- 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.
Either the taking up of matter in bulk by other matter, as in the dissolving of a gas by a liquid; or the taking up of energy from radiation by the medium through which the radiation is passing. In the first case, an absorption coefficient is defined as the amount of gas dissolved at standard conditions by a unit volume of the solvent. Absorption in this sense is a volume effect: The absorbed substance permeates the whole of the absorber. In absorption of the second type, attenuation is produced which in many cases follows Lambert's law and adds to the effects of scattering if the latter is present.
Industry:Science
In 1992, G. P. Chrousos and P. W. Gold defined stress as a state of threatened homeostasis, or instability to which a person (or animal) reacts with an adaptive response to preserve its internal equilibrium. Mild, brief, and controllable challenges could be perceived as pleasant or exciting and could be a positive input for emotional and intellectual development. However, as defined by H. Selye in 1976, more intense, persistent, and uncontrollable situations of threat or perceived threat may lead to maladaptive responses. In humans, these maladaptive responses include the development of mood disorders.
Industry:Science
Animals that inhabit the water column of oceans and lakes and lack the means to counteract transport currents. Zooplankton inhabit all layers of these water bodies to the greatest depths sampled, and constitute a major link between primary production and higher trophic levels in aquatic ecosystems. Many zooplankton are capable of strong swimming movements and may migrate vertically from tens to hundreds of meters; others have limited mobility and depend more on water turbulence to stay afloat. All zooplankton, however, lack the ability to maintain their position against the movement of large water masses.
Industry:Science
At times in history, there have been concerns that demand for wood (timber) would be greater than the ability to supply it, but that concern has recently dissipated. The wood supply and demand situation has changed because of market transitions, economic downturns, and continued forest growth. This article provides a concise overview of this change as it relates to the United States, looking at nationwide trends in the pulp and paper sector and the solid wood and composite wood product sectors (lumber and wood panels) and also nationwide trends in timber growth, timber removals, and real prices for timber.
Industry:Science
Digital data are ubiquitous in modern life, and the capabilities of current storage technologies are continually being challenged by applications such as the distribution of content, digital video, interactive multimedia, small personal data-storage devices, archiving of valuable digital assets, and downloading over high-speed networks. Current optical data-storage technologies, such as the compact disk (CD), digital versatile disk (DVD), and Blu-ray disk (BD) have been widely adopted because they provide random access to data, are inexpensive removable media, and rapidly replicate video and music content.
Industry:Science
Growth and development of plants are dependent on sunlight. Consequently, plants have evolved a sophisticated array of photoreceptor systems to control their growth. Phototropins are plant photoreceptors that are specifically receptive to UV-A/blue light (320–500 nm) (UV-A is one of the types of ultraviolet radiation produced by the Sun, in the wavelength range 320–400 nm; blue light has an approximate wavelength range of 400–500 nm). They control a range of responses concerned with optimizing the photosynthetic efficiency of plants, thereby promoting their growth, particularly under weak light conditions.
Industry:Science
Engineers who design systems using text specification documents focus their work upon the completed system to meet performance, time, and budget goals. Consistency and integrity are difficult to maintain within text documents for a single complex system, and they are more difficult to maintain as several systems are combined into higher-level systems, especially when these systems are maintained over decades, and evolve technically and in performance through updates. This system design approach frequently results in major changes during the system integration and test phase, and in time and budget overruns.
Industry:Science
Genetic modification is the newest scientific tool for developing improved crop varieties. Such crops can help to enhance agricultural productivity, boost food production, reduce the use of farm chemicals, and make our food healthier. Genetically modified (GM; also called transgenic, genetically engineered, or bioengineered) crops represent the fastest-adopted technology in the history of agriculture, yet they are not universally accepted because of perceived concerns about their safety. Skeptics believe that such crops may pose unrecognized risks to human and animal health and could damage the environment.
Industry:Science
Any radar equipment used by civil or military authorities for locating aircraft, ships, or ground vehicles; most commonly, in civil air-traffic management, a radar used by controllers to indicate the position of aircraft aloft or on the airport surface. Two types of air-traffic control surveillance radar are employed internationally. Ground-based conventional, or primary, radar operates by transmitting microwave pulses and detecting the resulting energy reflected from the aircraft body (airframe). Secondary surveillance radar employs cooperative radio receiver-transmitter units (transponders) on the aircraft.
Industry:Science
Disorders of the prostate gland that can cause voiding symptoms and sexual dysfunction. The three most common diseases are prostatitis, benign prostatic hyperplasia, and prostate cancer. Prostatitis is an inflammatory condition of the gland, causing a variety of voiding symptoms and pain in the area around the prostate. Benign prostatic hyperplasia is a benign growth of the inner portion of the gland that causes progressive obstruction of the urinary channel (urethra) at the base of the bladder. Prostate cancer is the most common nonskin malignancy in men and is a major health concern for the aging population.
Industry:Science
