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Resistance switching in oxides with inhomogeneous conductivity

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Chinese Physics B 2013年第6期22卷 1-18页

作者：尚大山孙继荣沈保根 Wuttig matthias Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences I.Physikalisches Institut(IA) RWTH Aachen University

Electric-field-induced resistance switching （RS） phenomena have been studied for over 60 years in metal/dielectrics/metal structures. In these experiments a wide range of dielectrics have been studied including binary transition metal oxides, perovskite oxides, chalcogenides, carbon- and silicon-based materials, as well as organic materials. RS phenomena can be used to store information and offer an attractive performance, which encompasses fast switching speeds, high scalability, and the desirable compatibility with Si-based complementary metal-oxide-semiconductor fabrication. This is promising for nonvolatile memory technology, i.e., resistance random access memory （RRAM）. However, a comprehensive understanding of the underlying mechanism is still lacking. This impedes faster product development as well as accurate assessment of the device performance potential. Generally speaking, RS occurs not in the entire dielectric but only in a small, confined region, which results from the local variation of conductivity in dielectrics. In this review, we focus on the RS in oxides with such an inhomogeneous conductivity. According to the origin of the conductivity inhomogeneity, the RS phenomena and their working mechanism are reviewed by dividing them into two aspects： interface RS, based on the change of contact resistance at metal/oxide interface due to the change of Schottky barrier and interface chemical layer, and bulk RS, realized by the formation, connection, and disconnection of conductive channels in the oxides. Finally the current challenges of RS investigation and the potential improvement of the RS performance for the nonvolatile memories are discussed.

关键词： resistance switching inhomogeneous conductivity transition metal oxide

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Smoking prevalence in the area of responsibility of the German Ministry of Defense——results of the employee survey in the context of occupational health management

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Military Medical Research 2020年第3期7卷 343-349页

作者： Stefan Sammito Annika Claus Dirk-matthias Rose Department I 3 Research&Development Air Force Centre of Aerospace MedicineCologneGermany Occupational Medicine Faculty of MedicineOtto-von-Guericke-University of MagdeburgMagdeburgGermany Institute for Teachers’Health Institute of OccupationalSocial and Environmental Medicine of the Johannes-Gutenberg University MainzMainzGermany

Background:Tobacco use,correlated with reduced physical fitness,is one of the leading causes of avoidable death *** increases the risk of dementia and can shorten the lifespan by 10 *** the German Armed Forces(Bundeswehr),figures on smoking behavior have not been comprehensively *** study analyzes current data in a large sample from this ***:Based on an employee survey as part of the Occupational Health Management System,data on smoking behavior from 13,326 participants were analyzed in relation to age,gender,professional status,education level and membership in military operational units versus other ***:Smoking behavior varied significantly(Polder),gender,professional status,military agency membership status,and education level(the lower the education level,the higher the smoking rates).With the exception of the downward trend in smoking behavior with increasing age among civilian employees,these results were all significant(P<0.005).Conclusions:This data analysis shows that smoking prevalence among personnel in the area of responsibility of the Federal Ministry of Defense is comparable to the current data from corresponding surveys of the German *** on gender,they generally show values that are slightly above those of the German *** well-known trend in the general population of decreasing smoking prevalence with increasing age is also seen in this ***,there are considerable differences in the smoking prevalence among individual subgroups(professional status,agency,gender,education level).The data show that particular young soldiers in the armed forces should be the target group for further preventive measures.

关键词： Prevention Smoking Military Health promotion

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Screening of the whole human cytochrome P450 complement(CYPome)with enzyme bag cocktails

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Journal of Pharmaceutical Analysis 2020年第3期10卷 271-276页

作者： Sangeeta Shrestha Sharma Shishir Sharma matthias Bureik School of Pharmaceutical Science and Technology Health Sciences PlatformTianjin UniversityTianjin300072China

We have previously introduced the use of permeabilized fission yeast cells(enzyme bags)that recombinantly express full-length CYPs for drug metabolism *** enzyme bags are cells with pores that function as enzymes in *** can easily be prepared without a need for ultracentrifugation and may be used in similar protocols as *** this study we report the preparation of enzyme bag cocktails that permit the testing of multiple CYPs in a single enzyme bag ***,we established a convenient testing scheme that permits a rapid screen of all human CYPs for activity towards any given candidate *** important aspect of this approach is the reduction of individual CYP test *** a cocktail containing many CYPs tests negative,it follows that all CYPs included in that cocktail need not be tested individually,thus saving time and *** new protocol was validated using two probe substrates.

