- 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.
A natural order of the class Arachnida, also called Araneida, commonly known as the spiders. These animals are widespread over most of the land areas of the world and are well adapted to many different habitats. They are known to be one of the oldest of all groups of arthropods, and their remains are known from the Devonian and Carboniferous geological deposits. Through successive geological periods spiders have become adapted to insects as their chief source of food. On the other hand, certain insects consume the eggs of spiders, others parasitize the eggs, and still others capture adults and place them in their nests for food for their young.
Industry:Science
A natural science concerned with the study of all living organisms. Although living organisms share some unifying themes, such as their origin from the same basic cellular structure and their molecular basis of inheritance, they are diverse in many other aspects. The diversity of life leads to many divisions in biological science involved with studying all aspects of living organisms. The primary divisions of study in biology consist of zoology (animals), botany (plants), and protistology (one-celled organisms), and are aimed at examining such topics as origins, structure, function, reproduction, growth and development, behavior, and evolution of the different organisms. In addition, biologists consider how living organisms interact with each other and the environment on an individual as well as group basis. Therefore, within these divisions are many subdivisions such as molecular and cellular biology, microbiology (the study of microbes such as bacteria and viruses), taxonomy (the classification of organisms into special groups), physiology (the study of function of the organism at any level), immunology (the investigation of the immune system), genetics (the study of inheritance), and ecology and evolution (the study of the interaction of an organism with its environment and how that interaction changes over time).
Industry:Science
A natural spring or fountain which discharges a column of water or steam into the air at more or less regular intervals. It may be regarded as a special type of spring. Perhaps the best-known area of geysers is in Yellowstone Park, Wyoming, where there are more than 100 active geysers and more than 3000 noneruptive hot springs. Other outstanding geysers are found in New Zealand and Iceland. The most famous geyser is probably Old Faithful (see <b>illus.</b>) in Yellowstone Park, which erupts about once an hour. Then for about 5 min the water spouts to a height of 100–150 ft (30–45 m). Other geysers are less regular, but some intermittently discharge water and steam to heights of 250 ft (75 m) or more.
Industry:Science
A natural, fresh-water surface stream that has considerable volume compared with its smaller tributaries. The tributaries are known as brooks, creeks, branches, or forks. Rivers are usually the main stems and larger tributaries of the drainage systems that convey surface runoff from the land. Rivers flow from headwater areas of small tributaries to their mouths, where they may discharge into the ocean, a major lake, or a desert basin.
Industry:Science
A naturally occurring mineral of wide interest, the high-pressure polymorph of SiO<sub>2</sub>. Coesite was first discovered and identified in various meteorite impact craters and in some tektites. Because it requires a unique physical condition, extremely high pressure, for its formation, its occurrence is diagnostic of a special natural phenomenon, in this case, the hypervelocity impact of a meteorite.
Industry:Science
A naturally occurring quaternary ammonium cation ester, with the formula CH<sub>3</sub>(O)COC<sub>2</sub>H<sub>4</sub>N(CH<sub>3</sub>)<sub>3</sub><sup>+</sup>, that plays a prominent role in nervous system function.
Industry:Science
A naturally occurring regulatory peptide that carries out numerous functions in the human body, including the inhibition of growth hormone secretion from the anterior pituitary gland. Somatostatin consists of 14 amino acids (see <b>illus.</b>); the two cysteine residues are joined by a disulfide bond so that the peptide forms a ring structure. A larger variant of this peptide, called somatostatin-28, is produced in some cells and has an additional 14 amino acids attached at the amino-terminal end of normal somatostatin (somatostatin-14).
Industry:Science
A naturally occurring rhombohedral zinc carbonate (ZnCO<sub>3</sub>), with a crystal structure similar to that of calcite (CaCO<sub>3</sub>). The structure consists of alternating layers of zinc ions (Zn<sup>2+</sup>) and carbonate ions (CO<sub>3</sub><sup>2-</sup>) oriented perpendicular to the <i>c</i> crystallographic axis. Smithsonite has a hardness on the Mohs scale of 4<sup>1</sup>/<sub>2</sub>, has a specific gravity of 4.30–4.45, and exhibits perfect rhombohedral cleavage. Optically, smithsonite is uniaxial negative, which means that it has a single optic axis and two principal refractive indices referred to as the ordinary refractive index and the extraordinary refractive index. Smithsonite is classified as optically negative because the ordinary refractive index is greater than the extraordinary index. (<i>N</i><sub><i>o</i></sub> > <i>N</i><sub><i>e</i></sub>).
Industry:Science
A naturally occurring solid object from interplanetary space that survives impact on a planetary surface. While in space, the object is called a meteoroid, and a meteor if it produces light or other visual effects as it passes through a planetary atmosphere. Various sounds, including hissing and thunderous detonations, have also been reported for large meteors arriving at Earth. Explosive surface impacts by large meteorites are believed to have created the plethora of craters on the solid planets and moons of the solar system. Meteor Crater, Arizona, is Earth's most famous example of an impact crater.
Industry:Science
A naturally occurring solid phase with a restricted chemical composition and a definite atomic arrangement. This is really an idealized definition insofar as some minerals (especially those that form at low temperature) have poorly defined atomic structures. A few solid geological materials (such as coal and obsidian) are not minerals because they have no ordered crystal structure and a completely variable composition. Rocks are usually made up of one or more minerals. In a thermodynamic sense, a mineral is a separate phase that is made up of one or more components. For example, the mineral olivine ((Fe,Mg)<sub>2</sub>SiO<sub>4</sub>) can be viewed as being made up of fayalite (Fe<sub>2</sub>SiO<sub>4</sub>) and forsterite (Mg<sub>2</sub>SiO<sub>4</sub>) in a solid solution.
Industry:Science
