PART I Basic theory for magnetics
Magnetic Isotope Theory of the Origin of Life on E
J. Chem. Chem. Eng. 10 (2016) 301-304doi: 10.17265/1934-7375/2016.06.007Magnetic Isotope Theory of the Origin of Life on EarthAibassov Yerkin1, Nakisbekov Narymzhan1, Yemelyanova Valentina1 and Savizky Ruben21. Research Institute of New Chemical Technologies and Materials, Kazakh National University Al-Farabi, Almaty 005012, Kazakhstan2. Columbia University, 3000 Broadway, New York, NY, 10027, USAAbstract: The authors have proposed a new of magnetic isotope theory of life on Earth. According to this theory the initial impetus for the beginning of the synthesis of organic compounds is the impact of electromagnetic radiation from the sun and energy radioactive isotopes.Key words: Theory of the origin of life on earth, magnetic field, radioactive isotope, synthesis organic compounds.1. IntroductionLife is one of the most complex phenomena of nature. The problem of the origin of life on Earth has long been haunted by many scientists [1-6]. Ever since man began to wonder, where was all alive, all this time been considered a set of hypotheses and assumptions about the origin of life.In this work, an opportunity to review and modify the theory of Oparin-Haldane as the most likely, is to make it further effect of the magnetic radiation and radioactive isotopes of energy.The authors first time offered to consider the effect of the magnetic field and the radioactivity to the first organic compounds in the origin of life on Earth.2. TheoryAt various times regarding the origin of life on Earth put forward the following three theories: the steady state of life, spontaneous and Oparin-Haldane’s “primordial soup”.Oparin suggested that solutions of high molecular compounds can be formed spontaneously increased concentration zone that is relatively separated from the external environment and may support communication with it. He called them coacervates.Corresponding author: Aibassov Erkin Zhakenovich, professor, research field: metal organic chemistry of uranium and thorium, As, Sb and Bi. According to his theory, the process to the origin of life can be divided into three stages: the emergence of organic substances; occurrence of protein; occurrenceof protein bodies. Planetary systems arose from the gas-dust material. Along with metals and metal oxides contained in it, hydrogen, ammonia, water and simple hydrocarbon—methane.Conditions for the start of the formation of protein structures have been established since the introductionof the primary ocean (broth). In the aquatic environment derivatives of hydrocarbons could be subjected to complex chemical changes and transformations. As a result of the complexity of the molecules could form more complex organic materials, namely carbohydrates.Science has shown that the application of ultraviolet rays can be artificially synthesized not only amino acids and other organic substances. According to the theory, a further step towards the emergenceof proteins could be the formation of coacervate drops. Molecules of water surrounded by a shell, joined together to form multimolecular complexes—coacervates. They also can occur by simply mixing a variety of polymers. Thus there is a self-assembly of polymer molecules in the formationof multimolecular. Drops were able to absorb substances from the outside on the type of open systems. Thus, coacervates can grow, multiply,exercise metabolism.All Rights Reserved.302In 1953, i mixture of H and began t temperature are formed. under vario evolution ca of solution (not reproduc 3. Results Electroma were predict magnetism, to date, the little studied investigate physicochem chemistry. Figs. 1 an Not only travel at theFig. 1 The e and magnetic shown in a veFig. 2 The f vertical plane in an experim H 2O, NH 3, CH to pass throu of 80 °C. It w Later also su ous conditio an occur whe (coacervates)ce itself.and Discus agnetic wave ted by the cla known as M magnetic ef d. Therefore, the effect o mical and th nd 2 show the is the wave o e speed of li electromagneti c fields. The fi ertical plane, a figure—plane-e, and the fluct Magneti ment Miller H 4, CO 2, CO i ugh her elec was found tha ugar nucleotid ons. Miller en fazovoobo . However, su ssiones as a gene assical laws o axwell’s equ ffects in chem the authors h of magnetic hermodynam e electromagn of electric and ight, but they ic oscillations igure—plane-p nd the fluctuat -polarized wavtuations of the ic Isotope Th —Urey placed in a closed ve ctric shocks at the amino a des were obta concluded osoblennom s uch a system eral phenome of electricity uations. Howe mistry have b have attempte effects on mic functions netic waves.d magnetic fi y have a lim can be represe polarized wave tions of the ma ve propagatingmagnetic field heory of the O d theessel at a acids ained that state m can enonand ever, been ed to the s in ieldsmitedorie whi vec dire the vec T whe F mov and left fiel osc orie dire T a gr I dire can ented in the fo e propagating agnetic field - i g from right td—in the horiz Origin of Life entation and ich can be i tor. The ele ection of wav wave propa tor E × B. Then we obtai ere, c is the sp From the v ving rectiline d down, while , but this pat d oscillating illating up a entation with ection is know Thus, the pola reat influence f the magne ection of the n go in the opp orm of self-pro from right to in the horizont to left. Fluctuazontal.on Eartha proportion immediately ectric field, ve propagatio agation in th in the followi ΔE/ΔB peed of light.viewpoint of early, the elec e the magneti ttern can be a right and le and down. T h a preferen wn as polariza arization of e e on the cours etic field and magnetic po posite directi opagating tran left. Fluctuat tal.ations in the e nate amount seen from t magnetic fi on are all ort he same dire ing equation: = c . f electromag ctric field can c field may v alternated wit eft, and a m This arbitrar nce to the ation (Fig. 3)lectromagnet se of chemica d enables to oles, whereas on.nsverse vibrati tions in the eleelectric field a t, E = c o B o ,the Poynting ield and the thogonal and ection as the :gnetic wave n fluctuate up vary right and th an electric magnetic field riness in the propagation ). tic waves has al reactions.o change the s the reaction ions of electric ectric field are re shown in a , g e d e e p d c d e n s e n ce a All Rights Reserved.Fig. 3 The pFig. 4 Chan a function ofThe theor problem o coacervate appeared eff shown that spontaneous and they m solutions”—among whi synthesis of organism. The impet RNA world moleculesw polarization of nging the direc the direction o ry has been un of accurate and the ge fective protei t the first sly from the li may enter i —colonies self ich were th lipids, and a tus for the dev d was the diswith enzymat Magneti f electromagnet tion of motion of the magnetic nable to offer reproductio enerations—s in structures. coacervates ipid synthesiz into symbios f-replicating he ribozyme community c velopment of scovery of ritic activity, a ic Isotope Th tic waves.n of the electron c field.r a solution to on—within single, rando However, it s were for zed abiogenic sis with “liv RNA molecu es catalyze can already ca f the theory o ibozymes—Rand therefore heory of the Ons aso the the omly was rmed cally, ving ules, the alled f the RNA e areableope bioc info crea DN auto cap T pos (ana NaN mag tem dos uran (e)It (2Fe,saltmix Origin of Life e to combine erate separatel chemical re ormation. Th atures were R NA, and the ocatalytic cy able of cataly The authors af sible for the a 1) In a 10 m alysis is nece NO 3, KHCO gnetic spectro mperature from e (from 5 m nium salts; (d the concentra t is possible t N NaCl +2) The water Cu, and othe t solution. Thxture of gases on Earth e the function ly proteins an eactions an hus, it is assu RNA-organis ey could be ycle formed yzing the synt ffirm, in the f authors to get mL test tube essary to pou O 3, NaHPO oscopy of the m 20 to 300 min to 60 m d) pressure (1ation of d- an to flow the Eq NH 4H 2PO 4 + H + KJ + ATP r soluble inor ers. The autho hen the soluti s: CO 2, CO, C ns that these nd DNA, that d storage umed that th sms without e the protot by the very thesis of their following exp t organic com e for NMR ur an aqueou O 4, UO 2(NO following op °C; (b) X-ra min); (c) conc 1 to 150 atm nd f-elements.q. (1):HCOOH + P → NH 2COO rganic salts o ors introduce ion was pass CH 4, H 2and N 303cells mostly is to catalyze of genetic e first living proteins and type of the y ribozymes r own copies.periment, it is mpounds. spectroscopy s solution of 3)2. Change ptions: (a) the ay irradiation centration of (weld vial));. ONa (1)f Na, K, Mg,e the uranium ed through a N 2.3y e c g d e s . s y f e e n f ; ), m a All Rights Reserved.Magnetic Isotope Theory of the Origin of Life on Earth 304It is possible to flow the Eq. (2):nCO2 + nH2O + hv → n(C6H12O6) (2) As a result of these experiments is necessary to pay attention to formation of an organic phase (NMR, IR and UV spectroscopy, etc.).3. ConclusionsThe authors affirm that the total dependence on the factors influencing the emergence of life on Earth, is described by the equation:Life = f (T, P, E, B, R),where, T is temperature, P is pressure, E is electrical field, B is magnetic fields, R is radiation.Thus, the authors have proposed a new of magnetic isotope theory of life on Earth. According to this theory the initial impetus for the beginning of the synthesis of organic compounds is the impact of electromagnetic radiation from the sun and energy radioactive isotopes. References[1]Lurquin, P. F. 2003. The Origins of Life and the Universe.Columbia University.[2]Rauchfuss, H. 2008. “Chemical Evolution and the Originof Life.” Springer 85-110.[3]Mulkidjanian, A. Y., and Galperin, M. Y. 2009. 1. On theOrigin of Life in the Zinc World. 2. Validation of theHypothesis on the Photosynthesizing Zinc Sulfide Edificesas Cradles of Life on Earth. Biology Direct.[4]Sugawara, T. 2011. “Self-Reproduction ofSupramolecular Giant Vesicles Combined with theAmplification of Encapsulated DNA.” Nature Chemistry1127.[5]Pons, M. L. 2011. “Early Archean Serpentine MudVolcanoes at Isua, Greenland, as a Niche for Early Life.”PNAS, Sept. 15.[6]Crick, F. “Life Itself: Its Origin and Nature.” Simon andSchuster 1981: 192.All Rights Reserved.。
部分物理类英文期刊缩写名称
