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351.
在汶川8.0级地震及其次生灾害的共用作用下,地震灾区生态环境变得更加脆弱.灾后3年灾区重建任务主要集中在经济社会方面,对生态环境重建的投入不足,以及灾区高碳化产业结构,造成灾区生态系统功能退化,灾区生态系统出现弱均衡现象,严重影响灾区生态系统的可持续发展.灾区生态弱均衡可防可控,通过在灾区树立低碳均衡发展思想,制定灾区生态低碳发展路径;加大节能减排工作力度,调整灾区产业结构;推行退耕还林政策,发展林木产业,推进生态农业低碳建设;构建森林碳汇示范基地,实施低碳生态战略,推动灾区生态系统全面可持续发展. 相似文献
352.
根据安徽省生态环境现状调查的结果,分析讨论了自然资源态势及其原因并提出相应的对策:耕地是土地利用的主要类型,面积减小、质量降低是主要耕地利用问题,实现耕地总量平衡是解决该问题的途径;森林资源主要表现龄组、林种、树种等结构不合理、蓄积量小、林地生产力低等,封山育林、调整林层结构、提高种植指数等措施可逐步健全森林生态系统和实现森林生态安全;安徽省水资源分布不均、利用效率不高、水体污染等生态问题,可通过“南水北调”、改善用水设施、利用科技手段提高用水效率和污水处理能力而得到解决。 相似文献
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根据“闭路开环”原理制定人口政策 总被引:1,自引:0,他引:1
可持续发展的基本理论是在代际之间公平、均衡地分配自然资源。这一过程是一个闭路与开环的反馈控制系统。本文界定了三代人间的一个生物代际交叉期、一个社会代际交叉期和二个经济代际交叉期 ,设计了资源代际均衡分配管理模型 ,即 :代际年限长度 (δ)模型 ,且根据δ模型和闭路开环原理对人口政策进行了创新性分析 相似文献
355.
格子Boltzmann方法及其在泥石流堆积研究中的应用 总被引:3,自引:0,他引:3
以格子Boltzmann方法为平台,结合泥石流流团模型的特点,建立了特殊的格子Boltzmann模型。该模型从平衡态分布函数和非平衡态分布函数两个层次精细刻画了泥石流运动的非线性特征及其复杂的流变关系,成功模拟了泥石流的堆积过程,研究了地面形态与泥石流堆积形态之间的关系。 相似文献
356.
Burchard H. Heede 《Environmental management》1985,9(5):427-432
Fallen trees and their large debris often form log steps in small mountain streams, where they are incorporated into the hydraulic geometry. The hypothesis here was that these log steps take the place of gravel bars that otherwise would have been required for channel slope adjustment. In this experiment, the treated as well as the control stream were located in virgin mixed conifer forests and until the study began, no human activity had interfered with the natural developments. All log steps were removed from a stream and the formation of new log steps was prohibited by periodic removal of fallen trees and branches. Five years later, 74% of all removed log steps had been replaced by gravel bars, thus proving the hypothesis that increased bedload movement was required to offset the loss of log steps. Implications are that streamside forests should be managed so that they can provide a steady supply of debris for channel stability. 相似文献
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Andrea Bigano Francesco Bosello Roberto Roson Richard S. J. Tol 《Mitigation and Adaptation Strategies for Global Change》2008,13(8):765-791
While climate change impacts on human life have well defined and different origins, the interactions among the diverse impacts
are not yet fully understood. Their final effects, however, especially those involving social-economic responses, are likely
to play an important role. This paper is one of the first attempts to disentangle and highlight the role of these interactions.
It focuses on the economic assessment of two specific climate change impacts: sea-level rise and changes in tourism flows.
By using a Computable General Equilibrium (CGE) model the two impacts categories are first analysed separately and then jointly.
Considered separately, in 2050, the forecasted 25 cm. of sea level rise imply a GDP loss ranging from (−) 0.1% in South East
Asia to almost no loss in Canada, while redistribution of tourism flows – which in terms of arrivals favours Western Europe,
Japan, Korea and Canada and penalises all the other world regions – triggers GDP losses ranging from (−) 0.5% in Small Island
States to (−) 0.0004% in Canada. GDP gainers are Australia, New Zealand, Western Europe, Middle East and South Asia. The impact
of sea level rise and tourism were simulated jointly and the results compared with those of the two disjoint simulations.
From a qualitative point of view, the joint effects are similar to the outcomes of the disjoint exercises; from a quantitative
perspective, however, impact interaction does play a significant role. In six cases out of 16 there is a detectable (higher
than 2% and peaking to 70%) difference between the sum of the outcomes in the disjoint simulation and the outcomes of the
joint simulations. Moreover, the relative contribution of each single impact category has been disentangled from the final
result. In the case under scrutiny, demand shocks induced by changes in tourism flows outweigh the supply-side shock induced
by the loss of coastal land.
相似文献
Francesco BoselloEmail: |