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A prediction method for the performance of a low-recoil gun with front nozzle

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Defence Technology（防务技术） 2019年第5期15卷 703-712页

作者： Cheng Cheng chong Wang Xiaobing Zhang School of Energy and Power Engineering Nanjing University of Science and Technology

One of the greatest challenges in the design of a gun is to balance muzzle velocity and recoil,especially for guns on aircrafts and deployable *** resolve the conflict between gun power and recoil force,a concept of rarefaction wave gun(RAVEN)was proposed to significantly reduce the weapon recoil and the heat in barrel,while minimally reducing the muzzle *** main principle of RAVEN is that the rarefaction wave will not reach the projectile base until the muzzle by delaying the venting time of an expansion nozzle at the *** on the RAVEN principle,the purpose of this paper is to provide an engineering method for predicting the performance of a low-recoil gun with front ***,a two-dimensional two-phase flow model of interior ballistic during the RAVEN firing cycle was *** simulation results were compared with the published data to validate the reliability and ***,the effects of the vent opening times and locations were investigated to determine the influence rules on the performance of the RAVEN with front *** according to the results above,simple nonlinear fitting formulas were provided to explain how the muzzle velocity and the recoil force change with the vent opening time and ***,a better vent venting opening time corresponding to the vent location was *** findings should make an important contribution to the field of engineering applications of the RAVEN.

关键词： Interior ballistic Low recoil Rarefaction wave Prediction method Two-dimensional

High-temperature frictional wear behavior of MCrAlY-based coatings deposited by atmosphere plasma spraying

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International Journal of Minerals,Metallurgy and Materials 2017年第2期24卷 222-228页

作者： chong Tao Lei Wang Xiu Song Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) Northeastern UniversityShenyang 110819China Baosteel Group Shanghai Meishan Iron&Steel Co.Ltd. Nanjing 210039China

Al2O3-r2O03/NiCoCrAIYTa coatings were prepared via atmosphere plasma spraying （APS）. The microstructure and phase com- position of the coatings were analyzed by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, laser confocal scanning microsco- py （LSCM）, and transmission electron microscopy （TEM）. The dry frictional wear behavior of the coatings at 500℃ in static air was inves- tigated and compared with that of 0Cr25Ni20 steel. The results show that the coatings comprise the slatted layers of oxide phases, unmelted particles, and pores. The hot abrasive resistance of the coatings is enhanced compared to that of 0Cr25Ni20, and their mass loss is approxi- mately one-fifteenth that of 0Cr25Ni20 steel. The main wear failure mechanisms of the coatings are abrasive wear, fatigue wear, and adhe- sive wear.

关键词： metal matrix composites composite coatings wear behavior high temperature properties plasma spraying

A Range-Based Node Localization Scheme for UWASNs Considering Noises and Aided With Neurodynamics Model

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IEEE/CAA Journal of Automatica Sinica 2023年第11期10卷 2168-2170页

作者： Lijuan Wang Xiujuan Du chong Li School of Computer Qinghai Normal UniversityQinghai Provincial Key Laboratory of IoTXining 810008 the State Key Laboratory of Tibetan Intelligent Information Processing and Application Xining 810008 Academy of Plateau Science and Sustainability Xining 810008China

Dear Editor,This letter focuses on the node localization problem in underwater acoustic sensor networks(UWASNs) with the time-dependent property and various noise disturbances. A range-based localization scheme aided with an integral-feedback-based neurodynamics(IND)model is proposed and referred to as IND-RS, which has the stability against the internal perturbations encountered during the solving process.

