| 释义 |
envelope
envelopea flat paper cover or wrapper: Put the letter into an envelope.
Not to be confused with:envelop – to wrap around; enfold; hide; enclose: Envelop the area with high walls.en·ve·lope E0167400 (ĕn′və-lōp′, ŏn′-)n.1. A flat paper container, especially for a letter, usually having a gummed flap.2. Something that envelops; a wrapping.3. Biology An enclosing structure or cover, such as a membrane or the outer coat of a virus.4. The bag containing the gas in a balloon or airship.5. The set of limitations within which a technological system, especially an aircraft, can perform safely and effectively.6. Astronomy a. A usually spherical region of interstellar matter surrounding a forming star and interacting with the star's gravitational and radiation fields.b. The coma of a comet.7. Mathematics A curve or surface that is tangent to every one of a family of curves or surfaces.Idiom: push the envelope To exceed or try to exceed the existing limits of a discipline or activity.
[French enveloppe, from envelopper, to envelop, from Old French envoloper; see envelop.]Usage Note: Some people dislike the pronunciation (ŏn′və-lōp′), arguing that it is pretentious for being pseudo-French and that it is unnecessary, since there is a perfectly acceptable Anglicized pronunciation, (ĕn′və-lōp′). But the pronunciation with (ŏn) is gaining in acceptability: in our 1992 survey, 30 percent of the Usage Panel used it exclusively, and another 9 percent used it occasionally; by 2011, 46 percent selected it as their preferred pronunciation. Both forms should be considered standard.envelope (ˈɛnvəˌləʊp; ˈɒn-) n1. a flat covering of paper, usually rectangular in shape and with a flap that can be folded over and sealed, used to enclose a letter, etc2. any covering or wrapper3. (Biology) biology any enclosing structure, such as a membrane, shell, or skin4. (Aeronautics) the bag enclosing the gas in a balloon5. (Mathematics) maths a curve or surface that is tangent to each one of a group of curves or surfaces6. (Electronics) electronics the sealed glass or metal housing of a valve, electric light, etc7. (General Physics) telecomm the outer shape of a modulated wave, formed by the peaks of successive cycles of the carrier wave8. push the envelope informal to push the boundaries of what is possible[C18: from French enveloppe, from envelopper to wrap around; see envelop; sense 8 from aeronautics jargon, referring to graphs of aircraft performance]en•ve•lope (ˈɛn vəˌloʊp, ˈɑn-)
n. 1. a flat paper container, as for a letter or thin package, usu. having a gummed flap or other means of closure. 2. something that envelops; a wrapper or surrounding cover. 3. a surrounding or enclosing part, as an integument or an outer membrane. 4. Geom. a curve or surface tangent to each member of a set of curves or surfaces. 5. the fabric structure enclosing the gasbag of an aerostat. 6. the gasbag itself. 7. the airtight glass or metal housing of a vacuum tube. 8. the technical limits within which an aircraft or electronic system may be safely operated. Idioms: push the envelope, to stretch established limits, as in technological advance or social innovation. [1700–10; < French enveloppe, derivative of envelopper to envelop] Thesaurus| Noun | 1. |  envelope - a flat (usually rectangular) container for a letter, thin package, etc.container - any object that can be used to hold things (especially a large metal boxlike object of standardized dimensions that can be loaded from one form of transport to another)window envelope - an envelope with a transparent panel that reveals the address on the enclosure | | 2. | envelope - any wrapper or coveringwrapping, wrapper, wrap - the covering (usually paper or cellophane) in which something is wrapped | | 3. | envelope - a curve that is tangent to each of a family of curvescurve, curved shape - the trace of a point whose direction of motion changes | | 4. | envelope - a natural covering (as by a fluid); "the spacecraft detected an envelope of gas around the comet"covering, natural covering, cover - a natural object that covers or envelops; "under a covering of dust"; "the fox was flushed from its cover" | | 5. | envelope - the maximum operating capability of a system (especially an aircraft); "test pilots try to push the envelope"operating capability, performance capability - the capability of a technological system to perform as intended | | 6. | envelope - the bag containing the gas in a balloongasbagbag - a flexible container with a single opening; "he stuffed his laundry into a large bag"balloon - large tough nonrigid bag filled with gas or heated air |
