| 释义 |
quadrant
quad·rant Q0006800 (kwŏd′rənt)n.1. Mathematics a. A circular arc of 90°; one fourth of the circumference of a circle.b. The plane area bounded by such an arc and two perpendicular radii.c. Any of the four areas into which a plane is divided by the reference axes in a Cartesian coordinate system, designated first, second, third, and fourth, counting counterclockwise from the area in which both coordinates are positive.2. A machine part or other mechanical device that is shaped like a quarter circle.3. An early instrument for measuring altitude of celestial bodies, consisting of a 90° graduated arc with a movable radius for measuring angles.
[Middle English, quarter of a day, from Latin quadrāns, quadrant-, a fourth part; see kwetwer- in Indo-European roots.]quadrant (ˈkwɒdrənt) n1. (Mathematics) geometry a. a quarter of the circumference of a circleb. the area enclosed by two perpendicular radii of a circle and its circumferencec. any of the four sections into which a plane is divided by two coordinate axes2. (Mechanical Engineering) a piece of a mechanism in the form of a quarter circle, esp one used as a cam or a gear sector3. (Astronomy) an instrument formerly used in astronomy and navigation for measuring the altitudes of stars, consisting of a graduated arc of 90° and a sighting mechanism attached to a movable arm[C14: from Latin quadrāns a quarter] quadrantal adjquad•rant (ˈkwɒd rənt)
n. 1. a quarter of a circle; an arc of 90°. 2. the area included between such an arc and two radii drawn one to each extremity. 3. something shaped like a quarter of a circle, as a part of a machine. 4. one of the four parts into which a plane, as the face of a heavenly body, is divided by two perpendicular lines: the first quadrant of the moon. 5. an instrument, usu. containing a graduated arc of 90°, used in astronomy, navigation, etc., for measuring altitudes. [1350–1400; Middle English < Latin quadrant-, s. of quadrāns fourth part] quad·rant (kwŏd′rənt)1. An arc equal to one quarter of the circumference of a circle; an arc of 90°.2. Any of the four regions into which a plane is divided by the axes of a Cartesian coordinate system. The quadrants are numbered counterclockwise one through four, beginning with the quadrant in which both the x- and y-coordinates are positive (usually the upper right quadrant).3. An instrument with an arc of 90°, used to measure the angle between a celestial object and the horizon.quadrant - A quarter of a circle or sphere.See also related terms for sphere.quadrantan instrument for measuring angular elevation, used in astronomy, navigation, surveying, etc., similar in principle to the sextant. — quadrantal, ad].See also: InstrumentsThesaurus| Noun | 1. | quadrant - a quarter of the circumference of a circlequarter-circleline - a spatial location defined by a real or imaginary unidimensional extent | | 2. | quadrant - any of the four areas into which a plane is divided by two orthogonal coordinate axesarea, country - a particular geographical region of indefinite boundary (usually serving some special purpose or distinguished by its people or culture or geography); "it was a mountainous area"; "Bible country" | | 3. | quadrant - the area enclosed by two perpendicular radii of a circlearea, country - a particular geographical region of indefinite boundary (usually serving some special purpose or distinguished by its people or culture or geography); "it was a mountainous area"; "Bible country" | | 4. |  quadrant - a measuring instrument for measuring altitude of heavenly bodiesmeasuring device, measuring instrument, measuring system - instrument that shows the extent or amount or quantity or degree of something |
Translations
quadrant
quadrant, in technology, angle-measuring device based on a scale of 90°. It is sometimes confused with the sextantsextant,
instrument for measuring the altitude of the sun or another celestial body; such measurements can then be used to determine the observer's geographical position or for other navigational, surveying, or astronomical applications.
..... Click the link for more information. , a similar instrument based on a scale of 60°. The quadrant is rarely used today.
quadrant. 1 In analytic geometry, one of the four regions of the plane determined by two lines, the x-axis and the y-axis. Commonly these lines are drawn perpendicular to each other, and the quadrants, or regions, they determine are numbered counterclockwise, beginning with the upper right quadrant. 2 In geometry, a region of a plane determined by two perpendicular radii of a circle and the circle itself. Thus two perpendicular diameters of a circle divide it into four regions, or quadrants.quadrant (kwod -rănt) An instrument dating back to antiquity and used for measuring altitudes and angular separations of stars. It remained the most important astronomical instrument until the telescope was invented. It consisted of a 90° graduated arc (a quarter circle) with a swiveling arm to which a sighting mechanism was attached. In the mural quadrant the graduated arc, often very large, was attached to a wall and was orientated along the observer's meridian. The mural quadrant was therefore the forerunner of the transit circle.QuadrantArc of a circle, forming one-quarter of its circumference.Quadrant (religion, spiritualism, and occult)The quadrants of a horoscope refer to four sets of three houses: Houses one, two, and three (first quadrant), houses four, five, and six (second quadrant), houses seven, eight, and nine (third quadrant), and houses ten, eleven, and twelve (fourth quadrant). A quadrant is also an instrument used to calculate the position of celestial bodies. In Europe, quadrants superseded the use of astrolabes during the Renaissance. Quadrant in astronomy, an astronomical angle-measuring instrument that was used to measure the altitudes of celestial bodies above the horizon and the angular separations between bodies. A quadrant consisted of a quarter-circle, whose arc was divided into degrees and fractions of a degree, usually mounted in a vertical plane. A straightedge with diopters or a viewing tube usually rotated around the axis passing through the center of the circle and situated perpendicularly to its plane. Large mural quadrants were used in the past at astronomical observatories; these were fixed to stone walls of the building. Quadrants cease to be used at the end of the 17th century. quadrant[′kwä·drənt] (anatomy) One of the four regions into which the abdomen may be divided for purposes of physical diagnosis. (electromagnetism) international henry (engineering) An instrument for measuring altitudes, used, for example, in astronomy, surveying, and gunnery; employs a sight that can be moved through a graduated 90° arc. A lever that can move through a 90° arc. (mathematics) A quarter of a circle; either an arc of 90° or the area bounded by such an arc and the two radii. Any of the four regions into which the plane is divided by a pair of coordinate axes. (mechanical engineering) A device for converting horizontal reciprocating motion to vertical reciprocating motion. (navigation) One of the four areas between consecutive equisignal zones of a four course radio range station. (naval architecture) A casting, forging, or built-up frame in the shape of a sector of a circle attached to the rudder stock and through which the steering gear leads turn the rudder. (optics) A double-reflecting instrument for measuring angles, used primarily for measuring altitudes of celestial bodies; the instrument was replaced by the sextant. (physiology) A sector of one-fourth of the field of vision of one or both eyes. quadrant1. An angle-measuring instrument used for measuring elevations. 2. A quarter-round molding. 3. A device for fastening together the upper and lower leaves of a Dutch door. 4. A quadrant stay.quadrant  Throttle quadrant. i. A quarter portion of a circle, centered on a NAVAID (navigational aid), oriented clock-wise from magnetic north. The divisions of the circle are as follows: NE quadrant from 000° to 089°, SE quadrant from 090° to 179°, SW quadrant from 180° to 269°, and NW quadrant from 270° to 359°.
