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Peeling behavior and spalling resistance of CFRP sheets bonded to bent concrete surfaces

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Acta Mechanica Sinica 2010年第2期26卷 257-264页

作者： hong yuan Faping Li MOE Key Lab of Disaster Forecast and Control in Engineering Institute of Applied Mechanics Jinan University 510632 Guangzhou China

In this paper, the peeling behavior and the spalling resistance effect of carbon fiber reinforced polymer （CFRP） sheets externally bonded to bent concrete surfaces are firstly investigated experimentally. Twenty one curved specimens and seven plane specimens are studied in the paper, in which curved specimens with bonded CFRP sheets can simulate the concrete spalling in tunnel, culvert, arch bridge etc., whereas plane specimens with bonded CFRP sheets can simulate the concrete spalling in beam bridge, slab bridge and pedestrian bridge. Three kinds of curved specimens with different radii of curvature are chosen by referring to practical tunnel structures, and plane specimens are used for comparison with curved ones. A peeling load is applied on the FRP sheet by loading a circular steel tube placed into the central notch of beam to debond CFRP sheets from the bent concrete surface, meanwhile full-range load-deflection curves are recorded by a MTS 831.10 Elastomer Test System. Based on the experimental results, a theoretical analysis is also conducted for the specimens. Both theoretical and experimental results show that only two material parameters, the interfacial fracture energy of CFRP-concrete interface and the tensile stiffness of CFRP sheets, are needed for describing the interfacial spalling behavior. It is found that the radius of curvature has remarkable influence on peeling load-deflection curves. The test methods and test results given in the paper are helpful and available for reference to the designer of tunnel strengthening.

关键词： FRP sheet · Interfacial fracture energy ·Debonding · Spalling resistance · Bent concrete surface

Practical fuel cells enabled by unprecedented oxygen reduction reaction on 3D nanostructured electrocatalysts

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Journal of Energy Chemistry 2020年第9期29卷 107-108,I0003页

作者： hong yuan Qiang Zhang Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

Oxygen reduction reaction(ORR)is of significance for energy conversion technologies such as fuel cells and metal-air batteries[1,2].Currently,the electrocatalysts still need to employ expensive precious metal platinum... 详细信息

关键词： Oxygen reduction reaction Fuel cells Precious metal electrocatalyst 3D nanostructured materials Electrocatalysis

Analysis of unmanned aerial vehicle navigation and height control system based on GPS

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Journal of Systems Engineering and Electronics 2010年第4期21卷 643-649页

作者： Jianjun Zhang hong yuan China Academy of Space Technology Beijing 100094 E R. China Academy of Opto-Electronics Chinese Academy of Sciences Beijing 100190 P. R. China

According to the characteristic of global positioning system（GPS） reflection signals,a GPS delay mapping receiver system scheme is put forward,which not only satisfies the unmanned aerial vehicle（UAV） guidance localization but also realizes height measurement.A code delay algorithm is put forward,which processes the direct and land reflected signal and outputs the navigation data and specular *** GPS terrain reflected echo signal mathematical equation is *** reflecting signal area,when the GPS signal passes the land,is *** height survey model reflected land surface characteristic is established.A simulation system which carries guidance localization of the UAV and the height measuring control through the GPS direct signal and the land reflected signal is designed,taken the GPS satellite as the illumination source,the receiver is put on the *** the UAV guidance signal,the GPS reflection signal and receiver＇s parallel processing are *** parallel processing reduces UAV＇s payload and raises system＇s operating *** simulation results confirms the validity of the model and also provides the basis for the UAV＇s optimization design.

关键词： height measuring global positioning system(GPS) reflected signal delay mapping receiver unmanned aerial vehicle(UAV).

Motor cortical circuit adaptations in parkinsonism

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Neural Regeneration Research 2024年第10期19卷 2107-2108页

作者： hong-yuan Chu Department of Neurodegenerative Science Van Andel Research InstituteGrand RapidsMIUSA Aligning Science Across Parkinson’s(ASAP)Collaborative Research Network

Parkinson's disease is a chronic and progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta,which leads to the featured motor impairment of parki... 详细信息

关键词： parkin impairment rigidity

Nanoelectrochemical architectures for high-spatial-resolution single cell analysis

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Science China Chemistry 2017年第10期60卷 1277-1284页

作者： Junyu Zhou Dechen Jiang hong-yuan Chen State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical Engineering Nanjing University Nanjing 210093 China

The analysis of single cells instead of cell populations is important for characterizing cellular heterogeneity and elucidating the cellular signalling pathways. Nanoelectrodes have emerged as an increasingly important tool for biomolecule analyses at the single-cell level with high spatial or temporal resolution. Various electrochemical methods, such as amperometry and scanning electrochemical microscopy(SECM), have been applied. Research to date has focused on the development of new nanoelectrochemical architectures, such as arrays, to achieve higher spatial resolution and faster analysis rates for single-cell analysis. In this review, the fabrication of these new nanoelectrochemical architectures and their applications in high spatial resolution single-cell analyses are discussed. The recent progress of Chinese researchers is highlighted.

