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Shock Wave Spectrum Forming around the Compound Five-Hole Probe and its Influence on Pneumatic Parameters Acquisition during Subsonic to Supersonic Flow

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Journal of Thermal Science 2024年第6期33卷 2019-2031页

作者： KAN Xiaoxu SUO Licheng LEI Haodong WU Wanyang ZHONG Jingjun Merchant Marine College Shanghai Maritime University

Supersonic wind tunnel experiment is one of the important measurements for developing advanced gas turbines,and supersonic multi-hole probes are sophisticated tools to measure pneumatic parameters in such ***,shock waves form around the probe head in supersonic flow,which affect the accuracy of *** this study,a supersonic five-hole probe is selected as the research ***,a compound five-hole pressure-temperature probe was designed and produced with 3D-printing ***,the shock wave spectrum was numerically calculated by three methods,which were the Mach number,density gradient,and shock function;in contrast to the other two methods,the shock function could accurately identify the types and ranges of shock and expansion *** results show that a strong shock wave is formed at the front section of the probe head,and the shock wave generated around the pressure measuring tube affects the total pressure and Mach number of the flow field,which causes the increase of *** intensity of the shock wave at the head of the pressure measuring tube is the largest,causing a decrease in the total pressure around the flow ***,to reduce the calculation errors caused by neglecting the compressibility of gases and the entropy increase,a gas compression factor δswas *** is proved that the error of the calculated pneumatic parameters is less than 5% and 10% in subsonic and supersonic condition,respectively,with the gas compression factor *** research results of this paper provide theoretical reference for the design and use of pneumatic probes during subsonic to supersonic flow.

关键词： numerical simulation pneumatic parameter pneumatic probes shock wave supersonic flow

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Integer multiple quantum image scaling based on NEQR and bicubic interpolation

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Chinese Physics B 2024年第4期33卷 259-273页

作者：蔡硕周日贵罗佳陈思哲 College of Information Engineering Shanghai Maritime UniversityShanghai 201306China Research Center of Intelligent Information Processing and Quantum Intelligent Computing Shanghai 201306China College of Merchant Marine Shanghai Maritime UniversityShanghai 201306China School of Mathematics and Computational Science Shangrao Normal UniversityShangrao 334001China

As a branch of quantum image processing,quantum image scaling has been widely ***,most of the existing quantum image scaling algorithms are based on nearest-neighbor interpolation and bilinear interpolation,the quantum version of bicubic interpolation has not yet been *** this work,we present the first quantum image scaling scheme for bicubic interpolation based on the novel enhanced quantum representation(NEQR).Our scheme can realize synchronous enlargement and reduction of the image with the size of 2^(n)×2^(n) by integral ***,the image is represented by NEQR and the original image coordinates are obtained through multiple CNOT ***,16 neighborhood pixels are obtained by quantum operation circuits,and the corresponding weights of these pixels are calculated by quantum arithmetic ***,a quantum matrix operation,instead of a classical convolution operation,is used to realize the sum of convolution of these *** simulation experiments and complexity analysis,we demonstrate that our scheme achieves exponential speedup over the classical bicubic interpolation algorithm,and has better effect than the quantum version of bilinear interpolation.

关键词： quantum image processing image scaling bicubic interpolation quantum circuit

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Two-dimensional transition metal MXene-based gas sensors:A review

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Chinese Chemical Letters 2024年第1期35卷 208-221页

作者： Junfeng Li Xiaojie Chen Xiaojie Zhu Yingchang Jiang Xueting Chang Shibin Sun College of Logistics and Engineering Shanghai Maritime UniversityShanghai 201306China institute of Marine Materials Science and Engineering Shanghai Maritime UniversityShanghai 201306China

As an emerging star in the family of two-dimensional(2D)materials,2D transition metal carbides,carbonitrides and nitrides,collectively referred to as MXenes,have large specific surface area,rich active sites,metallic conductivity and adjustable surface chemical *** features make MXenes promising candidates for gas-sensing *** the past few years,MXene-based sensors have drawn increasing attention due to their enhanced sensor *** on this,this review systematically represents the structure,synthesis methods and properties of MXenes,and summarizes their applications in gas ***,the types,structure,main synthesis methods and properties of MXenes are introduced in a comprehensive ***,the corresponding design principle and working mechanism of MXene-based gas sensor are ***,the sensing performances of pristine MXenes and the MXene-based nanocomposite are ***,some future opportunities and challenges of MXene-based sensors are pointed out.

