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Science China(Information Sciences) 2025年

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.

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Tuning the interfacial reaction environment via pH-dependent and induced ions to understand C–N bonds coupling performance in NO3- integrated CO2 reduction to carbon and nitrogen compounds over dual Cu-based N-doped carbon catalyst

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Journal of Energy Chemistry 2025年第1期100卷 273-285页

作者： Tianhang zhou Chen Shen Zhenghao Wu Xingying Lan Yi Xiao College of Carbon Neutrality Future Technology State Key Laboratory of Heavy Oil Processing China University of Petroleum (Beijing) Institute of Materials Science TU Darmstadt Department of Chemistry Xi'an Jiaotong-Liverpool University Department of Mechanical and Mechatronics Engineering and Waterloo Institute of Nanotechnology University of Waterloo Waterloo

Dual atomic catalysts （DAC）,particularly copper （Cu2）-based nitrogen （N） doped graphene,show great potential to effectively convert CO2and nitrate （NO3-） into important industrial chemicals such as ethylene,glycol,acetamide,and urea through an efficient catalytical process that involves C–C and C–N ***,the origin of the coupling activity remained unclear,which substantially hinders the rational design of Cu-based catalysts for the N-integrated CO2reduction reaction （CO2RR）.To address this challenge,this work performed advanced density functional theory calculations incorporating explicit solvation based on a Cu2-based N-doped carbon (Cu2N6C10) catalyst for *** calculations are aimed to gain insight into the reaction mechanisms for the synthesis of ethylene,acetamide,and urea via coupling in the interfacial reaction *** to the sluggishness of CO2,the formation of a solvation electric layer by anions （F-,Cl-,Br-,and I-） and cations (Na+,Mg2+,K+,and Ca2+) leads to electron transfer towards the Cu *** process significantly accelerates the reduction of *** results reveal that*CO intermediates play a pivotal role in N-integrated ***,the Cu2-based N-doped carbon catalyst examined in this study has demonstrated the most potential for C–N coupling to *** findings reveal that through the process of a condensation reaction between*CO and NH2OH for urea synthesis,*NO3-is reduced to*NH3,and*CO2to*CCO at dual Cu atom *** dual-site reduction facilitates the synthesis of acetamide through a nucleophilic reaction between NH3and the ketene ***,we found that the I-and Mg2+ions,influenced by pH,were highly effective for acetamide and ammonia synthesis,except when F-and Ca2+were ***,the mechanisms of C–N bond formation were investigated via ab-initio molecular dynamics simulations,and we found that adjusting the micro-environment can change the dominant side reaction,shift

关键词： Condensation reactions

Design and Application of Turbine Cascade Partitioned Endwall Profiling

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Journal of Thermal Science 2025年第1期34卷 110-128页

作者： ZENG Fei JIANG Ruiqi XUE Xingxu DU Wei LUO Lei zhou Xun AECC Hunan Aviation Powerplant Research Institute School of Energy Science and Technology Harbin Institute of Technology Science and Technology on Diesel Engine Turbocharging Laboratory China North Engine Research Institute

The influence of partitioned profiling design based on a large-pitch highly loaded cascade is studied by numerical *** partitioned profile is mainly composed of a pressure-side convex structure near the leading edge and a suction-side convex structure at the midstream and downstream sides of the *** influence of the change in the vertex axial position and peak value of the B-line on the secondary flow control is *** this paper,air(ideal gas) is selected as the flow *** average static pressure at the outlet and the average total temperature at the inlet are kept *** γ-θ is used as the turbulence *** results show that the pressure-side convex structure suppresses the spanwise and pitchwise migration of the inlet flow by adjusting the static pressure distribution of the flow field,so the development of the pressure-side leg of the horseshoe vortex is effectively *** suction-side convex structure adjusts the static pressure distribution of the flow field and increases the included angle between the cross-flow and suction surface,so the accumulation of low-momentum fluid,the development of a corner vortex and the flow separation at the trailing edge of the suction-side surface are all suppressed near the endwall-suction ***,the energy loss coefficient of the large-pitch highly loaded cascade is decreased from 0.0564 to 0.0485,representing a 25% reduction in secondary flow losses.

