Cov khoom ntawm hlau nplaum yog dab tsi? Cov hlau nplaum yog cov khoom tshwj xeeb. Lawv tuaj yeem thawb lossis rub rau lwm yam yam tsis tau kov lawv! Cov neeg tau paub txoghlau nplaumrau txhiab xyoo. Hauv tebchaws Greece thaum ub, tib neeg pom cov pob zeb zoo kawg nkaus hu ua lodestones uas ua zoo li hlau nplaum. Cov pob zeb tuaj yeem tig lawv tus kheej mus rau sab qaum teb thiab sab qab teb, ua ke nrog lub ntiaj teb magnetic teb.
Niaj hnub no, hlau nplaum tau siv ntau yam khoom peb siv txhua hnub. Tseem muaj ntau yam ntxiv los nthuav tawm txog yam khoom ntawm cov hlau nplaum yog dab tsi thiab peb tuaj yeem siv lawv li cas.
Cov khoom siv hlau nplaum
Txhua yam hauv ntiaj teb no qhia qee yam ntawm cov hlau nplaum. Tab sis lub zog ntawm cov hlau nplaum sib txawv heev ntawm cov khoom. Raws li cov khoom ntawm cov hlau nplaum, peb muaj tsib pawg loj: ferromagnetic, paramagnetic, diamagnetic, ferrimagnetic, thiab antiferromagnetic.
Ferromagnetic tej yam xws li hlau, cobalt, thiab npib tsib xee qhia qhov muaj zog tshaj hlau nplaum. Lawv cov qauv me me tuaj yeem piav qhia lawv lub zog rub mus rau qhov chaw sib nqus. Cov atoms nyob rau hauv ferromagnetic tej yam muaj unmatched electrons uas taw tes rau tib txoj kev nyob rau hauv cov cheeb tsam hu ua magnetic domains. Qhov no taw tes rau tib qho kev taw qhia nce qhov sib nqus teb thiab ua rau cov hlau nplaum ruaj khov.
Paramagnetic tej yam xws li txhuas thiab platinum kuj rub mus rau magnetic teb, tab sis lub zog yog ntau zog dua nyob rau hauv ferromagnetic yam. Cov electrons tsis sib xws hauv paramagnetic atoms taw tes rau hauv cov kev taw qhia ntawm daim teb thov tab sis tsis txhob khaws cov hlau nplaum thaum lub teb raug tshem tawm.
Diamagnetic tej yam xws li tooj liab thiab kub qhia ib tug qaug zog thawb tawm ntawm magnetic teb. Thaum muab tso rau hauv ib qho chaw sab nraud, lawv cov atoms ua rau induced magnetic teb nyob rau hauv opposite direction. Txawm li cas los xij, lawv tsis muaj atomic dipoles mus tas li.
Ferrimagnetic tej yam qhia complex sib nqus kev txiav txim qhov twg unmatched electrons ntawm atoms ntawm txawv lattices tawm tsam ib leeg, zoo li nyob rau hauv antiferromagnets. Tab sis ferrimagnets khaws cov hlau nplaum mus tas li vim qhov tsis sib haum xeeb ntawm cov hluav taws xob tsis sib xws. Ferrites zoo li magnetite yog txhua hnub ferromagnetic yam.
Table 1: Cov khoom siv hlau nplaum
Khoom siv | Magnetism | Piv txwv |
Ferromagnetic | Muaj zog heev attraction rau magnetic teb | Hlau, cobalt, npib tsib xee |
Paramagnetic | Tsis muaj zog attraction rau magnetic teb | Aluminium, platinum |
Diamagnetic | Tsis muaj zog repulsion los ntawm magnetic teb | Tooj, kub |
Ferrimagnetic | Complex alignment, mus tas li magnetization | Magnetite, ferrites |
Antiferromagnetic | Ua kom tiav kev sib tw, tsis muaj net magnetization | Chromium, manganese |
Sib nqus Domains
Txhua cov ntaub ntawv uas yog ferromagnetic muaj cov hlau nplaum me me hauv lawv hu ua atomic dipoles. Cov hlau nplaum me me no feem ntau taw tes rau hauv cov lus qhia random, yog li lawv tshem tawm ib leeg. Qhov no txhais tau tias cov khoom tsis muaj tag nrho cov hlau nplaum thaum nyob ib leeg. Tab sis thaum cov khoom ua magnetized, cov hlau nplaum me me hauv kab!
