全文获取类型
收费全文 | 2210篇 |
免费 | 18篇 |
国内免费 | 27篇 |
专业分类
安全科学 | 62篇 |
废物处理 | 70篇 |
环保管理 | 276篇 |
综合类 | 485篇 |
基础理论 | 454篇 |
环境理论 | 1篇 |
污染及防治 | 659篇 |
评价与监测 | 113篇 |
社会与环境 | 120篇 |
灾害及防治 | 15篇 |
出版年
2023年 | 22篇 |
2022年 | 19篇 |
2021年 | 31篇 |
2020年 | 24篇 |
2019年 | 31篇 |
2018年 | 54篇 |
2017年 | 57篇 |
2016年 | 67篇 |
2015年 | 75篇 |
2014年 | 84篇 |
2013年 | 108篇 |
2012年 | 90篇 |
2011年 | 144篇 |
2010年 | 121篇 |
2009年 | 137篇 |
2008年 | 124篇 |
2007年 | 129篇 |
2006年 | 94篇 |
2005年 | 68篇 |
2004年 | 93篇 |
2003年 | 59篇 |
2002年 | 79篇 |
2001年 | 71篇 |
2000年 | 41篇 |
1999年 | 20篇 |
1998年 | 23篇 |
1997年 | 29篇 |
1996年 | 23篇 |
1995年 | 33篇 |
1994年 | 26篇 |
1993年 | 9篇 |
1992年 | 20篇 |
1991年 | 27篇 |
1990年 | 14篇 |
1989年 | 20篇 |
1988年 | 9篇 |
1987年 | 6篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1982年 | 13篇 |
1981年 | 11篇 |
1980年 | 6篇 |
1979年 | 11篇 |
1970年 | 10篇 |
1967年 | 5篇 |
1966年 | 5篇 |
1965年 | 8篇 |
1964年 | 5篇 |
1960年 | 6篇 |
1956年 | 5篇 |
排序方式: 共有2255条查询结果,搜索用时 968 毫秒
661.
662.
Jochem F. M. van der Waals Walter J. V. Vermeulen 《Journal of Environmental Planning and Management》2002,45(4):549-569
This paper investigates the potential of a method for participatory policy making in the field of carbon dioxide (CO 2 ) reduction in housing: the CO 2 reduction workshop. This innovative method aims to involve relevant actors at an early stage of urban development and to formulate common ambitions for CO 2 reduction. Special attention is paid to the inputting of information about options for CO 2 reduction. The workshop was organized and evaluated in two planning processes for new housing estates in the Netherlands. The evaluation addresses the design of the workshop, the utilization of knowledge in the process, the effects of the workshop on the commitment and knowledge of the participants and the effects on the wider planning process. 相似文献
663.
Biodegradation of Waste Cellulose 总被引:1,自引:0,他引:1
Environmental issues such as the depletion of nonrenewable energy resources and pollution are very topical and would need more scientific attention in order to be addressed in a way beneficial to life. The extent of solid waste production is a global concern and development of its bioenergy potential can simultaneously address issues such as pollution control and renewable energy development. Various wastepaper materials, a major component of solid waste, have been treated with cellulase from Trichoderma viride to bioconvert its cellulose component into fermentable sugars that could be utilized as feedstock for bioproduct development. These paper materials exhibited different susceptibilities toward the cellulase and showed different sugarreleasing patterns when increasing amounts of each paper were treated with the enzyme. Bioconversion of paper with different enzyme concentrations and during various time intervals also resulted in nonsimilar sugar-releasing patterns. With all the paper materials, a general decline in efficiency was observed with increasing amounts of sugar produced during the different bioconversion variables investigated. 相似文献
664.
Limited natural resources and landfill space, as well as increasing amounts of ash produced from incineration of bio fuel and municipal solid waste, have created a demand for useful applications of ash, of which road construction is one application. Along national road 90, situated about 20 km west of Sollefteå in the middle of Sweden, an experiment road was constructed with a 40 cm bio fuel ash layer. The environmental impact of the ash layer was evaluated from soil solutions obtained by centrifugation of soil samples taken on four occasions during 2001–2003. Soil samples were taken in the ash layer, below the ash layer at two depths in the road and in the ditch. In the soil solutions, pH, conductivity, dissolved organic carbon (DOC) and the total concentration of cations (metals) and anions were determined. Two years after the application of the ash layers in the test road, the concentrations in the ash layer of K, SO4, Zn, and Hg had increased significantly while the concentration of Se, Mo and Cd had decreased significantly. Below the ash layer in the road an initial increase of pH was observed and the concentrations of K, SO4, Se, Mo and Cd increased significantly, while the concentrations of Cu and Hg decreased significantly in the road and also in the ditch. Cd was the element showing a potential risk of contamination of the groundwater. The concentrations of Ca in the ash layer indicated an ongoing hardening, which is important for the leaching rate and the strength of the road construction. 相似文献
665.