关键词： Vortex flow

Efficient OpenMP Based Z-curve Encoding and Decoding Algorithms

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Computers, Materials & Continua 2025年第1期82卷 1313-1327页

作者： Zicheng zhou Shaowen Sun Teng Liang Mengjuan Li Fengling Xia School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China Faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming650500China School of Communications Information Engineering Yunnan Communications Vocational and Technical CollegeKunming650500China Library Yunnan Normal UniversityKunming650500China Faculty of Civil Aviation and Aeronautics Kunming University of Science and TechnologyKunming650500China

Z-curve’s encoding and decoding algorithms are primely important in many Z-curve-based *** bit interleaving algorithm is the current state-of-the-art algorithm for encoding and decoding *** simple,its efficiency is hindered by the step-by-step coordinate shifting and bitwise *** tackle this problem,we first propose the efficient encoding algorithm LTFe and the corresponding decoding algorithm LTFd,which adopt two optimization methods to boost the algorithm’s efficiency:1)we design efficient lookup tables(LT)that convert encoding and decoding operations into table-lookup operations;2)we design a bit detection mechanism that skips partial order of a coordinate or a Z-value with consecutive 0s in the front,avoiding unnecessary iterative *** propose order-parallel and point-parallel OpenMP-based algorithms to exploit the modern multi-core *** results on discrete,skewed,and real datasets indicate that our point-parallel algorithms can be up to 12.6×faster than the existing algorithms.

关键词： Z-curve lookup table OpenMP bit detection mechanism

Integration of Electrical Properties and Polarization Loss Modulation on Atomic Fe–N‑RGO for Boosting Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第2期17卷 517-532页

作者： Kaili Zhang Yuefeng Yan Zhen Wang Guansheng Ma Dechang Jia Xiaoxiao Huang Yu zhou State Key Laboratory of Precision Welding&Joining of Materials and Structures Harbin Institute of TechnologyHarbin 150001People’s Republic of China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001People’s Republic of China MIIT Key Laboratory of Advanced Structural‑Functional Integration Materials&Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001People’s Republic of China

Developing effective strategies to regulate graphene’s conduction loss and polarization has become a key to expanding its application in the electromagnetic wave absorption(EMWA)*** on the unique energy band structure of graphene,regulating its bandgap and electrical properties by introducing heteroatoms is considered a feasible ***,metal-nitrogen doping reduced graphene oxide(M–N-RGO)was prepared by embedding a series of single metal atoms M–N_(4) sites(M=Mn,Fe,Co,Ni,Cu,Zn,Nb,Cd,and Sn)in RGO using an N-coordination atom-assisted *** composites had adjustable conductivity and polarization to optimize dielectric loss and impedance matching for efficient EMWA *** results showed that the minimum reflection loss(RL_(min))of Fe–N-RGO reaches−74.05 dB(2.0 mm)and the maximum effective absorption bandwidth(EAB_(max))is 7.05 GHz(1.89 mm)even with a low filler loading of only 1 wt%.Combined with X-ray absorption spectra(XAFS),atomic force microscopy,and density functional theory calculation analysis,the Fe–N_(4) can be used as the polarization center to increase dipole polarization,interface polarization and defect-induced polarization due to d-p orbital hybridization and structural ***,electron migration within the Fe further leads to conduction loss,thereby synergistically promoting energy *** study demonstrates the effectiveness of metal-nitrogen doping in regulating the graphene′s dielectric properties,which provides an important basis for further investigation of the loss mechanism.

关键词： Electromagnetic wave absorption Fe-N-RGO Dipole polarization Conduction loss Impedance matching

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Co/Co_(7)Fe_(3)heterostructures with controllable alloying degree on carbon spheres as bifunctional electrocatalyst forrechargeable zinc-air batteries

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 476-487页

作者： Junkang Chen Yongyue Zhuang Yanxin Qiao Yu Zhang Aihua Yuan Hu zhou School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere(NCS)decorated with dual-phase Co/Co_(7)Fe_(3)heterojunctions(CoFe@NCS).The phase composition of materials has been adjusted by controlling the alloying *** optimal CoFe_(0.08)@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm^(-2)for OER in an alkaline *** intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co_(7)Fe_(3)alloy and metallic Co *** the CoFe_(0.08)@NCS material is used as air-cathode catalyst of rechargeable liquid-state zinc-air battery(ZAB),the device shows a high peak power-density(157 mW·cm^(-2))and maintains a stable voltage gap over 150 h,outperforming those of the benchmark(Pt/C+RuO_(2))-based *** particular,the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending *** work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.

