基于双通道外部总线接口的LCD显示设计

以带有双通道外部总线接口的AT91SAM9263芯片为例,提出一种新的利用双通道外部总线接口实现LCD显示的方法。给出硬件电路、bootloader和Linux kernel等的具体实现,并测试系统性能,说明了双通道外部总线接口在提升系统性能方面的重要作用。     

基于ARM-Linux平台的机载数据采集记录装置设计

为适应现代飞行试验的要求,介绍了一种自主研发的基于ARM-Linux平台设计的机载数据采集记录装置,该装置能实时地获取飞机飞行时的各种参数,为飞机试飞的状况分析提供基本的数据和信息,并详细地介绍了该装置的软硬件构成。     

Corrosion Resistance of Ni-P Composite Coating on Mg Alloy： Critical Role of the Intermediate Phosphate Conversion Coating Layer for Suppressing Galvanic Couple Formation

Electroless nickel (EN) plating can give rise to the severe galvanic corrosion of the magnesium (Mg) alloy matrix, owing to its nobler electrochemical potential than Mg alloy. To hinder the formation of galvanic couple, an intermediate phosphate conversion coating (PCC) layer is introduced between the EN layer and the Mg alloy matrix. Since the ceramic-like PCC layer cannot be catalyzed, a low-cost Ag-activation technique is used to process the PCC layer before electroless plating. The cross-section morphology and element distribution of the PCC-EN composite coating indicate that the PCC intermediate layer can effectively separate the Mg alloy from the EN layer. Moreover, the results of electrochemical tests suggest that the PCC-EN composite coating has a better corrosion resistance in comparison with the EN coating and AZ91D Mg alloy.     

Hot Tearing Behavior of Mg-Gd-Y-X Alloys

Mg-Gd-Y-Zr alloy castings are widely used in the aerospace field owing to their high strength and excellent creep resistance. The castability of these alloys is also an important consideration for engineering application. Thus， the hot tearing susceptibilities (HTSs) of Mg-10Gd-1Y-1Zn-0.5Zr (VW91) alloy and Mg-10Gd-2Y-1Zn-0.5Zr (VW92) alloy are investigated with a constrained rod casting (CRC) mold. The microstructures and fracture surface are characterized by optical microscope and scanning electron microscope. The results unveil that the HTS of VW92 alloy is lower than that of VW91 alloy. The microstructures indicate that obvious tears can be observed in VW91 alloy， while the tears in VW92 alloy are tiny. The tear feeding and healing by eutectic are also observed in VW91 and VW92 alloys. Therefore， the lower hot tearing susceptibility of VW92 alloy is mainly attributed to the high amount of eutectic which feeds and heals tears. Besides， the effects of the coefficient of thermal expansion (CTE) and the fluidity of VW91 and VW92 alloys on their HTSs are discussed.