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Experiments on Gas Jet in the Wendelstein 7-AS Stellarator

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Plasma Science and Technology 2003年第5期5卷 1933-1938页

作者：姚良骅 J.Baldzuhn Southwestern institute of Physics Chengdu 610041China max-planck institut fuer Plasma physik EURATOM Ass.17491 GreifswaldGermany

Wendelstein 7-AS (W7-AS) pertains to an advanced helical stellarator. A new fuelling method, the supersonic molecular beam injection (SMBI, named Gas Jet in Germany) system was installed in W7-AS in May 2001 as a cooperation research item co-supported by the National Nature Science Foundation of China and the max-planck institute of Plasma Physics, Garching, Germany. The experiments of the gas jet with hydrogen or deuterium on W7-AS were implemented. The experimental results exhibit the following features such as high fuelling efficiency, stable high-density plasmas and reduction of the recycling fluxes from the vessel wall during injection. These crucial points show that the new fuelling method can be applied to long and stable discharges.

关键词： gas jet (Supersonic Molecular Beam) injection wendelstein 7-AS stellarator fuelling

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

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

晶格畸变分析及其在半导体量子点结构中的应用(英文)

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电子显微学报 2006年第3期25卷 190-199页

作者：金能韫 max-planck-institut fuer metallforschung D-70569 Stuttgart Germany

在适当的成像条件下可以直接从高分辨透射电子像(HRTEM)以接近原子级的分辨率进行晶格畸变分析。本综述介绍晶格畸变分析(LADIA)程序包及其在半导体自组装量子点(QD)系统中的应用。对多层InP小QD系统中畸变分布的分析表明:光致发光(PL)... 详细信息

在适当的成像条件下可以直接从高分辨透射电子像(HRTEM)以接近原子级的分辨率进行晶格畸变分析。本综述介绍晶格畸变分析(LADIA)程序包及其在半导体自组装量子点(QD)系统中的应用。对多层InP小QD系统中畸变分布的分析表明:光致发光(PL)能量峰位的红移和QD中的应变弛豫直接相关。在慢速生长的InAs大QD系统中应变引起的元素互溶是PL峰位蓝移的主要因素。多层系统中QD的垂直叠合可解释为间隔层厚度低于临界值时生长前沿的横向张应变的作用。研究了生长以后不同条件快速退火对QD稳定性的影响,观测到垂直叠合的InP QD中出现各向异性的退火不稳定性。

关键词：高分辨透射电子术(HRTEM) 定量高分辨透射电子术应变像半导体量子点光致发光

Al_2O_3/Al合金复合材料的蠕变与回蠕变行为

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金属学报 2000年第11期36卷 1223-1228页

作者：王浩伟 A.Wanner T.Bidlingmaier D.Vogt E. Arzt 上海交通大学金属基复合材料国家重点实验室上海200030 max-planck-institut fuer metallforschung and institut fuer Metallkunde

研究了挤压铸造Ａｌ_２Ｏ_３短纤维（体积分数为１５％）增强Ａｌ合金Ａｌ－Ｓｉ１２－Ｃｕ１－Ｍｇ１－Ｎｉ１复合材料的变载荷蠕变和回蠕变行为．结果表明，复合材料在主应力作用下蠕变当载荷突然降低后，表现为瞬态大应变量收缩... 详细信息

研究了挤压铸造Ａｌ_２Ｏ_３短纤维（体积分数为１５％）增强Ａｌ合金Ａｌ－Ｓｉ１２－Ｃｕ１－Ｍｇ１－Ｎｉ１复合材料的变载荷蠕变和回蠕变行为．结果表明，复合材料在主应力作用下蠕变当载荷突然降低后，表现为瞬态大应变量收缩以及随后的回蠕变．研究表明初始瞬态收缩完全是复合材料的弹性应变，有别于前人采用复合材料或纯金属、合金所得到的数倍于弹性应变结果．实验结果经数值回归得出回蠕变速率，回蠕变应变＝Ａ　ｌｎｔ＋Ｃ．指数ｎ在任一主应力应变阶段均接近于－１，系数Ａ取决于降载前复合材料积累的主应力蠕变状态，并随降载前主应力蠕变程度的增加而增大，表明复合材料回蠕变行为受到降载前主应力蠕变状态的制约．

关键词： Al2O3/Al复合材料短纤维蠕变回蠕变

Simulation of turbulent magnetic reconnection in the smallscale solar wind

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Science China Mathematics 2000年第6期43卷 629-637页

作者：魏奉思胡强 R.Schwen 冯学尚 Laboratory of Numerical Study for Heliospheric Physics Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China max-planck-institut fuer Aeronomie D-37189 Katlenburg-LindauGermany

Some observational examples for the possible occurrence of the turbulent magnetic reconnection in the solar wind are found by analysing Helios spacecraft’s high resolution data. The phenomena of turbulent magnetic reconnections in small scale solar wind are simulated by introducing a third order accuracy upwind compact difference scheme to the compressible two-dimensional MHD flow. Numerical results verify that the turbulent magnetic reconnection process could occur in small scale interplanetary solar wind, which is a basic feature characterizing the magnetic reconnection in high-magnetic Replolds number (R(inM) = 2 000-10 000) solar wind. The configurations of the magnetic reconnection could evolve from a single X-line to a multiple X-line reconnection, exhibiting a complex picture of the formation, merging and evolution of magnetic islands, and finally the magnetic reconnection would evolve into a low-energy state. Its life-span of evolution is about one hour order of magnitude. Various magnetic and flow signatures are recorded in the numerical test for different evolution stages and along different crossing paths, which could in principle explain and confirm the observational samples from the Helios spacecraft. These results are helpful for revealing the basic physical processes in the solar wind turbulence.

