INA-V牵伸的牵伸机理分析

对ＩＮＡ－Ｖ牵伸的后区牵伸机理进行了分析（摩擦力界分布、纤维变速点分布、纤维伸直效果及粗纱捻回的变化）,并进行了纱线质量的对比试验。     

大型全纤维曲轴TR镦锻装置失效分析

对大型全纤维曲轴TR镦锻装置中的模座进行了断裂失效分析,该装置在修改曲轴大法兰成形方式为全封闭成型后的第一次使用中,上、下模座均断裂.采用DEFORM一3D软件对该全纤维钢曲轴镦锻成形进行数值模拟,计算获得锻件成形力和模具充填效果.采用I-Dears软件对曲轴TR镦锻装置进行结构强度计算,获得了镦锻装置的应力和变形状态,分析了模座发生断裂失效的原因.计算结果表明,模座实际的断裂部位和裂纹方向与强度分析结果吻合.     

多级泵轴断裂分析

针对某化工企业引进的国外多级高压烃泵主轴发生断裂事故,结合该轴材料和断口形貌,运用机械可靠性设计原理和方法进行了计算和分析,以探寻其断裂的主要原因.计算分析结果与实际运行表明,该泵选型扬程过高,使泵轴的综合工作应力大,又存在局部应力集中,加之氯离子的腐蚀,因而轴的可靠性较低,导致发生疲劳失效而断裂.据此,文中提出了相应的改进措施.     

并条机牵伸变换齿轮的设计计算

阐述在保证棉纺工艺要求及具有较少变换齿轮个数的条件下，并条机牵伸变换齿轮的设计计算方法．文中用该方法举例设计了ＦＡ３０３高速并条机牵伸变换齿轮、牵伸微调齿轮并计算出其牵伸倍数．     

正压式狭缝牵伸器内部结构参数的优化

依据气体动力学不等熵流动理论,采用带旋流修正的κ-ε湍流模型对正压式狭缝牵伸器内部流场进行数值计算,得出正压式狭缝牵伸器参数引射段长度、狭缝宽度、牵伸段长度、空气刀口距离及喷射角对流场内压力和速度的影响,并提出了各参数的最优化数值.计算结果可为牵伸器内部结构的最优化设计提供理论依据,为提高长丝拉伸效率和拉伸速度给出了研究方向.     

CHERRY D-400MT型并条机主牵伸区工艺参数计算

日本CHERRY D—400MT型并条机围内引进很多。前文已对其牵伸机构及作用进行了分析,这里仅将该机主牵伸区内主要工艺参数计算的公式推导于后,供技术人员在工艺配置及工艺计算时参考。 1 各罗拉间相对位置 CHERRY D-400MT并条机主牵伸区各罗拉间相对位置如图1。     

冷媒泵轴断裂失效原因分析

针对冷媒泵轴在安装运行过程中短期内发生多次断裂事故,采用光学显微镜、X线荧光光谱仪、扫描电镜断口分析、能谱分析等手段,对其进行断裂失效分析。结果表明:冷媒泵轴材质成分符合标准要求,断口裂纹源呈典型的氢脆(氢致腐蚀)特征,断裂应为氢脆引起的快速开裂。     

混凝土拱坝的多轴强度与安全指标

为便于推算混凝土多轴强度,开展混凝土结构的多轴强度设计,本文针对任意的多参数强度准则,给出了用等比超载系数K_(OL)计算多轴强度的通用方法。以某已建成的拱坝为例,分别计算坝体的等比超载系数K_(OL)和失效距离系数K_(FD),并与单轴强度安全系数进行比较,指出混凝土拱坝按多轴强度设计的必要性。基于K_(FD)的定义和算例分析,建议将K_(FD)作为拱坝多轴强度安全设计和校核的指标。     

某车型转向器壳体断裂失效分析及结构优化

某车型在耐久试验过程中，转向器壳体安装位置处发生断裂。本文利用传统理论计算方法和有限元法对转向器分别进行强度分析，找出转向器断裂失效真因。进而对结构进行更改提升壳体强度。     

牵伸和热处理对聚丙烯熔喷非织造材料结构和力学性能的影响

熔喷非织造工艺是将熔融的热塑性树脂直接制成超细纤维非织造材料的一步法生产工艺,然而,熔喷非织造材料较差的力学性能限制了其在某些领域的应用.通过自制的热处理设备,在一定牵伸条件下对熔喷试样进行不同温度的热处理,并对其结构和力学性能变化进行了分析.结果表明:经牵伸和热处理后,试样纵向断裂伸长率不断下降,强力不断提高,130℃热处理后的效果最优,纵向强力提高了45.2%;横向强力在热处理后下降,断裂伸长率随温度升高先增大后减小,在80℃时达到最大.因此,经过牵伸和热处理的熔喷非织造材料可适用于对材料纵向强力要求高的应用领域.     

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