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Magnetic Moment Tensor Potentials for collinear spin-polarized materials reproduce different magnetic states of bcc Fe

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npj Computational Materials 2022年第1期8卷 107-112页

作者： Ivan Novikov Blazej grabowski Fritz Körmann Alexander Shapeev Skolkovo Institute of Science and Technology Skolkovo Innovation CenterNobel St.3Moscow143026Russia Institute for Materials Science University of StuttgartPfaffenwaldring 5570569StuttgartGermany Computational Materials Design Max-Planck-Institut für Eisenforschung GmbHD-40237DüsseldorfGermany Materials Science and Engineering Delft University of Technology2628 CDDelftThe Netherlands

We present the magnetic Moment Tensor Potentials(mMTPs),a class of machine-learning interatomic potentials,accurately reproducing both vibrational and magnetic degrees of freedom as provided,e.g.,from first-principles *** accuracy is achieved by a two-step minimization scheme that coarse-grains the atomic and the spin *** performance of the mMTPs is demonstrated for the prototype magnetic system bcc iron,with applications to phonon calculations for different magnetic states,and molecular-dynamics simulations with fluctuating magnetic moments.

关键词： magnetic fluctuating states

High-accuracy thermodynamic properties to the melting point from ab initio calculations aided by machine-learning potentials

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npj Computational Materials 2023年第1期9卷 2310-2321页

作者： Jong Hyun Jung Prashanth Srinivasan Axel Forslund Blazej grabowski Institute for Materials Science University of StuttgartPfaffenwaldring 5570569 StuttgartGermany

Accurate prediction of thermodynamic properties requires an extremely accurate representation of the free-energy *** are twofold—first,the inclusion of the relevant finite-temperature mechanisms,and second,a dense volume–temperature grid on which the calculations are performed.A systematic workflow for such calculations requires computational efficiency and reliability,and has not been available within an ab initio framework so ***,we elucidate such a framework involving direct upsampling,thermodynamic integration and machine-learning potentials,allowing us to incorporate,in particular,the full effect of anharmonic *** improved methodology has a five-times speed-up compared to state-of-the-art *** calculate equilibrium thermodynamic properties up to the melting point for bcc Nb,magnetic fcc Ni,fcc Al,and hcp Mg,and find remarkable agreement with experimental data.A strong impact of anharmonicity is observed specifically for *** introduced procedure paves the way for the development of ab initio thermodynamic databases.

关键词： harmonic point prediction

Performance of two complementary machine-learned potentials in modelling chemically complex systems

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npj Computational Materials 2023年第1期9卷 1008-1022页

作者： Konstantin gubaev Viktor Zaverkin Prashanth Srinivasan Andrew Ian Duff Johannes Kästner Blazej grabowski Institute for Materials Science University of StuttgartPfaffenwaldring 5570569 StuttgartGermany Institute for Theoretical Chemistry University of StuttgartPfaffenwaldring 5570569 StuttgartGermany Scientific Computing Department STFC Daresbury LaboratoryWarrington WA44ADUK Present address:NEC Laboratories Europe gmbH Kurfürsten-Anlage 3669115 HeidelbergGermany

Chemically complex multicomponent alloys possess exceptional properties derived from an inexhaustible compositional *** complexity however makes interatomic potential development *** explore two complementary machine-learned potentials—the moment tensor potential(MTP)and the gaussian moment neural network(gM-NN)—in simultaneously describing configurational and vibrational degrees of freedom in the Ta-V-Cr-W alloy *** models are equally accurate with excellent performance evaluated against *** achieve root-mean-square-errors(RMSEs)in energies of less than a few meV/atom across 0 K ordered and high-temperature disordered configurations included in the *** for compositions not in training,relative energy RMSEs at high temperatures are within a few meV/***-temperature molecular dynamics forces have similarly small RMSEs of about 0.15 eV/Åfor the disordered quaternary included in,and ternaries not part of *** achieve faster convergence with training size;gM-NNs are faster in *** learning is partially beneficial and should be complemented with conventional human-based training set generation.

