检索结果-南通市图书馆

An effective-field theory study of hexagonal Ising nanowire: Thermal and magnetic properties

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2014年第4期23卷 465-471页

作者： Yusuf Kocakaplan Ersin Kantar Institute of Science Erciyes University Department of Physics Erciyes University

By means of the effective-field theory （EFT） with correlations, the thermodynamic and magnetic quantities （such as magnetization, susceptibility, internal energy, specific heat, free energy, hysteresis curves, and compensation behaviors） of the spin-l/2 hexagonal Ising nanowire （HIN） system with core/shell structure have been presented. The hysteresis curves are obtained for different values of the system parameters, in both ferromagnetic and antiferromagnetic cases. It has been shown that the system only undergoes a second-order phase transition. Moreover, from the thermal variations of the total magnetization, the five compensation types can be found under certain conditions, namely the Q-, R-, S-, P-, and N-types.

关键词： hexagonal Ising nanowire effective-field theory hysteresis curve compensation behavior

Effect of alumina thickness on Al_2O_3/InP interface with post deposition annealing in oxygen ambient

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2014年第7期23卷 681-685页

作者：杨卓杨靖治黄永张锴郝跃 State Key Discipline Laboratory of Wide Band-gap Semiconductor Technology Xidian University

In this paper, the effect of alumina thickness on Al2O3/InP interface with post deposition annealing （PDA） in the oxygen ambient is studied. Atomic layer deposited （ALD） Al2O3 films with four different thickness values （5 nm, 7 nm, 9 nm, 11 rim） are deposited on InP substrates. The capacitance-voltage （C-V） measurement shows a negative correlation between the alumina thickness and the frequency dispersion. The X-ray photoelectronspectroscopy （XPS） data present significant growth of indium-phosphorus oxide near the Al2O3/InP interface, which indicates serious oxidation of InP during the oxygen annealing. The hysteresis curve shows an optimum thickness of 7 nm after PDA in an oxygen ambient at 500 ℃ for 10 min. It is demonstrated that both sides of the interface are impacted by oxygen during post deposition annealing. It is suggested that the final state of the interface is of reduced positively charged defects on Al2O3 side and oxidized InP, which degrades the interface.

关键词： Al2O3 oxygen annealing capacitance-voltage measurement hysteresis curve

Bond Behavior of Corroded Reinforcement in Concrete Wrapped with Carbon Fiber Reinforced Polymer Under Cyclic Loading

在线全文

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2013年第3期18卷 271-277页

作者：代晓东王小惠寇新建 Department of Civil Engineering Shanghai Jiaotong University

Bond behavior of corroded reinforcement in concrete wrapped with carbon fiber reinforced polymer (CFRP) under cyclic loading is experimentally investigated. An electrolyte corrosion technique is used to accelerate the corrosion of the steel bar in cylindrical concrete specimens. Wrapped specimens are strengthened with one layer of CFRP after the reinforcements are corroded. The experimental parameters investigated include: corrosion level, CFRP wrapped and number of loading cycles. Test results indicate that bond strength and area of hysteretic curve of CFRP wrapped specimens are larger than those of the unwrapped specimens. With increasing the number of loading cycles, the bond strength and area of hysteretic curve decrease gradually, especially at the 1st cyclic loading. The CFRP wrapping reduces the bond degradation rate effectively and prevents the bond-splitting failure of the corroded concrete specimens.

关键词： carbon fiber reinforced polymer (CFRP) bond corrosion cyclic loading hysteresis curve

Mechanical properties of disc-spring vibration isolators based on boundary friction

在线全文

学校读者我要写书评

暂无评论

Journal of Southeast University(English Edition) 2014年第1期30卷 39-44页

作者：贾方张凡成东南大学机械工程学院南京210096

To ascertain the influence of the boundary friction on mechanical properties of disc-spring vibration isolators a load-displacement hysteresis curve formula of disc-spring vibration isolators is derived on the basis of the energy conservation law as well as considering the effect of the boundary *** formula is validated through the finite element analysis and static load *** this basis the effect of the boundary friction on the bearing capacity is researched. Then the dynamic performance of disc-spring vibration isolators is studied by dynamic *** experimental results indicate that the boundary friction can promise a larger damping with a ratio of 0.23 for disc-spring vibration *** with the loading frequency the loading amplitude has a greater impact on the energy consumption dynamic stiffness and damping of vibration *** research can provide valuable information for the design of disc-spring vibration isolators.

