Stellar magnetosphere reconstruction from radio data. Multi-frequency VLA observations and

合集下载

史特拉(Stella)奖

小生第一次做这种style 的PPT，做的不好请见谅
离开驾驶座到後面去煮咖啡了
最後当然出了大车祸。幸好该位老兄还活著
他决定状告该车制造厂理由是；车子的说明书上没有说，不可以离开驾驶座到後面去煮咖啡。 **法** 院
1、判处得到 175万元 2、一辆新车
**法** 院
案子过後，该制造厂真的把这一条加在说明书上了。
Thanks for watching！
史天才买了一辆崭新的 32呎长的旅行车一位叫 MarvGresinski 的先生在奥克拉荷马（有床，有厕，有厨房的motorhome）。在回家的高速公路上……
80 70
90
speed m/s
100
110
手动
自动
他把自动驾驶定在70英里的时速
这是一个咖啡机

与植物保护专业相关的太赫兹方面的资料

与植物保护专业相关的太赫兹方面的资料下载提示：该文档是本店铺精心编制而成的，希望大家下载后，能够帮助大家解决实际问题。

文档下载后可定制修改，请根据实际需要进行调整和使用，谢谢！本店铺为大家提供各种类型的实用资料，如教育随笔、日记赏析、句子摘抄、古诗大全、经典美文、话题作文、工作总结、词语解析、文案摘录、其他资料等等，想了解不同资料格式和写法，敬请关注！Download tips: This document is carefully compiled by this editor. I hope that after you download it, it can help you solve practical problems. The document can be customized and modified after downloading, please adjust and use it according to actual needs, thank you! In addition, this shop provides you with various types of practical materials, such as educational essays, diary appreciation, sentence excerpts, ancient poems, classic articles, topic composition, work summary, word parsing, copy excerpts, other materials and so on, want to know different data formats and writing methods, please pay attention!太赫兹技术是指波长在0.11mm之间的电磁波的利用技术。

