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Carbon coating of air-sensitive insulating transition metal fluorides:An example study on α-Li3FeF6 high-performance cathode for lithium ion batteries

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Journal of Materials Science & Technology 2020年第20期52卷 107-115页

作者： Anna Basa Sławomir Wojtulewski Beata Kalska-Szostko maciej perkowski Elena Gonzalo Olga Chernyayeva Alois Kuhn Flaviano García-Alvarado Institute of Chemistry University of Bialystokul.K.Ciolkowskiego 1K15-245 BialystokPoland Departamento de Química y Bioquímica Facultad de FarmaciaUniversidad CEU San Pablo28668 Boadilla del MonteMadridSpain Polish Institute of Physical Chemistry Kasprzaka St.44/5201-224 WarsawPoland CIC Energigune Parque Tecnologico de Alava01510 MinanoAlavaSpain

Li_(3)FeF_(6)has been the focus of research of fluorine-based cathode materials for lithium-ion *** of the low electronic conductivity of Li3 FeF6,the decrease of particle size,by an energyconsuming long-time ball milling process with carbon,is necessary to achieve a high electrochemical *** most successful method to enhance electrochemical activity,carbon coating,seemed to be impracticable,so far,for sensitive fluorides like Li3 *** this work,carbon coating on Li3 FeF6 particles has been successfully achieved for the first time,while avoiding both extended hydrolysis and Fe(Ⅲ)-Fe(Ⅱ)*** heat treatment and atmosphere,yielding the maximal transformation of organic carbon to both graphitised and disordered carbon,has been *** coating,with a thickness of approximately 2.5 nm,has been achieved by controlled thermal decomposition of glucose,under air,at 300℃.Raman and X-ray photoelectron spectroscopy(XPS)experiments have proved the existence of carbon and Fe2O3 on the surface of Li3FeF6 *** spectroscopy indicates the presence of organic residues from glucose *** to further reduce the orga nic carbon content results in a decrease of the amorphous carbon coating *** carbon-coated Li3 FeF6 nanoparticles deliver 122 mA h g^(-1)(85%of theoretical capacity)significantly higher than that of a noncoated sample(58 mA h g^(-1)).Even more,a significant beneficial effect of carbon coating on both capacity retention and coulombic efficiency is observed.

关键词： Lithium iron fluoride Hydrolysable fluoride Lithium battery Cathode Carbon coating

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Gadolinium-modified titanium oxide materials for photoenergy applications:a review

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Journal of Rare Earths 2014年第6期32卷 487-495页

作者： maciej Zalas Faculty of Chemistry Adam Mickiewicz University in Poznań

Gadolinium doped titania materials were explored for application in photoenergy production. Incorporation of gadolinium into titania permitted improvement of photocatalytic or photovoltaic performance of the latter. This review provided a deep analysis of gadolinium applications in photoenergy processes and devices with the main focus on explanation of gadolinium doping effect on physicochemical properties of titania.

关键词： gadolinium doped titania Gd-TiO2 photocatalysis dye-sensitized solar cells photoenergy rare earths

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Statistical variation of characteristics of random packed beds of Raschig rings:The influence of the sample size

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Particuology 2021年第3期19卷 50-61页

作者： PawełNiegodajew maciej Marek Czestochowa University of Technology Department of Thermal Machineryal.Armii Krajowej 2142-200 CzestochowaPoland

Many studies on random packed beds have been dedicated to local porosity(void fraction)or orientation distribution of ***,despite the random nature of the considered packings,very little attention has been devoted to examination whether the number of particles used in experiments/simulations is sufficiently large to get reproducible *** reproducibility of the key packing parameters depends on the size of the population of particles(sample size)and ordering effects induced by the confining *** work investigates quantitatively the influence of the sample size on the statistical variation of the packed bed *** beds of Raschig rings were generated with a sequential algorithm and three column diameters were *** has been found that in the case of the orientation distribution the results depend strongly on the sample size,especially for slender columns,while the porosity profiles are well-reproducible characteristics even for relatively small packings of *** complementary results for full cylinders are also included.

