Opera (ital. opera, aynan — talif az lotini opera — mehnat, masnuot, asar), janri sanati musiqi-dramaviest. Asosi Opera— libretto dar in janr bo vositahoi dramaturgiyai musiqi, pesh az hama, tavassuti musiqii vokali (ovozi) tajassumkunanda meshavad. Opera hamchun janri murakkab dar khud namudhoi gunoguni sanoe: dramaturgiya, musiqi, sanati tasviri, khoreografiya va …

Onega, khalich dar qismi janubi bahri Safed. Tulash 185 kilometr, barash 50—100 kilometr; chuquriash to 36 metr. Jazirahoyash bisyorand (kalontarini onho jazirai Boloveskiy). Zimiston yakh mebandad. Dar sohili garbi, dar nazdikii shahri Belomorsk kanali Bahri Safedu Baltika bo bahri Safed payvast meshavad. Ba Onega daryohoi Onega, Kem, Vig merezand. Bandarhoyash: …

Operator, mafhumi matematikiest, ki ba manoi vase muvofiqati elementhoi du majmu X va U-ro ifoda mekunad, yanie bar har yak elementi kh i majmui X i on elemen­ti u-i majmui U-ro muvofiq meguzorad. Ba (mafhumkhri amal, inikos, tabdilot, funksiya, hammanost. Elementi u-ro obrazi elementi kh, kh-ro proobraz (timsol)-i u menomand. …

Onega, O n e g o, kulest dar shimoli garbi Qismi evropoii SSSR (dar RASS Karel, va viloyathoi Leningra­du Vologdai RSFSR). Masohat 9,7 hazor kilometr2. Chuquriash ba hisobi miyona 30 metr, joi chuqurtarinash 120 metr; hajmi ob 292 klometr3. Onega dar natijai harakathoi tektoniki ba vujud omada, az tasiri yakhbandihoi …

Operatori Laplas, lapla­sian, d e.l ta-o pe r a tor, D- operator, operatori differen­sialii khattiero guyand, ki funksiyai f(kh|, kh2, …, khya)-i az p tagyiryobanda (Kh|, kh2, …, khp) vobastaro ba funk­siyai Af = muvofiq meguzorad. Dar holati khususi Operatori Laplasro baroi funksiyam dutagyiryobandai f(kh, u) ba shakli zerin menavisand: …

Onicha (Onitscha), shahrest dar Nigeriya, dar sohili chapi daryoi Niger. Aholiash 220 hazor nafar (1975). Uzeli rohhoi shosse. Markazi parvarishi nakhli ravgandeh. Sanoati bofandagi va khurokvori (istehsoli ravgani nakhl) dorad.

Operatori khatti, ba fazohoi khatti umumiyat dodani mafhumi tab- dili khatty. Operatori khattii fazoi E gufta funksiyai G(kh)-ro me­nomand, ki baroi hamai kh muayyan buda, qimathoi on elementhoi fazoi khattii E meboshand va sharti zerinro qone megardonad: G (akh -j- Ru)! = aG(kh) + RG(u), dar on kh va u — …

Onkologiya (az yunoni onkos — jogar, omos va …logiya), yak sohai tibro guyand, ki peshgiri va muolijai bemorihoi omosiro meomuzad. Bemorihoi omosi az qadimulayyom malumand. Malumote, ki dar papirushoi Ebers (1550 to milod) zikr yoftaand, ba in shahodat medihand. Oid ba omosho dar asarhoi Buqrot, Jolinus, Sels, Ibni Sino, Ismoili …

Operatorho dar nazariyai k v a n t i, mafhumi matematikiest, ki dar apparata matematikii mekha­nikai kvanti va nazariyai kvantii maydon istifoda meshavad va baroi ba vektori muayyani holat yo (funk­siyai mavji) V muvofiq guzoshtani digar vektorhoi (funksiyahoi) muayyan khizmat mekunad. Vobastagii bayni Chg va ‘R’ dar shakli A ‘G’ …

Onomastika (az yunoni onomastikds — sanati nomguzori, onoma — nom), 1) yak shubai ilmi zabonshinosiro guyand, ki tarikhi paydoish va tahavvuli ismoi khosro meomu­zad; 2) majmui hama guna ismhoi khos (leksikai onomastiki), onim i ya, ki vobasta ba obekti nombarshavanda ba antroponimho (nomi ashkhos), etnonimho (nomi qavmho, millatho, khalqho), toponimho …