| 释义 |
lumen
lu·men L0286400 (lo͞o′mən)n. pl. lu·mens or lu·mi·na (-mə-nə) 1. Anatomy The inner open space or cavity of a tubular organ, as of a blood vessel or an intestine.2. Biology The interior of a membrane-bound compartment or organelle in a cell.3. Abbr. lm Physics The SI unit of luminous flux, equal to the amount of light per unit time passing through a solid angle of one steradian from a light source of one candela intensity radiating equally in all directions. See Table at measurement.
[Latin lūmen, an opening, light; see leuk- in Indo-European roots.]
lu′men·al, lu′min·al adj.lumen (ˈluːmɪn) n, pl -mens or -mina (-mɪnə) 1. (Units) the derived SI unit of luminous flux; the flux emitted in a solid angle of 1 steradian by a point source having a uniform intensity of 1 candela. Symbol: lm 2. (Anatomy) anatomy a passage, duct, or cavity in a tubular organ3. (Botany) a cavity within a plant cell enclosed by the cell walls[C19: New Latin, from Latin: light, aperture] ˈlumenal, ˈluminal adjlu•men (ˈlu mən)
n., pl. -mens, -mi•na (-mə nə) 1. the unit of luminous flux, equal to the luminous flux emitted in a unit solid angle by a point source of one candle intensity. Abbr.: lm 2. the canal, duct, or cavity of a tubular organ. [1870–75; < New Latin; Latin lūmen, s. lūmin- light, window] lu·men (lo͞o′mən)1. Anatomy The central space in a tubular organ, such as a blood vessel or intestine.2. Physics A unit used to measure the amount of light passing through a given area per second. One lumen is equal to the amount of light that passes through a given area (shaped like a cone) that is illuminated by a light with a brightness of one candela.Thesaurus| Noun | 1. | lumen - a unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directionslmluminous flux unit - a measure of luminous flux per unit area | | 2. | lumen - a cavity or passage in a tubular organ; "the lumen of the intestine"bodily cavity, cavum, cavity - (anatomy) a natural hollow or sinus within the body |
Translationslumen
lumen: see photometryphotometry
, branch of physics dealing with the measurement of the intensity of a source of light, such as an electric lamp, and with the intensity of light such a source may cast on a surface area.
..... Click the link for more information. .LumenA unit of light from one source. Light falling on 1 square foot of surface of an imaginary sphere having a 1-foot radius around 1 candle.Lumen the unit of luminous flux in the International System of Units. Symbol, 1m. One lumen is the luminous flux emitted by an isotropic point source in a with a luminous intensity of 1 candela in a solid angle of 1 steradian. lumen[′lü·mən] (anatomy) The interior space within a tubular structure, such as within a blood vessel, a duct, or the intestine. (optics) The unit of luminous flux, equal to the luminous flux emitted within a unit solid angle (1 steradian) from a point source having a uniform intensity of 1 candela, or to the luminous flux received on a unit surface, all points of which are at a unit distance from such a source. Symbolized lm. (science and technology) The space within a tube. lumen (lm)The SI unit of luminous flux equal to the luminous flux received on a unit surface, all points of which are equidistant from a point source having a uniform intensity of 1 candela.lumenA unit of measurement of the light intensity radiating in the air in all directions from a light source. Lumens define "luminous flux," which is energy within the range of frequencies we perceive as light. For example, a wax candle generates about 13 lumens; a 60-watt bulb approximately 800, and a 100-watt bulb 1,600 lumens.
Lumen Ratings for Data Projectors
When choosing a data projector, the lumen rating is an important specification. In a small, dark room, 500 lumens may be ample; however, in a conference room with normal lighting, 1,000 to 2,000 lumens is required. In a large, well-lit room, at least 2,000 lumens is necessary. This rating is derived by taking the average of photometer readings at several points on a full white image on the screen. See lux, ANSI lumen, Lm/W, candela and spectrum.lumen
lumen [lu´men] (L.) 1. the cavity or channel within a tube or tubular organ, as a blood vessel or the intestine.2. the SI unit of rate of flow of radiant energy, specifically that of the visible spectrum. adj., adj lu´minal.lu·men, pl. lu·mi·na, lu·mens (lū'men, -min-ă, -menz), 1. The space in the interior of a hollow tubular structure (for example, artery or intestine). 2. The unit of luminous flux; the luminous flux emitted in a unit solid angle of 1 steradian by a uniform point source of light having a luminous intensity of 1 candela. 3. The volume enclosed within the membranes of a mitochondrion or of the endoplasmic reticulum. 4. The bore of a catheter or hollow needle. [L. light, window] lumen (lo͞o′mən)n. pl. lu·mens or lu·mina (-mə-nə) 1. Anatomy The inner open space or cavity of a tubular organ, as of a blood vessel or an intestine.2. Biology The interior of a membrane-bound compartment or organelle in a cell.3. Abbr. lmPhysics The SI unit of luminous flux, equal to the amount of light per unit time passing through a solid angle of one steradian from a light source of one candela intensity radiating equally in all directions. See Table at measurement.
lu′men·al, lu′min·al adj.lu·men (lm), pl. lumina (lū'mĕn, -mi-nă) 1. The space in the interior of a tubular structure, such as an artery or intestine. 2. The unit of luminous flux; the luminous flux emitted in a unit solid angle of 1 steradian by a uniform point source of light having a luminous intensity of 1 candela. [L. light, window]lumen The inside of any tube, such as a blood vessel, an air passage (bronchus) or the intestine.lumen any cavity enclosed within a cell, or structure, such as the lumen of the gut.LumenThe inner cavity or canal of a tube-shaped organ, such as the bowel.Mentioned in: Amebiasislumen1. SI unit of luminous flux. It is equal to the flux emitted within a unit solid angle of one steradian by a point source with a luminous intensity of one candela. Symbol: lm. 2. The space in the interior of a tubular organ, such as an artery. See luminous flux; quantity of light; lux; SI unit.
| Table L4 Approximate luminance (in cd/m2) of some objects | | sun | 109 | | car headlight | 107 | | incandescent lamp (tungsten) | 106-107 | | fluorescent lamp | 104-105 | | clear sky at noon | 104 | | cloudy sky at noon | 103 | | shady street by day | 103-104 | | full moon | 103 | | book print under artificial light | >102 | | photopic vision | >10 | | street illumination | 1-10−1 | | mesopic vision | 10-10−3 | | cloudless night sky with full moon | 10−2 | | scotopic vision | <10−3 | | moonless and cloudless night sky | 10−3-10−6 |
lu·men, pl. lumina (lūmĕn, -mi-nă) 1. Space in interior of a hollow tubular structure (e.g., artery or intestine). 2. The bore of a catheter or hollow needle. [L. light, window]FinancialSeeLUXSee LM
LUMEN
| Acronym | Definition |
|---|
| LUMEN➣Loyola University Medical Education Network |
lumen
Synonyms for lumennoun a unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directionsSynonymsRelated Wordsnoun a cavity or passage in a tubular organRelated Words |