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Finite element analysis of small-scale hot compression testing

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Journal of Materials Science & Technology 2021年第17期76卷 174-188页

作者： patryk Jedrasiak Hugh Shercliff Department of Engineering University of CambridgeTrumpington StCambridgeCB21PZUK

This paper models hot compression testing using a dilatometer in loading *** small-scale tests provide a high throughput at low cost,but are susceptible to inhomogeneity due to friction and temperature gradients.A novel method is presented for correcting the true stress-strain constitutive response over the full range of temperatures,strain-rates and *** nominal response from the tests is used to predict the offset in the stress-strain curves due to inhomogeneity,and this stress offsetΔσis applied piecewise to the data,correcting the constitutive response in one iteration.A key new feature is the smoothing and fitting of the flow stress data as a function of temperature and strain-rate,at multiple discrete *** corrected model then provides quantitative prediction of the spatial and temporal variation in strain-rate and strain throughout the sample,needed to correlate the local deformation conditions with the microstructure and texture *** study uses a detailed series of 144 hot compression tests of a Zr-Nb *** this is an important wrought nuclear alloy in its own right,it also serves here as a test case for modelling the dilatometer for hot testing of high temperature alloys,particularly those with dualα-βphase microstructures(such as titanium alloys).

关键词： Finite element analysis Process modelling Hot compression testing Upsetting Zr alloys Ti alloys

Bonding effect of liquid magnesium with open-celled carbon foam in interpenetrating phase composite

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Journal of Magnesium and Alloys 2021年第1期9卷 156-165页

作者： Marcin Godzierz Anita Olszowka-Myalska Natalia Sobczak Rafal Nowak patryk wrze'sniowski Silesian University of Technology Faculty of Materials EngineeringKrasi´nskiego 8 street40-019 KatowicePoland Institute of Metallurgy and Materials Science Polish Academy of SciencesRaymonta 25 streetKrakówPoland Łukasiewicz Foundry Research Institute Zakopia´nska 73 street30-418 KrakówPoland

The issue of bonding formation in liquid metal/open-celled carbon foam(C_(of))systems was examined,taking into account the practical aspects of the synthesis of a new type of Mg-C metal material *** problem is complex due to the strong oxidation and intense evaporation of liquid magnesium,as well as the 3D geometry of the carbon component,where metal transport occurred through the foam cells’*** experiments performed at 700℃ in ceramic crucibles showed that spontaneous carbon foam infiltration by liquid metal is impossible under the applied conditions,either in an air atmosphere coupled with flux protection or under argon *** tests performed in a UHV chamber filled with static pure Ar by a sessile drop method,coupled with non-contact heating and capillary purification at a test temperature of 700℃ directly in the UHV chamber,showed non-wetting behavior of the Mg/C_(of)couple with a correspondingly high contact angle of about 135°.The graphite capillary was then moved down,the liquid drop being slightly pressed into the foam,but these changes did not induce effective foam *** the short contact time for the sessile drop test under an argon atmosphere,SEM+wDS analysis of the solidified Mg/C_(of)couple revealed the formation of an MgO interlayer at the interface,with a thickness of approx.1μ*** experimentally demonstrated presence of oxygen in the carbon foam sample,both before and after its contact with magnesium,points to oxide-type bonding being established between Mg and C_(of).This observation is in a good agreement with previous reports on the interface characterization of magnesium matrix composites reinforced with glassy carbon materials and carbon fibers by stir casting and pressure *** on the findings of this study,a general structural scheme of the bonding process between carbon foam and liquid magnesium,as an important stage in the syntheses of Mg-C composites,was proposed.

