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Detecting the core of a network by the centralities of the nodes

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Chinese Physics B 2024年第8期33卷 615-621页

作者：马佩杰任学藻朱军芳蒋艳群 school of Mathematics and science Southwest University of Science and TechnologyMianyang 621010China

Many networks exhibit the core/periphery ***/periphery structure is a type of meso-scale structure that consists of densely connected core nodes and sparsely connected peripheral *** nodes tend to be well-connected,both among themselves and to peripheral nodes,which tend not to be well-connected to other *** this brief report,we propose a new method to detect the core of a network by the centrality of each *** is discovered that such nodes with non-negative centralities often consist in the core of the *** simulation is carried out on different real *** results are checked by the objective *** checked results may show the effectiveness of the simulation results by the centralities of the nodes on the real ***,we discuss the characters of networks with the single core/periphery structure and point out the scope of the application of our method at the end of this paper.

关键词： complex network core/periphery structure the objective function

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Conductive catalysis by subsurface transition metals

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National science Review 2024年第1期11卷 86-93页

作者： Xin Deng Caiyan Zheng Yangsheng Li Zeyu Zhou Jiamin Wang Yihua Ran Zhenpeng Hu Fan Yang Landong Li Frontiers science Center for New Organic Matter College of ChemistryNankai University school of Physics Nankai University school of Physical science and Technology Shanghai Tech University school of Materials science and Engineering Nankai University Haihe Laboratory of Sustainable Chemical Transformations

The nature of catalysis has been hotly pursued for over a century, and current research is focused on understanding active centers and their electronic structures. Herein, the concept of conductive catalysis is proposed and verified by theoretical simulations and experimental observations. Metallic systems containing buried catalytically active transitional metals and exposed catalytically inert main group metals are constructed, and the electronic interaction between them via metallic bonding is disclosed. Through the electronic interaction, the catalytic properties of subsurface transitional metals(Pd or Rh) can be transferred to outermost main group metals(Al or Mg) for several important transformations like semi-hydrogenation,Suzuki-coupling and hydroformylation. The catalytic force is conductive, in analogy with the magnetic force and electrostatic force. The traditional definition of active centers is challenged by the concept of conductive catalysis and the electronic nature of catalysis is more easily understood. It might provide new opportunities for shielding traditional active centers against poisoning or leaching and allow for precise regulation of their catalytic properties by the conductive layer.

关键词： electronic interaction conductive catalysis subsurface transition metal

Adaptive neural network control of a 2-DOF helicopter system considering input constraints and global prescribed performance

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science China(Information sciences) 2024年第7期67卷 224-239页

作者： Zhijia ZHAO Jiale WU Zhijie LIU We HE C.L.Philip CHEN school of Mechanical and Electrical Engineering Guangzhou University school of Intelligence science and Technology and Key Laboratory of Intelligent Bionic Unmanned Systems of Ministry of Education University of Science and Technology Beijing school of Computer science and Engineering South China University of Technology Pazhou Lab

In this study, an adaptive neural network(NN) control is proposed for nonlinear two-degree-offreedom(2-DOF) helicopter systems considering the input constraints and global prescribed ***, radial basis function NN(RBFNN) is employed to estimate the unknown dynamics of the helicopter system. Second, a smooth nonaffine function is exploited to approximate and address nonlinear constraint functions. Subsequently, a new prescribed function is proposed, and an original constrained error is transformed into an equivalent unconstrained error using the error transformation and barrier function transformation methods. The analysis of the established Lyapunov function proves that the controlled system is globally uniformly bounded. Finally, the simulation and experimental results on a constructed Quanser's test platform verify the rationality and feasibility of the proposed control.

关键词： adaptive NN control 2-DOF helicopter global prescribed performance input constraints

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YOLOv5ST:A Lightweight and Fast Scene Text Detector

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Computers, Materials & Continua 2024年第4期79卷 909-926页

作者： Yiwei Liu Yingnan Zhao Yi Chen Zheng Hu Min Xia school of Computer and science Nanjing University of Information Science and TechnologyNanjing210044China school of Automation Nanjing University of Information Science and TechnologyNanjing210044China

