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   429篇
  免费   35篇
  国内免费   59篇
安全科学   77篇
废物处理   9篇
环保管理   86篇
综合类   239篇
基础理论   28篇
污染及防治   26篇
评价与监测   36篇
社会与环境   11篇
灾害及防治   11篇
  2024年   2篇
  2023年   12篇
  2022年   11篇
  2021年   17篇
  2020年   14篇
  2019年   8篇
  2018年   9篇
  2017年   10篇
  2016年   16篇
  2015年   13篇
  2014年   20篇
  2013年   25篇
  2012年   30篇
  2011年   42篇
  2010年   32篇
  2009年   29篇
  2008年   21篇
  2007年   28篇
  2006年   27篇
  2005年   28篇
  2004年   25篇
  2003年   25篇
  2002年   18篇
  2001年   12篇
  2000年   10篇
  1999年   5篇
  1998年   6篇
  1997年   9篇
  1996年   6篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1986年   1篇
  1983年   3篇
  1979年   1篇
  1977年   1篇
排序方式: 共有523条查询结果,搜索用时 31 毫秒
391.
本文介绍了石灰湿式洗涤法脱硫的改进思路 ,通过采用三级串联喷淋、低液气比和投加防垢剂等办法 ,成功解决了设备管道结垢问题。实践表明 ,该法具有工艺简单、投资省、操作简便、运行费用低、脱硫率高等特点。  相似文献   
392.
室内空气监测中的存在问题及对策   总被引:2,自引:0,他引:2  
张盛华 《环境技术》2005,23(1):13-14,24
阐述了在室内环境空气监测中关于监测标准的选择和室内空气监测要素的确定,分析了在执行过程标准中和规范监测市场中存在的问题,并就如何改进提出了建议,其目的是提高室内监测服务的质量,确保监测结果准确可靠。  相似文献   
393.
在简要回顾土壤环境质量研究现状的基础上,分析了土壤环境质量改进的必要性,指出目前缺乏系统性的土壤环境质量管理方法论。借助六西格玛管理的DMAIC模式,探讨了其在土壤环境质量改进中的应用,提出该方法可以为土壤环境质量持续改进提供科学方法论和有效手段。  相似文献   
394.
系统梳理固体废物管理政策的变迁逻辑,研究固体废物管理政策的聚焦内容和发展趋向,有助于明晰固体废物管理政策完善路径。研究立足于已颁布的固体废物管理政策,运用统计方法分析固体废物管理政策的文本结构和内容,找出中国固体废物管理政策变迁的内在逻辑;紧密结合当前“无废城市”建设的政策需求,提出政策优化完善路径。研究发现:固体废物管理政策文本类型多元、效力级别多样,政策框架体系逐步优化完善;固体废物管理政策热点具有鲜明的时代发展烙印和动态演变特征,政策涉及的领域越来越广,政策内容更具针对性和全面性,政策执行更具指向性和可操作性;无害化、减量化、资源化,污染防治、监督管理、二次污染、回收利用、循环经济等是政策关注焦点;政府从宏观层面强化顶层设计,以政策引导规范为主,注重政策协同、技术支撑、治理水平提升等助推无害化、减量化、资源化目标实现;固体废物管理政策实施的工具手段多元化、要素支撑多样化,固体废物管理的技术支撑关注度逐步提升、管理模式与治理路径已进入适应性转型。立足现实需要,固体废物管理的市场化政策与激励机制不足,适用性技术关注度不高,综合管理水平和治理能力亟待提升。结合国外“无废城市”建设的理论研究、实践行动和政策举措,从固体废物生命周期管理政策、技术范式政策、主体协同政策、引导激励政策及法律法规政策等方面提出中国“无废城市”建设的政策完善路径方向。  相似文献   
395.
The Process Safety Management (PSM) systems at the operating facilities in the Oil & Gas and in Chemical manufacturing industries have matured over the years and have become, at most facilities, very robust and sophisticated. These programs are administrated by Process Safety (PS) teams at both the corporate business units and plant levels and have been effective in reducing the number and severity of PS events across the industries over the past 25 years or so. Incidents however are occurring at a regular interval and in recent times several noteworthy PS events have occurred in the United States which have brought into question the effectiveness of the PSM programs at play. These facilities have been applying their PSM programs with the expectation that the number and severity of PS events would decrease over time. The expected result has not been realized, especially in context to those facilities that have undergone the recent incidents. Current paper reviews a few publicly available PS performance reports of Oil & Gas and Chemical manufacturing industries. The authors identified a few factors at play that have led to these PS events based on their experience, literature review, and incident investigation reports. Most of the factors are intertwined with multiple PSM elements and it requires a holistic approach to address them. Each of the factors is described and the path forward is proposed to improve the effectiveness of PSM programs.  相似文献   
396.
鉴于传统的城市交叉口交通冲突整体评价方法不能深入地分析和解决交叉口内部的交通安全问题,依据流量和相位时长关系确定分类交通冲突评价系数,计算出不同相位阶段中不同交通冲突类型(机-机、机-非、机-人)的交通冲突率和分类综合交通冲突率,从而比较和诊断交叉口内部危险性高的交通冲突类型及所在相位,并应用VISSIM仿真软件评估相应交通安全改善措施对路口交通效率的影响。以北京市光彩北路路口为对象进行实验分析,其结果表明,分类交通冲突技术与微观交通仿真分析的充分结合,可提高城市交叉口安全诊断的准确性及相应改善措施的有效性。  相似文献   
397.
This article evaluates the implementation of Proposition O, a stormwater cleanup measure, in Los Angeles, California. The measure was intended to create new funding to help the city comply with the Total Maximum Daily Load requirements under the federal Clean Water Act. Funding water quality objectives through a bond measure was necessary because the city had insufficient revenues to deploy new projects in its budget. The bond initiative required a supermajority vote (two-thirds of the voters), hence the public had to be convinced that such funding both was necessary and would be effective. The bond act language included project solicitation from the public, as well as multiple benefit objectives. Accordingly, nonprofit organizations mobilized to present projects that included creating new parks, using schoolyards for flood control and groundwater recharge, and replacing parking lots with permeable surfaces, among others. Yet few, if any, of these projects were retained for funding, as the city itself also had a list of priorities and higher technical expertise in justifying them as delivering water quality improvements. Our case study of the implementation of Proposition O points to the potentially different priorities for the renovation of urban infrastructure that are held by nonprofit organizations and city agencies and the importance of structuring public processes clearly so that there are no misimpressions about funding and implementation responsibilities that can lead to disillusionment with government, especially under conditions of fiscal constraints.  相似文献   
398.

