Advanced Materials Research Vols. 160-162

Abstract: The optical response of an atomic vapor can be controlled by using tunable quantum interference induced by external control field. A periodic layered medium whose unit cells consist of dielectric (e.g., GaAs) and EIT (electromagnetically induced transparency) atomic vapor is suggested. It is demonstrated that such an EIT-based periodic layered medium shows more flexible optical response (sensitive to frequency) than a conventional photonic crystal does. The controllable band structure that depends on the external control field can be applicable to designs of new devices such as photonic switches and photonic logic gates, where one laser field can be controlled by the other one, and would have potential applications in the field of integrated optical circuits and other related areas, e.g., the all-optical technique.

Abstract: The cyclohexanone production wastewater includes hazardous material such as cyclohexanone and cyclohexane which can harm the vessel of human body resulting in coagulation necrosis of viscera and brain. Our experiment choosed the cyclohexanone production wastewater to be investigated, and used the self-made anaerobic upflow bed filter (UBF) to deal with it. We try to find the optimal operational parameters which can make the degradation of hazardous materials maximizing. The COD removal efficiency was decreasing with the COD of influent’s increasing in starting stage, the shock load made the microbe in UBF can’t adapt the high VLR temporarily. In the running stage, the anaerobic sludge in UBF was incompact and the settleability of sludge was not very well. As the UBF running, the granular sludge shaped up greatly, the COD removal efficiency kept on 80%. The result showed that the UBF reactor was valid for hazardous material in cyclohexanone production wastewater.

Abstract: The aquatic ecosystem of lake is a complex open systems, this study that is based on the principles of maximum flux selects Caohai as the object, we apply complex systems analysis to construct eutropication model which is suitable for local conditions and select a larger time scale and control parameters to simulate the eutrophication status to find out the main factors and to put forward reasonable proposals for giving out optimal control techniques. This model can be expanded in time scale, spatial scale and the number of parameters, while the difficulty of calculation and analysis will not be increased. The trend and influencing factors of the system will be got at the same time.

Abstract: Dry and wet oxidation silica films doped with silicon ions were prepared using metal vapor vacuum arc (MEVVA) ion source implanter. The does of Si ion beams were kept constant at 3×1016 /cm2 and the energy varied from 42KeV to 70KeV. Five photoluminescence (PL) bands at the wavelength of 560nm, 580nm, 620nm, 650nm and 730nm have been observed at room temperature in all samples. The results of XRD showed none of Si nanocrystals were formed in the as-implanted silica films and originations of the PL bands were defects introduced by implantation. The 560nm PL band originated from oxygen surplus defect small peroxy radical (SPR), whereas the PL bands which ranges from the wavelength of 620nm to 730nm were attributed to non bridge oxygen hole center (NBOHC). Elevating implantation energy resulted in intensity increasing of 560nm PL band of dry oxidation samples but had inverse effects on wet oxidation samples. Influence mechanism of implantation energy on the defect photoluminescence was discussed in this article.

Abstract: The Fe3Al/Al2O3 composites were fabricated by plasma active sintering process. The Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment. The Fe3Al intermetallics compounds powders and Al2O3 powders were mixed together, so the Fe3Al/Al2O3 composites were fabricated by plasma active sintering process at 1200oC for 5min under the pressure of 30MPa. The phase composition and microstructure of the Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition and microstructure of the Fe3Al/Al2O3 composites produced by plasma active sintering process were investigated. The XRD patterns results showed that the Fe3Al intermetallics compounds powders were fabricated by mechanical alloying for 60h and heat treatment process. The XRD patterns results showed that there existed Fe3Al phase and Al2O3 phase in sintered composites. The microstructure showed that the mean particles size of the Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment was about 4-5μm. The Fe3Al/Al2O3 composites exhibited the homogenous and compact microstructure. The mean particles size of Fe3Al was about 2-3μm and mean particles size of Al2O3 was about 2-3μm. The Fe3Al/Al2O3 composites exhibited homogenous and compact microstructure with the increase of Fe3Al content. The density and relative density of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content.

Abstract: Over the last ten years, sulfuric acid dewpoint corrosion has become a more important concern in refinery furnaces since sulfur levels in fuels have increased. Electroless nickel phosphorous coating is one of the most widely used industrial coatings owing to its good corrosion resistance in many highly corrosive environments. In this work, electroless Ni-P-SiO2 composite coatings were prepared on AISI 1020 carbon steel. And the corrosion behaviors of Ni-P-SiO2, Ni-P coatings and carbon steel substrate were evaluated by immersion, electrochemical tests in 5%wt sulfuric acid solution, and dewpoint corrosion tests in simulated furnace flue gas. The experimental results indicated that corrosion resistance properties of Ni-P-SiO2 coating was best, followed by Ni-P coating and carbon steel was worst.

Abstract: By using electrochemical techniques, the electrochemical characteristic of Cr-based film coated 304 stainless steel (304SS) as proton exchange membrane fuel cell (PEMFC) bipolar plates, which was deposited by cathodic arc deposition technology, was studied. The results indicated that Cr, CrN, (TiCr)N and (TiN+Ti) film could not only decreased the steel’s contact resistance but also improved its corrosion resistance and the fuel cell stack’s performance. Since Cr, (CrN) and (TiCrN) film were more compact than (TiN+Ti) film, which contained the oxides of Ti, as bipolar plates, the performance for all film change in the following order: Cr film ≈(CrN) film ≈ (TiCrN) film >(TiN+Ti) film.

Abstract: The nonlinear viscoelastic response of a PVC-Coated Fabric has been studied. For the needs of the present study, creep and recovery tests in tension of both the warp and the weft directions at the different stress levels were executed while measurements were made of the creep and recovery strain response of the system. For the description of the viscoelastic behaviour of the material, Schapery’s nonlinear viscoelastic model was used. For the description of the nonlinear viscoelastic response and the determination of the nonlinear parameters, a method by using a combination of analytical formulations and numerical procedures based on a modified version of Schapery’s constitutive relationship where an instantaneous plastic and a transient plastic terms were added, has been developed. The method has been successfully applied to the current tests.

Abstract: Hot spot stress (HSS) approach is more applicable for fatigue evaluation, because it is more closer to the real stress at the welded notch than nominal stress.This paper studies a typical welded joint, fillet welded joint, which is used widely in high-speed car. Hot spot stress concentration factor is calculated under different nominal stress and loading methods. The S-N curves belong to nominal stress and hot spot stress were analysized. The result show that the difference between the S-N curves under different load style can be reduced greatly by hot spot stress. The hot spot stress characteristic variable was put forward, which is used to describe the influence from the welding size of the joint.

Abstract: Many experiments and analysis of folded honeycomb consisting of corrugated paperboards show that the use of linerboard can increase the energy absorption and weight of folded honeycombs. However, it reduces the energy absorption per unit volume and unit mass and increases the cushioning cost either. For the same corrugate shape, reducing corrugated size will increase the weight of folded honeycombs, and changing corrugated size will change the energy absorption per unit volume, but it can not change the cushioning cost. At a low relative density of corrugated sandwiches, the energy absorption per unit volume and unit mass rapidly increases, and the cushioning cost decreases when the relative density of corrugated sandwiches rises. While at a higher relative density, the energy absorption per unit volume and unit mass does not effectively increase with relative density of corrugated sandwiches. However, the cushioning cost may increases. Therefore, when designing the corrugated sandwich size, we can change the thickness of corrugate basis-paper or the corrugated size to change the relative density of corrugated sandwiches and the cushioning cost.