Magnetization tshwm sim thaum pab pawg ntawm atoms hu ua magnetic domains tau txais lawv cov hlau nplaum me me los taw qhia tib txoj kev. Cov hlau nplaum me me taw tes ua ke hauv txhua qhov chaw vim tias lawv muaj kev sib txuas zoo. Tab sis cov thawj sib txawv yuav taw tes rau hauv cov lus qhia random ua ntej magnetization tshwm sim.
Cov rog sab nraud zoo li cov hlau nplaum sib nqus tuaj yeem ua rau cov thawj loj hlob tuaj thiab ua rau lawv cov hlau nplaum me me. Qhov no ua rau cov hlau nplaum ruaj khov. Cov khoom siv cua sov kuj muab lub zog rau cov hlau nplaum me me kom txav mus los. Qhov no cia cov thawj coj ua lawv cov hlau nplaum me me.
Lwm yam uas cuam tshuam li cas ntawm cov hlau nplaum me me tau teeb tsa suav nrog kev ntxhov siab, thaj tsam lis, impurities, thiab demagnetizing teb. Lub zog ntawm cov hlau nplaum nyob ntawm seb muaj pes tsawg tus thawj coj tau txais lawv cov hlau nplaum me me los ua kab thiab lawv tiv thaiv sab nraud quab yuam sim ua rau lawv zoo li cas.
Sib nqus teb
Cov hlau nplaum ua rau qhov pom tsis pom nyob ib puag ncig lawv hu ua magnetic fields. Qhov sib nqus flux yog qhov chaw nyob ib ncig ntawm lub hlau nplaum uas koj tuaj yeem hnov nws lub zog. Txhawm rau pom qhov sib nqus flux, peb kos cov kab sib nqus. Ntau kab txhais tau hais tias muaj zog magnetic teb. Cov kab tawm los ntawm cov hlau nplaum sab qaum teb thiab nkhaus mus rau nws sab qab teb ncej.
Sib nqus teb tshwm sim thaum cov nqi hluav taws xob me me txav mus los. Hauv cov atoms, cov electrons tig thiab mus ncig hauv orbits. Txhua lub atom yog cov hlau nplaum me me nrog nws tus kheej sab qaum teb thiab sab qab teb ncej. Nyob rau hauv cov ntaub ntawv sib nqus, cov hlau nplaum me me hauv cov npe kab. Qhov no muab tag nrho lawv cov magnetic teb los ua ib qho loj magnetic teb taw qhia ib txoj kev. Qhov no yog li cas cov hlau nplaum ruaj khov tau txais cov hlau nplaum muaj zog.
Qhov tsis pom kev sib nqus yog muaj zog dua thiab ze rau cov hlau nplaum. Nws tau qaug zog thaum koj txav mus deb. Cov hlau nplaum me me muaj cov hlau nplaum me me thiab tsis muaj zog. Cov hlau nplaum loj dua muaj cov hlau nplaum loj dua thiab muaj zog dua.
Sib Nqus Ncej
Cov hlau nplaum muaj cov ncej qaum teb thiab sab qab teb. Cov no yog cov cheeb tsam uas cov hlau nplaum muaj zog tshaj plaws. Cov ncej sab nraud nyiam ib leeg. Sab qaum teb thiab sab qab teb ncej txuas ua ke. Tib ncej thawb tawm ntawm ib leeg. Ob tug ncej sab qaum teb los yog ob tug ncej qab teb tawm tsam thiab thawb sib nrug.
Qhov no tshwm sim vim hais tias ntawm txoj kev uas tsis pom cov magnetic teb kab ntws. Cov kab mus los ntawm tus ncej qaum teb mus rau sab qab teb ncej hauv cov hlau nplaum. Nyob rau theem atomic, txhua lub hlau nplaum me me sab hauv muaj cov kab hlau nplaum uas ntws mus rau sab qaum teb mus rau sab qab teb. Nyob rau hauv ib tug hlau nplaum, tag nrho cov me me hlau nplaum kab lawv cov magnetic teb.
Cov hlau nplaum ruaj khov
Txawm hais tias qee cov ntaub ntawv zoo li hlau yog ib txwm sib nqus, cov hlau nplaum ruaj khov feem ntau yog tsim los ntawm kev sib nqus. Hlau, npib tsib xee, cobalt, lossis alloys feem ntau ua cov hlau nplaum zoo tshaj plaws.
Magnetization suav nrog nthuav tawm cov khoom mus rau qhov muaj zog sab nraud magnetic teb los ntawm electromagnet lossis lwm cov hlau nplaum ruaj khov. Qhov no ua rau cov hlau nplaum sib nqus loj hlob thiab ua kom zoo nrog rau sab nraud, tsim cov hlau nplaum ruaj khov. Cov hlau nplaum tawv tiv thaiv demagnetization, thaum cov hlau nplaum mos poob lawv cov hlau nplaum yooj yim dua.
