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Shannon information entropies for rectangular multiple quantum well systems with constant total lengths

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Chinese Physics B 2018年第4期27卷 154-163页

作者： m Solaimani Guo-Hua Sun shi-Hai Dong Department of Physics Faculty of Science Qom University of Technology Qom Iran Catedrática CONACyT CIC lnstituto Politécnico Nacional Unidad Profesional ALM CDMX C. P. 07700 Mexico Laboratorio de Informacién Cuántica CIDETEC Instituto Politécnico Nacional Unidad Profesional ALM CDMX C. P. 07700 Mexico

We first study the Shannon information entropies of constant total length multiple quantum well systems and then explore the effects of the number of wells and confining potential depth on position and momentum information entropy density as well as the corresponding Shannon *** find that for small full width at half maximum（FWHm） of the position entropy density,the FWHm of the momentum entropy density is large and vice *** increasing the confined potential depth,the FWHm of the position entropy density decreases while the FWHm of the momentum entropy density *** increasing the potential depth,the frequency of the position entropy density oscillation within the quantum barrier decreases while that of the position entropy density oscillation within the quantum well *** increasing the number of wells,the frequency of the position entropy density oscillation decreases inside the barriers while it increases inside the quantum *** an example,we might localize the ground state as well as the position entropy densities of the1 st,2 nd,and 6 th excited states for a four-well quantum ***,we verify the Bialynicki–Birula–mycieslki（BBm）inequality.

关键词： position and momentum Shannon entropies multiple quantum well entropy densities

Crack Initiation mechanism of z3CN20.09m Duplex Stainless Steel during Corrosion Fatigue in Water and Air at 290 °C

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Journal of materials Science & Technology 2015年第11期31卷 1144-1150页

作者： H.C.Wu B.Yang Y.z.shi Q.Gao Y.Q.Wang State Key Laboratory for Advanced metals and materials University of Science and Technology Beijing Collaborative Innovation Center of Universal Iron & Steel Technology School of materials Science and Engineering Anhui University of Technology

The crack initiation mechanism of a z3CN20.09m duplex stainless steel （DSS） during corrosion fatigue （CF） in water and air at 290 ℃ was investigated by using a CF cracking machine and a scanning electron microscopy （SEm）. The cracks were initiated successively at the persistent stip bands （PSBs）, phase boundaries （PBs） and pitting corrosion points （PCPs） of the specimens when they were tested in water at 290 ℃, while in airat 290 ℃ the cracks were only initiated at the PSBs and PBs. And the cracks were found mainly to initiate at the PSBs and PBs when the specimens were tested in water and air at 290 ℃, respectively. The results also reveal that the cracks were likely to be initiated at the first 20% of fatigue life of the specimens tested in water at 290 ℃. However, the cracks were not found until 50% of fatigue life when tested in air at 290 ℃. moreover, the crack numbers of the specimens tested in water at 290 ℃ were much more than those tested in air at 290 ℃.

关键词： Duplex stainless steel Corrosion fatigue Crack initiation High temperature water

LOW CYCLE FATIGUE AND CREEP-FATIGUE BEHAVIOR OF A HIGH TEmPERATURE ALLOY ON SmOOTH AND NOTCHED SPECImENS

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Acta metallurgica Sinica(English Letters) 1999年第1期12卷 40-45页

作者： shi, H.J. Liu, S.L. He, Y.H. Duan, z.X. Tsinghua Univ Beijing China

A series of low cycle fatigue and creepfatigue tests on smooth specimens and notched specimens were performed with a high temperature alloy used in the manufacture of aeroengine turbine discs. The cyclic stressstrain behavior and fracture characteristics of the notched specimens were emphatically investigated. A comparison of fatigue behavior between smooth and notched specimens was done and lifetime of notched specimens was evaluated. At the same temperature, the fatiguecreep lives of the smooth specimens are far greater than that of the notched specimens.

