- 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 large, geologically significant group of dark, rock-forming silicate minerals. Pyroxene is found in abundance in a wide variety of igneous and metamorphic rocks. Because of their structural complexity and their diversity of chemical composition and geologic occurrence, these minerals have been intensively studied by using a wide variety of modern analytical techniques. Knowledge of pyroxene compositions, crystal structures, phase relations, and detailed microstructures provides important information about the origin and thermal history of rocks in which they occur.
Industry:Science
A large, relatively stable portion of the Earth's crust. Although ocean basins originally were considered low cratons, today the term applies only to continents. Continental (high) cratons are the broad heartlands of continents with subdued topography, encompassing the largest areas of most continents. Cratons experience only broad (epeirogenic) warping and occasional faulting in contrast to the much more structurally mobile or unstable zones of continents, which include mountain ranges, such as the Himalaya, and rift zones, such as those of East Africa. The terminology used today to express these contrasts was first proposed by the German geologist L. Kober in 1921. <i>Kratogen</i> referred to stable continental platforms, and <i>orogen</i> to mountain or orogenic belts. Later authors shortened the former term to kraton or craton. A complementary term, taphrogen, coined in the 1940s, encompasses the rift structures.
Industry:Science
A large, strikingly distinct tree, <i>Gymnocladus dioica</i>, which usually grows 80–90 ft (24–27 m) high, but sometimes attains a height of 110 ft (33 m) and a diameter of 5 ft (1.5 m). The species name, <i>dioica</i>, means that the tree is dioecious; that is, male and female flowers are on different individuals. It grows from eastern Nebraska, Kansas, and Oklahoma to southern Ontario, western New York, and Pennsylvania, and southwestward to Louisiana. It can readily be recognized when in fruit by its leguminous pods containing hard, heavy, red-brown seeds, which were used by early settlers as a substitute for coffee; hence the name coffee tree. The branches are stout and thick, and the bark has thin, twisted ridges. The leaves are twice pinnate, and the winter buds, sunken in the bark, are superposed, two or three together (see <b>illus.</b>). Never a common tree, it is sometimes cultivated in parks and gardens of the eastern United States and northern and central Europe. It is sometimes used as a street tree. The wood is hard and reddish, and is used for construction. It is durable in contact with the soil and is also used for railroad ties and fenceposts.
Industry:Science
A large, strongly built watch especially designed for precise timekeeping on ships at sea. The name is sometimes loosely applied to any fine watch.
Industry:Science
A large, usually abrupt rise in electric current in the presence of a small increase in electric voltage. Breakdown may be intentional and controlled or it may be accidental. Lightning is the most familiar example of breakdown.
Industry:Science
A large, widespread order of petaloid monocotyledons consisting of 29 families and about 26,000 species. Asparagales are clearly circumscribed in deoxyribonucleic acid (DNA) sequence analyses but are difficult to define morphologically, and separation from Liliales has proved particularly problematic. Phytomelan, a dark seedcoat pigment present in most families of Asparagales but not found in other plants, is an obvious characteric of this order, although seeds of the largest family, Orchidaceae, and a few other taxa lack phytomelan. Most Asparagales are herbaceous perennials, but there are some vines including some species of asparagus (Asparagaceae), and woody taxa including aloes (Asphodelaceae). The order contains many horticultural taxa, including members of Orchidaceae (orchids), Amaryllidaceae (daffodils, belladonna lilies, and others), Iridaceae (irises, gladiolus, freesias), Convallariaceae (lily of the valley, Solomon's seal), and Hemerocallidaceae (daylilies), in addition to food crops including onions, leeks, and garlic (Alliaceae).
Industry:Science
A large-scale imaging and redshift survey which, when complete, will map in detail over one quarter of the sky, determining the positions and brightness of over 100 million celestial objects and the redshifts of over a million galaxies and quasars. A primary objective of the survey is to obtain a map of the three-dimensional distribution of galaxies in the universe
Industry:Science
A laser that uses a single atom as its gain medium was first realized in 1994. This laser uses a low-density beam of barium atoms traversing a small optical resonator with highly reflective mirrors. Light emission and amplification are achieved via quantized Rabi oscillation.
Industry:Science
A lateral appendage which is borne on a plant stem at a node (joint) and which usually has a bud in its axil. In most plants, leaves are flattened in form, although they may be nearly cylindrical with a sheathing base as in onion. Leaves usually contain chlorophyll and are the principal organs in which the important processes of photosynthesis and transpiration occur.
Industry:Science
A law of electromagnetism which expresses the contribution of a current element of length <i>dl</i> to the magnetic induction (flux density) <i>B</i> at a point near the current. Ampère's law, sometimes called Laplace's law, was derived by A. M. Ampère after a series of experiments during 1820–1825. It plays a fundamental role in the International System (SI) definition of the ampere.
Industry:Science
