[Spectral classification based on Bayes decision].

The rapid development of astronomical observation has led to many large sky surveys such as SDSS (Sloan digital sky survey) and LAMOST (large sky area multi-object spectroscopic telescope). Since these surveys have produced very large numbers of spectra, automated spectral analysis becomes desirable and necessary. The present paper studies the spectral classification method based on Bayes decision theory, which divides spectra into three types: star, galaxy and quasar.

[Simultaneous determination of nine organochlorine pesticide residues in textile by high performance liquid chromatography].

A method for the simultaneous determination of pesticide and herbicide residues in cotton textile by high performance liquid chromatography coupled with diode array detector (HPLC-DAD) has been established. The pesticides and herbicides determined were 2,4-dichlorophenoxy (2,4-D), 2-methyl-4-chlorophenoxy acetic acid (MCPA), dichlorprop, mecoprop, 2,4, 5-trichlorophenoxy (2, 4, 5-T), 2-methyl-4-chlorophenoxy butyric acid (MCPB), beta-endosulfan, methoxychlor and 2, 2-bis (p-chlorophenyl)-1, 1-dichloroethene (DDE). Pesticide and herbicide residues in cotton products were extracted with acetone-petroleum ether by ultrasonic instrument.

[Determination of isophthalic acid in polyethylene glycol terephthalate fiber by high performance liquid chromatography].

The isophthalic acid(IPA) is present in polyethylene glycol terephthalate(PET) at small level, but plays an important role for the properties of polyester fiber. Thus the PET sample was hydrolysated by 100 g/L of sodium hydrate in methanol at 70 degrees C during 10 h and finally assayed by HPLC. A reversed-phase high performance liquid chromatographic method for the separation of isophthalic acid from terephthalic acid(TPA) has been developed.

[Structural identification of carboxylic esters by pyrolysis gas chromatography].

A pyrolysis gas chromatographic method has been investigated for structural identification of carboxylic esters. The method can be applied to identify not only pure components, but also those separated by thin layer chromatography and scraped from the TLC plate without removing the adsorbent. The samples were pyrolyzed in tube furnace pyrolyzer at 500 degrees C (conventional pyrolysis) or were pyrolyzed at 550 degrees C after mixing with soda-lime powder (pyrolysis with soda-lime).