关键词： low cycle fatigue creepfatigue stress concentration notch effect

Infrared, Diffuse Reflectance and Dielectric Studies ofAntimony Trisulphide

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Journal of materials Science & Technology 1998年第4期14卷 344-348页

作者： Hanafi, z.m. Ismail, F.m. Khalil, m.Sh. Inorganic Chemistry Dept. National Research Centre Dokki Cairo Egypt

Infrared absorption spectra of orange, black and transferred Sb//2S//3 samples have been studied in the spectral range 200-4000 cm** minus **1. The pronounced difference between the different samples is the appearance of excess sulphur present in the orange and transferred samples except those of transferred at 543 K and the black Sb//2S//3. The change of sharpness of some IR peaks reveals the amorphous/crystalline change. The effect of the degree of crystallinity and stoichiometry on the energy gap values was investigated by using optical method. The obtained dielectric parameters epsilon prime and epsilon double prime of the different samples are thoroughly affected by the degree of crystallinity and smoothly affected by either the frequency or the temperature or both, except at lower frequencies. (Edited author abstract) 26 Refs.

关键词： Antimony compounds

Antimonene-based saturable absorber for a soliton mode-locked and Q-switched fiber laser in the 2 μm wavelength region

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Chinese Physics B 2023年第6期32卷 259-269页

作者： H Ahmad B Nizamani m z Samion N Yusoff m F Ismail Photonics Research Centre Universiti Malaya50603 Kuala LumpurMalaysia Physics Department Faculty of ScienceUniversiti Malaya50603 Kuala LumpurMalaysia Distinguished Visiting Professor Universiti Kuala Lumpur British Malaysian Institute(UniKL BMI)Batu 8Jln Sungai Pusu53100SelangorMalaysia

We demonstrate antimonene as a saturable absorber(SA) to generate an ultrafast mode-locked and Q-switched laser in the 2 μm wavelength region. The two antimonene-based SAs were prepared and inserted separately in a thulium–holmiumdoped fiber laser to produce the pulsed laser. Antimonene was coated onto a tapered fiber to generate soliton mode-locked pulses and used in thin-film form for the generation of Q-switched pulses. The mode-locking was stable within a pump power of 267 m W–511 m W, and the laser operated at a central wavelength of 1897.4 nm. The mode-locked laser had a pulse width of 1.3 ps and a repetition rate of 12.6 mHz, with a signal-to-noise ratio of 64 d B. Q-switched laser operation was stable at a wavelength of 1890.1 nm within a pump power of 312 m W–381 m W. With the increase in pump power from 312 m W to 381 m W, the repetition rate increased to a maximum of 56.63 k Hz and the pulse width decreased to a minimum value of 2.85 μs. Wide-range tunability of the Q-switched laser was also realized within the wavelength range of1882 nm–1936 nm.

关键词： mode-locking Q-switched fiber laser optical saturable absorber

mECHANICS OF CARBON NANOSCROLLS: A REVIEW

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Acta mechanica Solida Sinica 2010年第6期23卷 484-497页

作者： Xinghua shi Nicola m. Pugno Huajian Gao School of Engineering Brown University 610 Barus & Holley 182 Hope Street Providence RI 02912 USA Laboratory of Bio-inspired Nanomechanics 'Giuseppe maria Pugno ' Department of Structural Engineering Politecnico di Torino Corso Duca degli Abruzzi 24 10129 Torino Italy

Carbon nanoscrolls （CNSs） belong to the same class of carbon-based nanomaterials as carbon nanotubes but are much less studied in spite of their great potential for applications in nanotechnology and bioengineering. Fundamental description, understanding and regulation of such materials will ultimately lead to a new generation of integrated systems that utilize their unique properties. In this review, we describe some of the recent advances in theoretical investi- gation on structural and dynamical behavior of CNS, as well as relevant simulation techniques. Theoretically it has been found that a stable equilibrium core size of CNS can be uniquely determined or tuned from the basal graphene length, the interlayer spacing, the interaction energy between layers of CNS and the bending stiffness of graphene. Perturbations of the surface energy, which can be controlled by an electric field, will cause a CNS to undergo breathing oscillatory motion as well as translational rolling motion on a substrate. The tunable core size of CNS also enables it to serve potentially as transmembrane water channels in biological systems.

