[Determination of W, Mo and other 8 elements in powder metallurgical materials by ICP-AES].

Samples were dissolved using nitric acid, perchloride acid and hydrofluoride acid in the medium of 0.025 mol x L(-1) EDTA with a kind of standard solutions, and the element contents of Ni, Cu, V, Mn, W, Mo, Co and Cr were determined by ICP-AES method. After investigating the spectral interfere from matrix element and coexistent elements, optimum spectral lines were selected for each analyzed element, and the analytical precision, detection limits and recoveries were measured.

[Simultaneous determination of phenol and resorcinol by dual-wavelength spectrophotometric linear regression method].

Spectrophotometric simultaneous determination of phenol and resorcinol was studied. The absorption spectra of these two components severely overlap in ultraviolet spectral range. In the wavelength range of 250-290 nm, the absorbances of phenol and resorcinol were measured with an internal of 0.

[Fluorimetric determination of trace ruthenium in anode slime of alkali chloride factory with 1,10-phenanthroline].

The complex reaction of ruthenium with 1,10-phenanthroline was studied. In the medium of pH 5 HAc-NaAc buffer and NH2OH * HCl solution, ruthenium reacts with 1,10-phenanthroline to form a 1 : 3 complex by heating in a boiling water bath for 5 min. The fluorescence peak excitation wavelength is 448 nm, and the emission peak wavelength is 586 nm.

[Spectrophotometric simultaneous determination of pyrocatechol, resorcinol and hydroquinone by LM-BP neural network].

By means of artificial neural network and Levenberg Marquardt Back Propagation (LM-BP) train algorithm, the three components of pyrocatechol, resorcinol and hydroquinone were determined simultaneously. The absorption spectra of these three components severely overlap in ultraviolet spectral range. Three wavelengths at 283.

[The pattern of Levenberg-Marquardt backpropagation algorithm for recognition of coronary heart disease patients based on microamount of elements in human blood].

The contents of four microamount elements (Sr, Cu, Mg and Zn) in human blood were chosen as recognition index of coronary heart disease patients and normal persons. The recognition pattern of Levenberg-Marquardt Backpropagation algorithm has been established. The first-layer transfer function is Tansig function; the second-layer transfer function is linear Purelin function.

[Spectrophotometric determination of microamount phosphorus with crystal violet-heteropoly molybdophosphoric acid in the presence of starch].

The determination of phosphorus with crystal violet-heteropoly molybdophosphoric acid in the presence of starch has been studied. In the medium of 0.15 mol.