- 行业: Printing & publishing
- Number of terms: 178089
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McGraw Hill Financial, Inc. is an American publicly traded corporation headquartered in Rockefeller Center in New York City. Its primary areas of business are financial, publishing, and business services.
A threaded machine part used to join parts of a machine or structure. Screw fasteners are used when a connection that can be disassembled and reconnected and that must resist tension and shear is required. A nut and bolt is a common screw fastener. Bolt material is chosen to have an extended stress-strain characteristic free from a pronounced yield point. Nut material is chosen for slight plastic flow.
Industry:Science
A three-dimensional geometric figure consisting of points continuously connected, and separated from the rest of space by a surface called the boundary of the solid. Points on the boundary are usually considered part of the solid. A solid is bounded if there exists a sphere having finite radius that could enclose the solid. A solid is convex if all points of any line segment having end points on the boundary also are points of the solid.
Industry:Science
A three-terminal semiconductor junction device with four regions of alternating conductivity type (<i>pnpn</i>), also called a thyristor. This switching device has a characteristic such that, once it conducts, the voltage in the circuit in which it conducts must drop below a threshold before the controlled rectifier regains control. Such devices are useful as high-current switches and may be used to drive electromagnets and relays.
Industry:Science
A thyristor-controlled (hence static) generator of reactive power, either lagging or leading, or both. The word var stands for volt ampere reactive, or reactive power. The device is also called a static reactive compensator.
Industry:Science
A tiny fossil fish found only in rocks of Middle Devonian age within a small geographic region of Caithness, Scotland, and principally at one site, Achanaras Quarry, where it is surprisingly abundant. One of the most enigmatic of all fossil fishes, <i>Palaeospondylus gunni</i> was discovered in 1890 by Marcus and John Gunn and described by Ramsay Traquair. Its original environment was a large, deep, freshwater lake system with a broad diversity of fishes. Unusually for a tiny fish, <i>Palaeospondylus</i> is typically found in sediments associated with the deepest part of the lake.
Industry:Science
A tool used primarily in manufacturing facilities as a control device to measure productive output in relation to labor input within a specific time period. The measurement of the work content is accomplished through the use of time standards (which are usually the result of a stopwatch time study), predetermined time standards (methods-time measurement, the work-factor system), or some other form of work-measurement technique designed to measure tasks of labor under normal and average conditions.
Industry:Science
A topological group with only countably many connected components whose identity component is open and is an analytic group. An analytic group or connected Lie group is a topological group with the additional structure of a smooth manifold such that multiplication and inversion are smooth. Many groups that arise naturally as groups of symmetries of physical or mathematical systems are Lie groups. The study of Lie groups has applications to analytic function theory, differential equations, differential geometry, Fourier analysis, algebraic number theory, algebraic geometry, quantum mechanics, relativity, and elementary particle theory.
Industry:Science
A total sequence of food operations, including the growth and selection of raw materials, harvesting, processing, preservation, and distribution. In general, the aim of all food manufacturing operations is to extend the availability of seasonal crops to year-round use.
Industry:Science
A tower- or buildinglike device in which atmospheric air (the heat receiver) circulates in direct or indirect contact with warmer water (the heat source) and the water is thereby cooled. A cooling tower may serve as the heat sink in a conventional thermodynamic process, such as refrigeration or steam power generation, or it may be used in any process in which water is used as the vehicle for heat removal, and when it is convenient or desirable to make final heat rejection to atmospheric air. Water, acting as the heat-transfer fluid, gives up heat to atmospheric air, and thus cooled, is recirculated through the system, affording economical operation of the process.
Industry:Science
A toxic chemical that is used to kill pest rodents and sometimes other pest mammals, including moles, rabbits, and hares. Rodenticides are the least widely used of the pesticides, which also include insecticides, fungicides, and herbicides.
Industry:Science
