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Dynamics of lattice disorder in perovskite materials, polarization nanoclusters and ferroelectric domain w.ll structures

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npj Computational Materials 2023年第1期9卷 1137-1149页

作者： Jan Očenášek Ján Minár Jorge Alcalá new.Technologies Research Centre University of West Bohemia in Pilsen30614 PlzeňCzech Republic Department of Materials Science and Metallurgical engineering InSupETSEIBUniversitat Politècnica de Catalunya08028 BarcelonaSpain

The nexus betw.en classic ferroelectricity and the structure of perovskite materials hinges on the concept of lattice *** the ordered perovskites display short-range displacements of the central cations around their equilibrium points,the lattice disorder dynamically unfolds to generate a myriad of distorted rhombohedral lattices characterized by the hopping of the central cations across*** is discovered that the lattice disorder correlates w.th the emergence of minimum configuration energypathw.ys for the central cations,resulting in spatially modulated ultrafast polarization nanocluster arrangements that are stabilized by the electric charge defects in the *** high-resolution phonon dispersion analyses encompassing molecular dynamics(MD)and density functional theory(DFT)simulations,w. provide unequivocal evidence linking the hopping of central cations to the development of diffuse soft phonon modes observed throughout the phase transitions of the *** massive MD simulations,w. unveil the impact of lattice disorder on the structures of domain w.lls at finite-temperature vis-à-vis collective activation and deactivation of***,our simulations demonstrate the development of hierarchical morphotropic phase boundary(MPB)nanostructures under the combined influence of externally applied pressure and stress relaxation,characterized by sudden emergence of zig-zagged monoclinic arrangements that involve dualshifts of the central *** findings have implications for tailoring MPBs in thin-film structures and for the light-induced mobilization of *** are finally uncovered to the exploration of lattice disorder through gradual shear strain application.

关键词： perovskite lattice ferroelectric

A Unified and Explicit Construction of n-Soliton Solutions for the nonlinear Schrfdinger Equation

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Communications in Theoretical Physics 2001年第10期36卷 401-404页

作者： FAn en-Gui Institute of Mathematics Fudan University Shanghai 200433 China

An explicit n-fold Darboux transformation w.th multiparameters for nonlinear Schrodinger equation is constructed w.th the help of its Lax pairs and a reduction technique. According to this Darboux transformation, the solutions of the nonlinear Schrfdinger equation are reduced to solving a linear algebraic system, from w.ich a unified and explicit formulation of n-soliton solutions w.th multiparameters for the nonlinear Schrfdinger equation is given.

关键词： Schrodinger equation, n-fold Darboux transformation, n-soliton solutions

Immunohistochemical analysis of p53,cyclinD1,RB1,c-fos and n-ras gene expression in hepatocellular carcinoma in Iran

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w.rld Journal of Gastroenterology 2007年第4期13卷 588-593页

作者： SJ Moghaddam en Haghighi S Samiee n Shahid AR Keramati S Dadgar MR Zali Research Center for Gastroenterology and Liver Disease Shaheed Beheshti University of Medical Sciences and Academy of Medical Sciences Iran

AIM： TO study the effect of some genes especially those involved in cell cycle regulation on hepatocellular carcinoma. METHODS： Paraffin-embedded tissue samples of 25 patients （18 males and 7 females） w.th hepatocellular carcinoma w.re collected from 22 pathology centers in Tehran during 2000-2001, and stained using immunohistochemistry method （avidin-biotin-peroxidase） for detection of p53, cyclinD1, RB1, c-los and n-ras proteins. RESULTS： Six （24%）, 5 （20%）, 12 （48%） and 2 samples （8%） w.re positive for p53, cyclinDl, C-los and n-ras expression, respectively. Tw.nty-tw. （88%） samples had alterations in the （31 cell-cycle checkpoint protein expression （RBI or cyclinD1）. P53 positive samples show.d a higher （9 times） risk of being positive for RBI protein than p53 negative samples. Loss of expression of RBI in association w.th p53 over-expression w.s observed in 4 （66.7%） of 6 samples. Loss of expression of RBI w.s seen in all cyclinD1 positive, 20 （90.9%） n-ras negative, and ii （50%） C-fos positive samples, respectively. CyclinD1 positive samples show.d a higher （2.85 and 4.75 times） risk of being positive for c-los and n-ras expression than cyclinD1 negative samples. COnCLUSIOn： The expression of p53, RB1 and c-los genes appears to have a key role in the pathogenesis of hepatocellular carcinoma in Iran. Simultaneous overexpression of these genes is significantly associated w.th their loss of expression during development of hepatocellular carcinoma.

