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China Communications 2024年第1期21卷 242-259页

作者： Hao Jiang hongming zhang Ting Liu College of Artificial Intelligence Nanjing University of Information Science and Technology210044China National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsChina

In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)*** the proposed sum-of-sinusoids(SoS)channel model,the waves that emerge from the transmitter undergo line-of-sight(LoS)and non-line-of-sight(NLoS)propagation to the receiver,which makes the model suitable for describing numerous V2X wireless communication scenarios for sixth-generation(6G).We derive expressions for the real and imaginary parts of the complex channel impulse response(CIR),which characterize the physical propagation characteristics of V2X wireless *** statistical properties of the real and imaginary parts of the complex CIRs,i.e.,autocorrelation functions(ACFs),Doppler power spectral densities(PSDs),cross-correlation functions(CCFs),and variances of ACFs and CCFs,are derived and *** results are generated and match those predicted by the underlying theory,demonstrating the accuracy of our derivation and *** proposed framework and underlying theory arise as an efficient tool to investigate the statistical properties of 6G MIMO V2X communication systems.

关键词： complex CIRs LoS and NLoS propagation components MIMO V2X communication environments SoS simulation channel model statistical properties

Collaborative Multiple Access And Energy-Efficient Resource Allocation in Distributed Maritime Wireless Networks

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China Communications 2022年第4期19卷 137-153页

作者： Xueyan Cao hongming zhang Mugen Peng State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

With the rapid increasing of maritime activities, maritime wireless networks(MWNs) with high reliability, high energy efficiency, and low delay are required. However, the centralized networking with fixed resource scheduling is not suitable for MWNs due to the special environment. In this paper,we introduce the collaborative relay communication in distributed MWNs to improve the link reliability, and propose an orthogonal time-frequency resource block reservation based multiple access(RRMA) scheme for both one-hop direct link and two-hop collaborative relay link to reduce the interference. To further improve the network performance, we formulate an energy efficiency(EE) maximization resource allocation problem and solve it by an iterative algorithm based on the Dinkelbach method. Finally, numerical results are provided to investigate the proposed RRMA scheme and resource allocation algorithm, showing that the low outage probability and transmission delay can be attained by the proposed RRMA scheme. Moreover,the proposed resource allocation algorithm is capable of achieving high EE in distributed MWNs.

关键词： maritime wireless networks distributed multiple access resource allocation energy efficiency maximization

Performance analysis of a low-complexity nonorthogonal multiple access scheme in visible light communication downlinks using pulse modulations

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Intelligent and Converged Networks 2021年第1期2卷 50-65页

作者： Jian Song Tian Cao hongming zhang Beijing National Research Center for Information Science and Technology(BNRist) Department of Electronic EngineeringTsinghua UniversityBeijing 100084China Key Laboratory of Digital TV System of Guangdong Province and Shenzhen City Research Institute of Tsinghua University in ShenzhenShenzhen 518057China Beijing National Research Center for Information Science and Technology(BNRist) and Department of Electronic EngineeringTsinghua UniversityBeijing 100084China

Although Successive Interference Cancellation(SIC)decoding is widely adopted in Nonorthogonal Multiple Access(NOMA)schemes for the recovery of user data at acceptable complexity,the imperfect SIC would cause Error Propagation(EP),which can severely degrade system *** this work,we propose an SIC-free NOMA scheme in pulse modulation based Visible Light Communication(VLC)downlinks,including two types of users with different data rate *** bit-rate users adopt on-off keying,whereas high bit-rate ones use Multiple Pulse Position Modulation(MPPM).The soft decision decoding scheme is exploited by high bit-rate users to decode MPPM signals,which could fundamentally eliminate the detrimental effect of EP;the scheme is also easier and faster to execute compared with the conventional SIC decoding *** of the symbol error rate and achievable data rate for two types of users are *** of the Monte Carlo simulation are provided to confirm the correctness of theoretical results.

关键词： visible light communication nonorthogonal multiple access error propagation on-off keying multiple pulse position modulation symbol error rate achievable data rate

Vector Approximate Message Passing with Sparse Bayesian Learning for Gaussian Mixture Prior

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China Communications 2023年第5期20卷 57-69页

作者： Chengyao Ruan Zaichen zhang Hao Jiang Jian Dang Liang Wu hongming zhang National Mobile Communications Research Laboratory Frontiers Science Center for Mobile Information Communication and SecuritySoutheast UniversityNanjing 210096China Purple Mountain Laboratories No.9 Mozhou East RoadNanjing 211111China School of Artificial Intelligence Nanjing University of Information Science and TechnologyNanjing 210044China School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

Compressed sensing(CS)aims for seeking appropriate algorithms to recover a sparse vector from noisy linear ***,various Bayesian-based algorithms such as sparse Bayesian learning(SBL)and approximate message passing(AMP)based algorithms have been *** SBL,it has accurate performance with robustness while its computational complexity is high due to matrix *** AMP,its performance is guaranteed by the severe restriction of the measurement matrix,which limits its application in solving CS *** overcome the drawbacks of the above algorithms,in this paper,we present a low complexity algorithm for the single linear model that incorporates the vector AMP(VAMP)into the SBL structure with expectation maximization(EM).Specifically,we apply the variance auto-tuning into the VAMP to implement the E step in SBL,which decrease the iterations that require to converge compared with VAMP-EM algorithm when using a Gaussian mixture(GM)*** results show that the proposed algorithm has better performance with high robustness under various cases of difficult measurement matrices.

