- 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.
Nitrogen is an element of contrasts. In ecological systems, nitrogen is both abundant and limiting, is an essential nutrient and a pollutant, and is driven by natural and human-induced ecological processes. This makes nitrogen an important yet complex element at the center of a number of environmental issues, and one that is of increasing concern in forest conservation.
Industry:Science
Numerical systems defining the quantitative relations of the components of mixtures. In solutions the concentration is expressed as the mass, volume, or number of moles of solute present in proportion to the amount of solvent or of total solution. Each scale of concentration has significant features of experimental simplicity or of theoretically significant relationship.
Industry:Science
In physics, the term work refers to the transference of energy that occurs when a force is applied to a body that is moving in such a way that the force has a component in the direction of the body's motion. Therefore work is done on a weight that is being lifted, or on a spring that is being stretched or compressed, or on a gas that is undergoing compression in a cylinder.
Industry:Science
Mostly autotrophic microscopic algae which inhabit the illuminated surface waters of the sea, estuaries, lakes, and ponds. Many are motile. Some perform diel (diurnal) vertical migrations, others do not. Some nonmotile forms regulate their buoyancy. However, their locomotor abilities are limited, and they are largely transported by horizontal and vertical water motions.
Industry:Science
Once considered novelties, small, portable pen-based computers (sometimes called personal digital assistants or PDAs) are growing in popularity, fueled by the demands of an increasingly mobile information society. This situation is the direct result of advances in component miniaturization, improvements in user interface design, and progress in pattern recognition research.
Industry:Science
Ratio of the force exerted by a machine (the output) to the force exerted on the machine, usually by an operator (the input). The term is useful in discussing a simple machine, where it becomes a figure of merit. It is not particularly useful, however, when applied to more complicated machines, where other considerations become more important than a simple ratio of forces.
Industry:Science
Low-molecular-mass (generally 500–1000 daltons) molecules that have a high specificity for chelating or binding iron. Siderophores are produced by many microorganisms, including bacteria, yeast, and fungi, to obtain iron from the environment. More than 500 different siderophores have been identified from microorganisms. Some bacteria produce more than one type of siderophore.
Industry:Science
Plans that link employee compensation to some measure of company success. Wage incentive plans throughout the United States are varied. Some plans endeavor to link compensation to the company's performance history, others to department or unit performance, others to individual or team success. However, the majority of wage incentive plans are linked to individual achievement.
Industry:Science
Movement of a vehicle through the atmosphere at a speed appreciably below that of sound waves. Subsonic flight extends from zero (hovering) to a speed approximately 85% of sonic speed corresponding to the ambient temperature. At higher vehicle velocities the local velocity of air passing over the vehicle surface may exceed sonic speed, and true subsonic flight no longer exists.
Industry:Science
In sinusoidal alternating-current theory, the cosine of the phase angle between the voltage across and the current through electrical circuitry. It equals the ratio of the mean power dissipated to the product of the root-mean-square voltage and current, and is unity for a circuit containing only pure resistances. It is less than unity if inductances and capacitances are involved.
Industry:Science
