Fr.: système standard
Photometric system used as a reference.
standard temperature and pressure (STP)
damâ o fešâr-e estândé
Fr.: conditions normales de température et de pression
1) The most commonly used definition is temperature of 273.15 K (0 °C) and
pressure of 1 → atmosphere.
Fr.: temps standard
The time in any of the 24 internationally agreed time zones into which the Earth's surface is divided. The primary zone is centered on the Greenwich meridian (0° longitude).
Fr.: valeurs standard
Photometric values of selected stars in a standard system.
Fr.: onde stationnaire
A wave produced by the simultaneous transmission of two similar wave motions in opposite directions. Same as stationary wave.
Standing verbal adjective from stand, cognate with Pers. istâdan, as below; → wave.
Istân pr.p. of istâdan "to stand;" Mid.Pers. êstâtan; O.Pers./Av. sta- "to stand, stand still; set;" Av. hištaiti; cf. Skt. sthâ- "to stand;" Gk. histemi "put, place, weigh," stasis "a standing still;" L. stare "to stand;" Lith. statau "place;" O.N. standa, Goth. standan, O.H.G. stantan, Swed. stå, Du. staan, Ger. stehen; O.E. standan; PIE base *sta- "to stand;" mowj, → wave.
Fr.: conte, histoire
A narrative, either true or fictitious, in prose or verse, designed to interest, amuse, or instruct the hearer or reader; tale (Dictionary.com).
M.E. storie, from O.Fr. estorie, estoire "story, chronicle, history," from L.L. storia, shortened from L. historia "history, account, tale, story," → history.
Dâstân "story, fable, romance."
The season that starts when the Sun, during its apparent yearly motion, attains the celestial longitude 90 degrees in the Northern Hemisphere and 270 degrees in the Southern Hemisphere. The current length of the summer season, around the epoch 2000, is 93.65 days.
M.E. sumer, from O.E. sumor (cf. O.S., O.N., O.H.G. sumar, O.Fris. sumur, M.Du. somer, Du. zomer, Ger. Sommer), from PIE base *sem- "summer;" cf. Av. ham- "summer;" Mid.Pers. hāin "summer;" Skt. sámā- "half-year, season;" Arm. am "year," amarn "summer;" O.Ir. sam "summer;" O.Welsh ham "summer."
From Mid.Pers. tâpistân, ultimately from Proto-Iranain *tap-stā-
"hot, heat season, time, place." The first component
*tap- "to shine, radiate;" cf. Mod.Pers.
tâbidan, variants tâftban "to shine," tafsidan
"to become hot;" Mid.Pers. tâftan
"to heat, burn, shine;" taftan "to become hot;" Parthian t'b "to shine;"
Av. tāp-, taf- "to warm up, heat," tafsat "became hot,"
tāpaiieiti "to create warmth;"
cf. Skt. tap- "to heat, be/become hot; to spoil, injure, damage; to suffer,"
tapati "burns;" L. tepere "to be warm," tepidus "warm;"
PIE base *tep- "to be warm."
Fr.: solstice d'été
The moment in the northern hemisphere when the → Sun attains its highest → declination of 23°26' (or 23°.44) with respect the → equator plane. It happens when the Earth's axis is orientated directly toward the Sun, on 21 or 22 June. During the northern solstice the Sun appears to be directly overhead at noon for places situated at → latitude 23.44 degrees north, known as the → tropic of Cancer. The summer solstice can occur at any moment during the day. Two successive summer solstices are shifted in time by about 6 h. The summer solstice in the northern hemisphere is the → winter solstice in the southern hemisphere.
Fr.: triangle d'été
Fr.: conjonction supérieure
The conjunction of a planet with the Sun which occurs when the planet is beyond the Sun. → inferior conjunction.
The level that must be reached for a physical effect to begin or be noticeable.
M.E. threschold, O.E. threscold, threscwald "doorsill, point of entering."
Âstâné "threshold; a place of rest or sleeping," variant âstân; Mid.Pers. âstânak; ultimately from Proto-Iranian *ā-stānaka-, from *stā- "to stand;" cf. O.Pers./Av. sta- "to stand, stand still; set;" Av. hištaiti; Mid.Pers. êstâtan "to stand;" Mod.Pers. istâdan "to stand;" cf. Skt. sthâ- "to stand;" Gk. histemi "put, place, weigh," stasis "a standing still;" L. stare "to stand;" Lith. statau "place;" Goth. standan; PIE base *sta- "to stand."
Fr.: seuil d'énergie
The minimum energy necessary for the occurrence of some chemical/physical effect.
threshold of reaction
Fr.: seuil de réaction
The minimum energy, for an incident particle or photon, below which a particular reaction does not occur.
Fr.: seuil de signal
The minimum intensity of a signal that can be detected and recognized.
Fr.: conjonction triple
A rare event involving a particularly intricate set of movements of two planets or a planet and a star where they meet each other three times in a short period either in opposition or at the time of inferior conjunction, if an inferior planet is involved. The visible movement of the planet or the planets in the sky is therefore normally prograde at the first conjunction, retrograde at the second conjunction and again prograde at the third conjunction.
cistân-e partowhâ-ye keyhâni-ye ultar-meh-kâruž
Fr.: énigme des rayons cosmiques de très haute énergie
The question of the origin and nature of the → ultra high energy cosmic rays. According to the → GZK cutoff, the UHECRs should be nearby. They are expected to be exceptional, therefore visible by some astrophysical counterpart. However, there is nothing visible (within a few tens of → Mpc) in the direction of all the UHECR detected up to now.
M.E., OE; cf. O.Fris., Du. winter, O.S., O.H.G. wintar, Ger. winter, Dan., Swed. vinter, Goth. wintrus "winter"),
Zemestân "winter," related to zam "cold," Mid.Pers. zam, zamistân "winter;" Av. zimô "winter;" cf. Skt. hima- "cold, frost;" Ossetic zymæg/zumæg "winter;" Gk. xeimon "winter;" L. hiems "winter;" Lith. ziema "winter;" PIE *gheim- "snow, winter."
Fr.: solstice d'hiver
The moment in the northern hemisphere when the → Sun attains its lowest → declination of -23°26' (or -23°.44) with respect the → equator plane. It happens when the Earth's axis is orientated directly away from the Sun, on 21 or 22 December. During the northern winter solstice the Sun appears to be directly overhead at noon for places situated at → latitude 23.44 degrees south, known as the → tropic of Capricorn. The winter solstice can occur at any moment during the day. Two successive winter solstices are shifted in time by about 6 h. The winter solstice in the northern hemisphere is the → summer solstice in the southern hemisphere.