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631.
地震谣言平息后的思考 总被引:2,自引:1,他引:1
对福建省沿海地区 1999年“9· 2 6”地震谣言的来因、传播过程及平息效果进行了分析讨论。给出了地震谣言平息后的几点思考 相似文献
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海岸湿地是由低地、滩涂与生物群落组合的海岸环境。中国海岸湿地环境受季风波浪、潮汐与大河影响的河海交互作用为特征,地跨39个纬度带,其面积约占中国湿地总面积的1/5。按成因与表相可分为:河口芦苇、草滩湿地,平原海岸草滩盐沼湿地及在华南隐蔽港湾顶部红树林沼泽湿地3种类型。均具有潮上带、潮间带与潮下带分带特性。海岸湿地是珍贵的新生空间资源,但由于滥伐垦殖、外来生物种属入侵危害、陆源水沙减少及海平面上升招致海岸侵蚀、盐潮入侵与内涝频繁等灾害影响,海岸湿地环境质量下降,面临着解决海岸湿地生态保护与沿海人民生计这一新生矛盾问题。需沿流域进行陆海结合的系统研究与对比总结,找出湿地保护与开发的临界度,全面规划实施。 相似文献
636.
海岸带土地开发利用及生态环境效应研究简述 总被引:1,自引:0,他引:1
海岸带土地利用变化是影响海岸带生态环境的一个重要方面,也是目前国内外学术界广为关注和研究的热点问题,研究海岸带土地利用变化及其对生态环境的影响对于了解区域的生态环境演变乃至全球变化具有重要意义。分析海岸带土地利用变化研究在全球变化研究中的地位,阐述海岸带地区土地利用变化及生态环境效应研究,对研究全球气候变化、海平面上升、陆地与海洋交互作用及由此引起的岸线变迁、入海营养盐和悬浮物及沉积物等物质通量变化、海岸带生物多样性、海岸带区域乃至整个全球C、N等物质总循环等都具有重要意义。基于以上研究,简述海岸带土地利用变化及其对生态环境影响研究进展,总结分析海岸带土地利用变化及环境效应影响研究目标和重点研究内容 相似文献
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A GIS Approach to Model Sediment Reduction Susceptibility of Mixed Sand and Gravel Beaches 总被引:3,自引:0,他引:3
The morphological form of mixed sand and gravel beaches is distinct, and the process/response system and complex dynamics
of these beaches are not well understood. Process response models developed for pure sand or gravel beaches cannot be directly
applied to these beaches. The Canterbury Bight coastline is apparently abundantly supplied with sediments from large rivers
and coastal alluvial cliffs, but a large part of this coastline is experiencing long-term erosion. Sediment budget models
provide little evidence to suggest sediments are stored within this system. Current sediment budget models inadequately quantify
and account for the processes responsible for the patterns of erosion and accretion of this coastline. We outline a new method
to extrapolate from laboratory experiments to the field using a geographical information system approach to model sediment
reduction susceptibility for the Canterbury Bight. Sediment samples from ten representative sites were tumbled in a concrete
mixer for an equivalent distance of 40 km. From the textural mixture and weight loss over 40 km tumbling, we applied regression
techniques to generate a predictive equation for Sediment Reduction Susceptibility (SRS). We used Inverse Distance Weighting
(IDW) to extrapolate the results from fifty-five sites with data on textural sediment composition to field locations with
no data along the Canterbury Bight, creating a continuous sediment reductions susceptibility surface. Isolines of regular
SRS intervals were then derived from the continuous surface to create a contour map of sediment reductions susceptibility
for the Canterbury Bight. Results highlighted the variability in SRS along this coastline. 相似文献
639.
Kumar PK 《Environmental monitoring and assessment》2006,123(1-3):333-344
This study presents the results of the impact assessment analysis of the coastal zones of Cochin along the southwest coast of India. The climatological cycle of sea level derived for the region for the period 1939–2003 has shown a range of about 17 cm. From the results obtained on the coastal sedimentary environments, it is found that climate-induced sea level rise scenarios will bring profound effects. It is also revealed that the mean beach slope and relief play a vital role in land loss of the region. The local relief of coastal zone will decrease as sea level rises, thus increasing the percentage of land above mean sea level subjected to episodic inundations. Results of the yearly probability of damages indicated the urgency to upgrade the existing designs of coastal protection structures. A brief characterisation of the issues on infrastructure and uncertainties in policy planning also are attempted. 相似文献
640.
Results from two 'Mussel Watch'-type monitoring programs were compared: the Réseau National d'Observation de la qualité du milieu marin (RNO), the French monitoring network, and the Mussel Watch Project of the U.S. National Status and Trends (NS&T) Program. 80 RNO sites (47 for mussels and 33 for oysters) and 89 NS&T sites (45 for mussels and 44 for oysters) provided a basis for the comparison of median concentrations of commonly measured trace metals (mercury, lead, zinc, cadmium and copper) and organic chemicals. Lower lead and lindane concentrations in the U.S. were explained by their respective history of use. Differences in Zn and Cu, essential elements for both mussels and oysters, could be due to specific internal regulation processes. Higher cadmium concentrations in the U.S. are possibly related to U.S. coastal areas being richer in nutrients or to a lesser use of this element as a general anticorrosive in France. We could not find any plausible explanation for higher mercury concentrations in France. This first attempt of a comparison of national chemical monitoring programs raises the need for deeper understanding of possible contamination sources. 相似文献