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A new method for evaluating wedges of steel plates and strips

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Journal of Iron and Steel Research International 2024年第7期31卷 1719-1735页

作者： Xiao-bao Ma Xiao-xin Ma Tao Wang Zhong-kai ren Yu-cheng ren College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina Ministry of Education Engineering Research Center of Advanced Metal Composite Forming Technology and Equipment Taiyuan University of TechnologyTaiyuan 030024ShanxiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment Taiyuan University of TechnologyTaiyuan 030024ShanxiChina China National Heavy Machinery Research Institute Co. Ltd.Xi'an 710018ShaanxiChina Faculty of Mechanical Engineering Hebei University of ArchitectureZhangjiakou 075000HebeiChina

To overcome the inaccuracy problem of the traditional wedge evaluation of steel plates and strips caused by the ran-domness of the thicknesses of two local points and improve the reliability of the wedge index,the double-centroid method for the wedge evaluation was proposed,and a model based on the centroid theory was ***,an integral model for the discrete thickness values of the cross-section profiles was *** discussion focused on the distinct characteristics of the two-point method,asymmetric method,and double-centroid method in evaluating the asymmetric distribution of *** three methods were employed to evaluate the wedge values of both the theoretical and measured cross-sections of steel plates and strips,and the accuracies of three wedge evaluation models were analyzed and *** results showed that the double-centroid method objectively reflects the degree and variation characteristics of the wedge values of the cross-sections of steel plates and strips,and this method is feasible,reliable,and outstanding.

关键词： Steel plate and strip Wedge Two-point method Double-centroid method Reliability

A Feature Selection Method Based on Hybrid Dung Beetle Optimization Algorithm and Slap Swarm Algorithm

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Computers, Materials & Continua 2024年第8期80卷 2979-3000页

作者： Wei Liu Tengteng ren School of Information Science and Engineering Shenyang Ligong UniversityShenyang110158China

Feature Selection(FS)is a key pre-processing step in pattern recognition and data mining tasks,which can effectively avoid the impact of irrelevant and redundant features on the performance of classification *** recent years,meta-heuristic algorithms have been widely used in FS problems,so a Hybrid Binary Chaotic Salp Swarm Dung Beetle Optimization(HBCSSDBO)algorithm is proposed in this paper to improve the effect of *** this hybrid algorithm,the original continuous optimization algorithm is converted into binary form by the S-type transfer function and applied to the FS *** combining the K nearest neighbor(KNN)classifier,the comparative experiments for FS are carried out between the proposed method and four advanced meta-heuristic algorithms on 16 UCI(University of California,Irvine)*** evaluation metrics such as average adaptation,average prediction accuracy,and average running time are chosen to judge and compare the *** selected dataset is also discussed by categorizing it into three dimensions:high,medium,and low *** results show that the HBCSSDBO feature selection method has the ability to obtain a good subset of features while maintaining high classification accuracy,shows better optimization *** addition,the results of statistical tests confirm the significant validity of the method.

关键词： Feature selection dung beetle optimization KNN transfer function HBCSSDBO

Event-triggered H_(∞) consensus control for input-constrained multi-agent systems via reinforcement learning

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Control Theory and Technology 2024年第1期22卷 25-38页

作者： Jinxuan Zhang Chang-E ren College of Information Engineering Capital Normal UniversityBeijing100089China

This article presents an event-triggered H_(∞) consensus control scheme using reinforcement learning (RL) for nonlinear second-order multi-agent systems (MASs) with control constraints. First, considering control constraints, the constrained H_(∞) consensus problem is transformed into a multi-player zero-sum game with non-quadratic performance functions. Then, an event-triggered control method is presented to conserve communication resources and a new triggering condition is developed for each agent to make the triggering threshold independent of the disturbance attenuation level. To derive the optimal controller that can minimize the cost function in the case of worst disturbance, a constrained Hamilton–Jacobi–Bellman (HJB) equation is defined. Since it is difficult to solve analytically due to its strongly non-linearity, reinforcement learning (RL) is implemented to obtain the optimal controller. In specific, the optimal performance function and the worst-case disturbance are approximated by a time-triggered critic network;meanwhile, the optimal controller is approximated by event-triggered actor network. After that, Lyapunov analysis is utilized to prove the uniformly ultimately bounded (UUB) stability of the system and that the network weight errors are UUB. Finally, a simulation example is utilized to demonstrate the effectiveness of the control strategy provided.