Scene text detection is an important task in computer *** this paper,we present YOLOv5 Scene Text(YOLOv5ST),an optimized architecture based on YOLOv5 v6.0 tailored for fast scene text *** primary goal is to enhance inference speed without sacrificing significant detection accuracy,thereby enabling robust performance on resource-constrained devices like drones,closed-circuit television cameras,and other embedded *** achieve this,we propose key modifications to the network architecture to lighten the original backbone and improve feature aggregation,including replacing standard convolution with depth-wise convolution,adopting the C2 sequence module in place of C3,employing Spatial Pyramid Pooling Global(SPPG)instead of Spatial Pyramid Pooling Fast(SPPF)and integrating Bi-directional Feature Pyramid Network(BiFPN)into the *** results demonstrate a remarkable 26%improvement in inference speed compared to the baseline,with only marginal reductions of 1.6%and 4.2%in mean average precision(mAP)at the intersection over union(IoU)thresholds of 0.5 and 0.5:0.95,*** work represents a significant advancement in scene text detection,striking a balance between speed and accuracy,making it well-suited for performance-constrained environments.

关键词： Scene text detection YOLOv5 lightweight object detection

Formal Verification of Data Modifications in Cloud Block Storage Based on Separation Logic

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Chinese Journal of Electronics 2024年第1期33卷 112-127页

作者： Bowen ZHANG Zhao JIN Hanpin WANG Yongzhi CAO Key Laboratory of High Confidence Software Technologies (MOE) School of Computer Science Peking University school of Computer and Artificial Intelligence Zhengzhou University school of Computer science and Cyber Engineering Guangzhou University

Cloud storage is now widely used, but its reliability has always been a major concern. Cloud block storage(CBS) is a famous type of cloud storage. It has the closest architecture to the underlying storage and can provide interfaces for other types. Data modifications in CBS have potential risks such as null reference or data *** verification of these operations can improve the reliability of CBS to some extent. Although separation logic is a mainstream approach to verifying program correctness, the complex architecture of CBS creates some challenges for verifications. This paper develops a proof system based on separation logic for verifying the CBS data modifications. The proof system can represent the CBS architecture, describe the properties of the CBS system state, and specify the behavior of CBS data modifications. Using the interactive verification approach from Coq, the proof system is implemented as a verification tool. With this tool, the paper builds machine-checked proofs for the functional correctness of CBS data modifications. This work can thus analyze the reliability of cloud storage from a formal perspective.

关键词： Cloud computing Behavioral sciences Reliability Formal verification

Heterogeneous engineering of MnSe@NC@ReS2 core-shell nanowires for advanced sodium-/potassium-ion batteries

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Rare Metals 2024年第8期43卷 3713-3723页

作者： Sheng-Jun Lu Jin-Yi Lin Cai-Hong Wang Yu-Fei Zhang Yi Zhang Hao-Sen Fan College of Materials science and Metallurgy Engineering Guizhou University school of Energy science and Engineering Nanjing Tech University school of Chemistry and Chemical Engineering Guangzhou University

Sodium-ion batteries（SIBs） and potassium-ion batteries（PIBs） have been attracting great attentions and widely been exploited due to the abundant sodium/potassium ***,the preparation of high-powered anode materials for SIBs/PIBs plays a decisive role for the commercial applications of SIBs/PIBs in the *** selenides are a class of potential anode materials for SIBs/PIBs because of their small band gap and high electrical *** this work,MnSe and ReS2core-shell nanowires connecting by polydopamine derived carbon nanotube（MnSe@NC@ReS2） have been successfully synthesized from growing ReS2nanosheets array on the surface of MnSe@NC nano wires,which present excellent Na+/K+storage *** applied as SIBs anode,the specific capacity of 300 mAh·g-1was maintwined after 400 cycles at the current density of 1.0 A·***,it could also keep 120 mAh·g-1specific capacity after 900 cycles at 1.0 A·g-1for the anode of *** heterogeneous engineering and one-dimensional-two-dimensional（1D-2D） hybrid strategies could provide an ideal strategy for the synthesis of new hetero-structured anode materials with outstanding battery performance for SIBs and PIBs.

