- 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 gummy exudate used in the manufacture of chewing gum. It is contained in the bark of a tall evergreen tree, <i>Manilkara zapota</i> (see <b>illus.</b>), belonging to the sapodilla family (Sapotaceae). The species is a native of Mexico and Central America. The latex (secretion) is collected and carefully boiled to remove excess moisture. When the water content is reduced to 33%, the chicle is poured off and molded into blocks. Crude chicle contains resin, arabin, gutta, sugar, calcium, and different soluble salts. For refining, it is broken up, washed in strong alkali, neutralized with sodium acid phosphate, rewashed, dried, and powdered. The resulting product is an amorphous, pale-pink powder, insoluble in water, and forming a sticky paste when heated. In the manufacture of chewing gum, the chicle is cleaned, filtered, and sterilized, and various flavoring materials and sugar are added.
Industry:Science
A harbor is a geographic location with a body of water of sufficient depth for vessels to enter to seek rest, obtain supplies, and find shelter from storms or other natural phenomena. Harbors typically are naturally occurring but may be constructed. The modern harbor is a place where vessels are built, launched, anchored, and repaired, and usually contains terminals for incoming and outgoing vessels to transport cargo and people. Harbors typically are used for commercial, naval, and fishery vessels, as well as refuge for small craft. Most harbors that accommodate large vessels are situated at the mouth of a river or at some point where it is easy to transfer cargoes inland by river barges, railroads, or trucks.
Industry:Science
A hard, dense sedimentary rock composed of fine-grained silica (SiO<sub>2</sub>). Chert is characterized by a semivitreous to dull luster and a splintery to conchoidal fracture, and is most commonly gray, black, reddish brown, or green. Chert is also used as a field term to describe silica-rich rocks which may be impure; common impurities include carbonates, iron and manganese oxides, and clay minerals. When impurities change the texture of the rock to the extent that it is less dense and hard than chert, and has the appearance of unglazed porcelain, the rock is then called porcellanite or siliceous shale. The term flint is synonymous with chert, but its use has become restricted to archeological artifacts and to nodular chert that occurs in chalk. The term chert, however, is preferred for the nodular deposits. Jasper refers to red or yellow quartz chert associated with iron ore or containing iron oxide. Novaculite is a white chert of great purity and uniform grain size, and is composed chiefly of quartz; the term is mostly restricted to descriptions of Paleozoic cherts in Oklahoma and Arkansas. Chert synonyms that have become obsolete include silexite, petrosilex, phthanite, and hornstone.
Industry:Science
A hard, dense silicate mineral which occurs as crystals of cubic symmetry in a wide range of geologic environments. The general chemical formula of the silicate garnet group is A<sub>3</sub>B<sub>2</sub>(SiO<sub>4</sub>)<sub>3</sub> where, in natural occurrences, the A cations are dominantly Fe<sup>2</sup>, Mn<sup>2</sup>, Mg, and Ca and the B cations are Al, Fe<sup>3</sup>, and Cr<sup>3</sup>.
Industry:Science
A hard, red or yellow-brown wood which takes a high polish and is extensively used for furniture and cabinetwork. The West Indies mahogany tree (<i>Swietenia mahagoni</i>), a native of tropical regions in North and South America, is a large evergreen tree with smooth pinnate leaves (see <b>illus.</b>). Together with other species it yields the world's most valuable cabinet wood. Varieties with ornamental figures in the grain are highly prized. In the United States it occurs naturally only in the extreme southern tip of Florida, but it is planted elsewhere in the state as an ornamental and shade tree. The cigarbox or West Indian cedar (<i>Cedrela odorata</i>) belongs to the same family.
Industry:Science
A hard, transparent, glasslike thermoplastic resin. Polystyrene is characterized by excellent electrical insulation properties, relatively high resistance to water, high refractive index, clarity, and low softening temperature.
Industry:Science
A hardy biennial, <i>Pastinaca sativa</i>, of Mediterranean origin belonging to the plant order Umbellales. The parsnip is grown for its thickened taproot and is used primarily as a cooked vegetable. Propagation is by seed; cultural practices are similar to those used for carrot, except that a longer growing season is required. Parsnip seed retains its viability only 1–2 years. Harvesting begins in late fall or early winter, usually 100–125 days after planting. Exposure of mature roots to low temperatures, not necessarily freezing, improves the quality of the root by favoring the conversion of starch to sugar.
Industry:Science
A hardy perennial crucifer, <i>Armoracia rusticana</i>, of eastern European origin belonging to the plant order Capparales. Horseradish is grown for its pungent roots, which are generally grated, mixed with vinegar and salt, and used as a condiment or relish. Propagation is by root cuttings, and the crop is grown like an annual. The individual roots or sets are uncovered by hand usually twice during the summer and stripped of all side roots (see <b>illus.</b>). Maliner Kren is a common variety. Harvesting of the roots occurs in the fall, usually 3½ to 4 months after planting. Production in the United States is limited to northern areas; Illinois, Wisconsin, and Missouri are important producing states.
Industry:Science
A hardy perennial, <i>Allium sativum</i>, of Asiatic origin and belonging to the plant order Liliales. Garlic is grown for its pungent bulbs, segments of which are used primarily for seasoning. Europeans have grown it for more than 200 years. Propagation is commonly by bulb segments, sometimes called cloves; seeds are seldom produced. Cultural practices are similar to those used for onions. Popular varieties are Italian, Tahiti, and Creole or Mexican. Harvest of the mature dry bulbs is 7–8 months after planting. Garlic salt is made from dehydrated cloves. California is the most important producing state; smaller acreages are planted to garlic in Louisiana and Texas.
Industry:Science
A hardy, cool-season crucifer (<i>Brassica oleracea</i> var. <i>capitata</i>) of Mediterranean origin and belonging to the plant order Capparales. Cabbage is grown for its head of overlapping leaves (see <b>illus.</b>), which are generally eaten raw in salads, cooked fresh, or processed into sauerkraut. Because it normally produces seed the second year, cabbage is considered to be a biennial by most authorities. Others regard it as a perennial because it will remain vegetative unless subjected to cold weather.
Industry:Science
