Advanced Materials Research Vols. 926-930

Abstract: Crystallization kinetics experiment of calcium sulfate dehydrates, which is prepared by bittern under 20°C and 120r/min conditions, is carried out. According to the results of the experimental data, nucleation density n⁰ of gypsum crystals is proportional to the residence time, and the rate of crystal growth line G is inversely proportional to the residence time. Meanwhile, the crystallization kinetics formula is derived to be: B⁰ = 5.78×10²G^0.87.

Abstract: Antibacterial paper for packaging was sprayed by nanochitosan as antibacterial ingredients. The bacteriostatic circle method was adopted to evaluate its antibacterial effect on E.coli and Staphylococcus aureus. We investigated the effects of different concentrations of nanochitosan on antibacterial paper thickness, tensile strength, bursting strength, folding strength and antibacterial properties.The results showed that: tensile strength, bursting strength and folding strength of the antibacterial paper is better than the control paper and the thickness has no obvious change. The antibacterial paper enhanced the antibacterial effect following the increasing concentration of nanochitosan. The same concentration of nanochitosan antibacterial paper, its inhibitory effect on E.coli was greater than that of Staphylococcus aureus.

Abstract: Phase field model coupled with flow field is solved by the adaptive finite element method. The simulation results show that the forced flow can induce side-branches though there is no thermal noise. When the flow velocity is low, the symmetry of dendrite morphology is slightly influenced by forced flow. With the increase of flow velocity, the symmetry of dendrite morphology is collapsed completely.

Abstract: Sorption behaviors of propranolol (PRO) on montmorillonite and kaolinite in the presence of fulvic acid (FA) and humic acid (HA) were investigated. Complexation of propranolol with FA/HA also have been studied using the fluorescence quenching method. PRO could be complexed by FA and HA strongly in the 5-9 pH range. PRO sorption was found to be higher on montmorillonite than on kaolinite. In the presence of FA/HA, the sorption of PRO on montmorillonite and kaolinite was inhibited and enhanced respectively. The mechanism is due to the free PRO and complexed PRO has different affinity to montmorillonite and kaolinite surfaces.

Abstract: Nitrite and natural organic matters (NOM) are well known to be involved in photochemical processes occurring in natural waters. In this study, phenol is chosen as model molecule to investigate the role of nitrite ions or NOM towards the transformation of organic matters in aqueous solutions under simulated sunlight irradiation. All experiments were performed in pure water at pH 7. The results indicated that phenol phototransformation rate increased with increasing nitrite or NOM concentrations as expected. And •OH radical was demonstrated to be the main relative free radical according to the electron paramagnetic resonance (EPR) and isopropanol quenching experiments. But unexpectedly, the presence of NOM would inhibit nitrite ions-sensitized photolysis of phenol, and it might be attributed to the ROS quenching and light screening effect of NOM. The results imply that for accurate ecological risk assessment of organic pollutants, the integrated effect of water constituent on the environmental photochemical behavior of organic pollutants should not be ignored.

Abstract: Using H₂O₂ and 4-nitrobenzenethiol as substrates, the catalytic behavior of a hydrophobic guest artificial glutathione peroxidase (GPx) (ADA-Te-ADA) was detailed investigated. The relation between the catalytic rate of ADA-Te-ADA and the property of solvent used in the determination of catalytic rate was revealed. Typically, Ethanol, DMSO, DMF and CH₃CN were selected as the co-solvents in the determination of catalytic rates. It indicated that ADA-Te-ADA exhibited the typical solvent-dependent catalytic behavior. Especially, the higher catalytic rate was observed when polar protic solvent (ethanol) was used compared with other co-solvents. It suggested that polar protic solvent was the appropriate co-solvent for the assay of catalytic activity of hydrophobic artificial GPx. Additionally, the strong polarity of polar aprotic solvent plays an important role in the enhancement of GPx catalytic activity. This study bodes well for the understanding of the catalytic behavior of hydrophobic guest artificial GPx .

Abstract: SiC poly-type geometric structure, electronic structure and energy have been subjected to systematic study based on first principle calculation method given in density functional theory. After calculation, the energy results show that 4H-SiC system energy is the lowest and stablest, while 2H-SiC system energy is the highest and unstablest; the calculation results of the band structure show that six SiC poly-types are indirect wide band gap semiconductor, with valence band top on point Γ of Brillouin zone, conduction band bottom on point M of Brillouin zone; with the increase of hexagonality, the energy gap and valence band width are gradually getting smaller, with largest splitting of orbital energy level on 2H-SiC valence band top, reaching to 0.122 eV, while the splitting of orbital energy level on 8H-SiC valence band top is the smallest, with 0.027 eV only.

Abstract: The effect of fermentation by Lentinus edodes hypha on active ingredient of blueberry pomace was studied, and the changes of fermentation products with protein, flavonoid and anthocyanin content were evaluated by spectrophotometric analysis. The protein content decreased slowly, and the flavonoid content in the first 66 h increased the highest level 0.09 mg/g, the anthocyanin content decreased during the first fermentation process, then increased to 0.568 mg/g at 30 h. The fermentation product of ellagic acid and gallic acid content were analyzed by using HPLC Method, the ellagic acid content decreased, and the gallic acid content increased first and then decreased, reached the highest value for the 0.310 mg/g in the first 54 h.

Abstract: The paper based on a comparative study between poplar wood and modified poplar wood, concerning dimensional stability, physical and mechanical properties. The result showed that air-dry density and ASE value of modified wood samples were increasing in different levels with change of the modifier concentration, compared with untreated poplar wood. The air-dry density of modified wood reached 0.41 g/cm3 with increase of 5.3% compared to poplar wood. ASE reached 47.8% and the water-absorption ratio decreased by 38% at most when the modifier concentration was 30 wt.%. Moreover, the MOE and MOR of modified poplar wood increased up to 27.4% and 13% respectively when the modifier concentration was 25 wt.%. The SEM spectrum showed some wood rays and the gaps between staggered fibers were filled by modifier.

Abstract: It discussed repairing the worn engine crankshaft with chromium series metal powder-cored wire. The Mo, Mn, V, Ti metal powder and the SiC ultrafine particles, WC nanopowder added in chromium series metal powder-cored wire. That made the surfacing layer obtained high bonding strength, high hardness, and obtained high fracture toughness. The result indicated the SiC ultrafine particles/WC nanopowder could promotion the in-situ reaction in the surfacing layer, formed the dissemination strengthening, the melting strengthening and so on multi-mechanism strengthening effect. SiC and the metal matrix was not merely the mechanical bond, the partial regions were by the chemical bond. That realized in the structure continuity. And the repaired crankshaft surface wear-resisting disposition enhanced 24% than the original.