Nkag siab txog ntau hom hluav taws xob ultraviolet (UV) thiab lawv cov teebmeem ntawm biology yog qhov tseem ceeb ua ntej sim txiav txim siab seb lub teeb UV twg yog qhov txaus ntshai tshaj plaws. Peb hom ntawm UV hluav taws xob feem ntau txawv los ntawm lawv cov wavelength, kev siv zog, thiab kev nkag mus rau lub zog:UVA, UVB, thiab UVC. Txawm hais tias muaj kev phom sij cuam tshuam nrog txhua hom UV hluav taws xob, UVA lub teeb feem ntau suav tias yog qhov txaus ntshai tshaj plaws thaum ntsuas raws li nws cov yam ntxwv ntawm lub cev thiab muaj peev xwm ua rau raug mob tam sim ntawd. Kev kuaj xyuas txhua yam thiab yog vim li cas UVA yog qhov tshwj xeeb tuaj yeem pom hauv qab no.
Cov yam ntxwv tseem ceeb ntawm peb hom UV hluav taws xob
Lub wavelength uas UV hluav taws xob raug faib ncaj qha cuam tshuam rau nws lub zog thiab muaj peev xwm ua mob rau cov ntaub so ntswg lom. Hauv qab no yog cov ntsiab lus ntawm txhua yam:
UVA (ntev{0}} wavelength UV) (315–400 nm)
Lub wavelength ntau yam uas ze tshaj rau pom lub teeb yog 315 txog 400 nanometers (nm).
Txij li cov wavelengths ntev dua muaj tsawg zog ib photon, daim ntawv no ntawm UV muaj qis zog.
Lub hnub yog lub hauv paus ntuj tsim, txawm hais tias cov khoom siv dag zog xws li lub txaj tanning, lub teeb dub, thiab qee cov khoom siv LED kuj tso tawm cov khoom no.
Kev nkag mus: Muaj peev xwm ncav cuag lub qhov muag lub lens thiab retina ntawm kev nkag mus rau dermis, cov txheej txheem tob ntawm daim tawv nqaij.
UVB (nruab nrab- wavelength UV, 280–315 nm)
Ntau qhov wavelength: 280-315nm.
Qib Zog: Ntau dua li UVA, tso cai rau kom nrawm dua qhov deterioration.
Natural Source: Hnub Ci; Tsuas yog nyob ib ncig ntawm 5% ntawm UVB rays ncav cuag lub ntiaj teb nto tom qab absorbed los ntawm ozone txheej.
Kev nkag mus: cuam tshuam rau lub cornea ntawm lub qhov muag nrog rau cov epidermis, txheej txheej ntawm daim tawv nqaij.
UVC (luv-Vavelength UV, 100–280 nm)
Lub electromagnetic spectrum qhov luv tshaj thiab ze tshaj wavelength nyob ze X-rays yog nyob nruab nrab ntawm 100 thiab 280 nm.
Vim nws qhov luv wavelength, nws muaj lub zog siab tshaj plaws thiab tseem ua rau muaj kev puas tsuaj ntau tshaj plaws.
Natural Source: Feem ntau thaiv los ntawm txheej ozone; cov cuab yeej siv hauv tsev, cov dej lim dej, thiab cov teeb pom kev zoo yog cov piv txwv ntawm cov khoom siv dag zog.
Kev nkag mus: Lub cornea ntawm lub qhov muag thiab cov txheej txheej sab nrauv ntawm daim tawv nqaij nqus nws, tab sis nws lub zog loj tam sim ua rau nws puas.
Kev Tshawb Fawb Txog Kev Tshawb Fawb Txog Vim li cas UVA thiaj li muaj kev phom sij tsawg
Lub peev xwm ntawm UV teeb los cuam tshuam cov hlwb los ntawm oxidative kev nyuaj siab, DNA kev puas tsuaj, thiab ionization txiav txim siab nws cov proportional toxicity. Cov hauv qab no piav qhia vim li cas UVA tsis txaus ntshai tshaj UVB thiab UVC tam sim no:
Txo Ionizing muaj peev xwm thiab lub zog
Piv rau UVB thiab UVC, uas muaj luv wavelengths, UVA muaj zog tsawg vim nws lub wavelength ntev (315-400 nm).
Qhov txawv tseem ceeb: UVA feem ntau ua rau DNA tsis ncaj qha los ntawm kev tsim cov dawb radicals, tab sis UVC thiab siab -lub zog UVB tuaj yeem cuam tshuam ncaj qha DNA bonds (ionization). UVA cov teebmeem ua rau qis qis thiab qeeb qeeb vim qhov tshwm sim.
Tsawg cuam tshuam rau ntawm qhov muag thiab tawv nqaij
Cov teebmeem ntawm daim tawv nqaij: UVA ua rau wrinkles thiab pigmentation los ntawm degrading collagen thiab elastin, uas yog ib qho tseem ceeb rau kev yees duab. Nws tseem ua rau mob qog noj ntshav ntawm daim tawv nqaij, txawm hais tias feem ntau tsuas yog tom qab ntau xyoo ntawm kev sib kis.
Ntawm qhov tod tes, UVB yog thawj qhov ua rau ntawm basal cell thiab squamous cell carcinomas thiab ua rau muaj tshav kub sai, lossis erythema. Unblocked UVC yuav ua rau cov ntaub so ntswg puas thiab mob hnyav, kub hnyiab.
Teebmeem ntawm Lub Qhov Muag: Lub sijhawm dhau mus, UVA rays tuaj yeem ua rau cataracts thiab macular degeneration vim lawv tuaj yeem dhau los ntawm lub qhov muag ntawm lub qhov muag thiab mus txog retina.
