Formula Bragg. Diffraction yi efestileni lwendawo

Eli nqaku libonisa indlela Bragg ifomula, wafunda intsingiselo yalo ihlabathi lanamhlanje. Thina uchaze iindlela yokuphanda izinto eziye kwenzeka ngenxa kwafunyanwa electron diffraction kwi eziqinileyo.

Science and ungquzulwano

Isibakala sokuba izizukulwana ezahlukeneyo akuyi baqondane, nkqu Turgenev wabhala inoveli "Ooyise and Sons." Kwaye ke inyaniso yile: usapho ubomi engominyaka ilikhulu, abantwana bahloniphe abantu abadala, bonke bayaxhasana, uze kwakhona - kunye notshintsho yonke into. Kwaye zonke izinto kwinzululwazi. Akumangalisi yamaKatolika iCawa njengophuhliso ababephikisana ulwazi yendalo nayiphi na intshukumo kungakhokelela ekubeni kwenziwe utshintsho ongalawulekiyo ehlabathini. Enye into eyaba lutshintsha imbono yococeko, kwaye ngoku abantu abadala bamangaliswa ukukhangela phantsi, inzala yabo uhlambe izandla phambi kokutya, kwaye ihlamba amazinyo abo. wokungalivumi lukaMakhulu bahlunguzele iintloko zabo: "Kutheni, sasihlala kakuhle ngaphandle kuyo, yaye akukho nto wazala abantwana mabini. Kwaye konke oku ubunyulu yakho azakulimaza kuphela kwaye kuyo inkohlakalo. "

Enye hypothesis kwi indawo iiplanethi - kwaye ngoku yonke indawo, ulutsha abantu abafundileyo ngokuxoxa Hewana kunye eziwa, yerediyo kunye nohlobo iMilky Way, ngelixa abo badala onomsindo: "Yimfitshimfitshi na, yintoni na ukusetyenziswa kwesithuba engaphandle kunye nakumacandelo yasezulwini, yintoni umahluko, njengoko ujikeleza iMars Venus wayeza kuhamba ngokuzenzekela kulwimi olungagqibekanga ngcono wayeselekhulile, bekuya kuba luncedo ngakumbi. "

A technology impumelelo, kwenzeka ngenxa yokuba i eyaziwa diffraction isithuba nothango - yaye zonke ezinye epokothweni yi efowuni. Ngelo xesha abantu abadala abandikrokrela: "Ayikho into elungileyo ayikho le miyalezo ngokukhawuleza, kungenjalo into le leta." Noko ke, njengokuba ngamazwi njengoko izandi, abanini izixhobo ezahlukeneyo ndiyaqonda babe uhlobo enikiweyo, phantse njengomoya. Yaye bambalwa abantu bacinge malunga ezisebenza umsebenzi wabo ngendlela omkhulu ingqondo yomntu asenzele eminye iminyaka emibini okanye engamakhulu amathathu.

Ekuqaleni kwenkulungwane yamashumi amabini

Ngenkulungwane yeshumi elinesithoba emva kwexesha, abantu ujongene nengxaki kolwazi zonke iziganeko ezivulekileyo. Oku kwakukholelwa ukuba physics esele sazi yonke into, kwaye uhlala ukufumana kuphela ngaphandle iinkcukacha. Noko ke, kwafunyanwa Planck ukuba lowo ufaka isicelo kunye discontinuity sekuba ithi ngokoqobo wazibhukuqa iingcamango ezidlulileyo malunga isakhiwo mbandela.

Ivula bawa omnye emva komnye, abaphengululi hlasi iimbono ezivela ezandleni zomnye. Yeengcinga ephakamayo, wavavanywa, kuxoxwe, walahlwa. Enye into Qiniseka yabangela amakhulu amatsha, yaye kwakukho abantu abaninzi bafuna iimpendulo.