envelopenoun wrapping, casing, case, covering, cover, skin, shell, coating, jacket, sleeve, sheath, wrapper She opened the envelope and withdrew a typed note.Translationsenvelope (ˈenvələup) noun a thin, flat wrapper or cover, especially for a letter. The letter arrived in a long envelope. 信封 信封envelope
back-of-the-envelope calculationA calculation or mathematical formulation that is approximated in a quick, informal, and rough manner, as might be sketched out on a scrap of paper (such as the back of an envelope). When it came time to pay the bill, we had to do some back-of-the-envelope calculations to figure out who owed how much.the opening of an envelopeAny event, celebration, or ceremony, no matter how trivial or unremarkable, that one attends purely for the sake of visibility. Often said in relation to celebrities or media personalities who make a point of attending anything that will give them more public exposure. In a bid to cultivate a media buzz around herself, the Internet sensation has been to the openings of films, book launches, and celebrity galas. With the way she carries on, she'd even go to the opening of an envelope!See also: envelope, of, openingenvelop (oneself, someone, or something) in (something)To wrap oneself, someone, or something in something. As soon as I got in from the cold, I enveloped myself in a blanket and sat in front of the fire. The snowstorm enveloped our area even faster than predicted with white-out conditions.See also: enveloppush the envelopeTo expand on, exceed, or test the limits of the established norm or standard. The company is renowned for pushing the envelope whenever they develop a new piece of technology. If you want to make a name for yourself in the art world, then you can't be afraid of pushing the envelope. It's a natural stage for most teenagers to push the envelope of their parents' rules.See also: envelope, pushon the back of an envelopeCalculated, prepared, or drafted in an overly quick, informal, or rough manner, as might be scribbled on a scrap of paper (such as the back of an envelope). It seems clear that they devised this legislation on the back of an envelope. Now, don't come up with these figures on the back of an envelope—I want you to be thorough and double check each sum and calculation.See also: back, envelope, of, onpush the envelopeFig. to expand the definition, categorization, dimensions, or perimeters of something. The engineers wanted to completely redesign the product, but couldn't push the envelope because of a very restricted budget.See also: envelope, pushpush the envelopeExceed the limits of what is normally done, be innovative, as in They are pushing the envelope in using only new fabrics for winter clothing. This idiom comes from aviation, the envelope alluding to the technical limits of a plane's performance, which, on a graph, appear as a rising slope as limits of speed and stress are approached and falls off when the capacity is exceeded and the pilot loses control; safety lies within these limits, or envelope, and exceeding them exposes pilot and plane to risk. [Slang; late 1960s] See also: envelope, pushon the back of an envelope If a piece of work was written or planned on the back of an envelope, it was prepared too quickly, with little thought or care. These proposals were sketched out on the back of an envelope. The screenplay sounds as if it's been written on the back of an envelope. Note: You can also talk about a back-of-an-envelope calculation or account to talk about something that is not accurate. According to his back-of-an-envelope calculation, a solar square of mirrors of this size would provide enough energy to supply the whole state.See also: back, envelope, of, onpush the envelope If you push the envelope, you do something to a greater degree or in a more extreme way than it has been done before. We have to keep pushing the envelope, trying new technologies and developing better methods. There's a valuable place for fashion and design that pushes the envelope a bit. Note: Rather than referring to stationery, the sense of envelope here is probably the one used to refer to the shape of a wave in electronics or a curve in mathematics. Pushing or stretching the envelope suggests changing the properties of the wave or curve. See also: envelope, pushpush the envelope (or the edge of the envelope) approach or extend the limits of what is possible. informal This expression was originally aviation slang and related to graphs of aerodynamic performance on which the envelope is the boundary line representing an aircraft's capabilities. 