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Flexible organic light-emitting diodes with poly-3,4-ethylene-dioxythiophene as transparent anode

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Chinese Science Bulletin 2002年第23期47卷 1979-1982页

作者： Qiu, y Duan, L Wang, ld Tsinghua Univ Organ Optoelect Lab Beijing 100084 Peoples R China

The flexible oragnic light-emitting diodes (OLEDs) fabricated on poly -3,4-ethylenedioxythiophene/poly -styrenesulfonate(PEDOT/PSS) coated substrates were demonstrated. How the fabricating processes and the device structure will affect the device performance was studied and the atomic force microscopy was employed to analyze the mophorlogy of the conducting polymer anode. Under optimized conditions, flexible OLEDs with PEDOT anode showed the brightness up to 2760 cd/m2 and maximum external quantum efficiency of 1.4%. These data are comparable to those of conventional flexible OLEDs with ITO anode.

关键词： PEDOT oragnic light-emitting diodes flexible display.

HOldITCH THEOREM FOR THE CLOSED SPACE CURVES IN LORENTzIAN 3-SPACE

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Acta Mathematica Scientia 2011年第1期31卷 172-180页

作者： Handan y.ldιrιm Salim yce Nuri Kuruoglu Department of Mathematics Faculty of Science stanbul University Department of Mathematics Faculty of Arts and Science Yιldιz Technical University Department of Mathematics and Computer Sciences Bahesehir University Faculty of Arts and Science Besiktas 34100 stanbul Turkey

In this article, we give the area formula of the closed projection curve of a closed space curve in Lorentzian 3-space L3. For the 1-parameter closed Lorentzian space motion in L3, we obtain a Holditch Theorem taking into account the Lorentzian matrix multiplication for the closed space curves by using their othogonal projections onto the Euclidean plane in the fixed Lorentzian space. Moreover, we generalize this Holditch Theorem for noncollinear three fixed points of the moving Lorentzian space and any other fixed point on the plane which is determined by these three fixed points.

关键词： Lorentzian matrix multiplication Lorentzian motion Holditch Theorem orthogonal projection area

A Study on the Estimation of Prefabricated Glass Fiber Reinforced Concrete Panel Strength Values with an Artificial Neural Network Model

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Computers, Materials & Continua 2016年第4期52卷 41-52页

作者： S.A.y.ldızel A.U.Öztürk Manisa Celal Bayar University Engineering FacultyTurkey

In this study,artificial neural networks trained with swarm based artificial bee colony optimization algorithm was implemented for prediction of the modulus of rapture values of the fabricated glass fiber reinforced concrete *** the application of the ANN models,143 different four-point bending test results of glass fiber reinforced concrete mixes with the varied parameters of temperature,fiber content and slump values were introduced the artificial bee colony optimization and conventional back propagation *** and the testing results of the corresponding models showed that artificial neural networks trained with the artificial bee colony optimization algorithm have remarkable potential for the prediction of modulus of rupture values and this method can be used as a preliminary decision criterion for quality check of the fabricated products.

关键词： Neural network glass fiber reinforced concrete glass fiber

First Detailed Photometric Investigation on the Nature of Contact Binary System AA Cet

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Research in Astronomy and Astrophysics 2023年第7期23卷 154-163页

作者： M.F.y.ldırım F.Soydugan Çanakkale Onsekiz Mart University Astrophysics Research Center and Ulupınar Observatory17020ÇanakkaleTurkey Çanakkale Onsekiz Mart University Faculty of SciencesDepartment of Physics17020ÇanakkaleTurkey

