Debye Temperature of the MgCNi3 Superconductor

We have determined the Dabye temperature of the MgCNi3 superconductor by using the Rietveld refinement method based on the powder x-ray diffraction data.MgCNi3 crystallizes in the cubic perovskite structure with space group Pm3m and lattice constant a=3.8089A.The temperature factors of the atoms Mg,C and Ni are 0.52,0.45 and 0.44,respectively.The Debye temperature of MgCNi3 is calculated to be ΘD=440K.     

Solution of the Energy Level of Hydrogen－Like Atom for the Debye Shidlding Potential

The first-order revision and the approximation analytical formula of the energy levels for hydrogen-like atoms under the condition of Debye shielding potential are achieved by means of the Rayleigh-Schroedinger perturbation theory.meanwhile,the corresponding recurrence relations are obtained from the use of the solution of power series,Based on the above solutions and with the use of energy consistent method the equivalent value of second-order reversion under the condition of Debye shielding potential is produced as well and the esult is compared with the data obtained by the numerical method.Besides,the critical bond-state and corresponding cut-off conditions are discussed.     

Vibrations of Au?? and FeAu?? nanoparticles and the limits of the Debye temperature concept

We present first-principles calculations of the vibrational density of states (VDOS), the specific heat and the mean-squared displacement of the five lowest-energy isomers of Au(13) and of two low-energy FeAu(12) nanoparticles. We find that the vibrational contributions to the Helmholtz energy do not affect the energy ordering of the isomers. As expected, for nanoparticles the vibrational density of states differs dramatically from the function proposed by the Debye model. We demonstrate that, for the nanoclusters we studied, the alternative calculations of the 'Debye temperature' yield significantly inconsistent results. We conclude that T(D) obtained from a particular thermodynamic property is neither applicable for deriving conclusions about other thermodynamic properties nor correlated with atomic bond strengths. Instead, in order to describe the temperature dependence of a nanoparticle's mean-squared displacement and its specific-heat capacity, what is necessary is its discrete phonon spectrum.     

Solution of the level of approximation analytic formula of hydrogen-like atom for the Debye shielding potential by means of the power series

The first-order revision and the approximation analytical formula of the energy levels for hydrogen-like atoms in condition of the Debye shielding potential are achieved by means of the Rayleigh Schrodinger perturbation theory and the power series;meanwhile,the corresponding recurrence relations are got with the use of the solution of power series. Basic on mentioned above and with the use of energy consistent method, the equivalent value of second-order revision in condition of the Debye shielding potential as well be got and the result is compared with the data obtained by the numerical method. Beside, the critical bond-state and corresponding cut off of conditions are discussed.     

Solution of the level of approximation analytic formula of hydrogen-like atom for the Debye shielding potential by means of the power series

The first-order revision and the approximation analytical formula of the energy levels for hydrogen-like atoms in condition of the Debye shielding potential are achieved by means of the Rayleigh Schrdinger perturbation theory and the power series;meanwhile,the corresponding recurrence relations are got with the use of the solution of power series.Basic on mentioned above and with the use of energy consistent method,the equivalent value of second-order revision in condition of the Debye shielding potential as well be got and the result is compared with the data obtained by the numerical method.Beside,the critical bond-state and corresponding cut off of conditions are discussed.     

On the Calculation of the Debye Temperature and Crystal–Liquid Phase Transition Temperature of a Binary Substitution Alloy

A method of estimating the interatomic pair interaction potential parameters for a binary substitution alloy with consideration for the deviation of its lattice parameter from the Vegard law is proposed. This method is used as a basis to calculate the Debye temperature and Grüneisen parameters of a SiGe alloy. It is shown that all these function nonlinearly variate with a change in the germanium concentration. Based on this technique and Lindemann's melting criterion, a method for calculating the liquidus and solidus temperatures of a disordered substitution alloy is proposed. The method is tested on the SiGe alloy and demonstrates good agreement with experimental data. It is shown that when the size of a nanocrystal of a solid substitution solution decreases, the difference between the liquidus and solidus temperatures decreases the more, the more noticeably the nanocrystal shape is deflected from the most energetically optimal shape.

     

Determination of interface layer thickness of a pseudo two—phase system by extension of the Debye equation

The Debye equation with slit-smeared small angle x-ray scattering(SAXS) data is extended form an ideal two-phase system to a pseudo two-phase system with the presence of the interface layer,and a simple accurate solution is proposed to determine the average thickness of the interface layer in porous materials.This method is tested by experimental SAXS data,which were measured at 25℃,of organo-modified mesoporous silica prepared by condensation of tetraethoxysiland(TEOS) and methyltriethoxysilane(MTES) using non-ionic neutral surfactant as template under neutral condition.     

