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初相捷变波形优化设计与信号处理方法研究

信号处理 2024年第1期40卷 114-125页

作者：刘泉华刘子豪任丽香范花玉北京理工大学雷达技术研究院北京100081 卫星导航电子信息技术教育部重点实验室(北京理工大学) 北京100081 北京理工大学长三角研究院浙江嘉兴314033 北京理工大学重庆创新中心重庆401135

捷变波形具备一定的距离和速度模糊抑制能力,同时兼具优良的低截获和抗干扰性能,为雷达系统提供了新的信号处理维度。初相捷变波形相对简单,工程实现难度小,为实现波形设计和信号处理闭环,本文开展了初相捷变波形优化设计与信号处理方... 详细信息

捷变波形具备一定的距离和速度模糊抑制能力,同时兼具优良的低截获和抗干扰性能,为雷达系统提供了新的信号处理维度。初相捷变波形相对简单,工程实现难度小,为实现波形设计和信号处理闭环,本文开展了初相捷变波形优化设计与信号处理方法研究。首先,介绍了初相捷变波形的距离选通特性,进而构建了基于距离选通特性的初相捷变波形优化设计模型,并通过Majorization-Minimization算法和牛顿法进行求解。所提算法可采用平方迭代法加快收敛速度,经仿真验证,与随机产生的初相捷变波形相比,所提算法可以显著改善优化后初相捷变波形的距离选通特性。其次,基于初相捷变波形的抗折叠杂波性能,探讨了基于距离选通特性的自适应杂波抑制算法,即利用初相捷变波形空时维导向矢量的距离选通特点,实现分距离段杂波抑制,使得近距主副瓣杂波不会折叠到远距离段,经仿真与实测数据验证,所提算法在强杂波环境下具备良好的远距低速目标探测能力。最后,研究了基于距离选通和交替反演的干扰抑制算法,利用远距支援干扰滞后于目标回波的特点,并基于初相捷变波形的距离选通特性,通过距离段间交替投影实现干扰与目标回波的分距离段重构,经仿真验证,所提算法可以实现对远距支援干扰的有效抑制。

关键词：初相捷变波形距离选通特性抗折叠杂波干扰抑制

一种基于深度强化学习的频率捷变雷达智能频点决策方法

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雷达学报（中英文） 2024年第1期13卷 227-239页

作者：张嘉翔张凯翔梁振楠陈新亮刘泉华北京理工大学信息与电子学院雷达技术研究所北京100081 北京理工大学重庆创新中心重庆401120 北京理工大学长三角研究院(嘉兴) 嘉兴314000 卫星导航电子信息技术教育部重点实验室(北京理工大学) 北京100081

自卫式干扰机发射的瞄准干扰使多种基于信号处理的被动干扰抑制方法失效,对现代雷达产生了严重威胁,频率捷变作为一种主动对抗方式为对抗瞄准干扰提供了可能。针对传统随机跳频抗干扰性能不稳定、频点选取自由度有限、策略学习所需时间... 详细信息

自卫式干扰机发射的瞄准干扰使多种基于信号处理的被动干扰抑制方法失效,对现代雷达产生了严重威胁,频率捷变作为一种主动对抗方式为对抗瞄准干扰提供了可能。针对传统随机跳频抗干扰性能不稳定、频点选取自由度有限、策略学习所需时间长等问题,该文面向频率捷变雷达,提出了一种快速自适应跳频策略学习方法。首先设计了一种频点可重复选取的频率捷变波形,为最优解提供了更多选择。在此基础上,通过利用雷达与干扰机持续对抗收集到的数据,基于深度强化学习的探索与反馈机制,不断优化频点选取策略。具体来说,通过将上一时刻雷达频点及当前时刻感知到的干扰频点作为强化学习输入,神经网络智能选取当前时刻各子脉冲频点,并根据目标检测结果以及信干噪比两方面评价抗干扰效能,从而优化策略直至最优。从提高最优策略收敛速度出发,设计的输入状态不依赖历史时间步、引入贪婪策略平衡搜索-利用机制、配合信干噪比提高奖励差异。多组仿真实验结果表明,所提方法能够收敛到最优策略且具备较高的收敛效率。

