St Petersburg Polytechnic University Journal-Physics and Mathematics最新文献_第9页

Experimental investigation of low-frequency pulsed Lorentz force influence on the motion of Galinstan melt 低频脉冲洛伦兹力对Galinstan熔体运动影响的实验研究

IF 0.2

St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-10-01 DOI: 10.1016/j.spjpm.2016.08.002

Diana A. Musaeva , Vladimir K. Ilyin , Vadims Geža , Egbert Baake

{"title":"Experimental investigation of low-frequency pulsed Lorentz force influence on the motion of Galinstan melt","authors":"Diana A. Musaeva , Vladimir K. Ilyin , Vadims Geža , Egbert Baake","doi":"10.1016/j.spjpm.2016.08.002","DOIUrl":"10.1016/j.spjpm.2016.08.002","url":null,"abstract":"<div><p>The paper presents the results of the numerical and physical experiments, aimed at assessing the influence of pulsed force of electromagnetic field on the melt motion and the fluid velocities. The experiment was performed on the eutectic alloy Galinstan in the cylindrical volume, where an ultrasonic Doppler velocimeter was employed for velocity measurements under conditions of pulsed and steady EM field application. A numerical simulation of the melt flow, forced by the steady EM force, involved a 2D axisymmetric model. The <em>k</em>-ε turbulence model was used to obtain the information about the melt velocities. The verification of the numerical model was carried out for the steady case. The effects of pulsed and steadily applied Lorentz force were compared using the physical experiment. An intensity of the velocity pulsations in Galinstan for the pulsed frequencies in the range from 0.05 to 1Hz considerably exceeded the values measured in the permanently stirred melt. For higher values of pulsed frequencies (from 1 to 10Hz) the effect decreases and only slightly differs from the influence of the permanently applied Lorentz force.</p></div>","PeriodicalId":41808,"journal":{"name":"St Petersburg Polytechnic University Journal-Physics and Mathematics","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.spjpm.2016.08.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72457696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

On homogenous solutions of the problem of a rectangular cantilever plate bending 矩形悬臂板弯曲问题的齐次解

IF 0.2

St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-10-01 DOI: 10.1016/j.spjpm.2016.08.007

Mikhail V. Sukhoterin, Sergey O. Baryshnikov, Kseniya O. Lomteva

{"title":"On homogenous solutions of the problem of a rectangular cantilever plate bending","authors":"Mikhail V. Sukhoterin, Sergey O. Baryshnikov, Kseniya O. Lomteva","doi":"10.1016/j.spjpm.2016.08.007","DOIUrl":"10.1016/j.spjpm.2016.08.007","url":null,"abstract":"<div><p>The paper considers the method suggested by Papkovich for rectangular plates and its application for a cantilever plate bending under a uniform load. The required function of the bendings is chosen in the form of a sum of the corresponding beam function and a biharmonic function, which is a series in terms of unorthogonal eigenfunctions of the problem. The eigenfunctions satisfy the homogenous boundary conditions on the longitudinal edges (the clamped and the opposite ones). It is suggested to find series coefficients from the condition of the minimum residuals effect on the corresponding displacements of the transverse edges. It leads to an infinite system of linear algebraic equations for the required coefficients in the complex form. The coefficients of homogenous solutions were found for the cases in which the approximating series contained sequentially 2, 3,...,7 terms. The eigenvalues, the bendings of the edge opposite to the clamped edge, and the bending moments in the clamped section were calculated. Convergence of the reduction method and stability of the computational process were analyzed.</p></div>","PeriodicalId":41808,"journal":{"name":"St Petersburg Polytechnic University Journal-Physics and Mathematics","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.spjpm.2016.08.007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80172660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

The effect of electron emission processes on micro- and nanoparticle charges in the dusty plasma for engineering applications 电子发射过程对尘埃等离子体中微粒子和纳米粒子电荷的影响

IF 0.2

St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-10-01 DOI: 10.1016/j.spjpm.2016.08.006

