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Science China(Information Sciences) 2025年第2期68卷 200-215页

作者： Yunxiang MA Tong ZHOU department of Automation Tsinghua University department of Automation and BNRist Tsinghua University

This paper investigates the identifiability of structured systems with a matrix fraction description and attacks practical difficulties in estimating parameters under finite frequency responses. The numerator and denominator polynomial matrices depend affinely on system parameters, which can represent a broad range of systems, especially circuits and mechanical systems. Except for assuming that the denominator matrix is invertible, no further assumptions are adopted. A criterion is provided for validating this assumption utilizing graph theories and matroids. A sufficient and necessary criterion for global identifiability based on the rank of a numerical matrix is given and can be recursively verified with each frequency point,which is computationally attractive for large-scale systems. For an identifiable system, an ellipsoid approximation is obtained for the set of parameters whose corresponding system frequency responses deviate within a specific range from those of the system at a specific parameter value. Using this approximation, explicit expressions for absolute and relative sloppiness have been derived, which can be used to quantify the difficulty of identifying system parameters. Comparisons with the well-known Fisher information matrix have also been performed through a mechanical system, revealing significant differences in quantifying parameter estimation hardness.

关键词： identifiability sloppiness structured system matrix fraction graph theory matroid

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Transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 177-192页

作者： M.NAVEED M.IMRAN T.ASGHAR Z.ABBAS department of Mathematics Division of Science and TechnologyUniversity of Education department of Mathematics The Islamia University of Bahawalpur

This paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. The influence of magnetic fields is also inspected in terms of their physical characteristics. To depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).The effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

关键词： analytical solution Cattaneo-Christov heat and mass flux chemical reaction gyrotactic microorganism hybrid nanofluid O368 oscillating curved stretchable sheet

The dynamic effects of solar eclipses of October 25,2022,and October 14,2023,on GPS-derived total electron content

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Geodesy and Geodynamics 2025年第1期16卷 75-86页

作者： Vishal Chauhan Vishakha Rakesh Singh Shishupal Singh Vikram Singh Om Prakash Singh department of Physics Graphic Era Hill University department of Petroleum Engineering Graphic Era (Deemed to be University) department of Physics St.John's College department of Applied Sciences & Humanities Institute of Engineering & Technology

This study analyzes total electron content(TEC) variations during two solar eclipse events that occurred on October 25, 2022, and October 14, 2023. The solar eclipse of October 25, 2022, was a partial solar eclipse, while the eclipse of October 14, 2023, was an annular solar eclipse. For this study, the data of eight International GNSS Service(IGS) stations from different eclipse coverage zones are used to analyze TEC variations. It is found that the stations located in the maximum eclipse cover zone exhibited notable decreases in TEC values. The minimum variation of about 11.76% in TEC values is observed at the station situating in about 20 percent eclipse cover zone, while it varies from 22% to 38% at the stations falling in about 60 percent eclipse cover zone. The highest variation in TEC values of about 44% is found at the stations in about 80 percent eclipse cover zone. The time of occurrence of maximum depletion in TEC values at each station is in line with their longitudinal sequence. Atmospheric gravity waves(AGWs) are also observed by performing wavelet analysis on TEC data. The global TEC maps visualize and confirm observed TEC variations, providing spatial and temporal insights into the ionospheric response. This analysis highlights the influence of station location and eclipse coverage on the magnitude and spatial distribution of TEC variations.

