The α-Fe fibers were prepared successfully by the method of electrodepositing in porous alumina template. The results indicated that the diameter of the fibers was 300 nm and the length of them increased along with t...
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The α-Fe fibers were prepared successfully by the method of electrodepositing in porous alumina template. The results indicated that the diameter of the fibers was 300 nm and the length of them increased along with the electrodepositing time increasing. The saturation magnetization per m2 of the iron fibers increased with the increasing of the length/diameter ratio, but the coercive field decreased.
The transport dynamics of proton exchange membrane fuel cell( PEMFC) is very important to understand its working mechanism and to realize optimization control. A single-channel, three-dimensional model has been develo...
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The transport dynamics of proton exchange membrane fuel cell( PEMFC) is very important to understand its working mechanism and to realize optimization control. A single-channel, three-dimensional model has been developed to study the change of relative humidity of reactant and current density;Dynamic simulation includes average number of H2O/SO42- of membrane surface at cathode, diffusion of oxygen, pressure of channel inlet/outlet, gas flow rate and so on. The conclusion has reference significance regarding the correlated research.
Ca3Cc2O6 is one kind of potential oxide thermoelectric materials. Sol-gel method was applied to synthesize Ca3Co2O6 powder, dried gel and powders are studied systemically with testing measures of the TG/DSC, XRD and S...
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Ca3Cc2O6 is one kind of potential oxide thermoelectric materials. Sol-gel method was applied to synthesize Ca3Co2O6 powder, dried gel and powders are studied systemically with testing measures of the TG/DSC, XRD and SEM. The pH, glycol and calcined temperature were taken into account as main influence factors. It was found during the research that the use of glycol can lighten agglomerates, benefit to auto-combustion, and had no effect on the phases finally. At the same time, Ca3Co2O6 was the offspring of decomposed Ca3Co4O9 at certain calcined condition.
Microstructures of highly compact IrO2 films, deposited on Si (100) substrates by pulsed laser deposition of Ir target at different oxygen partial pressures, were characterized with X-ray diffraction (XRD), Raman spec...
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Microstructures of highly compact IrO2 films, deposited on Si (100) substrates by pulsed laser deposition of Ir target at different oxygen partial pressures, were characterized with X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM).The results show that the films, grown at an oxygen partial pressure of 20 Pa and at a substrate temperature in the range of 250°-500°C, are polycrystalline and that as the substrate temperature rises, IrO2 surface becomes rougher with bigger grains.
The article reported a method of boronize medium absorbing microwave to fabricate boronization layer in the steel surface, and compares it with traditional boronization. The results indicated that the boron atoms for ...
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The article reported a method of boronize medium absorbing microwave to fabricate boronization layer in the steel surface, and compares it with traditional boronization. The results indicated that the boron atoms for the development of boronization layer were rooted in those produced by medium decomposition and gaseous boride, just like the traditional boronization. The growth of boronization layer in microwave was characterized with less than or equal 002> crystal orientation. Its growth rate of boronization layer was faster than that in traditional treatment. Besides temperature effect, growth rate was also influenced by activity boron atom in microwave diffusion in boronization layer.
In this research, we developed a three-dimensional finite-difference-time-domain algorithm that incorporated the Lorentz-Drude model through the use of Z-transform technique. This algorithm was used to compute the spe...
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In this research, we developed a three-dimensional finite-difference-time-domain algorithm that incorporated the Lorentz-Drude model through the use of Z-transform technique. This algorithm was used to compute the spectral response of infrared bandpass filters which consisted of the openings of cross-shaped structures in a thin gold film. In creating structures, a graphical user interface was built using Matlab development environment. The created structures were then simulated by running the simulation code written in Fortran. It was observed that cross-shaped structures with large center-broadening effect yielded the highest transmission intensity among the structures that were simulated with a transmittance of approximately 80% at the wavelength of 1.2 μm.
Water management is critical for high performance of proton exchanges membrane fuel cell (PEMFC). The liquid water transport model for gradient structure gas diffusion layer of PEMFC was established based on the capil...
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Water management is critical for high performance of proton exchanges membrane fuel cell (PEMFC). The liquid water transport model for gradient structure gas diffusion layer of PEMFC was established based on the capillary pressure theory, and then the liquid water flux through GDL was calculated based on the assumption that a fixed liquid saturation difference exists between the interfaces of catalyst layer/GDL and GDL/gas channel, the results were analyzed. Results showed that under steady condition the liquid water flux through GDL increasing with the increasing of porosity, GDL with gradient porosity was more favorable for liquid water to be discharged from MEA to gas channel;the larger the gradient was, the more easily the liquid water was to be discharged out.
TiB2 powders coated with BN were prepared by Hybridization System making use of dry impact blending method to achieve powder surface modification. Parameters of coating were analyzed and the most appropriate condition...
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TiB2 powders coated with BN were prepared by Hybridization System making use of dry impact blending method to achieve powder surface modification. Parameters of coating were analyzed and the most appropriate condition was summarized. Scan electron microscope of JSM-5610LV and transmission electron microscope of H-600STEM/EDS were used to observe the microstructure of coated powders. Results show that treatment time, rotation speed, granularity ratio of TiB2 to BN, pretreatment of materials etc influence the coating results evidently. Mixing raw materials and coating with BN under the appropriate condition can get round TiB2/BN composite powder with smooth surface and compact coating layer.
Highly ordered CoFe2O4 nanowire arrays were prepared in anodic aluminum oxide (AAO) templates with two diameters (50 nm and 200 nm) by Sol-gel method. The scanning electron microscope (SEM), transmission electron micr...
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Highly ordered CoFe2O4 nanowire arrays were prepared in anodic aluminum oxide (AAO) templates with two diameters (50 nm and 200 nm) by Sol-gel method. The scanning electron microscope (SEM), transmission electron microscope (TEM) and high-resolution transmission electron microscope (HRTEM) were used to characterize the structures of the nanowire arrays. The hysteresis loops of the CoFe2O4 nanowire arrays reveal that there was no preferential magnetic orientation in both of the nanowire arrays with different diameters. The measured coercivity of CoFe2O4 nanowire arrays with smaller diameter (50 nm) was larger than that of the nanowire arrays with bigger diameter (200 nm). The possible explanation for this behavior was given.
TiB_2 ceramics powder was synthesized from B_2O_3-TiO_2-Mg system. The effects of TiB_2 addition as diluent on the combustion synthesis process were investigated. The results of thermodynamic calculation and experimen...
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TiB_2 ceramics powder was synthesized from B_2O_3-TiO_2-Mg system. The effects of TiB_2 addition as diluent on the combustion synthesis process were investigated. The results of thermodynamic calculation and experiments show that the increase of TiB_2 content ranging from 0 to 20wt% can reduce the adiabatic temperature T_(ad) from 3100 K to 2896 K and combustion temperature T_c from 2139 K to 1621 K respectively. The particle size and half width of the particle distribution are also increased with the addition of TiB_2 increasing from 0 to 20wt%. The combustion product is a mixture of TiB_2, MgO, and other intermediate phases. The leached product contains mainly TiB_2, TiO_2 and TiN, and its oxygen content is 7.77wt%.
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