- 行业: Printing & publishing
- Number of terms: 178089
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- 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.
Probably the best known of the alcohols, ethyl alcohol, formula CH<sub>3</sub>CH<sub>2</sub>OH, is also called alcohol, ethanol, grain alcohol, industrial alcohol, fermentation alcohol, cologne spirits, ethyl hydroxide, and methylcarbinol. Pure ethyl alcohol is a colorless, limpid, volatile liquid which is flammable and toxic and has a pungent taste. It boils at 78.4°C (173°F) and melts at −112.3°C (−170.1°F), has a specific gravity of 0.7851 at 20°C (68°F), and is soluble in water and most organic liquids. It is one of the most important industrial organic chemicals. Ethyl alcohol is produced by chemical synthesis and by fermentation or biosynthetic processes.
Industry:Science
Recent work in the Mojave Desert of southern California increases understanding of sediment transport by wind in response to climatic changes in arid regions. Studies of the geomorphology and sediments of sand dunes have been combined with luminescence dating of these deposits to develop a chronology of periods of eolian deposition. A comparison of this chronology with the proxy record of the region's climatic change that has been derived from lake and alluvial-fan deposits, paleobotanical studies, and tree rings aids in understanding the conditions that favor eolian sediment accumulation there and in developing a process-response model for such eolian systems.
Industry:Science
Multicomponent couplings (MCCs), also called multicomponent reactions (MCRs), are special types of synthetic organic reactions in which three or more starting materials react to generate a single product. The product forms either sequentially in a tandem or domino fashion, or all at once. All or most of the atoms of those starting materials are incorporated into the newly formed product. MCCs are highly convergent, as a new molecule is formed from several starting molecules in one operation. One-component and two-component reactions are divergent, and complex molecules have to be synthesized by many sequential reaction steps, each involving one or two components.
Industry:Science
Production of a film of material often on a heated surface and in a vacuum. Physical vapor deposition technology is used in a variety of applications. Coatings are produced from a wide range of materials, including metals, alloys, compound, cermets, and composites. The two basic processes for physical vapor deposition are evaporation deposition and sputter deposition. In evaporation, thermal energy converts a solid or liquid target material to the vapor phase. In sputtering, the target is biased to a negative potential and bombarded by positive ions of the working gas from the plasma, which knock out the target atoms and convert them to vapor by momentum transfer.
Industry:Science
Individual organisms within a species vary morphologically (size, shape, color), physiologically, behaviorally, and demographically. Some humans are tall, some are short; some are blond, some are brunette. Some trees in a species grow tall with narrow, compact crowns; others are more stocky with dense, wide-radius crowns. Some dogs in a litter are more active and aggressive than some of the others. These variations are of genetic interest in terms of whether they are heritable. They are of ecological and evolutionary interest in terms of the environmental influences that shape them, both nongenetically in the present and genetically over an evolutionary time scale.
Industry:Science
Interest in fish swimming stems not only from the agility of certain species of fish and mammals in water but also from the fact that fish propulsion is so different from that of ships and submarines. Whereas these craft are designed to avoid unsteady motions as much as possible, fish employ rhythmic motions as their principal mode for swimming and turning. Recent studies have demonstrated that fish exploit unsteadiness to generate large, short-duration forces; coordinate the rhythmic unsteady body and tail motion to minimize the energy required for steady propulsion; and coordinate the motion of the body and tail to minimize the expended energy during maneuvering.
Industry:Science
Lysosome-related organelles are a diverse group of specialized intracellular membrane-enclosed compartments that exhibit certain characteristics of lysosomes (major membrane-bound digestive structures involved in intracellular degradation of biological materials in all eukaryotic cells). Lysosomes contain a unique collection of digestive enzymes and membrane proteins, maintain an acidic luminal pH, and receive ingested as well as newly synthesized materials. Although most of these features are shared to a certain extent by all lysosome-related organelles, each of these organelles also contains cell-type–specific components responsible for its specialized functions.
Industry:Science
Normal development of all organs and maintenance of their physiological functions are critically dependent on vascularization. The quantity and quality of the vascularization are tightly controlled to meet the specific anatomical and physiological requirements of each organ. In fine-tuning the vascularization, blood vessels and their corresponding organ exchange chemical signals to control morphogenesis and homeostasis. Failure or malfunctioning of this “crosstalk” between the blood vessels and the organ can lead to disease conditions. Therefore, it is important to understand the molecular nature of this crosstalk, which underlies the development of future therapies.
Industry:Science
Mechanical sizes of mating parts such that, when assembled, they are accurately positioned in relation to each other. Locational fits are intended only to determine the orientation of the parts. For normally stationary parts that require ease of assembly or disassembly, for parts that fit snugly, and for parts that move yet fit closely as in spigots, slight clearance is provided between parts. Where accuracy of location is important, transition fits are used. In these fits the holes and shafts are normally nearly the same diameter. For greater accuracy of location, the shafts are made slightly larger than the holes; such fits are termed location interference fits.
Industry:Science
Learning based upon the consequences of behavior. For example, a rat may learn to press a lever when this action produces food. Instrumental or operant behavior is the behavior by which an organism changes its environment. The particular instances of behavior that produce consequences are called responses. Classes of responses having characteristic consequences are called operant classes; responses in an operant class operate on (act upon) the environment. For example, a rat's lever-press responses may include pressing with the left or with the right paw, sitting on the lever, and so on, but all these taken together constitute the operant class called lever pressing.
Industry:Science
