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Hubbard U through polaronic defect states

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npj Computational Materials 2022年第1期8卷 2504-2511页

作者： Stefano Falletta alfredo Pasquarello Chaire de Simulationàl’Echelle Atomique(CSEA) Ecole Polytechnique Fédérale de Lausanne(EPFL)CH-1015LausanneSwitzerland

Since the preliminary work of Anisimov and co-workers,the Hubbard corrected DFT+U functional has been used for predicting properties of correlated materials by applying on-site effective Coulomb interactions to specific ***,the determination of the Hubbard U parameter has remained under intense discussion despite the multitude of approaches ***,we define a selection criterion based on the use of polaronic defect states for the enforcement of the piecewise linearity of the total energy upon electron occupation.A good agreement with results from piecewise linear hybrid functionals is found for the electronic and structural properties of polarons,including the formation *** values of U determined in this way are found to give a robust description of the polaron energetics upon variation of the considered *** particular,we also address a polaron hopping pathway,finding that the determined value of U leads to accurate energetics without requiring a configurational-dependent *** is emphasized that the selection of U should be based on physical properties directly associated with the orbitals to which U is applied,rather than on more global properties such as band gaps and band *** comparison,we also determine U through a well-established linear-response scheme finding noticeably different values of U and consequently different formation *** origins of these discrepancies are *** case studies,we consider the self-trapped electron in BiVO_(4),the self-trapped hole in MgO,the Li-trapped hole in MgO,and the Al-trapped hole inα-SiO_(2).

关键词： Hubbard polaron piecewise

Planar matrices and arrays of Feynman diagrams:poles for higher k

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Communications in Theoretical Physics 2024年第4期76卷 1-13页

作者： alfredo Guevara Yong Zhang Perimeter Institute for Theoretical Physics WaterlooON N2L 2Y5Canada Department of Physics&Astronomy University of WaterlooWaterlooON N2L 3G1Canada Society of Fellows Harvard UniversityCambridgeMA 02138United States of America CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesNo.19A Yuquan RoadBejing 100049China

Planar arrays of tree diagrams were introduced as a generalization of Feynman diagrams that enable the computation of biadjoint amplitudes m_(n)(^(k))for k>*** this follow-up work,we investigate the poles of m_(n)(^(k))from the perspective of such *** general k,we characterize the underlying polytope as a Flag Complex and propose a computation of the amplitude-based solely on the knowledge of the poles,whose number is drastically less than the number of the full *** an example,we first provide all the poles for the cases(k,n)=(3,7),(3,8),(3,9),(3,10),(4,8)and(4,9)in terms of their planar arrays of degenerate Feynman *** then implement simple compatibility criteria together with an addition operation between arrays and recover the full collections/arrays for such *** the way,we implement hard and soft kinematical limits,which provide a map between the poles in kinematic space and their combinatoric *** use the operation to give a proof of a previously conjectured combinatorial duality for arrays in(k,n)and(n-k,n).We also outline the relation to boundary maps of the hypersimplex Δ_(k,n) and rays in the tropical Grassmannian Tr(k,n).

关键词： Feynman diagrams biadjoint amplitudes poles

Pork Meat Quality of Preto Alentejano and Commercial Largewhite Landrace Cross

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Journal of Integrative Agriculture 2013年第11期12卷 1961-1971页

作者： alfredo Teixeira Sandra Rodrigues Veterinary and Animal Reserch Centre (CECAV) Agrarian School of Polytechnic Institute of BraganaCampus Sta Apolónia Apt.1172Bragan a 5301-855Portugal Mountain Research Centre(CIMO) Agrarian School of Polytechnic Institute of BraganaCampus Sta Apolónia Apt.1172Bragan a 5301-855Portugal

This work aimed to evaluate the physical-chemical characteristics of pork from a local breed （Portuguese black pork called Preto Alentejano） and a commercial breed. Sixteen animals were used, 4 females and 4 males from each breed. Animals had 80-100 kg of live weight. The longissimus muscle between the 5th thoracic vertebra and the 10th lumbar vertebra was used in the analysis. Samples were analysed for protein, fat, pigments, ashes, dry mater, water-holding capacity, and texture. Results of fat and pigments contents indicate signiifcant （P〈0.05 and P〈0.01） differences for all treatments. For protein, ashes, dry mater, water-holding capacity and texture, no signiifcant differences were found for sex. In the analysis of fatty acids composition, ten were detected, being the main ones C16：0, C18：0, C16：1, C18：1, C18：2. There was a predominance of monounsaturated fatty acids （MUFA）, followed by saturated （SFA） and polyunsaturated （PUFA）. Differences were signiifcant for sex （P〈0.01） and breed （P〈0.01）. Preto Alentejano breed and females presented the higher percentages of SFA （P〈0.01） and MUFA （P〈0.001） fatty acids. Differences between breeds might be due to breed production system and feed differences.