等离子体书籍全集

Plasma Physics Books（非常全的等离子体物理书单）General PublicP. I. John, Plasma Sciences and the Creation of Wealth, Tata-McGraw-Hill, New Delhi, 2005.Yaffa & Shalom Eliezer, The Fourth State of Matter, Hilger, Bristol, 1989 (2nd edition, 2001).John W. Freeman, Storms in Space, Cambridge, 2001.Kenneth R. Lang, The Cambridge Encyclopedia of the Sun, Cambridge Press, 2001.Hans Wilhelmsson, Fusion: A Voyage Through the Plasma Universe, IOP, 1999. Steven T. Suess and Bruce T. Tsurutani, From the Sun: Auroras, Magnetic Storms, Solar Flares, Cosmic Rays, American Geophysical Union, 1998. T. Kenneth Fowler, The Fusion Quest, Johns Hopkins Press, 1997. Kenneth R. Lang, Sun, Earth and Sky, Springer-Verlag, Berlin, 1995, 1997. Gareth Wynn-Williams, The Fullness of Space, Cambridge, 1992.Paul D. Thompson, Gases & Plasmas, Lippincott Company, Philadelphia, 1966 (out of print)IntroductoryPlasma Science: Basic Physics of the Local Cosmos, National Academy Press, Washington D.C., 2004.A. A. Harms et al., Principles of Fusion Energy, World Scientific, 2000. R. Hazeltine and F. Waelbroeck, The Framework of Plasma Physics, Perseus Books, 1998.Plasma Science: From Fundamental Research to Technological Applications, National Academy Press, Washington D.C., 1995.R. J. Goldston and P. H. Rutherford, Introduction to Plasma Physics, IOP, 1995.Richard Dendy, Plasma Physics, Cambridge, 1993, 1995.Francis Chen, Introduction to Plasma Physics and Controlled Fusion, Plenum Press, 1974, 1988.Basic Plasma PhysicsNonequilibrium Phenomena in Plasmas, A. Surjalal Sharma and Predhiman Kaw, eds., Springer, 2005.Takashi Fujimoto, Plasma Spectroscopy, Clarendon Press, Oxford, 2004. J. Goedbloed and S. Poedts, Principles of Magnetohydrodynamics: With Applications to Laboratory and Astrophysical Plasmas, Cambridge, 2004. T. Tajima, Computational Plasma Physics with Applications to Fusion and Astrophysics, Westview Press, 2004.William Kruer, The Physics of Laser Plasma Interactions, Westview Press,2003.Y. Elskens and D. Escande, Microscopic Dynamics of Plasmas and Chaos, IOP, 2002.Per Helander and Dieter J. Sigmar, Collisional Transport in Magnetized Plasmas, Cambridge, 2002.Paul Gibbon, Short Pulse Laser Interactions with Matter, Imperial College Press, 2000.R. Davidson, The Physics of Nonneutral Plasmas, Imperial College Press, 2001.V. A. Rozhansky and L. D. Tsendin, Transport Phenomena in Partially Ionized Plasma, Taylor & Francis Group, London, 2001.H. Wilhelmsson and E. Lazzaro, Reaction-Diffusion in the Physics of Hot Plasmas, IOP, 2000.J. T. Mendonca, Theory of Photon Acceleration, IOP, 2000.Paul Gibbon, Short Pulse Laser Interactions with Matter, Imperial College Press, 2000.J. Weiland, Collective Modes in Inhomogeneous Plasmas, IOP, 1999. S. S. Moiseev, V. Oraevsky, and V. Pungin, Non-Linear Instabilities in Plasmas and Hydrodynamics, IOP Press, 1999.Vladimir Fortov and Igor Iakubov, The Physics of Non-Ideal Plasma, Imperial College Press, 1999.Plasma Chemistry, L. S. Polak and Yu A. Lebedev, eds., Cambridge, 1999. V. V. Antsiferov and G. I. Smirnov, Coherent Radiation Processes in Plasmas, Cambridge, 1999.M. Brambilla, Kinetic Theory of Plasma Waves: Homogeneous Plasmas, Oxford, 1998.Hans R.Griem, Principles of Plasma Spectroscopy,Cambridge, 1997.W. Horton and Y-H Ichikawa, Chaos and Structures in Nonlinear Plasmas, World Scientific, 1996.The Physics of Dusty Plasmas, P. Shukla, D. Mendis & V. Chow, editors, World Scientific, 1996.Toshiro Ohnuma, Radiation Phenomena in Plasmas, World Scientific, 1996.C. S. Liu and V. K. Tripathi, Interaction of Electromagnetic Waves with Electron Beams and Plasmas, World Scientific, 1995E. A. Oks, Plasma Spectroscopy, Springer-Verlag, 1995.W. Lochte-Holtgreven, Plasma Diagnostics, North-Holland, 1968, APS 1995. Dusty and Dirty Plasmas, Noise, and Chaos in Space and in the Laboratory, H. Kikuchi, editor, Plenum Press, NY, 1995.Sanborn C. Brown, Basic data of plasma physics, AIP Press, 1994.V. Shevelko and L. Vainshtein, Atomic Physics for Hot Plasmas, Oxford, 1993.Setsuo Ichimaru, Statistical Plasma Physics, Vol. 1. Basic Principles, Vol. 2. Condensed Plasmas, Perseus Books, 1992, 1994.Thomas Stix, Waves in Plasmas, AIP Press, 1992.Nonlinear and Relativistic Effects in Plasmas, V. Stefan, ed., AIP, 1992.A. Mikhailovskii, Electromagnetic Instabililties in an Inhomogeneous Plasma, IOP, 1992.R. A. Cairns, Radiofrequency Heating of Plasmas, IOP, 1991.Ronald Davidson, An Introduction to the Physics of Nonneutral Plasma, Addison-Wesley, 1990.W. Manheimer and C. Lashmore-Davies, MHD and Microinstabilities in Confined Plasmas, IOP, 1989.R. C. Cross, An Introduction to Alfven Waves, Hilger, Bristol, 1988.A. Galeev and R. Sudan, Basic Plasma Physics, North-Holland, 1989(selections from Handbook of Plasma Physics, Vol. 1 & 2, 1983, 1984) J. P. Freidberg, Ideal Magnetohydrodynamics, Plenum Pr., NY, 1987. Plasma Waves and Instabilities, C. L. Grabbe, ed., American Assoc. of Physics Teachers, 1986.Dwight Nicholson, Introduction to Plasma Theory, Wiley, 1983.E. Lifshitz and L. Pitaevskii, Physical Kinetics: Volume 10, Elsevier, 1981.N. Krall and A. Trivelpiece, Principles of Plasma Physics, McGraw-Hill, 1973.Fusion PlasmasJeffrey Freidberg, Plasma Physics and Fusion Energy, Cambridge Univ. Press, 2007.Plasma Physics: Confinement, Transport and Collective Effects, A. Dinklage et al., eds., Springer-Verlag, 2005.G. McCracken and P. Stott, Fusion: The Energy of the Universe, Elsevier, 2005.J. Wesson, Tokomaks, 3rd ed., Oxford Univ. Press, 2004.C. Braams and P. Stott, Nuclear Fusion: Half a Century of Magnetic Confinement Fusion, IOP Press, 2002.R. Davidson and H. Qin, Physics of Intense Charged Particle Beams in High Energy Accelerators, Imperial College Press, 2001.P. C. Stangeby, The Plasma Boundary of Magnetic Fusion Devices, IOP Press, 2000.Paul M. Bellan, Spheromaks, Imperial College Press, 2000.M. Liberman, J. Degroot, A. Toor, and L. Spielman, Physics of High-Density Z-Pinch Plasmas, Springer, 1999.M. Wakatani, Stellerator and Heliotron Devices, Oxford Univ. Press, 1998. J. Lindl, Inertial Confinement Fusion, Springer, 1998.A. B. Mikahilovskii, Instabilities in a Confined Plasma, IOP, 1998. Laser Plasma Interactions 5: Inertial Confinement Fusion, M. Hooper, ed., IOP, 1996.Physics of High Energy Particles in Toroidal Systems, T. Tajima and M.Okamoto, eds., AIP Press, 1994.M. N. Rosenbluth, New Ideas in Tokamak Confinement, Springer, 1994. B. Kadomtsev and I. Kurchatov, Tokamak Plasma: A Complex Physics System, IOP, 1993.M. Nezlin and I. Kurchatov, Physics of Intense Beams in Plasmas, IOP, 1993.H. L. Berk, Fusion, Magnetic Confinement, in Encyclopedia of Applied Physics, Vol. 6, pp. 575-607, VCH Publishers, Inc., 1993.Richard D. Hazeltine and James D. Meiss, Plasma Confinement, Perseus Books, 1992.High-frequency Plasma Heating, ed. A. Litvak, AIP, 1992.K. Nishikawa, and M. Wakatani, Plasma Physics: Basic Theory with Fusion Applications, Springer-Verlag, 1990.Kenro Miyamoto, Plasma Physics for Nuclear Fusion, MIT Press, 1980, 1989. J. Reece Roth, Introduction to Fusion Energy, Lincoln Rembrandt, Charlottesville, 1986.Weston Stacey, Fusion: An Introduction to the Physics and Techniques of Magnetic Confinement Fusion, Wiley, 1984.Space PlasmasThe Mars Plasma Environment, C. T. Russell, ed., Springer, 2007. Cosmic Magnetic Fields, R. Wielebinski and R. Beck, eds., Springer-Verlag, 2005.Wolfgang Kundt, Astrophysics: A New Approach, Springer-Verlag, 2005.D. A. Gurnett and A. Bhattacharjee, Introduction to Plasma Physics with Space and Laboratory Applications, Cambridge, 2005.James Lequeux, The Interstellar Medium, Springer-Verlag, 2005.A. C. Das, Space Plasma Physics: An Introduction, Narosa Publishing House, New Delhi, 2004.Gunther Rudiger and Rainer Hollerbach, The Magnetic Universe: Geophysical and Astrophysical Dynamo Theory , Wiley-VCH, 2004.Gerd W. Prolss, Physics of the Earth's Space Environment, Springer-Verlag, 2004.Solar and Space Weather Radiophysics, Astrophysics and Space Science Library, Vol. 314, Dale Gary and C. Keller, eds., Kluwer, 2004.J. Goedbloed and S. Poedts, Principles of Magnetohydrodynamics: With Applications to Laboratory and Astrophysical Plasmas, Cambridge, 2004. M-B Kallenrode, Space Physics: An Intro to Plasmas and Particles in the Heliosphere and Magnetospheres, Springer-Verlag, 2001, 2004.Toshi Tajima, Computational Plasma Physics: With Applications to Fusion & Astrophysics, Perseus, 2004.Markus Aschwanden, Physics of the Solar Corona, Springer-Verlag, 2004. Exploration of the Outer Heliosphere and the Local Interstellar Medium,NAS/NRC, National Academies Press, Washington, DC, 2004.Space Plasma Simulation, Jorg Buchner et al., eds.,Springer-Verlag, 2003 Alan C. Tribble, The Space Environment: Implications for Spacecraft Design, Princeton, 2003.Arnoldo O. Benz, Plasma Astrophysics: Kinetic Processes in Solar and Stellar Coronae, Kluwer Academic Publ., 2002.Syun-Ichi Akasofu, Exploring the Secrets of the Aurora, Kluwer Academic Publ., 2002.Arnold Hanslmeier, The Sun and Space Weather, Kluwer Academic Publ., 2002.H. Kikuchi, Electrodynamics in Dusty and Dirty Plasmas -Gravito-Electrodynamics and EHD, Kluwer, 2001.Space Weather, Paul Song, Howard J. Singer, and George L. Siscoe, eds., Geophys. Mono. 125, American Geophysical Union, 2001.Plasma Astrophysics, B. Coppi et al, eds.Vol. 142, Int'l School of Physics Enrico Fermi, 2000.E. Priest and T. Forbes, Magnetic Reconnection: MHD Theory and Applications, Cambridge, 2000.F. Verheest, Waves in Dusty Space Plasmas, Kluwer, 2000.A. Choudhuri, The Physics of Fluids and Plasmas: An Intro for Astrophysicists, Cambridge, 1999.Jorg Buchner, Plasma Astrophysics and Space Physics, Kluwer Academic Publ., 1999.Vinod Krishan, Astrophysical Plasmas and Fluids, Kluwer Academic Publ., 1999.Magnetic Helicity in Space and Laboratory Plasmas, M. R. Brown, R. C. Canfield, A. A. Pevtsov, eds., Geophys. Mono. 111, American Geophysical Union, 1999.Sun-Earth Plasma Connections, J. L. Burch, R. Carovillano, S. Antiochos, ed., Geophys. Mono. 109, American Geophysical Union, 1999. Measurement Techniques in Space Plasmas, Particles, ...Fields, R. F. Pfaff, J. Borovsky, D. Young, eds., Geophys. Mono. volumes 102, 103, American Geophysical Union, 1998.D. Bryant, Electron Acceleration in the Aurora and Beyond, IOP, 1998. M.-B. Kallenrode, Space Physics: Plasmas and particles in the Heliosphere and Magnetosheres, Springer, 1998.T. Tajima and K. Shibata, Plasma Astrophysics, Addison-Wesley, 1997. R. A. Treumann and W. Baumjohann, Advanced Space Plasma Physics, World Scientific, 1997.J. F. Lemaire, D. Heynderickx, and D. N. Baker, eds., Radiation Belts: Models and Standards, Geophys. Mono. 97, American Geophysical Union, 1996. W. Baumjohann and R. A. Treumann, Basic Space Plasma Physics, World Scientific, 1996.V. V. Zheleznyakov, Radiation in Astrophysical Plasmas, Kluwer Academic Publ., Dordrecht, 1996.The Physics of Dusty Plasmas, P. Shukla, D. Mendis and V. Chow, eds., World Scientific, 1996.Plasma Astrophysics and Cosmology, Anthony L. Peratt, ed., Kluwer, 1995. Margaret Kivelson and Chris Russell, Introduction to Space Physics, Cambridge, 1995.J. Buchner, Physics of Space Plasmas, MIT Press, 1995.Charles F. Kennel, Convection and Substorms, Oxford Univ. Press, 1995. Leonard F. Burlaga, Interplanetary Magnetohydrodynamics, Oxford Press, 1995.P. Sturrock, Plasma Physics: An Intro to the Theory of Astrophysical, Geophysical, and Laboratory Plasmas, Cambridge, 2004.J. G. Kirk, D. B. Melrose, and E. R. Priest, Plasma Astrophysics, Springer-Verlag, 1994.Sergei Sazhin, Whistler-mode Waves in a Hot Plasma, Cambridge Univ. Press, 1993.S. Peter Gary, Theory of Space Plasma Microinstabilities, Cambridge, 1993. Anthony Peratt, Physics of the Plasma Universe, Springer-Verlag, 1992. George Parks, Physics of Space Plasmas, Addison-Wesley, 1991. Modeling Magnetospheric Plasma Processes, G. Wilson, ed., American Geophysical Union, 1991.F. Curtis Michel, Theory of Neutron Star Magnetospheres, U. Chicago, 1991. Numerical Simulation of Space Plasmas, B. Lembege and J. Eastwood, eds., North-Holland, 1988.Donald Melrose, Instabilities in Space and Laboratory Plasmas, Cambridge, 1986.Eric Priest, Solar Magnetohydrodynamics, Reidel, 1985.Plasma TechnologyPlasma Technology for Textiles, R. Shishoo, ed., Woodhead Publ., Cambridge, 2007.The Physics and Technology of Ion Sources, Ian Brown, ed., Wiley, 2004.A. Fridman and L. Kennedy, Plasma Physics and Engineering, Taylor and Francis, 2004.Emerging Applications of Vacuum-ARC-Produced Plasma, Ion, and Electron Beams, E. Oks and I. Brown, eds, Kluwer, 2003.Bundesministerium fur Bildung und Forschung, Plasma Technology, BMBF (www.bmbf.de), Germany, 2001 (in German and English -www.bmbf.de/pub/plasma_technology.pdf)J. Reece Roth, Industrial Plasma Engineering, Vol. 2 - Applications, IOP, 2001.E. Bazelyan and Y. Raizer, Lightning Physics and Lightning Protection, IOP, 2000.K. Muraoka and M. Maeda, Laser Aided Diagnostics of Gases and Plasmas,IOP, 2000.Yu. M. Aliev, H. Schluter, and A. Shivarova, Guided-Wave-Produced Plasmas, Springer, 2000.W. N. G. Hitchon, Plasma Processes for Semiconductor Fabrication, Cambridge, 1999.Dusty Plasmas: Physics, Chemistry and Technological Impacts in Plasma Processing, Andre Bouchoule, ed., Zukov and O. Solonenko, eds., Lavoisier, 1999.Thermal Plasmas and New Materials Technology, vol 1&2, M. Zukov and O. Solonenko, eds., Cambridge, 1999.H. Zhang, Ion Sources, AIP, 1999.M. Sugawara, Plasma Etching: Fundamentals and Applications, Oxford, 1998. Microlithography: Science and Technology, J. R. Sheats and B. W. Smith, eds., Marcel Dekker, NY, 1998.I. C. E. Turcu and J. B. Dance, X-Rays from Laser Plasmas, Wiley, 1998. Generation and Application of High Power Microwaves, R. Cairns and A. Phelps, eds., IOP, 1997.Environmental Aspects in Plasma Science, Sugiyama, L., T. Stix, and W. Mannheimer, eds., AIP Press, 1997.Y. P. Raizer and J. E. Allen, Gas Discharge Physics, AIP, 1997. Plasma Science and the Environment, W. Manheimer, L. Sugiyama, and T. Stix, eds., AIP, 1996.R. Geller, Electron Cyclotron Resonance Ion Sources and ECR Plasmas, IOP, 1996.Dynamics of Transport in Plasmas and Charged Beams, G. Maino and M. Ottaviani, eds., World Scientific, 1996.12th International Symposium on Plasma Chemistry, J. V. Heberlein, D. W. Ernie, and J. T. Roberts, Int'l Union of Pure and Applied Chemistry, Univ. of Minnesota Pr., Minneapolis, Aug., 1995. Rimini, E., Ion Implantation: Basics to Device Fabrication, Kluwer Academic Publishing, Boston,1995.Stephen O. Dean and N. Poltoratskaya, "Applications of Fusion and Plasma Device Technologies," in Plasma Devices and Operations, Vol. 4, 1995. J. Reece Roth, Industrial Plasma Engineering, Vol. 1 - Principles, IOP, 1995.Michael Lieberman and Allan Lichtenberg, Principles of Plasma Discharges and Materials Processing, Wiley & Sons, 1994.Alfred Grill, Cold Plasma in Materials Fabrication, IEEE Press, 1994. J. C. Miller, Laser Ablation, Springer-Verlag,1994.Plasma Spraying: Theory and Applications, ed. R. Suryanarayanan, World Scientific, 1993.Non-thermal Plasma Techniques for Pollution Control, B. M. Penetrante and S. E. Schulteis, eds., NATO-ASI Series G, Vol. 34, Parts A and B, 1993.Plasma Technology: Fundamentals and Applications, eds. M. Capitelli and C. Gorse, Plenum Press, 1992.Dry Etching for VLSI, eds. A. J. van Roosmalen, J. A. G. Baggerman, S.J.H. Brader, Plenum Press, NY, 1991.Handbook of Plasma Processing Technology, eds. S. Rossnagel, J. Cuomo, and W. Westwood, Noyes Publications, 1990.Plasma Polymerization and Plasma Interactions with Polymeric Materials, ed. H. Yasuda, Wiley & Sons, 1990.Plasma Diagnostics, eds. O. Auciello and D. Flamm, Academic Press, 1989. Plasma Etching, eds. D. Manos and D. Flamm, Academic Press, 1989.A. Chambers, R. Fitch, Walmley, S. Coldfield, andB. Halliday, Basic Vacuum Technology, IOP Publ., 1989.Russ Morgan, Plasma Etching in Semiconductor Fabrication, Elsevier, 1985. Plasma Diagnostic Techniques, eds. R. Hudlestone and S. Leonard, Academic Press, 1978. Techniques and Applications of Plasma Chemistry, eds. J. Hollahan and A. Bell, Wiley & Sons, 1974.Computational Plasma PhysicsT. Tajima, Computational Plasma Physics: With Applications to Fusion and Astrophysics, Addison Wesley, 1989.C. K. Birdsall, and A. B. Langdon, Plasma Physics via Computer Simulation, McGraw-Hill, 1985, 1991.Hockney and Eastwood, Computer Simulation using Particles, Adam Hilger, 1988._______________________________________________________New and Special SourcesPlasma science materials from Russia and other FSU statesare a specialty of Cambridge International Science Publishing.William Beaty's Nikola Tesla and Tesla Coil pageand resources on ball lightningVladimir Rokov and Martin Uman, Lightning Physics and Effects, Cambridge Press, 2003.。

磁罗经校正师英语资料

磁罗经校正师英语资料Being a magnetic compass adjuster is not just a career for me, but a passion that I have been cultivating for years. 磁罗经校正不仅仅是我的职业，更是我多年来培养的一种激情。

I have always been fascinated by the intricacies of magnetic fields and their impact on navigation, which led me to pursue a career in this specialized field. 我一直被磁场的复杂性以及它们对导航的影响所吸引，这促使我选择在这个专业领域发展。

