Lub peev xwm kub yog qhov muaj peev xwm nqus tau qee qhov cua sov thaum cua sov lossis muab tawm thaum txias. Lub peev xwm kub ntawm lub cev yog qhov sib piv ntawm qhov tsis muaj qhov kawg ntawm cov cua sov uas lub cev tau txais mus rau qhov sib npaug ntawm nws qhov ntsuas kub. Tus nqi yog ntsuas hauv J / K. Hauv kev xyaum, tus nqi sib txawv me ntsis yog siv - tshwj xeeb cua sov.
Definition
qhov kub tshwj xeeb txhais li cas? Qhov no yog qhov muaj feem cuam tshuam rau ib qho ntawm cov khoom. Yog li, tus nqi ntawm cov khoom tuaj yeem ntsuas hauv cubic meters, kilograms, lossis txawm nyob hauv moles. Nws nyob ntawm dab tsi? Nyob rau hauv physics, lub peev xwm cua sov nyob ncaj qha rau ntawm qhov ntau npaum li cas nws hais txog, uas txhais tau hais tias lawv paub qhov txawv ntawm cov molar, huab hwm coj thiab volumetric tshav kub muaj peev xwm. Hauv kev tsim kho kev lag luam, koj yuav tsis pom qhov ntsuas molar, tab sis koj yuav pom lwm tus txhua lub sijhawm.
Yuav ua li cas cuam tshuam qhov peev xwm kub?
Lub peev xwm kub yog dab tsi, koj paub, tab sis qhov txiaj ntsig dab tsi cuam tshuam rau qhov ntsuas tseem tsis tau meej. Tus nqi ntawm lub peev xwm tshwj xeeb yog cuam tshuam ncaj qha los ntawm ntau yam:tshuaj kub, siab thiab lwm yam thermodynamic yam ntxwv.
Raws li qhov kub ntawm cov khoom lag luam nce, nws lub peev xwm tshwj xeeb kub nce, tab sis qee yam khoom muaj qhov nkhaus tsis zoo hauv qhov kev sib raug zoo no. Piv txwv li, nrog rau qhov nce ntawm qhov ntsuas kub ntawm xoom mus rau peb caug-tsib degrees, qhov tshwj xeeb kub muaj peev xwm ntawm cov dej pib txo qis, thiab yog tias qhov kev txwv nyob nruab nrab ntawm peb caug-tsib thiab ib puas degrees, ces qhov ntsuas, ntawm qhov tsis sib xws, yuav nce.
Nws yog ib qho tsim nyog sau cia tias qhov ntsuas kuj nyob ntawm seb qhov ntsuas kub npaum li cas ntawm cov khoom (siab, ntim, thiab lwm yam) raug tso cai hloov pauv. Piv txwv li, qhov tshwj xeeb kub ntawm qhov ruaj khov siab thiab qhov ntim ruaj khov yuav txawv.
Yuav ua li cas xam cov parameter?
Koj puas xav paub qhov muaj peev xwm cua sov yog dab tsi? Cov mis laij lej yog raws li nram no: C \u003d Q / (m ΔT). Cov nqi no yog dab tsi? Q yog cov cua kub uas cov khoom tau txais thaum cua sov (los yog tso tawm los ntawm cov khoom thaum txias). m yog qhov loj ntawm cov khoom, thiab ΔT yog qhov sib txawv ntawm qhov kawg thiab thawj qhov kub ntawm cov khoom. Hauv qab no yog ib lub rooj ntawm lub peev xwm kub ntawm qee cov ntaub ntawv.
Yuav ua li cas txog qhov ntsuas kub?
