无线传感器网络通信技术与标准化分析

通过分析现有无线传感器网络标准,并对Zig Bee、蓝牙以及Wi-Fi这3种最常用标准的优缺点进行详细比较,探讨了无线传感器网络通信技术面临的挑战,进一步研究策略和未来发展趋势。     

ZigBee信标同步算法设计与仿真

由于受到时钟准确性和精度要求的影响,传统网络中的时间同步算法已经不能满足无线传感器网络的要求.根据ZigBee郊术的特点,研究了基于CSMA-CA机制的具有针对性的信标同步算法.给出了相应的算法分析、算法流程,以及在NS2平台中的仿真结果与性能分析,同时给出了在信标网络与非信标网络中的效果对比.     

表面双稳铁电液晶中的层结构

从铁电液晶（ Ｆ Ｌ Ｃ）的物性出发， 描述了表面双稳铁电液晶（ Ｓ Ｓ Ｆ Ｌ Ｃ）显示结构原理和相应特点； 系统地介绍了 Ｓ Ｓ Ｆ Ｌ Ｃ 中的液晶层结构分类及相关特征。阐述了不同层结构对液晶器件双稳态的获得及电光特性的影响。     

Myoglobin Detection: Utilizing Functional Magnetic Hybrid and Silica Micro Particles and Simple Molding Based Micro Channel Fabrication

A magnetic separator attached in a zig zag flow channel assembly has been fabricated to detect myoglobin on the micro particles. An anti‐myoglobin conjugated magnetic hybrid and myoglobin conjugated silica micro particles were prepared and used for myoglobin detection on channel. For the detections, the competitive assay principle was followed based on affinity interaction of anti‐myoglobin‐myoglobin. The caliberation curve was plotted based on the deposit percentage of myoglobin conjugated silica micro particles. The calibration curve of the myoglobin showed the linear range between 1 × 10^?8 ‐ 5 × 10^?11 (M) (R² = 0.9944). The minimum detectable concentration was 300 pg/mL. Hence all that concludes that, the application of zig zag flow channel with magnetic separator has offered new, simple and rapid approach for detecting myoglobin in whole blood samples with in 30 min.     

基丁ZigBee的矿井生命安全监控系统设计

该文针对矿井生命安全,提出了一个具有成本效益、灵活的解决方案。这个方案中的多传感器模块用于井下环境监测,能够自动测量数据,最后通过无线通信进行传输。该系统中的微控制器用于收集传感器上的数据并决定是否发出警报声告知煤矿工人,以及通过ZigBee向地面控制中心发送紧急通知。利用基于IEEE802．15．4标准的ZigBee技术来实现监控系统的硬件设备和地面控制中心的短距离无线通信。     

Self‐Assembly of Polyoxometalate‐Supported Ln‐H nydroxo/Oxo Clusters with 1D Extended Structure: [LnIII(H2O)7Cr(OH)6Mo6O18]n·4nH2O (Ln = Ce,Sm, Eu)

Three novel polyoxometalate compounds consisting of Anderson‐type anions and trivalent lanthanide cations, [Ln(H₂O)₇Cr(OH)₆Mo₆O₁₈]_n·4nH₂O (Ln = Ce 1 ; Sm 2 ; Eu 3 ), have been synthesized in aqueous solution and characterized by single crystal X‐ray diffraction, elemental analyses, IR spectra, and TG analyses. Single crystal X‐ray diffractions reveal that the structures of the 1:1 composite compound formed by the heteropolyanion [Cr(OH)₆Mo₆O₁₈]^3? as the building unit and the [Ln(H₂O)₇]³⁺ complex fragment as the linker, which exhibit a type of zig‐zag chain with alternating cations and anions through the Mo‐Ot′‐Ln‐Ot′‐Mo linkage in the crystal. The magnetic properties of 1 ? 3 have been studied by measuring their magnetic susceptibility over the temperature range of 2‐300 K. The UV‐vis spectra of 1 give the Mo‐O and Cr^III‐O charge transfer transitions at 203 and 543 nm, respectively. In addition, the fluorescent characteristic transition of the Eu³⁺ ions in compound 3 is reported.     

基于嵌入式GPRS技术的大区域火灾监控系统

针对当前的大区域内火情监控以人工为主,实时性较差,报警存在延时的问题;在需求分析的基础上,设计并实现了一种基于嵌入式与GPRS技术的大区域火情监控系统,硬件平台以嵌入式 S3C2410 芯片配合温度传感器LM75A以及相关外围电路,采集处理传感温度信息,利用GPRS网络的大范围数据通信能力传递各种火情信息,软件采用了分层的设计思想,将整个系统的软件设计分为用户应用层、网络集成层、硬件驱动层3个层次结构进行设计,利用SMS的方式进行火灾报警,避免了人工检测时主观强,实时性差的弊端;系统经过大量的实际数据测试证明,误差率基本能够保持在15%以内,比传统算法,报警准确率提高了27.4%,大区域控制范围在1平方公里,报警性能良好,具有很强的实际应用价值。