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Journal of Magnesium and Alloys 2022年第3期10卷 877-887页

作者： Anna Dobkowska Boguslawa Adamczyk-Cieslak Milena Koralnik Witold Chromiński Jiri Kubasek Jakub Ciftci dariusz Kuc Jaroslaw Mizera Faculty of Materials Science and Engineering Warsaw University of Technology141 WoloskaStWarsaw 02-507Poland Department of Metals and Corrosion Engineering University of Chemistry and TechnologyTechnicka 5Prague 616628Czechia Institute of Materials Engineering Silesian University of TechnologyKrasiÂnskiego 8Katowice 40-019Poland

The microstructure-dependent corrosion resistance of dual structured fine-grained Mg-7.5 Li-3 Al-lZn has been *** alloys were extruded using extrusion with a forward-backward rotating die(KoBo,a newly developed SPD method)at two different extrusion *** fine-grained microstructures formed in the alloys were characterized,and the influence of grain refinement on corrosion resistance was *** fine-grained(α+β)Mg-Li alloys,a higher extrusion ratio led to more intensive grain refinement;however,this relationship did not improve their corrosion resistance in a chloride-containing *** corrosion resistance of the alloys was mainly controlled by the refinement ofα(Mg)andβ(Li),along with the distribution of second *** presence of MgLi_(2) Al at grain boundaries facilitated their dissolution.

关键词： Corrosion Grain refinement Grain size distribution Magnesium alloy.

Microstructure and corrosion resistance of a duplex structured Mg–7.5Li–3Al–1Zn

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Journal of Magnesium and Alloys 2021年第2期9卷 467-477页

作者： Anna Dobkowska Bogusława Adamczyk–Cieslak JiríKubásek Dalibor Vojtech dariusz Kuc Eugeniusz Hadasik Jarosław Mizera Faculty of Materials Science and Engineering Warsaw University of Technology141 Wołoska St02-507 WarsawPoland Chemistry Department Western University of Ontario1151 Richmond StLondonON N6A 5B7Canada Department of Metals and Corrosion Engineering University of Chemistry and TechnologyTechnicka 516628 Prague 6Czechia Institute of Materials Engineering Silesian University of TechnologyKrasinskiego 8St40-019 KatowicePoland

This study describes the corrosion resistance of extruded,and extruded with post-processing annealing,Mg–7.5 Li–3 Al–1 Zn *** results demonstrate that extrusion at 350°C with an extrusion speed 0.5 s^(-1) does not lead to the full recrystallization of the alloy,and the material still exhibits a dendritic *** post-processing annealing triggers the microstructure transformation,and the relative composition of the alloy *** ratio ofβ(Li)toα(Mg)in the extruded alloy was 29–71%;after annealing amount ofβ(Li)increased,and the ratio ofβ(Li)toα(Mg)in the annealed alloy was 35–65%.Corrosion testing shows that in 3.5 wt%Na Cl the extruded alloys immediately undergo strong *** a result of the subsequent annealing,an improvement of corrosion resistance is *** higher amount ofβ(Li)in the annealed alloy reduces the area ratio of cathodic to anodic sites of corrosion,and this makes the annealed alloy more resistive under the analyzed conditions.

关键词： Magnesium-Lithium corrosion Extrusion Annealing

Water level changes in Polish lakes during 1976–2010

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Journal of Geographical Sciences 2016年第1期26卷 83-101页

作者： dariusz WRZESI?SKI Mariusz PTAK Institute of Physical Geography and Environmental Planning Adam Mickiewicz University

The paper presents the analysis of tendencies in water level changes in 32 lakes in Poland during 1976–*** of monthly,seasonal,and annual precipitation and air temperature for 9 meteorological stations were also *** trend analysis for all of the studied series of water levels in lakes showed high spatial and temporal *** of annual water levels in the case of 6 lakes showed statistically significant increasing tendencies,and in 7 lakes,significant decreasing *** of annual amplitudes in the majority of lakes(22) showed a decreasing trend,but they were statistically significant only in three *** tendencies for air temperature fluctuations are more statistically significant than *** key role in determining water level changes is played by local factors,particularly including human economic activity,obscuring the effect of natural factors on water level *** paper describes cases of changes in water levels in lakes under anthropopressure related to among others: agricultural irrigations,hydropower infrastructure,water transfers,navigation,or mining.

关键词： lake-level trends lake-level regime Mann-Kandell Test climate change human activity

Discrete-time dynamic graphical games:model-free reinforcement learning solution

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Control Theory and Technology 2015年第1期13卷 55-69页

作者： Mohammed I.ABOUHEAF Frank L.LEWIS Magdi S.MAHMOUD dariusz G.MIKULSKI Systems Engineering Department King Fahd University of Petroleum & Mineral UTA Research Institute University of Texas at ArlingtonFort Worth Texas U.S.A. State Key Laboratory of Synthetical Automation for Process Industries Northeastern University Ground Vehicle Robotics (GVR) U.S. Army TARDEC Warren MI U.S.A.

