Thin,Millimeter Scale Fingernail Sensors for Thermal Characterization of Nail Bed Tissue

Thin, flexible, body‐worn technologies that allow precise, quantitative monitoring of physiological status are of broad current interest due to their potential to improve the cost and effectiveness of healthcare. Although the surface of the skin represents one of the most widely explored points of integration, recently developed millimeter scale wireless sensor platforms allow deployment on alternative surfaces of the body, such as the finger/toenails and the teeth. The work described here introduces a collection of ideas in materials science, device engineering and computational techniques that enables precise characterization of the thermal transport characteristics of the nail bed tissue from measurements on the surface of the nail. Systematic in vitro studies demonstrate the underlying measurement principles, the theoretical models for optimized sensor design and the associated experimental procedures for determining the thermal conductivity of the tissue. Measurements performed on human subjects highlight capabilities in tracking changes in perfusion of the nail bed tissues in response to various external stimuli.     

三电平逆变器直接转矩控制仿真分析

对三电平逆变器直接转矩控制的基本原理,拓扑结构,控制原理,及控制策略进行了详细的分析,给出了一种结合三电平特性的异步电机数学模型,通过仿真验证了建立在该模型下的中点钳位式三电平逆变器直接转矩控制的良好动静态特性.     

Porous alumina nano-membranes: Soft replica molding for large area UV-nanoimprint lithography

High-density ordered arrays of h-PDMS nanopillars were fabricated using an anodic aluminium oxide (AAO) template. The pore diameter and the interpore distance of the replica h-PDMS molding are well consistent with that of AAO template. The inverse h-PDMS has the surface characteristic of hydrophobic and surface energy of 130°. Hexagonally arranged array can be obtained by UV-nanoimprint lithography using our proposed h-PDMS mold, and their morphologies can be transferred truly. Besides, the h-PDMS mold has been used to fabricate photonic crystal structure on GaN by nanoimprint process, which could be found an application in the light output of GaN LED.     

Characterization,Cathodoluminescence, and Field‐Emission Properties of Morphology‐Tunable CdS Micro/Nanostructures

High‐quality, uniform one‐dimensional CdS micro/nanostructures with different morphologies—microrods, sub‐microwires and nanotips—are fabricated through an easy and effective thermal evaporation process. Their structural, cathodoluminescence and field‐emission properties are systematically investigated. Microrods and nanotips exhibit sharp near‐band‐edge emission and broad deep‐level emission, whereas sub‐microwires show only the deep‐level emission. A significant decrease in a deep‐level/near‐band‐edge intensity ratio is observed along a tapered nanotip towards a smaller diameter part. This behavior is understood by consideration of defect concentrations in the nanotips, as analyzed with high‐resolution transmission electron microscopy. Field‐emission measurements show that the nanotips possess the best field‐emission characteristics among all 1D CdS nanostructures reported to date, with a relatively low turn‐on field of 5.28 V µm^?1 and the highest field‐enhancement factor of 4 819. The field‐enhancement factor, turn‐on and threshold fields are discussed related to structure morphology and vacuum gap variations under emission.     

Synergy of Pickering Emulsion and Sol‐Gel Process for the Construction of an Efficient,Recyclable Enzyme Cascade System

An efficient, easily recyclable enzyme cascade system based on nanoparticle‐stabilized capsules (NPSCs) is constructed through a synergy of a Pickering emulsion and sol‐gel process. Specifically, oligodopa‐coated titania nanoparticles (biomimetic titania) containing the first enzyme (FateDH) are synthesized through a bioadhesion‐assisted biomimetic mineralization approach. The biomimetic titania is then spontaneously assembled at the interface between the oil phase (hexadecane/butyl titanate (BuTi) mixture) and water phase during the formation of Pickering emulsions. The sol‐gel process of BuTi can produce not only butanol for assisting the formation of Pickering emulsions but also titania gel particles (sol‐gel titania) for cross‐linking the biomimetic titania through catechol‐titanium chelating. The NPSCs obtained, which contain the first enzyme, conjugate the second enzyme (FaldDH) onto the surface for constructing the enzyme cascade system. The system exhibits high activity and stability, particularly, superior recyclability for conversion of CO₂ into formaldehyde. In detail, the system shows a formaldehyde yield of 50.0%, and can quickly float onto the air/water interface soon after stopping the agitation of reaction mixtures, which ensures that the formaldehyde yield keeps almost unaltered after 10 times recycling. This study will be useful for facile construction of a wealth of catalytic systems with efficient, recyclable attributes.     