I believe that a magnetic compass adjuster plays a crucial role in ensuring the accuracy and reliability of navigation systems, which are essential for safe and efficient marine operations. 我相信磁罗经校正师在确保导航系统的准确性和可靠性方面起着至关重要的作用，这对于安全高效的航海操作至关重要。

In my line of work, attention to detail is paramount as even the slightest deviation in magnetic compass readings can have serious consequences for navigation. 在我的工作中，注重细节至关重要，因为即使磁罗经读数有细微的偏差，也会对导航产生严重后果。

I take great pride in my ability to meticulously calibrate magnetic compasses to ensure they are in perfect alignment with the Earth's magnetic field.我以自己精密校准磁罗经的能力感到非常自豪，确保它们与地球磁场完美对齐。

钛掺杂氧化镁薄膜二次电子发射倍增特性研究

钛掺杂氧化镁薄膜二次电子发射倍增特性研究崔乃元，王思展，王志浩，刘宇明，李蔓，王璐（北京卫星环境工程研究所，北京 100094）摘要：氧化镁具有较高的二次电子发射系数，适合作为制备多级放大装置的二次电子发射材料。

文章采用磁控溅射法制备高质量氧化镁薄膜和钛掺杂氧化镁薄膜，并对薄膜进行形貌表征，研究其二次电子发射倍增特性，包括氧化镁薄膜电子倍增器的增益特性以及增益衰减情况。

结果表明：高压源电压和电流的增大均可提高电子倍增器的电流增益倍数；掺杂Ti 不仅能提高电子倍增器的增益效能，且相比纯氧化镁薄膜，钛掺杂氧化镁薄膜的增益衰减明显放缓，能够将倍增器的寿命延长2倍以上。

关键词：氧化镁薄膜；钛掺杂；磁控溅射；二次电子发射；电子倍增特性中图分类号：TB34文献标志码：A 文章编号：1673-1379(2021)06-0687-06DOI: 10.12126/see.2021.06.012The secondary electron emission multiplication characteristics oftitanium-doped magnesium oxide thin filmsCUI Naiyuan, WANG Sizhan, WANG Zhihao, LIU Yuming, LI Man, WANG Lu(Beijing Institute of Spacecraft Environment Engineering, Beijing 100094, China)Abstract: The magnesium oxide, due to its high secondary electron emission coefficient, is suitable as asecondary electron emission material for the preparation of multi-stage amplification devices. In this paper, the high-quality magnesium oxide films and the titanium-doped magnesium oxide films are prepared by the magnetron sputtering, and the morphology of the films is characterized. In addition, the secondary electron emission multiplication characteristics of the films used in the MgO film electron multiplier are studied. The gain characteristics and the gain reduction of the electron multiplier are also analyzed. It is shown that the increase of the voltage or the current of the high voltage source can both increase the current gain multiple of the electron multiplier; the titanium doping, for example, the Ti-doped MgO film in comparison with the pure MgO film, can not only increase the gain of the electron multiplier, but also extend the working life of the multiplier more than two times.Keywords: magnesium oxide thin films; titanium doping; magnetron sputtering; secondary electron emission; electron multiplication characteristics收稿日期：2021-06-29；修回日期：2021-12-14基金项目：国家自然科学基金项目（编号：1187021136）引用格式：崔乃元, 王思展, 王志浩, 等. 钛掺杂氧化镁薄膜二次电子发射倍增特性研究[J]. 航天器环境工程, 2021, 38(6):687-692CUI N Y, WANG S Z, WANG Z H, et al. The secondary electron emission multiplication characteristics of titanium-doped magnesium oxide thin films[J]. Spacecraft Environment Engineering, 2021, 38(6): 687-692第 38 卷第 6 期航天器环境工程Vol. 38, No. 62021 年 12 月SPACECRAFT ENVIRONMENT ENGINEERING 687E-mail: ***************Tel: (010)68116407, 68116408, 68116544. All Rights Reserved.0 引言原子频率标准（以下简称频标）技术被广泛应用于守时和授时服务，常见的原子频标有铷原子频标、铯原子频标和氢原子频标等。

解密太阳系的奥秘：探索宇宙中行星和恒星的新发现

解密太阳系的奥秘：探索宇宙中行星和恒星的新发现1. 引言1.1 概述太阳系作为人类研究和探索的焦点之一，一直充满着令人着迷的奥秘。

随着科技的进步和观测技术的革新，我们对行星和恒星有了更深入的认识和理解。

本文将带领读者一起解密太阳系中行星和恒星的奥秘，并介绍最新的发现和研究成果。

1.2 文章结构本文主要分为五个部分。

首先，在第二部分中，我们将讨论太阳系的形成与演化过程，探索行星形成的奥秘以及冥王星地位变迁等问题。

接下来，在第三部分中，我们将介绍最新外太空行星观测技术进展，以及火星水资源探测结果和木星及其卫星探索的新突破。

然后，在第四部分中，我们将深入了解各种恒星类型和特征，并解析恒星寿命和演化过程。

此外，我们还将关注恒星间相互影响和对恒星团进行研究的进展。

最后，在第五部分中，我们将介绍一些前沿研究方向，包括超新星爆发暴涨模拟预测研究最新成果和黑洞世界边缘实验监测进展。

同时，我们还将思考观测数据背后的宇宙奥秘，并展望未来的挑战。

1.3 目的本文的目的是通过解密太阳系的奥秘，帮助读者了解行星和恒星的形成、演化和特征。

通过介绍最新的科学研究成果，我们希望激发读者对宇宙未知之谜的好奇心，并让他们对前沿研究方向有所了解。

希望读者能在本文中收获全新的知识，对宇宙充满更多的敬畏和探索欲望。

2. 太阳系的形成与演化2.1 形成过程太阳系的形成是一个约46亿年前发生的复杂过程。

最早的证据可以追溯到恒星诞生的星云，大约在宇宙诞生之后的几百万年内。

根据现代天文学家的理论和模型，太阳系的形成经历了以下几个关键步骤：首先，巨大而稳定的分子云被引力作用开始崩塌。

这种云由气体和尘埃组成，并且可能是由超新星爆炸释放出来的物质。

随着云坍缩，材料开始绕着中心点旋转。

这个旋转过程形成了一个扁平的圆盘结构，称为原行星盘或原始太阳盘。

在这个盘中，物质逐渐聚集并且形成更加紧密和密集的区域。

在原行星盘中，尘埃和气体汇聚成更大而更重的类地行星、巨型气态行星以及其他天体。

关于探索宇宙是否有意义的英语作文

关于探索宇宙是否有意义的英语作文Exploring the Cosmos: A Meaningful EndeavorThe vastness of the universe has long captivated the human imagination, inspiring us to venture beyond the confines of our own planet and unravel the mysteries that lie among the stars. As we gaze up at the night sky, we are confronted with the profound question of whether the pursuit of cosmic exploration holds any true meaning or significance. This inquiry has been the subject of much philosophical and scientific debate, and it is one that deserves careful consideration.At the heart of this discussion lies the fundamental question of our place in the grand scheme of the universe. Are we alone in this vast expanse or are there other forms of intelligent life waiting to be discovered? The search for extraterrestrial intelligence has been a driving force behind many of the most ambitious space exploration programs, as the prospect of making contact with another civilization holds the potential to transform our understanding of the universe and our own existence.Beyond the search for life, the exploration of the cosmos offers us aunique opportunity to expand the boundaries of human knowledge and capabilities. The development of advanced technologies, such as powerful telescopes, interplanetary spacecraft, and cutting-edge sensors, has allowed us to gather unprecedented amounts of data about the composition, structure, and evolution of celestial bodies. This knowledge, in turn, has the potential to unlock new insights into the fundamental laws of physics, the origins of our solar system, and the very nature of the universe itself.Moreover, the pursuit of space exploration has had a profound impact on our understanding of our own planet and the fragility of the environment that sustains us. The iconic images of Earth taken from space have served as a powerful reminder of the interconnectedness of all life on our shared home, inspiring a greater sense of global responsibility and environmental stewardship. As we venture further into the cosmos, we may uncover new insights that could help us address the pressing challenges facing our planet, such as climate change, resource depletion, and the need for sustainable energy solutions.However, the exploration of the cosmos is not without its critics. Some argue that the immense resources and funding devoted to space programs could be better allocated towards addressing pressing social and economic issues on Earth, such as poverty, healthcare, and education. Others question the inherent value ofspace exploration, arguing that the knowledge gained does not directly improve the quality of life for the majority of the population.These concerns are valid and deserve consideration, but they must be weighed against the broader benefits and potential of space exploration. The pursuit of knowledge and the expansion of human understanding have long been recognized as essential drivers of progress and innovation. The insights and technologies developed through space exploration have often found practical applications that have improved the lives of people around the world, from advancements in medical imaging to the development of more efficient communication systems.Moreover, the act of exploring the unknown and pushing the boundaries of human capabilities can have a profound impact on our collective spirit and sense of purpose. The achievements of space programs, such as the Apollo moon landings and the ongoing exploration of Mars, have inspired generations of people to dream big, to pursue their passions, and to strive for greatness. This intangible, yet invaluable, benefit of space exploration should not be overlooked.In conclusion, the exploration of the cosmos is a deeply meaningful and worthwhile endeavor that holds the potential to transform our understanding of the universe and our place within it. While thechallenges and criticisms of space exploration must be taken seriously, the long-term benefits of this pursuit, both tangible and intangible, far outweigh the costs. As we continue to push the boundaries of human knowledge and capabilities, the exploration of the cosmos will remain a crucial and inspiring part of our shared human journey.。

拉米样凯亚超星系团的英语

拉米样凯亚超星系团的英语
本文将介绍拉米样凯亚超星系团(TheRamyakyaSupercluster)。

这个超星系团位于宇宙中心附近，由多个星系团和星系群组成。

它的名字来自于梵文中的“拉米亚”和“凯亚”，分别意为“光辉的”和“宝石的”。

该超星系团最大的星系团是弗兰克林星系团 (Franklin Cluster)，它包含了数千亿颗星星。

拉米样凯亚超星系团的总质量约为10^16个太阳质量，是宇宙中最大的超星系团之一。

该超星系团还包括了其他著名星系团，如珀尔曼星系团(Perelman Cluster)、阿波罗星系团 (Apollo Cluster)和达芬奇星系团 (Da Vinci Cluster)等。

这些星系团中的许多星系和星系群都已被仔细研究和观测。

除了包含大量星系和星系团外，拉米样凯亚超星系团还是一颗活跃的星系团。

它包含了许多射电星系和类星体，这些天体能够产生高能宇宙射线和强磁场。

此外，该超星系团中还存在大量暗物质，这些暗物质对宇宙的结构和演化起着重要作用。

总之，拉米样凯亚超星系团是一个重要的天文学研究目标，它能够帮助我们更好地了解宇宙的结构和演化。

- 1 -。

A New Approach for Filtering Nonlinear Systems

computational overhead as the number of calculations demanded for the generation of the Jacobian and the predictions of state estimate and covariance are large. In this paper we describe a new approach to generalising the Kalman ﬁlter to systems with nonlinear state transition and observation models. In Section 2 we describe the basic ﬁltering problem and the notation used in this paper. In Section 3 we describe the new ﬁlter. The fourth section presents a summary of the theoretical analysis of the performance of the new ﬁlter against that of the EKF. In Section 5 we demonstrate the new ﬁlter in a highly nonlinear application and we conclude with a discussion of the implications of this new ﬁlter1
Tቤተ መጻሕፍቲ ባይዱ
= = =
δij Q(i), δij R(i), 0, ∀i, j.
(3) (4) (5)

英语天文知识英语30题

英语天文知识英语30题1. Which is the largest planet in the solar system?A. EarthB. JupiterC. MarsD. Venus答案：B。