Kev xam lub peev xwm ntawm cov cua sov tsis yog ib txoj haujlwm yooj yim, tshwj xeeb tshaj yog tias tsuas yog siv cov txheej txheem thermodynamic xwb, nws tsis tuaj yeem ua nws ntau dua. Yog li ntawd, physicists siv cov txheej txheem ntawm statistical physics los yog kev paub txog microstructure ntawm cov khoom. Yuav xam li cas rau roj? Thaum tshav kub kub muaj peev xwm ntawm cov pa rojyog xam los ntawm kev xam qhov nruab nrab lub zog ntawm thermal motion ntawm ib tug neeg molecules nyob rau hauv ib yam khoom. Kev txav ntawm cov molecules tuaj yeem yog hom kev txhais lus thiab kev sib hloov, thiab hauv ib lub molecule tuaj yeem muaj tag nrho cov atom lossis kev co ntawm atoms. Classical txheeb cais hais tias rau txhua qib ntawm kev ywj pheej ntawm kev sib hloov thiab kev txhais lus, muaj ib qho nqi nyob rau hauv molar tshav kub muaj peev xwm ntawm cov pa, uas yog sib npaug rau R / 2, thiab rau txhua vibrational degree ntawm kev ywj pheej, tus nqi yog sib npaug rau R. Txoj cai no tseem hu ua txoj cai sib npaug.
Tib lub sijhawm, ib qho ntawm cov pa roj monatomic sib txawv los ntawm tsuas yog peb txhais qib ntawm kev ywj pheej, thiab yog li ntawd nws lub peev xwm kub yuav tsum sib npaug rau 3R / 2, uas yog pom zoo nrog kev sim. Txhua lub diatomic gas molecule muaj peb qhov kev txhais, ob qhov kev sib hloov thiab ib qho kev vibrational degrees ntawm kev ywj pheej, uas txhais tau hais tias txoj cai sib npaug yuav yog 7R / 2, thiab kev paub tau pom tias lub peev xwm ntawm cov mole ntawm cov roj diatomic ntawm qhov kub thiab txias yog 5R /. 2. Vim li cas thiaj muaj qhov tsis sib xws hauv kev xav? Txhua yam yog vim lub fact tias thaum tsim lub tshav kub muaj peev xwm, nws yuav tsum tau coj mus rau hauv tus account ntau yam quantum teebmeem, nyob rau hauv lwm yam lus, siv quantum txheeb cais. Raws li koj tuaj yeem pom, lub peev xwm cua sov yog lub tswv yim nyuaj heev.
Quantum mechanics hais tias txhua qhov system ntawm cov khoom uas oscillate lossis tig, suav nrog cov roj molecule, tuaj yeem muaj qee qhov sib txawv ntawm lub zog. Yog hais tias lub zog ntawm thermal motion nyob rau hauv lub nruab system tsis txaus rau excite oscillations ntawm qhov yuav tsum tau zaus, ces cov oscillations yuav tsis pab. Thaum tshav kub kub muaj peev xwm ntawm qhov system.
Hauv cov khoom khib nyiab, cov thermal txav ntawm atoms yog qhov tsis muaj zog oscillation nyob ze ntawm qee qhov kev sib npaug, qhov no siv rau cov nodes ntawm cov siv lead ua lattice. Ib lub atom muaj peb vibrational degrees ntawm kev ywj pheej thiab, raws li txoj cai, lub molar tshav kub muaj peev xwm ntawm ib tug yog sib npaug zos rau 3nR, qhov twg n yog tus naj npawb ntawm cov atoms uas twb muaj lawm nyob rau hauv lub molecule. Hauv kev xyaum, tus nqi no yog qhov txwv uas lub peev xwm kub ntawm lub cev nyhav ntawm qhov kub thiab txias. Tus nqi yog ua tiav nrog qhov kub thiab txias hloov hauv ntau lub ntsiab lus, qhov no siv rau cov hlau, nrog rau cov sib txuas yooj yim. Lub peev xwm kub ntawm cov hlau lead thiab lwm yam tshuaj kuj raug txiav txim.
Dab tsi yog qhov kub thiab txias?
