Extended hybrid pressure and velocity boundary conditions for D3Q27 lattice Boltzmann model

The extended hybrid electronic-ionic, thermal, magnetic, electric and force couple fields pressure and velocity boundary conditions for D3Q27 lattice Boltzmann model is established. Then, the closed-form solutions of extended distribution functions are derived. Last, the Fukushima nuclear plant Cesium-137 penetration case is discussed.     

基于金融服务供应链的极端洪水灾害风险应急合作模型研究

基于金融服务供应链管理的基本思想,建立极端洪水灾害风险应急金融服务供应链,分析此应急金融服务供应链中各成员的利益函数模型之间的关系,结果表明,经营性政府的效益与公众利益呈正相关性,经营性政府的效益与保险公司的利润呈负相关性;同时,考虑当经营性政府效益和保险公司利润固定时,保险公司的保费,经营性政府对公众购买保险的补贴率和政府为了避免保险公司在极端洪水灾害发生后破产概率过高,给予的转移支付之间的关系.     

气象灾害评估分析的AHM方法研究

文章采用属性层次模型(AHM)对主要气象灾害的风险承受能力与控制能力进行评价分析,并与层次分析法(AHP)进行比较,结果表明属性层次模型(AHM)比层次分析法(AHP)更便于计算,为气象灾害风险承受能力与控制能力的评价与风险决策问题提供了更实用更科学的依据。     

台风灾害下多种公路构筑物快速智能风险评估

针对台风灾害下公路上构筑物种类多样、数量众多的特点, 提出一种快速化、智能化的公路台风灾害风险评估模型. 在对公路灾害风险的可能性分析中, 建立边坡、桥梁、隧道出入口、路基以及路面统一框架下的三层灾害风险事故可能性指标体系, 其中承灾体自身因素的底层指标根据不同构筑物特点, 从关键风险指标、构筑物自身状况和承灾体破坏因子三个方面选取, 从而使自动化、智能化评估成为可能; 在对公路灾害风险损失的定量计算中, 将事故可能性和事故损失耦合, 实现公路事故损失的风险评估自动化; 更加注重事故预防性和智能巡检, 建立了侧重于事故可能性的非对称公路灾害风险计算方法, 风险评估结果量化在0到1的范围内. 开发出相关的智能化风险评估系统平台, 实现对2019年8月10日台风“利奇马”影响下的宁波市国省道公路的自动化、智能化灾害风险评估, 结果表明, 该评估模型能够快速、准确地形成台风灾害下公路上多种构筑物的风险评估, 便于筛选重点巡检对象.     

Development of accelerator mass spectrometry assisted by isotope-selective laser photodetachment for monitoring 129I

A prototype system was developed to investigate an isotope-selective laser photodetachment technique for a ¹²⁹I accelerator mass spectrometer. A pulsed ion source for negative iodine ions (I⁻) that employed laser ablation proved to be suitable for isotope-selective laser photodetachment. Laser photodetachment of pulsed negative iodine ions was estimated to have an efficiency of about 81% based on a model calculation for the prototype system with a tunable pulsed Ti:sapphire laser.     

基于奇异值分解对中国夏季降水模式误差订正的研究

利用奇异值分解(SVD)方法对国家气候中心气候业务模式CGCM的预报结果进行订正, 进而得到改进后的预报结果. 通过对1983–2011年中国夏季降水的模式预报和实际降水值各年份之间的耦合场进行SVD分解, 选取模式预报和实况降水相关性最好的前3–7个模态, 对这5种不同模态个数的订正结果加以对比, 选出对中国区域订正效果最好的模态个数, 得到模式预报的订正结果. 对2004–2009年6年进行交叉回报试验, 以距平相关系数和均方根误差作为评判标准来检验回报结果, 得出2004–2009大部分年份取前5个模态作为当年订正的模态个数时,订正效果最好. 利用已有的2004–2009年的模式和实际降水资料进行检验, 证实在大部分年份5个模态订正效果最好, 并将结果与系统误差订正法的结果相比较, 表明SVD法对2004–2009年 6年的订正结果中, 有4年比系统误差法的订正效果好. 以2010年作为预测年, 以1983–2009年27年交叉回报检验的结果确定模态个数, 对预测结果加以分析, 显示该方法具有潜在的业务应用价值. 关键词： 奇异值分解 模式预报订正 汛期降水     

Strength softening models of soil and its application in rainfall-induced landslidesimulation

In this study, strength softening models are developed for exploring rainfall-induced landslide mechanism based on Mohr-Coulombstrength theory with both saturation degree and temporal evolution into consideration. According tothe ratio of two time scales available, the model can be classified into three categories, i.e., instant softeningmodel, delay softeningmodel, and couplingsoftening model.Corresponding evolution functions are specified to represent these kinds of softening processes andthen applied to simulate landslide of homogeneous slopes triggered by rainfall, therefrom, usefulconclusions can be drawn in the end.     

火灾中铜导线及其熔珠显微结构的SEM分析

用SEM观察分析了在各种模拟实验条件下铜导线及其熔珠熔痕的几种显微组织结构特征,结果表明：单股粗铜导线的火烧、二次短路熔珠熔痕与一次短路、过负荷、接触不良造成的熔珠熔痕其显微结构有明显不同,可为火灾原因的鉴定提供参考依据．而多股细铜导线火烧和二次短路及过负荷产生的熔珠熔痕,其显微结构中均出现等轴晶和柱状晶及较小再结晶颗粒,与一次短路结构较难以区别,因此无法为火灾原因的鉴定提供依据．     

The practical research on flood risk analysis based on IIOSM and fuzzy α-cut technique

Flood disasters are one of the most common and destructive natural hazards all over the world. In this paper, improved interior-outer-set model (IIOSM) based on information diffusion theory is introduced in detail to assess flood risk in an effort to obtain accurate analytical results that represent the actual situation. Then fuzzy α-cut technique is applied to calculate the fuzzy expected values under the possibility–probability distribution (PPD) calculated by IIOSM. Taking the value of α throughout the interval (0, 1], we correspondingly get access to the conservative risk value (R_C) and venture risk value (R_V). Selection of α, R_C and R_V is dependent on present technical conditions and risk preference of different people. To illustrate the procedure of IIOSM and fuzzy α-cut technique, we employ them respectively to analyze the flood risk in Sanshui District, located in the center of Guangdong province in China. The results, such as risk value estimations, as well as fuzzy expected values, i.e. R_C and R_V under the given α-cut level, can reflect the flood risk quite accurately. The outcomes of this research based on IIOSM and fuzzy α-cut technique offer new insights to carry out an efficient way for various flood protection strategies.     

基于复杂网络的灾害蔓延模型评价及改进

介绍了几种已存在的复杂网络上的灾害蔓延模型,在对模型进行优缺点评价的基础上,给出了一种网络中存在冗余系统的改进模型.对不同的模型,在不同的网络结构下,仿真分析了蔓延过程的差异以及重要参数的作用.结果表明网络中存在冗余系统的灾害蔓延过程变缓,相应有了更多的应急、补救时间,同时也解释了现实生活中大规模灾害事件很少发生的原因. 关键词： 复杂网络 灾害蔓延 冗余系统