关键词： disc-spring vibration isolator boundary friction hysteresis curve dynamic stiffness damping finite element analysis FEA

Cyclic stress-strain behavior of structural steel with yield- strength up to 460 N/mm^2

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2014年第2期8卷 178-186页

作者： Yiyi CHEN Wei SUN Tak-Ming CHAN State Key Laboratory of Disaster Reduction in Civil Engineering Tong/i University Shanghai 200092 China Architecture Design & Research Institute of Tongji University (Group) Co. Ltd. Shanghai 200092 China School of Engineering University of Warwick Coventry CV4 7AL UK I

This paper presents a constitutive model based on Ramberg-Osgood equation to describe the hysteresis material behavior of structural carbon steel with nominal yield strength between 235 to 420 N/mm^2. The proposed model was calibrated against a series of cyclic material tests with strain amplitude varying from 0.5% to 2.0%. A simple relationship between the modular parameter K and the yield strengthfy was proposed. The calibrated Ramberg-Osgood model revealed excellent agreement with the experimental results and captured further the experimental behavior of test specimens with nominal yield strength of 460 N/mm^2. The proposed constitutive model was also adopted in conjunction with the combined kinematic/isotropic materials description in ABAQUS to mimic a full scale experimental test under cyclic loading. The numerical results revealed close agreement with the experimental observations.

关键词： constitutive model finite element analysis hysteresis curve Ramberg-Osgood equation

Effect of sintering temperature on structural,magnetic,dielectric and optical properties of Ni-Mn-Zn ferrites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Dielectrics 2021年第6期11卷 59-67页

作者： Nazia Khatun Mohammad Sajjad Hossain MostHosney Ara Begum Suravi Islam Nazmul Islam Tanvir Riyadh Hossen Bhuiyan Md.Al-Mamun Industrial Physics Division Bangladesh Council of Scientific and Industrial Research(BCSIR)Dhaka 1205Bangladesh Fiber and Polymer Division Bangladesh Council of Scientific and Industrial Research(BCSIR)Dhaka 1205Bangladesh Atomic Energy Centre(AEC) Dhaka 1000Bangladesh

Spinel ferrite Ni_(0.08)Mn_(0.90)Zn_(0.02)Fe_(2)O_(4)was prepared by a conventional ceramic process followed by sintering at three different temperatures(1050°C,1100°C and 1150°C).X-ray diffraction(XRD)investigations stated the single-phase cubic spinel structure and the FTIR spectra revealed two prominent bands within the wavenumber region from 600 cm^(−1)to 400 cm^(−1).Surface morphol-ogy showed highly crystalline grain development with sizes ranging from 0.27μm to 0.88μ*** magnetic hysteresis curve at ambient temperature revealed a significant effect of sintering temperature on both coercivity(Hc)and saturation magnetization(Ms).Temperature caused a decrease in DC electrical resistivity,while the electron transport increased,suggesting the semicon-ducting nature of all samples and that they well followed the Arrhenius law from which their activation energies were *** values of Curie temperature(Tc)and activation energy were influenced by the sintering ***-dependent dielectric behavior(100 Hz-1 MHz)was also analyzed,which may be interpreted by the Maxwell-Wagner-type *** UV-vis-NIR reflectance curve was analyzed to calculate the bandgap of ferrites,which showed a decreasing trend with increasing sintering temperature.

