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301.
The spring waters of Tuzla–Icmeler are on the Marmara Sea coast in Tuzla town of Istanbul city. The springs discharge a natural
sodium chloride mineral water that consumed for ages for therapeutic purposes attributed to their chemical properties. Development
of springs commenced during the Ottoman times and a surface collection structure was built at the discharge point of the main
spring. Two deep wells were drilled to tap mineral water within the past decades. The bottled water of these springs is also
sold for a couple of years and its consumption as a beverage is increasing. The geochemical properties of these springs were
investigated by several researchers in the past. This study comprises geochemical and geophysical measurements performed between
July 2001 and July 2002 in order to construct a conceptual hydrogeological model for environmental and land use planning purposes.
The seasonal evaluation of Tuzla–Icmeler (mineral spring) shows that the chemical properties fluctuate from the beginning
of summer until the beginning of winter. This indicates that the overdraft of water during the summer season causes the movement
and mix of normal groundwater with the mineralized groundwater. As a result, mixing of less mineralized groundwater decreases
the salinity of mineralized groundwater. Using the site-specific hydrogeological, geochemical and geophysical data, zones
of protection areas were delineated in order to prevent a possible pollution access to the springs and surroundings from nearby
dockyards, dwellings and vehicle traffic. For this purpose, a new land use plan was proposed using the existing settlement
sustainability plans. 相似文献
302.
Lake Sapanca is exposed to heavy urbanization and industrialization because of its natural beauty and its proximity to the
metropolitan İstanbul, Turkey. In this study, it was aimed to investigate seasonal changes of some heavy metals (Pb, Cr, Cu,
Mn, Ni, Zn and Cd) concentration of surface sediment. Nine different stations were chosen as sampling points. Samples were
taken every three months and the seasonal and annual average concentration of the elements were determined. Seasonal highest
values of heavy metals were observed as follows; Cr, Cu, Mn, Ni and Zn in Summer, Cd in Autumn. There was no seasonal difference
for Pb, Cr and Cd. It seems that Lake Sapanca has not been polluted yet. However, it was found that Cu and Ni concentrations
in surface sediment exceed lowest effect level. 相似文献
303.
304.
Haojun Lei Kaisheng Yao Bin Yang Lingtian Xie Guangguo Ying 《Frontiers of Environmental Science & Engineering》2023,17(4):46
305.
为了研究九龙江流域河流中溶解碳变化规律,分别于2017年7月与2018年1月对九龙江河水溶解无机碳(DIC)与溶解有机碳(DOC)进行了分析。丰水季河水DIC浓度为7.50~49.04 mg/L,平均值为22.12 mg/L,枯水季DIC浓度为8.84~84.91 mg/L,平均浓度41.17 mg/L,丰水季河水中的DOC浓度为0.54~2.89 mg/L,平均值为1.04 mg/L,枯水季河水中DOC浓度变化在1.34~3.56 mg/L之间,平均值为2.34 mg/L,据此计算了九龙江河水DOC、DIC的入海通量。研究结果表明九龙江河水中溶解碳具有显著的时空变化特征,通过与中国其他河流溶解碳数据对比,解释了碳酸盐岩的风化、气候变化、河流中浮游植物以及人类活动对九龙江河流溶解碳浓度的影响。 相似文献
306.
青岛近岸海域二甲基硫排放和大气中二甲基硫浓度变化 总被引:7,自引:1,他引:6
为研究我国受人为干扰严重的近岸海域DMS排放规律,利用固体吸附-解吸的富集采样方法和冷却预浓缩的分析方法,分别在2001年夏秋季和2002年春秋季,对青岛近岸海域海水和大气中的二甲基硫进行了采样和分析.结果表明,海水中DMS浓度和海气排放通量呈现明显的空间分布和季节变化.夏季,青岛近岸的海水DMS平均浓度最高,达1169.47 ng·L-1;春季最低,只有226.99 ng·L-1.河口区、风景旅游区和奥运赛场区在夏季有显著的从高到低的浓度梯度变化,而春秋季不明显.DMS海气排放通量主要由海水浓度决定,因此两者呈现一致的变化规律.海洋大气中的DMS也呈现夏季较高(256.44 ng·m-3),秋季较低(195.64 ng·m-3)的季节变化.文中还初步探讨了大气DMS的日变化情况. 相似文献
307.
Rosa María Pérez-Pastor Susana García-Alonso Alberto José Quejido Cabezas 《Environmental science and pollution research international》1999,6(3):141-146
From November 1995 to October 1996, airborne concentrations of VOCs were measured in the Madrid area to study the organic
pollution in general, and the correlation between different pollutants in relation to such parameters as location and season.
Mean concentrations for up to 90 compounds were measured at four test sites, including both urban and suburban areas.
At the urban sites, maximum concentrations occurred in the autumn and winter, whereas minimum concentrations were reached
in summer and spring. Similar changes were obtained for the lesscontaminated site located in the SE of the city, whereas a
different pattern was found at the site in the NW of the city due to meteorological aspects. Mean levels of hydrocarbons in
Madrid were quite similar to those found in other European cities.
Chemometrical techniques were applied to the set of data in order to assess the influence of such factors as traffic, temperature
and seasonal variations on the VOC levels. 相似文献
308.
309.
V. Lindfors T. Laurila H. Hakola R. Steinbrecher J. Rinne 《Atmospheric environment (Oxford, England : 1994)》2000,34(29-30)
We present the first estimates of speciated monoterpene emissions from the North European coniferous forests. Measured emission factors and emission profiles of boreal tree species (Picea abies, Pinus sylvestris, Betula pendula, Salix phylicifolia, Populus tremula, and Alnus incana) were used together with detailed satellite land cover information and meteorological data in an emission model based on the Guenther emission algorithms. The variation of the coniferous biomass within the boreal region (60°N to 70°N) was obtained from forest inventory data, and the seasonal variability of the deciduous biomass was taken into account through simple boreal climatology parameterisation. The annual biogenic emissions in the boreal zone are dominated by coniferous species, but in the summer months, the deciduous contribution to the monoterpene and isoprene emissions is considerable. Norway spruce (Picea abies) is the most important isoprene emitter in the north European boreal forests. The biogenic emission fluxes in the South boreal zone are approximately twice as high as fluxes in the North boreal zone. α- and β-pinene, carene, and cineole are the most abundant emitted terpenes, with a strong contribution of isoprene and linalool during the summer months. 相似文献
310.
Whitfield PH 《Environmental monitoring and assessment》2001,67(1-2):217-238
Climatic and hydrologic variations between the decades 1976–1985 and 1986–1995 are examined at 34 climate stations and 275 hydrology stations. The variations in climate are distributedacross a broad spatial area. Temperatures were generally warmerin the most recent decade, with many stations showing significantincreases during the spring and fall. No significant decreases intemperature were found. Significant increases in temperature weremore frequent in the south than in the northern portions of theregion. Significant changes in precipitation were also more prevalent in the south. In coastal areas, there were significantdecreases in precipitation during the dry season, and significantincreases during the wet season. In the BC interior, significantprecipitation decreases occurred during the fall, with significant increases during the winter and spring. In the norththere were few changes in precipitation. The hydrologic responsesto these variations in climate follow six distinctive patterns.The spatial distribution of these patterns suggests that indifferent ecozones, small variations in climate, particularlytemperature, elicit different hydrologic responses. 相似文献