关键词： MXene Gas sensors Synthesis Stability Gas-sensing mechanism Gas-sensing performance

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Westward Migration of Tropical Cyclone Activity in the Western North Pacific during 1982–2020:Features and Possible Causes

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Journal of Meteorological Research 2024年第1期38卷 1-9页

作者： Jian ZHONG Huadong DU Yuqin WU Yuehua PENG China Satellite maritime Tracking and Control Department Jiangyin 2144312 College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 4100733 Dalian Naval Academy Dalian 1160184 institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029

The westward migration of tropical cyclone(TC)activity has been identified in the western North Pacific(WNP),but the related features and causes remain ***,based on the best track data from China,Japan,and the US,and the NCEP–NCAR reanalysis data in 1982–2020,we investigate characteristics of the westward migration of the WNP TC activity with various metrics,and reveal possible causes for the migration of TC tracks through analyzing its seasonality and dependence on environmental *** results show that the WNP TCs show significant westward migrations in a number of metrics,including location of tracks,genesis,the first track point at which TC reaches its lifetime-maximum intensity,and the last track point in the TC *** is found that TC tracks exhibit more significant westward migrations in the easterly steering flow than in the westerly steering ***,the TC longitude shift shows notable seasonal variations,for which the TCs in the easterlies move further west than those in the westerlies during July–September,vice versa during October–*** dependence of the westward migration of TC tracks on background steering flow is associated with the different environmental *** westward shift in the westerly steering is mainly due to the reduced vertical wind shear(VWS),while the weakened zonal easterly steering and reduced VWS are both closely related to the westward migration in the easterly *** results have important implications for understanding current and future variations in TC longitude shift.

关键词： tropical cyclone westward migration steering flow vertical wind shear

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Geometric properties of the first singlet S-wave excited state of two-electron atoms near the critical nuclear charge

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Chinese Physics B 2024年第10期33卷 213-219页

作者： Tong Chen Sanjiang Yang Wanping Zhou Xuesong Mei d Haoxue Qiao School of Physics and Technology Wuhan UniversityWuhan 430072China College of Physics and Electronic Science Hubei Normal UniversityHuangshi 435002China School of Physics and Telecommunications Huanggang Normal UniversityHuanggang 438000China Wuhan maritime Communication Research institute Wuhan 430072China

The geometric structure parameters and radial density distribution of 1s2s1S excited state of the two-electron atomic system near the critical nuclear charge Z_(c)were calculated in detail under tripled Hylleraas basis *** to the localized behavior observed in the ground and the doubly excited 2p^(23)Pe states,for this state our results identify that while the behavior of the inner electron increasingly resembles that of a hydrogen-like atomic system,the outer electron in the excited state exhibits diffused hydrogen-like character and becomes perpendicular to the inner electron as nuclear charge Z approaches Z_(c).This study provides insights into the electronic structure and stability of the two-electron system in the vicinity of the critical nuclear charge.

关键词： critical nuclear charge two-electron atomic system geometric structure density distribution

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Efficient Nonnegative Tensor Decomposition Using Alternating Direction Proximal Method of Multipliers

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Chinese Journal of Electronics 2024年第5期33卷 1308-1316页

作者： Deqing WANG Guoqiang HU State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences institutes for Robotics and Intelligent Manufacturing Chinese Academy of Sciences Key Laboratory of Marine Robotics Liaoning Province College of Artificial Intelligence Dalian Maritime University

Nonnegative CANDECOMP/PARAFAC（NCP） tensor decomposition is a powerful tool for multiway signal processing. The alternating direction method of multipliers（ADMM） optimization algorithm has become increasingly popular for solving tensor decomposition problems in the block coordinate descent framework. However,the ADMM-based NCP algorithm suffers from rank deficiency and slow convergence for some large-scale and highly sparse tensor data. The proximal algorithm is preferred to enhance optimization algorithms and improve convergence properties. In this study, we propose a novel NCP algorithm using the alternating direction proximal method of multipliers（ADPMM） that consists of the proximal algorithm. The proposed NCP algorithm can guarantee convergence and overcome the rank deficiency. Moreover, we implement the proposed NCP using an inexact scheme that alternatively optimizes the subproblems. Each subproblem is optimized by a finite number of inner iterations yielding fast computation speed. Our NCP algorithm is a hybrid of alternating optimization and ADPMM and is named *** experimental results on synthetic and real-world tensors demonstrate the effectiveness and efficiency of our proposed algorithm.

关键词： Nonnegative CANDECOMP/PARAFAC Alternating direction proximal method of multipliers Tensor decomposition Proximal algorithm Proximal algorithm Sparse regularization Sparse regularization Proximal algorithm Sparse regularization FACTORIZATION OPTIMIZATION ORGANIZATION ALGORITHMS MATRIX

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Discovery of the Significant Impacts of Swell Propagation on Global Wave Climate Change

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Journal of Ocean University of China 2024年第3期23卷 594-604页

作者： ZHENG Chongwei Dalian Naval Academy Dalian 116018China Marine Resources and Environment Research Group on the maritime Silk Road Dalian 116018China

This study compared the differences in the wave climate in the South China Sea and North Indian Ocean under these two datasets:ERA-40 wave reanalysis and Mei’s hindcast wave *** the numerical calculation of regional ocean waves,the wave climate characteristics exhibited significant bias if the influence of external swells(swells from afar)was not fully considered,which may provide an incorrect basis for global climate change analysis.1)The trends of the significant wave height(SWH)obtained from the two datasets showed significant differences,such as those of the Bay of Bengal and the Java Sea in *** the past 45 years,SWH from ERA-40(SWH-ERA)exhibited a significant annual increase in low-latitude waters of the North Indian Ocean(0.2-0.6 cm yr^(-1))and South China Sea(0.2-0.8 cm yr^(-1)).2)In the Bay of Bengal,the SWH-ERA in each month was generally 0.5 m higher than the SWH from Mei’s hindcast wave data(SWH-Mei)and can reach 1.0 m higher in some months.3)In the Bay of Bengal,SWH-ERA and SWH-Mei increased significantly at annual rates of 0.13 and 0.27 cm yr^(-1),*** increasing trend was mainly reflected after ***-ERA showed a trough in 1975(1.33 m)and a crest in 1992(1.83 m),which were not reflected in SWH-Mei.

