- 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.
A section of animal agriculture concerned with the production of milk and milk products. The mammary gland in mammals was developed for the nourishment of their young. Over the centuries humans have selected some mammals, especially the cow, goat, and water buffalo, for their ability to produce quantities of milk in excess of the requirements of their young. At the same time humans have improved the management and nutrition of the animals so that they can produce milk more efficiently. The production of milk includes selection of animals, breeding, raising young stock, feed production, nutrition, housing, milking, milk handling, sanitation, disease control, and disposal of milk, surplus animals, and manure.
Industry:Science
A section of the alimentary canal that is interposed between the pharynx and the stomach. Because of divergent specializations in the various vertebrates, the esophagus cannot be described in general terms and is not always distinguishable.
Industry:Science
A sedimentary rock containing solid, combustible organic matter in a mineral matrix. The organic matter, often called kerogen, is largely insoluble in petroleum solvents, but decomposes to yield oil when heated. Although “oil shale” is used as a lithologic term, it is actually an economic term referring to the rock's ability to yield oil; oil shale appears to be the cheapest source after natural petroleum for large amounts of liquid fuels. No real minimum oil yield or content of organic matter can be established to distinguish oil shale from sedimentary rocks. Additional names given to oil shales include black shale, bituminous shale, carbonaceous shale, coaly shale, cannel shale, cannel coal, lignitic shale, torbanite, tasmanite, gas shale, organic shale, kerosine shale, coorongite, maharahu, kukersite, kerogen shale, algal shale, and “the rock that burns.”
Industry:Science
A segment of a troughlike glaciated valley partly filled by an arm of the sea. It differs from other glaciated valleys only in the fact of submergence. The floors of many fiords are elongate basins excavated in bedrock, and in consequence are shallower at the fiord mouths than in the inland direction. The seaward rims of such basins represent lessening of glacial erosion at the coastline, where the former glacier ceased to be confined by valley walls and could spread laterally. Some rims are heightened by glacial drift deposited upon them in the form of an end moraine.
Industry:Science
A segment of deoxyribonucleic acid (DNA) transcribed into ribonucleic acid (RNA) as part of a longer strand of RNA, called heterogeneous nuclear RNA (hnRNA), but that does not survive the processes of messenger RNA (mRNA) maturation. Hence, genes are split into portions, termed exons, that appear in mRNAs or in structural RNAs, and introns. During the maturation of pre-mRNA to mature mRNA, a series of control processes occur that specify and narrow down the set of mRNAs that become functionally active in a given cell. These processes multiply the species of transcripts through the differential combination of exons and the inclusion of parts of introns into the functional mRNAs; thus, several mRNA products can be generated from a single gene in a controlled manner. For example, certain exons may be included or spliced out during mRNA maturation (alternative splicing of the same hnRNA molecule), or two different hnRNA molecules may form during the splicing reaction of one mRNA transcript, a process termed trans-splicing.
Industry:Science
A segment of the Earth's crust, generally long as compared to its width, that has been upthrown relative to the adjacent rocks (see <b>illus.</b>). Horsts range in size from those that have lengths and upward displacement of a few inches to those that are tens of miles long with upward displacements of thousands of feet. The faults bounding a horst on either side commonly have inclinations of 50–70° toward the downthrown blocks, and the direction of movement on these displacements indicates that they are gravity faults. These relationships suggest that horsts develop in regions where the crust has undergone extension. They may form in the crests of anticlines or domes, or may be related to broad regional warpings.
Industry:Science
A seismic event that is caused by the mining of underground or surface openings in a high-stress environment. The Mine Safety and Health Administration (MSHA) defines a rock burst as “a sudden and violent failure of a large volume of overstressed rock, resulting in the instantaneous release of large amounts of accumulated energy.” Underground, a rock burst sounds like a loud blast. On the surface, a rock burst sounds like a sonic boom, while the ground and structures on the surface shake as if a small earthquake had occurred.
Industry:Science
A selective absorption phenomenon observable in a wide variety of polycrystalline compounds containing nonspherical atomic nuclei when placed in a magnetic radio-frequency field. Nuclear quadrupole resonance (NQR) is very similar to nuclear magnetic resonance (NMR), and was originated in the late 1940s by H. G. Dehmelt and H. Krüger as an inexpensive (no stable homogeneous large magnetic field is required) alternative way to study nuclear moments.
Industry:Science
A self-contained system that can automatically determine the position, velocity, and attitude of a moving vehicle for the purpose of directing its future course. Based on prior knowledge of time, gravitational field, initial position, initial velocity, and initial orientation relative to a known reference frame (coordinate system), an inertial navigation system (INS) is capable of determining its present position, velocity, and orientation without the aid of external information. The generated navigational data are used to determine the future course for a vehicle to follow in order to bring it to its destination. Such systems have found application in the guidance and control of submarines, ships, aircraft, missiles, and spacecraft. The sensors making these measurements, based on one of the basic properties of mass—inertia, are gyroscopes (gyros) and accelerometers.
Industry:Science
A self-luminous body that during its life generates (or will generate) energy and support by thermonuclear fusion.
Industry:Science
