一种宽电压输入范围降压稳压电路的设计

为了解决高压恒流源芯片内部低压模块供电问题,通过集成降压预调整电路、前置基准源和线性稳压器3个模块,设计了一种宽电压输入范围的降压稳压电路.采用0.6μm BCD工艺模型进行仿真验证.结果显示,降压预调整电路低压跟随时压差在50mV内.输入在6～40V范围内变化时,偏置和基准的变化分别为1.13mV和0.3mV幅度.线性稳压器直流下PSRR可达-85dB,在1MHz工作频率下,输入电压为6V和40V时,模拟电源变化幅度分别不超过24mV和46mV,数字电源变化幅度分别不超过0.3V和0.8V.该降压稳压电路已成功应用于高压LED恒流源中.     

埋置电容PCB工艺的开发和量产

根据客户埋置电容PCB量产需求,开发了A与B两种埋容材料的埋置电容工艺,分别为A单面蚀刻工艺与B双面蚀刻工艺。针对客户特殊设计的特殊要求,成功开发了0.1 mm激光通孔埋容板工艺。根据两种埋容材料的不同工艺,进行了理论研究和批量生产,重点研究了翘曲、板损、埋容精度控制、误差控制等问题,设计了埋容板插板架来解决阻焊油墨制作问题并推广。进行上述研究的同时,总结出适合我司的埋容工艺,形成埋容板生产控制文件,实现公司埋容板从试板向量产的飞跃,为公司提供了新的利润增长点。     

基于VC＋＋6．0和数据库的档案管理系统设计与实现

随着信息科技的发展,特别是计算机技术越来越广泛且深入的应用,为企业信息化管理提供了重要手段。介绍在VisualC＋＋6．0与Access开发环境下,利用标准的SQL结构化查询语言,选用ODBC数据库访问技术,将原有的纸质档案信息存储在数据库中,以实现企业产品档案管理系统。通过设置不同级别的访问权限,可实现对产品信息数据的有效管理。该系统试运行稳定,实践证明其开发流程适于中小型企业数据库管理系统的建立。     

基于激光扫描技术的三维模型重建

通过分析三维激光扫描系统获取的点云数据,得到了利用点云数据构建三维模型的技术、方法和流程。介绍了利用地面三维激光扫描仪获取点云数据的过程以及结合RiSCAN PRO软件和Geomagic Studio软件进行建模的方法。对原始测量的点云数据进行处理(去除噪声,平滑,对多站点数据做拼接配准,提取目标建筑物等)得到正确和完整的目标建筑物的表面信息,然后构建三角网建立它的三维表面模型,最后通过所拍的照片进行纹理映射得到真实的三维模型。实验结果表明,利用上述方法可以有效地处理三维激光扫描获取的点云数据,实现对建筑物快速三维可视化建模。     

Controllable 1D Patterned Assembly of Colloidal Quantum Dots on PbSO4 Nanoribbons

Control of the 1D self‐assembly pattern of colloidal quantum dots (QDs) on PbSO₄ nanoribbon (NRb) templates is achieved. The internal structure of the NRbs is investigated by X‐ray diffraction, revealing the isotropic packing of the PbSO₄ nanoclusters in the NRbs. Colloidal QDs in a chloroform/hexane mixture are adsorbed onto the region close to the edges of the NRbs and form a 1D assembly of straight single line or double lines by controlling the amount of OAm. This is the first demonstration of a densely packed 1D self‐assembly of colloidal QDs with a straight line pattern without the use of any molecular bridge or adhesive. Atomic force microscopy measurements of the NRbs show depressions in the phase profile along the width of the NRbs, corresponding to the position of the 1D QD chain. The amount of adsorbed QDs on the NRbs in solution decreases as the addition of OAm increases, suggesting that additional OAm prevents interaction between the QDs and NRbs but facilitates the uniform adsorption of the 1D assembly. The low‐dimensional self‐assembly of colloidal QDs in this study opens up the possibility for the creation of anisotropically assembled QD superstructures.     

