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Nonlinear dynamic modeling of planar moving Timoshenko beam considering non-rigid non-elastic axial effects

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 479-496页

作者： m.ABBAsI GAVARI m.R.HOmAEINEZHAD Faculty of mechanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible *** manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse *** accurately model the elastic behavior,Timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation *** applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(PDEs).Then,the assumed mode method(Amm)is used to solve this nonlinear system of governing equations with appropriate shape *** assumed modes can be obtained after solving the characteristic equation of a Timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the *** addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is *** the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the ***,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element *** comparison confirms the validity of the proposed dynamic model for the *** to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms.

关键词： planar moving Timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(Amm) nonlinear motion analysis

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)

Concomitant determination of hematological indices supported the application of the albumin-bilirubin score in non-malignant liver diseases

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World Journal of Hepatology 2024年第9期16卷 1308-1311页

作者： marwan s m Al-Nimer Department of Pharmacology College of MedicineUniversity of DiyalaBaqubah 32001Iraq

The albumin-bilirubin(ALBI)score is a useful prognostic marker that predicts mortality in patients suffering from terminal ***,it has been reported that ALBI score is a predictor of non-malignant liver *** cutoff point of the ALBI score that distinguishes hepatocellular carcinoma from non-malignant liver disease is still not ***,the ALBI score is a sensi-tive rather than a specific predictor of the poor outcomes of liver *** are many hematological indices and ratios that are utilized as prognostic *** these biomarkers are the neutrophil-to-lymphocyte ratio,platelet-to-lymphocyte ratio(PLR),and platelet-hemoglobin ratio(PHR),which are useful discriminating prognostic biomarkers for liver diseases,e.g.,hepato-cellular carcinoma,hepatitis,liver fibrosis,*** is evidence that PLR and PHR are prognostic biomarkers that predict the poor outcomes of ***,concomitant measurements of ALBI score and PHR or ALBI score and PLR will improve the predictive value that can differentiate hepatocellular carcinoma from non-malignant diseases.

关键词： Albumin-bilirubin score Hepatocellular carcinoma Non-malignant diseases Platelet-lymphocyte ratio Platelet-hemoglobin ratio

Effect of solidification cooling rate on microstructure and tribology characteristics of Zn-4si alloy

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International Journal of minerals,metallurgy and materials 2024年第2期31卷 362-373页

作者： F.Akbari m.Golkaram s.Beyrami G.shirazi K.mantashloo R.Taghiabadi m.saghafi Yazdi I.Ansarian Department of metallurgy and material science Imam Khomeini International University(IKIU)Qazvin ***Iran

The main objective of this work was to modify the microstructure and enhance the tribological properties of a new Zn-4si al-loy through a high solidification cooling rate(sCR).According to the results,by increasing the sCR from 2.0 to 59.5℃/s the average size of primary si particles and that of the grains reduced from 76.1 and 3780μm to less than about 14.6 and 460μm,***-ing the sCR also enhanced the microstructural homogeneity,decreased the porosity content(by 50%),and increased the matrix hardness(by 36%).These microstructural changes enhanced the tribological *** instance,under the applied pressure of 0.5 mPa,an in-crease in the sCR from 2.0 to 59.5℃/s decreased the wear rate and the average friction coefficient of the alloy by 57%and 23%,*** wear mechanism was also changed from the severe delamination,adhesion,and abrasion in the slowly-cooled alloy to the mild tribolayer delamination/abrasion in the high-cooling-rate-solidified sample.

关键词： zinc-silicon alloy primary silicon solidification cooling rate tribology sliding wear

Elucidating the structure-activity relationship of Cu-Ag bimetallic catalysts for electrochemical CO_(2) reduction

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Journal of Energy Chemistry 2024年第6期93卷 345-351,I0009页

作者： Qining Huang Lili Wan Qingxuan ren Jingshan Luo Institute of Photoelectronic Thin Film Devices and Technology State Key Laboratory of Photovoltaic Materials and CellsKey Laboratory of Photoelectronic Thin Film Devices and Technology of TianjinMinistry of Education Engineering Research Center of Thin Film Photoelectronic TechnologyNankai UniversityTianjin 300350China Frontiers science Center for New Organic matter Nankai UniversityTianjin 300071China Haihe Laboratory of sustainable Chemical Transformations Tianjin 300192China

Developing bimetallic catalysts is an effective strategy for enhancing the activity and selectivity of electrochemical CO_(2) reduction reactions,where understanding the structure-activity relationship is essential for catalyst ***,we prepared two Cu-Ag bimetallic catalysts with Ag nanoparticles attached to the top or the bottom of Cu *** tested in a flow cell,the Cu-Ag catalyst with Ag nanoparticles on the bottom achieved a faradaic efficiency of 54%for ethylene production,much higher than the catalyst with Ag nanoparticles on the *** catalysts were further studied in the H-cell and zero-gap mEA *** was found that placing the two metals in the intensified reaction zone is crucial to triggering the tandem reaction of bimetallic *** work elucidates the structure-activity relationship of bimetallic catalysts for CO_(2) reduction and demonstrates the importance of considering both catalyst structures and cell characteristics to achieve high activity and selectivity.