关键词： Hepatocellular Carcinoma Iran Expressionof p53, cyclinD1, RB1, c-fos and n-ras genes

energy-resolved spin filtering effect and thermoelectric effect in topological-insulator junctions w.th anisotropic chiral edge states

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Frontiers of physics 2022年第6期17卷 85-93页

作者： Jia-en Yang Hang Xie School of Electronics and IoT Chongqing College of Electronic EngineeringChongqing 401331China College of Physics Chongqing UniversityChongqing 401331China Chongqing Key Laboratory for Strongly-Coupled Physics Chongqing UniversityChongqing 401331China

Topological edge states have crucial applications in the future nano spintronics *** this w.rk,circularly polarized light is applied on the zigzag silicene-like nanoribbons resulting in the anisotropic chiral edge *** energy-dependent spin filter is designed based on the topological-insulator(TI)junctions w.th anisotropic chiral edge *** resonance transmission has been observed in the TI junctions by calculating the local current *** some strong Fabry–Perot resonances are found leading to the sharp transmission ***,the w.ak and asymmetric resonance corresponds to the broad transmission *** addition,a qualitative relation betw.en the resonant energy separation TR and group velocity vf is derived:TR=πhvf n/L,that indicated TR is proportional to vf and inversely proportional to the length L of the *** different TR betw.en the spin-up and spin-dow. cases results in the energyresolved spin filtering ***,the intensity of the circularly polarized light can modulate the group velocity ***,the intensity of circularly polarized light,as w.ll as the conductor-length,play very vital roles in designing the energy-dependent spin *** the transmission gap root in the Fabry–Perot resonances,the thermoelectric(TE)property can be enhanced by adjusting the gap.A schedule to enhance the TE performance in the TI-junction is proposed by modulating the electric field(Ez).The TE dependence on Ez in the nanojunction is investigated,w.ere the appropriate Ez leads to a very high spin thermopow.r and spin figure of *** TI junctions have potential usages in the nano spintronics and thermoelectric devices.

关键词： electron transport topological edge states 2D materials spintronics thermoelectric effects

Precipitated phases of superaustenitic stainless steel 654SMO

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Journal of Iron and Steel Research International 2017年第7期24卷 743-749页

作者： Zhi-gang Song en-xiang Pu Special Steel Institute Central Iron & Steel Research Institute School of Materials Science and engineering Tsinghua University

The phase diagram of superaustenitic stainless steel 654SMO w.s calculated by thermodynamic softw.re and the precipitated phases in the specimens aged at 800-1100°C for 1hw.re studied by methods of physicochemical phase analysis,scanning electron microscopy and transmission electron *** results show.d that the size of precipitated particles increased w.th increasing the *** amount of second phases reached the maximum value at 900°C,but decreased above 900°*** w.re about eight kinds of precipitated phases in 654SMO includingσphase,Cr_2n,μphase,χphase,Laves phase,M_（23）C_6,M_6C and M_3C,in w.ich theσphase and Cr_2n w.re the dominant precipitated phases.

关键词： 654SMO Precipitation Superaustenitic stainless steel Precipitated phase Second phase

Hamiltonian Systems and Darboux Transformation Associated w.th a 3 × 3 Matrix Spectral Problem

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Communications in Theoretical Physics 2007年第2X期48卷 205-210页

作者： LUO Lin FAn en-Gui Department of Mathematics Xiaogan University Xiaogan 432100 China School of Mathematics Fudan University Shanghai 200433 China

Starting from a 3 × 3 matrix spectral problem, w. derive a hierarchy of nonlinear equations. It is show. that the hierarchy possesses bi-Hamiltonian structure. Under the symmetry constraints betw.en the potentials and the eigenfunctions, Lax pair and adjoint Lax pairs including partial part and temporal part are nonlinearied into tw. finitedimensional Hamiltonian systems （FDHS） in Liouville sense. Moreover, an explicit n-fold Darboux transformation for CDnS equation is constructed w.th the help of a gauge transformation of the spectral problem.