关键词： H_(∞)optimal control Input constrains Multi-agent systems(MASs) Reinforcement learning(RL)

Polyelectrolyte Complexes and Coacervates Formed by De novo-Designed Peptides and Oligonucleotide

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Chinese Journal of Polymer Science 2024年第9期42卷 1333-1340,I0007页

作者： Tian-Hao ren De-Hai Liang Beijing National Laboratory for Molecular Sciences Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

The liquid-liquid phase separation of biopolymers in living cells contains multiple interactions and occurs in a dynamic *** the regulation mechanism is still a *** this work,we designed a series of peptides(XXLY)_(6)SSSGSS and studied their complexation and coacervation behavior with single-stranded ***“X”and“Y”are varied to combine known amounts of charged and non-charged amino acids,together with the introduction of secondary structures and pH *** show that the electrostatic interaction,which is described as charge density,controls both the strength of complexation and the degree of chain relaxation,and thus determines the growth and size of the *** hydrophobic interaction is prominent when the charges are ***,the secondary structures of peptides exhibit profound effect on the morphology of the phases,such as solid phase to liquid phase *** study gains insight into the phase separation under physiological *** is also helpful to create coacervates with desirable structures and functions.

关键词： Polyelectrolyte complex Coacervate Peptides Secondary structure Electrostatic interaction

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Finite-size-induced non-Hermitian phase transitions in real space

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 105-111页

作者： Hongfei Wang Biye Xie Wei ren Department of Physics International Center for Quantum and Molecular StructuresShanghai UniversityShanghai 200444China School of Science and Engineering The Chinese University of Hong KongShenzhen 518172China

While non-Hermiticity provokes intriguing phenomena without Hermitian counterparts, e.g., the skin effect and the breakdown of bulk-boundary correspondence, attracting extensive attention both in fundamental physics and device engineering, the role of finite sizes therein remains elusive. Here, we propose a class of finite-size-induced non-Hermitian phase transitions, relying upon higher-order topological invariants associated with real-space wave functions. The phase diagrams for general non-Hermitian chiral models are further acquired to demonstrate our topological definition. Such phase transitions are elucidated qualitatively by an effective intercell coupling alteration that depends on finite sizes in respective directions. Besides, we mimic these phenomena by analogizing the circuit Laplacian in finite-size electric circuits with nonreciprocal couplings. The resultant admittance spectra agree with our theoretical predictions. Our findings shed light on the finite-size mechanism of non-Hermitian topological phase transitions and pave the way for applications in switching and sensing.

关键词： non-Hermitian phase transitions finite-size effects higher-order topological invariants

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Recent progress in single crystal perovskite X-ray detectors

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Science China(Information Sciences) 2024年第3期67卷 5-19页

作者： Xiao LIU Jun ren Yu-Ang CHEN Xiangshun GENG Dan XIE Tian-Ling ren School of Integrated Circuits Tsinghua University Beijing National Research Center for Information Science and Technology (BNRist)

Perovskites have attracted extensive attention as radiation detection material due to their long carrier diffusion length and lifetime, high absorption coefficient, and flexible manufacturing process. Compared with polycrystalline structures, single crystal perovskites improve the performance of optoelectronic devices due to their low defect state density, better photoelectric characteristics, and chemical ***, we review the recent progress of single crystal perovskite X-ray detectors. First, we briefly introduced the basic concepts, detection mechanisms, figure of merits of perovskite X-ray detectors, and the preparation methods of single crystal perovskites. Then, we summarized the significant advancements in single crystal perovskite X-ray detectors in recent times. Finally, we discussed the critical challenges and some practicable solutions for developing high-performance X-ray detectors.