Vasiliy N. Savin, Sergey I. Mol'kov

{"title":"The effect of electron emission processes on micro- and nanoparticle charges in the dusty plasma for engineering applications","authors":"Vasiliy N. Savin, Sergey I. Mol'kov","doi":"10.1016/j.spjpm.2016.08.006","DOIUrl":"10.1016/j.spjpm.2016.08.006","url":null,"abstract":"<div><p>In this paper, the charge-balance, the energy-balance and the moment equations and Poisson's equation have been used to describe the charging process for a dust particle in the undisturbed plasma taking into account the emission variety (secondary electron, electron-ion, thermal-field electron and photoelectron types) in the intermediate regime of ion motion. Such an approach was associated with the fact that the dust-particle charge specified by the parameters of the above-mentioned plasma depends heavily on electron emission from the particle surface. Collisions between ions and atoms as well as ionization also essentially affect the formation of the ion flux onto the surface of dust particles. The computational procedure we propose has allowed solving the chosen set of equations for an arbitrary relationship between the ion mean free path, the particle radius and the Debye length. The electron emission was shown to decrease the absolute value of the dust-particle charge. Moreover, the collisions with atoms lead to the ion flux deceleration onto the particle surface whereas the depth of the disturbance space of plasma increased with decreasing the ionization frequency.</p></div>","PeriodicalId":41808,"journal":{"name":"St Petersburg Polytechnic University Journal-Physics and Mathematics","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.spjpm.2016.08.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83964268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The influence of moisture on charge relaxation in modified polyimide films 水分对改性聚酰亚胺薄膜中电荷弛豫的影响

IF 0.2

St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-10-01 DOI: 10.1016/j.spjpm.2016.08.008

Almaz M. Kamalov, Margarita E. Borisova

引用次数: 7

Geometric modeling of midi-fullerenes growth from C24 to C48 中富勒烯从C24到C48生长的几何模型

IF 0.2

St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-10-01 DOI: 10.1016/j.spjpm.2016.07.001

Alexander I. Melker, Maria A. Krupina

引用次数: 9

The applicability of Raman spectroscopy for estimation of interfaces thickness in the AlN/GaN superlattices 拉曼光谱在估算AlN/GaN超晶格界面厚度中的适用性

IF 0.2

St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.014

Dmitrii V. Pankin, Mikhail B. Smirnov

引用次数: 0

The limitation of the Purkinje cells’ impulse activity in the laboratory mice's cerebellum by in vivo activation of SK channels 体内活化SK通道对实验小鼠小脑浦肯野细胞冲动活动的限制

IF 0.2

St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.006

Polina A. Egorova , Olga L. Vlasova , Ilya B. Bezprozvanny

引用次数: 0

Principles to construct disjunctive cuts 构造析取切割的原则

IF 0.2

St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.002

Vitaly I. Khokhlyuk

引用次数: 0

A semi-infinite crack of mode III in the bimaterial wedge 双材料楔体中III型半无限裂纹

IF 0.2

St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.010

Victor V. Tikhomirov

引用次数: 0

The exact analytical solution of the problem on the average number of spikes of the narrowband Gaussian stochastic process 窄带高斯随机过程尖峰平均数目问题的精确解析解

IF 0.2

St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.007

Ivan D. Lobanov, Alexander V. Denisov

{"title":"The exact analytical solution of the problem on the average number of spikes of the narrowband Gaussian stochastic process","authors":"Ivan D. Lobanov, Alexander V. Denisov","doi":"10.1016/j.spjpm.2016.05.007","DOIUrl":"10.1016/j.spjpm.2016.05.007","url":null,"abstract":"<div><p>In this article, the problem of the number of spikes (level crossings) of the stationary narrowband Gaussian process has been considered. The process was specified by an exponentially-cosine autocorrelation function. The problem had been solved earlier by Rice in terms of the joint probabilities’ density of the process and its derivative with respect to time, but in our article we obtained the solution using the functional of probabilities’ density (the functional was obtained by Amiantov), as well as an expansion of the canonical stochastic process. In this article, the optimal canonical expansion of a narrowband stochastic process based on the work of Filimonov and Denisov was also considered to solve the problem. The application of all these resources allowed obtaining an exact analytical solution of the problem on spikes of stationary narrowband Gaussian process. The obtained formulae could be used to solve, for example, some problems about the residual resource of some radiotechnical products, about the breaking sea waves and others.</p></div>","PeriodicalId":41808,"journal":{"name":"St Petersburg Polytechnic University Journal-Physics and Mathematics","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2016-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.spjpm.2016.05.007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90201230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0