参考文献所引用期刊常采用缩写名称. 下面列出了一些物理类论文所引用期刊, 其标准的缩写名称由黑体表示.Acta Chim ica Sin ica (化学学报)Acta Crystallogr aphicaActa Cytol ogicaActa Crystallogr aphica, Sect ion A: Crystal Physics, Diffraction, Theoretical and General CrystallographyActa Crystallogr aphica, Sect ion B: Structural Crystallography and Crystal ChemistryActa Phys icaActa Phys ica-Chim ica Sin ica (物理化学学报)Acta Phys ica AustriacaActa Phys ica Pol onicaActa Phys ica Sin ica-Ch inese Ed ition (物理学报)AcusticaAdv ances in Appl ied Mech anicsAdv ances in At omic and Mol ecular Phys icsAdv ances in Chem ical Phys icsAdv ances in Magn etic Reson anceAdv ances in Phys icsAdv ances in Quantum Chem istryAIP Conf erence Proc eedingsAkust icheskii Zh urnal [Sov iet Phys ics--- Acoust ics]Am erican J ournal of Phys icsAnal ytical Chem istryAnn als of Fluid Dyn amicsAnn als of Math ematicsAnn als of Phys ics (N ew Y ork)Annu al Rev iew of Nucl ear Sci enceAppl ied Opt icsAppl ied Phys ics Lett ersAppl ied Spectrosc opyAstron omical J ournalAstron omy and Astrophys icsAstrophys ical J ournalAstrophys ical J ournal, Lett ers to the EditorAstrophys ical J ournal, Suppl ement Ser iesAstrophys ical Lett ersAt omic Data and Nucl ear Data TablesAust ralian J ournal of Phys icsBell Syst em Tech nical J ournalBiogr aphical Mem oir s of Fell ows of the R oyal Soc ietyBiochem istryBiol ogy Lett ersBr itish J ournal of Appl ied Phys icsBull etin of the Acad emy of Sci ences of the USSR, Phys ical Ser ies (translation of Izvestiya Akademii Nauk SSSR, Seriya Fizicheskaya)Bull etin of the Am erican Astron omical Soc ietyBull etin of The Am erican Phys ical Soc ietyBull etin of the Astron omical Inst itutes of the Neth erlandsBull etin of the Chem ical Soc iety of J a p a nCan adian J ournal of Chem istryCan adian J ournal of Phys icsCan adian J ournal of Res earchChem ical J ournal of Chin ese U niversity (高等学校化学学报)Chem ical Phys icsChem ical Phys ics Lett ersChem ical Rev iewsChin ese Chem istry Lett ersChin ese J ournal of Chem istry (化学学报)Chin ese J ournal of Chem istry Phys ics (化学物理学报)Chin ese J ournal of Phys icsChin ese J ournal of Struct ural Chem istry (结构化学学报)Chin ese Phys icsChin ese Phys ics Lett ersChin ese Sci ence Bull etin (科学通报)Comments on Astrophys ics and Space Phys icsComments on At omic and Mol ecular Phys icsComments on Nucl ear and Part icle Phys icsComments on Plasma Phys ics and Controlled FusionComments on Solid State Phys icsCommun ications in Math ematical Phys icsCommun ications in Theor etical Phys icsCommun ications on Pure and Appl ied Math ematicsComput er Phys ics Commun icationsCryogenicsCzech oslovak J ournal of Phys icsDiscuss ions of the Faraday Soc ietyEarth and Planet ary Sci ence Lett ersElectron ics Lett ersExperientiaFields and QuantaFound ations of Phys icsHelv etica Chim ica ActaHelv etica Phys ica ActaHigh Temp erature ( USSR) (translation of Teplofizika Vysokikh Temperatur)IBM J ournal of Res earch and Dev elopmentIcarusIEEE J ournal of Quantum Electron icsIEEE Trans actions on Antennas and Propag ationIEEE Trans actions on Electron DevicesIEEE Trans actions on Inf ormation TheoryIEEE Trans actions on Instrum entation and Meas urementIEEE Trans actions on Magn eticsIEEE Trans actions on Microwave Theory and Tech niquesIEEE Trans actions on Nucl ear Sci enceIEEE Trans actions on Sonics and Ultrason icsInd ustrial and Eng ineering Chem istryInfrared Phys icsInorg anic Chem istryInorg anic Mater ials ( USSR) (translation of Izvestiya Akademii Nauk SSSR, Neorganicheskie Materialy) Instrum ents and Exp erimental Tech niques ( USSR) (translation of Pribory i Tekhnika Eksperimenta) Int ernational J ournal of Magn etismInt ernational J ournal of Quantum Chem istryInt ernational J ournal of Quantum Chem istry, Part 1Int ernational J ournal of Quantum Chem istry, Part 2Int ernational J ournal of Theor etical Phys icsJ a p a n ese J ournal of Appl ied Phys icsJ a p a n ese J ournal of Phys icsJETP Lett ers (translation of Pis'ma v Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki)J ournal de Chim ie Phys iqueJ ournal de Phys ique ( Paris)J ournal de Phys ique et le RadiumJ ournal of Appl ied Crystallogr aphyJ ournal of Appl ied Phys icsJ ournal of Appl ied Spectrosc opy ( USSR) (translation of Zhurnal Prikladnoi Spektroskopii)J ournal of Atmos pheric and Terr estrial Phys icsJ ournal of Atmos pheric Sci encesJ ournal of At omic and Mol ecular Phys ics (原子与分子物理学报)J ournal of Chem ical Phys icsJ ournal of Comput ational Phys icsJ ournal of Cryst al GrowthJ ournal of Fluid Mech anicsJ ournal of Geophys ical Res earchJ ournal of High Energy Phys icsJ ournal of Inorg anic and Nucl ear Chem istryJ ournal of Low Temp erature Phys icsJ ournal of Lumin escenceJ ournal of Macromol ecular Sci ence, [Part B] Phys icsJ ournal of Math ematical Phys icsJ ournal of Mol ecular Spectrosc opyJ ournal of Non-Cryst alline SolidsJ ournal of Nucl ear EnergyJ ournal of Nucl ear Energy, Part C: Plasma Physics, Accelerators, Thermonuclear ResearchJ ournal of Nucl ear Mater ialsJ ournal of Phys ical and Chem ical Ref erence DataJ ournal of Phys ical Chem istryJ ournal of Phys ics A: General PhysicsJ ournal of Phys ics and Chem istry of SolidsJ ournal of Phys ics B: At omic, Mol ecular and Opt ical Phys icsJ ournal of Phys ics: Cond ensed MatterJ ournal of Phys ics D: Appl ied Phys icsJ ournal of Phys ics E: Scientific InstrumentsJ ournal of Phys ics F: Metal PhysicsJ ournal of Phys ics ( Moscow)J ournal of Plasma Phys icsJ ournal of Polym er Sci enceJ ournal of Polym er Sci ence, Polym er Lett ers Ed itionJ ournal of Polym er Sci ence, Polym er Phys ics Ed itionJ ournal of Quant itative Spectrosc opy & Radiat ive TransferJ ournal of Res earch of the Nat iona l Bur eau of Stand ardsJ ournal of Res earch of the Nat iona l Bur eau of Stand ards, Sect ion A: Physics and ChemistryJ ournal of Res earch of the Nat iona l Bur eau of Stand ards, Sect ion B: Mathematical SciencesJ ournal of Res earch of the Nat iona l Bur eau of Stand ards, Sect ion C: Engineering and Instrumentation J ournal of Sci entific Instrum entsJ ournal of Sound and Vib rationJ ournal of Speech and Hear ing Disord ersJ ournal of Speech and Hear ing Res earchJ ournal of Stat istical Phys icsJ ournal of the Acoust ical Soc iety of Am ericaJ ournal of the Am erican Ceram ic Soc ietyJ ournal of the Am erican Chem ical Soc ietyJ ournal of the Am erican Inst itute of Electr ical Eng ineersJ ournal of the Audio Eng ineering Soc ietyJ ournal of the Chem ical Soc ietyJ ournal of the Electrochem ical Soc ietyJ ournal of the Mech anics and Phys ics of SolidsJ ournal of the Opt ical Soc iety of Am ericaJ ournal of the Phys ical Soc iety of J a p a nJ ournal of the R oyal Soc iety InterfaceJ ournal of Vac uum Sci ence and Technol ogyMater ials Res earch Bull etinMed ical Phys icsMem oirs of the R oyal Astron omical Soc ietyMol ecular Cryst als and Liq uid Cryst alsMol ecular Phys icsMon thly Not ices of the R oyal Astron omical Soc ietyNat iona l Bur eau of Stand ards ( U.S.), Circ ularNat iona l Bur eau of Stand ards ( U.S.), Misc ellaneous Publ icationNat iona l Bur eau of Stand ards ( U.S.), Spec ial Publ icationNature( London)Notes and Rec ords of the R oyal Soc ietyNucl ear Data, Sect ion ANucl ear Data, Sect ion BNucl ear FusionNucl ear Instrum entsNucl ear Instrum ents & MethodsNucl ear Phys icsNucl ear Phys ics ANucl ear Phys ics BNucl ear Sci ence and Eng ineeringOpt ica ActaOpt ics and Spectrosc opy ( USSR) (translation of Optika i Spektroskopiya)Opt ics Commun icationsOpt ics Lett ersOpt ics NewsOptik( Stuttgart)Philips Res earch Rep ortsPhilos ophical Mag azinePhil osophical Trans actions of the R oyal Soc iety of LondonPhil osophical Trans actions of the R oyal Soc iety A: Mathematical, Physical and Engineering Sciences Phil osophical Trans actions of the R oyal Soc iety B: Biological SciencesPhys ical Rev iewPhys ical Rev iew A: Atomic, Molecular, and Optical PhysicsPhys ical Rev iew B: Solid StatePhys ical Rev iew C: Nuclear PhysicsPhys ical Rev iew D: Particles and FieldsPhys ical Rev iew E: Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary TopicsPhys ical Rev iew Lett ersPhys ical Rev iew S pecial T opics - Accel erators and Beams (close up ST, without periods)Phys ica Status SolidiPhys ica Status Solidi A: Applied ResearchPhys ica Status Solidi B: Basic ResearchPhysica( Utrecht)Phys ics and Chem istry of SolidsPhys ics Lett ersPhys ics Lett ers APhys ics Lett ers BPhysics( N ew Y ork)Phys ics of FluidsPhys ics of Met als and Mettalogr aphy ( USSR) (translation of Fizika Metallov i Metallovedenie) Phys ics Teach erPhys ics TodayPlasma Phys icsProc eedings of the Cambridge Philos ophical Soc ietyProc eedings of the IEEEProc eedings of the IREProc eedings of the Nat iona l Acad emy of Sci ences of the U nited S tates of A mericaProc eedings of the Phys ical Soc iety, LondonProc eedings of the Phys ical Soc iety, London, Sect ion AProc eedings of the Phys ical Soc iety, London, Sect ion BProc eedings of the R oyal Soc iety of LondonProc eedings of the R oyal Soc iety A: Mathematical, Physical and Engineering SciencesProc eedings of the R oyal Soc iety B: Biological SciencesProg ress of Theor etical Phys icsPubl ications of the Astron omical Soc iety of the Pac ificRadiat ion Eff ectsRadiologyRadio Sci enceRCA Rev iewRep orts on Prog ress in Phys icsRev iew of Sci entific Instrum entsRev iew of Mod ern Phys icsRuss ian J ournal of Phys ical Chem istry (translation of Zhurnal Fizicheskoi Khimii)ScienceSci entific Am ericanSci ence in China Ser ies G (中国科学G辑)Sol ar Phys icsSolid State Commun icationsSolid-State Electron icsSpectrochim ica ActaSpectrochim ica Acta, Part A: Molecular SpectroscopySpectrochim ica Acta, Part B: Atomic SpectroscopySurf ace Sci enceTetrahedronTheor etica Chim ica ActaThin Solid FilmsTrans actions of the Am erican Crystallogr aphic Assoc iationTrans actions of the Am erican Geophys ical UnionTrans actions of the Am erican Inst itute of Min ing, Metall urgical and Pet roleum Eng ineers Trans actions of the Am erican Nucl ear Soc ietyTrans actions of the Am erican Soc iety for Met alsTrans actions of the Am erican Soc iety of Mech anical Eng ineersTrans actions of the Br itish Ceram ic Soc ietyTrans actions of the Faraday Soc ietyTrans actions of the Metall urgical Soc iety of AIMETrans actions of the Soc iety of Rheol ogyUltrasonicsZ eitschrift für Anal ytische Chem ieZ eitschrift für Angew andte Phys ikZ eitschrift für Anorg anische und Allg emeine Chem ieZ eitschrift für Astrophys ikZ eitschrift für Elektrochem ieZ eitschrift für Kristallogr aphie, Kristallgeom etrie, Kristallphys ik, Kristallchem ieZ eitschrift für Metallk un d eZ eitschrift für Naturforsch ungZ eitschrift für Naturforsch ung, Teil A: Physik, Physikalische Chemie, KosmophysikZ eitschrift für Phys ikZ eitschrift für Phys ik A: Atoms and NucleiZ eitschrift für Phys ik B: Condensed Matter and QuantaZ eitschrift für Phys ik C: Particles and FieldsZ eitschrift für Phys 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磁学基础
