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Turbo Message Passing Based Burst Interference Cancellation for Data Detection in Massive MIMO-OFDM Systems

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China Communications 2024年第2期21卷 143-154页

作者： Wenjun Jiang Zhihao Ou xiaojun Yuan Li Wang National Key Laboratory of Wireless Communications University of Electronic Science and Technology of ChinaChengdu 611731China

This paper investigates the fundamental data detection problem with burst interference in massive multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM) systems. In particular, burst interference may occur only on data symbols but not on pilot symbols, which means that interference information cannot be premeasured. To cancel the burst interference, we first revisit the uplink multi-user system and develop a matrixform system model, where the covariance pattern and the low-rank property of the interference matrix is discussed. Then, we propose a turbo message passing based burst interference cancellation(TMP-BIC) algorithm to solve the data detection problem, where the constellation information of target data is fully exploited to refine its estimate. Furthermore, in the TMP-BIC algorithm, we design one module to cope with the interference matrix by exploiting its lowrank property. Numerical results demonstrate that the proposed algorithm can effectively mitigate the adverse effects of burst interference and approach the interference-free bound.

关键词： burst interference cancellation data detection massive multiple-input multiple-output(MIMO) message passing orthogonal frequency division multiplexing(OFDM)

Mutual Information Maximization via Joint Power Allocation in Integrated Sensing and Communications System

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China Communications 2024年第2期21卷 129-142页

作者： Jia Zhu Junsheng Mu Yuanhao Cui xiaojun Jing School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

In this paper, we focus on the power allocation of Integrated Sensing and Communication(ISAC) with orthogonal frequency division multiplexing(OFDM) waveform. In order to improve the spectrum utilization efficiency in ISAC, we propose a design scheme based on spectrum sharing, that is,to maximize the mutual information(MI) of radar sensing while ensuring certain communication rate and transmission power constraints. In the proposed scheme, three cases are considered for the scattering off the target due to the communication signals,as negligible signal, beneficial signal, and interference signal to radar sensing, respectively, thus requiring three power allocation schemes. However,the corresponding power allocation schemes are nonconvex and their closed-form solutions are unavailable as a consequence. Motivated by this, alternating optimization(AO), sequence convex programming(SCP) and Lagrange multiplier are individually combined for three suboptimal solutions corresponding with three power allocation schemes. By combining the three algorithms, we transform the non-convex problem which is difficult to deal with into a convex problem which is easy to solve and obtain the suboptimal solution of the corresponding optimization problem. Numerical results show that, compared with the allocation results of the existing algorithms, the proposed joint design algorithm significantly improves the radar performance.

关键词： coexistence communications multicarrier radar mutual information spectrum sharing

Localized CdS homojunctions with optimal ratio of high and low index facets to dynamically boost H_(2)O splitting into H_(2)energy

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Journal of Materials Science & Technology 2024年第4期171卷 94-100页

作者： xiaojun Wang Yiqi Zhang Shujuan Jiang Jiakun Su Shaoqing Song School of Materials Science&Chemical Engineering Ningbo UniversityNingbo 330013China School of New Energy Ningbo University of TechnologyNingbo 315336China Tchnology Center China Tobacco Jiangxi Industrial LLCNanchang 330096China

Localized CdS homojunctions with optimal ratio of high and low index facets are constructed to dy-namically boost H_(2)O splitting into H_(2)energy by hydrothermal method in combination with *** density functional theory,hall effect,and in situ diffuse reflectance infrared Fourier transform spec-troscopy,it is revealed that photo-irradiated e^(−)and h^(+)can be spatially separated and directionally trans-ferred to the reductive high-index facet{002}and oxidative low-index facet{110}of localized CdS homo-junction induced by Fermi level difference of both high and low index facets to dehydrogenate ^(∗)-OH and coupled ^(∗)-O intermediates for H_(2)and O_(2)yield,respectively,along with a solar conversion into hydrogen of 1.93%by AM 1.5 G irradiation at 65℃.The study work suggests a scientific perspective on the optimal ratio of high and low index facets to understand photo-generated charge carrier transfer dynamically and their photocatalytic principle for H_(2)O splitting reaction in kinetics.

