开口同轴探头测量微波集成电路基片的复介电常数

本文论述了开口同轴（无外加法兰）非破坏测量微波集成电路基片复介电常数的方法。文中阐明了开口同轴FDTD法的建模与测量原理。由于FDTD法建模是一种全波分析方法，出此该模型相当准确。在S和X波段测量了聚四氟乙烯材料和另一种介质基片的复介电常数，所得结果与它们的典型值非常吻合。开口同轴法测量具有非破坏性，适于现场测量，而且具有设备简单、操作方便、测量精度高等优点。     

开口式微波加热器的研究

应用时域有限差分法(FDTD)分析和计算了一种开口式同轴加热装置。同时讨论和计算了为防止微波泄漏而设计在腔体外围的扼流槽的作用。测量结果与计算结果有相当高的一致性。表明这种装置可以在中心处产生高温,而在设计相关的微波装置时,使用时域有限差分法又是十分有效的。     

波导填充有耗各向异性介质的有限元分析

通过引入对应于原有系统的伴随系统,推导出了有耗不均匀各向异性波导系统的变分方程。对满足γａ＝ （－ γ）σ限制条件的伴随场存在的条件进行了分析,给出了不同情况下伴随场与原有场的关系式。利用有限元方法对铁氧体移相器进行了计算分析,其结果验证了该方法的正确性     

微波和毫米波铁氧体移相器

本文详细论述了微波频段普遍使用的三种铁氧体移相器(即双环铁氧体移相器、双模铁氧体移相器和旋转场铁氧体移相器)的性能,讨论了由铁氧体饱和磁化强度值所确定的这三种器件的使用频率。     

普通房间内扬声器频响的短音主客观评价

在普通房间混响场中,扬声器低频响应使用可控长度的短音（猝发音）来评价。与传统信号（如阶跃式正弦波和各种噪声信号）相比,短音拥有许多实用价值,还可对系统进行快速主观评价。     

微波烧结技术中的烧结场型研究

本文着重论述微波烧结技术中的烧结场型设计问题,并指出微波场型“构造”方法在设计中的重要作用。同时,几种新的烧结场型,如混合场、模式互补场、同步回输式行波场被具体分析。     

高灵敏度微波测湿传感器

本文提出了一种提高微波测湿传感器灵敏度的新机理——微扰增强机理。设计出高灵敏度的带消失模谐振腔的单面开口式矩形双频腔,并给出该腔的理论分析。实验结果表明:在20℃一张厚8(μm)、湿度8％的电容器纸能够使测量模产生3MHz左右的频移。     

VRLA蓄电池在光伏发电系统中的研究与应用

在早期光伏发电系统中,一般使用开口式铅酸蓄电池作为储能装置,但开口式铅酸蓄电池有需要加酸加水维护,酸液易污染环境等缺点,不利于无人值守使用及环保。     

音箱的低频问题

一、音箱设计主要是低频设计 音箱不论是Hi-Fi音箱、扩声音箱、家庭影院音箱……都有一个设计问题，包括扬声器单元的选择、分频器设计、箱体设计、造型设计等。目前广泛采用的Small理论。是将音箱看成是一个高通滤波器，根据低频扬声器单元的参数fs（扬声器谐振频率）、Qts（扬声器总质量因数）、Vas（场声器等效容积）等，再考虑你对低频性能的要求及调整方法，确定箱体体积等（开口箱还包括开口的面积和长度……）。     

基于超材料的多波段小型化天线

基于负折射率传输线（Epsilon Negative Transmission Line,ENG-TL）理论和开口谐振环的负磁导率特性,提出了一种加载ENG-TL结构和互补开口谐振环（Complementary Split Ring Resonators,CSRR）结构的单极子天线模型.该结构实现了单极子天线的小型化多频带.仿真和实验结果表明:所设计的单极子天线覆盖了WLAN（2.4/5.2/5.8 GHz）和WiMAX（3.5/5.8 GHz）频段.     

开放式仿真系统的设计与关键技术

从综合电子战系统仿真中基本的要素出发 ,分析关键技术的实现途径 ,架构可支持多平台、多功能的开放式仿真系统 ,并尽量使其满足一定条件下的分布式仿真应用     

Trust in open versus closed social media: The relative influence of user- and marketer-generated content in social network services on customer trust

Recently, “closed” or “private” social network services (SNSs) have emerged and become popular; this popularity is primarily driven by privacy issues and information overload in open SNSs such as Twitter or Facebook. Scholars and practitioners are interested in the relationship between product reviews and customer trust in both closed and open SNSs, but we do not fully understand why, how, or what types of online product reviews in open or closed SNSs influence trust. This paper explores how customer trust in content is influenced by different types of content generators and SNSs. The results of our experiments show that user-generated content (UGC) has a stronger effect on customers’ cognitive trust than does marketer-generated content (MGC) and that the effect of product reviews in closed SNSs on customers’ cognitive and emotional trust is greater than the effect in open SNSs. Finally, we find that the interaction between content generator types and SNS types affects customers’ emotional trust. This paper contributes to the empirical research on SNSs and online product reviews and has practical implications.     

基于PKI和PMI的生物认证系统研究

生物认证技术作为一种准确高效的身份认证方法越来越广泛的应用于身份认证领域.但是目前还没有一种面向开放式网络的通用生物认证系统出现.由于在开放式网络中,基于X.509的公钥基础设施和权限管理基础设施(PMI)是目前应用广泛且有效的身份认证技术和权限管理技术,所以在PKI和PMI技术基础上,该文创新性的提出了一种基于生物证书的能实现身份认证和权限管理的通用生物认证系统.最后通过设计一个能实现身份认证和权限管理系统的高安全性生物智能卡,验证了基于PKI和PMI生物认证系统的可行性和可操作性.     