磁学基础－磁现象
东汉王充在《论衡》中写道： “司南之杓，投之于地，其柢指南”
8
磁学基础－磁现象
最初发现的磁体是被称为“天然磁 石”的矿物，其中含有主要成分为 Fe3O4，能吸引其他物体，很像磁铁.
9
磁学基础－磁现象
十八世纪三十年代一名英国商人，在一 次航行过程中，船只遭到雷击，在整理物 品时他惊奇的发现一箱铁质刀具竟然有了 磁性。后来，富兰克林听说此事，他用莱 顿瓶电击缝衣针，发现缝衣针也有了磁性。 这个故事说明什么？
电和磁之间存在着联 系，电流具有磁效应。
10
磁学基础－物质的磁性
磁与电究竟存在什么联系?
11
物质的磁性
环型电流的磁矩: m
磁矩的方向：右手螺旋定则确定
is
i
n
磁矩大小 = 电流强度· 回路所围面积
12
磁学基础－物质的磁性
磁性的起源 Origin of Magnetism
13
磁学基础－物质的磁性 电子的轨道磁矩和自旋磁矩
4
磁学基础－磁学发展的历史
在欧洲，公元1190年以前没有一点关于磁石能指方向 的史料，而在这一年航行于地中海的船上却确有了指 南针，很可能是由那时期进行中国和阿拉伯间贸易的 海船传去的。 法国物理学家库仑于1785年确立了静电荷间相互作用 力的规律——库仑定律之后，又对磁极进行了类似的 实验而证明：同样的定律也适用于磁极之间的相互作 用。 丹麦物理学家奥斯特在1820年发现，一条通过电流的 导线会使其近处静悬着的磁针偏转，显示出电流在其 周围的空间产生了磁场，这是证明电和磁现象密切结 合的第一个实验结果。
3
磁学基础－磁学发展的历史
这就是物理磁性读后感
这就是物理磁性读后感英文回答："This Is Physics: Magnetism" is a comprehensive and well-written introduction to the fundamental principles of magnetism. The author, J. Richard Gott, provides a clear and concise explanation of the basic concepts of magnetism, such as the magnetic field, magnetic poles, and the magnetic force. The book also includes a number of interesting historical anecdotes and thought experiments that help to illustrate the concepts of magnetism.Overall, "This Is Physics: Magnetism" is an excellent resource for anyone who wants to learn more about the fascinating world of magnetism. The book is well-written, engaging, and informative, and it provides a solid foundation for further study in the field of magnetism.中文回答：《这就是物理，磁学》是一本全面且写得精辟的磁学基础原理入门书籍。
作者J·理查德·戈特对磁场的磁极、磁力等磁学基础概念做出了清晰简洁的阐释。
离散分布电荷静电问题的有限元解法(IJMECS-V14-N4-5)
I.J. Modern Education and Computer Science, 2022, 4, 57-66Published Online August 2022 in MECS (/)DOI: 10.5815/ijmecs.2022.04.05Solution for Using FEMM in Electrostatic Problems with Discrete Distribution Electric ChargeMihaela OsaciPolitehnica University of Timisoara, Revolutiei no.5, Hunedoara, RomaniaCorina Daniela CunțanPolitehnica University of Timisoara, Revolutiei no.5, Hunedoara, RomaniaIoan BaciuPolitehnica University of Timisoara, Revolutiei no.5, Hunedoara, RomaniaReceived: 26 January 2022; Accepted: 19 April 2022; Published: 08 August 2022Abstract: Finite Element Method Magnetics (FEMM) is an open source software package for solving electromagnetic problems based on the finite element method. The application can numerically solve linear electrostatic problems and magnetostatic 2D problems, respectively low frequency magnetic, linear harmonic and nonlinear. FEMM is a product much used in science and engineering that, in the last 15 years, has begun to be used more and more in the academic environment. Despite the fact that FEMM can be used to solve complex problems in science and engineering, electrostatic FEMM cannot work directly with discrete electric charge distributions, that is, point electric charge. This work presents a FEMM model for simulating point electric charge that can be used in case of electrostatic problems with discrete charge distributions. The numerical solution for the electrostatic field is compared with the analytical solution. This model can be used in the case of an assembly of point electric charges with axial symmetry.Index Terms:Teaching tools, modalities of teaching, computer-assisted training, finite element method, numerical modeling in electromagnetism.1.IntroductionIn the age of digital technology, computer-assisted training is one of the basic teaching tools of modern education [1, 2, 3]. Electromagnetic field theory is one of the most difficult courses studied by students of the specialization of electrical engineering and other related specializations. Since few problems of electromagnetic field theory have analytical solutions, the use of software packages for modeling and simulation are extremely necessary, make learning in this field much more efficient and improve the individual and team work of students [4, 5]. Since numerical modeling in electromagnetism has become a tool extensively used by engineers, scientists and researchers [7], in electrical engineering programs, lately, there is a growing emphasis on teaching design-oriented courses [6]. This category mainly includes courses that are based on the application of techniques of numerical modeling of the electromagnetic field in solving specific problems in the technique.In the modern teaching of numerical methods for the electromagnetic field very useful are the software applications with graphical interface that allow the design, implementation, processing and post-processing of an electromagnetic field problem. For university use, and generally in the educational environment, such an application should be easy to use, offer programming support in scripting language, The ability to import and export files and further support in engineering design activity. Among applications with a graphic interface for the numerical solutions of differential equations with partial derivatives by the finite element method here: ANSYS [8, 9], Comsole Multiphysics [10, 11] and FEMM (Finite Element Method Magnetics) [12, 13, 14, 15].FEMM is an open source analysis software package with finite elements for electrostatic, magneto-static and low frequency electromagnetism problems. It is a simple to use, good quality, accurate and low cost freeware product usedin both science and engineering. Besides electromagnetism, it helps to solve complex problems in other areas such as materials science, industry, medicine, physics, robotics, astronomy and space engineering [16, 17, 18, 19, 20, 21, 22, 23, 24].For some 15 years, there have been a number of concerns aimed at exploring the ability of FEMM to meet the needs of electromagnetism teaching in higher education and beyond. A number of quantitative and qualitative studies and illustrative examples are intended to support the usefulness of this package of programs in the educational environment [13, 14, 15].Although FEMM is a widely used software in electromagnetism, has no support for electrostatic problems with discrete distribution of electric charge.In the specialized literature are offered two types of solutions for the implementation of FEMM of the load with discrete distribution [22]: the introduction of the discrete load through the properties of the node and the introduction of the discrete load as load of the inner armature of very small radius of a cylindrical capacitor implemented planar. The first solution lead to distort the shape of the electric field lines. The second solution is forced because in the planar implementation the depth parameter must be introduced, which means the length of the capacitor .Our work presents a solution for using FEMM software in issues with discreet electric charge distribution, much closer to reality, which can help improve the learning experience in electromagnetism at both university and college levels.Our work reinforces the idea that FEMM can also be used in classical areas [24], such as physics, where more emphasis is placed on the analytical aspect of problem solving, with electric and magnetic fields often seen as abstract notions, difficult to understand by students and students.2. FEMM Model for Point Electric ChargeFEMM is a 2D finite element modeling tool. In general, to solve a problem with the FEMM, the problem design is defined and created in the appropriate pre-processor and then one of the FEA solvers available for that type of problem is used [25]. Finally, the results can be analyzed in the postprocessor. The application interface is easy to use and allows to define the problem adding suitable objects, symbols and materials. DXF files with problem design or expanded metadata can also be imported. The application supports LUA scripting using, which allows to schedule specific actions. a. Electric charge point - analytical modelFrom the electrostatic (Coulomb’s theorem) it is known that the electric field created in the air, for example by a point electric charge q at the distance r of the electric charge is in size:24qE r πε= (1)And the electrical potential at a point at a distance R from the load creating the field is:4qV r πε= (2)For example, using a Matlab script it is easy to calculate the electric field and potential at a given distance from an electric charge that creates this field-fig.1.Fig. 1. Matlab script for the electric charge-analytical solutionRunning this script for the distance of 1cm and a positive electric charge of 1C gives the results from Fig.2 and Fig.3.Fig.2. Analytical results - electric chargeFig. 3. Graphical representations of the analytical solution: E=f(r) și V=f(r)b.Electric point charge - FEMM modelOnce a planar type problem has been defined, with units of measure for cm-fig length. 4, the first idea of implementing a point-of-form electric charge in FEMM starts with the point property definition, with “Add property” -fig.5. In the “Nodal Property” dialog fill in “Name” and select “Point Charge Density Property”. Due to the parameter depth - Fig. 4, for total charge of 1C, at “Point Charge Density, C/m” must be entered 100 (100C/m 1cm=1C).Fig. 4. Defining the problem with the natural idea of implementationFig. 