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深部大跨度硐室在高应力下常出现明显的围岩变形破坏,严重的会影响矿井的正常生产甚至引发事故。以新庄煤矿机头硐室受围压破坏变形为工程背景,分析机头硐室巷变形破坏的地质因素,提出采用顶部卸压法进行硐室维护的方案,并模拟卸压前后围岩应力及变形的变化。数值模拟结果表明顶部卸压后,硐室围岩应力重新分布,围岩应力下降和向深部转移;硐室顶底板围岩铅垂应力及两帮水平应力均减小,顶板围岩铅垂应力平均减少61.5%,底板浅部0-2 m区间内围岩铅垂应力接近0,水平应力平均减小75.4%。从模拟结果看,顶部卸压实施后有利于机头硐室的长期稳定。 相似文献
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广州市生态风险重点及其防范策略 总被引:5,自引:0,他引:5
为了构建更适宜居住生活、更适宜创业发展的山水田园型生态城市,为实现城市可持续发展的总目标,广州市必须系统而有重点地防范生态风险,解决制约广州城市发展的重点和潜在的战略生态问题,保障城市生态安全。本文着重探讨了广州城市发展中的台风、暴雨、洪涝、临海重工业的发展布局与近岸海域生态系统的保护、饮用水保障与水环境质量、机动车尾气污染与大气环境质量等重点生态环境问题及其防范策略。 相似文献
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童建生 《中国安全生产科学技术》2007,3(4):103-106
某核电站(二期)工程存储有大量的炸药用以工程建设的负挖炸石、提供施工用的碎石。为保证炸药仓库的安全,对该仓库的监控系统进行了技术改造。改造后的安防系统是将计算机网络技术、现代通信技术、现代控制技术、视频显示技术、电子探测技术、现代软件工程、图像处理技术等有机结合,集信息、通信、控制、指挥为一体,实现信息和资源共享,便于统一指挥和调度,形成一个高效、智能、立体的炸药仓库安防管理系统。 相似文献
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企业参与污染物排放标准的制定是提高标准实效性的手段,问题在于怎样的法律设置才能保障企业参与的权利同时规制企业的参与行为。文章首先论证得出法律保障企业参与的必要性,即通过立法保障企业的参与符合国内外参与型行政理论;具有提高排放标准的制定效率、减少企业参与负面影响的现实必要性;同时有助于将标准行政主管部门与企业间的利益权衡前置,增强标准制定的针对性和可操作性。文章同时分析了实现企业有效参与对相关立法的应然要求及我国现行法律规制不同程度的缺失;企业参与阶段、征求意见的执行、排放标准制定过程的监督机制等方面存在的问题,并最终提出以完善标准化法及相关管理办法为途径,充分保障企业的参与权利、程序性规制其参与行为、明确各参与主体的法律责任、完善司法救济和配套制度等立法建议。 相似文献
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The analysis of the isotopic composition of nuclear or non-nuclear solid materials is performed in a variety of fields, e.g., for quality assurance in the production of nuclear fuels, as signatures in forensics, nuclear safeguards, and non-proliferation control, in material characterization, geology, and archeology. We have investigated the capability of laser ablation (New Wave Research, 213 nm) coupled to time-of-flight (TOF) ICP-MS (GBC OptiMass 8000) as a rapid analytical protocol for multi-isotope screening of nuclear and non-nuclear solid samples. This includes natural and non-natural isotopic compositions for elements including Cu, Zr, Mo, Cd, In, Ba, Ta, W, Re, Pt, Pb, and U, in pure metals, alloys, and glasses. Without correcting for mass bias (mass fractionation), an overall precision and accuracy of about 4% (1σ) can be achieved by minimizing the deposited laser power and thus fractionation (mass removal based on thermal properties). The precision and accuracy in combination with literally no or minimized sample preparation enables a rapid isotope screening of solid samples that is of particular interest to support nuclear forensic and safeguard analysis. 相似文献
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流域水资源安全性及其保障措施 总被引:2,自引:3,他引:2
针对人们对流域水资源安全的内涵理解不深,以及目前我国存在许多影响流域水资源安全性的问题,如过度开发及生态退化、水资源短缺而浪费严重与使用效率低、产业结构和布局欠佳、水生态环境治理滞后、管理体制及其创新不足、水域污染日益加剧等问题,笔者从广义和狭义的角度,系统阐述流域水资源安全的内涵;提出建立流域水资源安全供给与需求保障体系、“市场-政府-社会”三维一体的流域水资源管理保障机制以及流域水资源安全技术保障体系,为流域水资源安全保障提供了技术支持和科学依据。 相似文献
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Of the numerous inherent safety assessment tools, a dynamic metric capable of investigating and incorporating the temporal risk evolution when conducting Inherently Safer Modifications (ISMs) is yet to be established. To this end, this work developed a Dynamic Inherent Safety Metric (DISM) and validated its functionality and viability through a case study. Firstly, the Information-Flow-based Accident-causing Model (IFAM) was adapted to construct the topology of Bayesian Networks (BN). Then, Bayesian deductive reasoning was executed to do crucial risk identification by ranking posterior probabilities. Finally, risk-based ISMs were performed to address the relatively contributing risk factors. The case study results show that the fire and explosion risk decreased by approximately a third after implementing ISMs, thus demonstrating that the modified processing scenario could be inherently safer than the original processing scenario. The newly developed inherent safety metric (i.e., DISM) can assist in temporal risk identification and assessment, and it is expected to function as a novel assessment tool for measuring and comparing the inherent safeness before and after implementing ISMs with simultaneous considerations on the time-varying risk factors. 相似文献
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介绍了生态安全产生的历史背景?通过分析生态安全的定义、内涵及生态安全的研究意义,引申出生态安全的特点,提出保障生态安全的若干措施。 相似文献