An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

<< < D l dar dat de deb dec dec dec def deg del den dep des det dev dia dif dif dih dip dir dis dis dis dis diu dog Dop dou Dre Dum dus dyn dys > >>

Number of Results: 685
directed edge
  لبه‌ی ِ سودار   
labe-ye sudâr

Fr.: graphe orienté   

In → graph theory, an edge where endpoints are distinguished; one is the head and the other is the tail. A directed edge is specified as an ordered pair of → vertices, u, v and is denoted by (u, v) or uv.

directed; → edge.

directed graph
  نگاره‌ی ِ سودار   
negâre-ye sudâr

Fr.: graphe orienté   

In → graph theory, a graph with → directed edges. Also calle → digraph.

directed; → graph.

directed path
  په ِ سودار   
pah-e sudâr

Fr.: chemin orienté   

In a → directed graph, a path in which all → edges are oriented in the same direction.

directed; → edge.

direction
  راستا، سو؛ ۲) راشتاری   
1) râstâ, su (#); 2) râštâri

Fr.: direction   

1) A position to which motion or another position is referred.
2) The act or an instance of directing.

M.E. direccioun, from M.Fr., from L. direction-, stem of directio "arranging in line, straightening," → direct.

1) Râstâ, from directdirect + dimension suffix; su, from Mid.Pers. sôk "side."
2) Râštâri, noun from râštârdirector + suffix -i.

direction angle
  زاویه‌ی ِ راستا   
zâviye-ye râstâ

Fr.: angle de direction   

An angle made by a given vector and a coordinate axis.
The angle between the North and a chosen direction.

direct; → angle.

director
  راشتار   
râštâr

Fr.: directeur   

A person who directs a project, a group, a production.

From → direct + -tor a suffix found in loanwords from L., forming personal agent nouns from verbs.

Râštâr, from râšt- stem of râštidandirect + -âr suffix of agent noun (as in parastâr "nurse").

Dirichlet condition
  بوتار ِ دیریکله   
butâr-e Dirichlet

Fr.: condition de Dirichlet   

One of the following conditions for a → Fourier series to converge:
1) The function f(x) is defined and single valued, except possibly at a finite number of points in the interval -π, +π.
2) f(x) has a period of 2π.
3) f(x) and f'(x) are → piecewise continuous functions on -π, +π.
Then, the Fourier series converges to:
(a) f(x) if x is a point of continuity.
(b) (f(x + 0) + f(x - 0))/2, if x is a point of discontinuity.

Named after Peter Gustav Lejeune Dirichlet (1805-1859), German mathematician who made valuable contributions to → number theory, → analysis, and → mechanics; → condition.

dirt
  چرک   
cerk (#)

Fr.: saleté   

A substance, such as mud or dust, that soils someone or something (OxfordDictionaries.com)

Metathesis of M.E. drit, drytt "mud, dirt, dung," from O.N. drit, cognate with O.E. dritan.

Cerk "dirt, filth."

dirty
  چرکین   
cerkin (#)

Fr.: sal   

Covered or marked with an unclean substance. → dirty ice, → dirty iceball model.

dirt + suffix -y.

dirty ice
  یخ ِ چرکین   
yax-e cerkin

Fr.: glace sale   

Interstellar ice grains with graphite, silicates, or other chemical compounds adsorbed on their surfaces.

dirty; → ice.

dirty iceball model
  مدل ِ گلوله‌ی ِ یخ   
model-e golule-ye yax

Fr.: modèle de la boule de glace sale   

A model for a → cometary nucleus proposed by Fred Whipple (1950-51), according to which the nucleus is a solid body (a few kilometers across) made up of various → ices (→ frozen water, → methane, → ammonia, → carbon dioxide, and → hydrogen cyanide) in which → dust is embedded. Dust particles are liberated when the ices vaporize as the → comet approaches the → Sun, and they get blown away by → solar radiation pressure, often forming impressive, gently curved → dust tails.

dirty; → ice; → ball; → model.

dis-
     
vâ- (#)

Fr.: dis-   

A prefix meaning "lack of, not" (e.g. dishonest); "do the opposite of" (e.g. disallow); "apart, away" (e.g. discard); before f, dif-; before some consonants (b, d, l, m, n, r, s, v, and sometimes g and j) di-.

From O.Fr. des-, from L. dis- "apart," from PIE *dis- "apart, asunder" (cf. O.E. te-, O.S. ti-, O.H.G. ze-, Ger. zer-). The PIE root is a secondary form of *dwis- and is thus related to L. → bis "twice."

Vâ- prefix denoting "separation; repetition; open; reversal, opposition; off; away," variant of bâz-, from Mid.Pers. abâz-, apâc-; O.Pers. apa- [pref.] "away, from;" Av. apa- [pref.] "away, from," apaš [adv.] "toward the back;" cf. Skt. ápāñc "situated behind."

disallocate
  واتسکیدن   
vâteskidan

Fr.: desallouer   

Computers: To cancel the assignment of a particular resource to a user.

dis- + → allocate.

disallocation
  واتسک   
vâtesk

Fr.: desallouation   

The act of disallocating or the state of being disallocated.

dis- + → allocate.

disapproval
  واسند   
vâsand

Fr.: déapprobation   

The act or state of disapproving; a condemnatory feeling, look, or utterance.

dis-; → approval.

disapprove
  واسندیدن   
vâsandidan

Fr.: désapprover   

To withhold approval from; decline to sanction.

dis-; → approve.

discharge
  وابار   
vâbâr

Fr.: décharge   

The removal or transference of an electric charge, as by the conversion of chemical energy to electrical energy.
The sudden and momentary equalization of a difference of potential, as between two terminals.

From M.E. deschargen, from O.Fr. deschargier "unload," from L.L. discarricare, from → dis- "do the opposite of" + carricare "to load a cart," from carrus "cart."

Vâbâr, from vâ- reversal prefix, → de- + bârcharge.

disciplinarity
  هاوشانیگی، هاوشان‌مندی   
hâvešânigi, hâvešânmandi

Fr.: disciplinarité   

The quality or state of being → disciplinary.

disciplinary; → -ity.

disciplinary
  هاوشانی، هاوشان‌مند   
hâvešâni, hâvešânmand

Fr.: disciplinaire   

Of, for, or constituting a → discipline. See also → interdisciplinary, → multidisciplinary, and → transdisciplinary.

discipline; → -ary.

discipline
  هاوشان   
hâvešân

Fr.: discipline   

1) A branch of learning or instruction.
2) A system of rules for behavior, methods of practice, etc.

M.E., from M.Fr. discipline, descepline, from L. disciplina literally "teaching, instruction," from discipulus "pupil, student, follower," from dis- + cipere, combining form of capere "to take," → concept, + -ulus, → -ule.

Hâvešân, from hâveš "disciple, pupil," Mid.Pers. hâvišt "disciple, pupil;" Av. hāvišta- "disciple, pupil," + -ân a suffix denoting "group, order, system."

<< < D l dar dat de deb dec dec dec def deg del den dep des det dev dia dif dif dih dip dir dis dis dis dis diu dog Dop dou Dre Dum dus dyn dys > >>