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Energy-Efficient Traffic Offloading for RSMA-Based Hybrid Satellite Terrestrial Networks with Deep Reinforcement Learning

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China Communications 2024年第2期21卷 49-58页

作者： Qingmiao Zhang Lidong zhu Yanyan Chen shan Jiang National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of ChinaChengdu 611731China The Higher Educational Key Laboratory for Flexible Manufacturing Equipment Integration of Fujian Province Xiamen Institute of TechnologyXiamen 361021China China Mobile(Jiangxi)Communications Group Co. LtdYichun 336000China

As the demands of massive connections and vast coverage rapidly grow in the next wireless communication networks, rate splitting multiple access(RSMA) is considered to be the new promising access scheme since it can provide higher efficiency with limited spectrum resources. In this paper, combining spectrum splitting with rate splitting, we propose to allocate resources with traffic offloading in hybrid satellite terrestrial networks. A novel deep reinforcement learning method is adopted to solve this challenging non-convex problem. However, the neverending learning process could prohibit its practical implementation. Therefore, we introduce the switch mechanism to avoid unnecessary learning. Additionally, the QoS constraint in the scheme can rule out unsuccessful transmission. The simulation results validates the energy efficiency performance and the convergence speed of the proposed algorithm.

关键词： deep reinforcement learning energy efficiency hybrid satellite terrestrial networks rate splitting multiple access traffic offloading

A novel matrix topology-based analysis method of thermal circuits for reliability optimization of HSER

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Chinese Journal of Aeronautics 2024年第4期37卷 479-492页

作者： Huimin LIANG Bo LI Jiaxin YOU shan JIANG Mengtong zhu Aobo WANG Department of Electrical Engineering Harbin Institute of TechnologyHarbin 150001China Nanjing Research Institute of Electronics Technology Nanjing 210008China

Hermetically Sealed Electromagnetic Relay(HSER), used in aviation and aerospace,demands high reliability due to its critical applications. Given its complex operating conditions, efficient thermal analysis is essential for optimizing reliability. The commonly used Finite Element Method(FEM) is often time-consuming and may not be efficient or adaptable for complex multi-dimensional system calculations and design processes. This paper introduces an analysis method for thermal networks based on matrix perspective technology, encompassing matrix transformation, backpropagation of the heat path model, temperature rise calculation, solution comparison, and product implementation. Using the similarity theory of heat circuits, a basic thermal unit is established. Based on the fundamental connection between key components, a thermal network for a typical HSER is designed. An experimental system is set up, and the thermal network model's accuracy is confirmed using test data. Employing the topology analysis method, the topology of the thermal network is analyzed under both coil-energized and de-energized states. Potential thermal paths are identified, leading to optimized solutions for the HSER. Utilizing these solutions, the thermal path matrix topology model is backpropagated to the thermal path for temperature rise calculations. When compared to prototype HSER test data, the efficiency and accuracy of this matrix topology-based analysis method are confirmed.

关键词： Thermal networks HSER(Hermetically Sealed Electromagnetic Relay) Heat-circuit topology model Heat-circuit matrix Optimization design

Effects of impregnation sequence on the NH_(3)-SCR activity and hydrothermal stability of a Ce-Nb/SnO_(2) catalyst

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Journal of Environmental Sciences 2024年第4期138卷 450-457页

作者： Ying zhu Wenpo shan Zhihua Lian Jingjing Liu Yan Zhang Hong He Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control Ningbo Urban Environment Observation and Research StationInstitute of Urban EnvironmentChinese Academy of SciencesNingbo 315800China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Hydrothermal stability is crucial for the practical application of deNO_(x)catalyst on diesel vehicles,for the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR).SnO_(2)-based materials possess superior hydrothermal stability,which is attractive for the development of NH_(3)-SCR catalyst.In this work,a series of Ce-Nb/SnO_(2)catalysts,with Ce and Nb loading on SnO_(2)support,were prepared by impregnation method.It was found that,the NH_(3)-SCR activities and hydrothermal stabilities of the Ce-Nb/SnO_(2)catalysts significantly varied with the impregnation sequences,and the Ce-Nb(f)/SnO_(2) catalyst that firstly impregnated Nb and then impregnated Ce exhibited the best performance.The characterization results revealed that CeNb(f)/SnO_(2)possessed appropriate acidity and redox capability.Furthermore,the strong synergistic effect between Nb and Sn species stabilized the structure and maintained the dispersion of acid sites.This study may provide a new understanding for the effect of impregnation sequence on activity and hydrothermal stability and a new environmental-friendly NH_(3)-SCR catalyst with potential applications for NO_(x)removal from diesel and hydrogenfueled engines.

