Kev Sib Txuas Hlau: Cov Khoom Thiab Cov Kev Siv Hauv Lub Neej Txhua Hnub
Pendahuluuan
Hauv ntiaj teb ntawm chemistry, kev sib txuas ntawm cov tshuaj lom neeg yog ib qho tseem ceeb heev vim nws yog lub hauv paus ntawm txhua yam tshuaj lom neeg. Ib hom kev sib txuas ntawm cov tshuaj lom neeg uas ua lub luag haujlwm tseem ceeb hauv ntau yam ntawm lub neej thiab thev naus laus zis yog kev sib txuas ntawm cov hlau. Hauv tsab xov xwm no, peb yuav tshawb nrhiav cov yam ntxwv, cov txheej txheem, thiab ntau yam kev siv ntawm kev sib txuas ntawm cov hlau hauv lub neej txhua hnub.
Kev Txhais Lus ntawm Cov Hlau Sib Koom Tes
Kev sib txuas ntawm cov hlau yog ib hom kev sib txuas tshuaj uas tshwm sim ntawm cov hlau atoms. Hauv kev sib txuas ntawm cov hlau, cov electrons valence ntawm cov hlau atoms tsis raug khi nruj rau ib qho atom tab sis muaj kev ywj pheej txav mus los ntawm cov atoms hauv "hiav txwv ntawm cov electrons." Tus qauv no, hu ua "hiav txwv ntawm cov electrons", piav qhia txog ntau yam khoom tshwj xeeb ntawm cov hlau.
Hauv kev sib txuas ntawm cov hlau, cov hlau atoms sib tshooj hauv ib lub network siv lead ua ke uas muaj kev txiav txim siab zoo. Txhua lub atom hlau pab ib lossis ntau lub electrons rau hauv lub hiav txwv electron no. Cov electrons no txav mus los ywj pheej hauv lub network siv lead ua ke, ua rau muaj kev xa hluav taws xob thiab cua sov zoo.
Cov Qauv thiab Cov Khoom Siv Ib Txwm Muaj ntawm Cov Hlau Sib Koom Tes
1. Kev Ua Hluav Taws Xob thiab Kev Ua Kub
Ib qho ntawm cov yam ntxwv tseem ceeb tshaj plaws ntawm cov hlau yog lawv lub peev xwm los coj hluav taws xob thiab cua sov zoo. Kev coj hluav taws xob ntawm cov hlau yog vim muaj cov electrons dawb, txav tau hauv lawv cov qauv siv lead ua. Thaum lub zog hluav taws xob raug siv rau cov hlau, cov electrons no txav mus rau qhov kawg zoo, tsim hluav taws xob. Ib yam li kev coj hluav taws xob thermal, kev txav mus los dawb ntawm cov electrons no kuj tso cai rau kev hloov pauv lub zog thermal zoo.
2. Xim ci ntsa iab
Feem ntau cov hlau muaj lub teeb ci ntsa iab uas cuam tshuam lub teeb. Lub teeb ci ntsa iab no yog los ntawm kev sib cuam tshuam ntawm cov electrons dawb nrog cov photons teeb. Vim tias cov electrons hauv cov hlau sib txuas yooj yim polarized, lawv muaj peev xwm cuam tshuam lub teeb, ua rau muaj lub teeb ci ntsa iab thiab zoo nkauj.
3. Kev ruaj khov thiab lub zog
Cov hlau sib txuas ua rau muaj kev ruaj khov thiab muaj zog. Cov khoom no ua rau cov hlau muaj txiaj ntsig zoo rau ntau yam kev tsim kho thiab kev siv hauv kev lag luam. Lub network crystalline uas khi ua ke, tuav ua ke los ntawm "hiav txwv ntawm cov hluav taws xob," tso cai rau cov hlau kom tiv taus kev ntxhov siab yam tsis yooj yim tawg.
4. Kev yoog tau thiab kev yoog tau
Feem ntau cov hlau yog yas thiab ductile, txhais tau tias lawv tuaj yeem rub mus rau hauv hlau lossis ua rau ntau yam duab yam tsis muaj kev tawg. Qhov no yog vim muaj peev xwm ntawm cov hlau atoms kom swb dhau ib leeg yam tsis rhuav tshem cov bonds uas tuav lawv ua ke. Qhov no tshwm sim vim muaj kev sib txuas zoo, sib xws ntawm cov electrons dawb.
5. Kev Ceev Ceev
Feem ntau cov hlau muaj qhov ceev siab. Qhov no yog vim tias cov atoms hauv cov hlau tau khi ua ke nruj nreem hauv cov qauv crystalline. Qhov ceev siab no muab cov hlau muaj zog thiab ruaj khov, ua rau lawv yog cov khoom siv zoo tagnrho rau cov ntawv thov uas xav tau lub zog siab thiab ruaj khov.
Txoj Kev Sib Txuas Hlau
Yuav kom nkag siab ntxiv txog kev sib txuas ntawm cov hlau, nws yog ib qho tseem ceeb kom nkag siab txog txoj kev sib txuas no ua haujlwm li cas. Txoj kev sib txuas ntawm cov hlau tuaj yeem piav qhia los ntawm kev siv txoj kev xav ntawm cov hlau, uas piav qhia txog cov qauv zog ntawm cov khoom siv.
