| 释义 |
delta
Del·ta D0115950 (dĕl′tə) An area of the south-central United States extending on either side of the Mississippi River from Memphis, Tennessee, to Vicksburg, Mississippi. An important cotton-producing region, it is noted for its folk culture, especially as the home of some of the earliest blues music.
 deltasatellite image of theNile River delta, Egyptdel·ta D0115950 (dĕl′tə)n.1. The fourth letter of the Greek alphabet. See Table at alphabet.2. An object shaped like a triangle.3. a. A usually triangular alluvial deposit at the mouth of a river.b. A similar deposit at the mouth of a tidal inlet, caused by tidal currents.4. Mathematics A finite increment in a variable.adj. Chemistry 1. Being in the fourth position relative to a designated carbon atom in an organic molecule at which an atom or a group may be substituted.2. Referring to the fourth of a group of isomers, or molecules of similar origin or properties, determined arbitrarily by those who discover or classify them. Used in combination.
[Middle English, from Latin, from Greek, of Phoenician origin; see dl in Semitic roots.]
del·ta′ic (-tā′ĭk), del′tic (-tĭk) adj.delta (ˈdɛltə) n1. (Letters of the Alphabet (Foreign)) the fourth letter in the Greek alphabet (Δ, δ), a consonant transliterated as d2. an object resembling a capital delta in shape3. (Physical Geography) (capital when part of name) the flat alluvial area at the mouth of some rivers where the mainstream splits up into several distributaries: the Mississippi Delta. 4. (Mathematics) maths a finite increment in a variable[C16: via Latin from Greek, of Semitic origin; compare Hebrew dāleth] deltaic, ˈdeltic adj
Delta (ˈdɛltə) n1. (Celestial Objects) (foll by the genitive case of a specified constellation) usually the fourth brightest star in a constellation2. (Astronautics) any of a group of US launch vehicles used to put unmanned satellites into orbit3. (Communications & Information) communications a code word for the letter d
Delta (ˈdɛltə) n (Placename) a state of Nigeria, on the Niger river delta on the Gulf of Guinea. Capital: Asaba. Pop: 4 098 391 (2006). Area: 17 698 sq km (6833 sq miles)del•ta (ˈdɛl tə)
n., pl. -tas. 1. the fourth letter of the Greek alphabet (Δ, δ). 2. the fourth in a series of items. 3. anything triangular, like the Greek capital delta (Δ). 4. Math. an incremental change in a variable, as Δ or δ. 5. a nearly flat plain of alluvial, often triangular, deposit between diverging branches of the mouth of a river. 6. (cap.) a star that is usu. the fourth brightest of a constellation: Delta Crucis. [1350–1400; Middle English < Latin < Greek délta; akin to Hebrew dāleth] del•ta′ic (-ˈteɪ ɪk) adj. del·ta (dĕl′tə) A usually triangular mass of sediment, especially silt and sand, deposited at the mouth of a river. Deltas form when a river flows into a body of standing water, such as a sea or lake.deltaFlat, alluvial land at a river mouth where it splits into many streams called distributaries.Thesaurus| Noun | 1. |  delta - a low triangular area of alluvial deposits where a river divides before entering a larger body of water; "the Mississippi River delta"; "the Nile delta"alluvial deposit, alluvial sediment, alluvium, alluvion - clay or silt or gravel carried by rushing streams and deposited where the stream slows downgeological formation, formation - (geology) the geological features of the earth | | 2. | delta - an object shaped like an equilateral triangleequiangular triangle, equilateral triangle - a three-sided regular polygon | | 3. | delta - the 4th letter of the Greek alphabetGreek alphabet - the alphabet used by ancient Greeksalphabetic character, letter of the alphabet, letter - the conventional characters of the alphabet used to represent speech; "his grandmother taught him his letters" |
Translationsdelta (ˈdeltə) noun a roughly triangular area of land formed at the mouth of a river which reaches the sea in two or more branches. the delta of the Nile. (河流的)三角洲 （河流的）三角洲 delta
delta [from triangular shape of the Nile delta, like the Greek letter delta], a deposit of clay, silt, and sand formed at the mouth of a river where the stream loses velocity and drops part of its sediment load. No delta is formed if the coast is sinking or if there is an ocean or tidal current strong enough to prevent sediment deposition. Coarse particles settle first, with fine clays last and found at the outer regions of the delta. The three main varieties of deltas are the arcuate (the Nile), the bird's-foot (the Mississippi), and the cuspate (the Tiber). The Nile, Mississippi, Niger, Rhine, Danube, Kuban, Volga, Amu Darya, Indus, Ganges-Brahmaputra, Ayeyarwady, Tigris and Euphrates, and Huang He (Yellow) rivers are among those that have formed large deltas, many of which are fertile lands that support dense agricultural populations.delta (del -tă) (δ) 1. The fourth letter of the Greek alphabet, used in stellar nomenclature usually to designate the fourth-brightest star in a constellation or sometimes to indicate a star's position in a group. 