关键词： breed sex pork meat quality

Experimental modelling of flocculation processes-the case of Paraiba do Sul Estuary

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International Journal of Sediment Research 2014年第3期29卷 378-390页

作者： alfredo TRENTO Susana VINZON Department of Hydraulics National University of LitoralSanta FeArgentina Programa de Engenharia Oceanica(PEnO)/COPPE Federal University of Rio de JaneiroRio de JaneiroBrazil

The aggregation dynamics of fine sediments was analysed through laboratory tests using Couette and disk *** was shown that floc sizes tend to increase as concentrations grow both in fresh and salt water,in agreement with the aggregation theory,and that equilibrium diameters are slightly greater in salt environments for flocs developed either under shear stress or by differential *** transport and the aggregation processes were preliminarily studied in the estuary of the Paraiba do Sul River using a particle tracking model and field *** floc breakup process by shear stress was included in the *** stresses,which were determined by fractal dimensions and differential density,were accounted *** the calibration of the collision efficiency coefficients,the numerical model was able to predict floc sizes comparable with those measured at the Paraiba do Sul estuary,which,in turn,were similar to those obtained during the laboratory experiments in the Couette flocculator.

关键词： Flocs Flocculators Transport proceses Paraiba do Sul

Range-separated hybrid functionals for accurate prediction of band gaps of extended systems

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npj Computational Materials 2023年第1期9卷 1237-1245页

作者： Jing Yang Stefano Falletta alfredo Pasquarello Chaire de Simulationàl’Echelle Atomique(CSEA) Ecole Polytechnique Fédérale de Lausanne(EPFL)Lausanne CH-1015Switzerland

In this work,we systematically evaluate the accuracy in band gap prediction of range-separated hybrid functionals on a large set of semiconducting and insulating materials and carry out comparisons with the performance of their global *** observe that all the range-separated hybrid functionals that correctly describe the long-range dielectric screening significantly improve upon standard hybrid functionals such as PBE0 and *** choice of the short-range Fock exchange fraction and the screening length can further reduce the predicted *** then propose a universal expression for the selection of the inverse screening parameter as a function of the short-range and long-range Fock exchange fractions,which results in a mean absolute error as small as 0.15 eV for band gap prediction.

关键词： separated functionals exchange

Hydrodynamic finite-size scaling of the thermal conductivity in glasses

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npj Computational Materials 2023年第1期9卷 696-706页

作者： alfredo Fiorentino Paolo Pegolo Stefano Baroni SISSA—Scuola Internazionale Superiore di Studi Avanzati 34136 TriesteItaly CNR-IOM—Istituto Officina Materiali SISSA Unit34136 TriesteItaly

In the past few years,the theory of thermal transport in amorphous solids has been substantially extended beyond the Allen-Feldman *** resulting formulation,based on the Green-Kubo linear response or the Wigner-transport equation,bridges this model for glasses with the traditional Boltzmann kinetic approach for *** computational effort required by these methods usually scales as the cube of the number of atoms,thus severely limiting the size range of computationally affordable glass *** hydrodynamic arguments,we show how this issue can be overcome through a simple formula to extrapolate a reliable estimate of the bulk thermal conductivity of glasses from finite models of moderate *** showcase our findings for realistic models of paradigmatic glassy materials.

关键词： glasses conductivity thermal

Effects of seismic devices on transverse responses of piers in the Sutong Bridge

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Earthquake Engineering and Engineering Vibration 2015年第4期14卷 611-623页

作者： Shen Xing alfredo Camara Ye Aijun State Key Laboratory for Disaster Reduction in Civil Engineering Tongji University Department of Civil and Engineering City UniversityLondonUnited Kingdom PhD

