Kunamagama athile adala ukudideka olimini oluvamile lwansuku zonke. Phakathi kwala magama sinawo i-luminescence, i-fluorescence ne-phosphorescence. Ingabe ayalingana amagama? Ihluke kanjani futhi ngayinye ibhekisela kuphi?
Konke lokhu sizokubona kulesi sihloko, ngakho ungaphuthelwa.
Yini i-luminescence
Igama elithi luminescence ngokuyisisekelo libhekisela ekukhishweni kokukhanya. Endaweni yethu, izinto eziningi zikhipha ukukhanya ngenxa yamandla eziwathola elangeni, okuyinto Yibhizinisi elikhanya kakhulu elibonakala kithi. Ngokungafani nenyanga, ebonakala ikhipha ukukhanya, empeleni iveza ukukhanya kwelanga, isebenza ngendlela efanayo nesibuko samatshe esikhulukazi. Ukuze uqonde kangcono ukuthi i-luminescence isebenza kanjani ezintweni ezahlukene, ungabonisana umthelela wezimo zezinkanyezi ku-luminescence.
Ngokuyisisekelo, kunezinhlobo ezintathu eziyinhloko ze-luminescence: i-fluorescence, i-phosphorescence ne-chemiluminescence. Phakathi kwazo, i-fluorescence ne-phosphorescence zihlukaniswa njengezinhlobo ze-photoluminescence. Umehluko phakathi kwe-photoluminescence kanye ne-chemiluminescence usesimeni sokusebenza kwe-luminescence; Ku-photoluminescence, ukukhanya kusebenza njenge-trigger, kuyilapho ku-chemiluminescence, ukusabela kwamakhemikhali kuqala ukukhishwa kokukhanya.
Kokubili i-fluorescence ne-phosphorescence, okuyizinhlobo ze-photoluminescence, zincike ekhonweni lento lokumunca ukukhanya bese ngokulandelayo likukhiphe ngobude begagasi elide, okubonisa ukuncipha kwamandla. Nokho, Ubude besikhathi sale nqubo buhluka kakhulu. Ekuphenduleni kwe-fluorescent, ukuphuma kokukhanya kwenzeka ngokushesha futhi kubonakala kuphela ngenkathi umthombo wokukhanya uhlala usebenza (njengamalambu e-ultraviolet).
Ngokuphambene, ukusabela kwe-phosphorescent kuvumela okokusebenza ukuthi kugcine amandla amuncwa, okuwavumela ukuthi akhiphe ukukhanya kamuva, okuholela ekukhanyeni okuqhubekayo ngisho nangemva kokuba umthombo wokukhanya ucishiwe. Ngakho-ke, uma i-luminescence inyamalala ngokushesha, ihlukaniswa njenge-fluorescence; Uma iphikelela, ibonakala njenge-phosphorescence; futhi uma idinga ukusabela kwamakhemikhali ukuze isebenze, ibizwa nge-chemiluminescence.
Izibonelo zalokhu zingatholakala kuzigigaba zemvelo kanye nezinhlelo zokusebenza zobuchwepheshe, njengaku izinto ze-fluorescent kanye ne-phosphorescent. Isibonelo, umuntu angacabanga nge-nightclub lapho indwangu namazinyo kukhanya ngaphansi kokukhanya okumnyama (i-fluorescence), isibonakaliso sokuphuma esiphuthumayo sikhipha ukukhanya (phosphorescence), nezinti ezikhanyayo nazo zikhiqiza ukukhanya (chemiluminescence). Futhi ekuphawuleni izinto nasezifundweni zesayensi, lapho umehluko wesikhathi se-luminescence ubalulekile.
I-Fluorescence
Izinto ezikhipha ukukhanya ngokushesha zibizwa nge-fluorescent. Kulezi zinto, ama-athomu amunca amandla, abangele ukuthi bangene esimweni "sokuthokoza". Lapho zibuyela esimweni sazo esivamile cishe engxenyeni eyizinkulungwane eziyikhulu yomzuzwana (kusukela kumasekhondi angu-10^-9 kuya ku-10^-6), zikhulula la mandla ngendlela yezinhlayiya ezincane zokukhanya ezaziwa ngokuthi ama-photon.
