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A Coupled Model Study on the Intensification of the Asian Summer Monsoon in IPCC SRES Scenarios

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Advances in Atmospheric Sciences 2005年第6期22卷 798-806页

作者： Min WEI max-planck-institut fur Meteorologie Bundesstrasse 53 D-20146 Hamburg Germany

The Asian summer monsoon is an important part of the climate system. Investigating the response of the Asian summer monsoon to changing concentrations of greenhouse gases and aerosols will be meaningful to understand and predict climate variability and climate change not only in Asia but also globally. In order to diagnose the impacts of future anthropogenic emissions on monsoon climates, a coupled general circulation model of the atmosphere and the ocean has been used at the max-planck-institute for Meteorology. In addition to carbon dioxide, the major well mixed greenhouse gases such as methane, nitrous oxide, several chlorofluorocarbons, and CFC substitute gases are prescribed as a function of time. The sulfur cycle is simulated interactively, and both the direct aerosol effect and the indirect cloud albedo effect are considered. furthermore, changes in tropospheric ozone have been pre-calculated with a chemical transport model and prescribed as a function of time and space in the climate simulations. Concentrations of greenhouse gases and anthropogenic emissions of sulfur dioxide are prescribed according to observations （1860-1990） and projected into the future （1990-2100） according to the Scenarios A2 and B2 in Special Report on Emissions Scenarios （SRES, Nakcenovic et al., 2000） developed by the Intergovernmental Panel on Climate Change （IPCC）. It is found that the Indian summer monsoon is enhanced in the scenarios in terms of both mean precipitation and interannual variability. An increase in precipitation is simulated for northern China but a decrease for the southern part. furthermore, the simulated future increase in monsoon variability seems to be linked to enhanced ENSO variability towards the end of the scenario integrations.

关键词： asian summer monsoon climate change IPCC SRES scenarios

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

Changes of crystallinity and spherulite morphology in isotactic polypropylene after rolling and heat treatment

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维普期刊数据库

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Journal of University of Science and Technology Beijing 2008年第4期15卷 514-520页

作者： Juan Jia Weimin Mao Dierk Raabe School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China max-planck-institut fur Eisenforschung Max-Planck-Str. 1 Düsseldorf 40237 Germany

The spherulite morphology of the rolled and subsequent heat-treated isotactic polypropylene （iPP） was observed by polarized microscopy, and the crystallinity evolution of materials was also measured by the wide angle X-ray scattering （WAXS）. Rolling led to the oblate spherulites in the deformed iPP samples. The sheared crystalline lamellae broke apart into sets of crystalline blocks during rolling. As a result, the crystallinity of the iPP samples was greatly reduced during deformation, which induced the unclear spherulites and spherulite boundaries. Subsequent heat treatment resulted in the strong reerystallization of the rolled iPP samples. But the recrystaUizatinn in this work only meant the rearrangement of the macromolecule along the unbroken crystalline lamellae and the existing small crystalline blocks in the deformed spherulites. Heat treatment did not change the shape of the spherulites formed during deformation. The recrystallization also resulted in very clear spherulites and spherulite boundaries.

关键词： isotaetic polypropylene (iPP) rolling heat treatment X-ray diffraction crystallinity spherulites

Thermodynamic and rate variational formulation of models for inhomogeneous gradient materials with microstructure and application to phase field modeling

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Acta Mechanica Sinica 2015年第2期31卷 162-172页

作者： Svyatoslav Gladkov Bob Svendsen Material Mechanics RWTH Aachen Aachen Germany Microstructure Physics and Alloy Design Max-Planck-Institut fur Eisenforschung DusseldorfGermany

In this work,thermodynamic models for the energetics and kinetics of inhomogeneous gradient materials with microstructure are formulated in the context of continuum thermodynamics and material *** simplicity,attention is restricted to isothermal *** materials of interest here are characterized by（1） first- and secondorder gradients of the deformation field and（2） a kinematic microstructure field and its gradient（e.g.,in the sense of director,micromorphic or Cosserat microstructure）.Material inhomogeneity takes the form of multiple phases and chemical constituents,modeled here with the help of corresponding phase *** requirements together with the dissipation principle result in the reduced model field and constitutive *** cases of these include the wellknown Cahn-Hilliard and Ginzburg-Landau *** the last part of the work,initial boundary value problems for this class of materials are formulated with the help of rate variational methods.

