Cov txheej txheem:
- Yuav ua li cas ua pov thawj ib lub teeb tsis muaj qhov ntom ntom?
- Txhua qhov chaw ntom ntom yog dab tsi?
- Is 1 N nowhere dens?
- txhais li cas yog tias lub teeb ntom ntom?
Video: Tab tsi yog qhov chaw ntom ntom?
2024 Tus sau: Fiona Howard | [email protected]. Kawg hloov kho: 2024-01-10 06:38
Hauv kev ua lej, qhov chaw me me ntawm qhov chaw topological hu ua tsis muaj qhov ntom ntom lossis tsis tshua muaj yog tias nws kaw muaj qhov khoob sab hauv. Nyob rau hauv ib qho kev xav xoob heev, nws yog ib lub teeb uas nws cov ntsiab lus tsis nruj nruj nyob txhua qhov chaw. Piv txwv li, cov integers tsis muaj qhov ntom ntom ntawm qhov tiag, qhov qhib pob tsis yog.
Yuav ua li cas ua pov thawj ib lub teeb tsis muaj qhov ntom ntom?
A subset A ⊆ X hu ua tsis muaj qhov ntom ntom hauv X yog tias sab hauv ntawm qhov kaw A yog khoob, i.e. (A)◦=∅. Txwv tsis pub, A tsis nyob qhov twg ntom iff nws muaj nyob rau hauv lub kaw kaw nrog khoob sab hauv. Dhau mus ntxiv, peb tuaj yeem hais sib npaug tias A tsis nyob qhov twg ntom ntom iff nws cov khoom ntxiv muaj cov txheej qhib ntom ntom (vim li cas?).
Txhua qhov chaw ntom ntom yog dab tsi?
A subset A ntawm qhov chaw topological X yog qhov ntom ntom uas qhov kaw yog tag nrho qhov chaw X (qee tus kws sau ntawv siv cov lus nyob txhua qhov chaw ntom ntom). Ib qho kev txhais lwm txoj hauv kev yog: a teeb A uas cuam tshuam txhua qhov tsis muaj qhov qhib subset ntawm X.
Is 1 N nowhere dens?
Ib qho piv txwv ntawm lub teeb uas tsis raug kaw tab sis tseem tsis muaj qhov ntom ntom {1n|
∈N}. Nws muaj ib lub ntsiab lus txwv uas tsis yog nyob rau hauv lub teeb (xws li 0), tab sis nws qhov kaw tseem tsis muaj qhov ntom ntom vim tias tsis muaj qhov qhib qhov sib txawv hauv {1n|n∈N}∪{0}.
txhais li cas yog tias lub teeb ntom ntom?
Hauv topology thiab lwm yam ntawm kev ua lej, ib qho chaw A ntawm qhov chaw topological X hu ua ntom (hauv X) yog txhua qhov taw tes x hauv X yog nyob rau A lossis yog qhov txwv ntawm A; uas yog, kaw ntawm A yog tag nrho cov teeb X.
Pom zoo:
Puas yog qhov ntom ntom yog tshuaj lom neeg?
Cov piv txwv zoo ntawm lub cev muaj xws li qhov ntom ntom, xim, hardness, melting thiab boiling point, thiab hluav taws xob conductivity. … Piv txwv ntawm cov khoom muaj xws li flammability, toxicity, acidity, reactivity (ntau hom), thiab kub ntawm combustion.
Kev kwv yees qhov ntom ntom ntom?
Hauv kev txheeb cais, cov tshuaj kwv yees ntom ntom yog qhov tsis yog-ntsuas txoj kev ua haujlwm ntawm kev sib txawv. Kernel Qhov Kev kwv yees yog ib cov teeb meem uas du cov teeb meem uas tau ua, raws li cov ntaub ntawv finite. Koj suav li cas kernel ntom?
Puas yog qhov ntom ntom yog cov cuab yeej macroscopic?
“ Cov khoom muaj teeb meem hauv ntauyog hu ua macroscopic properties. … Cov khoom muaj feem xyuam nrog lub tshuab macroscopic suav nrog - siab, kub, ntom, ntim, viscosity, tsis kam, qhov nro ntawm cov kua thiab lwm yam . piv txwv ntawm cov khoom macroscopic yog dab tsi?
Nyob hauv quantum mechanical qauv ib qhov chaw ntom ntom nyob qhov twg?
Ib huab cua hluav taws xob muaj qhov sib txawv: qhov ntom ntom qhov twg cov hluav taws xob feem ntau yuav yogthiab qhov ntom ntom uas cov hluav taws xob tsawg tsawg yuav yog (Daim duab 1) . Electrons nyob qhov twg hauv quantum mechanical qauv?
Puas yog cov pa roj muaj qhov ntom ntom?
Gas ntom. Ib qho tseem ceeb ntawm cov khoom siv roj yog nws qhov ntom ntom. … Tab sis rau cov pa roj, qhov ceev tuaj yeem sib txawv ntawm ntau yam vim tias cov molecules dawb txav. Huab cua ntawm lub ntiaj teb muaj qhov sib txawv heev dua li huab cua 50 mais saum lub ntiaj teb .
