- 行业: Printing & publishing
- Number of terms: 178089
- Number of blossaries: 0
- 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 Moon had long been thought to be dry and barren. Then, the discovery of ice on the planet Mercury raised the possibility that ice may exist in permanently shadowed regions of the Moon's poles. The <i>Clementine</i> spacecraft used radar observations of the lunar south pole in 1994 to detect water, but those data were not conclusive. The <i>Lunar Prospector</i> returned data in 1998 that proved more conclusively that water ice deposits exist on the Moon. Such deposits would be significant for any future human exploration and development of the Moon.
Industry:Science
The process used to convert a three-dimensional image intensity into a one-dimensional television signal waveform. The image information captured by a television camera conveys color intensity (in terms of red, green, and blue primary colors) at each spatial location, with horizontal and vertical coordinates, and at each time instance. Thus, the image intensity is multidimensional, since it involves two spatial dimensions and time. It needs to be converted to a unidimensional signal so that processing, storage, communications, and display can take place.
Industry:Science
The study of insects that have a direct influence on humanity. Though this includes beneficial as well as harmful species, most attention is devoted to the latter and how they become pests and are controlled. The emphasis on managing harmful insects reflects the immediacy and seriousness of pest problems, particularly the destruction of agricultural products and the transmission of disease. These are highly visible problems, whereas the benefits gained from useful insects are, in most cases, not so clearly understood or so well documented economically.
Industry:Science
The middle era of the three major divisions of the Phanerozoic Eon (Paleozoic, Mesozoic, and Cenozoic eras) of geologic time, encompassing an interval from 251 to 65 million years ago (Ma) based on various isotopic-age dates. The Mesozoic Era is known also as the Age of the Dinosaurs and the interval of middle life. The Mesozoic Erathem (the largest recognized time-stratigraphic unit) encompasses all sedimentary rocks, body and trace fossils of organisms preserved, metamorphic rocks, and intrusive and extrusive igneous rocks formed during the Mesozoic Era.
Industry:Science
The third planet from the Sun and the largest of the four inner, or terrestrial, planets. The Sun is an average-sized, middle-aged star situated toward the outer edge of one of the spiral arms of the Milky Way Galaxy. So far as is known, Earth is unique in the solar system in having life. Whether life exists in the universe beyond the solar system is unknown. However, recent discoveries have proven that there are planets in orbit around many nearby stars, so there are possibly billions of Earth-like planets in the universe where life may yet be discovered.
Industry:Science
The property of compounds (isomers) which have the same molecular formula but different physical and chemical properties. The difference in properties is caused by a difference in molecular structure (that is, molecular architecture). A typical example is dimethyl ether, CH<sub>3</sub>OCH<sub>3</sub>, a chemically quite inert gas which condenses at −24°C (−11°F), and ethyl alcohol, CH<sub>3</sub>CH<sub>2</sub>OH, a liquid of substantial chemical reactivity which boils at 78°C (172°F); both compounds have the molecular formula C<sub>2</sub>H<sub>6</sub>O.
Industry:Science
The set of ideas that prescribe the manufacture and use of implements before written history. Technology is the principal means through which the human species has succeeded in occupying most of the world. The prehistoric record documents that for over 2 million years the human lineage has been making and using implements. Archeologists tend to use the term “artifact” for any material that was modified by ancient humans, whether this material was used or not, and the term “tool” for any material that was used by ancient humans, whether it was modified or not.
Industry:Science
The name given to the type of carved gemstone in which the figure is engraved into the surface of the stone, rather than left in relief by cutting away the background, as in a cameo. Intaglios are almost as old as recorded history, for this type of carving was popular in ancient Egypt in the form of cylinders. The cylinder, as well as the more familiar form of intaglio, was popular for impressing seals on sealing wax. Intaglios have been carved in a variety of gem materials, including emerald, crystalline quartz, hematite, and the various forms of chalcedony.
Industry:Science
The study of the light-induced behavior of various metal compounds. The physical and chemical properties of substances are generally altered by the absorption of light. Typical metal compounds have a characteristic number (coordination number) of molecules or ions (ligands) directly bonded to the metal center. Many of these compounds are colored, and it is possible that some metal compounds could mediate the transformation of solar radiation into useful chemical or electrical energy, or that they might scatter light in such a way that its frequency is increased.
Industry:Science
The process by which animal cells internalize particulate material (such as cellular debris and microorganisms), macromolecules (such as proteins and complex sugars), and low-molecular-weight molecules (such as vitamins and simple sugars). The size difference among these different nutrient sources requires cells to develop a hierarchical plan for endocytosis. Thus, cells engage in at least three different types of endocytosis: phagocytosis where cells engulf particulate material, receptor-mediated-endocytosis of macromolecules, and potocytosis of small molecules.
Industry:Science
