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Ultra-wide dual-band Rydberg atomic receiver based on space division multiplexing radio-frequency chip modules

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Chip 2024年第2期3卷 53-61页

作者： Li-Hua zhang Bang Liu Zong-Kai Liu Zheng-yuan zhang shi-Yao Shao Qi-Feng Wang yu Ma Tian-yu Han Guang-Can Guo Dong-Sheng Ding Bao-Sen shi Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China

Detecting microwave signals over a wide frequency range is endowed with numerous advantages as it enables simultaneous transmission of a large amount of information and access to more spectrum *** capability is crucial for applications such as microwave communication,remote sensing and ***,conventional microwave receiving systems are limited by amplifiers and band-pass filters that can only operate efficiently in a specific frequency ***,these systems can only process signals within a three-fold frequency range,which limits the data transfer bandwidth of the microwave communication *** novel atom-integrated microwave sensors,for example,radio-frequency(RF)chip–coupled Rydberg atomic receiver,provides opportunities for a large working bandwidth of microwave sensing at the atomic *** the current work,an ultrawide dual-band RF sensing scheme was demonstrated by spacedivision multiplexing two RF-chip-integrated atomic receiver *** system can simultaneously receive dual-band microwave signals that span a frequency range exceeding 6 octaves(300 MHz and 24 GHz).This work paves the way for multi-band microwave reception applications within an ultra-wide range by RF-chip-integrated Rydberg atomic sensor.

关键词： Dual-band Rydberg Radio-frequency chip Atomic receiver Space-division multiplexing

Nanoindentation behavior and creep-induced cracking of long-term crept austenitic steel at 650℃

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Journal of Iron and Steel Research International 2024年第2期31卷 464-474页

作者： Zhen zhang yu-hang Duan Shuai Wang Jin-shan Chen An-zhe Wang Xiang-yang Mao yuan-ji shi Jie zhang Ming Liu Zheng-fei Hu School of Materials Science and Engineering Nanjing Institute of TechnologyNanjing211167JiangsuChina Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing211167JiangsuChina Jiangsu Wind Power Engineering Technology Center Nanjing210023JiangsuChina Nanjing Vocational University of Industry Technology Nanjing210023JiangsuChina Baoshan Iron&Steel Co. Ltd.Shanghai201900China Fujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou350116FujianChina School of Materials Science and Engineering Tongji UniversityShanghai201804China

The grain boundary(GB)damage of long-term crept HR3C(25Cr–20Ni–Nb–N)austenitic steel with solid solution state was investigated by nanoindentation test accompanied with in-situ electron back-scattered *** corresponding microstructure was characterized by scanning electron microscopy and transmission electron *** show that the increase in nanoindentation hardness at the GBs and triple grain junctions may be related to the dislocation accumulation and carbide growth during the *** M23C6 and dislocations piling-up at the GB accelerate the nucleation and coalescence of creep cavity along the *** nanoindentation hardness in grains varies with orientation of the stress *** orientation difference of neighbor grains may induce local high geometrically necessary dislocation densities and strain gradients near the GB,consequently causing stress concentration and subsequent crack growth at specific GBs.

关键词： Austenitic steel Creep Nanoindentation Grain orientation Creep-induced cracking

Carboxylic bacterial cellulose fiber-based hydrogel electrolyte with imidazole-type ionic liquid for dendrite-free zinc metal batteries

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Materials Reports(Energy) 2024年第2期4卷 45-53页

作者： Tianyun zhang Xiaohong shi yu Li Sambasivam Sangaraju Fujuan Wang Liang Yang Fen Ran School of Mechanical and Electronical Engineering Lanzhou University of TechnologyLanzhou730050PR China State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals School of Materials Science and EngineeringLanzhou University of TechnologyLanzhou730500PR China National Water and Energy Center United Arab Emirates UniversityAl Ain15551United Arab Emirates

Aqueous zinc metal batteries are regarded as the most promising energy storage system due to their advantages of high safety,low cost,and high theoretical ***,the growth of dendrites and the occurrence of side reactions hinder the development of zinc metal *** previous attempts to design advanced hydrogel electrolytes,achieving high mechanical performance and ionic conductivity of hydrogel electrolytes has remained *** this work,a hydrogel electrolyte with an ionic crosslinked network is prepared by carboxylic bacterial cellulose fiber and imidazole-type ionic liquid,following by a covalent network of *** hydrogel electrolyte possesses a superior ionic conductivity of 43.76 mS cm^(−1),leading to a Zn^(2+)migration number of 0.45,and high mechanical performance with an elastic modulus of 3.48 GPa and an elongation at breaking of 38.36%.More importantly,under the anion-coordination effect of the carboxyl group in bacterial cellulose and[BF4]−in imidazole-type ionic liquid,the solvation sheath of hydrated Zn^(2+)ions and the nucleation overpotential of Zn plating are *** results of cycled testing show that the growth of zinc dendrites is effectively inhibited and the generation of irreversible by-products is *** the carboxylic bacterial cellulose-based hydrogel electrolyte,the Zn||Zn symmetric batteries offer good cyclability as well as Zn||Ti batteries.

