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Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 543-562页

作者： H.M.FEIZABAD M.H.YAS department of Mechanical Engineering Razi UniversityKermanshah ***Iran

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent *** fibers are renowned for their good mechanical properties,abundance,and short cycle *** beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic *** different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the *** elastic properties of the composite are determined with the law of *** Hamilton’s principle,the governing equations of motion are *** generalized differential quadrature method(GDQM)is then applied to the equations to obtain the *** achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam ***,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber ***,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(FG)beam elastic foundation generalized differential quadrature method(GDQM)

Manipulation of internal blockage in triangular triple quantum dot

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Chinese Physics B 2024年第5期33卷 588-593页

作者：齐月魏建华 department of Physics Renmin UniversityBeijing 100876China

We utilize the calculation of hierarchical equations of motion to demonstrate that the spin-dependent properties between adjacent quantum dots(QDs)can be changed by breaking the internal symmetry configuration,corresponding to the inversion of dominant chiral *** the linear triple quantum dots(LTQDs)connected to two electron reservoirs,we can observe that the blockage appears at the triangle triple quantum dots(TTQDs)by gradually increasing the coupling strength between next-nearest double *** the initial coupling between LTQDs has altered,the internal chiral circulation also undergoes the corresponding transform,thus achieving qualitative regulation and detection of the blocking *** also investigate the response of the chiral circulation to the dot–lead coupling strength,indicating the overall robust chiral circulation of the TTQDs frustration.

关键词： quantum dots chiral topology blocking

Dynamic and electrical responses of a curved sandwich beam with glass reinforced laminate layers and a pliable core in the presence of a piezoelectric layer under low-velocity impact

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 155-178页

作者： N.SHAHVEISI S.FELI department of Mechanical Engineering Razi UniversityKermanshah ***Iran

The dynamic responses and generated voltage in a curved sandwich beam with glass reinforced laminate(GRL)layers and a pliable core in the presence of a piezoelectric layer under low-velocity impact(LVI)are *** current study aims to carry out a dynamic analysis on the sandwich beam when the impactor hits the top face sheet with an initial *** the layer analysis,the high-order shear deformation theory(HSDT)and Frostig's second model for the displacement fields of the core layer are *** classical non-adhesive elastic contact theory and Hunter's principle are used to calculate the dynamic responses in terms of *** order to validate the analytical method,the outcomes of the current investigation are compared with those gained by the experimental tests carried out by other researchers for a rectangular composite plate subject to the *** element(FE)simulations are conducted by means of the ABAQUS *** effects of the parameters such as foam modulus,layer material,fiber angle,impactor mass,and its velocity on the generated voltage are reviewed.

关键词： analytical model piezoelectric layer curved sandwich beam glass reinforced laminate(GRL) pliable core low-velocity impact(LVI) classical non-adhesive elastic contact theory

The reformation of catalyst:From a trial-and-error synthesis to rational design

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Nano Research 2024年第4期17卷 3261-3301页

作者： Ligang Wang Jiabin Wu Shunwu Wang Huan Liu Yao Wang Dingsheng Wang department of Chemistry Tsinghua UniversityBeijing 100084China

The appropriate catalysts can accelerate the reaction rate and effectively boost the efficient conversion of various molecules,which is of great importance in the study of chemistry,chemical industry,energy,materials and environmental ***,efficient,environmentally friendly,and easy to operate synthesis methods have been used to prepare various types of *** previous studies have reported the synthesis and characterization of the aforementioned catalysts,more still remain in trial and error methods,without in-depth consideration and improvement of traditional synthesis ***,we comprehensively summarize and compare the preparation methods of the trial-and-error synthesis strategy,structure–activity relationships and density functional theory(DFT)guided catalysts rational design for nanomaterials and atomically dispersed *** also discuss in detail the utilization of the nanomaterials and single atom catalysts for converting small molecules(H_(2)O,O_(2),CO_(2),N_(2),etc.)into value-added products driven by electrocatalysis,photocatalysis,and ***,the challenges and outlooks of mass preparation and production of efficient and green catalysts through conventional trial and error synthesis and DFT theory are featured in accordance with its current development.

