Advanced Materials Research Vols. 152-153

Abstract: In order to be informed of the electric car running state parameter in the monitoring center in real-time, this system based on ARM9 - S3C2440 as core chip for data collection and transmission, it completed the data acquisition of the electric car running state by CAN module and wireless transmission the data by GPRS module and AT instructions. This paper has described basic principle of this system, main hardware circuits, program flow charts and parts of the source program. Through the actual test, results show that the system has higher reliability, it realized understand motor speed, battery operating conditions and so on in remote monitor.

Abstract: In this paper, the feasibility of preparing activated carbon from corncob furfural residue with ZnCl2 by microwave irradiation was studied. The effect of the ratio by weight of ZnCl2 to corncob furfural residue, ZnCl2 solution soaking time, microwave irradiation time and the pH value of ZnCl2 solution on the quality of activated carbon was investigated. On the condition that the microwave power is 800 W and ZnCl2 solution mass concentration is 50%, the best technological parameter on preparing activated carbon with ZnCl2 by microwave irradiation is obtained: at the ratio of 3.5:1 by weight of ZnCl2 to corncob furfural residue, microwave irradiation time is 20 min, ZnCl2 solution soaking time is 12 h, the pH value of ZnCl2 solution is 2, the activated carbon yield reached 33.1% and the decolorizing capacity for methylene blue is 202.5 mg/g, the product is used in treating Cr6+ solution(pH value 4.0, concentration 50 mg/L), its adsorption capacity of Cr6+ is 7.583 mg/g.

Abstract: The influences of RE and P complex modification on microstructure and impact toughness of hypereutectic Al-24Si alloy are investigated. The result shows that the coarse block primary silicon is refined obviously and its edges and angles are blunted under the influences of the complex modification of RE and P. The large needle eutectic silicon is modified to the short-rod or particle ones also. The alloys have the finest microstructure and highest impact toughness when adding about 0.10% P and 0.9% RE into alloys. Compared with the unmodified alloy, the average size of primary silicon in the modified alloys refined from 93.5μm to 24.1μm and the impact toughness of alloys increases to 11.0062J/cm2 from 7.3572J/cm2. The excellent impact toughness of alloys can be attributed to the increase of initiation energy and expand energy of the cracks caused by the refinement of primary silicon and eutectic silicon after complex modified with P and RE.

Abstract: New chitosan/poly (vinyl alcohol) (PVA) nanofibers functionalized with silver nanoparticles were electrospun using solutions of PVA blended with silver nanoparticles-chitosan composites. The structure of the electrospun fibers were studied with the aid of scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results indicated that the electrospun fibers smoothly with 220 to 650 nm diameter, and the silver nanoparticles were successfully embed into the fibers which show high antibacterial activity against E.coli.

Abstract: N,N-dimethyl-O-quaternary ammonium chitosan(NNQAC) was synthesized from chitosan by N-dimethylation then quaternized by 2,3-epoxy propyl trimethyl ammonium chloride. The structure of NNQAC was characterized by FTIR. Properties of quaternary ammonium chitosans, including solubility, antimicrobial activity, water-absorption and water-retention ability, were investigated. The results showed that NNQAC was water–soluble in neutral and basic environments. The moisture-absorption and retention abilities of NNQAC were higher than that of chitosan and equivalent to hyaluronic acid. The antibacterial activities of NNQAC were tested against Bacillus subtilis, Escherichia coli and Staphylococcus aureus. In water medium, NNQAC exhibited MIC values in the range of 10 to 2.5 μg/mL.

Abstract: High-porosity NiTi shape memory alloy has pseudo-elasticity and shape memory effect for energy absorption and convenient on-line repair without replace. In this paper, high-porosity NiTi alloys with interconnected and well distributed pores were fabricated successfully by sintering, using NaCl as temporary space-holders. Optical microscope, SEM and XRD have been used to investigate the porosity and pore structures. The results show that porosity can be up to 88%.The size and porosity of the pores depend mainly on the addition of salts in the compacts, and are also related to temperature and forming pressure.

Abstract: The transition fillet radius and surface roughness have a great influence on the part’s fatigue life. In this paper, we analyzed the reasons of a light vehicle’s knuckle arm fracture theoretically by finite element method and took corrective measures such as enlarging the transition fillet and improving the surface quality. After simulation test, we learned that these measures enhance the fatigue life of knuckle arm indeed.

Abstract: To apply copper alginate fibers in medical as a new alginate fiber, copper alginate fibers were researched and evaluated against Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus), using antibacterial zone and flash shaking method to analyze anti-bacterial mechanism by the scanning electron microscopy (SEM). The results showed that copper alginate fibers had antibacterial effects, the antibacterial rate against E.coli and S.aureus were 97.4% and 66.2%, respectively; SEM images indicated that bacteria obviously changed after contacting with fibers, the main reason was that copper ion had a damaging effect on pericellular and cell wall. Furthermore, bacterial osmotic pressure was changed and protein synthesis were impeded, and then the normal metabolism of bacteria was destroyed, and finally, bacteria died.

Abstract: The ibuprofen (IBU) was selected as a model of the poor-water drugs, and the IBU-loaded chitosan/β-cyclodextrin/trisodium citrate nanoparticles were prepared via the ionic cross-linking method. The drug-loading capacity, particle size, zeta potential and surface morphology of the obtained nanoparticles were characterized. The results showed that the IBU had been successfully loaded into the nanoparticles, and showed good drug-loading capacity. The prepared nanoparticles were spherical morphology with an average size of 293.7 nm and a Zeta potential of +30.72 mV. The in vitro release studies showed that the controlled release of IBU from the nanoparticles was followed.

Abstract: Silver plating cenosphere powders were developed by electroless plating method. After being mixed with silver plating cenosphere powders and curing agent, silicone rubber composites was obtained. The surface morphology, microstructure and cross-section of Ag-coated cenosphere powders and composites were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The influence of different concentration of Ag-coated cenosphere powders on the conductivity, electromagnetic shielding interference effectiveness and mechanical properties of the silicone rubber was discussed from the point of view of condition of Ag-coated cenosphere powders and silicone rubber. The results showed that the smooth and compact silver coating was deposited on the surface of cenosphere powders. The Ag-coated cenosphere powders possessed good oxidation resistance and enough strength to resist being crushed during the preparation of composites. The adhension between the silver film and cenosphere powders was good. There existed the extreme shielding effectiveness (SE) of silicone rubber composites filled with Ag-coated cenosphere powders. The electrical conductivity no longer plays an important role in enhancing the SE of composites when the SE of composites reaches the extremum. When the content of the Ag-coated cenosphere powders was 180 parts per hundred of rubber (phr), the SE values of composites were typically above 80 dB and close to the extremum across the tested frequency range from 2.6 GHz to 3.95 GHz. And the mechanical properties of composites with 180 phr were not degraded obviously.