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   571篇
  免费   73篇
  国内免费   88篇
安全科学   57篇
废物处理   20篇
环保管理   173篇
综合类   279篇
基础理论   83篇
污染及防治   34篇
评价与监测   50篇
社会与环境   21篇
灾害及防治   15篇
  2024年   3篇
  2023年   7篇
  2022年   21篇
  2021年   19篇
  2020年   12篇
  2019年   25篇
  2018年   17篇
  2017年   39篇
  2016年   40篇
  2015年   32篇
  2014年   57篇
  2013年   61篇
  2012年   44篇
  2011年   52篇
  2010年   31篇
  2009年   37篇
  2008年   33篇
  2007年   37篇
  2006年   24篇
  2005年   25篇
  2004年   11篇
  2003年   18篇
  2002年   16篇
  2001年   14篇
  2000年   7篇
  1999年   6篇
  1998年   5篇
  1997年   4篇
  1996年   6篇
  1995年   2篇
  1994年   4篇
  1993年   1篇
  1989年   5篇
  1988年   2篇
  1986年   1篇
  1983年   1篇
  1982年   1篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   2篇
  1973年   1篇
  1972年   1篇
  1971年   2篇
排序方式: 共有732条查询结果,搜索用时 187 毫秒
181.
Many governments use technology incentives as an important component of their greenhouse gas abatement strategies. These carrots are intended to encourage the initial diffusion of new, greenhouse-gas-emissions-reducing technologies, in contrast to carbon taxes and emissions trading which provide a stick designed to reduce emissions by increasing the price of high-emitting technologies for all users. Technology incentives appear attractive, but their record in practice is mixed and economic theory suggests that in the absence of market failures, they are inefficient compared to taxes and trading. This study uses an agent-based model of technology diffusion and exploratory modeling, a new technique for decision-making under conditions of extreme uncertainty, to examine the conditions under which technology incentives should be a key building block of robust climate change policies. We find that a combined strategy of carbon taxes and technology incentives, as opposed to carbon taxes alone, is the best approach to greenhouse gas emissions reductions if the social benefits of early adoption sufficiently exceed the private benefits. Such social benefits can occur when economic actors have a wide variety of cost/performance preferences for new technologies and either new technologies have increasing returns to scale or potential adopters can reduce their uncertainty about the performance of new technologies by querying the experience of other adopters. We find that if decision-makers hold even modest expectations that such social benefits are significant or that the impacts of climate change will turn out to be serious then technology incentive programs may be a promising hedge against the threat of climate change.  相似文献   
182.
在掌握JJF1059-1999的基础上,对硝酸银标准滴定溶液浓度的不确定度进行评定,主要从方法概述、确定测量中不确定度的来源、建立数学模型、计算相对标准不确定度分量、合成相对标准不确定度、扩展不确定度等入手,详细介绍了硝酸银标准滴定溶液的不确定度评定过程。  相似文献   
183.
Life-cycle assessments are normally made without quantitative estimations of their uncertainty. More interest has been focused on sensitivity analysis. In ISO 14040, LCA standard and SETAC's ‘code of practice’ sensitivity and uncertainty analysis are recommended or even requested. In the EPS system, an analysis of significance and sensitivity has been carried out for several years. The article describes this procedure in ISO terms and generalises it for other types of life-cycle assessments.  相似文献   
184.
LPG沸腾液体扩展蒸气爆炸火球热辐射概率风险评估   总被引:9,自引:1,他引:9  
分析了火球热辐射的特点,针对LPG沸腾液体扩展蒸气爆炸火球造成的热辐射危害存在不确定性,建立了爆炸火球热辐射风险评估模型,提出了一种基于Monte-Carlo模拟的不确定性处理方法,引入实例计算了LPG沸腾液体扩展蒸气爆炸火球伤害范围、事故风险概率曲线方程和累计概率曲线方程,对于定量评估火球热辐射风险具有重要意义.  相似文献   
185.
