Molecular dynamics studies of atomic-scale tribological characteristics for different sliding systems

A slider-slab sliding model for hard-to-soft and soft-to-soft sliding systems with abrasive and non-abrasive wear conditions is used to investigate atomic-scale friction. The molecular dynamics simulation uses the Morse potential to calculate interatomic forces between atoms. Separation distance between the slider and the slab is changed to simulate repulsive and attractive interactive force fields exerted on interface between two sliding components. Effects of the interaction potential parameters on the sliding friction are investigated. The relationship of frictional force, normal force and temperature rise of the slider and the slab during sliding are established. Comparison of the hard-to-soft and the soft-to-soft sliding system are carried out and shows different tribological phenomena.     

ZVF型调节阀中不同阀瓣型线对局部流阻的影响

调节阀中不同阀瓣型线构成的通道，其局部流阻是不一样的。通过应用ANSYS2软件对DN50mmZVF型调节阀几种阀瓣型线在不同开度下构成的通道结构模型进行计算，从而得出流阻系数与开度的关系，并通过比较得到最佳阀瓣型线。该方法有很好的工程应用价值。     

聚脲改性聚酰胺多胺环氧氯丙烷涂布抗水剂的研究

制备了高含固量，稳定性好的聚脲改性聚酰胺多胺环氧氯丙烷，通过实验研究了其作为涂布抗水剂的应用工艺及作用机理，分析了多种因素对产品性能和贮存稳定性的影响。     

Optimization of abrasive water jet cutting of ductile materials

Full factorial design of experiments was developed in order to investigate the effects of jet pressure, abrasive mixing rate, cutting feed, and plate thickness upon three response variables, surface finish of cutting wear zone, percentage proportion of striation free area, and maximum width of cut. The set of sixteen experiments was performed on each of the following two ductile materials: AISI 4340 (high strength low alloy steel, hardened to 49HRc) and Aluminum 2219. Analysis of Variance (ANOVA) was performed on experimental data in order to determine the significance of effects of different parameters on the performance measures. It was found that cutting feed and thickness were highly influential parameters, while abrasive mixing rate is influential upon surface roughness only. Strong interaction was found between jet pressure and workpiece material. Multi-criteria numerical optimization was performed in order to simultaneously maximize/minimize different combinations of performance measures.     

高聚物中渗入C_(60)/C_(70)后计算内阻的压力函数法

应用宏观力学模型对高聚物渗入Ｃ６０／Ｃ７０后的微观内阻机理进行力学分析,提出分子滚珠轴承的设想,得出计算内阻的压力函数法和滚滑内阻权函数的概念。     

自干型有机硅耐烧蚀涂料制备及性能研究

针对室外露天使用的大型高温燃烧炉设备的表面防护,研制一种能够室温自干的有机硅耐烧蚀涂料。以特种环氧改性有机硅树脂作为成膜树脂,复配可熔融陶瓷粉、金属粉、耐高温填料制备有机硅耐烧蚀涂料。结果表明,所制备涂料适合在户外大面积施工应用,能在室温条件下自然干燥,无需高温加热固化,具有优异的耐热性与耐烧蚀性,可在500℃高温环境下长时间使用,可短时承受1000℃高温火焰烧蚀,并展现良好的耐中性盐雾与耐湿热性能,满足在室外大型高温燃烧炉设备表面施工与应用要求。     

开关磁阻电机调速系统在莱钢热轧带钢中的应用

文章介绍了开关磁阻电机调速系统的结构、原理及在莱钢轧钢厂热轧带钢生产线上的应用。     

Performance of N95 elastomeric respirators in high humidity and high coal dust concentration environmentOA

High humidity and high dust concentration in deep coal mines may severely challenge the performance of respirators worn by coal miners.This paper aims at quantitatively evaluating the respirators used in deep coal mines and providing scientific guidance for the respiratory protection of miners.Based on the self-designed in-situ PM_2.5collector,controllable PM_2.5generator,human breathing simulator,and respirator simulation testing system,under the simulated deep mine working ...     

单试样三点柔度法测金属材料JR曲线及其条件起裂值

在单试样卸载柔度法及单试样三曲线法基础上,提出了一种更简便的测定金属材料ＪＲ曲线及其条件起裂值的单试样三点预先度法,并用该方法测定了１Ｃｒ１／２Ｍｏ钢、１６ＭｎＲ风和ＷＣＦ６２钢的ＪＲ曲线及其条件起裂值,与标准的多试样法相比,误差均在工程许可范围内。     

浇注型耐热聚氨酯树脂材料的合成及性能

以二异氰酸酯(4,4’-二苯甲烷二异氰酸酯MDI;4,4’-二环己基甲烷二异氰酸酯Hl2MDI),聚醚多元醇(PPG),小分子交联扩链剂,催化剂及助剂合成了一系列耐热聚氨酯树脂材料。用FT-IR表征了结构,用X射线衍射分析了微观结构,用DSC,TGA对其热稳定性进行了分析测试,对力学性能也进行了测试。结果表明,合成的聚氨酯材料具有高耐热性和卓越的力学性能。