- 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 simultaneous execution of several interrelated computer programs. A sequential computer program consists of a series of instructions to be executed one after another. A concurrent program consists of several sequential programs to be executed in parallel. Each of the concurrently executing sequential programs is called a process. Process execution, although concurrent, is usually not independent. Processes may affect each other's behavior through shared data, shared resources, communication, and synchronization.
Industry:Science
The mathematical term ring is used to designate a type of algebraic system with two compositions satisfying most but not all the properties of addition and multiplication in the system of integers, 0, ±1, ±2, …. In precise terms a ring is a set <i>R</i> with two binary compositions called addition and multiplication whose results on an ordered pair (<i>a</i>,<i>b</i>), <i>a</i>,<i>b</i> in <i>R</i>, are denoted by <i>a</i> + <i>b</i> and <i>ab</i>, respectively. These compositions must satisfy the following conditions:
Industry:Science
The most famous of comets, associated with many important events in history. Records of Halley's Comet appear at least as far back as 240 <small>B.C.</small>, and they are found in the Bayeux Tapestry (the apparition of the comet in 1066) and in the <i>Nuremberg Chronicle</i> (the apparition of 1456 and probably those of 684 and 1301). The comet's size, activity, and favorably placed orbit, with the perihelion roughly halfway between the Sun and the Earth's orbit, ensure its visibility to the naked eye at each apparition.
Industry:Science
The process by which the vertebrate neural tube is formed. The primordium of the central nervous system is the neural plate, which arises at the close of gastrulation by inductive action of the chorda-mesoderm on the overlying ectoderm. The axial mesodermal substratum causes the neural ectoderm to thicken into a distinct plate across the dorsal midline and influences both its size and shape. Its shieldlike appearance, broader anteriorly and narrower posteriorly, presages the areas of brain and spinal cord, respectively.
Industry:Science
The study of biota that inhabit the soil and the processes that they mediate. The soil is a complex environment colonized by an immense diversity of microorganisms. Soil microbiology focuses on the soil viruses, bacteria, actinomycetes, fungi, and protozoa, but it has traditionally also included investigations of the soil animals such as the nematodes, mites, and other microarthropods. These organisms, collectively referred to as the soil biota, function in a belowground ecosystem based on plant roots and litter as food sources.
Industry:Science
The study of the occurrence, movement, and changes in the state of water in the atmosphere. The term is also used in a more restricted sense, especially by hydrologists, to mean the study of the exchange of water between the atmosphere and continental surfaces. This includes the processes of precipitation and direct condensation, and of evaporation and transpiration from natural surfaces. Considerable emphasis is placed on the statistics of precipitation as a function of area and time for given locations or geographic regions.
Industry:Science
The term “denudation” was introduced into the earth sciences in the early nineteenth century to refer to the removal of surface material that leads to the exposure of underlying strata and rock units. Now, denudation refers to all the weathering and erosional processes that contribute to the lowering of the land surface, potentially to the production of a peneplain as the product of a long period of erosion. Denudation is, thus, the complement of deposition, the accumulation of the products of denudation in sedimentation basins.
Industry:Science
The legal documents pursuant to which most professional engineering and architectural services are rendered. A contract is the statement of promises agreed to by two or more parties in order to effectuate a specific goal. For the law to enforce these promises, certain elements must be present: mutuality of obligation, that is, each of the parties must have an obligation to the others; a meeting of the minds, that is, it must appear that the parties agree; and all material elements of the proposed transaction must be provided for.
Industry:Science
The study of how trees grow and develop in terms of genetics; biochemistry; cellular, tissue, and organ functions; and interaction with environmental factors. While many physiological processes are similar in trees and other plants, particularly at the molecular and biochemical levels, trees possess unique physiologies that help determine their outward appearance. These physiological processes include carbon relations (photosynthesis, carbohydrate allocation), cold and drought resistance, water relations, and mineral nutrition.
Industry:Science
The measurement of direct current or voltage drop across an electrical insulating material to determine its resistance by the application of Ohm's law. The main purpose of electrical insulation is to isolate the energized components of a system from each other and from ground. This requires that the insulation resistance to the flow of current be as high as possible. Good insulators have resistances in the range of 10<sup>6</sup> to 10<sup>20</sup> ohms, and must also have acceptable mechanical, chemical, and thermal properties.
Industry:Science
