高效能空气净化器评价技术要求国家标准研究

本文论述了编制高效能空气净化器产品评价技术要求国家标准的意义和作用,介绍了标准研制的总体思路和原则,高效能空气净化器的定性和定量评价指标要求,测试、计算和评价方法等,通过国标的研制与实施,将引领并促进高效能空气净化器产品的生产与应用.     

数控机床操控器人机界面优化设计研究

目的控制器和显示器共同组成数控机床控制面板的整体界面,是机床接受与执行命令的交互平台。从人机交互角度,聚焦于控制器的界面布局进行优化设计。方法基于人机工程学理论的优化流程,采用现场访谈、现场观察等方法,将人机工程学的理论转化为具体考核指标。结论从人机工程学的研究角度出发,结合工业设计、用户体验设计学等内容,从功能区域分区、操纵器色彩设计等方面优化数控机床控制器的界面,提高系统整体效能及使用者满意度,为数控机床系统开发设计提供参考。     

Monitoring the Dynamic Process of Formation of Plasmonic Molecular Junctions during Single Nanoparticle Collisions

The capability to study the dynamic formation of plasmonic molecular junction is of fundamental importance, and it will provide new insights into molecular electronics/plasmonics, single‐entity electrochemistry, and nanooptoelectronics. Here, a facile method to form plasmonic molecular junctions is reported by utilizing single gold nanoparticle (NP) collision events at a highly curved gold nanoelectrode modified with a self‐assembled monolayer. By using time‐resolved electrochemical current measurement and surface‐enhanced Raman scattering spectroscopy, the current changes and the evolution of interfacial chemical bonding are successfully observed in the newly formed molecular tunnel junctions during and after the gold NP “hit‐n‐stay” and “hit‐n‐run” collision events. The results lead to an in‐depth understanding of the single NP motion and the associated molecular level changes during the formation of the plasmonic molecular junctions in a single NP collision event. This method also provides a new platform to study molecular changes at the single molecule level during electron transport in a dynamic molecular tunnel junction.     

智能耳诊机的软、硬件设计

本文从实际应用出发,详尽论述了“智能耳诊机”软、硬件设计的方法。对从事单片机开发应用的工程技术人员有较高的参考价值。     

Growth technique for producing high quality superconducting YBa2Cu3O7-δ single crystals

High quality single crystals of YBa₂Cu₃O_7- (YBCO) have been grown in yttria-stabilized zirconia crucibles by using a flux method. This method yields crystals with area 3 to 4 times larger than a previous method, and 3 to 5 times more crystals. Several crystals as large as 3×4mm² in thea-b plane are routinely obtained from each crucible. The samples typically range from 10 to 60 m thick. The superconductivity transition temperatureT _c of the crystals, measured by magnetic susceptibility, falls in the range 92.5 to 93 K and the smallest transition width (10 to 90%) is less than 0.25 K. Compared with the previous method, the surface is generally smoother, with less flux, and larger untwinned regions of 1 x 1 mm² are usually found.     

Preparation of nanometre size oxide particles using filter expansion aerosol generator

Crystalline zinc oxide particles of nanometre size (< 20 nm) particles were produced from a zinc acetate solution by using a filter expansion aerosol generator (FEAG). The FEAG is an aerosol generator that is operated at 60 torr reactor pressure and produces droplets of around 2 m. The shape of the particles produced by the FEAG were distinctively different from those produced by the ultrasonic spray source (USS). Results from scanning electron microscopy (SEM) and X-ray diffractometry (XRD) indicated that crystalline zinc oxide particles of nanometre size were produced at 600 °C in 0.02 s residence time. Weight loss of these particles, determined by thermogravimetric analysis (TGA), was 3 wt%. Based on the morphology change as a function of the reactor temperature and solute concentration, we proposed that the nanometre particles were formed by uniform precipitation at the drying stage and decomposition followed by disintegration into nanometre particles. It was also shown that exothermic decomposition of the solute was not required for the disintegration of the primary particles in the FEAG process. This result opened up an opportunity for producing carbon-free nanometre particles from nitrate salts by using the FEAG.     

基于SIMD结构的多标准LDPC译码器的VLSI实现

近年来,支持多标准的LDPC译码器已逐渐成为研究的热点.与传统译码器相比,所设计的LDPC译码器具有以下优点:1.实现了一个码率、码长可配置结构,进而可以支持多种标准;2.采用了一种改进型TPMP算法,使译码器的存储器容量大大减少,避免了因分块LDPC码的非规则性所造成的数据冲突问题;3.采用基于SIMD处理器的硬件结构,实现了硬件的高度规整性,易于芯片布局布线;4.设计了一个6级可配置流水线,可分时构造校验节点处理单元和变量节点处理单元,提高了硬件利用率和系统数据吞吐率.用这种架构实现了一个同时支持CMMB和DTMB两个标准的多标准LDPC译码器;芯片规模为75万门,时钟频率为220MHz,数据吞吐率为300Mbps.