Ngikhuluma ngokusemthethweni, I-Fluorescence iyinqubo yokukhipha imisebe lapho ama-electron ajabulile Badlula esimweni esiphansi kakhulu senjabulo (S1) baye endaweni ephansi (S0). Phakathi nalolu shintsho, i-electron ihlakaza amanye amandla ayo ngokukhululeka kokudlidliza, okuholela ekutheni i-photon ekhishiwe ibe namandla ancishisiwe, ngenxa yalokho, ubude begagasi ende.
Ngezinhlelo zokusebenza ezingokoqobo nezibonelo ze-fluorescence, ungabhekisela kokuthi "Izinhlelo zokusebenza nokusetshenziswa kwe-fluorescence kusayensi nobuchwepheshe".
I-Phosphorescence
Ukuze uqonde umehluko phakathi kwe-fluorescence ne-phosphorescence, kuyadingeka ukuhlola kafushane umqondo we-electron spin. I-Spin imele isici esiyisisekelo se-electron, esebenza njengohlobo lomfutho we-angular onomthelela ekuziphatheni kwayo ngaphakathi kwenkambu ye-electromagnetic. Lesi sakhiwo singathatha kuphela inani elingu-½ futhi singabonisa umumo obheke phezulu noma phansi. Ngaphakathi kwe-orbital efanayo ye-athomu, ama-electron ahlala ebonisa ukujikeleza kwe-antiparallel lapho esesimweni esiphansi se-singlet (S0). Ngemva kokunyuselwa kusimo senjabulo, i-electron igcina i-spin orientation yayo, okuholela ekwakhekeni kwesimo se-singlet ejabulile (S1), lapho kokubili ukujikeleza kwe-spin kuhlala kubhanqiwe ekucushweni kwe-antiparallel. Kubalulekile ukuqaphela ukuthi zonke izinqubo zokuphumula ezihlotshaniswa ne-fluorescence ziyi-spin-neutral, okuqinisekisa ukuthi i-electron spin orientation iyalondolozwa ngaso sonke isikhathi.
Endabeni ye-phosphorescence, Inqubo ihluka kakhulu, njengoba ihilela uguquko phakathi kwezifunda ezinemijikelezo ehlukene ye-spin.. Ukushintsha okusheshayo (kusuka ku-10^-11 kuya ku-10^-6 amasekhondi) kwenzeka phakathi kwamasistimu adlula endaweni yenjabulo ye-singlett (S1) ukuya kusimo senjabulo ye-triplet esivumayo (T1). Lolu shintsho luholela ekuguqulweni kwe-electron spin; Izimo eziwumphumela zibonakala ngama-parallel spins kuwo womabili ama-electron futhi ahlukaniswa njengama-metastable. Kulesi simo, ukuphumula kwenzeka nge-phosphorescence, okuholela kokunye ukuguqulwa kwe-electron spin kanye nokukhishwa okulandelayo kwe-photon.
Inguquko ebuyela esimweni esikhululekile se-singlet (S0) ingenzeka ngemva kokulibaziseka isikhathi eside (okuhluka ukusuka ku-10^-3 ukuya kumasekhondi angaphezu kuka-100). Phakathi nale nqubo yokuphumula, izindlela ezingasebenzisi imisebe zisebenzisa amandla engeziwe ekuphumuleni kwe-phosphorescent uma kuqhathaniswa ne-fluorescence, okuholela kumehluko omkhulu wamandla phakathi kwama-photons amuncwa nakhishiwe futhi, ngenxa yalokho, ukushintsha okukhulu kobude be-wavelength. Kuyathakazelisa ukubona ukuthi umehluko wesakhiwo se-athomu sezinto zokwakha ubangela kanjani lokhu kuhlukahluka kwezenzakalo ze-luminescence.
I-Excitation kanye ne-emission spectra
I-Luminescence yenzeka lapho ama-electron ento ejatshuliswa ukumunca ama-photon, bese ekhipha lawo mandla ngendlela yemisebe. Kwezinye izimo, Imisebe ekhishiwe ingaba nama-photon anamandla afanayo nobude begagasi njengalawo amuncwa; Lesi simo saziwa ngokuthi i-resonance fluorescence. Imvamisa, imisebe ekhishwayo inobude begagasi ende, okubonisa amandla aphansi uma kuqhathaniswa nama-photon amuncwa.
