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   830篇
  免费   124篇
  国内免费   105篇
安全科学   153篇
废物处理   25篇
环保管理   191篇
综合类   469篇
基础理论   112篇
污染及防治   29篇
评价与监测   20篇
社会与环境   36篇
灾害及防治   24篇
  2024年   18篇
  2023年   34篇
  2022年   41篇
  2021年   35篇
  2020年   28篇
  2019年   34篇
  2018年   26篇
  2017年   34篇
  2016年   42篇
  2015年   40篇
  2014年   63篇
  2013年   60篇
  2012年   79篇
  2011年   89篇
  2010年   55篇
  2009年   41篇
  2008年   37篇
  2007年   45篇
  2006年   39篇
  2005年   40篇
  2004年   17篇
  2003年   12篇
  2002年   17篇
  2001年   9篇
  2000年   11篇
  1999年   13篇
  1998年   7篇
  1997年   7篇
  1996年   8篇
  1995年   5篇
  1994年   9篇
  1993年   4篇
  1992年   4篇
  1991年   3篇
  1990年   5篇
  1989年   4篇
  1988年   3篇
  1987年   3篇
  1986年   3篇
  1985年   3篇
  1984年   2篇
  1983年   2篇
  1982年   5篇
  1981年   3篇
  1980年   3篇
  1978年   4篇
  1977年   2篇
  1976年   3篇
  1974年   2篇
  1972年   2篇
排序方式: 共有1059条查询结果,搜索用时 312 毫秒
791.
化工储罐爆炸产生的抛射碎片击中并破坏相邻罐体后,将引发多米诺效应。N guyen破坏概率模型认为,当罐壳受撞击后,残余壁厚小于某个临界值时就会被破坏,并假设该临界残余壁厚为定值,存在不合理之处。本文基于储罐壳体损失面积安全评价方法AP I 579,把撞击形成的复杂凹坑简化为圆锥形,分别针对圆柱储罐、球罐推导出圆锥形凹坑剩余强度系数的求解方法,并根据塑性失效理论确定了罐壳的临界剩余强度系数,由此建立了新的破坏准则。在此基础上,采用蒙特卡罗法进行模拟,建立了新的爆炸碎片对目标储罐的破坏概率模型,与N guyen模型相比,得出的破坏概率偏大,结果更为安全保守。通过对剩余强度系数与无量纲撞击深度和凹坑锥角的变化关系进行分析,证明N guyen模型中临界残余壁厚为定值的假设并不合理,而新的基于剩余强度系数计算的破坏概率更为准确合理。  相似文献   
792.
本文介绍了一种基于RFID技术的危险化学品仓储管理系统及应用方法。该系统在现有危险化学品仓储管理中引入RFID技术,可以将货物、标签、信息建立唯一的对应关系,将货物以“电子镜像”的方式实时、可靠地映射在管理系统中,彻底改变传统人工管理信息滞后、效率低下、易出差错的现状,实现危险化学品检验、入库、盘点、出库等作业环节的自动化数据采集和存储环境监控。本文也给出该系统未来的试点应用方向。  相似文献   
793.
变电站内主要危险废物为废矿物油、含矿物油废物,以及废铅酸蓄电池。结合危险废物临时贮存管理要求,分析了变电站内危险废物贮存现状及存在的环保问题。从环境保护角度提出了危险废物临时贮存设施事故油池、危废贮存间设计建议。  相似文献   
794.
第三方物流安全的现状分析及展望   总被引:1,自引:1,他引:0  
选择一个有代表性的第三方物流企业样本并结合相关资料进行安全现状研究;分析第三方物流的安全观念和安全管理人员的配备,运输和仓储两个核心环节的安全现状;采用适宜方法和资料从供应链角度进行安全管理分析。指出我国第三方物流在运输、仓储等环节的安全问题较多;从供应链角度来理解和管理物流安全,物流安全管理是发展方向,应建立健全第三方物流事故分类统计信息系统。  相似文献   
795.
The operational parameter MRT%FE, representing the mean residence time of different ages fractions of effluent within a completely mixed reactor, was evaluated and integrated with first order kinetics. The parameter was used to model Escherichia coli concentrations in a municipal wastewater reservoir managed under different operating conditions (continuous and discontinuous). The study was conducted during 2004-2005 in a reservoir receiving effluents from the activated sludge treatment plant of Caltagirone (Eastern Sicily - Italy). The analytical approach is applied to the hydraulic state variables of the system (daily stored volumes, inlet and outlet flows), and the physical-chemical (pH, temperature, EC, TSS, BOD(5), COD) and bacteriological wastewater parameters (E. coli, FC, FS). In order to evaluate the reliability of the proposed approach, predicted E. coli concentrations within the reservoir were compared with measured ones by the correlation coefficient, F-test and Sperman's index. The study included the evaluation of die-off coefficient K(T) (d(-1)), light extinction coefficient K (m(-1)) and their relationships with climatic factors. Results of the study confirm that E. coli removal is related to the fractions of fresh effluent remaining each day within the reservoir with MRT%FE of about 5-8d, significantly lower than the nominal detention time (about 27d). The E. coli die-off coefficient (K(T)) was higher during system discontinuous operations and correlated with incident solar radiation and water temperature.  相似文献   
796.
