玻璃切割机液压系统设计及系统性能仿真分析

为了优化系统参数,防止玻璃切割机在使用过程中发生运动部件爬行、运动速度不稳定的现象．首先根据使用要求拟定了液压传动系统原理图,确定了系统主要参数及液压缸的结构,然后利用液压系统原理建立了数学模型,并以此为基础利用AMESIM仿真软件建立了仿真模型,通过仿真得到了系统工作各阶段压力变化曲线、速度变化曲线。仿真结果表明,玻璃切割机液压系统工作各阶段压力、速度响应迅速,工进开始时速度波动幅度较大,但很快趋于稳定,与实际运行结果吻合,满足机床使用性能要求。     

Dry sliding wear of short glass fibre reinforced zinc–aluminium composites

The present investigation aims to evaluate the wear rate of ZA-27 alloy composites reinforced with short glass fibres from 1 to 5% in steps of 2 wt%. The compocasting method was used to fabricate the composites. A pin-on-disc wear testing machine was used to evaluate the wear rate. The results indicated that the wear rate of the composites was less than that of the matrix alloy, but increased with the increase in load and the sliding distance. It was found that above a critical applied load, there exists a transition from mild to severe wear both in the unreinforced alloy and in the composites, but the transition loads for the composites are much higher than that of the unreinforced alloy, and increases with the increase in weight% of glass fibres. The observations have been explained using scanning electron micrography (SEM) analysis of the worn surfaces and the subsurface of the composites.     

石蜡驱动器感应加热耦合场的数值模拟

结合实验结果,应用改进的ANSYS软件,采用一维轴对称模型对石蜡热膨胀驱动器中频感应加热温度及其分布进行了数值模拟.介绍了正弦电流感应加热中电磁-热耦合分析的数学模型和分析步骤,石蜡的固-液相转变分析和玻璃有效导热系数处理.结果表明,数值模拟算法是非常有效的,模拟结果与实验测试结果具有非常好的一致性.     

Mechanisms of actin stress fibre assembly

Stress fibres are contractile acto-myosin structures found from many types of non-muscle cells, where they are involved in adhesion, motility and morphogenesis. Stress fibres typically display a periodic alpha-actinin-myosin II pattern and are thus suggested to resemble the sarcomeric actin filament structures of muscle cells. Mammalian cells contain three categories of stress fibres: ventral stress fibres that are attached to focal adhesions at both ends, dorsal stress fibres that are attached to focal adhesions typically at one end and transverse arcs that are curved acto-myosin bundles, which do not directly attach to focal adhesions. In this review, we discuss the definition of stress fibres, organization of actin filaments and other components within these contractile structures, and the mechanisms of stress fibre assembly.     

车门玻璃升降器智能化软件的开发及其关键技术

以轿车车门玻璃升降器为研究对象,阐述了基于知识工程(Knowledge based engineering,KBE)的参数化、智能化车身零部件设计软件的开发过程及其关键技术。玻璃升降器设计系统是在集合最优的UG开发工具和设计方法的基础上,通过二次开发完成的。结合知识驱动自动化、知识熔接技术以及用户定义特征等重要的研究内容, 着重叙述该系统开发的工作流程及其所运用到的相关的关键的UG开发工具(UDU,KF,Wizard UI和UDF)以及有关开发的关键技术。作为基于UG平台而自主开发的车身部件参数化设计专用工具软件,该模块通过设计向导用户界面的设计风格,从实际应用上已经完全实现了车身部件设计的自动化和智能化,从而为车身设计人员提供了专业的智能化设计工具。     

变压吸附富氧装置在玻璃池窑的应用

变压吸附富氧装置在玻璃池窑的应用李化治郑克明（北京科技大学１０００８３）（沃克公司１０００２５）唐文龙（北京玻璃五厂）ＡｐｐｌｉｃａｔｉｏｎｏｆＯｘｙｇｅｎ－ＲｉｃｈＧａｓｂｙＰＳＡｏｎＧｌａｓｓＴａｎｋＦｕｒｎａｃｅ￥ＬｉＨｕａｚｈｉ（Ｕｎｉｖｅｒ...     

含氧化锂易熔瓶罐玻璃配方的研究与应用

含氧化锂易熔瓶罐玻璃配方的研究与应用魏绍先，吕远怀，杨立臣（沈阳玻璃制瓶厂１１００２１）ＳｔｕｄｙｏｎＣｏｍｐｏｓｉｔｉｏｎｓｏｆＣｏｎｔａｉｎｅｒＧｌａｓｓｅｓＣｏｎｔａｉｎｉｎｇＬｉｔｈｉｕｍＯｘｉｄｅａｎｄＴｈｅｉｒＡｐｐｌｉｃａｔｉｏｎｓ￥Ｗ...     

数字光盘玻璃基片的三步抛光技术

为得到超光滑的数字光盘母盘玻璃基片表面,研究玻璃基片的亚纳米级抛光技术。分别采用2 m、0.3 m超细氧化铈抛光液以及纳米氧化硅抛光液进行三步化学机械抛光(Chemical mechanical polishing, CMP),抛光后最终表面粗糙度Ra达到0.44 nm,为目前报道的数字光盘母盘玻璃基片抛光的最低值。原子力显微镜分析表明,抛光后的表面超光滑且无微观缺陷。通过对玻璃基片CMP中机械作用及化学作用进行分析,对抛光机理进行了探讨。     

Direct probing of solvent-induced charge degradation in polypropylene electret fibres via electrostatic force microscopy

Electrostatic force microscopy was used to directly probe solvent‐induced charge degradation in electret filter media. Electrostatic force gradient images of individual polypropylene electret fibres were used to quantify the extent of charge degradation caused by the immersion of the fibres into isopropanol. Electrostatic force gradient images were obtained by monitoring the shifts in phase and frequency between the oscillations of the biased atomic force microscopy (AFM) cantilever and those of the piezoelectric driver. Electrostatic force microscopy measurements were performed using non‐contact scans at a constant tip‐sample separation of 75 nm with varied bias voltages applied to the cantilever. Mathematical expressions, based on the capacitance of the tip‐sample system, were used to model the phase and frequency shifts as functions of the applied bias voltage to the tip and the offset voltage due to the fibre's charge. Quantitative agreement between the experimental data and the simplified model was observed.     

Hybrid composite friction materials reinforced with combination of potassium titanate whiskers and aramid fibre: Assessment of fade and recovery performance

Composite friction materials based on synergistic ternary combination of potassium titanate whiskers, aramid fibre and graphite have been characterized for friction braking performance on Krauss friction tester. The dynamics of friction build-up and friction-decay as a function of number of braking instances and modes of braking cycles have been found to be more consistent in the composites with ≥7.5 wt% of aramid fibres whereas the absolute friction effectiveness remained higher in the composites with ≥25 wt% of potassium titanate whiskers. Wear surface morphology has revealed topographical variations and their underlying role in controlling the friction and wear performance.