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61.
The preferential chlorination reaction of iron constituents in roasted ilmenite ore was studied in an experimental fluidized bed reactor. The influence of the roasting temperature on the selectivity of chlorination reactions was also examined. It was found that preferential iron chlorination is dependent on roasted product morphology. Effects of chemical and process variables in the fluidized bed reactor, such as chlorination temperature, chlorine gas partial pressure, gas-solid contact time and the quantity of coke added, were investigated in order to study the kinetics of the preferential chlorination reaction. A modified bubble assemblage model was applied to analyze behavior of gases and solids in the reactor. The chlorination reaction rate constant was found to be a function of temperature and coke quantity present. 相似文献
62.
63.
Yasushi Nagato Mikio Yamamoto Katsuhiko Nagai 《Journal of Low Temperature Physics》1998,110(5-6):1135-1171
Rough surface effects on p-wave Fermi superfluids are discussed on the basis of our recently proposed quasi-classical theory that can treat in a unified way the surface scattering ranging from the specular limit to the diffusive limit. We show how the transition temperature of the ABM state in a slab geometry depends on the surface roughness. In the diffusive limit, our result agrees with Kjäldmann et al. We consider the BW state, the ABM state and the polar state in a half-infinite geometry with a plane rough surface and discuss the self-consistent order parameter and the surface density of states at low temperatures. The rough surface effects on the Andreev scattering in the BW state are also discussed within the same framework. 相似文献
64.
Y Itoh N Fuwa H Muramoto Y Inaba E Kato Y Kikuchi 《Canadian Metallurgical Quarterly》1995,55(15):1066-1067
We report three cases in which continuous intra-arterial infusion therapy via the occipital artery was combined with radiotherapy for head and neck tumors. An angiographic catheter was inserted into the feeding artery of the tumor retrogradely via the occipital artery under fluoroscopic guidance. Patients treated were maxillary sinus cancer, tongue cancer and hemangiosarcoma. No complications occurred due to this procedure in any of the three patients. This procedure was considered very useful when the approach from the superficial temporal artery was not possible due to prior treatment. 相似文献
65.
Gas permeability in poly(vinyl-p-isopropylbenzoate) (PVp-i-PrB) was determined by a timelag method. The transport properties were discussed from comparison with the permeability data of other poly(vinyl esters), which were studied previously. All these polymers are structurally related, and the size of a side group or the position of its substituent was changed systematically. The isopropyl group of PVp-i-PrB is attached at the para position of a phenyl ring and is the largest in size. As a result gas diffusivity and therefore permeability were increased. The effect of the substituent on gas diffusivity was explained as it increases the interchain and intrachain distances. The discussion was supported from the comparison of the density data between PVp-i-PrB and other poly(vinyl esters). The diffusion coefficients of six glassy poly(vinyl esters) were correlated at their Tg and good correlations were shown to the free volume and its fraction. On the other hand, gas solubility was little affected by the change of an alkyl group on a phenyl ring. The solubility data of PVp-i-PrB and poly(vinyl benzoate) were shown to be clearly correlated with the critical properties of the penetrants. © 1995 John Wiley & Sons, Inc. 相似文献
66.
A new method of temperature compensation for a dc logarithmic amplifier is presented. By this method temperature effect on both parallel shift and slope variance of log I vs. VBE curve can be compensated easily by using only one compensating resistor of copper wire wound type. (hereafter called parallel and slope compensations.) An absolute compensation condition can be determined for each type of logarithmic transistors, like silicon NPN, germanium PNP irrespective of current measuring range. The temperature dependence of the logarithmic amplifier is reduced to 0.01 decade for the temperature range from 0°C to 50°C and the current range from 10-11 to 10-3A. 相似文献
67.
Ejima T Yamazaki A Banse T Saito K Kondo Y Ichimaru S Takenaka H 《Applied optics》2005,44(26):5446-5453
Reflection measurements in the 25-35 nm region were made for Mg/SiC and Mg/Y2O3 multilayers kept in a low-humidity atmosphere for 4 or 5 years. Aged Mg/SiC multilayers keep their reflectances, and the reflectance value at 31.2 nm is 0.44 at 10 degrees of the normal angle of incidence. Aged Mg/Y2O3 multilayers change reflectance as top layer materials, and the best value at 30.1 nm is 0.40 at 10 degrees. Reflection measurements are also made for Mg-based multilayers that are annealed from room temperature to 400 degrees C at 50 degrees C intervals. Both multilayers keep their reflectance at annealing temperatures of 200 degrees C. These results suggest that both Mg-based multilayers can be applied to practical optics. 相似文献
68.
Vinu A Shanmugapriya K Chandrasekar G Murugesan V Ariga K 《Journal of nanoscience and nanotechnology》2005,5(4):542-549
As nanoporous reactor, mesoporous silicates containing aluminum acidic site with n(Si)/n(Al) ratio up to 7 (AISBA-15) were prepared through a simple one-pot synthesis, which was recently developed by parts of us. The obtained materials were satisfactorily characterized by XRD and nitrogen adsorption/desorption and have regularly arranged hexagonal structures with pore diameters in the 9.6-11.8-nm range. The density and strength of the acid sites were determined using temperature-programmed desorption (TPD) of pyridine and controlled distribution between weak, moderate, and strong acid sites was demonstrated. The alkylation of ethylbenzene in a fixed-bed flow-type reactor using the AISBA-15 nanoporous reactor was carried out under various conditions such as temperature, feed ratio, flow rate, and time on stream. Interestingly, perfect regioselectivity between the m-isomer and the o-/p-isomers of diethylbenzene was achieved, where 100% selectivity of the m-isomer or the o-/p-isomers can be obtained by simply tuning the reaction temperature by using AISBA-15 catalyst with appropriate aluminum content. 相似文献
69.
A numerical method for analyzing the uniformity of flow from sheeting dies is presented. The method assumes that the flow is isothermal and that the material is a power law fluid. A uniformity index is defined and methods are presented which enable die dimensions to be established which will result in a specified uniformity at particular flow rates and pressure drops. The analysis shows that the flow index “n” of the power law is the key parameter determining the uniformity of flow from a sheeting die. 相似文献
70.