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941.
结合新疆绿洲城市及城镇的自然特点及发展实际,从加强城市环境功能区划工作的角,探讨了对绿洲城市及城镇的环境管理问题。 相似文献
942.
The immense value of a geographic information system for flood control has been experienced by the decision-markers of the
Dutch province of Gelderland during the flood of the Rivers Meuse (Maas) and Waal in January 1995. Super-imposing different
‘data layers’, GIS-experts could detect the weak parts in the dikes and generate and evacuation plan. Shortcomings within
the organization were experienced as well: important data could not be retrieved, and the coordination of efforts by the different
governmental departments and institutions was not optimal. To overcome these shortcomings and to optimize the modelling process,
a spatial decision support system (SDSS) is being proposed, aggregating several models, heuristic and procedural, into integrated
software tools. As becomes clear from two cases of flood control described, ‘emergency managers’ should be able to communicate
about spatial data available and have access to selected spatial data. In order to improve communication between data sources,
data processing and the use of relevant spatial data in GISs, a new ‘Spatial Information Infrastructure’ (SII) needs to be
developed. This requires both technical and organizational solutions and standards. Proper documentation of the data will
allow the GIS-experts to more quickly find, store, update and reuse the data. A range of ‘metadata’ services exist documenting
data sets, typically limited by thematic or national boundaries. There are no standards in common practice for structuring
and classifying spatial information. The user of spatial information cannot easily browse across Web-sites and compare products
from different suppliers. Even, if the search has been successful, the user all too often has to face a complex process of
negotiation, and highly technical data integration issues. A consortium of European GIS-experts has addressed these problems
and launched the ‘European Spatial Metadata Infrastructure’ (ESMI) project with the objective to link existing and future
metadata systems using Internet. 相似文献
943.
This research proposes an integrated framework to investigate human-dominated systems and provide a basic approach to urban
and regional studies in which the multiple interactions between economic and ecological processes are considered as a whole.
Humans generate patterns of land use, infrastructures and other settings and redistribute ecosystem functions as flows of
energy and matter for self-maintenance. To understand these emerging interactions between humans and ecological processes,
human activities (e.g. transformation processes, land conversions, use of resources) and biophysical agents such as geomorphology,
climate and natural cycles need to be considered. Emergy Analysis (spelled with an “m”) is then used as an environmental accounting
method to evaluate different categories of resource use with reference to their environmental cost. A case study of the Province
of Cagliari (in the island of Sardinia, Italy) is reported and the procedure for allocating emergy flows, assigning them to
districts and managing point data is discussed. Outcomes plotted on a map showed non-homogeneous spatial distribution of emergy
flows throughout the region, suggesting the way ecosystem functions are affected and restructured by the human economy. 相似文献
944.
Hur J Schlautman MA Karanfil T Smink J Song H Klaine SJ Hayes JC 《Environmental monitoring and assessment》2007,132(1-3):171-187
The Reedy River in South Carolina is affected by the urban area of Greenville, the third most populous city in the state,
and by the effluents from two large-scale municipal wastewater treatment plants (WWTPs) located on the river. Riverine water
chemistry was characterized using grab samples collected annually under spring season baseflow conditions. During the 4-year
time period associated with this study, climatic variations included two severe drought spring seasons (2001 and 2002), one
above-normal precipitation spring season (2003), and one below-normal precipitation spring season (2004). The influence of
drought and human activities on the baseflow chemistry of the river was evaluated by comparing concentrations of dissolved
anions, total metals, and other important water chemistry parameters for these different years. Concentrations of copper and
zinc, common non-point source contaminants related to urban activities, were not substantially elevated in the river within
the urban area under baseflow conditions when compared with headwater and tributary samples. In contrast, nitrate concentrations
increased from 1.2–1.6 mg/l up to 2.6–2.9 mg/l through the urban stream reach. Concentrations of other major anions (e.g.,
sulfate, nitrate) also increased along the reach, suggesting that the river receives continuous inputs of these species from
within the urban area. The highest concentrations of major cations and anions typically were observed immediately downstream
from the two WWTP effluent discharge locations. Attenuation of nitrate downstream from the WWTPs did not always track chloride
changes, suggesting that nitrate concentrations were being controlled by biochemical processes in addition to physical processes.