木星（Jupiter）是太阳系中最大的行星。

选项A 地球Earth）不是最大的行星。

选项C 火星（Mars）体积较小。

选项D 金星 Venus）也不是最大的行星。

2. The star at the center of our solar system is called _.A. the MoonB. the SunC. SaturnD. Pluto答案：B。

我们太阳系的中心恒星被称为太阳（the Sun）。

选项 A 月亮（the Moon）不是恒星。

选项C 土星（Saturn）是行星。

选项D 冥王星 Pluto）是矮行星。

3. Which planet is known as the "Red Planet"?A. MercuryB. VenusC. MarsD. Neptune答案：C。

火星（Mars）被称为“红色星球”。

选项A 水星（Mercury）不是红色的。

选项B 金星（Venus）不是红色星球。

选项D 海王星Neptune）不是红色的。

4. How many planets are there in the solar system?A. 8B. 9C. 10D. 11答案：A。

太阳系中有8 颗行星。

曾经冥王星被认为是第九颗行星，但现在冥王星被归类为矮行星。

5. Which planet is closest to the Sun?A. MercuryB. VenusC. EarthD. Mars答案：A。

水星（Mercury）是离太阳最近的行星。

选项B 金星Venus）距离太阳比水星远。

选项C 地球（Earth）距离太阳比水星远。

选项D 火星 Mars）距离太阳比水星远。

地月周期轨道对地月L1_与L2_附近Halo_轨道的可见性分析

地月周期轨道对地月L1与L2附近Halo轨道的可见性分析李星明果琳丽*伏瑞敏郑国宪王培培董联庆（北京空间机电研究所，北京 100094）摘　要　随着去往月球航天器的增多，现有的近地空间光学卫星与地基光学望远镜的探测能力已无法满足要求，急需增强地月空间观测能力，通过使用地月周期轨道来填补地月空间观测能力的不足被认为是一种有效手段。

针对地月周期轨道的特性，文章基于微分校正原理对三体轨道建模，并完成了算法的设计，提出了地月周期轨道的选择原则，并优选了3条轨道。

在地月周期轨道对地月拉格朗日点L1、L2附近Halo 轨道的可见性分析中，为方便评估，采用类球体的物体星等评估模型来定义可见性的评估标准；基于卫星工具包提供模型计算中涉及的自然天体、物体和观测卫星三者的时空关系，给出了可见性分析过程及结果，研究表明地月周期轨道对地月拉格朗日点L1、L2附近Halo 轨道均有不错的观测效果，其中轨道1对地月周期轨道的可见性综合最高，均大于95%。

关键词　地月周期轨道　微分校正　Halo 轨道　星等模型　可见性　空间探测中图分类号：V476.5 文献标志码：A 文章编号：1009-8518(2024)02-0053-13DOI ：10.3969/j.issn.1009-8518.2024.02.005Visibility Analysis of the Cislunar Periodic Orbit for the Halo Orbitsnear the Earth-Moon L1 and L2 PointsLI Xingming GUO Linli *FU Ruimin ZHENG Guoxian WANG Peipei DONG Lianqing（ Beijing Institute of Space Mechanics & Electricity, Beijing 100094, China ）Abstract With the increasing of spacecrafts going to the moon, the detection capability of the existing near-Earth space optical satellites and ground-based optical telescopes can no longer meet the observation requirements, and it is urgent to enhance the cislunar space observation capability. It is considered as an effective means to make up the deficiency of cislunar space observation capability for observations using the cislunar periodic orbit. According to the characteristics of the cislunar periodic orbit, the orbit is modeled based on the principle of differential correction and the algorithm is designed. An orbit selection principle is proposed and three optimized orbits are given. In the analysis of the visibility of the cislunar periodic orbit to the Halo Orbit near the cislunar Lagrange points L1 and L2, in order to facilitate the evaluation, the spheroid-like object magnitude evaluation model is used to define the evaluation criteria of visibility. Based on the spatiotemporal收稿日期：2023-12-05基金项目：重庆大学深空探测省部共建协同创新中心2021年开放课题（SKTC202101）引用格式：李星明, 果琳丽, 伏瑞敏, 等. 地月周期轨道对地月L1与L2附近Halo 轨道的可见性分析[J]. 航天返回与遥感,2024, 45(2): 53-65.LI Xingming, GUO Linli, FU Ruimin, et al. Visibility Analysis of the Cislunar Periodic Orbit for the Halo Orbits near the Earth-Moon L1 and L2 Points[J]. Spacecraft Recovery & Remote Sensing, 2024, 45(2): 53-65. (in Chinese)第 45 卷第 2 期航天返回与遥感2024 年 4 月SPACECRAFT RECOVERY & REMOTE SENSING5354航天返回与遥感2024 年第 45 卷relationship between natural objects, object and remote sensing satellites involved in the calculation of the model provided by the satellite toolkit, the visibility analysis process and results are presented. The results show that the cislunar periodic orbit has a good observation effect on the Halo Orbit near the cislunar lagrange points L1 and L2, and the visibility of the cislunar periodic orbit with serial number 1 is the highest, which is greater than 95%.Keywords　cislunar periodic orbit; differential correction; Halo Orbit; magnitude model; visibility analysis; space exploration0　引言近年来，随着各国地月空间探测活动的增加，地月空间内的航天器越来越多，为保障地月空间活动的顺利进行，识别这些物体显得极其重要。

关于Midjourney的一千个关键词

8建筑描述：高耸的摩天大楼Architectural descriptions: towering skyscrapers废弃的工厂abandoned factories破败的公寓楼dilapidated apartment buildings荒废的仓库deserted warehouses未来主义建筑futuristic buildings高达100层的摩天大楼skyscrapers up to 100 storeys high废弃的化工厂abandoned chemical plants破旧的公寓楼dilapidated apartment buildings废弃的地铁站abandoned underground stations钢铁巨兽的未来主义建筑futuristic buildings of steel giants独特的废弃矿井unique abandoned mines城市中心的高桥high bridges in the centre of cities破败的仓库区dilapidated warehouse areas未来主义立交桥futuristic overpasses巨型城市塔楼giant urban towers高层公寓high-rise flats混凝土丛林concrete jungles废弃的办公大楼abandoned office buildings高科技实验室high-tech laboratories宏伟的桥梁magnificent bridges巨大的地下设施huge underground facilities发电厂power plants防空洞air raid shelters高速公路桥motorway bridges废弃的工业区abandoned industrial areas未来主义的宇宙站futuristic cosmic stations高科技商业中心high-tech commercial centres科技领域的大型研发基地large R&D bases in the field of science and technology 高科技军事基地high-tech military bases科技学院science and technology colleges炼油厂oil refineries气象站weather stations军火库armouries研究所research institutes氛围与情感：无助的孤独Atmosphere and emotion: helpless loneliness 幸存者的希望hope of survivors犯罪行动的紧张tension of criminal action黑暗力量的压迫感oppression of dark forces黑暗的压迫感oppression of darkness绝望的孤独感loneliness of despair亢奋的兴奋感exhilarating excitement危险的紧张感tension of danger科技的未来感futuristic sense of technology刺激的冒险感exciting sense of adventure神秘的不可知感mysterious sense of unknowability迷幻的感觉psychedelic feeling幸存者的希望感sense of hope of survivors灰暗的丧失感grey sense of loss失落与绝望loss and despair未来世界的孤独感loneliness of a future world生存的希望与勇气hope of survival and courage科技带来的愉悦感the pleasure of technology黑客的兴奋感the excitement of hacking未来社会的不安感the uneasiness of future society高科技设备的刺激感the excitement of high-tech devices未知领域的神秘感the mystery of unknown territories科技研究的探索感the exploration of technological research 黑科技的迷茫感the confusion of black technology未来世界的理想主义the idealism of the future world科技的浪漫情怀the romance of technology科技带来的自由感the freedom that technology brings未来的疑惑与困惑the doubt and confusion of the future科技为人类带来的进步感the sense of progress that technology brings to humanity未来世界的危机感the crisis of the future world科技的创新和挑战the innovation and challenges of technology910光线与影子：闪耀的霓虹灯Light and shadow: shimmering neon lights黑暗中的影子shadows in the dark照亮城市的月光moonlight illuminating the city强烈的阳光strong sunlight熠熠生辉的霓虹灯glittering neon lights黑暗中的神秘影子mysterious shadows in the dark照亮城市的月光moonlight illuminating the city强烈的阳光strong sunlight折射光线下的变幻光影changing light in refracted light闪烁不定的烛光flickering candlelight星光下的美丽影像beautiful images in starlight柔和的阴影soft shadows梦幻般的光影效果dreamy light effects烟雾中的迷离影像misty images in smoke未来主义的夜景futuristic night scenes红色的霓虹灯光the red neon light充满幻想的星空fantasy starry skies机器人的投影projections of robots未来的科技光束beams of future technology黑暗中的眼睛eyes in the dark闪耀的星星shining stars照亮未来的激光光束laser beams illuminating the future强烈的太阳光线intense sun rays电影中的未来世界光影light and shadows in the future world in films虚拟现实中的光影light and shadows in virtual reality高科技眼镜的反射光reflected light from high-tech glasses未来世界中的阴影与光影shadows and light in the future world未来世界的幻想与现实交织fantasy and reality intertwined in the future world 机器人身上的光线投影light projections on robots未来的科技成为生活中的一部分the future of technology becoming a part of life黑暗中的未知形态unknown forms in the darkness.11能量与力量：高科技能量场Energy and power: high-tech energy fields激光束laser beams电磁脉冲electromagnetic pulses核反应堆nuclear reactors超级电池super batteries电磁脉冲的瘫痪力the paralysing power of electromagnetic pulses核反应堆的能量源the energy source of nuclear reactors超级电池的持久力the staying power of super batteries量子力学的变幻力量the shifting power of quantum mechanics黑洞的引力力量the gravitational power of black holes核聚变的能量释放力量the energy-releasing power of nuclear fusion电磁风暴的毁灭力量the destructive power of electromagnetic storms高速磁力驱动的力量the power of high-speed magnetic drives能量场的波动fluctuations in energy fields电子设备的节能模式energy-saving modes of electronic devices能量场的屏蔽效应the shielding effect of the field高科技武器的杀伤力the lethality of high-tech weapons机械臂的承重能力the weight-bearing capacity of mechanical arms科技设备的耗电量the power consumption of technological equipment 核反应堆的输出能力the output of nuclear reactors电磁脉冲的破坏力the destructive power of electromagnetic pulses飞船发动机的推力the thrust of spaceship engines高科技燃料的能量密度the energy density of high-tech fuels太阳能发电的效率the efficiency of solar power generation高科技设备的稳定性能the stability of high-tech equipment能量转换的效率the efficiency of energy conversion核聚变的热释放量the heat release of nuclear fusion高科技设备的传输效率the transmission efficiency of high-tech equipment 能量流动的稳定性the stability of energy flow12人工生命：合成人类Artificial life: synthetic humans机器人助手robotic assistants仿生生物bionic beings智能宠物intelligent pets克隆人类cloned humans合成人类的身体优势physical advantages of synthetic humans机器人助手的灵活性flexibility of robotic assistants仿生生物的自我进化self-evolution of bionic beings智能宠物的陪伴感companionship of intelligent pets克隆人类的完美基因perfect genes of cloned humans混合生物的多样性diversity of hybrid beings强化人类的肉体能力physical capabilities of enhanced humans多重人格的思维方式multiple personalities of thinking未来生命体的神秘力量mysterious powers of future lifeforms神秘生物的未知威胁unknown threat仿生机器人的情感emotions of bionic robots智能宠物的互动性interactivity of intelligent pets克隆人的道德争议moral controversies of human cloning合成人类的自我意识self-awareness of synthetic humans机器人助手的便利性convenience of robotic assistants仿生生物的生物力学特性biomechanical properties of bionic beings智能机器人的学习能力learning capabilities of intelligent robots虚拟人的真实感realism of virtual humans未来主义人类的演化evolution of futuristic humans机械生命体的意识认知consciousness perception of mechanical lifeforms人工智能的道德问题moral issues of artificial intelligence仿生人类的生理构造physiological constitution of bionic humans机器人研究的进展advances in robotics research人造生命的探索The Quest for Artificial Life人工智能的学习方法Learning Methods in Artificial Intelligence智能机器人的自我保护能力Self-Preservation Capabilities of Intelligent Robots 人类基因编辑的伦理问题Ethical Issues in Human Gene Editing合成生命体的可控性Controllability of Synthetic Lifeforms13奇异景象：穿越时空的漩涡Strange sights: vortexes through time and space奇怪的异形怪物strange alien monsters虚拟现实空间virtual reality space幻觉和幻觉药物hallucinations and hallucinogenic drugs神秘的传送门mysterious portals奇怪的异形怪物strange alien monsters虚拟现实空间的幻境illusions in virtual reality space错乱的现实世界the dislocated real world幻觉药物的迷幻体验psychedelic experiences with hallucinogenic drugs 未知力量的神秘现象mysterious phenomena of unknown forces远古遗迹的探索之旅voyages of exploration through ancient ruins黑暗维度的恐怖体验horrific experiences in dark dimensions未知星球的探险旅程expeditions to unknown planets时空隧道的扭曲warping of space-time tunnels illusions of virtual worlds虚拟世界的幻觉the emergence of technological aliens科技异形的出现the exploration of unknown planets未知星球的探索the reversal of the behaviour of bionic beings 仿生生命的逆转行为the erroneous reactions of high-tech devices 高科技设备的错误反应the outbreak of technological crises科技危机的爆发the descent of aliens外星人的降临the adventure of time travel时空旅行的冒险the fantastic path of human evolution人类进化的奇妙之路the unpredictability of technological research 科技研究的不可预知性the magnetic disturbance of cosmic space宇宙空间的磁场扰动the adventure of time travel时空穿越的冒险之旅the realisation of virtual worlds虚拟世界的实现the exploration of alien worlds异形世界的探索the virtual personality of Presence虚拟人格的存在感the stormy behaviour of high-tech devices高科技设备的暴走行为the mutant evolution of the space-time tunnel宇宙与星际：星际飞船Universe and Interstellar: Starships行星探测器Planetary Probes星系之间的太空旅行Intergalactic Space Travel14外星生命体Alien Lifeforms星际飞船的科技装备Technological Equipment for Starships行星探测器的探测工具Probing Tools for Planetary Probes星系之间的太空旅行的未知冒险Unknown Adventures of Intergalactic Space Travel外星生命体的威胁与猎捕Threats and Hunting of Alien Lifeforms人类殖民地的建设与发展Construction and Development of Human Colonies星际贸易的繁荣与危机Prosperity and Crisis of Interstellar Trade星际战争的血腥与残酷Bloodshed and Cruelty of Interstellar Wars太空探险的创新与进步Innovation and Progress of Space Exploration黑洞的奇妙力量与恐怖危险Black Holes Wonderful Powers and Terrible Dangers 未知星球的神秘环境与生命Mysterious Environments and Life on Unknown Planets 行星环境的探索Exploration of Planetary Environments太空旅行的冒险Adventures in Space Travel星系间的交通系统Intergalactic Transportation Systems未知星球的探测Exploration of Unknown Planets人类在宇宙中的生存Human Survival in the Universe太阳系的演化过程The Evolution of the Solar System未来的宇宙殖民计划Future Plans for Cosmic Colonisation太空站的生命保障系统Life Support Systems on Space Stations地外文明的探索Exploration of Extraterrestrial Civilisations恒星飞船的设计Design of Stellar Spaceships黑洞的奥秘The Mystery of Black Holes宇宙中的暗物质Dark Matter in the Universe星际探险队的挑战Interstellar The challenges of expeditions星际战争的爆发the outbreak of interstellar wars科技设备在太空中的应用the use of technological devices in space星际旅行的限制the limits of interstellar travel未来的星际战略the future of interstellar strategy。

