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   352篇
  免费   12篇
  国内免费   86篇
安全科学   18篇
废物处理   16篇
环保管理   28篇
综合类   178篇
基础理论   49篇
污染及防治   119篇
评价与监测   18篇
社会与环境   14篇
灾害及防治   10篇
  2023年   3篇
  2022年   14篇
  2021年   13篇
  2020年   4篇
  2019年   10篇
  2018年   18篇
  2017年   18篇
  2016年   13篇
  2015年   10篇
  2014年   21篇
  2013年   51篇
  2012年   25篇
  2011年   30篇
  2010年   31篇
  2009年   20篇
  2008年   28篇
  2007年   22篇
  2006年   23篇
  2005年   10篇
  2004年   10篇
  2003年   9篇
  2002年   7篇
  2001年   8篇
  2000年   13篇
  1999年   6篇
  1998年   4篇
  1997年   6篇
  1996年   3篇
  1995年   4篇
  1994年   2篇
  1993年   5篇
  1992年   1篇
  1991年   3篇
  1990年   2篇
  1987年   1篇
  1984年   1篇
  1976年   1篇
排序方式: 共有450条查询结果,搜索用时 31 毫秒
371.
A four-stage systematic tracking survey of 240 households was conducted from the summer of 2011 to the spring of 2012 in a Chinese city of Suzhou to determine the characteristics of household hazardous waste (HHW) generated by the city. Factor analysis and a regression model were used to study the major driving forces of HHW generation. The results indicate that the rate of HHW generation was 6.16 (0.16–31.74, 95% CI) g/person/day, which accounted for 2.23% of the household solid waste stream. The major waste categories contributing to total HHW were home cleaning products (21.33%), medicines (17.67%) and personal care products (15.19%). Packaging and containers (one-way) and products (single-use) accounted for over 80% of total HHW generation, implying a considerable potential to mitigate HHW generation by changing the packaging design and materials used by manufacturing enterprises. Strong correlations were observed between HHW generation (g/person/day) and the driving forces group of “household structure” and “consumer preferences” (among which the educational level of the household financial manager has the greatest impact). Furthermore, the HHW generation stream in Suzhou suggested the influence of another set of variables, such as local customs and culture, consumption patterns, and urban residential life-style. This study emphasizes that HHW should be categorized at its source (residential households) as an important step toward controlling the HHW hazards of Chinese cities.  相似文献   
372.
不同碳源对活性污泥反硝化能力的影响研究   总被引:2,自引:1,他引:1  
针对城镇污水处理中碳源不足影响系统脱氮能力的问题,分别以乙酸钠、葡萄糖作为外源性碳源,考察其对活性污泥反硝化脱氮能力的影响。研究结果表明:在碳源投加量分别为50,100,200 mg/L条件下,单位(g)NO-3-N去除增量所需乙酸钠/葡萄糖的投加量分别为8.24 g/49.02g、9.62g/22.57g、—/21.07g。乙酸钠可用作城镇污水脱氮除磷过程中的高效外源性碳源,但从污水处理运行经济性来看,需根据系统实际需去除NO-3-N的量,合理确定碳源投加量。  相似文献   
373.
毕海超  赵俊梅  李义  禹海清 《环境工程》2013,(Z1):336-339,496
以苯基三甲基溴化铵(PTMAB)对Na基蒙脱土(Na-MMT)进行有机改性,制备有机改性蒙脱土并研究其吸附脱硫性能,初步探索吸附脱硫机理。利用气相色谱进行脱硫效果分析。实验表明:有机改性蒙脱土脱硫效果最佳可达到33.5%(脱硫率)。通过XRD、FT-IR、DGA-TGA、XPS、TEM表征Na-MMT、PTMAB-MMT,表明有机阳离子已成功插层进入蒙脱土的硅酸盐片层。分析吸附机理,得出在最佳实验条件下(60℃,吸附时间3 h)吸附脱硫过程中占据主导地位的为物理吸附。  相似文献   
374.
