Applied Mechanics and Materials Vol. 472

Abstract: In this paper, a nanofabrication technology of alumina self-organization method for deep and self-arranged nanometer holes on high purity aluminum is presented. Deep and self-arranged nanometer holes can be used as antireflection structures, polarizing elements, guided-mode resonance filters and high efficiency diffraction optical elements. The fabrication technology provided an effective method for low-cost, large-scale manufacturing high aspect ratio nanoholes.The deep nanoholes structure is fabricated by two anodizing processes on aluminum. The theoretical calculation of reflectivity for the fabricated deep holes G-solver sofeware while the measurement setup for the reflectivity of the deep nanoholes is self-made optical parameter test system.The results show that the calculated reflectivity of the deep holes is below 8.0% within the visible wavelength range, while the measured reflectivity of the fabricated nanometer holes is under 8.30% within the wavelength range of 400-760nm and it agrees well with the theoretical analysis result.

Abstract: We examined the optical properties of nanolayered metal-dielectric lattices. At subwavelength regimes, the periodic array of metallic nanofilms demonstrates nonlocality-induced double refraction, conventional positive and as well as negative. In particular, we report on energy-flow considerations concerning both refractive behaviors concurrently. Numerical simulations provide transmittance of individual beams in Ag-TiO₂ metamaterials under different configurations. In regimes of the effective-medium theory predicting elliptic dispersion, negative refraction may be stronger than the expected positive refraction.

Abstract: In this work, a general expression of the thermo-acoustic (TA) emission from nanocrystalline porous silicon (nc-PS) is derived by using a fully thermally-mechanically coupled multilayer TA model. This expression takes thermal, mechanical, and geometry properties of every layer in a multilayer structure, as well as the thermal contact resistances between layers into consideration and hence agrees well with the experimental results. Therefore, many fundamental problems in thermally induced ultrasonic emission from nanoporous silicon can be studied.

Abstract: We report here a facile and green route to prepare graphene-based composites with titanium dioxide-cuprous oxide heterostructure. The as-prepared hybrid was characterized by X-ray diffraction, Fourier transform infrared spectrometer, Raman spectroscopy, and scanning electron microscopy. Photocatalytic degradation of Rhodamine B demonstrated that the as-prepared hybrid has high photocatalytic activities under the visible-light irradiation. We believe that the new graphene-based material would have a potential application in field of energy and sustainabliligy.

Abstract: Recentaly, semiconductor nanowires (NWs) exhibit unique electrical, optical, and mechanical properties. Single crystalline CdS uniform branched Nanowire was synthesized by a simple, template-free, low-temperature synthesis of CdS uniform branched Nanowires with the hexagonal wurtzite phase from powder CdS under chemical vapor deposition (CVD) technique is demonstrated. It is shown through extensive spectroscopic and structural characterization that the nanostructures we prepared was branched morphology. X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electronic microscopy (TEM) used to study the crystalline structure, composition and morphology of different samples results for this series of Bi₂S₃ seeds reveal major reaction consequences. Vaporliquidsolid (VLS) processes were proposed for the growth of the CdS uniform branched Nanowire. The results presented here presented the capacity to engineer nanowire p-n junctions exchange interactions via this strategies. Keywords:nanowire,Semiconductor,CVD

Abstract: Micro-electro-mechanical system (MEMS) have recently seen their field of application extended to military. This is mainly due to the fact that MEMS technologies present a great to reduce the mass, cost, power consumption, while improving the reliability, performance and smartness. Application of MEMS technology, the micropyrotechnic igniter are produced.The principle is based on the integration of lead styphnate (LTNR) material within a micropyrotechnic igniter, which is produced by MEMS with 3 by 3 micro-igniter. Each igniter contains three parts (the igniter chip, silicon chamber, lead styphnate). One import point is the optimization of the igniter process obtaining Ni-Cr bridges with about 13Ω, which is triggered by electrical power delivered to LTNR. The resistance of Ni-Cr bridges is used to sense the temperature on the LTNR which is in contact. The other one point is the optimization of silicon chamber process obtaining incorporate configuration of micropyrotechnic igniter. The ignition performance of micropyrotechnic igniter array are tested with ignition voltage less than 13V. The experimental results will deeply contribute to the micropyrotechnic system. This paper will discuss all these point.

Abstract: Among different biodiesel production technologies, microalgae biodiesel production has exhibited largest potential as an substitute of fossil fuels. Microalgae are effective photosynthetic microorganisms and ideal materials for biodiesel production because they have many advantages, such as the high lipid content, fast growth rate and good adaptability. Most key factor for the industrialization of microalgae biodiesel production is selecting the microalgae with rich lipid, which determines the production cost of microalgae biodiesel. The different breeding technologies of microalgae can significantly shorten the breeding time, reduce the production cost and obtain expected strains. The prospect of microalgael application in biodiesel production was also discussed.

Abstract: In order to establish quantitative structure-activity relationship (QSAR) model of cyclohexene derivatives as neuraminidase inhibitors, the relationships between the anti-influenza activity of 34 cyclohexene derivatives and their molecular connectivity indices (^mX) as well as their electrotopological state indices (I_m) were analyzed, meanwhile molecular structures of the substances were also effectively characterized. On the one hand, two molecular connectivity ⁰X, ³X and four electrotopological state indices I₁, I₃, I₆, I₁₆, which were obtained by optimization of multiple linear stepwise regression, were employed to found QSAR model through stepwise regression analysis, where the correlation coefficient of equation was 0.906 and the average absolute error between experimental values and estimates was 0.37. On the other hand, Using these structural parameters above as the input neurons, a satisfying neural network model with the 6-2-1 network architecture was also constructed by the back-propagation (BP) algorithm, where the total correlation coefficient reached up to 0.966 and the average absolute error between experimental values and estimates of the model decreased to 0.19. Therefore it was concluded that the results of BP network were better than those of multiple linear regression methods.

Abstract: Objective:To study the effect of oxymatrine on apoptosis of human carcinoma cell line MGC-803. Methods:Flow cytometry were conducted to investigate apoptosis rate and expression of Bcl-2 and Bax protein. Results: At the dose of oxymatrine were 1mg/ml,2mg/ml,the apoptosis rates in MGC-803 were higher than those of controls (p<0.05), the expression of Bcl-2 was decreased and Bax was increased significantly (p<0.05).Conclusion:Oxymatrine induces apoptosis in human carcinoma cell line MGC-803, its mechanism includes up-regulated expression of Bax and down-regulated expression of Bcl-2.

Abstract: Liquid hot water pretreatment, as an initial step in an alternative use of lignocellulosic biomass to produce fermentable sugar, was performed in this study. The effect of pretreatment temperature range from 160 to 200 °C on the hemicellulose degradation (the yields of glucose and xylose, as well as inhibitors) and cellulose enzymatic digestibility were evaluated. The results indicated that the maximum xylose yields (combined 2.23 g xylose and 13.20 g xylo-oligosaccharides per 100g raw material) in prehydrolysate liquid were obtained at 180 °C. The untreated and pretreated solid residues were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and fourier transform infrared spectroscopy (FT-IR). The results showed that liquid hot water pretreatment removed a large number of hemicellulose and resulted in enriched cellulose and lignin content in the pretreated residues. Due to the effective removal of hemicellulose, the maximum glucose yield in enzyme hydrolyzate reached 37.27 g per 100 g raw material (after the pretreatment temperature of 200°C), representing 90.13% of glucose in the sugarcane bagasse.