Fast Three Dimensional Recovery Method and Apparat

专利名称：Fast Three Dimensional Recovery Methodand Apparatus发明人：Miguel Arias Estrada,Alicia MoralesReyes,Maria Rosas Cholula,Gerardo SosaRamirez申请号：US12847680申请日：20100730公开号：US20100295926A1公开日：20101125专利内容由知识产权出版社提供专利附图：摘要：The present invention comprises a method and an apparatus for threedimensional modeling to allow dense depth maps to be recovered, without previous knowledge of the surface reflectance, from only a single pair of stereo images. Several initial steps are performed for stereo and radiometric calibration and rectification for obtaining accurate results. The apparatus for the stereo images acquisition includes internal light sources, these are automatically commuted by a illumination control in order to fulfill the reciprocity property, a stereo camera head composed by the necessary optics to acquire the reciprocal stereo images and a compatible PC interface. The invention is faster than other systems since it requires only two images for obtaining a dense depth model of objects with an arbitrary surface reflectance distribution allowing the system to be used in a wide range of applications such as metrology, quality control, medical and dynamic three dimensional modeling.申请人：Miguel Arias Estrada,Alicia Morales Reyes,Maria Rosas Cholula,Gerardo Sosa Ramirez地址：San Pedro Cholula MX,Mexico City MX,Puebla MX,Oaxaca MX国籍：MX,MX,MX,MX更多信息请下载全文后查看。

基于箍缩装置的高能量密度物理实验研究进展

·惯性约束聚变物理与技术·基于箍缩装置的高能量密度物理实验研究进展*黄显宾，徐　强，王昆仑，任晓东，周少彤，张思群，蔡红春，王贵林，张朝辉，贾月松，孙奇志，刘　盼，袁建强，李洪涛，王　勐，谢卫平，邓建军（中国工程物理研究院流体物理研究所，四川绵阳 621999）摘要：基于脉冲功率技术的箍缩装置能够在cm 空间尺度和百ns 时间尺度产生极端的高温、高压、高密度以及强辐射环境。

中物院流体物理研究所在已建成的10 MA 级的大型箍缩装置上开展多种负载构型的高能量密度物理实验研究。

利用Z 箍缩动态黑腔创造出了惯性约束聚变研究所需的高温辐射场；研究了金属箔套筒和固体套筒的内爆动力学特性；利用中低Z 材料内爆获得了可观的K 壳层线辐射并用于X 射线热-力学效应实验研究；磁驱动准等熵加载和冲击加载为材料动态特性研究提供了新的实验能力；采用环形二极管和反射三极管技术的轫致辐射源获得了高剂量（率）的X 射线和γ射线；利用磁驱动的径向金属箔模拟了天体物理中恒星射流的形成及其辐射的产生。

此外，还介绍了利用反场构型磁化靶聚变装置开展的预加热磁化等离子体靶形成等实验结果。

关键词：脉冲功率；高能量密度物理； Z 箍缩；惯性约束聚变；材料动力学特性；反场构型中图分类号： O539 文献标志码： A doi : 10.11884/HPLPB202133.200128Progress on high energy density physics experiments with pinch devicesHuang Xianbin ， Xu Qiang ， Wang Kunlun ， Ren Xiaodong ， Zhou Shaotong ， Zhang Siqun ， Cai Hongchun ，Wang Guilin ， Zhang Zhaohui ， Jia Yuesong ， Sun Qizhi ， Liu Pan ， Yuan Jianqiang ，Li Hongtao ， Wang Meng ， Xie Weiping ， Deng Jianjun（Institute of Fluid Physics , CAEP , P. O. Box 919-108, Mianyang 621900, China ）Abstract ： The pinch devices based on pulsed power technique can produce extreme conditions of temperature,pressure, density and strong radiation in spatial scale of cm and time scale of 100 ns. Numerous high energy density physics experiments are carried out on the 10 MA level pulsed power facility constructed at Institute of Fluid Physics,CAEP, which utilize a wide range of load configurations. Z-pinch driven dynamic hohlraums produce high temperature radiation field required for conducting inertial confinement fusion (ICF) experiments. Characteristics of implosion dynamics of metallic foils and solid liners are investigated and presented. Implosions using medium and low Z materials produce considerable K-shell line emissions, which are used to perform X-ray thermo-mechanical effect experiments. Magnetically driven isentropic compression and shock loading provide new experimental capabilities for research on dynamic materials properties. Ring diodes and reflex triodes are adopted to produce large X-ray or gamma-ray dose (rate) from bremsstrahlung. Magnetically driven radial metallic foils are used to simulate the formation of stellar jets and its radiation relevant to astrophysics. Additionally, experimental results of formation of preheated magnetized plasma target on a field reverse configuration (FRC) magnetized target fusion device are presented.Key words ： pulsed power ； high energy density physics ； Z-pinch ； inertial confinement fusion ； dynamic material properties ； field reverse configuration高能量密度状态是指物质被加热到大于1011 J/m 3的能量密度状态，或者被压缩到压强大于100 GPa 的高压状态[1]。

Harvesting Solar Energy from Space从太空捕获太阳能

Harvesting Solar Energy from Space从太空捕获太阳能作者：马泰奥·切里奥蒂/文陈俭贞/译来源：《英语世界》2024年第06期The idea of space-based solar power （SBSP）—using satellites to collect energy from the sun and “beam” it to collection points on Earth—has been around since at least the late 1960s. Despite its huge potential， the concept has not gained sufficient traction1 due to cost and technological hurdles.太空太阳能是指利用卫星从太阳收集能量，并将其“传送”到地球上的收集点。

这一概念至少在20世纪60年代末就出现了。

然而，尽管潜力巨大，由于成本和技术难题，太空太阳能尚未获得足够的关注。

Can some of these problems now be solved？ If so， SBSP could become a vital part of the world’s transition away from fossil fuels to green energy.目前能否解决部分成本和技术难题？如果可以，太空太阳能可能成为全球能源从化石燃料向绿色能源过渡的关键一環。

We already harvest energy from the sun. It’s collected directly through what we generally call solar power. This comprises different technologies such as photovoltaics2 （PV） and solar-thermal energy. The sun’s energy is also gathered indirectly： wind energy is an example of this， because breezes are generated by uneven heating of the atmosphere by the sun.我们已经从太阳获得了能量。

瓦形磁铁的退磁因子

瓦形磁铁的退磁因子英文回答：The demagnetization factor of a V-shaped magnet refers to the extent to which the magnet loses its magnetic properties over time. This factor is influenced by various factors, including the material composition of the magnet, its shape, and the external conditions it is exposed to.One of the main factors that affects the demagnetization factor of a V-shaped magnet is the material it is made of. Different materials have different magnetic properties and can retain their magnetism to varying degrees. For example, a magnet made of neodymium, which is a type of rare-earth magnet, has a high demagnetization factor and can lose its magnetism relatively quickly. On the other hand, a magnet made of ceramic or Alnico, which are commonly used in V-shaped magnets, has a lower demagnetization factor and can retain its magnetism for a longer period of time.Another factor that affects the demagnetization factor of a V-shaped magnet is its shape. The V-shaped design of the magnet can help to concentrate the magnetic field, making it stronger and more resistant to demagnetization. This is because the shape allows for a greater magneticflux density, which is the measure of the strength of the magnetic field. In contrast, a magnet with a different shape, such as a bar magnet or a disc magnet, may have a lower demagnetization factor due to the distribution of the magnetic field.External conditions, such as temperature and exposure to external magnetic fields, can also affect the demagnetization factor of a V-shaped magnet. High temperatures can cause the magnet to lose its magnetism more quickly, while exposure to strong external magnetic fields can interfere with the alignment of the magnetic domains within the magnet, leading to demagnetization.In conclusion, the demagnetization factor of a V-shaped magnet is influenced by factors such as the materialcomposition, shape, and external conditions. Understanding these factors can help in selecting the right magnet for a specific application and ensuring its long-term performance.中文回答：瓦形磁铁的退磁因子指的是磁铁随着时间的推移失去磁性的程度。