关键词： Heterogeneous engineering Core–shell nanowires MnSe@NC@ReS 2 nanowires Na + batteries K + batteries

Achieving high-efficient photocatalytic persulfate-activated degradation of tetracycline via carbon dots modified MIL-101(Fe)octahedrons

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Chinese Journal of Chemical Engineering 2024年第2期66卷 298-309页

作者： Hao Yuan Xinhai Sun Shuai Zhang Weilong Shi Feng Guo school of Material science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China school of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212003China

The synergistic reaction of photocatalysis and advanced oxidation is a valid strategy for the degradation of harmful antibiotic ***,carbon dots(CDs)modified MIL-101(Fe)octahedrons to form CDs/MIL-101(Fe)composite photocatalyst was synthesized for visible light-driven photocatalytic/persulfate(PS)-activated tetracycline(TC)*** electron spin resonance(ESR)spectra,scavenging experiment and electrochemical analysis were carried out to reveal that the high visible light-driven photocatalytic degradation activity of TC over CDs/MIL-101(Fe)photocatalysts is not only ascribed to the production of free active radicals in the CDs/MIL-101(Fe)/PS system(·OH,·SO_(4-),^(1)O_(2),h^(+)and·O_(2)^(-))but also attributed to the consumption of electrons caused by the PS,which can suppress the recombination of photo-generated carriers as well as strong light scattering and electron trapping effects of ***,the possible degradation pathways were proposed by analyzing intermediates via liquid chromatography-mass spectrometry *** research presents a rational design conception to construct a CDs/PS-based photocatalysis/advanced oxidation technology with high-efficient degradation activity for the remediation of organic antibiotic pollutant wastewater and for the improvement of carrier transport kinetics of photocatalysts.

关键词： Carbon dots MIL-101(Fe) Photocatalytic Persulfate activation Tetracycline degradation

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A N-CoSe/CoSe2-C@Cu hierarchical architecture as a current collector-integrated anode for potassium-ion batteries

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Rare Metals 2024年第8期43卷 3702-3712页

作者： Zi-Jie Mu Yan-Jun Gao Wen-Shuai Dong Zong-You Li Qing-Yi Song Han-Jiao Huang Li-Dong Xing Jian-Guo Zhang Wei Wang Qi-Yao Yu State Key Laboratory of Explosion science and Technology School of Mechatronical EngineeringBeijing Institute of Technology school of Metallurgical and Ecological Engineering University of Science and Technology Beijing

The highly reversible insertion/extraction of large-radius K+into electrode materials remains a tough goal,especially for con version-type ***,we design a current collector-integrated electrode（N-CoSe/CoSe2-C@Cu） as an advanced anode for potassium-ion battery（PIBs）.The conductive CoSe/CoSe2heterojunction with rich Se vacancy defects,conductive sp2N-doped carbon layer,and the elastic copper foil matrix can greatly accelerate the electron transfer and enhance the structural ***,the well-designed N-CoSe/CoSe2-C@Cu current collector-integrated electrode displays enhanced potassium storage performance with regard to a high capacity(325.1 mAh·g-1at 0.1 A·g-1after 200cycles),an exceptional rate capability(223.5 mAh·g-1at2000 mA·g-1),and an extraordinary long-term cycle stability(a capacity fading of only 0.019% per cycle over1200 cycles at 2000 mA·g-1).Impressively,ex situ scanning electron microscopy（SEM） characterizations prove that the elastic structure of copper foil is merged into the cleverly designed N-CoSe/CoSe2-C@Cu heterostructure,which buffers the deformation of structure and volume and greatly promotes the cycle life during the potassium/depotassium process.

关键词： Potassium-ion battery Integrated collector electrode CoSe CoSe 2 Heterojunction Copper foil matrix N-doped carbon

Dynamical switchable quantum nonreciprocity induced by off-resonant chiral two-photon driving

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science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 31-37页

作者： Da-Wei Liu Zi-Hao Li Shi-Lei Chao Ying Wu Liu-Gang Si school of Physics and Institute for Quantum science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

Optical nonreciprocity,which refers to the direction-dependent emission,scattering and absorption of photons,plays a very important role in quantum engineering and quantum information ***,we propose an all-optical approach to achieve the optical dynamical switchable quantum nonreciprocity by an off-resonant chiral two-photon driving in a single microring cavity,which differs from the conventional nonreciprocal *** is shown that the optical field with time-dependent statistical properties can be generated and the nonreciprocity flips periodically,with switchable photon blockade and photon-induced tunneling *** find that the dynamical system is robust and immune to the parameter variations,which loosens the parameter range of ***,the time window for one-way quantum information is sufficiently wide and *** work opens a new idea for the current quantum nonreciprocal research,which can facilitate a memory functionality and be used for future inmemory superconducting quantum *** other nonreciprocal quantum devices,i.e.,dynamical switchable nonreciprocal squeezing and entanglement,may be inspired by our method,which is expected to have important applications in future quantum technology.

关键词： dynamical switchable nonreciprocity single-photon source chiral two-photon driving

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