集装箱桥吊小车停止时机控制

本文通过分析桥吊的小车运行系统，建立了一个桥吊的小车运行系统模型，得出其运行的传递函数，并借助于MATLAB软件进行仿真，最终得出结论：如果要使集装箱桥吊停机对箱或对车达到很好的效果，须在θ(t)经过零的瞬间取消力F(t)才不致货物振荡。     

现役集装箱桥吊结构安全评估

介绍了评估现役集装箱桥吊是否安全可靠的较简单和实用的分析方法．它是基于对现役桥吊进行检测得到的数据进行目前桥吊结构整体确定性有限元计算，即首先结合可靠性分析和初始裂纹尺寸对疲劳强度的可靠性影响分析，求得现役桥吊结构的可靠性指标βc和疲劳可靠性指标βt，然后将其与给定的安全可靠性准则进行比较来评估现役桥吊结构的安全性．实例计算表明本方法可推广应用于其他类型的结构．     

集装箱正面吊后转向桥立仁轴故障报警装置

简单介绍了集装箱正面吊后转向桥立仁轴故障报警装置的特点和基本原理，指出该装置大大提高了机械的使用率，延长了使用寿命。每台正面吊可节约维修费用数万元。     

基于数据包络分析的集装箱港口绩效评价

从经济学的角度,提出了集装箱港口效率的内涵及其重要性,通过引入数据包络分析(DEA)模型并加以改进,选取集装箱港口的泊位长度、桥吊数量、集装箱吞吐量等作为输入／输出指标,从定量的角度研究集装箱港口的效率,以我国主要集装箱港口为例进行实证分析,测算出8大集装箱港口的相对效率,在对结果进行初步分析的基础上,提出了大连港集装箱发展的建议．     

带缓存区的集装箱港口岸边装卸工艺仿真分析

经过对传统装卸工艺流程的分析,考虑各种新型设备并结合集装箱港口布局,研究一种带有缓存区的新型岸边装卸工艺流程.在港口前沿增加了集装箱缓存区,并且应用计算机仿真软件Plant Simulation对装卸工艺进行仿真研究.在已知集卡数量和任务量条件下,以所有任务总的完成时间最小化为目标,使用PlantSimulation中的遗传算法工具寻找最优的缓存区数量.从而得到更合理和具体的新型装卸工艺.实验结果表明带缓存区的集装箱装卸工艺能够提高桥吊的利用率,也便于桥吊进行边装边卸工作,同时缩短了集卡的等待时间,方便了港口进行调度.     

桥吊司机操作曲线坐标提取与轨迹对比的方法研究

本文在现有的集装箱桥吊仿真训练器系统得出的桥吊司机装卸曲线图,包括操作手柄运动图（Real Time Joystick Movement Graph）、负载曲线图（Load Path）和最优曲线图（Optimal Path）的基础上讨论如何得到集装箱仿真训练器学员司机操作时吊具行走路径,即指定时刻吊具的所在的高度,并用相同的方法得到最优轨迹的高度,从而用二者高度进行比较的方法,来评价学员的操作水平。让学员在操作结束后能看到自己的操作轨迹和最优轨迹相比较的结果,从而更直观,更深刻认识自己的操作水平。     

基于向量式有限元的岸桥动力学分析

岸边集装箱起重机小车沿着大梁进行运动的同时也会带着吊重移动,为了对工作状况下的岸桥的结构行为进行确认需要进行移动吊重与小车作用下的动力学分析。岸桥是一种结构复杂的大型机械,一般使用有限元分析软件对其动力学行为进行模拟。向量式有限元作为一种新型理论,脱离了传统有限元软件与方法的束缚,在多个领域得到了应用。本文使用向量式有限元理论建立了岸桥整机模型,考虑了结构中的铰接点、质量点和耦合单元,进行高度变化的偏摆吊重与移动质量小车作用下的岸桥动力学分析。     

集装箱码头各种轮胎吊“油改电”方案选择探讨

轮胎吊场桥是现今集装箱码头的主要装卸设备。由于其存在特有的优缺点,当前我国各大中小型码头都正在进行、或准备进行轮胎吊的"油改电"改造。本文结合码头实际情况对四种最常见的油改电方案的影响进行分析对比,以期为各类码头的"油改电"方案选择提供一些明确地思路。     

集装箱桥吊司机眼动疲劳度分析

为揭示港口集装箱桥吊司机眼睛疲劳规律,采用视线跟踪技术和智能优化算法相结合,分析桥吊司机操作过程中的眼动参数与驾驶疲劳之间相关性,运用眼动参数建立驾驶疲劳推断评判模型.设计了驾驶员实测操作实验方案,确定注视时间百分比、注视点数目为眼动测量指标,研究眼动测量指标与驾驶疲劳的相关性.分析驾驶员眨眼、注视、眼跳三种眼动形式实测数据与驾驶疲劳的线性与非线性变化关系,求得注视分布变异系数,得到注视分布变异系数与驾驶疲劳之间的关系.     

自锚式吊拉组合体系桥主缆线形计算方法

基于分段悬链线理论,考虑自锚式吊拉组合体系桥主缆锚固点位置及桥塔高度的变化,分别介绍了其成桥和空缆状态主缆线形及主缆无应力长度的计算原理和步骤．考虑索鞍的影响,编制了主缆线形计算程序．算例验证结果表明该方法是正确可行的,所编程序具有收敛速度快、计算精度高、便于工程应用等特点,对自锚式吊拉组合体系桥的设计和施工都具有很好的指导作用．     

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     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has