- 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.
High-resolution flat-panel displays aim to achieve the visual and optical qualities of cathode-ray tubes, but with a significant reduction in overall size, weight, and power consumption. Among flat-panel displays, the benchmark for performance is the active-matrix liquid-crystal display. Field-emission displays are now emerging as a leading alternative for low-power, flat-panel multimedia applications and high-brightness automotive and avionic applications. Improvements in field-emission display technology have resulted from technological advances in vacuum microelectronics involving large-area lithography and thin-film processing, improved stability of field-emitter arrays, new emitter structures and materials, and improvements in low-voltage phosphor technology.
Industry:Science
Any difference, morphological or behavioral, between males and females of the same species. In many animals, the sex of an individual can be determined at a glance. For example, roosters have bright plumage, a large comb, and an elaborate tail, all of which are lacking in hens. Sexual dimorphism arises as a result of the different reproductive functions of the two sexes and is a consequence of both natural selection and sexual selection. Primary differences, such as the structure of the reproductive organs, are driven by natural selection and are key to the individual's function as a mother or father. Other differences such as the peacock's (<i>Pavo cristatus</i>) enormous tail are driven by sexual selection and increase the individual's success in acquiring mates.
Industry:Science
Beginning with the work of Ford W. Harris in 1915 on the economic order quantity (EOQ) model, many researchers developed a variety of mathematical models for minimizing the costs associated with holding inventories (raw materials, components, subassemblies, work in process, and finished goods) in industries and businesses. The subject dealing with these problems was initially called inventory control. These models were essentially single-decision-maker models involving one item. In those days, several reasons for holding sizable inventories were given, including economies of scale; uncertainties in demand, supply, delivery lead times, and prices; and a desire to hold buffer stocks as a cushion against unexpected swings in demand and to assure smooth production flow.
Industry:Science
Control by means of systems that include both digital and analog devices working together to enhance the controller's functionality. As computers and their associated memory have become cheaper, faster, and easier to use, engineers have used them to expand the capabilities of control systems. Most controllers built today are, to some extent, hybrids because digital implementation is usually cheaper and more reliable than analog. The computer in the controller can then be used easily to provide additional capability, such as better response to internal failures. However, the potential benefits of control systems combining the symbol manipulation and decision-making capability of the computer with the precise tracking capability of analog controllers are much greater.
Industry:Science
By analogy with the science of optics, those aspects of x-ray physics in which x-rays exhibit properties similar to those of light waves. X-ray optics may also be defined as the science of manipulating x-rays with instruments analogous to those used in visible-light optics. These instruments employ optical elements such as mirrors to focus and deflect x-rays, zone plates to form images, and diffraction gratings to analyze x-rays into their spectral components. X-ray optics is important in many fields, including x-ray astronomy, biology, medical research, thermonuclear fusion, and x-ray microlithography. It is essential to the construction of instruments that manipulate and analyze x-rays from synchrotrons and particle storage rings for synchrotron radiation research.
Industry:Science
In contrast to the creative freedom of painting or graphic illustration, map design must observe rigid limitations because the locations of geographic features such as rivers, national boundaries, and coastlines are tied to reality. Map design is defined as the systematic process of arranging and assigning meaning to elements on a map for the purpose of communicating geographic knowledge in a pleasing format. During the twentieth century, standardized symbols and designs evolved for reference maps such as topographic maps. However, nonstandard maps with unique purposes must be designed within a process that encompasses creativity, experimentation, and evaluation. Careful design is crucial to map effectiveness to avoid distorted or inaccurately represented information.
Industry:Science
Electromagnetic radiation in which wavelengths lie in the range from about 1 micrometer to 1 millimeter. This radiation therefore has wavelengths just a little longer than those of visible light and cannot be seen with the unaided eye. The radiation was discovered in 1800 by William Herschel, who used a prism to refract the light of the Sun onto mercury-in-glass thermometers placed just past the red end of the visible spectrum generated by the prism. Because the techniques and materials used to collect, focus, detect, and display infrared radiation are different from those of the visible, and because many of the applications of infrared radiation are also quite different, a technology has arisen, and many scientists and engineers have specialized in its application.
Industry:Science
Cancer arises independently in each individual as a result of genetic mutations that transform cells, leading to uncontrollable growth. However, there are two naturally occurring contagious cancers that have been detected. Devil facial tumor disease (DFTD) and canine transmissible venereal tumor (CTVT) each arose within a single individual, but then were able to spread from one individual to another. Moreover, both clonal cell lines lived on well beyond the normal life span of the host in which they arose. Although the two diseases are spread differently, with DFTD being spread between Tasmanian devils by biting and CTVT being transmitted during coitus in dogs, both appear to have arisen as a result of low levels of genetic diversity within the original host population.
Industry:Science
Bronchiolitis obliterans organizing pneumonia was first described in 1985 by Gary Epler as a disease distinct from other disorders of the lungs; it is also known as Epler's pneumonia. It is characterized by the formation of connective tissue masses in the lungs, filling the respiratory bronchioles and making breathing difficult and painful. BOOP presents clinically with initial “flulike” symptoms, followed by progressive dyspnea (shortness of breath), cough, fever, and weight loss. “Crackling” can be heard within the chest using a stethoscope. X-ray imagery shows bilateral patchy infiltrates in the alveoli of the lungs. Computed tomography (CT) shows bilateral areas of lung consolidation. This appears with a “ground-glass” haziness that is characteristic for the disease.
Industry:Science
Electronic devices based on the crystalline properties of semiconductors—transistors and integrated circuits—have unleashed immense computing power and transformed disciplines across science and industry. This success has spurred development of optical analogs. The fundamental principles of transistors can be traced to the interaction of the wavelike properties of electrons with the repetitive spacing of atoms found in semiconductor crystals. An optical device would rely instead on the interaction of the wavelike properties of photons with a periodic spacing of dielectric constants. Devices based on this principle are known as photonic crystal (PhC) devices. They offer for optics the same potential for miniaturization that has occurred for electronic integrated circuits.
Industry:Science
