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Science Bulletin 2018年第5期63卷 300-305页

作者： Xiaoli Li Shuguang Song Lifei Zhang E. Heidi Hofer The Key Laboratory of Orogenic Belts and Crustal Evolution MOE School of Earth and Space Sciences Peking University Beijing 100871 China institut fur Geowissenschaften Facheinheit Mineralogie Johann Wolfgang Goethe-Universitat D-60054 Germany

A newly developed microprobe-based methodology(the Flank Method)for Fe^(3+)/RFe quantification has been successfully applied to some natural garnets from the North Qilian eclogites by JEOL JXA-8100microprobe at Peking *** results demonstrated an obvious discrepancy in comparison with the outcomes by conventional stoichiometric *** methodology allows to measure theFe^(3+)/Rmeasurement of Fe^(3+)According to the compositional zonation displayed in the studied eclogitic garnets from North Qilian,a prograde metamorphic°C to 22 kbar,600°C was *** interestingly,the measured Fe^(3+)/RFe ratios in garnets decreasing from core to rim may probably imply that the oxygen fugacity(f O_2)declines with the depth of the subduction zone.

关键词： Microprobe Flank method Ferric iron GarnetNorth Qilian eclogite

Many faces of neuronal activity manipulation in Drosophila

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Neural Regeneration Research 2025年第9期20卷 2574-2576页

作者： Amber Krebs Steffen Kautzmann Christian Klämbt institut für Neuro-und Verhaltensbiologie MünsterGermany

Animals exhibit complex responses to external and internal *** information is computed by interconnected neurons that express numerous ion channels,which modulate the neuronal membrane *** can neuronal activity orchestrate complex motor patterns or allow learning from previous experience?To answer such questions,we need the ability not only to record,but also to modulate neuronal activity in both space(e.g.,neuronal subsets)and time.

关键词： manipulation potential. neuronal

Diameter evolution of selective area grown Ga-assisted GaAs nanowires

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Nano Research 2018年第5期11卷 2885-2893页

作者： Hanno Kupers Ryan B. Lewis Abbes Tahraoui Mathias Matalla Olaf Kruger Faebian Bastiman Henning Riechert Lutz Geelhaar Paul-Drude-institut fur Festkorperelektronik Hausvogteiplatz 5-7 10117 Berlin Germany Ferdinand-Braun-institut Leibniz-Institut fur Hochstfrequenztechnik Gustav-Kirchhoff-Strasse 4 12489 Berlin Germany

Tapering of vapour-liquid-solid （VLS） grown nanowires （NWs） is a widespread phenomenon resulting from dynamics of the liquid droplet during growth and direct vapour-solid （VS） growth on the sidewall. To investigate both effects in a highly controlled wa35 we developed a novel two-step growth approach for the selective area growth （SAG） of GaAs nanowires （NWs） by molecular beam epitaxy. In this growth approach optimum growth parameters are provided for the nucleation of NWs in a first step and for the shape variation during elongation in a second step, allowing NWs with a thin diameter （45 nrn） and an untapered morphology to be realized with high vertical yield. We quantify the flux dependence of radial VS growth and build a model that takes into account diffusion on the NW sidewalls to explain the observed VS growth rates. As our model is consistent with axial VLS growth we can combine it with an existing model for the diameter variation due to the droplet dynamics at the NW top. Thereby, we achieve full understanding of the diameter of NWs over their entire length and the evolution of the diameter and tapering during growth. We conclude that only the combination of droplet dynamics and VS growth results in an untapered morphology. This result enables NW shape engineering and has important implications for doping of NWs.

关键词： GaAs molecular beam epitaxy semiconductor growth model nanowire tapering

Almost nonnegative curvature operator and cohomology rings

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Frontiers of Mathematics in China 2016年第5期11卷 1259-1274页

作者： Martin HERRMANN Fakultat fur Mathematik Karlsruher Institut fur Technologie Kaiserstraβe 89-93 76133 Karlsruhe Germany

We give a survey of results on the construction of and obstructions to metrics of almost nonnegative curvature operator on closed manifolds and results on the cohomology rings of closed, simply-connected manifolds with a lower curvature and upper diameter bound. The latter is motivated by a question of Grove whether these condition imply finiteness of rational homotopy types. This question has answers by F. Fang-X. Rong, B. Totaro and recently A. Dessai and the present author.