2. Symbol for declination.Delta a lowland in the lower reaches of a river, made up of river sediments and dissected by a more or less ramified network of arms and channels. The name “delta” is derived from the capital letter of the Greek alphabet Δ (delta). Because of its resemblance to the Greek letter, the triangular lowland near the mouth of the Nile River was called a “delta” in antiquity. Deltas are formed as a result of the complex interaction of river discharge, wave motion, tides, and wind-driven onshore and offshore currents. The formation of a delta where there is a shallow beach begins with the appearance of spits near the mouth and underwater bars (deposits) in the riverbed or bars (estuarine bars, “alluviums”) at the edge of the sea. At high water, the deposits and estuarine bars gradually appear above the water and become low-lying islands that divide the riverbed into arms. Where the coastline is deeper, river-borne sediment is built by the waves into shoreline embankments that border the seaward edge of the delta. Favorable conditions for the rapid growth of a delta are an abundance of sediment deposited by a river, in some cases the lowering of the level of the waterway (or the tectonic elevation of the bank), the location of the river mouth at the apex of a bay or in a lagoon (obstructed deltas), and the shallowness of the basin into which a river discharges. The formation of deltas is impeded by strong tidal currents, wind-driven onshore and offshore currents, and the rapid elevation of the level of the body of water (rapid tectonic submergence). The rate of growth of deltas varies widely from several meters to hundreds of meters a year. For example, while the level of the Caspian Sea remained stable (1863-1914), the linear growth of the Volga delta was 94 m a year, but between 1930 and 1940, the delta grew by up to 0.7-1 km per year. Deltas evolving in the apexes of bays are called fill deltas, and those that develop on an open seacoast are called protruding deltas. A number of types of deltas are classified according to the method of formation and the stages of development: cuspate deltas (the Tiber), bird-foot deltas (the Mississippi), obstructed deltas (the Kamchatka), protruding deltas with an open, rounded seaward edge (the Niger), and multi-island deltas (the Volga). When there is a small quantity of sediment and the sea level drops, the river arms dissect the deposits that make up the surface of the estuarine section of land, which is of marine or other origin, and serrated deltas are formed (the Neva). The deltas of major rivers are often large: the area of the Amazon delta is 100,000 sq km, the Lena delta, 28,500 sq km, and the Volga delta, 19,000 sq km. The fertility of the soils and their moisture make lands of a sizable portion of many deltas very valuable as areas for intensive farming (for example, the deltas of the Nile, the Huang, and the Ganges). REFERENCESSamoilov, I. V. Ust’ia rek. Moscow, 1952.
Leont’ev, O. K. Osnovy geomorfologii morskikh beregov i dna. Moscow, 1961.
Zalogin, B. S., and N. A. Rodionov. Ust’evye oblasti rek SSSR. Moscow, 1969.O. K. LEONT’EV delta[′del·tə] (anatomy) A fingerprint focal point which is the point on a ridge at or in front of and nearest the center of the divergence of the type lines. (electronics) The difference between a partial-select output of a magnetic cell in a one state and a partial-select output of the same cell in a zero state. (geology) An alluvial deposit, usually triangular in shape, at the mouth of a river, stream, or tidal inlet. delta i. An aircraft with a triangle-shaped or delta wing. See delta aircraft.
ii. In parachuting, it means a free-fall position where the arms are held in a sweptback position from the shoulder. This position is used for horizontal travel.
iii. An aircraft with delta wing.
delta aircraft An aircraft with a delta (triangular shaped) wing. See delta (iii).
delta hinge The hinge about which the helicopter rotor blades are free to flap in a plane parallel to the hub axis.delta1. the fourth letter in the Greek alphabet (Δ or δ), a consonant transliterated as d 2. the flat alluvial area at the mouth of some rivers where the mainstream splits up into several distributaries 3. Maths a finite increment in a variable Delta (language)
1. An expression-based language developed by J.C. Cleavelandin 1978.
2. A string-processing language with single-character commandsfrom Tandem Computers.
3. A language for system specification of simulationexecution.
["System Description and the DELTA Language",E. Holback-Hansen et al, DELTA Proj Rep 4, Norweg Comput Ctr,Feb 1977].
4. A COBOL generating language produced by Delta Software Entwicklung GmbH.delta (2)A quantitative change, especially a small or incrementalone (this use is general in physics and engineering). "I justdoubled the speed of my program!" "What was the delta onprogram size?" "About 30 percent." (He doubled the speed ofhis program, but increased its size by only 30 percent.)delta (3)[Unix] A diff, especially a diff stored under the setof version-control tools called SCCS (Source Code ControlSystem) or RCS (Revision Control System). See change management.delta (4)A small quantity, but not as small as epsilon. Thejargon usage of delta and epsilon stems from thetraditional use of these letters in mathematics for very smallnumerical quantities, particularly in "epsilon-delta" proofsin limit theory (as in the differential calculus). The termdelta is often used, once epsilon has been mentioned, tomean a quantity that is slightly bigger than epsilon butstill very small. "The cost isn't epsilon, but it's delta"means that the cost isn't totally negligible, but it isnevertheless very small. Common constructions include "withindelta of ---", "within epsilon of ---": that is, "close to"and "even closer to".deltaAn incremental value between one number and another.delta
delta [del´tah] 1. the fourth letter of the Greek alphabet, Δ or δ; used in chemical names to denote the fourth of a series of isomeric compounds or the carbon atom fourth from the carboxyl group, or to denote the fourth of any series.2. a triangular area.Δ1. Fourth letter of the Greek alphabet, delta. 2. In chemistry, denotes a double bond, usually with a superscript to indicate position in a chain (Δ5), application of heat in a reaction (A  B), absence of heat treatment ( ), distance between two atoms in a molecule, or position of a substituent located on the fourth atom from the carboxyl or other primary functional group (δ); change (Δ); thickness (δ); chemical shift in NMR (δ). 3. anatomy a triangular surface.
