Chophimba Chowunikira cha Mafilimu achitsulo

Siliva inali chinthu chodziwika bwino chachitsulo mpaka pakati pa zaka za m'ma 1930, pomwe inali chinthu chachikulu chowunikira filimu ya zida zowunikira bwino, zomwe nthawi zambiri zimayikidwa mumadzimadzi. Njira yolumikizira mankhwala amadzimadzi idagwiritsidwa ntchito popanga magalasi ogwiritsira ntchito popanga zomangamanga, ndipo mu ntchitoyi, chitsulo chochepa kwambiri chinagwiritsidwa ntchito kuonetsetsa kuti filimu yasiliva imalumikizidwa pamwamba pa galasi, yomwe imatetezedwa ndi kuwonjezera mkuwa wakunja. Pakugwiritsa ntchito pamwamba pakunja, siliva imayanjanitsidwa ndi mpweya mumlengalenga ndipo imataya kuwala kwake chifukwa cha kupangika kwa siliva sulfide. Komabe, chifukwa cha kuwunikira kwakukulu kwa filimu yasiliva itangoyikidwa komanso kuti siliva imasanduka nthunzi mosavuta, imagwiritsidwabe ntchito ngati chinthu chofala chogwiritsa ntchito zigawo kwakanthawi kochepa. Siliva imagwiritsidwanso ntchito nthawi zambiri m'zigawo zomwe zimafuna zokutira kwakanthawi, monga mbale za interferometer kuti ziwone ngati zathyathyathya. Mu gawo lotsatira, tikambirana zambiri za mafilimu asiliva okhala ndi zokutira zoteteza.

M'zaka za m'ma 1930, John Strong, yemwe anali katswiri wodziwa magalasi a zakuthambo, anasintha mafilimu asiliva opangidwa ndi mankhwala ndi mafilimu a aluminiyamu okhala ndi nthunzi.
Aluminiyamu ndi chitsulo chomwe chimagwiritsidwa ntchito kwambiri popangira magalasi chifukwa cha kusasinthasintha kwake, kuwala kwa ultraviolet, kuoneka bwino, komanso kunyezimira kwa infrared, komanso kuthekera kwake kumamatira kwambiri kuzinthu zambiri, kuphatikiza mapulasitiki. Ngakhale kuti gawo lochepa la oxide nthawi zonse limapangidwa pamwamba pa magalasi a aluminiyamu nthawi yomweyo atangopangidwa, zomwe zimathandiza kupewa kuwonongeka kwina kwa pamwamba pa galasi, kunyezimira kwa magalasi a aluminiyamu kumachepa pang'onopang'ono akagwiritsidwa ntchito. Izi zili choncho chifukwa chakuti akagwiritsidwa ntchito, makamaka ngati galasi la aluminiyamu likuwonetsedwa kwathunthu kuntchito yakunja, fumbi ndi dothi zimasonkhana pamwamba pa galasi, motero zimachepetsa kunyezimira. Kugwira ntchito kwa zida zambiri sikukhudzidwa kwambiri ndi kuchepa pang'ono kwa kunyezimira. Komabe, nthawi zina pamene cholinga chake ndikusonkhanitsa mphamvu yayikulu yowala, popeza n'kovuta kuyeretsa magalasi a aluminiyamu popanda kuwononga gawo la filimu, zigawo zokulungidwa zimayikidwanso nthawi ndi nthawi. Izi zimagwira ntchito makamaka pa ma telescope akuluakulu owunikira. Popeza magalasi akuluakulu ndi akuluakulu komanso olemera, magalasi akuluakulu a telesikopu nthawi zambiri amapakidwanso chaka chilichonse ndi makina ophikira omwe amaikidwa mwapadera mu observatory, ndipo nthawi zambiri sazunguliridwa panthawi ya nthunzi, koma m'malo mwake magwero angapo a nthunzi amagwiritsidwa ntchito kuti atsimikizire kuti makulidwe a filimuyo ndi ofanana. Aluminiyamu imagwiritsidwabe ntchito m'matelesikopu ambiri masiku ano, koma matelesikopu ena atsopano amapakidwa nthunzi ndi mafilimu apamwamba kwambiri achitsulo omwe ali ndi utoto woteteza wasiliva.
Golide mwina ndiye chinthu chabwino kwambiri chopangira mafilimu owunikira a infrared. Popeza kuwunikira kwa mafilimu agolide kumachepa mofulumira m'dera looneka, m'machitidwe mafilimu agolide amagwiritsidwa ntchito pokhapokha pa mafunde opitilira 700 nm. Golide akamangiriridwa pagalasi, amapanga filimu yofewa yomwe imatha kuwonongeka. Komabe, golide amamatira kwambiri ku chromium kapena nickel-chromium (mafilimu otsutsa okhala ndi mafilimu a 80% nickel ndi 20% chromium), kotero chromium kapena nickel-chromium nthawi zambiri amagwiritsidwa ntchito ngati gawo lolekanitsa pakati pa filimu yagolide ndi gawo lagalasi.
Kuwunikira kwa Rhodium (Rh) ndi platinamu (Pt) ndi kochepa kwambiri kuposa zitsulo zina zomwe zatchulidwa pamwambapa, ndipo zimagwiritsidwa ntchito pokhapokha ngati pali zofunikira zapadera zotsutsana ndi dzimbiri. Mafilimu onse achitsulo amamatira mwamphamvu kugalasi. Magalasi a mano nthawi zambiri amakutidwa ndi rhodium chifukwa amakhala ndi zinthu zoyipa kwambiri zakunja ndipo ayenera kutenthedwa ndi kutentha. Filimu ya Rhodium imagwiritsidwanso ntchito m'magalasi a magalimoto ena, omwe nthawi zambiri amakhala owunikira kutsogolo omwe ali kunja kwa galimoto, ndipo amatha kukhudzidwa ndi nyengo, njira zoyeretsera, komanso chisamaliro chapadera poyeretsa. Nkhani zakale zidanena kuti ubwino wa filimu ya rhodium ndikuti imapereka kukhazikika bwino kuposa filimu ya aluminiyamu.

– Nkhaniyi yatulutsidwa ndiwopanga makina ophikira vacuumGuangdong Zhenhua