Advanced Materials Research Vols. 881-883

Abstract: In view of the cutting speed reduced and cutting quality became poor because cutting front changes to flat and amount of lag changes to large, light-gas eccentrically cutting method was proposed. Through the experiment and analysis of the results, the conclusion can be obtained that when laser beam is before gas jet, cutting speed can be improved. While offset distance have impacts to cutting result. If the offset distance is too small, it has no difference with light - gas coaxial cutting; if the offset distance is too large, it weakens the gas jet at the cutting surface, which is not conducive to cutting. It can achieve the best results when the offset distance is 0.3mm.The cutting quality with 1.5mm diameter nozzle is better than that of 2mm. Therefore within the allowable range in the offset distance the nozzle aperture should be reduced.

Abstract: Removed at authors request

Abstract: V/Si binary powders were mechanical alloyed in ball milling machine. The change of microstructure of V/Si powders during mechanical alloying was investigated. The results showed that during ball milling, the size of mixture powders was reduced gradually and the particle shape transited to a ball. Silicon atoms dissolved in vanadium lattice to be a solid solution. The crystal powders were eventually to amorphous state.

Abstract: Traditional procedure of firing glaze is usually time consuming, energy costly and not environmental friendly. This paper reports the result of laser glazing on whiteware, and compares the glossiness and chromaticity of the glazed color surfaces by using a spectrophotometer. The cobalt blue and cobalt black color glaze surfaces are prepared by either traditional firing or laser glazing. Study shows that laser glazing is practicable, the resultant color glaze surface has better glossiness but the chromaticity is slightly weaker than that processed by traditional firing. The method of laser glazing is simple, can save energy, and worth to study further.

Abstract: Silca and its composite powders added different amount of microsilica were ground in a planetary ball mill (QM-3SP4) at various grinding period with addition of a certain number of grinding aid. The effects of mechano-chemical on particle size, crystal size and lattice deformation in grinding process were analyzed. The phase compositions and size compositions of the treated powders were investigated by X-ray Diffraction (XRD) and Laser Particle Size Analyzers. With the increase of grinding time, the particle size decrease, the specific surface area increase, and the more amount of microsilica added, the smaller particle size the powders had after grinding. The XRD results showed that the diffraction peak intensity of powders weaken and gradually widen. The surface of the particle happened to amorphization, and occurred grain refinement and lattice distortion. Comparing with other treated powders, the change of the powders with the microsilica addition of 5% was larger. Even though the grinding time reached to 30h, the crystal transformation of SiO₂ has not been detected.

Abstract: To increase the utilization efficiency of LNG cold energy, this paper analyzes LNG regasification process basing on energy-grade analysis. The result shows that comprehensive utilization both of doing work and heat transfer is the most efficient. Moreover, this paper proposes a chart to select a suitable cold energy utilizaiton way.

Abstract: In this paper, ramie was degummed with hydrogen peroxide and then reduced with reducer. The reducing process can improved the strength and softness of the fiber by 20.96% and 23.88%, respectively. A comparison was made between the fiber oxidation degummed with reducing and degummed with traditional method. Compared with the fiber degummed with traditional method, the strength of the fiber oxidation degummed with reducing was 13.87% lower, but the elongation of the fiber is 12.27% higher.

Abstract: Ramie fiber is known as "China grass". In this paper, Ramie was treated in the experiment of high temperature, low temperature, high and low temperature conditions. The results show that the high temperature affects the strength and breaking elongation obviously for ramie fiber. Low temperature and high & low temperature cycle does not affect much on the strength and breaking elongation.

Abstract: We introduced a design of a novel cooling heat exchanger for crystallization process of MgSO₄.7H₂O, and described the concepts of primary nucleation and secondary nucleation. To avoid the primary nucleation during crystallization process, the super-cooling degree limit of the salt lake brine was measured to define the supersaturation limit to MgSO₄.7H₂O, and the result is 1.32°C at-1°C. In this design, a primary circulation of solution is employed with a large enough flow rate to control the super-cooling degree of solution not to exceed 0.7 °C. A secondary circulation of cooling media is designed to add to this system, instead of the coldest cooling media being fed to shell directly, it is fed to the circulation pipe of the shell. It will help to prevent the supersaturation of solution exceeding the metastable zone width, thus to gurantee no primary nucleation during the Epsom salt crysatllization process.

Abstract: In order to know the application of bentonite in color ink-jet paper, an acid bentonite was prepared by modifying with sulphuric acid. Both of sodium bentonite and acid bentonite were characterized and evaluated with scanning electron microscope. The study result from printing quality testing showed that if the formulation of acid bentonite, under the dosage of 35% PVA and PDMDAAC 3% respectively, was used as the pigment, the print effect could be better.