del·ta (Δ), (del'tă), 1. Fourth letter of the Greek alphabet, Δ (capital), δ (lower case). YY1 A gene on chromosome 14q that encodes a ubiquitous transcription factor belonging to the GLI-Kruppel class of zinc finger proteins, which directs histone deacetylases or histone acetyltransferases to myriad promoters activating or repressing their activity, implicating histone modification in YY1 activity.δ, ΔAbbreviation for delta; diopter.
del·ta (Δ, δ) (del'tă) 1. Fourth letter of the Greek alphabet. 2. chemistry A double bond, usually with a superscript to indicate position in a chain (Δ5); application of heat in a reaction (A B); absence of heat treatment (Δ); distance between two atoms in a molecule, or position of a substituent located on the fourth atom from the carboxyl or other primary functional group (δ); change (Δ); thickness (δ); chemical shift in NMR (δ). 3. anatomy A triangular surface. Δ , δ1. Fourth letter of the Greek alphabet, delta. 2. anatomy a triangular surface. LegalSeeDDelta
DeltaThe ratio of the change in price of an option to the change in price of the underlying asset. Also called the hedge ratio. Applies to derivative products. For a call option on a stock, a delta of 0.50 means that for every $1.00 that the stock goes up, the option price rises by $0.50. As options near expiration, in-the-money call option contracts approach a delta of 1.0, while in-the-money put options approach a delta of -1. See: hedge ratio, neutral hedge. Call deltas range from 0.00 to +1.00; put deltas range from 0.00 to -1.00. If the call delta is 0.69, the put delta is -0.31 (call delta minus 1 equals put delta; 0.69 -1 =-0.31).delta The change in the price of an option that results from a one-point change in the price of the underlying stock. For example, a delta of 0.5 indicates that the option will rise in price by 1/2 point (50¢) for each 1-point ($1) rise in the price of the underlying stock. Call options have positive deltas; put options have negative deltas.Delta.The relationship between an option's price and the price of the underlying stock or futures contract is called its delta. If the delta is 1, for example, the relationship of the prices is 1 to 1. That means there's a $1 change in the option price for every $1 change in the price of the underlying instrument. With a call option, an increase in the price of an underlying instrument typically results in an increase in the price of the option. An increase in a put option's price is usually triggered by a decrease in the price of the underlying instrument, since investors buy put options expecting its price to fall. DELTA
| Acronym | Definition |
|---|
| DELTA➣International Workshop on Electronic Design, Test, and Applications (IEEE) | | DELTA➣Diploma in English Language Teaching to Adults (University of Cambridge, UK) | | DELTA➣Distance Education and Learning Technology Applications (various organizations) | | DELTA➣Documentação de Estudos em Lingüística Teórica e Aplicada | | DELTA➣Danish Electronics, Light & Acoustics (Danish test lab) | | DELTA➣Description Language for Taxonomy | | DELTA➣Deaf Education Through Listening and Talking (UK) | | DELTA➣Defense Loan and Technical Assistance | | DELTA➣Development of European Learning Through Technological Advance | | DELTA➣Dortmund Electron Accelerator (University of Dortmund, Germany) | | DELTA➣Dietary Effects on Lipoproteins and Thrombogenic Activity (study) | | DELTA➣Direct Electronic Links for Tender Administration | | DELTA➣Daily Employee Log of Time and Activities | | DELTA➣Detailed Labor and Time Analysis | | DELTA➣Drone Experiment Laser Test Assessment | | DELTA➣UK Royal Flight Ground Command | | DELTA➣Derbyshire Learning and Technology Access (UK) | | DELTA➣Distinguished Elite Light Tactical Attachment (gaming clan) |
delta
Related to delta: Delta ForceWords related to deltanoun a low triangular area of alluvial deposits where a river divides before entering a larger body of waterRelated Words- alluvial deposit
- alluvial sediment
- alluvium
- alluvion
- geological formation
- formation
noun an object shaped like an equilateral triangleRelated Words- equiangular triangle
- equilateral triangle
noun the 4th letter of the Greek alphabetRelated Words- Greek alphabet
- alphabetic character
- letter of the alphabet
- letter
|