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Journal of Computational Mathematics 2018年第3期36卷 459-468页

作者： Daniel Rehfeldt Thorsten Koch Department of Mathematics Technische Universitat Berlin Germany zuse institute berlin and Technische Universitat berlin Germany

Transformations of Steiner tree problem variants have been frequently discussed in the literature. Besides allowing to easily transfer complexity results, they constitute a central pillar of exact state-of-the-art solvers for well-known variants such as the Steiner tree problem in graphs. In this article transformations for both the prize-collecting Steiner tree problem and the maximum-weight connected subgraph problem to the Steiner arborescence problem are introduced for the first time. Furthermore, the considerable implications for practical solving approaches will be demonstrated, including the computation of strong upper and lower bounds.

关键词： Prize-collecting Steiner tree problem Maximum-weight connected subgraphproblem Graph transformations Dual-ascent heuristics.

A Perturbation Result for Dynamical Contact Problems

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Numerical Mathematics(Theory,Methods and Applications) 2009年第3期2卷 237-257页

作者： Corinna Klapproth Peter Deuflhard Anton Schiela zuse institute berlin(ZIB) Takustrasse7D-14195 Berlin-DahlemGermany

This paper is intended to be a first step towards the continuous dependence of dynamical contact problems on the initial data as well as the uniqueness of a solution. Moreover,it provides the basis for a proof of the convergence of popular time integration schemes as the Newmark *** study a frictionless dynamical contact problem between both linearly elastic and viscoelastic bodies which is formulated via the Signorini contact *** viscoelastic materials fulfilling the Kelvin-Voigt constitutive law,we find a characterization of the class of problems which satisfy a perturbation result in a non-trivial mix of norms in function *** characterization is given in the form of a stability condition on the contact stresses at the contact ***,we present perturbation results for two well-established approximations of the classical Signorini condition:The Signorini condition formulated in velocities and the model of normal compliance,both satisfying even a sharper version of our stability condition.

关键词：接触问题 Newmark法摄动接触条件连续依赖性线性粘弹性粘弹性材料原始数据

TACKLING INDUSTRIAL-SCALE SUPPLY CHAIN PROBLEMS BY MIXED-INTEGER PROGRAMMING

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Journal of Computational Mathematics 2019年第6期37卷 866-888页

作者： Gerald Gamrath Ambros Gleixner Thorsten Koch Matt hias Miltenberger Dimitri Kniasew Dominik Schlogel Alexander Martin Dieter Weninger zuse institute berlin Department Optimization SAP SE SAP Optimization Friedrich-Alexander-Universitat Erlangen-NiimbeTg Department Mathematics

The modeling flexibility and the optimality guarantees provided by mixed-integer programming greatly aid the design of robust and future-proof decision support *** complexity of industrial-scale supply chain optimization,however,often poses limits to the application of general mixed-integer programming *** this paper we describe algorithmic innovations that help to ensure that MIP solver performance matches the complexity of the large supply chain problems and tight time limits encountered in *** computational evaluation is based on a diverse set,modeling real-world scenarios supplied by our industry partner SAP.

关键词： Supply chain management Supply network optimization Mixed-integer linear programming Primal heuristics Numerical stability Large-scale optimization

Are Ni/and Ni5Fe1/biochar catalysts suitable for synthetic natural gas production?A comparison with g-Al2O3 supported catalysts

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Green Energy & Environment 2023年第3期8卷 744-756页

作者： M.Gonzalez-Castano C.Morales J.C.Navarro de Miguel J.H.Boelte O.Klepel J.I.Flege H.Arellano-García Department of Process and Plant Technology Brandenburg University of Technology(BTU)Cottbus-SenftenbergPlatz der Deutschen 1Cottbus03046Germany Applied Physics and Semiconductor Spectroscopy Brandenburg University of Technology Cottbus-SenftenbergKonrad-Zuse-Strasse 1Cottbus03046Germany Department of Inorganic Chemistry Institute of Materials Science of SevilleConsejo Superior de Investigaciones Cientificas(CSIC)Universidad de Sevilla(US)Avenida Americo Vespucio 49Seville41092Spain institute of Materials Chemistry Brandenburg University of Technology Cottbus–SenftenbergUniversitatsplatz 1SenftenbergD-01968Germany

Among challenges implicit in the transition to the post-fossil fuel energetic model,the finite amount of resources available for the technological implementation of CO_(2) revalorizing processes arises as a central *** development of fully renewable catalytic systems with easier metal recovery strategies would promote the viability and sustainability of synthetic natural gas production circular *** Ni and NiFe catalysts supported over g-Al_(2)O_(3) oxide as reference materials,this work evaluates the potentiality of Ni and NiFe supported biochar catalysts for CO_(2) *** development of competitive biochar catalysts was found dependent on the creation of basic sites on the catalyst *** lower Turn Over Frequencies than Ni/Al catalyst,the absence of basic sites achieved over Ni/C catalyst was related to the depleted catalyst *** NiFe catalysts,analogous Ni_(5)Fe_(1) alloys were constituted over both alumina and biochar *** highest specific activity of the catalyst series,exhibited by the NiFe/C catalyst,was related to the development of surface basic sites along with weaker NiFe-C interactions,which resulted in increased Ni0:NiO surface populations under reaction *** summary,the present work establishes biochar supports as a competitive material to consider within the future low-carbon energetic panorama.

