Qhov sib txawv tseem ceeb ntawm stokes thiab cov kab tiv thaiv stokes yog cov kab stokes muaj qhov ntev wavelength tshaj lub wavelength ntawm cov hluav taws xob zoo siab uas yog lub luag haujlwm rau cov fluorescence los yog Raman nyhuv, whereas Anti-stokes kab tshwm sim nyob rau hauv fluorescence los yog Raman spectra. thaum cov atoms lossis cov molecules twb nyob rau hauv ib qho kev zoo siab.
Stokes kab sawv cev hluav taws xob ntawm cov wavelengths tshwj xeeb tam sim no nyob rau hauv kab spectra uas cuam tshuam nrog fluorescence thiab Raman nyhuv. Anti-stokes kab sawv cev rau cov hluav taws xob ntawm cov wavelengths tshwj xeeb tam sim no hauv fluorescence thiab hauv Raman spectra thaum cov atoms lossis molecules ntawm cov khoom muaj nyob hauv lub xeev zoo siab.
Stokes Kab yog dab tsi?
Stokes kab sawv cev cov hluav taws xob ntawm cov wavelengths tshwj xeeb tam sim no nyob rau hauv kab spectra cuam tshuam nrog fluorescence (emission ntawm lub teeb los ntawm ib yam khoom uas tau absorbed zog yav dhau los) thiab Raman nyhuv (hloov lub wavelength ntawm lub teeb uas tshwm sim thaum lub teeb beam. yog deflected los ntawm molecules). Qhov no tau muaj npe tom qab 19th-xyoo pua British physicist Sir George Gabriel Stokes. Cov kab stokes no feem ntau ntev wavelengths tshaj lub wavelength ntawm cov hluav taws xob zoo siab lub luag hauj lwm rau fluorescence los yog Raman nyhuv.
Stokes kab tuaj yeem piav qhia raws li cov photons tawg uas raug txo qis hauv lub zog txheeb ze rau qhov xwm txheej photons uas tuaj yeem cuam tshuam nrog cov molecule. Tsis tas li ntawd, qhov txo qis ntawm lub zog ntawm cov tawg tawg yog feem ntau yog proportional rau lub zog ntawm vibrational theem ntawm cov molecule.
Cov Kab Tiv Thaiv Stokes yog dab tsi?
Cov kab tiv thaiv stokes sawv cev rau cov hluav taws xob ntawm cov wavelengths tshwj xeeb tam sim no hauv fluorescence thiab hauv Raman spectra thaum cov atoms lossis molecules ntawm cov khoom muaj nyob rau hauv lub xeev zoo siab. Yog li ntawd, nws yog qhov opposite ntawm stokes kab. Ntawm no, cov kab hluav taws xob hluav taws xob muab cov txiaj ntsig ntawm lub zog ua ntej excitation thiab lub zog nqus los ntawm cov hluav taws xob zoo siab. Yog li ntawd, cov kab anti-stoke feem ntau muaj luv luv wavelength piv rau lub teeb uas ua rau lawv. Ntxiv mus, qhov sib txawv ntawm qhov zaus ntawm lub teeb emitted thiab absorbed lub teeb tuaj yeem hu ua Stokes hloov.
Daim duab 01: Raman Effect
Peb tuaj yeem piav qhia txog cov kab tiv thaiv kab mob raws li cov duab tawg tawg uas muaj zog ntau dua piv rau qhov xwm txheej photons uas tuaj cuam tshuam nrog cov molecule. Feem ntau, ua kom lub zog ntawm cov photons tawg yog proportional rau lub zog ntawm cov qib vibrational ntawm cov molecule.
Qhov txawv ntawm Stokes thiab Anti-Stokes Kab yog dab tsi?
Cov ntsiab lus stokes kab thiab cov kab tiv thaiv stokes yog qhov tseem ceeb hauv kev tshawb pom spectroscopic. Qhov sib txawv tseem ceeb ntawm stokes thiab anti-stokes kab yog cov kab stokes muaj lub wavelength ntev dua li lub wavelength ntawm cov hluav taws xob zoo siab uas yog lub luag hauj lwm rau cov fluorescence los yog Raman nyhuv, whereas Anti-stokes kab tshwm sim nyob rau hauv fluorescence los yog Raman spectra thaum atoms los yog molecules yog. twb nyob rau hauv lub xeev zoo siab. Thaum cov kab stokes tsis nyob rau hauv lub xeev zoo siab, cov kab tiv thaiv stokes twb nyob rau hauv lub xeev zoo siab.
Cov hauv qab no infographic nthuav tawm qhov sib txawv ntawm stokes thiab cov kab tiv thaiv kab hauv kab hauv daim ntawv hauv daim ntawv tabular rau ib sab ntawm kev sib piv.
Summary – Stokes vs Anti-Stokes Kab
Stokes kab thiab cov kab tiv thaiv stokes tau piav qhia hauv lub cev thiab tshuaj xyuas chemistry. Qhov sib txawv tseem ceeb ntawm stokes thiab anti-stokes kab yog cov kab stokes muaj lub wavelength ntev dua li lub wavelength ntawm cov hluav taws xob zoo siab uas yog lub luag hauj lwm rau cov fluorescence los yog Raman nyhuv, whereas Anti-stokes kab tshwm sim nyob rau hauv fluorescence los yog Raman spectra thaum atoms los yog molecules yog. twb nyob rau hauv lub xeev zoo siab.
