- 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 means for setting up electromagnetic fields of precisely determined intensity at microwave frequencies in unbounded regions of space. Such standards are used to evaluate field probes and antennas for measuring field strength and power density. The standardization of these devices is necessary before they are used for determining the performance of radar and communications systems or for assessing such systems for health and safety risks or electromagnetic compatibility.
Industry:Science
The measurement of self- or mutual inductance. An electrical reactance such as the angular frequency (2π<i>f</i>, where <i>f</i> is the frequency) times self- or mutual inductance is the ratio of the alternating voltage having the appropriate phase, which appears across specified terminals, to the current through the device. Commercial instruments often measure inductance from this ratio by comparing it with the voltage-to-current ratio associated with a noninductive resistor.
Industry:Science
The principle stating that the total virtual work done by all the forces acting on a system in static equilibrium is zero for a set of infinitesimal virtual displacements from equilibrium. The infinitesimal displacements are called virtual because they need not be obtained by a displacement that actually occurs in the system. The virtual work is the work done by the virtual displacements, which can be arbitrary, provided they are consistent with the constraints of the system.
Industry:Science
The parent compound of a group of organic heterocyclic compounds containing the indole nucleus, which is a benzene ring fused to a pyrrole ring as in indole itself. Indole can exist in two tautomeric forms, the more stable enamine form and the 3-H-indole or imine form. Unsubstituted 3-H-indoles (sometimes called indolenines) and a structural isomer of indole, isoindole, are not stable, but have been shown to be reaction intermediates. They are isolable when properly substituted.
Industry:Science
The planar surface of a heavier-than-air body whose primary purpose is to produce lift during flight. A wing is composed of a series of airfoil-shaped components joined together to form one integral structure. On an airplane, the wing also provides storage space for the fuel and undercarriage, and is often used as the structural anchor point for the propulsion systems. The wing also includes important flight-control surfaces, such as the aileron, flaps, slats, and spoilers.
Industry:Science
The simultaneous flow of two phases or two immiscible liquids within common boundaries. Two-phase flow has a wide range of engineering applications such as in the power generation, chemical, and oil industries. Flows of this type are important for the design of steam generators (steam–water flow), internal combustion engines, jet engines, condensers, cooling towers, extraction and distillation processes, refrigeration systems, and pipelines for transport of gas and oil mixtures.
Industry:Science
The process by which an electron is removed from an atom, molecule, or ion. This process is of basic importance to electrical conduction in gases, liquids, and solids. In the simplest case, ionization may be thought of as a transition between an initial state consisting of a neutral atom and a final state consisting of a positive ion and a free electron. In more complicated cases, a molecule may be converted to a heavy positive ion and a heavy negative ion which are separated.
Industry:Science
The single species <i>Ornithorhynchus anatinus</i> of the family Ornithorhynchidae in the order Monotremata, which occurs in eastern Australia and Tasmania. This mammal is a monotreme, which lays eggs and incubates them in a manner similar to birds. The platypus is also known as the duckbill, duckmole, and water mole. One of the most primitive mammals, it retains some reptilian characteristics. The female lacks a marsupium; however, marsupial or epipubic bones are well developed.
Industry:Science
The low-density outermost layer of the Earth above the Mohorovičić discontinuity (the Moho), a global boundary that is defined as the depth in the Earth where the compressional-wave seismic velocity increases rapidly or discontinuously to a value in excess of 4.7 mi/s (7.6 km/s; the upper mantle). The crust is also the cold, upper portion of the Earth's lithosphere, which in terms of plate tectonics is the mobile, outer layer that is underlain by the hot, convecting asthenosphere.
Industry:Science
The National Aeronautics and Space Administration (NASA) plans to launch the James Webb Space Telescope, which in many ways is the scientific and technological successor of the Hubble Space Telescope, in 2011. In 2002, the company now known as Northrop Grumman Space Technology (which was then TRW Space and Electronics) and its partners, Ball Aerospace and Eastman Kodak, were awarded the prime contract to build the observatory, formerly known as the Next Generation Space Telescope.
Industry:Science
