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Intermediate-mass black holes in Green pea galaxies (IMBH-GP) I:A candidate sample from LAMOST and SDSS

Science China(Physics,Mechanics & Astronomy) 2024年

作者： Ruqiu Lin Zhen-Ya Zheng Fang-Ting Yuan Jun-Xian Wang Chunyan Jiang Ning Jiang Lingzhi Wang Linhua Jiang Xiang Ji Shuairu Zhu Xiaodan Fu Key Laboratory for research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences School of Astronomy and Space Sciences University of Chinese Academy of Sciences CAS Key Laboratory for research in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China Chinese Academy of Sciences South America center for Astronomy (CASSACA) National Astronomical ObservatoriesChinese Academy of Sciences CAS Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Kavli Institute for Astronomy and Astrophysics Peking University Department of Astronomy School of Physics Peking University

The scaling relation of central massive black holes (MBHs) and their host galaxies is well-studied for supermassive BHs (SMBHs,MBH≥10～6M⊙).However,this relation has large uncertainties in the mass range of the intermediate-mass BHs (IMBHs,MBH～10～3-10～6M⊙).Since Green pea （GP） galaxies are luminous compact dwarf galaxies,which may be likely to host less massive SMBHs or even IMBHs,we systematically search for MBHs in a large sample of 2190 GP galaxies at z<0.4,selected from LAMOST and SDSS spectroscopic ***,we report a newly discovered sample of 59 MBHcandidates with broad Hα *** sample has a median stellar mass of 108.83±0.11M⊙and hosts MBHs with single-epoch virial masses ranging from MBH～104.7to 108.5M⊙(median 105.85±0.64M⊙).Among the 59 MBHcandidates,36 have black hole masses MBH≤10～6M⊙(IMBHcandidates),one of which even has MBH10～5M⊙.We find that the MBH-M*relation of our MBHsample is consistent with the MBH-Mbulgerelation for SMBHs,while is above the MBH-M*relation for MBHs in dwarf galaxies in the same mass ***,we show that 25 MBHcandidates,including 4 IMBHcandidates,have additional evidence of black hole activities,assessed through various methods such as the broad-line width,BPT diagram,mid-infrared color,X-ray luminosity,and radio *** studies show that it is very promising to find IMBHs in GP galaxies,and the BH sample so obtained enables us to probe the connection between the MBHs and compact dwarf galaxies in the low-redshift Universe.

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Silicon photonic spectrometer with multiple customized wavelength bands

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Photonics research 2024年第5期12卷 1016-1023页

作者： LONG ZHANG XIAOLIN YI DAJIAN LIU SHIHAN HONG GAOPENG WANG HENGZHEN CAO YAOCHENG SHI DAOXIN DAI State Key Laboratory for Modern Optical Instrumentation Center for Optical&Electromagnetic ResearchCollege of Optical Science and EngineeringInternational Research Center for Advanced PhotonicsZhejiang UniversityZjingang CampusHangzhou 310058China Intelligent Optics and Photonics research center Jiaxing Research InstituteZhejiang UniversityJiaxing 314000China Ningbo research Institute Zhejiang UniversityNingbo 315100China

A silicon photonic spectrometer with multiple customized wavelength bands is developed by introducing multiple channels of wideband optical filters based on multimode waveguide gratings(MWGs)for pre-filtering and the corresponding thermally tunable narrowband filter for high *** these multiple customized wavelength bands,the central wavelengths,bandwidths,and resolutions are designed flexibly as desired,so that the system is simplified and the footprint is minimized for several practical applications(e.g.,gas sensing).A customized silicon photonic spectrometer is designed and demonstrated experimentally with four wavelength bands centered around1310 nm,1560 nm,1570 nm,and 1930 nm,which is,to the best of our knowledge,the first on-chip spectrometer available for sensing multiple gas components like HF,CO,H_(2)S,and CO_(2).The spectral resolutions of the four wavelength bands are 0.11 nm,0.08 nm,0.08 nm,and 0.37 nm,*** a customized silicon photonic spectrometer shows great potential for various applications,including gas monitors,wearable biosensors,and portable spectral-domain optical coherence tomography.