关键词： Random packing Raschig rings Full cylinders Particle orientation Porosity Reproducibility

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Modeling of Propagation and Transformation of Transient Nonlinear Waves on A Current

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China Ocean Engineering 2013年第5期27卷 579-592页

作者： Wojciech Sulisz maciej Paprota Institute of Hydroengineering Polish Academy of Sciencies

A novel theoretical approach is applied to predict the propagation and transformation of transient nonlinear waves on a current. The problem was solved by applying an eigenfunction expansion method and the derived semi-analytical solution was employed to study the transformation of wave profile and the evolution of wave spectrum arising from the nonlinear interactions of wave components in a wave train which may lead to the formation of very large waves. The results show that the propagation of wave trains is significantly affected by a current. A relatively small current may substantially affect wave train components and the wave train shape. This is observed for both opposing and following current. The results demonstrate that the application of the nonlinear model has a substantial effect on the shape of a wave spectrum. A train of originally linear and very narrow-banded waves changes its one-peak spectrum to a multi-peak one in a fairly short distance from an initial position. The discrepancies between the wave trains predicted by applying the linear and nonlinear models increase with the increasing wavelength and become significant in shallow water even for waves with low steepness. Laboratory experiments were conducted in a wave flume to verify theoretical results. The free-surface elevations recorded by a system of wave gauges are compared with the results provided by the nonlinear model. Additional verification was achieved by applying a Fourier analysis and comparing wave amplitude spectra obtained from theoretical results with experimental data. A reasonable agreement between theoretical results and experimental data is observed for both amplitudes and phases. The model predicts fairly well multi-peak spectra, including wave spectra with significant nonlinear wave components.

关键词： numerical modeling transient waves current boundary conditions initial conditions

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Modelling of wave transmission through a pneumatic breakwater

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Journal of Hydrodynamics 2017年第2期29卷 283-292页

作者： maciej Paprota Wojciech Sulisz Institute of Hydro-Engineering of Polish Academy of Sciences GdafiskPoland

A theoretical approach is derived to study interaction of linear water waves with an air bubble curtain used as a pneumatic breakwater. Modelling of wave transmission through an aerial barrier is a complex task due to a need to cover processes associated with wave-current interaction, effects of two-phase flows, wave damping, etc.. An initial boundary-value problem is solved by applying an efficient eigenfunction expansion method and a time-stepping procedure. The derived semi-analytical solution is used to study the effect of basic parameters of the model on wave dissipative properties of the pneumatic breakwater. Results show that wave damping by the breakwater is mainly affected by an air flow rate. The increased air discharge results in higher velocities of ascending bubbles and increases aerial barrier width. This leads to a substantial reduction of transmitted wave heights, especially for waves of intermediate length and short waves. In order to verify the applicability of the presented theoretical approach, laboratory experiments are conducted in a wave flume for different wave regimes and pneumatic breakwater characteristics. The analysis of a wave trans- mission coefficient calculated numerically and measured in the laboratory confirms that the derived model can be used for a certain range of wave conditions.

关键词： Surface waves wave transmission wave-current interaction pneumatic breakwater numerical modelling

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Possibilities of Increase of Adhesion of the Cubic Boron Nitride Coatings by Applying an Interfacial Layers

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材料热处理学报 2004年第05B期25卷 1191-1194页

作者： maciej Kupczyk Poznan University of Technology Institute of Mechanical Engineering Poznan Poland

In the work the chosen investigations of the adhesion force of thin, superhard coatings to the cutting edges made of cemented carbides are presented. For identification of the adhesion force of coatings to substrate an automatic scratch tester constructed at Poznan University of Technology was applied. The estimation of the adhesion force (value of critical load measured during scratch test) was carried out on the base of the vibration signal. Results of investigations are pointed at the influence of a surface preparation (degreasing, etching, low and high-temperature sputtering) on a critical load values. It was found that the most effective method for surface preparation is low temperature sputtering. The influence of the TiC+Al2O3+TiN interfacial layer on increase of the adhesion force of BN coating to cemented carbides substrate was observed.