The TESS light curve(LC)of the marginal contact binary A A Cet was analyzed simultaneously with the radial velocity and the orbital period(OP)change of the system was *** physical parameters of the system were obtained by analyzing the LC of A A Cet with the Wilson-Devinney method,and the absolute parameters of the components were calculated using the results *** the components of AA Cet,the masses and radii were calculated as M_(1)=1.39±0.04 M_⊙,M_(2)=0.48±0.02 M_⊙,and R_(1)=1.64±0.03 R_⊙,R_(2)=1.01±0.04 R_⊙,*** Cet is a marginal contact binary with a temperature difference of 1305 K between its components.A total of 14 eclipse times were obtained from the TESS data and used in the OP analysis together with those collected from the *** has been observed that the change in the OP of AA Cet is in the form of a decreasing *** mass transfer between the components has been interpreted as the reason for this *** OP decrease amount of A A Cet was obtained as dP/dt=0.0062±0.0006 s yr^(-1).and the reason for this decrease was attributed to a 3.3(9)×10^(-8)M_⊙.mass transfer per year from the more massive component to the less massive *** age of A A Cet has been estimated as 7 Gyr,as the age of contact systems helps us to understand their evolution.

关键词： (stars:)binaries:eclipsing stars:fundamental parameters stars:individual(AA Cet)

Partition method and experimental validation for impact dynamics of flexible multibody system

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Acta Mechanica Sinica 2018年第3期34卷 482-492页

作者： J.y.Wang z.y.Liu J.z.Hong School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong University

The impact problem of a flexible multibody system is a non-smooth, high-transient, and strong-nonlinear dynamic process with variable boundary. How to model the contact/impact process accurately and efficiently is one of the main difficulties in many engineering applications. The numerical approaches being used widely in impact analysis are mainly from two fields： multibody system dynamics （MBS） and computational solid mechanics （CSM）. Approaches based on MBS provide a more efficient yet less accurate analysis of the contact/impact problems, while approaches based on CSM are well suited for particularly high accuracy needs, yet require very high computational effort. To bridge the gap between accuracy and efficiency in the dynamic simulation of a flexible multibody system with contacts/impacts, a partition method is presented considering that the contact body is divided into two parts, an impact region and a non-impact region. The impact region is modeled using the finite element method to guarantee the local accuracy, while the non-impact region is modeled using the modal reduction approach to raise the global efficiency. A three-dimensional rod-plate impact experiment is designed and performed to validate the numerical results. The principle for how to partition the contact bodies is proposed： the maximum radius of the impact region can be estimated by an analytical method, and the modal truncation orders of the non-impact region can be estimated by the highest frequency of the signal measured. The simulation results using the presented method are in good agreement with the experimental results. It shows that this method is an effec-rive formulation considering both accuracy and efficiency. Moreover, a more complicated multibody impact problem of a crank slider mechanism is investigated to strengthen this conclusion.

关键词： Partition method Impact dynamics Experimental investigation Efficiency and accuracy Partition principle

High-Speed Friction Stir Welding of T6-Treated B4Cp/6061Al Composite

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Acta Metallurgica Sinica(English Letters) 2020年第1期33卷 67-74页

作者： y.z.Li y.N.zan Q.z.Wang B.L.Xiao z.y.Ma Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China University of Science and Technology of China Shenyang 110016China

T6-treated 20 wt% B4 Cp/6061 Al sheets were joined under welding speeds of 400–1200 mm/min by friction stir welding(FSW) with a threaded cermet pin. The macro-defect-free FSW joints could be achieved at high welding speeds up to 1200 mm/min, but larger plunge depth was required at the welding speeds of 800 and 1200 mm/min to eliminate the tunnel defect. In the nugget zone(Nz) of the joints, the B4 C particles were broken up and uniformly redistributed. The Nz exhibited lower hardness than the base metal(BM), and the hardness value almost did not change with increasing welding speed, attributable to the dissolution of precipitates. Compared with the BM, the joints showed lower tensile strength. As the welding speed increased from 400 to 800 mm/min, the joint efficiencies were nearly the same and up to ~ 73%. When the welding speed increased up to 1200 mm/min, the tensile strength significantly decreased, due to the occurrence of kissing bond defect at the bottom of the Nz. With increasing welding speed, the fracture location of the joints transferred gradually from the heat-affected zone to the Nz due to the kissing bond defects.

