Yog tias koj muab cov number case los yog xim pleev xim rau hauv dej, thiab tom qab ntawd saib cov dej no hauv lub tshuab tsom, koj tuaj yeem pom qhov txav ceev ntawm cov khoom me me ntawm cov xuab zeb lossis cov xim sib txawv. Dab tsi provokes xws li txav?
Leej twg pom thiab thaum twg
Xyoo 1827, tus kws tshawb fawb Askiv Robert Brown tau pom los ntawm lub tshuab tsom iav ib tee dej, uas tau txais cov paj ntoos me me. Nws pom tias qhov me me ntawm paj ntoos tau seev cev, txav chaotically hauv cov kua. Yog li Brownian lub zog muaj npe tom qab tus kws tshawb fawb no tau tshawb pom - qhov kev txav ntawm cov khoom me tshaj plaws yaj hauv cov kua lossis roj. Tom qab soj ntsuam ntau hom paj ntoos hauv nws sau, tus kws kho tsiaj tau yaj cov hmoov nplej hauv dej.
Vim li ntawd, Brown tau ntseeg tias qhov kev ntxhov siab zoo li no tsis yog los ntawm cov kua nws tus kheej thiab tsis yog los ntawm kev cuam tshuam sab nraud ntawm cov kua, tab sis ncaj qha los ntawm kev txav mus los ntawm cov khoom me tshaj plaws. Cov khoom no, los ntawm kev sib piv nrog cov lus pom, hu ua "Brownian particle".
Kev txhim kho ntawm txoj kev xav, nws cov thwjtim
Tom qab ntawd, Brown qhov kev tshawb pom tau lees paub, nthuav dav thiab teev tseg, raws li txoj kev xav molecular kinetic, los ntawm A. Einstein thiab M. Smoluchowski. Thiab Fabkis physicist Perrin, nees nkaum xyoo tom qab, ua tsaug rau kev txhim kho ntawm microscopes nyob rau hauv tus txheej txheem ntawm kev kawm lub random motion ntawm ib tug Brownian particle, paub tseeb hais tias lub hav zoov ntawm molecules kom. Kev soj ntsuam ntawm Brownian tsab ntawv tsa suab tso cai rau Perrin los xam cov lej ntawm cov molecules hauv 1 mole ntawm cov pa roj thiab muab cov qauv barometric.
Qhov kev tshawb pom ntawm qhov txav ntawm Brownian particle tau ua pov thawj tias muaj cov khoom me me, txawm tias tsis pom hauv lub tshuab ntsuas - cov kua dej thiab lwm yam khoom. Nws yog cov molecules uas, nrog rau lawv qhov kev txav mus tas li, quab yuam cov khoom paj ntoos, soot lossis xim txav mus.
Definition and size
Yog tias koj saib cov khoom seem uas tau muab tshem tawm hauv dej los ntawm lub tshuab tsom iav, koj yuav pom tias cov nplej ntawm ntau qhov sib txawv coj txawv. Feem ntau voluminous hais, ntsib tib tus naj npawb ntawm shocks los ntawm txhua sab nyob rau hauv ib lub sij hawm ntawm lub sij hawm, tsis txhob pib txav. Thiab cov khoom me me rau tib lub sijhawm ib ntus tau txais kev cuam tshuam tsis sib haum xeeb, thawb lawv mus rau sab, thiab txav mus.
Dab tsi yog qhov loj ntawm Brownian particle raug rau cov molecules? Nws tau raug pov thawj pom tseeb tias cytoplasmic pollen nplej tsis loj dua 3 micrometers (µm), lossis 10-6 meters, lossis 10-3hli. Cov khoom loj dua tsis tuaj yeem koom nrog hauv qhov kev txav mus tas li nrhiav pom los ntawm Brown.
Yog li, cia peb teb cov lus nug "dab tsi yog Brownian particle". Cov no yog cov nplej me tshaj plaws ntawm cov khoom uas muaj qhov loj ntawm tsis pub tshaj 3 microns, uas tau raug tshem tawm hauv cov kua lossis roj, ua rau muaj kev ntxhov siab tas li nyob rau hauv kev cuam tshuam ntawm cov molecules ntawm nruab nrab uas lawv nyob.