5. Electric charge simulation through “Nodal Property ” Attach the property to the creeat point and define the boundary condition (Dirichlet condition, i.e. the electrical potential is null on the border).We will use the “Asymptotic Boundary Condition” method (as described in the Appendix to the FEMM manual [25]) to mimic an unbounded geometry. -fig.6. The results are shown in Fig.7. It is noticed that the results of the numerical simulation are far from the analytical results, which means that the natural idea presented just now is far from reality.Fig.6. Stages in the implementation of electric charge through “Nodal Property ”Fig. 7. Results of the implementation of electric charge through “Nodal Property ” The solution we propose starts from the observation that if in the expression of the electrical capacity of a spherical capacitor we make the outer radius to tend to infinity, we obtain the electrical capacity of a metal sphere charged withthe electric charge q - table 1, whose electrical potential is determined from q C V =,4r q q V C rπεε==, dV Edr =-,where 204r dV q E dr rπεε=-= as shown by the relation (1). Thus, the point electric charge can be simulated by a very small conductive metal sphere with a given charge, by defining an Axisymmetric Problem type-Fig. 8.Table 1. Electrical capacity and electric field created by a metal sphere charged with electric chargeFig.8. Defining the problem in the proposed solutionThe geometry of the problem is then constructed by placing the coordinate points (r,z) =(0,0.1) and (r,z) =(0,-0.1) that join by an arc to which the Conductors property is assigned-Fig.9.Fig.9. Defining the conductors property "Sim_sarc" and its association to the model arc An open border condition predefined by FEMM is used, with the Air material setting in the field of solutions -fig.10. The FEM network is generated and the solver is launched into execution and the result is obtained from fig.11.Fig. 10. The model of point electric chargeFig. 11. Numerical results3.Results and DiscussionFig. 11. shows that the numerical result is very close to the analytical result. For a better concordance can be refined the mesh of finished elements - fig. 12.Fig. 12. Numerical results after refining the finished item networkFig.13. shows the graphical representations of the numerical solution. Comparing these representations with the graphical representations of the analytical solution, a very good concordance is observed.Fig. 13. Graphical representations of the numerical solution: E=f(r) și V=f(r)The comparison between the analytical solution and the numerical solution can be better done by reading Table 2.Table 2. Comparison between the analytical solution and the numerical solution proposedType of solutionMesh size 0.1 Mesh size 0.01 E(V/m) V(V/m) E(V/m) V(V/m) Analytical solution9⋅1013 9⋅1011 9⋅1013 9⋅1011 Numerical solution 8.73707⋅1013 8.96668⋅1011 9.01085⋅1013 8.98723⋅1011For a better comparison between the analytical solution and the numerical solution, can be calculated the relative error in accord with relation:analytical solution numerical solution(%)100analytical solution E -=⋅ (3)In case of mesh size 0.1 the relative error is 2.92% and in case of refined mesh it obtained the relative error 0.12%. This analysis shows a very good concordance between the analytical values and the numerical values.3.1 Use of FEMM model for point electric charge for a set of point electric chargesThe model shown in the first subparagraph may be used in the case of a system of point electric charges if the system shows axial symmetry. For example, let's consider the example from din fig.14a, with q 1=10μC, q 2=5μC, r 1=1cm and r 2=2cm.a. b. c.Fig. 14. System of 2 point charges 3.2 Analytical solutionThe programming of the analytical solution was done in Matlab-fig 15, the solution being shown in fig. 16.Fig. 15. Matlab script for the analytical solution -system of electric chargesFig. 16. Analytical results - system of electric charges3.3Numerical solutionTo implement the numerical solution we choose the axis of symmetry to pass through the 2 charges, fig. 14b. Rotating fig. 14b. until the axis of symmetry reaches the upright position, fig. 14 c, the geometry of the problem to be solved using the point electric charge model shown in the previous paragraph is obtained. The numerical solution to the problem is shown in Fig. 17.Comparing the analytical solution of the problem shown in Fig. 16 with the numerical solution represented in Fig. 17, a very good concordance is observed.Fig. 17. Numerical results - electric charge system4.ConclusionsThe paper presents a solution for FEMM implementation of a point electric charge and the use of the proposed model in solving an electrostatic field problem for the case of a system of point electric charges. The model can be successfully used in electrostatics courses at both the university and college levels for a better understanding of the issue. The advantage of using the FEMM software package in the didactic activity is very high, given the fact that it is free and open source, easy to use and offers students the possibility to understand abstract concepts such as those of electric and magnetic fields and offers them skills in the design of electromagnetic devices, useful skills in their careers as future engineers.References[1]Y. Kong and I. Xie, “Professional Courses for Computer Engineering Education”, I. J. Modern Education and ComputerScience, 1, pp.1-8, 2010.[2] A. Herala, A. Knutas, E. Vanhalan and J. Kasurinen, “Experiences from Video Lectures in Software Engineering Education”,International Journal of Modern Education and Computer Science, Vol.9, No.5, 2017.[3]M. Mladenović, M. Rosić and S. Mladenović, “Comparing Elementary Students' Programming Success based on ProgrammingEnvironment”, International Journal of Modern Education and Computer Science, Vol. 8, No. 8, 2016.[4]K. K. Krutikov and V. V. Rozhkov, “Features of Electrical and Magnetic Skin Effect Modeling from AlternatingElectromagnetic Fields in FEMM”, Russian Electrical Engineering, Vol. 91, pp. 781–785, 2020[5]K.G. Brandisky, K.P. Stanchev, I.I. lacheva, R.D. Stancheva, S.K. Petrakieva, S.D. Terzieva, V.M. Mladenov, “Computer-Aided Education in Theoretical Electrical Engineering at the Technical University of Sofia: Part II”, in EUROCON 2005 - The International Conference on "Computer as a Tool", 2005[6] D. Kacprzak, P. Surdacki, H.D. Stryczewska, B. Guillemin, “Magnetic modelling projects in university courses - NewZealand and polish examples”, in IET 7th International Conference on Computation in Electromagnetics (CEM 2008), pp. 66 –67, 2008[7] D. Kacprzak, “Implementation of Finite Element Method Modelling Tools in Education Programs”, in6th InternationalConference on Computational Electromagnetics, 2006[8]“ANSYS”, [Online]. Available: https:///. [Accessed 2 March 2022][9]T. Stolarski, Y. Nakasone, S. Yoshimoto, Engineering Analysis with ANSYS Software, second edition, Elsevier PublishingHouse, 2018[10]W. B. J. Zimmerman, “Comsol Multiphysics and the Basics of Numerical Analysis”, Series on Stability, Vibration and Controlof Systems, Series A: Vol. 18 -Multiphysics Modeling with Finite Element Methods, pp. 27-63, 2006[11]“COMSOL”, [Online]. Available: https:///. [Accessed 2 March 2022][12]“FEMM-homepage”, [Online]. Available: https:///wiki/HomePage. [Accessed 2 March 2022][13]K. B. Baltzis, “The finite element method magnetics (FEMM) freeware package: May it serve as an educational tool inteaching electromagnetics?”, Education and Information Technologies, vol. 15(1), pp.19-36, 2010[14]K. B. Baltzis, “On the usage and potential applications of the finite element method magnetics (FEMM) package in theteaching of electromagnetics in higher education”, in 8th International Conference on Computer Based Learning in Science (CBLIS 2007), 2007[15]R. Crozier and M. Mueller, “A new Matlab and Octave interface to a popular magnetics finite element code”, in XXIIInternational Conference on Electrical Machines (ICEM), 2016[16]L. Hao, L. Xue, F. Huang, G. Cai, W. Qi, M. Zhang, Q. Han, Z. Wang, J. Lin, “A Microfluidic Biosensor Based on MagneticNanoparticle Separation, Quantum Dots Labeling and MnO2 Nanoflower Amplification for Rapid and Sensitive Detection of Salmonella Typhimurium”, Micromachines, Vol.11(3), pp. 281, 2020[17]T. A. Elmasri, M. A. Elmasri and E.S. Abdulhafid, “Finite Element Analysis of Free Energy Permanent Magnet Motor UsingSolidworks and Finite Element Method Magnetics (FEMM) Software”, Journal of Marine Sciences & Environmental Technologies, Vol. 5, Issue 2 , 2019[18]G. Priyandoko, P. Suwandono, N.R. Ismail, W.M. Utomo and S. Ubaidillah, “Development of Vibration IsolatorMagnetorheological Elastomer Based”, Journal of Physics: Conference Series, Vol. 1908, The 1st International Conference on Innovation and Application of Science and Technology (ICIASTECH 2019) 2-3 October 2019, Malang, Indonesia, 2021 [19]I. F. Lopes, D. C. Coelho, E. V. A. Bojorge, L. R. A. de Oliveira, “Underwater Wireless Power Transfer With High Toleranceto Misalignments”, Brazilian Power Electronics Conference (COBEP), 2021[20]M. Ya. Marusina and A. A. Silaev, “Improving the Efficiency of Mechatronic Systems Based on OptimizationPrinciples”, International Conference on Quality Management, Transport and Information Security, Information Technologies (IT&QM&IS), 2021[21] D. Leonardis, C. Loconsole and A. Frisoli, “A passive and scalable magnetic mechanism for braille cursor, an innovativerefreshable braille display”, Meccanica, vol. 55, pp.1639–1653, 2020[22]https:///en/document/read/7522512/simulation-of-electric-and-magnetic-fields-using-femm-fh-aachen-[23]G.Anghel, I.A. Anghel, M.D. Calin, E. Helerea, “Magnetics Tutorial. Modelling Permanent Magnets Using theElectromagnetic Software FEMM 4.2”, The International Scientific Conference eLearning and Software for Education;Bucharest "Carol I" National Defence University, Vol. 4, pp. 267-274, 2018[24]M. Boulé, “The role of Finite Element Method software in the teaching of electromagnetics”, Fourth InterdisciplinaryEngineering Design Education Conference, 2014[25]“FEMM-manual”, [Online]. Available: https:///Archives/doc/manual42.pdf. [Accessed 2 March 2022]Authors’ ProfilesMihaela Osaci, Lecturer, Polytechnica University of Timisoara, Engineering Faculty of Hunedoara /ElectricalEngineering & Industrial Informatics Department. Main activities and responsibilities: didactic and scientificresearch activities. Technical skills and competences: Physics, Electromagnetism, Nanomagnetism, Modeling andSimulation.Corina Daniela Cunţan, Lecturer, Polytechnic University of Timisoara, Engineering Faculty of Hunedoara/Electrical Engineering & Industrial Informatics Department. Main activities and responsibilities: didactic andscientific research activities. Technical skills and competences: Electronics Automatic management processes andApplications of electronics in industrial systems.Ioan Baciu, Lecturer, Polytechnic University of Timisoara, Engineering Faculty of Hunedoara /ElectricalEngineering & Industrial Informatics Department. Main activities and responsibilities: didactic and scientificresearch activities. Technical skills and competences: Electronics and Quality of electrical energy.How to cite this paper: Mihaela Osaci, Corina Daniela Cunțan, Ioan Baciu, "Solution for Using FEMM in Electrostatic Problems with Discrete Distribution Electric Charge", International Journal of Modern Education and Computer Science(IJMECS), Vol.14, No.4, pp. 57-66, 2022.DOI: 10.5815/ijmecs.2022.04.05。
