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Control method based on DRFNN sliding mode for multifunctional flexible multistate switch

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Global Energy Interconnection 2024年第2期7卷 190-205页

作者： Jianghua Liao wei Gao yan yang Gengjie yang College of Electrical Engineering and Automation Fuzhou UniversityFuzhou 350108P.R.China Faculty of Automation Huaiyin Institute of Technology Huai’an 223003P.R.China

To address the low accuracy and stability when applying classical control theory in distribution networks with distributed generation,a control method involving flexible multistate switches(FMSs)is proposed in this *** approach is based on an improved double-loop recursive fuzzy neural network(DRFNN)sliding mode,which is intended to stably achieve multiterminal power interaction and adaptive arc suppression for single-phase ground ***,an improved DRFNN sliding mode control(SMC)method is proposed to overcome the chattering and transient overshoot inherent in the classical SMC and reduce the reliance on a precise mathematical model of the control *** improve the robustness of the system,an adaptive parameter-adjustment strategy for the DRFNN is designed,where its dynamic mapping capabilities are leveraged to improve the transient compensation ***,a quasi-continuous second-order sliding mode controller with a calculus-driven sliding mode surface is developed to improve the current monitoring accuracy and enhance the system *** stability of the proposed method and the convergence of the network parameters are verified using the Lyapunov theorem.A simulation model of the three-port FMS with its control system is constructed in MATLAB/*** simulation result confirms the feasibility and effectiveness of the proposed control strategy based on a comparative analysis.

关键词： Distribution networks Flexible multistate switch Grounding fault arc suppression Double-loop recursive fuzzy neural network Quasi-continuous second-order sliding mode

Adhesion strength of tetrahydrofuran hydrates is dictated by substrate stiffness

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Petroleum Science 2024年第1期21卷 667-673页

作者： yan-Wen Lin Tong Li Yi Zhang wei-wei yan Xiao-Ming Chen Zhi-Sen Zhang Jian-yang Wu Department of Physics Research Institute for Biomimetics and Soft MatterJiujiang Research Institute and Fujian Provincial Key Laboratory for Soft Functional Materials ResearchXiamen UniversityXiamen361005FujianChina Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201ZhejiangChina Key Laboratory of Icing and Anti/De-icing China Aerodynamics Research and Development CenterMianyang621000SichuanChina Micro-and Nano-technology Research Center State Key Laboratory for Manufacturing Systems EngineeringXi’an Jiaotong UniversityXi’an710049ShaanxiChina Electronic Materials Research Lab Key Laboratory of the Ministry of EducationXi’an Jiaotong UniversityXi’an710049ShaanxiChina NTNU Nanomechanical Lab Norwegian University of Science and Technology(NTNU)Trondheim7491Norway

Understanding the hydrate adhesion is important to tackling hydrate accretion in ***,the relationship between the Tetrahydrofuran(THF)hydrate adhesion strength(AS)and surface stiffness on elastic coatings is systemically examined by experimental shear force measurements and theoretical *** mechanical factor-elastic modulus of the coatings greatly dictates the hydrate AS,which is explained by the adhesion mechanics theory,beyond the usual factors such as wettability and structural ***,the hydrate AS increases with reducing the thickness of the elastic coatings,resulted from the decrease of the apparent surface elastic *** effect of critical thickness for the elastic materials with variable elastic modulus on the hydrate AS is also *** study provides deep perspectives on the regulation of the hydrate AS by the elastic modulus of elastic materials,which is of significance to design anti-hydrate surfaces for mitigation of hydrate accretion in petro-pipelines.