关键词： Biochar catalysts Carbon catalysts Ni catalysts NiFe alloy Bimetallic catalysts Synthetic natural gas CO_(2)methanation

A Review of Transparent and Artificial Boundary Conditions Techniques for Linear and Nonlinear Schrodinger Equations

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Communications in Computational Physics 2008年第9期4卷 729-796页

作者： Xavier Antoine Anton Arnold Christophe Besse Matthias Ehrhardt Achim Schadle Institut Elie Cartan Nancy(IECN) Universite Henri Poincare Nancy 1UMR 7502INRIA CoridaNancy-UniversiteFrance. Institut fur Analysis und Scientific Computing Technische Universitat WienWiedner Hauptstr.81040 WienAustria. Project-Team SIMPAF INRIA Lille Nord Europe Research Centre Laboratoire Paul Painleve U.M.R CNRS 8524 Universite des Sciences et Technologies de LilleFrance. Weierstrass institute for Applied Analysis and Stochastics Mohrenstr.3910117 BerlinGermany. zuse-Institut berlin Takustrasse 714195 BerlinGermany.

In this review article we discuss different techniques to solve numerically the time-dependent Schrodinger equation on unbounded *** present in detail the most recent approaches and describe briefly alternative ideas pointing out the relations between these *** conclude with several numerical examples from different application areas to compare the presented *** mainly focus on the one-dimensional problem but also touch upon the situation in two space dimensions and the cubic nonlinear case.

关键词： Schrodinger equation transparent boundary conditions discrete convolution unbounded domain finite difference schemes finite elements

Investigation of Laser Induced Breakdown Spectroscopy(LIBS)for the Differentiation of Nerve and Gland Tissue-A Possible Application for a Laser Surgery Feedback Control Mechanism

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Plasma Science and Technology 2016年第6期18卷 654-660页

作者： F.MEHARI M.ROHDE C.KNIPFER R.KANAWADE F.KLAMPFL W.ADLER N.OETTER F.STELZLE M.SCHMIDT Clinical Photonics Lab Erlangen Graduate School in Advanced Optical Technologies(SAOT)Friedrich-Alexander-Universitat Erlangen-NurnbergPaul-Gordan-Str.691052 ErlangenGermany institute of Photonic Technologies Friedrich-Alexander-Universitat Erlangen-NiirnbergKonrad-Zuse-Str.3/591052 ErlangenGermany Department of Oral and Maxillofacial Surgery University Hospital ErlangenFriedrich-Alexander-Universitat Erlangen-NurnbergGliickstrasse 1191054 ErlangenGermany Chair of Biometry and Epidemiology Friedrich-Alexander-Universitat Erlangen-Niirnberg Waldstrabe 691054 ErlangenGermany

Laser surgery provides clean,fast and accurate modeling of ***,the inability to determine what kind of tissue is being ablated at the bottom of the cut may lead to the iatrogenic damage of structures that were meant to be *** this context,nerve preservation is one of the key challenges in any surgical *** example is the treatment of parotid gland pathologies,where the facial nerve（***） and its main branches run through and fan out inside the glands parenchyma.A feedback system that automatically stops the ablation to prevent nerve-tissue damage could greatly increase the applicability and safety of surgical laser *** the present study,Laser Induced Breakdown Spectroscopy（LIBS） is used to differentiate between nerve and gland tissue of an ex-vivo pig animal *** LIBS results obtained in this preliminary experiment suggest that the measured spectra,containing atomic and molecular emissions,can be used to differentiate between the two tissue *** measurements and differentiation were performed in open air and under normal stray light conditions.