关键词： Solar eclipse Ionosphere GPS TEC AGW

Self-assembly of two pairs of homochiral M2L4 coordination capsules with varied confined space using Tr?ger's base ligands

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Chinese Chemical Letters 2025年第2期36卷 360-365页

作者： Yi Zhou Wei Zhang Rong Fu Jiaxin Dong Yuxuan Liu Zihang Song Han Han Kang Cai College of Chemistry Nankai University department of Chemistry Northwestern University department of Chemistry The University of Hong Kong

Chiral coordination molecular cages/capsules with discrete nanoconfined chiral cavities demonstrate significant potential applications across various fields. In this study, we utilized Tr?ger's base as the building block to design and synthesize two pairs of enantiopure ligands. These ligands were then self-assembled with Pd(II) ions through chiral self-sorting coordination, resulting in the formation of two pairs of homochiral M2L4-type coordination molecular capsules. Notably, due to differences in the substitution positions on the Tr?ger's base, these two pairs of enantiomeric coordination molecular capsules exhibited distinct levels of cavity closures, cavity sizes, and host-guest recognition properties. This research offers valuable insights into the construction of novel chiral molecular capsules and the regulation of confined cavities.

关键词： Chirality Host-guest recognition Metal-organic capsule Self-sorting Tröger's base

RGB Color-Discriminable Photonic Synapse for Neuromorphic Vision System

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Nano-Micro Letters 2025年第4期17卷 39-62页

作者： Bum Ho Jeong Jaewon Lee Miju Ku Jongmin Lee Dohyung Kim Seokhyun Ham Kyu-Tae Lee Young-Beom Kim Hui Joon Park department of Organic and Nano Engineering&Human-Tech Convergence Program Hanyang UniversitySeoul 04763Korea department of Semiconductor Engineering Hanyang UniversitySeoul 04763Korea department of Mechanical Engineering Hanyang UniversitySeoul 04763Korea department of Physics Inha UniversityIncheon 22212Korea

To emulate the functionality of the human retina and achieve a neuromorphic visual system,the development of a photonic synapse capable of multispectral color discrimination is of paramount ***,attaining robust color discrimination across a wide intensity range,even irrespective of medium limitations in the channel layer,poses a significant ***,we propose an approach that can bestow the color-discriminating synaptic functionality upon a three-terminal transistor flash memory even with enhanced discriminating *** incorporating the strong induced dipole moment effect at the excitation,modulated by the wavelength of the incident light,into the floating gate,we achieve outstanding RGB color-discriminating synaptic functionality within a remarkable intensity range spanning from 0.05 to 40 mW cm^(-2).This approach is not restricted to a specific medium in the channel layer,thereby enhancing its *** effectiveness of this color-discriminating synaptic functionality is demonstrated through visual pre-processing of a photonic synapse array,involving the differentiation of RGB channels and the enhancement of image contrast with noise ***,a convolutional neural network can achieve an impressive inference accuracy of over 94%for Canadian-Institute-For-Advanced-Research-10 colorful image recognition task after the *** proposed approach offers a promising solution for achieving robust and versatile RGB color discrimination in photonic synapses,enabling significant advancements in artificial visual systems.

关键词： Organic field-effect transistor Photonic synapse Excited-state dipole moment RGB color discrimination Neuromorphic visual system

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Effects of rare-earth Pr3+-Dy3+ doping on structural,magnetic,optical and dielectric properties of Zn2Y hexaferrite

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Journal of Rare Earths 2025年第2期43卷 329-336页

作者： Ibrahim Mohammed Mohamed E.El Sayed Ali Shawabkeh Mohammad N.Murshed Ibtehaj F.Alshdoukhi Zeinhom M.El-Bahy J.Mohammed A.K.Srivastava department of Physics Lovely Professional University department of Science Technology Waziri Umaru Federal Polytechnic Birnin Kebbi Physics department Faculty of Science and ArtsKing Khalid University College of Engineering and Technology American University of the Middle East department of Basic Sciences College of Science and Health ProfessionsKing Saud Bin Abdulaziz University for Health ScienceKing Abdullah International Medical Research Center department of Chemistry Faculty of ScienceAl-Azhar University department of Physics Faculty of ScienceFederal University Dutse

