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A target parameter estimation method via atom-reconstruction in radar mainlobe jamming

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Journal of Systems Engineering and Electronics 2024年第2期35卷 350-360页

作者： ZHOU Bilei LIU weijian LI Rongfeng chen Hui ZHANG Liang DU Qinglei LI Binbin chen Hao Air Force Early Warning Academy Wuhan 430019China Aerospace Nanhu Electronic Information Technology Co. Ltd.Jingzhou 434000China

Mainlobe jamming(MLJ)brings a big challenge for radar target detection,tracking,and identification.The suppression of MLJ is a hard task and an open problem in the electronic counter-counter measures(ECCM)field.Target parameters and target direction estimation is difficult in radar MLJ.A target parameter estimation method via atom-reconstruction in radar MLJ is proposed in this paper.The proposed method can suppress the MLJ and simultaneously provide high estimation accuracy of target range and angle.Precisely,the eigen-projection matrix processing(EMP)algorithm is adopted to suppress the MLJ,and the target range is estimated effectively through the beamforming and pulse compression.Then the target angle can be effectively estimated by the atom-reconstruction method.Without any prior knowledge,the MLJ can be canceled,and the angle estimation accuracy is well preserved.Furthermore,the proposed method does not have strict requirement for radar array construction,and it can be applied for linear array and planar array.Moreover,the proposed method can effectively estimate the target azimuth and elevation simultaneously when the target azimuth(or elevation)equals to the jamming azimuth(or elevation),because the MLJ is suppressed in spatial plane dimension.

关键词： mainlobe jamming anti-jamming atom-reconstruction radar

Constructing a stable interface on Ni-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode via lactic acid-assisted engineering strategy

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Journal of Energy Chemistry 2024年第3期90卷 412-422,I0010页

作者： weijian Tang chengzhi Hu AFei Li Xiaoqin Huang Zhangxian chen Jianhui Su Weixin Zhang Institute of Energy Hefei Comprehensive National Science CenterHefei 230031AnhuiChina School of Chemistry and Chemical Engineering Hefei University of Technology and Anhui Key Laboratory of Controllable Chemical Reaction&Material Chemical EngineeringHefei 230009AnhuiChina School of Electrical Engineering and Automation Hefei University of TechnologyHefei 230009AnhuiChina

Ni-rich layered oxides are potential cathode materials for next-generation high energy density Li-ion batteries due to their high capacity and low cost.However,the inherently unstable surface properties,including high levels of residual Li compounds,dissolution of transition metal cations,and parasitic side reactions,have not been effectively addressed,leading to significant degradation in their electrochemical performance.In this study,we propose a simple and effective lactic acid-assisted interface engineering strategy to regulate the surface chemistry and properties of Ni-rich LiNi_(0.8)Co_(0.1)Mr_(0.1)O_(2) cathode.This novel surface treatment method successfully eliminates surface residual Li compounds,inhibits structural collapse,and mitigates cathode-electrolyte interface film growth.As a result,the lactic acidtreated LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) achieved a remarkable capacity retention of 91.7% after 100 cycles at 0.5 C(25℃) and outstanding rate capability of 149.5 mA h g^(-1) at 10 C,significantly outperforming the pristine material.Furthermore,a pouch-type full cell incorporating the modified LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode demonstrates impressive long-term cycle life,retaining 81.5% of its capacity after 500 cycles at 1 C.More importantly,the thermal stability of the modified cathode is also dramatically improved.This study offers a valuable surface modification strategy for enhancing the overall performance of Ni-rich cathode materials.

关键词： Residual Li Lactic acid Surface modification Carbon coating Layered cathode Ni-rich

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八步连续流全合成维生素B_(1)工艺研究

Engineering 2024年第1期32卷 226-232页

作者： Meifen Jiang Minjie Liu weijian Li Yingqi Xia Fen-Er chen Engineering Center of Catalysis and Synthesis for Chiral Molecules Department of ChemistryFudan UniversityShanghai 200433China Shanghai Engineering Research Center of Industrial Asymmetric Catalysis of Chiral Drugs Shanghai 200433China School of Science Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

Vitamin B_(1) is widely applied in the healthcare and food industry as an antineuritic and antioxidant to maintain the normal functioning of nerve conduction,the heart,and the gastrointestinal tract.This study reports on an integrated eight-step continuous-flow synthesis of vitamin B_(1) from commercially available 2-cyanoacetamide.The proposed continuous-flow process is based on advances in chemistry,engineering,and equipment design,and affords improved performance and safety compared with batch-mode manufacturing.Several challenges were precisely investigated and controlled,including mixing,unexpected clogging,solvent switches,an exothermic reaction,and the prevention of side reactions,using various micro-channel flow reactors,mixers,separators,and continuous filters.Vitamin B_(1) was produced with a separated yield of 47.7% and high purity,with a total residence time of about 3.5 h.This eight-step continuous-flow protocol enables technology involving up to six of the key principles of green chemistry.Hence,the application of flow technology is of paramount importance for improving security,reducing waste,and,in particular,improving the efficiency of batch operations that require several days for manufacturing.