In different parts of the world, there is an urgent need for redesigning and innovating farming systems. Such a process may be supported by model-based explorations that enable ex-ante evaluation of a broad range of alternatives. Since a variety of viable patterns of farm development exists related to farm resource endowment and farmer's strategy, model-based explorations should be able to capture the existing variation in resource endowment and strategies in order to have impact on strategic farm management. In this paper, we present an overview of the model-based explorative method based on the MILP model Farm Images, applied to explore options for sustainable development of vegetable farms in Canelón Grande, Uruguay. The method is used to gain insight into the impact of current farm resource endowment on the possibilities for sustainable development and on the resource use efficiency at farm scale. We maximized farm income for 128 different farm types in an environment-oriented scenario and in an income-oriented scenario. Farm types were defined by combining 4 farm sizes, 2 labor endowments, 4 irrigation endowments, 2 soil quality combinations and 2 mechanization levels. The results demonstrate a strong impact of farm resource endowment on possibilities for sustainable development, as well as synergy between labor, land and irrigated area on resource-use efficiency at farm scale. Farms with 10ha of land or less, representing 47% of the farms in the Canelón Grande region, could only achieve a family income higher than the average income of Uruguayan families when the irrigated area was ca. 40% of the farm area. The achievement of environmental targets was less costly in terms of income on farms with a low rather than high labor availability per unit area and on farms with irrigation facilities. 相似文献
666.
667.
Gummow B van den Broek J Kirsten WF Botha CJ Noordhuizen JP Heesterbeek JA 《Journal of environmental monitoring : JEM》2006,8(4):445-455
Various potential biomarkers were sampled for vanadium every 3-4 months from Bos indicus beef cattle farmed extensively immediately adjacent (high exposure (HE) group) and two km away (low exposure (LE) group) from a vanadium processing plant, respectively. Vanadium intake (mg vanadium kg(-1) bwt d(-1)) was modelled using environmental and physiological data as inputs. The vanadium intake ranged from 0.57 to 5.44 mg vanadium kg(-1) bwt d(-1) in the HE group and 0.41 to 2.61 mg vanadium kg(-1) bwt d(-1) in the LE group over a five-year period of monitoring. Samples collected from live sentinel animals over the five-year period included caudal coccygeal vertebrae, tail-switch hair, milk, urine, faeces, rib-bone biopsies and a wide range of blood clinical pathology and haematological parameters. The data was analysed for differences in response between the HE and LE groups. Where differences were found, a linear mixed-effects regression model was fitted to model the relationship between the exposure dose and the response variable. The model included the effects of age, duration of exposure and response, and allowed the prediction of the exposure dose given these inputs. Moreover, forty-two adult cattle were slaughtered over the five years. A wide range of tissue samples, rumen content and whole blood were taken from the cattle at slaughter for vanadium determination. In live animals, a difference in response was found between the HE group and LE group with respect to serum albumin (n = 36), monocyte (n = 36) and thrombocyte (n = 36) counts, and hair (n = 2) and faeces (n = 34) vanadium concentrations. No difference in vanadium concentrations could be shown for urine (n = 36), the traditional occupational health biomarker. Regression models are described for serum albumin, monocyte counts, faeces and hair, which showed the most promise as biomarkers. Average concentrations of vanadium in the tissues of slaughtered cattle ranged from 0.08 to 2.94 mg kg(-1) (wet-weight basis) and rumen content contained 16.67 mg kg(-1). Significant correlations were found between the exposure dose (end-dose) just prior to slaughter and the concentrations of vanadium in the coccygeal vertebrae, liver, diaphragm and rib-bone in descending order of magnitude. Other tissues showed poor correlation to the end-dose. Tissue levels of vanadium in healthy cattle include a much wider range than is currently reflected in the literature. The best tissue from slaughter animals for assessing chronic vanadium exposure is probably the liver. 相似文献
668.
Ian C. Meerkamp van Embden 《Umweltwissenschaften und Schadstoff-Forschung》1998,10(5):257-258
Ohne Zusammenfassung 相似文献
669.
Appelt Jonas L. Saphangthong Thatheva Malek Žiga Verburg Peter H. van Vliet Jasper 《Regional Environmental Change》2023,23(3):1-11
Regional Environmental Change - Understanding popular attitudes to climate change can be important in developing effective climate adaptation responses. However, in the Pacific region, which is at... 相似文献
670.
H. van Reeuwijk P. H. Fischer H. Harssema D. J. Briggs K. Smallbone E. Lebret 《Environmental monitoring and assessment》1998,50(1):37-51
Two-week average NO2 concentrations were measured in Amsterdam (NL), Huddersfield (UK) and Prague (CZ) at 80 sites in each study area, to assess small area spatial variation, using a tube type and a badge type passive sampler. The badges appeared to be less robust than the tubes. The lower detection limit for tubes and badges was 3.7 and 0.91 µg/m3, respectively for fortnightly measurements. Accuracy of the samplers was determined with reference methods (chemiluminescence). The mean ratio of the concentration measured by diffusion tube over that by the reference method was 1.16, 1.03 and 0.77 in Amsterdam, Huddersfield and Prague, respectively. Standardizing the badges for the results obtained in Amsterdam, the relative mean ratio of the concentration measured by the badges over that by the reference method was 0.95 and 0.58 in Huddersfield and Prague, respectively. NO2 concentrations measured by the two designs did not differ significantly. Mean NO2 concentrations were 36, 26 and 22 µg/m3 in Amsterdam, Huddersfield and Prague, respectively. The precision of duplicate tubes and badges was 8% and 11%, respectively. Both samplers are suitable for determining real variation in small area NO2 concentrations in the ranges which occurred. It is concluded that low-cost, simple NO2 passive samplers can provide reliable information about variation in NO2 concentrations within urban or rural areas on a small spatial scale. Based on its robustness and its precision, tubes were preferred over badges. 相似文献