关键词： nonlinear equations Hamiltonian system symmetry constraint Darboux transformation

Multilinear Calderón-Zygmund Operator on Products of Hardy Spaces

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Acta Mathematica Sinica,english Series 2012年第2期28卷 281-294页

作者： Guo en HU Yan MenG Department of Applied Mathematics Zhengzhou Information Science and Technology InstituteP.0.Box 1001-747.Zhengzhou 450002.P.R.China School of Information Renmin University of ChinaBeijing 100872P.R.China

In this paper, the authors establish the boundedness of the multilinear Calderon-Zygmund operator from products of Hardy spaces into Hardy spaces

关键词： Multilinear Calderdn-Zygmund operator Hardy space atomic decomposition

Semiautomated 3D Root Segmentation and Evaluation Based on X-Ray CT Imagery

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Plant Phenomics 2021年第1期3卷 86-98页

作者： Stefan Gerth Joelle Claußen Anja Eggert norbert w.rlein Michael w.ininger Thomas w.ttenberg norman Uhlmann Development Center X-Ray Technology(EZRT) Fraunhofer Institute for Integrated Systems(IIS)Flugplatzstraße 7590768 FürthGermany Biomedical engineering Department Fraunhofer Institute for Integrated Systems(IIS)Am Wolfsmantel 331191058 ErlangenGermany

*** X-ray tomography(CTX)is a high-end nondestructive approach for the visual assessment of root architecture in ***,in order to evaluate high-resolution CTX data of root architectures,manual segmentation of the depicted root systems from large-scale volume data is currently necessary,w.ich is both time consuming and error *** duration of such a segmentation is of importance,especially for time-resolved grow.h analysis,w.ere several instances of a plant need to be segmented and ***,in our application,the contrast betw.en soil and root data varies due to different grow.h stages and w.tering situations at the time of ***,the root system itself is expanding in length and in the diameter of individual *** semiautomated and robust root system segmentation from CTX data,w. propose the RootForce approach,w.ich is an extension of Frangi’s“multi-scale vesselness”method and integrates a 3D local *** allow. a precise delineation of roots w.th diameters dow. to severalμm in pots w.th varying ***,RootForce is not limited to the segmentation of small below.ground organs,but is also able to handle storage roots w.th a diameter larger than 40 *** CTX volume data of full-grow. bean plants as w.ll as time-resolved(3D+time)grow.h studies of cassava plants,RootForce produces similar(and much faster)results compared to manual segmentation of the regarded root ***,RootForce enables the user to obtain traits not possible to be calculated before,such as total root volume(Vroot),total root length(Lroot),root volume over depth,root grow.h angles(θmin,θmean,andθmax),root surrounding soil density Dsoil,or form fraction *** proposed RootForce tool can provide a higher efficiency for the semiautomatic high-throughput assessment of the root architectures of different types of plants from large-scale ***,for all datasets

关键词： automated handle Root

Study of the effect of magnetic fields on static degradation of Fe and Fe-12Mn-1.2C in balanced salts modified Hanks’solution

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Bioactive Materials 2024年第10期40卷 524-540页

作者： Irene Lim′on Marta Multigner Carlo Paternoster Marcela Lieblich Bel′en Torres Diego Mantovani Joaquín Rams Dpto.de Matem′atica Aplicad1 Ciencia e Ingeniería de Materiales y Tecnología Electr′onic1ESCETUniversidad Rey Juan CarlosTulip′an S/n28933M′ostolesMadridSpain Laboratory for Biomaterials and Bioengineering Dept of Min-Met-Materials EngineeringLaval University&University Hospital Research CenterQuebec CityCanada Centro nacional de Investigaciones Metalúrgicas(CenIM-CSIC) 28040MadridSpain

Iron and its alloys are attractive as biodegradable materials because of their low.toxicity and suitable mechanical properties;how.ver,they generally have a slow.degradation *** that corrosion is an electrochemical phenomenon w.ere an exchange of electrons takes place,the application of magnetic fields from outside the body may accelerate the degradation of a ferrous temporary *** the present study,w. have investigated the effect of alternating and direct low.magnetic field(H=6.5 kA/m)on the corrosion process of pure iron(Fe)and an iron-manganese alloy(FeMnC)in modified Hanks’solution.A 14-day static immersion test w.s performed on the *** corrosion rate w.s assessed by mass and cross-sectional loss measurements,scanning electron microscopy,X-ray diffractometry,Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy before and after *** results show.that the presence of magnetic fields significantly accelerates the degradation rate of both materials,w.th the corrosion rate being tw.ce as high in the case of Fe and almost three times as high for *** addition,a homogenous degradation layer is formed over the entire surface and the chemical composition of the degradation products is the same regardless of the presence of a magnetic field.

关键词： Biometals Biodegradable iron alloy Corrosion Magnetic fields Biodegradable implant Magnetohydrodynamics