- 行业: Printing & publishing
- Number of terms: 178089
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- Company Profile:
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.
The ease and economy with which a metal may be cut under average conditions. Frequently no truly quantitative assessment is made, but rather a rating or an index is established vis-à-vis a reference material. More quantitative comparisons are based on tool life. For example, maximum cutting speeds for a given tool life may be used as a rating of machinability. Alternatively, tool wear rate may be the basis for a machinability rating. Surface finish is sometimes used for assessing machinability.
Industry:Science
That aspect of visual sensation enabling a human observer to distinguish differences between two structure-free fields of light having the same size, shape, and duration. Although luminance differences alone permit such discriminations to be made, the term color is usually restricted to a class of differences still perceived at equal luminance. These depend upon physical differences in the spectral compositions of the two fields, usually revealed to the observer as differences of hue or saturation.
Industry:Science
The bear family (Ursidae) contains the largest terrestrial carnivores. Most taxonomists agree that there are eight extant species of bears in three subfamilies: Ursinae (American black, Asiatic black, brown, polar, Malayan Sun, and sloth bears); Tremarctinae (Andean or spectacled bear); and Ailuropodinae (giant panda). Bears currently inhabit North America, South America, Europe, and Asia. Habitats range from polar ice floes to tropical forests. They are absent from Australia, Africa, and Antarctica.
Industry:Science
The fractional part (portion) of a period through which the time variable of a periodic quantity (alternating electric current, vibration) has moved, as measured at any time instant from an arbitrary time origin. In the case of a sinusoidally varying quantity, the time origin is usually assumed to be the last point at which the value of the quantity was zero, passing from a negative to a positive value. It is customary to choose the origin so that the fractional part of the period is less than unity.
Industry:Science
Sugars serve as energy sources and building blocks for macromolecules, making them indispensable to living organisms. Yet, there is also a negative side to the actions of sugars. They fuel nonenzymatic glycation, a spontaneous posttranslational modification of proteins in vivo that results in the formation of advanced glycation end products (AGEs), which adversely effect biochemical, biomechanical, and cellular function and are implicated in the complications of diabetes and many age-related diseases.
Industry:Science
The application of acoustics to research on the properties of condensed matter at low temperatures. Acoustic techniques are readily adaptable to the cryogenic environment and make possible many measurements of the structural and thermodynamic properties of materials at temperatures approaching absolute zero (0 K, which is −460°F or −273°C). The study of sound propagation has also yielded major insights into the low-temperature phenomena of superconductivity in metals and superfluidity in liquid helium.
Industry:Science
The collection of computer programs that can solve equations or perform mathematical manipulations. The developing of mathematical equations that describe a process is called mathematical modeling. Once these equations are developed, they must be solved, and the solutions to the equations are then analyzed to determine what information they give about the process. Many discoveries have been made by studying how to solve the equations that model a process and by studying the solutions that are obtained.
Industry:Science
Systems in which combined production of electrical power and useful thermal energy is achieved by the sequential use of a fuel or fuels. The electrical power is produced by a generator that is most often powered by a prime mover such as a steam turbine, gas turbine, or reciprocating (piston) engine. Examples of useful thermal energy include hot exhaust gases, hot water, steam, or chilled water. Other names for cogeneration systems are combined heating and power (CHP), district heating, and total energy.
Industry:Science
The electromagnetically bound or Coulomb-bound pion-pion system, the π<sup>+</sup>π<sup>−</sup> atom, also called A<sub>2π</sub>. Nowadays, this doubly exotic system is called pionium. In some older literature the term pionium was used for atoms consisting of only one pion and a muon or an electron. Eighteen pion-muon (πμ) atoms, formed in the decay <i>K</i><sup>0</sup><sub><i>L</i></sub> → (πμ)<sub>atom</sub> ν were detected in 1976 in an experiment at Brookhaven National Laboratoty in Upton, New York.
Industry:Science
The addition of heat to steam of reduced pressure after the steam has given up some of its energy by expansion through the high-pressure stages of a turbine. The reheater tube banks are arranged within the setting of the steam-generating unit in such relation to the gas flow that the steam is restored to a high temperature. Under suitable conditions of initially high steam pressure and superheat, one or two stages of reheat can be advantageously employed to improve thermodynamic efficiency of the cycle.
Industry:Science
