
All six ecosystem initiatives evolved from many years of federal, provincial, First Nation, local government and community attention to the stresses on sensitive habitats and species, air and water quality, and the consequent threats to community livability. This paper assesses water quality aspect for the ecosystem initiatives and employs newly developed Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) which provides a convenient mean of summarizing complex water quality data that can be easily understood by the public, water distributors, planners, managers and policy makers. The CCME WQI incorporates three elements: Scope – the number of water quality parameters (variables) not meeting water quality objectives (F
1); Frequency – the number of times the objectives are not met (F
2); and Amplitude. the extent to which the objectives are not met (F
3). The index produces a number between 0 (worst) to 100 (best) to reflect the water quality. This study evaluates water quality of the Mackenzie – Great Bear sub-basin by employing two modes of objective functions (threshold values): one based on the CCME water quality guidelines and the other based on site-specific values that were determined by the statistical analysis of the historical data base. Results suggest that the water quality of the Mackenzie-Great Bear sub-basin is impacted by high turbidity and total (mostly particulate) trace metals due to high suspended sediment loads during the open water season. Comments are also provided on water quality and human health issues in the Mackenzie basin based on the findings and the usefulness of CCME water quality guidelines and site specific values. 相似文献
504.
505.
Thin-layer chromatography (TLC) is shown as an effective, inexpensive, reliable, and less time consuming technique for simple and effective monitoring of persistent toxicant-like DDT in its manufacturing plant effluent. Aqueous untreated and treated grab and composit effluent samples were collected, extracted with a solvent and concentrated and chromatographed both for qualitative and quantitative analysis for p, p′-DDT and related compounds. This technique was successful and can form an effective, inexpensive method to be used by the developing countries, which have limited financial resources. 相似文献
506.
507.
Dietary and industrial uses of cassava (Manihot esculenta Crantz) are threatened by the known presence of cyanide in the crop and its products. The toxic HCN content of cassava may be altered by some intrinsic and extrinsic factors in and around the plant, but the extent of any shifts in this regard due to stress conditions created by cassava green spider mites (CGM) Mononychellus tanajoa and mealybugs (CM) (Phenacoccus manihoti, now spreading epiphytotically in almost all cassava-growing areas in Africa, is unknown. In this study, we report variations in the total HCN content of leaf, stem and root tissues of six cassava clones differentially infested by these pests. 相似文献
508.
Shradha Panwar Devendra K. Agrawal Khilendra S. Kanwal Vertika Sharma Mahendra S. Lodhi 《Journal of Environmental Planning and Management》2010,53(7):907-923
This study provides an overview of the impacts of a proposed hydroelectric power project in the Western Himalayan region in India, using a primary database on floristic diversity and vegetation analysis. The remote sensing data revealed that in the submergence zone only mixed deciduous forest that occupies 807.5 ha area and has a wood biomass volume of 4,027,503 m3 is likely to be lost due to impoundment. A total of 165 plant species found in the submergence zone also occur in the influence and free draining catchment area of the project. In the influence zone of the project area only one tree species (Acer oblongum) is found under conservation threat category, which is also present in the free draining catchment of the project. The project affected population (6716 people) residing in the submergence and influence zone depend upon the surrounding forests for fuel wood, fodder, wild edibles etc., and most likely they will settle in the nearby areas, thus mounting more pressure on residual forests of the influence zone for various forest products. Further, from the vegetation analysis it is evident that several tree species (e.g. Lannea coromandelica, Terminalia alata, T. bellerica etc.), may face more pressure from exploitation as they provide a number of useful products and are represented in lower numbers in the forests of the project area. To compensate for the loss of various goods and services provided by the forests falling in the submergence zone and to offset the increased pressure of the project affected families on the forests of influence zone, a biodiversity management plan is suggested incorporating socio-economic considerations. 相似文献
509.
510.
Coal combustion in the power sector gives rise to the emission of primary and secondary particulate pollutants. Since the emission of pollutants depends on coal quality and combustion technology, and given that transport, transformation and deposition of contaminants depend on regional climatic conditions, specific studies for the power stations is needed to evaluate their environmental impacts. Monitoring of ambient respirable suspended particulate matter (RSPM) and suspended particulate matter (SPM) levels around a large coal-fired power station in India was carried out. The specific objectives were the determination of spatial and seasonal variability in RSPM and SPM levels, and their relationship with meteorological parameters such as wind velocity and relative humidity. The results have shown a marked seasonal trend and spatial variability in RSPM and SPM levels in the study area. Higher concentrations of ambient RSPM and SPM were found in downwind monitoring stations compared to upwind direction. Ratios of RSPM to SPM and correlation coefficient values between RSPM and SPM along with meteorological parameters were also worked out. Relative humidity and wind velocity have shown an inverse relation with particulate deposition pattern. 相似文献