全文获取类型
收费全文 | 459篇 |
免费 | 21篇 |
国内免费 | 57篇 |
专业分类
安全科学 | 30篇 |
废物处理 | 2篇 |
环保管理 | 34篇 |
综合类 | 190篇 |
基础理论 | 34篇 |
污染及防治 | 118篇 |
评价与监测 | 103篇 |
社会与环境 | 23篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 21篇 |
2022年 | 11篇 |
2021年 | 8篇 |
2020年 | 15篇 |
2019年 | 8篇 |
2018年 | 14篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 8篇 |
2014年 | 25篇 |
2013年 | 15篇 |
2012年 | 19篇 |
2011年 | 43篇 |
2010年 | 31篇 |
2009年 | 35篇 |
2008年 | 35篇 |
2007年 | 26篇 |
2006年 | 14篇 |
2005年 | 9篇 |
2004年 | 15篇 |
2003年 | 10篇 |
2002年 | 14篇 |
2001年 | 12篇 |
2000年 | 12篇 |
1999年 | 18篇 |
1998年 | 18篇 |
1997年 | 18篇 |
1996年 | 5篇 |
1995年 | 21篇 |
1994年 | 15篇 |
1993年 | 5篇 |
1992年 | 12篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有537条查询结果,搜索用时 78 毫秒
241.
Meijer SN Dachs J Fernandez P Camarero L Catalan J Del Vento S van Drooge B Jurado E Grimalt JO 《Environmental pollution (Barking, Essex : 1987)》2006,140(3):546-560
The BIODEP model in terms of atmosphere-lake interactions was developed. The model was applied to an oligotrophic, dimictic high altitude lake (Lake Redo, Pyrenees) for a range of polychlorinated biphenyl (PCB) congeners. High altitude lakes, which receive their contaminant inputs uniquely from the atmosphere through long-range atmospheric transport, provide ideal controlled environments for the study of the interactions between atmospheric depositional and water column biogeochemical processes. The BIODEP model was able to predict dissolved water concentrations and PCB accumulation in the lake sediment within a factor of 2. This shows that the BIODEP model captures the essential processes driving the sink of POPs in high altitude lakes and that POP occurrence in the lake is driven by direct atmospheric inputs with limited influence from the watershed. An important seasonal variability in water column concentrations is predicted which should have important implications in sampling strategies. Furthermore, it is shown that diffusive air-water exchange dominated the PCB dynamics in the lake, especially for the less chlorinated biphenyls. 相似文献
242.
Nitric oxide and nitrous oxide emission from Hungarian forest soils; linked with atmospheric N-deposition 总被引:1,自引:0,他引:1
Lszl Horvth Ern Führer Kate Lajtha 《Atmospheric environment (Oxford, England : 1994)》2006,40(40):7786-7795
Studies of forest nitrogen (N) budgets generally measure inputs from the atmosphere in wet and dry deposition and outputs via hydrologic export. Although denitrification has been shown to be important in many wetland ecosystems, emission of N oxides from forest soils is an important, and often overlooked, component of an ecosystem N budget. During 1 year (2002–03), emissions of nitric oxide (NO) and nitrous oxide (N2O) were measured from Sessile oak and Norway spruce forest soils in northeast Hungary. Accumulation in small static chambers followed by gas chromatography-mass spectrometry detection was used for the estimation of N2O emission flux. Because there are rapid chemical reactions of NO and ozone, small dynamic chambers were used for in situ NO flux measurements. Average soil emissions of NO were 1.2 and 2.1 μg N m−2 h−1, and for N2O were 15 and 20 μg N m−2 h−1, for spruce and oak soils, respectively. Due to the relatively high soil water content, and low C/N ratio in soil, denitrification processes dominate, resulting in an order of magnitude greater N2O emission rate compared to NO. The previously determined N balance between the atmosphere and the forest ecosystem was re-calculated using these soil emission figures. The total (dry+wet) atmospheric N-deposition to the soil was 1.42 and 1.59 g N m−2 yr−1 for spruce and oak, respectively, while the soil emissions are 0.14 and 0.20 g N m−2 yr−1. Thus, about 10–13% of N compounds deposited to the soil, mostly as and , were transformed in the soil and emitted back to the atmosphere, mostly as greenhouse gas (N2O). 相似文献
243.
The 5-day forward and backward trajectories of air mass transport to three Russian Arctic points for each day in April and July over a 10-year period from 1986 to 1995 have been analyzed. The important features and seasonal differences in air exchange processes in various areas of the Arctic have been investigated. Taking into account seasonal variations in aerosol scavenging mechanisms and velocities, the average contributions of large highly industrialized regions of the Russian Arctic air pollution were estimated for April and July. Reasonable correspondence between the calculated mean concentrations for six anthropogenic chemical elements (As, Ni, Pb, V, Zn, Cd) and experimentally determined values have been obtained. The atmospheric pollution transport from the Arctic was studied as yet another way of cleaning the Arctic atmosphere, in addition to the traditionally considered wet and dry depositions onto the surface. The average apportionment of conservative contaminants after passing the observation points was estimated for spring and summer. The air masses passing through the observation points in spring may take about 20–40% of pollutants out of the Arctic. In summer, however, more than 90% of pollutants transported into the Russian Arctic deposit within 5 days onto the surface inside the Arctic region. The monthly average fluxes of six anthropogenic elements onto the surface in the Russian Arctic were estimated for April and July. 相似文献
244.
