https://www.selleckchem.com/products/bzatp-triethylammonium-salt.html A rotating coordinate system model is used to describe the procedure of polarization detection in polarization optical time-domain reflectometry (POTDR), which reveals the relationship of the system response with respect to the initial state of polarization and the direction of the polarizer. On this basis, a 45° aligned dual-polarizer structure is proposed for the suppression of signal fading in the POTDR system. For ease of practical application, an integrated space optics scheme is implemented with the combination of three collimators, one beam splitter, and two polarizers whose principal axes are 45° aligned. Experimental results show that the possibility of signal fading occurrence is reduced from 35.5% in a traditional POTDR down to 6.5% using the proposed scheme.Laser-induced breakdown spectroscopy (LIBS) signals in water always suffer strong pulse-to-pulse fluctuations that result in poor stability of the spectrum. In this work, a spectrum normalization method based on acoustic signals measured by a hydrophone immersed in water was developed and compared with laser energy normalization. The characteristics of the acoustic signals were studied first, and the correlations between the acoustic signals and LIBS spectra were analyzed. It showed that the spectral line intensity has a better linear relationship with the acoustic energy than with the laser energy. Consequently, the acoustic normalization exhibited better performance on the reduction of LIBS spectral fluctuation versus laser energy normalization. Calibration curves of Mn, Sr, and Li were then built to assess the analytical performance of the proposed acoustic normalization method. Compared with the original spectral data, the average RSD_C values of all analyte elements were significantly reduced from 5.00% to 3.18%, and the average RSD_P values were reduced from 5.09% to 3.28%, by using the acoustic normalization method. These res