- 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 study of ancient climates. Climate is the long-term expression of weather; in the modern world, climate is most noticeably expressed in vegetation and soil types and characteristics of the land surface. To study ancient climates, paleoclimatologists must be familiar with various disciplines of geology, such as sedimentology and paleontology, and with climate dynamics, which includes aspects of geography and atmospheric and oceanic physics. A compelling need exists for societies to be able to predict climate change. Understanding the history of the Earth's climate system greatly enhances the ability to predict how it might behave in the future.
Industry:Science
The muscular system consists of muscle cells, the contractile elements with the specialized property of exerting tension during contraction, and associated connective tissues. The three morphologic types of muscles are voluntary muscle, involuntary muscle, and cardiac muscle. The voluntary, striated, or skeletal muscles are involved with general posture and movements of the head, body, and limbs. The involuntary, nonstriated, or smooth muscles are the muscles of the walls of hollow organs of the digestive, circulatory, respiratory, and reproductive systems, and other visceral structures. Cardiac muscle is the intrinsic muscle tissue of the heart.
Industry:Science
The ramjet engine relies on forward velocity to compress inlet air for the combustion process. In order to operate efficiently, a ramjet must be traveling at several times the speed of sound. At the present time, there is little demand for commercial or military transport in this flight regime, so the primary application for ramjets is in military single-use missiles. There are a number of systems around the world in various stages of development ranging from exploratory research to production. The scramjet engine is a close cousin, with the differentiating factor being the combustion process speed—subsonic for a ramjet and supersonic for a scramjet.
Industry:Science
The pressurized delivery of a metered amount of fuel into the intake airflow or combustion chambers of an internal combustion engine. Metering of the fuel charge may be performed mechanically or electronically. In a diesel engine, the fuel is injected directly into the combustion chamber (direct injection) or into a smaller connected auxiliary chamber (indirect injection). In the spark-ignition engine, the fuel is injected into the air before it enters the combustion chamber by spraying the fuel into the airstream passing through the throttle body (throttle-body injection) or into the air flowing through the port to the intake valve (port injection).
Industry:Science
The pure and applied science that is concerned with botany and management of crop and ornamental plants for utilization by humankind. Crop plants include those grown and used directly for food, feed, or fiber, such as cereal grains, soybeans, citrus, and cotton; those converted biologically to products of utility, such as forage plants, hops, and mulberry; and those used for medicinal or special products, such as digitalis, opium poppy, coffee, and cinnamon. In addition, many plant products such as crambe oil and rubber are used in industry where synthetic products have not been satisfactory. Ornamental plants are cultured for their esthetic value.
Industry:Science
The study of situations where, in a general sense, cause and effect are not proportional to each other; or more precisely, if the measure of what is considered to be the cause is doubled, the measure of its effect is not simply twice as large. Many examples have been known in physics for a long time, and they seemed well understood. Over the last few decades, however, physicists have noticed that this lack of proportionality in some of the basic laws of physics often leads to unexpected complications, if not to outright contradictions. Thus, the term nonlinear physics refers more narrowly to these developments in the understanding of physical reality.
Industry:Science
The radial distance from a rotation axis at which the mass of an object could be concentrated without altering the moment of inertia of the body about that axis. If the mass <i>M</i> of the body were actually concentrated at a distance <i>k</i> from the axis, the moment of inertia about that axis would be <i>Mk</i><sup>2</sup>. If this quantity is equal to the actual moment of inertia <i>I</i> about the rotation axis, then <i>k</i> is the radius of gyration given by <i>k</i> = √<span style="border-top:1px solid black;"><i>I</i>/<i>M</i></span>. The quantity <i>k</i> has dimensions of length and is measured in appropriate units of length such as meters.
Industry:Science
The study of the establishment, spread, and ecological impact of species translocated from one region or continent to another by humans. Biological invasions have gained attention as a tool for basic research, used to study the ecology and evolution of populations and of novel biotic interactions; and as a conservation issue tied to the preservation of biodiversity. The invasion of nonindigenous (also called exotic, alien, or nonnative) species is a serious concern for those charged with managing and protecting natural as well as managed ecosystems. For example, nonindigenous species negativley affect over one-third of the U.S. Endangered Species List.
Industry:Science
The removal of dissolved minerals (including salts) from seawater or brackish water. This may occur naturally as part of the hydrologic cycle, or as an engineered process. Engineered water desalination processes, which produce potable water from seawater or brackish water, have become important because many regions throughout the world suffer from water shortages caused by the uneven distribution of the natural water supply and by human use. The capacity of installed desalination plants around the world at the end of 1966 was 200,000 m<sup>3</sup>/day (53,000,000 gal/day); by 1998, it had increased to 22,700,000 m<sup>3</sup>/day (6000,000,000 gal/day).
Industry:Science
The representation of a wave that does not vary in a sinusoidal manner. Electric circuits containing nonlinear elements, such as iron-core magnetic devices, rectifying devices, and transistors, commonly produce nonsinusoidal currents and voltages. When these are repetitive functions of time, they are called nonsinusoidal periodic electric waves. Oscillograms, tabulated data, and sometimes mathematical functions for segments of such waves are often used to describe the variation through one cycle. The term cycle corresponds to 2π electrical radians and covers the period, which is the time interval <i>T</i> in seconds in which the wave repeats itself.
Industry:Science
