Neural networks with higher-order nonlinearity

Neural networks for associative memory based on the Hopfield relaxation model and matched filtering techniques with higher-order nonlinearity are proposed. These high-order models show dramatic improvement in memory storage capacity and error-correction capability in comparison to conventional binary autoassociative models     

Noise removal using fourth-order partial differential equation with applications to medical magnetic resonance images in space and time

We introduce a new method for image smoothing based on a fourth-order PDE model. The method is tested on a broad range of real medical magnetic resonance images, both in space and time, as well as on nonmedical synthesized test images. Our algorithm demonstrates good noise suppression without destruction of important anatomical or functional detail, even at poor signal-to-noise ratio. We have also compared our method with related PDE models.     

添加CuO对Ba_(3.99)Sm_(9.34)Ti_(18)O_(54)陶瓷烧结及微波介电性能的影响

采用传统固相工艺制备了Ba3.99Sm9.34Ti18O54(BSTO)微波介质陶瓷,研究了烧结助剂CuO对BSTO的结构及介电性能的影响。结果表明,添加CuO能较好促进BSTO晶粒致密化,降低烧结温度约140℃。当添加质量分数1.0%的CuO时,1220℃保温3h烧结的BSTO样品的介电性能较好:εr=86.87,Q·f=5138GHz(f=4.95GHz),τf=–10.84×10–6℃–1。     

A review on Ti3C2Tx-based nanomaterials:synthesis and applications in gas and humidity sensors

Ti3C2Tx,which is a novel two-dimensional (2D)material,has received enormous interest in the field of sensor technology due to its large surface area,excellent e...     

氧化镍薄膜气体传感器性能提升

本文的目的在于优化甲醛气体传感器.微型甲醛气体传感器设计是以石英玻璃当作基材,白金(Pt)被当作微型加热器电阻来加热感测层,并以氧化镍(NiO)薄膜作为感测层.当环境内有甲醛气体存在时,NiO薄膜层上导电度会增加,因而导致感测层电阻值降低.此微传感器,膜厚为0.34μm,在300℃反应时间只需6秒,灵敏度可达13.5 kΩ/ppb,最低侦测限度可以量测到40 ppb. 而本研究中针对不同的甲醛气体浓度,分别添加金当其催化剂、玻璃基材上共溅镀氧化镍与氧化铝、并比较有无指叉电极、改变基材温度…等,以提升其氧化镍薄膜感测性能.     

电子发射材料组成对Ba-W阴极性能的影响

利用TGA-DSC和XRD对阴极铝酸盐添加氧化钪(Sc2O3)前后的合成工艺、产物物相等进行了研究,对合成后铝酸盐与钨基的浸渍工艺、阴极的发射性能及蒸发速率进行了分析。结果表明:铝酸盐主晶相为Ba5CaAl4O12,添加w(Sc2O3)3%后,主晶相改变为Ba3CaAl2O7,熔点下降了48.5℃,铝酸盐的浸渍温度降低了130℃,浸渍度略有升高,保温时间缩短了0.5min。在阴极工作温度(1000～1100℃)范围之内,添加Sc2O3后制备的铝酸盐阴极直流发射密度是普通铝酸盐阴极的2倍以上;1100℃时平均蒸发速率是普通铝酸盐的61.5%,性能明显优于普通铝酸盐。     

一种战术通信数据组播实现方法

在战术通信系统中,一发多收的组播业务的应用越来越广泛。战术通信中的组播业务往往要求具备高适变性和高实时性,而民用网络中的IP组播、应用层组播均存在一定局限性,无法满足这些要求。针对这个问题,通过对现有IP组播和应用层组播技术特点和不足进行分析,提出了一种基于自定义协议和名址分离的战术通信数据组播设计与实现方案,可以很好地应对战术通信系统的高实时性、低带宽、高动态等特性需求。试验验证了此方案下组播业务需求的满足情况,测试结果表明,所提出的方案可有效提高组播数据在战术通信系统中的传输效率,为战术通信系统的通用组播方案设计提供了参考。     

考虑支管特性影响后并联水泵实际运行工作点的确定

针对简单的采用“横加法”来确定因分支管路长度以及各水泵入口点高差的不同,给各并联水泵运行工作点带来的影响进行了理论分析;同时给出了在考虑这些影响因素后各泵真实工作点的确定方法,为并联系统中水泵的合理选择和正确操作提供可参考的依据。     

高压直流输电系统开路试验原理分析与工程建议

开路试验是高压直流输电工程投运前必做的一项基本试验。该实验中触发角与直流电压的关系具有特殊性。从换流阀电路模型入手,详细分析了在不带线路工况下换流阀的导通情况,推导出理想情况下直流电压与触发角的关系,并给出了理想电压公式的适用条件。使用三沪I回直流输电工程一次模型,在EMTDC中进行了不带线路和带线路工况下的开路试验,并对试验结果进行了详细的分析。分析和实验结果表明:带线路工况下,直流电压在触发角小于60o后到达额定值是正常的。开路试验保护中设置电压判据是不合理的,可只采用电流原理判据作为试验是否成功的依据。     

Rapid prediction of solvation free energy and vapor pressure of liquid and solid from molecular dynamics simulation

We show that the solvation free energy and vapor pressure, important thermodynamic properties of pure substances in liquid or solid states, can be obtained from short, about 20 ps, molecular dynamics simulations. The method combines the determination of free energy of a chemical in vacuum using the normal‐mode analysis (NMA, energy minimization), and in the condensed phase using the two‐phase thermodynamic (2PT) model. We have examined the calculation results for common liquids and solids, including water, alcohol, acid, aromatics, and alkanes. The results, referred to as 2PT‐NMA, is comparable to those calculated from thermodynamic integration (TI) for liquids, and is readily applicable to solids, where simple TI is not applicable. Furthermore, the free energy from 2PT‐NMA converges (20 ps) much faster than that from TI (1 ns). The new method could be a very useful tool for fast screening of condensed phase pressure from the trajectory of MD simulations. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2298–2306, 2015