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Substrate topography as a powerful tool to modify glial cell biology and interactions

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Neural Regeneration Research 2025年第5期20卷 1390-1391页

作者： Pascal Achenbach Haktan Altinova Gary A.Brook Institute of Neuropathology RWTH Aachen University Hospital department of Neurosurgery RWTH Aachen University Hospital Aachen Germany berlin State Office for Health and Social Affairs(LAGeSo) BerlinGermany

Traumatic injuries to the central nervous system(CNS) result in disruption of the intricate network of axons which connect functionally related neurons that are widely distributed throughout the brain and spinal *** normal conditions,maintenance of this complex system is structurally and functionally supported by astrocytes (ACs)and other glial cells,the processes of which form a framework surrounding neuronal cell bodies,dendrites,axons,and synapses.

关键词： injuries topography system

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tuning the interfacial reaction environment via pH-dependent and induced ions to understand C–N bonds coupling performance in NO3- integrated CO2 reduction to carbon and nitrogen compounds over dual Cu-based N-doped carbon catalyst

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Journal of Energy Chemistry 2025年第1期100卷 273-285页

作者： Tianhang Zhou Chen Shen Zhenghao Wu Xingying Lan Yi Xiao College of Carbon Neutrality Future Technology State Key Laboratory of Heavy Oil Processing China University of Petroleum (Beijing) Institute of Materials Science TU Darmstadt department of Chemistry Xi'an Jiaotong-Liverpool University department of Mechanical and Mechatronics Engineering and Waterloo Institute of Nanotechnology University of Waterloo Waterloo

Dual atomic catalysts （DAC）,particularly copper （Cu2）-based nitrogen （N） doped graphene,show great potential to effectively convert CO2and nitrate （NO3-） into important industrial chemicals such as ethylene,glycol,acetamide,and urea through an efficient catalytical process that involves C–C and C–N ***,the origin of the coupling activity remained unclear,which substantially hinders the rational design of Cu-based catalysts for the N-integrated CO2reduction reaction （CO2RR）.To address this challenge,this work performed advanced density functional theory calculations incorporating explicit solvation based on a Cu2-based N-doped carbon (Cu2N6C10) catalyst for *** calculations are aimed to gain insight into the reaction mechanisms for the synthesis of ethylene,acetamide,and urea via coupling in the interfacial reaction *** to the sluggishness of CO2,the formation of a solvation electric layer by anions （F-,Cl-,Br-,and I-） and cations (Na+,Mg2+,K+,and Ca2+) leads to electron transfer towards the Cu *** process significantly accelerates the reduction of *** results reveal that*CO intermediates play a pivotal role in N-integrated ***,the Cu2-based N-doped carbon catalyst examined in this study has demonstrated the most potential for C–N coupling to *** findings reveal that through the process of a condensation reaction between*CO and NH2OH for urea synthesis,*NO3-is reduced to*NH3,and*CO2to*CCO at dual Cu atom *** dual-site reduction facilitates the synthesis of acetamide through a nucleophilic reaction between NH3and the ketene ***,we found that the I-and Mg2+ions,influenced by pH,were highly effective for acetamide and ammonia synthesis,except when F-and Ca2+were ***,the mechanisms of C–N bond formation were investigated via ab-initio molecular dynamics simulations,and we found that adjusting the micro-environment can change the dominant side reaction,shift

关键词： pH-dependent micro-environments C–N coupling Dual Cu-based nitrogen carbon catalysts Explicit solvation model Ion stabilizer AIMD

An Efficient Calculation of Photonic Crystal Band Structures Using Taylor Expansions

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Communications in Computational Physics 2014年第10期16卷 1355-1388页

作者： Dirk Klindworth Kersten Schmidt Research Center MATHEON TU BerlinDepartment of MathematicsStraße des 17.Juni 13610623 BerlinGermany.

In this paper we present an efficient algorithm for the calculation of photonic crystal band structures and band structures of photonic crystal *** method relies on the fact that the dispersion curves of the band structure are smooth functions of the quasi-momentum in the one-dimensional Brillouin *** show the derivation and computation of the group velocity,the group velocity dispersion,and any higher derivative of the dispersion *** derivatives are then employed in a Taylor expansion of the dispersion *** control the error of the Taylor expansion with the help of a residual estimate and introduce an adaptive scheme for the selection of nodes in the one-dimensional Brillouin zone at which we solve the underlying eigenvalue problem and compute the derivatives of the dispersion *** proposed algorithm is not only advantageous as it decreases the computational effort to compute the band structure but also because it allows for the identification of crossings and anti-crossings of dispersion curves,*** identification is not possible with the standard approach of solving the underlying eigenvalue problem at a discrete set of values of the quasi-momentum without taking the mode parity into account.

关键词： Photonic crystals band structure calculation group velocity Taylor expansion adaptivity

DEPOSITION OF TiBN HARD FILMS ON HOT-WORKING-STEEL DIES FOR ALUMINIUM EXTRUSION VIA A DUPLEX PROCESS

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Acta Metallurgica Sinica(English Letters) 2001年第6期14卷 408-414页

作者： K. Muller (Forschungszentrum Stranpressen, tu berlin, 13355 berlin, Germany) Forschungszentrum Stranpressen TU Berlin 13355 Berlin Germany

Hot working steels have been used as die materials for hot extrusion of aluminium. Due to tribological interaction at elevated temperature between the die bearing and the surface of extruded aluminium profiles, not only the surface quality of the extruded product, but also the lifetime of the dies decreases. Deposition of TiBN hard films on the die bearing could improve the die performance. Treatment should be done in a duplex process process combining a plasma nitriding pretreatment (PN) and a plasma assisted chemical vapour deposition (PACVD) of TiBN. In this study the influence of the process conditions on the properties of the duplex coatings was investigated. The relationship between structure and mechanical property was researched. For testing these TIBN hard films under elevated temperature conditions and for comparison with other possible coatings special extrusion dies with different coated bearings were used. The extrusion trials were performed on the 8MN-extrusion press at the research a nd development center for extrusion, Technical University of berlin.