关键词： NO_(x)emission control NH_(3)-SCR Hydrothermal stability Ce-Nb/SnO_(2)catalyst Impregnation sequence

Effect of Cr_(2)O_(3) on properties of CaO-SiO_(2)-Fe_(t)O-MgO system and dissolution behavior of lime

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Journal of Iron and Steel Research(International) 2024年第4期31卷 870-881页

作者： shan-nan Li Jian-li Li Yue Yu Hang-yu zhu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina

The productivity of the chrome-containing semi-steel converter smelting process is directly affected by the slag-forming speed during the converter preliminary stage.The effects of Cr_(2)O_(3) content on the physicochemical properties of the CaO-SiO_(2)-Fe_(t)O-MgO system,such as melting temperature,solidification behavior,mineral composition,and lime dissolution rate,were studied.The results showed that the slag was an amorphous phase at 1500℃.When Cr_(2)O_(3) was added,Ca(Fe,Mg)Si_(2)O_(6) and spinel were formed in the slag.With the increase in Cr_(2)O_(3) content,the amount of spinel precipitation increased,and the dendritic FegO_(4) crystal gradually changed into the granular(Fe,Mg)(Fe,Cr)2O_(4) crystal.As the Cr_(2)O_(3) content increased from O to 2.91 wt.%,the melting temperature of the slag rose,and the melting range of the slag expanded slightly,but the lime dissolution rate did not change.When the Cr_(2)O_(3) content further increased to 9.09 wt.%,the melting temperature continued to rise,the melting range rapidly expanded,and the lime dissolution rate decreased.

关键词： Cr_(2)O_(3) Vanadium-titanium magnetite Converter Slag Lime dissolution

Evolution and Application of Sealing Ability of Gypsum Caprocks under Temperature-Pressure Coupling:An Example of the ZS5 Well in the Tazhong Area of the Tarim Basin

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 168-184页

作者： LIU Hua ZHAO shan YANG Xianzhang zhu Yongfeng WANG Shen ZHANG Ke National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)QingdaoShandong 266580China School of Geosciences China University of Petroleum(East China)QingdaoShandong 266580China Laboratory for Marine Mineral Resources National Laboratory for Marine Science and TechnologyQingdaoShandong 266071China PetroChina Tarim Oil Field Company KorlaXinjiang 841001China

Gypsum caprocks'sealing ability is affected by temperature-pressure coupling.Due to the limitations of experimental conditions,there is still a lack of triaxial stress-strain experiments that simultaneously consider changes in temperature and pressure conditions,which limits the accuracy of the comprehensive evaluation of the brittle plastic evolution and sealing ability of gypsum rocks using temperature pressure coupling.Triaxial stress-strain tests were utilized to investigate the differences in the evolution of the confinement capacity of gypsum rocks under coupled temperaturepressure action and isothermal-variable pressure action on the basis of sample feasibility analysis.According to research,the gypsum rock's peak and residual strengths decrease under simultaneous increases in temperature and pressure over isothermal pressurization experimental conditions,and it becomes more ductile.This reduces the amount of time it takes for the rock to transition from brittle to plastic.When temperature is taken into account,both the brittle–plastic transformation's depth limit and the lithological transformation of gypsum rocks become shallower,and the evolution of gypsum rocks under variable temperature and pressure conditions is more complicated than that under isothermal pressurization.The sealing ability under the temperature-pressure coupling is more in line with the actual geological context when the application results of the Well#ZS5 are compared.This provides a theoretical basis for precisely determining the process of hydrocarbon accumulation and explains why the early hydrocarbon were not well preserved.

