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21.
This paper discusses some recent advances in spectrometric methods and approaches for mercury speciation analysis of environmental samples with focus on isotope dilution techniques for determination of mercury species' concentrations in gaseous samples and reaction rates in soils and sediments. Such analytical data is important inter alia in fundamental research on mercury biogeochemistry and for risk assessments of mercury-contaminated soils and sediments and for designing effective remedial actions. The paper describes how the use of enriched stable isotope tracers in mercury speciation analysis can improve the traceability and accuracy of results, facilitate rational method developments, and be useful for studying biogeochemical processes, i.e. rate of reactions and fluxes, of mercury species. In particular the possibilities to study and correct for unwanted species transformation reactions during sample treatment and to study "natural" transformations of species in environmental samples, or micro- and mesocosm ecosystems, during incubations are highlighted. Important considerations to generate relevant data in isotope tracer experiments as well as reliability and quality assurance of mercury speciation analysis in general are also discussed.  相似文献   
22.
Control of hazardous organic micropollutants is a challenging water quality issue. Dissolved humic organic matter (DOM) isolated from oxyhumolite coal mined in Bohemia was investigated as a complexation agent to remove polycyclic aromatic hydrocarbons (PAHs) and functionalized phenols from water by a two-stage process involving complexation and flocculation. After the formation of humic-contaminant complexes, ferric salts were added resulting in the precipitation and flocculation of the DOM and the associated pollutants. Flocculation experiments with ferric ion coagulants indicated that precipitation of oxyhumolite DOM together with the complexed contaminants occurred at lower ferric ion concentrations than with the reference DOM in acidic environments (pH approximately 3.5). The complexation-flocculation removal rates for non-reactive PAHs characterized by small localization energies of pi-electrons correlated well with the complexation constants. On the other hand, the combined complexation-flocculation removal rates for activated PAHs including trans-stilbene, anthracene and 9-methyl anthracene, as well as functionalized polar phenols, were higher than predicted from the complexation coefficients. Methodological studies revealed for the first time that the ferric ion coagulant contributed to enhanced removal rates, most probably due to ferric ion-catalyzed pollutant degradation resulting in oxidized products.  相似文献   
23.
The village with its characteristic zones of different land use from the center to the periphery is a basic unit of Europe's cultural landscapes. However, loss of the authentic pre-industrial village structure characterized by a fine-grained structure of arable land and wooded grasslands is a threat to both cultural heritage and biodiversity in many rural landscapes. Therefore, it is important that the extent and rate of change of such authentic villages in a landscape can be monitored. We studied to what extent loss of authenticity with increasing time after abandonment can be assessed by quantitative analysis and visual interpretation of satellite images. The study was carried out in the Bieszczady Mountains, SE Poland in 1999. Using Landsat Thematic Mapper data from 1998, both the grain size of landscape elements (size of fields) and land-cover composition (encroachment of shrub and forest) were quantitatively described 6 type villages representing different stages of deterioration of the authentic village structure. Historical maps were used to delineate the border of the villages and the former extension of forest and open land was measured. The present land use and the degree of abandonment expressed as grain size and forest encroachment were mapped using satellite data. Deterioration occurred along 2 transformation paths: abandonment and ultimately becoming forest, or intensified agriculture, respectively. To validate these results we classified 22 other villages in a 1000 km2 area by visual interpretation of the original satellite images into 1 of 4 types. We then collected historical data on human population changes over the past six decades. The classification of village authenticity was clearly related to the rate of human population decline. We address the importance of validating and applying this approach for rapid assessment of the authenticity of cultural landscapes in European regions being subject to ongoing as well as expected future change, related to expansion of the European Union. Finally, we argue that the village represents a scale at which integration of natural and social sciences is possible.  相似文献   
24.
Sonesson U  Anteson F  Davis J  Sjödén PO 《Ambio》2005,34(4-5):371-375
In environmental systems analysis of food production systems, the consumer phase (home transport, cooking, storing, and wastage) is an important contributor to the total life-cycle environmental impact. However, households are the least investigated part of the food chain. Information gathering about households involves difficulties; the number of households is large, and food-related activities are embedded in other household activities. In cooperation between researchers from environmental systems analysis and consumer research, Swedish households were surveyed by questionnaire, diary, and interviews. Data on home transport of food and wastage were collected. The average weekly driving distance was 28 to 63 km per household, depending on how trips made in conjunction with other errands are allocated. The wastage of prepared food ranged between 0 and 34% for different food categories, and wastage from storing between 0 and 164% (more food was discarded, e.g. by cleaning out a cupboard, than consumed). In both cases dairy products scored highest.  相似文献   
25.
个人行为必须对环境有利,这是现代社会日益增长的需求.在这场变革中,旨在改变人们态度的信息宣传是它的必备前提.信息宣传虽然可能是必不可少的,但是它本身并不足以完成促进变革的任务.我们认为,首先,许多影响环境的日常行为,都是习惯成自然的行为.可是,几乎没有人关注这个特点,并通过信息导向来改变这些习惯行为.另外一些情况下,行为更主要是由价值导向的.不过,除了可能的环境后果之外,还有其它信息更可能吸引行为人的注意,影响其行为选择.为了研究消费者行为,我们进行了调查和实验,研究什么样的信息条件更容易影响对环境关注水平不同的人们.基于这些研究,讨论对行为改变的含义.  相似文献   
26.