关键词： hard film plasma nitriding duplex process PN PA CVD and extrusion

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TRANSFORMATIONS FOR THE PRIZE-COLLECTING STEINER TREE PROBLEM AND THE MAXIMUM-WEIGHT CONNECTED SUBGRAPH PROBLEM TO SAP

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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.

WEAK-DUALITY BASED ADAPTIVE FINITE ELEMENT METHODS FOR PDE-CONSTRAINED OPTIMIZATION WITH POINTWISE GRADIENT STATE-CONSTRAINTS

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Journal of Computational mathematics 2012年第2期30卷 101-123页

作者： M. Hintermuer Michael Hinze Ronald H.W. Hoppe department of mathematics Humboldt-University of Berlin Germany department of mathematics University of Hamburg Germany department of mathematics University of Augsburg Germany and Department of MathematicsUniversity of Houston USA

Adaptive finite element methods for optimization problems for second order linear el- liptic partial differential equations subject to pointwise constraints on the l2-norm of the gradient of the state are considered. In a weak duality setting, i.e. without assuming a constraint qualification such as the existence of a Slater point, residual based a posteriori error estimators are derived. To overcome the lack in constraint qualification on the continuous level, the weak Fenchel dual is utilized. Several numerical tests illustrate the performance of the proposed error *** subject classification： 65N30, 90C46, 65N50, 49K20, 49N15, 65K10.

关键词： Adaptive finite element method A posteriori errors Dualization Low regu-larity Pointwise gradient constraints State constraints Weak solutions.

Parameterized Algorithmics for Computational Social Choice:Nine Research Challenges

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Tsinghua Science and Technology 2014年第4期19卷 358-373页

作者： Robert Bredereck Jiehua Chen Piotr Faliszewski Jiong Guo Rolf Niedermeier Gerhard J.Woeginger the Institut fr Softwaretechnik und Theoretische Informatik TU Berlin Berlin Germany AGH University of Science and Technology Kraków Poland the Cluster of Excellence Multimodal Computing and Interaction Universitt des SaarlandesSaarbrcken Germany the department of mathematics and Computer Science TU Eindhoven Eindhoven The Netherlands

Computational Social Choice is an interdisciplinary research area involving Economics, Political Science,and Social Science on the one side, and mathematics and Computer Science（including Artificial Intelligence and Multiagent Systems） on the other side. Typical computational problems studied in this field include the vulnerability of voting procedures against attacks, or preference aggregation in multi-agent systems. Parameterized Algorithmics is a subfield of Theoretical Computer Science seeking to exploit meaningful problem-specific parameters in order to identify tractable special cases of in general computationally hard problems. In this paper, we propose nine of our favorite research challenges concerning the parameterized complexity of problems appearing in this context. This work is dedicated to Jianer Chen, one of the strongest problem solvers in the history of parameterized algorithmics,on the occasion of his 60 th birthday.

关键词： NP-hard problems parameterized complexity fixed-parameter tractability kernelization exact algorithms voting decision making cake cutting

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HOW TO PROVE THE DISCRETE RELIABILITY FOR NONCONFORMING FINITE ELEMENT METHODS

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Journal of Computational mathematics 2020年第1期38卷 142-175页

作者： Carsten Carstensen Sophie Puttkammer department of mathematics Humboldt-Universitat zu BerlinUnter den Linden 610099 BerlinGermany

Optimal convergence rates of adaptive finite element methods are well understood in terms of the axioms of *** key ingredient is the discrete reliability of a residualbased a posteriori error estimator,which controls the error of two discrete finite element solutions based on two nested *** the error analysis of nonconforming finite element methods,like the Crouzeix-Raviart or Morley finite element schemes,the difference of the piecewise derivatives of discontinuous approximations to the distributional gradients of global Sobolev functions plays a dominant role and is the object of this *** nonconforming interpolation operator,which comes natural with the definition of the aforementioned nonconforming finite element in the sense of Ciarlet,allows for stability and approximation properties that enable direct proofs of the reliability for the residual that monitors the equilibrium *** novel approach of this paper is the suggestion of a right-inverse of this interpolation operator in conforming piecewise polynomials to design a nonconforming approximation of a given coarse-grid approximation on a refined *** results of this paper allow for simple proofs of the discrete reliability in any space dimension and multiply connected domains on general shape-regular triangulations beyond newest-vertex bisection of *** attention is on optimal constants in some standard discrete estimates listed in the appendices.

关键词： Discrete reliability Nonconforming finite element method Conforming companion Morley Crouzeix-Raviart Explicit constants Axioms of adaptivity

Temperature Hysteresis in Shape Memory Alloys

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Chinese Physics Letters 1991年第5期8卷 251-254页

作者： XU Huibin FB 9 Physikalische IngenieurwissenschaftTU BerlinFRG

The martensitic phase transformation which produces shape memory is connected with a *** of the applications of shape memory alloys require small hysteresis loops,other require large *** is therefore important to be able to control the size of the *** that purpose three different methods were introduced in the present *** vibration narrowed the hysteresis loops in both NiTi and CuZnAl alloys up to 17%,while the width of the hysteresis loops in a NiTi alloy decreased 3~4 times by addition of the third element *** help of a special heat treatment a nearly hysteresis-free phase transformation occured in a Ti-51Ni(at.%)*** size of the hysteresis is determined by the interfacial energies of the phase boundaries and these will be big,if the E-modulus and the lattice distortion are big.

关键词： alloys transformation alloy