Advanced Materials Research Vols. 926-930

Abstract: A layered structure of different copper oxides was produced by thermal oxidation of copper. The structure and microstructure of the different layers were investigated by scanning electron microscopy and transmission electron microscopy. From the substrate to the free surface, three different layers are formed, namely, Cu₂O layer, CuO layer and CuO nanowires. Based on our observations, a possible formation mechanism of layered copper oxides and CuO nanowires was proposed. The results shed light on the oxidation process of metals and provide insight into the synthesis of copper oxides and CuO nanowires.

Abstract: The composition and origin of organic matter (OM) released form three PM₁₀ samples obtained from biomass and oil combustion was investigated in this study. The Py-GC/MS system was applied and experiments were conducted at 5 °C/min to 750 °C. A difference in the composition and therefore in OM between the examined samples was observed. The greatest variation in released compounds was noted for PM₁₀ sample obtained from biomass combustion. Whereas the least variation in composition was observed for PM₁₀ sample obtained from B oil sample. The latter consisted in majority of squalene (81.5 %). As a result, the quantity of OM released by the biomass sample was greater by 18.2 % and 33.9 % that the quantity released by A and B oil samples, respectively.

Abstract: In this paper, the bandgap characteristics of binary colloidal crystals (BCCs) constructed with polystyrene (PS) particles are analyzed, and several binary colloidal crystals were fabricated, specifically the non-close packed structures with improved vertical deposit method. The SEM images and reflectance spectra of the structures exhibit fine orderly structures obtained.

Abstract: Contact angle measurement is a simple and quick method that expresses the surface wettability. Resulting values vary and depend on many factors that significantly affect the interpretation of results. In this paper a set of seventeen samples from different deposits with different genesis were subjected to a statistical evaluation, to determine the optimal number of measurements needed to obtain the desired standard deviation.

Abstract: Mg-doped ZnO thin films are successfully synthesized via an electro-deposition route, using urotropine as the complex agent. The XRD results show that Mg_xZn_1-xO films possess a wurtzite crystal structure and the (002) diffraction peak shifts to a high angle with Mg²⁺ concentration increasing, which indicate that a small quantity of Mg atoms is incorporated into the ZnO lattices. Raman scattering reveals that Mg-doping can eliminate the oxygen vacancies. The spectral position of the photoluminescence and optical band gap were successfully tuned from 3.3 to 3.72eV by adjusting the Mg content. Throughout this tuning range, the crystal quality was sufficiently preserved to maintain the excitonic nature of the material resulting in very efficient ultraviolet emission.

Abstract: This paper was according to the early crack identification on metal deep drawing, combined with the characteristics of the AE singal of deep drawing forming, determined to analyze it by db4 wavelet basis function for 3 layers, extracted the energy value at every point of the eight AE signal samples from deep drawing forming which crack state was known to constituted characteristic matrix, fuzzy equivalence matrix was obtained by a series of matrix transformation,which was regard as pattern library of crack that used in cluster analysis. Then extracted energy value at every point of AE signal from deep drawing experiments with there states unknown, calculate similarity between samples and the model we established by using euclidean distance formula after normalization processing, deep drawing state was determined by the principle of selecting near, finally compared the recognition result with crack situation deviced by naked eye and microscope, results show that the accuracy of fuzzy identification of early crackn based on fuzzy clustering is up to 90%.

Abstract: A novel Y zeolite-containing composite material was prepared via in situ crystallization with sepiolite and catalyst residue as starting materials, of which the BET surface area is up to 582 m²/g, the pore volume is 0.43 cm³/g, the relative crystallinity is as high as 55.7 %, the surface is smooth and regular, and Y zeolite particles are in the range of 0.4-1.0 mirons, the composite contains large number Y zeolite with more meso-macro porous structure.The alkalinity in reaction medium has a pronounced effect on the relative crystallinity of Y zeolite.

Abstract: High-purity alumina has excellent performance and wide application in high-tech industries and areas of modern materials, so industrialized, low-cost, non-polluting and sustainable development preparation process has become one of the priorities of present high-purity alumina powder research. The use of high purity alumina and its major domestic craft preparation methods are described in the paper.

Abstract: Aligned array electrospun nanofibers are preferred and even necessary in most of applications. Most research reported was focus on the quality and uniform of directions of the array nanofibers. This paper describes a simple method for fabrication of large area aligned naonofibers. A zigzag shape collector was used in the electrospinning system. Alignment of nanofibers was realized by this system. Nanofibers collected on the peak and valley of the Aluminum foil were oriented. This system is a hybrid structure of parallel electrodes and disc collector with tip-like top.