关键词： Cytochrome P450 Drug metabolism Fission yeast Luminescence Proluciferin

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Palladium-catalysed efficient synthesis of primary alkyl halides from terminal and internal alkenes

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National Science Review 2022年第12期9卷 63-65页

作者： Han-Jun Ai matthias Beller Xiao-Feng Wu Dalian National Laboratory for Clean Energy Dalian Institute of Chemical Physics Chinese Academy of Sciences Leibniz-Institut für Katalyse e.V.

The development of remote functionalization of alkenes has recently gained considerable attention as it offers the op-portunity to directly transform a mixture of unrefined olefin isomers into a single valuable fine c...

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A metamodel for heritage-based urban recovery

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Built Heritage 2023年第2期7卷 26-49页

作者： Christer Gustafsson matthias Ripp Department of Art History Uppsala University(SE)UppsalaSweden. Department of Archives&Preservation of Historical Monuments City of Regensburg(DE) RegensburgGermany.

Purpose:The purpose of this paper is to discuss the potential transfer of a metamodel for heritage-based urban development(HBUD)in a postcrisis urban recovery ***/methodology/approach:After an introduction to the feld of cultural heritage as a resource for urban development,the research question is elaborated,and the current understanding of urban heritage is *** use of the metamodel in a postcrisis urban recovery setting is described as a potential *** proposed metamodel is introduced along with the grounded theory and design research methodology through which it was *** specifc qualities of metamodels and how they can contribute to the proposed use are *** scenario is then developed further,and specifc ways in which the metamodel could contribute are ***,the metamodel is compared to other methods,such as the historic urban landscape(HUL)approach,and the limitations are ***:The metamodel can potentially be used in a postcrisis urban recovery *** metamodel cannot be used directly,owing to the nature of metamodels;however,it can be transferred to a specifc context and help to structure successful heritage-based urban recovery(HBUR)*** limitations/implications:One limitation is that it can be difcult to understand the diferences between models and *** with a comprehensive understanding of the nature of metamodels can this metamodel be applied,for example,to select appropriate models for *** metamodel can help to ensure that all relevant‘elements’are part of the processes designed for HBUR and emphasise the need for thorough planning,or scoping,of such ***/value:Metamodelling has not previously been used for HBUD or HBUR.

关键词： Urban heritage Recovery Resilience Sustainable development Metamodel Conservation

Experimental investigation of radiative heat propagation in a simplified generic packed bed

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Particuology 2024年第5期88卷 149-160页

作者： matthias Tyslik Lukas Pörtner Siegmar Wirtz Martin Schiemann Institute of Energy Plant Technology Ruhr-University Bochum44780 BochumGermany

A novel test rig for the investigation of radiative heat transfer in packed beds has been developed and is introduced with representative experimental *** individual components and the calibration are *** generic packed bed is realized in a simplified way by an arrangement of parallel rods,which represent particles in *** this arrangement,electrically heated rods provide the radiation propagating through the rod array to heat the passive counterparts.A sophisticated temperature-control scheme with a large number of thermocouples and infrared-imaging provides in-depth information about heat transfer in the *** radiation intensities are determined with a Fourier-transform infrared spectroscopy,which has been modified and validated for this specific *** order to compare the influence of different surface properties of particles on the heat propagation and surface reflections,rod samples made of stainless steel and magnesium oxide are *** influence of material properties becomes clearly visible by comparing the high radiation intensities resulting from a stainless steel rod array to the same geometry built from magnesium oxide *** addition,the influence of the surface properties is particularly evident in the infrared images since the reflections are significantly higher for the stainless steel samples than for the magnesium oxide *** experimental results in the current work demonstrate the ability of the test rig to provide data with a well-defined accuracy as a validation base for numerical radiation simulations in packed beds.

