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Carbon Xerogel-supported Iron as a Catalyst in Combustion Synthesis of Carbon Fibrous Nanostructures

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Journal of Materials Science & Technology 2012年第4期28卷 294-302页

作者： Wojciech Kiciński Joanna Lasota Institute of Chemistry Military University of Technology Kaliskiego 2 00-908 Warsaw Poland

The catalytically assisted self-propagating high-temperature synthesis of carbon fibrous nanostructures, where the iron-doped colloidal carbon xerogel is proposed as a catalyst system, was examined. The carbon xerogel was prepared through carbonization of an iron doped organic xerogel at temperatures ranging from 600 to 1050℃. The reaction between calcium carbide and hexachloroethane in the presence of sodium azide is exothermic enough to proceed at a high temperature, self-sustaining regime. The combustion reactions of those mixtures enriched with iron-doped carbon xerogels were conducted in a stainless steel reactor---calorimetric bomb under an initial pressure of 1 MPa of argon. Scanning electron microscopy analysis of the combustion products revealed low yield of various type of carbon fibers （presumably nanotubes）, which grew via the tip-growth mechanism. The fibrous nanostructures were found in the vicinity of the spot of ignition, while in the outer and cooler area of the reactor, dusty products with soot-like morphology dominated. No significant correlation between the pyrolysis temperature of the carbon xerogel and the morphology of the obtained carbon fibrous nanostructures was observed.

关键词： Combustion synthesis Carbon xerogel Carbon fibrous nanostructures Carbonnanotubes Scanning electron microscopy

Supplement to the paper “A collection of 505 papers on false or unconfirmed ferroelectric properties in single crystals, ceramics and polymers [Front. Phys. 14(6), 63301(2019)]”

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Frontiers of Physics 2021年第5期16卷 81-96页

作者： Zbigniew Tylczyński Faculty of Physics Adam Mickiewicz University

This supplement contains 222(angel number) further papers on false or unconfirmed ferroelectric properties in single crystals, ceramics and polymers and only concerns bulk materials. Thus, the number of such papers has reached huge value 727. The papers marked in red have drastically broken the principles of symmetry because they reported the existence of ferroelectricity in crystals without the polar axis.

关键词： ferroelectricity hysteresis loop single crystals multiferroic polymers

Chromized Layers Produced on Steel Surface by Means of CVD

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材料热处理学报 2004年第5B期25卷 807-809页

作者： KASPRZYCKA Ewa BOGDA■ski Bogdan JEZIORski Leopold JASI■ski Józef TORBUS Roman Institute of Precision Mechanics Warsaw PolandInstitute of Precision Mechanics Warsaw PolandInstitute of Materials Engineering Czestochowa University of Technology PolandInstitute of Materials Engineering Czestochowa University of Technology PolandInstitute of Materials Engineering Czestochowa University of Technology Poland

Chemical vapour deposition of chromium on the surface of carbon steel has been investigated using a novel CVD method that combines the low cost of pack cementation method with advantages of vacuum technique. The processes have been performed in chromium chlorides atmosphere at a low pressure range from 1 to 800 hPa, the treatment temperature 800 to 950°C. Studies of the layers thickness, the phase composition, Cr, C and Fe depth profiles in diffusion zone have been conducted. The effect of the vacuum level during the process and the process parameters such as time and temperature on layer diffusion growth on the carbon steel surface has been investigated.

关键词：扩散层热化学处理扩散镀铬碳化物层 CVD

Use of coals and wastes in a co-gasification process aimed at producing hydrogen rich gas

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International Journal of Coal Science & Technology 2022年第6期9卷 161-167页

作者： Rafal Gssior Adam Smoliński Polish Mining Group Inc. KatowicePoland Central Mining Institute KatowicePoland

The use of low-quality coals and flotoconcentrates is currently severely limited,and the problem of managing municipal waste from anthropogenic activities is currently a *** problems of reducing carbon dioxide emissions,utilizing the energy potential of waste and increasing its recycling have an impact on the costs of electricity *** the abundant streams of unused fuels,they can be considered as attractive energy materials,so environmentally-friendly and cost-effective options for their utilization should be developed.A study was conducted using steam co-gasification technology on selected coals,flotation concentrates and Refuse Derived Fuel(RDF)alternative *** low-quality coals were combined with RDF alternative fuel in a process aimed at hydrogen *** experiments produced gas with hydrogen concentrations ranging from 67%(vol.)to 68%(vol.)with low methane *** was observed that the addition of alternative fuels helped to increase the hydrogen concentration in *** was paid to the catalytic ability of the metal oxides contained in the fuel blend,with particular reference to K_(2)O and Al_(2)O_(3)and TiO_(2).

关键词： Coal Hydrogen Flotation concentrate Refuse derived fuel Catalytic capacity Catalysts

Experimental and Numerical Study on Determination of Forces During Cold Rolling of Shafts

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Journal of Iron and Steel Research International 2013年第10期20卷 57-63页

作者： Kowalik Marek Trzepieciński Tomasz Institute of Mechanical Engineering Technical University of Radom Department of Material Forming and Processing Rzeszow University of Technology

The influence of stress and friction conditions on material flow during longitudinal cold rolling of a shaft was investigated. The longitudinal cold rolling method makes it possible to form and finish-up machine parts in the rolling process, which is associated with strengthening of the material due to cold work. The experiments were car- ried out in order to determine the pressure force at the stage of squeezing on shafts formed by longitudinal cold roll- ing and made of constructional unalloyed steels S235JR and C45. The experimental results were compared with nu merieal simulation results obtained by using the MSC. Marc 2010 based on finite element method （FEM）. The influ- ence of deformation degree on structural changes and the increase of material strength are shown.

