检索结果-南通市图书馆

材料科学与工程（中英文B版） 2012年第1期2卷 81-89页

作者： Jiri Minster michal Micka Institute of Theoretical and Applied Mechanics of the Academy of Sciences of the Czech Republic Prague Czech Republic Faculty of Transportation Sciences Czech Technical University Prague 11000 Czech Republic

The aim of the paper is to find a practical numerical approach to define the time-dependent mechanical characteristics of a rheonomic material from microindentation data. The ANSYS FEM program for viscoelastic bodies is used for numerical simulations of the indentation process. All three parts of the indentation process (loading), dwell time with indentation creep and unloading, are well modelled and the histories of the relaxation modulus, the bulk or shear moduli are defined in the form of Prony series. The results obtained by numerical simulation are compared with satisfactory accuracy to the values from an analytical approach based on the linear theory of viscoelasticity and to results of standard macro tests of the material, which had been previously measured by the authors.

关键词：数值模拟形式定义标准材料压痕弹性特性时间变化 ANSYS有限元程序时间依赖性

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

用于固态照明的Mn^4+离子光谱学

发光学报 2020年第9期41卷 1011-1029页

作者： BRIK Mikhail G 马崇庚 SRIVASTAVA Alok M PIASECKI michal 重庆邮电大学理学院&“重庆邮电大学-伦敦布鲁内尔大学”交叉创新研究院重庆400065 塔尔图大学物理所爱沙尼亚塔尔图50411 琴斯托霍瓦师范大学物理所波兰琴斯托霍瓦42200 戴恩特里公司通用电气顾问部美国克利夫兰44110 东欧国立大学固态物理系乌克兰卢茨克43025

Mn^4+离子激活的荧光粉在固态照明领域作为红光发射的热点载体正日益受到关注。我们针对当前研究热度撰写了Mn^4+离子光谱学的回顾,并在回顾中聚焦了许多对红色荧光粉商业研制有价值的重要基础研究点。这些研究点涵盖了如何理解自由和... 详细信息

Mn^4+离子激活的荧光粉在固态照明领域作为红光发射的热点载体正日益受到关注。我们针对当前研究热度撰写了Mn^4+离子光谱学的回顾,并在回顾中聚焦了许多对红色荧光粉商业研制有价值的重要基础研究点。这些研究点涵盖了如何理解自由和晶场状态下Mn^4+离子的能级结构以及Mn^4+发射波长对基质的依赖关系。此外,我们就如何实验调控Mn^4+离子掺杂型荧光粉的发射波长和发光强度给出了许多实际可行的建议。更为重要的是,我们收集并讨论了100多种荧光粉基质中Mn^4+离子光谱学参数,对它们的理解将会为未来Mn^4+掺杂型红色荧光粉的实验开发奠定基础。

关键词： Mn^4+离子红色荧光粉白光LED

Design of the Composite Steel-Glass Beams with Semi-Rigid Polymer Adhesive Joint

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Civil Engineering and Architecture 2012年第8期6卷 1059-1069页

作者： michal Netusil Martina Eliasova Department of Steel and Timber Structures Faculty of Civil Engineering Czech Technical University in Prague Prague 14000 Czech Republic

New and high transparent structural element, steel-glass composite beam was developed in respect to fabrication, static-structural and architectural criteria and consists of steel flanges and glass web assembled together by semi-rigid polymer adhesive, which is the key element of whole composite system. These beams can be used mainly as members of high transparent roof or floor structure as well as stiffening fins for large area glass facades. This paper deals with experimental research performed at CTU （Czech Technical University） Prague, which started by adhesive selection and initial material tests by ISO527, continued via small-scale steel-glass connection tests and graduated by full-scale tests of hybrid beams with the span of 4 m. Generalized results of these experiments, analytical and numerical studies serve as device, how to accurately predict the behavior of the beam, describe the stress distribution along the cross section and safely and economically design such a kind of structure with semi-rigid shear connection, made by polymer adhesive.

