多路地震波无线检测系统

采用增量调制、移频键控、频分复用等技术实现地震波信号的采集、传输和数据处理。其电路结构简单，工作可靠，信噪比高，抗干扰能力强，测量精确。     

Preliminary telemetry data on the movement patterns and habitat use of European catfish (Silurus glanis) in a reservoir of the River Ebro, Spain

Abstract –  Knowledge of the movements and diel behaviour of the European catfish ( Silurus glanis ), the largest European freshwater fish, is limited to anecdotal information. In a preliminary telemetry study of European catfish, the spring diel movement patterns of five adult catfish were examined. After intraperitoneal insertion of the acoustic tags, the positions of the fish were recorded automatically in the Flix Reservoir (River Ebro, NE Spain). A marked nocturnal mobility pattern was observed throughout the study. During daytime, the catfish were consistently located in the littoral zone and spent extended periods of the day hidden in concealed habitats. Catfish movements were in a radial pattern, with upstream and downstream excursions followed by returns to a previously occupied location. Significant individual variations in movement pattern were observed among the tagged fish and within the 24 h cycle for each fish. Mean instantaneous swimming speed was 0.17 body lengths per second (BL·s⁻¹) at night but 0.09 BL·s⁻¹ during the daytime.     

Novel strategy for subcarrier and power allocation in OFDM based cognitive radio networks

In order to limit the interference caused by cognitive user within the range that primary users can tolerate. The mathematical optimization problem is formulated maximizing cognitive user’s capacity under the interference constraint at the primary receiver．When the signal to noise ratio of primary user changes according to the communication environment, the cognitive user can adaptively adjust its transmission power according to the interference control factor η. The optimal so1ution to the problem is obtained by utilizing the Lagrange method．A subcarrier and power allocation scheme are proposedamong multiple cognitive users, which is the performance tradeoff between fairness and system capacity. Simulation results show that the proposed scheme can efficiently guarantee the fairness of cognitive users and the capacity performance is close to the optimum.     

稻谷热风辅助射频干燥工艺及相关品质研究

新型热风辅助射频(HA-RF)技术已被证实在稻谷杀虫方面具有良好的效果,为探究其同步杀虫干燥的应用潜力,本研究重在探究HA-RF在稻谷干燥方面的效能,开发稻谷HA-RF干燥工艺并研究相关的品质变化.结果表明:极板间距为10.0 cm(射频加热速率6.10℃/min),干燥温度为60℃,样品厚度为3.0 cm时,稻谷HA-RF干燥效能最佳;HA-RF与热风(HA)干燥相比可缩短干燥时间34.6％,单位能耗也更低.此外,HA-RF与HA干燥相比对稻谷精米率、整精米率和爆腰率的影响无显著差异,但HA-RF干燥可以更好地保留维生素E,且对样品颜色和微观结构的影响也较小.该研究表明HA-RF是一种比HA干燥更加高效节能的技术,且干燥后稻谷品质更好,在稻谷同步干燥杀虫上具有一定应用潜力.     

现代通讯条件下通化市森林防火无线电通讯二级网的建设思路与探讨

在森林防火工作中，无线电超短波通讯网发挥着极其重要作用，本文就利用各种现代通讯技术为森林防火工作服务、合理建设森林防火无线电通讯网络等进行了探讨。     

Vehicle Monitoring Control and Scheduling Management System in a Scenic Area

In order to help tourists choose satisfying scenic spots, content hotels, convenient lines and convenient vehicles, vehicle monitoring control and scheduling management system in a scenic area is presented, which dispatches vehicle by appointments and the statistic of tourists at a sight spot and recommends the tour line by broadcasting in vehicle. Vehicle monitoring control and scheduling management system in a scenic area, a integrative vehicle management system, is an integration of GPS, GIS, trunked radio system, a management system of booking room and a tourist statistic system at a sight spot.     

射频识别技术在粮食供应链体系中的应用研究

将射频识别技术应用于粮食供应链系统中,力求实现供应链体系运行的快速与高效.介绍了射频识别技术的基本原理及特点,在此基础上构建了粮食供应链管理系统的系统模型,并给出了粮食供应链管理系统的系统架构,以及基于射频识别技术的实现过程,最后对现存的问题和相应对策进行了概述.     