关键词： shaft forming longitudinal working stepped shaft plastic deformation

Liquid Phase Evaporation on the Normal Shock Wave in Moist Air Transonic Flows in Nozzles

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Journal of Thermal Science 2017年第3期26卷 214-222页

作者： Slawomir Dykas Artur Szymański Miroslaw Majkut Institute of Power Engineering and Turbomachinery Silesian University of Technologyul.

This paper presents a numerical analysis of the atmospheric air transonic flow through de Laval nozzles. By nature, atmospheric air always contains a certain amount of water vapor. The calculations were made using a Laval nozzle with a high expansion rate and a convergent-divergent(CD) "half-nozzle", referred to as a transonic diffuser, with a much slower expansion rate. The calculations were performed using an in-house CFD code. The computational model made it possible to simulate the formation of the liquid phase due to spontaneous condensation of water vapor contained in moist air. The transonic flow calculations also take account of the presence of a normal shock wave in the nozzle supersonic part to analyze the effect of the liquid phase evaporation.

关键词： moist air condensation transonic flow shock wave CFD simulation in-house code

NONPARAMETRIC IDENTIFICATION OF MISO HAMMERSTEIN SYSTEM FROM STRUCTURED DATA

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Journal of Systems Science and Systems Engineering 2015年第1期24卷 68-80页

作者： Pawel Wachel Przemyslaw liwiński Zygmunt Hasiewicz Department of Control Systems and Mechatronics Wroclaw University of Technology

The problem of nonparametric identification of a multivariate nonlinearity in a D-input Hammer- stein system is examined. It is demonstrated that if the input measurements are structured, in the sense that there exists some hidden relation between them, i.e. if they are distributed on some （unknown） d-dimensional space M in IRD, d 〈 D, then the system nonlinearity can be recovered at points on M with the convergence rate O（n-1/（2＋d）） dependent on d. This rate is thus faster than the generic rate O（n-1/（2＋D）） achieved by typical nonparametric algorithms and controlled solely by the number of inputs D.

关键词： MISO Hammerstein system nonparametric system identification structured data conver-gence rate

Evolution of phase stresses in Al/SiCp composite during thermal cycling and compression test studied using diffraction and self-consistent models

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Journal of Materials Science & Technology 2020年第1期36卷 176-189页

作者： Przemyslaw Kot Andrzej Baczmański Elzbietaa Gadalińska Sebastian Wroński Marcin Wroński Miroslaw Wróbel Gizo Bokuchava Christian Scheffzük Krzysztof Wierzbanowski AGH University of Science and Technology Faculty of Physics and Applied Computer Scienceal.Mickiewicza 3030-059 Krakow.Poland Institute of Aviation Materials&Structures Research Centeral.Krakowska 110/11402-256 WarsawPoland AGH University of Science and Technology Faculty of Metals Engineering and Industrial Computer Scienceal.Mickiewicza 3030-059 KrakowPoland Joint Institute for Nuclear Research Frank Laboratory of Neutron PhysicsJoliot-Curie 6141980 DubnaRussia Karlsruhe Institute of Technology Institute of Applied GeosciencesAdenauerring 20b76131 KarlsruheGermany

In this work,the evolutions of stresses in both phases of the Al/SiCp composite subjected to thermal cycling during in situ compression test were measured using Time of Flight neutron *** was confirmed that inter-phase stresses in the studied composite can be caused by differences in the coefficient of thermal expansion for the reinforcement and matrix,leading to a different variation of phase volumes during sample heating or *** results of the diffraction experiment during thermal cycling were well predicted by the Thermo-Mechanical Self-Consistent *** experimental study of elastic-plastic deformation was carried out in situ on a unique diffractometer EPSILON-MDS(JINR in Dubna,Russia)with nine detector banks measuring interplanar spacings simultaneously in 9 orientations of scattering *** the first time,the performed analysis of experimental data allowed to study the evolution of full stress tensor in both phases of the composite and to consider the decomposition of this tensor into deviatoric and hydrostatic *** was found that the novel Developed Thermo-Mechanical SelfConsistent model correctly predicted stress evolution during compressive loading,taking into account the relaxation of thermal origin hydrostatic *** comparison of this model with experimental data at the macroscopic level and the level of phases showed that strengthening of the Al/SiCp composite is caused by stress transfer from the plastically deformed A12124 matrix to the elastic SiCp reinforcement,while thermal stresses relaxation does not significantly affect the overall composite properties.

关键词： Stress relaxation Strengthening mechanism Plastic deformation Multiscale model Metal matrix composites Neutron diffraction

Impact of atmospheric turbulence on coherent beam combining for laser weapon systems

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Defence Technology（防务技术） 2021年第4期17卷 1160-1167页

作者： Jan K.Jabczyński Przemysław Gontar Military University of Technology Gen.S.Kaliskiego 2Warsaw00-908Poland

The performance of a laser weapon system based on coherent beam combining(CBC)depends on its propagation properties in the *** this study,an analytical model based on partial coherent beam combining(PCBC)for assumed coherence coefficients between beams in a CBC lattice was *** Kolmogorov model of atmospheric turbulence and the Hufnagel-Valley model of C^(2)_(n) dependence on atmospheric parameters were *** simplified metrics were proposed to assess the CBC *** beam profiles(super-Gaussian,truncated Gaussian,etc.)and geometries were analyzed in terms of maximal intensity in the far *** approximate formula for PCBC efficiency dependent on the Fried radius was *** results of CBC modeling were compared to those of the Gaussian beam propagation model in a turbulent *** dependence of CBC performance on the C^(2)_(n) parameter,range,and elevation angle was *** could be concluded that the application of CBC for medium and long range propagation is impractical without an effective adaptive optics system.

关键词： Laser beams Beam combining Coherence Atmosphere turbulences