关键词：氮化硼界面间层耐磨性脆性

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Influence of the Discharge Voltage during Pulse-Plasma Process on the Durability of Edges coated with Superhard Coatings

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材料热处理学报 2004年第05B期25卷 883-887页

作者： maciej Kupczyk Poznan University of Technology Institute of Mechanical Engineering Poznan Poland

In the paper the experimental results concerning the functional quality of thin, superhard coatings produced on cutting edges is described. Boron nitride coatings were deposited on insert cutting edges made cemented carbides by the pulse-plasma method. The comparative investigations of mentioned coatings have been concerned of tool life of edges during steel machining. In these investigations for the purpose of additional increase of coated edge durability an interfacial layers were applied. Presented investigations particularly pointed out to essential influence of the values of discharge voltage on the coating structure and durability of edges coated with boron nitride.

关键词： PVD 耐磨覆层使用寿命放电电压边缘涂层超硬涂层

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Creating Local Reinforcement of a Channel in a Composite Casting Using Electromagnetic Separation

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Journal of Materials Science & Technology 2015年第9期31卷 918-922页

作者： Slawomir Golak maciej Dyzia Faculty of Materials Engineering and Metallurgy Silesian University of Technology

This article presents a new method to obtain local reinforcement in near-surface layers of channels in castings made of a particle-reinforced metal matrix composite in the alternating electromagnetic field generated by an inductor placed inside the channel. In centrifugal casting, the centrifugal force on the particles leads to the formation of composite structures, while in the proposed method, the electromag- netic force field on the particles results in the designed structure of the composite casting. The article reports the experimental verification of this method using an aluminium sleeve reinforced locally with SiC particles at the inner wall.

关键词： Metal matrix compositesFunctionally graded materialsElectromagnetic separation

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24-hour esophageal pH-monitoring in children suspected of gastroesophageal reflux disease: Analysis of intraesophageal pH monitoring values recorded in distal and proximal channel at diagnosis

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World Journal of Gastroenterology 2007年第38期13卷 5108-5115页

作者： Janusz Semeniuk maciej Kaczmarski Ⅲ Department of Pediatrics Medical University of Bialystok Poland

AIM: To assess values of 24-h esophageal pH-monitoring parameters with dual-channel probe (distal and proximal channel) in children suspected of gastroesophageal reflux disease (GERD). METHODS: 264 children suspected of gastroesophageal reflux (GER) were enrolled in a study (mean age χ = 20.78 ± 17.23 mo). The outcomes of this study, immunoallerrgological tests and positive result of oral food challenge test with a potentially noxious nutrient, enabled to qualify children into particular study groups. RESULTS: 32 (12.1%) infants (group 1) had physiological GER diagnosed. Pathological acid GER was confirmed in 138 (52.3%) children. Primary GER was diagnosed in 76 (28.8%) children (group 2) and GER secondary to allergy to cow milk protein and/or other food (CMA/FA) in 62 (23.5%) children (group 3). 32 (12.1%) of them had CMA/FA (group 4-reference group), and in remaining 62 (23.5%) children neither GER nor CMA/FA was confirmed (group 5). Mean values of pH monitoring parameters measured in distal and proximal channel were analyzed in individual groups. This analysis showed statistically significant differentiation of mean values in the case of: number of episodes of acid GER, episodes of acid GER lasting > 5 min, duration of the longest episode of acid GER in both channels, acid GER index total and supine in proximal channel. Statistically significant differences of mean values among examined groups, especially between group 2 and 3 in the case of total acid GER index (only distal channel) were confirmed. CONCLUSION: 24-h esophageal pH monitoring confirmed pathological acid GER in 52.3% of children with typical and atypical symptoms of GERD. The similar pH-monitoring values obtained in group 2 and 3 confirm the necessity of implementation of differential diagnosis for primary vs secondary cause of GER.

关键词： Children Gastroesophageal reflux disease 24-h esophageal pH-monitoring 2-channel probe Gastroesophageal reflux Primary and secondary CMA/ FA Oral food challenge test

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A Different Version of Flett's Mean Value Theorem and an Associated Functional Equation

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Acta Mathematica Sinica,English Series 2004年第6期20卷 1073-1078页

作者： Thomas RIEDEL maciej SABLIK Department of Mathematics University of Louisville Institute of Mathematics Silesian University

In this paper we present a mean value theorem derived from Flett's mean value theorem. It turns out that cubic polynomials have the midpoint of the interval as their mean value *** answer what class of functions have this property,we consider a functional equation associated with this mean value *** equation is then solved in a general setting on abelian groups.

关键词： Flett's mean value theorem Functional equations Polynomial functions

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