全文获取类型
收费全文 | 360篇 |
免费 | 6篇 |
国内免费 | 30篇 |
专业分类
安全科学 | 11篇 |
废物处理 | 10篇 |
环保管理 | 62篇 |
综合类 | 129篇 |
基础理论 | 67篇 |
污染及防治 | 84篇 |
评价与监测 | 18篇 |
社会与环境 | 12篇 |
灾害及防治 | 3篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 11篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 7篇 |
2014年 | 10篇 |
2013年 | 20篇 |
2012年 | 17篇 |
2011年 | 44篇 |
2010年 | 27篇 |
2009年 | 41篇 |
2008年 | 41篇 |
2007年 | 18篇 |
2006年 | 17篇 |
2005年 | 13篇 |
2004年 | 7篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 14篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 13篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有396条查询结果,搜索用时 797 毫秒
181.
Soil-erosion and runoff prevention by plant covers in a mountainous area (se spain): Implications for sustainable agriculture 总被引:1,自引:0,他引:1
V. H. Durán Zuazo J. R. Francia Martínez C. R. Rodríguez Pleguezuelo A. Martínez Raya B. Carcéles Rodríguez 《The Environmentalist》2006,26(4):309-319
In the Mediterranean region the intensities and amounts of soil loss and runoff on sloping land are governed by rainfall pattern
and vegetation cover. Over a two-year period (1998–1999), six wild species of aromatic and mellipherous plants (Thymus serpylloides subsp. Gadorensis, Thymus baeticus Boiss, Salvia lavandulifolia Vahl., Santolina rosmarinifolia L., Lavandula stoechas L. and Genista umbellata Poiret) were selected for erosion plots to determine their effectiveness in reducing water erosion on hillslopes of the Sierra
Nevada Mountain (SE Spain). The erosion plots (including a bare-soil plot as control), located at 1,345 m in altitude, were
2 m2 (2 m × 1 m) in area and had 13% incline. The lowest runoff and soil erosion rates, ranging from 9 to 26 mm yr−1 and from 0.01 to 0.31 Mg ha−1 yr−1, respectively, over the entire study period, were measured under the Thymus serpylloides. Lavandula stoechas L. registered the highest rates among the plant covers tested, runoff ranging from 77 to 127 mm yr−1 and erosion from 1.67 to 3.50 Mg ha−1 yr−1. In the bare-soil plot, runoff ranged from 154 to 210 mm yr−1 and erosion from 4.45 to 7.82 Mg ha−1 yr−1. According to the results, the lowest-growing plant covers (Thymus serpylloides and Salvia lavandulifolia Vahl.) discouraged the soil erosion and runoff more effectively than did the taller and open medium-sized shrubs (Santolina rosmarinifolia L., Genista umbellata Poiret, Thymus baeticus Boiss and Lavandula stoechas L.). Monitoring allowed more direct linkage to be made between plant covers and the prevention of erosion, with implications
for sustainable mountain agriculture and environmental protection. 相似文献
182.
含水介质中胞外聚合物的影响因素研究 总被引:1,自引:0,他引:1
明确含水介质中微生物胞外聚合物(EPS)生成量的影响因素,是解决含水层生物堵塞的关键问题.本文在现场样品采集和微生物培养的基础上,通过砂柱试验模拟人工回灌过程,系统研究了进水碳、氮、磷浓度、盐度和温度对含水介质中EPS组成和含量的影响.结果表明,砂柱中EPS最主要的成分为多糖和蛋白质,其中多糖占总量的72%~99%;砂柱生物堵塞程度与介质上附着的EPS含量呈正相关关系,当回灌水碳、氮、磷浓度、盐度和温度分别为50 mg·L-1、5 mg·L-1、1 mg·L-1、0.5%和30℃时,微生物EPS生成量最高,砂柱渗透系数降低最显著,堵塞程度最严重.此外,碳、磷浓度、盐度和温度是影响EPS生成量的主要因素,而氮浓度对其影响不大;碳浓度和盐度对EPS中多糖、蛋白质的组成影响较大,而氮、磷以及温度则影响不明显. 相似文献
183.
184.
185.
Pickett ST Cadenasso ML Grove JM Boone CG Groffman PM Irwin E Kaushal SS Marshall V McGrath BP Nilon CH Pouyat RV Szlavecz K Troy A Warren P 《Journal of environmental management》2011,92(3):331-362
Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs. 相似文献
186.
