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GS-orthogonalization OMP method for space target detection via bistatic space-based radar

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Chinese Journal of Aeronautics 2024年第7期37卷 333-351页

作者： Shuyu ZHENG Libing jiang Qingwei YANG yingjian zhao Zhuang WANG National Key Laboratory of Science and Technology on Automatic Target Recognition College of Electronic Science and TechnologyNational University of Defense TechnologyChangsha 410073China

A space-based bistatic radar system composed of two space-based radars as the transmitter and the receiver respectively has a wider surveillance region and a better early warning capability for high-speed targets,and it can detect focused space targets more flexibly than the monostatic radar system or the ground-based radar ***,the target echo signal is more difficult to process due to the high-speed motion of both space-based radars and space *** be specific,it will encounter the problems of Range Cell Migration(RCM)and Doppler Frequency Migration(DFM),which degrade the long-time coherent integration performance for target detection and localization *** solve this problem,a novel target detection method based on an improved Gram Schmidt(GS)-orthogonalization Orthogonal Matching Pursuit(OMP)algorithm is proposed in this ***,the echo model for bistatic space-based radar is constructed and the conditions for RCM and DFM are ***,the proposed GS-orthogonalization OMP method is applied to estimate the equivalent motion parameters of space ***,the RCM and DFM are corrected by the compensation function correlated with the estimated motion ***,coherent integration can be achieved by performing the Fast Fourier Transform(FFT)operation along the slow time direction on compensated echo *** simulations and real raw data results validate that the proposed GS-orthogonalization OMP algorithm achieves better motion parameter estimation performance and higher detection probability for space targets detection.

关键词： Bistatic space-based radar High-speed maneuvering space targets detection Range Cell Migration(RCM) Doppler Frequency Migration(DFM) Gram Schmidt(GS)-orthogonalization Orthogonal Matching Pursuit(OMP)algorithm

Electronic modulation of sprout-shaped NiCoP nanoarrays by N and Ce doping for efficient overall water splitting

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Nano Research 2024年第1期17卷 282-289页

作者： Ting zhao Guancheng Xu Bingbing Gong Jiahui jiang Li Zhang State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources College of ChemistryXinjiang UniversityUrumqi 830017China College of Chemical Engineering Xinjiang UniversityUrumqi 830017China

Bifunctional catalysts for hydrogen/oxygen evolution reactions(HER/OER)are urgently needed given the bright future of water splitting hydrogen production ***,the self-supporting N and Ce dual-doped NiCoP nanoarrays(denoted N,Ce-NiCoP/NF)grown on Ni foam are successfully *** the N,Ce-NiCoP/NF simultaneously acts as the HER and OER electrodes,the voltages of 1.54 and 2.14 V are obtained for driving 10 and 500 mA·cm^(-2)with a robust durability,and demonstrate its significant potential for practical water *** to both experiments and calculations,the electronic structure of NiCoP may be significantly altered by strategically incorporating N and Ce into the lattice,which in turn optimizes the Gibbs free energy of HER/OER intermediates and speeds up the water splitting ***,the sprout-shaped morphology significantly increases the exposure of active sites and facilitates charge/mass transfer,thereby augmenting catalyst *** study offers a potentially effective approach involving the regulation of anion and cation double doping,as well as architectural engineering,for the purpose of designing and optimizing innovative electrocatalysts.

关键词： transition metal phosphides overall water splitting elements doping nanoarrays

Dual-Defect Engineering Strategy Enables High-Durability Rechargeable Magnesium-Metal Batteries

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Nano-Micro Letters 2024年第9期16卷 449-461页

作者： Fuyu Chen Bai‑Qing zhao Kaifeng Huang Xiu‑Fen Ma Hong‑yi Li Xie Zhang jiang Diao Jili Yue Guangsheng Huang Jingfeng Wang Fusheng Pan National Innovation Center for Lndustry‑Education Integration of Energy Storage Technology School of Materials Science and EngineeringChongqing UniversityChongqing 400044People’s Republic of China National Magnesium Alloy Material Engineering Technology Research Center Chongqing UniversityChongqing 400044People’s Republic of China Materials and Energy Division Beijing Computational Science Research CenterBeijing 100193People’s Republic of China School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072People’s Republic of China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing 400044People’s Republic of China