ii. The housing in an aircraft cockpit on which the engine control lever (throttle) is mounted. The top of the quadrant is shaped like a quartercircle and, hence, the name.
iii. An instrument similar to a sextant but constructed with its arc graduated in degrees for a fourth of a circle. Often called a sextant.
iv. The fourth part of something, as a quadrant in a radio-range. See quadrant (v).
v. One of the four areas between consecutive equisignal zones of a four-course radio-range station.quadrant1. Geometrya. a quarter of the circumference of a circle b. the area enclosed by two perpendicular radii of a circle and its circumference c. any of the four sections into which a plane is divided by two coordinate axes 2. a piece of a mechanism in the form of a quarter circle, esp one used as a cam or a gear sector 3. an instrument formerly used in astronomy and navigation for measuring the altitudes of stars, consisting of a graduated arc of 90? and a sighting mechanism attached to a movable arm quadrant
quadrant [kwod´rant] 1. one fourth of the circumference of a circle.2. one of four corresponding parts, as of the abdominal surface, the dentition, the field of vision, or the tympanic membrane. Quadrants of the abdomen. From Polaski and Tatro, 1996.qua·drant (kwah'drănt), 1. One quarter of a circle. 2. anatomy roughly circular areas are divided for descriptive purposes into quadrants. The abdomen is divided into right upper and lower and left upper and lower quadrants by a horizontal and a vertical line intersecting at the umbilicus. The breast is divided into quadrants by vertical and horizontal lines that intersect in the center of the nipple. Quadrants of the ocular fundus (superior and inferior nasal, superior and inferior temporal) are demarcated by a horizontal and a vertical line intersecting at the optic disc. The tympanic membrane is divided into anterosuperior, anteroinferior, posterosuperior, and posteroinferior quadrants by a line drawn across the diameter of the drum in the axis of the handle of the malleus and another intersecting the first at right angles at the umbo. [L. quadrans, a quarter] quadrant A quarter–eg, the liver is in the right upper quadrant of the abdomen. See Left lower quadrant, Left upper quadrant, Right lower quadrant, Right upper quadrant. quad·rant (kwahd'rănt) 1. One quarter of a circle. anatomy Roughly circular areas are divided for descriptive purposes into quadrants. The abdomen is divided into right upper and lower and left upper and lower quadrants by a horizontal and a vertical line intersecting at the umbilicus. 2. Quadrants of the ocular fundus (superior and inferior nasal, superior and inferior temporal) are demarcated by a horizontal and a vertical line intersecting at the optic disc. The tympanic membrane is divided into anterosuperior, anteroinferior, posterosuperior, and posteroinferior quadrants by a line drawn across the diameter of the drum in the axis of the handle of the malleus and another intersecting the first at right angles at the umbo. [L. quadrans, a quarter]quad·rant (kwahd'rănt) 1. In dentistry, one quarter of combined dental arches; there are two maxillary and two mandibular quadrants. 2. One quarter of a circle; various anatomic structures are described as having quadrants. [L. quadrans, a quarter]Quadrant
QUADRANT. In angular measures, a quadrant is equal to ninety degrees. Vide Measure. Quadrant
QuadrantIn Cartesian coordinates, one fourth of the area divided by the x- and y-axes. Quadrants are numbered starting in the upper right and continuing clockwise. That is, the quadrant above the x-axis and to the right of the y-axis is the first quadrant, the one below the first is the second and so forth. Quadrants are used in technical analysis, economic analysis, and other fields involving mathematics.See QUAD
See QUADquadrant
Synonyms for quadrantnoun a quarter of the circumference of a circleSynonymsRelated Wordsnoun any of the four areas into which a plane is divided by two orthogonal coordinate axesRelated Wordsnoun the area enclosed by two perpendicular radii of a circleRelated Wordsnoun a measuring instrument for measuring altitude of heavenly bodiesRelated Words- measuring device
- measuring instrument
- measuring system
|