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Excitation Wavelength-Dependent Fluorescence of a Lanthanide Organic Metal Halide Cluster for Anti-Counterfeiting Applications

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Angewandte Chemie 2023年第52期135卷

作者： Hongyuan Zhao Qiujie Wang Ziying Wen Haibo Sun Sujun Ji Xuan Meng Ruiling Zhang Junke Jiang Zhe Tang Feng Liu Institute of Molecular Sciences and Engineering Institute of Frontier and Interdisciplinary Science Shandong University Qingdao 266237 P. R. China Materials Simulation and Modelling Department of Applied Physics and Center for Computational Energy Research Department of Applied Physics Eindhoven University of Technology 5600 MB Eindhoven The Netherlands Current address: Univ. Rennes ENSCR CNRS ISCR-UMR 6226 35000 Rennes France Life and Health Intelligent Research Institute Tianjin University of Technology Tianjin 300384 P. R. China

The achievement of significant photoluminescence (PL) in lanthanide ions (Ln 3+ ) has primarily relied on host sensitization, where energy is transferred from the excited host material to the Ln 3+ ions. However, this luminous mechanism involves only one optical antenna, namely the host material, which limits the accessibility of excitation wavelength-dependent (Ex-De) PL. Consequently, the wider application of Ln 3+ ions in light-emitting devices is hindered. In this study, we present an organic–inorganic compound, (DMA) 4 LnCl 7 (DMA + =[CH 3 NH 2 CH 3 ] + , Ln 3+ =Ce 3+ , Tb 3+ ), which serves as an independent host lattice material for efficient Ex-De emission by doping it with trivalent antimony (Sb 3+ ). The pristine (DMA) 4 LnCl 7 compounds exhibit high luminescence, maintaining the characteristic sharp emission bands of Ln 3+ and demonstrating a high PL quantum yield of 90–100 %. Upon Sb 3+ doping, the compound exhibits noticeable Ex-De emission with switchable colors. Through a detailed spectral study, we observe that the prominent energy transfer process observed in traditional host-sensitized systems is absent in these materials. Instead, they exhibit two independent emission centers from Ln 3+ and Sb 3+ , each displaying distinct features in luminous color and radiative lifetime. These findings open up new possibilities for designing Ex-De emitters based on Ln 3+ ions.

关键词： Anti-Counterfeiting Lanthanide Organic Metal Halide Cluster Luminophores Photoluminescence Rare-Earth Compounds

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Transferable classical force field for pure and mixed metal halide perovskites parameterized from first principles

arXiv

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arXiv 2021年

作者： Seijas-Bellido, Juan Antonio Samanta, Bipasa Valadez-Villalobos, Karen Jesús Gallardo, Juan Navas, Javier Balestra, Salvador R. G. Madero-Castro, Rafael María Vicent-Luna, Jose Manuel Tao, Shuxia Toroker, Maytal Caspary Anta, Juan Antonio Área de Química Física Universidad Pablo de Olavide Seville41013 Spain Department of Materials Science and Engineering Technion-Israel Institute of Technology Haifa3200003 Israel Departamento de Química Física Facultad de Ciencias Universidad de Cádiz E-11510 Puerto Real Cádiz Spain c/Sor Juana Inés de la Cruz 3 Madrid28049 Spain Materials Simulation and Modelling Department of Applied Physics Eindhoven University of Technology P.O. Box 513 Eindhoven5600MB Netherlands