本文从不同的时间尺度、空间尺度以及功能上对山地的生物多样性进行了讨论.尽管物种丰富度通常是自然保护所关注的主要内容,物种的遗传多样性也同样重要.热带安第斯山脉中像Calceolaria和Bartsia等物种的小面积分布同在一些高纬度山区(如斯堪的斯[Scandes]山脉)物种的分布情况形成强烈的反差,在高纬度山地中物种分布较广且很多为环极地的.近年来对高山植物进行分子层面的研究表明,种内的遗传多样性随纬度的升高有增加的趋势,这可能是由于冰川历史上物种分布的反复扩展与收缩所造成的.在热带山区,物种的分布在地理上狭窄得多,而这也常常是相对较晚时期物种发生局地分化的结果.因而从赤道到极地地区,尽管物种丰富度在不断减少,而遗传多样性却呈现出增加的趋势.最后,我们对低纬度山区和高纬度山区(热带安第斯山脉和斯堪的斯山脉)的生态系统多样性所做的对比研究表明,两者景观在树线过渡带、雪盖分布和气候条件等方面有着很大的差异,同时全球变化对两者所造成的影响也千差万别.  相似文献   
27.
Medically impairing occupational injuries sustained in traffic in Sweden were analysed. More than half of the cases with a permanent medical impairment were caused by minor injuries. Soft tissue injuries to the neck (whiplash injuries) made up nearly half of all permanently impairing injuries, and half of these were caused by rear-end collisions. As a final result, just over one third (37%) of the total group had a permanent decreased work capacity, or needed to change jobs because of residual problems from their injuries. Professional drivers had the highest injury incidence per employed and they accounted for 28% of the total number of permanent impairment cases, and for 43% of the fatalities. Professional drivers also had a higher percentage of serious injuries and severe permanent impairments than other occupational groups. This might be associated with the low use of safety belts (16%) compared to other occupational groups, where usage was 4–5 times higher. This occupational injury problem ought to be handled in the same way as other occupational safety problems, i.e. protective equipment in a vehicle should be used and the use of safe vehicles should be encouraged.  相似文献   
28.
Environmental indicators for long-range atmospheric transported heavy metals have been developed. The indicators are based on data for Pb and Cd from national moss surveys which are performed regularly in Norway. The interpolation programme kriging has been used to transform the data from irregular grids to regular grids. Contour maps have been produced, and areas above estimated background levels for Pb and Cd in mosses have been calculated. The indicators are used to characterise the atmospheric deposition of long-range atmospheric transported heavy metals and monitor the changes with time.  相似文献   
29.
在自然林火不再发生的同时,人们为了促进针叶树木的生长清除了落叶树种,并人为地将丰饶的森林变成了农地,由此,欧洲北部原有的针叶林景观发生了很大变化,一些地区的落叶林成分大大减少.然而,在乡村中落叶树种和落叶林得以保存下来,在一些弃耕的农田中也通过自然更新产生了新的落叶林木.我们在研究中做出以下假设,不同地区落叶林目前的分布格局与乡村中农业区和非农业区的分布相关,这种分布的形成又与当地的自然条件和以土地利用变化的形式表现的近期经济发展密切相关.我们的研究对象包括了瑞典北方针叶林和半北方针叶林区域中的6个地点--北博滕(Norrbotten)、翁厄曼兰(Angermanland)、耶姆特兰(Jamtland)、达拉纳(Dalarna)、Bergslagen和斯莫兰(Smaland),分析了乡村内农业区和非农业区中落叶林的空间分布.在每个地区,选择了6个以乡村为中心的5×5km样带.研究结果表明,在不同地区乡村中的不同景观区域,落叶林的分布和组成存在着明显差异.从单个乡村来看,翁厄曼兰中DEC(即落叶林成分)所占的比例平均最高(17%),而耶姆特兰则最低(2%).然而,农业区内和非农业区内DEC的数量却存在着规律性的地区差异,DEC在南方农业区内(斯莫兰)所占的比例最高,北方通常很低.对比之下,非农业区内DEC的数量在北方最高.相对较多的DEC出现在农业大量减少的地区的森林边缘地带(翁厄曼兰、达拉纳、Bergslagen).由于乡村在与落叶林有关的生物多样性中有着重要作用,因此本项研究的结果表明了对整个景观中的落叶林进行综合管理的必要性.通过本项研究,我们还可以看到卫星遥感数据可用于分析景观尺度上落叶树木和林分的空间分布.为了进行更为深入的研究,我们需要改进的专题分辨率以区分落叶林具相关生物特性意义的林分质量.  相似文献   
30.
The objective of this paper is to characterize the spatiotemporal variations of vegetation phenology along latitudinal and altitudinal gradients in Greenland, and to examine local and regional climatic drivers. Time-series from the Moderate Resolution Imaging Spectroradiometer (MODIS) were analyzed to obtain various phenological metrics for the period 2001–2015. MODIS-derived land surface temperatures were corrected for the sampling biases caused by cloud cover. Results indicate significant differences between West and East Greenland, in terms of both observed phenology during the study period, as well as the climatic response. The date of the start of season (SOS) was significantly earlier (24 days), length of season longer (25 days), and time-integrated NDVI higher in West Greenland. The sea ice concentration during May was found to have a significant effect on the date of the SOS only in West Greenland, with the strongest linkage detected in mid-western parts of Greenland.  相似文献   
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