关键词：频率捷变雷达抗干扰波形设计瞄准干扰深度Q网络

Advanced technology of high-resolution radar: target detection, tracking, imaging, and recognition

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Science China(Information Sciences) 2019年第4期62卷 5-30页

作者： Teng LONG Zhennan LIANG quanhua liu Radar Research Laboratory School of Information and Electronics Beijing Institute of Technology

In recent years, the performances of radar resolution, coverage, and detection accuracy have been significantly improved through the use of ultra-wideband, synthetic aperture and digital signal processing technologies. High-resolution radars(HRRs) utilize wideband signals and synthetic apertures to enhance the range and angular resolutions of tracking, respectively. They also generate one-, two-, and even threedimensional high-resolution images containing the feature information of targets, from which the targets can be precisely classified and identified. Advanced signal processing algorithms in HRRs obtain important information such as range-Doppler imaging, phase-derived ranging, and micro-motion features. However, the advantages and applications of HRRs are restricted by factors such as the reduced signal-to-noise ratio(SNR)of multi-scatter point targets, decreased tracking accuracy of multi-scatter point targets, high demands of motion compensation, and low sensitivity of the target attitude. Focusing on these problems, this paper systematically introduces the novel technologies of HRRs and discusses the issues and solutions relevant to detection, tracking, imaging, and recognition. Finally, it reviews the latest progress and representative results of HRR-based research, and suggests the future development of HRRs.

关键词： high-resolution radar integrated detection and tracking multiple target tracking phase-derived velocity inverse synthetic aperture radar(ISAR) hierarchical classification convolution neural network

On the environmental information for solar and wind energy facilities

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Science China Earth Sciences 2012年第5期55卷 796-801页

作者： WENG FuZhong liu quanhua ZOU XiaoLei National Oceanic and Atmospheric Administration Camp SpringsMD 20746USA Joint Center for Satellite Data Assimilation Camp SpringsMD 20746USA Department of Earth Ocean and Atmospheric SciencesFlorida State UniversityTallahassee FL 32306-4520USA Nanjing University of Information Science and Technology Nanjing 210044China

Wind and solar energy are projected to be major sources of the world's power in the coming *** this study,we first introduce satellite observations for surface solar irradiance and wind,and then discuss using the data for prediction and assessment of energy *** the current NCEP global forecast model (GFS),the global mean and standard deviation of solar power at the surface for the 5-d forecast are about 212 and 124 W/m2,*** a 24-h forecast of a 3-h mean,the relative error is about 30%,and for a prediction of the daily mean,it is about 15%.The relative error of wind power forecasts for a 24-h forecast of a 3-h mean and a daily mean is 70% and 35%,*** reanalysis results based on satellite observations and numerical weather prediction model are also used to study the distribution of solar and wind energy and the variation of the distribution related to climate *** significant trend in downward solar radiation is found at the surface in the reanalysis data *** wind power however exhibits a significant positive trend as the global temperature is warming up.A comparison of a decadal mean wind energy between two decades (from 1949 to 1958 *** 1999 to 2008) shows that most of Asia had experienced a decrease in surface wind ***,decisions about renewable energy developments need to consider such climate change scenarios.

关键词： wind energy solar energy predictability assessment

High-Precision Wideband Phase-Derived Velocity Measurement for Micro-Motion Extraction

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Journal of Beijing Institute of Technology 2017年第1期26卷 106-114页

作者： Yuan Jiang Huayu Fan quanhua liu Xinliang Chen School of Information and Electronics Beijing Institute of Technology Beijing 100081 China

A phase-derived velocity measurement method is proposed in a wideband coherent system,based on a precise echo model considering the inner pulse Doppler effect caused by fast moving *** Cramer-Rao low band of velocity measurement precision is deduced,demonstrating the high precision of the proposed *** and out-field experiments further validate the effectiveness of the proposed method in high-precision measurement and micro-motion extraction for targets with weak reflection *** with the long-time integration approaches for velocity measurement,the phase-derived method is easy to implement and meets the requirement for high data rate,which makes it suitable for micro-motion feature extraction in wideband systems.

