Applied Mechanics and Materials Vols. 138-139

Abstract: In this paper, three-dimensional automatic fuel measuring device of diesel engine test bed was created. The function of virtual assembly was achieved using virtual reality modeling language. Network virtual assembly can operate, browse and assemble automatic fuel measuring device remotely by embedding virtual assembly in web pages. The virtual assembly method presented in this paper can be easily extended to deal with many other problems in engineering system if control parameters are modified properly.

Abstract: Natural modes and flutter of the sweptback wing are analyzed at different temperatures. Natural frequencies are reduced as temperature increasing, the temperature gradient in the structure tend to reduce model stiffness due to changing in material properties and development of thermal stress, which degrade the structure stability. Results in this paper show that the 1^st~4^th order natural frequencies of sweptback wing in this paper decrease by about 12.09%, 15.06%, 14.31% and 12.57%respectively from room temperature to 450°C.The flutter frequency and velocity are also reduced as the decreasing of natural frequency due to the elevating of temperature by aero-heating; and the flutter frequency and velocity decrease by about 12.42% and 16.69% respectively as the temperature elevating from normal up to 450°C at Ma=3.0.

Abstract: Based on the numerical calculation of three-dimension flow field of the exhaust system, a code is developed by the reverse Monte-Carlo method (RMCM) to simulate the infrared radiation characteristics of the aeroengine exhaust system and the plume. A ray-tracing method (RTM) is introduced to seek the meshes of the flow field which the ray travels through to avoid the trouble of interpolation. The infrared radiation characteristics of a certain turbo-fan engine’s ejector nozzle in the waveband of 3-5μm is simulated at non-afterburning condition. The results of the simulation show that : (1)Because of the introduction of the secondary flow, the average temperature of the ejector nozzle’s core plume is 20K lower than the baseline one’s.(2) The infrared intensity for the ejector nozzle is most reduced relatively by 44.5% in comparison with the baseline nozzle along lateral direction.(3) The ejector nozzle has a better performance of infrared stealth.

Abstract: In order to give consistent and agreeable results in resistance and other hydrodynamic performance with some of the viscous Computational Fluid Dynamics methods which appear to have difficulties when applied to hulls, the investigation of the influential factors like mesh generation which affect the calculation results are taken by the simulation of different cases in the present paper. Through calculation and analysis, specifically with the CFD code FLUENT, an alternative set of computation parameters of mesh generation for engineering application is suggested. The application of the suggestion to the hull researched in this paper result in better agreements with corresponding model tests.

Abstract: In this paper dipole type optical antenna and V type optical antenna are designed using gold and glass substrates, we compared their resonance properties by finite-difference time-domain (FDTD) method, calculated and analyzed their distribution and field enhancement effects contrastively. The results showed that in the same projected length, the resonant frequency of dipole type optical antenna was higher than the V type optical antenna, while the resonance enhancement factor was lower than the V type optical antenna. These have certain reference significance for researching characteristics of nanoantenna based on surface plasma.

Abstract: An extracellular matrix-like poly (ε-caprolactone) (PCL)/gelatin core-shell nanofibrous scaffold with high hydrophilicity was developed by coaxial-elecrospinning. However, the behavior of vascular endothelial cells (ECs) on the modified scaffold remains limited. In this study, human umbilical vein ECs (HUVECs) were seeded onto PCL scaffolds with or without gelatin. Morphological changes of HUVECs were observed under confocal laser scanning microscopy (LSCM). HUVECs’ adhesion, proliferation and apoptosis were detected by MTT assay and flow cytometry (FCM). Our results showed that HUVECs on PCL/gelatin scaffolds with identical polygonal and cobblestone-like characteristics reached confluence after 7 days. Modification of PCL nanofibers significantly promoted the attachment of HUVECs onto scaffolds within 1 hour. Compared to pristine PCL, a two-fold increase in proliferation of HUVECs was also observed after 7 days, whereas the apoptosis of HUVECs was obviously reduced by 40% on the modified scaffolds. In summary, these results indicated modified PCL/gelatin scaffold developed by coaxial-elecrospinning can increase the adhesion, proliferation, and suppress apoptosis of HUVECs, suggesting it has a great potential and promising vascular graft in tissue engineering applications.