This paper introduces a model-free reinforcement learning technique that is used to solve a class of dynamic games known as dynamic graphical games. The graphical game results from to make all the agents synchronize to the state of a command multi-agent dynamical systems, where pinning control is used generator or a leader agent. Novel coupled Bellman equations and Hamiltonian functions are developed for the dynamic graphical games. The Hamiltonian mechanics are used to derive the necessary conditions for optimality. The solution for the dynamic graphical game is given in terms of the solution to a set of coupled Hamilton-Jacobi-Bellman equations developed herein. Nash equilibrium solution for the graphical game is given in terms of the solution to the underlying coupled Hamilton-Jacobi-Bellman equations. An online model-free policy iteration algorithm is developed to learn the Nash solution for the dynamic graphical game. This algorithm does not require any knowledge of the agents＇ dynamics. A proof of convergence for this multi-agent learning algorithm is given under mild assumption about the inter-connectivity properties of the graph. A gradient descent technique with critic network structures is used to implement the policy iteration algorithm to solve the graphical game online in real-time.

关键词： Dynamic graphical games Nash equilibrium discrete mechanics optimal control model-free reinforcementlearning policy iteration

Fabrication and long persistent luminescence of Ce3+-Cr3+co-doped yttrium aluminum gallium garnet transparent ceramics

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Journal of Rare Earths 2022年第11期40卷 1699-1705,I0002页

作者： Qiang Liu Wenli Wang Zhengfa Dai Vitali Boiko Haohong Chen Xin Liu Danyang Zhu Jian Xu dariusz Hreniak Jiang Li School of Material Science and Engineering Jjiangsu University Zhenjiang 212013China Key Laboratory of Transparent Opto-functional Inorganic Materials Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 201899China Institute of Low Temperature and Structure Research Polish Academy of SciencesOkolna 250-422WroclawPoland International Center for Young Scientists(ICYS) National Institute for Materials Science(NIMS)Tsukuba305-004 Japan Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBejing 100049China

Pe rsistent luminescence(Pers L)materials are widely used in safety indication,traffic and transportation signs,architectural decoration and other *** this paper,(Y_(1-x)Ce_(x))(Al_(0.9995)Cr_(0.0005))_(2)Ga_(3)O_(12)(x=0.001,0.002,0.003,0.005)transparent ceramics were successfully prepared by solid-state reaction method in air followed by HIP *** the increase of Cedoping concentration,the optical quality of the as-prepared ceramics is improved and the morphology is *** quenching occurs when the Ceconcentration is more than 0.2%.The as-prepared transparent ceramics we re annealed in different atmosphere *** the PersL decay curve s,the transparent ce ramics after air annealing show the best PersL performance:luminance with 4424.0 mcd/m^(2)and PersL duration over865 min after ceasing 365 nm excitation,*** effects of Cedoping concentration and annealing atmospheres are also discussed in detail.

关键词： Transparent ceramics Yttrium aluminum gallium garnet Persistent luminescence Rare earths

Ultrasound findings in autoimmune hepatitis

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World Journal of Gastroenterology 2018年第15期24卷 1583-1590页

作者： Yi Dong Andrej Potthoff Christoph Klinger Ana Paula Barreiros dariusz Pietrawski Christoph F Dietrich Department of Ultrasound Zhongshan Hospital Fudan University Department of Gastroenterology Hepatology and Endocrinology Medizinische Hochschule Hannover Department of Internal Medicine 1 Klinikum Ludwigsburg German Organ Transplantation Foundation Region Mitte Department of Internal Medicine 2 Caritas-Krankenhaus Bad Mergentheim

Ultrasound findings in autoimmune hepatitis(AIH) have not been reported systematically so far. The use of reliable and accurate noninvasive methods for determining fibrosis stage is important in evaluation of treatment efficacy and fibrosis regression in AIH. Imaging plays an important role in detection of complications and ruling out other possible causes of chronic liver diseases. Ultrasound elastography cutoff values in AIH patients are not the same as those in patients with chronic viral hepatitis or non-alcoholic fatty liver disease. AIH is characterized by wide fluctuations in inflammatory activity. Here we report on current knowledge of ultrasound findings in AIH.

关键词： Autoimmune hepatitis Fibrosis stage Ultrasound Elastography Chronic liver diseases

Analytical Solution of Helmholtz Equation in Anisotropic and Nonhomogeneous Region

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Journal of Energy and Power Engineering 2014年第7期8卷 1265-1271页

作者： dariusz Spalek Institute of Electrotechnics and Informatics Silesian University of Technology Gliwice PL 44-100 Poland

The analytical solution of Helmholtz equation for magnetic vector potential in anisotropic and nonhomogeneous region is presented. The solution is built of a combination of both Bessel and power functions. There are developed two examples that proof the accuracy of the proposed analytical solution. First example is showing the electromagnetic field analysis in slot of ferromagnetic rotor of electrical induction machine. The second example approaches electromagnetic field wave in resonator of the form of rectangular cavity The analytical solution presented is treated as an exact one and is being compared with the numerical solution, e.g., given by finite element method. The analytical solution can be used as a benchmark test for numerical algorithms,

关键词： Helmholtz equation anisotropic and nonhomogeneous region analytical and numerical solutions.