Elinye lamanqaku zaguquka ukuba awuyitshintshanga imbono ihlabathi, ukuvulwa uhlobo exananazileyo ngamasuntswana nezakhiwo. Ngaphandle kwalo, Bragg ifomula ibingayi avele. Ekuthiwa-ngumtshangatshangiso-yamasuntswana mbini wachaza isizathu kwezinye iimeko, electron liziphatha umzimba kokuba ubunzima (ngamanye corpuscle, yamasuntswana), kunye nezinye - ezifana wave ethereal. Izazinzulu ziye kudala kokuxabana, ndaba andikezi esiphelweni - ezinjalo iimpawu ezahlukeneyo izinto microworld bobabini.

Eli nqaku lichaza umyalelo Bragg, nto leyo ithetha ukuba asinamdla izinto zobumnini otshangatshangiswayo kwamasuntswana nezakhiwo na. Kuba specialist, le mibuzo zisoloko ingacaci, ngokuba ekoyiseni umbundu ngokomyalelo neenanometer ngobukhulu, siphulukana ukuqiniseka - uqalisa ukusebenza umgaqo Heisenberg. Noko ke, ngeenjongo emininzi uswele kelelo ngokwaneleyo rough. Ngoko kuyimfuneko ukuba uqale ukuchaza ezinye iinkalo ukudibanisa nokuthabatha kwamaza eziqhelekileyo, nto leyo ilula ngokwaneleyo ukucinga nokuqonda.

Waves kunye sinuses

Bambalwa abantu ebuntwaneni wayemthanda eli sebe algebra njengoko nezetrigonometry. Sine kwaye cosine, kodwa azikweli phezulu kunye elinekona babe inkqubo yabo Ukongeza, ukuthabatha, kunye nezinye zinguquko. Mhlawumbi abantwana baqonde le nto, umdla kangaka ukufunda. Kwaye abaninzi wazibuza ukuba kutheni na konke oku kuyimfuneko, apho yinxalenye yobomi bemihla ngemihla olu lwazi nga isicelo.

Konke kuxhomekeke abantu ba- nxanelwe ulwazi. Abanye abantu abanakho ulwazi olunjalo njengoko ilanga likhanya emini kunye nenyanga ebusuku, amanzi zimanzi, kwaye rock nzima. Kodwa kukho kwakhona abo banomdla, njengoko yonke amalungiselelo umntu ubona. Kuba uphando ngokungadinwayo acacise uzuze kakhulu ukufunda iimpawu nokulatyuza izicatshulwa, Isimanga, nokwakheka amasuntswana asisiqalelo. Umzekelo, electron diffraction ethobela ngqo le mithetho.

Ngokuba ekuqaleni, uqhaqho ngobungqola: uvale amehlo akho makhe nencum athwale ngokwabo.

Khawucinge kwisiqhoboshi sinusoid uPienaar umsele, uPienaar ifolo. Kwakungekho nto akawatshintshi loo manqaku, umgama ukusuka phezulu omnye zendunduma ukuya kwenye kuyafana yonke enye. Ukungavumelani kwe parameter xa uya ukusuka ubuninzi ku ubuncinane, efanayo sisabelo ngalinye curve. Ukuba kukho inani zokutshangatshangisa ezifanayo sine, ngoko ke umsebenzi uba nzima ngakumbi. Diffraction kwi efestileni lwendawo uxhomekeke ngqo kwi ukongeza kwamaza eziliqela. Imithetho yokusebenza kwabo kuxhomekeke kwizinto ezininzi.

Lokuqala - isigaba. Oko iindawo ezingabambi amagophe ezimbini. Ukuba ubuninzi komdlalo wabo ukuya millimitha wokugqibela, ukuba engile ukutyekela amagophe ziyafana - ngaba kabini onke amanani, lenyoka amaxesha amabini ephakamileyo, wancothuka usikrobana - kabini nzulu. Ukuba ngokuchasene - ezona curve omnye uwa ubuncinane omnye, amaza ukurhoxisa bodwa, zonke intlokoma eziguqulelwe kwi zero. Kwaye ukuba izigaba musa idibana inxenye kuphela - oko kukuthi, ezona zininzi curve omnye uwa phezu ukunyuka okanye ziyakweyela kwezinye, umfanekiso kube nzima kakhulu. Ngokubanzi, ifomula iqulathe Bragg engile kuphela, njengoko iya kucaca kamva. Nangona kunjalo, imithetho yentsebenziswano phakathi amaza ukunceda xiya esiphelweni ngokupheleleyo.