关键词： phase-derived velocity measurement micro-motion extraction wideband coherent sys-tem high-precision measurement

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苏合香丸治疗病毒性脑炎的临床效果

中国当代医药 2024年第16期31卷 46-49页

作者：高慧刘泉华黄茜茜江西省九江市第一人民医院神经内2科江西九江332000

目的探讨苏合香丸治疗病毒性脑炎的临床效果。方法选取2022年5月至2023年5月江西省九江市第一人民医院收治的60例病毒性脑炎患者作为研究对象,按照随机数字表法将其分为对照组和研究组,每组30例。对照组采用常规治疗方案,研究组采用常... 详细信息

目的探讨苏合香丸治疗病毒性脑炎的临床效果。方法选取2022年5月至2023年5月江西省九江市第一人民医院收治的60例病毒性脑炎患者作为研究对象,按照随机数字表法将其分为对照组和研究组,每组30例。对照组采用常规治疗方案,研究组采用常规治疗方案联合苏合香丸,比较两组患者的临床疗效、治疗前后脑脊液T淋巴细胞表达水平、脑脊液的相关指标、治疗期间不良反应发生情况。结果研究组临床治疗有效率高于对照组,CD3^(+)、CD4^(+)及CD4^(+)/CD8^(+)比值高于对照组,CD8^(+)、脑脊液蛋白定量、总细胞数和不良反应总发生率均低于对照组,差异有统计学意义(P<0.05)。结论苏合香丸治疗病毒性脑炎可提高临床疗效,缩短患者临床症状缓解时间,改善脑脊液相关指标水平,减少不良反应。

关键词：苏合香丸病毒性脑炎临床疗效脑脊液不良反应

A radar waveform bandwidth selection strategy for wideband tracking

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Science China(Information Sciences) 2019年第4期62卷 50-52页

作者： Shaoqiang CHANG Honggang ZHANG Teng LONG quanhua liu Le ZHENG Radar Research Laboratory School of Information and Electronics Beijing Institute of Technology Department of Electronic Engineering Tsinghua University Key Laboratory of Electronic and Information Technology in Satellite Navigation (Beijing Institute of Technology) Ministry of Education Electrical Engineering Department Columbia University

Dear editor,The performance of radar target detection and tracking is greatly influenced by waveform bandwidth. Ref. [1] proposes that very narrowband waveforms are usually employed for search, narrowband waveforms ar... 详细信息

关键词： A radar waveform bandwidth selection strategy for wideband tracking KT

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不同技术路线下的三元黑粉回收工艺对比论述

山东化工 2024年第6期53卷 133-135页

作者：毕凡彭明生王皓王伟邓同刘全华宜昌邦普宜化新材料有限公司湖北宜昌443000

对行业内三种最常见的黑粉处理工艺进行了详细阐述和对比。硫酸化焙烧使锂在高温条件下浸出,并通过后续的水浸方式使锂与钴镍等进行分离,含锂溶液经除杂后进入锂沉淀工序,钴镍渣则进入常规湿法冶金系统进行处理。还原焙烧路线利用氢气... 详细信息

对行业内三种最常见的黑粉处理工艺进行了详细阐述和对比。硫酸化焙烧使锂在高温条件下浸出,并通过后续的水浸方式使锂与钴镍等进行分离,含锂溶液经除杂后进入锂沉淀工序,钴镍渣则进入常规湿法冶金系统进行处理。还原焙烧路线利用氢气等还原性物质,在高温下使三价钴镍还原为单质,再通过水浸法使离子态锂与金属态的钴镍分离,含锂溶液在除杂后进行锂提取,单质态钴镍则进入常规湿法冶金系统进行回收处理。全溶-萃取法则直接将黑粉溶解后,经过浸出段粗除杂和萃取精除杂,再对萃取液蒸发提浓后进行锂沉淀,从而达到锂回收的目的。

关键词：锂回收硫酸化焙烧还原焙烧全溶萃取

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Prevalence of allergic diseases and risk factors of asthma among preschool children in urban Shanghai China

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Prevalence of allergic diseases and risk factors of asthma a...