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   1108篇
  免费   33篇
  国内免费   96篇
安全科学   75篇
废物处理   9篇
环保管理   156篇
综合类   418篇
基础理论   95篇
污染及防治   213篇
评价与监测   238篇
社会与环境   31篇
灾害及防治   2篇
  2024年   2篇
  2023年   31篇
  2022年   19篇
  2021年   32篇
  2020年   30篇
  2019年   25篇
  2018年   24篇
  2017年   35篇
  2016年   45篇
  2015年   38篇
  2014年   34篇
  2013年   40篇
  2012年   37篇
  2011年   65篇
  2010年   35篇
  2009年   93篇
  2008年   80篇
  2007年   78篇
  2006年   57篇
  2005年   40篇
  2004年   23篇
  2003年   29篇
  2002年   51篇
  2001年   45篇
  2000年   45篇
  1999年   43篇
  1998年   31篇
  1997年   30篇
  1996年   18篇
  1995年   15篇
  1994年   16篇
  1993年   11篇
  1992年   10篇
  1991年   8篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   2篇
  1985年   2篇
  1984年   2篇
  1982年   4篇
  1978年   1篇
  1977年   4篇
  1968年   1篇
排序方式: 共有1237条查询结果,搜索用时 171 毫秒
881.
Mounting research highlights the contribution of ecosystem services provided by urban forests to quality of life in cities, yet these services are rarely explicitly considered in environmental policy targets. We quantify regulating services provided by urban forests and evaluate their contribution to comply with policy targets of air quality and climate change mitigation in the municipality of Barcelona, Spain. We apply the i-Tree Eco model to quantify in biophysical and monetary terms the ecosystem services “air purification,” “global climate regulation,” and the ecosystem disservice “air pollution” associated with biogenic emissions. Our results show that the contribution of urban forests regulating services to abate pollution is substantial in absolute terms, yet modest when compared to overall city levels of air pollution and GHG emissions. We conclude that in order to be effective, green infrastructure-based efforts to offset urban pollution at the municipal level have to be coordinated with territorial policies at broader spatial scales.  相似文献   
882.
This article utilizes Support Vector Machines (SVM) for predicting global solar radiation (GSR) for Sharurha, a city in the southwest of Saudi Arabia. The SVM model was trained using measured air temperature and relative humidity. Measured data of 1812 values for the period from 1998–2002 were obtained. The measurement data of 1600 were used for training the SVM, and the remaining 212 were used for comparison between the measured and predicted values of GSR. The GSR values were predicted using the following four combinations of data sets: (i) Daily mean air temperature and day of the year as inputs, and global solar radiation as output; (ii) daily maximum air temperature and day of the year as inputs, and GSR as output; (iii) daily mean air temperature and relative humidity and day of the year as inputs, and GSR as output; and (iv) daily mean air temperature, day of the year, relative humidity, and previous day’s GSR as inputs, and GSR as output. The mean square error was found to be 0.0027, 0.0023, 0.0021, and 7.65 × 10?4 for case (i), (ii,), (iii), and (iv) respectively, while the corresponding absolute mean percentage errors were 5.64, 5.08, 4.48, and 2.8%. Obtained results show that the SVM method is capable of predicting GSR from measured values of temperature and relative humidity.  相似文献   
883.
当前我国大气污染形势严峻,严重损害人民群众身体健康,影响社会和谐稳定。为切实改善空气质量,国务院于2013年9月印发了《大气污染防治行动计划》(简称《行动计划》)。本研究测算了实施该行动计划所需投入资金,并定量评估了可能给中国带来的社会、经济、健康等影响。结果表明,《大气污染防治行动计划》直接投资共计需要资金约1.84万亿元,其中优化能源结构、移动源污染防治、工业企业污染治理、面源污染治理的投资需求约分别为2844亿元、14 067.66亿元、915.44亿元和615.72亿元;2017年全国因实施《大气污染防治行动计划》而减少的慢性死亡人数平均约为11.06万人,占人口总数的0.15‰,各地损失寿命年限均有所下降,即寿命有延长趋势;带来的社会经济影响为正效应,在2013—2017年,计划的实施将拉动我国GDP增长约20 403.01亿元,增加就业岗位约291.13万个。本研究对政策评估研究及未来大气污染治理发展方向具有重要参考价值。  相似文献   
884.