石油库储罐区池火灾事故后果模拟探讨   总被引:1,自引:0,他引:1  
石油库储罐区火灾、爆炸事故危害巨大.通过对某石油库储罐区池火灾事故后果进行预测评价,对石油库储罐区池火灾事故后果模拟方法进行了讨论和对比,为石油库安全管理、安全评价和应急救援预案编制提供有益的探索.  相似文献   
797.
便携式储油囊中网状聚氨酯泡沫材料阻燃抑爆性机理研究   总被引:1,自引:0,他引:1  
针对便携式储油囊的储油安全性,提出了在储油囊内填充网状聚氨酯泡沫材料的设想,通过对网状聚氨酯泡沫材料阻燃抑爆性的机理研究,得出网状聚氨酯泡沫材料在储油领域中具有广阔应用前景的结论.  相似文献   
798.
Geochemistry plays an important role when assessing the impact of CO2 storage. Due to the potential corrosive character of CO2, it might affect the chemical and physical properties of the wells, the reservoir and its surroundings and increase the environmental and financial risk of CO2 storage projects in deep geological structures. An overview of geochemical and solute transport modelling for CO2 storage purposes is given, its data requirements and gaps are highlighted, and its progress over the last 10 years is discussed. Four different application domains are identified: long-term integrity modelling, injectivity modelling, well integrity modelling and experimental modelling and their current state of the art is discussed. One of the major gaps remaining is the lack of basic thermodynamical and kinetic data at relevant temperature and pressure conditions for each of these four application domains. Real challenges are the coupled solute transport and geomechanical modelling, the modelling of impurities in the CO2 stream and pore-scale modelling applications.  相似文献   
799.
Storage of large amounts of carbon dioxide (CO2) in deep geologic formations for greenhouse-gas mitigation is gaining momentum and moving from its conceptual and testing stages towards widespread application. In this work we explore various optimization strategies for characterizing surface leakage (seepage) using near-surface measurement approaches such as accumulation chambers and eddy covariance towers. Seepage characterization objectives and limitations need to be defined carefully from the outset especially in light of large natural background variations that can mask seepage. The cost and sensitivity of seepage detection are related to four critical length scales pertaining to the size of the: (1) region that needs to be monitored; (2) footprint of the measurement approach, and (3) main seepage zone; (4) region in which concentrations or fluxes are influenced by seepage. Seepage characterization objectives may include one or all of the tasks of detecting, locating, and quantifying seepage. Each of these tasks has its own optimal strategy. Detecting and locating seepage in a region in which there is no expected or preferred location for seepage nor existing evidence for seepage requires monitoring on a fixed grid, e.g., using eddy covariance towers. The fixed-grid approaches needed to detect seepage are expected to require large numbers of eddy covariance towers for large-scale geologic CO2 storage. Once seepage has been detected and roughly located, seepage zones and features can be optimally pinpointed through a dynamic search strategy, e.g., employing accumulation chambers and/or soil-gas monitoring. Quantification of seepage rates can be done through measurements on a localized fixed grid once the seepage is pinpointed. Background measurements are essential for seepage detection in natural ecosystems. Artificial neural networks are considered as regression models useful for distinguishing natural system behavior from anomalous behavior suggestive of CO2 seepage without need for detailed understanding of natural system processes. Because of the local extrema in CO2 fluxes and concentrations in natural systems, simple steepest-descent algorithms are not effective and evolutionary computation algorithms are proposed as a paradigm for dynamic monitoring networks to pinpoint CO2 seepage areas.  相似文献   
800.
碳汇价值的形成和评价   总被引:6,自引:2,他引:6  
在碳减排形势下,如何评价固碳收益价值具有重要的理论与实践意义。论文首先从全球气候变化与碳排放的关联、碳排放与现有经济体系的关联、碳排放空间成为稀缺资源三个方面论证了碳汇效用价值形成的现实基础。然后评述了碳汇价值的构成与度量方法,指出了碳固定与碳蓄积价值的内涵差异。继而总结了碳汇价值的实现机制,认为可以通过碳交易、碳税和固碳项目实际成本3种机制实现碳价格,并在此基础上通过补偿实现碳汇价值。  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