1993 Albuquerque These are extremely witty and clever stories that consistently push the envelope of TV comedy. See also: envelope, pushpush the ˈenvelope do something in an extreme way in order to find out to what degree something is possible: Advertisements seem to be pushing the envelope of taste every day. ♢ People these days like to push the envelope with extreme sports. ▶ ˈenvelope-pushing noun, adj.: envelope-pushing technologyThis expression comes from the aeroplane industry. A plane’s envelope was the limit of its performance. Test pilots would need to push (the edge of) the envelope to see what the plane could and could not do.See also: envelope, push push the envelope To exceed or try to exceed the existing limits of a discipline or activity.See also: envelope, pushpush the envelopeGo to extremes, go beyond accepted limits. This term comes from flight testing in the 1960s, where envelope signifies the limits of safe performance, and pushing it means to fly an aircraft faster or higher or dive more steeply than had ever been attempted in order to see what it could do. By the 1980s the expression was used figuratively, and so widely that it has become a cliché. Opera singer Renée Fleming used it in The Inner Voice (2004): “You want to go out there, push the envelope, and do something you’ve never done before.”See also: envelope, pushenvelope
envelope1. Biology any enclosing structure, such as a membrane, shell, or skin 2. the bag enclosing the gas in a balloon 3. Maths a curve or surface that is tangent to each one of a group of curves or surfaces 4. Electronics the sealed glass or metal housing of a valve, electric light, etc. 5. Telecomm the outer shape of a modulated wave, formed by the peaks of successive cycles of the carrier wave EnvelopeThe boundary that separates a building’s conditioned and unconditioned spaces. The term usually refers to heat and air transfer, such as through walls, windows, and the roof. All of these are part of the building’s envelope. Also, the imaginary shape of a building indicating its maximum volume; used primarily to check the plan, setback, and other restrictions regarding zoning regulations.Envelope of a family of curves in a plane (or of surfaces in space), a curve (or surface) that touches at each of its points a single curve (or surface) of the family and is geometrically different from that curve (or surface) in an arbitrarily small neighborhood of the point of contact. The equation of the envelope of a plane family of curves defined by the equation f(x, y, C) = 0, which contains a parameter C, can be obtained by eliminating C from the system of equations 
Here it is assumed that f(x, y, C) has continuous partial derivatives of the first order with respect to all three arguments. In general, this elimination yields not only the envelope but also the locus of the singular points of the curves of the family, that is, the points for which f″x and f″y, vanish simultaneously.  Figure 1
The following are examples in the plane. (1) The family of circles of radius R whose centers lie on a line has as an envelope a pair of lines parallel to the line of the centers and located at a distance R from that line (see Figure 1). (2) Any curve is the envelope of the family of its tangents and of the family of its circles of curvature. (3) The envelope of the family of normals to a given curve is its evolute (the evolute of an ellipse is shown in Figure 2).  Figure 2
The envelope of a family of surfaces in space may touch each member of the family at a point or along a curve. For example, (1) the envelope of a family of spheres of radius R with centers lying on a single line is a circular cylinder of radius R whose axis is that line (the cylinder touches each sphere along a circle); (2) the envelope of a family of spheres of radius R whose centers lie in a single plane is a pair of planes parallel to the plane of the centers and located at a distance R from that plane (the planes forming the envelope touch each sphere in a point). The concept of an envelope has significance not only in geometry but also in certain problems in mathematical analysis (singular solutions in the theory of differential equations) and theoretical physics (the caustic and the wave front in optics). REFERENCESTolstov, G. P. “K otyskaniiu ogibaiushchei semeistva ploskikh krivykh.” Uspekhi matematicheskikh nauk, 1952, vol. 7, no. 4.
La Vallée Poussin, C. J. de. Kurs analiza beskonechno malykh, vol. 2. Leningrad-Moscow, 1933. (Translated from French.)