Cov hlau nplaum ruaj khov lub zog sib txuas nrog nws cov coercivity, qhov kev siv lub teb xav tau los demagnetize nws. Cov ntaub ntawv siab coercive tuaj yeem ua cov hlau nplaum ruaj khov, tab sis nyuaj dua rau magnetize thawj zaug. Qhov siab tshaj plaws sib nqus flux ceev los yog saturation magnetization thiab seem magnetization kuj cuam tshuam cov hlau nplaum lub zog.
Hluav taws xob
Ntxiv nrog rau cov hlau nplaum tas mus li, cov hlau nplaum siv hluav taws xob siv hluav taws xob los txhawb cov hlau nplaum ib ntus. Thaum cov hluav taws xob tam sim no dhau los ntawm cov xaim coiled, nws tsim cov hlau nplaum sib nqus mus rau lub coil lub axis. Lub zog teb nce nrog ntau lub voj voog thiab siab dua tam sim no.
Cov khoom hauv lub kauj kuj tseem ceeb. Cov hlau mos ua rau cov hlau nplaum muaj zog. Hlau tuaj yeem ua rau lub tshuab hluav taws xob nqa 100 npaug ntxiv. Tab sis hlau kuj qeeb qeeb npaum li cas cov hlau nplaum reacts.
Electromagnets xav tau lub zog kom nyob sib nqus. Cov hlau nplaum tas mus li tsis muaj. Tab sis electromagnets tuaj yeem qhib thiab tawm sai. Lawv lub hwj chim tuaj yeem hloov tam sim ntawd thiab. Qhov no ua rau lawv tsim nyog rau kev nqa cov hlau hnyav thiab MRI scans uas xav tau hloov pauv cov hlau nplaum.
Magnetic Strength thiab Sib Nqus Moment
Yuav ua li cas sib nqus ib yam dab tsi nyob ntawm seb ntau npaum li cas magnetism tshwm sim nyob ze ntawm magnetic teb. Nws zoo npaum li cas nrog lub magnetic teb hu ua magnetic moment. Qhov no yog nyob ntawm cov khoom siv lub tsev me me hu ua atoms, feem ntau yog electrons uas nyob ib leeg thiab tsis ua khub. Cov no ua zoo li cov hlau nplaum me me.
Cov hlau nplaum muaj zog tuaj yeem tuav tau ntau lub zog sib nqus ntws los ntawm nws. Qhov no yog hu ua saturation magnetization. Cov hlau nplaum muaj zog ua kom nws cov hlau nplaum ntau dua thaum qhov chaw sab nraud ploj mus. Qhov no hu ua remanence. Magnetism yog los ntawm electrons spinning thiab orbiting. Yog li me me quantum physics txoj cai tswj kev sib nqus lub zog.
Magnetic Properties
Ntau yam khoom tseem ceeb ntawm cov hlau nplaum pab ua kom pom kev sib nqus:
● Saturation Magnetization: Qhov siab tshaj plaws tau sib nqus flux ntom ntom ntawm cov khoom tuaj yeem tsim nyob rau hauv ib qho kev thov. Ntsuas hauv Teslas.
● Remanence: Qhov seem magnetization thaum tsav tsheb raug tshem tawm. Muaj pes tsawg magnetism nyob?
● Coercively: Lub zog rov qab magnetic teb xav tau los demagnetize cov khoom rov qab mus rau xoom. Resistant demagnetization.
● Permeability: Muaj peev xwm txhawb kev tsim cov hlau nplaum hauv nws tus kheej. High permeability concentrates sib nqus flux.
● Hysteresis: Txaus siab rau khaws cov hlau nplaum uas raug txwv. Cov ntaub ntawv nrog hysteresis tseem ceeb ua rau cov hlau nplaum ruaj khov.
Kev ua kom zoo rau cov khoom ntawm cov hlau nplaum no yog qhov tseem ceeb hauv kev xaiv cov khoom siv hlau nplaum tsim nyog rau daim ntawv thov, txawm tias ua tiav qhov siab tshaj plaws nyob rau hauv lub zog ruaj khov lossis ua kom muaj kev hloov pauv hloov pauv.
