Research On Characteristics Of Synchronous Fluorescence Spectra Of Living Phytoplankton

Synchronous fluorescence spectra refer to simultaneous scan of both the excitation and emission spectra at a constant offset value or difference between the emission and excitation wavelengths. Its spectra are much easier, selective and the interference of light scatter reduced. It is specially adapt to the multicomponent analysis. This thesis firstly studied the living phytoplankton using synchronous fluorescence spectra. And the chemometrics was also used to obtain qualitative and quantitative information. This paper aims to study the characteristics of synchronous fluorescence spectra of phytoplankton. Ten phytoplankton species, that is, Gymnodinium sp, Prorocentrum dentatum, Alexandrium tamarense; Skeletonema costatuma, Chaetocero didymus, Cylindrotheca closterium, Chaetoceros curvisetus, Chaetocero Debilis; Isochrysis galbana and Platymonas helgolanidica, belong to four divisions of the typical red-tide algae species and dominant species in the East China Sea, were chosen and cultured in lab under different temperatures and different illumination intensities. The main research work includes:1. Spectral feature extraction methods were studied. There were much noise in the original synchronous spectrum and the spectrum was rough. The valued information was covered. Pretreatment were made for the spectra with smoothing and standarding to get the slick spectra. Bayes discriminant analysis was used to test the repeatability of the characteristic spectra. The similarity between the same species and difference between the different species was also studied. The results show that Gymnodinium sp, Prorocentrum dentatum, Alexandrium tamarense; Chaetocero didymus, Cylindrotheca closterium, Chaetoceros curvisetus, Chaetoceros Debilis were difficult to be distinguished from one another because of their spectra's similarity . The recogination error rates were less than 8% neglecting the discriminant error of the five diatom species in various combinations of training sets and test sets at the temperatures of...