- 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.
Any alteration of hearing capacity. Hearing impairment can be of various degrees, including mild, moderate, severe, profound, or total. The degree of impairment typically is categorized by the loss of hearing sensitivity, that is, how loud sounds must be for a listener to hear them. The degree of impairment can refer either to the loss of hearing sensitivity for individual pitches of sounds for each ear separately or to an overall loss of hearing sensitivity for both ears. Hearing impairment is further categorized as unilateral if present in only one ear and as bilateral if present in both ears.
Industry:Science
Biological, or bacteriological, pollution in a stream indicated by the presence of the coliform group of organisms. While nonpathogenic itself, this group is a measure of the potential presence of contaminating organisms. Because of temperature, food supply, and predators, the environment provided by natural bodies of water is not favorable to the growth of pathogenic and coliform organisms. Physical factors, such as flocculation and sedimentation, also help remove bacteria. Any combination of these factors provides the basis for the biological self-purification capacity of natural water bodies.
Industry:Science
Chemical nomenclature expresses the structure of compounds. Various nomenclature systems are used. Hence, a compound may have several acceptable names. Which name is preferred depends on the context. Each nomenclature type has several dialects due to different languages or other national variations. Even though the language of science communication is increasingly English, there are still differences such as aluminium versus aluminum and sulfur versus sulphur for the names of elements, icosane versus eicosane for the C<sub>20</sub> hydrocarbon chain, and but-2-ene versus 2-butene for the locant.
Industry:Science
General rules concerning the transitions which may occur between the states of a quantum-mechanical physical system. They derive in almost all cases from the symmetry properties of the states and of the interaction which gives rise to the transitions. The system may have a classical (nonquantum) counterpart, and in this case the selection rules may often be related to the classical conserved quantities. A first use of selection rules is in determining the symmetry classes of the states, but in a great variety of ways they may yield other information about the system and the conservation laws.
Industry:Science
An oscillator that does not obey Hooke's law. This law is an idealized expression that assumes that a system displaced from equilibrium responds with a restoring force whose magnitude is proportional to the displacement. The use of Hooke's law results in a linear equation of motion that fails to describe many properties of the real world. Nature demonstrates two fundamentally different forms of nonlinearity, which may be called elastic anharmonicity and damping anharmonicity. To understand their difference, and the nature of a harmonic oscillator, it is necessary to understand potential functions.
Industry:Science
Construction of a mathematical model of the climate system of the Earth capable of simulating its behavior under present and altered conditions. The Earth's climate is continually changing over time scales ranging from hundreds of years to a few years. Since the climate is determined by the laws of classical physics, it should be possible in principle to construct such a model. The advent of a worldwide weather-observing system capable of gathering data for validation and the development and widespread routine use of digital computers have made this undertaking possible, starting in the mid-1970s.
Industry:Science
Calcite (CaCO<sub>3</sub>), the most common simple salt at the Earth's surface, is present in almost all geological environments. Depending on the nature and extent of impurities, calcite is usually white or light in color, and its physical and optical properties make it attractive when polished. It is not a very hard mineral (3 out of maximal 10 on the Mohs hardness scale), so rocks composed of calcite are relatively easy to quarry, carve, and polish. Calcite-bearing rocks have, therefore, been favored as building stones for centuries, and include marble, limestone, and calcite-cemented sandstone.
Industry:Science
Disorders affecting skeletal (voluntary) muscle. Every skeletal muscle consists of a large number of muscle fibers, each of which is a multinucleated cell containing the usual types of cellular inclusions, but also containing the myofibrils, which are the actual contractile elements. The myofibrils have a banded structure which gives the muscle fiber its characteristic striated appearance on histologic examination. Muscle fibers have been separated into two main groups based on their histochemical reaction: type 1 fibers, which are rich in mitochondria and oxidative activity, and type 2 fibers.
Industry:Science
Asymmetrical digital subscriber line is a high-throughput transmission system built upon the conventional telephone subscriber loop infrastructure originally designed for the “plain old telephone service” (POTS). Via a telephone subscriber loop, ADSL connects a user to a central office. The transmission throughput of ADSL is asymmetrical. In the downstream direction (from a central office to a user), the transmission throughput of ADSL is between 1 and 8 Mbps (megabits per second), while in the upstream direction (from a user to a central office) it is between 100 and 800 kbps (kilobits per second).
Industry:Science
At the center of every atom lies a small, dense nucleus, which carries more than 99.97% of the atomic mass in less than 10<sup>-12</sup> of its volume. The nucleus is a tightly bound system of protons and neutrons which is held together by strong forces that are not normally perceptible in nature because of their extremely short range. The small size, strong forces, and many particles in the nucleus result in a highly complex and unique quantal system that at present defies exact analysis. The study of the nucleus and the forces that hold it together constitute the field of nuclear structure physics.
Industry:Science