Rechargeable magnesium-metal batteries(RMMBs)are promising next-generation secondary batteries;however,their development is inhibited by the low capacity and short cycle lifespan of *** various strategies have been devised to enhance the Mg^(2+)migration kinetics and structural stability of cathodes,they fail to improve electronic conductivity,rendering the cathodes incompatible with magnesium-metal ***,we propose a dual-defect engineering strategy,namely,the incorporation of Mg^(2+)pre-intercalation defect(P-Mgd)and oxygen defect(Od),to simultaneously improve the Mg^(2+)migration kinetics,structural stability,and electronic conductivity of the cathodes of *** lamellar V_(2)O_(5)·nH_(2)O as a demo cathode material,we prepare a cathode comprising Mg_(0.07)V_(2)O_(5)·1.4H_(2)O nanobelts composited with reduced graphene oxide(MVOH/rGO)with P-Mgd and *** Od enlarges interlayer spacing,accelerates Mg^(2+)migration kinetics,and prevents structural collapse,while the P-Mgd stabilizes the lamellar structure and increases electronic ***,the MVOH/rGO cathode exhibits a high capacity of 197 mAh g^(−1),and the developed Mg foil//MVOH/rGO full cell demonstrates an incredible lifespan of 850 cycles at 0.1 A g^(−1),capable of powering a light-emitting *** proposed dual-defect engineering strategy provides new insights into developing high-durability,high-capacity cathodes,advancing the practical application of RMMBs,and other new secondary batteries.

关键词： Rechargeable magnesium-metal batteries Dual-defect engineering Vanadium-based cathode High durability Lamellar structure

Recent research progress in the mechanism and suppression of fusion welding-induced liquation cracking of nickel based superalloys

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 1072-1088页

作者： Zongli yi Jiguo Shan Yue zhao Zhenlin Zhang Aiping Wu Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China College of Engineering China Agricultural UniversityBeijing 100091China State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China School of Material Science and Engineering Southwest Jiaotong UniversityChengdu 610031China

Nickel-based superalloys are extensively used in the crucial hot-section components of industrial gas turbines,aeronautics,and astronautics because of their excellent mechanical properties and corrosion resistance at high *** welding serves as an effective means for joining and repairing these alloys;however,fusion welding-induced liquation cracking has been a challenging *** paper comprehensively reviewed recent liquation cracking,discussing the formation mechanisms,cracking criteria,and *** recent investigations,regulating material composition,changing the preweld heat treatment of the base metal,optimizing the welding process parameters,and applying auxiliary control methods are effective strategies for mitigating *** promote the application of nickel-based superalloys,further research on the combination impact of multiple elements on cracking prevention and specific quantitative criteria for liquation cracking is necessary.

关键词： nickel-based superalloy fusion welding liquation cracking cracking mechanism cracking suppression

Longitudinal changes in body weight of breastfeeding mothers in the first year after delivery and its relationship with human milk composition:a combined longitudinal and cross-sectional cohort study

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Food Science and Human Wellness 2024年第1期13卷 254-264页

作者： Huijuan Ruan Yajie Zhang Qingya Tang Xuan zhao Xuelin zhao yi Xiang Wei Geng yi Feng Wei Cai Department of Clinical Nutrition Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200092China Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition Shanghai Institute of Pediatric ResearchShanghai 200092China Department of Pediatric Surgery Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200092China

