- 行业: Printing & publishing
- Number of terms: 178089
- Number of blossaries: 0
- 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.
An arc discharge lamp with sodium vapor as the emitting species. Low-pressure and high-pressure types are in common commercial usage.
Industry:Science
An area of diminished precipitation on the lee side of mountains. There are marked rain shadows, for example, east of the coastal ranges of Washington, Oregon, and California, and over a larger region, much of it arid, east of the Cascade Range and Sierra Nevadas. Precipitation on the northern Oregon coast is around 100 in. (2.5 m) per year; east of the coastal ranges in the Willamette Valley it is about 40 in. (1.0 m); and east of the Cascades it drops to around 10 in. (0.25 m). All mountains decrease precipitation on their lee; but rain shadows, as is shown by annual totals, are sometimes not marked if moist air often comes from different directions, as in the Appalachian region.
Industry:Science
An area of mathematics concerned with the minimization (or maximization) of a linear function of several variables subject to linear equations and inequalities. Linear programming developed from three main areas: transportation problems, game theory, and input-output models. Work on all these areas took place before and during World War II, with major contributions by L. V. Kantorovich, J. von Neumann, and W. Leontief. The subject in its present form was created in 1947, when G. B. Dantzig defined the general model and proposed the first, and still the most widely used, method for its solution: the simplex method.
Industry:Science
An area of optics that encompasses the generation, transmission, modulation, amplification, conversion, and detection of light. A photon is the quantum unit of electromagnetic radiation. Whereas electronics involves the manipulation and operation of electrons, photonics involves the manipulation and operation of photons. Photonics and electronics are intimately related to each other. Fundamentally, photons are created and destroyed by the transition of electrons between energy states. Disciplines such as electrooptics, optoelectronics, quantum electronics, quantum optics, and light-wave technology involve principles, phenomena, devices, and systems that are related to photonics and electronics.
Industry:Science
An area of science concerned with the application of mathematical concepts to the physical sciences and the development of mathematical ideas in response to the needs of physics. Historically, the concept of mathematical physics was synonymous with that of theoretical physics. In present-day terminology, however, a distinction is made between the two. Whereas most of theoretical physics uses a large amount of mathematics as a tool and as a language, Mathematical physics places greater emphasis on mathematical rigor, and devotes attention to the development of areas of mathematics that are, or show promise to be, useful to physics. Henri Poincaré likened physics to a large library in which the books are furnished by the experimenters, and the index, without which the collection would be inaccessible and useless, by the mathematical physicists (in the older sense of the word). If that simile is accepted, there remains the remarkable fact that most of the organization and structure of the library, and even the existence of many of the books, is determined by the nature of the index, since both the language and the content of mathematics continue to have a powerful influence on ideas of the structure of nature. The results obtained by pure mathematicians, with no thought to applications, are almost always found to be both useful and effective in formulating physical theories.
Industry:Science
An area of study which draws from linguistics and psychology and focuses upon the comprehension and production of language in its spoken, written, and signed forms. Although psychologists have long been interested in language, and the field of linguistics is an older science than psychology, historically scientists in the two fields have had little contact. The two fields were thrown together, however, by the publications of Noam Chomsky in the late 1950s. Chomsky's writing had the effect of making psychologists acutely aware of their lack of knowledge about the structure of language, and the futility of focusing theoretical and research attention upon the surface structure of language while arguing that linguistics is as much concerned with the mind as psychologists should be. Psychologists, in turn, made linguists more aware of the larger cognitive context into which language fits as well as a broader set of methodological approaches available to scientifically test hypotheses about language. As a result, psycholinguists, who have a background of training in both linguistics and psychology, have been attempting since the early 1960s to gain a better understanding of the abstract rules which underlie human language and how they are acquired, used to communicate meaningful messages, and influenced by the biological and psychological context in which they occur. Research has been directed to the evolutionary development of language, the biological bases of language, the nature of the sound system, the rules of syntax, the nature of meaning, and the process of language acquisition.
Industry:Science
An area set aside for the cultivation of trees and shrubs for educational and scientific purposes. An arboretum differs from a botanical garden in emphasizing woody plants, whereas a botanical garden includes investigation of the growth and development of herbaceous plants, as well as trees and shrubs.
Industry:Science
An area supporting some vegetation beyond the northern limit of trees, between the upper limit of trees and the lower limit of perennial snow on mountains, and on the fringes of the Antarctic continent and its neighboring islands. The term is of Lapp or Russian origin, signifying treeless plains of northern regions. Biologists, and particularly plant ecologists, sometimes use the term tundra in the sense of the vegetation of the tundra landscape. Tundra has distinctive characteristics as a kind of landscape and as a biotic community, but these are expressed with great differences according to the geographic region.
Industry:Science
An arrangement of designed components that provides strength and stiffness to a built artifact such as a building, bridge, dam, automobile, airplane, or missile. The artifact itself is often referred to as a structure, even though its primary function is not to support but, for example, to house people, contain water, or transport goods.
Industry:Science
An arthropod-borne (primarily mosquito), acute, febrile, viral disease of humans and numerous species of animals, particularly ruminants. Rift Valley fever is caused by a ribonucleic acid (RNA) virus in the genus <i>Phlebovirus</i> of the family Bunyaviridae. In sheep and cattle, it is also known as infectious enzootic hepatitis. First described in the Rift Valley of Africa, the disease presently occurs in west, east, and south Africa and has extended as far north as Egypt. Outside of Africa, Rift Valley fever has spread to the island of Madagascar and the Arabian Peninsula (Saudi Arabia and Yemen).
Industry:Science