关键词： trial-and-error synthesis structure–activity relationships density functional theory(DFT)guidance nanomaterials atomically dispersed catalysts

Molecular Dynamics Simulations of Displacement Cascade in Ni-Based Concentrated Solid Solution Alloys

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Acta Mechanica Solida Sinica 2024年第1期37卷 82-89页

作者： Chaoquan Zhao Rongxuan Xie Chuanlong Xu Xiaobao Tian Qingyuan Wang Wentao Jiang Haidong Fan department of Mechanics Sichuan UniversityChengdu 610065China

Single-phase concentrated solid solution alloys(SP-CSAs),including high-entropy alloys,have received extensive attention due to their excellent irradiation *** this work,displacement cascade simulations are conducted using the molecular dynamics method to study the evolution of defects in Ni-based *** with pure Ni,the NiCr,NiCo,and NiCu alloys exhibit a larger number of Frankel pairs(FPs)in the thermal peak stage,but a smaller number of surviving ***,the NiFe alloy displays the opposite *** explain these different observations for NiFe and other alloys,the formation energy and migration energy of interstitials/vacancies are *** the NiFe alloy,both the formation energy and migration energy barrier are *** the other hand,in NiCr and other alloys,the formation energy of interstitials/vacancies is lower,as is the migration energy barrier of *** energy analysis agrees well with previous *** present work provides new insights into the mechanism behind the irradiation resistance of binary Ni-based SP-CSAs.

关键词： Molecular dynamics simulation Displacement cascade Point defect Ni-based concentrated solid solution alloys

High-resolution photogrammetry to measure physical aperture of two separated rock fracture surfaces

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 2922-2934页

作者： Masoud Torkan Mateusz Janiszewski Lauri Uotinen Alireza Baghbanan Mikael Rinne department of Civil Engineering Aalto UniversityEspooFinland department of Mining Engineering Isfahan University of TechnologyIsfahanIran

Photogrammetry,reconstructing three-dimensional(3D)models from overlapping two-dimensional(2D)photos,finds application in rock mechanics and rock engineering to extract geometrical details of reconstructed objects,for example rock *** properties are important for determining the mechanical stability,permeability,strength,and shear behavior of the rock *** can be used to reconstruct detailed 3D models of two separated rock fracture surfaces to characterize fracture roughness and physical aperture,which controls the fluid flow,hydromechanical and shear behavior of the rock *** research aimed to determine the optimal number of scale bars required to produce high-precision 3D models of a fracture surface.A workflow has been developed to define the physical aperture of a fracture using *** blocks of Kuru granite(25 cm×25 cm×10 cm)with an artificially induced fracture,were *** scaling 3D models,321 markers were used as ground control points(GCPs)with predefined distances on each *** the samples were wellmatched in their original positions,the entire block was *** data of the GCPs were extracted from the 3D model of the *** half was surveyed separately and georeferenced by GCPs and merged into the same coordinate *** fracture surfaces were extracted from the 3D models and the vertical distance between the two surfaces was digitally calculated as physical *** assessment of the photogrammetric reconstruction showed a 20-30 mm digital control distance accuracy when compared to known distances defined between *** attain this accuracy,the study found that at least 200 scale bars were ***,photogrammetry was employed to measure changes in aperture under normal *** results obtained from this approach were found to be in good agreement with those obtained using linear variable displacement transducers(LVDTs),with differences ran

关键词： Photogrammetry Physical aperture Rock fracture Predefined distances Markers

N, P co-doped 3D porous carbon with self-assembled morphological control via template-free method for potassiumion battery anodes

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Rare Metals 2024年第9期43卷 4243-4252页

作者： Jeehoon Yu Dae Kyom Kim Hong Geun Oh Seung-Keun Park Youngjae Yoo department of Advanced Materials Engineering Chung-Ang University

The larger ionic radius of potassium ions than that of lithium ions significantly limits the accomplishment of rapid diffusion kinetics in graphite electrodes for potassium-ion batteries （PIBs）,resulting in comparatively poor rate performance and cycle ***,we report a high-rate performance and cycling stability amorphous carbon electrode achieved through nitrogen and phosphorous *** as-prepared N,P co-doped carbon electrodes have distinct 3D structures with large surface areas,hierarchical pore architectures,and increased interlayer spaces resulting from the direct pyrolysis of supramolecular self-assembled aggregates without *** obtained electrode N3P1 exhibits a reversible specific capacity of 258 m Ah·g-1at a current density of 0.1A·g-1and a good long-term cycle performance (96.1%capacity retention after 800 cycles at 0.5 A·g-1).Kinetic investigations show that the N3P1 electrode with the welldeveloped porous structure and large number of surface defects exhibits capacitive-driven behavior at all scan rates,which may be attributed by N and P ***-situ transmission electron microscopy analyses in the fully discharged and charged states demonstrate structural stability and reversibility owing to the expanded interlayer *** suggested synthesis approach is simple and effective for producing heteroatom-doped carbon materials for PIBs and other advanced electrochemical energy storage materials.

