首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2641篇
  免费   77篇
  国内免费   26篇
安全科学   184篇
废物处理   159篇
环保管理   565篇
综合类   312篇
基础理论   604篇
环境理论   4篇
污染及防治   594篇
评价与监测   184篇
社会与环境   102篇
灾害及防治   36篇
  2023年   11篇
  2022年   19篇
  2021年   27篇
  2020年   27篇
  2019年   28篇
  2018年   61篇
  2017年   61篇
  2016年   83篇
  2015年   74篇
  2014年   78篇
  2013年   240篇
  2012年   112篇
  2011年   149篇
  2010年   115篇
  2009年   133篇
  2008年   131篇
  2007年   146篇
  2006年   139篇
  2005年   101篇
  2004年   92篇
  2003年   109篇
  2002年   72篇
  2001年   56篇
  2000年   57篇
  1999年   41篇
  1998年   39篇
  1997年   36篇
  1996年   34篇
  1995年   27篇
  1994年   36篇
  1993年   32篇
  1992年   22篇
  1991年   26篇
  1990年   16篇
  1989年   12篇
  1988年   17篇
  1987年   19篇
  1986年   14篇
  1985年   21篇
  1984年   12篇
  1983年   18篇
  1982年   20篇
  1981年   26篇
  1980年   13篇
  1979年   11篇
  1978年   6篇
  1977年   10篇
  1971年   6篇
  1957年   5篇
  1955年   5篇
排序方式: 共有2744条查询结果,搜索用时 183 毫秒
621.
622.
623.
624.
625.
626.
627.
628.
629.
Risk-based insurance is a commonly proposed and discussed flood risk adaptation mechanism in policy debates across the world such as in the United Kingdom and the United States of America. However, both risk-based premiums and growing risk pose increasing difficulties for insurance to remain affordable. An empirical concept of affordability is required as the affordability of adaption strategies is an important concern for policymakers, yet such a concept is not often examined. Therefore, a robust metric with a commonly acceptable affordability threshold is required. A robust metric allows for a previously normative concept to be quantified in monetary terms, and in this way, the metric is rendered more suitable for integration into public policy debates. This paper investigates the degree to which risk-based flood insurance premiums are unaffordable in Europe. In addition, this paper compares the outcomes generated by three different definitions of unaffordability in order to investigate the most robust definition. In doing so, the residual income definition was found to be the least sensitive to changes in the threshold. While this paper focuses on Europe, the selected definition can be employed elsewhere in the world and across adaption measures in order to develop a common metric for indicating the potential unaffordability problem.  相似文献   
630.
Biofuels vary greatly in their carbon intensity, depending on the specifics of how they are produced. Policy frameworks are needed to ensure that biofuels actually achieve intended reductions in greenhouse gas emissions. Current approaches do not account for important variables during cultivation that influence emissions. Estimating emissions based on biogeochemical models would allow accounting of farm-specific conditions, which in turn provides an incentive for producers to adopt low emissions practices. However, there are substantial uncertainties in the application of biogeochemical models. This paper proposes a policy framework that manages this uncertainty while retaining the ability of the models to account for (and hence incentivize) low emissions practices. The proposed framework is demonstrated on nitrous oxide (N2O) emissions from the cultivation of winter barley. The framework aggregates uncertainties over time, which (1) avoids penalizing producers for uncertainty in weather, (2) allows for a high degree of confidence in the emissions reductions achieved, and (3) attenuates the uncertainty penalties borne by producers within a timescale of several years. Results indicate that with effective management, N2O emissions from feedstock cultivation may be <?5% of the carbon intensity of gasoline, whereas the existing policy approach estimates emissions >?20% of the carbon intensity of gasoline. If these emissions reductions are monetized, the framework can provide up to $0.002 per liter credits (0.8 cents per gallon) to fuel producers, which could incentivize emissions mitigation practices by biofuel feedstock suppliers, such as avoiding fall N application on silty clay loam soils. The conservatism in the current approach fails to incentivize the adoption of biofuels, while the lack of specificity fails to incentivize site-level mitigation practices. Improved uncertainty accounting and consideration of farm-level practices will incentivize mitigation efforts at landscape to global scales.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号