工厂安全事故预测中的数学模型

利用AHP方法(层次分析法)对工厂安全事故进行了分析研究,引入了“事故数”的概念,依照量变引起质变的思想,构建了大事故预测的数学模型,为工厂安全检测提供了一种全新的量化检测手段.通过对山东××煤矿的应用,取得了较好的效果.     

Potre-H: A Dynamic Model for Rationuclide Transport in Agricultural Ecosystems

Abstract

This paper presents a dynamic compartment model that simulates the transfer of radionuclides through components of agricultural systems following deposition to ground, and predicts the resulting concentrations in food products. The system of linear differential equations corresponding to this model was solved analytically for release in the dormant season, before or after sowing, and for release in the growing season as a single or time dependent deposition. Model predictions have also been compared with levels ¹³¹I and ¹³⁷Cs in grass and milk resulting from the Chernobyl accident.     

An evaluation of the range-gated-imaging technology under dense aerosol environments

Range-gated-imaging system, which can be used to eliminate backscatter in strong scattering environments, is based on two high speed technologies. It uses high power, ultra-short pulse laser as the light source. And it opens the optical gate of an ICCD camera with a micro-channel-plate image intensifier in a very short time while the laser pulses reflected by the object is coming back to the ICCD camera. Using this range-gated-imaging technology, the effect of scattered light can be reduced and a clear image is obtained.In this paper, the test results of the range-gated-imaging system under dense aerosol environments, which simulates environments in the reactor containment building when the severe accident of the nuclear power plant occurred, are described. To evaluate the observation performance of the range-gated-imaging system under such dense fog environment, we made a test facility. Fog particles are sprayed into the test facility until fog concentration is reached to the postulated concentration level of the severe accident of the nuclear power plant. At such dense fog concentration conditions, we compared and evaluated the observation performances of the range-gated-imaging system and the CCD camera.     

Comprehensive whole-body counter surveys of Miharu-town school children for three consecutive years after the Fukushima NPP accident

Comprehensive whole-body counter surveys covering over 93% of the school children between the ages of 6 and 15 in Miharu town, Fukushima Prefecture, have been conducted for three consecutive years, in 2011, 2012 and 2013. Although the results of a questionnaire indicate that approximately 60% of the children have been regularly eating local or home-grown rice, in 2012 and 2013 no child was found to exceed the ¹³⁷Cs detection limit of 300 Bq/body.     

基于支持向量机的飞行事故率预测模型

飞行事故率是表征飞行安全水平的重要指标,其预测是典型的小样本问题.针对目前飞行事故率预测中存在的预测精度不高的问题,提出了一种基于回归支持向量机的飞行事故率预测建模方法.最后结合实际算例,采用SVR进行了飞行事故率预测建模并把预测结果与灰色预测和灰色马尔柯夫链预测进行了对比.仿真结果表明SVR具有很高的建模精度和泛化能力,从而验证了采用SVR进行航空飞行事故率预测的合理性和先进性.     

基于MATLAB的交通事故发生规律的模糊分布拟合

借助于数学软件MATLAB,运用模糊数学方法,探讨中国交通事故发生及危害的变化规律.首先,作中国交通事故统计数据的散点图,观察发现交通事故的变化同时具有线性增长总趋势和波动性特征,呈现出复杂的非线性组合特点;再对这些数据进行归一化处理,给出交通事故的模糊隶属函数;最后对交通数据进行分布拟合、组合回归处理,得到交通事故非线性模糊分布函数.结果表明,随着时间的变化,中国交通事故的死亡人数呈线性与正态叠加波动上升趋势,受伤人数呈线性与正弦叠加波动上升趋势,发生起数与损失折款都呈双峰正态分布波动趋势,2002年以来交通状况正在好转.得到的结果能客观地反映交通事故的现状分布和精确地刻划中国交通事故发生及危害变化规律,对于交通事故预测、综合治理具有重要的理论意义和应用价值,可供交通事故研究和有关部门制定交通安全管理决策作参考.     

SDH设备维护经典案例分析

在传输网的维护和建设过程中,SDH设备经常进行硬件扩容和软件升级等工作,在扩容中有些厂家的SDH设备会由于硬件版本不同产生一些疑难障碍.本文详细介绍了一次NEC SMS-2500A SDH设备在扩容中由于硬件版本不同造成设备阻断障碍的处理过程,希望对其他维护人员有所帮助.     

燃料与冷却剂相互作用的数值模拟

本文通过对MIXA06实验的模拟来研究发生在核反应堆严重事故情况下的燃料与冷却剂相互作用(FCIs)细粒化混合过程.采用基于泰勒不稳定性的水力学细粒化模型,对这种高温熔融物与低温冷却剂接触时的强烈热物理作用过程进行数值计算和预测,研究在低韦伯数条件下水力学细粒化模型的适用性.计算结果和参数敏感性分析结果表明,水力学模型低估了熔融液滴的细粒化率.     

燃料操作事故辐射影响定量分析

以红沿河核电厂为对象,开展了CPR1000燃料操作事故放射性核素的来源、迁移途径、释放方式研究,构建了燃料存储室以及外环境的源项计算模型。在此基础上,定量地论证了该事故所产生的辐射影响,结果表明：基于前0.5%概率水平的厂址气象条件,得到非居住区边界以及规划限制区外边界16个标准方位的公众剂量均可满足GB 6249-2011限值要求,且尚存一定裕量。通过关键参数的敏感性分析,进一步识别出了剂量最大方位、主导核素、关键时段,论证了事故分析截断时间取12 h的合理性、燃料操作起始时间取100 h的必要性。同时,进一步研究了水洗深度及正常通风隔离时间对公众剂量的影响规律,公众剂量随水洗深度增加呈指数降低趋势,随正常通风隔离延迟时间变长而快速增加,相关研究可为各核电厂设计决策提供支持。     

电梯安全运行的思考及制动性能分析

随着社会经济的发展,高层建筑不断涌现,电梯的使用愈加频繁。近年来电梯安全事故时有发生,电梯的安全问题不得不引起我们的思考。电梯的可靠制动是电梯安全运行的前提和保障,而大量的电梯事故实例与电梯制动故障有关,该文对电梯制动力及制动距离进行了分析探讨,对电梯制动性能的监测评价提供一个参考。