Many key features in photovoltaic perovskites occur in relatively long time scales and involve mixed compositions. This requires realistic but also numerically simple models. In this work we present a transferable classical force field to describe the mixed hybrid perovskite MAxFA1-xPb(BryI1-y)3for variable composition (∀ x,y ∈ [0,1]). The model includes Lennard-Jones and Buckingham potentials to describe the interactions between the atoms of the inorganic lattice and the organic molecule, and the AMBER model to describe intramolecular atomic interactions. Most of the parameters of the force field have been obtained by means of a genetic algorithm previously developed to parameterize the CsPb(BrxI1-x)3perovskite. The algorithm finds the best parameter set that simultaneously fits the DFT energies obtained for several crystalline structures with moderate degrees of distortion with respect to the equilibrium configuration. The resulting model reproduces correctly the XRD patterns, the expansion of the lattice upon I/Br substitution and the thermal expansion coefficients. We use the model to run classical molecular dynamics simulations with up to 8600 atoms and simulation times of up to 40 ns. From the simulations we have extracted the ion diffusion coefficient of the pure and mixed perovskites, presenting for the first time these values obtained by a fully dynamical method using a transferable model fitted to first principles calculations. The values here reported can be considered as the theoretical upper limit for ion migration dynamics induced by halide vacancies in photovoltaic perovskite devices under operational conditions. © 2021, CC BY.

关键词： Perovskite

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Diamond Magnetometry and Gradiometry Towards Subpicotesla dc Field Measurement

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Physical Review applied 2021年第6期15卷 064075-064075页

作者： Chen Zhang Farida Shagieva Matthias Widmann Michael Kübler Vadim Vorobyov Polina Kapitanova Elizaveta Nenasheva Ruth Corkill Oliver Rhrle Kazuo Nakamura Hitoshi Sumiya Shinobu Onoda Junichi Isoya Jörg Wrachtrup 3rd Institute of Physics University of Stuttgart Pfaffenwaldring 57 Stuttgart 70569 Germany TTI GmbH / TGZ SQUTEC Nobelstraße 15 Stuttgart 70569 Germany Department of Physics and Engineering ITMO University Saint Petersburg 197101 Russia Giricond Research Institute Ceramics Co. Ltd. Saint Petersburg 194223 Russia Institute for Modelling and Simulation of Biomechanical Systems Pfaffenwaldring 5a Stuttgart 70569 Germany Leading-Edge Energy System Research Institute Fundamental Technology Department Tokyo Gas Co. Ltd. Yokohama 230-0045 Japan Advanced Materials Labotratory Sumitomo Electric Industries Ltd. Itami 664-0016 Japan Takasaki Advanced Radiation Research Institute National Institutes for Quantum and Radiological Science and Technology Takasaki 370-1292 Japan Faculty of Pure and Applied Sciences University of Tsukuba Tsukuba 305-8573 Japan

Nitrogen-vacancy (N-V) centers in diamond have developed into a powerful solid-state platform for compact quantum sensors. However, high-sensitivity measurements usually come with additional constraints on the pumping intensity of the laser and the pulse control applied. Here, we demonstrate high-sensitivity N-V-ensemble-based magnetic field measurements with low-intensity optical excitation. Direct current magnetometry methods such as continuous-wave optically detected magnetic resonance and continuously excited Ramsey measurements combined with lock-in detection are compared to achieve an optimization. Gradiometry is also investigated as a step towards unshielded measurements of unknown gradients. The magnetometer demonstrates a minimum detectable field of 0.3–0.7 pT in a 73-s measurement when a flux guide with a sensing dimension of 2 mm is applied, corresponding to a magnetic field sensitivity of 2.6–6 pT/Hz. Combined with our previous efforts on diamond ac magnetometry, the diamond magnetometer is promising for performing wide-bandwidth magnetometry with picotesla sensitivity and a cubic-millimeter sensing volume under ambient conditions.

关键词： Methods in magnetism NV centers Quantum metrology Quantum sensing Nitrogen vacancy centers in diamond Optically detected magnetic resonance

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Two-scale FE-FFT-based thermo-mechanically coupled modeling of elasto-viscoplastic polycrystalline materials at finite strains

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PAMM 2023年第1期22卷

作者： Annika Schmidt Christian Gierden Johanna Waimann Bob Svendsen Stefanie Reese Institute of Applied Mechanics RWTH Aachen University Mies-van-der-Rohe-Straße 1 D-52074 Aachen Germany Modeling and simulation techniques for systems of polycrystalline materials RWTH Aachen University Mies-van-der-Rohe-Straße 1 D-52074 Aachen Germany Material Mechanics RWTH Aachen University Schinkelstraße 2 D-52062 Aachen Germany Microstructure Physics and Alloy Design Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 1 D-40237 Düsseldorf Germany