关键词： waveguide bands multiple

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Mobile-ionic FETs with ultra-scaled amorphous dielectric achieving ferroelectric behaviors and sub-kT/q swing with temperature down to 77 K

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Science China(Information Sciences) 2024年第1期67卷 312-313页

作者： Huan LIU Qiyu YANG Chengji JIN Jiajia CHEN Lulu CHOU Xiao YU Yan LIU Genquan HAN research center for Intelligent Chips School of Microelectronics Xidian University

The steep subthreshold swing (SS) could be achieved in negative capacitance field-effect transistors (NCFET) to reduce power dissipation in modern electronics. Polycrystalline Hf O2-based ferroelectric materials have attracted great interest due to their better thickness scalability and CMOS process compatibility [1].

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Aircraft parameter estimation using a stacked long short-term memory network and Levenberg-Marquardt method

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Chinese Journal of Aeronautics 2024年第2期37卷 123-136页

作者： Zhe HUI Yinan KONG Weigang YAO Gang CHEN School of Aerospace Science and Technology Xidian UniversityXi’an 710071China Computation Aerodynamics Institution China Aerodynamics Research and Development CenterMianyang 621000China Faculty of computing Engineering and MediaDe Montfort UniversityLeicester LE19BHUnited Kingdom School of Aerospace Engineering Xi’an Jiaotong UniversityXi’an 710049China

To effectively estimate the unknown aerodynamic parameters from the aircraft’s flight data,this paper proposes a novel aerodynamic parameter estimation method incorporating a stacked Long Short-Term Memory(LSTM)network model and the Levenberg-Marquardt(LM)*** stacked LSTM network model was designed to realize the aircraft dynamics modeling by utilizing a frame of nonlinear functional mapping based entirely on the measured input-output data of the aircraft system without requiring explicit postulation of the *** LM method combines the already-trained LSTM network model to optimize the unknown aerodynamic *** proposed method is applied by using the real flight data,generated by ATTAS aircraft and a bio-inspired morphing Unmanned Aerial Vehicle(UAV).The investigation reveals that for the two different flight data,the designed stacked LSTM network structure can maintain the efficacy of the network prediction capability only by appropriately adjusting the dropout rates of its hidden layers without changing other network parameters(i.e.,the initial weights,initial biases,number of hidden cells,time-steps,learning rate,and number of training iterations).Besides,the proposed method’s effectiveness and potential are demonstrated by comparing the estimated results of the ATTAS aircraft or the bio-inspired morphing UAV with the corresponding reference values or wind-tunnel results.

关键词： Parameter estimation LSTM network model LM method Aerodynamic parameters Flight data Aircraft dynamics modeling Network prediction capability Network parameters

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Chaotic Map-Based Authentication and Key Agreement Protocol with Low-Latency for Metasystem

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Computers, Materials & Continua 2024年第3期78卷 4471-4488页

作者： Guojun Wang Qi Liu School of Electronics&Information Engineering Nanjing University of Information Science&TechnologyNanjing210044China Yancheng Polytechnic College Yancheng224000China Jiangsu Province Engineering research center of Advanced computing and Intelligent Services School of SoftwareNanjing University of Information Science and TechnologyNanjingChina

With the rapid advancement in exploring perceptual interactions and digital twins,metaverse technology has emerged to transcend the constraints of space-time and reality,facilitating remote AI-based *** this dynamic metasystem environment,frequent information exchanges necessitate robust security measures,with Authentication and Key Agreement(AKA)serving as the primary line of defense to ensure communication ***,traditional AKA protocols fall short in meeting the low-latency requirements essential for synchronous interactions within the *** address this challenge and enable nearly latency-free interactions,a novel low-latency AKA protocol based on chaotic maps is *** protocol not only ensures mutual authentication of entities within the metasystem but also generates secure session *** security of these session keys is rigorously validated through formal proofs,formal verification,and informal *** confronted with the Dolev-Yao(DY)threat model,the session keys are formally demonstrated to be secure under the Real-or-Random(ROR)*** proposed protocol is further validated through simulations conducted using VMware workstation compiled in HLPSL language and C *** simulation results affirm the protocol’s effectiveness in resisting well-known attacks while achieving the desired low latency for optimal metaverse interactions.

