2D Metallic Transition-Metal Dichalcogenides: Structures,Synthesis, Properties,and Applications

2D materials and the associated heterostructures define an ideal material platform for investigating physical and chemical properties, and exhibiting new functional applications in (opto)electronic devices, electrocatalysis, and energy storage. 2D transition metal dichalcogenides (2D TMDs), as a member of the 2D materials family including 2D semiconducting TMDs (s-TMDs) and 2D metallic/semimetallic TMDs (m-TMDs) have attracted considerable attention in the scientific community. Over the past decade, the 2D s-TMDs have been extensively researched and reviewed elsewhere. Because of their distinctive physical properties including intrinsic magnetism, charge-density-wave order and superconductivity, and potential applications, such as high-performance electronic devices, catalysis, and as metal electrode contacts, 2D m-TMDs have grabbed widespread attention in recent years. However, reviews demonstrating the m-TMDs systematically and comprehensively have been rarely reported. Here, the recent advances in 2D m-TMDs in the aspects of their unique structures, synthetic approaches, distinctive physical properties, and functional applications are highlighted. Finally, the current challenges and perspectives are discussed.     

Recent progress of physical failure analysis of GaN HEMTs

Gallium nitride (GaN)-based high-electron mobility transistors (HEMTs) are widely used in high power and high frequency application fields,due to the outstanding physical and chemical properties of the GaN material.However,GaN HEMTs suffer from degradations and even failures during practical applications,making physical analyses of post-failure devices extremely significant for reliability improvements and further device optimizations.In this paper,common physical characterization techniques for post failure analyses are introduced,several failure mechanisms and corresponding failure phenomena are reviewed and summarized,and finally device optimization methods are discussed.     

知识定义的意图网络自治

通信网络的复杂性决定了意图网络自治是无法一蹴而就的,关键在于以全局视角,打通多个网络管控问题域,将网络规律、机理、策略凝练为知识,构建全场景资源调配的知识空间,最终实现意图网络的泛在智能化。围绕6G意图网络,将知识定义智能作为关键使能技术,以提高意图网络的感知和决策闭环能力,构建自学习、自运维的意图网络。实现完全的6G网络自治是一个长期目标,需要分步实现,从提供重复执行操作的替代方案,到执行网络环境和网络设备状态的感知和监控,根据多种因素和策略做出决策,以及有效感知最终用户体验,直到最后网络能够感知运营商和用户的意图,自我优化和演进。     

Bioinspired Intrinsic Versatile Hydrogel Fabricated by Amyloidal Toxin Simulant-Based Nanofibrous Assemblies for Accelerated Diabetic Wound Healing

Persistent microbial infection and decreased neovascularization are common issues associated with diabetic wound treatment. Hydrogel dressings that offer intrinsic antibacterial and angiogenesis-inducing may substantially avoid the use of antibiotics or angiogenic agents. Herein, a versatile hydrogel is fabricated using an amyloid-derived toxin simulant (Fmoc-LFKFFK-NH₂, FLN) as building blocks, inspired by the defense strategy of Staphylococcus aureus (S. aureus). The simulant assemblies of the hydrogel function as both matrix components and functional elements for diabetic wound treatment. The hydrogel undergoes quick assembly from random monomers to nanofibrils with abundant b-sheet driven by multiple non-covalent interactions. The developed hydrogel demonstrates excellent biocompatibility and accelerates angiogenesis via hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor A (VEGFA) signaling as a consequence of its amyloidal structure. The simulant-based nanofibrils endow the hydrogel with broad-spectrum antibacterial activity dominated by a membrane-disruption mechanism. In addition, the hydrogel exhibits excellent performance compared with the commercial hydrogel Prontosan in accelerating wound healing of diabetic mice infected with methicillin-resistant S. aureus (MRSA). This study highlights the fabrication of a single component and versatile hydrogel platform, thereby avoiding the drug-related side effects and complicated preparations and demonstrating its profound potential as a clinical dressing for the management of microbe-infected diabetic wounds.     

基于嵌入式Qtopia汽车BCM自动检测系统设计

汽车BCM在车身功能控制系统中起着举足轻重的作用,因此汽车BCM出厂前的功能检测一直得到企业和消费者的高度重视。目前多数企业仍使用人工测试的方法,而本次自动检测系统是采用三星公司的S3C2440作为核心控制器,在嵌入式Linux系统下使用Qtopia应用开发平台搭建控制界面添加检测控制程序,通过接口板连接汽车BCM从而实现自动检测功能。     

Circularly polarized patch antenna with simultaneously wide frequency tuning range and high gain performance

A tunable circularly polarized square patch antenna with parasitic elements is designed for a wide frequency tuning range and high gain characteristics. The proposed antenna is constructed by one main patch and four semi-elliptic parasitic units. By loading four varactor diodes and adjusting their capacitance values, the tunable feature is performed to reallocate the corresponding working frequency. Moreover, the diagonal corners of the antenna are cut and loaded with varactor diodes, which provide the appropriate perturbation between the two orthogonality modes of the antenna, so as to ensure the circular polarization characteristic in the entire operating tuning band. The experimental results demonstrate that the reflection coefficient and axial ratio are less than −13 dB and 3 dB, respectively. The proposed antenna features a relatively wide continuously tuning range of 24% within 1.9-2.3 GHz and a stable gain of over 7 dBi with a radiation efficiency of above 85%.     

Liquid Metal Based Island‐Bridge Architectures for All Printed Stretchable Electrochemical Devices

The adoption of epidermal electronics into everyday life requires new design and fabrication paradigms, transitioning away from traditional rigid, bulky electronics towards soft devices that adapt with high intimacy to the human body. Here, a new strategy is reported for fabricating achieving highly stretchable “island‐bridge” (IB) electrochemical devices based on thick‐film printing process involving merging the deterministic IB architecture with stress‐enduring composite silver (Ag) inks based on eutectic gallium‐indium particles (EGaInPs) as dynamic electrical anchors within the inside the percolated network. The fabrication of free‐standing soft Ag‐EGaInPs‐based serpentine “bridges” enables the printed microstructures to maintain mechanical and electrical properties under an extreme (≈800%) strain. Coupling these highly stretchable “bridges” with rigid multifunctional “island” electrodes allows the realization of electrochemical devices that can sustain high mechanical deformation while displaying an extremely attractive and stable electrochemical performance. The advantages and practical utility of the new printed Ag‐liquid metal‐based island‐bridge designs are discussed and illustrated using a wearable biofuel cell. Such new scalable and tunable fabrication strategy will allow to incorporate a wide range of materials into a single device towards a wide range of applications in wearable electronics.     

认知无线电线性自信号消除带内频谱感知方法

利用无线衰落信道AR模型,提出了一种不需要静默期的基于线性自信号消除的认知无线电主用户信号检测方法.该方法无需为避免静默期而频繁地中断通信,提高了通信效率和服务质量.仿真结果表明,该算法在多普勒频移较大时优于已有的无静默期带内频谱感知方法,在满足IEEE 802.22无线区域网主用户信号检测需求的同时,增强了系统频谱感...     

面向服务的舰载作战指挥控制系统集成研究

提出一种以业务为核心面向服务的舰载作战指挥控制系统软件集成架构方法。该软件架构采用SOA思想,利用业务流程来组织系统应用,实现以数据为中心向、以业务流程为中心的转向,使系统能够快速响应不断变化的应用需求;系统功能和数据作为可被发现和重用的资源均可在网络上发布,实现以平台为中心向以网络为中心的转向,从而提升舰载作战指挥控制系统在网络化、信息化条件下的互操作和信息共享能力。