关键词： Ferrites ceramic technique FTIR dielectric constant hysteresis curve bandgap

Finite Element Analysis (FEA) for the Beam-Column Joint Subjected to Cyclic Loading Was Performed Using ANSYS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Circuits and Systems 2016年第8期7卷 1581-1597页

作者： B. Venkatesan R. Ilangovan P. Jayabalan N. Mahendran N. Sakthieswaran Department of Civil Engineering University VOC College of Engineering Thoothukudi India Department of Civil Engineering University College of Engineering Dindigul India Deptartment of Civil Engineering National Institute of Technology Tiruchirappalli India Deptartment of Civil Engineering PSNA College of Engineering and Technology Dindigul India Department of Civil Engineering Anna University Regional Campus Tirunelveli India

This paper analyses the seismic performance of exterior beam-column joints strengthened with unconventional reinforcement detailing. The beam-column joint specimens were tested with reverse cyclic loading applied at the beam end. The samples were divided into two groups based on the joint reinforcement detailing. The first group (Group A) of three non-ductility specimens had joint detailing in accordance with the construction code of practice in India IS456-2000, and the second group (Group B) of three ductility specimens had joint reinforcement detailed as per IS13920-1993, with similar axial load cases as the first group. The experimental studies are proven with the analytical studies carried out by finite element models using ANSYS. The results show that the hysteresis simulation is satisfactory for both un-strengthened and ferrocement strengthened specimens. Furthermore, when ferrocement strengthening is employed, the strengthened beam-column joints exhibit better structural performance than the un-strengthened specimens of about 31.56% and 38.98 for DD-T1 and DD-T2 respectively. The analytical shear strength predictions were in line with the test results reported in the literature, thus adding confidence to the validity of the proposed models.

关键词： Beam-Column Joints Cyclic Load Ferrocement Ductility hysteresis curve ANSYS

Exchange Interactions at the Interface FMIAFM Nanocomposite Obtained by Mechanochemical Synthesis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Chemistry and Chemical Engineering 2013年第12期7卷 1149-1155页

作者： Lenine Campos Miranda Fabio Cavalcanti Lopes Andre Galembeck Eduardo Padron Hemaindez Materials Science Program Federal University of Pernambuco Recife 50740-560 Brazil Department of Physics Federal University of Pernambuco Recife 50740-560 Brazil Department of Chemistry Federal University of Pernambuco Recife 50740-560 Brazil Technology Center of Northeast Recife 50740-560 Brazil

This paper presents a study of the relationship between the magnetic properties and microstructure of nanocomposite Ni/MnO, Ni/CoO, Co/MnO, Co/CoO. The objective is to understand how the coupling interface FM/AFM （ferromagnetic/anti-ferromagnetic） manifests itself in magnetic response of these materials to an applied field. Sample preparation was performed using mechanochemical synthesis by means of a ball mill planetary type high power at normal atmosphere. The characterization was done by XRD （X-ray diffraction）, SEM （scanning electron microscopy） and VSM （vibrating sample magnetometry）. Analyzing the XRD peaks of the samples studied, there was a decrease in the average particle diameter with increasing milling time, which is important in the magnetic interactions of the atoms of the surface. In addition, the diffraction pattern showed formation of new phases by oxidation interfering with the magnetic measurements. Analyses by SEM show chipboard multiform nano- and micrometer-sized grains on the surface of the clusters being responsible for the interaction. The magnetic measurements show a strong coupling between the phases present in nanocomposites showing once again that the MS （mechanosynthesis） is a powerful technique for this kind of purpose. The effect of the decrease in crystallite size leads to large variations of magnetic properties of the material which have been specifically observed changes in HC （coercive field） in the RM （remanent magnetization） and SM （saturation magnetization）. The decrease in crystallite size in the course of grinding intensifies the effects that depend on the surface-to-volume ratio of the material. M vs. T measures were taken for different values of applied field and found a jump in the moment of the sample near the N6el temperature of the antiferromagnetic.

关键词： Nanocomposites mechanical alloying hysteresis curve coupling FM/AFM N6el temperature.

Experimental Research on Annular-Plate Joint Between Circular Steel-tube Column and H-shaped Steel Beam

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Experimental Research on Annular-Plate Joint Between Circula...