关键词： solar wind magnetic reconnection turbulence.

Microstructure Evolution during Friction Stir Welding of Aluminum Alloy AA2219

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Journal of Materials Science & Technology 2010年第8期26卷 747-753页

作者： K.S.Arora S.Pandey M.Schaper R.Kumar Mechanical Engineering Department Indian Institute of Technology institut fuer Werkstoffwissenschaft Technische Universitaet Dresden institut fuer Sicherheitsforschung Forschungszentrum Dresden-Rossendorf Engineering Division National Metallurgical Laboratory

The characterization of microstructure evolution in friction stir welded aluminum alloy was carried out by optical microscopy （OM） and transmission electron microscopy （TEM） and electron backscatter diffraction （EBSD）. The weld nugget consisted of very fine equiaxed grains and experienced dissolution of nearly half of metastable precipitates into the matrix during welding. Thermomechanically affected zone （TMAZ） also experienced dissolution of precipitates but to a lesser extent whereas coarsening of precipitates was observed in heat affected zone （HAZ）. Grain boundary misorientation measurements using EBSD indicated continuous dynamic recrystallization as the underlying mechanism for the fine equiaxed nugget grains. The yield and tensile strength of the weld decreased with comparison to base material. But due to the decrease of grain size and the dissolution of second phase precipitates, an increased Charpy energy value was observed in the weld n u gget.

关键词： Friction stir welding AA2219 Precipitates Vickers hardness Tensile testing Charpy impact energy

DETERMINATION OF THE SURFACE BINDING ENERGY OF A Cu/Li ALLOY BY MEASUREMENTS OF ANGULAR DISTRIBUTION OF SPUTTERED ATOMS

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Nuclear Science and Techniques 1990年第Z1期1卷 84-88页

作者：王纹泯 J.Roth Shanghai institute of Nuclear Research Academia Sinica Shanghai 201800 China max-planck-institut fuer Plasma physik D-8046 Garching Muenchen FRG

A copper based binary alloy containing 16.9 at % lithium has been bombarded with deuterium ions in energy range of 400 eV to 2 keV at the incidence angles of 70° and 80° away from the surface normal. The sputtered flux was condensed on Al- strips arranged arround the target in a cylindrical cup. 1.5 MeV proton backscattering and nuclear reaction 7Li(p, α)4He were used to detect the collected atoms of Cu and Li simultaneously. The angular distribution of sputtered atoms has been shown to be different for two components and strongly anisotropic for the grazing incidence. According to direct knock-on sputtering model and the experimental results the angle for the maximum differential sputtering yield is dependent on the incidence angle α, the bombarding energy E, the energy transfer factor γ= 4M1M2/(M1+ M2)2 and the surface binding energy U. With the assumption that the sputtered particles are diffracted by a planar barrier the surface binding energies of 2.3 eV for the Li component and 3.0 eV for the Cu component have been determined by fitting the measured angles of preferred ejection to the direct knock-on sputtering model, and the results agree well with a pair-binding model.

关键词： Surface binding energy Cu/Li alloy Angular distribution Sputtered atoms

Comparison between the eruptive X2.2 flare on 2011 February15 and confined X3.1 flare on 2014 October 24

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Research in Astronomy and Astrophysics 2015年第9期15卷 1537-1546页

作者： Ju Jing Yan Xu Jeongwoo Lee Nariaki V.Nitta Chang Liu Sung-Hong Park Thomas Wiegelmann Haimin Wang Center for Solar-Terrestrial Research New Jersey Institute of Technology Big Bear Solar Observatory Astronomy Program Department of Physics and Astronomy Seoul National University Lockheed Martin Solar and Astrophysics Laboratory institute for Astronomy Astrophysics Space Applications and Remote Sensing (IAASARS)National Observatory of Athens max-planck-institut fuer Sonnensystemforschung

We compare two contrasting X-class flares in terms of magnetic free energy, relative magnetic helicity and decay index of the active regions （ARs） in which they occurred. The events in question are the eruptive X2.2 flare from AR 11158 accompanied by a halo coronal mass ejection （CME） and the confined X3.1 flare from AR 12192 with no associated CME. These two flares exhibit similar behavior of free magnetic energy and helicity buildup for a few days preceding them. A major difference between the two flares is found to lie in the time-dependent change of magnetic helicity of the ARs that hosted them. AR 11158 shows a significant decrease in magnetic helicity starting -4 hours prior to the flare, but no apparent decrease in helicity is observed in AR 12192. By examining the magnetic helicity injection rates in terms of sign, we confirmed that the drastic decrease in magnetic helicity before the eruptive X2.2 flare was not caused by the injection of reversed helicity through the photosphere but rather the CME-related change in the coronal magnetic field. Another major difference we find is that AR 11158 had a significantly larger decay index and therefore weaker overlying field than AR 12192. These results suggest that the coronal magnetic helicity and the decay index of the overlying field can provide a clue about the occurrence of CMEs.

关键词： Sun: magnetic topology -- Sun: evolution -- Sun: flares -- Sun: coronal mass ejections (CMEs)