关键词： Nonnegative curvature homogeneous spaces curvature operator almost nonnegative curvature

Relationship Between Oct agonal Quasicrystal and β-Mn Type Crystal in Cut Description

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Chinese Physics Letters 1996年第3期13卷 199-202页

作者： LI Fang-hua CHENG Yi-fan institute of Physics Chinese Academy of SciencesBeijing 1000801 Max-Planck-institut fur Metallforschung Institut fur Werkstoff-WeissenschaftSeestrasse 9270147 StuttgartGermany

The transformation from the octagonal lattice to a square lattice is demonstrated straightforward under the cut description by introducing a peculiar linear phason *** calculated lattice parameter of the ft-Mn structure from the edge length of squares and rhombi forming the octagonal quasilattice is in agreement with experimental results.

关键词： strain. agonal lattice

CREEP DEFORMATION OF INTERMETALLIC ALLOYS

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Acta Metallurgica Sinica(English Letters) 1995年第Z1期8卷 431-440页

作者： Gerhard Sauthoff(Max-Planck-institut fur Eisenforschung GmbH., D-40074 Dusseldorf,Germany) Max-Planck-institut fur Eisenforschung GmbH Dusseldorf Germany

Intermetallics for structural applications at high temperatures must show a sufficient high temperature strength which is controlled by creep processes. In the first section the creep behaviour of single-phase intermetallic alloys is overviewed with respect to stress and temperature dependence and effects of composition and microstructure. It is shown in particular that creep deformation is controlled by diffusion. The second section refers to multiphase intermetallic alloys, and both particulate and non-particulate alloys are regarded. Data are presented for single-phase and multiphase alloys based on B2 phases and lesscommon phases and the consequences of diffusion control for alloy design are discussed.

关键词： creep B2 phases NiAl particulate alloys,multiphase alloys

BACKWARD ERROR ANALYSIS OF SYMPLECTIC INTEGRATORS FOR LINEAR SEPARABLE HAMILTONIAN SYSTEMS

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Journal of Computational Mathematics 2002年第5期20卷 449-460页

作者： PeterGrtz institut fur Praktische Mathematik Universitat Karlsruhe Englerstrabe 德国 Karlsruhe 276128

Presents a study that analyzed the symplecticness, stability and asymptotic of Runge-Kutta, partitioned Runge-Kutta, and Runge-Kutta-Nystr ? m methods applied to linear Hamiltonian systems. Numerical representation of the problem; Results in connection to P-stability; Details of the application of backward error analysis in the study.

关键词： Hamiltonian systems Backward error analysis Symplectic integrators.

Clustering of voltage-gated ion channels as an evolutionary trigger of myelin formation

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Neural Regeneration Research 2024年第8期19卷 1631-1632页

作者： Henrike Ohm Simone Rey Christian Klambt institut fur Neuro-und Verhaltensbiologie MunsterGermany

Neurons carry apical dendrites that perceive information and a basal axon that transmits the computed information towards its to *** axon originates at the axon hillock which is followed by the axon initial ***,action potentials are initiated that are based on millisecond long openings of specific voltagegated sodium and potassium channels that are conserved in all parahoxozoa(Placozoa,Cnidaria,Bilateria)(Li et al.,2015).

关键词： initiated carry potassium

Textural inspection of recrystallization process under bimodal particle distribution in pure Al-Mn alloy

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中国有色金属学会会刊：英文版 1999年第4期9卷 677-681页

作者：杨平 institut fur Metallkunde Und Metallphysik der RWTH Aachen 德国

Recrystallization in a pure Al-1. 3 % Mn alloy containing large undeformable particles was investigated at low annealing temperature with concurrent precipitation and emphasis was put on its orientational aspect. Results revealed significant changes in microstructure and microtexture due to an inhomogeneous precipitation as compared with those at high annealing temperatures. Despite the easy nucleation at large particles,precipitation substantially suppressed the growth of grains formed there and the texture was mainly influenced by the grains formed at grain boundaries.

关键词： recrystallization precipitation Al-Mn alloys

A glance at three-dimensional Alexandrov spaces

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Frontiers of Mathematics in China 2016年第5期11卷 1189-1206页

作者： Fernando GALAZ-GARCIA institut fur Algebra und Geometrie Karlsruher Institut fiir Technologie (KIT) Karlsruhe Germany

We discuss the topology and geometry of closed Alexandrov spaces of dimension three.

关键词： Alexandrov space group action 3-manifold