面向服务可靠性的云资源调度方法

随着云计算成为重要的信息基础设施,越来越多的应用迁移到云上,云服务的可靠性日益重要,尤其是边缘计算新模式的引入,对云服务可靠性提出了更高的要求.如何通过资源调度保障服务可靠性成为了当前研究的热点.为此,针对云-边协同的应用场景,开展面向服务可靠性的云资源调度方法研究,提出基于马尔科夫预测模型的云资源调度算法,实现节点负载判断、待迁移任务和节点选择、迁移路由的决策,以解决云服务节点失效情况下的任务调度和负载均衡问题,实现快速的云服务故障恢复,提高云服务的可靠性.实验结果表明,本文所提方法能够有效保证节点失效情况下的服务可靠性.     

基于STPA的机载平视显示系统安全性分析

平视显示（Head-up Display,HUD）系统属于航电安全关键系统,可以提高低能见度下的飞机运行安全,需要在系统研制过程中开展完善的风险识别与分析。随着系统复杂性的增加,传统方法很难捕获系统组件交互带来的危险。为此,采用系统理论过程分析（Systematic Theory Process Analysis,STPA）对HUD进行分析,充分考虑系统的多方交互,识别系统潜在的不安全控制行为,同时利用时间自动机理论及其工具UPPAAL对系统进行建模,验证STPA识别的不安全控制行为;最后设计了一个路径算法,对导致其发生的危险路径进行检索。结果表明,该方法能够识别出系统潜在的危险及其原因,减少了人为因素对分析的影响。     

一种占空比可调的高速电平转换电路

提出一种占空比可调的高速电平转换电路,能够将频率高达1.33 GHz的低电压域信号提升至高电压域输出。在传统电平转换电路的基础上,增加了占空比调节电路,使得电路工作在不同I/O域时,通过调整接入的PMOS管数量来间接调整控制管的宽长比,进而实现占空比可调。增加了快速响应电路,引入首尾相接的反相器组,通过正反馈功能,加速实现电平转换。基于Global Foundry 14 nm CMOS工艺进行电路设计,采用SPECTRE软件进行仿真。仿真结果表明,该电路能够实现从0.9 V核心电压到2.5 V I/O电压的稳定转换,传播延时为225 ps,占空比为49.63%。当高电压域电压变换为1.8 V后,通过占空比调节电路,使占空比仍可保持在50%左右。     

Exploiting In Situ Redox and Diffusion of Molybdenum to Enable Thin‐Film Circuitry for Low‐Cost Wireless Energy Harvesting

Direct additive fabrication of thin‐film electronics using a high‐mobility, wide‐bandgap amorphous oxide semiconductor (AOS) can pave the way for integration of efficient power circuits with digital electronics. For power rectifiers, vertical thin‐film diodes (V‐TFDs) offer superior efficiency and higher frequency operation compared to lateral thin‐film transistors (TFTs). However, the AOS V‐TFDs reported so far require additional fabrication steps and generally suffer from low voltage handling capability. Here, these challenges are overcome by exploiting in situ reactions of molybdenum (Mo) during the solution‐process deposition of amorphous zinc tin oxide film. The oxidation of Mo forms the rectifying contact of the V‐TFD, while the simultaneous diffusion of Mo increases the diode's voltage range of operation. The resulting V‐TFDs are demonstrated in a full‐wave rectifier for wireless energy harvesting from a commercial radio‐frequency identification reader. Finally, by using the same Mo film for V‐TFD rectifying contacts and TFT gate electrodes, this process allows simultaneous fabrication of both devices without any additional steps. The integration of TFTs alongside V‐TFDs opens a new fabrication route for future low‐cost and large‐area thin‐film circuitry with embedded power management.     

Fabrication and adhesion strength of Cu/Ni-Cr/polyimide films for flexible printed circuits

The adhesion strength of a Cu/Ni-Cr/polyimide flexible copper clad laminate (FCCL), was evaluated according to the thickness of the Ni-Cr (Ni:Cr = 95:5 ratio) seed layer using the 90° peel test. The changes in the morphology, chemical bonding and adhesion properties were characterized by SEM, AFM and XPS. The peel strength of the FCCL increased with increasing thickness of the Ni-Cr seed layer, due to the increase in the ion bombardment caused by the higher power used in the Ni-Cr sputtering process. This increase in the FCCL peel strength was attributed to the lower proportion of C-N bonds and higher proportion of C-O bonds in the polyimide surface. The adhesion strength between the metal and polyimide was mostly attributed to the chemical interaction between the metal layer and the functional groups of the polyimide.