关键词： Metasystem authentication and key agreement chaotic map secure communication

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Tuning mechanical and electrical performances of B_(4)C-TiB_(2)ceramics in a two-step spark plasma sintering process

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Journal of Advanced Ceramics 2024年第4期13卷 518-528页

作者： Jun Zhao Xingshuo Zhang Zongning Ma Dong Wang Xing Jin Songlin Ran Advanced Ceramics research center School of Materials Science and EngineeringAnhui University of TechnologyMaanshan 243002China Anhui Engineering research center for High Efficiency Intelligent Photovoltaic Module Chaohu UniversityHefei 238024China

B_(4)C–TiB_(2)is an advanced electrically conductive ceramic with excellent mechanical and electrical discharge machinable *** is challenging and rewarding to achieve highly conductive and hard B_(4)C–TiB_(2)composites at a minimum content of conductive TiB2 that has inferior hardness but double specific gravity of the B_(4)C matrix.A novel strategy was used to construct conductive networks in B_(4)C‒15 vol%TiB2 composite ceramics with B_(4)C,TiC,and amorphous B as raw materials by a two-step spark plasma sintering *** influences of particle size matching between B_(4)C and TiC on the conducting of the strategy and the microstructure were discussed based on the selective matrix grain growth *** mechanical and electrical properties were also systematically *** B_(4)C–15 vol%TiB2 composite ceramic prepared from 10.29µm B_(4)C and 0.05µm TiC powders exhibited a perfect three-dimensional interconnected conductive network with a maximum electrical conductivity of 4.25×10^(4)S/m,together with excellent mechanical properties including flexural strength,Vickers hardness,and fracture toughness of 691±58 MPa,30.30±0.61 GPa,and 5.75±0.32 MPa·m^(1/2),respectively,while the composite obtained from 3.12µm B_(4)C and 0.8µm TiC powders had the best mechanical properties including flexural strength,Vickers hardness,and fracture toughness of 827±35 MPa,32.01±0.51 GPa,and 6.45±0.22 MPa·m^(1/2),together with a decent electrical conductivity of 0.65×10^(4)S/m.

关键词： B_(4)C-TiB_(2) mechanical properties electrical conductivity conductive network

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A Bitcoin Address Multi-Classification Mechanism Based on Bipartite Graph-Based Maximization Consensus

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 783-800页

作者： Lejun Zhang Junjie Zhang Kentaroh Toyoda Yuan Liu Jing Qiu Zhihong Tian Ran Guo College of Information Engineering Yangzhou UniversityYangzhou225127China Cyberspace Institute Advanced Technology Guangzhou UniversityGuangzhou510006China research and Development center for E-Learning Ministry of EducationBeijing100039China Institute of High Performance computing(IHPC) Agency for ScienceTechnology and Research(A∗STAR)Singapore138632Singapore School of Physics and Materials Science Guangzhou UniversityGuangzhou510006China

Bitcoin is widely used as the most classic electronic currency for various electronic services such as exchanges,gambling,marketplaces,and also scams such as high-yield investment *** the services operated by a Bitcoin address can help determine the risk level of that address and build an alert model *** engineering can also be used to flesh out labeled addresses and to analyze the current state of Bitcoin in a small *** this paper,we address the problem of identifying multiple classes of Bitcoin services,and for the poor classification of individual addresses that do not have significant features,we propose a Bitcoin address identification scheme based on joint multi-model prediction using the mapping relationship between addresses and *** innovation of the method is to(1)Extract as many valuable features as possible when an address is given to facilitate the multi-class service identification task.(2)Unlike the general supervised model approach,this paper proposes a joint prediction scheme for multiple learners based on address-entity mapping ***,after obtaining the overall features,the address classification and entity clustering tasks are performed separately,and the results are subjected to graph-basedmaximization *** final result ismade to baseline the individual address classification results while satisfying the constraint of having similarly behaving entities as far as *** testing and evaluating over 26,000 Bitcoin addresses,our feature extraction method captures more useful *** addition,the combined multi-learner model obtained results that exceeded the baseline classifier reaching an accuracy of 77.4%.

关键词： Bitcoin multi-service classification graph maximization consensus data security

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Impacts of inter-satellite links on the ECOM model performance for BDS-3 MEO satellites

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Satellite Navigation 2024年第1期5卷 140-154页

作者： Chao Yang Jing Guo Xiaolong Xu Longyu Wang Qile Zhao GNSS research center Wuhan UniversityNo.129 Luoyu RoadWuhan430079China

