- 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 technique for taking x-ray pictures of cells, tissues, or sometimes the whole animal or plant, if it is a small one. Soft x-rays, those with low penetrating power and relatively long wavelengths, are required for this type of picture. The best pictures are obtained when the tissues contain deposits of metallic elements which have a high absorption capacity for x-rays.
Industry:Science
The modern study of friction may be said to have begun in the fifteenth century, when Leonardo da Vinci deduced the laws governing the motion of a rectangular block sliding over a planar surface. However, Guillaume Amontons is credited with the first published account of the classic friction laws, which in 1699 described his observations of solid surfaces in sliding contact.
Industry:Science
The test of a hypothesis under controlled conditions. The experiment is one of the distinctive tools of the scientist. It enables the scientist to put questions to nature and receive answers. These answers lead to new problems whose solutions require more complex experiments (seeking smaller differences), improved techniques, detailed plans, and better analysis of results.
Industry:Science
The National Aeronautics and Space Administration (NASA) and other organizations are pursuing ideas that are not merely refinements of existing technology, but possible breakthroughs that will result in more efficient rockets, unlimited power production, and greatly reduced cost. Other ideas, like inventions of the past, such as the transistor, may lead to unexpected results.
Industry:Science
The process or technique of reducing electrical interference to acceptable levels or to situations having no adverse effect. Suppression techniques may be applied to the interference source, the intervening path, the victim or receptor, or any combination. Normal strategy for interference control is to first suppress the source, if possible, since it may disturb many victims.
Industry:Science
The severe wasting syndrome that accompanies such diseases as cancer, infection, or parasitic infestation. Occasionally, it is also observed in noninvasive conditions, such as severe cardiac failure. The causes of cachexia are only partially understood. However, it is clear that most cachexia is caused by diminished consumption of nutrients rather than by a hypermetabolic state.
Industry:Science
The simplest trihydric alcohol, with the formula CH<sub>2</sub>OHCHOHCH<sub>2</sub>OH. The name glycerol is preferred for the pure chemical, but the commercial product is usually called glycerin. It is widely distributed in nature in the form of its esters, called glycerides. The glycerides are the principal constituents of the class of natural products known as fats and oils.
Industry:Science
The occurrence of cases of disease in excess of what is usually expected for a given period of time. Epidemics are commonly thought to involve outbreaks of acute infectious disease, such as measles, polio, or streptococcal sore throat. More recently, other types of health-related events such as homicide, drownings, and even hysteria have been considered to occur as “epidemics.”
Industry:Science
The plausible pathways by which the molecular precursors of life may have formed on the primitive Earth. Amino acids, the nitrogenous bases, and ribose phosphates can be prepared under conditions that might have prevailed on the primitive Earth. The linking together of amino acids to form polypeptides, and of nucleotides to form polynucleotides, has in principle been established.
Industry:Science
The process whereby a plant sheds one of its parts. Leaves, flowers, seeds, and fruits are parts commonly abscised. Almost any plant part, such as very small buds and bracts to branches several inches in diameter, and scales or sheets of bark, may be abscised by some species. However, other species, including many annual plants, may show little abscission, especially of leaves.
Industry:Science
