- 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.
Japanese food processors were the first to commercially preserve foods by high pressure. In 1990, these food products included commercially sterile (shelf-stable) jam, yogurt, and pourable salad dressing in 125-g (4.4–oz), hermetically sealed plastic cups. These products had a pH below 4.5 (acid food) to inhibit spore germination, and were treated with pressures in the range of 400 megapascals (60,000 lb/in.<sup>2</sup>). This treatment was sufficient to inactivate vegetative forms of yeasts, molds, and bacteria when the product was held at pressure for up to 20 min at room temperature. Because high isostatic pressure does not break covalent bonds, the flavors, colors, and nutritive contents of these foods were not changed by the process.
Industry:Science
Inflammation of the peritoneum, the serous membrane which lines the abdominal cavity and surrounds most of the abdominal organs. The condition may be caused by infectious organisms or foreign substances introduced into the abdominal cavity. The small amount of serous fluid normally present as a lubricant acts as an excellent culture medium for bacterial growth and also as a means of spreading invading materials. The source of such substances or organisms is commonly a gastrointestinal inflammation, especially if perforation has occurred. Appendicitis, peptic ulcer, cancer of the bowel, gallbladder disease, and dysentery are common sources of infection that may produce peritonitis, as well as blood-borne forms of tuberculosis and pneumonia.
Industry:Science
Natural gas, usually consisting primarily of methane, that has been processed into liquid form. It is increasingly used for transporting large quantities of natural gas across oceans with specially designed ships. The properties of LNG are those of liquid methane, slightly modified by minor constituents. Natural gas must be cooled to cryogenic temperatures to be liquefied and then stored in well-insulated containers. More than 600 ft<sup>3</sup> (17 m<sup>3</sup>) of natural gas condense into 1 ft<sup>3</sup> (0.028 m<sup>3</sup>) of liquid at about −258°F (−161°C). In this form, the gas can be conveniently stored and transported. At the receiving end, LNG is revaporized and then compressed and put into the natural gas distribution system.
Industry:Science
Proteins are biological macromolecules that carry out functions crucial for living organisms. Proteins make thermodynamically possible and kinetically achievable all biochemical processes and in this way regulate and coordinate the birth, growth, nutrition, excretion, division, reproduction, and, eventually, death of the organism. Proteins are fundamental elements in the replication and transfer of the genetic information stored in DNA and RNA molecules, thus ensuring the survival of the species. Proteins are the main structural element supporting the shapes and the morphological complexity of the living world. Proteins transduct the chemical and neuron signals needed for the adjustment of the organisms to their ever-changing environments.
Industry:Science
Solid solutions of one or more metals in copper. Many metals, although not all, alloy with copper to form solid solutions. Some insoluble metals and nonmetals are intentionally added to copper alloy to enhance certain characteristics. Copper alloys form a group of materials of major commercial importance because they are characterized by such useful mechanical properties as high ductility and formability and excellent corrosion resistance. Copper alloys are easily joined by soldering and brazing. Like gold alloys, copper alloys have decorative red, pink, yellow, and white colors. Copper has the second highest electrical and thermal conductivity of any metal. All these factors make copper alloys suitable for a wide variety of products.
Industry:Science
Smoke clouds used for screening purposes. Traditionally, smoke is defined as a visible aerosol (that is, a suspension of solid or liquid particles in a gas) resulting from incomplete combustion. Military screening smokes are a special case. They are generally composed of liquid droplets with a mean particle size around 1 micrometer, and produce a bright white cloud of long duration. The effectiveness of these aerosols results from their size and composition. The individual aerosol particles efficiently scatter light in all directions. This scattering, known as Mie scattering, reduces the intensity of any light passing through the cloud and produces considerable glare, the white cloud effect, to reduce the target-to-background contrast.
Industry:Science
One of the more highly specialized orders of the subphylum (or class) Crustacea. This order includes the shrimps, lobsters, hermit crabs, and true crabs. The order is so diverse that satisfactory definition is difficult, but a few characters are common to nearly all decapods. The most obvious is a head shield, or carapace, which covers and coalesces with all of the thoracic somites and which overhangs the gills on each side. The first three of the eight pairs of thoracic appendages are specialized as maxillipeds and closely associated with the true mouthparts. The last five pairs are walking legs or chelae (claws); this feature is the basis of the name Decapoda (= ten feet). The gills are usually well developed and arranged in several series.
Industry:Science
Paired, air-filled respiratory sacs, usually in the anterior or anteroventral part of the trunk of most tetrapods. Many elongated tetrapods, such as snakes, possess a simple lung, and one group of salamanders have lost their lungs completely with gas exchange occurring through the skin of the back. Lungs originated, however, early in fish evolution, presumably in the placoderms, as an adaptation to obtain atmospheric oxygen required for life in stagnant, oxygen-depleted waters. Lungs are still found in a few living species of fresh-water fishes (such as lungfish) in which they may fuse to form a single organ and may come to lie well dorsally in the body; in many fishes the lungs have evolved into the swim bladder, a dorsal hydrostatic organ.
Industry:Science
Since the discovery of human fossils at the Sierra de Atapuerca in northern Spain in 1979, there has been an extensive series of finds at several sites within this complex of caves. Overall, these human fossils are important finds that have contributed to clarifying the patterns and processes of human evolution in Europe and, by extension, to understanding the evolution of the genus <i>Homo</i>. Many questions have been posed and partially solved by the study of the Atapuerca finds: When did the first humans arrive in Europe? What was their genetic origin? How many waves of immigrants reached this continent? What was the origin of the Neanderthals? Thus, the Atapuerca finds have proven to be of key importance for the study of human evolution.
Industry:Science
One of the two principal orders of Palaeozoic corals, the other being the Tabulata. Rugose corals first appeared in the Middle Ordovician. The small number of known Cambrian corals include at least one species with superficial similarity, but it is not considered a direct ancestor of the Rugosa. The Rugosans diversified steadily during the Early and Middle Paleozoic to reach their greatest diversity in the Middle Devonian. A series of extinction events in the Late Devonian almost resulted in the disappearance of the group, but a handful of survivors rediversified to almost match peak diversity by the Late Mississippian. Thereafter, the group declined, slowly at first but more rapidly in the Permian, and became extinct at the end of the Permian.
Industry:Science