Basic Properties of Magnetic Materials：磁性材料的基本性质
Name(s)___________________ Basic Properties of Magnetic MaterialsEquipment NeededWasher and various metals, compass, two bar magnetsIntroductionWe will qualitatively study some of the basic properties of magnetic materials.Permanent magnets are materials that retain their magnetic properties for a long time. Materials which can be used to make permanent magnets are called hard magnetic materials. Some magnetic materials are naturally occurring. For example lodestone is composed of magnetite, an iron-bearing mineral and is a naturally occurring permanent magnet. Synthetic magnetic materials which are used to make permanent magnets are usually alnicos: iron alloys containing aluminum, nickel, and cobalt. Some permanent magnets are ferrites made of powdered iron oxide and barium/strontium carbonate ceramics. Permanent magnets generally are described as having north and south poles. When permanent magnets are brought near each other, like poles repel and opposite poles attract.Temporary magnets only act as magnets if they are in the presence of a magnetic field produced by a permanent magnet or an electric current. Magnetic materials from which temporary magnets are made are called soft magnetic materials. Any object that can be lifted or moved by a magnet is a temporary magnet. Objects such as these will eventually lose their magnetism once the permanent magnet is removed. Sometimes the object may retain weak magnetic properties.Non magnetic materials are materials that do not exhibit magnetic properties in the presence of a magnetic field. Pure aluminum is a metal that is non-magnetic. All non-metallic materials are also non-magnetic.Magnetic domains are clusters of aligned atoms in a material.In iron, for example, a magnetized atom will likely cause its neighbors to line up in the same direction, forming a larger field. This forms magnetic domains. The more aligned the domains are, the stronger the magnetic field.ExplorationTemporary magnetsMaterials which are always attracted to a magnet are known as temporary magnets.1. Bring a compass near a washer. Does the compass needle deflect? Does the washer seem to be a magnet?NOTE: If the washer seems to be magnetized, bang it or drop it several times and test it again. What happens?2. Now use a permanent magnet instead of the compass. Bring the metal washer near the North Pole of the magnet. What do you observe?3. Flip the washer over and bring it near the North Pole of the magnet. What do you observe?4. Does the washer always seem to be attracted to the magnet?Non magnetic materialsMaterials that do not exhibit magnetic properties are known as non-magnetic materials.5. Bring the North Pole of the compass near a brass ball. Does the compass needle deflect?6. Bring the South Pole of the compass near the brass ball. Does the compass needle deflect?7. Now use a permanent magnet instead of the compass. Bring the brass ball near the North Pole of the magnet. What do you observe?8. Based on these observations, does the brass ball appear to be a permanent magnet, a temporary magnet, or non magnetic? Explain.Classification of magnetic materials9. Classify the US nickel, the steel ball, the aluminum ball and one other metallic object of your choice as permanent magnets, temporary magnets, or non-magnets. List the observations you’ve made in order to arrive at this classification.Permanent magnets and two types of poles10. Take two permanent magnets. Bring the two North Pole sides together. What do you observe?11. Bring the two South Pole sides together. What do you observe?12. Bring a North Pole side towards the South Pole side. What do you observe?13. Bring the North Pole side of a magnet near a compass. How does the compass behave?14. Bring the South Pole near the compass. How does the compass behave?15. Explain how these observations demonstrate that the compass is a permanent magnet rather than just a piece of iron.Earth’s magnetic field16. Identify geographic North in the lab room. Which side of the compass needle points north? We define the pole of the compass that faces geographic north to be the “magnetic North” pole of the compass and the pole that faces geographic south to be the “magnetic South” pole of the compass. Given your observations about the behavior of the magnetic forces between like and opposite poles, indicate on the sketch below the magnetic North Pole of the Earth and magnetic South Pole of the Earth. Is the geographic North pole a magnetic North pole or a magnetic South pole? Explain.Paper clip fun!17. Use your permanent magnet and put one end of a paperclip on the magnet. Then try to hang as many additional paperclips as you can end-to-end from that first paperclip. How many were you able to attach?18. Use the concept of magnetic domains to explain why the paper clips stick to each other. Draw a diagram showing how the domains might look before and after the paper clips are attached to the magnet.19. Remove the paper clips from the magnet. Try to pick up other paperclips with the ones that were attached to the magnet. What happens? Explain.20. Try to demagnetize the paperclips by dropping or banging them. Do they pick up other paperclips after you do this? Can you re-magnetize them? Explain what is happening in the inside of the paperclips to cause them to demagnetize and re-magnetize.。
物理学专业英语
华中师范大学物理学院物理学专业英语仅供内部学习参考！2014一、课程的任务和教学目的通过学习《物理学专业英语》，学生将掌握物理学领域使用频率较高的专业词汇和表达方法，进而具备基本的阅读理解物理学专业文献的能力。
通过分析《物理学专业英语》课程教材中的范文，学生还将从英语角度理解物理学中个学科的研究内容和主要思想，提高学生的专业英语能力和了解物理学研究前沿的能力。
培养专业英语阅读能力，了解科技英语的特点，提高专业外语的阅读质量和阅读速度；掌握一定量的本专业英文词汇，基本达到能够独立完成一般性本专业外文资料的阅读；达到一定的笔译水平。
要求译文通顺、准确和专业化。
要求译文通顺、准确和专业化。
二、课程内容课程内容包括以下章节：物理学、经典力学、热力学、电磁学、光学、原子物理、统计力学、量子力学和狭义相对论三、基本要求1.充分利用课内时间保证充足的阅读量（约1200~1500词/学时），要求正确理解原文。
2.泛读适量课外相关英文读物，要求基本理解原文主要内容。
3.掌握基本专业词汇（不少于200词）。
4.应具有流利阅读、翻译及赏析专业英语文献，并能简单地进行写作的能力。
四、参考书目录1 Physics 物理学 (1)Introduction to physics (1)Classical and modern physics (2)Research fields (4)V ocabulary (7)2 Classical mechanics 经典力学 (10)Introduction (10)Description of classical mechanics (10)Momentum and collisions (14)Angular momentum (15)V ocabulary (16)3 Thermodynamics 热力学 (18)Introduction (18)Laws of thermodynamics (21)System models (22)Thermodynamic processes (27)Scope of thermodynamics (29)V ocabulary (30)4 Electromagnetism 电磁学 (33)Introduction (33)Electrostatics (33)Magnetostatics (35)Electromagnetic induction (40)V ocabulary (43)5 Optics 光学 (45)Introduction (45)Geometrical optics (45)Physical optics (47)Polarization (50)V ocabulary (51)6 Atomic physics 原子物理 (52)Introduction (52)Electronic configuration (52)Excitation and ionization (56)V ocabulary (59)7 Statistical mechanics 统计力学 (60)Overview (60)Fundamentals (60)Statistical ensembles (63)V ocabulary (65)8 Quantum mechanics 量子力学 (67)Introduction (67)Mathematical formulations (68)Quantization (71)Wave-particle duality (72)Quantum entanglement (75)V ocabulary (77)9 Special relativity 狭义相对论 (79)Introduction (79)Relativity of simultaneity (80)Lorentz transformations (80)Time dilation and length contraction (81)Mass-energy equivalence (82)Relativistic energy-momentum relation (86)V ocabulary (89)正文标记说明：蓝色Arial字体（例如energy）：已知的专业词汇蓝色Arial字体加下划线（例如electromagnetism）：新学的专业词汇黑色Times New Roman字体加下划线（例如postulate）：新学的普通词汇1 Physics 物理学1 Physics 物理学Introduction to physicsPhysics is a part of natural philosophy and a natural science that involves the study of matter and its motion through space and time, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic disciplines, perhaps the oldest through its inclusion of astronomy. Over the last two millennia, physics was a part of natural philosophy along with chemistry, certain branches of mathematics, and biology, but during the Scientific Revolution in the 17th century, the natural sciences emerged as unique research programs in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry,and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms of other sciences, while opening new avenues of research in areas such as mathematics and philosophy.Physics also makes significant contributions through advances in new technologies that arise from theoretical breakthroughs. For example, advances in the understanding of electromagnetism or nuclear physics led directly to the development of new products which have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus.Core theoriesThough physics deals with a wide variety of systems, certain theories are used by all physicists. Each of these theories were experimentally tested numerous times and found correct as an approximation of nature (within a certain domain of validity).For instance, the theory of classical mechanics accurately describes the motion of objects, provided they are much larger than atoms and moving at much less than the speed of light. These theories continue to be areas of active research, and a remarkable aspect of classical mechanics known as chaos was discovered in the 20th century, three centuries after the original formulation of classical mechanics by Isaac Newton (1642–1727) 【艾萨克·牛顿】.University PhysicsThese central theories are important tools for research into more specialized topics, and any physicist, regardless of his or her specialization, is expected to be literate in them. These include classical mechanics, quantum mechanics, thermodynamics and statistical mechanics, electromagnetism, and special relativity.Classical and modern physicsClassical mechanicsClassical physics includes the traditional branches and topics that were recognized and well-developed before the beginning of the 20th century—classical mechanics, acoustics, optics, thermodynamics, and electromagnetism.Classical mechanics is concerned with bodies acted on by forces and bodies in motion and may be divided into statics (study of the forces on a body or bodies at rest), kinematics (study of motion without regard to its causes), and dynamics (study of motion and the forces that affect it); mechanics may also be divided into solid mechanics and fluid mechanics (known together as continuum mechanics), the latter including such branches as hydrostatics, hydrodynamics, aerodynamics, and pneumatics.Acoustics is the study of how sound is produced, controlled, transmitted and received. Important modern branches of acoustics include ultrasonics, the study of sound waves of very high frequency beyond the range of human hearing; bioacoustics the physics of animal calls and hearing, and electroacoustics, the manipulation of audible sound waves using electronics.Optics, the study of light, is concerned not only with visible light but also with infrared and ultraviolet radiation, which exhibit all of the phenomena of visible light except visibility, e.g., reflection, refraction, interference, diffraction, dispersion, and polarization of light.Heat is a form of energy, the internal energy possessed by the particles of which a substance is composed; thermodynamics deals with the relationships between heat and other forms of energy.Electricity and magnetism have been studied as a single branch of physics since the intimate connection between them was discovered in the early 19th century; an electric current gives rise to a magnetic field and a changing magnetic field induces an electric current. Electrostatics deals with electric charges at rest, electrodynamics with moving charges, and magnetostatics with magnetic poles at rest.Modern PhysicsClassical physics is generally concerned with matter and energy on the normal scale of1 Physics 物理学observation, while much of modern physics is concerned with the behavior of matter and energy under extreme conditions or on the very large or very small scale.For example, atomic and nuclear physics studies matter on the smallest scale at which chemical elements can be identified.The physics of elementary particles is on an even smaller scale, as it is concerned with the most basic units of matter; this branch of physics is also known as high-energy physics because of the extremely high energies necessary to produce many types of particles in large particle accelerators. On this scale, ordinary, commonsense notions of space, time, matter, and energy are no longer valid.The two chief theories of modern physics present a different picture of the concepts of space, time, and matter from that presented by classical physics.Quantum theory is concerned with the discrete, rather than continuous, nature of many phenomena at the atomic and subatomic level, and with the complementary aspects of particles and waves in the description of such phenomena.The theory of relativity is concerned with the description of phenomena that take place in a frame of reference that is in motion with respect to an observer; the special theory of relativity is concerned with relative uniform motion in a straight line and the general theory of relativity with accelerated motion and its connection with gravitation.Both quantum theory and the theory of relativity find applications in all areas of modern physics.Difference between classical and modern physicsWhile physics aims to discover universal laws, its theories lie in explicit domains of applicability. Loosely speaking, the laws of classical physics accurately describe systems whose important length scales are greater than the atomic scale and whose motions are much slower than the speed of light. Outside of this domain, observations do not match their predictions.Albert Einstein【阿尔伯特·爱因斯坦】contributed the framework of special relativity, which replaced notions of absolute time and space with space-time and allowed an accurate description of systems whose components have speeds approaching the speed of light.Max Planck【普朗克】, Erwin Schrödinger【薛定谔】, and others introduced quantum mechanics, a probabilistic notion of particles and interactions that allowed an accurate description of atomic and subatomic scales.Later, quantum field theory unified quantum mechanics and special relativity.General relativity allowed for a dynamical, curved space-time, with which highly massiveUniversity Physicssystems and the large-scale structure of the universe can be well-described. General relativity has not yet been unified with the other fundamental descriptions; several candidate theories of quantum gravity are being developed.Research fieldsContemporary research in physics can be broadly divided into condensed matter physics; atomic, molecular, and optical physics; particle physics; astrophysics; geophysics and biophysics. Some physics departments also support research in Physics education.Since the 20th century, the individual fields of physics have become increasingly specialized, and today most physicists work in a single field for their entire careers. "Universalists" such as Albert Einstein (1879–1955) and Lev Landau (1908–1968)【列夫·朗道】, who worked in multiple fields of physics, are now very rare.Condensed matter physicsCondensed matter physics is the field of physics that deals with the macroscopic physical properties of matter. In particular, it is concerned with the "condensed" phases that appear whenever the number of particles in a system is extremely large and the interactions between them are strong.The most familiar examples of condensed phases are solids and liquids, which arise from the bonding by way of the electromagnetic force between atoms. More exotic condensed phases include the super-fluid and the Bose–Einstein condensate found in certain atomic systems at very low temperature, the superconducting phase exhibited by conduction electrons in certain materials,and the ferromagnetic and antiferromagnetic phases of spins on atomic lattices.Condensed matter physics is by far the largest field of contemporary physics.Historically, condensed matter physics grew out of solid-state physics, which is now considered one of its main subfields. The term condensed matter physics was apparently coined by Philip Anderson when he renamed his research group—previously solid-state theory—in 1967. In 1978, the Division of Solid State Physics of the American Physical Society was renamed as the Division of Condensed Matter Physics.Condensed matter physics has a large overlap with chemistry, materials science, nanotechnology and engineering.Atomic, molecular and optical physicsAtomic, molecular, and optical physics (AMO) is the study of matter–matter and light–matter interactions on the scale of single atoms and molecules.1 Physics 物理学The three areas are grouped together because of their interrelationships, the similarity of methods used, and the commonality of the energy scales that are relevant. All three areas include both classical, semi-classical and quantum treatments; they can treat their subject from a microscopic view (in contrast to a macroscopic view).Atomic physics studies the electron shells of atoms. Current research focuses on activities in quantum control, cooling and trapping of atoms and ions, low-temperature collision dynamics and the effects of electron correlation on structure and dynamics. Atomic physics is influenced by the nucleus (see, e.g., hyperfine splitting), but intra-nuclear phenomena such as fission and fusion are considered part of high-energy physics.Molecular physics focuses on multi-atomic structures and their internal and external interactions with matter and light.Optical physics is distinct from optics in that it tends to focus not on the control of classical light fields by macroscopic objects, but on the fundamental properties of optical fields and their interactions with matter in the microscopic realm.High-energy physics (particle physics) and nuclear physicsParticle physics is the study of the elementary constituents of matter and energy, and the interactions between them.In addition, particle physicists design and develop the high energy accelerators,detectors, and computer programs necessary for this research. The field is also called "high-energy physics" because many elementary particles do not occur naturally, but are created only during high-energy collisions of other particles.Currently, the interactions of elementary particles and fields are described by the Standard Model.●The model accounts for the 12 known particles of matter (quarks and leptons) thatinteract via the strong, weak, and electromagnetic fundamental forces.●Dynamics are described in terms of matter particles exchanging gauge bosons (gluons,W and Z bosons, and photons, respectively).●The Standard Model also predicts a particle known as the Higgs boson. In July 2012CERN, the European laboratory for particle physics, announced the detection of a particle consistent with the Higgs boson.Nuclear Physics is the field of physics that studies the constituents and interactions of atomic nuclei. The most commonly known applications of nuclear physics are nuclear power generation and nuclear weapons technology, but the research has provided application in many fields, including those in nuclear medicine and magnetic resonance imaging, ion implantation in materials engineering, and radiocarbon dating in geology and archaeology.University PhysicsAstrophysics and Physical CosmologyAstrophysics and astronomy are the application of the theories and methods of physics to the study of stellar structure, stellar evolution, the origin of the solar system, and related problems of cosmology. Because astrophysics is a broad subject, astrophysicists typically apply many disciplines of physics, including mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.The discovery by Karl Jansky in 1931 that radio signals were emitted by celestial bodies initiated the science of radio astronomy. Most recently, the frontiers of astronomy have been expanded by space exploration. Perturbations and interference from the earth's atmosphere make space-based observations necessary for infrared, ultraviolet, gamma-ray, and X-ray astronomy.Physical cosmology is the study of the formation and evolution of the universe on its largest scales. Albert Einstein's theory of relativity plays a central role in all modern cosmological theories. In the early 20th century, Hubble's discovery that the universe was expanding, as shown by the Hubble diagram, prompted rival explanations known as the steady state universe and the Big Bang.The Big Bang was confirmed by the