关键词： temperature-pressure coupling gypsum caprocks brittle-plastic evolution sealing capacity Tarim Basin

Arbitrary acoustic orbital angular momentum detection using dual-layer metasurfaces

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 106-112页

作者： Zhanlei Hao Haojie Chen Yuhang Yin shan zhu Yadong Xu Cheng-Wei Qiu Huanyang Chen Department of Physics College of Physical Science and TechnologyXiamen UniversityXiamen 361005China Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore Department of Mechanical and Electrical Engineering Xiamen UniversityXiamen 361005China Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China School of Physical Science and Technology and Jiangsu Key Laboratory of Thin Films Soochow UniversitySuzhou 215006China

Orbital angular momentum(OAM),with its unique physical properties and vast application prospects,has attracted widespread attention in various fields.Nonetheless,the development of valid and practical acoustic OAM detection methods continues to be a challenging endeavor.In this paper,we propose a novel construction method of dual-layer metasurfaces to achieve a doubleconversion process for the waveform reshaping and differentiated focusing of two-dimensional vortex sources with different OAMs.Specifically,by utilizing a concise formula,a one-to-one correspondence is established between the OAM of incident vortex waves and different imaging points.The fundamental principle of this special conversion relationship is rigorously constrained by the directional compensation of phase and the material parameters of dual-layer metasurfaces with different quadratic phase distributions.More importantly,the highly consistent results between numerical demonstrations and acoustic experiments further confirm the feasibility and effectiveness of the proposed OAM detection scheme.Our work provides a new perspective on the precise manipulation for the phase of vortex fields,holding potential applications in super-resolution imaging and the design of acoustic OAM-based devices.

关键词： arbitrary acoustic OAM detection vortex waves dual-layer metasurfaces waveform reshaping differentiated focusing acoustic experiments

Robust asymmetric Cherenkov radiation in tilted anisotropic medium

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 46-51页

作者： Shuwen Xue Yadong Xu Linkang Han Zhi Ning Chen Qiaoliang Bao shan zhu Huanyang Chen Institute of Electromagnetics and Acoustics and Department of Physics College of Physical Science and TechnologyJiujiang Research InstituteXiamen UniversityXiamen 361005China School of Physical Science and Technology Institute of Theoretical and Applied PhysicsSoochow UniversitySuzhou 215006China Department of Electrical and Computer Engineering National University of SingaporeSingapore 8117583Singapore Institute of Energy Materials Science(IEMS) University of Shanghai for Science and TechnologyShanghai 200093China

Cherenkov radiation(CR)is available for a wide variety of terahertz(THz)radiation sources,but its efficiency is deeply affected by intrinsic losses.We find that if the tilted angle(α)of anisotropic material and radiation angle(θ)meet the condition ofθ+α=π/2,the intensity of radiation fields for the charged particle bunch(CPB)moving from left to right cannot be influenced by intrinsic losses,which means long-distance radiation can be achieved.Furthermore,we observe an asymmetric CR when the CPB moves from the opposite direction.In addition,we select natural van der Waals(vd W)materialα-MoO3as an example,further confirming that the radiation field can reach the far field and the asymmetric CR radiation can also be observed.These wonderful properties with long-distance radiation will extend the application of CR to a certain extent for future design and fabrication.

