超超临界锅炉水冷壁爆管原因

通过对超超,豳界锅炉水冷壁爆管事故原因进行了分析,介绍了事故的处理经过,指出受热面管堵塞是造成管子超温爆管的根本原因,重点分析了受热面管堵塞爆管的各种影响因素,针对性地提出了解决措施。     

火焰加热液化轻烃容器破裂特性分析

液化轻烃的生产、储运过程中 ,由火焰加热引发容器破裂爆炸事故屡有发生。本文分析了液化轻烃容器受热破裂的危险性及其破裂特性 ,总结了事故的预防措施与技术。     

Experimental investigation on spontaneous ignition caused by pressurized hydrogen suddenly release into an S-shaped tube

An experimental investigation on the effects of continuous semicircular curved structure on spontaneous ignition during pressurized hydrogen suddenly release was conducted. An S-shaped tube with 700 mm in length and 10 mm in diameter was used in our experiments, and a straight tube with the same configuration was adopted for comparison. The results show that the continuously generated rarefaction waves and reflected shock waves make the pressure curves in the S-shaped tube more complicated. Meanwhile, the mean velocity and intensity of the leading shock wave undergo considerable attenuation when it propagates in the S-shaped structure. By comparing with the straight tube, the minimum critical pressure condition for spontaneous ignition in the S-shaped tube is slightly difficult to reach, but the difference is not huge. Nevertheless, the S-shaped structure can effectively promote hydrogen-air mixing and make combustion more intense. A secondary overpressure peak detected by the pressure transducer near the nozzle occurs in the spontaneous ignition cases and no such pressure increase is caught in the non-ignition cases. The transition from spontaneous combustion flame to a jet flame at the nozzle and the complete out-tube jet flame development process are captured and discussed.     

汶川地震滑坡发育特征及其影响因素

汶川地震是近年来我国发生的最严重的自然灾害,地震触发了大量的滑坡,造成了严重的人员伤亡和财产损失。根据汶川地震滑坡的调查和勘测,探讨了滑坡的发育特征及其影响因素,旨在为汶川地震滑坡的减灾防灾提供理论依据。分析了地震滑坡的优势坡度范围和最优坡度;地震滑坡面积-频率分布符合对数分布规律而不同于降雨等诱发滑坡的幂律分布。坡向与断层破裂方向的夹角控制着汶川地震滑坡频率、坡度和面积的分布,当坡向与断层破裂方向一致时,受地震抛掷作用滑坡发育的频率和面积的比例大、滑坡平均坡度小;当坡向与断层破裂方向相反和坡向与断层的倾向一致时,受地震撞击崩裂作用,滑坡发育的频率和面积的比例较小、滑坡平均坡度较大。     

对汶川地震小鱼洞地表破裂带的调查分析

2008年5月12日的汶川8.0级地震使龙门山断裂带形成了3条同震地表破裂带,这表明有多条活动断层同时参与地震破裂,其过程复杂,现象丰富。本文对小鱼洞地表破裂带及其与另2条地表破裂带的交汇区域进行了野外调查,并对小鱼洞地表破裂带的活动性质和展布特征进行了分析。小鱼洞地表破裂带位于彭州市小鱼洞镇附近,是汶川8.0级地震形成的一条走向NW的逆冲并具有左旋走滑分量的同震地表变形带。调查结果显示,小鱼洞地表破裂带表现出明显的分段性特征:小鱼洞镇一带的中段,逆冲量和走滑量最大;小鱼洞镇向东南方向延伸的南段,逆冲量和走滑量逐渐变小;小鱼洞镇向西北方向进入山区的北段,则表现为以逆冲为主的活动性质。     

荧光废水中COD_(Cr)闭管与开管消解测定方法研究

通过考察6个实验室中,标准溶液和标准样品的试验分析数据,得出闭管法较开管法具有更优的准确度、精密度和氧化能力,其闭管法的最佳氧化浓度(并非检测限)在150～850mg/L;结合水样的监测数据,研究了两种快速测定方法的优缺点和适用性,得出两种方法均普遍适合工业废水监测,其中闭管法在测定中、高浓度荧光废水时,结果更准确、更环保,而开管法适用于相对低浓度的废水测定;总结归纳了CODCr监测分析过程中影响准确性的因素及需要注意的问题。     

Amnion rupture sequence in a first trimester missed abortion

We report the diagnosis of amnion rupture sequence made by sonography and fetoscopy during the first trimester of gestation in a case of missed abortion. The investigation revealed a demised fetus with the characteristics of 9 weeks of development. The early fetus had an amnion adhesion at the tip of the nose and strands of amnion wrapped around the terminal phalanges of both feet. No defects in addition to the face and limb involvement were identified. The karyotype was normal: 46,XX. In the reported case, fetoscopy allowed confirmation of the sonographic diagnosis of an amnion rupture sequence in the first trimester of gestation and consequently helped to clarify the cause of abortion in this case of early fetal demise. Copyright © 2001 John Wiley & Sons, Ltd.     

HFL模型在海上压裂工艺过程风险评估中的应用

为有效降低海上压裂工艺过程事故发生的可能性,建立将危险与可操作性研究(HAZOP)、事故树分析(FTA)和保护层分析(LOPA)集成的量化风险评估模型(HFL模型)。阐述HFL模型的集成机理和分析流程。以海上压裂工艺过程高压管线危险性分析为实例,开展该模型的研究与应用。在运用HAZOP方法对危险源初步辨识基础上,构建高压管线超压的蝴蝶结模型(BTM),确定导致事故发生的9种风险因素和5种事故后果,并估算高压管线断裂事故场景的初始事件概率和剩余事故风险。结果表明,现有的独立保护层(IPL)即超压电子保护装置无法使事故风险达到可接受水平,需要通过增加新的IPL,即安装井口保护装置和泄压装置,提高压裂过程高压管线运行的可靠性,确保剩余事故风险处于可接受水平。     

Amniopatch for iatrogenic rupture of the fetal membranes

With the increased use of invasive fetal procedures, the number of women facing post-procedure membrane rupture is increasing. Here we review the use of platelets and fresh frozen plasma for sealing iatrogenic fetal membrane defects by describing the mechanisms of action of the amniopatch procedure as well as published experience. In cases of iatrogenic preterm pre-labour rupture of the membranes, amniopatch effectively seals the fetal membranes in over two-thirds of cases. There is a risk of 16% of in utero fetal death, which may occur at varying intervals from the procedure and often for unknown reasons. Amniopatch has also been used as a treatment of chorionic membrane separation. In summary, current experience suggests that in cases of early onset but persistent amniotic fluid leakage following an invasive fetal procedure, amniopatch is an option. Copyright © 2011 John Wiley & Sons, Ltd.