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   1421篇
  免费   163篇
  国内免费   214篇
安全科学   434篇
废物处理   36篇
环保管理   306篇
综合类   666篇
基础理论   110篇
污染及防治   83篇
评价与监测   70篇
社会与环境   55篇
灾害及防治   38篇
  2024年   4篇
  2023年   40篇
  2022年   33篇
  2021年   81篇
  2020年   80篇
  2019年   56篇
  2018年   29篇
  2017年   66篇
  2016年   91篇
  2015年   100篇
  2014年   96篇
  2013年   111篇
  2012年   115篇
  2011年   124篇
  2010年   69篇
  2009年   81篇
  2008年   49篇
  2007年   73篇
  2006年   79篇
  2005年   72篇
  2004年   33篇
  2003年   49篇
  2002年   36篇
  2001年   37篇
  2000年   18篇
  1999年   21篇
  1998年   14篇
  1997年   10篇
  1996年   20篇
  1995年   8篇
  1994年   10篇
  1993年   3篇
  1992年   11篇
  1989年   2篇
  1988年   7篇
  1987年   4篇
  1986年   2篇
  1982年   4篇
  1981年   4篇
  1980年   3篇
  1979年   3篇
  1978年   6篇
  1977年   4篇
  1976年   4篇
  1975年   2篇
  1974年   2篇
  1973年   5篇
  1972年   6篇
  1971年   11篇
  1970年   4篇
排序方式: 共有1798条查询结果,搜索用时 156 毫秒
291.

Introduction

This study examined the impact of the British Petroleum (BP) Baker Panel Report, reviewing the March 2005 BP-Texas City explosion, on the field of process safety.

Method

Three hundred eighty-four subscribers of a process safety listserv responded to a survey two years after the BP Baker Report was published.

Results

Results revealed respondents in the field of process safety are familiar with the BP Baker Report, feel it is important to the future safety of chemical processing, and believe that the findings are generalizable to other plants beyond BP-Texas City. Respondents indicated that few organizations have administered the publicly available BP Process Safety Culture Survey. Our results also showed that perceptions of contractors varied depending on whether respondents were part of processing organizations (internal perspective) or government or consulting agencies (external perspective).

Conclusions

This research provides some insight into the beliefs of chemical processing personnel regarding the transportability and generalizability of lessons learned from one organization to another.