Lokhu kushintshela kumaza amade amaza kwaziwa ngokuthi iStokes shift. Lapho ama-electron ejatshuliswa imisebe emifushane, engabonakali, akhuphukela ezifundeni zamandla aphezulu. Lapho zibuyela esimweni sazo sasekuqaleni, zikhipha ukukhanya okubonakalayo okunobude beza obufanayo, okuyisibonelo se-resonance fluorescence. Kodwa-ke, lawa ma-electron ajabulile angaphinde abuyele ezingeni lamandla elimaphakathi, okuholela ekukhishweni kwe-photon ekhanyayo ethwala amandla amancane kunalawo esasasa lokuqala. Lolu hlelo, lapho ibangelwa ukukhanya kwe-ultraviolet, ngokuvamile ibonakala njenge-fluorescence ngaphakathi kwe-spectrum ebonakalayo. Esimeni sezinto ze-phosphorescent, kukhona ukubambezeleka phakathi kwe-excitation yama-electron kumazinga aphezulu wamandla kanye nokubuyela kwawo esimweni esiphansi.
Isici esithakazelisayo okufanele siqashelwe ukuthi amandla nombala wokukhanya okukhiphayo kuncike entweni kanye nobude begagasi elivusa amadlingozi, okubalulekile ekwakhiweni kwezinto ze-fluorescent kanye ne-phosphorescent. Ubudlelwano phakathi kwamaza amaza okuvusa amadlingozi namaza okukhishwa, okwaziwa ngokuthi i-excitation kanye ne-emission spectra, buyisihluthulelo sokuqonda ukuthi lezi zenzakalo zenzeka kanjani futhi nini.
Kubalulekile ukuqaphela ukuthi i-wavelength ekhishwayo ayincikile kubude begagasi benjabulo, ngaphandle kwasezimeni lapho izinto zinezinto eziningi ze-luminescence. Ngenxa yalokho, amaminerali abonisa amakhono ahlukene okumunca ukukhanya kwe-ultraviolet kumaza athile; amanye ama-fluoresce ngaphansi kokukhanya kwe-ultraviolet amaza amafushane, kanti amanye akhanya ngaphansi kwamaza amade amade, kanti amanye abonisa i-fluorescence engacacile. Umbala wokukhanya okukhiphayo uvame ukuhluka kakhulu ngamaza amaza okuvusa ahlukahlukene.
Ukwenzeka kwalezi zenzakalo akugcini nje ekusebenziseni imisebe ye-ultraviolet; kunalokho, ukuvusa amadlingozi kungafinyelelwa nganoma yimiphi imisebe enamandla afanele. Ngokwesibonelo, Ama-X-ray ayakwazi ukunxenxa i-fluorescence ezintweni ezahlukahlukene, eziningi zazo futhi ezisabela ezinhlotsheni ezahlukene zemisebe. I-Magnesium tungstate, isibonelo, ibonisa ukuzwela cishe kuyo yonke imisebe enamaza amaza amafushane kuno-300 nm, ehlanganisa kokubili ukukhanya kwe-ultraviolet kanye ne-X-ray. Ngaphezu kwalokho, izinto ezithile zingajatshuliswa kalula ngama-electron, njengoba kuboniswa ama-phosphors asetshenziswa kumashubhu kamabonakude.
Futhi lezi zenzakalo zihlobana kanjani nezinye izenzakalo zemvelo?
Ukuqonda umehluko phakathi kwe-luminescence, i-fluorescence kanye ne-phosphorescence futhi kusiza ukuqonda izenzakalo zemvelo ezifana izingqimba zamafu e-cirrus nezinye izenzakalo zomkhathi. Lolu lwazi lunothisa ukuchazwa kwe-spectra yokukhanya kanye nokusebenzisana kokukhanya nezinto ezihlukahlukene endaweni yethu, kanye nokuvula umnyango wezinhlelo zokusebenza ezintsha zesayensi nezobuchwepheshe. Ukuthola ukuthi lezi zenzakalo zenzeka kanjani nokuthi yiziphi izimo ezizivunayo kungaba ukhiye wenqubekelaphambili ezindaweni ezifana ne-mineralogy, i-astronomy, ne-biomedicine.