关键词： dynamics underwater networks

Understanding Nonverbal Communication Cues of Human Personality Traits in Human-Robot Interaction

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IEEE/CAA Journal of Automatica Sinica 2020年第6期7卷 1465-1477页

作者： Zhihao Shen Armagan Elibol Nak Young chong Japan Advanced Institute of Science and Technology Ishikawa 923-1211Japan IEEE

With the increasing presence of robots in our daily life,there is a strong need and demand for the strategies to acquire a high quality interaction between robots and users by enabling robots to understand users’mood,intention,and other *** human-human interaction,personality traits have an important influence on human behavior,decision,mood,and many ***,we propose an efficient computational framework to endow the robot with the capability of understanding the user’s personality traits based on the user’s nonverbal communication cues represented by three visual features including the head motion,gaze,and body motion energy,and three vocal features including voice pitch,voice energy,and mel-frequency cepstral coefficient(MFCC).We used the Pepper robot in this study as a communication robot to interact with each participant by asking questions,and meanwhile,the robot extracts the nonverbal features from each participant’s habitual behavior using its on-board *** the other hand,each participant’s personality traits are evaluated with a *** then train the ridge regression and linear support vector machine(SVM)classifiers using the nonverbal features and personality trait labels from a questionnaire and evaluate the performance of the *** have verified the validity of the proposed models that showed promising binary classification performance on recognizing each of the Big Five personality traits of the participants based on individual differences in nonverbal communication cues.

关键词： Human-robot interaction machine learning nonverbal communication cues personality traits

Uncertainty Analysis for Ship-Bank Interaction Tests in A Circulating Water Channel

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China Ocean Engineering 2020年第3期34卷 352-361页

作者： LIU Han MA Ning GU Xie-chong School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration Shanghai Jiao Tong UniversityShanghai 200240China

This paper presents a systematic model test program to assess the uncertainty of the ship-bank interaction forces,using the planar motion mechanism(PMM)system in a circulating water channel(CWC).Therefore,the uncertainties due to ship-bank distance and water depth are considered,and they are calculated via the partial differentials of the regression formulae based on the test *** general part of the uncertainty analysis(UA)is performed according to the ITTC recommended procedure 7.5-02-06.04,while the uncertainty of speed is identified as the bias limit due to the flow velocity maldistribution in the *** each example test for the UA of ship-bank interaction forces,12 repeated measurements were *** from the UA show that the contribution of water depth error and flow velocity maldistribution to the total uncertainty is noticeable,and the paper explains how they increase with the change of the test *** present study will be useful in understanding the uncertainty regarding the ship-bank interaction force measurement in a CWC.

关键词： ship-bank interaction test uncertainty analysis circulating water channel bias limit ship-bank distance

Fundamental Understanding and Optimization Strategies for Dual‑Ion Batteries:A Review

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Nano-Micro Letters 2023年第8期15卷 205-224页

作者： chong Chen Chun‑Sing Lee Yongbing Tang Advanced Energy Storage Technology Research Center Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China Center of Super‑Diamond and Advanced Film(COSDAF) City University of Hong KongKowloon 999077Hong KongSARPeople’s Republic of China

There has been increasing demand for high-energy density and longcycle life rechargeable batteries to satisfy the ever-growing requirements for nextgeneration energy storage *** all available candidates,dual-ion batteries(DIBs)have drawn tremendous attention in the past few years from both academic and industrial battery communities because of their fascinating advantages of high working voltage,excellent safety,and environmental ***,the dynamic imbalance between the electrodes and the mismatch of traditional electrolyte systems remain *** fully employ the advantages of DIBs,the overall optimization of anode materials,cathode materials,and compatible electrolyte systems is urgently ***,we review the development history and the reaction mechanisms involved in ***,the optimization strategies toward DIB materials and electrolytes are *** addition,their energy-related applications are also ***,the research challenges and possible development directions of DIBs are outlined.

关键词： Dual-ion batteries Reaction mechanisms Optimization strategies Energy storage

Improved thermoelectric performance in n-type BiTe facilitated by defect engineering

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Rare Metals 2021年第10期40卷 2829-2837页

作者： Hao Zhu Ji-Yin Zhao chong Xiao Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