关键词： Hydrate Adhesion strength Elastic modulus Coatings

A reweighted damped singular spectrum analysis method for robust seismic noise suppression

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Petroleum Science 2024年第3期21卷 1671-1682页

作者： wei-Lin Huang yan-Xin Zhou yang Zhou wei-Jie Liu Ji-Dong Li State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum (Beijing) SINOPEC Petroleum Exploration and Production Research Institute SINOPEC Geophysical Research Institute

(Multichannel) Singular spectrum analysis is considered as one of the most effective methods for seismic incoherent noise suppression. It utilizes the low-rank feature of seismic signal and regards the noise suppression as a low-rank reconstruction problem. However, in some cases the seismic geophones receive some erratic disturbances and the amplitudes are dramatically larger than other receivers. The presence of this kind of noise, called erratic noise, makes singular spectrum analysis(SSA) reconstruction unstable and has undesirable effects on the final results. We robustify the low-rank reconstruction of seismic data by a reweighted damped SSA(RD-SSA) method. It incorporates the damped SSA, an improved version of SSA, into a reweighted framework. The damping operator is used to weaken the artificial disturbance introduced by the low-rank projection of both erratic and random noise. The central idea of the RD-SSA method is to iteratively approximate the observed data with the quadratic norm for the first iteration and the Tukeys bisquare norm for the rest iterations. The RD-SSA method can suppress seismic incoherent noise and keep the reconstruction process robust to the erratic disturbance. The feasibility of RD-SSA is validated via both synthetic and field data examples.

关键词： Singular spectrum analysis Damping operator Seismic erratic noise Seismic signal processing Robust low-rank reconstruction

Rotating Massive Strangeon Stars and X-Ray Plateau of Short GRBs

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Research in Astronomy and Astrophysics 2024年第3期24卷 47-57页

作者： Xi-yan yang Xiao-Yu Lai wei-wei Tan Ren-Xin Xu School of Physics and Optoelectronic Engineering Yangtze UniversityJingzhou 434023China Research Center for Astronomy Hubei University of EducationWuhan 4300205China Key Laboratory of Quark and Lepton Physics Central China Normal UniversityMinistry of EducationWuhan 430079China School of Physics Peking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China

Strangeon stars,which are proposed to describe the nature of pulsar-like compact stars,have passed various observational *** maximum mass of a non-rotating strangeon star could be high,which implies that the remnants of binary strangeon star mergers could even be long-lived massive strangeon *** study rigidly rotating strangeon stars in the slowly rotating approximation,using the Lennard-Jones model for the equation of *** can significantly increase the maximum mass of strangeon stars with unchanged baryon numbers,enlarging the mass-range of long-lived strangeon *** spin-down after merger,the decrease of radius of the remnant will lead to the release of gravitational *** into account the efficiency of converting the gravitational energy luminosity to the observed X-ray luminosity,we find that the gravitational energy could provide an alternative energy source for the plateau emission of X-ray *** fitting results of X-ray plateau emission of some short gamma-ray bursts suggest that the magnetic dipole field strength of the remnants can be much smaller than that of expected when the plateau emission is powered only by spin-down luminosity of magnetars.

关键词： dense matter-(stars) pulsars general-(stars) gamma-ray burst general

Effect of coral sand on the mechanical properties and hydration mechanism of magnesium potassium phosphate cement mortar

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第2期25卷 116-129页

作者： Hao LIU Huamei yang Houzhen wei Jining YU Qingshan MENG Rongtao yan College of Civil Engineering and Architecture Guilin University of TechnologyGuilin541004China Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering Guilin University of TechnologyGuilin541004China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China School of Intelligent Construction Wuchang University of TechnologyWuhan430002China Hydraulic Concrete Institute China Three Gorges CorporationBeijing100038China The First Railway Survey and Design Institute Group Corporation Xi’an710043China

