- 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 colorless liquid, H<sub>2</sub>NNH<sub>2</sub> (boiling point 114°C or 237°F), with a musty, ammonialike odor. Physically hydrazine is similar to water, but chemically it is reducing, decomposable, basic, and bifunctional. Its derivatives range from simple salts to ring compounds, polymers, and coordination complexes. Major uses of hydrazine include such diverse applications as rocket fuels (since combustion of hydrazine is highly exothermic), corrosion inhibition in boilers, and syntheses of biologically active materials.
Industry:Science
A colorless to white crystalline substance which occurs naturally as the mineral kalunite and is a constituent of the mineral alunite. Alum is produced as aluminum sulfate by treating bauxite with sulfuric acid to yield alum cake or by treating the bauxite with caustic soda to yield papermaker's alum. Other industrial alums are potash alum, ammonium alum, sodium alum, and chrom alum (potassium chromium sulfate). Major uses of alum are as an astringent, styptic, and emetic. For water purification alum is dissolved; it then crystallizes out into positively charged crystals that attract negatively charged organic impurities to form an aggregate sufficiently heavy to settle out. Alum is also used in sizing paper, dyeing fabrics, and tanning leather. With sodium bicarbonate it is used in baking powder and in some fire extinguishers.
Industry:Science
A colorless, highly toxic gas having the molecular formula C<sub>2</sub>N<sub>2</sub>. Cyanogen belongs to a class of compounds known as pseudohalogens, because of the similarity of their chemical behavior to that of the halogens. Liquid cyanogen boils at −21.17°C (−6.11°F) and freezes at −27.9°C (18.2°F) at 1 atm (10<sup>5</sup> Pa). The density of the liquid is 0.954 g/ml at the boiling point.
Industry:Science
A colorless, liquid, inflammable, aromatic hydrocarbon of chemical formula C<sub>6</sub>H<sub>6</sub> which boils at 80.1°C (176°F) and freezes at 5.4–5.5°C (41.7–41.9°F). In the older American and British technical literature benzene is designated by the German name benzol. In current usage the term benzol is commonly reserved for the less pure grades of benzene.
Industry:Science
A colorless, nearly odorless, sweet-tasting, hygroscopic liquid, formula HOCH<sub>2</sub>CH<sub>2</sub>OH. It is relatively nonvolatile and viscous and is the simplest member of the glycol family. Ethylene glycol freezes at −3°C (8.6°F), boils at 197.6°C (387.7°F), and is completely soluble in water, common alcohols, and phenol. Low molecular weight, low volatility, water solubility, and low solvent action on automobile finishes make ethylene glycol ideal as a radiator antifreeze and coolant; water mixtures (58–80% glycol) freeze below −46°C (−50°F).
Industry:Science
A colorless, odorless, tasteless gas, formula CO<sub>2</sub>, about 1.5 times as heavy as air. The specific volume at atmospheric pressure (100 kilopascals) and 70°F (21°C) is 8.74 ft<sup>3</sup>/lb (0.546 m<sup>3</sup>/kg). Under normal conditions, it is stable, inert, and nontoxic.
Industry:Science
A colorless, pungent liquid, CH<sub>3</sub>COOH, melting at 16.7°C (62.1°F) and boiling at 118.0°C (244.4°F). Acetic acid is the sour principle in vinegar. Concentrated acid is called glacial acetic acid because of its readiness to crystallize at cool temperatures. Acetic acid in vinegar arises through an aerobic fermentation of dilute ethanol solutions, such as wine, cider, and beer, with any of several varieties of <i>Acetobacter</i>.
Industry:Science
A combination instrument which provides an aircraft pilot with two distinct pieces of information: the aircraft's rate of turn about the vertical axis, and the relationship between this rate and the aircraft's angle of bank. It is also known as the needle and ball indicator or the turn and slip indicator.
Industry:Science
A combination of rigid or resistant bodies having definite motions and capable of performing useful work. The term mechanism is closely related but applies only to the physical arrangement that provides for the definite motions of the parts of a machine. For example, a wristwatch is a mechanism, but it does no useful work and thus is not a machine. Machines vary widely in appearance, function, and complexity from the simple hand-operated paper punch to the ocean liner, which is itself composed of many simple and complex machines. No matter how complicated in appearance, every machine may be broken down into smaller and smaller assemblies, until an analysis of the operation becomes dependent upon an understanding of a few basic concepts, most of which come from elementary physics.
Industry:Science
A combination of the techniques of electrophoresis and immunodiffusion used to separate the components of a mixture of antigens and make them visible by reaction with specific antibodies.
Industry:Science
