镉(Ⅱ)与对苯二甲酸和2,2′-联吡啶配合物光谱性质的理论研究

对镉(Ⅱ)与对苯二甲酸和2,2′-联吡啶配合物进行几何优化,在优化构型的基础上分析了其吸收光谱.结果表明主要贡献的激发态为16,17和26激发态而不是第一激发态,振子强度f为0.2052,0.3202和0.3234,对应的吸收波长为308.57,307.33和258.35 nm,与实验值310和253 nm相近.     

可编程数据平面技术综述

在软件定义网络中,可编程数据平面提供的编程能力是网络功能虚拟化的基石。可编程数据平面技术的核心是可编程能力与数据包处理性能。首先从数据平面的可编程性出发,探讨现有数据平面的数据包处理抽象。然后,分别对数据平面实施的目标平台与对应平台上的主要流表算法进行介绍,详细论述现有数据平面技术。最后,探讨了高性能数据平面技术存在的关键挑战。     

引入特征交互的红外与可见光图像自适应融合北大核心CSCD

在图像融合领域,现有的基于卷积神经网络(CNN)或Transformer架构的方法存在两个局限性:首先,浅层纹理特征与深层语义特征之间无法有效聚合;其次,红外与可见光特征的权重比例无法自适应变化。本文提出一种引入特征交互的红外与可见光图像自适应融合方法。首先,构建一种基于Transformer的特征交互模块,聚合跨尺度特征信息,增强特征表达能力。其次,设计一种融合模块,自适应地调整特征权重比例。所提出的融合方法通过两阶段训练策略完成。第一个阶段,应用创新的特征交互概念训练编码器,增强特征表达,重建特征图像。第二个阶段,基于设计的权重自适应调整模块训练红外与可见光特征融合任务。公开数据集的实验结果表明,与现有方法相比,本方法在主观和客观的评价方面均优于其他典型方法。     

一种双梁互补式光纤光栅位移传感器及在地铁隧道变形监测中的应用

本文提出了一种双梁互补式光纤光栅(fiber Bragg grating, FBG)位移传感器,实现了正负双向位移的测量。采用双“悬臂梁+楔形滑块”的结构,当一个悬臂梁受位移作用处于变形状态时,另一个悬臂梁不变形并提供温度补偿功能。传感器处于零值测点状态时,两个悬臂梁处于零弯曲状态,且双梁互为温度补偿,消除了温度影响。通过性能测试实验证明,该传感器在±50的量程内,灵敏度为29.369 pm/mm,测量重复性好。制备出8个传感器应用于某市地铁的变形安全监测,从道床沉降、道床环缝、管片环缝3个方面开展了变形测量。在长期监测期间,传感器工作稳定,被测结构变形状态稳定,表明该传感器具有良好的测量性能,适用于长期的结构健康监测。     

一种基于介质加载的地球覆盖波束天线设计

地球覆盖波束天线为低轨卫星与地面终端之间的数据传输建立了通道,文中研究了一种新型的介质 加载地球覆盖波束天线。基于介质加载的方法,文中提出了一种圆极化地球覆盖波束天线设计,该天线由馈电网 络、馈源和介质三部分组成,介质包括底部圆柱部分和顶部半球部分,馈源集成于介质内部。设计的地球覆盖波束 天线工作在C 波段,轴向0°~64°范围内增益在0 dBic 以上,40°方向增益为5. 2 dBic。天线尺寸紧凑,辐射波束具有 较好的空间截止特性,可满足立方星应用。     

Solution-Mediated Hybrid FAPbI3 Perovskite Quantum Dots for Over 15% Efficient Solar Cell

Organic–inorganic formamidinium lead triiodide (FAPbI₃) hybrid perovskite quantum dot (QD) is of great interest to photovoltaic (PV) community due to its narrow band gap, higher ambient stability, and long carrier lifetime. However, the surface ligand management of FAPbI₃ QD is still a key hurdle that impedes the design of high-efficiency solar cells. Herein, this study first develops a solution-mediated ligand exchange (SMLE) for preparing FAPbI₃ QD film with enhanced electronic coupling. By dissolving optimal methylammonium iodide (MAI) into antisolvent to treat the FAPbI₃ QD solution, the SMLE can not only effectively replace the long-chain ligands, but also passivate the A- and X-site vacancies. By combining experimental and theoretical results, this study demonstrates that the SMLE engineered FAPbI₃ QD exhibits lower defect density, which is beneficial for fabricating high-quality QD arrays with desired morphology and carrier transport. Consequently, the SMLE FAPbI₃ QD based solar cell outputs a champion efficiency of 15.10% together with improved long-term ambient storage stability, which is currently the highest reported value for hybrid perovskite QD solar cells. These results would provide new design principle of hybrid perovskite QDs toward high-performance optoelectronic application.     