维诺德·科斯拉

方式进行绿色事业不可行，要成功必须大胆实验。
目前，曾被科斯拉戏称是“轻率的科学试验”的
投资，已孕育出了可以把煤转换成天然气的巨点能
源公司(GreatPoint Energy)、拥有新型玻璃产品的
Soladigm公司、生产高效能发动机的生态马达公司
(EcoMotors)、节能照明设备企业Soraa等知名公司。
引入欧洲之前，我会先咨询他的意见。我需要他提出
建议。”
科斯拉始终笃信科技的力量，“科学实验才是解
决全球气候问题的关键因素，而不是其他附加的东
西。”
整理/陈博
94 WORLD ENVIRONMENT 2016年第1期总第158期
Copyright©博看网 . All Rights Reserved.
风险投资领域钱生钱的模式，被很多人看来包含
着赤裸裸的资本主义逐利精神，科斯拉也被很多人
质疑。贝宝(PayPal)的合伙创始人亿万富翁皮特·泰
尔(Peter Thiel)曾公开质疑称，“ 清洁技术其实是
一场灾难，现在连硅谷的投资家们都很少谈论它了。
在交通和清洁能源上的失败表明了清洁能源政策的
失败。”但科斯拉对此不屑一顾，他的回应简洁有力，
“我要挑战任何认为清洁能源科技是一场灾难的人”，
“清洁技术必将提供一个比硅谷已有的传统市场大许
多倍的新市场。”
科斯拉风险投资公司聘请了英国前首相托尼·布
莱尔担任公司顾问，以为了能在全球范围内更好地推
广清洁技术。科斯拉说:“托尼的加盟，将使我们这些
在硅谷的技术呆子们获得更大的帮助。在将某项技术
2009年9月，科斯拉风险投资公司推出总额11亿美元的“绿色基金”，用于促进可再生能源和其他清洁能源技术的发展，该基金是有史以来针对清洁能源的最大ቤተ መጻሕፍቲ ባይዱ模基金、全球最大的清洁技术投资基金之一，目前该基金募资已超过10亿美元。

Solar-stellar astrophysics and dark matter

Solar-stellar astrophysics and dark matter Sylvaine Turck-Chièze;Ilídio Lopes【期刊名称】《天文和天体物理学研究》【年(卷),期】2012(012)008【摘要】In this review,we recall how stars contribute to the search for dark matter and the specific role of the Sun.We describe a more complete picture of the solar interior that emerges from neutrino detections,gravity and acoustic mode measurements of the Solar and Heliospheric Observatory (SOHO) satellite,becoming a reference for the most common stars in the Universe.The Sun is a unique star in that we can observe directly the effect of dark matter.The absence of a signature related to Weakly Interacting Massive Particles (WIMPs) in its core disfavors a WIMP mass range below 12 GeV.We give arguments to continue this search on the Sun and other promising cases.We also examine another dark matter candidate,the sterile neutrino,and infer the limitations of the classical structural equations.Open questions on the young Sun,when planets formed,and on its present internal dynamics are finally discussed.Future directions are proposed for the next decade:a better description of the solar core,a generalization to stars coming from seismic missions and a better understanding of the dynamics of our galaxy which are all crucial keys for understanding dark matter.【总页数】32页(P1107-1138)【作者】Sylvaine Turck-Chièze;Ilídio Lopes【作者单位】CEA/IRFU/Service d'Astrophysique, AIM, CE Saclay, 91191 Gif sur Yvette, France;Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Universidade Técnica de Lisb oa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal;Departamento de Física, Escola de Ci(e)ncia e Tecnologia, Universidade de(E)vora, Colégio Luis António Verney, 7002-554(E)vora, Portugal【正文语种】中文【相关文献】1.Dark Matter: Astrophysical Evidence and Constraints [J], GONG Yan; CHEN Xuelei2.Astrophysics and Dark Matter Theory [J], Auguste Meessen3.Dark Matter Cosmology and Astrophysics [J], Vladimir S. Netchitailo4.Physical Reality and Essence of Imaginary Numbers in Astrophysics: Dark Matter, Dark Energy, Dark Space [J], Alexander Alexandrovich Antonov5.Astrophysical and Cosmological Probes of Dark Matter [J], Matts Roos因版权原因，仅展示原文概要，查看原文内容请购买。

粒子在磁场中的能量

粒子在磁场中的能量：概念、计算、辐射和应用本文主要介绍了粒子在磁场中的能量的概念和计算方法，以及一些相关的物理现象和应用。

首先，我们回顾了磁场对带电粒子的洛伦兹力和广义势能的作用，以及磁场中带电粒子的运动方程和拉格朗日函数。

其次，我们介绍了同步辐射和回旋辐射这两种重要的磁场中带电粒子的辐射机制，以及它们的功率和谱分布等特性。

最后，我们举例说明了磁场中带电粒子的能量在同步加速器、天体物理和核聚变等领域的应用和意义。

一、磁场对带电粒子的作用1.1 洛伦兹力当一个带电粒子以速度v在电场E和磁场B中运动时，它所受到的力称为洛伦兹力（Lorentz force），其表达式为：F=q(E+v×B)其中q是粒子的电荷量，×表示向量叉乘。

洛伦兹力可以分解为两部分：一部分是电场力F E=q E，它沿着电场方向作用于粒子；另一部分是磁场力F B=q v×B，它垂直于粒子速度和磁场方向作用于粒子。

由于磁场力垂直于粒子速度，所以它不改变粒子的动能，只改变粒子的运动方向。

因此，磁场不对带电粒子做功，也就是说，磁场不改变带电粒子的能量。

1.2 广义势能虽然磁场不对带电粒子做功，但是我们仍然可以定义一个广义势能（generalized potential energy）来描述磁场对带电粒子的作用。

广义势能是一个含有速度的势能，它可以使得带电粒子在电磁场中的运动方程仍然具有保守体系拉格朗日方程（Lagrange equation）的形式。

为了得到广义势能，我们首先要引入两个重要的物理量：电磁场的标势（scalar potential）φ和矢势（vector potential）A。

它们是由麦克斯韦方程组（Maxwell equations）导出的两个标量函数和一个矢量函数，可以表示为：B=∇×AE=−∇φ−∂A ∂t其中∇表示梯度算符，×表示向量叉乘。

利用标势和矢势，我们可以将洛伦兹力写成如下的形式：F=q(−∇φ−∂A∂t+v×(∇×A))为了将洛伦兹力写成广义势能的形式，我们可以将其分量形式写出来，例如x方向的分量为：F x=q(−∂φ∂x−∂A x∂t+v y(∂A y∂x−∂A x∂y)−v z(∂A x∂z−∂A z∂x))我们可以发现，上式中的每一项都可以表示为一个函数U的偏导数，即：F x=−q ∂U∂x+qdd t∂U∂v x其中：U=φ−A⋅v 这就是带电粒子在电磁场中的广义势能，而粒子的拉格朗日函数则为：L=12mv2−qφ+q A⋅v上式表明，运动带电粒子的动力动量（kinetic momentum）和磁势动量（magnetic potential momentum）之和p（在分析力学中称为正则动量（canonical momentum））是守恒的。

