- 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.
The parallel of latitude approximately 66°30' north of the Equator, or 23.5° from the North Pole. Named for the northern constellation Bear, the Arctic Circle has the same angular distance from the Equator as the inclination of the Earth's axis from the plane of the ecliptic. Thus, when the Earth in its orbit is at the Northern Hemisphere summer solstice, June 21, and the North Pole is tilted 23.5° toward the Sun, the Sun's rays extend beyond the pole 23.5° to the Arctic Circle, giving that parallel 24 h of sunlight. On this same date the Sun's rays at noon will just reach the horizon at the Antarctic Circle, 66°30' south. The highest altitude of the noon Sun at the Arctic Circle is on June 21, when it is 47° above the horizon.
Industry:Science
The study of the distribution of diseases in populations and of factors that influence the occurrence of disease. Epidemiology examines epidemic (excess) and endemic (always present) diseases; it is based on the observation that most disease does not occur randomly, but is related to environmental and personal characteristics that vary by place, time, and subgroup of the population. The epidemiologist attempts to determine who is prone to a particular disease; where risk of the disease is highest; when the disease is most likely to occur and its trends over time; what exposure its victims have in common; how much the risk is increased through exposure; and how many cases of the disease could be avoided by eliminating the exposure.
Industry:Science
The processing technique employing a suspension or fluidization of small solid particles in a vertically rising stream of fluid—usually gas—so that fluid and solid come into intimate contact. This is a tool with many applications in the petroleum and chemical process industries. There are major possibilities of even greater growth and utility in the future. Suspensions of solid particles by vertically rising liquid streams are of lesser interest in modern processing, but have been shown to be of use, particularly in liquid contacting of ion-exchange resins. However, they come in this same classification and their use involves techniques of liquid settling, both free and hindered (sedimentation), classification, and density flotation.
Industry:Science
The study of the structure of metals and alloys by various methods, especially light and electron microscopy. Light microscopy of metals is conducted with reflected light on surfaces suitably prepared to reveal structural features. The method is often called optical microscopy or light optical microscopy. A resolution of about 200 nanometers and a linear magnification of at most 2000× can be obtained. Electron microscopy is generally carried out by the scanning electron microscope (SEM) on specimen surfaces or by the transmission electron microscope (TEM) on electron-transparent thin foils prepared from bulk materials. Magnifications can range from 10× to greater than 1,000,000×, sufficient to resolve individual atoms or planes of atoms.
Industry:Science
The plant <i>Oryza sativa</i> is the major source of food for nearly one-half of the world's population. In China, Japan, Korea, the Philippines, India, and other countries of Asia, rice is far more important than wheat as a source of carbohydrates. In some countries of the Orient the consumption of rice per capita is estimated at 200–400 lb (90–180 kg) per year. In contrast, the yearly per capita consumption of rice in the United States is only about 8 lb (3.6 kg). The most important rice-producing countries are mainland China, India, and Indonesia, but in many smaller countries rice is the leading food crop. In the United States, rice production is largely concentrated in selected areas of Arkansas, California, Louisiana, and Texas.
Industry:Science
The occurrence in an organism of an immune response to one of its own tissues, that is, a response to a self constituent. Foreign substances to which an organism makes a protective immune response are called nonself. Efficient discrimination between self and nonself, the basis of normal immune function, depends upon a function known as immune tolerance, which means an inertness to substances that could be capable of provoking an immune response. Failure of immune tolerance to self constituents results in an autoimmune response which is often, although not invariably, associated with autoimmune disease. Autoimmune disease occurs when the autoimmune response to self constituents has damaging effects of a structural or functional character.
Industry:Science
The net pressure exerted on a surface or interface by an acoustic wave. One might presume that the back-and-forth oscillation of fluid caused by the passage of an acoustic wave will not exert any net force on an object, and this is true for sound waves normally encountered. (The sound power of a normal speaking voice is less than one-millionth of the electric power of a 100-W light.) Intense sound waves, however, can exert net forces in one direction of sufficient magnitude (proportional to the sound intensity) to balance gravitational forces and thus levitate an object in air. These acoustic forces, generated by acoustic radiation pressure, are generally not of the magnitude to lift a table off the floor, although such is not inconceivable.
Industry:Science
The succession of events that culminates in the asexual reproduction of a cell; also known as cell division cycle. In a typical cell cycle, the parent cell doubles its volume, mass, and complement of chromosomes, then sorts its doubled contents to opposite sides of the cell, and finally divides in half to yield two genetically identical offspring. Implicit in the term cycle is the idea that division brings the double-sized parent cell back to its original size and chromosome number, and ready to begin another cell cycle. This idea fits well with the behavior of many unicellular organisms, but for multicellular organisms the daughter cells may differ from their parent cell and from each other in terms of size, shape, and differentiation state.
Industry:Science
The motion of an axis fixed in a body around a direction fixed in space. If the angle between the two is constant so that the axis sweeps out a circular cone, the motion is pure precession; oscillation of the angle is called nutation. An example of precession is the motion of the Earth's polar axis around the normal to the plane of the ecliptic; this is the precession of the equinoxes. A fast-spinning top, with nonvertical axis, which precesses slowly around the vertical direction, is another example. In both examples the precession is due to torque acting on the body. Another kind of precession, called free or fast precession, with a rate which is comparable to the rotation rate of the body, is seen, for instance, in a coin spun into the air.
Industry:Science
The set of physical quantities that play a fundamental role in basic physical theories, primarily at the atomic and subatomic levels, including also those quantities that provide the connection between microscopic physics and the macroscopic world. Examples of fundamental constants are the velocity of light in vacuum <i>c</i>; the Planck constant <i>h</i>; the universal gravitation constant <i>G</i>; the electron charge <i>e</i>; the masses of the proton, the neutron, and the electron, <i>m<sub>p</sub></i>, <i>m<sub>n</sub></i>, and <i>m<sub>e</sub></i>; the Boltzmann constant <i>k</i>; and the Avogadro constant <i>N<sub>A</sub></i>; as well as any physical constant such as the fine-structure constant α that is a combination of these constants.
Industry:Science