山区土地利用多功能时空分异特征及影响因素分析

射频加热作为一种新型的热加工技术,在果蔬烫漂工艺中应用潜力巨大。介电特性是影响果蔬射频加热的主要因素,其大小受到电磁场频率、温度以及水等因素的影响,依据介电特性变化可以对果蔬烫漂工艺进行优化改进。该文选用富士和秦冠2个苹果品种,采用末端开路同轴探头技术测定了不同温度(20、40、60、80、95 ℃),不同频率（12～3 000 MHz）下,苹果的介电特性的变化规律。采用6 kW、27.12 MHz的射频加热系统在不同极板间距（110、120、130 mm）下,对苹果块进行加热处理,通过荧光光纤测温探头监测样品的中心温度,得到3种不同极板间距下苹果块中心温度从25升至95 ℃的升温曲线和升温速率。用红外热像仪测定加热前后苹果块表面的温度分布,研究了苹果块射频加热均匀性。结果表明：苹果果肉的介电常数和损耗因子在12～3 000 MHz之间随着频率的增大先降低,后增大,再降低;温度对苹果果肉的介电常数和损耗因子的影响没有特定的规律;射频加热苹果块时,极板间距110 mm时升温最快,130 mm时升温最慢,各需要120和150 s。且苹果块中心温度随时间近似线性增长,射频加热过程中,苹果块表面温度分布表现出中心加热现象,即中心温度高,边缘温度低。     

基于RFID/GIS物联网的肉品跟踪及追溯系统设计与实现

为了提高肉品跟踪与追溯系统信息的实时性、准确性和可靠性,该文介绍了无线射频识别技术（RFID）、物联网及电子产品代码（EPC）系统相关技术,提出了基于无线射频识别技术的肉品企业资源平台架构,详细研究和分析了肉品销售阶段的信息流程,设计了基于无线射频识别技术的肉品销售跟踪及追溯体系,包括跟踪系统和追溯系统。跟踪系统通过在销售节点上的产品电子代码系统,对附有无线射频识别芯片标签的肉品信息进行跟踪。追溯系统通过对象名解析服务（ONS）服务器,查出肉品销售相关节点实体标记语言（PML）服务器的地址,进而获得肉品的     

基于温度感知RFID标签的冷链厢体中温度监测

针对温度感知RFID(radio frequency identification)标签应用于冷链物流温度监测中缺乏有效数据验证的问题,该研究通过将42个温度感知RFID标签部署于冷链模拟平台中,划分了7个横截面、3个纵截面和两个层,设置了机械降温-冷链维持-自然回温3个不同阶段,同时在42个监测位点中选择7个位点同步部署了便携式温度记录仪,获取了不同条件下的温度监测数据,并与便携式温度记录仪数据和CFD(computational fluid dynamics)模拟数据进行了比较。7个温度感知RFID标签与便携式温度记录仪同步监测位点的数据表明,两种监测方法温差分布于±0.5℃范围内的数据点最多,占43.6%,温差分布于-1.0~-0.5℃区间的数据占了24.6%,考虑到2种设备自身的温度采集精度,温差在±0.8℃范围内可接的,其比例占71.3%,因此利用温度感知RFID标签进行冷链温度监测是可行的。对42个位点在3个不同阶段的温度监测数据表明,机械降温阶段各位点用时在1 h以内、冷链维持阶段大部分位点表现出温度在在0~4℃之间振荡的特征、自然回温阶段用时约49 h。深入分析机械降温阶段及冷链维持阶段不同截面的温度监测数据,结果表明3种截面均表现为降温初始阶段温度差值不稳定、稳定后具有明显的分布特征且离出风口较近降温较快的特点。以横截面2和横截面6平均温度为例,将温度感知RFID标签数据采集数据与CFD模拟数据进行比较,去除测量精度的干扰,截面2的均方根误差为0.73℃、平均相对误差为13.58%、截面6的均方根误差为0.56℃、平均相对误差为10.94%,具有较好的空间一致性。研究结果可为实现冷链物流中低成本、连续的温度监测奠定基础。