关键词： Photocatalytic H_(2)evolution Homojunction Localized field Ratio of high low index facets In-situ DRIFTS

Time-domain dynamic constitutive model suitable for mucky soil site seismic response

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 1-13页

作者： Dong Qing Chen Su Jin Liguo Zhou Zhenghua Li xiaojun Architectural Engineering Institute Huaiyin Institute of TechnologyHuai’an 223600China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100020China Institute of Geophysics China Earthquake AdministrationBeijing 100089China College of Transportation Science and Engineering Nanjing Tech UniversityNanjing 211816China

Soil nonlinear behavior displays noticeable effects on the site seismic *** study proposes a new functional expression of the skeleton curve to replace the hyperbolic skeleton *** integrating shear modulus and combining the dynamic skeleton curve and the damping degradation coefficient,the constitutive equation of the logarithmic dynamic skeleton can be obtained,which considers the damping effect in a soil dynamics *** on the finite difference method and the multi-transmitting boundary condition,a 1D site seismic response analysis program called Soilresp1D has been developed herein and used to analyze the time-domain seismic response in three types of *** the same time,this study also provides numerical simulation results based on the hyperbolic constitutive model and the equivalent linear *** results verify the rationality of the new soil dynamic constitutive *** can analyze the mucky soil site nonlinear seismic response,reflecting the deformation characteristics and damping effect of the silty *** hysteresis loop area is more extensive,and the residual strain is evident.

关键词： seismic response time-domain dynamic constitutive model logarithmic dynamic skeleton dampening effect mucky soil

Controlled flight of a self-powered micro blimp driven by insect-sized flapping-wing thrusters

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Chinese Journal of Aeronautics 2024年第6期37卷 127-136页

作者： Xian YU Zhiwei LIU Jiaming LENG Mingjing QI xiaojun YAN School of Energy and Power Engineering Beihang UniversityBeijing 100191China Collaborative Innovation Center of Advanced Aero-Engine Beijing 100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics Beihang UniversityBeijng 100191China Beijing Key Laboratory of Aero-Engine Structure and Strength Beihang UniversityBeijing 100191China

Micro aerial platforms face significant challenges in achieving long controlled endurance as most of the energy is consumed to overcome the weight of the *** this study,we present a controllable micro blimp that addresses this issue through the use of a helium-filled *** micro blimp has a long axis of 23 cm and is propelled by four insect-sized flapping-wing thrusters,each weighing 80 mg and with a wingspan of 3.5 *** distributed thrusters enable controlled motions and provide the micro blimp with an advantage in flight endurance compared to multirotors or flapping-wing micro aerial vehicles at the same size *** enhance the performance of the controlled flight,we propose a wireless control module that enables manipulation from a distance of up to 100 ***,a smartphone application is developed to send instructions to the circuit board,allowing the blimp to turn left and right,ascend and descend,and achieve a combination of these movements *** findings demonstrate that this micro blimp is one of the smallest controlled self-powered micro blimps to date.

关键词： Microairvehicle Aircraft control Self-powered micro blimp Flapping-wing thruster Wireless flight

Power equipment vibration visualization using intelligent sensing method based on event-sensing principle

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Global Energy Interconnection 2024年第2期7卷 228-240页

作者： Mingzhe Zhao xiaojun Shen Lei Su Zihang Dong Tongji University No.1239 Siping RoadYangpu DistrictShanghai 200092P.R.China State Grid Shanghai Municipal Electric Power Company Electric Power Science Research Institute Shanghai 200437P.R.China Department of Electrical and Electronic Engineering Imperial College LondonLondonSW72AZU.K.

Vibration measurements can be used to evaluate the operation status of power equipment and are widely applied in equipment quality inspection and fault ***-sensing technology can sense the change in surface light intensity caused by object vibration and provide a visual description of vibration *** on the analysis of the principle underlying the transformation of vibration behavior into event flow data by an event sensor,this paper proposes an algorithm to reconstruct event flow data into a relationship correlating vibration displacement and time to extract the amplitude-frequency characteristics of the vibration signal.A vibration measurement test platform is constructed,and feasibility and effectiveness tests are performed for the vibration motor and other power *** results show that event-sensing technology can effectively perceive the surface vibration behavior of power and provide a wide dynamic ***,the vibration measurement and visualization algorithm for power equipment constructed using this technology offers high measurement accuracy and *** results of this study provide a new noncontact and visual method for locating vibrations and performing amplitude-frequency analysis on power equipment.

关键词： Power equipment Event sensing Non contact measurement Graphic display Feasibility

Ultralow friction PTFE/PEEK heterolayer:A new solid lubrication approach toward simplicity

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Friction 2024年第1期12卷 120-135页

作者： Wei SUN Jiaxin YE Qingrui SONG Yi FENG xiaojun LIU School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China Institute of Tribology School of Mechanical EngineeringHefei University of TechnologyHefei 230009China

Tribological applications of polytetrafluoroethylene(PTFE)are often limited by technological complexity to overcome its poor wear ***,a PTFE/polyetheretherketone(PEEK)heterolayer(HL)was proposed and evaluated as a new solid lubrication ***-on-disk tribometry found the lowest friction coefficient(μ)of 0.031 and ultralow wear for the PEEK/HL under typical *** friction coefficient of the HL surpasses those of the state-of-the-art polymeric coatings/composites by at least 200%,and approaches that of highly lubricated *** investigations revealed multi-length physical and chemical heterogeneity of the HL that best facilitates a tribofilm with high subsurface stability and surface *** technological simplicity and robustness of the HL’s high lubricity make it a promising new type of solid lubrication toward greater reliability and longevity.