关键词： nanoelectrochemical architectures single-cell analysis high spatial resolution high throughput

Research on regional ionospheric tec modeling using RBF neural network

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Science China(Technological Sciences) 2014年第6期57卷 1198-1205页

作者： HUANG Zhi yuan hong School of Physics and Electronic Engineering Jiangsu Normal University Academy of Opto-electronics Chinese Academy of Sciences

Machine learning techniques which are about the construction and study of system that can learn from data are combined with many application fields.A method on ionospheric total electron content(TEC)mapping is proposed based on radical basis function(RBF)neural network improved by Gaussian mixture model(GMM).Due to the complicated ionospheric behavior over China,GMM is used to determine the center of basis function in the unsupervised training *** descent is performed to update the weights function on a sum of squared output error function in the supervised learning *** TEC values from the center for orbit determination in Europe(CODE)global ionospheric maps covering the period from 2007to 2010 are used to investigate the performance of the developed network *** independent validation,the simulated TEC values at different latitudes(20°N,30°N and 40°N)along 120°E longitude are analyzed and *** results show that the simulated TEC from the RBF network based model has good agreement with the observed CODE TEC with acceptable *** theoretical research indicates that RBF can offer a powerful and reliable alternative to the design of ionospheric TEC forecast technologies and thus make a significant contribution to the ionospheric modeling efforts in China.

关键词： RBF neural network ionosphere TEC modeling

The evolution and failure mechanism of lithium metal anode under practical working conditions

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Journal of Energy Chemistry 2020年第9期29卷 424-425,I0012页

作者： Jia Liu hong yuan Beijing Key Laboratory of Lignocellulosic Chemistry Beijing Forestry UniversityBeijing 100083China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China

Lithium(Li)metal is regarded as a promising anode material to render the Li batteries with high energy density and therefore satisfy the ever-growing energy demands of high-end storage devices[1].Unfortunately,the dendrite growth accompanied with accumulation of"dead Li"leads to low Coulombic efficiency,poor cycling lifespan,and even severe safety hazards,critically hindering the practical implementation of Li metal batteries[2,3].

关键词： Practical lithium metal anode Electrochemical diagram Failure mechanism Plating/stripping behavior

THEORETICAL MODEL ON INTERFACE FAILURE MECHANISM OF REINFORCED CONCRETE CONTINUOUS BEAM STRENGTHENED BY FRP

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Acta Mechanica Solida Sinica 2009年第2期22卷 161-170页

作者： hong yuan Zifeng Lin MOE Key Lab of Disaster Forecast and Control in Engineering Institute of Applied Mechanics Jinan University Guangzhou 510632 China

Fiber reinforced polymer （FRP） composites are increasingly being used for the re-pair and strengthening of deteriorated concrete structural components through adhesive bonding of prefabricated strips/plates and the wet lay-up of fabric. Interfacial bond failure modes have attracted the attention of researchers because of the importance. The objective of the present study is to analyse the interface failure mechanism of reinforced concrete continuous beam strength-ened by FRP. An analytical solution has been firstly presented to predict the entire debonding process of the model. The realistic bi-linear bond-slip interfacial law was adopted to study this problem. The crack propagation process of the loaded model was divided into four stages （elastic,elastic-softening,elastic-softening-debonded and softening-debonded stage）. Among them,elastic-softening-debonded stage has four sub-stages. The equations are solved by adding suitable stress and displacement boundary conditions. Finally,critical value of bond length is determined to make the failure mechanism in the paper effective by solving the simultaneously linear algebraic equations. The interaction between the upper and lower FRP plates can be neglected if axial stiffness ratio of the concrete-to-plate prism is large enough.

关键词： FRP interface bond-slip law critical length continuous beam ultimate load

GREEN QUASIFUNCTION METHOD FOR FREE VIBRATION OF CLAMPED THIN PLATES

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Acta Mechanica Solida Sinica 2012年第1期25卷 37-45页

作者： Shanqing Li hong yuan MOE Key Laboratory of Disaster Forecast and Control in Engineering Institute of Applied MechanicsJinan UniversityGuangzhou 510632China

The Green quasifunction method is employed to solve the free vibration problem of clamped thin plates.A Green quasifunction is established by using the fundamental solution and boundary equation of the *** function satisfies the homogeneous boundary condition of the *** mode shape differential equation of the free vibration problem of clamped thin plates is reduced to Fredholm integral equation of the second kind by Green *** of the kernel of integral equation is overcome by choosing a suitable form of the normalized boundary *** examples demonstrate the validity of the present *** with both the series solution and ANSYS finite-element solution shows fine *** present method is a novel and effective mathematical one.

关键词： Green function integral equation R-function clamped thin plates free vibration