“X”的意思、由来-开放百科全书

X (named ex {{IPAc-en|ɛ|k|s}}, plural exes^[1]) is the 24th and antepenultimate letter in the modern English alphabet and the ISO basic Latin alphabet.

History

In Ancient Greek, 'Χ' and 'Ψ' were among several variants of the same letter, used originally for {{IPA|/kʰ/}} and later, in western areas such as Arcadia, as a simplification of the digraph 'ΧΣ' for {{IPA|/ks/}}. In the end, more conservative eastern forms became the standard of Classical Greek, and thus 'Χ' (Chi) stood for {{IPA|/kʰ/}} (later {{IPA|/x/}}; palatalized to {{IPA|[ç]}} in Modern Greek before front vowels). However, the Etruscans had taken over 'Χ' from western Greek, and it therefore stands for {{IPA|/ks/}} in Etruscan and Latin.

The letter 'Χ' ~ 'Ψ' for {{IPA|/kʰ/}} was a Greek addition to the alphabet, placed after the Semitic letters along with phi 'Φ' for {{IPA|/pʰ/}}.

Use in writing systems

English

In English orthography, {{angbr|x}} is typically pronounced as the voiceless consonant cluster {{IPAc-en|k|s}} when it follows the stressed vowel (e.g. ox), and the voiced consonant {{IPAc-en|ɡ|z}} when it precedes the stressed vowel (e.g. exam). It is also pronounced {{IPAc-en|ɡ|z}} when it precedes a silent {{angbr|h}} and a stressed vowel (e.g. exhaust).^[2] Before {{angbr|i}} or {{angbr|u}}, it can be pronounced {{IPAc-en|k|ʃ}} or {{IPAc-en|ɡ|ʒ}} (e.g. sexual and luxury); these result from earlier {{IPAc-en|k|s|j}} and {{IPAc-en|g|z|j}}. It also makes the sound {{IPAc-en|k|ʃ}} in words ending in -xion (typically used only in British-based spellings of the language; American spellings tend to use -ction). When {{angbr|x}} ends a word, it is always {{IPAc-en|k|s}} (e.g. fax), except in loan words such as faux (see French, below).

There are very few English words that start with {{angbr|x}} (the fewest number of any letter). When {{angbr|x}} does start a word, it is usually pronounced {{IPAc-en|z}} (e.g. xylophone, xenophobia, and xanthan); in rare recent loanwords or foreign proper names, it can also be pronounced {{IPAc-en|s}} (e.g. the obsolete Vietnamese monetary unit xu) or {{IPAc-en|ʃ}} (e.g. Chinese names starting with Xi like Xiaomi or Xinjiang). Many of the words that start with {{angbr|x}} are of Greek origin, or standardized trademarks (Xerox) or acronyms (XC). In abbreviations, it can represent "trans-" (e.g. XMIT for transmit, XFER for transfer), "cross-" (e.g. X-ing for crossing, XREF for cross-reference), "Christ-" as shorthand for the labarum (e.g. Xmas for Christmas, Xian for Christian), the "crys-" in crystal (XTAL), or various words starting with "ex-" (e.g. XL for extra large, XOR for exclusive-or).

X is the third least frequently used letter in English (after {{angbr|q}} and {{angbr|z}}), with a frequency of about 0.15% in words.^[3]

Other languages

In Latin, {{angbr|x}} stood for {{IPA|[ks]}}. In some languages, as a result of assorted phonetic changes, handwriting adaptations or simply spelling convention, {{angbr|x}} has other pronunciations:

Additionally, in languages for which the Latin alphabet has been adapted only recently, {{angbr|x}} has been used for various sounds, in some cases inspired by European usage, but in others, for consonants uncommon in Europe. For these no Latin letter stands out as an obvious choice, and since most of the various European pronunciations of {{angbr|x}} can be written by other means, the letter becomes available for more unusual sounds.

Other systems

In the International Phonetic Alphabet, {{angbr|{{IPA|x}}}} represents a voiceless velar fricative.

Other uses

In mathematics, x is commonly used as the name for an independent variable or unknown value. The modern tradition of using x to represent an unknown was introduced by René Descartes in La Géométrie (1637).^[5] As a result of its use in algebra, X is often used to represent unknowns in other circumstances (e.g. X-rays, Generation X, The X-Files, and The Man from Planet X; see also Malcolm X).

