- 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.
Environmental engineering intersects both the structure and function of environmental systems (natural and human-made) and the myriad issues that arise from human intervention in those systems. Traditionally, environmental engineers have dealt with problems such as the management of pond and stream quality, contamination from industrial or agricultural waste, fish kills, and the development of effective mitigation strategies for air, soil, and water pollution, to name some. For environmental engineers, these problems are not just technically complex, but also must take into account the social demand for the resources involved, as well as zoning, regulatory, and legal constraints.
Industry:Science
Genomics is the study of all of the genetic material in an organism. Metagenomics is the analysis of many genomes simultaneously, usually from a group of microorganisms (bacteria and archaea as well as eukarytoic microorganisms: fungi, algae, and protozoa). It involves extracting deoxyribonucleic acid (DNA) from a collection of microorganisms, cloning the DNA into a suitable vector, and analyzing the resulting clones. Metagenomic analysis has led to the discovery of new genes, enzymes, and antibiotics. The collective microbial metagenome of the world represents one of the greatest untapped resources for biotechnology as well as for understanding the workings of the natural world.
Industry:Science
In broad terms, the interaction between a material and its environment that results in a degradation of the physical, mechanical, or even esthetic properties of that material. More specifically, corrosion is usually associated with the oxidation and/or dissolution of a metal, oxide, or semiconductor. For example, immersing a piece of iron in a moderately acidic solution is a typical example of corrosion; the vigorous reaction is the electrochemical oxidation of iron from the zero valence state to divalent ferrous ions (Fe<sup>+2</sup>) dissolved in the water. Corrosion encompasses principles from diverse fields such as electrochemistry, metallurgy, physics, chemistry, and biology.
Industry:Science
Diabetes mellitus is a disorder characterized by the presence of excess glucose in the blood and tissues of the body. The word “diabetes” comes from the Greek for “a siphon,” referring to the discharge of an excess quantity of urine; the word “mellitus” comes from Latin for “honey.” Thus, diabetes mellitus refers to the passage of large amounts of sweet urine. Diabetes is a disease in which the pancreatic hormone insulin is either not produced or not properly used by the body. It is characterized as a chronic metabolic disorder with hyperglycemia (high blood sugar) and abnormal energy metabolism. Diabetes is caused by a combination of genetic, autoimmune, and environmental factors.
Industry:Science
In an aircraft, the combination of outside fairing panels that provide the aerodynamic lifting surfaces and the inside supporting members that transmit the lifting force to the fuselage. The structure of a wing is an integration of the environment external to the vehicle wing, the aerodynamic shape of the wing, and the proposed use of the vehicle. The interaction of these three aspects of design leads to the selection of material, to the general structural layout, and, finally, to the detailed choice of structural shapes, material thickness, joints, and attachments. The result is a structural framework covered with a metal skin that also contributes to the load-carrying function.
Industry:Science
Gamma-ray astronomy, a new window for viewing the universe, is providing important opportunities for testing current understanding of the evolution of stars and galaxies. Recently, using a gamma-ray telescope in orbit around the Earth, scientists discovered a cloud of positrons—the antimatter counterpart of the electron—in a part of the Milky Way Galaxy where there are no known sources of positrons. This discovery is causing scientists to rethink the theories for the production and transport of positrons in the Milky Way Galaxy, and may provide clues to improve understanding of the creation of elements in stars and the history of stellar evolution in the central region of the Galaxy.
Industry:Science
Bioinformatics tools aim to exploit the potential of computers to model and understand complex biological systems and phenomena. Initially, the approach used by most bioinformatics tools was more analytical and engineering-like, separating DNA from all other factors and isolating the sequence for a better understanding of the DNA structure. Today, the genomics approach combines various elements, while taking into consideration their relationships as well as evolutionary aspects in space and time. A more global approach is being developed that accounts for biomolecules in their environment, including intra- and intermolecular interactions at the cell, tissue, organ, and organism level.
Industry:Science
Cadmium resembles zinc in its chemical properties, and its occurrence for commercial purposes is with zinc ores. A relatively rare element in the Earth's crust, cadmium ranks in abundance between mercury and silver. Most cadmium occurs in solid solution in the zinc sulfide mineral called sphalerite. Although cadmium may be recovered from some lead and copper ores, it is associated with the zinc which is also found in these ores. Although a few zinc concentrates contain as much as 1–2% cadmium, typical content ranges from 0.06 to 0.5%. Since cadmium is entirely a by-product metal, the supply available is closely aligned with zinc production, averaging about 0.4% of zinc production.
Industry:Science
As one of the world's most abundant and accessible renewable resources, wood has been of immense utility and value to humans. Wood can be durable (resistant to decay and insect attack) and long-lasting, and has often survived as fossil or archeological material; it is therefore one of the major sources of information on past vegetation, climate, and civilization. When wood is burned to form charcoal, the carbonized product is completely inert, but retains most of the anatomical characteristics of the original wood and can similarly be studied. Charcoal with good preservation is known from at least as far back as the Carboniferous Period, when conifers first appeared in the fossil record.
Industry:Science
Deterioration of plant products after harvest is a major limitation on food resources worldwide. Estimates of losses for all food production range from 10 to 30%, but much greater losses are common in developing countries. Enough food is lost annually to feed a population equal to that of the United States. Negative effects are not confined to economic losses and hunger. Since many of the pathogens responsible for deterioration of foodstuffs also produce substances highly toxic to humans and livestock, food safety is an issue as well. The impact of postharvest plant pathogens in food deterioration and food safety has become a top-ranking issue for plant pathologists in the United States.
Industry:Science
