Phase engineering of Pd–Te nanoplates via potential energy trapping

Phase modulation of noble metal alloys(NMAs)is critically important in nanoscience since the distinct atomic arrangements can largely determine their physicochemical properties.However,the precise modulation of NMAs is formidably challenging,because thermodynamically stable phases are generally preferential compared to those metastable ones.Herein,we proposed a potential energy trapping strategy for phase modulation of Pd–Te alloys with solvents.Thereinto,ethylene glycol can increase the energy barrier for both Pd leaching and Te introduction,forming metastable Pd20Te7 phase.Inversely,N,N-dimethylformamide is unable to trap metastable phase,inducing the phase evolution to thermodynamically stable PdTe phase,and the precise phase modulation was realized including Pd20Te7,PdTe and PdTe2 phases.The Pd–Te alloys displayed phase-dependent formic acid oxidation catalytic performance with PdTe phase showing the best.This work proposes a strategy for creating metastable phase with potential energy trap,which may deepen the understanding of phase engineering for noble metal-based nanocrystals.

Collective Excitations and Nonlinear Dynamics of 1D BEC with Two-and Three-body Interactions in Anharmonic Traps

The collective excitations of low-dimensional Bose-Einstein condensates with two- and three-body interactions in anharmonic potentials are investigated. Using the standard variational approach, the governing equations of motions for the low-energy excitations are obtained by solving time-dependent Gross-Pitaevskii-Ginzburg equation, and the excitation spectrums are calculated in small amplitude limit. The frequency shift and nonlinear mode coupling induced by the anharmonic distortion （adding cubic, quartic, or quintic terra to a harmonic trap） are studied.

Micro-scale Additive Manufacturing Using the Optical Potential Generated by a Bessel Beam

In this study,we proposed a novel micro-scale additive manufacturing method based on the optical potential formed by a Bessel beam.The proposed technique is expected to show no deterioration in manufacturing resolution due to heat genera-tion,to be applicable to various materials,and to be able to be performed in an air environment.The basic principle of the proposed method involves accumulating and stacking particles dispersed in air by using optical radiation pressure.In this paper,the trajectory of the accumulated particles was numerically estimated and experimentally observed.The numerical and experimental results agreed well;specfially,the back ground flow carried the particles to the optical axis of the Bessel beam,and then the particles were localized at the bottom of the optical potential valley on the substrate.Finally,a pillar structure was fabricated with polystyrene particles having a diameter of 1 um,which indicated that the proposed technique was promising for practical applications.

Bose-Einstein Condensate in a Linear Trap with a Dimple Potential

We study Bose-Einstein condensation in a linear trap with a dimple potential where we model dimple potentials by Dirac δ function. Attractive and repulsive dimple potentials are taken into account. This model allows simple, explicit numerical and analytical investigations of noninteracting gases. Thus, the Schrdinger equation is used instead of the Gross-Pitaevski equation. We calculate the atomic density, the chemical potential, the critical temperature and the condensate fraction. The role of the relative depth of the dimple potential with respect to the linear trap in large condensate formation at enhanced temperatures is clearly revealed. Moreover, we also present a semi-classical method for calculating various quantities such as entropy analytically. Moreover, we compare the results of this paper with the results of a previous paper in which the harmonic trap with a dimple potential in 1D is investigated.

quantum gases power law potential grand potential condensation hierarchy

The changes in characteristics of Bose condensation of ideal Bose gas due to an external generic power law potential U =∑~d_（i=1）ci｜xi/ai｜~（ni） are studied carefully. Detailed calculation of Kim et al.（J. Phys. Condens. Matter 11（1999） 10269） yielded the hierarchy of condensation transitions with changing fractional dimensionality. In this manuscript, some theorems regarding specific heat at constant volume CV are presented. Careful examination of these theorems reveal the existence of hidden hierarchy of the condensation transition in trapped systems as well.