constant phase
3.The Direct Digital Frequency Synthesizer is a kind of fully digitized frequency synthesizer, which consists of the phase accumulator, the sine look-up table, the digital to analog converter and the low band filter. It is of high frequency resolution, fast frequency switching speed, low phase noise, the ability to switch frequencies while maintaining constant phase, and the ability to producing arbitrary waveforms.
4.The structural and thermodynamic properties of zinc-blende phase of GaN have been investigated systematically using the molecular dynamics method with Buckingham potential model. These properties including lattice constant, phase transition pressure (from the zinc-blende to the rock-salt structure), thermal expansion, isothermal bulk modulus, and heat capacity at constant pressure were calculated in a wide range of temperatures (300—3000?K) and pressures (0—65?GPa).
5.Sampling frequency and time constant of phase-locked amplifier were increased by using microcomputer.
8.The theoretical results on far-infrared absorption in small metal particle-insulator composite and the dielectric constant of oil/water two-phase random composite system are in good agreement with experimental data.
9.In the temperature range from 300 to 873 K, the lattice constant of the bcc-structured phase exhibits a nearly linear decrease with the increase of annealing temperature. This is mainly due to the segregation of Cu atoms from the bcc Fe_ 80 Cu_ 20 alloy to form the face centered cubic (fcc) Cu phase.