关键词： Steel-glass composite beam polymer adhesive FE modeling semi-rigid joint.

Antigravity—Its Manifestations and Origin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Astronomy and Astrophysics 2013年第3期3卷 227-235页

作者： michal Krizek Lawrence Somer Institute of Mathematics Academy of SciencesPragueCzech Republic Department of Mathematics Catholic University of AmericaWashington DCUSA

Dark energy has been introduced in order to explain the observed acceleration of the expansion of our Universe. It seems to be distributed almost uniformly and it has an essential influence on the present value of the Hubble constant which characterizes the rate of this expansion. The Newtonian theory of gravitation is formulated so that the laws of conservation of energy and momentum hold. However, the Universe is designed so that the total amount of energy is slowly, but continually increasing, since its expansion is accelerating. Our examples show that even the Solar System and also our Galaxy imperceptibly expand thanks to dark energy whose origins are tiny antigravity forces. We claim that these forces appear due to the finite speed of gravitational interaction, which causes gravitational aberration effects. We show that effects of dark energy are observable;they are not only globally, but also in local systems. These effects can be measured and are comparable with the present value of the Hubble constant.

关键词： Hubble Parameter Dark Energy Antigravity Cosmological Constant Gravitational Aberration Conservation of Energy and Momentum Law Solar System

Electronic and optical properties of semiconductor and graphene quantum dots

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2012年第3期7卷 328-352页

作者： Wei-dong Sheng Marek Korkusinski Alev Devrim Güçlü michal Zielinski Pawel Potasz Eugene S.Kadantsev Oleksandr Voznyy Pawel Hawrylak Institute of Microstructural Sciences National Research Council of CanadaOttawaCanada Department of Physics Fudan UniversityShanghai 200433China Institute of Physics Nicalaus Copernicus University TorunPoland Institute of Physics Wroclaw University of TechnologyWroclawPoland

Our recent work on the electronic and optical properties of semiconductor and graphene quan- tum dots is reviewed. For strained self-assembled InAs quantum dots on GaAs or InP substrate atomic positions and strain distribution are described using valence-force field approach and con- tinuous elasticity theory. The strain is coupled with the effective mass, k ~ p, effective bond-orbital and atomistic tight-binding models for the description of the conduction and valence band states. The single-particle states are used as input to the calculation of optical properties, with electron- electron interactions included via configuration interaction （CI） method. This methodology is used to describe multiexciton complexes in quantum dot lasers, and in particular the hidden symmetry as the underlying principle of multiexciton energy levels, manipulating emission from biexcitons for entangled photon pairs, and optical control and detection of electron spins using gates. The self-assembled quantum dots are compared with graphene quantum dots, one carbon atom-thick nanostructures. It is shown that the control of size, shape and character of the edge of graphene dots allows to manipulate simultaneously the electronic, optical, and magnetic properties in a single material system.

关键词： quantum dots electronic structure multiexciton graphene magnetism

Potential energy surfaces and fission fragment mass yields of even-even superheavy nuclei

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2021年第12期45卷 155-174页

作者： Pavel V.Kostryukov Artur Dobrowolski Bozena Nerlo-Pomorska michal Warda Zhigang Xiao Yongjing Chen Lile Liu Jun-Long Tian Krzysztof Pomorski Institute of Physics Maria Curie Sklodowska University20-031 LublinPoland Department of Physics Tsinghua UniversityBeijing 100084China Institute of Atomic Energy Beijing 102413China School of Physics and Electrical Engineering Anyang Normal UniversityAnyang 455000China

Potential energy surfaces and fission barriers of superheavy nuclei are analyzed in a macroscopic-microscopic *** Lublin-Strasbourg Drop(LSD)model is used to obtain the macroscopic part of the energy,whereas the shell and pairing energy corrections are evaluated using the Yukawa-folded potential;a standard flooding technique is utilized to determine barrier heights.A Fourier shape parametrization containing only three deformation parameters is shown to effectively reproduce the nuclear shapes of nuclei approaching *** addition,a non-axial degree of freedom is taken into account to better describe the structure of nuclei around the ground state and in the saddle *** addition to the symmetric fission valley,a new highly asymmetric fission mode is predicted in most superheavy *** fission fragment mass distributions of the considered nuclei are obtained by solving 3D Langevin equations.

