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Model Studies in Heterogeneous Catalysis

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Model Studies in Heterogeneous Catalysis

2005年纳米和表面科学与技术全国会议

作者： hans-joachim freund Fritz-Haber-Institut der Max-Planck-Gesellschaft Dept.of Chemical Physics Faradayweg 4-6 D-14195 BerlinGermany

Model catalyst systems have been prepared by growth of metal nano-aggregates onthin wellordered oxide films of alumina,silica and *** systems lendthemselves to structural and morphological characterization via scanning probemicroscopies and transmission electron microscopy at the atomic scale and bridge to acertain extent the materials gap between metal single crystal studies and theinvestigation of real catalyst samples.

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原子尺度上的异质催化

物理 2007年第5期36卷 370-376页

作者：路军岭高鸿钧时东霞 Shamil Shaikhutdinov hans-joachim freund 中国科学院物理研究所北京凝聚态物理国家实验室 Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-614195 Berlin Germany Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-614195 BerlinGermany

现实中的催化剂是个相当复杂的系统体系,且为粉末状,限制了多种表面科学表征手段的应用.科学家通过建立简化的催化剂模型,充分利用目前多种有力的科技分析手段,如扫描隧道显微镜(STM)、透射电镜(TEM)、光电子能谱(XPS)、傅里叶变换红外... 详细信息

现实中的催化剂是个相当复杂的系统体系,且为粉末状,限制了多种表面科学表征手段的应用.科学家通过建立简化的催化剂模型,充分利用目前多种有力的科技分析手段,如扫描隧道显微镜(STM)、透射电镜(TEM)、光电子能谱(XPS)、傅里叶变换红外吸收谱(FTIR)、电子能量损失谱(EELS)等,直观地在原子尺度上研究催化反应的机理,从而使得人们能够设计出选择性能更高、催化性能更好的催化剂.

关键词：异质催化剂模型扫描隧道显微镜(STM) 光电子能谱(XPS) 傅里叶变换红外吸收谱(FTIR) 纳米颗粒氧化物薄膜

Mo（001）表面CaO薄膜过渡层结构的STM研究

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Mo（001）表面CaO薄膜过渡层结构的STM研究

Building Blocks of Nature

中国化学会第29届学术年会

作者：邵翔 Niklas Nilius hans-joachim freund 中国科学技术大学化学物理系 Fritz-haber Institute of Max-Planck Society Faradayweg 4-614195 BerlinGermany

生长在金属衬底表面的氧化物薄膜,在其厚度较薄的时候往往具有有别于体相氧化物的表面性质。这一方面是由于金属基底的电子态可以直接投射到表面上,影响表面分子过程;另一方面,也往往由于基底的晶格失配而导致薄膜结构相对于体相结构有... 详细信息

生长在金属衬底表面的氧化物薄膜,在其厚度较薄的时候往往具有有别于体相氧化物的表面性质。这一方面是由于金属基底的电子态可以直接投射到表面上,影响表面分子过程;另一方面,也往往由于基底的晶格失配而导致薄膜结构相对于体相结构有偏离,只是随着膜厚增加而不断趋于体相结构。我们在Mo（001）表面成功的制备了CaO（001）单晶化薄膜[1]。然而体系的晶格失配较大,达到了11%,因此薄膜采取了Stranski-Krostanov模式进行生长,即先在Mo（001）表面形成4-5层具有CaxMo1-xO结构的过渡层[2],随后纯相的CaO才开始以岛状形式生长并弥合成膜。我们特别的研究了其中的过渡层薄膜。为了补偿晶格失配造成的应力,其化学组成随着膜厚发生渐变,相应的电子结构也随之变化。而在不同制备条件下,其结构也会不同。另外,对于分子和金属的吸附,这种过度层也展现出了一定的有趣性质。这些性质可以用来调控负载金属的催化活性。

关键词： CaO 薄膜过渡层调控 STM

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第3期10卷 1226-1303页

作者： hans joachim Dudek Retired Auf dem Komp Germany

By means of a representation of the elementary objects by the Lagrange density and by the commutators of the communication relations, correlations can be formed using the Fourier transform, which under the conditions of the Hamilton principle, describes correlation structures of the elementary objects with oscillator properties. The correlation structures obtained in this way are characterized by physical information, the essential component of which is the action. The correlation structures describe the physical properties and their interactions under the sole condition of the Hamilton’s principle. The structure, the properties and the interactions of elementary objects can be led back in this way to a fundamental four dimensional structure, which is therefore in their different modifications the building block of nature. With the presented method, an alternative interpretation of elementary physical effects to quantum mechanics is obtained. This report provides an overview of the fundamentals and statements of physical information theory and its consequences for understanding the nature of elementary objects.