Due to the general pursuit of technological advancement, structural components need to meet increasingly higher standards. In order to optimize the performance behavior of the used materials, detailed knowledge of the overall as well as microscopic material behavior under certain mechanical and thermal loading conditions is required. Hence, we present a two-scale finite element (FE) and fast Fourier transformation (FFT)-based method incorporating finite strains and a thermo-mechanically coupled constitutive model for elasto-viscoplastic polycrystalline materials. Assuming that the length scale of the microscale is sufficiently smaller compared to the length scale of the macroscale, we consider the macroscopic and microscopic boundary value problem as two coupled subproblems. The macroscopic boundary value problem is solved utilizing the finite element method. In each macroscopic integration point, the microscopic boundary value problem is embedded as a periodic unit cell whose solution fields are computed utilizing fast Fourier transforms and a Newton-Krylov solver. The scale transition is performed by defining the macroscopic quantities via the volume averages of their microscopic counterparts. In order to demonstrate the use of the proposed framework, we predict the macroscopic and microscopic fields of a polycrystalline material within a numerical example using an efficient and accurate FE-FFT-based two-scale method.

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FFT-based simulation of evolving microstructures utilizing an adapting reduced set of Fourier modes

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PAMM 2023年第1期22卷

作者： Christian Gierden Johanna Waimann Bob Svendsen Stefanie Reese Institute of Applied Mechanics RWTH Aachen University Mies-van-der-Rohe-Straße 1 D-52074 Aachen Germany Modeling and simulation techniques for systems of polycrystalline materials RWTH Aachen University Mies-van-der-Rohe-Straße 1 D-52074 Aachen Germany Material Mechanics RWTH Aachen University Schinkelstraße 2 D-52062 Aachen Germany Microstructure Physics and Alloy Design Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 1 D-40237 Düsseldorf Germany

The mechanical behavior of a periodic heterogeneous microstructure may be predicted by using a fast Fourier transform (FFT) based simulation approach. To reduce the computational effort of this method, we introduced a model order reduction (MOR) technique utilizing a reduced set of Fourier modes for the computations in Fourier space. To increase the accuracy of this MOR technique we developed a geometrically adapted sampling pattern for choosing the considered Fourier modes based on the representation of phases within the microstructure. Since the phase distribution of, for example, martensite and austenite in a polycrystalline microstructure evolves with increasing mechanical or thermal loads, the set of considered Fourier modes should also evolve according to the underlying micromechanical fields. We present the accuracy and the adaptability of this adaptive reduced set of Fourier modes by investigating the micromechanical fields of a polycrystal considering such phase transformations.

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Diamond magnetometry and gradiometry towards subpicotesla DC field measurement

arXiv

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arXiv 2020年

作者： Zhang, Chen Shagieva, Farida Widmann, Matthias Kübler, Michael Vorobyov, Vadim Kapitanova, Polina Nenasheva, Elizaveta Corkill, Ruth Röhrle, Oliver Nakamura, Kazuo Sumiya, Hitoshi Onoda, Shinobu Isoya, Junichi Wrachtrup, Jörg 3rd Institute of Physics University of Stuttgart Pfaffenwaldring 57 Stuttgart70569 Germany TTI GmbH TGZ SQUTEC Nobelstraße 15 Stuttgart70569 Germany Department of Physics and Engineering ITMO University Saint Petersburg197101 Russia Giricond Research Institute Ceramics Co. Ltd. Saint Petersburg194223 Russia Institute for Modelling and Simulation of Biomechanical Systems Paffenwaldring 5a Stuttgart70569 Germany Leading-Edge Energy System Research Institute Fundamental Technology Dept. Tokyo Gas Co. Ltd. Yokohama230-0045 Japan Advanced Materials Labotratory Sumitomo Electric Industries Ltd. Itami664-0016 Japan Takasaki Advanced Radiation Research Institute National Institutes for Quantum and Radiological Science and Technology Takasaki370-1292 Japan Faculty of Pure and Applied Sciences University of Tsukuba Tsukuba305-8573 Japan