关键词： Graphene

Energy transport for ion acoustic waves in a spin polarized quantum plasma

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Communications in Theoretical Physics 2020年第1期72卷 124-129页

作者： m Ayub z Iqbal H A Shah G murtaza Salam Chair Department of PhysicsG.C.UniversityKatchery RoadLahore 54000Pakistan Department of Physics G.C.UniversityKatchery RoadLahore 54000Pakistan Department of Physics Mirpur University of Science and TechnologyMirpur-10250(AJK)Pakistan

The separate spin evolution quantum hydrodynamics(SSE-QHD)model is used to investigate the energy behavior for ion acoustic waves in degenerate quantum *** results show that the energy flow speed decreases with spin polarization *** is also shown that it decreases with the increasing rate up to a certain range of wave number and then it goes to zero *** is observed that Bohm potential suppresses the energy flow *** is also noticed that the energy flow speed deviates from the group velocity even in the absence of Bohm potential ***,the contribution of of Bohm poential effect in spin polarized plasma reduces the extent of deviation.

关键词： spin polarization quantum plasma ion acoustic wave energy flow speed

Non-monotonic temperature evolution of nonlocal structure–dynamics correlation in Cuzr glass-forming liquids

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Chinese Physics B 2021年第7期30卷 370-375页

作者： W J Jiang m z Li Department of Physics and Beijing Key Laboratory of Opto-electronic Functional materials&micro-nano Devices Renmin University of ChinaBeijing 100872China

The structure–dynamics correlations in a nonlocal manner were investigated in Cuzr metallic glass-forming liquids via classical molecular dynamics simulations.A spatial coarse-graining approach was employed to incorporate the nonlocal structural information of given structural order parameters in the structure–dynamics *** is found that the correlation between structure order parameters and dynamics increases with increasing coarse-graining length and has a characteristic length ***,the characteristic correlation length exhibits a non-monotonic temperature evolution as temperature approaches glass transition temperature,which is not sensitive to the considered structure order *** results unveil a striking change in the structure–dynamics correlation,which involves no fitting theoretical *** findings provide new insight into the structure–dynamics correlation in glass transition.

关键词： metallic glass-forming liquid structure–dynamics correlation molecular dynamics simulation

Crystallization kinetics of overlapping phases in Se70Te15Sb15 using isoconversional methods

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Progress in Natural Science:materials International 2015年第2期25卷 169-177页

作者： m.A.Abdel-Rahim m.m.Hafiz A.z.mahmoud Physics Department Faculty of ScienceAssiut University Assiut 71516 Egypt

The crystallization kinetics of Se70Te15Sb15 chalcogenide glass was studied by Differential Scanning Calorimetry(DSC) under non-isothermal conditions. This glass was found to have a double glass transition and double overlapped crystalline phases. The overlapped crystalline phases were successfully separated using the Gaussian fit model. The activation energy, Ec, and Avrami index, n, were determined by analyzing the data using the matausita et. al. method. A strong heating rate depending on the activation energy for the two crystalline peaks was observed. The results indicated that the transformation from amorphous to crystalline phases is a complex process involving different mechanisms of nucleation and growth. The variation of activation energy with crystalline fraction was determined by Kissenger–Akahira–Sunose(KAS) method. The obtained results of directly fitting the experimental DSC data to the calculated DSC curves indicated that the crystallization process of Se70Te15Sb15 glass cannot be satisfactorily described by the Johnson–mehl–Avrami(JmA) model. Simulation results indicated that the Sestak–Berggren(SB) model is more suitable to describe the crystallization process for the studied glass. The crystalline phases for the two events were identified by using x-ray diffraction(XRD) and scanning electron microscopy(SEm).

关键词： Chalcogenides glasses Differential Scanning Calorimetry(DSC) Electron microscopy X-ray diffraction