关键词： Magnesium matrix composite Open-celled carbon foam Interpenetrating phase composites wetting Interface

Environmental behavior of engineered biochars and their aging processes in soil

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Biochar 2019年第4期1卷 339-351页

作者： wenyan Duan patryk Oleszczuk Bo Pan Baoshan Xing Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500People’s Republic of China Yunnan Key Lab of Soil Carbon Sequestration and Pollution Control Kunming University of Science and TechnologyKunming 650500People’s Republic of China Department of Environmental Chemistry University of Maria Skłodowska-Curiepl.M.Curie-Sklodowskiej 320-031 LublinPoland Stockbridge School of Agriculture University of MassachusettsAmherstMA 01003USA

In recent years,due to the broad application of biochars,the preparation,environmental behavior and aging processes of biochars have attracted wide attention globally,especially the modification of ***,most of the studies only consider the improvement of biochar properties right after the modification,but neglect a complete evaluation of the long-term stability and eco-toxicity of these newly developed materials after entering the *** the development and utilization of biochars,engineered biochars(EngBCs)will soon enter the market,but its environmental risk still remains *** literature does not provide adequate information on how aging of EngBCs will affect their properties,and indirectly impact the properties of soils(cycle of elements and organic matter).Therefore,this review paper summarizes the aging process and environmental risk of biochars,aiming at better understanding the interactions between EngBCs and soil components or *** importantly,this review is to point out the contradictory speculations of environmental behavior of EngBCs studied at the present *** to the modification,the EngBCs stability may be significantly ***,the formation of functional group on EngBCs will enhance their interaction with soil minerals to form biochars-mineral complex,and thus EngBCs could be *** impacts of EngBCs after entering the environment are also ***,understanding EngBCs environmental behavior is critical,which is helpful to reduce the potential risk and to produce EngBCs following the rule of sustainable development and safety to the environment.

关键词： Biochar modification Stability Toxicity Soil components Organic contaminants

Enhanced photodegradation activity of ZnO:Eu3+and ZnO:Eu3+@Au 3D hierarchical structures

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Journal of Rare Earths 2020年第1期38卷 21-28页

作者： Nataliya Babayevska Igor Iatsunskyi patryk Florczak Marcin Jarek Barbara Peplińska Stefan Jurga NanoBioMedical Centre Adam Mickiewicz University

In this work the flower-like hierarchical structures(HS) based on 3 D pristine ZnO,ZnO:Eu^3+ and ZnO:Eu^3+ @Au were successfully obtained by a template-free solvothermal and deposition-precipitation *** decolorization/photodegradation of these structures towards model organic dye(rhodamine 6 G) was *** synthesized ZnO-based HS were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),UV-vis and photoluminescence(PL) *** proposed synthesis approaches allow to obtain highly crystalline 3 D ZnO,ZnO:Eu^3+ and ZnO:Eu^3+ @Au *** of scanning microscopy show that ZnO flower-like HS are assemblies from smaller components,forming larger ones,the whole ZnO structure was approximately 3 μ*** nanoparticles(size^10 nm)are successfully deposited on ZnO HS *** studies show that ZnO is an ideal matrix for incorporation of Eu^3+ ions in broad concentration range(Eu^3+=1.0 at%-5.0 at%) with an efficient red *** strong UV emission in ZnO,as well as ZnO;Eu^3+HS is observed under 325 nm *** of ZnO HS matrix by Eu^3+ions leads to the red shift of deep level emission peak(DLE).The PL intensity reaches the maximum up to 5 at% Eu^3+.The photocatalytic properties of ZnO and ZnO:Eu^3+ @Au HS were investigated under UV-Vis light irradiation towards rhodamine 6 *** obtained results demonstrate the synergetic effect of the deposited gold nanoparticles and Eu3^+ doping on photocatalytic activity of ZnO:Eu^3+@Au HS in comparison to pristine ZnO and ZnO:Eu^3+ HS.

