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The scattering mechanism of squall lines with C-Band dual polarization *** Ⅰ:echo characteristics and particles phase recognition

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Frontiers of Earth Science 2022年第2期16卷 221-235页

作者： Jiashan ZHU Ming WEI Sinan GAO Hanfeng HU Lei MA Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China leihua electronic technology research institute of aviation industry corporation of China Wuxi 214063China

Squall line is a kind of common mesoscale disaster *** present,there are few studies on the elaborate detection of squall line by dual polarization *** the dual polarization upgrade of weather radar network,we need to study the relationship between squall line echoes of base data and polarization data to reveal new echo phenomena and formation *** relationship between radar parameters and atmospheric physical processes also need to be *** on the NUIST CDP radar,a squall line in the Yangtze and Huaihe River basin that occurred from July 30 to 31,2014 is *** results show that polarization parameters have obvious advantages in the characteristics analysis of size,phase state,shape and orientation of the water condensate *** phase states of water condensate particles in convection cell can be distinguished through comparative *** phase states exist in the squall line,including small,medium and large raindrops,melting hails,dry hails and ice crystal particles and the Z_(DR)column can be used to identify the location of the main *** addition,the polarization parameters are more sensitive to the melting *** gust front is presented as a narrow linear echo in Z affected by strong *** is an obvious velocity convergence line in V and approximately 0.70 inρ_(HV).The Z_(DR)can be used as a criterion to distinguish the horizontal and vertical scale of *** deforming turbulence,which is affected by environmental airflow,will cause an abnormally high Z_(DR)in the gust front and a negative Z_(DR)before and after the gust *** variation of Z_(DR)depends on the turbulence arrangement,orientation and relative position between turbulence and *** dual polarization parameter characteristics offer insights into understanding the structure and evolution of the squall line.

关键词： dual polarization Doppler radar RHI squall line gust front turbulence

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Remaining useful life prediction of aircraft lithium-ion batteries based on F-distribution particle filter and kernel smoothing algorithm

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Chinese Journal of Aeronautics 2020年第5期33卷 1517-1531页

作者： Kai ZHANG Peng ZHAO Canfei SUN Youren WANG Zewang CHEN College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China aviation industry corporation leihua electronic technology research institute Wuxi 214000China Testing and Verification Center Aviation Key Laboratory of Science and Technology on Fault Diagnosis and Health ManagementShanghai 201601China

As an emergency and auxiliary power source for aircraft,lithium(Li)-ion batteries are important components of aerospace power *** Remaining Useful Life(RUL)prediction of Li-ion batteries is a key technology to ensure the reliable operation of aviation power *** Filter(PF)is an effective method to predict the RUL of Li-ion batteries because of its uncertainty representation and management ***,there are problems that particle weights cannot be updated in the prediction stage and particles *** settle these issues,an innovative technique of F-distribution PF and Kernel Smoothing(FPFKS)algorithm is *** the prediction stage,the weights of the particles are dynamically updated by the F kernel instead of being fixed all the ***,a first-order independent Markov capacity degradation model is ***,the kernel smoothing algorithm is integrated into PF,so that the variance of the parameters of capacity degradation model keeps *** based on NASA battery data sets show that FPFKS can be excellently applied to RUL prediction of Liion batteries.

关键词： F-distribution Kernel smoothing Lithium-ion batteries Markov model Particle filter Prediction Remaining useful life

Multi-functional layered double hydroxides supported by nanoporous gold toward overall hydrazine splitting

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Frontiers of Chemical Science and Engineering 2024年第1期18卷 61-69页

作者： Yongji Qin Huijie Cao Qian Liu Shaoqing Yang Xincai Feng Hao Wang Meiling Lian Dongxing Zhang Hua Wang Jun Luo Xijun Liu ShenSi Lab Shenzhen Institute for Advanced StudyUniversity of Electronic Science and Technology of ChinaShenzhen 518110China institute for New Energy Materials and Low-Carbon Technologies School of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured MaterialsSchool of ResourcesEnvironment and MaterialsGuangxi UniversityNanning 530004China institute for Advanced Study Chengdu UniversityChengdu 610106China China National Coal Group corporation Beijing 100120China Tianjin Engineering research Center of Civil aviation Energy Environment and Green Development School of Transportation Science and EngineeringCivil Aviation University of ChinaTianjin 300300China

