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摇摆晶体法研究六角密堆单晶体中的位错结构(英文)

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金属学报 1997年第2期33卷 198-206页

作者： Y.Hao F.Mucklich G.Petzow max-planck-institut fur Metallforschung Institut fur WerkstoffwissenschaftPulverme-tallurgisches LaboratioriumHeisenbergstr570569 StuttgartGermany institute fur Werkstoffwissenschaftern Universitat des Saarlandes 66041 Saarbrucken

单晶体在其生长过程中可引入大量位错而导致晶体点阵的弯曲和畸变．利用考虑了运动学衍射理论的Krivoglaz模型进行理论计算．选择具有良好光学性能并可做为X射线单色器的被单晶做为样品，研究其摇摆曲线．不同滑移系统的基面位错、柱面... 详细信息

单晶体在其生长过程中可引入大量位错而导致晶体点阵的弯曲和畸变．利用考虑了运动学衍射理论的Krivoglaz模型进行理论计算．选择具有良好光学性能并可做为X射线单色器的被单晶做为样品，研究其摇摆曲线．不同滑移系统的基面位错、柱面位错影响不同的反射，研究相应反射的摇摆曲线可测定晶体内的位错结构，这对发展晶体单色器具有重要作用，可通过控制生长条件、热处理条件得到所需要的简单位铝结构．

关键词：铍单晶摇摆晶体法位错单晶

FeO-rich silicates and Ca, Al-rich inclusions in Qingzhen andYamato 691 (EH3) meteorites: Evidence for migration of mass in the solar nebula

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Chinese Science Bulletin 2002年第2期47卷 150-153页

作者： LIN Yangting OUYANG Ziyuan A.EI Goresy Guangzhou institute of Geochemistry Chinese Academy of SciencesGuangzhou 510640China institute of Geochemistry Chinese Academy of SciencesGuiyang 550002China max-planck-institut fur Chemie

The Qingzhen and Yamato 691 (EH3) enstatite chondrites, which formed under extremely reducing condi-tions, are studied using the scanning electron microscope and electron probe microanalyzer. Both meteorites contain FeO-rich silicates and minor Ca, Al-rich inclusions. Most FeO-rich silicates are Ca-poor pyroxenes and occur as frag-ments in matrix. A few grains of FeO-rich silicates were found in chondrules, and FeO-rich olivine is rare. In Qingzhen, FeO-rich silicates commonly contain abundant dust-like Ni-poor metals, which probably formed through reduction of FeO. In contrast, only a few fragments of FeO-rich silicates in Yamato 691 enclose dust-like metals. This difference is consistent with a more reducing condition of Qingzhen than Yamato 691. Ca, Al-rich inclusions have similar modal compositions and mineral chemistry as their counterparts in carbonaceous chondrites. We suggest that (1) the FeO-rich silicates probably formed in oxidized regions of the solar nebula, and then moved into the

关键词： solar nebula meteorite enstatite chondrite reduction migration.

On-target temporal characterization of optical pulses at relativistic intensity

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Light(Science & Applications) 2019年第1期8卷 278-286页

作者： Vyacheslav E.Leshchenko Alexander Kessel Olga Jahn Mathias Kruger Andreas Münzer Sergei ATrushin Laszlo Veisz Zsuzsanna Major Stefan Karsch max-planck-institut fur Quantenoptik 85748 GarchingGermany Department fur Physik Ludwig-Maximilians-Universitat Munchen85748 GarchingGermany Department of Physics Umea UniversityUmeåSE-90187Sweden Department of Physics The Ohio State UniversityColumbusOH 43210USA GSI Helmholtzzentrum fur Schwerionenforschung GmbH PlanckstraBe 164291 DarmstadtGermany Helmholtz-institut Jena Frobelstieg 307743 JenaGermany

High-field experiments are very sensitive to the exact value of the peak intensity of an optical pulse due to the nonlinearity of the underlying ***,precise knowledge of the pulse intensity,which is mainly limited by the accuracy of the temporal characterization,is a key prerequisite for the correct interpretation of experimental *** the detection of energy and spatial profile is well established,the unambiguous temporal characterization of intense optical pulses,another important parameter required for intensity evaluation,remains a challenge,especially at relativistic intensities and a few-cycle pulse ***,we report on the progress in the temporal characterization of intense laser pulses and present the relativistic surface second harmonic generation dispersion scan(RSSHG-D-scan)—a new approach allowing direct on-target temporal characterization of high-energy,few-cycle optical pulses at relativistic intensity.