关键词： Electrochemical CO_(2)reduction Bimetallic catalyst Cu-Ag structure-activity relationship

search for production of dark fermion candidates in association with heavy neutral gauge boson decaying to dimuon in proton-proton collisions at√s=8 TeV using Cms open data

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Chinese Physics C 2024年第4期48卷 6-13页

作者： Y.mahmoud H.Abdallah m.T.Hussein s.Elgammal Centre for theoretical physics The British University in EgyptEgypt Physics Department Faculty of ScienceCairo UniversityEgypt

In this study,we conducted a search for dark matter using a part of the data recorded by the Cms experiment during run-I of the LHC in 2012 with a center of mass energy of 8 TeV and an integrated luminosity of 11.6 fb−*** data were gathered from the Cms open *** matter,in the framework of the simplified model(mono-Z′),can be produced from proton-proton collisions in association with a new hypothetical gauge boson,Z′.Thus,the search was conducted in the dimuon plus large missing transverse momentum *** benchmark scenario of mono-Z′,which is known as light vector,was used for interpreting the Cms open *** evidence of dark matter was observed,and exclusion limits were set on the masses of dark matter and Z′at 95%confidence level.

关键词： dark matter large hadron collider Cms open data search for new physics dark fermion

Cr-induced fusion reactions to synthesize superheavy elements

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Nuclear science and Techniques 2024年第5期35卷 122-130页

作者： s.madhu H.C.manjunatha N.sowmya B.m.Rajesh L.seenappa R.s.susheela Department of Physics R V College of EngineeringBangalore 560074India Visvesvaraya Technological University BelagaviKarnataka 590018India Department of Physics Government First Grade CollegeSrinivasapurKarnataka 563135India Department of Physics Government First Grade CollegeDevanahallyKarnataka 562110India Department of Physics Government First Grade CollegeMulbagalKarnataka 563131India Department of Physics Government First Grade collegeNanjangudOoty RoadMysore 571301India

We investigated ^(50,52-54)Cr-induced fusion reactions for the synthesis of the superheavy element in the 104≤Z≤122 *** cross sections produced in this investigation using ^(54)Cr projectiles were compared with those obtained in prior *** estimated cross sections from this analysis are consistent with the findings of prior *** the current study,the predicted cross section was found to be 42fb at 236 meV for ^(53)Cr+^(243)Am,23.2 fb at 236 meV for ^(54)Cr+^(247)Cm,95.6 fb at 240 meV for ^(53)Cr+248Bk,and 1.33 fb at 242 meV for ^(53)Cr+***,these projected cross sections with excitation energy and beam energy will be useful in future Cr-induced fusion reaction investigations.

关键词： Fusion cross sections Compound nucleus formation probability survival probability Evaporation residue cross sections

Enhanced activation of peroxymonosulfate by Fe/N co-doped ordered mesoporous carbon with dual active sites for efficient removal of m-cresol

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Chinese Journal of Chemical Engineering 2024年第1期65卷 130-144页

作者： Donghui Li Wenzhe Wu Xue ren Xixi Zhao Hongbing song meng Xiao Quanhong Zhu Hengjun Gai Tingting Huang College of Chemical Engineering Qingdao University of Science and TechnologyQingdao 266042China school of Chemical&Environmental Engineering China University of Mining&Technology-BeijingBeijing 100083China

The novel Fe-N co-doped ordered mesoporous carbon with high catalytic activity in m-cresol removal was prepared by urea-assisted impregnation and simple pyrolysis *** the preparation of the Fe-NC catalyst,the complexation of N elements in urea could anchor Fe,and the formation of C3N4during urea pyrolysis could also prevent migration and aggregation of Fe species,which jointly improve the dispersion and stability of *** FeN4sites and highly dispersed Fe nanoparticles synergistically trigger the dual-site peroxymonosulfate (Pms) activation for highly efficient m-cresol degradation,while the ordered mesoporous structure of the catalyst could improve the mass transfer rate of the catalytic process,which together promote catalytic degradation of m-cresol by Pms *** oxygen species (ROs) analytic experiments demonstrate that the system degrades m-cresol by free radical pathway mainly based on sO_(4)^(-)·and·OH,and partially based on·OH as the active components,and a possible Pms activation mechanism by 5Fe-50 for m-cresol degradation was *** study can provide theoretical guidance for the preparation of efficient and stable catalysts for the degradation of organic pollutants by activated Pms.

关键词： Degradation Peroxymonosulfate Fe(II)/Fe(III)/FeN4 Ordered mesopores carbon Catalyst Radical

Fault diagnosis of HVAC system with imbalanced data using multi-scale convolution composite neural network

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Building simulation 2024年第3期17卷 371-386页

作者： Rouhui Wu Yizhu ren mengying Tan Lei Nie school of mechanical Engineering Hubei University of TechnologyWuhan430068China Industrial Research Institute of Xiangyang Hubei University of Technology Xiangyang441100China

Accurate fault diagnosis of heating,ventilation,and air conditioning(HVAC)systems is of significant importance for maintaining normal operation,reducing energy consumption,and minimizing maintenance ***,in practical applications,it is challenging to obtain sufficient fault data for HVAC systems,leading to imbalanced data,where the number of fault samples is much smaller than that of normal ***,most existing HVAC system fault diagnosis methods heavily rely on balanced training sets to achieve high fault diagnosis ***,to address this issue,a composite neural network fault diagnosis model is proposed,which combines smOTETomek,multi-scale one-dimensional convolutional neural networks(m1DCNN),and support vector machine(sVm).This method first utilizes smOTETomek to augment the minority class samples in the imbalanced dataset,achieving a balanced number of faulty and normal ***,it employs the m1DCNN model to extract feature information from the augmented ***,it replaces the original softmax classifier with an sVm classifier for classification,thus enhancing the fault diagnosis *** the smOTETomek-m1DCNN-sVm method,we conducted fault diagnosis validation on both the AsHRAE RP-1043 dataset and experimental dataset with an imbalance ratio of 1:*** results demonstrate the superiority of this approach,providing a novel and promising solution for intelligent building management,with accuracy and F1 scores of 98.45%and 100%for the RP-1043 dataset and experimental dataset,respectively.

关键词： fault diagnosis chiller imbalanced data smOTETomek multi-scale neural networks