Layered double hydroxides have demonstrated great potential for the oxygen evolution reaction,which is a crucial half-reaction of overall water ***,it remains challenging to apply layered double hydroxides in other electrochemical reactions with high efficiency and ***,we report two-dimensional multifunctional layered double hydroxides derived from metalorganic framework sheet precursors supported by nanoporous gold with high porosity,which exhibit appealing performances toward oxygen/hydrogen evolution reactions,hydrazine oxidation reaction,and overall hydrazine *** as-prepared catalyst only requires an overpotential of 233 mV to reach 10 mA·cm^(-2) toward oxygen evolution *** overall hydrazine splitting cell only needs a cell voltage of 0.984 V to deliver 10 mA·cm^(-2),which is far more superior than that of the overall water splitting system(1.849 V).The appealing performances of the catalyst can be contributed to the synergistic effect between the metal components of the layered double hydroxides and the supporting effect of the nanoporous gold substrate,which could endow the sample with high surface area and excellent conductivity,resulting in superior activity and stability.

关键词： layered double hydroxide oxygen evolution reaction hydrazine oxidation reaction overall hydrazine splitting hydrogen production

A Hybrid Method Combining Improved K-means Algorithm with BADA Model for Generating Nominal Flight Profiles

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第4期33卷 414-424页

作者： Tang Xinmin Gu Junwei Shen Zhiyuan Chen Ping Li Bo College of Civil aviation Nanjing University of Aeronautics and Astronautics The 28th research institute of China electronic technology Group corporation

A high-precision nominal flight profile,involving controllers′intentions is critical for 4Dtrajectory estimation in modern automatic air traffic control *** proposed a novel method to effectively improve the accuracy of the nominal flight profile,including the nominal altitude profile and the speed ***,considering the characteristics of trajectory data,we developed an improved K-means *** approach was to measure the similarity between different altitude profiles by integrating the space warp edit distance algorithm,thereby to acquire several fitted nominal flight altitude *** approach breaks the constraints of traditional K-means ***,to eliminate the influence of meteorological factors,we introduced historical gridded binary data to determine the en-route wind speed and temperature via inverse distance weighted ***,we facilitated the true airspeed determined by speed triangle relationships and the calibrated airspeed determined by aircraft data model to extract a more accurate nominal speed profile from each cluster,therefore we could describe the airspeed profiles above and below the airspeed transition altitude,*** experimental results showed that the proposed method could obtain a highly accurate nominal flight profile,which reflects the actual aircraft flight status.

关键词： air transportation flight profile K-means algorithm space warp edit distance(SWED)algorithm trajectory prediction

The Application of a Meteo-hydrological Forecasting System with Rainfall Bias Correction in a Small and Medium-sized Catchment

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Journal of Tropical Meteorology 2022年第2期28卷 154-168页

作者： GAO Yu-fang WU Yu-qing CHEN Yao-deng YU Wei GU Tian-wei WU Ya-zhen School of Applied Meteorology Nanjing University of Information Science and TechnologyNanjing 210044 China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing 210044 China Weather Tech Services LLCLongmontCO 80503 USA leihua electronic and technology research institute Aviation Industry Corporation of ChinaWuxiJiangsu 214000 China

Meteo-hydrological forecasting models are an effective way to generate high-resolution gridded rainfall data for water source research and flood *** quality of rainfall data in terms of both intensity and distribution is very important for establishing a reliable meteo-hydrological forecasting *** improve the accuracy of rainfall data,the successive correction method is introduced to correct the bias of rainfall,and a meteo-hydrological forecasting model based on WRF and WRF-Hydro is applied for streamflow forecast over the Zhanghe River catchment in *** performance of WRF rainfall is compared with the China Meteorological Administration Multi-source Precipitation Analysis System(CMPAS),and the simulated streamflow from the model is further *** shows that the corrected WRF rainfall is more similar to the CMPAS in both temporal and spatial distribution than the original WRF *** contrast,the statistical metrics of the corrected WRF rainfall are *** the corrected WRF rainfall is used to drive the WRF-Hydro model,the simulated streamflow of most events is significantly improved in both hydrographs and volume than that of using the original WRF *** the studied events,the largest improvement of the NSE is from-0.68 to *** proves that correcting the bias of WRF rainfall with the successive correction method can greatly improve the performance of streamflow *** general,the WRF/WRF-Hydro meteo-hydrological forecasting model based on the successive correction method has the potential to provide better streamflow forecast in the Zhanghe River catchment.

