- 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.
One of the two subclasses of liverworts (class Hepaticopsida). The plants may be thallose, with little or no tissue differentiation, or they may be organized into erect or prostrate stems with leafy appendages. The leaves, generally one cell in thickness, are mostly arranged in three rows, with the third row of underleaves commonly reduced or even lacking. Oil bodies are usually present in all of the cells. The rhizoids are smooth. The capsules, generally dehiscing by four valves, are usually elevated on a long, delicate, short-lived seta. The spore mother cells are deeply lobed.
Industry:Science
One of the two divisions of the seed plants of about 600 to 700 species extant on all continents except Antarctica. The most familiar and common representatives are the evergreen, cone-bearing trees of the Pinales. Because the ovules (young seeds) are exposed directly to the air at the time of pollination, the Pinophyta are commonly known as the gymnosperms, in contrast to the other division of flowering plants, the angiosperms (division Magnoliophyta), which have the ovules enclosed in an ovary. The division Pinophyta consists of three classes: Ginkgoopsida, Cycadopsida, and Pinopsida.
Industry:Science
In the last 100 years, humans have synthesized thousands of new chemicals, some of which have been released in large amounts into the biosphere. Other, naturally occurring pollutants such as cyanides, phenols, polycyclic aromatic compounds, or long-chain aliphatic hydrocarbons originate from coal or crude oil. These may be hazardous if accidentally or deliberately released, because they exhibit acute or chronic toxicity. However, many of these organic compounds can be eliminated by microorganisms (natural or genetically modified), if the appropriate process conditions can be established.
Industry:Science
Making, processing, and interpreting measurements of the physical properties of the Earth with the objective of practical application of the findings. Most exploration geophysics is conducted to find commercial accumulations of oil, gas, coal, or other minerals, but geophysical investigations are also employed with engineering objectives, in studies aimed at predicting the nature of the Earth for the foundations of roads, buildings, dams, tunnels, nuclear power plants, and other structures, and in the search for geothermal areas, water resources, pollution, archeological ruins, and so on.
Industry:Science
Matter which is made up of antiparticles. At the most fundamental level every type of elementary particle has its anti-counterpart, its antiparticle. The existence of antiparticles was implied by the relativistic wave equation derived in 1928 by P. A. M. Dirac in his successful attempt to reconcile quantum mechanics and special relativity. The antiparticle of the electron (the positron) was first observed in cosmic rays by C. D. Anderson in 1932, while that of the proton (the antiproton) was produced in the laboratory and observed by E. Segré, O. Chamberlain, and their colleagues in 1955.
Industry:Science
Models are used to represent real systems in an understandable way. They take many forms. A conceptual model explains the way a system works. In environmental studies, for example, a conceptual model may delineate all the factors and parameters for determining how a particle moves in the atmosphere after it has been released from a power plant. A conceptual model may also help identify the major influences on where a chemical is emitted and how likely it is to be found in the environment. Such models need to be developed to help target sources of data for assessing environmental problems.
Industry:Science
Optical lithography provides a high-productivity, profitable means of making microcircuits on silicon wafers by imaging increasingly smaller features in photoresist. Polarization lithography specifically refers to the use of polarized light for illumination within an optical lithographic system to improve the quality of the imaging and the resolution. In the quest for ever-greater resolution, modern fabrication facilities all use some form of polarization lithography to produce high-technology computer chips. This article discusses basics of polarization lithography and why it is important.
Industry:Science
Medium- to coarse-grained, mica-bearing metamorphic rock with well-developed foliation termed schistosity. Schist is derived primarily from fine-grained, mica-bearing rocks such as shales and slates. The schistosity is formed by rotation, recrystallization, and new growth of mica; it is deformational in origin. The planar to wavy foliation is defined by the strong preferred orientation of platy minerals, primarily muscovite, biotite, and chlorite. The relatively large grain size of these minerals (up to centimeters) produces the characteristic strong reflection when light shines on the rock.
Industry:Science
Pathologies of the heart and its blood vessels. Almost all cardiovascular disorders eventually progress to serious debilitating stages characterized by heart failure (reduced pumping function), dysrhythmias (abnormal electrical rhythms), and sudden death. Coronary atherosclerosis, a disease causing obstruction of the arteries that supply nutrient blood to heart muscle, is the leading cause of cardiovascular mortality. Hypertension (high blood pressure) is another important cause. Valvular heart disease, cardiomyopathies (disease of heart muscle), and congenital heart disease are less common.
Industry:Science
Organic, or biological, evolution is the modification of living organisms during their descent, generation by generation, from common ancestors. It is to be distinguished from other phenomena to which the term evolution is often applied, such as chemical evolution, cultural evolution, or the origin of life from nonliving matter. Organic evolution includes two major processes: anagenesis, the alteration of the genetic properties of a single lineage over time; and cladogenesis, or branching, whereby a single lineage splits into two or more distinct lineages that continue to change anagenetically.
Industry:Science