This study was conducted to investigate the properties of Pr3+-Dy3+doped Zn2Y-type hexaferrite for potential technological applications.X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR） and field-emission scanning electron microscopy（FESEM） were used to analyze structural *** crystallite size in the synthesized samples varies between 57.54 and 68.57 *** vibrational bands at 400 and 600 cm-1,common to all hexaferrites,were confirmed through *** FESEM analysis reveals an agglomeration of magnetic grains and a decrease in the average grain size from 1.24 to1.06 μ*** M-H loops show that,with x values of 0.0,0.1,and 0.2,the saturation magnetization is determined to be 34.76,34.23,and 32.52 emu/g,*** corresponding coercivity values are21.24,30.39,and 33.99 ***-visible spectroscopy using Tauc theory reveals an increase in the optical band gap from 2.32 to 2.50 eV,indicating a tunable energy band structure by incorporating Pr3+-Dy3+*** dielectric constant increases,whereas AC conductivity decreases with increased Pr3+-Dy3+*** obtained results suggest the potential suitability of these materials for various technological applications.

关键词： Dielectric constant Magnetic hysteresis Optical band gap Pr3+-Dy3+ Rare earths Zn2Y-type hexaferrite

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Evidence for active generation and seepage of sub-salt natural gas/condensate blend in the east offshore Nile Delta, Egypt: Integrated geochemical, petrophysical and seismic attribute approaches

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Petroleum Science 2025年第1期22卷 130-150页

作者： Mahmoud Leila Ahmed A.Radwan Amir Ismail Emad A.Eysa Geology department Faculty of Science Mansoura University School of Mining and Geosciences Nazarbayev University department of Geology Faculty of Science Al-Azhar UniversityAssiut Branch department of Geology Faculty of Science Helwan University department of Physical and Environmental Sciences Texas A&M University—Corpus Christi Geology department Faculty of Science Zagazig University

Offshore Nile Delta in Egypt represents an enormous hydrocarbon province with recent projected gas and condensate discoveries of more than 50 trillion cubic feet “TCF”. Most of these occur in the post-salt hydrocarbon plays where biogenic gases are dominant. This study integrates organic geochemistry,seismic geomorphology and petrophysics in order to decipher the origin, and accumulation conditions of the wet gas/condensate blend in the Upper Miocene sub-salt Wakar Formation sandstones in Port Fouad Marine “PFM” Field, offshore Nile Delta. Hydrocarbon pay zones are scattered thin（ 1 w.t.%, hydrogen index“HI” > 200 mg HC/g TOC） and mature(Tmax> 430°C, vitrinite reflectance “VR” > 0.6 %R_o), source rocks are restricted to Upper Miocene Wakar and Oligo-Miocene Tineh formations. The latter contains more mature organofacies（up to 1.2 %R_o） and type II/III kerogen, thereby demonstrating a good capability to generate wet gases. The studied gas is wet and has thermogenic origin with signs of secondary microbial alteration, whereas the condensate contains a mixture of marine and terrestrial input. Molecular biomarkers of the condensate, isotopic and molecular composition of the gas reveals a generation of condensate prior to gas expulsion from the source. The Wakar sandstones have a heterogeneous pore system where three reservoir rock types（RRTI, RRTII and RRTIII）. RRTI rocks present the bulk composition of the Wakar pay zones. Spatial distribution of RRTI facies likely control the accumulation of the sub-salt hydrocarbons. Our results provide a new evidence on an active petroleum system in the sub-salt Paleogene successions in the offshore Nile Delta where concomitant generation of ga

关键词： Petrophysical evaluation Source rock Hydrocarbon geochemistry Biomarkers Gas chimneys Rock-typing

Logic-in-memory cell enabling binary and ternary Boolean logics

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Science China(Information Sciences) 2025年第2期68卷 370-379页

作者： Jeongyun OH Juhee JEON Yunwoo SHIN Kyougah CHO Sangsig KIM department of Electrical Engineering Korea University

