半球谐振陀螺温度特性及补偿分析

半球谐振陀螺仪(HRG)是一种高精度、高可靠、长寿命的新型固体振动陀螺仪。温度变化会影响半球谐振陀螺的漂移、零偏等性能指标。为减小这种影响,该文通过研究分析半球谐振陀螺的温度特性,设计了温度补偿电路。采用温度补偿电路后,半球陀螺漂移精度从0.05 (°)/h提高到0.03 (°)/h。     

基于不同衬底的二氧化硅可调复用器/解复用器的单片集成芯片研究

分别设计制备了基于石英衬底和硅衬底的16通道200 GHz二氧化硅可调复用器/解复用器.该器件由一个16通道200 GHz的阵列波导光栅(AWG)和Mach-Zehnder干涉型热光可调光衰减器(VOA)阵列构成.在衰减量达到20 dB的时候,基于石英衬底的器件的外加偏压和功耗分别是11.7V和110 mW;而基于硅衬底的器件的外加偏压和功耗分别是22V和380mW.分析了基于不同衬底的器件性能出现差别的原因,并设计了新的结构,提高了器件性能.     

基于游标干涉的新型高灵敏度微环传感器

设计并分析了一种基于游标效应的光学传感器.采用截面尺寸为220 nm×500 nm的SOI矩形波导来进行分析.传感器的灵敏度为4.5×104 nm/RIU,探测极限低于10-4RIU.该传感器最重要的优点是,即使器件有很高的传输损耗和低的Q因子,仍有很高的灵敏度和低的探测极限.分析了热光效应对基于游标效应传感器的影响.分析结果也同样适用于其他基于游标效应的传感器.     

汽车电子的历史,现状与展望

电子技术的发展与应用极大地改善了汽车的功能和特征。从发动机控制到底盘设计，从音响系统到各种功能的传感器，电子革命对汽车正在产生越来越大的影响。本文综合美国汽车电子工业的有关资料，介绍汽车电子的发展历史与现状，以及美国汽车工业界对汽车电子发展的预测，分析关键技术的发展策略。     

React‐on‐Demand (RoD) Fabrication of Highly Conductive Metal–Polymer Hybrid Structure for Flexible Electronics via One‐Step Direct Writing or Printing

As a fast prototyping technique, direct writing of flexible electronics is gaining popularity for its low‐cost, simplicity, ultrahigh portability, and ease of use. However, the latest handwritten circuits reported either have relative low conductivity or require additional post‐treatment, keeping this emerging technology away from end‐users. Here, a one‐step react‐on‐demand (RoD) method for fabricating flexible circuits with ultralow sheet resistance, enhanced safety, and durability is proposed. With the special functionalized substrate, a real‐time 3D synthesis of silver plates in microscale is triggered on‐demand right beneath the tip in the water‐swelled polyvinyl alcohol (PVA) coating, forming a 3D metal–polymer hybrid structure of ≈7 µm with one single stroke. The as‐fabricated silver traces show an enhanced durability and ultralow sheet resistance down to 4 mΩ sq^?1 which is by far the lowest sheet resistance reported in literatures achieved by direct writing. Meanwhile, PVA seal small particles inside the film, adding additional safety to this technology. Since neither nanomaterials nor a harsh fabrication environment are required, the proposed method remains low cost, user friendly, and accessible to end users. With little effort, the RoD approach can be extended to various printing systems, offering a particle‐free, sintering‐free solution for high‐resolution, high‐speed production of flexible electronics.     

Field-Free Manipulation of Skyrmion Creation and Annihilation by Tunable Strain Engineering

Creation and annihilation of skyrmions are two crucial issues for constructing skyrmion-based memory and logic devices. To date, these operations were mainly achieved by means of external magnetic, electrical, and optical modulations. In this work, we demonstrated an effective strain-induced skyrmion nucleation/annihilation phenomenon in [Pt/Co/Ta]_n multilayers utilizing the shape memory effect of a TiNiNb substrate. A tunable tensile strain up to 1.0% can be realized in the films by thermally driving phase transition of the substrate, which significantly decreases the nucleation field of skyrmions by as many as 400 Oe and facilitates the field-free manipulation of skyrmions with the strain. Such a strain effect can be attributed to the synergetic interplay of the planar magnetic moment twirling and decrement of interfacial Dzyaloshinskii–Moriya interaction. In addition, the strain tunability is found to be strongly related to the strain direction due to magnetoelastic interaction. These findings provide a novel strategy for developing strain-assisted skyrmion-based memory and logic devices.     

有无外磁场下铁在H_2SO_4 K_2Cr_2O_7溶液中的电化学状态和阴极极化行为

在[H_2SO_4]为0.1～2mol/L,[K_2Cr_2O_7]为0.01～0.4mol/L的范围内,研究了Fe/H_2SO_4 K_2Cr_2O_7系统的电化学状态和阴极极化行为,讨论了[H_2SO_4]、[K_2Cr_2O_7]和[H_2SO_4]/[K_2Cr_2O_7]比值与Fe的电化学状态的关系。分析了所出现的五种类型阴极极化曲线和外磁场对阴极过程的影响。     

柠檬酸对液相燃烧合成尖晶石型LiMn2O4的影响

以醋酸锰和醋酸锂为原料，柠檬酸为燃料，研究了不同柠檬酸用量及不同硝酸浓度改性对液态燃烧合成法制备尖晶石型LiMn2O4的影响。结果表明，柠檬酸与锰离子的摩尔比≤0．5时，所得产物的主晶相为LiMn2O4，含有极少Mn2O3等杂质；〉0．5时，所得产物主要为Mn2O3，LiMn2O4含量较少。燃烧反应产物中LiMn2O4相对含量随硝酸浓度的升高而增加，当柠檬酸与锰离子的摩尔比为0．1，硝酸浓度为2mol／L时，所得尖晶石型LiMn2O4较纯净且结晶性较好，但晶体粒子尺寸分布不均。     

Growth mechanism of black ceramic layers formed by microarc oxidation

Black ceramic layer containing V₂O₃ was obtained on aluminum alloy surface by microarc oxidation. When ammonium metavanadate (NH₄VO₃) with a 6g/L concentration was added into the commonly used (NaPO₃)₆ and Na₂SiO₃ solution, obtained ceramic layers change from white appearance to black. Surface and cross-section morphology of the ceramic layer were revealed by SEM. In-layer concentration and chemical state of vanadium were investigated by EDS and XPS, respectively. Layer thickness was measured by eddy current thickness meter. Compared with inner sublayer, an outer sublayer with a thickness of approximate 4μm formed on the surface which shows higher vanadium concentration. It is proposed that the V₂O₃ formed in this sublayer causes the obtained black appearance. During the microarc oxidation process, VO₃⁻ contained in the solution adsorbed on the surface of metastable oxide phases and transit to vanadium oxide by the instantaneous high temperature in the heat-affected zone of microarc. It is found that the growth of the black ceramic layer has two different stages. At the first stage the micro-zones containing vanadium are formed and expanded. After the microarc oxidation processing was started for 3min, the adsorption of VO₃⁻ on the metastable oxides plays a primary role in the growth of the black ceramic layers.     

在"读图时代"建造

“读图时代”与建筑实践报纸、杂志、小册子、广告牌、电子公告栏、T恤衫和小茶杯上的符号和图案,大街上的商品推广秀、电影首映式和乐队演唱会、电台的声音、电视屏幕的影像,还有几乎与用电插座一样多的互联网接口等等,这是一个媒体无所不在的时代,也是信息迅速膨胀和广泛传播