关键词： Thermal radiation Spectral reflections Fourier-transform infrared spectroscopy

Modelling and Numerical Valuation of Power Derivatives in Energy Markets

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Advances in Applied Mathematics and Mechanics 2012年第3期4卷 259-293页

作者： Mai Huong Nguyen matthias Ehrhardt Institut fur Mathematik Technische Universitat BerlinStrasse des 17.Juni 13610623 BerlinGermany Lehrstuhl fur Angewandte Mathematik und Numerische Analysis Fachbereich C-Mathematik und NaturwissenschaftenBergische Universitat WuppertalGaußstr.2042119 WuppertalGermany

In this work we investigate the pricing of swing options in a model where the underlying asset follows a jump diffusion *** focus on the derivation of the partial integro-differential equation(PIDE)which will be applied to swing contracts and construct a novel pay-off function from a tree-based pay-off matrix that can be used as initial condition in the PIDE *** valuing swing type derivatives we develop a theta implicit-explicit finite difference scheme to discretize the PIDE using a Gaussian quadrature method for the integral *** on known results for the classical theta-method the existence and uniqueness of solution to the new implicit-explicit finite difference method is *** numerical examples illustrate the usability of the proposed method and allow us to analyse the sensitivity of swing options with respect to model *** particular the effects of number of exercise rights,jump intensities and dividend yields will be investigated in depth.

关键词： Swing options jump-diffusion process mean-reverting Black-Scholes equation energy market partial integro-differential equation theta-method Implicit-Explicit-Scheme

Prosaposin hyperglycosylation: a novel tumor immune escape mechanism and implications for cancer immunotherapy

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Signal Transduction and Targeted Therapy 2024年第8期9卷 3150-3152页

作者： matthias Peipp Diana Dudziak Christian Kellner Division of Antibody-Based Immunotherapy Department of Medicine IChristian-Albrechts University and University Hospital Schleswig-HolsteinKielGermany institute of Immunology Jena University HospitalFriedrich-Schiller-UniversityJenaGermany Comprehensive Cancer Center Central Germany Jena/Leipzig JenaGermany Division of Transfusion Medicine Cell Therapeutics and HaemostaseologyLMU University HospitalLMU MunichMunichGermany

In a recent article published in Science,Sharma et *** the essential role of saposins in cross-presentation of tumor membraneassociated antigens by dendritic cells(DC)to CD8^(+)T cells.1 However,antigen cross-presentation,which is fundamental in cancer cell elimination,is hindered in tumor DC by hyperglycosylation of the common saposin precursor prosaposin(pSAP)leading to impaired T cell tumor immunity-yet,the potential of recombinant pSAP to re-establish T cell responses may offer a novel way to counteract immune evasion in a therapeutic approach.

关键词： impaired immunity

Robust reconstruction of curved line structures in noisy point clouds

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Visual Informatics 2021年第3期5卷 1-14页

作者： Marcel Ritter Daniel Schiffner matthias Harders Interactive Graphics and Simulation Group Department of Computer ScienceUniversity of InnsbruckAustria Airborne Hydromapping GmbH InnsbruckAustria DIPF|Leibniz Institute for Research and Information Education FrankfurtGermany

Point-based geometry representations have become widely used in numerous contexts,ranging from particle-based simulations,over stereo image matching,to depth sensing via light detection and *** application focus is on the reconstruction of curved line structures in noisy 3D point cloud *** algorithms operating on such point clouds often rely on the notion of a local *** the latter,our approach employs multi-scale neighborhoods,for which weighted covariance measures of local points are *** line structures are reconstructed via vector field tracing,using a bidirectional piecewise streamline *** also introduce an automatic selection of optimal starting points via multi-scale geometric *** pipeline development and choice of parameters was driven by an extensive,automated initial analysis process on over a million prototype test *** behavior of our approach is controlled by several parameters—the majority being set automatically,leaving only three to be controlled by a *** an extensive,automated final evaluation,we cover over one hundred thousand parameter sets,including 3D test geometries with varying curvature,sharp corners,intersections,data holes,and systematically applied varying types of ***,we analyzed different choices for the point of reference in the co-variance computation;using a weighted mean performed best in most *** addition,we compared our method to current,publicly available line reconstruction *** to thirty times faster execution times were achieved in some cases,at comparable error ***,we also demonstrate an exemplary application on four real-world 3D light detection and ranging datasets,extracting power line cables.

关键词： Computational geometry Noisy point clouds Line reconstruction Automatic Adaptive control