关键词： alloy faster complex

Condensation of pyrylium salts with mixed anhydrides:aryl ethers,aryl amines and sterically congested aromatics

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Organic Chemistry Frontiers 2022年第2期9卷 294-298页

作者： Daniel grabowski Susanne Alef Steven Becker Ute Muller gregor Schnakenburg Sigurd Hoger aKekulé-Institut für Organische Chemie und Biochemie Rheinische Friedrich-Wilhelms-Universität BonnGerhard-Domagk-Str.153121 BonnGermany bInstitut für Anorganische Chemie Universität BonnGerhard-Domagk-Str.153121 BonnGermany

The condensation of easily accessible and widely functionalizable 2,4,6-triaryl pyrylium salts with mixed anhydrides,formed in situ fromα-functionalized sodium acetates and an anhydride solvent,leads in good yields to the corresponding 2,4,6-triaryl benzenes functionalized at their 1-position.4-(Trifluoromethyl)benzoic anhydride has been proven as being the solvent of choice and ortho-disubstituted diphenyl ethers,triphenyl amines and phenyl carbazoles with different functionalizations are *** addition,sterically hindered anthracene diacetate is condensed with two bis-bromophenyl pyrylium salts which leads after intramolecular Yamamoto coupling to *** these,the anthracene core is surrounded by phenylenes and protected from photooxidation,leading to a highly stable blue emitting material.

关键词： material. anhydride salts

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Journal of Materials Science & Technology 2022年第16期111卷 99-110页

作者： Vioni Dwi Sartika Won Seok Choi gwanghyo Choi Jaewook Han Sung-Jin Chang Won-Seok Ko Blazej grabowski Pyuck-Pa Choi Department of Materials Science and Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea gangwon Regional Division Korea Institute of Industrial TechnologyGangwon 25440Republic of Korea Division of Measurement and Analysis National Nanofab CenterDaejeon 34141Republic of Korea School of Materials Science and Engineering University of UlsanUlsan 44610Republic of Korea Institute for Materials Science University of StuttgartPfaffenwaldring 5570569 StuttgartGermany

We report laser cladding of pure titanium on a CoCrMo alloy using directed energy *** electron microscopy,the microstructural evolution upon varying the process parameters,especially laser power and powder feed rate,was investigated in relation to crack *** layers showing dilution rates of more than 5%contained cracks due to the formation of the brittle Co_(2)Ti intermetallic *** observed cracks could be ascribed to a mismatch in thermal expansion and a resulting stress of more than 440 MPa acting on the Co_(2)Ti phase,as determined by density functional theory and ***,an excess laser energy caused chemical inhomogeneity and unmelted Ti powder particles,while a deficient laser energy resulted in a lack of *** cracks nor partially melted powders were observed for a powder feed rate of 3 g/min and a laser power of 225–300 W,for which the dilution rate was minimized to less than 5%.For such samples,the cladding layers comprised pureα-Ti and a uniform CoT i interface with Co_(2)Ti islands.

关键词： Additive manufacturing Dissimilar metal joining Titanium Cobalt-based alloy

A machine learning approach to model solute grain boundary segregation

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npj Computational Materials 2018年第1期4卷 130-137页

作者： Liam Huber Raheleh Hadian Blazej grabowski Jörg Neugebauer Max-Planck-Institut für Eisenforschung gmbH D-40237 DüsseldorfGermany

Even minute amounts of one solute atom per one million bulk atoms may give rise to qualitative changes in the mechanical response and fracture resistance of modern structural *** changes are commonly related to enrichment by several orders of magnitude of the solutes at structural defects in the host *** underlying concept—segregation—is thus fundamental in materials *** include it in modern strategies of materials design,accurate and realistic computational modelling tools are ***,the enormous number of defect configurations as well as sites solutes can occupy requires models which rely on severe *** the present study we combine a high-throughput study containing more than 1 million data points with machine learning to derive a computationally highly efficient framework which opens the opportunity to model this important mechanism on a routine basis.

