铸造耐磨材料在硝酸中的磨料磨损试验研究

研究了１种珠光体钢及２种白口铸铁在硝酸中的磨粒磨损，结果表明，所有３种材料均发生了腐蚀与磨损相互催化的叠加作用，导致严重磨损。     

疲劳磨损和压碎磨损的应力计算

本文利用弹性接触理论对接触面的切应力和法应力进行叠加，然后经数值积分求出接触面附近区域的应力曲线．利用所作的应力曲线，进一步研究了疲劳磨损、剥层、压碎磨损的形成机理     

轮胎偏磨损机理及数值解析方法研究

在车辆-轮胎-地面系统力学范畴内对轮胎偏磨损机理进行了探讨，定义了轮胎偏磨损的概念，指出了滑移力和滑移速度在轮胎轴向和周向上的梯度变化是造成轮胎偏磨损的根本原因．着重介绍了现有轮胎偏磨损预测计算模型：有限单元法，单位磨损里程表示法及磨损能量计算法．并对这三种方法进行了比较和评价，提出今后轮胎偏磨损的研究发展方向．     

基于组合型阈值分割的在线立铣刀侧刃磨损测量

在实际生产中，现场测量立铣刀侧刃磨损是一项艰巨的工作．光照条件、刀具空间几何形状和初始位置的标定等因素对刀具磨损参数的测量精度影响很大．针对上述问题，提出了一种基于组合型阈值分割方法的在线立铣刀侧刃磨损测量方法，在保证测量精度的情况下最大限度地获取刀具磨损参数的有效信息．首先，提出一种图像剪切策略对捕捉到的磨损区域不同光强下的原始照片进行预处理，选取弱光下的刀尖区域和强光下的均匀磨损区域作为数据源；其次，对该数据源采用包含改进的直方图法和局部阈值分割法的组合型阈值分割法进行磨损区域提取；然后，将两种方法的结果进行叠加，去除磨损区域以外的多种噪声，并根据第1步的剪切位置，将分割后的刀尖区域图像与均匀磨损区域图像拼接，得到完整的磨损区域；最后，利用最小二乘法求出原始切削刃位置，标定磨损区域图像，计算刀具磨损参数．在立铣刀磨损实验中，测得侧刃的最大磨损量的精度大于98%，最大误差不超过5μm．实验结果表明，本文提出的方法能够获取全面的磨损区域信息，给出完整的磨损区域和精确的刀具磨损参数，有助于更加可靠地评估刀具磨损状态．     

陶瓷刀具切削不锈钢的切削性能及其失效机理分析

考察了Ｓｉ３Ｎ４基和Ｔｉ（ＣＮ）基两种陶瓷刀具切削１Ｃｒ１８Ｎｉ９Ｔｉ不锈钢的耐磨性能，对磨损表面进行了观察和分析，结果表明：ＦＤ０３在进刀量为０．１ｍｍ时，磨损值随切速变化比较稳定，在切速１．６ｍ／ｓ时出现最小磨损。进刀量为０．４ｍｍ时，磨损值出现跳跃，ＦＤ０３的主要磨损机制为微崩和粘着剥落；ＦＤ２２在两种进刀量条件下，出现了最佳切削速度（２．２ｍ／ｓ），其主要磨损机制是高温引起的陶瓷粘结剂的熔化导致粘着剥落。     

增韧Al_2O_3陶瓷的摩擦学性能研究（Ⅰ）──无润滑条件下淬火GCr15钢与陶瓷对磨

本文对三种不同性能的Ａｌ２Ｏ３陶瓷与淬火钢在无润滑条件下的摩擦磨损机理进行实验分析，发现摩擦付的摩擦系数几乎与陶瓷的力学性能无关，但陶瓷的磨损速率与陶瓷力学性能特别是断裂韧性之间存在一定的关系．在于摩擦条件下，由于粘着力作用，金属从对偶件转移到陶瓷表面，转移的金属膜厚度往往超过陶瓷峰元的高度，从而隔开了陶瓷与金属的直接接触，陶瓷的主要磨损机制是摩擦表面的裂纹源在疲劳应力作用下沿薄弱的晶界扩展，最终形成磨拉的脱落，造成陶瓷磨损．     

陶瓷刀具硬态车削铁基烧结合金的磨损性能

通过对Al2O3／(W，Ti)C陶瓷刀具硬态车削铁基烧结合全的试验研究，分析了刀具的磨损特性及机理，探讨了切削参数、材料特性对刀具磨损的影响．结果表明：Al2O3基陶瓷刀具是硬态车削铁基烧结合金的一种较理想的刀具材料，其主要磨损机制为伴随有微崩刃和剥落的磨粒磨损和粘附磨损；当切削速度过高时，刀具的破损为主要失效形式．     

团球γ+(Fe,Mn)3C/γ钢基自生复合材料的磨损机理及临界载荷确定

利用MPX-2000型主轴盘销式磨损试验机和扫描电子显微镜(SEM)研究了团球γ (Fe，Mn)3C共晶体增强奥氏体钢基自生复合材料(EAMC)在干摩擦磨损工况下的滑动磨损特征．试验表明，EAMC的磨损过程存在跑合与稳态磨损2个阶段，跑合阶段中主要发生奥氏体基体的强烈塑性变形与流动，稳态磨损阶段中的磨损机制主要为剥层磨损．团球共晶体作为主要的承载物体承受摩擦磨损作用，推迟位错集中区的形成和磨粒在对偶件上的积聚，能有效地减小EAMC磨屑的形成和脱落，降低EAMC的磨损量，提高EAMC向严重磨损转变的，临界载荷．修正了颗粒增强复合材料向严重磨损转变的临界载荷判据，采用该判据所确定的EAMC临界载荷与实验结果吻合．     

陶瓷磨削中金刚石砂轮磨损形式及其生成原因

设计并进行了模拟金属结合剂金刚石砂轮磨削陶瓷的试验．在扫描电镜下，对金刚石砂轮块磨损形貌进行直接观察研究，揭示砂轮磨损形式．利用摩擦学系统分析方法，对磨削系统中的关键要素，如金刚石砂轮、陶瓷工件、空气介质及冷却液等对金刚石砂轮磨损的影响进行了探讨，研究了金刚石砂轮磨损的生成原因     

NiCrBSi激光熔敷层组织及腐蚀磨损行为

应用５ｋｗ—ＣＯ２激光器在４５钢基材上进行镍基合金激光熔敷处理．观察并测定了激光熔敷层的组织及显微硬度分布，着重探讨了该合金激光熔敷层在不同条件下的腐蚀磨损行为．试验结果表明，在酸性介质中，激光溶敷层的腐蚀磨损速率随介质浓度及冲击速度的提高而线性增加，其中冲击速度影响较为显著．激光熔敷层的腐蚀磨损失效是以磨料磨损为主，失效机制是显微切削并伴随着凿削磨损。     

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