- 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.
The apparent, visible surface of the Sun. The photosphere is a gaseous atmospheric layer a few hundred miles deep with a diameter of 864,000 mi (1,391,000 km; usually considered the diameter of the Sun) and an average temperature of approximately 5800 K (10,500°F). Radiation emitted from the photosphere accounts for most of the solar energy flux at the Earth. The solar photosphere provides a natural laboratory for the study of dynamical and magnetic processes in a hot, highly ionized gas.
Industry:Science
The death and disappearance of a species. The fossil record shows that extinctions have been frequent in the history of life. Mass extinctions refer to the loss of a large number of species in a relatively short period of time. Episodes of mass extinction occur at times of rapid global environmental change; five such events are known from the fossil record of the past 600 million years. Human activity is causing extinctions on a scale comparable to the mass extinctions in the fossil record.
Industry:Science
The human brain is an organ that possesses a vast potential for adaptation and change in response to experience. This mutability, which is referred to as brain plasticity, enables humans to solve new problems, learn, and forget. Research reveals two important insights into brain plasticity: (1) Plasticity is influenced by a surprisingly large number of life experiences. (2) The brain retains plasticity into senescence, although the developing brain is likely to have greater capacity for change.
Industry:Science
The condition for which the impedance of a given electric, acoustic, or dynamic system is very high, approaching infinity. In an electric circuit consisting of a capacitor and a coil in parallel, antiresonance occurs when the alternating-current line voltage and the resultant current are in phase. Under these conditions the line current is very small because of the high impedance of the parallel circuit at antiresonance. The branch currents are almost equal in magnitude and opposite in phase.
Industry:Science
The increased frequency of newly discovered types of inherited cancers has influenced researchers to focus on determining the origin, location, and mechanisms that create errors (mutations) within the deoxyribonucleic acid (DNA) replication sequences of certain genes. This article discusses how the mismatching of certain base-pair sequences leads to the induction of several types of colon cancer, and the genetic mutations which are believed to be responsible for the production of breast cancers.
Industry:Science
The determination of the magnitude of the normal force applied by a fluid to a unit area. Pressure measurements are generally classified as absolute pressure, gauge pressure, or differential pressure. Absolute pressure is the pressure referenced to perfect vacuum, which by definition has zero pressure. Gauge pressure is the difference between an absolute pressure and the pressure of the atmosphere. Differential pressure is the difference between any two pressures, neither of which is atmospheric.
Industry:Science
The genes, or deoxyribonucleic acid (DNA), in bacterial and eukaryotic cells are transcribed into ribonucleic acid (RNA). Messenger RNA (mRNA) serves as a template for the translation of amino acid building blocks into proteins. This flow of genetic information from the gene through RNA to the protein has been called the central dogma of molecular biology. The discovery of processes that change the informational content of RNA (RNA editing) came as a considerable surprise to molecular biologists.
Industry:Science
The branch of engineering that deals with the generation, transmission, and utilization of heat and mechanical power, and with the production of tools and machines. This distinction begins in college where, after 1 year of common engineering studies, a person can be identified as a student of mechanical engineering. After college, mechanical engineers may enter many industries. Common areas of industrial employment for mechanical engineers are private electric power and machinery manufacturing.
Industry:Science
The dried, nearly ripe fruit (berries) of a climbing vine, <i>Piper cubeba</i>, of the pepper family (Piperaceae). This species is native to eastern India and Indomalaysia. The crushed berries are smoked, and the inhaled smoke produces a soothing effect in certain respiratory ailments. Cubebs are used in medicine as a stimulant, expectorant, and diuretic. Medicinal properties of cubeb are due to the presence of a volatile oil which formerly was thought to stimulate healing of mucous membranes.
Industry:Science
The apparent path of the Sun across the sky over the course of a year. The Earth's mean orbit defines the ecliptic plane, and an observer on Earth sees the Sun, traveling in this plane over the course of a year, follow the ecliptic. The orbits of the Moon and planets are at slight angles to the ecliptic, but these objects never appear too far in the sky from the ecliptic, which is often drawn on star maps. The ecliptic was identified by Greek and Babylonian scientists in about the fifth century B.C.
Industry:Science
