AbstractConsidering the difficulty of detecting the fault condition of copper flotation in real-time, a new fault condition detection method based on the wavelet multi-scale binary image is proposed. Firstly, the froth gray image is decomposed into approximation sub-images and detailed sub-images by wavelet transformation, whereby the approximation sub-images of different scales are restructured and binarized. Then a new feature that is directly related to froth morphology, namely the equivalent size feature, is obtained by calculating the white area of each binary image according to the space-frequency relationship of a two-dimensional wavelet transformation. After this, the equivalent size distribution of the froth image can be obtained through the equivalent size feature. At last, the equivalent size distributions of different froth images are compared in order to classify the froth images under different flotation conditions. Experiment results, together with the industrial field data, show that this method can simply and effectively detect fault conditions in the copper flotation process.

A series of 6-substituted purines were synthesized from commercially available 2-amino-6-chloropurine with appropriate reagents, and nine new compounds 7, 8, and 11-17 have been discovered. The compounds synthesized were identified by elemental analysis, ¹H NMR, as well as mass spectral data. All the title compounds were screened for their antifungal activities, under the method of the disc diffusion, using three species of fungi - Bacillus subtillis, Aspergillus niger, and Candida tropicalis- and some of the compounds showed promising activities.

Se preparó una serie de purinas 6-sustituidas a partir de la 2-amino-6-cloropurina, que está disponible comercialmente, y de los reactivos apropiados, de los cuales los derivados 7, 8 y 11-17 no han sido reportados previamente. Los compuestos sintetizados se caracterizaron por análisis elemental, RMN ¹H y espectrometría de masas. Todos los compuestos se evaluaron en su actividad antifúngica, a través del método de difusión de discos, sobre tres especies de hongos - Bacillus subtillis, Aspergillus niger y Candida tropicalis-, mostrando algunos de ellos una actividad promisoria.