Advanced Materials Research Vol. 898

Abstract: In this paper we propose an effective method to model quantum dot superlattice silicon tandem solar cell. The Schrödinger equation is solved through finite difference method (FDM) to calculate energy band of three-dimensional silicon quantum dots embedded in the matrix of SiO₂ and Si₃N₄.We simulate the quantum dot superlattice as regularly spaced array of equally sized cubic dots in respective matrix. For simplicity, we consider only one period of the structure in calculation. From the result, the effects of matrix material, dot size and inter-dot distance on the bandgap are obtained.

Abstract: We applied the discrete element method (DEM) to analyze the normal impact properties of elastoplastic spherical particles. DEM simulation of impact between two identical elastoplastic spheres is carried out to validate the proposed model. The numerical results show well agreement with the FEM solution. Based on this model, the effects of impact parameters such as velocity, yield strength, elastic modulus, Poissons ratio, and mass density, on the loss factor in impact process, are then analyzed.

Abstract: Based on the multi-roller-pressing flexible stretch forming (MRPFSF) process, force loading and displacement loading were researched. The process of spherical parts of 08AL sheet material were simulated by means of an explicit finite element method. The variations of the forming force in stretch-forming process and the distribution of stress after springback were analyzed comparatively for both loading methods. The results show that the change of the forming force in the force loading method has fluctuation. With the depressing of rollers, the vibration amplitude is smaller. At the end of forming, the forming forces of both loading methods are gradually consistent. The stress distribution of spherical parts formed by the two loading method is accordant.

Abstract: Cutting temperature is an important factor for nylon cutting properties. The glass transition temperature is suitable to determine cutting conditions. By applying finite element method to this research, the cutting temperatures variation on workpiece and chip with time under different cutting parameters are calculated. It is proved that cutting temperature on workpiece surface is higher than that on chip and decreases quickly. The cutting parameters have great effects on workpiece cutting temperature. The cutting temperatures increase with cutting parameters increase. In addition, the cutting feed has the most effects on cutting temperature.

Abstract: The injection molding process of micro plate devices requires several concerns in order to produce a quality output. In part of determining the best parameter settings, among other considerations that need to be taken are the types of plastic materials selected and the mold design. Molding parameters such as packing time, cooling temperature, molding and melting temperatures, packing and injection pressures are the most important factors affecting warpage of the micro plate part. These factors and their interactions were investigated in this research. The effects of processing parameter on the warpage of flat micro devices were analyzed according to the Taguchi method. In this paper, based on the range analysis, the parameter effective sequence was got, as well as the best processing parameters. The molding packing time has the strongest effects on the warpage, and the molding temperature is the secondary parameter. The cooling time has the lowest effects.

Abstract: Dense iron-containing hydroxyapatite (HA)/titanium composites were synthesized via pressureless sintering at a relatively low temperature using nanosized HA powders and Ti-Fe mixed powders. XRD analysis showed that desirable Ti phase still remained in the HA matrix. The addition of iron improved the densification by enhancing the sinterability of titanium, and reduced the decomposition rate of HA and the interaction between HA and titanium. The mechanical tests showed that both the flexural strength and fracture toughness of the composites were significantly improved. The Ti-Fe reinforcing particles exhibited plastic stretching and bridged an advancing crack, making a significant contribution to the improvement of mechanical properties of the composites.

Abstract: Using the CIS(Configuration Interaction with Single Substitute) method, we calculate the excited state structure and vibrational frequencies of cycloheptanone ion.

Abstract: Our theoretical study aims to analyze ionization and dissociation mechanism of cyclopentanone in the excited states and gives out a result with proved and directed significance for the corresponding experiments. Using the CIS(Configuration Interaction with Single Substitute) method, and 6-31+G (d, p) basis set, we calculated the frequency of excited state of cyclopentanone ion molecule. Studies on the possible way of obtain C₂H⁺₄ small fragments by cyclopentanone ion

Abstract: Rapid-dissolving multiple-component composite nanoparticles of acetaminophen (APAP) fabricated using electrospraying were reported. A series of analyses were undertaken to characterize the resultant nanoparticles in terms of their morphology, physical form of the components and functional performance. A traditional casting film consisting of the same components and compositions was prepared as control. Field-emission scanning electron microscopy revealed that the nanoparticles had an average diameter of 880 ± 170 nm. X-ray diffraction verified that both the active pharmaceutical ingredients APAP and the sweetener sucralose existed in an amorphous state in the polymer matrix polyvinylpyrrolidone K25 as a result of the second-order interactions between the components, as verified by Attenuated total reflectance-Fourier transform infrared spectra. In vitro dissolution studies showed that the nanoparticles could rapidly release the incorporated APAP within one minute, significantly faster than the casting film and the raw APAP powders. Electrospraying is a highly useful tool for preparation of nanoparticles to enhance the dissolution of poorly water soluble active ingredients and to develop rapid-dissolving drug delivery systems. .

Abstract: Our theoretical study aims to the way of obtain C₄H₅O⁺ fragments laser-induced by cyclicketone ion (C₇H₁₂O⁺) excited state, using the CIS(Configuration Interaction with Single Substitute) method, and gives out a result with proved and directed significance for the corresponding experiments.