BiTe is a potentially attractive candidate for thermoelectric applications because it is the structural analogue of the state-of-the-art thermoelectric material,bismuth telluride(Bi_(2)Te_(3)). However, BiTe has attracted little attention due to its small band gap and high electron concentration. In this study, remarkable increase in thermoelectric performance in the n-type Bi_(1-x)Sb_(x)Te compounds through tuning the carrier concentration with chemical doping is shown. The Seebeck coefficient of Bi_(1-x)Sb_(x)Te increases remarkably while the electronic thermal conductivity decreases gradually as Sb content is increased, leading to enhanced thermoelectric figure of merit(ZT). Moreover, the simultaneous optimization of the electrical and thermal transport properties leads the peak temperature of the figure of merit to shift toward lower temperature with Sb content increasing in Bi_(1-x)Sb_(x)Te, thus making Bi_(1-x)Sb_(x)Te a potential alternative to bismuth telluride for near-room-temperature thermoelectric applications. In addition, the presence of multiple low-frequency optical phonons and their coupling with the long-wavelength heat carrying acoustic phonons in all the Bi_(1-x)Sb_(x)Te investigated are revealed based on the combined Debye-Einstein model. The present results provide the underlying mechanism connecting thermoelectric performance and lattice dynamics in Bi_(1-x)Sb_(x)Te compounds.

关键词： BiTe Thermoelectric material Carrier concentration Defect engineering Einstein oscillators Near-room-temperature application

Nitrogen cycling and environmental impacts in upland agricultural soils in North China： A review

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Journal of Integrative Agriculture 2017年第12期16卷 2848-2862页

作者： JU Xiao-tang ZHANG chong College of Resources and En vironmen tal Sciences China Agricultural University Beijing 100193 P.R. China

The upland agricultural soils in North China are distributed north of a line between the Kunlun Mountains, the Qinling Mountains and the Huaihe River. They occur in arid, semi-arid and semi-humid regions and crop production often depends on rain-fed or irrigation to supplement rainfall. This paper summarizes the characteristics of gross nitrogen（N） transformation, the fate of N fertilizer and soil N as well as the N loss pathway, and makes suggestions for proper N management in the region. The soils of the region are characterized by strong N mineralization and nitrification, and weak immobilization and denitrification ability, which lead to the production and accumulation of nitrate in the soil profile. Large amounts of accumulated nitrate have been observed in the vadose-zone in soils due to excess N fertilization in the past three decades, and this nitrate is subject to occasional leaching which leads to groundwater nitrate contamination. Under farmer＇s conventional high N fertilization practice in the winter wheat-summer maize rotation system（N application rate was approximately 600 kg ha–1 yr–1）, crop N uptake, soil residual N, NH_3 volatilization, NO_3~– leaching, and denitrification loss accounted for around 27, 30, 23, 18 and 2% of the applied fertilizer N, respectively. NH_3 volatilization and NO_3~– leaching were the most important N loss pathways while soil residual N was an important fate of N fertilizer for replenishing soil N depletion from crop production. The upland agricultural soils in North China are a large source of N_2O and total emissions in this region make up a large proportion（approximately 54%） of Chinese cropland N_2O emissions. The “non-coupled strong ammonia oxidation” process is an important mechanism of N_2O production. Slowing down ammonia oxidation after ammonium-N fertilizer or urea application and avoiding transient high soil NH4＋ concentrations are key measures for reducing N_2O emissions in this region. Further N management shou

关键词： N transformation NH3 volatilization ammonia oxidation NO3- leaching N2O emission upland agricultural soils

CDCC Approaches and Roles of Closed Channels in d-Nucleus Reactions

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Communications in Theoretical Physics 2008年第9期50卷 719-724页

作者： AN Hai-Xia CAI chong-Hai Department of Physics Nankai University Tianjin 300071 China

The effect of deuteron breakup in d-nucleus reaction is treated with the continuum discretized coupled channels （CDCC） approach, and the effects on the total reaction cross sections and elastic scattering angular distributions are studied by comparing the calculations of CDCC and spherical optical model with our global deuteron optical potential [Phys. Rev. C 73 （2006） 054605] below 200 MeV, for target nuclei ranging from ^12C to ^208Pb. The contributions from the closed channels to the total reaction and breakup cross sections, and angular distributions of elastic scattering are also seriously discussed.

关键词： CDCC approach closed channel spherical optical model global deuteron optical potential