Record breaking heat waves have been recorded in Adelaide, Australia in recent years and climate change would likely increase the frequency, duration and severity of heat waves. This paper describes the governance and institutional arrangements during the development of an adaptation strategy (herein referred to as heat-health policy) for heat waves in Adelaide, Australia. In-depth, semi-structured interviews were conducted between June and August 2011 among 18 stakeholders who were involved in the participatory process during the development of the heat-health policy. Informed consent was obtained and interviews were recorded, transcribed verbatim and the data analysed using framework analysis. Interview data were supplemented by data gathered through a review of documents associated with the process. The results found that the process of developing the heat-health policy was initiated by the state government and comprised of stakeholders from both the state and non-state sectors. There was a high level of leadership and political commitment demonstrated during the process, given that the different players wanted a policy to be in place before any future heat wave. A Steering Committee was established that provided coordination and oversight in addition to the Emergency Management Act within the state which provided the legislative framework during the heat-health policy development process. Although the decision-making authority was controlled by a controlled by a public institution, to a larger extent, there was collaborative decision-making by virtue of the context in which the heat-health policy was developed. An assurance mechanism established during the process was among the factors that ensured accountability during the participatory process. Overall, the development of the heat-health policy in Adelaide was largely successful, attributed to the extent of political commitment from the state government and the sound institutional and legislative framework that facilitated the process. Good governance and institutional arrangements provide the enabling environment, the structures, systems and resources that would facilitate the development of adaptation strategies such as heat-health policies.  相似文献   
375.
There is a need to formulate water environment standards (WESs) from the current water quality criteria (WQC) in China. To this end, we briefly summarize typical mechanisms applied in several countries with longer histories of developing WESs, and three limitations to formulating WESs in China were identified. After analyzing the feasibility factors including economic development, scientific support capability and environmental policies, we realized that China is still not ready for a complete change from its current nation-wide unified WES system to a local-standard-based system. Thus, we proposed a framework for transformation from WQC to WESs in China. The framework consists of three parts, including responsibilities, processes and policies. The responsibilities include research authorization, development of guidelines, and collection of information, at both national and local levels; the processes include four steps and an impact factor system to establish water quality standards; and the policies include seven specific proposals.  相似文献   
376.
在石化重点防护区布设雷电预警设备,相临预警点自动组网,实现小区域雷电临近预警,同时可预判雷电运动趋势。根据预警等级执行相应的应急预案,做到及时管控雷电可能造成重大危害的关键作业,并通过雷电运动趋势提前告知雷电运动下游企业采取必要应急措施,从而防止发生雷击引起的燃爆和人身伤亡事故,促进安全生产。  相似文献   
377.
本文主要列举了美国Dasibi1000环境空气自动监测系统中的主要监测仪器氮氧化物、二氧化硫、可吸入颗粒物等分析仪在日常运行中容易出现的一些的常见故障。由于此套仪器设备具有自检功能。可通过仪器面板提示的故障信息找到故障所在。并对其形成原因进行了系统分析和总结。同时提出了一些排除故障的方法和步骤以及避免出现这些故障所需的日常维护。  相似文献   
378.
试论复垦的概念及其与生态重建的关系   总被引:1,自引:0,他引:1  
基于国内外大量的文献资料,在剖析国外对“土地复垦”的定义、目标的理解和介绍有关国外复垦法规、复垦研究内容和历史的基础上,从复垦和生态重建的基本概念入手,深入探讨了二者内涵与关系,认为:“复垦”的研究十分重视生态原则,也一直将生态重建作为其研究的焦点。因此,“复垦”一词的实质是既恢复土地资源,又重建生态平衡,即“复垦”包括土地复垦和生态重建两方面。  相似文献   
379.
本文分析了海南岛农业土地资源利用的优势与制约因素 ,论述了农业土地资源的特点 ,指出了农业土地资源可持续利用的对策。  相似文献   
380.
苏州河市郊段底泥中CODCr和NH3-N的空间分布特征   总被引:3,自引:2,他引:3  
对苏州河截流区外河段(城郊段)东大盈河口-北新泾,按河道形态,支流与城镇分布等因素,沿程采集24个底泥柱样,测定其不同部位不同深度底泥中CODcr和NH3-N含量,分析CODcr和NH3-N在沿程和垂向上的分布特征及其成因,结果表明,底泥中污染沿程分布呈不规则波状起伏,东大盈河、蕴藻浜、盐铁塘、封浜、华漕港、新槎浦等支流口浮泥层中NH3-N含量达250mg/kg,超过背景值3部。在垂向分布上,底泥  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