关键词： asymmetric Cherenkov radiation intrinsic losses long-distance radiation

Characterization,expression dynamics,and potential function of OPA1 for regulation of mitochondrial morphology during spermiogenesis in Phascolosoma esculenta

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Journal of Oceanology and Limnology 2024年第1期42卷 187-200页

作者： Xinming GAO Binbin FENG Chen DU Congcong HOU shan JIN Daojun TANG Junquan zhu Key Laboratory of Applied Marine Biotechnology by the Ministry of Education and Key Laboratory of Marine Biotechnology of Zhejiang Province School of Marine SciencesNingbo UniversityNingbo 315211China College of Ecology Lishui UniversityLishui 323000China

Mitochondria undergo morphological changes during spermatogenesis in some animals.The mechanism and role of mitochondrial morphology regulation,however,remain somewhat unclear.In this study,we analyzed the molecular characteristics,expression dynamics and subcellular localization of optic atrophy protein 1(OPA1),a mitochondrial fusion and cristae maintenance-related protein,to reveal the possible regulatory mechanisms underlying mitochondrial morphology in Phascolosoma esculenta spermiogenesis.The full-length cDNA of the P.esculenta opa1 gene(Pe-opa1)is 3743 bp in length and encodes 975 amino acids.The Pe-OPA1 protein is highly conservative and includes a transmembrane domain,a GTPase domain,two helical bundle domains,and a lipid-interacting stalk.Gene and protein expression was higher in the coelomic fluid(a site of spermatid development)of male P.esculenta and increased first and then decreased from March to December.Moreover,their expression during the breeding stage was significantly higher than during the non-breeding stage,suggesting that Pe-OPA1 is involved in P.esculenta reproduction.The Pe-OPA1 protein was more abundant in components consisting of many spermatids than in components without,indicating that Pe-OPA1 mainly plays a role in the spermatid in coelomic fluid.Moreover,Pe-OPA1 was mainly detected in the spermatid mitochondria.Immunofluorescence experiments showed that the Pe-OPA1 are constitutively expressed and co-localized with mitochondria during spermiogenesis,suggesting its involvement in P.esculenta spermiogenesis.These results provide evidence for Pe-OPA1's involvement in the regulation of mitochondrial morphology during spermiogenesis.

关键词： optic atrophy protein 1(OPA1) spermiogenesis Phascolosoma esculenta mitochondrial dynamics spermatid

End-to-End Paired Ambisonic-Binaural Audio Rendering

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 502-513页

作者： Yin zhu Qiuqiang Kong Junjie Shi Shilei Liu Xuzhou Ye Ju-Chiang Wang Hongming shan Junping Zhang shanghai Key Laboratory of Intelligent Information Processing School of Computer ScienceFudan UniversityShanghai 200433China Beijing ByteDance Technology Co.Ltd. Shanghai 201102China. Chinese University of Hong Kong Hong KongChina IEEE Institute of Science and Technology for Brain-Inspired Intelligence and MOE Frontiers Center for Brain Science Fudan UniversityShanghai 200433 shanghai Center for Brain Science and Brain-Inspired Technology Shanghai 200031China

Binaural rendering is of great interest to virtual reality and immersive media. Although humans can naturally use their two ears to perceive the spatial information contained in sounds, it is a challenging task for machines to achieve binaural rendering since the description of a sound field often requires multiple channels and even the metadata of the sound sources. In addition, the perceived sound varies from person to person even in the same sound field. Previous methods generally rely on individual-dependent head-related transferred function(HRTF)datasets and optimization algorithms that act on HRTFs. In practical applications, there are two major drawbacks to existing methods. The first is a high personalization cost, as traditional methods achieve personalized needs by measuring HRTFs. The second is insufficient accuracy because the optimization goal of traditional methods is to retain another part of information that is more important in perception at the cost of discarding a part of the information. Therefore, it is desirable to develop novel techniques to achieve personalization and accuracy at a low cost. To this end, we focus on the binaural rendering of ambisonic and propose 1) channel-shared encoder and channel-compared attention integrated into neural networks and 2) a loss function quantifying interaural level differences to deal with spatial information. To verify the proposed method, we collect and release the first paired ambisonic-binaural dataset and introduce three metrics to evaluate the content information and spatial information accuracy of the end-to-end methods. Extensive experimental results on the collected dataset demonstrate the superior performance of the proposed method and the shortcomings of previous methods.

关键词： Ambisonic attention binaural rendering neural network