关键词： ultralow friction anti-wear polytetrafluoroethylene(PTFE) heterolayer(HL)

Enhanced Fenton-like process over Cu/L(+)-ascorbic acid co-doping mesoporous silica for toxicity reduction of emerging contaminants

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Frontiers of Environmental Science & Engineering 2024年第4期18卷 49-60页

作者： Yuhang Liu Wenxuan Deng xiaojun Wu Chun Hu Lai Lyu Key Laboratory for Water Quality and Conservation of the Pearl River Delta(Ministry of Education) Institute of Environmental Research at Greater BayGuangzhou UniversityGuangzhou 510006China

Effective removal of emerging contaminants(ECs)to minimize their impacts on human health and the natural environment is a global *** the removal of ECs in water,we fabricated a seaweed spherical microsphere catalyst with Cu cation-πstructures by in situ doping of Cu species and ascorbic acid in mesoporous silica(Cu-C-MSNs)via a hydrothermal *** results indicate that bisphenol A(BPA)is substantially degraded within 5 min under natural conditions,with its biological toxicity considerably ***,industrial wastewater could also be effectively purified by Cu-C-MSNs/H_(2)O_(2) *** presence of metal sites and the complexation of ECs via cation-πinteraction andπ-πstacking on the catalyst surface were directly responsible for the polarization distribution of electrons,thus activating H_(2)O_(2) and dissolved oxygen(DO).The removal of contaminants could be attributed primarily to 1)the activation of H_(2)O_(2) into ^(·)OH to attack the contaminants and 2)self-cleavage because of the transfer of electrons from the contaminants to the *** study provides an innovative solution for the effective treatment of ECs and has positive implications for easing global environmental crises.

关键词： Cation-πstructures Polarization electric field Fenton-like process Contaminants cleavage

Constructing Built-In Electric Fields with Semiconductor Junctions and Schottky Junctions Based on Mo-MXene/Mo-Metal Sulfides for Electromagnetic Response

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Nano-Micro Letters 2024年第10期16卷 453-473页

作者： xiaojun Zeng Xiao Jiang Ya Ning Yanfeng Gao Renchao Che School of Materials Science and Engineering Jingdezhen Ceramic UniversityJingdezhen 333403People's Republic of China School of Materials Science and Engineering Shanghai UniversityShanghai 200444People's Republic of China Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative MaterialsAcademy for Engineering and TechnologyFudan UniversityShanghai 200438People's Republic of China Zhejiang Laboratory Hangzhou 311100People's Republic of China

The exploration of novel multivariate heterostructures has emerged as a pivotal strategy for developing high-performance electromagnetic wave(EMW)absorption ***,the loss mechanism in traditional heterostructures is relatively simple,guided by empirical observations,and is not *** this work,we presented a novel semiconductor-semiconductor-metal heterostructure sys-tem,Mo-MXene/Mo-metal sulfides(metal=Sn,Fe,Mn,Co,Ni,Zn,and Cu),including semiconductor junctions and Mott-Schottky *** skillfully combining these distinct functional components(Mo-MXene,MoS_(2),metal sulfides),we can engineer a multiple heterogeneous interface with superior absorption capabilities,broad effective absorption bandwidths,and ultrathin matching *** successful establishment of semiconductor-semiconductor-metal heterostructures gives rise to a built-in electric field that intensifies electron transfer,as confirmed by density functional theory,which collaborates with multiple dielectric polarization mechanisms to substantially amplify EMW *** detailed a successful synthesis of a series of Mo-MXene/Mo-metal sulfides featuring both semiconductor-semiconductor and semiconductor-metal *** achievements were most pronounced in Mo-MXene/Mo-Sn sulfide,which achieved remarkable reflection loss values of-70.6 dB at a matching thickness of only 1.885 *** cross-section calculations indicate that these MXene/Mo-metal sulfides have tremendous potential in practical military stealth *** work marks a departure from conventional component design limitations and presents a novel pathway for the creation of advanced MXene-based composites with potent EMW absorption capabilities.

关键词： Semiconductor-semiconductor-metal heterostructure Semiconductor junctions Mott-Schottky junctions Built-in electric field Electromagnetic wave absorption