Cov khoom yog crystalline thiab amorphous lub cev. Crystal - yog li nyob rau hauv ancient sij hawm lawv hu ua dej khov. Thiab tom qab ntawd lawv tau pib hu ua quartz thiab pob zeb siv lead ua siv lead ua, xav txog cov khoom siv no los ua dej khov petrified. Crystals yog ntuj thiab dag (synthetic). Lawv tau siv rau hauv kev lag luam hniav nyiaj hniav kub, kho qhov muag, xov tooj cua engineering thiab hluav taws xob, raws li kev txhawb nqa rau cov khoom hauv cov khoom siv tshwj xeeb, ua cov khoom siv tawv tawv heev.
Crystalline lub cev yog tus cwj pwm los ntawm hardness, muaj ib qho chaw tsis tu ncua nyob rau hauv qhov chaw ntawm molecules, ions los yog atoms, uas ua rau peb-dimensional periodic siv lead ua lattice (cov qauv). Outwardly, qhov no yog qhia los ntawm ib tug tej yam symmetry ntawm cov duab ntawm ib tug khoom lub cev thiab nws cov yam ntxwv ntawm lub cev. Nyob rau hauv daim ntawv sab nraud, crystalline lub cev muaj kev cuam tshuam cov symmetry nyob rau hauv lub internalparticle packing. Qhov no txiav txim siab qhov sib npaug ntawm cov ces kaum ntawm lub ntsej muag ntawm tag nrho cov muaju uas muaj tib yam khoom.
Qhov kev ncua deb ntawm qhov chaw mus rau qhov chaw nruab nrab ntawm cov atoms nyob sib ze kuj yuav sib npaug hauv lawv (yog tias lawv nyob ntawm tib txoj kab ncaj nraim, ces qhov kev ncua deb no yuav zoo ib yam raws tag nrho cov kab ntev). Tab sis rau cov atoms dag ntawm txoj kab ncaj nraim nrog kev sib txawv, qhov kev ncua deb ntawm cov chaw ntawm atoms yuav txawv. Qhov xwm txheej no piav qhia txog anisotropy. Anisotropy yog qhov sib txawv tseem ceeb ntawm crystalline thiab amorphous lub cev.
Ntau tshaj 90% ntawm cov khib nyiab tuaj yeem faib ua cov khoom siv lead ua. Nyob rau hauv cov xwm, lawv muaj nyob rau hauv daim ntawv ntawm ib tug crystals thiab polycrystals. Ib leeg muaju - ib leeg, lub ntsej muag uas sawv cev los ntawm cov polygons tsis tu ncua; Lawv yog cov yam ntxwv ntawm lub xub ntiag ntawm ib tug nruam siv lead ua lattice thiab anisotropy ntawm lub cev muaj zog.
Polycrystals - lub cev uas muaj ntau lub pob zeb me me, "loj" ua ke me ntsis chaotically. Polycrystals yog hlau, qab zib, pob zeb, xuab zeb. Nyob rau hauv xws li lub cev (piv txwv li, ib tug hlau fragment), anisotropy feem ntau tsis tshwm sim vim lub random txheej txheem, txawm hais tias anisotropy yog inherent nyob rau hauv ib tug crystal crystal ntawm lub cev.
Lwm yam khoom ntawm crystalline lub cev: nruj me ntsis ntsuas kub ntawm crystallization thiab melting (muaj cov ntsiab lus tseem ceeb), lub zog, elasticity, hluav taws xob conductivity, sib nqus conductivity, thermal conductivity.
Amorphous - tsis muaj duab. Yog li ntawd lo lus no yog txhais los ntawm Greek. Amorphous lub cev yog tsim los ntawm xwm. Piv txwv li, amber, wax, volcanic iav. Tus txiv neej tau koom nrog hauv kev tsim cov khoom tsim amorphous lub cev - iav thiab resins (artificial), paraffin, plastics (polymer), rosin, naphthalene, var. Cov tshuaj amorphous tsis muaj cov khoom siv lead ua lattice vim qhov kev hloov pauv ntawm cov molecules (atoms, ions) hauv cov qauv ntawm lub cev. Yog li ntawd, cov khoom ntawm lub cev rau txhua lub cev amorphous yog isotropic - tib yam hauv txhua qhov kev qhia. Rau lub cev amorphous, tsis muaj qhov tseem ceeb ntawm lub melting point; lawv maj mam soften thaum rhuab thiab tig mus rau hauv cov kua nplaum. Amorphous lub cev raug muab tso rau nruab nrab (hloov) txoj haujlwm nruab nrab ntawm cov kua thiab crystalline lub cev: ntawm qhov kub tsis tshua muaj lawv tawv thiab ua elastic, ntxiv rau, lawv tuaj yeem cuam tshuam rau hauv cov duab tsis zoo. Thaum qhov kub thiab txias, cov khoom qub no nthuav tawm cov yas, ua kua nplaum.
Tam sim no koj paub tias lub cev crystalline yog dab tsi!
