近线性神经和元非线性神经元

人工神经网络(ANN)中普遍采用的神经元模型具有单调有界的I／O特性,该文称其为近线性神经元(ALN,approximate－linear neuron),ALN既简化了网络的复杂性,也是限制ANN能力的一个瓶径.通过比较Hopfield神经网络的稳定性和Conway生命游戏的复杂行为,该文提出非线性神经元(NLN,non－linear neuron)的概念,其I／O特性是完全非线性的.ALN可以进一步提高ANN的非线性,从而增强它的功能,余数制神经网络是一个例子.     

Characterization of alendronate sodium-loaded UHMWPE for anti-osteolysis in orthopedic applications

Ultra-high molecule weight polyethylene (UHMWPE) loaded with alendronate sodium (ALN), a potential drug to prevent debris-induced osteolysis, was developed in our previous study. This study aims to investigate the wear performance of UHMWPE-ALNs. In this study, wear test, mechanical test, differential scanning calorimetry (DSC) and contact angle test were applied to characterize the wear performance, mechanical behavior and physical properties of UHMWPE-ALNs. The effect of ALN on the wear performance of UHMWPE-ALNs was investigated by scanning electron microscope (SEM), back scattering electrons (BSE) and energy dispersive X-ray spectrum (EDX). The results of wear test showed that the friction coefficient and volumetric loss of UHMWPE-ALN 0.5 wt.% were comparable with those of UHMWPE. The result of SEM-BSE-EDX revealed that the wear debris detached easily from the ALN-agglomerated regions, which was mainly responsible for the decrease of wear resistance of UHMWPE-ALN 1.0 wt.%. The loaded ALN resulted in the increase of hydrophilicity of UHMWPE-ALNs. The decrease of toughness and crystallinity of UHMWPE-ALN 1.0 wt.% attributed to the non-uniform distribution of ALN. The UHMWPE-ALN 0.5 wt.%, in which no ALN agglomeration was observed, possessed approving mechanical properties and wear performance, might have potential clinical application to prevent the debris-induced osteolysis in prosthetic joints.     

G522MnNi5材质锤头铸件裂纹原因分析

材质为G522MnNi5的上锤头零件,在铸造过程中产生严重裂纹,通过对裂纹部位进行化学成分分析、金相组织分析以及电镜及能谱分析,确定由于冒口下Al含量偏高产生Al N组织,并富集于晶界,形成延迟性脆性裂纹。     

Integrated classifier simulator and neurochip VHDL implementation

In this work, the development of a simulator for a system capable of recognizing and classifying patterns into certain classes (families) is investigated. The classification system integrating hardware and software components is presented. The entire system simulator is developed using Java programming language, while its hardware parts are implemented and simulated using VHDL.     

Impact of post-deposition annealing on surface,bulk and interface properties of RF sputtered AlN films

Abstract

C axis oriented AlN films were deposited on silicon substrate by radio frequency reactive magnetron sputtering. Subsequently the films were annealed in a horizontal furnace at temperatures ranging from 400 to 800°C for 30 min in nitrogen ambient. The change in the morphological properties with annealing temperatures was investigated using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and atomic force microscopy techniques. Morphological studies revealed that the annealing increased surface roughness and grain size. In addition, Al–N bond density along with the crystallinity of the deposited films was improved with annealing. The electrical properties, namely the insulator charge density (Q _in) and the interface electronic state density (D _it), were estimated by the capacitance–voltage (C–V) measurements. It was found that the Q _in increased, but the D _it decreased with annealing temperature. Lower leakage current with improved resistivity and dielectric behaviour was also observed with annealing.     

AIN陶瓷粉末制备方法综述

就国内外AlN粉末合成的研究情况,综述了直接氮化法、Al_2O_3碳热还原法、自蔓延高温合成法、等离子体法、气溶胶法等几种主要的AlN粉末制备方法的特点和研究进展,分析了制备AlN粉末的主要发展方向。     

基于HIP4081的厚膜H桥电机驱动电路设计

为了实现小体积、高可靠的电机驱动与控制,利用HIP4081专用芯片和ALN厚膜混合集成技术,设计一种基于HIP4081的厚膜H桥电机驱动电路,完成了H桥式驱动电路对电机双向转动和调速的控制.经实际应用,该电路不仅安全可靠地实现了电机的双向转动和调速功能,且产品体积小,导热性能好,效率高;还能在恶劣的使用环境下安全工作,提高了驱动电路和系统的可靠性,适合军、民两用.     

Phosphoric acid treated AlN powder for aqueous processing of net-shape dense AlN and β-SiAlON parts

Abstract

Due to fast hydrolysis of AlN when in contact with water, AlN based ceramics are processed in organic solvents, which are volatile, expensive, harmful to the health and environment. The present work intends to protect AlN powder against hydrolysis in order to enable aqueous processing of AlN based ceramics. A commercial AlN powder was treated in an ethanol solution of H₃PO₄ and Al(H₂PO₄)₃ kept at 80°C for 24 h to protect it from hydrolysis. The dispersing behaviour of the treated AlN powder in water and the ability to consolidate defect free parts of AlN and β-Si₄Al₂O₂N₆ ceramics from aqueous suspensions by slip casting and gelcasting techniques were studied. The consolidated parts were then sintered in a graphite furnace and the sintered bodies exhibited properties [bulk density (BD), apparent porosity (AP), crystalline phase composition and microstructural features] similar to those reported in literature for the same materials processed from organic media.     

无线局域网通信安全机制研究

随着无线局域网（WLAN）应用规模不断扩大,其通信安全问题备受业界关注。通过分析现有的WLAN在物理层、数据链路层和网络层三个层次的安全机制,从访问控制和数据加密两个方面指出了其局限性和缺陷,提出了运用隔离技术、升级加密方案和VPN技术等措施构建多层次的安全体系,确保WLAN通信安全。     

硫酸铝和蔗糖合成ALN纳米粉实验研究

利用硫酸铝和蔗糖合成ALN纳米粉，通过X射线衍射仪对实验产物进行物相分析，以确定产物的物相组成。采用PhilipsEM420分析电子显微镜观察ALN颗粒粒度为50nm，同时对合成机理进行了研究。通过实验结果表明该方法可行。