关键词： Zinc oxide Hierarchical structures Europium Gold Photocatalysis Rhodamine 6G

Cooperation within the 17+1:Challenges and Opportunities

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Cooperation Within the 17+1:Challenges and Opportunities

作者： patryk LECZYCKI 山东大学

学位级别：硕士

The interest of global powers in the Central-Eastern Europe region has been becoming increasingly more apparent over the past couple *** following dissertation focuses on the cooperation between the countries of the region and *** author analyzes the historical background of multilateral cooperation frameworks in CEE that concern China,characterizes the process of establishment of the frameworks and later compares it to the chosen case studies of bilateral relations of Poland,Hungary and *** inclusion of bilateral case studies serves the purpose of exposing China’s process of forming cordial relations and strengthening *** analysis of multilateral and bilateral cooperation correspond to the thesis’ main research *** the chapters on multilateral and bilateral cooperation present opportunities and challenges in their respective ***,the author touches upon the subject of the effects of the COVID-19 pandemic and other challenges that might affect the future of cooperation between China and the CEE *** concludes that even though there have been numerous challenges,the trends in cooperation between the CEE region and China are positive.

关键词： China-CEEC multilateralism bilateralism BRI2.0 COVID-19 paradiplomacy

Spring recharge and groundwater flow patterns in flysch aquifer in the Polonina wetlińska Massif in the Carpathian Mountains

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Journal of Mountain Science 2021年第4期18卷 819-833页

作者： Karolina MOSTOwIK Damian KRZYCZMAN Eliza PLACZKOwSKA Bartlomiej RZONCA Janusz SIwEK patryk wACLAwCZYK Institute of Geography and Spatial Management Jagiellonian University in KrakowGronostajowa St.730-387 KrakowPoland Institute of Geography and Spatial Organization Polish Academy of SciencesSw.Jana St.2231-018 KrakowPoland

Flysch-type aquifers in the Eastern Carpathians usually feed periodic and low-discharge springs. However, in some areas, such as in the upper part of the Polonina wetlińska Massif, perennial springs with a relatively high discharge were identified. Therefore, the aim of this study was to identify recharge and groundwater flow patterns of three high-discharge springs based on the response of spring discharge to rainfall and on the relationship between specific electrical conductivity of water and spring discharge. The relation between spring discharge and rainfall was investigated by crosscorrelation analyses. Generally, cumulative rainfall over a period from 10 days to 3 months is most strongly correlated with discharge;however, the response time of spring discharge varies throughout the year. Faster response to rainfall occurs in the spring after snowmelt, while in the summer and autumn months the response time increases. Two flow systems were identified: 1) a relatively deep, fissure-pore flow system with a long response time to precipitation and 2) a shallow, fissure-dominated system with a short response time, which is superimposed on the longer response. A small range of specific electrical conductivity combined with the varying discharge of two springs suggests that dilution of groundwater by rainwater does not play a significant role. The differences in the studied springs’ response to rainfall can be attributed to the recharge area, regolith features and local bedrock structures, i.e. occurrence of joints and faults, monoclinal dip of rock layers and gravitational slope deformations including ridge-top trenches, which, thus far, have been underestimated in determining groundwater storage capacity in the flysch part of the Carpathians.

关键词： Cross-correlation Rainfall recharge Spring response Sedimentary rocks Poland

Timing of surgical repair of bile duct injuries after laparoscopic cholecystectomy: A systematic review

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world Journal of Hepatology 2022年第2期14卷 442-455页

作者： patryk Kambakamba Sinead Cremen Beat Möckli Michael Linecker Department of HPB and Transplant Surgery St.Vincent’s University Hospital DublinDublin d04 T6F4Ireland Department of Surgery Cantonal Hospital GlarusGlarus 8750Switzerland Department of Visceral and Transplantation Surgery University of Geneva HospitalsGeneva 1205Switzerland Department of Surgery and Transplantation University Medical Center Schleswig HolsteinKiel 24105Germany