关键词： sparse Bayesian learning approximate message passing compressed sensing expectation propagation

Hydrolytic dehydrogenation of ammonia borane catalyzed by poly(amidoamine) dendrimers-modified reduced graphene oxide nanosheets supported Ag_(0.3)Co_(0.7) nanoparticles

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Journal of Materials Science & Technology 2018年第12期34卷 2350-2358页

作者： Dandan Ke Jin Wang hongming zhang Yuan Li Lu zhang Xin Zhao Shumin Han Hebei Key Laboratory of Applied Chemistry School of Environmental and Chemical EngineeringYanshan University State Key Laboratory of Metastable Materials Science and Technology Yanshan University School of Materials and Metallurgy Inner Mongolia University of Science and Technology

Poly(amidoamine) dendrimers-modified reduced graphene oxide nanosheets(PAMAM/rGO) composite was selected as a carrier of heterogeneous Ag0.3Co0.7nanoparticles in order to obtain an excellent catalyst for ammonia borane(AB) hydrolysis. During the synthetic processes, GO could easily assembled with PAMAM by the electrostatic and hydrogen-bonding interactions. Structural characterization revealed that Ag0.3Co0.7bimetallic nanoparticles with uniform size distribution of 5 nm are well dispersed on PAMAM/rGO composite architecture. Ag0.3Co0.7@PAMAM/rGO was found to be a highly active and reusable catalyst in hydrogen generation from the hydrolysis of AB with a turnover frequency value(TOF) of 19.79 molH2min-1molM-1at 25.0±0.1℃ and retained 75.4% of their initial activity with a complete release of hydrogen in five runs. The relatively high TOF value and low apparent activation energy(34.21 kJ mol-1) make these Ag0.3Co0.7@PAMAM/rGO NPs as a high-efficient catalyst for catalytic dehydrogenation of AB facilitating the development of practically applicable energy storage materials.

关键词： Ammonia borane Reduced graphene oxide Ammonia borane Ag_(0.3)Co_(0.7) bimetallic nanoparticles Hydrolytic dehydrogenation

In-situ fabrication of particulate reinforced aluminum matrix composites under high-frequency pulsed electromagnetic field

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Journal of University of Science and Technology Beijing 2007年第5期14卷 460-463页

作者： Guirong Li Yutao Zhao Qixun Dai Hongjie zhang hongming Wang School of Materials Science and Engineering Jiangsu University Zhenjiang 212013 China

Pulsed magnetic field is generated when imposing pulse signal on high-frequency magnetic field. Distribution of the inner magnetic intensity in induction coils tends to be uniform. Furthermore oscillation and disturbance phenomena appear in the melt. In. situ Al2O3 and Al3Zr particulate reinforced aluminum matrix composites have been synthesized by direct melt reaction using AlZr（CO3）2 components under a foreign field. The size of reinforced particulates is 2-3 μm. They are well distributed in the matrix. Thermodynamic and kinetic analysis show that high-frequency pulsed magnetic field accelerates heat and mass transfer processes and improves the kinetic condition of in-situ fabrication.

关键词： in-situ synthesis aluminum matrix composites pulsed magnetic field thermodynamics kinetics

Capacity Optimization Using Augmented Lagrange Method in Intelligent Reflecting Surface-Based MIMO Communication Systems

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China Communications 2020年第12期17卷 123-138页

作者： Daina Chang Hao Jiang Jie Zhou hongming zhang Mithun Mukherjee College of Electronic and Information Engineering Nanjing University of Information Science and TechnologyNanjing 210044China College of Artificial Intelligence Nanjing University of Information Science and TechnologyNanjing 210044China National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

In this paper,we present an algorithm for capacity optimization in intelligent reflecting surface(IRS)-based multiple-input multiple-output(MIMO)communication *** maximize the capacity of elements in IRS,we use augmented Lagrange method with the equivalent transformations on the covariance matrix and reflection matrix *** results an adjustable phase shift on the incident ***,we reshape the complex-valued covariance matrix and reflection matrix to a vector for the ease of calculating partial derivatives to find the search ***,the quasi-Newton updates and modified Broyden-Fletcher-Goldfarb-Shano(BFGS)method in the complex domain form are used to find the local ***,numerical simulation results demonstrate that our proposed IRS-aided system using the algorithm performs better than the state-of-the-art and the conventional communication systems.