关键词： Vitamin B_(1) Continuous-flow synthesis Micro-reactor Continuous manufacturing

Zhuangyao Jianshen pill(壮腰健肾丸) ameliorates testosterone-induced benign postatic hyperplasia in rats

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Journal of Traditional Chinese Medicine 2024年第4期 694-702页

作者： ZHENG Jingrui chen weijian YE Binbin MO Ziyao DU Qunqun QIN Renan NIE Ke School of Chinese Materia Medica Guangdong Pharmaceutical University Modern Chinese Medicine Research Institute Guangzhou Baiyunshan Chenliji Pharmaceutical Factory Co.Ltd.

OBJECTIVE: To determine the therapeutic effects of the Zhuangyao Jianshen pill(壮腰健肾丸, ZYJSP) against benign prostatic hyperplasia(BPH) and investigate the underlying mechanism. METHODS: Forty-eight male Sprague-Dawley rats were randomly divided into six groups: Control group, BPH model group, finasteride-treated group, ZYJSP low, medium and high dose groups. Except for the control group, 40 rats were castrated and injected with testosterone propionate(TP) for 28 consecutive day to induce BPH. Meanwhile, the corresponding drugs were administered by gavage. The prostate wet weight, prostate index(PI), and the histopathological changes in the prostate were measured as the basis for examining the efficacy of ZYJSP against BPH. Levels of the serum sex hormones, oxidative stress markers, inflammatory markers, renal function markers, growth factors, and Cyclin D1 expression in prostate were measured to characterize the therapeutic mechanism of ZYJSP against BPH. RESULTS: ZYJSP administration significantly reduced prostate wet weight and PI and ameliorated histological changes of the prostate in TP-treated castrated rats. TP markedly increased the levels of creatinine, blood urea nitrogen and growth factors in the serum as well as the expression of the Cyclin D1 in the prostate. Most of these markers were significantly decreased by ZYJSP. ZYJSP significantly restored the dysregulation of testosterone, estradiol, and dihydrotestosterone caused by TP. Furthermore, ZYJSP relieved TP-induced prostate injury and exhibited both anti-inflammatory and anti-oxidant activity by decreasing interleukin-6, interleukin-8, and malondialdehyde levels and increasing the activity of superoxide dismutase in the serum. CONCLUSION: These findings indicate that ZYJSP can effectively ameliorate BPH induced by TP in castrated rats, and the underlying mechanism might be related to regulating sex hormone balance, reducing oxidative stress, and inhibiting the inflammatory response.

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Graph convolution machine for context-aware recommender system

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Frontiers of Computer Science 2022年第6期16卷 81-92页

作者： Jiancan WU Xiangnan HE Xiang WANG Qifan WANG weijian chen Jianxun LIAN Xing XIE School of Information Science and Technology University of Science and Technology of ChinaHefei230026China National University of Singapore 5 Prince George’s ParkSingapore118404Singapore Google Research Mountain ViewCA94043USA Microsoft Research Asia Beijing100190China

The latest advance in recommendation shows that better user and item representations can be learned via performing graph convolutions on the user-item interaction graph.However,such finding is mostly restricted to the collaborative filtering(CF)scenario,where the interaction contexts are not available.In this work,we extend the advantages of graph convolutions to context-aware recommender system(CARS,which represents a generic type of models that can handle various side information).We propose Graph Convolution Machine(GCM),an end-to-end framework that consists of three components:an encoder,graph convolution(GC)layers,and a decoder.The encoder projects users,items,and contexts into embedding vectors,which are passed to the GC layers that refine user and item embeddings with context-aware graph convolutions on the user-item graph.The decoder digests the refined embeddings to output the prediction score by considering the interactions among user,item,and context embeddings.We conduct experiments on three real-world datasets from Yelp and Amazon,validating the effectiveness of GCM and the benefits of performing graph convolutions for CARS.

关键词： context-aware recommender systems graph convolution

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中国人类世科学研究新进展

地球科学进展 2024年第1期39卷 1-11页

作者：周卫健赵雪陈宁中国科学院地球环境研究所黄土与第四纪地质国家重点实验室陕西西安710061 陕西省加速器质谱技术及应用重点实验室西安加速器质谱中心陕西西安710061 西安地球环境创新研究院陕西西安710061 西安交通大学陕西西安710049

国际地层委员会人类世工作组决议人类世应由全球界线层型剖面和点位(“金钉子”)定义为一个正式的地质年代单位。20世纪中叶以来人类活动突变式增强,改变了原有的地球演化速率和方向,对地球环境造成极为显著的影响,并在地质记录中留下... 详细信息

