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Polar Coronal Holes During Solar Cycles 22 and 23

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Chinese Journal of Astronomy and Astrophysics 2005年第5期5卷 531-538页

作者： Jun Zhang J. Woch S. Solanki National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 max-planck-institut fiir Sonnensystemforschung Katlenburg-Lindau D-37191 Germany

Data from the Solar Wind Ion Composition Spectrometer （SWICS） on Ulysses and synoptic maps from Kitt Peak are used to analyze the polar coronal holes of solar activity cycles 22 and 23 （from 1990 to end of 2003）. In the beginning of the declining phase of solar cycles 22 and 23, the north polar coronal holes （PCHs） appear about one year earlier than the ones in the south polar region. The solar wind velocity and the solar wind ionic charge composition exhibit a characteristic dependence on the solar wind source position within a PCH. from the center toward the boundary of a young PCH, the solar wind velocity decreases, coinciding with a shift of the ionic charge composition toward higher charge states. However, for an old PCH, the ionic charge composition does not show any obvious change, although the latitude evolution of the velocity is similar to that of a young PCH.

关键词： Sun: coronal - Sun: particle emission - Sun: solar wind

Influence of sample preparation on nanoindentation results of twinninginduced plasticity steel

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International Journal of Minerals,Metallurgy and Materials 2021年第5期28卷 877-887页

作者： Jiali Zhang Stefan Zaefferer institute for Materials Applications in Mechanical Engineering RWTH Aachen UniversityAachen 52062Germany max-planck-institut für Eisenforschung Düsseldorf 40237Germany

Nanoindentation is an attractive characterization technique,as it not only measures the local properties of a material but also facilitates understanding of deformation mechanisms at submicron ***,because of the complex stress-strain field and the small scale of the deformation under the nanoindenter,the results can be easily influenced by artifacts induced during sample *** this work,a systematic study was conducted to better understand the influence of sample preparation methods on the nanoindentation results of ductile *** experiments were conducted on a steel(Fe-22Mn-0.65C,wt%)with twinning-induced plasticity(TWIP),which was selected for its large grain size and sensitivity to different surface preparation *** grouping the results obtained from each nanoindent,chemical polishing was found to be the best sample preparation method with respect to the resulting mechanical properties of the *** contrast,the presence of a deformation layer left by mechanical polishing and surface damage induced by focused ion beam(FIB)scanning were confirmed by the dislocation-nucleation-induced pop-in events of nanoindentation.

关键词： TWIP steels nanoindentation mechanical polishing chemical polishing pop-in

A Mercury Orbiter Mission Study

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紫金山天文台台刊 1996年第3期15卷 12-19页

作者： W.K.H Schmidt max-planck-institut fur Aeronomie 37191 katl enburg- LindauGermany

A short review of the Assessment Study results of a Mercury Obriter mission which ws propoesd to ESA in 1993 is given.

关键词：侧切肠面吐血加成比压旧址田令幻山

Exploration of the Outer Planets:The Galileo and Cassini Missions

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紫金山天文台台刊 1996年第2期15卷 89-96页

作者： W.-H.Ip max-planck-institut fuer Aeronomie D-37191 Katlenburg-Lindau Germany

the space age has brought spectacular advances in our knowledge of the solar *** flyby observations of the outer planets by the Voyagerspacecraft have been crost *** discoveries are now to be supple-mented by the Galileo Oribter to Jupiter and the Cassini Orbiter to *** the successful operations of the atmospheric probe in December 1995,the Galileo spacecraft is now in orbit around Jupiter and its comprehensive scientific observations of the Jovian system have just *** Cassini spacecraft with the Huygens atmospheric probe to Titan will be launched in 1937 with an arrival date at Saturn in *** everything goes well,these two projects will be followed by a Pluto Express mission for fast flyby reconnaissance and a Neptune Orbiter.

关键词：贾让

Vibrational Analysis of Oxygen Adsorption on Cs and CO Coadsorbate Precovered Ru(0001)Surface

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Chinese Physics Letters 1999年第6期16卷 428-430页

作者： HE Pei-mo Karl Jacobi Department of Physics Zhejiang UniversityHangzhou 310027 fritz-Haber-institut der max-planck-Gesellschaft Faradayweg 4-6D-14195 BerlinGermany

Vibrational analysis of oxygen adsorption on the Cs and CO coadsorbate precovered Ru(0001)surface was carried out by means of high-resolution electron energy loss *** submonolayer Cs coverages on Ru(0001)j an appropriate amount of CO adsorption leads to formation of(2x2)-Cs+2CO *** oxygen adsorption on this Cs and CO coadsorbate precovered surface results in a remarkable change of high-resolution electron energy loss *** loss peak of C-O stretch mode for 2x2 island species decreases in intensity,which is accompanied by appearance of new bands at about 87 and 240 *** results show that Cs adatoms and CO molecules are rearranged upon oxygen adsorption,and are correlated with coexistence of bare surface CO and a mixed phase of Cs,CO,and O.