关键词： Bacterial cellulose fiber Ionic liquids Carboxylic group Gel electrolyte Zn metal batteries

Interface structure of α-Mg/14H-LPSO:First-principles prediction and experimental study

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Journal of Rare Earths 2024年第9期42卷 1792-1799,I0006页

作者： yuan shi Xiaohua zhang Hongyan yue Chao Li School of Materials Science and Chemical Engineering Harbin University of Science and TechnologyHarbin150040China

The interfacial structure of the α-Mg/14H-LPSO phase in rare earth-including magnesium alloy was investigated via high-angle annular dark-field scanning transmission electron microscopy(HAADFSTEM) imaging and first-principles calculations of density-functional *** possible interfacial models were constructed according to the different terminations of the LPSO phase,and the corresponding interfacial energies were calculated,from which the four most stable structures(Terl-MgY-hollow,Ter2-Zn-hollow,Ter3-MgYII-hollow and Ter4-Mg-bridge) were *** interfacial phase diagrams related to the Y chemical potentials were obtained from the calculations,and the most stable interfacial structure was ***-MgY-hollow and Ter2-Zn-hollow have the lowest interfacial energies in the range of-0.7 eV <Δμγ<-0.6 eV,where fluctuating change of state is the minimized and the interface is the most *** separation work of the two models was calculated to predict the bonding strength of the structures at both ends of the *** calculation results show that the maximum interfacial separation work is 1.45 J/m^(2) for the interface model of α-Mg and 14H-LPSO phase structure with Ter2-Zn-hollow termination.

关键词： Rare earths Magnesium alloy HAADF-STEM LPSO First-principles Interface

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Topology optimization of AISI 4140 steel with surface texture filled by multi-solid lubricants for enhancing tribological properties

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Friction 2024年第9期12卷 2033-2051页

作者： Qipeng HUANG Chaohua WU Xiaoliang shi Kaipeng zhang School of Mechanical and Electronic Engineering Wuhan University of TechnologyWuhan 430070China School of Transportation and Logistics Engineering Wuhan University of TechnologyWuhan 430063China

Wind power gears will be excessively worn due to lubrication failure during ***,the tribological properties of rubbing pairs are improved by filling solid lubricants into surface *** texture design,three types of topological textures(Circle(C),Hexagon(H),and Circle/Hexagon(CH))were obtained by cell topology optimization,and then three cases with 20%,30%,and 40%density were designed for each ***,SnAgCu and TiC were deposited in texture of AISI 4140 steel(AS)to obtain 9 kinds of self-lubricating *** them,AS with 30%CH density(AS-CH30)exhibits excellent mechanical and tribological *** with AS-C and AS-H,the maximum equivalent stress of AS-CH was decreased by 10.86%and 5.37%,*** coefficient and wear rate of AS-CH30 were 79.68%and 78%lower than those of *** excellent tribological performances of AS-CH30 can be attributed to the synergistic effect of topological surface and solid *** surface can not only reduce fluctuation of equivalent stress,but also promote the stored lubricants to be easily transferred at the contact interface to form a 200 nm lubricating film containing solid lubricants(mainly),oxides and wear debris.

关键词： topological texture nano-TiC self-lubricating solid lubrication

Thermal Decomposition and Oxidative Decomposition Mechanism of HFC-134a by Experimental and DFT Method

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Journal of Thermal Science 2024年第5期33卷 1990-2003页

作者： XU yunting zhang Kai DAI Xiaoye shi Lin Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Energy and Power EngineeringTsinghua UniversityBeijing 100084China

In response to the Kigali Amendment to the Montreal Protocol and global low-carbon emission environmental requirements,the phase-out and decomposition of numerous HFC refrigerants have become urgent,necessitating efficient and mild decomposition *** study investigates the thermal decomposition and oxidative thermal decomposition pathways of the typical hydrofluorocarbon refrigerant HFC-134a,employing a combination of experimental and quantum chemical DFT simulation *** chemical simulations reveal that the initial reaction bond cleavage serves as the rate-determining step during the thermal decomposition process,with the most easily detectable closed-shell products including CF_(2)=CHF,HF,CH_(3)F,CHF_(3),CH_(2)F_(2),and CF_(4).Reactive oxygen species can significantly reduce the Gibbs free energy barrier for HFC-134a *** achieve efficient degradation of HFC-134a,appropriate catalysts should be developed and selected to increase the level of reactive oxygen species in the reaction *** studies further corroborate that HFC-134a may undergo degradation through distinct reaction pathways under varying temperature(240℃to360℃)and pressure(0.1 MPa to 4.5 MPa)conditions,in agreement with simulation predictions.