BACKGROUND The surgical management of bile duct injuries(BDIs)after laparoscopic cholecystectomy(LC)is challenging and the optimal timing of surgery remains *** primary aim of this study was to systematically evaluate the evidence behind the timing of BDI repair after LC in the *** To assess timing of surgical repair of BDI and postoperative *** The MEDLINE,EMBASE,and The Cochrane Library databases were systematically screened up to August *** of bias was assessed via the Newcastle Ottawa *** primary outcomes of this review included the timing of BDI repair and postoperative *** A total of 439 abstracts were screened,and 24 studies were included with 15609 patients included in this *** the 5229 BDIs reported,4934(94%)were classified as major *** of bile duct repair was immediate(14%,n=705),early(28%,n=1367),delayed(28%,n=1367),or late(26%,n=1286).Standardization of definition for timing of repair was remarkably poor among *** for immediate repair ranged fromwk after LC while early repair ranged from24 h to>12 wk after LC)and late repair(>6 wk after LC)showed a broad *** The lack of standardization among studies precludes any conclusive recommendation on optimal timing of BDI repair after *** finding indicates an urgent need for a standardized reporting system of BDI repair.

关键词： Bile duct injury Major bile duct injury Laparoscopic cholecystectomy Surgical repair Immediate repair Early repair Delayed repair Late repair Biliary reconstruction Standardization of bile duct injury repair reporting

Spatial niche segregation between bird species in the Bia?owieza primeval forest(NE Poland)

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Forest Ecosystems 2023年第4期10卷 483-493页

作者： Oliwia Karpińska Katarzyna Kamionka-Kanclerska patryk Czortek Marcin K.Dyderski Dorota Czeszczewik Siedlce University of Natural Sciences and Humanities Faculty of Exact and Natural SciencesInstitute of Biological Sciences 2. Biatowieza Geobotanical StationFaculty of BiologyUniversity of Warsaw Institute of Dendrology Polish Academy of Sciences

Drivers of bird niche separation in temperate primeval forests have not yet been determined,due to the low number of intact forest ***,we analyzed the general patterns of niche usage on trees by birds’ *** tested how tree species affect the sharing of space in an assemblage of birds and their level of *** conducted our study in the Bialowieza primeval forest(NE Poland).During two breeding seasons,we observed bird positions on trees,divided into three vertical and six horizontal zones in 768 observation *** on the interaction networks framework we calculated the Kullback-Leibler distance d’ as a metric of species specialization and the resource range RR index,which estimates the species’ specificity based on the fraction of space utilized with a non-zero *** d’ index was the highest in the lower understory for all parts of the tree on the basis of the position from the *** RR index was the highest in the lower understory for all parts based on the position from the *** the tree species,the lowest d’ index was observed in all tree species together,and hornbeam,whereas the highest in *** the tree species level,the RR index was the lowest for *** show tree species importance in forest space sharing in the case of bird ***,alder,and spruce are universal species that were used by birds almost *** contrast,oak,lime,and maple were only partially *** species with less complex structures could shape bird assemblages,as they could offer birds much fewer niches to ***,we showed that high specialization and niche separation are drivers of high bird *** maintaining a diverse stand structure is crucial for biodiversity conservation.

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阅读过程中适应性眼动控制的出现:理论和数据(中文)

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心理与行为研究 2011年第1期9卷 45-52页

作者： Erik D. Reichle Yanping Liu patryk A. Laurent University of Pittsburgh The Johns Hopkins University

Computational models of eye-movement control during reading provide precise quantitative descriptions of the perceptual, cognitive, and motoric processing that guide readers′ eyes, but are based on numerous equivocal a priori theoretical assumptions. This article describes an alternative approach to understanding eye-movement control: Using reinforcement learning to examine how complex eye-movement behaviors emerge from the requirement to identify words rapidly in the context of known psychological and physiological constraints(e.g., limited visual acuity). An example simulation is reported, as are key results from an fMRI experiment that demonstrates that structures implicated in reinforcement learning support the learning of eye-movement behavior in humans.

关键词：心理学行为研究理论