Sib nqus Hysteresis
Cov hlau nplaum tuaj yeem ua hauv txoj kev zoo siab! Magnets nthuav tawm qhov tshwm sim hu ua hysteresis. Lawv magnetization ua raws txoj kev sib txawv txhua zaus koj mus ncig ntawm sab nraud magnetic teb. Txoj kev meej nyob ntawm cov hlau nplaum ua ntej keeb kwm ntawm magnetization.
Koj tuaj yeem pom qhov no thaum koj npaj yuav ua li cas qhov sib nqus flux ntom ntom B hloov pauv raws li qhov siv hlau nplaum H hloov. Cov zajlus no ua rau lub voj hu ua hysteresis voj.
Thaum xub thawj, cov cheeb tsam sib nqus me me hauv cov hlau nplaum hu ua domains maj mam kab thaum koj nce H. Thaum lawv tag nrho cov kab, ntxiv rau H tsis hloov B. Tom qab ntawd, thaum koj txo H, B ua raws qhov sib txawv nkhaus. Thaum H yog xoom, qee qhov magnetization tseem tshuav los ntawm qhov sib xyaw ua ke. Koj yuav tsum tau siv lub magnetic teb nyob rau hauv qhov opposite direction coj lub magnetization rov qab mus rau xoom.
Cov cheeb tsam hauv lub voj voog hysteresis qhia tau hais tias lub zog poob thaum cov thawj hloov pauv txhua lub voj voog. Cov hlau nplaum tawv muaj qhov dav dav thiab lub zog loj poob. Cov duab ntawm lub voj kuj qhia koj txog cov hlau nplaum lub zog, zoo li nws nyob li cas magnetized thiab nws nyuaj npaum li cas rau demagnetize.
Kev kub ntxhov
Lub zog cua sov tuaj yeem cuam tshuam cov hlau nplaum coj li cas! Raws li qhov kub thiab txias, cov cheeb tsam me me sib nqus hauv cov hlau nplaum hu ua domains tau jiggled ncig los ntawm lub zog cua sov. Qhov no ua rau magnetization poob qis. Ntawm qhov kub siab Curie, lub tshav kub lub zog cuam tshuam qhov kev txiav txim sib nqus, thiab cov hlau nplaum mus tas li ploj mus.
Nws yooj yim npaum li cas rau cov hlau nplaum poob nws cov hlau nplaum nyob ntawm nws qhov kub thiab txias Curie. Qhov kub Curie siab tshaj plaws ntawm cov khoom ntshiab yog hlau ntawm 1043 K. Ntxiv cov khoom xws li npib tsib xee thiab cobalt los ua cov alloys ua rau Curie point siab dua. Thaum tshav kub kub-resistant cov hlau nplaum ruaj khov cia koj siv cov hlau nplaum hauv cov ntawv thov xws li cov tshuab hluav taws xob thiab cov motors.
Cov hlau nplaum txias hauv qab ntawm Curie point ua rau cov hlau nplaum nce ntxiv. Superconducting electromagnets tsuas yog ua haujlwm ntawm qhov txias txias qhov twg hluav taws xob tsis kam ploj mus ua kom muaj zog, kav ntev hlau nplaum.
Table 2: Qhov kub thiab txias cuam tshuam rau hlau nplaum
Kub nyhuv | Kev piav qhia |
Curie Kub | Tshaj qhov kub no, cov hlau nplaum ruaj khov ploj lawm |
Thermal Agitation | tuaj yeem cuam tshuam kev sib raug zoo ntawm cov khoom sib nqus |
Txias hauv qab Curie Point | Nce magnetization raws li thermal motion txo |
Cryogenic kub | Pab kom superconducting electromagnets nrog kev ua haujlwm tsis tu ncua, muaj zog ua haujlwm siab |
Daim ntawv thov sib nqus
Magnets yog ntau yam cuab yeej pom nyob thoob plaws thaj chaw muaj kev lag luam hauv kev siv xws li:
● Cov Motors - Spinning electric motors cia siab rau cov hlau nplaum converting ntawm txhua yam thiab hluav taws xob zog los ntawm electromagnetic induction. Cov motors me tsav cov khoom siv los ntawm cov kiv cua mus rau hard drives.
● Generators - Turbine generators tsim hluav taws xob los ntawm kev sib hloov cov hlau nplaum ze ntawm cov hlau coils, inducing tam sim no ntws.
● Sib nqus cia - Hard disk drives sau cov ntaub ntawv los ntawm flipping lub magnetization ntawm me me domains ntawm ib tug ferromagnetic disk.
● Levitation - Maglev tsheb ciav hlau siv cov hlau nplaum kom ntab saum toj ntawm txoj kev, tshem tawm kev sib txhuam kom ntsiag to, mus ncig zoo.