Tsis pub dhau ob peb teev ntawm kev raug, UVB thiab UVC ua rau muaj kev puas tsuaj loj rau lub pob txha thiab pob txha, ua rau muaj teeb meem xws li photokeratitis (corneal sunburn).
Qhov xwm txheej tshwm sim: Tus txiv neej- tsim thiab Ntuj qhov chaw
Kev Tiv Thaiv Ntuj: Txij li feem ntau UVB thiab UVC rays raug thaiv los ntawm ozone txheej, kwv yees li 95% ntawm UV hluav taws xob uas ncav cuag lub ntiaj teb saum npoo yog UVA. Vim tias UVA rays tsis tu ncua nyob rau hauv tib neeg lub cev, lawv tau txuas mus rau kev puas tsuaj ntawm daim tawv nqaij.
Kev Siv Artificial: Vim tias UVA qhov qis qis ua rau muaj kev tswj hwm ntau dua, nws yog siv rau hauv txaj tanning, yees duab, thiab tshuaj kho mob (xws li kev kho psoriasis). Txawm li cas los xij, vim tias lawv muaj kev pheej hmoo ntau ntxiv, cov khoom siv hluav taws xob UVB thiab UVC (xws li cov teeb pom kev zoo) yuav tsum tau ceev faj heev.
Kev ntseeg cuav: UVA tsis yog "kev nyab xeeb."
UVA tsis yog qhov tsis muaj tseeb, txawm tias nws yog hom UV txaus ntshai tshaj plaws. Tej myths xwb muaj xws li:
"Kev mob qog nqaij hlav ntawm daim tawv nqaij tsis yog los ntawm UVA."
UVA inhibits lub cev tiv thaiv kab mob thiab ua rau tsis ncaj ncees rau DNA, uas ua rau melanoma, hom mob cancer ntawm daim tawv nqaij. Kev pheej hmoo yog nce los ntawm kev raug mob ntau zaus (piv txwv li, tanning txaj).
"UVA tsis ua mob qhov muag."
Retinal degeneration thiab cataracts tuaj yeem tshwm sim los ntawm kev raug UVA ntev. Txawm hais tias qhov tshwm sim yuav siv sijhawm los tshwm sim, kev tiv thaiv tseem ceeb heev.
Cov txheej txheem kev nyab xeeb dav dav rau txhua hom UV
Kev ceev faj yog qhov tseem ceeb tsis hais txog hom UV:
Siv dav - spectrum sunscreen (SPF 30+) uas tiv thaiv UVA thiab UVB rays los tiv thaiv koj cov tawv nqaij.
Thaum lub hnub muaj zog tshaj plaws, nrhiav npog thiab hnav cov iav tiv thaiv, xws li lub kaus mom thiab lub tes tsho ntev.
Hnav looj tsom iav dub uas thaiv 99-100% ntawm UVA thiab UVB hluav taws xob tiv thaiv koj ob lub qhov muag.
Tsis txhob saib ncaj qha ntawm qhov chaw UV, xws li cov teeb pom kev zoo lossis UV LEDs.
Ceeb Toom Txog Artificial Sources:
Ua raws li cov khoom siv UV cov chaw tsim khoom cov lus qhia (xws li, kaw cov tshuaj tua kab mob thoob plaws hauv kev siv).
Rau ib qho kev raug mob hauv qhov xwm txheej, siv UV- cov khoom thaiv.
Kev siv tswv yim thiab kev puas tsuaj
Kev siv UVA: Tanning txaj: Txawm hais tias tseem muaj kev phom sij, siv UVA kom tawv nqaij tsis muaj nws hlawv tam sim ntawd.
Lub teeb dub: Siv hauv kev tshawb fawb thiab kev lom zem, cov no tsawg - sivUVA teebtsis txaus ntshai tshwj tsis yog lawv raug saib ncaj qha.
Daim ntawv thov UVB: nruj me ntsis tswj cov tshuaj tiv thaiv kom tsis txhob kub hnyiab thiab txwv tsis pub siv tshuaj kho mob (xws li phototherapy rau dermatitis).
Cov ntawv thov rau UVCs suav nrog kev ua kom tsis muaj menyuam hauv chav kuaj thiab tsev kho mob, uas ib txwm ua hauv cov txheej txheem kaw los tiv thaiv tib neeg.
Hauv cov ntsiab lus, UVA yog "tsawg kawg," txawm tias nws yuav tsum tau siv ceev faj.
Vim tias nws qhov kev siv qis dua, kev ua haujlwm qeeb qeeb, thiab txo qis kev pheej hmoo ntawm kev raug mob hnyav, UVA yog qhov txaus ntshai tshaj plaws ntawm peb hom UVA, UVB, thiab UVC. Tab sis qhov kev xaiv no tsis ua rau nws muaj kev phom sij tsawg dua: Qhov cuam tshuam ntawm UVA ntawm daim tawv nqaij thiab qhov muag hais txog qhov tsim nyog ntawm kev tiv thaiv ib txwm los ntawm ob qho tib si ntuj thiab txiv neej- tsim los. Cov lus qhia tseem ceeb tshaj plaws yog tias txhua qhov hluav taws xob UV yuav tsum raug hwm; los ntawm kev paub txog lawv cov kev pheej hmoo tshwj xeeb, peb tuaj yeem sib npaug lawv cov ntawv thov muaj txiaj ntsig (xws li kev kho mob thiab ua kom tsis muaj menyuam) nrog kev ceev faj los tiv thaiv peb txoj kev noj qab haus huv. Peb tuaj yeem txo qhov txaus ntshai thiab ua kom muaj txiaj ntsig zoo ntawm UV thev naus laus zis los ntawm kev hais txog kev kawm thiab kev ceev faj.
http://www.benweilight.com/professional-lighting/uv-lighting/uv-light-black-light-for-halloween.html