Objective:Postpartum weight retention(PPWR)is a common problem among women after *** main objectives of this study are to understand the changes in body weight of breastfeeding mothers during long-term follow-up and preliminarily explore the relationship between maternal body weight and human milk composition,including macronutrients,leptin,and ***:The study included a longitudinal cohort(122 mothers),and a cross-sectional cohort(37 mothers).The human milk,maternal weight,and dietary surveys were collected in the longitudinal cohort at different follow-up time points(1-14 days postpartum,2-4 months postpartum,5-7 months postpartum,and 12-17 months postpartum).The maternal body weight was analyzed using the responses in the survey questionnaires.A milk analyzer based on the mid-infrared spectroscopy(MIRS)was used to determine milk composition,and nutrition analysis software evaluated dietary *** the cross-sectional cohort,participating mothers were asked to provide blood and human milk samples and pertinent information related to maternal body *** body composition was measured by bioelectrical impedance analysis(BIA),while ELISA analyzed leptin and adiponectin in milk and ***:At 5-7 months postpartum,the PPWR of breastfeeding mothers was(2.46±3.59)*** 12-17 months postpartum,the PPWR was(0.98±4.06)*** was found to be negatively correlated with milk fat content within 14 days postpartum and positively correlated at 2-4 months *** addition,the maternal weight and body muscle mass were positively correlated with leptin and adiponectin in *** leptin was positively correlated with the mother’s body weight,body mass index(BMI),FAT percentage,and body fat mass,while plasma adiponectin did not correlate with any *** results also indicate that the PPWR did not correlate with leptin and adiponectin in plasma or ***:Breastfeeding mothers may retain considerable weight gai

关键词： Human milk Milk composition Body weight Body mass index(BMI) Weight gain Postpartum weight retention

Carbon efficiency modeling and optimization of solar-powered cellular networks

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Science China(Information Sciences) 2024年第5期67卷 228-243页

作者： Yuxi zhao Xiaohu GE Wen YAN Tao HAN yi ZHONG School of Electronic Information and Communications Huazhong University of Science and Technology Huawei Technology Co. Ltd.

As wireless communication traffic experiences rapid growth, the carbon emissions caused by the communication industry are also on the rise. To achieve “carbon neutrality”, researchers are considering the use of renewable energy sources to power cellular networks, thereby reducing carbon emissions. However, a challenge arises when using renewable energy, specifically owing to the unpredictable nature of both the energy consumption of the cellular network and the power generation from renewable sources. This inconsistency results in low renewable energy utilization and reduced carbon efficiency. Herein, we construct a carbon efficiency model of solar-powered cellular networks using practical data from solar radiation. We propose a mechanism that alternately optimizes the performance of the renewable energy network and the cellular network. This approach is based on convex optimization theory and the Dinkelback algorithm, and it leads to the design of a carbon efficiency optimization algorithm. This algorithm aims to improve the carbon efficiency of cellular networks and reduce their carbon emissions. Simulation results demonstrate that our optimization scheme yields a maximum improvement of 2.56 × 108bps/g in the carbon efficiency of the cellular network as compared to conventional power allocation schemes such as the traditional water filling method and heuristic energy sharing and charge/discharge algorithms.

关键词： cellular networks renewable energy carbon efficiency convex optimization theory dinkelbach

Exploiting demand-side heterogeneous flexible resources in risk management of power system frequency

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Science China(Technological Sciences) 2024年第5期67卷 1612-1627页

作者： YAO Yu SONG YongHua YE ChengJin DING yi zhao YuMing College of Electrical Engineering Zhejiang UniversityHangzhou310027China State Key Laboratory of Internet of Things for Smart City University of MacaoMacao SAR519000China Shenzhen Power Supply Bureau Co. Ltd.Shenzhen518051China

More demand-side flexible resources(DFRs)are participating in the frequency regulation of renewable power systems,whose heterogeneous characteristics have a significant impact on the system frequency ***,selecting suitable DFRs poses a formidable challenge for independent system operators(ISO).In this paper,a reserve allocation methodology for heterogeneous DFRs is proposed to manage the risk of power system ***,a performance curve is developed to describe the cost,capacity,and response speed of ***,a clustering method for multiple distributed DFRs is conducted to calculate the aggregated performance curves and uncertainty ***,the frequency security criterion considering DFRs’performance is constructed,whose linearity makes it can be easily coupled into the system scheduling model and ***,a risk management model for DFRs considering frequency-chance-constraint is proposed to make a trade-off between cost and frequency ***,the model is transformed into mixed integer second-order cone programming(MISOCP)and solved by the commercial *** proposed model is validated by the IEEE 30 and IEEE 118 bus systems.

