Cov qauv ua qauv thiab cov kauj ruam rau electron microscopy
Ua ntej siv lub tshuab hluav taws xob xa hluav taws xob los soj ntsuam cov qauv lom neeg, cov qauv yuav tsum tau ua ua ntej. Cov kws tshawb fawb siv cov txheej txheem sib txawv raws li kev tshawb fawb sib txawv xav tau.
Fixation: Txhawm rau khaws cov hnoos qeev kom ntau li ntau tau, glutaraldehyde yog siv los ua kom tawv nqaij thiab osmic acid yog siv los ua cov rog.
Txias fixation: Cov qauv no tau khov sai sai hauv cov kua ethane kom cov dej tsis crystallize thiab hloov cov dej khov amorphous. Cov qauv khaws cia hauv txoj kev no muaj kev puas tsuaj tsawg dua, tab sis qhov sib piv ntawm cov duab yog tsawg heev.
Lub cev qhuav dej: Siv ethanol thiab acetone los hloov dej.
Padded: Cov qauv tuaj yeem muab faib tom qab padded.
Segmentation: Cov qauv yog txiav rau hauv nyias slices siv lub pob zeb diamond hniav.
Staining: Heavy atoms xws li txhuas lossis uranium tawg electrons ntau dua li cov atoms sib dua thiab tuaj yeem siv los ua kom qhov sib txawv.
Ua ntej siv lub tshuab hluav taws xob xa hluav taws xob los soj ntsuam cov hlau, cov qauv yuav tsum yog
Cov kab mob nyob hauv lub tshuab hluav taws xob electron
Txiav rau hauv nyias nyias nyias (li 0.1 hli) thiab tom qab ntawd siv electrolytic polishing txuas ntxiv thinning cov hlau feem ntau xaus rau kev tsim ib lub qhov nyob hauv nruab nrab ntawm cov qauv uas cov electrons tuaj yeem dhau ntawm cov hlau nyias nyob ntawd. Cov hlau tsis tuaj yeem ua electrolytically polished los yog cov ntaub ntawv uas tsis yog-conductive lossis tsis zoo conductivity, xws li silicon, feem ntau thinned mechanically thiab tom qab ntawd ua tiav siv ion ntaus. Txhawm rau tiv thaiv cov qauv uas tsis yog-conductive los ntawm kev khaws cov hluav taws xob zoo li qub hauv lub tshuab ntsuas hluav taws xob hauv lub tshuab ntsuas hluav taws xob lawv cov chaw yuav tsum tau them nrog txheej txheej conductive.
Vim li cas electron microscopes muaj kev daws teeb meem siab dua?
Raws li lub npe qhia, lub thiaj li hu ua electron microscope yog lub tshuab microscope uas siv cov kab hluav taws xob ua lub teeb pom kev zoo. Txij li cov kab hluav taws xob tuaj yeem khoov tau raws li qhov kev txiav txim ntawm sab nraud magnetic teb los yog hluav taws xob teb, tsim ib qho tshwm sim refraction zoo ib yam li cov teeb pom kev dhau los ntawm iav, peb tuaj yeem siv cov nyhuv ntawm lub cev los tsim "lens" rau cov kab hluav taws xob, yog li ntawd. tsim lub tshuab electron microscope. Tus yam ntxwv ntawm lub tshuab hluav taws xob xa hluav taws xob (TEM) yog peb siv cov kab hluav taws xob uas dhau los ntawm cov qauv mus rau cov duab, uas txawv ntawm lub tshuab ntsuas hluav taws xob (Scanning Electron Microscope, SEM). Txij li lub wavelength ntawm electron tsis muaj tsawg dua lub wavelength ntawm pom lub teeb (lub wavelength ntawm 100kV electron tsis yog 0.0037nm, thaum lub wavelength ntawm violet lub teeb yog 400nm), raws li optical txoj kev xav, peb tuaj yeem cia siab tias qhov kev daws teeb meem ntawm electron microscopes yuav tsum zoo dua li ntawm optical microscopes. Qhov tseeb, lub peev xwm daws teeb meem ntawm niaj hnub electron microscopes tau mus txog 0.1nm. Phau ntawv xaiv ntawm physics rau cov tub ntxhais kawm theem siab piav qhia ntau ntxiv (cov ntaub ntawv me me tom qab cov nyhuv photoelectric)
