2014-07-25 11:53 供稿单位: 新航道
De Broglie wavelength
A wavelength, given by = h/mv, which is associated with matter. Louis de Broglie proposed the idea that matter could be treated as waves in 1923 and applied this theory successfully to small particles like electrons.
中国英语培训 Decay constant
A constant, , not to be confused with wavelength, that defines the speed at which a radioactive element undergoes decay. The greater is, the faster the element decays.
中国英语培训 A logorithmic unit for measuring the volume of sound, which is the square of the amplitude of sound waves.
The process by which a gas turns directly into a solid because it cannot exist as a liquid at certain pressures.
中国英语培训 Destructive interference
中国英语培训 The cancellation of one wave by another wave that is exactly out of phase with the first. Despite the dramatic name of this phenomenon, nothing is “destroyed” by this interference—the two waves emerge intact once they have passed each other.
中国英语培训 The bending of light at the corners of objects or as it passes through narrow slits or apertures.
A sheet, film, or screen with a pattern of equally spaced slits. Typically the width of the slits and space between them is chosen to generate a particular diffraction pattern.
中国英语培训 The property of a vector that distinguishes it from a scalar: while scalars have only a magnitude, vectors have both a magnitude and a direction. When graphing vectors in the xy-coordinate space, direction is usually given by the angle measured counterclockwise from the x-axis to the vector.
中国英语培训 Two quantities are directly proportional if an increase in one results in a proportional increase in the other, and a decrease in one results in a proportional decrease in the other. In a formula defining a certain quantity, those quantities to which it's directly proportional will appear in the numerator.