Surface Oxygen Coordination of Hydrogen Bond Chemistry for Aqueous Ammonium Ion Hybrid Supercapacitor

Aqueous ammonium ion hybrid supercapacitor (A-HSC) combines the charge storage mechanisms of surface adsorption and bulk intercalation, making it a low-cost, safe, and sustainable energy storage candidate. However, its development is hindered by the low capacity and unclear charge storage fundamentals. Here, the strategy of phosphate ion-assisted surface functionalization is used to increase the ammonium ion storage capacity of an α-MoO₃ electrode. Moreover, the understanding of charge storage mechanisms via structural characterization, electrochemical analysis, and theoretical calculation is advanced. It is shown that NH₄⁺ intercalation into layered α-MoO₃ is not dominant in the A-HSC system; rather, the charge storage mainly depends on the adsorption energy of surface “O” to NH₄⁺. It is further revealed that the hydrogen bond chemistry of the coordination between “O” of surface phosphate ion and NH₄⁺ is the reason for the capacity increase of MoO₃. This study not only advances the basic understanding of rechargeable aqueous A-HSC but also demonstrates the promising future of surface engineering strategies for energy storage devices.     

A Hybrid Strategy-Based Ultra-Narrow Stretchable Microelectrodes with Cell-Level Resolution

Stretchable ultra-narrow (e.g., 10 µm in width) microelectrodes are crucial for the electrophysiological monitoring of single cells providing the fundamental understanding to the working mechanism of neuro network or other electrically functional cells. Current fabrication strategies either focus on the preparation of normal stretchable electrodes with hundreds of micrometers or millimeters in width by using inorganic conductive materials or develop conductive organic polymer gel for ultra-narrow electrodes which suffer from low stretchability and instability for long-term implantation, therefore, it is still highly desirable to explore bio-interfacial ultra-narrow stretchable inorganic electrodes. Herein, a hybrid strategy is reported to prepare ultra-narrow multi-channel stretchable microelectrodes without using photolithography or laser-assisting etching. A 10 µm × 10 µm monitoring window is fabricated with enhanced interfacial impedance by the special rough surface. The stretchability achieves to 120% for this 10 µm-width stretchable electrode. Supported by these superior properties, it is demonstrated that the stretchable microelectrodes can detect electrophysiological signals of single cells in vitro and collect electrophysiological signals more precisely in vivo. The reported strategy will open up the accessible preparation of the fine-size stretchable microelectrode. It will significantly improve the resolution of monitoring and stimulation of inorganic stretchable electrodes.     

Recent Progress of Bismuth Effect on All-Inorganic Lead-Free Metal Halide Derivatives: Crystals Structure,Luminescence Properties,and Applications

Bismuth (Bi³⁺)-included lead-free metal halide (LFMH) materials attract much attention in lighting, display, photodetectors, X-ray detectors, and photovoltaic fields, due to the tunable luminescence and optoelectronic performance in response to crystal and electronic structure, morphology, and particle sizes. This review summarizes Bi³⁺-included LFMH materials about their preparation approach, crystal and electronic structure properties, luminescence performance, and emerging applications. Notably, Bi³⁺ ions not only can act as framework cation to construct stable LFMH structure, but can also incorporate into LFMH materials as activators or sensitizers to generate remarkable luminescence tuning and band engineering. The Bi³⁺ effect on the luminescence and optoelectronic properties of LFMH materials, including, promotion of exciton localization, enhancement of light absorption in near-ultraviolet region, action as sensitizer ions to transfer energy to rare earth or transition metal ions and emission of highly-efficient light is systematically summarized. The proposed structure-luminescence relationship offers guidance for the optimization of current Bi³⁺-included LFMH materials and the exploitation of new LFMH derivatives.