基于物联网的矿井通风机监控系统研究

针对当前矿井通风机监控系统功能单一、反馈控制能力差能等特点,提出一种基于物联网的矿井通风机监控系统。该系统利用传感器、Wi Fi技术实现监控系统实时数据传输和反馈报警控制功能。详细描述了矿井通风机监控系统构成及各硬件设计原理图,介绍了系统的底层驱动设计及软件设计流程。通过实验证明该矿井通风机监控系统能实时传输数据,视频监控稳定,能实现报警控制,可在移动平台或者PC机上进行监控,具有一定的推广价值。     

新型太赫兹光子晶体OAM光纤设计

太赫兹通信兼具微波通信和光波通信的优势,是解决通信容量紧缺难题的最有效技术手段之一。针对太赫兹波段吸收损耗严重及抗外在扰动差,难以支持长距传输问题,设计了一种基于环形光子晶体光纤(PCF)结构的新型太赫兹光纤。以现有常见材料作为光纤基底材质,通过创新光纤结构中空气孔排布方式,抵消材料高吸收损耗,以支持高性能轨道角动量(OAM)模式传输。选择最优参数,实现6个OAM模式群的高模式质量、低限制损耗和宽带宽的稳定传输。在0.2~0.9 THz宽波段内,实现模式纯度超过88.9%,限制损耗小于10^-7 dB/m。通过软件仿真实验设计,解决了太赫兹与OAM技术相结合的关键问题,为模分复用(MDM)技术在太赫兹通信系统的应用奠定了理论研究基础。     

Fault-Tolerant Control for Markovian Jump Delay Systems with an Adaptive Observer Approach

This paper investigates the problem of fault estimation and fault-tolerant control for a class of Markovian jump systems with mode-dependent interval time-varying delay and Lipschitz nonlinearities. In this paper, a new adaptive fault observer is designed to solve the problem of fault estimation. The proposed observer can estimate the states and faults simultaneously, whether faults are of time-varying or constant characterization. Based on the fault estimation, a fault-tolerant controller is designed to stabilize the closed-loop system. Sufficient conditions for the existence of the observer gain and fault-tolerant controller gain are got by a set of linear matrix inequalities. Finally, a numerical example is presented to illustrate the effectiveness of the proposed fault-tolerant control method.     

Design and Experimental Demonstration of Cherenkov Radiation Source Based on Metallic Photonic Crystal Slow Wave Structure

This paper presents a kind of Cherenkov radiation source based on metallic photonic crystal (MPC) slow-wave structure (SWS) cavity. The Cherenkov source designed by linear theory works at 34.7 GHz when the cathode voltage is 550 kV. The three-dimensional particle-in-cell (PIC) simulation of the SWS shows the operating frequency of 35.56 GHz with a single TM₀₁ mode is basically consistent with the theoretically one under the same parameters. An experiment was implemented to testify the results of theory and PIC simulation. The experimental system includes a cathode emitting unit, the SWS, a magnetic system, an output antenna, and detectors. Experimental results show that the operating frequency through detecting the retarded time of wave propagation in waveguides is around 35.5 GHz with a single TM₀₁ mode and an output power reaching 54 MW. It indicates that the MPC structure can reduce mode competition. The purpose of the paper is to show in theory and in preliminary experiment that a SWS with PBG can produce microwaves in TM₀₁ mode. But it still provides a good experimental and theoretical foundation for designing high-power microwave devices.     

伪卫星定位系统中组网布局研究

为达到伪卫星在任一时间、地点都能对目标进行精确可靠定位,对影响定位精度的关键技术—组网布局进行讨论。分析伪卫星及伪卫星定位系统的基本概念,探讨影响组网布局的3个因素：伪卫星定位系统的定位原理、伪卫星的＂视距＂范围和几何衰减因子。结果表明,几何精度因子GDOP与被观测伪卫星所构成的四面体体积成反比。     

固态继电器输入端电磁脉冲效应研究

通过方波电流注入方法对某型号固态继电器的输入端电磁脉冲效应进行了实验研究,给出了输入端方波注入对固态继电器输出端性能影响的实验结果,为固态继电器的产品设计及实际应用提供参考。     

核电站辅助过滤器壳体设计

以开发出适合我国压水堆核电站的辅助过滤器来代替进口产品为背景,以核电站蒸汽发生器排污系统中过滤器壳体为设计对象,按照常规设计法,遵循GB150．2011,对过滤器壳体依次进行了筒体、封头、进出水接管及壳体开孔补强和法兰密封设计。最后将所设计的壳体导入有限元分析软件ANSYS11．0进行强度验证,结果表明其强度满足要求。     

基于AMBE-1000与nRF401的无线语音传输系统的实现

介绍了Digital Voice System. Inc公司的AMBE-1000芯片与挪威Nordic 公司的nRF401芯片的特点与工作原理,给出了一种基于AMBE-1000和nRF401的无线语音传输系统的实现.系统采用AMBE-1000 结合TCM320AC36C进行语音信号的处理;同时,采用nRF401传输数字化后的语音信号;在整体上,采用AT89C52 处理器负责接口之间的数据处理.提出了系统的硬件设计、软件流程.此系统具有无需许可证、功耗低、使用方便等特点,可广泛应用于无线语音传输系统的产品设计中.     

中兴通讯CDMA2000 ALL-IP灵活的组网解决方案

CDMA2000 ALL-IP产品推出了包含Ap接口在内的ALL-IP接口解决方案,丰富了网络架构.中兴通讯CDMA2000 ALL-IP产品技术先进,容量大,接口协议丰富,具有兼容性和演进性.描述了中兴通讯CDMA2000ALL-IP网络灵活的组网方案,主要针对CDMA网络演进到LMSD阶段后,分析实现BSC与核心网之间A接口分组传输后带来的一系列网络架构优势,组网方式的灵活.     

Blind recognition of RSC based on logarithmic conformity

A new algorithm based on logarithmic conformity was proposed.Firstly,based on the probability of total RSC coding equation,the concept of logarithmic coincidence degree,which could measure the establishment of coding equation,was introduced.Then because of constraint length of RSC,the polynomial database could be generated,and then logarithmic conformity of every polynomial could be calculated when traversing the database.As the results,the RSC could be recognized,because the correct polynomial could make the conformity maximum.The algorithm has small amount of calculation because of finite traversal,which was only related to amount of intercepted data,besides,this algorithm has good error tolerance by soft decisions.The simulation results show that the correct ratio of recognition can reach 90% at SNR of 0 dB and its performances are obviously superior to those of existing algorithms.