Introduction

This article summarizes the main findings from a study designed to examine the legal process in Canada as it applies to alcohol-impaired driving from the point of view of Crown prosecutors and defense counsel, and to identify evidentiary or procedural factors that may impact the legal process, the rights of the accused, and interactions of all parts in the legal process.

Method

The data in this study were collected by means of a survey that was mailed out to the population of Crown prosecutors and defense counsel in Canada. In total, 765 prosecutors and 270 defense lawyers or an estimated 33% of all Canadian prosecutors and 15% of defense lawyers completed and returned the questionnaire. The "systems improvement" paradigm was used to interpret the findings and draw conclusions. Such an approach acknowledges the importance of the context in which countermeasures are implemented and delivered and the structures or entities used to deliver countermeasures to a designated target group.

Results

Results on type of charges and breath alcohol concentration, caseload, case outcomes, case preparation time, conviction rate at trial and overall conviction rate, reasons for acquittals and time to resolve cases are described.

Discussion

The findings from this national survey suggest that there are important challenges within the criminal justice system that impede the effective and efficient processing of impaired driving cases. Some of these challenges occur as a function of practices and policies, while others occur as a function of legislation.

Impact on industry

This study illustrates that a "system improvements" approach that acknowledges the importance of all elements of the criminal justice system and the interaction between those elements, can be beneficial in overcoming the alcohol-impaired driving problem.  相似文献   
399.
何洋  陈戈  陈智寅 《四川环境》2021,(1):143-150
以四川省某高速公路沿线的居民噪声投诉案件为例,开展了敏感点声环境质量现状及既有声屏障措施效果调查分析,并采用文献调研及Cadna/A软件建模计算的方法,分别从噪声源、噪声传播途径、敏感建筑物三个层次进行了敏感点降噪措施改善研究,研究结果可为高速公路营运单位解决实际噪声扰民问题提供技术支撑,研究过程及方法可供类似项目参考...  相似文献   
400.
改进水环境质量评价方法对于提高水环境管理水平具有重要意义。根据传统灰色关联分析原理,采用"中心化"的灰色关联无量纲化处理方法,对丹江口流域2012年河流中11个典型断面水体污染因子进行评价。结果表明,参评的11个断面中有9个符合地表水Ⅱ类水质标准,2个断面符合地表水Ⅳ类水质标准,整体水质满足国家南水北调水源地水质标准要求,改进的灰色关联分析方法在评价水质时较为科学、合理。  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