密集假信号与诱饵组合干扰研究

为有效对抗反导防御系统,实现提高导弹突防能力的目的,研究了一种针对线性调频脉冲压缩体制雷达的密集假信号干扰技术。从理论上分析密集假信号对脉压雷达的干扰机理,并在目标前后仿真实现了可控数量、时延的密集假信号干扰。最后结合诱饵技术从改变弹头相当位置、对抗灵巧噪声剔除技术、提高导弹突防概率三个方面对组合干扰进行探讨。研究表明,密集假信号与诱饵组合干扰可以提高导弹的突防能力。     

WDM光网络关键技术研究

信息爆炸导致了对带宽的无限需要,而波分复用（ＷＤＭ）系统在满足不断增长的带宽需求的同时还具有不可比拟的联网优势,文中着重研究了ＷＤＭ光网络的关键技术。     

一种新型三维光正交码的设计

基于光正交码(OOC)编码技术,提出了一种新型空/时/频三维OOC的设计方案,对光信号在时、频和空域进行编码,该码具有理想的自/互相关特性。通过仿真比较,在容量和系统的误码率等性能方面比一、二维OOC都有较大的提高,因而能很好地适应未来高密集光纤通信。     

传感器网络中基于二元簇的节能路由算法

传感器网络中的分簇算法已经被证明能够有效地节约能量。据此提出了一种基于二元簇的路由算法,其基本思想是网络中的每个节点同时属于2个不同簇,利用二元性来减少在路由发现中的资源浪费,并能够更加确定地发现路由以节约资源。理论分析和模拟实验都表明,该算法在能量消耗和网络生命周期延长方面较优。     

基于功率特征的抗密集多假目标干扰跟踪技术

针对密集多假目标干扰下,真假目标识别困难、跟踪精度低的问题,提出了基于功率特征的抗干扰技术。首先,对干扰条件下的雷达量测进行信号似然比预处理,剔除杂波;然后,进行角度卡方检验及同源量测融合,以充分利用虚假目标信息;最后,根据真假目标功率特征构建“分贝数冶加权因子,并结合位置信息,实现真实目标的功率/ 位置双重加权,从而大大削弱干扰信号的影响,达到抗干扰的目的。仿真实验表明,该技术能较好地适应密集多假目标干扰环境,并取得较高的跟踪精度。     

Highly Dispersed NiO Clusters Induced Electron Delocalization of Ni?N?C Catalysts for Enhanced CO2 Electroreduction

Oxygen-regulated Ni-based single-atom catalysts (SACs) show great potential in accelerating the kinetics of electrocatalytic CO₂ reduction reaction (CO₂RR). However, it remains a challenge to precisely control the coordination environment of Ni O moieties and achieve high activity at high overpotentials. Herein, a facile carbonization coupled oxidation strategy is developed to mass produce NiO clusters-decorated Ni N C SACs that exhibit a high Faradaic efficiency of CO (maximum of 96.5%) over a wide potential range (−0.9 to −1.3 V versus reversible hydrogen electrode) and a high turnover frequency for CO production of 10 120 h⁻¹ even at the high overpotential of 1.19 V. Density functional theory calculations reveal that the highly dispersed NiO clusters induce electron delocalization of active sites and reduce the energy barriers for *COOH intermediates formation from CO₂, leading to an enhanced reaction kinetics for CO production. This study opens a new universal pathway for the construction of oxygen-regulated metal-based SACs for various catalytic applications.     

Hybrid Catalyst Coupling Zn Single Atoms and CuNx Clusters for Synergetic Catalytic Reduction of CO2

Reverse water-gas shift (RWGS) reaction is the initial and necessary step of CO₂ hydrogenation to high value-added products, and regulating the selectivity of CO is still a fundamental challenge. In the present study, an efficient catalyst (CuZnN_x@C-N) composed by Zn single atoms and Cu clusters stabilized by nitrogen sites is reported. It contains saturated four-coordinate Zn-N₄ sites and low valence CuN_x clusters. Monodisperse Zn induces the aggregation of pyridinic N to form Zn-N₄ and N₄ structures, which show strong Lewis basicity and has strong adsorption for *CO₂ and *COOH intermediates, but weak adsorption for *CO, thus greatly improves the CO₂ conversion and CO selectivity. The catalyst calcined at 700 °C exhibits the highest CO₂ conversion of 43.6% under atmospheric pressure, which is 18.33 times of Cu-ZnO and close to the thermodynamic equilibrium conversion rate (49.9%) of CO₂. In the catalytic process, CuN_x not only adsorbs and activates H₂, but also cooperates with the adjacent Zn-N₄ and N₄ structures to jointly activate CO₂ molecules and further promotes the hydrogenation of CO₂. This synergistic mechanism will provide new insights for developing efficient hydrogenation catalysts.     

基于网格梯度的边界点检测算法的研究

为了快速有效地检测聚类的边界点,提出了网格梯度、边界网格的概念以及一种基于网格梯度的边界点检测算法(Boundary Points Detecting Based Gradient of Grid,BPGG),该算法先求出网格的梯度值,根据此值判断该网格是否为边界网格,进而确定聚类边界点.实验表明该算法可以在含有任意形状、大规模数据集上快速有效地检测出聚类的边界点,并去除噪声.     

超密集网中一种基于人工蜂群的节能分簇算法

超密集网络中,密集部署的低功率基站将会加大系统的能耗,并且造成紧缺频谱资源的浪费.探寻干扰协调和系统节能的可行性方法在超密集网络架构下提出基站的休眠—唤醒—活跃机制,减小了休眠基站直接转为活跃状态的开启时间;另外,提出一种基于人工蜂群染色分簇算法,尽可能使用最少的颜色给拓扑图中的小区染色,并对簇内活跃基站进行优化功率分配.经仿真表明,休眠—唤醒—活跃机制能够提升系统的能源效率,染色分簇算法也可以改善用户的频谱效率和吞吐量.     

集成检波模块的高精度激光波长稳定系统

基于半导体激光器(LD)波长和温度之间的变化原理,对LD输出波长的稳定性进行了实验研究。采用集成有检波器件的LD组件,设计了高精度的激光波长稳定系统。该系统不需要添加任何附加装置,利用温度对波长漂移进行补偿控制,实现了波长的实时锁定。通过增加注入电流、改变设定温度的方法对系统进行验证。实验表明,该系统的波长控制精度≤士2pm;在整个激光器的寿命周期内,系统的波长稳定度≤2pm。