关键词： Hamilton Principle as Global Law in Physics Physical Information Generated by Action Correlation Space Mass and Charge Formation Interpretation of Physical Effects

The effect of Laves phases and nano-precipitates on the electrochemical corrosion resistance of Mg-Al-Ca alloys under alkaline conditions

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Journal of Magnesium and Alloys 2024年第6期12卷 2447-2461页

作者： Markus Felten Veronika Chaineux Siyuan Zhang Ali Tehranchi Tilmann Hickel Christina Scheu Joshua Spille Marta Lipińska-Chwałek joachim Mayer Benjamin Berkels Marcus hans Imke Greving Silja Flenner Sandra Sefa Daniela Zander Chair of Corrosion and Corrosion Protection RWTH Aachen UniversityAachen 52072 Germany Max-Planck-Institut für Eisenforschung GmbH Düsseldorf 40237 Germany Central Facility for Electron Microscopy RWTH Aachen UniversityAachen 52074 Germany Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons Forschungszentrum Jülich GmbHJülich 52428Germany Mathematical Image and Signal Processing Aachen Institute for Advanced Study in Computational Engineering ScienceRWTH Aachen UniversityAachen 52062 Germany Materials Chemistry RWTH Aachen UniversityAachen 52074 Germany Institute of Materials Physics Helmholtz-Zentrum HereonGeesthacht 21502 Germany

The electrochemical corrosion mechanisms of Mg alloys were extensively studied in previous investigations of different chemical com-positions,modified surface states and various electrolyte ***,recent research focused on the active state of Mg dissolution,leading to unresolved effects of secondary phases adjacent to a stableα-solid solution passive *** present study investigates the fundamental electrochemical corrosion mechanisms of three different Laves phases with varying phase morphologies and phase fractions in the passive state of Mg-Al-Ca *** microstructure was characterized by(transmission-)electron microscopy and synchrotron-based transmission X-ray *** electrochemical corrosion resistance was determined with a standard three-electrode setup and advanced in-situ flow cell measurements.A new electrochemical activity sequence(C15>C36>α-Mg>C14)was obtained,as a result of a stable passive layer formation on theα-solid ***,nm-scale Mg-rich precipitates were identified within the Laves phases,which tend to inhibit the corrosion kinetics.

关键词： Laves phase STEM Magnesium Corrosion Passive layer

Impact of renewable energies on the operation and economicsituation of coal fired power stations： Actual situation of coalfired power stations in Germany

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Frontiers in Energy 2017年第2期11卷 119-125页

作者： hans-joachim KRAUTZ Alexander LISK joachim POSSELT Christian KATZER Department for Power Plant Technology Brandenburg University of Technology Cottbus-Senftenberg 03046 Cottbus Gemany

Due to the fluctuating character of the renewable energy sources the demand of conventional power plants for flexibility is increasing. In the recent years, in Germany there has been a fast rise of production capacity of renewable energies, especially from wind turbines, photovoltaic installations, and biomass plants. The installed nominal power of wind turbines is actually (December 2016) 42 GW and of photovoltaic installations 40?GW. The renewable electric energy production in Germany is about 190?TWh/a, which represents a share of 33% of the yearly demand. The increased need for flexibility affects both the power gradients as well as the minimum load of conventional power plants. Due to this flexibility behaviour, conventional power plants are faced with problems concerning the durability of power plant components, corrosion, more maintenance effort and consequently the overall life expectancy. Another consequence of the increasing share of renewable energies is the decreasing full load operating hours, especially of coal fired and gas power plants. Along with decreasing revenues from the energy exchange market, coal fired power plants are faced with new economically challenges.

