装备承制单位履约信誉等级评估模型

装备承制单位在装备研制生产过程中会出现失信问题,开展科学合理的信誉评估工作具有重要意义.运用解释结构模型构建了递阶层次结构的装备承制单位履约信誉评估指标体系,给出了基于三角白化权函数的装备承制单位履约信誉灰色聚类等级评估模型,并通过实例对给出的方法进行分析和验证.验证结果表明:该方法简便、有效,可为军方评价承制单位的信誉度提供数量分析参考.     

融合多注意力机制与PointRCNN的三维点云目标检测

针对三维不规则的点云格式和密度不均匀的问题,提出了一种融合多注意力机制与PointRCNN网络用于三维点云目标检测。本实验主要对PointRCNN两阶段网络分别进行改进,首先,把通道注意力与空间注意力机制串行通过调节输入到第一阶段各网络层的分布,批量归一化进一步快速识别三维特征;其次,引入交叉位置注意力机制到第二阶段网络为了避免交叉路径出现位置偏差,从而进一步精细化三维目标位置以进行特征提取。在KITTI数据集上实验结果表明：相比于PointRCNN检测网络,改进的网络在小汽车和行人测试上平均均值精度(mAP)分别提高了1.2%、1.9%。因此改进的方法在解决了点云格式不规则和密度不均匀问题的同时还保证了检测精度。     

宽频段太赫兹辐射计高吸收率涂层的特性

为了对宽频段高吸收率太赫兹辐射计的特性进行表征,研究了吸收涂层材料的特性;对常见的吸波材料在太赫兹波段的吸收率进行仿真,探寻在太赫兹波段具有高吸收率的材料;将碳化硅与3M黑漆进行混合,以进一步提高涂层的吸收率,并通过仿真调整涂层内碳化硅颗粒的尺寸;根据仿真结果制备混合涂层,利用太赫兹时域光谱仪对混合涂层样品进行测量。结果表明:该混合涂层样品的光谱吸收率大于0.99,与仿真结果基本吻合。     

Manipulation of Conductive Domain Walls in Confined Ferroelectric Nanoislands

Conductive ferroelectric domain walls—ultranarrow configurable conduction paths—have been considered as essential building blocks for future programmable domain wall electronics. For applications in high‐density devices, it is imperative to explore the conductive domain walls in small confined systems, while earlier investigations have hitherto focused on thin films or bulk single. Here, an observation and manipulation of conductive domain walls confined within small BiFeO₃ nanoislands aligned in high‐density arrays are demonstrated. Using conductive atomic force microscopy, various types of conductive domain walls, including the head‐to‐head charged domain walls (CDWs), zigzag domain walls, and typical 71° head‐to‐tail neutral domain walls (NDWs), are distinctly visualized. The CDWs exhibit remarkably enhanced metallic conductivity with current of ≈nA order in magnitude and 10⁴ times larger than that inside domains (0.01–0.1 pA), while the semiconducting NDWs allow much smaller current (≈10 pA) than the CDWs. The substantial difference in conductivity for dissimilar walls enables manipulations of various wall conduction states for individual addressable nanoislands via electrical tuning of domain structures. A controllable writing of four distinctive states in individual nanoislands can be achieved, showing application potentials for developing multilevel high‐density memories.     

Associative Memory for Image Recovery with a High‐Performance Memristor Array

Associative memory is one of the significant characteristics of the biological brain. However, it has yet to be realized in a large memristor array due to the high requirements on the memristor device. In this work, the multilevel memristor cell is optimized by employing an electro‐thermal modulation layer. Memristor devices show both high resistance, cell‐to‐cell uniformity, and multilevel resistive switching behaviors with good reliability. A Hopfield neural network is experimentally demonstrated on a 1k memristor array that is capable of realizing the associative memory function for emotion image recovery. By using both asynchronous and synchronous refresh schemes, complete emotion images can be recalled from partial information.     

