车-人碰撞事故中车辆最小行驶速度预估方法

为给仿真车-人碰撞事故提供可靠的事故车辆车速近似值,基于经典力学理论及若干假设,推导出行人第一落地点抛距与事故车辆车速的关系,并据此获得了两个有价值的预估事故车辆最小车速模型:其一用于平坦路面,其二则用于有坡度路面.然后借助已有研究成果及Pc-Crash仿真试验数据,对所得模型进行了验证,结果表明,所得模型有效、可行.最后,通过给出的一例真实车-人碰撞事故案例,演示并进一步验证了所得模型.     

人车事故再现方法研究

人车事故再现方法主要包括基于数学解析法的简易模型、基于半解析法的经验模型和基于PC-Crash和Madymo软件的三维多刚体仿真模型三类。根据国家车辆事故深度调查体系中一起人车正碰事故现场痕迹(例如制动痕迹、车辆损坏、行人损伤、抛距等)以及车辆尺寸和人体测量学参数等,分别用这三类方法进行事故再现研究,比较了碰撞车速和抛距等计算结果。基于多刚体仿真模型详细分析了行人最终位置、运动学过程、人车碰撞区域以及行人损伤等。通过图表定性地评估了必要的输入输出参数、需要耗费的时间、适用范围及精度等模型参数。     

电动自行车-轿车碰撞形态对骑车人抛距的影响研究

为研究电动自行车与轿车前部不同碰撞形态对骑车人抛距的影响,从国家车辆事故深度调查体系中选出与轿车碰撞的电动自行车事故案例21起,利用PC-Crash仿真软件建立轿车与电动自行车的碰撞模型。在此基础上进行计算机模拟实验,分析了不同碰撞形态下骑车人的动态响应过程,研究车速、碰撞夹角对骑车人抛距的影响。结果表明:骑车人横向抛距随着电动自行车速度的增加而增大;骑车人相对于轿车速度方向上的横向速度分量越大,其横向抛距越大;骑车人纵向抛距随轿车速度的增加而增大,电动自行车速度和碰撞夹角对纵向抛距影响不大。     

基于多刚体动力学的人-车碰撞事故形态重构研究

交通事故重构已成为事故鉴定的重要技术手段,对还原交通事故碰撞过程十分有效。目前绝大多数重构技术均依赖于事故现场碰撞信息的采集;但准确性较低且缺乏通用性。针对某真实人-车碰撞事故案例,基于多刚体动力学原理,建立人-车碰撞数字化模型;并借助其重构事故发生时的各参与方运动状态,实现车辆损伤信息与行人冲击损伤机理的多重融合。通过行人最终位置、车辆受损区域、行人损伤等事故现场信息,验证数字重构模型的准确性。研究成果可为进一步探讨汽车前部结构设计与人员损伤的内在联系提供理论支撑;亦对制定有效规范的交通行为举措,保护交通事故中弱势群体具有较重要意义。     

人车碰撞事故的行人伤害研究

将多体动力学方法与行人伤害分析相结合对一起真实的人车碰撞事故进行了准确的仿真再现,研究分析了碰撞过程中行人的动力学响应和伤害.事故再现结果与实际情况及法医尸检结论吻合,有效地验证了方法和模型的正确性.在此基础上计算得出行人头部及下肢伤害与汽车碰撞速度的变化关系,可为改善汽车的行人安全性提供参考.     

人车碰撞事故的行人初始状态研究

为进一步提高人车碰撞再现的逼真度,研究碰撞前行人初始状态及相应的仿真实现方法,提出一种基于行走的行人假人的事故再现方法.该方法利用行人多刚体仿真模型,计算行人行走过程的动态响应,并以此确定事故再现所需的行人姿态、速度等参数.通过对一起真实事故的研究,应用不同的行人初始状态确定方法进行人车碰撞仿真,分析了不同方法对再现结果的影响.     

轿车-电动自行车侧面碰撞事故再现分析

为了再现轿车与电动自行车的侧面碰撞事故,利用PC-Crash进行了轿车与电动自行车的侧面碰撞模拟试验,分析了不同车辆碰撞速度下骑车人头部与车辆引擎罩及风挡玻璃撞击的位置,探讨了车辆碰撞速度与骑车人头部损伤的关系,建立了骑车人抛距模型,并与国外模型进行了对比.研究结果表明:碰撞车速为50 km/h可以认为是骑车人头部伤害的碰撞速度阈值;当碰撞车速低于40 km/h时,车辆撞击运动和静止的电动自行车,骑车人抛距变化的趋势基本相似;当碰撞车速高于40 km/h时,与撞击运动的电动自行车相比,车辆与静止的电动自行车碰撞的骑车人抛距略大,而电动自行车的抛距分布较为离散.利用骑车人头部与车辆的碰撞位置、骑车人头部损伤及骑车人抛距能够有效地再现轿车与电动自行车侧面碰撞事故的碰撞速度.     

电动自行车—轿车碰撞形态对骑车人抛距的影响

为研究电动自行车与轿车前部不同碰撞形态对骑车人抛距的影响,从国家车辆事故深度调查体系中选出与轿车碰撞的电动自行车事故案例21起,利用PC-Crash仿真软件建立轿车与电动自行车的碰撞模型。在此基础上进行计算机模拟试验,分析了不同碰撞形态下骑车人的动态响应过程。研究车速、碰撞夹角对骑车人抛距的影响。结果表明:骑车人横向抛距随着电动自行车速度的增加而增大;骑车人相对于轿车速度方向上的横向速度分量越大,其横向抛距越大;骑车人纵向抛距随轿车速度的增加而增大,电动自行车速度和碰撞夹角对纵向抛距影响不大。     

轿车-电瓶车事故中碰撞初速度与抛距关系研究

为研究轿车碰撞初速度与电动自行车、骑车人抛距的关系,运用 MADYMO软件,建立轿车、电动自行车-骑车人的多刚体碰撞模型。通过仿真结果与监控录像截图及数据的对比,其误差小于1％,验证了模型的准确性。并通过改变模型中轿车的碰撞初速度21次,对得到的数据结果进行数学拟合,得出轿车制动距离、电动自行车滑行距离、骑车人头部与地面第一次接触距离、骑车人最终落点距离等参数与轿车碰撞初速度之间的关系公式6个。这些公式为交通事故中轿车车速的鉴定,提供了一定的参考依据。     

基于大灯碎片分布场的汽车碰撞事故再现模型

为建立汽车大灯碎片分布场的抛距与汽车碰撞速度间数学模型,研制了汽车模拟碰撞装置,并以汽车碰撞时所产生的汽车大灯碎片为研究对象,通过卖车碰撞模拟试验,分析一定初始条件下大灯碎片偏移角度、抛距随碰撞速度的变化关系.试验结果表明:汽车碰撞速度影响碎片抛距,且大灯碎片偏移角度分布场区域一定;在无制动力影响情形下的碰撞,大灯碎片偏移角度分布区域为-12.5°～12.5°;而有制动力影响情形下的碰撞,其分布区域为-12.5°～20°;依据大灯碎片分布场抛距与碰撞速度间关系,建立大灯碎片分布场事故再现模型.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with