Damaged structures on coral islands have been spalling and cracking due to the dual corrosion of tides and *** ensure easy access to aggregate materials,magnesium potassium phosphate cement(MKPC)and coral sand(CS)are mixed to repair damaged structures on coral ***,CS is significantly different from land-sourced sand in mineral composition,particle morphology,and *** has a substantial impact on the hydration characteristics and macroscopic properties of MKPC ***,in this study we investigated the compressive strength,interfacial mechanical properties,and corrosion resistance of MKPC CS *** in the morphology,microstructure,and relative contents of hydration products were revealed by scanning electron microscope-energy dispersive spectrometer(SEM-EDS)and X-ray diffraction(XRD).The results indicated that the compressive strength increased linearly with the interfacial micro-hardness,and then stabilized after long-term immersion in pure water and Na2SO4 solution,showing excellent corrosion *** with MKPC river sand(RS)mortar,the hydration products of CS mortar were an intermediate product 6KPO2·8H2O with a relative content of 3.9%at 1 h and 4.1%at 12 *** hydration product MgKPO_(4)·6H_(2)O increased rapidly after 7-d curing,with an increased growth rate of 1100%.Our results showed that CS promoted the nucleation and formation of hydration products of MKPC,resulting in better crystallinity,tighter overlapping,and a denser interfacial transition *** results of this study provide technical support for applying MKPC mortar as a rapid repair material for damaged structures on coral islands.

关键词： Magnesium potassium phosphate cement(MKPC) Coral sand(CS) Mechanical properties Corrosion resistance Hydration mechanism

A Video Captioning Method by Semantic Topic-Guided Generation

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Computers, Materials & Continua 2024年第1期78卷 1071-1093页

作者： Ou Ye Xinli wei Zhenhua Yu yan Fu Ying yang College of Computer Science and Technology Xi’an University of Science and TechnologyXi’an710054China

In the video captioning methods based on an encoder-decoder,limited visual features are extracted by an encoder,and a natural sentence of the video content is generated using a ***,this kind ofmethod is dependent on a single video input source and few visual labels,and there is a problem with semantic alignment between video contents and generated natural sentences,which are not suitable for accurately comprehending and describing the video *** address this issue,this paper proposes a video captioning method by semantic topic-guided ***,a 3D convolutional neural network is utilized to extract the spatiotemporal features of videos during the ***,the semantic topics of video data are extracted using the visual labels retrieved from similar video *** the decoding,a decoder is constructed by combining a novel Enhance-TopK sampling algorithm with a Generative Pre-trained Transformer-2 deep neural network,which decreases the influence of“deviation”in the semantic mapping process between videos and texts by jointly decoding a baseline and semantic topics of video *** this process,the designed Enhance-TopK sampling algorithm can alleviate a long-tail problem by dynamically adjusting the probability distribution of the predicted ***,the experiments are conducted on two publicly used Microsoft Research Video Description andMicrosoft Research-Video to Text *** experimental results demonstrate that the proposed method outperforms several state-of-art ***,the performance indicators Bilingual Evaluation Understudy,Metric for Evaluation of Translation with Explicit Ordering,Recall Oriented Understudy for Gisting Evaluation-longest common subsequence,and Consensus-based Image Description Evaluation of the proposed method are improved by 1.2%,0.1%,0.3%,and 2.4% on the Microsoft Research Video Description dataset,and 0.1%,1.0%,0.1%,and 2.8% on the Microsoft Research-Video to Text dataset

关键词： Video captioning encoder-decoder semantic topic jointly decoding Enhance-TopK sampling

PVP/PAN-derived porous carbon fiber for zinc-ion hybrid supercapacitors

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Rare Metals 2024年第7期43卷 3066-3073页

作者： Shu-Hua yang Wen-Qing Fu yan-wei Cui Bing-Qiang Cao Materials Center for Energy and Photoelectrochemical Conversion School of Material Science and EngineeringUniversity of Jinan

