全文获取类型
收费全文 | 3814篇 |
免费 | 147篇 |
国内免费 | 236篇 |
专业分类
安全科学 | 1399篇 |
废物处理 | 96篇 |
环保管理 | 1092篇 |
综合类 | 884篇 |
基础理论 | 198篇 |
污染及防治 | 129篇 |
评价与监测 | 127篇 |
社会与环境 | 155篇 |
灾害及防治 | 117篇 |
出版年
2024年 | 4篇 |
2023年 | 33篇 |
2022年 | 35篇 |
2021年 | 90篇 |
2020年 | 109篇 |
2019年 | 54篇 |
2018年 | 36篇 |
2017年 | 52篇 |
2016年 | 82篇 |
2015年 | 54篇 |
2014年 | 99篇 |
2013年 | 120篇 |
2012年 | 136篇 |
2011年 | 133篇 |
2010年 | 108篇 |
2009年 | 104篇 |
2008年 | 133篇 |
2007年 | 121篇 |
2006年 | 123篇 |
2005年 | 159篇 |
2004年 | 215篇 |
2003年 | 199篇 |
2002年 | 258篇 |
2001年 | 209篇 |
2000年 | 264篇 |
1999年 | 228篇 |
1998年 | 190篇 |
1997年 | 143篇 |
1996年 | 251篇 |
1995年 | 124篇 |
1994年 | 43篇 |
1993年 | 39篇 |
1992年 | 31篇 |
1991年 | 19篇 |
1990年 | 9篇 |
1989年 | 14篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 29篇 |
1984年 | 46篇 |
1983年 | 39篇 |
1982年 | 8篇 |
1981年 | 3篇 |
1980年 | 8篇 |
1978年 | 8篇 |
1974年 | 1篇 |
1972年 | 2篇 |
1971年 | 15篇 |
1967年 | 1篇 |
排序方式: 共有4197条查询结果,搜索用时 250 毫秒
711.
712.
为了探究矿井通风网络复杂度与风机控制力的关系,提出分支关联度、最小距离、通风网络复杂度和风机控制力的概念。利用vCad2.0进行数字实验,对网络复杂度与风机控制力的关系进行定量研究。结果表明:随着网络复杂度的增加,矿井通风系统的有效风量率减小,且认为该值减小到60%时,视为风机控制力的极限,此时网络拓扑结构为风机所能控制的最大网络复杂度。地面集中供风时,同时工作的中段数量存在上限,最大值为7。将结论用于某有色金属矿进行实证研究,找出该矿深部中段通风困难的原因,为矿井进一步整改提供理论依据。 相似文献
713.
目前中国由于建设项目繁多,在役塔机数量急剧上升,若不加强监管和提升控制手段,安全事故隐患会随着塔机数量的增加剧增。本文对塔机安全事故发生的主要原因进行了分析,介绍了塔机安全监控和评估系统的技术现状,对一种新研发的塔机安全监控与评估系统做了简要阐述。同时通过对试点工程的应用,指出了本塔机安全监控和评估系统的优势,为塔机的安全作业监控提供了一个新的技术方法和手段。 相似文献
714.
本文针对特种设备检验的社会化问题进行了探讨,着重对社会检验机构的独立性、公正性和公益服务性问题进行了分析。就如何更好的保证特种设备安全的情况下引进民间资本参与检验以及如何确保检验机构的公正性和公益服务性提出了自己的见解。 相似文献
715.
周伯虎 《中国特种设备安全》2014,(6):50-51
文章根据某大型企业电动葫芦的使用现状,从设备运行、安全操作、使用成本、安全检测及相关法律法规等角度分析,论证了延长电动葫芦检验周期的可行性和必要性,提出了节约检验机构检测资源、降低企业安全监管成本,提高企业安全管理绩效的新观点。 相似文献
716.
717.
Common cause failure describes a condition where several components share the same source of failure that causes them to fail or become unavailable simultaneously. The objective of this paper is to present an improved approach to common cause failure modelling within reliability analyses. The currently used methods allow one component to share common characteristics with only one group of components, which may be affected by the same source of failure. Therefore, an improved method was developed, where components can be assigned to several groups of components that are susceptible to faulty operation with respect to their similar characteristics. A mathematical derivation of the method is presented and the theory is applied to smaller theoretical samples and to a simplified real example. The results show that the new method enables a more detailed reliability analysis. The results prove that consideration of common cause failures using the improved method may decrease the system reliability compared to traditional common cause failure consideration. The system reliability decreases more, if the redundant components have more similarities and are therefore assigned to several common cause failure groups. 相似文献
718.
The research presented in this paper was carried out in four process industry plants in the Netherlands, to identify factors that have the potential to increase safety and reliability while maintaining or improving job satisfaction. The data used were gathered as part of broader trajectories in these firms, aiming at the simultaneous improvement of productivity and safety, while maintaining or improving worker satisfaction. The results show that participative leadership is crucial for combining an increase in safety and reliability with job satisfaction. Participative leadership has a positive effect on job satisfaction and through proper maintenance also on the prevention and absence of disturbances and on the reliability of the production process. The results of this research show the importance of participative leadership for safety, reliability and worker satisfaction, especially during organizational change. Other important factors are operator competences, teamwork, proper handling of variance and disturbances, and proper maintenance. It also confirms that apart from technological factors associated with proper maintenance, people and team related factors are important for increasing safety and reliability in the process industry, especially for being prepared for disturbances and to be able to cope adequately with them. 相似文献
719.
In this study, an integrated “Health, Safety, and Environment (HSE)” and maintenance systems are presented. Multivariate analysis is used for continuous performance assessment and improvement of these systems. The two subjects of “Maintenance System” and “HSE” have been individually investigated several times in different studies. However, few studies have been done to integrate these two systems and provide an integrated system for their implementation. This study evaluates current maintenance and HSE systems of a Gas Transmission Unit by Data Envelopment Analysis (DEA) and Principal Component Analysis (PCA). Moreover, decision making units (DMUs) are examined and ranked. Employees are considered as DMUs. This is done through investigating and measuring their efficiencies and identifying the inefficient and less-efficient units. Since an increase in the number of inputs does not lead to an increase in the number of outputs with the same scale, an output-oriented DEA with a Variable Returns to Scale (VRS) is used. The Fuzzy DEA (FDEA) is also used in this research to decrease uncertainty existing in qualitative indicators and human error. Finally, suggestions are given to improve those DMUs. The managers and employees of the gas transmission unit constitute the statistical population of the study. To achieve the objectives of this study, standard questionnaires with respect to HSE and Maintenance system are completed by operators. The proposed approach would help policy makers and top managers of Gas Transmission Company to have a more comprehensive and thorough understanding the working conditions with respect to the maintenance and HSE features. 相似文献
720.
The current risk management approach for the Norwegian offshore petroleum industry came into effect in 2001 and has been stable with minor changes for 15 years. Relatively few new installations were slated for development until quite recently, and several new projects have been started in the last few years. The paper considers the risk management approach in the pre-FEED phase and builds on two case studies selected from the most recent cases. These case studies have been evaluated with respect to how uncertainties are considered in the early phase, based on the submission of the Plan for Development and Operation, their evaluations by authorities and the supporting documents. Both case studies involve new concepts for which there is no experience from similar environments and/or water depths. In spite of what could have been expected, the case studies conclude that uncertainties have not been in focus at all during concept development. This appears to be definitely the case for the licensees, but also to be the case for the authorities. Some suggestions are presented for what could have been considered by the licensees and authorities. 相似文献