It may also be used as a typographic approximation for the multiplication sign. In mathematical typesetting, x meaning an algebraic variable is normally in italic type (

), partly to avoid confusion with the multiplication symbol. In fonts containing both x (the letter) and × (the multiplication sign), the two glyphs are dissimilar.

It can be used as an abbreviation for 'between' in the context of historical dating; e.g., '1483 x 1485'.

Maps and other images sometimes use an X to label a specific location, leading to the expression "X marks the spot".^[6]

In art or fashion, the use of X indicates a collaboration by two or more artists, e.g. Aaron Koblin x Takashi Kawashima. This application, which originated in Japan, now extends to other kinds of collaboration outside the art world.^[9]

Related characters

Descendants and related characters in the Latin alphabet

Ancestors and siblings in other alphabets

Computing codes

In the C programming language, 'x' preceded by zero (0x or 0X) is used to denote hexadecimal literal values.

Other representations

See also

References

1. ^"X", Oxford English Dictionary, 2nd edition (1989); Merriam-Webster's Third New International Dictionary of the English Language, Unabridged (1993); "ex", op. cit.
2. ^{{cite book |first=Richard |last=Venezky|title=The Structure of English Orthography|url=https://books.google.com/books?id=Mrt_G_RrJykC&pg=PA5|date=1 January 1970 |location=The Hague|publisher=Walter de Gruyter|isbn=978-3-11-080447-8|page=40}}
3. ^{{cite web |last=Mička |first=Pavel |title=Letter frequency (English) |url=http://en.algoritmy.net/article/40379/Letter-frequency-English |website=Algoritmy.net |accessdate=9 February 2014}}
4. ^{{cite web |url=http://www.dizionario.rai.it |title=Dizionario di ortografia e pronunzia |trans-title=Dictionary of Spelling and Pronunciation |language=Italian |website=Dizionario di ortografia e pronunzia |accessdate=9 February 2014}}
5. ^{{cite book |url=https://books.google.com/books?id=_byqAAAAQBAJ&pg=PA380&dq=webster+x&hl=en&sa=X&ved=0ahUKEwi2w7XMsPzJAhUB4yYKHW83C9kQ6AEIITAB#v=onepage&q=unknown&f=false |title=A History of Mathematical Notations |first=Florian |last=Cajori |publisher=Open Court Publishing |year=1928 |place=Chicago|page=381 }} See History of algebra.
6. ^{{cite web | url=http://www.dictionary.com/browse/x-marks-the-spot | title=X marks the spot | accessdate=21 June 2016}}
7. ^{{cite book |last=Gordon |first=Arthur E. | url=https://books.google.com/books?id=ywI6SDUggk4C&q=ix#v=snippet&q=%22roman%20numerals%22&f=false | title=Illustrated Introduction to Latin Epigraphy | publisher=University of California Press | date=1983 | accessdate=3 October 2015 | page=44}}
8. ^{{cite book |last=King |first=David A. | url=https://books.google.com/books?id=PapljPXaSbwC&lpg=PA282&dq=roman%20numerals%20letters&pg=PA282#v=onepage&q&f=false | title=The Ciphers of the Monks | year=2001 | page=282 |quote=In the course of time, I, V and X became identical with three letters of the alphabet; originally, however, they bore no relation to these letters.}}
9. ^{{cite web|url=http://arkitip.com/product/x-mark-of-collaboration-issue-no-0053x/|title=X: Mark of Collaboration - Issue No. 0053X - Arkitip, Inc.|author=|date=|website=arkitip.com}}
10. ^{{cite web|url=https://www.unicode.org/L2/L2004/04132-n2740-phonetic.pdf|title=L2/04-132 Proposal to add additional phonetic characters to the UCS|date=2004-04-19|first=Peter|last=Constable}}
11. ^{{cite web|url=https://www.unicode.org/L2/L2011/11202-n4081-teuthonista.pdf|title=L2/11-202: Revised proposal to encode “Teuthonista” phonetic characters in the UCS|date=2011-06-02|first1=Michael|last1=Everson|first2=Alois|last2=Dicklberger|first3=Karl|last3=Pentzlin|first4=Eveline|last4=Wandl-Vogt}}
12. ^{{cite web|url=https://www.unicode.org/L2/L2004/04191-n2788-laryngeals.pdf|title=L2/04-191: Proposal to encode six Indo-Europeanist phonetic characters in the UCS|date=2004-06-07|first1=Deborah|last1=Anderson|first2=Michael|last2=Everson}}