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World Journal of Stem Cells 2019年第6期11卷 347-374页

作者： Urszula Kozlowska Agnieszka Krawczenko Katarzyna Futoma Tomasz Jurek Marta Rorat dariusz Patrzalek Aleksandra Klimczak Hirszfeld Institute of Immunology and Experimental Therapy Polish Academy of SciencesWroclaw 53-114Poland Department of Forensic Medicine Wroclaw Medical UniversityWroclaw 50-345Poland Faculty of Health Science Department of PhysiotherapyWroclaw Medical UniversityWroclaw 50-367Poland

BACKGROUND Mesenchymal stromal/stem cells (MSCs) constitute a promising tool in regenerative medicine and can be isolated from different human tissues. However, their biological properties are still not fully characterized. Whereas MSCs from different tissue exhibit many common characteristics, their biological activity and some markers are different and depend on their tissue of origin. Understanding the factors that underlie MSC biology should constitute important points for consideration for researchers interested in clinical MSC application. AIM To characterize the biological activity of MSCs during longterm culture isolated from: bone marrow (BM-MSCs), adipose tissue (AT-MSCs), skeletal muscles (SMMSCs), and skin (SK-MSCs). METHODS MSCs were isolated from the tissues, cultured for 10 passages, and assessed for: phenotype with immunofluorescence and flow cytometry, multipotency with differentiation capacity for osteo-, chondro-, and adipogenesis, stemness markers with qPCR for mRNA for Sox2 and Oct4, and genetic stability for p53 and c-Myc;27 bioactive factors were screened using the multiplex ELISA array, and spontaneous fusion involving a co-culture of SM-MSCs with BM-MSCs or AT-MSCs stained with PKH26 (red) or PKH67 (green) was performed. RESULTS All MSCs showed the basic MSC phenotype;however, their expression decreased during the follow-up period, as confirmed by fluorescence intensity. The examined MSCs express CD146 marker associated with proangiogenic properties;however their expression decreased in AT-MSCs and SM-MSCs, but was maintained in BM-MSCs. In contrast, in SK-MSCs CD146 expression increased in late passages. All MSCs, except BM-MSCs, expressed PW1, a marker associated with differentiation capacity and apoptosis. BM-MSCs and AT-MSCs expressed stemness markers Sox2 and Oct4 in long-term culture. All MSCs showed a stable p53 and c-Myc expression. BM-MSCs and AT-MSCs maintained their differentiation capacity during the follow-up period. In contrast

关键词： Mesenchymal stem/progenitor cells Bone marrow MSCs Adipose tissue MSCs Muscle-derived MSCs Skin-derived MSCs Cytokines and trophic factors of MSCs Spontaneous fusion of MSCs

Simulation Study of the Influence of the Hidden and Exposed Stations for the Efficiency of IEEE 802.15.4 LR-WPAN Networks

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Wireless Sensor Network 2010年第1期2卷 7-17页

作者： dariusz KOSCIELNIK AGH University of Science and Technology Department of ElectronicsKrakówPoland

This article presents an analysis of wireless personal area networks with low transmission rate, utilized more and more often in industrial or alarm systems, as well as in sensor networks. The structure of these systems and available ways of transmission are defined by the IEEE 802.15.4 standard. The main characteristics of this standard are given in the first part of this article. The second part contains the description of simulation tests that have been realized. Their results make available an evaluation of the effective transmission rate of a transmission channel, the resistance to the phenomenon of hidden station as well as sensibility to the problem of the exposed station.

关键词： Wireless Network Sensor Network Lr-Wpan Csma/Ca Slotted-Csma/Ca Transmission Protocol Hidden Station Exposed Station

Study of the relationship between average prices of residential properties and selected economic factors in the years 2000-2002 in Szczecin

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Chinese Business Review 2010年第6期9卷 43-50,64页

作者： dariusz Pechorzewski Szczecin Renovation Center Ltd. Szczecin 70-440 Poland Institute of Economic Analyses Diagnoses and Forecasts Szczecin 70-415 Poland

The article presents the development unemployment and interest rates against the average of important economic variables such as GDP dynamics, transaction prices in one of the local property markets in Poland in the years 2000-2002. The strength, direction and time delay of the relationships between these variables and transaction prices have been considered during the only period of decline in property prices in the years 2000-2002. The specified relationships have been described using linear regression equations.

关键词： local property markets demand determinants of demand