基于CCAE的药筒抽壳性能的影响因素分析研究

为了解决大口径火炮药筒在射击时存在卡壳或者抽壳困难的问题,采用药筒划分不同区域的办法,对不同钢材、不同温度以及同一钢材不同材料参数这3种工况进行有限元仿真计算。结果表明药筒口部和药筒斜肩部抽壳力的占比较多;不同钢材对药筒抽壳力有一定的影响,其中30#钢相比20#钢、45#钢而言更容易抽壳;依据实验要求更换钢材材料参数,计算得出的抽壳力相比修改参数之前下降约50%左右,效果十分显著;温度升高对应的抽壳力也就越大,温度对抽壳的影响不可忽视。因此,在设计中应合理地在不同分区采用不同材料,确保更换材料参数可以降低药筒口部和药筒斜肩部的抽壳力,同时降低药筒温度,从而顺利抽壳。     

Flexible,Conformal Organic Synaptic Transistors on Elastomer for Biomedical Applications

Bioelectronics in synaptic transistors for future biomedical applications, such as implanted treatments and human–machine interfaces, must be flexible with good mechanical compatibility with biological tissues. The rigid nature and high deposition temperature in conventional inorganic synaptic transistors restrict the development of flexible, conformal synaptic devices. Here, the dinaphtho[2,3‐b:2′,3′‐f]thieno[3,2‐b]‐thiophene organic synaptic transistor on elastic polydimethylsiloxane is demonstrated to avoid these limitations. The unique advantages of organic materials in low Young's modulus and low temperature process enable seamless adherence of organic synaptic transistors on arbitrary‐shaped objects. On 3D curved surfaces, the essential synaptic functions, such as potentiation/depression, short/long‐term synaptic plasticity, and spike voltage–dependent plasticity, are successfully realized. The time‐dependent surface potential characterization reveals the slow polarization of dipoles in the dielectric is responsible for hysteresis and synaptic behaviors. This work represents that organic materials offer a potential platform to realize the flexible, conformal synaptic transistors for the development of wearable and implantable artificial neuromorphic systems.     

陀螺罗经性能测试方法研究

本文通过分析航海型电罗经的工作原理,提出了陀螺罗经的通用测试平台设计方法, 以及陀螺球性能参数相关的计算方法,通过陀螺罗经测试平台的数据采集,将数据结合陀螺球性能参数进行解算,可以定量的鉴定陀螺球的性能并可以数字输出鉴定结果数据,并将数据通过上位机软件图形显示,测试结果自动计算生成。通过该平台的设计大大提高了陀螺罗经试验测试水平,提高了测试效率。     

基于有线网络的统一智慧业务云平台设计及实现

本文论述如何搭建统一智慧业务云平台,为地市、区县分公司提供统一的智慧业务平台支撑,可实现门户展现快速上线、数据对接、应用管理等轻量级信息发布类应用,促进有线网络运营商政企业务的发展.     

基于信号处理技术的光纤激光器脉冲振幅均衡研究

为解决当前光纤激光器脉冲振幅均衡过程中存在的一些难题,提高光纤激光器脉冲振幅均衡精度,提出了基于信号处理技术的光纤激光器脉冲振幅均衡方法研究.首先通过信号重采样技术将光纤激光器脉冲振幅信号变为阶比值固定的信号,然后根据小波调节方法提取不同阶比分量,最后利用机器学习算法实现光纤激光器脉冲振幅均衡.仿真实验结果表明,所提方...