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关键词： Heavy metal detection   Wireless and passive RFID tag sensor   Rapid and onsite detection   Impedance matching   Spectral sensing  

摘要： In this work, a wireless and passive radio frequency identification (RFID) tag sensor, which integrated a reduced graphene oxide/ion-selective membrane (rGO/ISM) chemiresistive sensing component, was developed for the onsite detection of Pb2+ in soil. Additionally, a new detection method combining impedance mismatch and spectral sensing technique for Pb2+ was proposed. Furthermore, the sensing mechanism of the RFID tag sensor was investigated in terms of the field-effect transistor (FET) transfer curve and antenna reflection coefficient. The charge density in the sensing component was altered by Pb2+, reducing resistance and modifying the tag antenna impedance. Impedance mismatch between the antenna and RFID chip was thereby induced, with varying degrees of mismatch directly altering the light-emitting diode (LED) luminous intensity on the tag sensor. Rapid detection (<2 s) via luminous intensity monitoring eliminated a vector network analyser (VNA), achieving a detection limit of 1.96 mu g/L. Ultimately, the sensing performance of the RFID tag sensor was verified through the detection of Pb2+ in real soil samples (recovery rates of 99-101 %, and RMSEs of 2.08-7.32 mu g/kg), indicating that the tag sensor offers a simple and effective solution for rapid and onsite detection of hazardous heavy metals in soil, with potential for practical application.

关键词： 复合标签   精准识别   双频RFID   路侧标识  

摘要： 为了解决高速公路多义性路径精准识别与收费的问题,设计了双频RFID复合标签的高速路径识别系统.高速路径识别收费系统由省结算计费中心、路段分中心、车道收费系统和路侧标识系统组成.采用模块化的设计方法,完成了5.8 GHz频段ETC高速路径复合RFID有源标签识别系统的总体架构设计,定制了核心主设备软硬件系统方案(双频复合RFID标签),并按照模块功能逐步分析实现.经过测试,该系统的数据读取准确率达到了98%,满足车辆路径信息的精准识别和车辆行驶路径精准判定,具有较强的推广价值.

关键词： Health care   RFID   Hospital competition   Pharmaceutical supply chain   Game theory  

摘要： Amid hospitals' efforts to enhance operational efficiency and slash costs, addressing inventory inaccuracies in hospital pharmaceutical supply chain has gained urgency. Although radio frequency identification (RFID) technology effectively reduces such inaccuracies, its introduction in vendor-managed inventory (VMI) remains debatable for vendors given the impact of competitive inter-hospital environment and corresponding implementation costs. This study develops a three-level Stackelberg game model to analyze the vendor's strategy regarding RFID adoption within the pharmaceutical supply chain, taking into account different types of competition between hospitals (i.e., public vs. public and public vs. private). We find that the vendor's RFID adoption strategy under both forms of competition is counter-intuitive, with RFID being adopted even when the intensity of RFID in reducing inventory inaccuracy is low, provided the reimbursement rate for public hospital is high. Furthermore, homogeneous competition increases the vendor's need for higher RFID intensity, while heterogeneous competition heightens the requirement for a favorable reimbursement rate. Finally, both homogeneous and heterogeneous competition can facilitate RFID adoption, with the preference depending on diagnosis cost, reimbursement rate and RFID intensity. This study offers fresh perspectives on the intricacies of vendors' decision-making processes for RFID adoption in healthcare, emphasizing the significance of competitive dynamics and strategic management of medical consumables.

关键词： 射频识别标签   遗留手术物品   医用纱布   研究现状   挑战及发展趋势  

摘要： 体内遗留手术物品是医疗领域的高危医疗事故。为减少手术遗留事故的发生，多种技术已被应用于医用纱布的管理。其中，射频识别标签在医用纱布智能化管理中的应用展现出显著优势，但尚缺乏系统梳理该技术在实际应用中的情况。文章在简要介绍已有的代表性技术后，重点总结了射频识别技术在预防医用纱布遗留情况的研究进展及应用现状，并概括了目前该技术在实际应用中存在的挑战及未来发展趋势。

关键词： Absence or Presence Coding   Chipless RFID tag   Frequency Shift Coding   Stepped Impedance Resonator  

摘要： This paper introduces a novel compact planar multiresonator with high surface encoding capacity, specifically designed for chipless RFID tag applications. The tag features eight Stepped Impedance Resonators (SIR) that operate within the 2.85 GHz to 5.37 GHz frequency range, providing a bandwidth of 2.52 GHz. A key characteristic of the tag is its ability to achieve unique resonating frequencies by modifying the dimensions of the stem and the width of the serif of each Stepped Impedance Resonator. The prototype tag is designed and fabricated on an RT5880 lossy substrate, which has a dielectric constant of 2.2 and a loss tangent of 0.0009. The tag’s identity is encoded in the spectral domain using the Absence or Presence Coding (APC) Technique and the Frequency Shift Coding (FSC) Technique. The reliability of the proposed design is validated through measured results from the fabricated prototype.

