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1.
Knowledge of the vibrational properties of nanoparticles is of fundamental interest since it is a signature of their morphology, and it can be utilized to characterize their physical properties. In addition, the vibration characteristics of the nanoparticles coupled with surrounding media and subjected to magnetic field are of recent interest. This paper develops an analytical approach to study the radial breathing-mode frequency of elastically confined spherical nanoparticles subjected to magnetic field. Based on Maxwell's equations, the nonlocal differential equation of radial motion is derived in terms of radial displacement and Lorentz's force. Bessel functions are used to obtain a frequency equation. The model is justified by a good agreement between the results given by the present model and available experimental and atomic simulation data. Furthermore, the model is used to elucidate the effect of nanoparticle size, the magnetic field and the stiffness of the elastic medium on the radial breathing-mode frequencies of several nanoparticles. Our results reveal that the effects of the magnetic field and the elastic medium are significant for nanoparticle with small size. 相似文献
2.
V. V. Sagaradze N. V. Kataeva V. A. Zavalishin K. A. Kozlov V. V. Makarov A. R. Kuznetsov 《哲学杂志》2020,100(14):1868-1879
ABSTRACT The authors present the results of an investigation in Fe–Ni-Cr austenitic alloys of the low-temperature deformation-induced segregations of nickel that form in the micro regions being (i) located close to grain- and subgrain boundaries and (ii) characteristic of the concentration and magnetic inhomogeneities indicated by the appearance of a dark diffraction contrast at the electron diffraction patterns taken from these regions typical (at the same time) of an enhanced value of Curie temperature. The observed effects were connected with the micro distortions caused by the local change of lattice parameter because of an increase in nickel concentration, as well as in the result of a magnetostriction dilatation. Using methods of the X-ray energy dispersive spectroscopy (XEDS) and atomic-probe body-section radiography (tomography – APT) has made it possible to determine the borders of those regions of austenite that were characteristic of an enhanced concentration of nickel in the fields of the localisation of a deformation-induced segregation of nickel in the vicinity of grain (subgrain) boundaries of austenitic alloys of the types Fe–13Cr–30Ni and Fe–37Ni–3Ti. 相似文献
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V. V. Kuznetsov N. V. Morozova V. N. Kudryavtsev 《Russian Journal of Electrochemistry》2006,42(6):665-669
Dependences of the current and the chemical composition of cathodic deposits on the electrolysis time are studied in an ammonia-citrate electrolyte for the deposition of a nickel-molybdenum alloy in potentiostatic conditions. At potentials less negative than ?0.93 V, no nickel-molybdenum alloy deposition occurs and in the course of electrolysis there is observed a decrease in the current, which is connected with the blocking of the electrode surface by the formed molybdenum oxides. In the region of potentials of deposition of a nickel-molybdenum alloy there is realized the following shape of a time dependence of the current. Within the first few seconds of the electrolysis process, the current somewhat decreases. Then there occurs its increase, which is connected with the alloy deposition on the cathode. In the course of electrolysis there occurs a decrease in the molybdenum content in the cathodic deposit. 相似文献
7.
根据Co P非晶态合金结构的短程有序和结构中可能存在P -P相互作用的实验事实 ,选择了单磷原子簇模型ConP(n =1~ 5 )和双磷原子簇模型ConP2 (n =1~ 4 ) ,用密度泛函理论方法对其进行计算 .结果表明 ,在单磷Co2 P( 2 ) 、Co3 P( 1) 及Co4P( 2 ) 模型体系中 ,Co原子供给P原子电子 ,与电负性规则一致 ,同时Co和P之间具较强化学作用 ,可以形成稳定的原子簇 ;而在双磷和单磷原子簇Co5P( 1) 模型体系中 ,形成的原子簇不稳定 ,采用单磷Co2 P( 2 ) 、Co3 P( 1) 及Co4P( 2 ) 模型能较好地反映Co P非晶态合金的结构特点 . 相似文献
8.
Non-isothermal short-range-order kinetics of binary alloys as influenced by solute-vacancy complexes
A model describing the roles of bound and unbound vacancies is proposed in order to predict defect decay and short-range-order
kinetics of quenched binary alloys during linear heating experiments. This is an alternative treatment of a previous approach.
The model has been applied to the differential scanning calorimetry (DSC) curves of Cu-5 at.% Zn quenched from different temperatures.
An expression to calculate the activation energy for migration of solute-vacancy complexes was also developed which make use
of DSC trace data. A value of 89.12±0.32 kJ mol-1 was obtained for the above alloy. The relative contribution of bound and unbound vacancies to partition of effective activation
energy corresponding to the ordering process as influenced by quenching temperature was also assessed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
A Raney-Ag catalyst was prepared by leaching out aluminium from a Raney Ag-Al alloy with NaOH solution. The kinetics of leaching
has been investigated in a stirred-batch-reactor at various temperatures by using alloy particles of different sizes. The
kinetic model best fitting the experimental results has been determined.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
10.
《Journal of Physics and Chemistry of Solids》2004,65(4):799-803
The application of theoretical methods based on density functional theory using generalized-gradient approximation functionals provides reasonable estimates of the exchange coupling constants for polynuclear transition metal complexes. Calculations for the complete, non-modeled Fe19 complex have been performed and a comparison with the experimental magnetic susceptibility values using Monte Carlo simulations is presented. 相似文献