Dab tsi yog superconducting khoom
Apr 24, 2021
Thaum tus kub poob rau qee qhov kub tseem ceeb, qhov tsis kam ntawm qee yam khoom ploj mus. Qhov tshwm sim no hu ua kev ua haujlwm superconductivity, thiab cov ntaub ntawv nrog qhov tshwm sim no yog hu ua cov ntaub ntawv txheej txheem superconducting. Lwm qhov tshwj xeeb ntawm cov superconductors yog tias thaum qhov tsis kam poob, cov hlau kab induction yuav tsis hla tus superconductor. Qhov tshwm sim no hu ua diamagnetism.
Lub resistivity ntawm cov hlau dav dav (xws li tooj liab) maj mam poob qis nrog qhov txo kub. Thaum qhov ntsuas kub ze rau 0K, nws qhov kev kam nce mus txog ib qho nqi. Xyoo 1919, tus kws tshawb fawb Dutch Onnes siv cov kua roj helium kom txias cov mercury. Thaum twg qhov kub tau poob qis mus rau 4.2K (piv txwv li -269 ° C), nws pom tias qhov tsis kam ntawm cov tshuaj mercury tag.
Superconductivity thiab diamagnetism yog ob qho tseem ceeb cov yam ntxwv ntawm superconductors. Qhov ntsuas kub ua kom qhov tsis kam ntawm cov superconductor xoom yog hu ua qhov ntsuas kub tseem ceeb (TC). Qhov teeb meem hauv kev tshawb fawb ntawm cov ntaub ntawv superconducting yog tawg los ntawm" ntsuas kub tsis haum"
Cov ntaub ntawv coj los ua cov ntaub ntawv tshwj xeeb sawv cev los ntawm NbTi thiab Nb3Sn tau ua lag luam, thiab tau coj mus siv rau ntau thaj chaw xws li nuclear sib nqus resonance tib neeg cov duab (NMRI), cov hlau nplaum superconducting thiab cov hlau nplaum loj loj; SQUID tau siv los ua qauv ntawm superconductor tsis muaj zog cov kev siv tam sim no. Nws ua lub luag haujlwm tseem ceeb hauv kev ntsuas ntawm lub ntsuas hluav taws xob tsis muaj zog, thiab nws cov rhiab yeej tsis muaj peev xwm tiv thaiv tau los ntawm lwm cov khoom siv tsis yog superconducting. Txawm li cas los xij, vim tias qhov ntsuas kub tseem ceeb ntawm cov pa hluav taws xob muaj zog tshaj qhov ntsuas qis tsawg dhau, lawv yuav tsum tau siv cov khoom siv kim thiab ua kua helium (4.2K), uas muaj kev txwv hnyav rau kev tsim cov ntawv thov kev siv hluav taws xob tsawg.
Qhov tshwm sim ntawm kev kub ceev oxide superconductors tau tawg ntawm qhov ntsuas kub thiab tsa cov ntawv thov kub ntawm superconductivity los ntawm kua helium (4.2K) rau kua nitrogen (77K). Piv nrog kua dej helium, kua nitrogen yog cov roj tub yees zoo heev thiab muaj peev xwm ua kom muaj cua sov ntau dua, uas coj tau yooj yim rau kev siv engineering. Ntxiv rau, cov superconductors siab-kub muaj cov khoom sib nqus heev thiab tuaj yeem siv los tsim cov teb loj muaj zog tshaj 20T.
Cov ntawv thov tshwj xeeb tshaj plaws ntawm cov ntaub ntawv superconducting yog cov tshuab tsim hluav taws xob, lub zog hluav taws xob thiab lub zog cia. Siv cov ntaub ntawv txheej txheem ua kom lub zog sib nqus ntawm lub tshuab hluav taws xob tsis zoo tuaj yeem ua rau lub zog sib nqus ntawm lub tshuab hluav taws xob tau nce mus txog 50,000 txog 60,000 Gauss, thiab yuav luag tsis muaj lub zog poob. Piv nrog cov tshuab hluav taws xob ua ke, qhov muaj peev xwm ntawm cov neeg tsis muaj hluav taws xob loj ntxiv tau nce 5 ~ 10 zaug, kev tsim hluav taws xob muaj peev xwm nce ntxiv 50%; superconducting kis kab thiab superconducting transformers tuaj yeem xa lub zog rau cov neeg siv yuav luag yam tsis poob. Raws li kev txheeb cais, kwv yees li 15% ntawm lub zog tuag hauv tooj liab lossis txhuas xaim hluav taws xob kis tau rau ntawm txoj kab xa xov. Hauv Suav teb, cov fais fab txhua xyoo poob yog ntau tshaj 100 billion degrees. Yog tias nws hloov mus rau kev tswj hwm lub zog hluav taws xob, lub zog txuag tau zoo ib yam li cov kaum tawm tshiab ntawm cov tsev ua hluav taws xob loj; txoj cai ua haujlwm ntawm kev ua haujlwm rau cov tsheb ciav hlau superlev yog siv cov khoom sib nqus ntawm cov txheej txheem superconducting los txo cov ntaub ntawv coj los ua ntau yam. Cov khoom siv khoom zoo yog muab tso rau saum cov hlau nplaum ruaj khov (lossis cov hlau nplaum tas li). Vim tias lub diamagnetism ntawm tus superconductor, cov kab sib nqus ntawm cov hlau nplaum tsis tuaj yeem hla dhau ntawm tus superconductor. Kev quab yuam zog yuav tsim nyob nruab nrab ntawm cov hlau nplaum (lossis magnetic teb) thiab lub superconductor, ua rau lub superconductor levitate saum nws. Hom kev sib nqus levitation no tuaj yeem siv los ua cov kev kub ceev superconducting sib nqus levitation tsheb ciav hlau, xws li lub tsheb ciav hlau qhov ceev ntawm Shanghai Pudong International Airport; rau kev ua haujlwm hauv cov khoos phis tawm, cov koos pis tawj muaj qhov siab xav tau tuab ntawm cov khoom sib txuas thiab cov kab sib txuas ntawm cov xov sib xyaws sib xyaw ua ke, tab sis cov voj voos muaj ntau cov cua sov tau tsim thaum ua haujlwm. Yog tias cov khoom siv superconducting nrog cov tsis kam ze rau xoom siv los ua cov hlau txuas lossis lub tshuab hluav taws xob uas muaj qhov kub nruab nrog ultra-micro cua sov, yuav tsis muaj teeb meem kub kom tsis muaj teeb meem thiab qhov nrawm ntawm lub koos pij tawj tuaj yeem hloov kho tau zoo heev.
