- 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.
Refraction is one of the most fundamental phenomena in nature. It gives rise to such well-known effects as the apparent bending of objects partly immersed in water, rainbows, mirages, green flashes, and haloes. Refraction is also utilized in many existing optical instruments, including microscopes, telescopes, and eyeglasses. All these phenomena and applications rely on conventional or “positive” refraction. What would the world look like if the sign of refraction were reversed?
Industry:Science
Recent research with carbon has amplified knowledge of fullerenes, especially the C<sub>36</sub> molecule and nanotubes. Carbon is an important element occurring in a staggering number of compounds, many with extensive industrial uses. Carbon is found in nature in two pure crystalline forms: as diamond, an insulator that is the hardest material known; and as graphite, a soft, electrically conducting material. Graphite is used in pencil lead and as a lubricant, among other things.
Industry:Science
Schemes for locating astronomical objects in space. To an observer on the Earth's surface, the stars of the night sky appear to be placed upon a spherical shell of infinite radius with the observer at the center. Celestial objects appear to move with respect to the stars, and at any given time their position on this imaginary sphere, called the celestial sphere, can be specified by two angles, called celestial coordinates, whose values depend upon what coordinate system is used.
Industry:Science
Seeds, the defining organs of the seed plants, or spermatophytes, protect and disperse the next generation of plants, represented by the young sporophytes (embryos). Being the result of millions of years of evolution and representing the most complicated organs a seed plant will ever produce in its life, seeds can tell us a lot about how primitive or advanced a given species is in evolutionary terms, about its natural relationships, and its dispersal mode and germination behavior.
Industry:Science
Solidification of droplets of molten material free-falling against an upward stream of air in a tower. It is a process used extensively in nitrogen fertilizer manufacturing. Melt is dispersed in the top of the tower at a temperature just above the solidification point of the material being processed. The dispersion arrangement, air flow, tower dimensions, and feed material are selected so the droplets approach a spherical shape and solidify before reaching the bottom of the tower.
Industry:Science
Oligo(few)saccharide(sugar): A carbohydrate molecule composed of 3–20 monosaccharides. Generally, free oligosaccharides do not quantitatively constitute a significant proportion of naturally occurring carbohydrates. Most carbohydrates that occur in nature are in the form of monosaccharides (such as blood sugar, or glucose), disaccharides (such as table sugar, or sucrose, and milk sugar, or lactose), and polysaccharides (such as starch and glycogen, polyglucose molecules, or chitin).
Industry:Science
Plants that retain their green foliage throughout the year. Popularly, needle-leaved trees (pine, fir, juniper, spruce) and certain broad-leaved shrubs (rhododendron, laurel) are called evergreens. In warm regions many broad-leaved trees (magnolia, live oak) are evergreen, and in the tropics most trees are evergreen and nearly all have broad leaves. Many herbaceous biennials and perennials have basal rosettes with leaves close to the ground that remain green throughout the winter.
Industry:Science
Solutions selected or prepared to minimize changes in hydrogen ion concentration which would otherwise tend to occur as a result of a chemical reaction. In general, chemical buffers are systems which, once constituted, tend to resist further change due to external influences. Thus it is possible, for example, to make buffers resistant to changes in temperature, pressure, volume, redox potential, or acidity. The commonest buffer in chemical solution systems is the acid-base buffer.
Industry:Science
In November 2003 the known solar system grew significantly larger with the discovery of a new object, Sedna, 90 astronomical units from the Sun. (1 AU = 150 × 10<sup>6</sup> km = 93 × 10<sup>6</sup> mi, the average distance from the Earth to the Sun.) For comparison, Jupiter orbits 5 AU and Neptune 30 AU from the Sun. Objects in the Kuiper Belt, discovered beginning in 1992, orbit beyond Neptune at typical distances of around 40 AU, and are likely to be the closest relatives to Sedna.
Industry:Science
In the early development of many tissues and organs of complex, multicellular organisms, the action of one group of cells on another that leads to the establishment of the developmental pathway in the responding tissue. The groups of cells which influence the responding cells are termed the inducing tissue. Since specific inducing tissues cannot act on all types of cells, those cells which can respond are referred to as competent to react to the action of a specific inducer stimulus.
Industry:Science