● Cov khoom siv kho mob - MRI cov tshuab siv cov hlau nplaum muaj zog superconducting los kuaj xyuas cov kev hloov hauv lub cev magnetic teb rau kev kuaj pom.
● Kev Tshawb Fawb - Mass spectrometers khoov cov khoom siv nrog cov hlau nplaum los txiav txim siab lawv cov qauv thiab tshuaj lom neeg.
● Lub zog tauj dua tshiab - Sib nqus bearings stabilize flywheels, khaws cia lub zog kinetic sau los ntawm cov cua los yog hnub ci.
Sib nqus Levitation
Sib nqus levitation, lossis maglev, siv cov hlau nplaum ua kom cov khoom ntab! Magnets thawb tawm ntawm ib leeg. Tab sis tshwj xeeb hlau nplaum teeb tuaj yeem ua kom ruaj khov.
Fast maglev tsheb ciav hlau twb khiav hauv Asia thiab Europe. Floating saum tus khiav txhais tau tias tsis muaj kev sib txhuam los ntawm lub log, yog li ntawd maglev tsheb ciav hlau mus tshaj 600 km / h! Tsis muaj lub log lossis cov kabmob, lawv nyob ntsiag to thiab smoother kom nrawm thiab nres. Lawv kuj siv zog tsawg dua cov tsheb ciav hlau ib txwm muaj.
Maglev siv tau rau ntau tshaj li tsheb ciav hlau! Nws tuaj yeem pab tsim lub dav hlau dav hlau, ua cov khoom siv accelerators, tsim cov kabmob tsis muaj kev sib txhuam, thiab nres kev vibration hauv cov tsev. Engineers tseem tab tom txhim kho cov hlau nplaum muaj zog heev. Qhov no yuav cia maglev tsheb ciav hlau txuas tag nrho lub nroog yav tom ntej.
Ntxiv ntxiv txog yuav ua li cas maglev ua haujlwm, kev siv lub ntiaj teb tiag tiag, thiab yav tom ntej muaj peev xwm piav qhia txog lub tswv yim zoo tshaj no yooj yim. Cov tub ntxhais hluas tuaj yeem nkag siab txog cov tsheb ciav hlau ntab los ntawm kev sib txhuam tsis muaj zog hlau nplaum thiab xav txog lwm yam kev siv ntawm cov tshuab txias no.
Xaus
Los ntawm cov hlau nplaum me me mus rau mais-ntev hlau nplaum uas muaj zog fusion reactors, hlau nplaum yog qhov tseem ceeb hauv peb lub neej txhua hnub. Nkag siab txog cov khoom tshwj xeeb ntawm cov hlau nplaum txuas ntxiv ua rau muaj kev tshawb pom uas ua rau cov ntawv thov tshiab. Tej thaj chaw zoo li spintronics thiab magnetic monopoles tuav tau rau tiam tom ntej electronics thiab txawm quantum computers.
Nrog ntau yam tseem yuav nkag siab txog quantum foundations ntawm magnetism, kev tshawb fawb yuav nthuav qhia lawv cov peev xwm loj heev. Tseem muaj ntau ntxiv los tshawb pom txog yam khoom ntawm cov hlau nplaum tuaj yeem pab peb ua tiav.
FAQs txog Properties of Magnets
Dab tsi yog units ntawm magnetic teb zog?
Magnetic teb lub zog yog xam nyob rau hauv amperes ib 'meter' (A / m) los yog teslas (T). Ib tug tesla sib npaug ib tug newton ib ampere 'meter'. Lub ntiaj teb lub zog hlau nplaum yog nyob ib ncig ntawm 0.5 gauss lossis 50 microteslas.
Yuav ua li cas koj xam magnetic flux?
Qhov sib nqus flux los ntawm qhov chaw yog xam los ntawm kev sib npaug ntawm qhov sib nqus ntawm lub zog, qhov chaw perpendicular, thiab lub cosine ntawm lub kaum sab xis.
Cov khoom siv dab tsi yog siv hauv cov hlau nplaum superconducting?
Superconducting hlau nplaum feem ntau siv superconductors zoo li niobium-titanium los yog niobium-tin coils txias los ntawm kua helium. Newer high-temperature superconductors tso cai kom tsis tshua muaj huab cua txias xav tau rau kev ua haujlwm siab.
Meta Description
Tshawb lub ntiaj teb ntxim nyiam ntawm cov hlau nplaum. Kawm txog cov ntaub ntawv, thaj chaw, thaj chaw, thiab lwm yam khoom ntawm cov hlau nplaum!