Inter-satellite link(ISL)plays an essential role in current and future Global Navigation Satellite System(GNSS).In this study,we investigate the impact of ISL observations on precise orbit determination for BeiDou-3 Navigation Satellite System(BDS-3)Medium Earth Orbit(MEO)satellites based on different Extended CODE Orbit Models(ECOM).Thanks to the better observation geometry of the Ka-band ISL data compared to the L-band data for BDS-3 MEO satellites,the ISL solution substantially reduces Orbit Boundary Discontinuity(OBD)errors,except for C30,which suffers from unstable Ka-band hardware *** the external quality analysis,ISL significantly enhances the reliability of the orbit of MEO satellites manufactured by the China Academy of Space Technology(CAST).The standard deviation(STD)of the satellite laser ranging(SLR)residuals is approximately 2.5 cm,and the root mean square(RMS)is reduced by 10–23%compared to L-band ***,the Sun-elongation angle dependent systematic error in SLR residuals nearly vanishes based on the reduced 5-parameter ECOM(ECOM1)or extended 7-parameter ECOM(ECOM2)with ISL *** is because the ISL reduces the correlation between state parameters and solar radiation pressure(SRP)parameters as well as those among SRP parameters,leading to a more accurate estimation of both orbit and SRP perturbations,particularly those along B *** confirms that the deficiency of the SRP models for BDS-3 CAST satellites can be compensated by using better observation geometry from ISL *** the other hand,for the satellite manufactured by Shanghai Engineering center for Microsatellites(SECM),the ISL allows for a more accurate estimation of the Bc_(1)parameter in the ECOM1 *** only reduces linear systematic error,possibly because the impact generated by the satellite bus cannot be entirely absorbed by the B-direction parameters.

关键词： BDS-3 MEO Inter-satellite link Solar radiation pressure ECOM

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A wide-linear-range and low-hysteresis resistive strain sensor made of double-threaded conductive yarn for human movement detection

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Journal of Materials Science & Technology 2024年第5期172卷 202-212页

作者： Fei Huang Jiyong Hu Xiong Yan Shanghai Frontier Science research center for Modern Textiles Donghua UniversityShanghai 201620China

Yarn-based flexible strain sensors with advantages in wearability and integrability have attracted wide ***,it is still a big challenge to achieve yarn-based strain sensors with a wide linear strain range,low hysteresis,and durability synchronously that can be used for full range detection of human body ***,a new structure,double-threaded conductive yarn with rhythmic strain distribu-tion,is reported to markedly widen the linear strain range of microcrack-based stretchable strain sensors.A new method of winding and thermally adhering hot-melt filaments on the surface of the elastic fiber is used to achieve double-threaded yarn(DTY)with rhythmic strain *** proposed strategy,the integration of heterogeneous materials,is reported to significantly reduce the mechanical hysteresis of composite *** strain distribution of the DTY during stretching causes multi-level micro-cracks in different regions of the carbon nanotube(CNT)conductive layer deposited on the surface of the ***,the sensing performance of DTY-based strain sensor can be adjusted by designing the structural *** final prepared flexible strain sensor has the advantages of a wide linear strain range(100%),great sensitivity(GF=12.43),low hysteresis,rapid response(158 ms),high repeatability(>2000 cycles at 50%strain),and hydrophobicity,*** sensor can monitor human motion repeatedly and stably well,and shows great advantages in flexible wearable devices.

关键词： Double-threaded yarn Strain redistribution Hysteresis Human motion monitoring

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Single-atomic activation on ZnIn_(2)S_(4)basal planes boosts photocatalytic hydrogen evolution

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Nano research 2024年第7期17卷 5949-5955页

作者： Jianpeng Cui Ying Wang Luxue Lin Xiaotian Yang Xuyu Luo Shiying Guo Xiaoyong Xu College of Physics Science and Technology and Center for Interdisciplinary ResearchYangzhou UniversityYangzhou 225002China

The use of single-atom cocatalysts plays a crucial role in enhancing artificial photocatalysis,where the precise construction of stable and efficient single-atom configuration is essential but remains ***,we report a simple one-step hydrothermal method for preparing single-atomic Mo modified ZnIn_(2)S_(4)(Mo-ZIS)nanosheets as a highly active photocatalytic hydrogen evolution(PHE)*** Mo substituting for portion of In atoms in ZIS nanosheets induces the spatial charge redistribution,which not only promotes the separation of photogenerated charge carriers but also optimizes the Gibbs free energy of adsorbing H*on S atoms at basal *** a result,Mo-ZIS exhibits an impressive PHE rate as high as 6.71 mmol·g^(−1)·h^(−1),over 10 times that of the pristine ZIS,with an apparent quantum efficiency(AQE)up to 38.8%at 420 *** study gains insights into the coordination configuration and electronic modulation resulting from single-atomic decoration,providing mechanistic cognitions for the development of advanced photocatalysts via non-precious metal atomic modification.

关键词： photocatalytic hydrogen evolution ZnIn_(2)S_(4) single-atom activation Gibbs free energy

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