关键词： laser induced breakdown spectroscopy plasma chemical composition nerveparotid gland

Four-dimensional light shaping: manipulating ultrafast spatiotemporal foci in space and time

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Light(Science & Applications) 2017年第1期6卷 293-299页

作者： Bangshan Sun Patrick S Salter Clemens Roider Alexander Jesacher Johannes Strauss Johannes Heberle Michael Schmidt Martin J Booth Department of Engineering Science University of OxfordParks RoadOxford OX13PJUK institute of Photonic Technologies Friedrich-Alexander-University Erlangen-NurembergKonrad-Zuse-Strasse 3/5Erlangen 91052Germany Division of Biomedical Physics Innsbruck Medical UniversityMullerstrasse 44Innsbruck 6020Austria Graduate School in Advanced Optical Technologies(SAOT) Friedrich-Alexander University Erlangen-NurembergPaul-Gordan-Strasse 6Erlangen 91052Germany Centre for Neural Circuits and Behaviour University of OxfordMansfield RoadOxford OX13SRUK

The spectral dispersion of ultrashort pulses allows the simultaneous focusing of light in both space and time,which creates socalled spatiotemporal *** space–time coupling may be combined with the existing holographic techniques to give a further dimension of control when generating focal light *** the present study,it is shown that a phase-only hologram placed in the pupil plane of an objective and illuminated by a spatially chirped ultrashort pulse can be used to generate threedimensional arrays of spatio-temporally focused *** exploiting the pulse front tilt generated at focus when applying simultaneous spatial and temporal focusing(SSTF),it is possible to overlap neighboring foci in time to create a smooth intensity *** resulting light field displays a high level of axial confinement,with experimental demonstrations given through two-photon microscopy and the non-linear laser fabrication of glass.

关键词： laser material processing light shaping spatiotemporal focusing ultrafast lasers

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基于表面等离子体耦合的高密度金纳米线阵列

物理学报 2012年第23期61卷 422-427页

作者：闫红丹 Peter Lemmens Johannes Ahrens Martin Brring Sven Burger Winfried Daum Gerhard Lilienkamp Sandra Korte Aidin Lak Meinhard Schilling institute for Condensed Matter Physics Technische Universitt Carolo-WilhelminaBraunschweigGermany 38106 International Graduate School of Metrology Technische Universitat Carolo-WilhelminaBraunschweigGermany 38106 Institut für Anorganische und Analytische Chemie Technische Universitt Carolo-WilhelminaBraunschweigGermany 38106 Konrad-zuse-Zentrum für Informationstechnik BerlinGermany 14195 institute of Energy Research and Physical Technologies Technische Universitt ClausthalClausthal-ZellerfeldGermany 38678 institute of Electrical Measurement and Fundamental Electrical Engineering Technische Universitt Carolo-WilhelminaBraunschweigGermany 38106

利用电化学沉积法在阳极氧化铝模板中制备了高长径比(20—100)金纳米线阵列,并用扫描俄歇电子显微镜对其结构进行了表征.紫外可见吸收光谱显示金纳米线的表面等离子共振包含横向吸收峰(transverse mode)和纵向吸收峰(longitudinal mode)... 详细信息

利用电化学沉积法在阳极氧化铝模板中制备了高长径比(20—100)金纳米线阵列,并用扫描俄歇电子显微镜对其结构进行了表征.紫外可见吸收光谱显示金纳米线的表面等离子共振包含横向吸收峰(transverse mode)和纵向吸收峰(longitudinal mode),具有很强的各向异性特征.纵向吸收峰的强度与入射光的偏振方向和入射角度有关,随着长径比的增加纵向吸收峰位置向高能方向移动.将纳米线之间的表面等离子体能量耦合与分子H聚合体的吸收光谱行为做了比较,认为相邻纳米线间的多重耦合使纵向吸收峰出现蓝移.利用有限元分析法模拟了电场在纳米线阵列和单根纳米线表面的不同分布.

关键词：表面等离子体共振金纳米线阵列阳极氧化铝模板

3D particle tracking velocimetry for the determination of temporally resolved particle trajectories within laser powder bed fusion of metals

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International Journal of Extreme Manufacturing 2019年第3期1卷 96-105页

作者： Eric Eschner Tobias Staudt Michael Schmidt institute of Photonic Technologies Friedrich-Alexander-Universität Erlangen-NürnbergKonrad-Zuse-Str.3/5D-91052ErlangenGermany Graduate School in Advanced Optical Technologies Friedrich-Alexander-Universität Erlangen-NürnbergPaul-Gordan-Str.6D-91052ErlangenGermany

Within this work,we present a system for the measurement of the three-dimensional(3D)trajectories of spatters and entrained particles during laser powder bed fusion(L-PBF)of *** is comprised of two ultrahigh-speed cameras and a reconstruction task specific processing reconstruction *** system enables an automated determination of 3D measures from the trajectories of a large number of tracked *** evolving from an underdetermined geometrical situation induced by a two-camera setup is resolved within the tracking using a priori knowledge of L-PBF of *** processing steps were optimized to run on a graphics processing unit to allow the processing of large amounts of data within an appropriate time *** overall approach was validated by a comparison of the measurement results to synthetic images with a known 3D ground truth.

关键词： powder bed fusion laser image processing additive manufacturing high-speed imaging 3D particle velocimetry