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a r X i v :a s t r o -p h /0610395v 1 13 O c t 2006Astronomy &Astrophysics manuscript no.cuvir cESO 2008February 5,2008Stellar magnetosphere reconstruction from radio dataMulti-frequency VLA observations and 3D-simulations of CU VirginisP.Leto 1,C.Trigilio 2,C.S.Buemi 2,G.Umana 2,and F.Leone 21INAF -Istituto di Radioastronomia Sezione di Noto,CP 161,Noto (SR),Italy2INAF -Osservatorio Astroﬁsico di Catania,Via S.Soﬁa 78,95123Catania,ItalyReceived;AcceptedABSTRACTAims.In order to fully understand the physical processes in the magnetospheres of the Magnetic Chemically Peculiar stars,we performed multi-frequency radio observations of CU Virginis.The radio emission of this kind of stars arises from the interaction between energetic electrons and magnetic ﬁeld.Our analysis is used to test the physical scenario proposed for the radio emission from the MCP stars and to derive quantitative information about physical parameters not directly observable.Methods.The radio data were acquired with the VLA and cover the whole rotational period of CU Virginis.For each observed frequency the radio light curves of the total ﬂux density and fraction of circular polarization were ﬁtted using a three-dimensional MCP magnetospheric model simulating the stellar radio emission as a function of the magnetospheric physical parameters.Results.The observations show a clear correlation between the radio emission and the orientation of the magnetosphere of this oblique rotator.Radio emission is explained as the result of the acceleration of the wind particles in the current sheets just beyond the Alfv´e n radius,that eventually return toward the star following the magnetic ﬁeld and emitting radiation by gyrosyncrotron mechanism.The accelerated electrons we probed with our simulations have a hard energetic spectrum (N (E )∝E −2)and the acceleration process has an e ﬃciency of about 10−3.The Alfv´e n radius we determined is in the range of 12−17R ∗and,for a dipolar ﬁeld of 3000Gauss at the magnetic pole of the star,we determine a mass loss from the star of about 10−12M ⊙yr −1.In the inner magnetosphere,inside the Alfv´e nradius,the conﬁned stellar wind accumulates and reaches temperatures in the range of 105−106K,and a detectable X-ray emission is expected.Key words.stars:chemically peculiar –stars:circumstellar matter –stars:individual:CU Vir –stars:magnetic ﬁeld –stars:mass loss –radiocontinuum:stars1.IntroductionMagnetic Chemically Peculiar (MCP)stars are characterized by periodic variability of the e ﬀective magnetic ﬁeld through the stellar rotational period.The magnetic ﬁeld topology of this kind of star has been commonly regarded as a magnetic dipole tilted with respect to the rotation axis (Babcock 1949;Stibbs 1950),even if MCP stars with a multipolar magnetic ﬁeld are also known (Landstreet 1990;Mathys 1991).In some cases,MCP stars are characterized by an anisotropic stellar wind (Shore et al.1987;Shore &Brown 1990),as a consequence of the wind interaction with the dipo-lar magnetic ﬁeld (Shore 1987).The resulting magnetosphere is structured in a “wind zone”at high magnetic latitudes,where the gas ﬂows draw the magnetic ﬁeld out to open structures,and a “dead zone”,where the magnetic ﬁeld topology is closed and the gastrapped.2P.Leto,et al.:Stellar magnetosphere reconstruction from radio dataTable1.Results of the observations.For each observing scan,the mean UT time,the totalﬂux density(Stokes I)at the three observed frequency(I5,I8.4and I15),the corresponding errors(σ)and the circular polarizedﬂux density,Stokes V(V5,V8.4and V15),are reported:UT I5(σ)V5(σ) UT I8.4(σ)V8.4(σ) UT I15(σ)V15(σ)[mJy][mJy][mJy][mJy][mJy][mJy]00:30:452.78(0.05)<3σ(0.05)01:37:003.18(0.04)<3σ(0.04)02:51:504.1(0.1)<3σ(0.1)01:23:053.27(0.05)0.32(0.05)02:36:553.87(0.04)<3σ(0.04)03:51:354.3(0.1)<3σ(0.1)02:22:553.64(0.04)<3σ(0.04)03:38:504.40(0.04)<3σ(0.04)04:51:253.4(0.1)<3σ(0.1)03:22:454.13(0.04)<3σ(0.04)04:36:354.42(0.03)<3σ(0.03)05:51:203.3(0.1)<3σ(0.1)04:22:354.44(0.04)<3σ(0.04)05:36:303.69(0.03)<3σ(0.03)06:51:152.1(0.1)<3σ(0.1)05:22:253.48(0.04)<3σ(0.04)06:36:202.85(0.03)<3σ(0.03)07:44:203.0(0.1)<3σ(0.1)06:22:152.78(0.04)<3σ(0.04)07:30:252.85(0.04)0.22(0.04).........07:18:553.96(0.05)0.58(0.05)..................08:13:453.57(0.05)0.27(0.05)..................02:10:154.87(0.04)0.43(0.04)02:23:404.85(0.03)0.77(0.03)02:38:103.3(0.1)0.4(0.1)03:08:354.87(0.04)0.37(0.04)03:21:354.97(0.03)0.56(0.03)03:35:553.0(0.1)<3σ(0.1)04:06:254.68(0.04)0.34(0.04)04:19:254.52(0.03)0.57(0.03)04:33:453.6(0.15)<3σ(0.15)05:04:503.73(0.04)<3σ(0.04)05:18:203.50(0.04)0.28(0.04)05:32:453.3(0.15)<3σ(0.15)06:03:353.79(0.04)<3σ(0.04)06:17:053.88(0.04)<3σ(0.04)06:31:353.4(0.15)<3σ(0.15)07:02:303.98(0.04)<3σ(0.04)07:15:154.01(0.04)<3σ(0.04).........07:54:304.38(0.05)<3σ(0.05)..................01:21:353.95(0.05)<3σ(0.05)01:35:054.31(0.04)−0.14(0.04)02:47:253.3(0.1)<3σ(0.1)02:19:554.10(0.04)<3σ(0.04)02:32:554.18(0.04)−0.21(0.04)03:45:152.5(0.1)<3σ(0.1)03:17:453.47(0.04)<3σ(0.04)03:30:453.54(0.03)<3σ(0.03)04:44:102.7(0.1)<3σ(0.1)04:16:053.12(0.04)<3σ(0.04)04:29:353.05(0.03)0.16(0.03)05:43:003.3(0.1)<3σ(0.1)05:15:053.28(0.04)0.50(0.04)05:28:253.58(0.03)0.39(0.03)06:41:503.7(0.1)<3σ(0.1)06:13:554.38(0.04)0.44(0.04)06:27:204.33(0.03)0.53(0.03).........07:09:304.69(0.04)0.43(0.04)07:20:554.67(0.04)0.93(0.04).........riodically variable.The conﬁrmation of this hypothesis comes from the observations of HD37017and HD37479(Leone& Umana1993)and of HD133880(Lim et al.1996),performed at 5GHz,that revealed the presence of rotationalﬂux modulation. In particular,the observedﬂux light curves of HD37017and HD37479,which are characterized by a simple dipolar mag-neticﬁeld,show a radio emission minimum coincident with the zero of the longitudinal magneticﬁeld,whereas the emission is maximum at the magneticﬁeld extrema.Among radio MCP stars,only CU Virginis(HD124224)is characterized by a strong1.4GHzﬂux enhancement around phases0.4and0.8,with a right hand circular polarization of almost100%(Trigilio et al.2000,TLL00).This discovery has been explained in terms of Electron Cyclotron Maser Emission (ECME)from energetic electrons accelerated in the current sheets near the Alfv´e n surface(where the thermal plus kinetic plasma pressure equals the magnetic one)and reﬂected out-ward by magnetic mirroring in the inner magnetospheric lay-ers.In a previous paper(Trigilio et al.2004,TLU04),we devel-oped a three-dimensional numerical model of the radio emis-sion from MCP stars with a dipolarﬁeld.On the basis of suc-cessfull simulated5GHzﬂux light curves of HD37017and HD37479,whose study allowed us to conﬁrm the qualitative scenario proposed to explain the origin of non-thermal radio emitting electrons.We showed that the combined eﬀect of a tilted dipolar magnetic topology and the presence of a thermal plasma trapped in the“dead-zone”can produce the observed phase modulation of the stellar radio emission.In this paper we present the multifrequency microwave ob-servations of CU Virginis,a well studied Si-group MCP star. To investigate the physical conditions of the stellar magneto-sphere,the radio light curves of CU Vir are compared with the results of the numerical simulations performed using our3D model.We present here an implementation of our code to also treat circular polarization.2.Observations and data reductionThe observations were carried out using the VLA1in three dif-ferent runs,on June02,07and12,1998.Each run was ap-proximately eight hours long.We observed at four frequencies (1.4,5,8.4and15GHz)using two independent and contigu-ous bands of50MHz in Right and Left Circular PolarizationsP.Leto,et al.:Stellar magnetosphere reconstruction from radio data3Fig.1.Top panel:e ﬀective magnetic ﬁeld of CU Vir versus rotational phase (triangles:data by Borra &Landstreet 1980;squares:data by Pyper et al.1998).Other panels:phase mod-ulation of Stokes I and Stokes V ﬂux density at 15,8.4and 5GHz.For comparison,the 1.4GHz Stokes V (lowest panel)by TLL00is reported.The three days of observations are distin-guished with di ﬀerent symbols to point out the repeatability of the radio emission in time.(RCP and LCP).The observations were performed using the entire array (conﬁguration array moving A →B)alternating all the frequencies.Because of the ≈0.52d rotational period and with the aim to obtain a complete rotational phase coverage,we assumed at any frequency an observing cycle consisting of ≈10minutes on source,preceded and followed by ≈2minutes on the phase calibrator (1354−021).To avoid redundancy in the phase cov-erage for each frequency,the observing sequence was changed in each run.The ﬂux density scale was determined by daily observa-tions of 3C286.The data were calibrated and mapped using the standard procedures of the Astronomical Image Processing System (AIPS).The ﬂux density and fraction of circular polar-ization were obtained by ﬁtting a two-dimensional Gaussian,task JMFIT,at the source position in the cleaned maps (sepa-rately for the Stokes I and Stokes V 2)integrated over the du-ration of each individual scan.As the uncertainty in the ﬂux density measurements we assume the r.m.s.of the map.Results are summarized in Table 1.The measurements performed at 1.4GHz have been presented elsewhere (TLL00).3.The radio behavior of CU VirIn Fig.1,for each observed frequency,we report the radio ﬂux density measured in both Stokes I and V versus the rotational phase.This was computed adopting the ephemeris referred to light minimum reported by Pyper et al.(1998):HJD =2435178.6417+0d.52067780E JD <24460000d .52070308E JD >2446000In the lowest panel of Fig.1the measures performed in Stokes V at 1.4GHz from TLL00are also displayed.The top panel of Fig.1shows the average longitudinal com-ponent of the magnetic ﬁeld as a function of the rotational phase (data are from Borra &Landstreet 1980and Pyper et al.1998).The ﬂux variability with the stellar rotational period sug-gests that the radio emission at 15,8.4and 5GHz arises from a stable co-rotating magnetosphere and that the radio source is optically thick.For Stokes I the radio emission minimum ap-pears to be coincident with the null magnetic ﬁeld (Φ≈0.4and Φ≈0.8),whereas the two maxima,clearly visible at 5and 8.4GHz,are related to stellar orientations coinciding with the two extrema of the stellar magnetic ﬁeld (Φ≈0.1and Φ≈0.6).Stokes V is detected at all the observed frequencies close to Φ≈0.1,whereas at Φ≈0.6the circular polarization is de-tected only at 8.4GHz.The circularly polarized ﬂux density reaches its positive (RCP)maximum value when the e ﬀective magnetic ﬁeld strength is also maximum.This means that ra-dio ﬂux emitted in a direction close to the magnetic north pole,where magnetic ﬁeld lines are mainly radially oriented (relative to the outside stellar surface),is partially right hand polarized.Negative values of Stokes V (LCP)have been detected only at 8.4GHz around Φ≈0.6,when the magnetic south pole is clos-est to the line of sight.The phase modulation of the Stokes I ﬂux density has been observed in other MCP stars at 5GHz (Leone 1991;Leone &Umana 1993;Lim et al.1996).Our dataset represents an ex-tension of previous studies for the (almost simultaneous)multi-frequency observation of both total and circular polarized ﬂux4P.Leto,et al.:Stellar magnetosphere reconstruction from radiodataFig.2.Schematic view of the magnetosphere of an MCP star assuming a central dipolar magnetic ﬁeld.The dashed line shows the Alfv´e n surface:the largest magnetic ﬁeld line de-limiting the middle magnetosphere is drawn with a dotted line outside the Alfv´e n surface.The length l represents the current sheets region where the non-thermal electrons are e ﬃciently accelerated.The inner magnetosphere is ﬁlled with hot thermal plasma and cold material accumulates in the form of a torus near the stellar surface.with a detailed phase coverage of the rotational period.This al-lows us to monitor the variations of an MCP star radio spectrum through its entire stellar rotation.On average the observed radio spectra are ﬂat with a slightly negative power law index α≈−0.1(I ν∝να).This,together with the low fraction of circular polarization (about 10%),supports the idea that non-thermal gyrosynchrotron from a non-homogeneous source is responsible for the observed ra-dio emission.4.The modelOur 3-D model samples the magnetosphere of the star in a three dimensional grid,assumes a set of physical parameters,com-putes emission and absorption coe ﬃcients for gyrosynchrotron emission,and solves the equation of transfer for polarized radi-ation in terms of Stokes I and V (appendix A).From the best ﬁt of the observed ﬂuxes,we determine the most probable physics of the magnetosphere.4.1.Basic pictureThe model was developed (TLU04)on the basis of the physi-cal scenario proposed by Andr´e et al.(1988)and Linsky et al.