This paper analyses whether China's export VAT rebates and export taxes are driven by environmental concerns. Since China struggles to enforce environmental regulation, trade policy can be used as a second-best environmental policy. In a general equilibrium model it is possible to show that the second-best export tax increases in a product's pollution intensity. The empirical analysis investigates whether the export tax equivalent of partial VAT rebates and export taxes are higher for products which are more pollution intensive along several dimensions. The results indicate that the VAT rebate rates are set in a way that discourages exports of water pollution intensive, SO2 intensive and energy intensive products from 2007 on. Moreover, the conservation of natural resources such as minerals, metals, wood products and precious stones seems to be a key determinant of China's export VAT rebate rates. There is little evidence that export taxes are motivated by environmental concerns.  相似文献   
885.
VB可视化集成环境下空气污染指数计算与分析系统   总被引:2,自引:0,他引:2       下载免费PDF全文
探讨了以VB可视化集成环境为平台,在Windows操作系统下开发空气污染指数计算与分析系统的基本模型和方法,指出开发空气污染指数计算与分析系统的关键是建立可视化用户界面和相应的事件驱动过程的代码编写,阐述了空气污染指数计算与分析系统的优越性,列出了系统功能的主要内容和开发方法,并且简单介绍了空气污染指数的算法。  相似文献   
886.
光电技术在大气氮氧化物检测中的应用   总被引:5,自引:0,他引:5  
介绍了大气中氮氧化物的组成,综述了激光诱导荧光法、光纤传感法、激光雷达探测法和化学发光法测定大气中氮氧化物的原理和特点,指出光电技术已在大气氮氧化物检测中得到了广泛的应用,并具有良好的发展前景。  相似文献   
887.
赵秀杰 《环境与发展》2020,(1):77-77,79
近年来,由于我国经济的迅速发展和环保意识的欠缺,致使现阶段我国生态环境污染较为严重[1]。本文对大气污染治理时存在的问题加以分析,以污染原因为依据,提出合理、科学的解决方案。  相似文献   
888.
随着城市化建设的不断发展,大气环境所遭受的破坏也越来越严重,近年常发生的雾霾天气就是大气环境被破坏的证明,人们长期处在这样的大气环境中将令身体健康遭受极其严重的损害。我国对大气环境治理非常重视,正在全面开展大气污染监测与防治工作,本文对此作了简要分析,希望对提升大气污染监测与防治效果具有一定促进作用。  相似文献   
889.
陈颖  黄昌付 《环境与发展》2020,(4):162-162,165
大气污染作为环境污染的关键部分,一直困扰着人们的生活,而传统监测设备由于技术具有一定的滞后性,无法满足当前环境监测的需要。而网格化监测有着传统监测设备不具备的优势,在大气污染防治方面发挥着重要的作用,为环境污染治理提供重要的数据保障。基于此,本文主要对大气污染防治网格化监测含义及优势进行了总结概括,并重点对网格化监测的应用展开分析。  相似文献   
890.
The harmful effect of manmade particles on natural processes and human health is documented by a large number of studies showing a positive correlation between particulate matter (PM) concentration and health effects. Diminution of this health risk necessitates among others the precise knowledge of the particle sources, their physical and chemical properties and their dissemination in the environment. Pb isotope ratios have been successfully used during the past decades as tracers of anthropogenic Pb disseminated in the biosphere. Here we show that tree bark biomonitoring with lead (Pb), strontium (Sr) and neodymium (Nd) isotope ratios as tracers allow a thorough analysis of the impacts of industrial and other anthropogenic emissions on the urban environment. This is the first comprehensive multi-isotope tracer study of atmospheric pollution in an urban environment allowing to identify and to integrate the different plume paths of emissions in a digital map system. This innovative approach might become an important tool for environmental management and policy-making processes dealing especially with risks and surveillance of air quality in the urban environment.  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