Yesibini - awo. Oku ukuphakama humps kunye agcwalise. Ukuba kubude negophe of sentimitha mnye, kunye nezinye - amabini, ngoko ke kufuneka abulawe ngokulandelelanayo. Oko kukuthi, ukuba wave ubude ubuninzi ngeesentimitha ezimbini iwela ngokungqongqo emimangweni iyimitha ubuncinane sentimitha elinye, musa ukusirhoxisa enye kwenye, kodwa kunciphisa kuphela ukuphakama lencinibakazi yokuqala yokuphazamiseka. Umzekelo, diffraction ye electron ixhomekeke awo oscillation, nto leyo ebonisa amandla abo.

izinga - Wesithathu. Le umgama phakathi kweendawo ezimbini efanayo kwigophe, ezifana akholise okanye ubuncinane. Ukuba amaza izinto ezahlukeneyo, ngoko ngaxa ethile umile ezimbini ntaba kukhomba, ngokulandelelana, lisongwe ngokupheleleyo. oku akusekho kwixesha elilandelayo kwenzeka, ezona lokugqibela lube ngokuhla. Ke ezona lwamaza omnye uwa ngqongqo ubuncinane enye, unika isiphumo liphantsi kule nokubekwa. Isiphumo, njengokuba usazi, naye entsonkothileyo kakhulu, kodwa ngamaxesha athile. Khawube nomfanekiso kungekudala emva kwakhona, kwaye kwakhona ezimbini ngaxeshanye akholise. Ngoko, xa isicelo kwamaza kunye ezitsho ezahlukeneyo kuvela umahluko awo oscillation entsha.

Okwesine - ulwalathiso. Ngesiqhelo, xa kuqwalaselwa lokutshangatshangisa ezimbini efanayo (kulo mzekelo iliza sine), kukholelwa ukuba ngaxeshanye kwamanye ngokuzenzekelayo. Noko ke, kwihlabathi lokwenene izinto ezahlukeneyo, ulwalathiso kuba nantoni na phakathi isithuba-ntathu. Ngaloo ndlela, wongezelela okanye sisuswe amaza kuphela ehamba ngaxeshanye. Ukuba aye kumacala angafaniyo, akukho intsebenziswano phakathi kwabo. UMthetho Bragg umi kanye kwinto yokuba imiqadi parallel kuphela kwakheka.

Ukungenela kunye Diffraction

Noko ke, radiation magnetic - ayikho ncam igagasi sine. ithi Huygens 'umgaqo ukuba ingongoma nganye eliphakathi ukuya wavefront lifikelele ngayo (okanye ukuphazamiseka) ngumthombo yesibini ngamaza ukulenza. Ngenxa yoko, umzuzwana ukusasazeka, yithi, i yokukhanya ngawo onke amaxesha ayangenana. Le ukuphazamiseka.

Esi simo isizathu sokuba ukukhanya ngakumbi, yaye amaza uyakwazi ngokubanzi ukugoba ngeenxa imiqobo. Into yokugqibela kuthiwa diffraction. Ukuba umfundi akabi sayikhumbula loo esikolweni, siza kubonisa ukuba slits emibini screen emnyama, zikhanyiswe kukukhanya eziqhelekileyo ezimhlophe a akholise enzima ubuncinane yenkqubo ukhanyiso, okt koonotsheluza akayi kuba ngamandla ezimbini ezifanayo, yaye ezininzi ezahlukahlukeneyo.

