某装配车间吊车梁荷载试验研究

以某单层轻钢结构厂房装配车间的原设计吊车更换为大吨位工程为背景,进行厂房装配车间DL-3吊车梁、DL-4吊车梁、DCL-2A吊车梁吊车更换大吨位后吊车梁荷载试验研究,结果表明：吊车梁理论值大于试验值,但均小于限值。在试验加载和卸载过程中,每级荷载作用下吊车梁跨中底部翼缘单向应变变化与荷载增量基本呈线性关系,卸载完成后各吊车梁均存在不同程度的应变回弹,符合弹性阶段的要求。可见该装配车间DL-3吊车梁、DL-4吊车梁、DCL-2A吊车梁能够在更换大吨位吊车后安全工作,满足变形要求,可继续使用。     

小浪底水利枢纽水电站地下厂房岩壁吊车梁的施工

小浪底地下厂房吊车梁，采用岩壁吊车梁型式，预应力锚杆采和双层保护后张法。在岩壁吊车梁施工中，质量高，进度快，集预裂爆破，光面爆破、深孔梯段爆破、预应力锚杆的制作与安装等新工艺技术为一体，取得了较好的技术经济效果，丰富和充实了我国岩壁吊车梁施工的工艺。     

钢筋混凝土吊车梁钢筋疲劳可靠度分析

基于吊车载荷随机数学模型和钢筋的疲劳试验结果，进行了吊车梁钢筋的疲劳累积损伤概率分析，提出了钢筋混凝土吊车梁的钢筋疲劳可靠性分析和疲劳寿命估计方法     

小跨度连续吊车梁的有限元算法

厂房钢结构连续吊车梁相比目前普遍采用的单跨简支吊车梁,具有更好的竖向刚度和经济性。但由于连续吊车梁在移动荷载下的内力分析难度较大,工程设计中罕有采用。本次研究采用有限元程序,对两等跨等截面小跨度吊车梁的仿真分析,得出连续吊车梁在中轻级吊车荷载作用下的控制内力和变形挠度,对比单跨简支吊车梁,提出满足工程设计的简单实用的小跨度连续吊车梁内力计算方法。     

CFRP加固钢结构吊车梁疲劳有限元分析及应用

钢结构吊车梁疲劳破坏是其未达到设计使用年限破坏的主要原因。文章提出"实体-桁架-壳元"有限元分析模型对吊车梁采用CFRP加固前、后的疲劳性能进行分析,发现粘贴CFRP可以有效地降低焊趾处的应力集中问题,明显改善吊车梁的疲劳性能,从而延长吊车梁的使用寿命。与传统的钢结构加固方法相比,吊车梁粘贴CFRP加固后其性能恢复非常显著。分析结果表明,所采用的有限元数值模型可以分析CFRP加固钢结构,对钢结构吊车梁应用CFRP加固的方法也为类似工程提供参考。     

在偏心荷载作用下钢吊车梁的静力试验研究

在国內外部曾发现厂房中,有相当数量承受重级工作制吊车的钢吊车梁使用时间不长,在上翼缘焊缝及其附近腹板处即出现纵向裂缝以至丧失承载能力。这说明现行设计规范对承受重级工作制吊车的钢吊车梁的设计规定还未能全面反映其实际工作状态。本文正是研究这个问题的一个方面。通过偏轨静力试验探索了以下几个问题:1.偏心扭矩对吊车梁腹板应力及变形的影响;2.改变横向加劲肋间距对吊车梁附加弯曲应力的影响;3.水平力对吊车梁的应力及变形的影响;4.吊车轨道对局部荷载的分布作用;5.不同制动结构对吊车梁应力、变形的影响及制动结构的工作情况。对于所探索问题的有关理论分析,另有专题报告。     

钢筋混凝土吊车梁承载能力设计可靠度研究

钢筋混凝土吊车梁承载能力设计,因缺乏吊车荷载及组合效应的概率模型,荷载分项系数由工程经验确定,设计可靠度控制水平未知.针对吊车梁正截面抗弯、斜截面抗剪承载能力设计方法,引入吊车荷载概率模型和统计结果,将基本参量无量纲化,进行设计可靠指标校核.吊车梁单向、双向抗弯设计可靠指标分别为5.79和5.87,斜截面抗剪设计可靠指标为5.31.钢筋混凝土吊车梁承载能力设计可靠指标偏高,设计偏保守.定量分析各参量对吊车梁可靠度的影响,为设计及维护提出合理建议.     

轻钢厂房吊车梁水平刚度的讨论

为了减小吊车梁在使用过程中的振动,应该提高其横向水平刚度。吊车梁的横向水平刚度由横向弯曲刚度和截面的扭转刚度两部分组成。对于中级和轻级工作制的吊车梁,规范指出无须验算其水平位移,往往会导致使用时的过大振动,并且设计人员在利用软件计算结果时要考虑梁的扭转刚度,准确计算吊车梁的横向水平刚度。     

在偏心荷载作用下钢吊车梁的静力试验研究

在国内外都曾发现厂房中,有相当数量承受重级工作制吊车的铜吊车梁使用时间不长,在上翼缘焊缝及其附近腹板处即出现纵向裂缝以至丧失承载能力。这说明现行设计规范对承受重级工作制吊车的钢吊车梁的设计规定还未能全面反映其实际工作状态。本文正是研究这个问题的一个方面。通过偏轨静力试验探索了以下几个问题:1.偏心扭矩对吊车梁腹板应力及变形的影响;2.改变横向加劲肋间距对吊车梁附加弯曲应力的影响;3.水平力对吊车梁的应力及变形的影响;4.吊车轨道时局部荷载的分布作用;5.不同制动结构对吊车梁座力、变形的影响及制动结构的工作情况。对于所探索问题的有关理论分析,另有专题报告。     

基于nCode design-life的某钢结构吊车梁疲劳可靠性

近年来对吊车梁的调查显示,由于吊车梁的受力复杂,钢吊车梁在往复载荷作用下会提前出现不同程度的疲劳裂缝,危害生产安全与降低经济效益,疲劳寿命的研究可以有效的预防和减小破坏等问题的概率并可对于寿命进行延长.本文采用S-N方法,运用ANSYS有限元软件与nCode Design-life疲劳软件相结合的方式,通过对目标吊车梁的实际受力状态进行模拟并对其进行疲劳可靠性分析,找出最易破坏的节点及最不利位置.取吊车梁一端为基准,设置电葫芦在吊车三个不同位置的工况进行分析,得出三组此破坏点的循环数据,其最小循环值则为吊车梁往复载荷后的最易损坏处.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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