Peb twb paub lawm tias qhov muaj peev xwm kub npaum li cas, tab sis yog peb tham txog qhov kub thiab txias, qhov nqi yuav suav li cas? Yog hais tias peb tab tom tham txog qhov ntsuas kub tsis tshua muaj, ces lub peev xwm kub ntawm lub cev muaj zog ces hloov mus rau qhov sib npaug rau T 3 lossis hu ua Debye tshav kub txoj cai. Lub ntsiab tseem ceeb rau kev paub qhov txawv ntawm qhov kub thiab txias ntawm qhov qis yog qhov kev sib piv ib txwm ntawm lawv nrog cov yam ntxwv tsis zoo rau cov khoom siv tshwj xeeb - qhov no tuaj yeem yog tus yam ntxwv lossis Debye kub q D. Tus nqi nthuav tawm yog teeb tsa los ntawm kev vibration spectrum ntawm atoms hauv cov khoom thiab nyob ntawm cov qauv siv lead ua.
Hauv cov hlau, cov khoom siv hluav taws xob ua rau muaj kev cuam tshuam rau lub peev xwm kub. Qhov no ntawm qhov hluav taws xob muaj peev xwm suav nrogFermi-Dirac txheeb cais, uas coj cov electrons mus rau hauv tus account. Lub peev xwm hluav taws xob hluav taws xob hluav taws xob ntawm cov hlau, uas yog proportional rau lub peev xwm kub ib txwm, yog tus nqi me me, thiab nws txhawb nqa lub peev xwm ntawm cov hlau tsuas yog nyob rau qhov kub ntawm qhov zero kiag li. Tom qab ntawd lub lattice cua sov muaj peev xwm ua me me thiab tuaj yeem tsis quav ntsej.
Mass heat peev
Cov cua kub tshwj xeeb yog cov cua sov uas yuav tsum tau coj mus rau ib chav tsev ntawm cov khoom kom sov cov khoom hauv ib chav tsev kub. Tus nqi no yog qhia los ntawm tsab ntawv C thiab nws yog ntsuas hauv joules muab faib los ntawm ib kilogram ib kelvin - J / (kg K). Nov yog txhua yam hais txog qhov muaj peev xwm ua kom sov.
Lub peev xwm ua kom sov yog dab tsi?
Lub peev xwm hluav taws kub yog ib qho ntawm cov cua sov uas yuav tsum tau muab ntxiv rau hauv chav tsev ntim ntawm cov khoom lag luam thiaj li ua kom sov nws hauv ib chav tsev kub. Qhov ntsuas no yog ntsuas hauv joules faib los ntawm ib lub cubic meter ib kelvin lossis J / (m³ K). Nyob rau hauv ntau lub tsev siv phau ntawv, nws yog qhov loj tshwj xeeb kub muaj peev xwm ntawm kev ua haujlwm uas tau txiav txim siab.
Kev siv lub peev xwm ua kom sov hauv kev tsim kho kev lag luam
Ntau cov khoom siv hluav taws xob siv hluav taws xob tau nquag siv hauv kev tsim cov phab ntsa kub-resistant. Qhov no yog qhov tseem ceeb heev rau cov tsev uas muaj cov yam ntxwv ntawm cov cua sov ua ntu zus. Piv txwv li, qhov cub. Cov khoom siv cua sov thiab cov phab ntsa tsim los ntawm lawv zoo kawg nkaus khaws cov cua sov, khaws cia rau lub sijhawm cua sov ntawm lub sijhawm thiab maj mam tso cua sov tom qab tua.system, yog li tso cai kom tswj tau qhov kub thiab txias nyob rau ib hnub.
Yog li, qhov kub ntau khaws cia hauv cov qauv, qhov yooj yim dua thiab ruaj khov qhov kub hauv chav yuav.