Raws li txoj kev xav ntawm cov band, hauv cov hlau, cov atomic orbitals nthuav dav thiab sib koom ua ke los tsim cov energy bands. Muaj ob hom bands tseem ceeb: cov conduction band thiab cov valence band. Cov conduction band tso cai rau cov electrons txav mus los ywj pheej, thaum cov valence band muaj cov electrons uas khi nruj dua rau lub nucleus atomic. Thaum cov atomic orbitals ntawm cov hlau atoms sib cuam tshuam, lawv tsim cov energy bands no, uas tso cai rau kev txav mus los ywj pheej ntawm cov electrons.
Kev Siv Hlau Sib Txuas Hauv Lub Neej Txhua Hnub
1. Khoom Siv Hluav Taws Xob
Kev siv hluav taws xob yog ib qho ntawm cov teb uas vam khom rau kev coj hluav taws xob ntawm cov hlau. Cov khoom xws li cov xov hlau conductor, cov kab hluav taws xob ntawm cov laug cam luam tawm (PCBs), thiab cov khoom hauv cov khoom semiconductor txhua tus siv cov hlau los coj hluav taws xob.
2. Kev Tsim Kho thiab Kev Tsim Kho
Cov hlau xws li hlau, txhuas, thiab tooj liab yog siv dav hauv kev lag luam kev tsim kho. Hlau, uas muaj cov pa roj carbon ntxiv, yog siv dav hauv kev tsim kho thiab choj vim nws lub zog thiab kev ruaj khov. Aluminium feem ntau yog siv rau cov thav qhov rais thiab cov khoom siv vim nws lub teeb tab sis muaj zog.
3. Tsheb
Kev lag luam tsheb siv ntau yam hlau los tsim cov tsheb uas ruaj khov thiab siv tau ntev. Cov hlau tsis xeb, txhuas, thiab lwm yam hlau sib xyaw yog qhov tseem ceeb rau kev tsim cov thav tsheb, cav, thiab lwm yam khoom.
4. Kev Noj Qab Haus Huv thiab Tshuaj Kho Mob
Cov hlau kuj tseem ceeb heev rau kev kho mob. Piv txwv li, titanium yog cov khoom siv xaiv rau kev cog hniav vim nws qhov sib xws hauv lub cev, uas txhais tau tias nws tsis ua rau muaj kev cuam tshuam tsis zoo rau lub cev tib neeg. Ntxiv mus, cov cuab yeej phais feem ntau yog ua los ntawm cov hlau tsis xeb.
5. Zog thiab Kev Tsim Kho Vaj Tse
Cov hlau kuj tseem ceeb heev rau kev lag luam fais fab, tshwj xeeb tshaj yog hauv kev tsim cov hluav taws xob thiab cov khoom siv tsim hluav taws xob. Tooj liab thiab txhuas siv rau hauv cov xov hluav taws xob los xa hluav taws xob los ntawm cov chaw tsim hluav taws xob mus rau cov tsev thiab cov lag luam. Ntxiv mus, cov hlau siv rau hauv cov thev naus laus zis hluav taws xob rov ua dua tshiab xws li cov vaj huam sib luag hnub ci thiab cov cua tshuab.
6. Khoom Siv Rau Cov Neeg Siv Khoom
Ntau yam khoom siv niaj hnub, xws li cov khoom siv hauv tsev, riam, thiab cov khoom siv hluav taws xob, feem ntau yog siv hlau. Piv txwv li, cov khoom siv ua noj ua haus uas ua los ntawm cov hlau tsis xeb yog nrov heev vim nws ruaj khov thiab ua tau cua sov zoo heev.
Xaus
Kev sib txuas ntawm cov hlau yog ib hom kev sib txuas tshuaj lom neeg tseem ceeb heev thiab muaj ntau yam kev siv hauv lub neej txhua hnub. Txij li kev ua hluav taws xob thiab thermal conductivity mus rau lub zog thiab kev ruaj khov, cov yam ntxwv tshwj xeeb ntawm kev sib txuas ntawm cov hlau ua rau nws tsis tuaj yeem hloov pauv tau hauv ntau yam ntawm kev siv tshuab thiab kev lag luam.
Los ntawm kev nkag siab zoo dua txog kev sib txuas ntawm cov hlau, peb tsis yog tsuas yog nkag siab zoo dua txog kev nce qib ntawm thev naus laus zis uas twb muaj lawm xwb tab sis kuj tseem tsim cov khoom siv thiab cov thev naus laus zis tshiab, ua haujlwm tau zoo dua thiab tshiab dua. Kev txav mus los ntawm cov hluav taws xob hauv kev sib txuas ntawm cov hlau qhib ntau lub sijhawm rau kev tsim cov khoom siv ruaj khov, ua tau zoo, thiab siv tau ntau yam, ua rau nws yog lub hauv paus tseem ceeb ntawm peb txoj kev nce qib ntawm thev naus laus zis.
