水溶性聚合物型极压润滑剂的性能及机理初探

本文研究了含活性元素Zn,S,P,Mo,Sn的水溶性聚合物型润滑剂的润滑、极压性能.将此类润滑剂以0.2%～1%的量加入水中时,其磨斑直径D_(30)~(40)=0.45mm,平均相对分子质量=2000～5000;将此类润滑剂加到石油钻井泥浆中时,其润滑系数降低率为56%～73%.文中初步探讨了由于聚合物所特有的粘弹性在边界润滑状态下的润滑减摩机理.     

高石墨铜基复合自润滑材料的组织结构与性能

以Cu-Ni粉末为基体,添加定量的W,SiC,Y2O3和MoS2相,以粉末冶金方法制备石墨质量分数分别为3%,3.5%,4%,4.5%和5%的高石墨含量铜基复合自润滑材料.利用金相显微镜、扫描电镜、X射线衍射仪、共聚焦成像仪和摩擦试验机对样品的组织结构和性能进行分析.结果表明:材料的最佳烧结温度为910℃,烧结时间为4 h;材料的组织由铜的α固溶体,Cu0.8Ni0.19,WMoS2,SiC和石墨等组成.力学性能随着石墨含量的增加而降低,但自润滑效果比较好.在保证材料基体具有高力学性能的基础上,提高材料中固体润滑相的含量,是制备高耐磨自润滑材料的关键因素.     

酚醛树脂固体润滑棒的性能研究

选用酚醛树脂(PF)、二硫化钼和石墨以及其他添加剂作为固体润滑材料基材,利用冷压烧结法制备了固体润滑棒.研究了酚醛的含量、MoS2与石墨的配比对润滑棒的物理性能、摩擦学性能的影响.结果表明,随着酚醛含量的增多,试件的邵氏硬度、抗冲击强度、膨胀率逐渐增大,摩擦润滑膜的表面张力减小,当酚醛与石墨比例为3∶10时,体现了较好的摩擦学特性;减磨组元中MoS2的比例过高或过低都不利于润滑膜承载能力的提高,当MoS2与石墨的比例为1∶1时,固体润滑棒的减摩、耐磨性能最佳;通过正交试验法,以摩擦系数和磨损率试验指标,确定了固体润滑棒的工艺参数.     

粘结石墨基固体润滑涂层的微动摩擦磨损性能

为了探讨粘结石墨基固体润滑涂层的微动摩擦磨损性能的作用机理,使用SRV 微动摩擦磨损试验机对粘结石墨基固体润滑涂层在微动试验条件下的摩擦学性能以及抗承载能力进行研究,对其磨痕形貌和对偶转移膜进行分析.研究结果表明粘结石墨基固体润滑涂层的磨损率随着试验载荷和摩擦速度的增大而减小;而摩擦因数随着试验载荷增大而减小,随摩擦速度增大而缓慢增大;在微动摩擦过程中,高载高速可以促进高质量转移膜在对偶表面形成,从而使得粘结石墨基固体润滑涂层具有良好的抗承载能力和优异的抗磨减摩性能.     

微沟槽形貌对水润滑轴承混合润滑特性影响的研究

建立了计入轴承内表面微沟槽形貌的水润滑轴承混合润滑(Mixed-EHDL)数值计算模型,着重研究了不同运行工况下,半椭圆形、矩形、等腰三角形、左三角形、右三角形等多种微沟槽形貌对水润滑轴承混合润滑特性的影响.研究表明:在所有微沟槽形貌中,混合润滑性能与承载性能优劣排序依次为右三角形、等腰三角形、左三角形、半椭圆形、矩形;在弹流润滑阶段,微沟槽形貌对水润滑轴承摩擦系数几乎无影响,而在混合润滑阶段,不同微沟槽形貌下接触载荷以及摩擦系数之间的差异随转速的增加呈现出先增大后减小最后趋于统一的规律性;在承载区,由于沟槽内水膜增压能力以及抽吸作用的不同引起了水润滑轴承混合润滑性能的差异,其中右三角形表现最优,而矩形最差.     

粉末冶金复合材料水润滑条件下的摩擦学性能

针对水液压元件摩擦副润滑困难、使用寿命短等方面的不足,制备了一种以316L不锈钢粉末冶金材料为基体、含有纳米金刚石颗粒悬浮液填充孔隙的复合材料,在水润滑条件下对复合材料和碳纤维增强聚醚醚酮(CFRPEEK)进行了端面摩擦磨损试验,并将其与316L不锈钢材料、316L粉末冶金材料、316L粉末冶金材料+润滑油进行了对比,研究了复合材料的摩擦学性能.结果发现:在500 r/min转速、400 N外载荷下,复合材料和CFRPEEK配对的平均摩擦因数为0.027,CFRPEEK的磨损率为0.128×10~(-16)m~3/(N·m),均小于其余三种配对方式,表明复合材料具有较好的摩擦学性能.复合材料表面产生了抛光效应,主要磨损机理为犁削效应;配对的CFRPEEK磨损机理为犁削机理,纳米金刚石颗粒的加入有效抑制了塑性变形的发生.     

纯铝在耐热铝合金高温变形过程中的润滑作用

采用圆环压缩法检测Al-Fe-V-Si系合金在喷射沉积高温时变形的摩擦因数,研究未加润滑剂、加石墨+机油润滑、加纯铝润滑、加纯铝+石墨+机油润滑4种条件下的摩擦因数随变形温度变化的情况,并探讨其润滑机理。研究结果表明,纯铝润滑以及纯铝+石墨+机油润滑均能有效地改善摩擦状况,其摩擦因数只有未加润滑剂时的1/3~1/4。采用纯铝润滑制备出外径×内径×长度为417 mm×340 mm×300 mm的正挤压管材,采用纯铝+石墨+机油润滑反挤制备出外径×内径×长度为520 mm×460 mm×1 000 mm的管材。     

双润滑铜基粉末冶金滑板载流磨耗试验与分析

针对研制的新型滑板进行了载流磨耗试验。室内磨耗试验造成滑板和接触导线磨损的主要原因是粘着磨损,工业运行试验中造成磨损的主要原因是粘着磨损、磨粒磨损和冲击磨损;受电弓滑板与接触导线的磨损是机械作用和强电流作用的综合结果,并相互影响和激化。在铜基滑板中加入固体润滑剂石墨和铅,以及采取外部双侧用高强石墨加强润滑起到了较好的润滑效果;由于粘着磨损和冲击磨损在滑板总磨损中占有相当比重,提高抗粘着性和提高机械强度是减小滑板磨损的有效途径,改善润滑效果是减磨的最有效办法。     

硫化异丁烯对航空钢油气润滑的影响

直升机齿轮传动要求有30⁶0 min的干运转能力,以免减速器润滑系统出现故障时,造成灾难性的后果。采用油气润滑方式,对T321进行不同质量分数的抗磨效果对比试验,为降低试验成本,以销盘摩擦磨损试验代替齿轮传动试验。不同含量的硫化异丁烯分别加入到DOD-L-85734航空油中,做航空钢摩擦副45 min的油气润滑试验。结果表明:抗磨效果最好的是添加量1%,只喷油气4次、用油量仅0.02 mL,则其45 min的磨痕宽度仅为427μm,而干摩擦仅50 s的磨痕宽度却为632μm。含抗磨剂的油气润滑为解决直升机传动系统干运转问题提供了一种可行方案。     

设备润滑误区与合理润滑管理建议

通过对目前存在的润滑误区的阐述和分析,提出五点润滑管理建议,希望能对从事设备润滑管理的同仁一定的启发和帮助,提高设备的合理润滑管理.     

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     

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