嵌入式网络连通检测器的实现

介绍了以太网连通错误管理（CFM）的技术背景,指出纯软件开发的以太网的CFM模块具有局限性,并无法满足协议多变的特点。该模块是在SOPC系统上实现IEEE802．1ag协议中连通性检测功能。系统采用Altera公司提供的DE2开发板作为实现平台,实现了能以毫秒级速度发送及分级告警的嵌入式网络连通检测器。用两个开发板模拟一个小型的网络,通过PC机来对开发板进行操作和控制,利用对开发板上的LCD显示屏及LED显示灯进行监测,验证连通检测器的功能及性能。     

Mo-Modified ZnIn2S4@NiTiO3 S-Scheme Heterojunction with Enhanced Interfacial Electric Field for Efficient Visible-Light-Driven Hydrogen Evolution

Designing and developing visible-light-responsive materials for solar to chemical energy is an efficient and promising approach to green and sustainable carbon-neutral energy systems. Herein, a facile in situ growth hydrothermal strategy using Mo-modified ZnIn₂S₄ (Mo-ZIS) nanosheets coupled with NiTiO₃ (NTO) microrods to synthesize multifunctional Mo-modified ZIS wrapped NTO microrods (Mo-ZIS@NTO) photocatalyst with enhanced interfacial electric field (IEF) effect and typical S-scheme heterojunction is reported. Mo-ZIS@NTO catalyst possesses wide-spectrum light absorption properties, excellent visible light-to-thermal energy effect, electron mobility, charges transfer, and strong IEF and exhibits excellent solar-to-chemical energy conversion for efficient visible-light-driven photocatalytic hydrogen evolution. Notably, the engineered Mo_1.4-ZIS@NTO catalyst exhibits superior performance with H₂ evolution rate of up to 14.06 mmol g⁻¹ h^{− 1} and the apparent quantum efficiency of 44.1% at 420 nm. The scientific explorations provide an in-depth understanding of microstructure, S-scheme heterojunction, enhanced IEF, Mo-dopant facilitation effect. Moreover, the theoretical simulations verify the critical role of Mo element in promoting the adsorption and activation of H₂O molecules, modulating the H adsorption behavior on active S sites, and thus accelerating the overall catalytic efficiency. The photocatalytic hydrogen evolution mechanism via S-scheme heterojunction with adjustable IEF regulation over Mo_1.4-ZIS@NTO is also demonstrated.     

稳健的机载预警雷达多通道海杂波抑制方法研究

在机载预警雷达对海洋背景运动目标的探测过程中,雷达平台的高速运动状态使得海杂波多普勒谱发生严重展宽现象,影响目标的检测性能.针对此问题,空-时自适应处理是一种有效的杂波抑制技术,该技术利用杂波的空-时2维耦合特性进行杂波抑制.但相对于陆地杂波而言,海杂波的内部复杂运动特性使得杂波空-时谱发生展宽现象,导致杂波多普勒频率与空间锥角不再保持一一对应关系,从而影响杂波抑制效果.针对海杂波的运动特性,该文提出一种稳健的基于子空间投影的杂波抑制处理算法,所提算法通过滤波凹口自适应展宽技术和先滑窗滤波后自适应处理技术来提高杂波抑制的稳健性.最后通过仿真的海杂波数据和实测海杂波数据验证了所提算法的有效性.     

N掺杂Cu2O薄膜的低温沉积及快速热退火研究

采用氧化亚铜(Cu_2O)陶瓷靶,利用射频磁控溅射沉积法在氮气和氩气的混合气氛下制备了N掺杂Cu_2O(Cu_2O∶N)薄膜,并在N_2气氛下对薄膜进行了快速热退火处理,研究了N_2流量和退火温度对Cu_2O∶N薄膜的生长行为、物相结构、表面形貌及光电性能的影响。结果显示,在衬底温度300℃、N_2流量12sccm条件下生长的薄膜为纯相Cu_2O薄膜;在N_2气氛下对预沉积薄膜进行快速热退火处理不影响薄膜的物相结构,薄膜的结晶质量随退火温度(450℃)的升高而显著改善;快速热退火处理能改善薄膜的结晶质量和缺陷,降低光生载流子的散射,增强载流子的传输,预沉积Cu_2O∶N薄膜经400℃退火处理后展示出较好的电性能,薄膜的霍尔迁移率(μ)为27.8cm~2·V~(-1)·s~(-1)、电阻率(ρ)为2.47×10~3Ω·cm。研究表明低温溅射沉积和快速热退火处理能有效改善Cu_2O∶N薄膜的光电性能。     

空域反转阵导向最小方差波束形成

文章研究了基于空域反转阵（Spatial Reversion Array,SRVA）的导向最小方差（Steered Minimum Variance,STMV）波束形成方法。根据空域反转阵的原理将均匀线阵列的快拍进行空间反转,再与原阵列快拍卷积,得到孔径扩大近一倍的空域反转阵,提高阵列性能。将同样的方法用于构造空域反转阵的导向向量,实现其导向最小方差（SRVA-STMV）波束形成。仿真和海试试验结果表明,相较于常规的STMV波束形成,空域反转阵STMV波束形成能够获得更窄的主瓣、更低的旁瓣、更高的输出信干噪比以及更好的多目标分辨能力。     

铲齿成形铣刀重磨误差的分析和重磨前角的优化

本文先提出了γｆ＞０的铲齿成形铣刀因重磨而引起的廓形高度误差的计算方法,分析了重磨误差的规律。在此基础上又进一步提出了重磨前角的修正和优化。     

高速数据采集系统的设计与实现

由于雷达数据处理的要求,需要对雷达数据进行实时地存储记录。本文介绍了一种基于光纤通道的高速数据采集系统,以FPGA为平台,PCIExpress为接口,链式DMA为传输模式,实现了最高速率为6Gbps的数据采集系统。     

光学遥感器薄膜加热片阻值计算及应用

论述了航天用薄膜加热器的工作原理,推导和总结了同一加热区内三种不同串、并联关系的薄膜加热片单位面积阻值的通用计算公式。最后通过实例验证了该公式的正确性。对于具有复杂加热区的空间光学遥感器,依据该公式可以方便快捷地设计出各种串、并联关系的薄膜加热器。     

A reference-based blind source extraction algorithm

By utilizing a priori information available as reference, constrained independent component analysis (cICA) or independent component analysis with reference (ICA-R) achieves some advantages over other methods. However, ICA-R is very time-consuming; moreover, it is very difficult to determine its threshold parameter, once the value is improperly chosen the algorithm will fail to converge. In order to overcome these drawbacks, a very simple blind source extraction method, whose optimization function is simply the closeness measure between the desired output and its corresponding reference in ICA-R, is proposed in this paper. Experiments with synthesized data and real-world electrocardiograph data confirm its validity and superiority.