245.
The newly-developed cavity ring-down laser absorption spectroscopy analyzer with special calibration protocols has enabled the direct measurement of atmospheric vapor isotopes at high spatial and temporal resolution. This paper presents real-time hydrogen and oxygen stable isotope data for atmospheric water vapor above the sea surface, over a wide range of latitudes spanning from 38°N to 69°S. Our results showed relatively higher values of 8180 and 82H in the subtropical regions than those in the tropical and high latitude regions, and also a notable decreasing trend in the Antarctic coastal region. By combining the hydrogen and oxygen isotope data with meteoric water line and backward trajectory model analysis, we explored the kinetic fractionation caused by subsiding air masses and related saturated vapor pressure in the subtropics, and the evaporation-driven kinetic fractionation in the Antarctic region. Simultaneous observations of meteorological and marine variables were used to interpret the isotopic composition characteristics and influential factors, indicating that d-excess is negatively correlated with humidity across a wide range of latitudes and weather conditions worldwide. Coincident with previous studies, d-excess is also positively correlated with sea surface temperature and air temperature (Tair), with greater sensitivity to Tair. Thus, atmospheric vapor isotopes measured with high accuracy and good spatial- temporal resolution could act as informative tracers for exploring the water cycle at different regional scales. Such monitoring efforts should be undertaken over a longer time period and in different regions of the world. 相似文献
246.
选用模糊综合评价法,对溧阳市1985~2011年环境空气质量进行了综合评价,选用SO2、NO2、TSP/PM10作为评价因素,通过计算各评价因素权重分配系数和隶属度,分析了长期空气环境质量变化趋势。结果表明:TSP/PM 10为1985年以来溧阳市首要环境空气质量制约因素,20世纪80年代中期全市空气质量主要隶属于一级标准,20世纪80年代后期主要隶属于二级标准,20世纪90年代初期主要隶属于三级标准,20世纪90年代中后期至今主要隶属于二级标准,近几年受TSP/PM1 0因素影响,在三级标准的隶属度有上升趋势;自20世纪90年代中期始,NO 2超越SO2成为继PM 10之后制约空气质量的第2大因素;经济发展对环境空气质量的规模效应较为显著,技术减排效应逐步显现。 相似文献
247.
Microwave assisted digestion followed by ICP-MS for determination of trace metals in atmospheric and lake ecosystem 总被引:1,自引:0,他引:1
The study of trace metals in the atmosphere and lake water is important due to their critical effects on humans,aquatic animals and the geochemical balance of ecosystems. The objective of this study was to investigate the concentration of trace metals in atmospheric and lake water samples during the rainy season(before and after precipitation)between November and December 2015. Typical methods of sample preparation for trace metal determination such as cloud point extraction,solid phase extraction and dispersive liquid–liquid micro-extraction are time-consuming and difficult to perform; therefore,there is a crucial need for development of more effective sample preparation procedure. A convection microwave assisted digestion procedure for extraction of trace metals was developed for use prior to inductively couple plasma-mass spectrometric determination. The result showed that metals like zinc(133.50–419.30 μg/m~3)and aluminum(53.58–378.93 μg/m~3)had higher concentrations in atmospheric samples as compared to lake samples before precipitation.On the other hand,the concentrations of zinc,aluminum,chromium and arsenic were significantly higher in lake samples after precipitation and lower in atmospheric samples. The relationship between physicochemical parameters(pH and turbidity)and heavy metal concentrations was investigated as well. Furthermore,enrichment factor analysis indicated that anthropogenic sources such as soil dust,biomass burning and fuel combustion influenced the metal concentrations in the atmosphere. 相似文献
248.
选择上海城市化地区的绿地、水体、道路、工地及空中5个类型的环境区域,定期收集大气干湿沉降。测定其大气沉降通量及CODCr、TN、TP的沉降量,并计算分析了其对城市景观水体水质的影响。研究结果表明:在仅受大气干湿沉降影响的条件下,水质处于地表水V类中值、水深为0.5m、1.0m、1.5m和2.0m的城市景观水体,经过28d、54d、83d和214d即可转变为劣V类水体。通过实例分析,提出了应对大气干湿沉降影响的水质保持措施。研究成果为城市景观水体的水质保育提供了评价依据与借鉴。 相似文献
249.
250.
采用毛细管柱气相色谱氢火焰离子化检测器测定环境空气中的樟脑,选择硅胶为吸附剂,甲醇/丙酮混合溶剂(体积比90∶10)为解析剂.方法在0.544 mg/L~109 mg/L范围内线性良好,检出限为0.06 mg/L,当采样体积为20 L时,最低检出质量浓度为0.003 mg/m3,标准溶液平行测定的RSD≤3.8%,空白... 相似文献