关键词： wave climate climatic trend monthly variation annual variation external swell

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Adaptive nonlinear Kalman filters based on credibility theory with noise correlation

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Chinese Journal of Aeronautics 2024年第6期37卷 232-243页

作者： Quanbo GE Zihao SONG Bingtao ZHU Bingjun ZHANG School of Automation Nanjing University of Information Science and TechnologyNanjing 210044China jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology Nanjing 210044China School of Electrical and Automation Engineering East China Jiaotong UniversityNanchang 330013China School of Logistics Engineering Shanghai Maritime UniversityShanghai 201306China School of Electronic and Information Engineering Tongji UniversityShanghai 200092China

To solve the divergence problem and overcome the difficulty in guaranteeing filtering accuracy during estimation of the process noise covariance or the measurement noise covariance with traditional new information-based nonlinear filtering methods,we design a new method for estimating noise statistical characteristics of nonlinear systems based on the credibility Kalman Filter(KF)theory considering noise *** method first extends credibility to the Unscented Kalman Filter(UKF)and Extended Kalman Filter(EKF)based on the credibility ***,an optimization model for nonlinear credibility under noise related conditions is established considering noise correlation.A combination of filtering smoothing and credibility iteration formula is used to improve the real-time performance of the nonlinear adaptive credibility KF algorithm,further expanding its application scenarios,and the derivation process of the formula theory is ***,the performance of the nonlinear credibility filtering algorithm is simulated and analyzed from multiple perspectives,and a comparative analysis conducted on specific experimental *** simulation and experimental results show that the proposed credibility EKF and credibility UKF algorithms can estimate the noise covariance more accurately and effectively with lower average estimation time than traditional methods,indicating that the proposed algorithm has stable estimation performance and good real-time performance.

关键词： Kalman filter Extended Kalman Filter(EKF) Unscented Kalman Filter(UKF) Credibility Noise correlation

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Achieving high power factor in GaSb with intrinsically high mobility via Ge doping

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Rare Metals 2024年第10期43卷 5435-5441页

作者： Yan-Ci Yan Guo-Wei Wang Qi-Hong Xiong Xu Lu Peng Chen Wei Zou Deng-Feng Li Hong Wu Yun Zhou Xiao-Yuan Zhou School of Science Chongqing University of Posts and Telecommunications College of Physics Chongqing University College of Ocean Science and Engineering Shanghai Maritime University

The thermoelectric power factor is as crucial as their overall thermoelectric ***-based compounds are deemed to achieve high power factor owing to their intrinsically high mobility compared to classical thermoelectric ***,the carrier concentration of pristine GaSb is considerably lower than the optimum value,which hinders its ability to attain high electrical *** this paper,we present the investigations on the thermoelectric performance of p-type *** experimental results reveal that Ge doping can effectively tune the carrier concentration.

关键词： Carrier concentration

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Assessment of corrected time-step method for nominal ionospheric gradient calculation: A comparative analysis with spatial approaches

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Earth and Planetary Physics 2024年第4期8卷 641-649页

作者： Slamet Supriadi Prayitno Abadi Susumu Saito Harry Bangkit Dwiko Unggul Prabowo Adi Purwono Ginaldi Ari Nugroho Research Center for Smart Mechatronics National Research and Innovation Agency(BRIN)BandungIndonesia Research Center for Climate and Atmosphere BRINBandungIndonesia School of Electrical Engineering Telkom UniversityKab.BandungIndonesia Electronic Navigation Research institute National Institute of MaritimePort and Aviation TechnologyTokyoJapan Research Center for Space BRINBandungIndonesia

The effect of ionospheric delay on the ground-based augmentation system under normal conditions can be mitigated by determining the value of the nominal ionospheric gradient(σvig).The nominal ionospheric gradient is generally obtained from Continuously Operating Reference Stations data by using the spatial single-difference method(mixed-pair,station-pair,or satellite-pair)or the temporal single-difference method(time-step).The time-step method uses only a single receiver,but it still contains ionospheric temporal *** introduce a corrected time-step method using a fixed-ionospheric pierce point from the geostationary equatorial orbit satellite and test it through simulations based on the global ionospheric *** also investigate the effect of satellite paths on the corrected time-step method in the region of the equator,which tends to be in a more north–south direction and to have less coverage for the east–west ionospheric *** study also addresses the limitations of temporal variation correction coverage and recommends using only the correction from *** processes are developed under simulations because observational data are still difficult to *** findings demonstrate that the corrected time-step method yieldsσvig values consistent with other approaches.

关键词： ground-based augmentation system nominal ionospheric gradient time-step correction global ionospheric model

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