关键词： bifunctional electrocatalysts oxygen reduction reaction oxygen evolution reaction zinc-air battery metal/alloy carbon sphere

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Detection using mask adaptive transformers in unmanned aerial vehicle imagery

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Optoelectronics Letters 2025年第2期21卷 113-120页

作者： YE Huibiao FAN Weiming GUO Yuping WANG Xuna zhou Dalin China Telecommunication Corporation Zhejiang Branch Innovation Center for Smart Medical Technologies & Devices Binjiang Institute of Zhejiang University School of Computing University of Portsmouth

Drone photography is an essential building block of intelligent transportation,enabling wide-ranging monitoring,precise positioning,and rapid ***,the high computational cost of transformer-based methods in object detection tasks hinders real-time result transmission in drone target detection ***,we propose mask adaptive transformer (MAT) tailored for such ***,we introduce a structure that supports collaborative token sparsification in support windows,enhancing fault tolerance and reducing computational *** structure comprises two modules:a binary mask strategy and adaptive window self-attention (A-WSA).The binary mask strategy focuses on significant objects in various complex *** A-WSA mechanism is employed to self-attend for balance perfomance and computational cost to select objects and isolate all contextual *** experiments on the challenging CarPK and VisDrone datasets demonstrate the effectiveness and superiority of the proposed ***,it achieves a mean average precision (mAP@0.5) improvement of 1.25%over car detector based on you only look once version 5 (CD-YOLOv5) on the CarPK dataset and a 3.75%average precision(AP@0.5) improvement over cascaded zoom-in detector (CZ Det) on the VisDrone dataset.

关键词： Drones

Simulations of electron zebra stripes in the inner radiation belt using a composite empirical electric field model

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Science China Earth Sciences 2025年第1期68卷 27-38页

作者： Ziyang WANG Ying LIU Qiugang ZONG Hong ZOU Yuguang YE Xuzhi zhou Chao YUE Shan WANG Institute of Space Physics and Applied Technology Peking University State Key Laboratory of Lunar and Planetary Science Macau University of Science and Technology

The phenomenon termed “zebra stripes” manifests as regular patterns in the energy-space(L shell) spectrum of energetic electrons(ranging from tens to hundreds ke V) within the inner radiation belt. These structures exhibit drift-periodic behavior and commonly arise from large-scale electric field perturbations near the substorm onsets. In this study, we introduce a composite electric field model and replicate the formation, structure, and evolution of zebra stripes using a bounce-averaged test particle code under this electric field model. High-resolution measurements of energetic electrons obtained from the Van Allen Probes and the recently launched Macao Science Satellites-1 are used as initial conditions and served to validate our test particle simulations. Comparative analyses between observed data and simulations demonstrate our test particle method's efficacy in capturing zebra stripes' general behavior. Moreover, the composite model proves capable of reproducing realistic variations in the electric field within the inner radiation belt to a certain extent. Nevertheless, subtle differences emerge in the flux strength and the positions of stripes. These disparities primarily stem from limitations inherent in the electric field model and the initial conditions of the simulation. Acknowledging that the model represents an average case, it is conceivable that real-world scenarios may deviate from the average, thereby introducing variations in the observed phenomena.

关键词： Zebra stripes Inner radiation belt Large-scale electric fields Van Allen Probes Macao Science Satellite

Synergistically S/N self-doped biochar as a green bifunctional cathode catalyst in electrochemical degradation of organic pollutant

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Green Energy & Environment 2025年第1期10卷 214-230页

作者： Xuechun Wang Huizhong Wu Jiana Jing Ge Song Xuyang Zhang Minghua zhou Raf Dewil Key Laboratory of Pollution Process and Environmental Criteria Ministry of EducationCollege of Environmental Science and EngineeringNankai UniversityTianjin300350China Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution Nankai UniversityTianjin300350China Tianjin Advanced Water Treatment Technology International Joint Research Center College of Environmental Science and EngineeringNankai UniversityTianjin300350China Department of Chemical Engineering KU LeuvenJ.De Nayerlaan 5Sint-Katelijne-Waver B2860Belgium