关键词： spectroscopy. adsorption Adsorption

High-Resolution Electron Energy Loss Spectroscopy of Cs Vibration on the Ru (0001) Surface

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Chinese Physics Letters 1998年第12期15卷 907-909页

作者： HE Pei-mo Karl Jacobi Department of Physics Zhejiang UniversityHangzhou 310027 Fiitz-Haber-institut der max-planck-Gesellschaft Faradayweg 4-6D-14195 BerlinGermany

By using a newly implemented high-resolution electron energy loss spectrometer with better resolution,a new loss at a energy near to double energy of the Cs-Ru stretching vibration,and its dependence on Cs coverage for Cs overlayer on Ru(0001)were *** the energy is slightly smaller than the double energy of the Cs-Ru vibration(intrinsic loss),overtone excitation must be responsible for this new loss observed,but two-phonon process is not excluded.

关键词： stretching Electron slightly

IO and Its Plasma Torus

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紫金山天文台台刊 1996年第3期15卷 65-86页

作者： Nicolas Thomas max-planck-institut Cur Aeronomie D-37189 Katlenburg-LindauGermany

A brief review of our courrent understanding of the interaction between the innermost Galilean satellite,Io,and Jupiter’s magnetosphere is *** consideration is given to the neutral clouds and lo plasma torus which have been monitored by ground-based and Earth-orbiting observations for the past 25 *** investigation of observed phenomena in the neutral clouds has revealed several processes which have a direct bearing on the nature of the interaction and suggest that a revision of the existing concept is *** variability in the torus indicates the presence of complex plasma processes which at present remain *** where further research is necessary are outlined.

关键词： Solary System:satellites Solar System:Io space plasmas observations

Propagating disturbances along fan-like coronal loops in an active region

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Research in Astronomy and Astrophysics 2015年第11期15卷 1832-1842页

作者： Sudip Mandal Tanmoy Samanta Dipankar Banerjee S.Krishna Prasad Luca Teriaca Indian institute of Astrophysics Astrophysics Research Centre School of Mathematics and Physics Queen’s University Belfast max-planck-institut fuer Sonnensystemforschung (MPS)

Propagating disturbances are often observed in active region fan-like coronal loops. They were thought to be due to slow mode magnetohydrodynamic waves based on some of the observed properties. However, recent studies involving spectroscopy indicate that they could be due to high speed quasi-periodic upflows which are difficult to distinguish from upward propagating slow waves. In this context, we have studied a fan loop structure in the active region AR 11465 using simultaneous spectroscopic and imaging observations from the Extreme Ultraviolet Imaging Spectrometer onboard Hinode and Atmospheric Imaging Assembly onboard Solar Dynamics Observatory. Analysis of the data shows significant oscillations at different locations. We explore the variations in different line parameters to determine whether the waves or flows could cause these oscillations to improve the current understanding of the nature of these disturbances.

关键词： wavelet simultaneous distinguish Extreme propagating Solar fitting pixel spectroscopic Roberts

Hierarchical microstructure of a titanium alloy fabricated by electron beam selective melting

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Journal of Materials Science & Technology 2020年第7期42卷 1-9页

作者： Jixin Yang Yiqiang Chen Yongjiang Huang Zhiliang Ning Baokun Liu Chao Guo Jianfei Suna National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China max-planck-institut für Eisenforschung Max-Planck-Straße 140237 DusseldorfGermany Tianjin SciTsinghua QuickBeam Tech.Co. Ltd.Tianjin 300300China

Here,a near alpha-type Ti6.5 Al2 Zr1 Mo1 V alloy has been fabricated by electron beam selective melting(EBSM).Near-equiaxed grains existed in the first few layers,whereas elongated columnar priorβgrains almost parallel to the building direction formed in the subsequent built *** ofβphase gradually decreased as the build height ***α'with twins and dislocations emerged and microhardness value reached the maximum in the top region,whereas onlyα/βphase appeared in other regions in the EBSMed *** phase transformations can be observed with the change of peak temperatures during each thermal *** a sufficient dwell time,martensiteα'in the middle and bottom regions in-situ decomposed intoα+βand coarsened by the heat conduction from the subsequent ***βprecipitates nucleated heterogeneously insideα'plates and at plate-plate interfaces during the subsequent EBSM *** the phase transformation during the heating process and the cooling process,the existence time of different phases was combined with cycle heating and cooling to clarify the dynamic evolution of micro structure under complex thermal history of EBSM,favoring the fabrication of high-performance titanium alloy components.

关键词： Electron beam selective melting Titanium alloys Martensite Microstructure evolution Thermal cycles