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671.
Objective: This study aimed to explore the relationship between crash types and different freeway segments and identify the factors contributing to crashes on different freeway segments. Unlike most of the previous studies on freeway segments, this study separately investigates basic freeway segments, single ramp influence segments, and multiple ramp influence segments.

Methods: Nonlinear canonical correlation analysis (NLCCA) and proportionality test were used to identify the relationship between crash types and different freeway segments. The data sets for the different freeway segments accumulated for this study consist of 9,867 crash samples with complete information on all 22 chosen variables. A multinomial logit model (MNL) was used to estimate the influence of crash factors on different freeway segments.

Results: The results show that weaving and diverge overlap influence segments (WD) are more likely to have injury or fatal crashes; diverge and diverge overlap influence segments (DD) are more likely to have property damage–only (PDO) crashes; merge and merge overlap influence segments (MM) are more likely to have sideswipe crashes; and WD have non-sideswipe crashes; WD and weaving overlap influence segments (MW) are more likely to have rear end crashes; and MM segments are less likely to have hit object crashes. The contributing factors are identified by MNL and the results show that different traffic variables, environmental variables, vehicle variables, driver variables, and geometric variables significantly affected the likelihood of crashes on different freeway segments.

Conclusions: Investigation of crash types and factors contributing to crashes on different freeway segments is based on multiple ramp influence segments, which can promote a better understanding of the safety performance of various freeway segments.  相似文献   

672.
Coastal and ocean planning comprises a broad field of practice. The goals, political processes, and approaches applied to planning initiatives may vary widely. However, all planning processes ultimately require adequate information on both the biophysical and social attributes of a planning region. In coastal and ocean planning practice, there are well‐established methods to assess biophysical attributes; however, less is understood about the role and assessment of social data. We conducted the first global assessment of the incorporation of social data in coastal and ocean planning. We drew on a comprehensive review of planning initiatives and a survey of coastal and ocean practitioners. There was significantly more incorporation of social data in multiuse versus conservation‐oriented planning. Practitioners engaged a wide range of social data, including governance, economic, and cultural attributes of planning regions and human impacts data. Less attention was given to ecosystem services and social–ecological linkages, both of which could improve coastal and ocean planning practice. Although practitioners recognize the value of social data, little funding is devoted to its collection and incorporation in plans. Increased capacity and sophistication in acquiring critical social and ecological data for planning is necessary to develop plans for more resilient coastal and ocean ecosystems and communities. We suggest that improving social data monitoring, and in particular spatial social data, to complement biophysical data, is necessary for providing holistic information for decision‐support tools and other methods. Moving beyond people as impacts to people as beneficiaries, through ecosystem services assessments, holds much potential to better incorporate the tenets of ecosystem‐based management into coastal and ocean planning by providing targets for linked biodiversity conservation and human welfare outcomes. La Práctica Actual y los Prospectos Futuros para los Datos Sociales en la Planeación Costera y Oceánica  相似文献   
673.
Culturomic tools enable the exploration of trends in human–nature interactions, although they entail inherent biases and necessitate careful validation. Furthermore, people may engage with nature across different culturomic data sets differently. We evaluated people's digital interest and engagement with plant species based on Wikipedia and Google data and explored the conservation implications of these temporal interest patterns. As a case study, we explored the digital footprints of the most popular plant species in Israel. We analyzed 4 years of daily page views from Hebrew Wikipedia and 10 years of daily Google search volume in Israel. We modeled popularity of plant species in these 2 data sets based on a suite of plant attributes. We further explored the seasonal trends of people's interest in each species. We found differences in how people interacted digitally with plants in Wikipedia and Google. Overall, in Google, searches for species that have utility to humans were more common, whereas in Wikipedia, plants that serve as cultural emblems received more attention. Furthermore, in Google, popular species attracted more attention over time, opposite to the trend in Wikipedia. In Google, interest in species with short bloom duration exhibited more pronounced seasonal patterns, whereas in Wikipedia, seasonality of interest increased as bloom duration increased. Together, our results suggest that people's digital interactions with nature may be inherently different depending on the sources explored, which may affect use of this information for conservation. Although culturomics holds much promise, better understanding of its underpinnings is important when translating insights into conservation actions.  相似文献   
674.