关键词： optical relativistic intensity

The Translational Apparatus of Plastids and Its Role in Plant Development

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Molecular Plant 2014年第7期7卷 1105-1120页

作者： Nadine Tiller Ralph Bock max-planck-institut for Molekulare Pflanzenphysiologie Am Muhlenberg 1 D-14476 Potsdam-Golm Germany

Chloroplasts （plastids） possess a genome and their own machinery to express it. Translation in plastids occurs on bacterial-type 70S ribosomes utilizing a set of tRNAs that is entirely encoded in the plastid genome. In recent years, the components of the chloroplast translational apparatus have been intensely studied by proteomic approaches and by reverse genetics in the model systems tobacco （plastid-encoded components） and Arabidopsis （nucleus-encoded components）. This work has provided important new insights into the structure, function, and biogenesis of chloroplast ribosomes, and also has shed fresh light on the molecular mechanisms of the translation process in plastids. In addition, mutants affected in plastid translation have yielded strong genetic evidence for chloroplast genes and gene products influencing plant develop- ment at various levels, presumably via retrograde signaling pathway（s）. In this review, we describe recent progress with the functional analysis of components of the chloroplast translational machinery and discuss the currently available evidence that supports a significant impact of plastid translational activity on plant anatomy and morphology.

关键词： plastid translation ribosome ribosomal protein evolution plastid transformation retrograde signaling leaf development palisade cell.

Clumpy metal concentrations in elliptical galaxies NGC 4374 and NGC 4636

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Research in Astronomy and Astrophysics 2010年第3期10卷 220-226页

作者： Hai-Guang Xu Jun-Hua Gu Li-Yi Gu Zhong-Li Zhang Yu Wang Tao An Department of Physics Shanghai Jiao Tong University Shanghai 200240 China max-planck institut fur Astrophysik D-85740 Garching Germany Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China

We present a high spatial resolution study of metal distributions in the nearby, gas-rich elliptical galaxies NGC 4374 and NGC 4636 with the Chandra ACIS archive data. We define the hardness ratio HRFeL as the ratio of the emission in 0.65- 1.4 keV to that in 0.3-0.6 keV and 1.4-3.5 keV （after the magnesium and silicon lines are excluded）, and HRcont as the ratio of the emission in 1.4-3.5keV to that in 0.3- 0.6 keV, so that the HRFeL and HRcont maps can be used to trace the iron abundance and gas temperature distributions, respectively. By applying the a Trous wavelet algorithm to the obtained emission hardness ratio maps, we reveal that the HRFeL distributions are highly irregular, exhibiting strong spatial variations on 0.1-1 Re scales, which do not follow the HRcont distributions. Since the effect of temperature variation is small, we conclude that most of the high-HRFeL regions are very likely to possess higher abundances than the ambient gas. We also find that these high-HRFeL substructures are not associated with either the LMXB or globular cluster populations, thus their origins should be related to AGN activity or mergers.

关键词： galaxies: elliptical and lenticular cD -- galaxies: individual (NGC 4374 NGC 4636) -- galaxies: ISM -- ISM: abundances -- X-rays: galaxies

Emerging progress: photochemical transformation of nitroso compounds

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Science China Chemistry 2025年第1期68卷 118-133页

作者： Ze-Le Chen Qiang-Qiang Li Armido Studer Jun Xuan Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials School of Chemistry & Chemical Engineering Anhui University Organisch-Chemisches institut Universitat Münster

Nitroso compounds have emerged as highly valuable reaction partners or reagents in organic synthesis due to their rich *** versatile profile of these compounds allows them to function as electrophiles, nucleophiles, diradicals, and radical acceptors in diverse transformations. In recent years, notable progress has been made in harnessing photochemical reactions with nitroso compounds to prepare N,O-containing structures using mild and eco-friendly conditions. Various nitroso compounds like nitrosoarenes, acyloxy nitroso compounds, N-nitrosoamines and nitrites have received significant attention for their ability to introduce NO moieties into complex molecules that are otherwise difficult to access. In this review, we provide an overview of the recent advancements in the visible light-induced conversion of nitroso compounds, with particular emphasis on their role as bifunctional reagents and acceptors of radicals, carbenes and nitrenes.