不确定条件下矿产资源的最优开采   总被引:2,自引:0,他引:2  
通过一个连续时间的随机动态规划模型,探讨了市场需求、资源存量的不确定性以及勘探活动对矿产资源价格和开采速度的影响,并给出了随机条件下Hotelling法则的表达形式.模型结果显示:不确定性对资源价格变化速度的影响主要取决于开采成本,如果相对于资源存量来说开采成本是不变的或者开采的规模成本是不变的,则不确定性对资源价格的变化速度没有影响.反之,如果开采的规模成本是递增的,则不确定性会加速资源价格的变化.此外,不确定性的存在将加快资源的开采速度.至于勘探活动,它一方面降低了地质条件的不确定性,另一方面增加了资源的存量,所以勘探活动降低了资源价格和开采速度的变化率,减少了不确定性对资源开采的影响.  相似文献   
186.
资源是社会经济持续发展的动力,也是人类赖以生存的基本条件。在资源开发和利用过程中人们对所存在的不确定性和不可逆性重视不够,从而使资源得不到合理的开发和利用甚至遭到破坏。本文分析了资源利用中的不确定性和不可逆性,为资源的合理开发做了探索性研究,为同行们更深入的研究这种不确定性问题起到一个引领的铺垫作用。  相似文献   
187.
State variables in many renewable resource management problems, such as the abundance of a fish stock, are imperfectly observed over time. In systems characterized by state uncertainty, decision makers often invest in monitoring to learn about the level of a stock. We develop a stochastic bioeconomic model of marine invasive species management under state uncertainty. The decision maker in our model simultaneously evaluates optimal investment in monitoring and population control. Using a recently-devised method for solving continuous-state Partially Observable Markov Decision Processes (POMDPs), we find that the ability to learn through monitoring can alter the role of population control in the optimal policy function, for example by reducing control intensity in favor of monitoring. Optimal monitoring depends on the management context, including in our application lionfish population structure. The rich transient dynamics of our model depend critically on the relationship between the initial conditions for information and invader abundance.  相似文献   
188.
This research analyses the application of spatially explicit sensitivity and uncertainty analysis for GIS (Geographic Information System) multicriteria decision analysis (MCDA) within a multi-dimensional vulnerability assessment regarding flooding in the Salzach river catchment in Austria. The research methodology is based on a spatially explicit sensitivity and uncertainty analysis of GIS-CDA for an assessment of the social, economic, and environmental dimensions of vulnerability. The main objective of this research is to demonstrate how a unified approach of uncertainty and sensitivity analysis can be applied to minimise the associated uncertainty within each dimension of the vulnerability assessment. The methodology proposed for achieving this objective is composed of four main steps. The first step is computing criteria weights using the analytic hierarchy process (AHP). In the second step, Monte Carlo simulation is applied to calculate the uncertainties associated with AHP weights. In the third step, the global sensitivity analysis (GSA) is employed in the form of a model-independent method of output variance decomposition, in which the variability of the different vulnerability assessments is apportioned to every criterion weight, generating one first-order (S) and one total effect (ST) sensitivity index map per criterion weight. Finally, in the fourth step, an ordered weighted averaging method is applied to model the final vulnerability maps. The results of this research demonstrate the robustness of spatially explicit GSA for minimising the uncertainty associated with GIS-MCDA models. Based on these results, we conclude that applying the variance-based GSA enables assessment of the importance of each input factor for the results of the GIS-MCDA method, both spatially and statistically, thus allowing us to introduce and recommend GIS-based GSA as a useful methodology for minimising the uncertainty of GIS-MCDA.  相似文献   
189.
邢书才  田衎  樊?强 《化工环保》2017,37(3):362-365
研制了水污染分析校准用汞溶液。采用原子荧光光谱法对样品进行了均匀性和稳定性检验,对样品的量值进行了验证并进行了不确定度评定。检验结果表明:汞溶液均匀性良好,室温条件下可稳定36个月以上;样品的标准值为100 mg/L,扩展不确定度为2 mg/L。样品量值与美国AccuStandard公司同种标准物质具有一致性。可用于水中汞检测的测定标准、质量控制、分析方法研究以及实验室能力验证等方面。  相似文献   
190.
为对智慧工地全生命周期的本质安全度进行分析与评价,综合运用本质安全理论,构建智慧工地本质安全度评价模型.首先,根据智慧工地本质安全定义,将智慧工地本质安全度划分为初始级、简单级、标准级、成熟级和卓越级5个等级;其次,基于智慧工地的生产现状,构建包括人员管理系统、机械设备管理系统、现场监测预警系统、过程控制管理系统等4个...  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