Ukuba zephetshana ayikho okufakwe ukukhanya, kwaye bathi kufuneka kakhulu electron emzimbeni (okanye, umzekelo, alpha amasuntswana), sifumana kanye umfanekiso ofanayo. Electron ke diffracted kwaye aphazamise. Kungenxa kule abonakalise wave yimvelo yabo. Kufuneka kuqatshelwe ukuba Bragg diffraction (ekuthethwa nje Bragg) sikuko ukusasazeka oluluqilima amaza kwi ezikrobeni ngamaxesha lingqamane kwisigaba ngesiganeko kunye nencum saa.

okuqinileyo

Nalo eli binzana, ngamnye nonxulumano zabo. Noko ke, isiqina - into isebe article of physics ukuba lifunda isakhiwo kunye neempawu ziikristale, iiglasi neeseramiki. Kuchazwe ngezantsi waziwa kuphela kukuba xa izazinzulu ziye zaphuhliswa isiseko lokuvandlakanya X-ray.

Ngoko ke, ngathi ngembonakalo yikristale - yimeko iziyobisi xa eziba athom ziyathandwa indawo echazwe kakuhle endaweni isithuba omnye komnye, kwaye electron simahla njengoko kweqokobhe electron zishwankathelwe. Eyona uphawu umzimba isiqina - periodicity. Ukuba umfundi kanye wayenomdla physics okanye chemistry, mhlawumbi pops up ngomfanekiso entlokweni yakhe , ngathi ngembonakalo yikristale emkhusaneni yetyuwa (igama izimbiwa - halite, ifomula NaCl).

iintlobo ezimbini athom aba close contact kakhulu, ezakha isakhiwo ngokwaneleyo ashinyeneyo. Sodium kunye nefomu eneSandi chloro kuzo zonke zontathu nemilinganiselo emkhusaneni cc, engontsini leyo aa Incopho na omnye komnye. Ngoko ke, ixesha (okanye unit iseli) - ityhubhu, apho eziphezulu zontathu zenza atom iintlobo mnye, abanye abathathu - omnye. Intlawulo enye kwenye iityhubhu ezinjalo, kusenokwenzeka ukuba ufumane nomkhenkce ongapheliyo. Zonke atom ukuba ibekwe ngaphakathi imilinganiselo ezimbini sikwenze moya crystallographic. Oko kukuthi, ukuba iyunithi iseli ye-ntathu, kodwa iqela elinye, phindwa amaxesha amaninzi (kwimeko efanelekileyo - inani olungenasiphelo amaxesha), it yakha phezu olunye yikristale. Ezi imiphezulu zininzi kangaka kwaye ingqamene omnye komnye.

Umgama interplanar - kungasisalathisi esibalulekileyo elicacisa, umzekelo, uzinzo karhulumente esiqinileyo. Ukuba imilinganiso ezimbini, lo mgama lincinane, kwaye eyesithathu - esikhulu, ngoko ke into ke lula exfoliates. Lichaza, umzekelo, mica, owathatha abantu iglasi ngaphambili kwi windows.

Kwakheka nezithako

Noko ke, rock ityuwa - umzekelo olula kunene: iindidi ezimbini kuphela athom kunye macala ecacileyo cubic. Icandelo Geology, ekuthiwa mineralogy, ukufunda umzimba njengekristale. peculiarity wabo ukuba ubisi wemichiza iquka iintlobo 10-11-athom. Kwaye isakhiwo unzima kakhulu: tetrahedrons, iityhubhu kunye eziphezulu eku xhulumaneni kwi engile ezahlukeneyo ukwakha amajelo misindo iimilo ezahlukeneyo, nemisele yamanzi, ichess ezintsonkothileyo okanye uqhagamshelwano le nale. Ezinjalo, umzekelo, isakhiwo aku- mhle, zokuhomba kakhulu ezinqabileyo ndikunyibilikise ngokufezekileyo Russian charoite ngamatye. iipateni zakhe purple emihle ukuze ziphucule intloko - ke igama wokumbiwa. Kodwa kulwakhiwo elinzima eli parallel langoku kwezinye moya nganye crystallographic.

Oku kuvumela kungenxa kubukho diffraction of elektroni kwi yikristale emkhusaneni ukuchonga ubume babo.