High Optical Gain of Solution-Processed Mixed-Cation CsPbBr3 Thin Films towards Enhanced Amplified Spontaneous Emission

A solution-processed thin film made of all-inorganic CsPbBr₃ perovskite is a promising candidate for low-cost and flexible green-color lasers. However, the amplified spontaneous emission (ASE) of solution-processed CsPbBr₃ films still experiences a high threshold owing to poor morphology and insufficient optical gain. Here, a multiple-cation doping strategy is demonstrated to develop compact, smooth thin films of Cs_0.87(FAMA)_0.13PbBr₃/(NMA)₂PbBr₄ (FA: formamidinium; MA: methylammonium; NMA: naphthylmethylammonium) with a record high net modal optical gain of ≈ 3030 cm⁻¹ and low propagation loss of 1.0 cm⁻¹. The FA and MA cations improve the crystallization kinetics to form continuous films, and the NMA cations reduce the grain dimension, increase film dispersibility/uniformity, and enhance spatial confinement to promote optical gain. Room-temperature ASE is demonstrated under a low threshold of ≈ 3.8  µ J cm⁻² without degradation after four months of storage in glove box or excitation by 3 × 10⁷ laser pulses. These findings provide insights into enhancing the optical gain and lowering the threshold of perovskite lasers in terms of molecular synthesis and microstructure engineering.     

A BFSK and OOK IF demodulation circuit with 2.8 μs settling time and re-configurable image rejection functions for MICS/BCC applications

A BFSK and OOK IF base-band circuit is provided to implement the low-IF RF receivers for a dualband MICS/BCC network controller.In order to transfer the massive vital data immediately,the IF circuit is comprised of the fast-settling feed-forward programmable gain amplifier (PGA),a Gm-C complex filter,the fixed gain amplifier (FGA) and a 4-input quadratic sum demodulator.A novel auto-switched coarse gain-setting method is adopted in the PGA to enhance the reaction speed and narrow the output signal range.Also the PGA does not suffer the same stability constraint as open-loop topologies.The complex filter fulfills the function of image rejection,in which the center frequency and bandwidth can be adjusted individually.The FGA is used to ameliorate the linearity and the 'quadratic sum' demodulator can reduce the overall power consumption.The designed IF circuit is fabricated with SMIC 0.18/μm CMOS process.The chip area is about 5.36 mm2.Measurement results are given to verify the design goals.     

Over 16.7% Efficiency Organic‐Silicon Heterojunction Solar Cells with Solution‐Processed Dopant‐Free Contacts for Both Polarities

Realization of synchronous improvement in optical management and electrical engineering is necessary to achieve high‐performance photovoltaic device. However, inherent challenges are faced in organic‐silicon heterojunction solar cells (HSCs) due to the poor contact property of polymer on structured silicon surface. Herein, a remarkable efficiency boost from 12.6% to over 16.7% in poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate)/n‐silicon (PEDOT:PSS/n‐Si) HSCs by independent optimization of hole‐/electron‐selective contacts only relying on solution‐based processes is realized. A bilayer PEDOT:PSS film with different functionalizations is utilized to synchronously realize conformal contact and effective carrier collection on textured Si surface, making the photogenerated carriers be well separated at heterojunction interface. Meanwhile, fullerene derivative is used as electron‐transporting layer at the rear n‐Si/Al interface to reduce the contact barrier. The study of carriers' transport and independent optimization on separately contacted layers may lead to an effective and simplified path to fabricate high‐performance organic‐silicon heterojunction devices.     

雷达用微波功率器件的发展趋势

本文从雷达技术发展的角度阐述了雷达用微波功率器件的发展趋势，并指出今后将主要发展ＭＰＭ，ＭＭＩＣ，毫米波真空器件和真空微电子器件。     

紧凑型荧光灯(CFL)高压驱动器L6567原理及应用

ＳＴ公司新推出的ＣＦＬ高压半桥驱动器Ｌ６５６７可为ＣＦＬ灯丝预热、点火和稳压工作提供所必要的控制功能。文章在介绍了Ｌ６５６７的功能特点和工作原理的基础上,重点介绍了Ｌ６５６７在ＣＦＬ镇流器中的应用电路与设计方法。