Molecular Kinetic Theory
Brownian tsab ntawv tsa suab tsis nres, tsis qeeb hauv lub sijhawm. Qhov no piav qhia lub tswvyim ntawm molecular kinetic txoj kev xav, uas hais tias cov molecules ntawm ib yam khoom nyob rau hauv tas li thermal zog. Nrog rau qhov nce ntawm qhov kub ntawm qhov nruab nrab, qhov ceev ntawm kev txav ntawm cov molecules nce, thiab raws li, Brownian particle, uas raug rau molecular cuam tshuam, kuj accelerates.
Ntxiv rau qhov kub ntawm qhov teeb meem, qhov ceev ntawm Brownian motion kuj nyob ntawm qhov viscosity ntawm qhov nruab nrab thiab qhov loj ntawm cov khoom tshem tawm. Lub zog yuav ncav cuag nws qhov siab tshaj plaws ceev thaum qhov kub ntawm cov khoom nyob ib puag ncig cov khoom siab, cov khoom nws tus kheej yuav tsis khov, thiab cov plua plav yuav yog qhov tsawg tshaj plaws.
Molecules ntawm ib yam khoom uas cov khoom me tshaj plaws nyob, random sib tsoo, siv lub zog tshwm sim (tsim lub laub), ua rau kev hloov pauv ntawm cov paj ntoos txav mus. Tab sis xws li kev hloov pauv yog luv luv nyob rau lub sijhawm, thiab yuav luag tam sim ntawd cov kev taw qhia ntawm kev siv zog hloov pauv, uas ua rau muaj kev hloov pauv ntawm kev txav mus los.
Qhov piv txwv yooj yim tshaj plaws thiab pom tseeb tshaj plaws uas tso cai rau koj nkag siab tias Brownian particle yog qhov txav ntawm cov plua plav, pom hauv oblique hnub ci. Nyob rau hauv 99-55 xyoo. BC e. Tus kws sau paj huam Roman thaum ub Lucretius tau piav qhia meej txog qhov ua rau muaj kev hloov pauv tsis zoo nyob rau hauv cov paj huam philosophical "Rau Qhov Xwm Txheej."
Saib ntawm no: thaum twg lub hnub ci dhau los
Nyob rau hauv peb lub tsev thiab qhov tsaus ntuj txiav los ntawm nws cov rays, Ntau lub cev me hauv qhov khoob, koj yuav pom, flickering,
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rushing rov qab thiab tawm hauv lub ci ci ci ntawm lub teeb.
Koj puas tuaj yeem nkag siab los ntawm qhov no ua rau nkees nkees
pib ntawm tej yam nyob rau hauv lub emptiness loj yog nyob tsis tswm.
yog li hais txog tej yam zoo pab kom nkag siab
yam me me, piav qhia txoj hauv kev rau lawv nkag siab.
Ntxhais, vim koj yuav tsum xyuam xim
Kev ntxhov siab hauv lub cev flickering hauv tshav ntuj
Koj paub dab tsi los ntawm nws tseem ceeb thiab txav, Dab tsi tshwm sim hauv nws zais thiab zais ntawm qhov pom.
Rau koj yuav pom muaj pes tsawg plua plav hloov
Txoj kev los ntawm qhov kev poob siab zais thiab ya rov qab, Nyob ib txhis rov qab mus rau txhua qhov kev qhia.
Ntev ua ntej qhov kev tshwm sim ntawm niaj hnub magnifying technology, Lucretius, soj ntsuam ib qho analogue ntawm lub zog pom los ntawm Brown, tuaj mus rau qhov xaus hais tias qhov me me ntawm cov teeb meem muaj nyob. Brown tau lees paub qhov no los ntawm kev ua ib qho kev tshawb pom tseem ceeb tshaj plaws.