Il’in, V. A., and E. G. Pozniak. Osnovy matematicheskogo analiza, 3rd ed., part 1. Moscow, 1971.envelope[′en·və‚lōp] (communications) A curve drawn to pass through the peaks of a graph, such as that of a moduated radio-frequency carrier signal. (cell and molecular biology) The sum of all cell-surface elements that are located outside the plasma membrane. (engineering) The glass or metal housing of an electron tube or the glass housing of an incandescent lamp. (mathematics) The envelope of a one-parameter family of curves is a curve which has a common tangent with each member of the family. The envelope of a one-parameter family of surfaces is the surface swept out by the characteristic curves of the family. (virology) The outer membranous lipoprotein coat of certain viruses. Also known as bulb. envelope1. The imaginary shape of a building indicating its maximum volume; used to check the plan and setback (and similar restrictions) with respect to zoning regulations. 2. The folded-over, continuous edge formed by turning the lowest ply of a built-up roofing membrane over the top surface layer; prevents bitumen from dripping through the exposed edge joints and seepage of water into the insulation.envelope(1) A range of frequencies for a particular operation.
(2) A group of bits or items that is packaged and treated as a single unit.
(3) See also pushing the envelope.Envelope (dreams)Mail or letters usually come in envelopes. When we see envelopes in our dreams, we are typically dreaming about receiving news, information, or messages from someone specific or from the world at large. If you are the individual that looks forward to mail, this dream may be positive. However, if you dread the envelopes that typically hold the monthly bills, then this dream may have negative and anxiety provoking symbolism. Typically, however, dreaming about receiving letters has positive and at times spiritual connotations. You may be coming into awareness about some aspect of your life where you make new realizations and get to the “truth” of things. Some believe that seeing many unopened envelopes in your dreams may represent missed opportunities.envelope
envelope [en´vĕ-lōp] 1. an encompassing structure or membrane.2. in virology, the outer lipoprotein coat of a large virus, surrounding the capsid and usually furnished, at least partially, by the host cell. Called also peplos.3. in bacteriology, the cell wall and the plasma membrane considered together.nuclear envelope the condensed double layer of lipids and proteins enclosing the cell nucleus and separating it from the cytoplasm; its two concentric membranes, inner and outer, are separated by a perinuclear space.en·ve·lope (en'vĕ-lōp), Avoid the mispronunciation ahn'vĕ-lōp.In anatomy, a structure that encloses or covers.envelope (ĕn′və-lōp′, ŏn′-)n. Biology An enclosing structure or cover, such as a membrane or the outer coat of a virus.en·ve·lope (en'vĕ-lōp) anatomy Any structure that encloses or covers. envelope any enclosing structure, such as a membrane or skin. In bacteria, it is the part of the cell enclosing the cytoplasm, i.e. the cytoplasmic membrane cell wall and capsule. In VIRUSES, it is the outer lipid-containing layer of some virions.en·ve·lope (en'vĕ-lōp) In anatomy, a structure that encloses or covers. Envelope
EnvelopeIn technical analysis, two moving averages of a security's price indicating its upper and lower limits. That is, a price tends not to move above the higher moving average or below the lower moving average. Analysts use envelopes to help them determine buy and sell signals. When a price reaches the higher moving average, analysts may declare a sell signal, while they may declare a buy signal when a price reaches the lower moving average.See ENV
See EPenvelope
Synonyms for envelopenoun wrappingSynonyms- wrapping
- casing
- case
- covering
- cover
- skin
- shell
- coating
- jacket
- sleeve
- sheath
- wrapper
Synonyms for envelopenoun a flat (usually rectangular) container for a letter, thin package, etcRelated Wordsnoun any wrapper or coveringRelated Wordsnoun a curve that is tangent to each of a family of curvesRelated Wordsnoun a natural covering (as by a fluid)Related Words- covering
- natural covering
- cover
noun the maximum operating capability of a system (especially an aircraft)Related Words- operating capability
- performance capability
noun the bag containing the gas in a balloonSynonymsRelated Words |