关键词： flexible load operation minimal load power gradients power plant maintenance corrosion life expectancy

Metamorphic Evolution of Chloritoid-Bearing Micaschist from the Variscan Elstergebirge: Evidences for Stacking of High-Pressure Rocks in the Saxothuringian Zone of Central Europe

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Journal of Earth Science 2020年第3期31卷 425-446页

作者： Gelareh Rahimi hans-joachim Massonne Fakultat Chemie Universitat Stuttgart70569 StuttgartGermany School of Earth Sciences China University of GeosciencesWuhan 430074China

A chloritoid-garnet-bearing micaschist from the southern part of the Elstergebirge was studied to better understand the Variscan orogenic evolution in the Saxothuringian zone of the northwestern Bohemian *** on the textural relations and compositions of minerals,especially of zoned garnet and potassic white mica,a P-T path was reconstructed using contoured P-T *** U-Th-Pb dating of monazite in the micaschist was undertaken with the electron *** micaschist experienced P-T conditions along a clockwise path between 16 kbar at 510℃and 5 kbar at 555℃followed by isobaric heating to about 600℃.Monazite ages range between 315 and 480 Ma with the most prominent maxima and side maxima at 346.0±1.1(2σ),357.3±2.3,and 368.3±1.7 *** older than 380 Ma were related to detrital monazite pointing to a Devonian sedimentary *** ages around 325 Ma were assigned to the isobaric heating by nearby post-tectonic *** high-pressure event,being the result of the collision of Laurussia and Gondwana after closure of the Rheic Ocean,occurred in the Late *** exhumation to 15-20 km(5 kbar)ended probably in the Early *** high-pressure micaschists from the Fichtelgebirge to the Erzgebirge crystalline complexes are suggested to represent a single nappe within a metamorphic nappe *** nappe is composed of metasedimentary slices,which experienced different peak pressures rather than representing a coherent crustal section.

关键词： Saxothuringian micaschist chloritoid garnet monazite dating Variscan P-T path

A Mixed—Mode BIST Scheme Based on Folding Compression

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Journal of Computer Science & Technology 2002年第2期17卷 203-212页

作者：梁华国 Sybille Hellebrand hans-joachim Wunderlich Department of Computer and Information Hefei University of Technology Hefei 230009. P.R. China Institute of Applied Computer Science University of Innsbruck Austria Institute of Computer Science University of Stuttgart Germany

In this paper a new scheme for mixed mode scan-based BIST is presented with complete fault coverage, and some new concepts of folding set and computing are *** scheme applies single feedback polynomial of LFSR for generating pseudo-random patterns, as well as for compressing and extending seeds of folding sets and an LFSR, where we encode seed of folding set as an initial seed of LFSR. Moreover these new techniques are 100%compatible with scan design. Experimental results show that the proposed scheme outperforms previously published approaches based on the reseeding of LFSRs.

关键词： BIST random pattern testing LFSR folding set encoding seed

Pressure-Temperature Evolution of a Mylonitic Gneiss from the Lower Seve Nappe in the Handol Area,Central Sweden

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Journal of Earth Science 2021年第6期32卷 1496-1511页

作者： Botao Li hans-joachim Massonne Xiaoping Yuan School of Earth Sciences China University of GeosciencesWuhan430074China Fakultät Chemie Universität Stuttgart70569StuttgartGermany

Ultrahigh-pressure metamorphism has recently been reported from various crustal rocks in the Seve Nappe Complex(SNC)in which microdiamonds were ***,in gneiss from the Lower Seve Nappe(LSN),neither any direct petrographic indication for UHP was reported nor the metamorphic evolution was well *** studied a mylonitic gneiss from the Handol area of the LSN and applied phase-diagram modeling and Ti-in-biotite *** on the compositions of garnet and biotite and observed mineral assemblages,a path was reconstructed passing through about 8 kbar and 730℃at prograde ***-pressure and initial retrograde stages occurred at 9.0–10.2 kbar at 745-775℃,and 7–9 kbar at<750℃,*** ultrahigh-pressure evidence was recognized compatible with medium-pressure metamorphism deduced in earlier studies of gneiss from the *** higher peak pressures were reported recently for metamorphic rocks of the LSN,a possible interpretation is that slices or erased blocks were subducted,metamorphosed at different depths,and exhumed in a subduction ***,the dominant gneiss of the SNC experienced only a medium-pressure metamorphism in the upper part of the downgoing Baltica *** from different depth levels were brought together in an exhumation channel located between Baltica and the overlying plate.

关键词： Lower Seve Nappe Swedish Caledonides mylonitic gneiss P-T pseudosection modeling Ti-in-biotite thermometry metamorphic rocks