Isakhiwo elektroni

Ukuze echaza ngokwaneleyo iindlela ukufunda ubume mba, ngokusekelwe diffraction of elektroni, umntu unokucinga ukuba iibhola waphoswa ngaphakathi ibhokisi. Emva koko bala ukuba mingaphi iibhola bounced umva kwaye oko engile. Emva koko, indlela apho inkoliso iibhola Bouncing, wahlulelwa kwibhokisi ifomu.

Kakade ke, lo mbono rough. Kodwa kule modeli ekrwada, indlela apho elona nani likhulu iibhola Bouncing - incopho diffraction. Ngenxa yoko, elektroni (okanye X ray) bombarding phezu yikristale. Ezinye zazo "ziyaxinga" kulo mbandela, kodwa ezinye zibhalwe. Ngaphezu koko, ukuba kubonakala kuphela iinqwelomoya crystallographic. Ekubeni moya akukho namnye, kodwa ke kubo, ngoko wongezelela kuphela amaza ezibonisiweyo ngaxeshanye enye kwenye (siye saxubusha ngasentla). Ngoko ke wafumana uphawu ibe kuluhlu, apho vangama ngobunzulu kuxhomekeke engile lweziganeko. Diffraction incopho ibonisa ubukho moya kwi-engile efunda. Lo mfanekiso kubangele kuhlalutywa ukufumana isakhiwo ngqo yikristale.

ifomula

Uhlalutyo yenziwa ngokunxulumene nemithetho ethile. Bona isekelwe ifomula Bragg. Kubonakala ngathi le nto:

2D sinθ = nλ, apho:

• d - izithuba interplanar;
• θ - slip-engile (iengile Incedisa engile reflection);
• n - umyalelo kwincopho diffraction (nenombolo evumayo, ngamanye 1, 2, 3 ...);
• λ - ombala radiation ngesiganeko.

Njengoko umfundi ubona, i-engile asithatyathwa namnye okuye ifunyenwe ngqo kwisifundo kwaye ezongezelelweyo noko. Kufuneka kwakhona ucacise malunga nexabiso n, elibhekisela imbono "diffraction incopho." Ukuphazamisa Le fomyula iqulethe nenombolo ezintle ikhankanya ulandelelwano ubuninzi waphawula.

Le illuminance lomkhusane olu lingelo lisikwe-mbini, umzekelo, kuxhomekeke umahluko cosine endleleni. Ekubeni cosine - umsebenzi ngamaxesha, emva ikhusi elimnyama, kule meko akukho kuphela kwincopho ephambili, kodwa ibe nazo ezimbalwa kakhulu amandla emacaleni aso. Siphila kwihlabathi ofanelekileyo, nto leyo efanele ngokupheleleyo iifomyula zemathematika, ezi bands bekuya kuba inani ongapheliyo. Nakuba kunjalo, eneneni inani kwiindawo ukukhanya ofunda entweni kwaye kuxhomekeke kwamaza, ububanzi lisikwe, kunye nomgama phakathi umthombo ukukhanya.

Ekubeni diffraction - Njengesiphumo esithe ngqo lencinibakazi yohlobo amasuntswana ukukhanya sabaqalayo, ngamanye enoba na uphazamiseko, ngoko ifomula ubandakanya Bragg umyalelo diffraction incopho. Hi ndlela leyi, le nto yenza kube nzima kakhulu kwi izibalo lokuqala zovavanyo. Okwangoku, zonke utshintshwano ezinxulumene nezimo-moya kunye ekubaleni isakhiwo kangangoko evela ipateni diffraction, ezenziwa ngoomatshini. Bona ukubala ukuba zeziphi iincopho zizinto ezahlukeneyo, yaye yintoni - yesibini okanye umyalelo yesithathu imigca ephambili spectra.

Phambi kokuba kuqaliswe lweekhompyutha ejikeleza kunye ujongano olulula (yayilula, ekubeni kwiintlobo yenkqubo izibalo - kodwa izixhobo ezingcono) oko konke kwenziwa ngesandla. Kwaye nangona azibenzi isalamane lwalo inxaki ka Bragg, into, ukuqinisekisa lenyaniso amaxabiso bakufumana, kwathabatha ixesha elininzi neenzame. Izazinzulu ziye ihlolwe kwaye retested - hayi iintshulube indlela yakhe ukubona apho ezona non-inqununu, nenokuthi ezonakalisa izibalo.