success of Big Bang nucleo-synthesis and the discovery of the cosmic microwave background in 1964. The Big Bang model rests on two theoretical pillars: Albert Einstein's general relativity and the cosmological principle (On a sufficiently large scale, the properties of the Universe are the same for all observers). Cosmologists have recently established the ΛCDM model (the standard model of Big Bang cosmology) of the evolution of the universe, which includes cosmic inflation, dark energy and dark matter.Current research frontiersIn condensed matter physics, an important unsolved theoretical problem is that of high-temperature superconductivity. Many condensed matter experiments are aiming to fabricate workable spintronics and quantum computers.In particle physics, the first pieces of experimental evidence for physics beyond the Standard Model have begun to appear. Foremost among these are indications that neutrinos have non-zero mass. These experimental results appear to have solved the long-standing solar neutrino problem, and the physics of massive neutrinos remains an area of active theoretical and experimental research. Particle accelerators have begun probing energy scales in the TeV range, in which experimentalists are hoping to find evidence for the super-symmetric particles, after discovery of the Higgs boson.Theoretical attempts to unify quantum mechanics and general relativity into a single theory1 Physics 物理学of quantum gravity, a program ongoing for over half a century, have not yet been decisively resolved. The current leading candidates are M-theory, superstring theory and loop quantum gravity.Many astronomical and cosmological phenomena have yet to be satisfactorily explained, including the existence of ultra-high energy cosmic rays, the baryon asymmetry, the acceleration of the universe and the anomalous rotation rates of galaxies.Although much progress has been made in high-energy, quantum, and astronomical physics, many everyday phenomena involving complexity, chaos, or turbulence are still poorly understood. Complex problems that seem like they could be solved by a clever application of dynamics and mechanics remain unsolved; examples include the formation of sand-piles, nodes in trickling water, the shape of water droplets, mechanisms of surface tension catastrophes, and self-sorting in shaken heterogeneous collections.These complex phenomena have received growing attention since the 1970s for several reasons, including the availability of modern mathematical methods and computers, which enabled complex systems to be modeled in new ways. Complex physics has become part of increasingly interdisciplinary research, as exemplified by the study of turbulence in aerodynamics and the observation of pattern formation in biological systems.Vocabulary★natural science 自然科学academic disciplines 学科astronomy 天文学in their own right 凭他们本身的实力intersects相交，交叉interdisciplinary交叉学科的，跨学科的★quantum 量子的theoretical breakthroughs 理论突破★electromagnetism 电磁学dramatically显著地★thermodynamics热力学★calculus微积分validity★classical mechanics 经典力学chaos 混沌literate 学者★quantum mechanics量子力学★thermodynamics and statistical mechanics热力学与统计物理★special relativity狭义相对论is concerned with 关注，讨论，考虑acoustics 声学★optics 光学statics静力学at rest 静息kinematics运动学★dynamics动力学ultrasonics超声学manipulation 操作，处理，使用University Physicsinfrared红外ultraviolet紫外radiation辐射reflection 反射refraction 折射★interference 干涉★diffraction 衍射dispersion散射★polarization 极化，偏振internal energy 内能Electricity电性Magnetism 磁性intimate 亲密的induces 诱导，感应scale尺度★elementary particles基本粒子★high-energy physics 高能物理particle accelerators 粒子加速器valid 有效的，正当的★discrete离散的continuous 连续的complementary 互补的★frame of reference 参照系★the special theory of relativity 狭义相对论★general theory of relativity 广义相对论gravitation 重力，万有引力explicit 详细的，清楚的★quantum field theory 量子场论★condensed matter physics凝聚态物理astrophysics天体物理geophysics地球物理Universalist博学多才者★Macroscopic宏观Exotic奇异的★Superconducting 超导Ferromagnetic铁磁质Antiferromagnetic 反铁磁质★Spin自旋Lattice 晶格，点阵，网格★Society社会，学会★microscopic微观的hyperfine splitting超精细分裂fission分裂，裂变fusion熔合，聚变constituents成分，组分accelerators加速器detectors 检测器★quarks夸克lepton 轻子gauge bosons规范玻色子gluons胶子★Higgs boson希格斯玻色子CERN欧洲核子研究中心★Magnetic Resonance Imaging磁共振成像，核磁共振ion implantation 离子注入radiocarbon dating放射性碳年代测定法geology地质学archaeology考古学stellar 恒星cosmology宇宙论celestial bodies 天体Hubble diagram 哈勃图Rival竞争的★Big Bang大爆炸nucleo-synthesis核聚合，核合成pillar支柱cosmological principle宇宙学原理ΛCDM modelΛ-冷暗物质模型cosmic inflation宇宙膨胀1 Physics 物理学fabricate制造，建造spintronics自旋电子元件，自旋电子学★neutrinos 中微子superstring 超弦baryon重子turbulence湍流，扰动，骚动catastrophes突变，灾变，灾难heterogeneous collections异质性集合pattern formation模式形成University Physics2 Classical mechanics 经典力学IntroductionIn physics, classical mechanics is one of the two major sub-fields of mechanics, which is concerned with the set of physical laws describing the motion of bodies under the action of a system of forces. The study of the motion of bodies is an ancient one, making classical mechanics one of the oldest and largest subjects in science, engineering and technology.Classical mechanics describes the motion of macroscopic objects, from projectiles to parts of machinery, as well as astronomical objects, such as spacecraft, planets, stars, and galaxies. Besides this, many specializations within the subject deal with gases, liquids, solids, and other specific sub-topics.Classical mechanics provides extremely accurate results as long as the domain of study is restricted to large objects and the speeds involved do not approach the speed of light. When the objects being dealt with become sufficiently small, it becomes necessary to introduce the other major sub-field of mechanics, quantum mechanics, which reconciles the macroscopic laws of physics with the atomic nature of matter and handles the wave–particle duality of atoms and molecules. In the case of high velocity objects approaching the speed of light, classical mechanics is enhanced by special relativity. General relativity unifies special relativity with Newton's law of universal gravitation, allowing physicists to handle gravitation at a deeper level.The initial stage in the development of classical mechanics is often referred to as Newtonian mechanics, and is associated with the physical concepts employed by and the mathematical methods invented by Newton himself, in parallel with Leibniz【莱布尼兹】, and others.Later, more abstract and general methods were developed, leading to reformulations of classical mechanics known as Lagrangian mechanics and Hamiltonian mechanics. These advances were largely made in the 18th and 19th centuries, and they extend substantially beyond Newton's work, particularly through their use of analytical mechanics. Ultimately, the mathematics developed for these were central to the creation of quantum mechanics.Description of classical mechanicsThe following introduces the basic concepts of classical mechanics. For simplicity, it often2 Classical mechanics 经典力学models real-world objects as point particles, objects with negligible size. The motion of a point particle is characterized by a small number of parameters: its position, mass, and the forces applied to it.In reality, the kind of objects that classical mechanics can describe always have a non-zero size. (The physics of very small particles, such as the electron, is more accurately described by quantum mechanics). Objects with non-zero size have more complicated behavior than hypothetical point particles, because of the additional degrees of freedom—for example, a baseball can spin while it is moving. However, the results for point particles can be used to study such objects by treating them as composite objects, made up of a large number of interacting point particles. The center of mass of a composite object behaves like a point particle.Classical mechanics uses common-sense notions of how matter and forces exist and interact. It assumes that matter and energy have definite, knowable attributes such as where an object is in space and its speed. It also assumes that objects may be directly influenced only by their immediate surroundings, known as the principle of locality.In quantum mechanics objects may have unknowable position or velocity, or instantaneously interact with other objects at a distance.Position and its derivativesThe position of a point particle is defined with respect to an arbitrary fixed reference point, O, in space, usually accompanied by a coordinate system, with the reference point located at the origin of the coordinate system. It is defined as the vector r from O to the particle.In general, the point particle need not be stationary relative to O, so r is a function of t, the time elapsed since an arbitrary initial time.In pre-Einstein relativity (known as Galilean relativity), time is considered an absolute, i.e., the time interval between any given pair of events is the same for all observers. In addition to relying on absolute time, classical mechanics assumes Euclidean geometry for the structure of space.Velocity and speedThe velocity, or the rate of change of position with time, is defined as the derivative of the position with respect to time. In classical mechanics, velocities are directly additive and subtractive as vector quantities; they must be dealt with using vector analysis.When both objects are moving in the same direction, the difference can be given in terms of speed only by ignoring direction.University PhysicsAccelerationThe acceleration , or rate of change of velocity, is the derivative of the velocity with respect to time (the second derivative of the position with respect to time).Acceleration can arise from a change with time of the magnitude of the velocity or of the direction of the velocity or both . If only the magnitude v of the velocity decreases, this is sometimes referred to as deceleration , but generally any change in the velocity with time, including deceleration, is simply referred to as acceleration.Inertial frames of referenceWhile the position and velocity and acceleration of a particle can be referred to any observer in any state of motion, classical mechanics assumes the existence of a special family of reference frames in terms of which the mechanical laws of nature take a comparatively simple form. These special reference frames are called inertial frames .An inertial frame is such that when an object without any force