关键词： single crystal perovskites carrier transport radiation detection X-ray detectors X-ray imaging

Boundary-lubricated biomaterials with drug delivery for osteoarthritis treatment

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Friction 2024年第10期12卷 2167-2187页

作者： Junyu WU Kaixuan ren Jingbo YIN Department of Polymer Materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

The good lubrication ability of articular cartilage holds significant importance in our daily ***(OA),the most prevalent degenerative joint disease,causes cartilage damage,increased friction,and ***,the current clinical treatments for OA exhibit some ***,the sustained drug release systems with lubricating function have attracted considerable attention for treating *** review introduces the lubrication mechanism of cartilage,focusing particularly on the boundary lubrication *** research progress of boundary-lubricated biomaterials with drug delivery,including microcarriers,hydrogels,and nanoparticles in the treatment of OA by improving inter-articular lubrication and relieving inflammation is discussed and *** efficacy and challenges of boundary-lubricated biomaterials with drug delivery in the treatment of OA are summarized,and the prospects are also discussed.

关键词： osteoarthritis joint friction boundary lubrication hydration lubrication drug delivery

An effective bimetallic oxide catalyst of RuO_(2)-Co_(3)O_(4) for alkaline overall water splitting

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Nano Research 2024年第5期17卷 3785-3793页

作者： Fangfang ren Jiayu Xu Ligang Feng College of Chemical and Environmental Engineering Yancheng Teachers UniversityYancheng 224007China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

The rational design of effective bifunctional electrocatalysts is of paramount importance for overall water-splitting technology in sustainable energy ***,bimetallic oxide catalysts(RuO_(2)-Co_(3)O_(4))derived from Ru combined MOF-derivatives(MOF=metal-organic framework)were demonstrated effective for overall water splitting in an alkaline solution,owing to the combined merits such as the two-dimensional interconnected network structure,the synergetic coupling effects and increased chemical *** as-prepared RuO_(2)-Co_(3)O_(4) only requires an overpotential of 260 mV for oxygen evolution and 75 mV for hydrogen evolution at 10 mA/cm^(2) in 1 M KOH solution;a low cell voltage of 1.54 V was required to reach the kinetic current density of 10 mA/cm^(2) for the water electrolysis when supporting on glass carbon electrode,and very good stability for 40 h was *** and theoretical results demonstrated the electronic structure optimization of bimetallic RuO_(2)-Co_(3)O_(4) compared to the individual metal oxide,which promoted interface charges redistribution and the d-band center downshift,resulting in increased activity and stability for water-splitting *** work provides a feasible approach for developing bimetallic oxides for application in energy-relevant electrocatalysis reactions.

关键词： ruthenium dioxide cobalt oxide metal-organic frameworks heterostructures overall water splitting

Supercoiled DNA Minicircles under Double-strand Breaks

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Chinese Journal of Polymer Science 2024年第9期42卷 1353-1359,I0007页

作者： Ye-Peng Qiao Chun-Lai ren National Laboratory of Solid State Microstructures and Department of Physics Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210093China

Understanding how supercoiled DNA releases intramolecular stress is essential for its functional ***,the molecular mechanism underlying the relaxation process remains insufficiently *** we employed MD simulations based on the oxDNA2 model to investigate the relaxation process of a 336-base pair supercoiled minicircular DNA under double-strand breaks with two fixed *** simulations show that the conformational changes in the DNA occur continuously,with intramolecular stress release happening abruptly only when the DNA chain traverses the breakage *** relaxation process is influenced not only by the separation distance between the fixed ends but also their ***,we observe an inhibitory effect on the relaxation characterized by small angles,where short terminal loops impede DNA conformational adjustments,preserving the supercoiled *** findings elucidate the intricate interplay between DNA conformational change,DNA motion and intramolecular stress release,shedding light on the mechanisms governing the relaxation of supercoiled DNA at the molecular level.

关键词： Supercoiled DNA DNA minicircle DNA relaxation oxDNA model MD simulation

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