国际地层委员会人类世工作组决议人类世应由全球界线层型剖面和点位(“金钉子”)定义为一个正式的地质年代单位。20世纪中叶以来人类活动突变式增强,改变了原有的地球演化速率和方向,对地球环境造成极为显著的影响,并在地质记录中留下清晰的具有全球同步特性的物理、化学和生物印记,为识别这一年代地层单位的底界提供了最佳选择。当前,全球共有12个人类世“金钉子”候选剖面和点位参评。与此同时,中国学者在人类活动代用指标体系构建、人类世候选“金钉子”研究与国际对比方面取得了突出进展,发现人工放射性核素、微塑料、δ^(13)C、δ^(15)N和硅藻等均可作为人类活动理想的标志物,且远离城市和人类活动影响的中国四海龙湾玛珥湖沉积物剖面对全球信号敏感,^(239,240)Pu浓度于1953年快速增加,多环芳烃、^(129)I、烟炱^(14)C、碳球粒、DNA、δ^(13)C和重金属等指标在1953年前后均存在系统性变化,因此提出1953年作为人类世底界。中国四海龙湾湖沉积物剖面与日本别府海湾沉积物剖面被人类世工作组提议作为人类世“金钉子”辅助剖面。未来人类世科学研究的最终目标应是在阐明人类活动对地球系统影响的基础上,深化人地系统耦合与适应的可持续发展理论和技术创新。

关键词：四海龙湾玛珥湖钚同位素金钉子人类世科学

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天波超视距雷达非均匀采样信号频谱重构

系统工程与电子技术 2024年第4期46卷 1236-1246页

作者：陈子睿陈阿磊刘维建杨军陈文峰马晓岩空军预警学院湖北武汉430019

受瞬态干扰影响和空海同时探测的需求,在长相参积累时间条件下,天波超视距雷达(over-the-horizon radar,OTHR)回波信号的有效采样点往往缺损且非均匀,严重影响目标检测性能。针对此问题,提出了一种基于压缩感知的OTHR频谱重构方法。首先... 详细信息

受瞬态干扰影响和空海同时探测的需求,在长相参积累时间条件下,天波超视距雷达(over-the-horizon radar,OTHR)回波信号的有效采样点往往缺损且非均匀,严重影响目标检测性能。针对此问题,提出了一种基于压缩感知的OTHR频谱重构方法。首先,建立了OTHR频域信号的稀疏模型;然后,提出了快速自适应复近似消息传递(fast adaptive complex approximate message passing,FACAMP)频谱重构算法并给出了算法实现步骤;最后,利用FACAMP算法实现了OTHR频谱重构并分析了重构性能。与现有重构算法相比,FACAMP算法具有重构精度高、运算复杂度低、可自适应调整参数和保留背景噪声高斯性的优势。理论分析和仿真实验均验证了所提算法的有效性。

关键词：天波超视距雷达压缩感知频谱重构复近似消息传递

Quasi-Situ Characterization of Deformation in Low-Carbon Steel with Equiaxed and Lamellar Microstructure Treated by the Quenching and Partitioning Process

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Acta Metallurgica Sinica(English Letters) 2020年第12期33卷 1657-1665页

作者： Pengfei Gao weijian chen Feng Li Beijia Ning Zhengzhi Zhao Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation Beijing 100083China

The relationship between microstructure morphology and mechanical properties of the low-carbon steel(Fe-0.20 C-2.59 Mn-2.13 Si)treated by diff erent intercritical annealed quenching and partitioning(Q&P)processes was investigated through interrupted tensile tests plus quasi-situ electron backscatter diff raction measurements.Results show that size and distribution of retained austenite(RA)directly aff ect the sequence of deformation induced martensitic transformation.As strain increases,the equiaxed RA grains wrapped by ferrite transform fi rst,followed by the equiaxed and fi lm-like RA grains adjacent to martensite.Compared with traditional intercritical annealed Q&P steel with equiaxed structure,the steel with quenching pretreatment contains uniform lamellar structure and the relatively fi lm-like type of RA,leading to the higher yield strength,tensile strength,and elongation,as well as the steady increase in dislocation density upon straining.

关键词： Steel Quenching and partitioning Austenite Martensitic transformation Electron backscatter diffraction(EBSD) Tensile test

Magnetic resonance perfusion imaging evaluation in perfusion abnormalities of the cerebellum after supratentorial unilateral hyperacute cerebral infarction

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Neural Regeneration Research 2012年第12期7卷 906-911页

作者： Pan Liang Yunjun Yang weijian chen Yuxia Duan Hongqing Wang Xiaotong Wang Department of Radiology First Affiliated Hospital of Wenzhou Medical College Wenzhou 325000 Zhejiang Province China Second Affiliated Hospital of Wenzhou Medical College Wenzhou 325000 Zhejiang Province China

Magnetic resonance imaging （MRI） data of 10 patients with hyperacute cerebral infarction （≤6 hours） were retrospectively analyzed.Six patients exhibited perfusion defects on negative enhancement integral maps,four patients exhibited perfusion differences in pseudo-color on mean time to enhance maps,and three patients exhibited perfusion differences in pseudo-color on time to minimum maps.Dynamic susceptibility contrast-enhanced perfusion weighted imaging revealed a significant increase in region negative enhancement integral in the affected hemisphere of patients with cerebral infarction.The results suggest that dynamic susceptibility contrast-enhanced perfusion weighted imaging can clearly detect perfusion abnormalities in the cerebellum after unilateral hyperacute cerebral infarction.

关键词： magnetic resonance imaging magnetic resonance-perfusion-weighted imaging cerebral infarction cerebral perfusion functional neurological deficit