Nws tsim nyog sau cia tias cov cib thiab pob zeb zoo tib yam siv hauv kev tsim vaj tsev muaj peev xwm qis dua li cov polystyrene nthuav dav. Yog tias peb noj ecowool, ces nws yog peb zaug ntau tshaj qhov kub-siv tshaj li pob zeb. Nws yuav tsum tau muab sau tseg tias nyob rau hauv cov mis nyuj rau xam lub tshav kub muaj peev xwm, nws tsis yog nyob rau hauv vain uas muaj loj. Vim yog qhov loj loj loj ntawm pob zeb lossis cib, piv nrog ecowool, nws tso cai rau khaws cov cua kub ntau hauv cov phab ntsa pob zeb ntawm cov qauv thiab ua kom txhua hnub kub hloov pauv. Tsuas yog ib qho me me ntawm cov rwb thaiv tsev nyob hauv txhua lub tsev thav duab, txawm tias muaj peev xwm ua kom sov tau zoo, yog qhov tsis muaj zog tshaj plaws rau txhua lub thav duab technologies. Txhawm rau daws qhov teeb meem no, cov khoom siv hluav taws xob zoo nkauj tau teeb tsa hauv txhua lub tsev. Nws yog dab tsi? Cov no yog cov yam ntxwv ntawm cov khoom uas muaj qhov loj me nrog qhov ntsuas kub zoo heev.
Piv txwv ntawm cov khoom siv hluav taws xob hauv lub neej
Nws yuav ua li cas? Piv txwv li, qee yam ntawm phab ntsa cib, lub qhov cub loj lossis qhov cub, pob zeb ua vaj tse.
Rooj tog hauv ib lub tsev lossis chav tsev yog qhov khoom siv hluav taws xob zoo heev, vim tias plywood, chipboard thiab ntoo tuaj yeem khaws cov cua sov hauv ib kilogram ntawm qhov hnyav peb zaug ntau dua li cov cib tsis zoo.
Puas muaj qhov tsis zoo hauv cov khoom siv cua sov? Tau kawg, lub ntsiab tsis zoo ntawm txoj kev no yogqhov tseeb hais tias lub tshav kub accumulator yuav tsum tau tsim nyob rau hauv lub theem ntawm tsim ib tug ncej tsev layout. Tag nrho vim qhov tseeb tias nws hnyav heev, thiab qhov no yuav tsum tau coj mus rau hauv tus account thaum tsim lub hauv paus, thiab tom qab ntawd xav txog yuav ua li cas cov khoom no yuav raug muab tso rau sab hauv. Nws yog tsim nyog hais tias nws yog ib qho tsim nyog yuav tsum coj mus rau hauv tus account tsis tsuas yog cov huab hwm coj, nws yuav tsum tau soj ntsuam ob qho tib si yam ntxwv hauv kev ua haujlwm: huab hwm coj thiab lub peev xwm kub. Piv txwv li, yog tias koj siv kub nrog qhov hnyav tsis txaus ntawm nees nkaum tons ntawm ib lub cubic meter raws li qhov chaw cia cua sov, ces cov khoom yuav ua haujlwm raws li nws yuav tsum tsuas yog nees nkaum-peb feem pua zoo dua li lub pob zeb pob zeb, uas hnyav ob thiab ib nrab tons.
Cov tshuaj twg yog qhov zoo tshaj plaws rau kev cia cua sov?
Cov khoom lag luam zoo tshaj plaws rau lub tshuab hluav taws xob tsis yog pob zeb thiab cib! Tooj, tooj liab thiab hlau ua haujlwm zoo ntawm qhov no, tab sis lawv hnyav heev. Oddly txaus, tab sis qhov zoo tshaj plaws tshav kub accumulator yog dej! Cov kua muaj lub peev xwm ua kom sov zoo, qhov loj tshaj plaws ntawm cov khoom muaj rau peb. Tsuas yog helium gases (5190 J / (kg K) thiab hydrogen (14300 J / (kg K)) muaj peev xwm ua kom sov ntau dua, tab sis lawv muaj teeb meem rau kev siv hauv kev xyaum. xav tau.