关键词： IRS capacity augmented Lagrange quasi-Newton updates BFGS

Digital Relief Generation from 3D Models

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Chinese Journal of Mechanical Engineering 2016年第6期29卷 1128-1133页

作者： WANG Meili SUN Yu zhang hongming QIAN Kun CHANG Jian HE Dongjian College of Information Engineering Northwest A & F University National Center for Computer Animation Bournemouth University College of Mechanical and Electronic Engineering Northwest A & F University

It is difficult to extend image-based relief generation to high-relief generation, as the images contain insufficient height information. To generate reliefs from three-dimensional （3D） models, it is necessary to extract the height fields from the model, but this can only generate bas-reliefs. To overcome this problem, an efficient method is proposed to generate bas-reliefs and high-reliefs directly from 3D meshes. To produce relief features that are visually appropriate, the 3D meshes are first scaled. 3D unsharp masking is used to enhance the visual features in the 3D mesh, and average smoothing and Laplacian smoothing are implemented to achieve better smoothing results. A nonlinear variable scaling scheme is then employed to generate the final bas-reliefs and high-reliefs. Using the proposed method, relief models can be generated from arbitrary viewing positions with different gestures and combinations of multiple 3D models. The generated relief models can be printed by 3D printers. The proposed method provides a means of generating both high-reliefs and bas-reliefs in an efficient and effective way under the appropriate scaling factors.

关键词： high-relief bas-relief mesh enhancement scaling

The electrochemical characteristics of AB_(4)-type rare earth-Mg-Ni-based superlattice structure hydrogen storage alloys for nickel metal hydride battery

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Journal of Magnesium and Alloys 2021年第6期9卷 2039-2048页

作者： Wenfeng Wang Xiaoxue Liu Lu zhang Shuang zhang Wei Guo Yumeng Zhao hongming zhang Yuan Li Shumin Han State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004PR China School of Environmental and Chemical Engineering Yanshan UniversityQinhuangdao 066004PR China

Rare earth-Mg-Ni-based alloys with superlattice structures are new generation negative electrode materials for the nickel metal hydride *** them,the novel AB_(4)-type superlattice structure alloy is supposed to have superior cycling stability and rate *** its preparation is hindered by the crucial requirement of temperature and the special composition which is close to the other superlattice ***,we prepare rare earth-Mg-Ni-based alloy and study the phase transformation of alloys to make clear the formation of AB_(4)-type *** is found Pr_(5)Co_(19)-type phase is converted from Ce_(5)Co_(19)-type phase and shows good stability at higher temperature compared to the Ce_(5)Co_(19)-type phase in the range of 930-970℃.Afterwards,with further 5℃increasing,AB_(4)-type superlattice structure forms at a temperature of 975℃by consuming Pr_(5)Co_(19)-type *** contrast with A_(5)B_(19)-type alloy,AB_(4)-type alloy has superior rate capability owing to the dominant advantages of charge transfer and hydrogen ***,AB_(4)-type alloy shows long lifespan whose capacity retention rates are 89.2%at the 100;cycle and 82.8%at the 200;cycle,***_(4)-type alloy delivers 1.53 wt.%hydrogen storage capacity at room temperature and exhibits higher plateau pressure than Pr_(5)Co_(19)-type *** work provides novel AB_(4)-type alloy with preferable electrochemical performance as negative electrode material to inspire the development of nickel metal hydride batteries.

关键词： Nickel metal hydride batteries Hydrogen storage alloys AB_(4)-type superlattice structure Electrochemical performance Kinetics properties

Open and close-ended CoMoS_(3) nanotubes for hydrogen evolution in acidic and basic conditions

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Journal of Energy Chemistry 2021年第6期30卷 34-40,I0002页

作者： Yuan Li Xuewei Hou Jing Gu Veronika Mikhaylova Kangli Chen hongming zhang Shumin Han Hebei Key Laboratory of Applied Chemistry School of Environmental and Chemical EngineeringYanshan UniversityQinhuangdao 066004HebeiChina Department of Chemistry and Biochemistry San Diego State UniversitySan DiegoCA 92182-1030United States

Electrochemical hydrogen evolution reaction(HER) is a promising route to harvest high-purity hydrogen(H_(2)).Efficient and selective energy transformations rely on the development of novel catalytic materials in terms of compositions and structures that survive under harsh *** study focuses on a unique nanostructured CoMoS_(3) catalyst for HER under strong acidic and basic *** morphologies of the catalysts are fine-tuned by altering reaction times in a hydrothermal *** reaction time generates twisted thin-sheet CoMoS_(3)(12 h),which spins into a nanotube with an extended synthetic time(16 h).As the reaction time increases to 20 h,the CoMoS_(3) composite creates open-ended nanotubes,facilitating reactants to penetrate and react actively in the inner space of the ***,prolonged reaction time(24 h) results in the formation of the close-ended CoMoS_(3) *** find out that the open-ended structure plays an important role in achieving fast kinetics as well as creating more active sites in HER *** catalyst delivers a profound performance under both acidic and basic conditions,with overpotentials of 93 mV and 115 mV(at a current density of 10 mA/cm^(2)) in the acidic and basic electrolytes,***,it shows superior long-term durability in both *** work will provide a great foundation for understanding the morphology effect with the same composited catalyst towards energy conversion reactions,not limited to HER.

关键词： Hydrogen evolution reaction Catalysts Bimetallic sulfides