Feature‐Based Relation Classification Using Quantified Relatedness Information

Feature selection is very important for feature‐based relation classification tasks. While most of the existing works on feature selection rely on linguistic information acquired using parsers, this letter proposes new features, including probabilistic and semantic relatedness features, to manifest the relatedness between patterns and certain relation types in an explicit way. The impact of each feature set is evaluated using both a chisquare estimator and a performance evaluation. The experiments show that the impact of relatedness features is superior to existing well‐known linguistic features, and the contribution of relatedness features cannot be substituted using other normally used linguistic feature sets.     

Spectrally‐Efficient Decode‐and‐Forward Scheme Based on Constellation Rotation

A spectrally‐efficient scheme is proposed for orthogonal decode‐and‐forward relaying. By utilizing constellation rotation, the scheme can achieve twice the spectral efficiency as that of the conventional one, with low implementation complexity. It can offer a full diversity order as well, whereas the loss in coding gain is less than 1 dB for practical environments.     

Controlled Synthesis of Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>/Ag Core–Shell Composite Nanoparticles with High Electrical Conductivity

The presented method provides an easy processing route to synthesize Fe₃O₄/Ag core–shell composite nanoparticles. Their structures were characterized by x-ray diffraction and transmission electron microscopy. The average size of the Fe₃O₄ core and Ag shell was about 32.0 nm and 5.0 nm (or 28.0 nm), respectively. Furthermore, magnetic measurements showed that the composite nanoparticles exhibited typical superparamagnetic behavior, specific saturation magnetization of ca. 24.0 emu/g, and intrinsic coercivity of 106.0 Oe. At the same time, high conductivity (64.7 S/cm) of the composite nanoparticles was also observed. This method provides an opportunity to synthesize other core–shell (Fe₃O₄) nanoparticles in a single step.     

智能测控系统中的RS485总线和CAN总线

20世纪80年代德国Bosch公司成功开发出控制器局域网(CAN)总线,为分布式控制系统实现各节点之间实时、可靠的数据通信提供了强有力的技术支持,其成功应用于工业机动控制、铁路引擎控制单元、船用电子设备、医用设备、复杂传感器等诸多领域.而基于RS485总线的网络分布式测控系统,由于具有结构简单、抗干扰能力强、传输距离远、成本低等优点,因此被广泛应用于工业现场.文中简要介绍了RS485和CAN总线特点,给出了CAN总线应用于测控网络的构建方法,同时针对RS485总线网络中的通讯冲突问题,寻求了一种有效的解决办法.     

固态发射机固态功放管特点及更换浅析

固态发射机因工作带宽较宽,无散弹效应,信噪比高等优点,占据了90％以上的份额。为了更好地使用和维修发射机,笔者就大功率MOSFET场效应晶体管的特点及其更换方法做了相关技术探讨。     

氧化物缓冲层制备Si(111)基GaN纳米线

采用氧化物缓冲层,通过射频磁控溅射系统依次在n型Si(111)衬底上沉积Ga2O3/ZnO(Ga2O3/MgO)薄膜,然后将薄膜于950℃氨化合成GaN纳米结构,氨化时间为15min。采用X射线衍射(XRD)、傅里叶红外吸收谱(FTIR)和高分辨透射电镜(HRTEM)对样品的结构进行了分析,结果显示两种缓冲层下制备的样品均为六方纤锌矿单晶GaN纳米结构,且缓冲层的取向对纳米线的生长方向有很大影响;采用扫描电镜(SEM)对样品的形貌进行了测试,发现纳米线表面光滑,长度可达几十微米,表明采用氧化物缓冲层制备了高质量的GaN线。同时对GaN纳米线的生长机理进行了简单讨论。     

Mutual injection-locking of two individual double-clad fibre lasers

Phase-locking and coherent beam combination of two individual double-clad fibre lasers by a novel extra-cavity mutual injection-locking method are proposed and experimentally demonstrated. Steady interference stripes with high contrast ratio (about 0.5) are observed. The output power of the phase-locked array exceeds 11 W and the power-combining efficiency is about 80%. No power-restriction optical components are utilised in the phase-locking experiment and the output power can be further up-scaled.     

基于故障树的接口模块Flash测试方法改进研究

故障树分析法是一种系统、可靠、逻辑性强的分析方法。分析接口模块硬件结构,建立UserFlash测试故障树模型、对故障分支进行分析,查明测试报故的原因,通过机理分析,改进Flash测试方法并进行验证。结果表明,改进后的测试方法能有效提高测试通过率和延长芯片使用寿命,具有很强的工程应用价值。     

关于物流机器人配送在社区疫情隔离中的应用探讨

机器人系统通常用于人工介入成本过高、危险过大或者效率过低的任务。近年来,随着人工智能、自动驾驶、物联网等众多相关学科的全面发展,机器人在很多行业的应用也越来越广泛、成熟;与民众生活密切相关的物流机器人的配送应用也在逐步发展;互联网下,电商的充分发展为物流机器人的配送应用提供了明确的应用场景。而在抗击新型冠状病毒肺炎疫情时期,区域人群需要实行严格隔离,隔断病毒人传人的感染途径。针对这样的状况,物流机器人可发挥其巨大优势,为民众提供物资配送服务,可有效隔断病毒人际传播,避免人员配送过程中可能带来的病毒扩散风险,针对性地解决疫情隔离阶段物资供给最后一里的难题。     

$nhbox{-ZnO}/nhbox{-GaAs}$ Heterostructured White Light-Emitting Diode: Nanoscale Interface Analysis and Electroluminescence Studies

n-ZnO/n-GaAs heterostructured light-emitting diodes have been fabricated by a low-cost ultrasonic spray pyrolysis technique. Nanoscale interface analysis was carried out with scanning transmission electron microscopy. An ~ 8.6-nm-thick amorphous GaAsZnInO was found in the n -ZnO/n-GaAs interface. A strong and broad white electroluminescence band centered at ~ 525 nm and a weak near-infrared emission peaked at ~ 815 nm were observed when n-GaAs was positively biased. The 815-nm emission is believed to be related to the interface layer, and the 525-nm emission is assigned to the recombination of electrons from conduction band to deep-level holes in the ZnO layer.