基于道岔转辙机动作功率曲线关联分析道岔故障

为准确掌握道岔转换设备的工作状况,及时预测其故障趋势,真正实现"状态修",提出一种基于道岔转辙机动作功率曲线关联分析道岔故障的方法.以高速铁路用S700K交流道岔转辙机典型动作功率曲线为例,从道岔转辙机典型动作功率曲线类型、道岔故障关联分析2方面,阐述基于道岔转辙机动作功率曲线关联分析道岔故障的总体思路,道岔转辙机动作功率曲线的提取、数据压缩及相关性分析.结果表明:该方法能够指导关联分析道岔故障,提高实际的道岔检修质量,减少维修成本,为实现"状态修"提供数据支撑.该方法不仅是工程可行的,而且具有良好的应用推广价值.     

Degradable and Fully Recyclable Dynamic Thermoset Elastomer for 3D-Printed Wearable Electronics

Wearable electronics have become an important part of daily lives. However, its rapid development results in the problem of electronic waste (e-waste). Consequently, recyclable materials suitable for wearable electronics are highly sought after. In this study, a conductive recyclable composite (PFBC) is designed based on a dynamic covalently cross-linked elastomer and hierarchical hybrid nanofillers. The PFBC shows excellent wide-ranging properties including processability, elasticity, conductivity, and stability, which are superior to previous materials used for recyclable electronics, and exhibits outstanding mechanical properties and environmental tolerance including high temperature, high humidity, brine, and ethanol owing to its covalent cross-linking. Reversible dissociation of Diels–Alder networks allows for convenient processing and recycling. After three recycles, the toughness of the PFBC remained at 10.1 MJ m⁻³, which is conspicuous among the reported recyclable electronic materials. Three types of PFBC-based wearable electronics including a triboelectric nanogenerator, a capacitive pressure sensor, and a flexible keyboard, are successfully 3D printed with excellent performance. The PFBC possessed both recyclability and degradability, the combination of which provides a new way to reduce e-waste. This is the first work to recycle electronics using direct 3D printing and presents promising new design principles and materials for wearable electronics.     

Pillar[5]arene-Modified Gold Nanorods as Nanocarriers for Multi-Modal Imaging-Guided Synergistic Photodynamic-Photothermal Therapy

Supramolecular approaches have opened up vast possibilities to construct versatile materials, especially those with stimuli-responsiveness and integrated functionalities of multi-modal diagnosis and synergistic therapeutics. In this study, a hybrid theranostic nanosystem named TTPY-Py⊂CP5@AuNR is constructed via facile host–guest interactions, where TTPY-Py is a photosensitizer with aggregation-induced emission and CP5@AuNR represents the carboxylatopillar[5]arene (CP5)-modified Au nanorods. TTPY-Py⊂CP5@AuNR integrates the respective advantages of TTPY-Py and CP5@AuNR such as the high performance of reactive oxygen species generation and photothermal conversion, and meanwhile shows fluorescence responses to both temperature and pH stimuli. The successful modification of CP5 macrocycles on AuNRs surfaces can eliminate the cytotoxicity of AuNRs and enable them to serve as the nanocarrier of TTPY-Py for further theranostic applications. Significantly, in vitro and in vivo evaluations demonstrate that this supramolecular nanotheranostic system possesses multiple modalities including intensive fluorescence imaging (FLI), photoacoustic imaging (PAI), efficient photodynamic therapy (PDT), and photothermal therapy (PTT), indicating its great potential for FLI-PAI imaging-guided synergistic PDT-PTT therapy. Moreover, TTPY-Py can be released upon activation by the acidic environment of lysosomes and then specifically light up mitochondria. This study demonstrates a new strategy for the design of versatile nanotheranostics for accurate tumor imaging and cancer therapies.     

灵巧噪声干扰实现方法仿真研究

针对如何高效干扰采用复杂波形的相参雷达的问题,展开了对灵巧噪声干扰概念和实现方式的讨论.基于工程应用,详细分析了视频信号卷积调制灵巧噪声干扰的本质,提出了“延时叠加”的工程实现方法并建模仿真,对其可能达到的干扰效果进行了分析.     