Nitrogen vacancy (NV) centers in diamond have developed into a powerful solid-state platform for compact quantum sensors. However, high sensitivity measurements usually come with additional constraints on the pumping intensity of the laser and the pulse control applied. Here, we demonstrate high sensitivity NV ensemble based magnetic field measurements with low-intensity optical excitation. DC magnetometry methods like, e.g., continuous-wave optically detected magnetic resonance and continuously excited Ramsey measurements combined with lock-in detection, are compared to get an optimization. Gradiometry is also investigated as a step towards unshielded measurements of unknown gradients. The magnetometer demonstrates a minimum detectable field of 0.3 − 0.7 pT in a 73 s measurement by further applying a flux guide with a sensing dimension of 2 mm, corresponding to a magnetic field sensitivity of 2.6 − 6 pT/√Hz. Combined with our previous efforts on the diamond AC magnetometry, the diamond magnetometer is promising to perform wide bandwidth magnetometry with picotesla sensitivity and a cubic-millimeter sensing volume under ambient conditions. Copyright © 2020, The Authors. All rights reserved.

关键词： Magnetometers

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An environment for sustainable research software in Germany and beyond: Current state, open challenges, and call for action

arXiv

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arXiv 2020年

作者： Anzt, Hartwig Bach, Felix Druskat, Stephan Löffler, Frank Loewe, Axel Renard, Bernhard Y. Seemann, Gunnar Struck, Alexander Achhammer, Elke Aggarwal, Piush Appel, Franziska Bader, Michael Brusch, Lutz Busse, Christian Chourdakis, Gerasimos Dabrowski, Piotr W. Ebert, Peter Flemisch, Bernd Friedl, Sven Fritzsch, Bernadette Funk, Maximilian D. Gast, Volker Goth, Florian Grad, Jean-Noël Hermann, Sibylle Hohmann, Florian Janosch, Stephan Kutra, Dominik Linxweiler, Jan Muth, Thilo Peters-Kottig, Wolfgang Rack, Fabian Raters, Fabian H.C. Rave, Stephan Reina, Guido Reißig, Malte Ropinski, Timo Schaarschmidt, Joerg Seibold, Heidi Thiele, Jan P. Uekerman, Benjamin Unger, Stefan Weeber, Rudolf Germany Innovative Computing Lab University of Tennessee KnoxvilleTN United States Department of English Studies Friedrich Schiller University Jena Germany Germany Department of Computer Science Humboldt-Universität zu Berlin Germany Heinz Nixdorf Chair for Distributed Information Systems Friedrich Schiller University Jena Germany Michael Stifel Center Jena Germany Center for Computation and Technology Louisiana State University Baton Rouge United States Germany Robert Koch Institute Berlin Germany Hasso Plattner Institute Faculty of Digital Engineering University of Potsdam Germany Institute for Experimental Cardiovascular Medicine University Heart Centre Freiburg Bad Krozingen Germany Faculty of Medicine University of Freiburg Freiburg Germany Matters of Activity. Image Space Material. Cluster of Excellence at Humboldt-Universität zu Berlin Germany Technische Universität München Germany Language Technology Lab Universität Duisburg-Essen Germany Germany Department of Informatics Technical University of Munich Germany Technische Universität Dresden Germany Deutsches Krebsforschungszentrum Heidelberg Germany Scientific Computing in Computer Science Technical University Munich Germany School of Computing Communication and Business Hochschule für Technik und Wirtschaft Berlin Germany Center for Bioinformatics Saar Saarland Informatics Campus Germany Institute for Modelling Hydraulic and Environmental Systems University of Stuttgart Germany Berlin Institute of Health Germany Scientific Computing Alfred Wegener Institute Helmholtz Center for Polar and Marine Research Bremerhaven Germany Max-Planck-Gesellschaft e.V. Institut für Theoretische Physik und Astrophysik Universität Würzburg Germany Institut für Computerphysik University of Stuttgart Germany University Library University of Stuttgart Germany Universität Bremen Germany Max Planck Institute of Molecular Cell Biology and Genetics Dresden Germany European Molecular Biology Laboratory Heidelb