关键词： streamflow forecast bias correction meteo-hydrological forecasting model WRF WRF-Hydro

Self-adapting RF Stealth Signal Design Method in RATR

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Transactions of Nanjing University of Aeronautics and Astronautics 2021年第6期38卷 1020-1027页

作者： XIAO Yongsheng HUANG Lizhen HE Fengshou ZHOU Jianjiang Key Laboratory of Jiangxi Province for Image Processing and Pattern Recognition Nanchang Hangkong UniversityNanchang 330063P.R.China College of electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China leihua electronic technology research institute Aviation Industry Corporation of ChinaLtd.Wuxi 214063P.R.China

Combining the mutual information theory and the sequential hypothesis testing(SHT)method,a selfadapting radio frequency(RF)stealth signal design method is proposed. The channel information is gained through the radar echo and feeds back to the radar system,and then the radar system adaptively designs the transmission waveform. So the close-loop system is formed. The correlations between these transmission waveforms are decreased because of the adaptive change of these transmission waveforms,and the number of illuminations is reduced for adopting the SHT,which lowers the transmission power of the radar system. The radar system using the new method possesses the RF stealth performance. Aiming at the application of radar automatic target recognition(RATR),experimental simulations show the effectiveness and feasibility of the proposed method.

关键词： radio frequency stealth sequential hypothesis testing mutual information close-loop system

research on stabilizing and tracking control system of tracking and sighting pod

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控制理论与应用（英文版） 2012年第1期10卷 107-112页

作者： Shanzhong LIU Hong CHE Longhe SUN electronic Information Engineering College Henan University of Science ＆ Technology Luoyang Henan 471003 China The 613th research institute of aviation industry corporation of China Luoyang Henan 471009 China

With the coupling among three-axis platform frames of tracking and sighting pod taken into considera- tion, the kinetic equations are set up according to the kinetic characteristic. Moreover, by predigesting the equations, the math model suitable for controller design is gained. An H-infinity controller combining with Kalman filter is designed for stabilizing loop of tracking and sighting pod platform frames. Fuzzy PID controllers corresponding to each tracking loop of three-axis frames are designed. The control system designed in this study, in which the effects of the coupling among frames and parameters variation are taken into consideration, is closer to practical situation. The control system is dynam- ically simulated under the condition of multidisturbance. The simulation results show that the entire stabilization tracking control system has good robustness and high tracking precision, which fulfils the need of stabilizing and tracking control of trackin~ and si^htin~ pod.

关键词： Tracking and sighting pod Modeling Robustness Fuzzy PID control H-infinity control

Linear theory of beam–wave interaction in double-slot coupled cavity travelling wave tube

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Chinese Physics B 2016年第3期25卷 424-427页

作者：何昉明谢文球罗积润朱敏郭炜 Radar research (Beijing) Leihua Electronic Technology Institute AVIC Beijing 100017 China aviation Key Laboratory of Science and technology on AISSS Wuxi 214063 China institute of electronics Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100039 China

A three-dimensional model of the double-slot coupled cavity slow-wave structure （CCSWS） with a solid round elec- tron beam for the beam-wave interaction is presented. Based on the ＂cold＂ dispersion, the ＂hot＂ dispersion equation is derived with the Maxwell equations by using the variable separation method and the field-matching method. Through numerical calculations, the effects of the electron beam parameters and the staggered angle between adjacent walls on the linear gain are analyzed.

关键词： double-slot coupled cavity slow-wave structure beam-wave interaction field matching method,small signal gain

Enhancing redshift phenomenon in time-resolved photoluminescence spectra of AlGaN epilayer

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Chinese Physics B 2017年第7期26卷 399-402页

作者：李维金鹏王维颖毛德丰潘旭王晓亮王占国 Science and technology on Metrology and Calibration Laboratory Changcheng Institute of Metrology & MeasurementAviation Industry Corporation of China Key Laboratory of Semiconductor Materials Science Institute of Semiconductors College of Materials Science and Opto-Electronic TechnologyUniversity of Chinese Academy of Sciences Chinese Academy of Sciences

AlGaN epitaxial layer has been studied by means of temperature-dependent time-integrated photoluminescence（PL）and time-resolved photoluminescence（TRPL）. An enhancing redshift phenomenon in TRPL spectra with increasing temperature was observed, and the localized excitons behaved like quasi two-dimensional excitons between 6 K and 90 K. We demonstrated that these behaviors are caused by a change in the carrier dynamics with increasing temperature due to the competition of carriers＇ localization and delocalization in the AlGaN alloy.

关键词： AlGaN time-resolved photoluminescence localized excitons