Eco-labelling is the practice of eco information provision that most directly addresses consumer behaviour. Nowadays, consumers are facing difficulties in perceiving and understanding existing eco labels. In previous work, we proposed the conceptual framework of eco information individualisation which tailors eco labels according to the specific needs of individual users using contextual technologies. This paper extends the conceptual framework by introducing a more structured way of considering the personal data and product data requirements, and reports the development of a design toolkit that aims to support designers in the designing of individualised eco information. A design workshop was carried out to introduce the concept to designers, and evaluate the usability and usefulness of the toolkit. Positive responses were received. The design outputs generated from the workshop were considered largely feasible and have the potential to be developed into digital prototypes. These indicate that it is possible for designers to learn to design eco information individualisation in a short time. This paper is a step towards a greater understanding of designing individualised eco information.  相似文献   
675.
1985年以来江苏省土地利用变化对人类活动程度的响应   总被引:3,自引:0,他引:3  
利用1985、1995、2005和2008年4期遥感影像解译获取的土地利用变化数据,从土地利用变化速度、转移方向和土地利用程度方面,借助GIS空间分析和图谱分析技术及Ucinet社会网络分析软件,全面定量分析江苏省1985年以来人类活动作用下土地利用时空变化规律。研究表明:(1)1985~1995、1995~2005、2005~2008年3个时段江苏省的土地利用综合动态分别为12.95%、17.17%、15.03%,反应了人类活动对江苏省土地利用变化的影响程度呈现出"缓慢影响—剧烈影响—影响减缓"的倒U型曲线规律;(2)1985年以来,耕地、建设用地和水域之间的空间转移是江苏省土地利用转移的关键,也是人类影响土地利用最主要的表现形式,3种地类的相互转移占所有土地转移流的80%以上,其中耕地转为建设用地所占比例最大,主要分布苏锡常及南京4市的市辖区,以及昆山、江阴等经济发达的县市及苏北的宿迁市、淮安市、徐州市;(3)1985年以来,追求净产出(利润)的增长是土地利用变化的内在动力,导致建设用地增加及耕地减少,使得全省土地利用程度整体水平不断升高;受可驱动的有效资本量控制,经济发达的苏南地区一直是人类活动影响土地利用最为剧烈的区域,而苏北地区随着经济实力的不断提升土地利用受人类活动影响的程度也在逐渐增强。  相似文献   
676.
研究西南地区陆地植被生态系统净初级生产力(NPP)的时空演变特征及其驱动力,对区域生态环境保护具有重要的现实意义.利用2000~2021年MODIS NPP、1999~2021年基于站点的气象数据和2000~2020年土地利用类型等数据,结合主成分分析、残差分析、Theil-Sen Median趋势分析和偏相关分析等方法,研究西南地区陆地植被生态系统NPP时空演变及其对驱动力的响应特征.结果表明,时间上,2000~2021年西南地区植被NPP呈波动上升趋势,速率为3.54g·(m2·a)-1.气候变化和人类活动影响下,农田、草地和森林生态系统NPP均呈上升趋势,但农田生态系统NPP的上升趋势最为显著.空间上,西南地区植被NPP呈上升趋势的面积占比为89.06%,显著上升和极显著上升的区域主要分布在广西南部、四川东部、重庆西部,以及云南和贵州交界处.气候变化和人类活动对西南地区植被生长具有双重影响,气候变化和人类活动影响下农田生态系统NPP呈上升趋势的面积占比均高于草地和森林生态系统.西南地区植被NPP与各气象因子的相关性呈明显地域差异.区域尺...  相似文献   
677.
草原区作为影响我国陆地生态系统碳水循环和生态安全的重点区域,对气候变化和人类活动极为敏感.然而,有关气候变化和人类活动对该区域植被恢复相对贡献的认识尚存分歧.以生态系统净初级生产力(NPP)为评价指标,通过对比MODIS观测的实际NPP和基于Thornthwaite Memorial模型估算的潜在NPP的趋势差异,量化了2000~2020年气候变化和人类活动对我国典型草原区(北方温性草原区和青藏高原高寒草原区)植被恢复的相对作用.结果表明,研究区内93%的草地植被呈恢复趋势,NPP平均增加速率达(以C计)2.12 g·(m2·a)-1(P<0.01),其中,近一半植被恢复区受气候变化和人为活动共同控制,约36%和10%植被恢复区分别受气候变化和人类活动的独立控制;此外,不同草地类型气候变化主导植被恢复的面积占比差异大,主要表现为高寒草地明显高于温性草地,气候条件越干旱,气候主导面积占比越大.人类活动不是北方温性草原区和青藏高原高寒草原区植被恢复的主要原因,但在气候条件恶化地区,人类活动可降低甚至抵消气候变化对植被的负面影响.未来需加强长...  相似文献   
678.
