[Raman, FTIR spectra and normal mode analysis of acetanilide].

The Raman and FTIR spectra of acetanilide (ACN) were measured experimentally in the regions of 3 500-50 and 3 500-600 cm(-1) respectively. The equilibrium geometry and vibration frequencies of ACN were calculated based on density functional theory (DFT) method (B3LYP/6-311G(d, p)). The results showed that the theoretical calculation of molecular structure parameters are in good agreement with previous report and better than the ones calculated based on 6-31G(d), and the calculated frequencies agree well with the experimental ones.

[Application of pyroelectric infrared sensor to radio control alarm system].

A radio control alarm system was developed, which is composed of a pyroelectric infrared detecting module, a radio receiving/transmitting module, a digital encoding/decoding IC, and a voice recoding/playing module. When somebody enters the surveillance area, the infrared sensor will receive and transform the radiant energy into electric signal, which is amplified by internal circuits, and then generates a control signal to start transmitting system. As the encoded pulse is modulated by the transmitting module, a radio control signal will be spread to space; When received, the signal will be demodulated, amplified, shaped and decoded to trigger the recoding/playing circuits, which play the recoded voice to awake watch people.