Advanced Materials Research Vols. 915-916

Abstract: It is discribed that the reductive method of copper in the reduction tube and how to optimize oxygen dosing of Vario EL III elemental analyzer.

Abstract: The distribution of temperatures and stresses in the die during high pressure die casting are computed through commercially finite element software developed by Wincast team, Germany. The deformation of the die during its continual running is predicted under the conditions without and with air cooling. The simulated results show that the regions of die, which contact with the casting, is subjected to compressed stresses and the other regions of the die subjected to tensile stresses. Compressed stresses are changed steeply from tensile to compress on the boundary between the casting and the inner cavity walls, which will results in hot-fatigue in those regions of the die. Setting cooling channel within the die is an efficient measure for eliminating hot-fatigue and prolonging life of the die.

Abstract: Intermittent pulsed arc welding using micro heat control, it can be used to repair the defect of metal parts. But the droplet transfer mode is different from the general pulsed TIG. The image signals of intermittent pulsed droplet transfer are acquired using speed camera systems. Then, the characteristics of droplet transfer for intermittent pulsed arc welding were discussed. The results showed that in the Intermittent pulsed arc welding repair process, welding wire and substrate surface were melted by instantaneous high voltage arc and formed drop wise droplet. And with gravity and surface tension the droplet jitter, roll, and then cooled and solidified rapidly. The change of microstructure is continuous from the substrate to the droplet, showing a good metallurgical bonding.

Abstract: A Compact and precise gonio-stage for Grazing incidence X-ray absorption fine structure (GIXAFS) measurement is presented in this paper. The gonio-stage can provide a range of 0-35mrad and a resolution of 0.012mrad. An expert alignment can be realized automatically by computer program to obtain precise initial condition. An accuracy verification test of angle control carried out on BL7C station in KEK gives a satisfied result. At last, high quality GIXAFS spectra for 200nm thick HfO₂/Si thin film were obtained.

Abstract: Using the method of complex analysis and by constructing conformal mapping, the study investigated the antiplane shearing problem of circular holes with 2^k periodic cracks in one-dimensional hexagonal quasicrystals. Wherefrom we simulated the problem of antiplane shearing in circular holes of cross-cracks, single-cracks, symmetrical double-cracks, symmetrical four-cracks, as well as periodic straight cracks, and provided an analytic solution to the crack tip stress intensity factor (SIF).

Abstract: Finishing needle is a micro finishing tool, used for increasing smooth finish and enhancing the material performance of the mipor finishing. Because of the tiny size and complicated shape, at present, only the traditional manual grinding is being used in the domestic. Manual processing needs high technical requirements and strong dependence. It is difficult to guarantee the quality of the processing. Therefore, this paper studies the automatic processing of micro-finishing tool, develops an automatic processing apparatus and the experiments show that this device can achieve automatic processing of finishing needle basically.

Abstract: Based on previous measured data and adsorption isotherms experiment of six coal samples from different stratification of the southern Qinshui basin, discussed the diversity between different stratification on adsorption characteristics and its main controlling factors. The results show that: In the macro level, bright coal layer has the highest adsorption capacity, Langmuir volume (VL) is up to 40m³/t ; the adsorption capacity of dull coal and semi-dull coal is relatively low. By analyzing the relationship between the Langmuir volume of coal petrography and various factors, discovering the Langmuir volume has a positive correlation with vitrinite content, vitrinite reflectance, fixed carbon content, and micro-pores content, but negative correlation with ash, while it has no significant linear relationship between moisture, porosity, permeability. By grey relational analysis, it shows that the impact is in descending order from vitrinite content to fixed carbon content, vitrinite reflectance, micro-pores content, ash content.

Abstract: This paper focused on the influences of different coal macrolithotypes on the coal reservoir properties, using a variety of testing methods studied the connection between macro-lithotype of coal and properties. When coal lithotypes changing from dull coal, bright coal, semibright coal to semidull coal, the adsorption pores change from enclosed types to open, adsorption capacities improved in turn, which is favorable to adsorption, desorption and diffusion of coalbed methane. Seepage pores of bright coal are the most developed, semidull coal and semibright coal less, dull coal the least. The permeability of coal has a positive correlation between microfissure density and large pore content. Different macrolithotype of the same coal seam changes with the permeability could be divided into three stages, including fractures decrease rapidly stage, fractures decrease slowly stage and fractures tend to be closed stage.

Abstract: With XRD and IR, the authors conducted studies on the intercalation of acrylamide and salts of fatty acids in kaolinite of coal-bearing strata and its stability. The acrylamaide and the salts of fatty acids were successfully intercalated into kaolinite by virtue of polar organic complexes, which acted the part of entrainer. The basic spacing changed from origin value of 0.718nm to 1.122nm and 1.132nm respectively after the intercalation was perfectly accomplished in kaolinite. The phenomenon that organic complexes are intercalated into kaolinite and form a stable interlayer is probably related to the formation of hydrogen bonds between the inner-surface hydroxyls and the intercalated molecules.

Abstract: For refractory oxidised copper ores of Huidong Sichuan province, studing the different depressants on the influence of oxidised copper ores flotation behavior. The results showed that: the depressanting effect of the combination of sodium hexametaphosphate primarily is better. When the dosage of the combination of sodium hexametaphosphate and sodium humate reagent is 300 g/t, ratio is 2:1,the recovery of copper concentrate is 83.31and the grade is 19.01 in the closed circuit experiment.