The relative trends in decreasing nitrate concentrations with downstream distance appeared to depend on drought versus non-drought
conditions, with biological processes presumably serving as a more important control during non-drought spring seasons. 相似文献
945.
Managing volunteers: FEMA's Urban Search and Rescue programme and interactions with unaffiliated responders in disaster response 总被引:1,自引:0,他引:1
In the aftermath of disasters it is not uncommon for a large number of individuals, ranging from professional technical responders to untrained, albeit well meaning, volunteers, to converge on site of a disaster in order to offer to help victims or other responders. Because volunteers can be both a help and a hindrance in disaster response, they pose a paradox to professional responders at the scene. Through focus group interviews and in-depth structured interviews, this paper presents an extended example of how Urban Search and Rescue (US&R) task forces, a type of professional technical-responder organisation, interact with and utilise volunteers. Findings show that US&R task forces evaluate the volunteers in terms of their presumed legitimacy, utility, and potential liability or danger posed during the disaster response. Other responses to volunteers such as a feeling of powerlessness or the use of volunteers in non-technical ways are also explored. This paper demonstrates some key aspects of the relationship between volunteers and formal response organisations in disasters. 相似文献
946.
LIU Chuanfeng 《中国减灾(英文版)》2001,(4)
1 Climate background Although the La Nina event caused the decrease of the mean temperature in the tropical regions of the Pacific Ocean, the year 2000 had remained one of the hottest since 1860 when records of the global mean temperature began. The temperature in the areas to the north of 20扤 from December 1999 to November 2000 marked the second warmest in history. The mean temperature of the global surface in 2000 was 0. 60C above the average during the period 1880?999, and was close to … 相似文献
947.
Atmospheric concentrations of nitric acid (HNO3), sulfur dioxide (SO2), particulate nitrate and particulate sulfate on the urban- and mountain-facing sides of Mt. Gokurakuji were measured from November 2002 to October 2003, in order to evaluate
the effects of anthropogenic activity on air quality and dry deposited nitrate and sulfate on the surfaces of pine foliage.
The results showed that HNO3, SO2 and concentrations were significantly higher (P < 0.05) on the urban-facing side (1.54, 2.48 and 0.65 μg m−3, respectively) than the mountain-facing side (0.67, 1.19 and 0.37 μg m−3, respectively), while concentrations did not differ significantly between the two sides (urban-facing: 2.80 μg m−3; mountain−facing: 2.05 μg m−3). Indirect estimates of dry deposition rates of nitrate and sulfate to the surfaces of pine foliage based on the measured
concentrations approximately agreed with the measured values determined by the foliar rinsing technique in a previous study.
It was found that HNO3 was the major source (approximately 80%) of dry deposited nitrate on pine foliage, while the contribution from was about equal to that from SO2. In conclusion, HNO3 and SO2 appear to be dominant species reflecting higher dry deposition rates of nitrate and sulfate on the urban-facing side compared
to the mountain-facing side of Mt. Gokurakuji. 相似文献
948.
重庆城市电网工频电磁环境现状及安全性分析 总被引:1,自引:0,他引:1
在现场实测的基础上,分析研究了重庆城市电网中各种电压等级、各种类型变电站周边环境,多种形式架空线路下方区域以及地下电缆周围工频电磁环境的现状,对比国家现行标准限值,评价重庆城市电网的工频电磁环境的安全性,同时也指出随着架空线密度的增加,周围工频电场不但不增加,反而有降低的现象.目前擅自在输电线路下建房或增加房屋高度是危及电磁环境安全的主要问题,应加大监管力度,减少日后不必要的环保纠纷. 相似文献
949.
根据2000--2012年全国城镇生活污水排放量数据,建立了相应的GM(1,1)模型和预测函数。通过后验差检验等对预测函数进行了评估,并对2013--2017年城镇生活污水排放量进行了预测,结果表明,2013--2017年全国城镇生活污水的排放量逐年增加,呈上升趋势,从2013年的477.2736亿t上升到2017年的624.1022亿t;灰色预测模型和方法简单易用,利用较少的数据即可进行精度较高的预测。 相似文献
950.