Irineu Bianchini Jr. Marcela Bianchessi da Cunha Santino 《Ecological modelling》2011,222(7):1263-1271
The formation of man-made reservoirs generates several impacts on water quality. In order to minimize some of these impacts mathematical models are currently used. This paper aims to discuss the issue associated with the degradation of plant resources (leaves, branches, barks and litter) that remain within the watershed of the new man-made lakes and parameterize a kinetic model related to decay of plant detritus. In these environments, the short-term variation of limnological parameters is mainly connected with biomass decay drowned during the filling operation. The kinetics of the degradation processes in reservoirs are discussed on the basis of information with related to detritus sources and the chemical properties of different types of compounds (i.e. labile and refractory fractions). Overall, the parameterization of the (first order) kinetic model showed that refractory fractions (ca. 86%) are predominant and the mineralization is a slow process, constituting the main route for decomposition and being affected by changes of environmental variables. The mineralization of labile and hydrosoluble compounds (ca. 14%) is responsible for the short-term water quality variation owing to decomposition; basically, the intensities of these changes depend on the labile/soluble compounds content of detritus and its chemical composition. 相似文献
187.
The effect of textile mill wastewater on germination, delay index, physiological growth parameters, and plant pigments of two cultivars of chickpea was studied. The aim of this study was to evaluate the suitability of textile mill wastewater (treated and untreated) at different concentrations (0, 6.25, 12.5, 25, 50, 75, and 100%) for irrigational purposes. The textile effluent did not show any inhibitory effect on seed germination at a lower concentration (6.25%). The other reported plant parameters (delay index, root length, shoot length, dry weight, chlorophyll, and carotenoid) also followed a similar trend. Seeds germinated in 100% effluents but did not survive for longer periods. It has also been concluded that the effect of the textile effluent is cultivar-specific, and due care should be taken before using the textile mill wastewater for irrigation purposes. 相似文献
188.
Greenhouse evaluation and environmental impact assessment of different urine-derived struvite fertilizers as phosphorus sources for plants 总被引:1,自引:0,他引:1
Samantha Antonini Maria Alejandra AriasThomas Eichert Joachim Clemens 《Chemosphere》2012,89(10):1202-1210
A selection of six urine-derived struvite fertilizers generated by innovative precipitation technologies was assessed for their quality and their effectiveness as phosphorus sources for crops. Struvite purity was influenced by drying techniques and magnesium dosage. In a greenhouse experiment, the urine fertilizers led to biomass yields and phosphorus uptakes comparable to or higher than those induced by a commercial mineral fertilizer. Heavy metal concentrations of the different struvite fertilizers were below the threshold limits specified by the German Fertilizer and Sewage Sludge Regulations. The computed loading rates of heavy metals to agricultural land were also below the threshold limits decreed by the Federal Soil Protection Act. Urine-derived struvite contributed less to heavy metal inputs to farmland than other recycling products or commercial mineral and organic fertilizers. When combined with other soil conditioners, urine-derived struvite is an efficient fertilizer which covers the magnesium and more than half of the phosphorus demand of crops. 相似文献
189.
《Process Safety and Environmental Protection》2014,92(5):412-422
The accident rate in the chemical process industry (CPI) has not been decreasing although majority of accident causes have been identified and could have been prevented by using existing knowledge. These recurring accidents show that the existing knowledge has not been used effectively. In this paper, accident knowledge learned from earlier accident analyses are utilized to predict the common design errors during chemical plant design. An accident prevention approach throughout process design life cycle is proposed for a safer design consideration where designers are guided to identify common design errors, accident contributors and critical points to look for. The accident prevention approach has been applied to analyze the BP Texas City Refinery Explosion and Fire tragedy. 相似文献
190.
Manuel Chacón-Fuentes Leonardo Bardehle Marcelo Lizama Ivette Seguel 《Chemistry and Ecology》2019,35(2):115-127
Plant domestication can modify flavonoid concentration, generating a decrease in plants subjected to cultivation, but when cultivated plants are transferred to their original wild area, flavonoids can be recovered. In this framework, a native shrub from Chile, Ugni molinae, has been domesticated due to their high phenolic composition. We hypothesised that plant domestication results in a decrease of flavonoid in cultivated plants, and that when they are exposed to a reciprocal transplant experiment, the flavonoid content can be recovered. Hence, a reciprocal transplant experiment for analysing the flavonoids of cultivated plants transferred to their original wild environments was carried out. Methanolic leaf extracts from two cultivated ecotypes and their respectively wild ancestors were collected for flavonoid analysis. Four flavonols and two isoflavonoids were identified and quantified by liquid chromatography. Results showed differences in flavonoids concentrations between wild (290?µg/g) and cultivated (160?µg/g) plants. Furthermore, when wild plants were transferred to cultivated areas, a reduction in flavonoids of 80?µg/g was observed. Moreover, rutin was the most abundant compound (36.09%) detected by chromatography in Mehuín wild plants. Our results showed that cultivated plants transferred to their respective wild environment presented a capacity of recover myricetin, daidzin and genistin content. 相似文献