关键词： angle sensor   flexible sensor   multi-parameter characterization   quadratic regression fitting (QRF)   RFID  

摘要： This paper presents a flexible radio frequency (RF) sensor for measuring rotational angle. The sensor consists of a nested rectangular spiral inductor and two rectangular capacitors to form a radio frequency identification tag, which utilizes inductive coupling with an antenna for data transmission. The sensor has a wide dynamic detection range, accurately measuring rotation angles from 0° to 180°. Specifically, within the range of 0°–30°, the sensor exhibits exceptionally high sensitivity with 4.95 MHz/° and 0.093 dB/°. In the range of 90°–180°, frequency overlap occurs, so we take full advantage of the multi-parameter characterization of RF devices and jointly characterize the angle using the resonant frequency and return loss. The results were then subjected to quadratic regression fitting, which showed a high degree of agreement with the test results. Experiments have validated the sensor's performance, showing good reusability and a fast response speed. Compared to traditional passive angle sensors, this sensor combines RF sensing technology with flexible materials. The designed flexible wireless angle sensor is recommended for human joint measurement.

摘要： In the present study, a passive ‘arch shape’ spiral resonator-based chipless Radio Frequency Identification (RFID) tag is proposed having 8-bit of data capacity. The 8-bit tag is based on the frequency domain spectral signature method and its backscattered radar cross section (RCS) is analysed with the help of the bi-static method of measurement. The operating range of the tag varies from 2 to 6 GHz, achieving the industrial scientific and medical (ISM) band and ultra-wide band of frequencies. The 8-bit data generated from the tag should be transmitted with proper encryption and decryption along with an adequate error correction method. In this regard, a novel approach is proposed, in which the backscattered RCS is processed to achieve the bits in a coded form with the reduction of bit error. Here, the convolutional coding techniques have been adopted to process and encode the backscattered signal. This encoding method is frequency-domain coding, based on the sequence of the RCS of the proposed tag. The proposed encoding technique is based on the trellis diagram, in which some combination of the sequence is shuffled to produce a new sequence. To decode the encoded signal, the Viterbi algorithm is proposed. The bit transformation is validated by calculating the bit-error graph and using a comparison table.

关键词： Ammonia   Antennas   Dielectric constant   Sensors   Microstrip antennas   Sensitivity   Microstrip   Temperature sensors   Temperature measurement   Substrates  

摘要： Ammonia is a toxic and flammable gas, and chemical resistance sensors have great potential in practical ammonia monitoring applications. For scenarios where there is a lack of circuit wired connection, it is important to explore a passive wireless, low-cost, and universal means of detecting ammonia. However, due to the limitations of single-frequency operation and interference from environmental factors (e.g., temperature, humidity, and interfere gas), research in this area is still ongoing. In this article, a dual-band patch antenna-based passive ammonia sensor utilizing chipless radio frequency identification (RFID)-inspired technology was designed. Meanwhile, the antenna’s performance parameters, including return loss, voltage standing wave ratio (VSWR), and normalized impedance, were optimized. Porous zinc stannate (Zn2SnO4) was selected as the sensing material, Zn2SnO4 material was characterized using energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The cross-shaped recess in the center of the antenna was coated with Zn2SnO4 to create the sensing unit. The passive sensor was operated at two distinct frequency bands, centered around 2.3 and 4.5 GHz and exhibited advantageous characteristics such as a simple structure, mechanical flexibility, and high gain. The sensor demonstrated excellent stability and sensitivity at daily operating temperatures ( $25~^{\circ }$ C). The limit of detection (LOD) method reveals that the detectable ammonia concentration is 40 ppm at the low-frequency point and 30 ppm at the high-frequency point. The reaction process between surface adsorbed oxygen species and ammonia is described to verify the passive sensing mechanism. This work presented chipless RFID-inspired technology with a specific emphasis on passive ammonia detection, offering potential applications in environmental monitoring and industrial safety.

关键词： RFID   电力物联网   认证   国密算法   BAN逻辑  

摘要： 随着电力物联网技术的快速发展， 建设能源互联网具有重大意义。电力物联终端设备的识别认证是保障能源互联网安全稳定运行的基础。为实现海量电力终端设备信息高效采集与安全认证，本文提出一种面向电力物联网的RFID认证方案，该方案利用RFID技术，基于国密SM3和SM4算法设计，既实现了阅读器与电力设备之间的相互认证，也保障了电力通信数据的传输安全，降低了设备标签的计算复杂度。安全性分析表明，该方案满足不可追踪性、抗重放攻击、抗去同步攻击、抗拒绝服务攻击等安全特性，BAN逻辑分析进一步表明该方案满足相互认证性。性能分析表明，该方案在标签计算量、存储量、通信量及数据库搜索效率方面具有较好的性能优势。

摘要： The measurement of in situ abrasion has been investigated since the early 20th Century and it is thought to represent a significant loss from coastal sediment budgets of some mixed sediment beaches. Traditional methods of tracking pebbles or cobbles to assess abrasion have numerous shortcomings, however, Radio Frequency Identification (RFID) now makes it feasible to track and relocate tagged particles on a beach. In this study, RFID was used to quantify pebble and cobble abrasion on a mixed sand and gravel beach, South Island, New Zealand. A total of 228 greywacke pebbles and cobbles were tagged and released on two occasions on the study beach. Some of these pebbles and cobbles were relocated on the first two days after release and then again at intervals of months with a maximum recovery period of 15 months. Particles were weighed each time they were relocated to assess abrasion and their positions recorded to calculate the distance travelled from the initial release point. The mean daily abrasion rate of pebbles and cobbles was 0.02 %/day in weight, equivalent to 7.30 %/year in weight. A significant correlation was found between abrasion and transport distance and wave energy. These results contribute to the small database of abrasion rates for mixed sediment beaches. The study also provides detailed data on cross-shore and alongshore displacement, as well as burial depth. Comparison with previous studies from around the world suggests that a universally applicable abrasion rate for all mixed beaches is unattainable.