Impact on Industry

This study has implications for both organizational scientists and engineers in that it reveals perceptions about the primary mechanism used to share lessons learned within one industry about one major catastrophe (i.e., investigation reports). This study provides preliminary information about the perceived impact of a report such as this one.  相似文献   
292.
A major chemical company established a formal incident investigation and reporting system several years ago. The original system focused heavily on worker-related injuries, illnesses, and near-misses and was used primarily to track statistics reportable to the Occupational Safety and Health Administration (OSHA). This Occupational Injury and Illness (OII) approach has been recognized to be an ineffective tool for measuring, predicting, and preventing process safety incidents. The Center for Chemical Process Safety (CCPS) recently published guidelines on how to establish safety metrics for the measurement and reduction of process safety incidents. The process safety metrics approach relies upon leading and lagging metrics to improve organization process safety. This paper is a case study of the analysis of one organization’s incident database, which represents approximately five years of data from over a dozen facilities. The aim of this investigation was to extract useful process safety metrics from the incident investigation and reporting system, which would be pertinent to the types of process units and process functions at these facilities. This paper will discuss the approach taken to extract process incident information from an OII-based database and present the difficulties of performing an analysis on such a database. This paper provides guidance on how to migrate an existing OII-based reporting system to a program that includes process safety metrics in accordance with industry best practices.  相似文献   
293.
294.
现场测定煤层透气性系数计算方法的优化研究   总被引:1,自引:1,他引:0  
为深入分析瓦斯在煤层内流动的阻力特性,根据煤层瓦斯径向不稳定流动理论,探讨煤层透气性系数的本质内涵及物理意义,指出其现场应用过程中存在的不足。基于无因次流量准数Y和时间准数F0之间的关系,对系数a,b值进行修正,提出透气性系数公式的优化计算方法。给出对比2种计算方法的现场应用实例。结果表明,优化方法的计算过程不必采用试算,计算结果的相对误差小于2%,可满足现场应用的实际要求。依据现场测定值可计算出AB的区间范围,据此可直接选择相应公式计算煤层透气性系数。  相似文献   
295.
在国家公园体制改革背景下,“建立以国家公园为主体的自然保护地体系”对我国自然保护地优化整合提出了系列要求。福建省正在进行自然保护地优化整合,泰宁县是全省自然保护地交叉重叠最复杂的区域之一。以泰宁县为例,基于实地调研和专家意见,构建了三个优化整合的情景规划方案:(1)维持现状,不整合;(2)以泰宁国家地质公园为主体的整合;(3)以泰宁国家公园为主体的整合。基于对方案的成本效益比较,结果显示:方案3的存在和使用价值最高,成本持中;方案1的价值保护持中,成本最低;方案2价值最低,成本最高。研究为福建省县市尺度开展自然保护地优化整合提供思路和技术支持,亦为国内外自然保护地的边界优化提供参考。  相似文献   
296.
随着全球化的气候问题日益严重和“低碳革命”的兴起,低碳物流已成为现代物流业发展的必然趋势.结合国内外学者对低碳物流的研究文献,从物流过程的碳排放测量、物流环节的低碳控制、物流系统的低碳设计方面系统回顾了国内外学者在低碳物流领域的研究成果,梳理了低碳物流的发展历程,并对现有的研究成果进行了分析,以期为相关学者的后续研究提供思路.  相似文献   
297.
为了解决煤矿掘进面风筒出风口参数不能动态变化,而传统风幕全断面控尘效果不理想引起的粉尘浓度高等问题,通过分析风幕和出风口参数对粉尘分布规律的影响,以此得到合理的出风口风流与风幕综合调控方案,降低粉尘浓度。以陕西神木柠条塔煤矿N1212巷道为研究对象,利用Fluent软件建立出风口风流与风幕综合调控的粉尘场有限元模型,设计出风口风流及风幕综合调控响应曲面实验,得到最佳综合调控方案为:风幕射流出口宽度为0.16 m,风幕射流出口速度为6 m/s,出风口口径为0.9 m,出风口右偏角度为3°。搭建相似模拟实验平台来验证最佳综合调控方案,研究结果表明:调控后回风侧行人呼吸处和司机位置处粉尘平均浓度分别降低89%和81%,有效改善掘进面作业环境。  相似文献   
298.
通过对湍球塔 (TCA)内三维流场的数值计算 ,找到了较佳的结构参数 ,在此基础上进行的试验表明 ,计算结果与试验结果相吻合。计算程序可为 TCA的设计及保证其长期安全经济运行提供理论依据。  相似文献   
299.
ABSTRACT: A spatial linear program that strategically arranges and schedules forest treatments so as to meet peak stormflow objectives is formulated and demonstrated. The approach uses simulated spatial routing of stormflows nested as short‐term time schedules within longer‐term forest planning time periods. A simple case example is used to demonstrate the formulation and explore its spatial sensitivity.  相似文献   
300.
ABSTRACT: Review of recent literature indicates an emergence in the use of combinatorial methods such as simulated annealing in ground water management during the past nine to ten years. While previous studies demonstrated the feasibility of using these methods, a general finding was that computational processing requirements were inordinately high relative to gradient‐based methods. An enhanced annealing algorithm was developed and used to demonstrate the potential for greatly improving the computational efficiency of simulated annealing as an optimization method for ground water management applications. The algorithm incorporates “directional search” and “memory” capabilities. Selecting search directions based on better understanding of the current neighborhood of the configuration space was shown to improve algorithm performance. Also, “memory” concepts derived from the Tabu Search Method show particular promise for improving the rate and quality of convergence. Performance of the enhanced annealing method was evaluated and the resultant management method was demonstrated using an example from the literature.  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