Asymptotic behavior of the Schrödinger–Debye system with refractive index of quadratic wave amplitude

We obtain local well-posedness for the one-dimensional Schrödinger–Debye interactions in nonlinear optics in the spaces \(L^2\times L^p,\; 1\le p < \infty \). When \(p=1\) we show that the local solutions extend globally. In the focusing regime, we consider a family of solutions \(\{(u_{\tau }, v_{\tau })\}_{\tau >0}\) in \( H^1\times H^1\) associated to an initial data family \(\{(u_{\tau _0},v_{\tau _0})\}_{\tau >0}\) uniformly bounded in \(H^1\times L^2\), where \(\tau \) is a small response time parameter. We prove that \(\left( u_{\tau }, v_{\tau }\right) \) converges to \(\left( u, -|u|^2\right) \) in the space \(L^{\infty }_{[0, T]}L^2_x\times L^1_{[0, T]}L^2_x\) whenever \(u_{\tau _0}\) converges to \(u_0\) in \(H^1\) as long as \(\tau \) tends to 0, where u is the solution of the one-dimensional cubic nonlinear Schrödinger equation with the initial data \(u_0\). The convergence of \(v_{\tau }\) for \(-|u|^2\) in the space \(L^{\infty }_{[0, T]}L^2_x\) is shown under compatibility conditions of the initial data. For non-compatible data, we prove convergence except for a corrector term which looks like an initial layer phenomenon.     

Debye屏蔽势下的Na原子

结合自由Na原子的l-依赖模型势, 采用B-样条基组展开方法计算了等离子体环境中Na原子的的基态能量、振子强度、偶极极化率、四极极化率、八极极化率等随Debye长度的变化. 其中原子的等离子体效应采用Debye屏蔽模型. 计算结果与其他研究者的结果符合得很好; 在Debye屏蔽等离子体环境下下基态能量的结果与Sahoo [Sahoo S Ho Y K 2006 Phys. Plasmas 13, 063301]和Li [Li H W and Kar S, 2012 Phys. Plasmas 19, 073303]用其他模型所得的结果基本一致; 电偶极、四极和八极极化率随Debye长度的变化趋势一致, 数值结果和Li和Kar [Li H W and Kar S, 2012 Phys. Plasmas 19, 073303] 的数量级一致.     

Debye屏蔽势下的Na原子

结合自由Na原子的l-依赖模型势, 采用B-样条基组展开方法计算了等离子体环境中Na原子的的基态能量、振子强度、偶极极化率、四极极化率、八极极化率等随Debye长度的变化. 其中原子的等离子体效应采用Debye屏蔽模型. 计算结果与其他研究者的结果符合得很好; 在Debye屏蔽等离子体环境下下基态能量的结果与Sahoo [Sahoo S Ho Y K 2006 Phys. Plasmas 13, 063301]和Li [Li H W and Kar S, 2012 Phys. Plasmas 19, 073303]用其他模型所得的结果基本一致; 电偶极、四极和八极极化率随Debye长度的变化趋势一致, 数值结果和Li和Kar [Li H W and Kar S, 2012 Phys. Plasmas 19, 073303] 的数量级一致.     

Investigation of the Spectral Line Intensities of the ν9 Band of the Trans-Conformer of Ethylene

Russian Physics Journal - The intensities of 740 vibrational-rotational lines of the ν9 fundamental band in the IR spectrum of the trans-C2H2D2 molecule are first analyzed. The...     

Description of the evolution of the state of “josephson atoms” in the context of the informational interpretation of quantum mechanics

The evolution of a quantum system is informationally interpreted and used to describe decay in the coherent states of Josephson atoms, including qubits based on two- and three-junction superconducting quantum interferometers. The reduced Lindblad equation is employed to examine the measurement procedure of the Josephson qubit state and the influence of a measuring device on its coherent-state decay.     

On the interpretation of the results of the experimental test of the Askar’yan effect

The effect of the environment on the results of measuring the radio radiation spectrum is considered in the experimental simulation of the cascade shower by a high-energy γ-ray beam in a dense medium. The calculation shows that the character of the measured energy spectrum depends on the location of the receiving antenna with respect to the shower axis.     

A comparison of the reproducibility of the parameters of the ¹³C-aminopyrine breath test for the assessment of hepatic function

This study determined the within-subject and between-subject variability of different ways of expressing the results of the (13)C-aminopyrine breath test ((13)C-ABT) and the effect of shortening the test duration. The (13)C-ABT was conducted on three separate occasions in 10 healthy volunteers and on a single occasion in 22 patients with established liver cirrhosis. The within-subject variability of cumulative percentage dose recovered (cPDR), using measured CO(2) production rate (VCO(2)), in the reference group over three trials was 15% over 120 min. Higher within-subject variability in cPDR would have been evident if the test was terminated at either 30 or 60 min. Substitution of predicted VCO(2) to calculate cPDR yielded comparable values at all time points. Significant differences between cirrhotics and reference group were evident after just 10 min using PDR/h, cPDR or enrichment (all P<0.05). The ABT demonstrates clinically acceptable reproducibility. Shortening of the duration may make the test more acceptable clinically, but it is associated with increasing imprecision.     