interactions (an idealized situation) is viewed from it, it appears either to be at rest or in a state of uniform motion in a straight line. This is the fundamental definition of an inertial frame. They are characterized by the requirement that all forces entering the observer's physical laws originate in identifiable sources (charges, gravitational bodies, and so forth).A non-inertial reference frame is one accelerating with respect to an inertial one, and in such a non-inertial frame a particle is subject to acceleration by fictitious forces that enter the equations of motion solely as a result of its accelerated motion, and do not originate in identifiable sources. These fictitious forces are in addition to the real forces recognized in an inertial frame.A key concept of inertial frames is the method for identifying them. For practical purposes, reference frames that are un-accelerated with respect to the distant stars are regarded as good approximations to inertial frames.Forces; Newton's second lawNewton was the first to mathematically express the relationship between force and momentum . Some physicists interpret Newton's second law of motion as a definition of force and mass, while others consider it a fundamental postulate, a law of nature. Either interpretation has the same mathematical consequences, historically known as "Newton's Second Law":a m t v m t p F ===d )(d d dThe quantity m v is called the (canonical ) momentum . The net force on a particle is thus equal to rate of change of momentum of the particle with time.So long as the force acting on a particle is known, Newton's second law is sufficient to。
Magnetic
Magnetic HealingDecember 30, 2007Our body is a magnetic field and our tissues contain magnetite. There is a significant amount of magnetite near the pineal gland in the brain. The pineal gland secretes hormones throughout the body.Magnetic healing (or magnetic therapy) is a form of alternative medicine involving magnetic fields. Ardent proponents claim that subjecting certain parts of the body to doses of magnetic fields has a beneficial effect. This belief has led to the popularization of an industry involving the sale of magnetic-based products for "healing" purposes: magnetic bracelets and jewelry; magnetic straps for wrists, ankles and the back; shoe insoles, mattresses and magnetic blankets; and even water that has been "magnetized". Magnetic products in the market come in various strengths, shapes, sizes and forms. The price varies from the nominal to very expensive depending on what kinds of materials are used.Magnetic healing is not a new concept. It was used by ancient civilizations thousands of years ago, including the Egyptians and the Greeks. Aristotle expounded on the use of magnets as a therapeutic means of healing sometime around 350 BC. The Greek physician Galan used magnets to heal in 200 BC. Persian physicians were treating muscle spasms with magnets in 1000. Paracelsus, a Swiss physician, advocated magnetic therapy in the 1500s.The therapy is said to work in a non-invasive way to cure many painful conditions, primarily back disorders, arthritis and joint aches by directly affixing the magnets on the painful part of the body. The therapy makes use of the static magnetic fields produced by permanent magnets, involving the application of electromagnetic waves to the patient. Magnetic fields from permanent magnets are said to speed up the healing process of the body and relieve pains. Some of the common ailments treated using magnetic therapy are insomnia, carpal tunnel syndrome, arthritis, headaches, and backaches. It is believed that magnets must be placed precisely in order to reap the full effect of the treatment. When a magnet is put on the affected area of the body, it relaxes the walls of the capillaries, hence increasing the flow of blood to the painful area. They are also said to interfere with muscle contractions, thus preventing muscle spasms, which are thought to be the underlying cause of many types of pain. Plus, magnets impede the ability of nerve cells to transmit pain messages to the brain. While over-the-counter pain relieving medications like aspirin can be used to control chronic pain, however, magnets do not have any risk of side effects.Magnet therapy is most effective when used in conjunction with other forms of alternative healing therapies like acupuncture. Being placed at pressure points to relieve soreness, magnets open up microscopic blood vessels and facilitate better blood flow. Conversely, magnets can also be used to change the direction of blood flow and thus prevent the spread of inflammation.However, the mainstream scientific community generally considers the therapy pseudoscientific.。
大学英文版电磁学讲义1-9
9.2 Magnetization and Bound Currents 磁化和束缚电流
The volume density of bound current(束缚电流体密度): J x =∇ ×M x . The surface density of bound current(束缚电流面密度): K b x = M x × n . (9.13) (9.12)
J by =−∂ M z /∂ x .
. => J b =∇× M For M = M k Fig. 9.8.
K =M × n M= n m k
increasing in the Fig. 9.9 M z x k +x direction. The bound current is ∂M z J b =∇ × M=− j ∂x
9.4 Problems Involving Free Currents and Magnetic Materials 包含自由电流和磁介质的问题
Using Ampere's law of H, we can solve some problems in magnetic material with symmetry. Example 5: An infinite slab of a conducting material(无穷大导体平板) with magnetic susceptibility m carries a certain current distribution. The slab is parallel to the x y plane, between z = −a and z = a. It carries a free i . Above the x y plane the current volume current density J f z = J 0 z / a is out of the page, below it is into the page.
大学英文版电磁学讲义1-2
Chapter 1 History and Perspective 历史与前景
The electromagnetic interaction(电磁相互作用) is one of the fundamental interactions(基本相互作用) of the physical world. Interaction: atoms and molecules. Phenomenon: sunshine, lightning, rainbows. Technology: communication with NASA's planetary probes(行星探测器), electromagnetic medical imaging(医学成象), computer electronics.
Additi i A y B y j A z B z k
Multiplication: 乘法
Chapter 1 History and Perspective 历史与前景 Modern theory of gravity: Einstein's general relativity(广义相对论).
Elementary Charges, Photons, and QED 基本电荷, 光子和量子电动力学
1.1 Brief history of the science of electromagnetism 电磁科学简史
Electric and magnetic phenomena have been known for millenia. Ancient Greece. Amber(琥珀) rubbed with animal fur can attract small bits of matter. The force between natural magnets(磁铁), ferromagnetism(铁磁性). Early part of the scientific revolution in 1600. Gilbert. an important book.
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Chapter 2 Magnetic components: transformers and inductors
Inductor: One core plus one winding
Magnetic flux Φ
i
v
Φ1 Φκ Φ2
Its operation is governed by: Ampere’s Law Faraday’s Law
E = RI E Electromotive force R Resistance I Electric current
Φ
i
+ -
Ni
Rm
le Rm = µ 0 µ r Ae
+ -
E
R
l R= ρA
Magnetic circuit
Electric circuit
v i
Φ1 Φc Φ2
Φ1
R1
Φc
Magnetic circuit
Adding an airgap reduces the effect of temperature variation on inductance
For a gapped core
B Bm Br a Bs
lc Br1 = Br ( ) lc + µ r l g
B Bm a Bs
-Hm
b -Hc O
lc µ r µ 0 N 2 Ae ( ) L= lc lc + µ r l g
µ r lc µe = lc + µ r l g
lc = 50mm, l g = 0.2mm
µ 0 µ e N 2 Ae L= lc
∆µ e ∆µ r lc = µe µ r lc + µ r l g
µ r = 3000, ∆µ r = 500 ∆µ e = 1.28% µe
Cp s Rp Vp lk 1 ip im Cp Lp Rc Rs
T1
lk 2 is Cs Vs
Ns i p = im + is Np N p i p ≈ N s is only if Lp is large enough and im → 0 Vp Vs ≈ Np Ns only if Rp Rs lk1 and lk2 are low enough
+ -
Ni Rc
R2
Φ2
Φ c = Φ1 + Φ 2 Ni = Φ c Rc + Φ1 R1 = Φ c Rc + Φ 2 R2 R1 R2 = Φ c ( Rc + ) R1 + R2
Total reluctance
Faraday’s Law
Φ
dB dΦ e = −N = − NS dt dt
N: turns number of the winding S: Area enclosed by the winding B: Flux density(µ0µrH)
For a gapped core
NΦ NBcore Ae µ 0 µ r N 2 Ae µ 0 N 2 Ae ( L= = = = I I lc + µ r l g lc
µe
lc ∆L ∆µ e ∆µ r µ e ∆µ r = = = L µe µr µr µ r lc + µ r l g
Since
Chapter 1 Roles of magnetics in switching mode power supply
Transformer DM filter PFC inductor Output filter
L
Inductor
CM filter
Magnetic components are present in every switching power supply
Chapter 3 Magnetic materials and properties
Magnetic materials for power application
Ferrites: Oxides containing ferric ions as the main constituent (Fe, Mn, Co, Ni, Cu, Zn, Mg, Cd) MnZn: High permeability, NiZn: low permeability, high resistivity 3F3, 3F4, 3F45, 3C85, 3C90, 3C96, TP4 Powdered core materials: MPP(Molybdenum Permalloy Powder), 80% NiFeMo MPP( High Flux(Dura flux): 50% NiFe Koolµ: 85% FeAlSi Powdered Iron: Pure Fe Amorphous: Iron-based (79 % Fe), cobalt-based (77 % Co), Nanocrystalline materials(approx.73.5 % Fe)
µi
d Hc Hm H
Br
Br1
b O
d Ni 0 Ni 1 Ni
c
Hysteresis loop
c
The remanent flux density is also decreased for gapped core
Fringing Effect for Gapped Core
Magnetic flux generates spinning electric currents. Electric currents can spin in: • Magnet wire…………...Bad - Hot! • Foil or planar windings….Don’t ask
Transformers: Energy transfer element
• provide isolation between two parts of a system • transform impedances • store and transfer energy (flyback transformer) • sense voltages and currents (potential and current transformers)
Np Ns Is
Us
Load
A typical transformer circuit
Equivalent electrical model for a transformer
Cps Rp lk 1 ip im Cp Lp Rc Rs
T1
lk 2 is Cs
Rp, Rs: winding resistances lk1,lk2: leakage inductances Lp: magnetizing inductance of primary winding Cp, Cs: Self-capacitances Cps: inter-winding capacitance Rc: equivalent core resistance
r r r ∇ × H = J = σE r r ∂B ∇× E = − ∂t
If neglecting leakage flux Φκ Flux continuity
Φ = Φ1 = Φ2
Ampere’s Law
Analog
Ni = Hle = Rm Φ
Magnetomotive force Ni Reluctance Rm Magnetic flux Φ
lg
i
v
Bcore
µ 0 µ r NI µ 0 µ r NI = = lc + µ r l g le
le = lc + µ r l g
Hcore, Bcore: Magnetic field intensity, and flux density within the core
Hale Waihona Puke lc, lg: Magnetic path length of the core and air gap
lk2' is' Rc Rs' Vs'=0
Vp
Lp
Rp
lk1 ip im is' Rc
lk2'
Rp
lk1 ip im is' ip ≈ is'
lk2'
Vp
Lp
Vs' Rs'
Vp
Vs'=0 Rs'
lk2' = n2lk2, Rs' = n2Rs, n = Np/Ns
Short circuit test result: (Rp+Rs')+jω (lk1+lk2')
Chapter 1 Roles of magnetics in switching mode power supply
Inductors: Energy storage element
• filter switched waveforms (as part of input and output filters) • create sinusoidal variations of voltage or current (with capacitors, as in resonant converters) • limit the rate of change of current (as in snubber circuits) • limit transient current
-
e +
Ni = Hle = Rm Φ