某建筑结构火灾后的加固处理

对某建筑结构火灾中的受损情况进行了现场调查,并对火灾后的结构性能进行了检测。通过分析检测结果,综合评定了结构的受损情况,针对受损伤较重的结构制定了具体的加固维修方案。采用外包钢板法加固受损梁、柱结构,以现浇楼面板置换受损的空心板,加固后的结构完全能满足使用要求。此经验可为类似的建筑结构加固处理提供参考。     

Health risks of residential wood heat

The resurgence in the use of wood in the United States for residential heating has been accompanied by a dramatic increase in deaths and injuries from residential fires. Toxic materials present in woodsmoke also appear to present a significant public health hazard. As a result of these factors, production of residential wood heat can be up to two orders of magnitude more hazardous than generation of an equivalent amount of electric energy at a coal-fired power plant. Proper care in installation and operation of wood stoves, as well as technological innovations that control wood-stove emissions, can greatly reduce the health and safety hazards of residential heating with wood.     

集中排烟公路隧道入口段火灾下诱导风速研究

为研究集中排烟模式下公路隧道入口段发生火灾时的合理诱导风速,以某公路隧道为背景,运用火灾动力学模拟软件FDS对隧道人口段火灾时不同坡度、不同诱导风速的16组火灾工况进行模拟研究,通过对各工况下隧道内的温度场分布及烟气控制效果模拟结果的分析,得到了各工况下的合理诱导风速,研究结果可为公路隧道集中排烟系统关键设计参数提供参考.     

不同侧压力系数下圆形巷道变形破裂规律分析

为研究侧压力系数对巷道周边岩体稳定性的影响,以一条深埋圆形巷道工程为背景,采用离散颗粒元软件PFC3D分析了5种侧压力系数下巷道周边岩体的应力差、位移、破裂分布模式和微裂纹数等,得到了圆形巷道周边岩体应力、变形和破裂随侧压力系数的变化规律。结果表明,1)随侧压力系数增大,巷道顶底部浅部岩体主应力差先增大后减小,深部岩体主应力差逐渐增大;而巷道两帮浅部岩体主应力差变化较小,深部岩体主应力差先减小后增大。这表明在相同埋深情况下,高侧压力系数不一定会对帮部岩体造成更大的破坏,但更容易使顶板产生高剪应力,不利于顶板岩体的稳定。2)侧压力系数越大,巷道顶板岩体竖向位移就越小,且其由拱顶往外平滑递减的规律性也越不明显,而帮部岩体水平位移变化规律与顶板岩体相反。3)巷道顶底部围岩在侧压力系数较大的情况下较易发生破裂,并随侧压力系数增大,其破裂范围越来越大;巷道两帮岩体则在不同侧压力系数下均会发生破裂,且其破裂范围随侧压力系数增大而略减小。4)不同侧压力系数下,巷道岩体总裂纹数都随开挖时间呈指数增长;且当巷道开挖完成后,岩体总裂纹数与侧压力系数呈抛物线关系。     

浅谈如何提高木材采伐作业的本质安全

阐述了木材采伐作业的危险性,分析了木材采伐作业的危险因素,提出了提高采伐作业的本质安全的对策措施.     

Forest Stand Dynamics and Livestock Grazing in Historical Context

Abstract:  Livestock grazing has been implicated as a cause of the unhealthy condition of ponderosa pine forest stands in the western United States. An evaluation of livestock grazing impacts on natural resources requires an understanding of the context in which grazing occurred. Context should include timing of grazing, duration of grazing, intensity of grazing, and species of grazing animal. Historical context, when and under what circumstances grazing occurred, is also an important consideration. Many of the dense ponderosa pine forests and less-than-desirable forest health conditions of today originated in the early 1900s. Contributing to that condition was a convergence of fire, climate, and grazing factors that were unique to that time. During that time period, substantially fewer low-intensity ground fires (those that thinned dense stands of younger trees) were the result of reduced fine fuels (grazing), a substantial reduction in fires initiated by Native Americans, and effective fire-suppression programs. Especially favorable climate years for tree reproduction occurred during the early 1900s. Exceptionally heavy, unregulated, unmanaged grazing by very large numbers of horses, cattle, and sheep during the late nineteenth and early twentieth centuries occurred in most of the U.S. West and beginning earlier in portions of the Southwest. Today, livestock numbers on public lands are substantially lower than they were during this time and grazing is generally managed. Grazing then and grazing now are not the same.     

火灾、爆炸危险指数评价法在汽车加油站的应用

本文提出了火灾、爆炸危险指数评价法在汽车加油站应用时的一些系数的选取应用的几点意见 ,以期应用该评价法时更符合实际情况 ,更准确。并用实例加以说明     

袋式除尘器和静电除尘器在电厂除尘系统中运用的性能对比分析

针对目前火电厂除尘系统应用现状和当前环保要求,通过对袋式除尘器和静电除尘器在火电厂燃煤锅炉除尘系统中的应用,对袋式除尘器和静电除尘器在技术性能上的差异作了简单的对比分析,以指导除尘器在目前火电厂燃煤锅炉除尘系统中的具体应用。     

安全文化产业发育研究

通过问卷调查和资料研究,分析了中国安全文化建设与安全文化产业发育的相互关系,研究了安全文化建设与安全文化产业发育两者之间影响和关系,指出二者共同发展的必要性和重要性,以及影响我国安全文化产业发展的有关因素,提出了我国安全文化产业发展的建议。     

如何保证热水锅炉的安全运行

针对热水锅炉的特点,阐述了如何保证热水锅炉的安全运行.