Yuav ua li cas electromagnetic teb (EMF)

Electromagnetic teb thiab tawg nyob ib ncig ntawm peb. Nws yog txaus ntxeev tus tes hloov qhov - thiab lub teeb tawm mus, tig rau koj lub computer - thiab koj muaj nyob hauv internet, hu ib tug xov tooj nyob rau hauv koj lub xov tooj txawb - thiab koj yuav sib txuas lus nrog nyob deb continents. Nyob rau hauv qhov tseeb, nws tau tsim lub neej tshiab nimno hluav taws xob khoom siv lub ntiaj teb no raws li peb paub nws. Qhia, txawm li cas los, qhov teeb meem tsa nyob rau hauv tsis ntev los no xyoo uas lub electromagnetic teb (EMF) generated los ntawm qhov hluav taws xob khoom mus yuav muaj teeb meem. Yog muaj tseeb no? Sim kom to taub.

Peb pib nrog ib tug txhais. Electromagnetic teb, raws li paub los ntawm physics tsev kawm ntawv cov hoob kawm, roos ib tug tshwj xeeb daim ntawv ntawm qhov teeb meem. Ib tug tseem ceeb feature ntawm cov teb - muaj peev xwm mus nrog tej yam lub cev thiab hais muaj hluav taws xob xwb. Raws li lub npe implies, lub electromagnetic teb yog ib tug sau ntawm sib nqus thiab hluav taws xob teb, nyob rau hauv uas cov ntaub ntawv lawv thiaj li zoo txog tias lawv pom tau hais tias ib chav tsev. Nta ntawm kev sis raug zoo nrog them cov khoom yog piav nrog kev pab los ntawm lub Lorentz quab yuam.

Thawj electromagnetic teb tau lej qhia nyob rau hauv Maxwell lub kev tshawb xav nyob rau hauv 1864. Ua tau, nws tau ices indivisible magnetic thiab hluav taws xob teb. Ib tug rau txim ntawm txoj kev tshawb xav yog qhov tseeb hais tias tej perturbation (hloov) ntawm lub electromagnetic teb yog qhov ua rau ntawm electromagnetic vuag propagating nyob rau hauv vacuo nrog cov kev ceev ntawm lub teeb. Suav pom hais tias lub teeb (tag nrho cov feem ntawm lub spectrum: lub infrared, pom, ultraviolet) nws yog ib qho electromagnetic yoj. Feem ntau, classifying emission wavelength paub qhov txawv cov X-ray, xov tooj cua thiab thiaj li nyob.

Cov tsos ntawm Maxwell lub ziag twb preceded los ntawm lub chaw ua hauj lwm ntawm Faraday (nyob rau hauv 1831) rau txoj kev tshawb no ntawm electromagnetic induction nyob rau hauv ib tug neeg xyuas pib tsiv los yog muab tso rau hauv ib qho alternating magnetic teb. Txawm ua ntej lawm, nyob rau hauv 1819, H. Oersted pom hais tias thaum nyob ze ib tug neeg xyuas pib muab compass, nws koob lo los ntawm lub ntuj magnetic ncej ntawm lub ntiaj teb, uas pom tias ib tug ncaj qha kev txuas ntawm magnetic thiab hluav taws xob teb.

Tag nrho cov no yuav qhia tau tias tej khoom siv roj yog ib tug generator ntawm electromagnetic vuag. Qhov no tej khoom vaj tse yog tshwj xeeb yog cov lus hais rau ib co kev pab kiag li lawm thiab siab tam sim no circuits. Ob leeg thawj thiab thib ob yog tam sim no tam sim no nyob rau hauv yuav luag txhua txhua lub tsev. Txij li thaum EMF siv tsis tau tsuas yog conductive ntaub ntawv tab sis kuj nyob rau hauv dielectrics (eg, lub tshuab nqus tsev), tus neeg ntawd yog ib txwm nyob rau hauv lub cheeb tsam ntawm lawv ua.

Yog hais tias ua ntej lawm, thaum lub chav tsev yog ib tug "qhov muag teev Ilyich", cov lus nug rankled. Tam sim no txhua yam yog sib txawv: cov electromagnetic teb ntsuas yog tau siv tshwj xeeb seev los ntsuas lub teb lub dag lub zog. Ob yam yog tsau EMF nyob rau hauv ib tug tej yam ntau zaus (nyob ntawm seb lub rhiab heev ntawm lub twj paj nruag). Cov ntaub ntawv SanPiN teev PDN (permissible cai). Nyob rau hauv qhauj thiab loj tuam txhab uas muag tsis tseg cov tshev mis yog ua PDN EMF. Nws yuav tsum tau muab sau tseg tias zaum kawg tshwm sim ntawm cov kev tshawb fawb ntawm EMF los ntawm cov uas muaj sia nyob yog tseem muaj. Yog li ntawd, piv txwv li, thaum ua hauj lwm nrog computer technology yog xav kom mus npaj ib tug 15-feeb so tom qab txhua txhua teev - cia li nyob rau hauv rooj plaub ... Cov kev tshab txhais yog heev yooj yim: nyob ib ncig ntawm tus neeg xyuas pib muaj ib tug sib nqus teb, ces muaj yog tseem lub EMF. Cov khoom yog kev ruaj ntseg kiag nyob rau hauv cov kev tshwm sim hais tias thaum rho los ntawm cov phab ntsa qhov hluav taws xob lub hwj huam qaum.

Nws yog pom tseeb tias mus kiag li tso tseg kev siv hluav taws xob khoom siv, ob peb twv. Txawm li cas los, nyob rau hauv tas li ntawd, koj muaj peev xwm tiv thaiv koj tus kheej los ntawm kev txuas lub tsev khoom siv mus rau ib tug grounded network, uas tej zaum yog tsis sau rau cov ntaub ntawv, thiab cov "ntws" nyob rau hauv lub hauv av voj. Ntau extenders, tshwj xeeb tshaj yog nyob rau hauv coiled lub nplhaib, vim nco kev sib nrig sib EMF. Thiab, ntawm chav kawm, koj yuav tsum tsis txhob mus ze kev tso kawm ntawm ntau pab kiag li lawm thiab.