Calculation of the phase diagram of the TiZr alloy and investigation of the tendency toward separation of the ω phase

The electronic, structural, and thermodynamic properties of the TiZr equiatomic alloy have been calculated in terms of the electron density functional theory and Debye-Grüneisen model. The calculated lattice parameters a and c/a agree well with experimental data for the α, ω, and β phases. It has been shown that the ω phase is stable at atmospheric pressure and low temperatures, and it remains energetically more favorable up to T = 600 K. In the temperature range 600 K < T < 900 K, the α phase becomes stable, and above 900 K, the β phase of the TiZr alloy is stable. The phase diagram constructed in this study agrees qualitatively with the available experimental data. A tendency toward separation of the TiZr equiatomic alloy in the ω phase has been analyzed. It has been demonstrated that, in the ground state, the TiZr equiatomic alloy in the ω phase exhibits a tendency toward ordering rather than toward phase separation.     

Evaluation of the Intensities of Spectral Lines under the Influence of Interferences and the Determination of Global Maxima of the Mass–Spectrum Peaks

We describe the technique by which the intensity of spectral lines can be evaluated and the global maxima of the mass–spectrum peaks under the influence of pulse interferences can be defined using an experimental setup based on a commercial MX–7304A mass spectrometer, IBM personal computer (PC), and a digital extremum regulator that allows one to ignore local extrema and bring about automatic search for a global maximum of the mass–spectrum peak and its tracking with an accuracy of 0.0012% at a speed of response of 50 kHz, elevated speeds of the scanning of masses 500 amu/sec, and stability of regulation.     

Analysis of the Structure of Thin Films of Zn‐Porphyrins by the Kinetics of the Fluorescence Anisotropy

The structure of thin films of Zntetraoctylphenylporphyrin (ZnTOPP) obtained by the spinning method is investigated. The kinetics of the decay of the fluorescence anisotropy of the films is analyzed in the form of a sum of exponents and by simulating the orientation of ZnTOPP complexes on the substrate (quartz) surface with allowance for the processes of the electron excitation energy transfer. The ZnTOPP films have a lamellar structure where individual layers form ordered domains. Within a domain, linear nonintersecting stacks of molecules are formed. In each stack the planes of the molecules are collinear, oriented perpendicularly to the surface of the substrate base, and form an angle of 45° with the directing axis of a stack.     

Analysis of the Structure of the Bands in the IR Spectrum of β-D Glucose by the Regularized Method of Deconvolution

Deconvolution of the IR absorption spectrum of -D glucose in the spectral range 1500–450 cm^–1 has been carried out. The results of the deconvolution were compared with the IR and Raman spectra recorded at room and low temperatures and with the data obtained by theoretical calculations for the frequencies of the normal vibrations of the -D glucose molecule in the crystalline state. It is shown that deconvolution of the IR spectra recorded at room temperature makes it possible to separate the bands observed experimentally only at a very low temperature of the sample and a number of components that were not resolved earlier. The number of bands separated on deconvolution of the IR spectra of -D glucose in the spectral range 1500–450 cm^–1 is more than twice the number of visible absorption maxima in the usual spectrum. The results of deconvolution of the IR spectrum of -D glucose are in good agreement with the data of theoretical calculations for the frequencies of the normal vibrations of the -D glucose molecule in the crystalline state. The existence of the factor-group (Davydov) splitting of a number of frequencies of the nondegenerate fundamental vibrations of molecules in a crystal cell has been revealed in the IR spectrum of -D glucose. It was concluded that the model of an isolated molecule is insufficient for detailed theoretical interpretation of the vibrational spectra of carbohydrates.     

Measurement of the integrated luminosity of the Phase 2 data of the Belle Ⅱ experiment

From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ experiment.Using Bhabha and digamma events,we measure the integrated luminosity of the data sample to be(496.3±0.3±3.0) pb~(-1),where the first uncertainty is statistical and the second is systematic.This work provides a basis for future luminosity measurements at Belle Ⅱ.     

The Structure of the Algebra of Observables in the Intermediate Situation of the ∈-Model

We look at the action of the spin-1/2 operatorsof quantum mechanics on the state of an entity in aphysical way, and use this as a guideline to define theoperators of the intermediate situations of a general spin-1/2 measurement model called the-model. Then we test the possible linearity ofthe operators so constructed.