- 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.
A mutagen is a substance or agent that induces heritable change in cells or organisms. A carcinogen is a substance that induces unregulated growth processes in cells or tissues of multicellular animals, leading to the disease called cancer. Although mutagen and carcinogen are not synonymous terms, the ability of a substance to induce mutations and its ability to induce cancer are strongly correlated. Mutagenesis refers to processes that result in genetic change, and carcinogenesis (the processes of tumor development) may result from mutagenic events.
Industry:Science
A name applied to certain varieties of a variable group of loose-skinned citrus fruits belonging to the species <i>Citrus reticulata</i>. Although mandarin and tangerine are often used interchangeably to designate the whole group, tangerine is applied more strictly to those varieties (cultivars) having deep-orange or scarlet rinds, whereas the term mandarin is more properly used to include all members of this quite variable group of citrus fruits.
Industry:Science
A name associated with several animals in four different orders of living mammals (see <b>table</b>). They are so named because they are insectivorous, having a diet of ants and termites which they detect mainly by smell. These animals provide a good example of the evolutionary concept of convergence, in which similar adaptations are made by organisms of different groups. The animal most frequently associated with this name is the giant anteater (<i>Myrmecophaga tridactyla</i>), a ground-dwelling member of the family Myrmecophagidae in the order Xenarthra (see <b>illustration</b>). Three arboreal species—the northern tamandua (<i>Tamandua mexicana</i>), southern tamandua (<i>T. tetradactyla</i>), and the silky, or pygmy, anteater (<i>Cyclopes didactylus</i>)—are also classified in this family. They are found in Central and South America from Mexico to northern Argentina. Although they share membership in Xenarthra with sloths and armadillos, anteaters are the only toothless members of the order. Tamanduas and silky anteaters do possess either distinct tooth sockets or vestiges, which indicate that the teeth have been lost in the course of phylogenetic development. All members of the order Xenarthra differ from all other mammals by having xenarthrous vertebrae, lumbar vertebrae that have additional articulations (xenarthrales) to provide reinforcement for digging.
Industry:Science
A name commonly applied to two trees, the black locust (<i>Robinia pseudoacacia</i>) and the honey locust (<i>Gleditsia triacanthos</i>). Both of these commercially important trees have podlike fruits similar to those of the pea or bean.
Industry:Science
A name given primarily to certain members of the freshwater family Centrarchidae, as well as to members of the marine family Molidae and the freshwater family Elassomatidae. These fishes are characterized by brilliant metallic skin coloration, especially on the cheeks and belly.
Industry:Science
A name given to a group of magnesium-iron silicate minerals crystallizing in the orthorhombic system. Crystals are usually of simple habit, a combination of the dipyramid with prisms and pinacoids. The luster is vitreous and the color olive green, giving rise to the name olivine. Hardness is 6½–7 on Mohs scale; specific gravity is 3.27–3.39, increasing with increase in iron content.
Industry:Science
A name given to manifestations of the magnetic self-attraction of parallel electric currents having the same direction. The effect at modest current levels of a few amperes can usually be neglected, but when current levels approach a million amperes such as occur in electrochemistry, the effect can be damaging and must be taken into account by electrical engineers. Since the late 1940s the pinch effect in a gas discharge has been studied intensively in laboratories throughout the world, since it presents a possible way of achieving the magnetic confinement of a hot plasma (a highly ionized gas) necessary for the successful operation of a thermonuclear or fusion reactor.
Industry:Science
A name originally applied to nonrigid airships and usually implying small size. Early blimps contained about 100,000 ft<sup>3</sup> (2800 m<sup>3</sup>) and were only a fraction of the size of the rigid airships of that period. The nonrigid pressure-type airship, however, did not stay small; each succeeding model built was substantially larger than its predecessor until ships with volumes of approximately 1,500,000 ft<sup>3</sup> (42,000 m<sup>3</sup>) were operational in the U.S. Navy. With the advent of these larger sizes it appeared that the name blimp would be replaced by the more general term airship. However, the principles of construction of these ships are basically the same regardless of the size.
Industry:Science
A name that may be applied correctly to two distinct minerals. The two true jades are jadeite and nephrite. In addition, a variety of other minerals are incorrectly called jade. Idocrase is called California jade, dyed calcite is called Mexican jade, and green grossularite garnet is called Transvaal or South African jade. The most commonly encountered jade substitute is the mineral serpentine. It is often called new jade or Korean jade. The most widely distributed and earliest known true type is nephrite, the less valuable of the two. Jadeite, the most precious of gemstones to the Chinese, is much rarer and more expensive.
Industry:Science
A name used to designate a large group of citrus fruits in the species <i>Citrus reticulata</i> and some of its hybrids. This group is variable in the character of trees and fruits since the term is used in a general sense to include many different forms, such as tangerines, King oranges, Temple oranges, tangelos (hybrids between grapefruit and tangerine), Satsuma oranges, and Calamondin, presumably a hybrid between a mandarin and a kumquat.
Industry:Science