关键词： 3D porous structures Amorphous carbons Nitrogen and phosphorous co-doping Potassium-ion batteries

Pipeline Embolization Device for intracranial aneurysms presenting with mass effect:a large Chinese cohort

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Stroke & Vascular Neurology 2024年第1期9卷 50-58页

作者： Yang Zhao Junlin Lu Hongqi Zhang Tianxiao LI Donglei Song Sheng Guan Aisha Maimaitili Yunyan Wang Wenfeng Feng Yang Wang Jieqing Wan Guohua Mao Huaizhang Shi Xinjian Yang Jianmin Liu Yuanli Zhao department of Neurosurgery Beijing Tiantan HospitalCapital Medical UniversityBeijingChina department of Neurosurgery Peking University International HospitalBeijingChina department of Neurosurgery West China HospitalSichuan UniversityChengduSichuanChina department of Neurosurgery Xuanwu HospitalCapital Medical UniversityBeijingChina department of Interventional Neuroradiology Zhengzhou University People's HospitalZhengzhouHenanChina department of Neurosurgery Shanghai Donglei Brain HospitalShanghaiChina department of Interventional Neuroradiology The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenanChina department of Neurosurgery The First Affiliated Hospital of Xinjiang Medical UniversityUrumqiXinjiangChina department of Neurosurgery Qilu Hospital of Shandong University QingdaoJinanShandongChina department of Neurosurgery Nanfang HospitalSouthern Medical UniversityGuangzhouGuangdongChina department of Neurosurgery The First Affiliated Hospital of Nanchang UniversityNanchangJiangxiChina department of Neurosurgery Renji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghaiChina department of Neurosurgery The Second Affiliated Hospital of Nanchang UniversityNanchangJiangxiChina department of Neurosurgery The First Affiliated Hospital of Harbin Medical UniversityHarbinHeilongjiangChina department of Neurosurgery Changhai HospitalNaval Medical UniversityShanghaiChina

Background Unruptured intracranial aneurysm treatment aims to reduce the risk of aneurysm rupture and bleeding,relieves symptoms and improve the quality of life for *** study aimed to assess the safety and efficacy of Pipeline Embolization Device(PED,Covidien/Medtronic,Irvine,CA)treatment for intracranial aneurysms presenting with mass effect in real-world *** We selected patients from the PED in China Post-Market Multi-Center Registry Study with mass effect *** study endpoints included postoperative mass effect deterioration and mass effect relief at follow-up(3–36 months).We conducted multivariate analysis to identify factors associated with mass effect *** analyses by aneurysm location,size and form were also *** This study included 218 patients with a mean age of 54.3±11.8 years and a female predominance of 74.0%(162/218).The postoperative mass effect deterioration rate was 9.6%(21/218).During a median follow-up period of 8.4 months,the mass effect relief rate was 71.6%(156/218).Notably,immediate aneurysm occlusion following treatment was significantly associated with mass effect relief(OR 0.392,95%CI,0.170 to 0.907,p=0.029).Subgroup analysis demonstrated that adjunctive coiling contributed to mass effect relief in cavernous aneurysms,while dense embolism impeded symptom relief in aneurysms<10mm and saccular *** Our data confirmed the efficacy of PED in relieving mass *** findings of this study provide support for endovascular treatment to alleviate mass effect in unruptured intracranial *** registration number NCT03831672.

关键词： aneurysm intracranial Irvine

A Comprehensive Review on Charging Topologies and Power Electronic Converter Solutions for Electric Vehicles

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 675-694页

作者： Abdelfatah Ali Hossam H.H.Mousa Mostafa F.Shaaban Maher A.Azzouz Ahmed S.A.Awad the department of Electrical Engineering American University of Sharjah26666 SharjahUnited Arab Emirates the department of Electrical Engineering South Valley University83523 QenaEgypt the department of Electrical and Computer Engineering University of WindsorWindsorON N9B 3P4 Canada Electrical Engineering department Qatar UniversityDoha 2713Qatar department of Electrical and Computer Engineering Sultan Qaboos UniversityMuscat123Oman

Electric vehicles(EVs)are becoming more popular worldwide due to environmental concerns,fuel security,and price *** performance of EVs relies on the energy stored in their batteries,which can be charged using either AC(slow)or DC(fast)***,EVs can also be used as mobile power storage devices using vehicle-to-grid(V2G)*** electronic converters(PECs)have a constructive role in EV applications,both in charging EVs and in ***,this paper comprehensively investigates the state of the art of EV charging topologies and PEC solutions for EV *** examines PECs from the point of view of their classifications,configurations,control approaches,and future research prospects and their impacts on power *** can be classified into various topologies:DC-DC converters,AC-DC converters,DC-AC converters,and AC-AC *** address the limitations of traditional DC-DC converters such as switching losses,size,and high-electromagnetic interference(EMI),resonant converters and multiport converters are being used in high-voltage EV ***,power-train converters have been modified for high-efficiency and reliability in EV *** paper offers an overview of charging topologies,PECs,challenges with solutions,and future trends in the field of the EV charging station applications.

关键词： Charging station charging topology electric vehicle power electronic converter vehicle-to-grid