| 词条 | Eta |
| 释义 |
Eta (uppercase {{Script|Grek|Η}}, lowercase {{Script|Grek|η}}; {{lang-grc|ἦτα}} ē̂ta {{IPA-el|êːtaː|}} or {{lang-ell|ήτα}} ita {{IPA-el|ˈita|}}) is the seventh letter of the Greek alphabet. Originally denoting a consonant /h/, its sound value in the classical Attic dialect of Ancient Greek was a long vowel {{IPA|[ɛː]}}, raised to {{IPA-el|i|}} in hellenistic Greek, a process known as iotacism. In the system of Greek numerals it has a value of 8. It was derived from the Phoenician letter heth . Letters that arose from eta include the Latin H and the Cyrillic letter И. HistoryConsonant h{{main|Heta (letter)}}The letter shape 'H' was originally used in most Greek dialects to represent the sound /h/, a voiceless glottal fricative. In this function, it was borrowed in the 8th century BC by the Etruscan and other Old Italic alphabets, which were based on the Euboean form of the Greek alphabet. This also gave rise to the Latin alphabet with its letter H. Other regional variants of the Greek alphabet (epichoric alphabets), in dialects that still preserved the sound /h/, employed various glyph shapes for consonantal heta side by side with the new vocalic eta for some time. In the southern Italian colonies of Heracleia and Tarentum, the letter shape was reduced to a "half-heta" lacking the right vertical stem (Ͱ). From this sign later developed the sign for rough breathing or spiritus asper, which brought back the marking of the /h/ sound into the standardized post-classical (polytonic) orthography.[1] Dionysius Thrax in the second century BC records that the letter name was still pronounced heta (ἥτα), correctly explaining this irregularity by stating "in the old days the letter Η served to stand for the rough breathing, as it still does with the Romans."[2]Long eIn the East Ionic dialect, however, the sound /h/ disappeared by the sixth century BC, and the letter was re-used initially to represent a development of a long vowel {{IPA|/aː/}}, which later merged in East Ionic with {{IPA|/ɛː/}} instead.[3] In 403 BC, Athens took over the Ionian spelling system and with it the vocalic use of H (even though it still also had the /h/ sound itself at that time). This later became the standard orthography in all of Greece. ItacismDuring the time of post-classical Koiné Greek, the {{IPA|/ɛː/}} sound represented by eta was raised and merged with several other formerly distinct vowels, a phenomenon called itacism after the new pronunciation of the letter name as ita instead of eta. Itacism is continued into Modern Greek, where the letter name is pronounced {{IPA|[ˈita]}} and represents the sound /i/ (a close front unrounded vowel). It shares this function with several other letters (ι, υ) and digraphs (ει, οι), which are all pronounced alike. This phenomenon at large is called iotacism. Cyrillic scriptEta was also borrowed with the sound value of [i] into the Cyrillic script, where it gave rise to the Cyrillic letter И. UsesLetterIn Modern Greek, due to iotacism, the letter (pronounced {{IPA-el|ˈita|}}) represents a close front unrounded vowel, {{IPA|/i/}}. In Classical Greek, it represented a long open-mid front unrounded vowel, {{IPA|/ɛː/}}. SymbolUpper caseThe uppercase letter Η is used as a symbol in textual criticism for the Alexandrian text-type (from Hesychius, its once-supposed editor). In chemistry, the letter H as symbol of enthalpy sometimes is said to be a Greek eta, but since enthalpy comes from ἐνθάλπος, which begins in a smooth breathing and epsilon, it is more likely a Latin H for 'heat'. In information theory the uppercase Greek letter H is used to represent the concept of entropy of a discrete random variable. Lower caseThe lowercase letter η is used as a symbol in:
Character encodings
|0397|name1=Greek Capital Letter Eta |03B7|name2=Greek Small Letter Eta |0370|name3=Greek Capital Letter Heta |0371|name4=Greek Small Letter Heta |2C8E|name5=Coptic Capital Letter Hate |2C8F|name6=Coptic Small Letter Hate |map2=DOS Greek|map2char1=86|map2char2=9E |map3=DOS Greek-2|map3char1=AA|map3char2=E1 |map4=Windows 1253|map4char1=C7|map4char2=E7 |namedref1=TeX|ref1char2=\\eta }}
|1D6AE|name1=Mathematical Bold Capital Eta |1D6C8|name2=Mathematical Bold Small Eta |1D6E8|name3=Mathematical Italic Capital Eta |1D702|name4=Mathematical Italic Small Eta |1D722|name5=Mathematical Bold Italic Capital Eta |1D73C|name6=Mathematical Bold Italic Small Eta }}{{charmap |1D75C|name1=Mathematical Sans-Serif Bold Capital Eta |1D776|name2=Mathematical Sans-Serif Bold Small Eta |1D796|name3=Mathematical Sans-Serif Bold Italic Capital Eta |1D7B0|name4=Mathematical Sans-Serif Bold Italic Small Eta }} These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style. References{{Wiktionary|Η|η}}1. ^Nick Nicholas (2003), "Greek /h/" {{webarchive|url=https://archive.is/20130901210905/http://www.tlg.uci.edu/~opoudjis//unicode/unicode_aitch.html |date=2013-09-01 }} 2. ^{{lang|grc|παρὰ τοῖς ἀρχαίοις ὁ τύπος τοῦ Η ἐν τύπῳ δασείας ἔκειτο, ὥσπερ καὶ νῦν <παρὰ> τοῖς Ῥωμαίοις}} Alfredus Hilgard (ed), "In artis Dionysianae §6" in Grammatici Graeci. Scholia in Dionysii Thracis Artem Grammaticam (1901), p. 486. 3. ^{{cite book|title=New Comparative Grammar of Greek and Latin|first=Andrew L.|last=Sihler|edition=illustrated|publisher=Oxford University Press|year=1995|location=New York|ISBN=0-19-508345-8|url=https://books.google.com/books?id=IeHmqKY2BqoC|pages=10–20}} 2 : Greek letters|Vowel letters |
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