- 行业: Printing & publishing
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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 geotroposphere is the region that forms an interface between the Earth's soil and its lower troposphere (the lowest region of the atmosphere). It extends from the lower levels of the soil's vadose (unsaturated) zone, ranging from centimeters to meters deep depending on the depth of the water table, to the upper levels of the mixing zone in the troposphere, ranging from meters to hundreds of meters in altitude depending on the troposphere's vertical temperature profile (atmospheric stability). Emerging research on the geotroposphere considers the production, transport, and transformation of pollutants and nonpollutants in the soil and lower troposphere with an emphasis on the basic physical, chemical, and microbiological processes involved. The objective of this research is to control environmental pollution and, as a result, protect public health.
Industry:Science
That branch of electrical engineering dealing with the transmission and reception of information. Information can be transmitted over many different types of pathways, such as satellite channels, underwater acoustic channels, telephone cables, and fiber-optic links. Characteristically, any communications link is noisy. The receiver never receives the information-bearing waveform as it was originally transmitted. Rather, what is received is, at best, the sum of what was transmitted and noise. In reality, what is more likely to be received is a distorted version of what was transmitted, with noise and perhaps interference. Consequently, the design and implementation of a communications link are dependent upon statistical signal-processing techniques in order to provide the most efficient extraction of the desired information from the received waveform.
Industry:Science
The emergence of the new field of evolutionary developmental biology (“evo-devo”) has been fueled by the discovery that many very distantly related organisms utilize highly similar genes and molecules to establish important structural patterns during their development (defining, for example, the borders between the head, trunk, abdomen, and tail). The goal of research in this field is to determine how evolutionary mechanisms (such as mutation and natural selection) act on embryonic development, generating diversity in the body plans of various organisms but also constraining the possible directions of evolutionary change. Of particular interest are the so-called macroevolutionary transitions, in which a major change in morphology occurred, such as the emergence of limbed vertebrates (tetrapods) from fish or the evolution of birds from dinosaurian ancestors.
Industry:Science
The function of a manufacturing enterprise responsible for the planning, scheduling, and coordination of all production activities. The planning phase involves forecasting demand and translating the demand forecast into a production plan that optimizes the company's objective, which is usually to maximize profit while optimizing customer satisfaction. The twin objectives of maximum profit and maximum customer satisfaction are not always compatible. Sometimes, a highly-valued customer may request a product that must be made under high-cost conditions. During the scheduling phase the production plan is translated into a detailed, sometimes hour-by-hour, schedule of products to be made. During the coordination phase, actual product output is compared with scheduled product output, and this information is used to adjust production plans and production schedules.
Industry:Science
The field at the interface between biochemistry and inorganic chemistry; also known as inorganic biochemistry or metallobiochemistry. This field involves the application of the principles of inorganic chemistry to problems of biology and biochemistry. Because most biological components are organic, that is, they involve the chemistry of carbon compounds, the combination of the prefix bio- and inorganic may appear contradictory. However, organisms require a number of other elements to carry out their basic functions. Many of these elements are present as metal ions that are involved in crucial biological processes such as respiration, metabolism, cell division, muscle contraction, nerve impulse transmission, and gene regulation. The characterization of the interactions between such metal centers and biological components is the heart of bioinorganic chemistry.
Industry:Science
The largest of the membrane-bounded organelles which characterize eukaryotic cells; it is thought of as the control center since it contains the bulk of the cell's genetic information in the form of deoxyribonucleic acid (DNA). The nucleus has two major functions: (1) It is the site of synthesis of ribonucleic acid (RNA), which in turn directs the formation of the protein molecules on which all life depends; and (2) in any cell preparing for division, the nucleus precisely duplicates its DNA for later distribution to cell progeny. The discovery of the nucleus dates back to 1710, when the Dutch microscopist Antonie van Leeuwenhoek noted a centrally located “clear” area in living blood cells of birds and amphibians. However, it was not until 1831 that the British botanist Robert Brown first used the term nucleus and provided a precise morphological description.
Industry:Science
The interaction of electrically conducting fluids with magnetic fields. The fluids can be ionized gases (commonly called plasmas) or liquid metals. Magnetohydrodynamic (MHD) phenomena occur naturally in the Earth's interior, constituting the dynamo that produces the Earth's magnetic field; in the magnetosphere that surrounds the Earth; and in the Sun and throughout astrophysics. In the laboratory, magnetohydrodynamics is important in the magnetic confinement of plasmas in experiments on controlled thermonuclear fusion. Magnetohydrodynamic principles are also used in plasma accelerators for ion thrusters for spacecraft propulsion, for light–ion-beam powered inertial confinement, and for magnetohydrodynamic power generation. Magnetic fields can also be spontaneously generated in inertial confinement experiments, making magnetohydrodynamics relevant in this area.
Industry:Science
The Earth system extends from the uppermost ionosphere to the innermost solid core of the planet and exhibits a wide variety of phenomena, such as climate change, ocean circulation, earthquakes, and geomagnetism. A vast number of parameters and precise models are needed to understand these complicated phenomena, which can significantly affect human society. Until recently, even the state-of-the-art supercomputers were not sufficiently powerful to run realistic numerical models of these phenomena. The Earth Simulator has been designed to provide a powerful tool for investigating these phenomena numerically with unprecedented resolution. It was built in 2002 as a collaborative project of the National Space Development Agency of Japan (NASDA), Japan Atomic Energy Research Institute (JAERI), and Japan Agency for Marine-Earth Science and Technology Center (JAMSTEC).
Industry:Science
The electronic energy band of a crystalline solid which is partially occupied by electrons. The electrons in this energy band can increase their energies by going to higher energy levels within the band when an electric field is applied to accelerate them or when the temperature of the crystal is raised. These electrons are called conduction electrons, as distinct from the electrons in filled energy bands which, as a whole, do not contribute to electrical and thermal conduction. In metallic conductors the conduction electrons correspond to the valence electrons (or a portion of the valence electrons) of the constituent atoms. In semiconductors and insulators at sufficiently low temperatures, the conduction band is empty of electrons. Conduction electrons come from thermal excitation of electrons from a lower energy band or from impurity atoms in the crystal.
Industry:Science
The elements are conveniently, but arbitrarily, divided into metals and nonmetals. The nonmetals do not conduct electricity readily, are not ductile, do not have a complex refractive index, and in general have high ionization potentials. The nonmetals vary widely in physical properties. Hydrogen is a colorless permanent gas; bromine is a dark-red, volatile liquid; and carbon, as diamond, is a solid of great hardness and high refractive index. If the periodic table is divided diagonally from upper left to lower right, all the nonmetals are on the right-hand side of the diagonal. Examples of elements which do not fit neatly into this useful but arbitrary classification are tin, which exists in two allotropic modifications, one definitely metallic and the other with many properties of a nonmetal, and tellurium and antimony. Such elements are called metalloids.
Industry:Science