关键词： Continuum thermodynamics Material inhomogeneity Conservative Non-conservative phase fields

Tracking moving magnetic features in the photosphere

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Science China(Physics,Mechanics & Astronomy) 2009年第11期52卷 1737-1748页

作者： BCHNER Jrg max-planck-institut fr Sonnensystemforschung

This research aims for an objective identification, tracking, and a statistical analysis of the Moving Magnetic Features (MMFs) around sunspots using SOHO/MDI high-resolution magnetograms. To this end, we develop a computerized tracking program and study the motion and magnetism of the outflows of MMFs around 26 sunspots. Our method locates 4-27 MMFs per hour, with higher counts for large sunspots. We differentiate MMFs into type α that have a polarity opposite to the parent sunspots, and type β that share the sunspot's polarity. These sunspots' MMF subsets exhibit a wide range of central tendencies which have distinctive correlations with the sunspots. In general, α-MMFs emerge farther from the sunspot, carry less flux, and move faster than β-MMFs. The typical α/β-MMFs emerge at 2.2 - 8.1/0.1 - 3.2 Mm outside the penumbra limb, with lifetimes of 1.1 - 3.1/1.3 - 2.0 h. They are 1.1 - 6.6/1.4 - 3.6 Mm2 in area and carry 1.4 - 12.5/4.8 - 11.4 ×1018 Mx of flux. They travel a distance of 2.7 - 5.9/2.8 - 3.6 Mm with the speed of 0.5 - 0.9/0.4 - 0.7 km/s. Compared to the α-MMFs produced by large sunspots, those of small spots are smaller. They emerge closer to sunspot, move farther, live longer, and carry less flux. β-MMFs show much less correlation with the sunspots. The flux outflow carried by the MMFs ranges from 0.2 to 8.3 × 1019Mx· h-1 and does not show obvious correlation with the sunspots' evolution. The frequency distributions of the MMFs' distance traveled, area, and flux are exponential. This suggests the existence of numerous small, weak, and short-timescale magnetic objects which might contribute to the sunspot flux outflow.

关键词： sun activity magnetic fields photosphere sunspots moat moving magnetic features

Development of Powerful RF Plasma Sources for Present and Future NBI Systems

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Plasma Science and Technology 2004年第1期6卷 2135-2140页

作者： E.Speth NBI-Team max-planck-institut fiir Plasmaphysik 85748 Garching Germany EURATOM-AssociationMax-Planck-Institut fiir Plasmaphysik 85748 Garching Germany EURATOM-Association

This paper deals with the topic of RF plasma sources and their application inhigh-power neutral beam heating systems for nuclear fusion devices. RF sources represent aninteresting alternative to the conventional arc discharge sources. Due to the absence of hotfilaments they exhibit an inherent simplicity both in mechanical and electrical aspects andconsequently offer advantages in terms of cost savings, gain in availability and reliability andreduced maintenance. This renders the RF plasma source attractive for any long pulse (> 10 sec) NBIsystem and in particular for the ITER NBI system. The latter, however, requires that the RF plasmasource is also capable of delivering negative rather than positive hydrogen ions. In the first partof the paper the types, characteristics and operation experience of RF plasma sources for positiveions in operation are described. The second part is devoted to the development for ITER NBI: thebasic requirements, physics and technology issues and the present status are discussed.

关键词： neutral beam injection negative ions RF plasma source

Super-large-scale structures in the distribution of infrared galaxies

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Science China Mathematics 1999年第8期42卷 873-882页

作者：邓祖淦夏晓阳 G.Borner max-planck-institut for Astrophysik 85740 Garching

Typical scales in the distribution of IRAS galaxies with the unnormalized pair count method. Samples are those provided by QDOT redshift survey and sorted out from the IRAS faint sources catalog. Analysis is concentrated on the structures at super-large scales. The results show that statistically significant typical scales do exist in the distribution of all these samples from both 2-dimensiortal and 3-dimensional analyses. These scales are consistent with those found from the analyses of galaxies and clusters of galaxies by Mo et al. and also consistent with those found from analysis of quasars by Deng et al. The analysis provides additional evidence for the existence of typical scales in the large-scale structure of the universe. The existence of typical scales challenges all the existing models on the formation of galaxies and structures.

关键词： cosmology large-scale structures galaxies evolution formation.

The International Rosetta Mission

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紫金山天文台台刊 1996年第3期15卷 3-11页

作者： H.U.Keller max-planck-institut fur Aeronomie37189 Katlenburg-LindauGermany

The European Space Agency (ESA) launched its science programme Horizon 2000 in themid *** programme encompasses four big missions, the cornerstones,in addition tosmaller missions. The four cornerstones are:SOHO/Cluster a solary observatory and in situmeasurements of the Earth magnetosphere,XMM and X-ray observatory,Rosetta a comet ren-dezvous mission,and FIRST a far infrared *** was successfully launched

关键词：卜甲加成入声

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Cometary Physics

紫金山天文台台刊 1996年第2期15卷 26-39页

作者： H.U.Keller max-planck-institut fur Aeronomie 37189 Katlenburg-Lindau Germany

Unpredicted apparitions of bright comets appearing on the night sky for a few months movingfast among the stars have intrigued mankind whenever the sky was observed. Records ofcomets are found in the oldest documents and can be still useful as demonstrated during the as-sessment of the non-gravitational forces acting on comet Halley(Yeomans and Kiang, 1981).chinese records with relatively precise positions from more than 2000 years ago gave

关键词： Cometary Physics than