In computing systems, processing and memory units have been integrated into logic-in-memory(LiM) to enhance the computational efficiency and performance. LiM has been attempted to perform not only binary but also ternary logic functions, which reduces computing complexity. Herein, we demonstrate a binary and ternary LiM(BT-LiM) cell with eight triple-gated(TG) feedback field-effect transistors(FBFETs) reconfigured into n-or p-channel modes. The TG FBFETs exhibit symmetrical latch-up voltages and an on-current ratio of 1.02 between the n-and p-channel modes, which indicates a high potential for reconfigurable logic applications. The BT-LiM cell can perform YES, NOT, AND, OR, NAND, NOR, XNOR, and XOR logic functions in a single cell because of these reconfigurable characteristics. Further, binary and ternary logic functions are realized in the cell without a programming stage, and the cell maintains the results of the logic functions under zero-bias conditions. This study achieves multifunctional LiM that can operate all binary and ternary Boolean logics.

关键词： logic-in-memory reconfigurable channel modes ternary logic triple-gated feedback field-effect transistors

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Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheimer porous medium

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 193-208页

作者： K.MUHAMMAD M.SARFRAZ department of Humanities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology department of Mathematics Quaid-i-Azam University

This article presents a mathematical model addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate remains stationary, while the other moves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheimer porous medium. A mixture of water-based fluid with gold(Au) and silicon dioxide(Si O2) nanoparticles is formulated. In contrast to the conventional Fourier's heat flux equation, this study employs the Cattaneo-Christov heat flux equation. A uniform magnetic field is applied perpendicular to the flow direction, invoking magnetohydrodynamic(MHD) effects. Further, the model accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem is solved via NDSolve in MATHEMATICA. Numerical and statistical analyses are conducted to provide insights into the behavior of the nanomaterials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling systems and optimizing thermal management strategies. It is observed that the squeezing motion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed more vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less time in the region between the plates. The thermal relaxation, however, abruptly changes the temperature, leading to a decrease in the temperature fluctuations.

关键词： convective boundary condition Darcy-Forchheimer medium hybrid nanofluid Joule heating magnetohydrodynamic (MHD) numerical solution O175.2 O361 regression analysis squeezing flow

Disordered hyperuniformity and thermal transport in monolayer amorphous carbon

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Science China(Physics,Mechanics & Astronomy) 2025年第2期68卷 145-152页

作者： Nianjie Liang Yuxi Wang Bai Song department of Energy and Resources Engineering Peking UniversityBeijing 100871China department of Advanced Manufacturing and Robotics Peking UniversityBeijing 100871China

Disordered hyperuniformity(DHU)is a recently discovered novel state of amorphous systems characterized by strongly suppressed density fluctuations at large length scales as in crystalline materials,which offers great potential for achieving unusual mechanical,electronic,and photonic ***,despite the fundamental and technological importance of thermal transport in amorphous solids,the effect of DHU remains largely ***,we theoretically study thermal transport in a class of two-dimensional DHU materials—monolayer amorphous carbon(MAC).Beginning with a perfect graphene lattice,we continuously apply Stone-Wales transformations to generate a series of MAC models with varied degrees of disorder and defects,which are quantified through comprehensive structural analysis including the so-called hyperuniformity index(H),where a smaller H indicates a higher degree of ***,we conduct molecular dynamics simulations to obtain the thermal conductivity(κ).A significant correlation between the thermal transport behavior and degree of hyperuniformity is observed,with the room-temperatureκdecreasing from 26.3 to 5.3 W m^(-1)K^(-1)while H is tuned from 0.0004 to ***,two distinct transport regimes are identified,including a nearly-DHU regime at small H(<0.005)whereκdrops sharply and a non-DHU region at larger H whereκbecomes relatively ***-resolved analysis reveals longer lifetime and higher participation ratio for the heat carriers in nearly-DHU MAC,implying that the hidden long-range correlations could support extended modes that enhance *** work highlights the impact of DHU on the thermal properties of amorphous materials and represents a conceptual advancement that is worthy of future exploration.

关键词： disordered hyperuniformity thermal transport amorphous material two-dimensional monolayer amorphous carbon

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