Abstract: To explore the preparation method and characters of a new gold nanoshells on maganese-zinc ferrite (Mn_o.5Zn_o.5Fe₂O₄@Au) composite nanoparticles. Mn_o.5Zn_o.5Fe₂O₄@Au nanoparticles with core/shell structure were synthesized by reduction of Au³⁺ with trisodium citrate in the presence of Mn_o.5Zn_o.5Fe₂O₄ magnetic nanoparticles (MZF-NPs) prepared by improved co-preciption with the character of superparamagnetism and detected by transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), energy dispersive spectrometry (EDS) and Marven laser particle size analyzer.Thermodynamic test was used to observe temperature change of various doses of Mn_o.5Zn_o.5Fe₂O₄@Au nanoparticles. The cytotoxicity of the Mn_o.5Zn_o.5Fe₂O₄@Au composite nanoparticles in vitro was tested by the MTT assay. The therapeutic effect of Mn_o.5Zn_o.5Fe₂O₄@Au composite nanoparticles combined with magnetic fluid hyperthermia (MFH) on human glioma cells were evaluated in vitro by an MTT assay.The results indicated that the Mn_o.5Zn_o.5Fe₂O₄@Au composite nanoparticles were prepared successfully. The core/shell particles were spherical with exact average diameter of them was 66.9nm.EDS showed each Mn_o.5Zn_o.5Fe₂O₄@Au nanoparticle contained Mn, Zn, Fe, O and Au elements, and this proved Au had successfully attached to Mn_0.5Zn_0.5Fe₂O₄.The result of thermodynamic test showed that Mn_o.5Zn_o.5Fe₂O₄@Au composite nanoparticles could serve as a heating source under alternating magnetic field (AMF) exposure leading to reach their steady temperature (40-45°C). Moreover, Mn_o.5Zn_o.5Fe₂O₄@Au composite nanoparticles didn’t show cytotoxicity in vitro. The therapeutic result reveals that Mn_o.5Zn_o.5Fe₂O₄@Au composite nanoparticles can significantly inhibit the growth of glioma cells.The conclusion was that the self-prepared Mn_o.5Zn_o.5Fe₂O₄@Au composite nanoparticles had strong magnetic responsiveness and good power absorption capabilities in the high frequency AMF,then they could suggested to be useful for glioma hyperthemia. Mn_o.5Zn_o.5Fe₂O₄ @Au composite nanoparticles can not only be directed to tumor region in a given magnetic field more exactly but also produce marked thermotherapy.

Abstract: The corn stalk was fermented by Cellulomonas flavigena to produce reducing sugar, then the production was re-fermented by Trichosporon cutaneum to produce microbial oils. The best process conditions were obtained by orthogonal test through measuring the content of reducing sugar and microbial oils in product. The results show that the reducing sugar content of the corn stalk fermented by Cellulomonas flavigena is 5.720mg/mL under the inoculum of Cellulomonas flavigena of 5 % at 31°C for 3 d . The microbial oils content of the corn stalk re-fermented by Trichosporon cutaneum is 1.27g per 100g fermentation products under the inoculum of Trichosporon cutaneum of 11 % at 28°C for 7d . There is a certain feasibility to produce microbial oil fermented by Cellulomonas flavigena and Trichosporon cutaneum with corn straws. The research provides a new way for utilization of corn stalk and also provides a new method for development of microbial oils.

Abstract: In order to design and implement a computer aided instruction system; the application of the artificial intelligence technology is studied in depth using statistical quality control as example. Firstly the statistical quality control teaching was analyzed. And then the design ideas of the computer aided instruction system are put forward. And then the structure of the expert teaching system is designed. And then the interacting ways of the expert system was analyzed. Finally the application of the expert teaching system was summarized.

Abstract: Green tea powder and polyphenol oxidase extracted from eggplant has been used to explore the optimum condition for theaflavins synthesis under single factor and orthogonal experimental design. The results showed that pH value had significant effect on theaflavins synthesis. The optimum reaction condition was, under the temperature of 25°C, the system pH value 4.5, substrates concentration 2.5 g/L, and 35 mL crude enzyme with 196 U, reaction time 40 min, then the total content of theaflavins reached to 7.45 mg.