- 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 fifth brightest of all stars and the third brightest in the northern sky. It will be the north polar star in about 12,000 years. In moving through the Milky Way Galaxy, the Sun is generally heading toward the position now occupied by Vega. At a distance of 7.8 parsecs (25.3 light-years, or 2.4 × 10<sup>14</sup> km, or 1.49 × 10<sup>14</sup> mi), Vega, or α Lyrae, is the prototypical star of spectral class A0V, indicating that it has an effective surface temperature of 9600 K (16,800°F) and derives its energy from the thermonuclear burning of hydrogen in a stable core region. Stars of this class have main-sequence lifetimes of about 5 × 10<sup>8</sup> years, 20 times shorter than the Sun. Vega's spectrum shows strong features due to hydrogen in the star's outer layers. The sharpness of these features implies that Vega is pointing its rotation axis nearly at the Sun. In comparison with the Sun, Vega is approximately 2.9 times larger in diameter, 2.5 times more massive, and 60 times more luminous.
Industry:Science
The atmospheric layer that is immediately above the troposphere and contains most of the Earth's ozone. Here temperature increases upward because of absorption of solar ultraviolet light by ozone. Since ozone is created in sunlight from oxygen, a by-product of photosynthesis, the stratosphere exists because of life on Earth. In turn, the ozone layer allows life to thrive by absorbing harmful solar ultraviolet radiation. The mixing ratio of ozone is largest (10 parts per million by volume) near an altitude of 30 km (18 mi) over the Equator. The distribution of ozone is controlled by solar radiation, temperature, wind, reactive trace chemicals, and volcanic aerosols.
Industry:Science
Standardized methods of collection, evaluation or verification, storage, and retrieval of data about a patient. The three broad areas of any information system—input, data transformation, and output—suffice to describe an existing system, but they are insufficient to design a new one. To these must be added the action that is expected to take place on the basis of the data output from the system, thereby defining the purpose of the system, and the feedback from such action to the system input, which places the system in a specific medical environment. Crucial to any information system, and especially for a medical system, is the accuracy of the input data, which is of more significance than mere precision. A medical information system is a part of necessary time management that is intended to maximize the amount of data and procedure information in order to make the most accurate clinical decisions. As such, an information management system must be interactive to serve clinical decision purposes.
Industry:Science
The deposit of liquid water resulting from condensation of atmospheric water vapor to exposed surfaces that cool during the night. Dewfall is noticeable in the early morning after a calm, cool, clear night, usually as beads of liquid water on the outside and upward-facing surfaces of trees, buildings, and so forth. If the ground is moist, some of the condensed water can be the result of distillation of surface moisture. Dew forms when the surface temperature drops sufficiently to saturate air in contact with the surface (that is, when the surface drops to below atmospheric dew-point temperature); when the surface cools to below freezing temperature, frost occurs.
Industry:Science
The 180° meridian, where each day officially begins and ends. As a person travels eastward, against the apparent movement of the Sun, 1 h is gained for every 15° of longitude; traveling westward, time is lost at the same rate. Two people starting from any meridian and traveling around the world in opposite directions at the same speed would have the same time when they meet, but would be 1 day apart in date. If there were no international agreement as to where each day should begin and end, there could be any number of places so designated. To eliminate such confusion, the International Meridian Conference, in 1884, designated the 180° meridian as the location for the beginning of each day. Thus, when a traveler goes west across the line, a day is lost; if it is Monday to the east, it will be Tuesday immediately as the traveler crosses the International Date Line. In traveling eastward a day is gained; if it is Monday to the west of the line, it will be Sunday immediately after the line is crossed.
Industry:Science
The discovery of high-temperature superconducting materials in 1986 unleashed a worldwide flurry of research with high hopes for an ensuing technological revolution in electronics, transportation, and energy fields. In the 10 following years, valuable scientific knowledge was acquired which is beginning to lead to these expected technological advances. The essential property of superconductors, namely infinite electrical conductivity (zero resistance) in steady current flow, leads to many possible applications, including faster electronics requiring less power; smaller, more efficient motors and generators; and more efficient transfer and storage of electrical energy.
Industry:Science
The art and science of preserving the use of the electromagnetic spectrum for friendly forces while denying its use to the enemy. This is accomplished via use of techniques, devices, and equipment by an adversary to deny or counteract an enemy's use of radar, communications, guidance, or other radiowave devices. The principal techniques that are employed are called electronic countermeasures (ECM). Because of the growing use of optical and infrared techniques for communications, guidance, detection, and control, they are sometimes called electromagnetic, rather than electronic, countermeasures to convey more adequately the idea that countermeasures are not confined to the portion of the spectrum where electronic techniques alone are applicable but may be used throughout the electromagnetic spectrum. Other techniques include the use of antiradiation weapons designed specifically to home on and destroy radars, and the attempts to reduce the electromagnetic signatures of aircraft, missiles, and ground vehicles.
Industry:Science
The Global Navigation Satellite System (GLONASS) is a space-based radionavigation system being developed by the Russian Federation. Having much in common with the United States' Global Positioning System (GPS), GLONASS can provide accurate estimates of position, velocity, and time to users worldwide. Both systems were planned in the 1970s primarily for military use, and are operated by the respective defense departments. Each country has committed to make a subset of the signals available for civil use without any user fees. Detailed descriptions of these signals have been made available for each system so that receiver manufacturers can build and sell user equipment.
Industry:Science
The Digital Object Identifier (DOI) is an Internet-based global naming and resolution system that provides for the precise identification, retrieval, and trading of digital items in the form of articles, books, images, bibliographies, supporting data, videos, charts, tables, audio, and other electronic files. Development of the DOI system began in 1996 when content creators and technologists jointly recognized that information and entertainment objects could not be commercially distributed on the Internet unless there was a common system of unique identification for those objects. These early stakeholders envisioned an unambiguous, machine-readable identifier that could be used for all electronic communications and transactions involving content throughout its life cycle, including its creation, editing, publication, distribution, and archiving. Such an identifier would be especially critical for commercial transactions, from initial licensing through sales tracking, royalty computation, and financial reporting.
Industry:Science
The diversification in form and function of flowers, the reproductive structures of angiosperms (flowering plants), provides some of the most compelling examples of adaptation by natural selection. Flowers vary enormously in size and display greater structural variation than the equivalent structures in any other group of organisms. This diversity provides outstanding opportunities for investigating the functional association between floral traits and plant mating. The recent integration of theoretical, comparative, and experimental approaches in evolutionary biology is giving rise to new insights into the relations between floral diversity and plant mating strategies.
Industry:Science