单振东  刘顿  骆汉  刘建伟  张丽梅  魏宇航 《环境科学》2023,44(11):6215-6225
承德接坝区位于农牧过渡区,对气候变化和人类活动极为敏感.以植被净初级生产力(NPP)作为评价指标,基于Thornthwaite Memorial模型计算潜在NPP和MODIS NPP遥感影像获取实际NPP数据,利用潜在NPP与实际NPP间的差值衡量人类活动作用下NPP的大小,运用Slope趋势和变异系数法分析实际NPP、潜在NPP和人类活动作用下NPP的变化趋势及稳定性分布,并采用相关系数法分析实际NPP与年降水量和年均气温间的相关性,最终量化气候变化和人类活动对该区域植被变化的影响.结果表明,潜在NPP自西北向东南递增,其变化趋势和稳定性均为自西向东递增.实际NPP与年降水量和年均气温呈正相关区域面积占比分别是99.87%和91.66%.该区域99.85%的植被得到改善且变化稳定,主要是由气候因素和人类活动共同主导(99.71%),而植被退化完全是由人为因素所导致(0.15%).  相似文献   
679.
长江流域总氮排放量预测   总被引:1,自引:0,他引:1  
丁肇慰  郑华 《环境科学》2021,42(12):5768-5776
水环境污染是长江流域突出的环境问题之一,预测污染物排放特征可为流域水污染防治提供科学基础.本研究综合采用灰色理论预测模型、Conversion of land use and its effects at small region extent(CLUE-S)模型以及 Integrated valuation of ecosystem services and tradeoffs(InVEST)模型,预测2025年长江流域非点源以及点源总氮排放趋势.结果表明:①非点源总氮排放呈减少趋势,2015~2025年区域非点源总氮排放量减少23.96%,中下游农业区总氮排放骤减,而上游局部地区呈增加趋势;②点源总氮排放总体呈现增加趋势,2015~2025年区域点源总氮排放量增加1.79%,主要是由于城镇废水排放的增加以及中下游沿江城市群生活污水排放显著增加,而中下游丘陵地区点源总氮排放呈现减少趋势;③长江流域总氮排放量呈现减少趋势,2015~2025年减少2.67%,但仍有37.64%区域呈现总氮排放增加的趋势.长江流域未来应加强对上游面源污染治理以及中下游工业、城镇废水排放的管控.采用多模型结合的手段可以精细揭示了长江流域总氮排放空间格局及未来趋势,可为明确流域总氮排放控制目标提供科学基础,也可为实现高效的水环境治理提供科学依据.  相似文献   
680.
黄河水环境特征与氮磷负荷时空分布   总被引:3,自引:2,他引:1  
韩谞  潘保柱  陈越  刘亚平  侯易明 《环境科学》2021,42(12):5786-5795
黄河是我国西北和华北地区重要的供水水源,由于地形和降雨等自然因素以及频繁的人类活动影响,黄河流域水环境问题日渐凸显.为明确黄河干流水环境特征、水质现状以及流域氮磷负荷时空分布,本研究于2019年的4~5月和10~11月对黄河干流全河段水环境进行了调查研究.基于野外采样研究结果以及室内实验数据,结果发现:①从源区至河口多个水体理化参数逐渐上升的趋势反映了越来越频繁的人类活动以及中下游水土流失等的共同作用,此外,水库对溶质的截留与沉积具有显著的效果;②两个季节水质差异较小,从源区至河口水质等级由"优秀"下降至"一般";③降雨是黄河流域氮磷赋存形态及其负荷具有季节性差异的关键因素;④黄河流域内氮磷赋存形态及其负荷所具有的空间差异性主要受控于人类活动与水土流失的影响.本研究结果可为控制黄河流域入河氮磷负荷以及改善水质提供科学依据.  相似文献   
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