St Petersburg Polytechnic University Journal-Physics and Mathematics最新文献_第10页

Elastic strain energy behavior in the polymer nanocrystals 聚合物纳米晶体的弹性应变能行为

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St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.005

Alexander I. Slutsker , Yuri I. Polikarpov , Dmitry D. Karov

引用次数: 2

Synthesis of electrostatic fields for transportation of charged particle beams 带电粒子束输运的静电场合成

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St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.009

Vladimir V. Pavlov, Nadezhda K. Krasnova

{"title":"Synthesis of electrostatic fields for transportation of charged particle beams","authors":"Vladimir V. Pavlov, Nadezhda K. Krasnova","doi":"10.1016/j.spjpm.2016.05.009","DOIUrl":"10.1016/j.spjpm.2016.05.009","url":null,"abstract":"<div>In this paper, an approach to creating corpuscular-optical devices for transportation and transformation of charged particle beams has been elucidated. These devices are able to optimize and create the most convenient configuration of ionic or electron paths. The approach relies upon the inverse dynamics problem formulated on the basis of the Hamilton-Jacobi equation. The motion in the symmetry plane of a three-dimensional (3D) field was considered. The problem was solved by analytical methods. An algorithm for constructing electric fields providing the particle motion on the desired trajectories was described. А key to this algorithm lies with a concept of conformal transformation from the theory of complex-valued function. This procedure was illustrated by examples. Quadratic potential was chosen as a basis. Three functions of conformal transformation were considered, providing the rotation of the focused charged particle beam at a fixed angle, the transformation of divergent flow to parallel one. The calculated two-dimensional potentials were extended into 3D-space by power series expansion on transverse coordinate. Device embodiments were suggested on the basis of the calculated field structures.</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.2016.05.009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73028913","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 borders of existence of anomalous convection flow in the inclined square cylinder: Numerical determination 斜方柱面内异常对流存在的边界:数值确定

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St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.013

Albert N. Sharifulin , Anatoliy N. Poludnitsin

引用次数: 1

The study of Cu/Nb interface diffusion using molecular dynamics simulation Cu/Nb界面扩散的分子动力学模拟研究

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St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.004

Ivan V. Nelasov, Aleksey G. Lipnitskii

引用次数: 3

The formation of the angular dependences of the inelastically scattered electrons by their quantum transport near the surface of a solid 非弹性散射电子在固体表面附近的量子输运所形成的角依赖关系

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St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.015

Vadim V. Korablev, Victor V. Dubov

引用次数: 0

A new opinion of the greenhouse effect

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St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.008

Valery P. Oktyabrskiy

引用次数: 28

The composition and the structure of thin films based on metal porphyrin complexes 金属卟啉配合物薄膜的组成和结构

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St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.001

Nikolay M. Romanov, Irina B. Zakharova

引用次数: 3

Kohonen self-organizing map application to representative sample formation in the training of the multilayer perceptron 多层感知器训练中Kohonen自组织映射在代表性样本形成中的应用

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St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.012

Aleksey A. Pastukhov, Alexander A. Prokofiev

{"title":"Kohonen self-organizing map application to representative sample formation in the training of the multilayer perceptron","authors":"Aleksey A. Pastukhov, Alexander A. Prokofiev","doi":"10.1016/j.spjpm.2016.05.012","DOIUrl":"10.1016/j.spjpm.2016.05.012","url":null,"abstract":"<div>In this paper, we have considered the issue of effectively forming a representative sample for training the neural network of the multilayer perceptron (MLP) type. The main problems arising in the process of the factor space division into the test, validation and training sets were formulated. An approach based on the use of clustering that allowed to increase the entropy of the training set was put forward. Kohonen's self-organizing maps (SOM) were examined as an effective clustering procedure. Based on such maps, the clustering of factor spaces of different dimensions was carried out, and a representative sample was formed. To verify our approach we synthesized the MLP neural network and trained it. The training technique was performed with the sets formed both with and without clustering. The approach under consideration was concluded to have an influence on the increase in the entropy of the training set and (as a result) to lead to the quality improvement of MLP training with the small dimension of the factor space.</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.2016.05.012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85925483","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: 16

On analytic characteristic functions and processes governed by SDEs 论SDEs控制的解析特征函数和过程

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St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.011

Sergey V. Berezin

引用次数: 2

The interaction between light impurities and vacancies in titanium and aluminum metals: A DFT study 钛和铝金属中轻杂质与空位的相互作用:DFT研究

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St Petersburg Polytechnic University Journal-Physics and Mathematics Pub Date : 2016-06-01 DOI: 10.1016/j.spjpm.2016.05.003

Andrey I. Kartamyshev , Dat Duy Vo , Alexey G. Lipnitskii

{"title":"The interaction between light impurities and vacancies in titanium and aluminum metals: A DFT study","authors":"Andrey I. Kartamyshev , Dat Duy Vo , Alexey G. Lipnitskii","doi":"10.1016/j.spjpm.2016.05.003","DOIUrl":"10.1016/j.spjpm.2016.05.003","url":null,"abstract":"<div>In this paper, we present binding energies between hydrogen (H), carbon (C), nitrogen (N) and oxygen (O) atoms and a vacancy in the hexagonal closed-packed (HCP) lattice of titanium (Ti) and the face centered cubic (FCC) lattice of aluminum (Al), calculated using the density functional theory (DFT). We have also investigated the trapping of up to five hydrogen atoms by a vacancy and the reduction of the vacancy formation energy, due to the formation of a hydrogen–vacancy complex. We used the molecular-dynamics modeling with consecutive relaxation at 0K to obtain an atomic configuration of the vacancy–impurity complex, corresponding to the global energy minimum. According to our calculations, C–V, H–V, C– (H–V), N–(H–V) complexes are stable in the Al lattice with only H–V complex being stable in Ti. The formation of C–(H–V) and N–(H–V) complexes in the Al lattice results in the negative vacancy formation energy. The formation of H–V complex decreases the vacancy formation energy by 0.26eV in the Ti lattice. A vacancy in the Ti lattice can trap up to four hydrogen atoms.</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.2016.05.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79995797","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: 4