关键词： demand-side heterogenous flexible resources risk management of power system frequency performance curve aggregation method mixed integer second-order cone programming

Visible Light Indoor Positioning System Based on Pisarenko Harmonic Decomposition and Neural Network

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Chinese Journal of Electronics 2024年第1期33卷 195-203页

作者： Li zhao yi REN Qi WANG Lange DENG Feng ZHANG School of Electronic Information Engineering Xi’an Technological University

Visible-light indoor positioning is a new generation of positioning technology that can be integrated into smart lighting and optical communications. The current received signal strength(RSS)-based visible-light positioning systems struggle to overcome the interferences of background and indoor-reflected noise. Meanwhile, when ensuring the lighting, it is impossible to use the superposition of each light source to accurately distinguish light source information; furthermore, it is difficult to achieve accurate positioning in complex indoor environments. This study proposes an indoor positioning method based on a combination of power spectral density detection and a neural network. The system integrates the mechanism for visible-light radiation detection with RSS theory, to build a back propagation neural network model fitting for multiple reflection channels. Different frequency signals are loaded to different light sources at the beacon end, and the characteristic frequency and power vectors are obtained at the location end using the Pisarenko harmonic decomposition method. Then, a complete fingerprint database is established to train the neural network model and conduct location tests. Finally, the location effectiveness of the proposed algorithm is verified via actual positioning experiments. The simulation results show that, when four groups of sinusoidal waves with different frequencies are superimposed with white noise, the maximum frequency error is 0.104 Hz and the maximum power error is 0.0362 W. For the measured positioning stage, a 0.8 m × 0.8 m × 0.8 m solid wood stereoscopic positioning model is constructed, and the average error is 4.28 cm. This study provides an effective method for separating multi-source signal energies, overcoming background noise, and improving indoor visible-light positioning accuracies.

关键词： Neural networks Measurement uncertainty Position measurement Harmonic analysis Light emitting diodes Frequency estimation Indoor positioning systems

Adaptable "bubble particles" prepared by green aqueous phase reshaping for completely removing odor

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Nano Research 2024年第3期17卷 2172-2180页

作者： Jiajia Ma yichang Xia Tienan zhao Wenfeng Hu Weifeng Zhang Qinfei Ke yi zhao Shanghai Frontiers Science Center of Advanced Textiles Donghua UniversityShanghai 201620China Engineering Research Center of Technical Textiles Ministry of EducationDonghua UniversityShanghai 201620China School of Fashion Engineering Central Laboratory Shanghai University of Engineering ScienceShanghai 201620China Department of Materials Science and Engineering National University of SingaporeSingapore 117575Singapore School of Perfume and Aroma Technology Shanghai Institute of TechnologyShanghai 201418China

Facile and ecofriendly loading of micro/nano function-specific substances to create functional materials is a trend being pursued by ***,current micro/nano particles loading approaches are often hindered by issues such as uneven distribution,unsatisfactory stability and complicate *** this work,we present an aqueous phase reshaping method that only utilizes the moisture to fabricate the"bubble particles",which could perfectly cater to the topography of the *** green preparation of bubble particles adopts an absolutely zero-pollution method,realizing the firm loading of particles on the *** the preparation and loading of particles overcomes the traditional complicate process,while the aqueous phase reshaping ensures uniform and firm loading of the"bubble particles"onto the *** mechanism demonstrates a significant enhancement in the interface relation after aqueous phase reshaping,with a 121-fold increase in contact surface area achieved by reducing the height by 1μ***,we explore for the first time the influence of the nature of the receiving substrate on the interface morphology of particles during electrostatic spraying,which has important guiding significance for the interface relationship of electrostatic spraying and even electrostatic spinning *** also screen out the natural antibacterial essential oil linalool as the effective specialized antibacterial agent,which can specifically inhibit the odor-producing Proteus in urine,with an antibacterial rate of up to 100%.Taken together,this simple,ecofriendly method for fabricating functional materials with optimal interface stability appears highly promising for use in various products formed by electrostatic spraying/spinning.

关键词： bubble particle electrostatic spraying aqueous phase reshaping interface bonding remove odor nano spraying