关键词： grain solute boundary

The zero-dimensional model of the scavenging process in the opposed-piston two-stroke aircraft diesel engine

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Propulsion and Power Research 2019年第4期8卷 300-309页

作者： Ł.grabowski K.Pietrykowski P.Karpinski Lublin University of Technology Faculty of Mechanical EngineeringDepartment of ThermodynamicsFluid Mechanics and Aviation Propulsion SystemsNadbystrzycka 36 Str.Lublin20-618Poland

The analysis of the scavenging process in two-stroke engines is important in terms of achieved performance and emission of toxic *** amount of mass of air used for the scavenging process and the amount mass of gas retained in the cylinder affect engine *** designing two-stroke engines,the most efficient charge exchange process defined by the scavenging efficiency parameter is *** process of charge exchange in a twostroke opposed-piston aircraft diesel engine based on the assumed scavenging model was analyzed in this *** charge exchange process was performed by a mechanical centrifugal compressor.A zero-dimensional engine model created in the AVL BOOST program was used for the *** simulation tests were performed for the selected operating conditions,*** continuous *** analysis of the charge exchange process was accompanied by obtaining the basic engine operating parameters from the simulation calculations.

关键词： Diesel engine Opposed-piston engine Scavenging Supercharger

Reproductive ecology of the seabob shrimp Xiphopenaeus kroyeri(Heller,1862)in a coastal area of Southern Brazil

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中国海洋湖沼学报：英文版 2016年第1期34卷 125-135页

作者： grabowski Raphael Cezar NEgREIROS-FRANSOZO Maria Lucia CASTILHO Antonio Leao Zoology Department Botucatu Biosciences InstituteSao Paulo State UniversityBotucatu

The predictability of certain environmental factors that affect the life cycle of the seabob shrimp Xiphopenaeus kroyeri(Heller,1862) was evaluated in a study of its reproductive biology in an area adjacent to Babitonga Bay,State of Santa Catarina,Brazil. Monthly sampling was conducted from July 2010 through June 2011 at depths of 5,8,11,14,and 17 m.76 004 individuals were obtained,with a pronounced peak in absolute abundance in austral autumn(34 208),coinciding with the annual closed season from March to May. grain size composition of the sediment showed the closest relationship to the distribution of individuals(multiple linear regression,P g habit. The observed correlations between the abundance of reproductive males(bearing spermatophores) and females with spent gonads(cross-correlation,P g) suggest that the peak of reproductive males preceded the peak offemale ones. This result agrees with the pattern expected for females,which copulate in post-ecdysis(spent gonads). Spawning seemed to take place at greater depths,as evidenced by the concentration of reproductive females in these areas. The reproductive activities observed here confirm that this species follows a tropical/subtropical reproductive pattern,spawning continuously throughout the year,with the highest peaks in spring and autumn. The data indicate that the juvenile recruitment period observed in August-September resulted from the reproductive output noted in April–May. Additionally,the reproductive period recorded in November led to the juvenile peak observed in March–May.

关键词： crustacean fisheries Dendrobranchiata environmental effects recruitment spawning

Retrospective Analysis of the Correlation between TMD, Headache and Bruxism

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Open Journal of Stomatology 2023年第4期13卷 125-133页

作者： Audrey Morris Patricia grabowski Tanya Al Talib Neamat Hassan Abubakr School of Dental Medicine University of Nevada Las Vegas Nevada USA

Aims: To evaluate the association between bruxism, headaches, and temporomandibular disorder (TMD). Methods: A keyword search of the clinical notes of patients’ charts in AxiUmTM was performed using the search terms “TMD”, “headache”, and “sleep bruxism” to identify these patients. The inclusion criteria were patients with partial of full dentition, aged 18 to 65 years old who attended the UNLV School of Dental Medicine clinics between January 2014 and September 2018. Patients with incomplete records and those who were completely edentulous formed the exclusion criteria. Data were analyzed using the Pearson Correlation Coefficient. Results: The final sample was made up of 529 patients. The highest percentage of study subjects were in the age range of 29 - 34 (17.9%), with a statistically significant correlation to pain on opening (P = 0.0403). Females showed a statistically significant correlation to TMJ clicking (P = 0.0033). Caucasians also had a statistically significant correlation to TMJ clicking (P = 0.0001). In addition, a statistically significant correlation between pain on opening or chewing and headaches was also observed (P = 0.0081). Conclusion: Within the limitations of the present study, Caucasians, and females presented with more TMJ clicking than the other study subjects. Young adults, in particular, experienced more pain on opening or chewing.

关键词： TMD Bruxism Headaches TMJ Clicking Pain