Porous carbon fibers are promising cathodes for zinc-ion hybrid supercapacitors（ZHSs） owing to their abundant active sites,great conductivity,and stable physical and chemical ***,designing a proper preparation technique to regulate the microstructure of carbon fibers still remains a great ***,a poly vinylpyrrolidone/po-lyacry lonitrile（PVP/PAN）-derived porous carbon fiber is developed via the PVP/PAN blend electrospinning and hydrothermal selective PVP removal *** hydrothermal selective PVP removal strategy can effectively avoid a cross-linking between PVP and PAN during the traditional stabilization at air *** PVP/PAN-derived porous carbon fiber,the sufficient micropores provide abundant space for the Zn2+storage,whereas the proper mesopores contribute to the fast ion *** hierarchical porous structures endow ZHSs with high specific capacity and high-rate *** ZHS assembled with the optimal PVP/PAN-derived porous carbon fiber（PVP-PANC-0.8） displays an outstanding specific capacity of 208 mAh·g-1,high rate capability（49.5%） from 0.5 to 5 A·g-1,and 72.25% capacity retention after 10,000 cycles at 0.5 A·g-1.

关键词： Zinc-ion hybrid supercapacitors Porous carbon fibers Hierarchical porous structures Electrospinning

Micro-sized nanoaggregates:Spray-drying-assisted fabrication and applications

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Particuology 2024年第2期85卷 22-48页

作者： Dan-Lei yang Rong-Kun Liu yan wei Qian Sun Jie-Xin Wang School of Life Sciences and Chemical Engineering Jiangsu Second Normal UniversityNanjing210013China State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing100029China Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology School of Chemistry and Chemical EngineeringGuangxi UniversityNanning530004China

The applications of nanoparticles suffer from their extremely small size and intrinsic trend of *** nanoparticles to form micro-sized nanoaggregates(MNAs)with increased size,ordered structure,as well as controllable size,shape,and morphology is a crucial step in various fields of science and technology to maintain the unique characteristics of nanoparticles while obtaining greatly enhanced or new performance at the *** structure of MNAs prominently affects their functionality,which is determined by the arrangement of nanoparticles and the interaction between primary *** methods have been proposed to prepare the MNAs,in which spray-drying technology stands out considering the feasibility,scalability for industry,cost,and *** assembly of nanoparticles through spray-drying under tunable process parameters yields diverse physical properties and structural arrangements of nanoparticles of the MNAs,they therefore exhibit enormous potential in a wide range of application *** review presents the construction and applications of spray-dried *** factors that influence the size,morphology,and structure of the MNAs are discussed in *** addition,the outstanding application performance resulting from the tightly packed nanoparticles in regular-shaped MNAs obtained by the spray-drying process is illustrated.

关键词： Spray-drying Micro-sized nanoaggregates Applications

Weak interaction-steered evolution of polyoxovanadate-based metal-organic polyhedra from transformation via interlock to packing

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Chinese Chemical Letters 2024年第2期35卷 527-533页

作者： yan-Hu Wang Ke-wei Tong Chao-Qin Chen Jing Du Peng yang College of Chemistry and Chemical Engineering Advanced Catalytic Engineering Research Center of the Ministry of EducationHunan UniversityChangsha 410082China College of Chemistry and Materials Science Testing and Analysis CenterHebei Normal UniversityShijiazhuang 050024China

A bottleneck in biomimetic synthesis consists in the full copy of,for example,the hierarchical structure of proteins directed by weak *** contrast with covalent bonds bearing definite orientation and high stability,weak intermolecular forces within a continuous dynamic equilibrium can be hardly tamed for molecular *** this endeavor,a ligand-dominated strategy that embodies tunable electrostatic repulsion andπ···πstacking was first employed to shape polyoxovanadate-based metal-organic polyhedra(VMOPs).Structural evolution involving transformation,interlock,and discovery of an unprecedented prototype of the Star of David was hence *** only as a handy tool for the primary structural control over VMOPs,these weak forces allow for an advanced management on the spatial distribution of such manmade macromolecules as well as the associated physicochemical behaviors,representing an ideal model for simulating and interpreting the conformation-function relationship of proteins.

关键词： Polyoxometalates Polyoxovanadates Metal-organic polyhedron Interlock Weak intermolecular forces