五年制高职贫困生资助现状与改善策略——以江苏联合职业技术学院无锡交通分院为例

教育扶贫是国家扶贫攻坚大战略中的一个重要方面。职业教育扶贫有其自身的特性, 需要进一步加强对学 生资助的精准度。通过个案分析, 有助于把握五年制高职贫困生的共性问题, 了解这类群体的心理状况和 现实需求, 为开展精准资助提供依据。改善五年制高职学生教育扶贫是一项系统性工作, 需从规范贫困认 定、推进信息共享、优化扶贫方案等方面系统推进, 实现教育扶贫的公平、公正。     

Fault-Tolerant Cooperative Spectrum Sensing Scheme for Cognitive Radio Networks

In order to solve the uncertainty resulting from shadowing effect and resist the attack from malicious cognitive radio (CR) users, we propose a fault-tolerant cooperative spectrum sensing scheme for CR networks, where an energy detection-based local spectrum sensing is performed at each CR user, a coefficient is used to weight each CR user’s sensing result, a linear weighted fusion process is performed at the fusion center (FC) to combine received sensing results. For a fault-tolerant cooperative spectrum sensing scheme, the most important issue is to distinguish whether the CR user is reliable or not. In this paper, a reputation-based cooperative mechanism is presented to alleviate the influence of the unreliable sensing results from CR users suffering shadowing and the false sensing data from malicious CR users on the detection result at the FC. In proposed fault-tolerant cooperative scheme, each cooperative CR user has a reputation degree which is initialized and adjusted by the FC and used to weight the sensing result from the corresponding user in the fusion process at the FC. And then, two reputation degree adjusting methods are presented to manage the reputation degree of each CR user. Simulation results show that the proposed scheme can not only weaken the harmful influence caused by malicious CR users, but also alleviate the corrupted detection problem resulting from destructive channel condition between the primary transmitter and the CR user. Moreover, the detection performance of the fault-tolerant cooperative scheme, which has a feasible computational complexity and needs no instantaneous SNRs, is close to that of the optimal scheme.     

无人机机载测控设备统一帧结构研究

提出了飞控计算机与测控系统之间接口的统一帧结构设计新的方法和思路,初步建立了完备的格式化通信信息集。对帧结构进行动态配置,使帧结构具有通用化功能和可操作性。探讨了帧结构校验方法,使之具有检/纠错功能。理论分析表明,新的统一帧结构设计能够有效提高无人机测控系统机载设备的通用化。     

并行测试技术及在智能弹药检测中的应用研究

并行测试技术拥有减少测试时间、降低测试成本的强大优势,正成为研究热点之一。针对传统顺序测试方法测试智能弹药效率低的问题,提出采用并行测试技术对智能弹药质量状况进行检测,为低成本、高效检测智能弹药提供了一种新方案。介绍了并行测试技术的相关理论,结合智能弹药检测需求,在智能弹药检测系统中引入并行测试技术,并针对其组建提出三点关键技术。分析表明,方案设计合理,相比传统检测方法,成本低、测试效率高。     

基于信息量估计法的MIDI音频隐写分析

为了保障网络信息安全,提出一种针对MIDI格式的专用音频隐写分析算法具有重要的意义。分析了MIDI音频LSB替换机制,提取特征量力度值进行统计分析,采用信息量估计法针对MIDI音频进行LSB隐写检测分析。实验表明,信息量估计法在嵌入率较大时,漏检率和虚警率都较低,可以作为MIDI音频的专用隐写分析方法。     

基于DSP的继电保护测试仪信号采集装置硬件设计

继电保护测试仪检定技术是栓定继电保护测试设备性能指标是否满足要求的技术。详细介绍基于DSP的继电保护测试仪数据采集系统。该系统可以精确采集继电保护测试仪的各项参数指标,采集数据准确可靠,为继电保护测试仪检定装置的研究提供了良好的基础。重点描述该采集装置的硬件组成和电路设计,并简要分析各部分的功能及主要芯片的工作方式。