- 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 measurement of surface features and configuration of an area or a region, and the graphic expression of those features. Surveying is the art and science of measurement of points on, above, or under the surface of the Earth. Topographic maps show the natural and cultural features of a piece of land. The natural features include configuration (relief), hydrography, and vegetation. The cultural features include roads, buildings, bridges, political boundaries, and the sectional breakdown of the land. Topographic maps are used by a wide variety of people, such as engineers designing a new road; backpackers finding their way into remote areas; scientists describing soil or vegetation types, wildlife habitat, or hydrology; and military personnel planning field operations.
Industry:Science
The main objective of ensuring safety in building design is to reduce the level of damage to the building and its contents and to minimize the loss of life in the event of an accident or natural hazard. To achieve this objective, buildings should be designed to have adequate resistance against accidental loads. In the design against accidental fire, the building should be able to withstand the fire for a reasonable time, and the fire should be contained within a localized part of the building. Several safety measures must be taken to meet the expected performance, including evacuating people from the building, detecting and suppressing the fire, stopping the fire from spreading, and protecting the load-bearing members from losing their strength at elevated temperatures.
Industry:Science
The regulation of lipid metabolism and glucose utilization is critical for the maintenance of cellular energy homeostasis. Cells have developed several means to respond to internal and external stimuli that would signify an imbalance in metabolic processes and energy utilization. These means include rapid responses such as phosphorylation events as well as latent effects on gene transcription. Ultimately, the result of altered gene expression is the synthesis of new signaling molecules and enzymes that are able to meet the physiological needs of the cell and the organism. Thus, important components of the cell must be a sensor of fatty acids and their metabolites, and an effector of nuclear transcriptional regulation. These roles may be fulfilled by one type of protein.
Industry:Science
The study of processes and reactions whose developments have been inspired by the biological membrane. Faithful modeling of the biomembrane is not an objective of membrane mimetic chemistry. Rather, only the essential components of natural systems are recreated from relatively simple, synthesized molecules. Mimetic systems are designed for well-defined purposes. The insight gained into the functioning of real membranes is considered a bonus. (The term membrane mimetic is more restrictive than the term biomimetic. Biomimetic chemistry is directed at the mechanistic elucidation of biochemical reactions and at the development of new compounds modeled on, and expected to mimic, specific biological systems. The focal point of most biomimetic chemistry is enzyme modeling.)
Industry:Science
The rapid progress of wireless communication, embedded micro-electro-mechanical systems (MEMS), and microsensing technologies has made wireless sensor networks (WSNs) possible. A WSN consists of many inexpensive wireless sensors, which are capable of collecting, storing, processing environmental information, and communicating with neighboring nodes. In the past, sensors were connected by wired networks. With the development of ad hoc networking technologies, tiny sensors can communicate through wireless links in a more convenient manner. Much research has been dedicated to this area, including energy-efficient media access control (MAC) protocols, routing and transport protocols, self-organizing schemes, sensor deployment and coverage issues, and localization algorithms.
Industry:Science
The series of elements beginning with actinium (atomic number 89) and including thorium, protactinium, uranium, and the transuranium elements through the element lawrencium (atomic number 103). These elements, chemically similar, have a strong chemical resemblance to the lanthanide, or rare-earth, elements of atomic numbers 57 to 71. Their atomic numbers, names, and chemical symbols are 89, actinium (Ac), the prototype element, sometimes not included as an actual member of the actinide series; 90, thorium (Th); 91, protactinium (Pa); 92, uranium (U); 93, neptunium (Np); 94, plutonium (Pu); 95, americium (Am); 96, curium (Cm); 97, berkelium (Bk); 98, californium (Cf); 99, einsteinium (Es); 100, fermium (Fm); 101, mendelevium (Md); 102, nobelium (No); 103, lawrencium (Lr).
Industry:Science
The most common oxide on the Earth's surface, constituting 12% of the crust by volume. Quartz is a crystalline form of silicon dioxide (SiO<sub>2</sub>). When cooling magmas solidify into igneous rocks and when preexisting rocks metamorphose into new mineral assemblages, the crystallization of quartz is favored by the sheer abundance of silica in the crustal environment. Among the igneous rocks, quartz is especially common within granites, granodiorites, pegmatites, and rhyolites. In addition, quartz can be observed in low- to high-grade metamorphic rocks, including phyllites, quartzites, schists, granulites, and eclogites. Because hydrothermal fluids are enriched in dissolved silica, the passage of fluids through rock fractures results in the emplacement of quartz veins.
Industry:Science
The measurement of very small amounts of radioactivity. This can be achieved by measuring radioactivity in large samples or modifying conventional radiation-detection instruments for greater detection sensitivity, or both. All approaches must take into account the characteristics of the radiations, notably the very short range and intense energy deposition of alpha particles, intermediate range and energy deposition of beta particles, and high penetration of matter with low linear energy transfer by gamma rays. These techniques are important for measuring radionuclides from naturally occurring terrestrial and cosmic-ray-produced sources, and anthropogenic radionuclides to characterize the decay schemes of newly formed isotopes and analyze environmental and biological samples.
Industry:Science
The Mississippi River ranks as the third longest river in the world, and it is eighth in terms of average water volume discharged. The river and its tributaries collect runoff and sediment from 31 states, making it the second largest watershed in the world. The sediment-laden Mississippi has, over thousands of years, built a vast wetland system along the lowland coast of Louisiana. Due to the delta-forming processes of the river, the nutrient-rich salt-water and fresh-water marshes and estuaries are nursery grounds for one of the most productive fisheries in the world. Louisiana's wetlands also buffer New Orleans and other coastal towns from erosion and high-velocity hurricane winds, and serve as important habitat for 15 million migratory birds and many other wildlife species.
Industry:Science
The process of producing enlarged images of the interior of thin, usually small specimens by penetration of low-energy (0.1–10 keV) x-rays. The magnification can be obtained geometrically during the exposure by subsequent enlargement of the initial image by optical or electronic means, or by a combination of both processes. As with radiography on other size scales, microradiography shows the spatial distribution of mass and elemental composition of the sample. If a pulsed (flash) source or time-gated detector is employed, radiographs also provide stop-motion details of fast-changing objects. Microradiography has numerous applications in biology, material science, the characterization of fabricated microstructures, and assessment of plasma-driven compression of thermonuclear fuel.
Industry:Science