The Sutong Bridge in China opened to traffic in 2008, and is an arterial connection between the cities of Nantong and Suzhou. It is a cable-stayed bridge with a main span of 1,088 m. Due to a tight construction schedule and lack of suitable seismic devices at the time, fixed supports were installed between the piers and the girder in the transverse direction. As a result, significant transverse seismic forces could occur in the piers and foundations, especially during a return period of a 2500-year earthquake. Therefore, the piers, foundations and fixed bearings had to be designed extraordinarily strong. However, when larger earthquakes occur, the bearings, piers and foundations are still vulnerable. The recent rapid developments in seismic technology and the performance-based design approach offer a better opportunity to optimize the transverse seismic design for the Sutong Bridge piers. The optimized design can be applied to the Sutong Bridge(as a retrofit), as well as other bridges. Seismic design alternatives utilizing viscous fluid dampers(VFD), or friction pendulum sliding bearings(FPSB), or transverse yielding metallic dampers(TYMD) are thoroughly studied in this work, and the results are compared with those from the current condition with fixed transverse supports and a hypothetical condition in which only sliding bearings are provided on top of the piers(the girder can move "freely" in the transverse direction during the earthquake, except for frictional forces of the sliding bearings). Parametric analyses were performed to optimize the design of these proposed seismic devices. From the comparison of the peak bridge responses in these configurations, it was found that both VFD and TYMD are very effective in the reduction of transverse seismic forces in piers, while at the same time keeping the relative transverse displacements between piers and the box girder within acceptable limits. However, compared to VFD, TYMD do not interact with the longitudinal disp

关键词： Sutong Bridge cable-stayed bridge seismic devices transverse response bridge piers viscous fluid dampers(VFD) friction pendulum sliding bearings(FPSB) transverse yielding metallic dampers(TYMD)

The enhanced X-ray Timing and Polarimetry mission—eXTP

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Science China(Physics,Mechanics & Astronomy) 2019年第2期62卷 3-27页

作者： ShuangNan Zhang Andrea Santangelo Marco Feroci YuPeng Xu FangJun Lu Yong Chen Hua Feng Shu Zhang Sφren Brandt Margarita Hernanz Luca Baldini Enrico Bozzo Riccardo Campana Alessandra De Rosa YongWei Dong Yuri Evangelista Vladimir Karas Norbert Meidinger Aline Meuris Kirpal Nandra Teng Pan Giovanni Pareschi Piotr Orleanski QiuShi Huang Stephane Schanne Giorgia Sironi Daniele Spiga Jiri Svoboda Gianpiero Tagliaferri Christoph Tenzer Andrea Vacchi Silvia Zane Dave Walton ZhanShan Wang Berend Winter Xin Wu Jean J.M.in't Zand Mahdi Ahangarianabhari Giovanni Ambrosi Filippo Ambrosino Marco Barbera Stefano Basso Jörg Bayer Ronaldo Bellazzini Pierluigi Bellutti Bruna Bertucci Giuseppe Bertuccio Giacomo Borghi XueLei Cao Franck Cadoux Francesco Ceraudo TianXiang Chen Yu Peng Chen Jerome Chevenez Marta Civitani Wei Cui WeiWei Cui Thomas Dauser Ettore Del Monte Sergio Di Cosimo Sebastian Diebold Victor Doroshenko Michal Dovciak YuanYuan Du Lorenzo Ducci QingMei Fan Yannick Favre Fabio Fuschino JoséLuis Ga'lvez Min Gao MingYu Ge Olivier Gevin Marco Grassi QuanYing Gu YuDong Gu DaWei Han Bin Hong Wei Hu Long Ji ShuMei Jia WeiChun Jiang Thomas Kennedy Ingo Kreykenbohm Irfan Kuvvetli Claudio Labanti Luca Latronico Gang Li MaoShun Li Xian Li Wei Li ZhengWei Li Olivier Limousin HongWei Liu XiaoJing Liu Bo Lu Tao Luo Daniele Macera Piero Malcovati Adrian Martindale Malgorzata Michalska Bin Meng Massimo Minuti alfredo morbidini Fabio Muleri Stephane Paltani Emanuele Perinati Antonino Picciotto Claudio Piemonte JinLu Qu Alexandre Rachevski Irina Rashevskaya Jerome Rodriguez Thomas Schanz ZhengXiang Shen LiZhi Sheng JiangBo Song LiMing Song Carmelo Sgro Liang Sun Ying Tan Phil Uttley Bo Wang DianLong Wang GuoFeng Wang Juan Wang LangPing Wang YuSa Wang Anna L.Watts XiangYang Wen Jörn Wilms ShaoLin Xiong JiaWei Yang Sheng Yang YanJi Yang Nian Yu WenDa Zhang Gianluigi Zampa Nicola Zampa Andrzej A.Zdziarski AiMei Zhang ChengMo Zhang Fan Zhang Long Zhang Tong Zhang Yi Zhang XiaoLi Zhang ZiLiang Zhang BaoSheng Zhao ShiJie Zheng Yu Peng Zhou Key Laboratory for Particle Astrophysics Institute of High Energy PhysicsChinese Academy of Sciences Institut für Astronomie und Astrophysik Eberhard Karls Universität INAF-Istituto di Astrofisica e Planetologia Spaziali INFN-Roma Tor Vergata Via della Ricerca Scientifica 1 Department of Engineering Physics and Center for Astrophysics Tsinghua University DTU Building 327DK-2800 Kongens Institute of Space Sciences 08193 Cerdanyola del Valles Institut d’Estudis Espacials de Catalunya Sezione di Pisa Istituto Nazionale di Fisica NucleareLargo Bruno Pontecorvo3 Department of Astronomy University of Genevachemin d’Ecogia 16 Osservatorio di Astrofisica e Scienza Dello Spazio di Bologna Istituto Nazionale di Astofisica Astronomical Institute Czech Academy of Sciences Max Planck Institute for Extraterrestrial Physics Giessenbachstr.1 CEA Paris-Saclay/IRFU Beijing Institute of Spacecraft System Engineering CAST Osservatorio Astronomico di Brera Istituto Nazionale di Astofisica Space Research Center Polish Academy of Sciences Key Laboratory of Advanced Material Microstructure of Education Ministry of China Institute of Precision Optical EngineeringSchool of Physics Science and EngineeringTongji University Department of Physics and Center for Astrophysics Tsinghua University Universita’degli Studi di Udine Via delle Scienze 206 Mullard Space Science Laboratory University College London Department of Nuclear and Particle Physics University of Geneva SRON Netherlands Institute for Space Research Politecnico di Milano Sezione di Perugia Istituto Nazionale di Fisica Nucleare Dipartimento di Fisica e Chimica Fondazione Bruno Kessler Dr.Karl Remeis-Observatory and Erlangen Centre for Astroparticle Physics Universität Erlangen-Nürnberg University of Pavia Department of ElectronicsInformation and Biomedical Engineering and INFN Pavia Sezione di Torino Istituto Nazionale di Fisica NucleareVia Pietro Giuria1 Department of Physics and Astronomy University of Leicester Sezione di Trieste Istituto Nazionale di Fisica Nucleare

