Dictionary of Material Science and High Energy Physics Part 9 pptx

... conservation of energy and momentum.density of modes The number of modes of the radiation field in an energy range dE. Thedensity of modes is a function of the boundaryconditions ofthe spaceunder ... single point particlein three-dimensional space has three degrees of freedom; a system of N point particles has 3Ndegrees of freedom.De Haas–Van Alphan effect In 193 0, DeHaas and Van Alphan ... represents a degree of freedom of the distribution.(2) The number of independent coordinatesneeded for the description of the microscopicstate of a system is called the number of degrees of freedom....

... inthe study of Brownian motion in 190 5 and 190 6,the concept was significantly extended by H.Nyquist ( 192 8), L. Onsager ( 193 1), H.B. Callen and T.A. Welton ( 195 1), and R. Kubo ( 195 7).See also ... shift). energy spectrum The set of energy eigen-states of a physical system. The set of possibleoutcomes of a measurement of the energy; alsoknown as the set of allowed energies. energy- time ... closely spaced points and not onthe path between them.exchange energy Part of the energy of asystem of many electrons (or any other type of fermion) that depends on the total spin of thesystem....

... ina flow field.kinetic energy A form of energy associatedwith motion. Every moving particle has kinetic energy. The kinetic energy of a non-relativisticparticle with mass m and speed v is equal ... =m1m2m1+m2is the reduced mass for particles of mass m1 and m2, and r = r1− r2are therelative position vectors of particles 1 and 2.Suitable sets of center -of- mass coordinates canbe similarly ... energy levels of this extra electron lie close to the con-duction band of silicon (∼ 0.05 eV below) and can thus be excited to the conduction band and added to the number of charge carriers. Someuses of...