2024 Tus sau: Elizabeth Oswald | [email protected]. Kawg hloov kho: 2024-01-13 00:07
Kev siv cov phiaj xwm tsis tu ncua hauv astronomical thiab lwm yam kev tshawb fawb tau pib poob qis hauv thaum ntxov 1980s vim tias lawv tau maj mam hloov los ntawm cov khoom siv sib txuas (CCDs), uas kuj muab zoo kawg nkaus dimension stability.
Vim li cas CCDs nyiam tshaj daim phiaj duab?
CCD siv piv rau Plate siv:
Qhov rhiab thiab kev daws teeb meem muaj peev xwm ntawm CCD sensor yog ntau dua li cov phaj. … Tsis tas li ntawd xwb, peb muaj cov chaw soj ntsuam zoo li Hubble Space Telescope uas siv CCD tag nrho. Daim phiaj duab siv hauv lub voj voog yuav ua tsis tau.
Thaum twg kev yees duab siv thawj zaug rau hnub qub?
Thawj daim duab ntawm ib qho khoom siv hnub qub (Lub hli) tau muab coj los rau hauv 1840, tab sis nws tsis yog txog rau thaum xyoo pua 19th uas tau nce qib hauv thev naus laus zis tso cai rau kev yees duab stellar kom ntxaws.
Thaum twg iav phaj thaij duab tsim tau?
Invented los ntawm Dr. Richard L. Maddox thiab thawj zaug muaj nyob rau hauv 1873, cov phaj qhuav tsis zoo yog thawj qhov kev lag luam muaj kev vam meej hauv cov duab nruab nrab.
Lawv pom dab tsi thaum daim duab thaij duab tsim tawm?
Thaum cov ntsev tau muab tso ze rau ntawm daim duab thaij duab npog nrog daim ntawv opaque, lub phaj tau pom tias muaj pos huab. Qhov tshwm sim tau pom tias muaj ntau rau txhua qhov uranium ntsev tau kawm thiab yogxaus tias yog ib qho cuab yeej ntawm uranium atom.
Pom zoo:
Dab tsi yog qhov hloov pauv thiab hloov pauv hloov pauv?
Point mutations hloov ib leeg nucleotide. Frameshift kev hloov pauv yog ntxiv lossis tshem tawm ntawm nucleotides uas ua rau muaj kev hloov pauv hauv kev nyeem ntawv. frameshift thiab point mutation yog dab tsi? Ib qho kev hloov pauv cuam tshuam rau ib khub hauv paus.
Qhov kev hloov pauv no puas yuav ua rau muaj kev hloov pauv hloov pauv?
Yog li, yog tias muaj kev hloov pauv, piv txwv li, kev ntxig lossis tshem tawm ntawm nucleotide, tshwm sim, qhov no tuaj yeem ua rau kev hloov pauv ntawm kev nyeem ntawv. Nws hloov tag nrho cov amino acid ib ntus. Cov kev hloov pauv no yog hu ua frameshift mutation (tseem hu ua kev nyeem ntawv hloov pauv, nyeem ntawv hloov pauv, lossis framing yuam kev).
Qhov twg yog qhov kev hloov pauv hloov pauv hloov pauv?
Semiconservative replication piav qhia txog cov txheej txheem ntawm DNA replication nyob rau hauv tag nrho cov paub hlwb. DNA replication tshwm sim ntawm ntau lub hauv paus pib ntawm kev rov ua dua raws DNA qauv strand. Raws li DNA ob chav helix yog unwound by helicase, replication tshwm sim nyias ntawm txhua tus qauv strand nyob rau hauv antiparallel cov lus qhia.
Qhov kev hloov pauv twg yog xav tias yuav cuam tshuam los ntawm kev hloov pauv hloov pauv?
Dependent Variable Qhov sib txawv uas nyob ntawm lwm yam uas ntsuas. Cov kev hloov pauv no yuav tsum tau hloov pauv raws li qhov kev sim ua haujlwm ntawm tus kheej hloov pauv lossis hloov pauv. Nws yog cov nyhuv presumed. Qhov kev tshawb fawb hloov pauv twg yog qhov tshwm sim?
Los ntawm kev hloov pauv hloov pauv hloov pauv?
Kev hloov pauv hloov pauv hloov pauv (TMA) yog qhov isothermal (tsis hloov pauv nucleic acid kub), ib leeg-tube nucleic acid amplification system siv ob lub enzymes, RNA polymerase thiab thim rov qab kev sau ntawv. … Cov txheej txheem no tuaj yeem siv los tsom rau RNA thiab DNA.