关键词： nitroso compounds photochemistry radical reaction carbene transformation nitrosoarenes

Dynamic carbon surface chemistry: Revealing the role of carbon in electrolytic water oxidation

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Journal of Energy Chemistry 2020年第8期29卷 155-159,I0006页

作者： Yuxiao Ding Qingqing Gu Alexander Klyushin Xing Huang Sakeb H.Choudhury Ioannis Spanos Feihong Song Rik Mom Pascal Dungen Anna K.Mechler Robert Schlogl Saskia Heumann max planck institute for Chemical Energy Conversion Stiftstrasse 34-36Mtilheim an der Ruhr 45470Germany Fritz-Haber-institut der max-planck Gesellschaft Faradayweg 4-6Berlin 14195Germany Research Group Catalysis for Energy Helmholtz-Zentrum Berlin fur Materialien und Energie GmbHAlbert-Einstein-Strasse 1512489 BerlinGermany

Carbon materials have been widely used as electrodes, but the mechanistic roles are still not clear due to the complexity of the carbon surface chemistry. Herein we clarify that intrinsic material properties of carbon have to be activated by extrinsic factors. Pure carbon has no catalytic activity when used as electrode for electrocatalytic water oxidation. The evolution of oxygen functional groups on the carbon surface with increasing potential and the subsequent formation of real active sites with iron impurities from the electrolyte have been confirmed. These in-situ formed active sites protect the carbon from deep oxidation. This unprecedented finding not only provides insight into the dynamic evolution of carbon electrode surface chemistry and raises awareness of the need for detailed surface analysis under operando conditions, but also suggests a direction for the development of scalable and high-performance carbonbased electrode systems for various electrochemical applications.

关键词： Carbon chemistry Carbon catalysis Carbon electrode Water splitting Iron impurity

Teaching solid mechanics to artificial intelligence—a fast solver for heterogeneous materials

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npj Computational Materials 2021年第1期7卷 899-908页

作者： Jaber Rezaei Mianroodi Nima H.Siboni Dierk Raabe Microstructure Physics and Alloy Design Max-Planck-Institut für EisenforschungDüsseldorfGermany DeepMetis BerlinGermany

We propose a deep neural network(DNN)as a fast surrogate model for local stress calculations in inhomogeneous non-linear *** show that the DNN predicts the local stresses with 3.8%mean absolute percentage error(MAPE)for the case of heterogeneous elastic media and a mechanical contrast of up to factor of 1.5 among neighboring domains,while performing 103 times faster than spectral *** DNN model proves suited for reproducing the stress distribution in geometries different from those used for *** the case of elasto-plastic materials with up to 4 times mechanical contrast in yield stress among adjacent regions,the trained model simulates the micromechanics with a MAPE of 6.4%in one single forward evaluation of the network,without any *** results reveal an efficient approach to solve non-linear mechanical problems,with an acceleration up to a factor of 8300 for elastic-plastic materials compared to typical solvers.

关键词： artificial network faster

Ab initio energetic study of oxide ceramics with rare-earth elements

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Rare Metals 2006年第5期25卷 549-555页

作者： Matvei Zinkevich Fritz Aldinger max-planck-institut für Metallforschung Institut für Nichtmetallische Anorganische MaterialienUniversitt StuttgartHeisenbergstrasse 3D-70569 StuttgartGermany

Ab initio energetic calculations based on the density functional theory （DFF） and the projector augmented wave method （PAW） for determining the polymorphisms of lanthanide sesquioxides Ln2O3 （where Ln = rare-earth element, Y, and Sc）, LnMO3 perovskites （where M = AI and Ga）, and Ln2B207 pyrochlores （where B = Ti, Zr, and Hf） were reported. The relative lattice stabilities agreed well with the critically assessed results or the experimental results except the C-type Ln2O3 with a cubic structure, for which the calculated total energies were considerably more negative. With the increase of the Ln^3＋-cation radius, the polymorphic structures showed a degenerative tendency. The tendencies and quantities of the enthalpies of formation of the ternary oxide ceramics synthesized from their constituent binary oxides reasonably agreed with the available experimental results, and valuable thermodynamic properties were afforded to the compound, for which no experimental data is available. The enthalpies of formation of both perovskites and pyrochlores tend to become more negative with the increase of the Ln^3＋-cation radius.

关键词： rare earth oxide ceramics ab initio calculation lattice stability enthalpy of formation