Biomass-derived heteroatom self-doped cathode catalysts has attracted considerable interest for electrochemical advanced oxidation processes(EAOPs)due to its high performance and sustainable ***,we illustrated the morphological fates of waste leaf-derived graphitic carbon(WLGC)produced from waste ginkgo leaves via pyrolysis temperature regulation and used as bifunctional cathode catalyst for simultaneous H_(2)O_(2) electrochemical generation and organic pollutant degradation,discovering S/N-self-doping shown to facilitate a synergistic effect on reactive oxygen species(ROS)*** the optimum temperature of 800℃,the WLGC exhibited a H_(2)O_(2) selectivity of 94.2%and tetracycline removal of 99.3%within 60 *** functional theory calculations and in-situ Fourier transformed infrared spectroscopy verified that graphitic N was the critical site for H_(2)O_(2) *** pyridinic N and thiophene S were the main active sites responsible for_OH generation,N vacancies were the active sites to produce ^(1)O_(2) from *** performance of the novel cathode for tetracycline degradation remains well under a wide pH range(3–11),maintaining excellent stability in 10 *** is also industrially applicable,achieving satisfactory performance treating in real water *** system facilitates both radical and non-radical degradation,offering valuable advances in the preparation of cost-effective and sustainable electrocatalysts and hold strong potentials in metal-free EAOPs for organic pollutant degradation.

关键词： Biochar S and N self-doping H_(2)O_(2)production In-situ FTIR Metal-free electrochemical advanced oxidation processes

AZD1775 synergizes with SLC7A11 inhibition to promote ferroptosis

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Science China Life Sciences 2025年第1期68卷 204-218页

作者： Chen Xiong Hong Ling Yingdan Huang Hanzhi Dong Bangxiang Xie Qian Hao Xiang zhou Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences Fudan University Department of Oncology Shanghai Medical CollegeFudan University Department of Breast Surgery Fudan University Shanghai Cancer CenterFudan University Department of Oncology First Affiliated Hospital of Nanchang University Beijing Institute of Hepatology Beijing Youan HospitalCapital Medical University Beijing Engineering Research Center for Precision Medicine and Transformation of Hepatitis and Liver Cancer Key Laboratory of Breast Cancer in Shanghai Fudan University Shanghai Cancer CenterFudan University Shanghai Key Laboratory of Medical Epigenetics International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology)Institutes of Biomedical SciencesFudan University

Tumor suppressor p53-mediated cell cycle arrest and DNA damage repair may exert cytoprotective effects against cancer therapies, including WEE1 inhibition. Considering that p53 activation can also lead to multiple types of cell death, the role of this tumor suppressor in WEE1 inhibitor-based therapies remains disputed. In this study, we reported that nucleolar stress-mediated p53 activation enhanced the WEE1 inhibitor AZD1775-induced ferroptosis to suppress lung cancer growth. Our findings showed that AZD1775 promoted ferroptosis by blocking cystine uptake, an action similar to that of Erastin. Meanwhile, inhibition of WEE1 by the WEE1 inhibitors or si RNAs induced compensatory upregulation of SLC7A11, which conferred resistance to ferroptosis. Mechanistically, AZD1775 prevented the enrichment of H3K9me3, a histone marker of transcriptional repression, on the SLC7A11 promoter by repressing the expression of the histone methyltransferase SETDB1, thereby enhancing NRF2-mediated SLC7A11 transcription. This finding was also validated using the H3K9me3 inhibitor BRD4770. Remarkably, we found that the nucleolar stress-inducing agent Actinomycin D(Act. D) inhibited SLC7A11 expression by activating p53, thus augmenting AZD1775-induced ferroptosis. Moreover, the combination of AZD1775 and Act. D synergistically suppressed wild-type p53-harboring lung cancer cell growth both in vitro and in vivo. Altogether, our study demonstrates that AZD1775 promotes ferroptosis by targeting cystine uptake but also mediates the adaptive activation of SLC7A11 through the WEE1-SETDB1 cascade and NRF2-induced transcription, and inhibition of SLC7A11 by Act. D boosts the anti-tumor efficacy of AZD1775 by enhancing ferroptosis in cancers with wild-type p53.

关键词： p53 NRF2 SLC7A11 WEE1 AZD1775 ferroptosis nucleolar stress