关键词： nuclear fission mac-mic model fission barrier heights fragment mass yields

Modeling of Earth Magnetic Field Disturbances Induced by Ferromagnetic Objects

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Mechanics Engineering and Automation 2015年第7期5卷 411-414页

作者： michal Nowicki Roman Szewczyk Industrial Research Institute for Automations and Measurements PIAP Warsaw 02-486 Poland Institute of Metrology and Biomedical Engineering Warsaw University of Technology Warsaw 02-525 Poland

This paper presents the methodology and results of modelling of Earth magnetic field disturbances induced by ferromagnetic objects. The modeling was carried out using the finite elements calculations, and the results were compared with the measurements. The special test stand, consisting of magnetovision scanner and Helmholtz coils, has been used. The measurement system is able to measure the distribution of planar magnetic induction vectors, and to differentiate the sources of measured disturbances.

关键词： Magnetovision magnetic anomalies FEM (finite element method)

Assessment of the Erosive Wear Kinetics of Epoxy Coatings Modified with Nanofillers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Surface Engineered Materials and Advanced Technology 2013年第1期3卷 89-93页

作者： Danuta Kotnarowska michal Przerwa Department of Mechanical Engineering University of Technology and HumanitiesRadomPoland

The paper presents results of investigation on the erosive wear kinetics of epoxy coatings modified with alumina or silica nanoparticles. Natural weathering caused a decrease of their erosive wear resistance. After a 3-year natural weathering, highest erosive wear resistance showed the epoxy coating modified with alumina nanoparticles.

关键词： Polymer Coating Nanofillers Erosive Wear Resistance Natural Weathering

Miniature Actuators and Scaling Effect

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mechanics Engineering and Automation 2013年第6期3卷 393-396页

作者： Tatiana Kelemenova michal Kelemen The Department of Biomedical Engineering and Measurement Faculty of Mechanical Engineering Technical University ofKosice Kosice 042 00 Slovakia The Department of Applied Mechanics and Mechatronics Faculty of Mechanical Engineering Technical University of KosiceKosice 042 00 Slovakia

The paper deals with miniature actuators and scaling effect, which occurs in using of these actuators. Scaling effect describes how much decreased performance in miniaturized actuator is. Scaling effect law helps to make perfect decision for right type of actuator. This analysis should be as the first strategic step for actuator selection. Research in area of in-pipe machine shows that scaling effect in both used actuator types （electromagnetic and piezoelectric） is the same. Passive forces cannot be neglected, because of their values, which are comparable with active forces in system. There is a potential risk, that designed system will have bigger passive forces than active forces and system cannot fulfill requirements. Energy sources selection has also important role in system design with respecting the energy requirements of selected actuator. Consequently, energy balance is also important viewpoint for actuator selection.

关键词： Actuator mechatronics scale effect.

The IGCP 491 meeting, “Devonian Vertebrates of the Continental Margins”

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Episodes 2005年第4期28卷 292-293页

作者： Vachik Hairapetian michal Ginter Department of Geology Azad University Khorasgan branch Esfahan IRAN Institute of Geology University of Warsaw Warszawa POLAND

The first of two meetings of IGCP 491 project ＂Middle Palaeozoic Vertebrate Biogeography, Palaeogeography and Climate＂ planned for 2005 was held in Yerevan, Armenia, from 22 to 27 May. The major focus of the conferenee was on the neritic to hemipelagic vertebrate faunas of the Middle to Upper Devonian on the northern edge of Gondwana and their relationships to contemporaneous faunas of Laurasia and the rest of Gondwana. It was the third general meeting of the project, alter conferences in Riga, Latvia （2003） and Gramado, Brazil （2004）.

关键词：泥盆纪大陆构造气候变化地质条件