(1992).The model involves the interaction between the dipolar magnetic ﬁeld and the stellar wind resulting in the formation of “current sheets”outside the equatorial region of the Alfv´e nTable 2.Adopted stellar parameters for CU Virginis.Distance [pc]D 80†Stellar Radius [R ⊙]R ∗ 2.2a Polar Magnetic Field [Gauss]B p 3000d Rotation Axis Inclination [degree]i 43d Magnetic Axis Obliquity [degree]β74dP.Leto,et al.:Stellar magnetosphere reconstruction from radio data5 Table3.Input parameters of the3-D modelSymbol Range Simulation step Size of Alfv´e n radius[R∗]r A6–30∆r A=1Thickness of magnetic shell[R∗]l0.3–30∆log l=0.05Relativistic electron density[cm−3]n r1–107∆log n r=0.25Relativistic electron energy power-law indexδ2–3∆δ=0.5Temperature of the trapped thermal plasma at stellar surface[K]T p0104–107∆log T p=1Electron density of the thermal plasma at stellar surface[cm−3]n p0108–1011∆log n p=0.225Cross-sectional size of the Cold Torus[R∗]d ct1–6∆d ct=1Temperature of the plasma of the Cold Torus[K]T ct103–105∆log T ct=0.25 Electron density number of the plasma in the Cold Torus[cm−3]n ct109–1012∆log n ct=0.5r A12–17[R∗]δ2d ct5[R∗]l/r A0.05–0.2n r∝r A/l0.88–3.54[×103cm−3]n p0=105.95T0.68p0n ct≥105.95T0.68ct6P.Leto,et al.:Stellar magnetosphere reconstruction from radio dataparison between CU Vir observed and computedﬂux density and degree of circular polarization,as a function of rotational phase.The free parametersδand d ct are determined with an un-certainty smaller than the simulation steps.Weﬁnd acceptablesolutions for r A in the range12–17R∗,l in0.05–0.2r Aand n r in0.88×103–3.54×103cm−3.We note that the rela-tion n r∝r A/l holds(Table4).An important conclusion canbe drawn:the column density of the relativistic electrons at theAlfv´e n radius is univocally determined by r A.For the diﬀerentvalues of the Alfv´e n radius deduced from our simulations thecolumn density is in the range3.2×1014−4.6×1014cm−2.Regarding the physical properties of the thermal plasmatrapped in the inner magnetosphere,we found that the valuesof the electron number density and temperature that accountfor the observed spectral index are related asn p0=105.95T0.68p0,(1)while for the plasma in the cold torusn ct≥105.95T0.68ct.In terms of free-free absorption coeﬃcients(Dulk1985),κν=9.7810−3n22× 18.2+38π= 1P.Leto,et al.:Stellar magnetosphere reconstruction from radio data7 Table5.Results for wind,mass loss and inner magnetosphere:as a function of the Alfv´e n radius r A,the spherical wind massloss rate˙M,the eﬀective mass loss˙M act and the number densityof the electrons of the wind at the Alfv´e n point n w(r A)are re-ported.In the last two columns,temperature(T p0)and numberdensity(n p)at the base of the magnetosphere are also reported.a)v∞=400km s−1121.610−106.810−12 3.904.941041.40109 131.010−103.910−12 2.093.391041.08109 146.410−112.310−12 1.172.371048.54108 154.310−111.410−120.681.721046.89108 162.910−119.210−130.411.261045.58108 172.010−116.010−130.250.941044.58108r A˙M˙M act n w(r A)T p0n p[R∗][M⊙yr−1][M⊙yr−1][106cm−3][K][cm−3]c)v∞=800km s−1122.410−101.010−11 2.919.541042.17109 131.610−106.310−12 1.626.801041.73109 141.010−103.610−120.944.691041.35109 157.210−112.410−120.563.551041.12109 165.010−111.610−120.352.641049.18108 173.610−111.110−120.222.021047.661088P.Leto,et al.:Stellar magnetosphere reconstruction from radiodataFig.6.Simulated maps for stellar orientations associated with the radio light curve extrema.On the left side the corresponding radio maps are displayed;the theoretical bightness spatial distribution is averaged over half the rotational period and convolved with the1mas beam of the VLBI array.The contours are10%,20%,30%,50%,70%,90%of the peakbrightness.Fig.5.Top panels:Maps,as a functions of i andβ,of the nor-malizedχ2obtained for the light curves at8.4GHz,totalﬂux(left)and fraction of circular polarization(right).Theχ2min-ima are respectively≈2and≈1.6.Bottom panel:product ofthe two top panels.Kushinig et al.1999;TLL00;Glagolevskij&Gerth2002)can-not be neglected.A simple dipole provides a symmetric totalﬂux light curve and an enhancement of the fraction of polar-ization when the line of sight is close to the magnetic pole,where the magnetic lines are almost parallel.In the presenceof multipolar components the radioﬂux light curves would notbe symmetric and the fraction of the polarization would be re-duced.6.DiscussionIn the following we will analyze physical information aboutthe stellar magnetosphere that can be inferred from the resultsof our simulations.6.1.The acceleration processThe convergence of the value of the spectral index of the emit-ting electron distribution(N(E)∝E−δ)towardδ=2indicatesthat the acceleration process occurs in the current sheets justoutside the Alfv´e n radius.This value agrees with the one de-rived in the case of solarﬂares by Zharkova&Gordovskyy(2005),who found a spectral indexδ=2for the non-thermalelectrons accelerated in the neutral reconnecting current sheetsof solar magnetic loops.In addition,from the ratio between n r(Table4)and the density of the electrons of the wind at theP.Leto,et al.:Stellar magnetosphere reconstruction from radio data9 Alfv´e n point n w(r A)(Table5),we can estimate that the eﬃ-ciency of the acceleration process for non-thermal electrons is2×10−3±1.The eﬃcency inferred by our analysis is consis-tent with the acceleration eﬃciency in large stationary unstablecurrent sheets associated with coronal loops during solarﬂares(Vlahos et al.2004).6.2.The radio emitting regionWe investigated the possibility of discrimining among the pre-vious possible values of the Alfv´e n radius by using high an-gular resolution radio observations in the future.In Fig.6thebrightness spatial distributions at8.4GHz obtained for the ex-treme values of r A(respectively12and17R∗)are shown.Thesimulated radio maps have been calculated for three rotationalphases:the stellar orientations that show the north and southpoles,associated with the two maxima and the orientation thatgives a null eﬀective magneticﬁeld,associated with the mini-mum of the radio light curve.In the right panel of Fig.6,thediﬀerent extension of the radio source for the two cases an-alyzed is clearly visible.However such a diﬀerence is not soobvious when looking at the radio emission arising from re-gions near the stellar surface,where the highest fraction of themagnetospheric radio emission originates.For the Very Long Baseline Interferometry(VLBI)tech-nique,that can be used to map CU Vir at milli arcsecond scales,we derived two“synthetic”maps at VLBI resolution,shown onthe left side of Fig.6,obtained as the average of hypothetical8hours observation around the stellar phase coinciding withthe null eﬀective magneticﬁeld,convolved with a Gaussian1mas beam.It is clear that the present capability of VLBI obser-vations does not allow us to discriminate between the extremevalues of the Alfv´e n radius of CU Vir predicted by our model.6.3.The thermal plasmaThe physical condition in the inner magnetosphere play an im-portant role in the emerging radioﬂux because of the free-freeabsorption by the plasma,which aﬀects the modulation of theradio light curves and the spectrum of the source.The compar-ison between our model prediction and multifrequency obser-vations reveals the presence of a torus of material colder anddenser than the trapped thermal plasma.This is necessary toreproduce the correct scale of the totalﬂux density in the15GHz light curve of CU Vir.The electron number density(n ct)and temperature(T ct)of the plasma of the cold torus,are withinthe shaded area of the plane log T−log n shown in Fig.4,wherethe optical depth of the cold torus is higher than1at15GHz.Higher frequency measurements(for example22and43GHz)could characterize the spatial distribution of the thermal plasmain the deep magnetospheric regions,near the stellar surface.The temperature and density of the thermal plasma trappedin the inner magnetosphere are assigned for a given Alfv´e n ra-dius and wind velocity(Table5).As a by-product of our anal-ysis,we estimate the X-ray emission from the thermal plasmatrapped in the stellar inner magnetosphere of CU Vir as a func-tion of r A and v∞.Following the same procedure described inFig.7.Predicted X-rayﬂuxes of the inner magnetosphere ofCU Vir for the solutions of our3-D model.TLU04,for each element of the3D cubic grid that samplesthe magnetosphere,we computed the thermal bremsstrahlungemission coeﬃcients and the emerging power integrated be-tween0.1and10keV,in the typical energy range of X-raytelescopes like Chandra and XMM.The resulting X-rayﬂuxesat the Earth are displayed in Fig.7.The stellar X-ray emission is a function of the size of theAlfv´e n surface(Fig.7)and,in particular,it decreases as theAlfv´e n radius increases.This is a consequence of the lowertemperature and density of the plasma in the inner magneto-sphere for increasing r A.For the same reason,lower wind ve-locities cause a lower X-ray emission.On the basis of the values derived from our calculations,we conclude that the X-ray emission from CU Vir is belowthe detection limit of the ROSAT all sky survey(the averagebackground at the position of CU Vir in the RASS is higherthan10−12erg cm−2s−1).Nevertheless,for exposure times of afew tens of kilo-seconds,Chandra and XMM can reach an X-ray detection limit close to10−15erg cm−2s−1,which is lowerthan the X-rayﬂuxes predicted from several model solutions.Within our model,measurement of the X-rayﬂux of CU Vircould place an important constraint on the physical conditionin the magnetosphere.7.ConclusionThe radio magnetosphere of CU Vir has been extensively stud-ied using of theﬁrst multifrequency VLA observations,cov-ering the entire rotational period,for both the totalﬂux den-sity(Stokes I)and the circular polarization(Stokes V).We havesuccessfully modeled the observedﬂux modulation and the cir-cular polarization light curves using the3D model developedby us(TLU04),modiﬁed to resolve the circular polarizationintensity.We pointed out the importance of multi-frequency and dualpolarization observations throughout the rotational period togain insight into the physical conditions of the circumstellarenvironments surrounding MCP stars.10P.Leto,et al.:Stellar magnetosphere reconstruction from radio dataOur results are:-We conﬁrm the physical scenario proposed by Andr´e et al.(1988)and Linsky et al.(1992)and the MCWS model pro-posed by Babel&Montermle(1997);-The size of the CU Vir inner magnetosphere has been con-strained in the range:r A=12−17R∗;-we evaluated the mass loss rate of CU Vir,which up to now was not determined for this star,to be about10−12M⊙yr−1; -the temperature of the thermal electrons trapped in the in-ner magnetosphere can reach105−106K and can give de-tectable X-ray emission;-the presence of an accumulation of cold and dense material around the star has been shown and limits for its size and physical conditions(temperature and density)are given; -the acceleration in the current sheets produces a non-thermal electron population with a hard energetic spectrum (N(E)∝E−δwithδ=2),and the acceleration process has an eﬃciency of about10−3.The limits of our model to reproduce all the observed fea-tures,for example the two peaks at phases≈0.4and≈0.85 observed in the5GHz light curve for the circular polarization and the shape of the light curves at15GHz,have been inter-preted respectively as due to the residual of the ECME mech-anism(responsible for the features previously observed at1.4 GHz,TLL00)and as evidence of a multipolar component in the magneticﬁeld of CU Vir.Acknowledgements.We thank the referee for his/her constructive crit-icism which enabled us to improve this paper.ReferencesAndr´e,P.,Montermle,T.,Feigelson,E.D.,Stine,P.C.,Klein,K.L.1988,ApJ,335,940Babcock,H.W.1949,Observatory,69,191Babel,J.1996,A&A,309,867Babel,J.,Montermle,T.1997,A&A,323,121Borra,E.F.,Landstreet,J.D.1980,ApJS,42,421Drake,S.A.,Abbot,D.C.,Bastian,T.S.,Bieging,J.H.,Churchwell,E., Dulk,G.,Linsky,J.L.1987,ApJ,322,902Dulk,G.A.1985,ARA&A,23,169European Space Agency1997,Hypparcos Catalogue SP-1200 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362,281(TLL00)Trigilio,C.,Leto,P.,Umana,G.,Leone,F.,Buemi,C.S.2004,A&A, 418,593(TLU04)Usov,V.V.,Melrose,D.B.1992,ApJ,395,575Vlahos,L.,Isliker,H.,Lepreti,F.2004,ApJ,608,540Zharkova,V.V.,Gordovskyy,M.2005,MNRAS,356,1107Appendix A:Calculation of circular polarization The circularly polarized intensity may be obtained using the relation,given by Ramaty(1969):V=2 I+aθ+1+aθ−2 (A.1)where I±are solutions of the radiative transfer equation for the ordinary(sign“+”)and extraordinary(sign“−”)modes(Klein &Trotter1984):dnθ±2=|cosψ±|nθ±∂θwithθthe angle between the wave vector and the magnetic ﬁeld.The equation A.2was numerically solved,along a path parallel to the line of sight,using the method developed by us in TLU04.In accordance with classical physics,for propagation paral-lel to the magneticﬁeld lines(θ=0and aθ±=±1),the ordinary mode is characterized by the electricﬁeld vector rotating in the sense of the electrons,counterclockwise in the case of a wave approaching the observer,therefore the polarization sense for the ordinary mode is LCP;conversely the extraordinary mode has a polarization sense RCP.VLA measurements of the wave circular polarization state are in accordance with the IAU and IEEE orientation/sign con-vention,unlike the classical physics usage.Therefore to com-pare our simulations with the VLA observations we have to change the sign of the result of equation A.1.。