关键词： HFC-134a pyrolysis oxidative thermal decomposition DFT refrigerant

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Deciphering TADF Mechanisms in Metal-Free Organic Emitters BrA-HBI:Utilizing Optimally Tuned Range-Separated Functionals for Insight

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Chinese Physics Letters 2024年第9期41卷 28-37页

作者： Chunyue yu Hang Yin Jie Guo Wentian zhang Ying shi Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China

Metal-free organic emitters,characterized by their thermally activated delayed fluorescence(TADF)properties,offer considerable promise for the creation of highly efficient organic light-emitting diodes(OLEDs).Recently,Shao et *** a novel excited state intramolecular proton transfer(ESIPT)system BrA-HBI,demonstrating an emission quantum yield of up to 50%[***.32,2201256(2022)].However,many open issues cannot be answered solely by experimental means only and require detailed theoretical *** instance,what causes the activation of TADF from the Keto*tautomer and leads to fluorescence quenching in the Enol^(*)form?Herein,we provide a theoretical investigation on the TADF mechanism of the BrA-HBI molecule by optimally tuned range-separated *** findings reveal that ESIPT occurs in the BrA-HBI ***,we have disclosed the reason for the fluorescence quenching of the Enol^(*)form and determined that the T_(2)state plays a dominant role in the TADF *** addition,double hybrid density functionals method was utilized to verify the reliability of optimally tuned range separation functionals on the calculation of the TADF mechanism in *** findings not only provide a theoretical reference for development of highly efficient organic light-emitting diodes,but also demonstrate the effectiveness of the optimally tuned range-separated functionals in predicting the luminescence properties of TADF molecules.

关键词： optimal finding separated

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Your personal choices in transportation and food are important for lowering carbon emissions

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Frontiers of Environmental Science & Engineering 2024年第6期18卷 27-32页

作者： Bruce Logan Fang zhang Wulin Yang Le shi Institute of Energy and the Environment The Pennsylvania State UniversityUniversity ParkPA 16802USA School of Environment Tsinghua UniversityBeijing 100084China College of Environmental Sciences and Engineering Peking UniversityBeijing 100871China College of Environmental and Resource Sciences Zhejiang UniversityHangzhou 310058China

There is a global need to reduce greenhouse gas emissions to limit the extent of climate change.A better understanding of how our own activities and lifestyle influence our energy use and carbon emissions can help us enable changes in activities that can lead to reductions in carbon *** we discuss an approach based on examining carbon emissions from the perspective of the unit C,where 1 C is the CO_(2)from food a person would on average eat every *** approach shows that total CO_(2)emissions in China,normalized by the population,is 22.5 C while carbon emissions for a person in the US is 43.9 C.A better appreciation of our own energy use can be obtained by calculating carbon emissions from our own activities in units of C,for example for driving a car gasoline or electric vehicle a certain number of kilometers,using electricity for our homes,and eating different *** this information,we can see how our carbon emissions compare to national averages in different countries and make decisions that could lower our personal CO_(2)emissions.

关键词： Carbon dioxide Climate change Daily energy Greenhouse gas

Effect of geometry simplification and boundary condition specification on flow field and aerodynamic noise in the train head and bogie region of high-speed trains

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第9期25卷 716-731页

作者： Jiawei shi yuan HE Jiye zhang Tian LI State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China Institute of Sound and Vibration Research Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthampton SO171BJUK

The purpose of this study is to determine a suitable modeling method to make computational fluid dynamics(CFD)simulation more efficient for aeroacoustics optimization of the bogie region of high-speed *** this end,four modeling methods are considered,which involve different geometry simplifications and boundary condition *** corresponding models are named the three-car marshalling model,computational domain shortening model,carbody shortening model,and sub-domain *** the detached eddy simulation(DES)model and Ffowcs Williams-Hawkings(FW-H)equation,the unsteady flow field and far-field noise of the four models are *** evaluate the effect of the different modeling methods,the time-averaged flow field,fluctuating flow field,and far-field noise results of the four models are compared and analyzed in detail with the results of the three-car marshalling model used as basis for *** results show that the flow field results of the bogie region predicted by the four models have relatively high ***,the usage of the non-time varying outlet boundary conditions in the computational domain shortening model and sub-domain model could affect the pressure fluctuation on the upstream carbody *** only the bogie region is used as the source surface,the differences between the far-field noise results of the three simplified models and the three-car marshalling model are all within 1 dB;when the train head is used as the source surface,the results of the carbody shortening model and the three-car marshalling model are more consistent.

关键词： Bogie region Train head Flow field Aerodynamic noise Geometry simplification Boundary conditions