- 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.
From the time of the steam engine in the 1830s, innovation has been a hallmark of the U.S. rail industry. However, the train control technology used on U.S. railroads has remained virtually unchanged for several decades, aside from design upgrades using microprocessors and modern electronics. These twentieth-century systems still rely heavily on locomotive crews to comply with standard operating rules, follow verbal commands from dispatchers, and obey trackside rail signals.
Industry:Science
Dilute alloys of base metals which contain a few percent of beryllium in a precipitation-hardening system. They are the principal useful beryllium alloys manufactured today. Although beryllium has some solid solubility in copper, silver, gold, nickel, cobalt, platinum, palladium, and iron and forms precipitation-hardening alloys with these metals, the copper-beryllium system and, to a considerably lesser degree, the nickel-beryllium alloys are the only ones used commercially.
Industry:Science
Any one of a number of related integral quantities which serve as the basis for general formulations of the dynamics of both classical and quantum-mechanical systems. The term has been associated with four quantities: the fundamental action <i>S</i>, for general paths of a dynamical system; the classical action <i>S</i><sub><i>C</i></sub>, for the actual path; the modified action <i>S</i>′, for paths restricted to a particular energy; and action variables, for periodic motions.
Industry:Science
C<i>P</i> symmetry is the technical name for an almost, but not quite, exact symmetry of the laws of physics. It is the symmetry between the laws of physics for matter and those for antimatter. <i>CP</i> violation refers to the very small effects showing that this symmetry is not exact. The symmetry appears to be exact for strong interactions and for electromagnetic and gravitational interactions. Only in a few weak interaction processes is any violation of this symmetry found.
Industry:Science
Cell death triggered by extracellular signals or genetically determined events and carried out by physiological processes within the cell. It is therefore sometimes called “programmed cell death” as opposed to uncontrolled cell death following acute injury. Apoptosis is characterized by a systematic breakdown of cellular structure, including cytoplasmic shrinkage, breakdown of chromatin and structural proteins of the cell nucleus, and blistering (blebbing) of the cell membrane.
Industry:Science
At the close of World War II, as high-power microwave technology became available, engineers and scientists reexamined the idea, originally proposed by N. Tesla, of transmitting electric power to distant locations by means of radio waves. In the 1960s, these efforts resulted in the idea of a solar power satellite, a concept that was extensively developed in the late 1970s. Field experiments concerning microwave energy transmission were carried out in the late 1980s and the 1990s.
Industry:Science
Forensic science is defined as “the identification, collection, preservation, analysis, and interpretation of physical evidence that is relevant to a criminal act or process of interest.” When a criminal act involves the use of a microbial agent, such as a pathogenic virus, bacterium, or fungus, a microbial forensic investigation will focus on tracing the source of that agent and collecting evidence for use in the attribution of the event and the prosecution of those responsible.
Industry:Science
Heat, a form of kinetic energy, is transferred in three ways: conduction, convection, and radiation. Heat can be transferred only if a temperature difference exists, and then only in the direction of decreasing temperature. Beyond this, the mechanisms and laws governing each of these ways are quite different. This article gives introductory information on the three types of heat transfer (also called thermal transfer) and on important industrial devices called heat exchangers.
Industry:Science
Boreholes or wells are one of the most expensive investments made by oil and gas companies. Petrophysics, in the oil and gas business, is the study of the physical properties of rocks, and it attempts to measure the mineralogy and amount of open pore space available to store hydrocarbons. Well logs, which are paper or digital plots of depth versus various petrophysical measurements taken from a borehole, are often the only record of the rocks and fluids encountered in drilling a well.
Industry:Science
Attractive or repulsive interactions that occur between all atoms and molecules. Intermolecular forces become significant at molecular separations of about 1 nanometer or less, but are much weaker than the forces associated with chemical bonding. They are important, however, because they are responsible for many of the physical properties of solids, liquids, and gases. These forces are also largely responsible for the three-dimensional arrangements of biological molecules and polymers.
Industry:Science