Research software has become a central asset in academic research. It optimizes existing and enables new research methods, implements and embeds research knowledge, and constitutes an essential research product in itself. Research software must be sustainable in order to understand, replicate, reproduce, and build upon existing research or conduct new research effectively. In other words, software must be available, discoverable, usable, and adaptable to new needs, both now and in the future. Research software therefore requires an environment that supports sustainability. Hence, a change is needed in the way research software development and maintenance are currently motivated, incentivized, funded, structurally and infrastructurally supported, and legally treated. Failing to do so will threaten the quality and validity of research. In this paper, we identify challenges for research software sustainability in Germany and beyond, in terms of motivation, selection, research software engineering personnel, funding, infrastructure, and legal aspects. Besides researchers, we specifically address political and academic decision-makers to increase awareness of the importance and needs of sustainable research software practices. In particular, we recommend strategies and measures to create an environment for sustainable research software, with the ultimate goal to ensure that software-driven research is valid, reproducible and sustainable, and that software is recognized as a first class citizen in research. This paper is the outcome of two workshops run in Germany in 2019, at deRSE19 - the first International Conference of Research Software Engineers in Germany - and a dedicated DFG-supported follow-up workshop in Berlin. Copyright © 2020, The Authors. All rights reserved.

关键词： Software design

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26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 Antwerp, Belgium. 15-20 July 2017 Abstracts

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BMC NEUROSCIENCE 2017年第SUPPL 1期18卷 95-176页

作者： [Anonymous] Department of Neuroscience Yale University New Haven CT 06520 USA Department Physiology & Pharmacology SUNY Downstate Brooklyn NY 11203 USA NYU School of Engineering 6 MetroTech Center Brooklyn NY 11201 USA Departament de Matemàtica Aplicada Universitat Politècnica de Catalunya Barcelona 08028 Spain Institut de Neurobiologie de la Méditerrannée (INMED) INSERM UMR901 Aix-Marseille Univ Marseille France Center of Neural Science New York University New York NY USA Aix-Marseille Univ INSERM INS Inst Neurosci Syst Marseille France Laboratoire de Physique Théorique et Modélisation CNRS UMR 8089 Université de Cergy-Pontoise 95300 Cergy-Pontoise Cedex France Department of Mathematics and Computer Science ENSAT Abdelmalek Essaadi’s University Tangier Morocco Laboratory of Natural Computation Department of Information and Electrical Engineering and Applied Mathematics University of Salerno 84084 Fisciano SA Italy Department of Medicine University of Salerno 84083 Lancusi SA Italy Dipartimento di Fisica Università degli Studi Aldo Moro Bari and INFN Sezione Di Bari Italy Data Analysis Department Ghent University Ghent Belgium Coma Science Group University of Liège Liège Belgium Cruces Hospital and Ikerbasque Research Center Bilbao Spain BIOtech Department of Industrial Engineering University of Trento and IRCS-PAT FBK 38010 Trento Italy Department of Data Analysis Ghent University Ghent 9000 Belgium The Wellcome Trust Centre for Neuroimaging University College London London WC1N 3BG UK Department of Electronic Engineering NED University of Engineering and Technology Karachi Pakistan Blue Brain Project École Polytechnique Fédérale de Lausanne Lausanne Switzerland Departement of Mathematics Swansea University Swansea Wales UK Laboratory for Topology and Neuroscience at the Brain Mind Institute École polytechnique fédérale de Lausanne Lausanne Switzerland Institute of Mathematics University of Aberdeen Aberdeen Scotland UK Department of Integrativ

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