Theory kanye umkhuba

ukufunyanwa nguMmangaliso, ogqibeleleyo zombini Wolfe kunye Bragg wabanikela ezandleni uluntu sisixhobo esifunekayo ekufundeni efihliweyo de izakhiwo eziqinileyo. Noko ke, njengokuba sisazi, ithiyori - into elungileyo; kodwa xa kusenziwa kusoloko eyahlukileyo kancinci. Nje ngaphezu kwaba umbuzo ziikristale. Kodwa nayiphi na thiyori ibhekisela kwimeko efanelekileyo. Oko kukuthi isithuba isiphako-free obungenasiphelo apho isakhiwo kwemithetho phindo hayi aphulwe.

Nangona kunjalo, i-real, nokuba zicocekile kwaye ikhule elebhu, nezo zinto crystalline kuko. Phakathi ezakhiwe zendalo wafumana ndlovu ogqibeleleyo - yimpumelelo enkulu. Imiqathango Bragg (oluvakaliswe formula ngasentla) nekhulu ekhulwini amatyala isicelo nomkhenkce lokwenene. Kubo, kuyo nayiphi na imeko, kukho isiphako enjalo, njengoko kumphezulu. Vumela umfundi akuthethi ukubhidanisa engenangqondo kwezinye iingxelo: kumphezulu ngumthombo nje kuphela iziphene, kodwa eso siphene.

Ngokomzekelo, amandla imixokelelwane kwakheka ngaphakathi yikristale yahlukile kuleyo ixabiso lwemimandla umda. Oku kuthetha ukuba kuyimfuneko ukwazisa uhlobo lilonke kunye izikhewu. Oko kukuthi, xa experimenter wazisusa electron vangama spectrum okanye X-ray kumzimba eziqinileyo, bafumana kuphela ekujikeni, kwaye engile lulahlekiso. Umzekelo, θ = 25 ± 0.5 degrees. Le grafu kubonakaliswa into yokuba incopho diffraction (formula leyo lenxaki Bragg) has a ububanzi kwaye estrip, kwaye awubhityanga umgca ngqo egqibeleleyo kwindawo yexabiso.

Iintsomi iimpazamo

Ngoko ke kuvela, zonke izihloko, akunjalo?! Ukuze elithile. Xa umlinganiselo lobushushu wena uze ufumane 37 phezu ithemometha, oku ichanekile ngokupheleleyo. lobushushu emzimbeni wakho yahlukile amaxabiso engqongqo. Kodwa ke into ephambili ukuba loo crazy ukuba abagulayo lixesha ukuphathwa. Kwaye wena nogqirha wakho Akukhathaliseki ukuba eneneni ithemometha yabonisa 37.029.

Kwaye zesayensi - okoko nje imposiso akayeki ukwenza isigqibo, kuya kuthathelwa ingqalelo, kodwa kugxininisa ukubaluleka yokuqala. Ukongeza, iinkcukacha-manani zibonisa: de Lemposiso ngaphantsi kwe anesihlanu ekhulwini, oko nokungahoywa. Iziphumo ezifunyenwe kule amalinge apho le meko zilandelayo Bragg Kwakhona imposiso. Izazinzulu abenza izibalo, kuba ngokuqhelekileyo kuboniswe. Noko ke, ngokuba izicelo ezithile, ngamanye amazwi, ukuqonda oko enjengesakhiwo ngumkhenkce, impazamo ayibalulekanga kakhulu (ixesha elide kangangoko incinci).

Kubalulekile ukuphawula ukuba isixhobo ngasinye, nkqu kumgca yesikolo, kusoloko kukho ukungaqiniseki. Eli nani ithatha ingqalelo imilinganiselo kunye, xa kukho imfuneko, kubandakanywa kwipaselana equlethe impazamo iyonke.