Novel half-mode substrate integrated waveguide bandpass filters using semi-hexagonal resonators

In this paper, a novel bandpass filter is presented, designed, and implemented by using a triple mode semi-hexagonal Half-Mode Substrate Integrated Waveguide (HMSIW) cavity, which has the advantages of compact size, low insertion loss, and high selectivity in upper and lower passband. To realize a triple mode filter, the first resonant mode is shifted to near the next two modes using a via hole perturbation. Two microstrip open stubs connected to open edge of HMSIW resonator are introduced to generate two transmission zeros in the lower passband. The position of transmission zeros could be controlled by adjusting the coupling gap between the microstrip open stub resonators. By etching an E-shape slot on the top plate of HMSIW resonator, two other transmission zeros are produced in the upper passband. A wide-band planar six-pole bandpass filter, which has the advantages of wide bandwidth and small size, is also proposed and fabricated by cascading two triple mode resonators. Measured results indicate that 29% and 47% fractional bandwidth, as well as approximately 1 dB and 1.1 dB insertion loss, are achieved for the proposed filters. Measured results of all those filters agree well with the simulated results.     

基于Web远程开放式数控系统设计

为促进新一代数控系统的研究,深入分析了开放式数控系统设计原则,提出了一种面向Web的开放式数控系统设计框架,通过网络化的远程配置、远程管理实现数控系统的开放性,利用基于Web浏览器的操作界面,缩短数控系统的开放周期,同时提高数控系统的易操作性。对数控系统的功能组成进行分析,给出了开放式数控系统功能模块的划分与实现策略。实践证明,开放式数控系统具有良好的可扩展性和可重构特性,可根据不同的应用场合、应用对象对数控中的功能模块进行升级和重构设计。     

Intent-based networks for 6G: Insights and challenges

Intent-Based Networks (IBNs), which are originally proposed to introduce Artificial Intelligence (AI) into the sixth-generation (6G) wireless networks, can effectively solve the challenges of traditional networks in terms of efficiency, flexibility, and security. IBNs are mainly used to transform users’ business intent into network configuration, operation, and maintenance strategies, which are prominent for designing the AI-enabled 6G networks. In particular, in order to meet the massive, intelligent service demands and overcome the time-varying radio propagation, IBNs can continuously learn and adapt to the time-varying network environment based on the massive collected network data in real-time. From the aspects of both the core network and radio access network, this article comprehensively surveys the architectures and key techniques of IBNs for 6G. In particular, the demonstration platforms of IBNs, such as the Apstra Operating System, Forward Networks Verification Platform, and One Convergence Service Interaction Platform, are presented. Moreover, the industrial development of IBNs is elaborated, including the emerging new products and startups to solve the problems of open data platforms, automated network operations, and preemptive network fault diagnosis. Finally, several open issues and challenges are identified as well to spur future researches.     

一种LED驱动芯片开路检测电路设计与实现

小间距发光二极管(LED)显示屏凭借其画面清晰细腻、色彩自然真实、流畅无闪烁等优点,得到广泛应用。为解决小间距LED显示屏因寄生电容影响而产生的开路十字架问题,采用在模拟电路部分判断开路状态并产生开路信号,在数字部分根据开路信号记录开路位置并屏蔽输出的方式,设计了一种新的检测过程简单、精确度高、面积小、功耗低、支持实时检测的电路,并在某款多路恒流LED驱动芯片中得到应用,成功解决了开路十字架问题。仿真结果和实际样片测试结果表明,所设计的开路检测电路检测精确简单、功耗低,并支持实时检测。     

一种改进的载波抑制调制光毫米波信号的产生方案

为了克服光纤无线(ROF)系统中色散对光载波抑制(OCS)调制光毫米波信号传输的影响,提出一种改进的OCS调制方案。使用双驱动马赫-曾德尔调制器(MZM),通过调整两路输入射频信号相位、基带信号增益和直流偏置电压将2.5Gbit/s数据信号仅调制到(OCS)信号的一个边带上传输。理论分析表明,与传统OCS调制光毫米波信号产生方案相比,本文方案解决了色度色散引起的码元走离问题,大大增加了传输距离。仿真实验结果表明,经过110km光纤传输后信号的眼图仍然十分清晰,在BER=10-10条件下,信号经过20、40和60km光纤传输后的功率代价分别为0.78、1.7和1.9dB。     

Answer Extraction Based on Merging Score Strategy of Hot Terms

Answer extraction (AE) is one of the key technologies in developing the open domain Question&an-swer (Q&A) system . Its task is to yield the highest score to the expected answer based on an effective answer score strategy. We introduce an answer extraction method by Merging score strategy (MSS) based on hot terms. The hot terms are defined according to their lexical and syn-tactic features to highlight the role of the question terms. To cope with the syntactic diversities of the corpus, we propose four improved candidate answer score algorithms. Each of them is based on the lexical function of hot terms and their syntactic relationships with the candidate an-swers. Two independent corpus score algorithms are pro-posed to tap the role of the corpus in ranking the candi-date answers. Six algorithms are adopted in MSS to tap the complementary action among the corpus, the candi-date answers and the questions. Experiments demonstrate the effectiveness of the proposed strategy.     

数值吸收边界条件在OSRC方法中的应用

本文引入一种数值吸收边界条件,将其应用于解决开放空间电磁散射问题的表面辐射条件法(OSRC)之中。本文使用这种边界条件对理想导电及均匀电磁可穿透材料圆柱散射体的表面场进行了数值计算,并与使用二阶微分算子B_2型的吸收边界条件的结果作了比较。所有结果说明,这种数值吸收边界条件特大大改善OSRC方法的精度。