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   214篇
  免费   3篇
  国内免费   8篇
安全科学   12篇
废物处理   2篇
环保管理   101篇
综合类   56篇
基础理论   7篇
污染及防治   17篇
评价与监测   16篇
社会与环境   12篇
灾害及防治   2篇
  2023年   1篇
  2022年   8篇
  2021年   6篇
  2020年   12篇
  2019年   2篇
  2018年   3篇
  2017年   1篇
  2016年   3篇
  2015年   6篇
  2014年   15篇
  2013年   12篇
  2012年   10篇
  2011年   14篇
  2010年   2篇
  2009年   15篇
  2008年   19篇
  2007年   19篇
  2006年   7篇
  2005年   7篇
  2004年   2篇
  2003年   5篇
  2002年   2篇
  2001年   6篇
  2000年   7篇
  1999年   3篇
  1998年   7篇
  1997年   1篇
  1996年   5篇
  1995年   3篇
  1994年   1篇
  1993年   1篇
  1990年   2篇
  1987年   5篇
  1986年   3篇
  1985年   2篇
  1984年   4篇
  1983年   3篇
  1982年   1篇
排序方式: 共有225条查询结果,搜索用时 31 毫秒
221.
大浦镇农村生活污染公众调查研究   总被引:7,自引:0,他引:7  
以毗邻太湖的宜兴市大浦镇为例,在环境现状调查和公民环境意识调查的基础上,对水网区农村生活引起的非点源污染问题进行了调查研究。分析了研究区农村厕所的类型和生活污水的排放途径,得出了各类型厕所使用比例、生活污水直接或间接排向河流的排放比例。指出农村生活引起的非点源污染已成为水网区非点源污染的重要组成部分。  相似文献   
222.
The pollution levels, composition characteristics and sources of atmospheric PM2.5 were investigated based on field measurement at a rural site in the North China Plain (NCP) from pre-heating period to heating period in winter of 2017. The hourly average concentrations of PM2.5 frequently exceeded 150 µg/m3 and even achieved 400 µg/m3, indicating that the PM2.5 pollution was still very serious despite the implementation of stricter control measures in the rural area. Compared with the pre-heating period, the mean concentrations of organic carbon (OC), element carbon (EC) and chlorine ion (Cl?) during the heating period increased by 20.8%, 36.6% and 38.8%, accompanying with increments of their proportions in PM2.5 from 37.5%, 9.8% and 5.5% to 42.9%, 12.7% and 7.2%, respectively. The significant increase of both their concentrations and proportions during the heating period was mainly ascribed to the residential coal combustion. The proportions of sulfate, nitrate and ammonium respectively increased from 9.9%, 10.9% and 9.0% in nighttime to 13.8%, 16.2% and 11.1% in daytime, implying that the daytime photochemical reactions made remarkable contributions to the secondary inorganic aerosols. The simulation results from WRF-Chem revealed that the emission of residential coal combustion in the rural area was underestimated by the current emission inventory. Six sources identified by positive matrix factorization (PMF) based on the measurement were residential coal combustion, secondary formation of inorganic aerosols, biomass burning, vehicle emission and raising dust, contributing to atmospheric PM2.5 of 40.5%, 21.2%, 16.4%, 10.8%, 8.6% and 2.5%, respectively.  相似文献   
223.
通过调查问卷与实地监测等手段,以陕西关中东部地区的4镇8村为例研究农村居民生活污水排放特点,并分析其影响因素及机理。结果表明:关中东部地区与陕西其他地区(陕南、陕北)相比,农村生活源水污染物排放量关中最高,陕南、陕北次之。SPSS相关性检测显示:河流水期、农耕规律、收入水平、文化程度及年龄结构等因素与TN、TP、NH3〖FK(W。*9〗〖CD*2〗〖FK)〗N污染物产排系数显著相关。  相似文献   
224.
农村生活垃圾产生特征及分类收集模式   总被引:7,自引:0,他引:7  
以南京市高淳县的一个村为研究对象,依托新建的农村生活垃圾分类收集系统,对该区域生活垃圾的产生量、组成成分及其动态变化进行了调查研究,从垃圾分类收集模式的运行效果和经济可行性对其进行了分析。结果表明,该地区农村人均垃圾产生量为0.4 kg/d ,但随季节有一定的波动,这主要是由食品类消费的季节性变动而引起。垃圾组成以有机垃圾为主,约占55%,可回收垃圾、其他垃圾和有害垃圾所占比例分别为30.5%、14.2%和0.34%。通过认真的宣传和指导,村民在较短的时间内基本都可以做到正确分类;垃圾分类收集系统的户均建设成本为21元,运行费用比分类收集前每户每月增加3.2元 。  相似文献   
225.
An extensive visibility monitoring was carried out simultaneously in the urban area of Gwangju and the rural area of Anmyon, Korea. This study examines patterns of visibility impairment and haze-forming pollutant concentrations on both sites resulting from natural and anthropogenic sources of gases and particles. Optical visibility measurements by a transmissometer, a nephelometer and an aethalometer provide aerosol light extinction, scattering, and absorption coefficients for both sites. In order to investigate the physico-chemical characteristics of atmospheric aerosols, aerosol samples were collected by various aerosol samplers at GJVMS (Gwangju Visibility Monitoring Station) and at KGAWO (Korea Global Atmosphere Watch Observatory), respectively. In addition, haze characteristics causing visibility impairment at those two sites were analyzed to obtain source contributions by regionally transported aerosols using grid analysis and display system (GrADS) from NECP reanalysis data. During the intensive monitoring period, ammonium sulfate was dominantly responsible for the fine particle mass loading at GJVMS, whereas organic carbon was the largest contributor at KGAWO. Light scattering by particles accounted for 52.8 to 81.3% of the range at the urban site, GJVMS and for 72.1 to 94.2% of the range at the rural site, KGAWO. Light absorption by the EC and NO2 was between 14.5 and 34.8% at GJVMS, which was higher than the observed 1.1 ∼ 6.8% at KGAWO, respectively. Light scattering by aerosol was higher in the rural area than in the urban area. And organic carbon concentration was observed to be significantly higher than the concentration of elemental carbon at KGAWO. These haze-forming carbonaceous particles originate from anthropogenic pollutants at the urban atmosphere but they can be produced by natural environments such as marine and forest at the rural atmosphere.  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