关键词： Metal-matrix composites Microstructures Mechanical properties Friction stir welding High-speed welding

LOW CyCLE FATIGUE BEHAVIOR OF Az91HP ALLOy IN AS HIGHP RESSURE DIE CASTING

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Acta Metallurgica Sinica(English Letters) 2000年第4期13卷 961-966页

作者： Liu, z. Xu, y.y. Wang, z.G. Wang, y. Liu, z.y. Inst of Metal Research Chinese Acad of Sciences Shenyang China

Fully reversed total strain-controlled low-cycle fatigue tests were conducted at room temperature in air to study the fatigue behavior of Az91HP magnesium alloy in as high pressure die casting and subsequently heat treatment. All the specimens in different heat histories exhibit cyclic strain hardening in different degrees. It is difficult to distinguish the fatigue behavior of the die casting specimens from that of the solution aging specimens. The solution treated specimens show longer fatigue life at high strain amplitude and shorter fatigue life at low strain amplitude than the die casting and solution aging specimens though they have the lowest yield strength with higher strain hardening. Fatigue fracture surfaces for strain amplitude larger than 0.005 show very similar to those found by monotonic tensile tests. The SEM examination reveals that the regions of fatigue crack growth and final fracture can be characterized by quasi-cleavage mechanisms, but some shallow dimples, slip bands and secondary cracks are found on the fracture surface in the fracture crack growth areas.

关键词： Cracks Die casting Fatigue of materials Heat treatment

Microstructural characteristics and mechanical properties of the hot extruded Mg-zn-y-Nd alloys

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Journal of Materials Science & Technology 2021年第1期60卷 44-55页

作者： B.N.Du z.y.Hu L.y.Sheng D.K.Xu y.X.Qiao B.J.Wang J.Wang y.F.zheng T.F.Xi Shenzhen Institute Peking UniversityShenzhen 518057China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Jiangsu University of Science and Technology Zhenjiang 212003China Shenzhen yezhan Electronics Co. LtdShenzhen 518110China

A new type of Mg-zn-y-Nd alloy for degradable orthopedic implants was *** the present study,the zn and y content was adjusted and their influences on the microstructures and mechanical behaviors were discussed in *** results showed that the as-extruded Mg-zn-y-Nd alloys are mainly composed of fine dynamic recrystallized grains(DRXed grains),la rge unDRXed grains and linearly distributed secondary *** cha nge of zn content exerts little influence on the grain structure of the extruded Mg-zn-y-Nd alloy,while the increase of y content would hinder the dynamic recrystallization process and the growth of the DRXed grains,thus the size and volume fraction of the equiaxed DRXed grains *** tensile and compressive properties are very little affected by zn content because of the similar grain *** y content increases,the tensile yield strength(TyS) and ultimate strength(TUS) increase while the elongation decreases,this is caused by a combined strengthening effect of grain refinement,texture,precipitation and *** compressive yield strength(CyS) and ultimate strength(CUS) of Mg-zn-y-Nd alloy with diffe rent y content exhibit a similar tendency as the tensile test.

关键词： Mg-zn-y-Nd alloy Microstructure Tensile properties Compressive properties Basal texture Twin

Preface to the Special Issue:Friction Stir Welding and Processing

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Acta Metallurgica Sinica(English Letters) 2020年第1期33卷 1-2页

作者： z.y.Ma Institute of Metal Research Chinese Academy of SciencesShenyangChina

Friction stir welding(FSW),a highly effi cient solid-state joining technique,was invented at The Welding Institute,UK,in *** frictional and adiabatic heating,plastic deformation and solid-state diff usion,FSW has been widely accepted as a“green”welding technology owing to its energy effi ciency and environment ***,FSW has achieved broad application in various industries,such as aerospace and transportation,and is considered the most signifi cant development in the fi eld of material joining over the past two *** stir processing(FSP),later developed based on the fundamental principles of FSW,has been demonstrated as an eff ective and versatile metalworking technique for modifying and fabricating metallic materials.

关键词： FSP Preface to the Special Issue:Friction Stir Welding and Processing