基于虚拟仪器的频率测量研究

阐述了一种基于虚拟仪器的正弦信号频率测量设计方案.结合相关原理和求导原理,提出了一种新的频率测量算法,该设计方案已成功应用于某型导弹的自动测试系统.实践证明,这项技术能提高测量精度,同时也能降低费用.     

Deep levels in superlattices

The physics governing deep levels in superlattices and quantum wells is elucidated, with emphasis on the importance of shallow-deep transitions caused by a band edge passing through a deep level, and the accompanying change in doping character of the impurity.     

X射线管结构与焦斑关系研究

X射线管是X射线机的心脏,是产生X射线的源泉<参考文献原文>。其焦斑大小及分布对整机图像清晰度起着决定性的作用。通过对X射线管结构特点、焦斑产生机理、电极结构与焦斑相关性实验的测试数据及理论分析等多方面的论述,探讨了X射线管结构尺寸对焦斑的影响。通过系列实验及理论分析表明:X射线管阴极结构对焦斑有巨大的影响。借助计算机模拟仿真计算,合理设计阴极结构,能够获取大小适中、分布均匀的焦斑,从而达到改善X射线机图像清晰度的目的。     

谱曲软件的开发与应用

随着科学技术的飞速发展,以及人民物质精神文化生活质量的逐渐提高,人们对于音乐的追求也越来越高。大型的演唱会和各类综合文艺晚会不仅要求演员艺术水平高超,对音乐效果和音乐表现力也有了较高需求。由此,MID（I乐器数字接口）应运而生。通过MIDI技术可以将不同乐器的优势集中到一起,形成其他乐器无法创作比拟的特殊音乐效果,但是,MIDI技术无法实现对音乐作品乐谱的分析。因此,迫切需要一种能够实现乐谱分析的软件程序对MIDI乐谱文件进行解析,实时翻译成乐谱来满足演奏者的需求。本文基于以上背景,提出了一种解析MIDI文件的谱曲软件分析工具开发方案,可以实现对MIDI乐谱文件的分析,将其翻译成对应的乐谱,使乐谱能够直观展示在演奏者面前。     

Joint frequency and time resource partitioning for OFDM-based small cell networks

This paper investigates the problem of distributed joint channel and time slot selection for interference mitigation in the multiple microcells system, where each microcell user determines which channel it should occupy and when it should get access to the serving microcell base station. Considering the characteristics of local interference, a distributed inter-cell time–frequency resource scheduling scheme is proposed, where neighboring users can get access to the same channel at different time slots or different channels at the same time slot. Then, a game is formulated to model the problem, in which the utility function of a individual user is the number of neighboring users occupying the same channel at the same time slot. It is proved to be an exact potential game with at least one pure strategy Nash Equilibrium (NE) point. Moreover, in order to achieve global interference minimization via local information, we propose the Heterogeneous Independent Revision Process (HIRP) to obtain the NE, which allows all users to update their selections simultaneously. Finally, numerical results show that our proposed HIRP guarantees that the interference minimization game converges to the NE and the proposed scheme acquires better performance compared with other existing interference management scheme.     

Work Function Tunability of Refractory Metal Nitrides by Lanthanum or Aluminum Doping for Advanced CMOS Devices

A lanthanum (La)-doped HfN is investigated as an n-type metal gate electrode on SiO₂ with tunable work function. The variation of La concentration in (HfinfinLa_1-x)N_y modulates the gate work function from 4.6 to 3.9 eV and remains stable after high-temperature annealing (900degC to 1000degC), which makes it suitable for n-channel MOSFET application. An ultrathin high-fc dielectric layer was formed at the metal/SiO₂ interface due to the (HfinfinLa_1-x)N_y and SiO₂ interaction during annealing. This causes a slight reduction in the effective oxide thickness and improves the tunneling current of the gate dielectric by two to three orders. We also report the tunability of TaN with Al doping, which is suitable for a p-type metal gate work function. Based on our results, several dual-gate integration processes by incorporating lanthanum or aluminum into a refractory metal nitride for CMOS technology are proposed.     

High-density NiSi nanocrystals embedded in Al2O3/SiO2 double-barrier for robust retention of nonvolatile memory

NiSi nanocrystals of high density and good uniformity were synthesized by vapor–solid–solid growth in a gas source molecular beam epitaxy system using Si₂H₆ as Si precursor and Ni as catalyst. A metal–oxide–semiconductor memory device with NiSi nanocrystal–Al₂O₃/SiO₂ double-barrier structure was fabricated. Large memory window and excellent retention at both room temperature and high temperature of 85 °C were demonstrated.     

基于红外传感器的智能车系统设计

以飞思卡尔半导体公司的MC9S12DG128B系列MCU为核心,设计智能车的系统框架,软件和硬件的设计方案。详细介绍了电源模块和电机驱动模块在设计过程中遇到的问题和解决方案。     

窄带物联网信号对卫星广播电视接收的影响分析

窄带物联网(NB IoT)下行信号采用功率密度谱提升技术,NB IoT下行信号可能和某些卫星数字广播频道对应的中频频率相同,当卫星数字广播电视接收站距离NB-IoT基站较近时,在某些条件下,会对卫星数字广播接收的中频信号产生同频串扰,导致接收误码率高,严重影响音频广播节目的 接收质量,通过变换本振频率可以避免干扰.通过...