- 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.
In an information system the goal of computer security is to provide computer-system components that exhibit accuracy, availability, and confidentiality. Such computer systems must be developed, implemented, and operated with a combination of managerial, operational, and technical components. A computer system cannot provide adequate service if any component is inappropriate to the user requirements.
Industry:Science
Any molecule or atom that possesses one unpaired electron. This definition does not include transition- metal ions or molecules with more than one unpaired electron, such as dioxygen (O<sub>2</sub>). Most chemists accept this definition; however, some spectroscopists employ a looser definition, in which they define any transient species (atom, molecule, or ion) in the gas phase to be a free radical.
Industry:Science
Compositional variation of a crystalline substance due to substitution or omission of various atomic constituents within a crystal structure. Solid solutions can be classified as substitutional, interstitial, or omissional. They may also be categorized by the nature of their thermodynamic properties, such as enthalpy, entropy, and free energy (for example ideal, nonideal, and regular solid solutions).
Industry:Science
Fine-grained sediment and sedimentary rock dominantly composed of the microscopic remains of the unicellular, silica-secreting plankton diatoms and radiolarians. Minor constituents include extremely small shards of sponge spicules and other microorganisms such as silicoflagellates. Siliceous sedimentary rock sequences are often highly porous and can form excellent petroleum source and reservoir rocks.
Industry:Science
Functional magnetic resonance imaging is a noninvasive technique for measuring and mapping neural activity in the brain. In a typical fMRI experiment, volunteers lie inside an MRI scanner and perform a cognitive task. During the task, a series of three-dimensional images are taken of the participant's brain. Typically, these images have a spatial resolution of 3–4 mm and a temporal resolution of 1–4 s.
Industry:Science
Any tree of the genus <i>Populus</i>, family Salicaceae, marked by simple, alternate leaves that are usually broader than those of the willow, the other American representative of this family. Poplars have scaly buds, bitter bark, flowers and fruit in catkins, and a five-angled pith. The Janka hardness for poplar is 432 lb-force (196 kg-force); its density is 29 lb/ft<sup>3</sup> (465 kg/m<sup>3</sup>).
Industry:Science
An unmarked group of the fish subclass Neopterygii consisting of several fossil orders (see Phylogeny below) and the extant orders, Lepisosteiformes and Amiiformes. The holosteans are descended from the older Chondrostei and in turn are ancestral to the great mass of modern bony fishes, the Teleostei. It is not certain whether holosteans evolved from a single stock or multiple stocks of the Chondrostei.
Industry:Science
Coevolution is a term used to describe the mutual changes in two or more species, usually one following the other, that affect their interactions. Flowering plants (angiosperms) and their pollinators are often used as the classic example of this evolutionary phenomenon. The plant and the pollinator place evolutionary pressure on each other for changes in morphology, physiology, or habits that benefit both.
Industry:Science
Contraction of multiple microbial infections. Such infections, which can occur in humans and animals, may be sequential or concurrent. For example, the initial infection may predispose the host to subsequent microbial infections, or the initial infecting microorganism may induce a state of immunosuppression. Concurrent infections are caused by various combinations of viruses, bacteria, fungi, and parasites.
Industry:Science
Experiments in which a beam of incident electrons, atoms, or molecules is deflected by collisions with an atom or molecule. Such experiments provide tests of the theory of scattering as well as information about atomic and molecular forces. Scattering experiments can be designed to simulate conditions in planetary atmospheres, electrical discharges, gas lasers, fusion reactors, stars, and planetary nebulae.
Industry:Science
