- 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.
The kingdom comprising all single-celled forms of living organisms in both the five-kingdom and six-kingdom systems of classification. Kingdom Protista encompasses both Protozoa and Protophyta, allowing considerable integration in the classification of both these animallike and plantlike organisms, all of whose living functions as individuals are carried out within a single cell membrane. Among the kingdoms of cellular organisms, this definition can be used to distinguish the Protista from the Metazoa (sometimes named Animalia) for many-celled animals, or from the Fungi and from the Metaphyta (or Plantae) for many-celled green plants. This system simplifies the lower-level classification (orders and superfamilies) where closely allied forms of flagellate protistans may possess chlorophyll and, therefore, be plantlike in their metabolism, or lack chlorophyll and feed as animals. However, there are other difficulties, not only of semantics but also of fundamental biology, involved in attempting diagnostic separation of the Protista from the other major groups of living organisms.
Industry:Science
The incident radiant energy emitted by the Sun, which reaches a unit horizontal area of the Earth's surface. The term is a contraction of incoming solar radiation. About 99.9% of the Sun's energy is in the spectral range of 0.15–4.0 micrometers. About 95% of this energy is in the range of 0.3–2.4 μm; 1.2% is below 0.3 μm, and 3.6% is above 2.4 μm. The bulk of the insolation (99%) is in the spectral region of 0.25–4.0 μm; about 40% is found in the visible region of 0.4–0.7 μm and only 10% is in wavelengths shorter than the visible. Energy of wavelengths shorter than 0.29 μm is absorbed high in the atmosphere by nitrogen, oxygen, and ozone.
Industry:Science
The cell membrane, made up of roughly 70% lipids and 30% protein, serves as an effective barrier to maintain the differences in composition between the intracellular and the extracellular space. The majority of the energy required to sustain cellular function is expended in maintaining large differences in electrolyte ion concentrations across the cell membrane. The lipid bilayer of the membrane serves this barrier role remarkably well by establishing a nonpolar region through which an ion must pass to cross the membrane. The energy required to move a hydrated ion from the aqueous phase into the nonpolar lipid phase is extremely high, thus providing a strong impediment to passive ion diffusion across the lipid bilayer. On the other hand, many of the membrane proteins facilitate and regulate membrane ion transport. The presence of these proteins thus enhances the ability of the mammalian cell membrane to actively transport certain ions.
Industry:Science
The continuing progression of miniaturization technology for electronic devices has brought us into the nano regime. In our daily lives, we are using nanodevices, which consist of artificial nanostructures less than 100 nanometers in size. To fabricate these nanodevices accurately, we have to measure at the nanometer scale various values, such as length and resistivity. Despite the importance of nanoscale measurement technology, or nanometrology, we have only limited solutions. New metrological methods are now urgently required for the further development and improvement of nanodevices. Recently, new tools for nanometrology have been developed.
Industry:Science
The art and science of crop and livestock production. In its broadest sense, agriculture comprises the entire range of technologies associated with the production of useful products from plants and animals, including soil cultivation, crop and livestock management, and the activities of processing and marketing. The term agribusiness has been coined to include all the technologies that mesh in the total inputs and outputs of the farming sector. In this light, agriculture encompasses the whole range of economic activities involved in manufacturing and distributing the industrial inputs used in farming; the farm production of crops, animals, and animal products; the processing of these materials into finished products; and the provision of products at a time and place demanded by consumers. The proportion of the United States economy dedicated to the production of food and fiber products is about one-sixth of the total national product.
Industry:Science
The CANDU pressurized heavy-water reactor (PHWR) is based on more than 50 years of nuclear technology development. An ongoing comprehensive product development program is advancing all aspects of CANDU technology, with a focus on improving economics, enhancing safety, and ensuring fuel-cycle flexibility to secure fuel supply for the foreseeable future. The development program retains the essential features of CANDU reactors: high neutron economy, utilization of natural rather than enriched uranium, modular core components for easy upgrading and plant life extension, simple fuel bundle designs for on-power fueling, and emphasis on passive safety.
Industry:Science
The first star recognized to have a periodic brightness variation. Mira (officially designated Omicron Ceti, in the constellation Cetus, the Whale) was discovered in 1596 by David Fabricius (or Fabricus), a clergyman and an amateur astronomer from Esens in East Friesland (now in Germany), while he was searching for Mercury. He mistook it for a nova because it later faded from view. However, he saw it reappear 14 years later. Not until 1638 was it recognized to be the first known variable star, when Johann Holwarda, from Franeker, also in Friesland (now in the Netherlands), rediscovered it, and in 1639 determined its period to be 11 months. In 1642, Johannes Hevelius of Danzig, who also observed the star, called it Mira, meaning The Wonderful. Mira is the prototype of an entire class of Mira-type pulsating long-period variables. Although it once resembled the Sun, Mira has evolved into a cool red giant star that is at the end of its life.
Industry:Science
The advent of high-spatial-resolution scanning probe microscopes, such as the scanning tunneling microscope, has afforded a remarkable view of atomic- and molecular-scale surface dynamics. In particular, use of scanning tunneling microscopy (STM) for the detailed investigation of surface behavior has extended the boundaries associated with the measurement, comprehension, and ultimately application of nanoscale phenomena. The fundamental understanding of surface dynamics at the atomic and molecular scale influences catalyst customization and use, structural alloy compositions, microelectronic device fabrication, and molecule-based nanoelectronics.
Industry:Science
The application of genetic principles to the improvement of cultivated plants, with heavy dependence upon the related sciences of statistics, pathology, physiology, and biochemistry. The aim of plant breeding is to produce new and improved types of farm crops or decorative plants, to better serve the needs of the farmer, the processor, and the ultimate consumer. New varieties of cultivated plants can result only from genetic reorganization that gives rise to improvements over the existing varieties in particular characteristics or in combinations of characteristics. In consequence, plant breeding can be regarded as a branch of applied genetics, but it also makes use of the knowledge and techniques of many aspects of plant science, especially physiology and pathology. Related disciplines, like biochemistry and entomology, are also important, and the application of mathematical statistics in the design and analysis of experiments is essential.
Industry:Science
1 − υ<sup>2</sup>/<i>c</i><sup>2</sup></span> in the direction of motion, where <i>c</i> is the speed of light.">The contraction of a moving body in the direction of its motion. In 1892 G. F. FitzGerald and H. A. Lorentz proposed independently that the failure of the Michelson-Morley experiment to detect an absolute motion of the Earth in space arose from a physical contraction of the interferometer in the direction of the Earth's motion. According to this hypothesis, as formulated more exactly by Albert Einstein in the special theory of relativity, a body in motion with speed υ is contracted by a factor √<span style="border-top:1px solid black;">1 − υ<sup>2</sup>/<i>c</i><sup>2</sup></span> in the direction of motion, where <i>c</i> is the speed of light.
Industry:Science