In this paper we present the enhanced X-ray Timing and Polarimetry mission—eXTP. eXTP is a space science mission designed to study fundamental physics under extreme conditions of density, gravity and magnetism. The mission aims at determining the equation of state of matter at supra-nuclear density, measuring effects of QED, and understanding the dynamics of matter in strong-field gravity. In addition to investigating fundamental physics, eXTP will be a very powerful observatory for astrophysics that will provide observations of unprecedented quality on a variety of galactic and extragalactic objects. In particular, its wide field monitoring capabilities will be highly instrumental to detect the electro-magnetic counterparts of gravitational wave *** paper provides a detailed description of:(1) the technological and technical aspects, and the expected performance of the instruments of the scientific payload;(2) the elements and functions of the mission, from the spacecraft to the ground segment.

关键词： X-ray instrumentation X-ray polarimetry X-ray timing space mission:eXTP

Effect of magnesium on the aluminothermic reduction rate of zinc oxide obtained from spent alkaline battery anodes for the preparation of Al–Zn–Mg alloys

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International Journal of Minerals,Metallurgy and Materials 2016年第4期23卷 458-465页

作者： Rocio Ochoa alfredo Flores Jesus Torres Cinvestav-Saltillo

The aluminothermic reduction of zinc oxide（ZnO） from alkaline battery anodes using molten Al may be a good option for the elaboration of secondary 7000-series alloys. This process is affected by the initial content of Mg within molten Al, which decreases the surface tension of the molten metal and conversely increases the wettability of ZnO particles. The effect of initial Mg concentration on the aluminothermic reduction rate of ZnO was analyzed at the following values： 0.90wt%, 1.20wt%, 4.00t%, 4.25wt%, and 4.40wt%. The ZnO particles were incorporated by mechanical agitation using a graphite paddle inside a bath of molten Al maintained at a constant temperature of 1123 K and at a constant agitation speed of 250 r/min, the treatment time was 240 min and the ZnO particle size was 450？500 mesh. The results show an increase in Zn concentration in the prepared alloys up to 5.43wt% for the highest initial concentration of Mg. The reaction products obtained were characterized by scanning electron microscopy and X-ray diffraction, and the efficiency of the reaction was measured on the basis of the different concentrations of Mg studied.

关键词： aluminothermic reduction alkaline batteries zinc oxide waste utilization aluminum zinc magnesium alloys