集电极偏置电流对硅npn晶体管γ辐照效应的影响

对硅npn双极晶体管(C2060)室温下不同集电极偏置电流条件下γ辐照的总剂量效应进行了研究.结果表明,npn晶体管的辐照损伤程度随着辐照总剂量的增加而增加;尤其是实验中发现:在相同的辐照总剂量下随着辐照时集电极偏置电流的增加,晶体管的辐照损伤程度却在减轻.空间电荷模型的观点并不能很好地解释辐照损伤与辐照集电极偏置电流的关系.文章对空间电荷模型进行了修正,认为除氧化物俘获电荷和界面俘获电荷外,还会在外基区Si-SiO2界面附近形成电中性的电偶极子.利用修正后的理论可以很好地解释所有的实验结果.     

基于DSP的双频超声波流量计硬件电路设计

超声波流量测量技术是一种利用超声波信号在流体中传播时所载流体的流速信息来测量流体流量的新的测量技术,他具有非接触式测量、测量精度高、测量范围宽、安装维护方便等特点,特别适合用于临时管道流量、大口径管道流量以及危险性流体流量的测量。本文介绍了一种采用数字信号处理技术的双频超声波流量计的硬件电路设计方法。     

Multistimuli‐Responsive Display Materials to Encrypt Differentiated Information in Bright and Dark Fields

Visually readable codes play a crucial role in anticounterfeiting measures. However, current coding approaches do not enable time‐dependent codes to be visually read, adjusted, and differentiated in bright and dark fields. Here, using a combined strategy of piezoelectric lattice selection, oxygen vacancy engineering, and activator doping, a lanthanide ion‐doped titanate is developed that integrates mechano‐, thermo‐, and photo‐responsive color change (>18 h for bright field), persistent luminescence (>6 h for dark field), and stimulus‐triggered multimodal luminescence. The feasibility of optical encoding, visual displaying, and stimulus‐responsive encrypting of time‐dependent, dual‐field information by using the developed material is demonstrated. In particular, the differentiated display of dual‐field modes is achieved by combining mechanostimulated abolition of only the persistent luminescence and thermo‐ and photostimulated reversal of both the color change and persistent luminescence. The results provide new insights for designing advanced materials and encryption technologies for photonic displays, information security, and intelligent anticounterfeiting.     

一种低调谐增益变化的宽带电感电容压控振荡器

设计了一个应用于数字电视调谐器的宽带电感电容压控振荡器.该振荡器包含了一个开关可变电容阵列,用以抑制调谐增益的变化.整个电路采用0.18μm CMOS工艺实现.测试结果表明:压控振荡器的频率范围从1.17GHz至2.03GHz(53.8%);调谐增益从69MHz/V变化至93MHz/V,其变化幅度与最大值相比为25.8%;最差相位噪声为-126dBc/Hz@1MHz;在1.5V电源电压下,压控振荡器的功耗约为9mW.     

Anti-collusion fingerprinting for multimedia

Digital fingerprinting is a technique for identifying users who use multimedia content for unintended purposes, such as redistribution. These fingerprints are typically embedded into the content using watermarking techniques that are designed to be robust to a variety of attacks. A cost-effective attack against such digital fingerprints is collusion, where several differently marked copies of the same content are combined to disrupt the underlying fingerprints. We investigate the problem of designing fingerprints that can withstand collusion and allow for the identification of colluders. We begin by introducing the collusion problem for additive embedding. We then study the effect that averaging collusion has on orthogonal modulation. We introduce a tree-structured detection algorithm for identifying the fingerprints associated with K colluders that requires O(Klog(n/K)) correlations for a group of n users. We next develop a fingerprinting scheme based on code modulation that does not require as many basis signals as orthogonal modulation. We propose a new class of codes, called anti-collusion codes (ACCs), which have the property that the composition of any subset of K or fewer codevectors is unique. Using this property, we can therefore identify groups of K or fewer colluders. We present a construction of binary-valued ACC under the logical AND operation that uses the theory of combinatorial designs and is suitable for both the on-off keying and antipodal form of binary code modulation. In order to accommodate n users, our code construction requires only O(/spl radic/n) orthogonal signals for a given number of colluders. We introduce three different detection strategies that can be used with our ACC for identifying a suspect set of colluders. We demonstrate the performance of our ACC for fingerprinting multimedia and identifying colluders through experiments using Gaussian signals and real images.     

基于瑞萨微控制器的温度控制系统设计

为了提高传统温度控制系统的性能,将PID控制理论与嵌入式系统相结合,采用瑞萨电子公司的H8S/2166作为核心处理器,AD公司的AD7705以及热敏电阻温度传感器作为温度检测单元,利用4×6小键盘、LCD显示器和S1D13305液晶控制器达到良好的人机交互,设计出了一个应用于化工领域的嵌入式实时温度控制系统。相比于传统温度控制系统,该系统提供了更强的计算能力和可扩展能力,采用增量PID控制算法实现复杂控制。通过实验,该系统能达到0.1℃的温度控制精度以及小于120 s的温度稳定时间。     

基于低压高精度运放的带隙基准电压源设计

基于传统带隙基准源的电路结构,采用电平移位的折叠共源共栅输入级和甲乙类互补推挽共源输出级改进了其运算放大器的性能,并结合一阶温度补偿、电流负反馈技术设计了一款低温度系数、高电源电压抑制比(PSRR)的低压基准电压源。利用华润上华公司的CSMC 0.35μm标准CMOS工艺对电路进行了Hspice仿真,该带隙基准源电路的电源工作范围为1.5～2.3 V,输出基准电压为(600±0.2)mV;工作温度为10～130℃,输出电压仅变化8μV,温度系数为1.86×10-6/℃,低频时PSRR为-72 dB。实际流片进行测试,结果表明达到了预期结果。     

TFT-LCD中隔垫物密度与Push Mura和低温气泡的关系

研究了隔垫物密度对Push Mura和低温气泡的影响.实验表明,通过增加隔垫物密度,能提高液晶面板的抗压强度,降低Push Mura发生率.但是,隔垫物密度过高会引起低温气泡发生.当隔垫物密度控制在适当范围内时,既能大大改善Push Mura,又不会发生低温气泡,且不影响产品的光学特性.     

HIPSCS：基于HIP的安全IP通信系统

针对主机标识协议(HIP, host identity protocol)实际部署应用的相关问题,设计实现了一种基于HIP的安全IP通信系统(HIPSCS, HIP based secure communication system)。该系统通过将主机标识(HI, host identifier)和用户身份证书唯一关联,实现了主机身份的实名化,以保障网络报文的源地址真实可信,并通过IPsec技术加密所有通信数据以达到安全通信目的。实现并在实验室环境中部署了HIPSCS原型系统。实验表明此通信系统可用性强,并能很好地支持移动通信。     

基于ERP环境下商务智能的企业信息化研究

物联网、云计算和移动互联网的出现和发展,促进了商务智能在ERP的应用,加速了企业信息化的进程.本文通过研究企业信息化,ERP和商务智能三者的联系,指出商务智能在ERP环境下的企业信息化存在的问题和机遇,并提出一种基于云计算的可行的商务智能的ERP系统.