Analytic solution of quasicrystal microsphere considering the thermoelectric effect and surface effect in the elastic matrix

The incorporation of the quasicrystalline phase into the metal matrix offers a wide range of potential applications in particle-reinforced metal-matrix composites.The analytic solution of the piezoelectric quasicrystal(QC)microsphere considering the thermoelectric effect and surface effect contained in the elastic matrix is presented in this study.The governing equations for the QC microsphere in the matrix subject to the external electric loading are derived based on the nonlocal elastic theory,electro-elastic interface theory,and eigenvalue method.A comparison between the existing results and the finite-element simulation validates the present approach.Numerical examples reveal the effects of temperature variation,nonlocal parameters,surface properties,elastic coefficients,and phason coefficients on the phonon,phason,and electric fields.The results indicate that the QC microsphere enhances the mechanical properties of the matrix.The results are useful for the design and understanding of the characterization of QCs in micro-structures.

Multi-Domain Parallel Computing for Strength Analysis of Whole Aircraft Model

In the Windows XP 64 bit operating system environment, several common PC were used to build a cluster system, establishing the distributed memory parallel (DMP) computing system. A finite element model of whole aircraft with about 260 million degrees of freedom (DOF) was developed using three-node and four-node thin shell element and two-node beam element. With the large commercial finite element software MSC.MARC and employing two kinds of domain decomposition method (DDM) respectively, realized the parallel solving for the static strength analysis of the whole aircraft model, which offered a high cost-effective solution for solving large-scale and complex finite element models.

Improving open-circuit voltage and short-circuit current of high-efficiency silicon-based planar heterojunction solar cells by combining V_(2)O_(5)with PEDOT:PSS

In recent years,a novel PEDOT:PSS/n-Si planar heterojunction solar cell has been extensively studied in the photovoltaic field.Different V_(2)O_(5)-IPA concentrations mixed in PEDOT:PSS samples as hole transport layer were prepared by means of spin coating technique and mechanical mixing of organic and inorganic materials.V_(2)O_(5)was studied for its effects on the surface morphology,chemical composition,and optical transmittance of PEDOT:PSS films.The findings of the study show that the addition of V_(2)O_(5)particles changes the surface morphology of PEDOT:PSS films and promotes its superior ohmic contact with the Si interface.Furthermore,PEDOT:PSS incorporated with V_(2)O_(5)particles that have outstanding optical and semiconductor properties reduces the rate of carrier recombination at the device interface and blocks electron transport to the anode in the fabricated Si-based solar cells.When compared to conventional PEDOT:PSS/Si planar heterojunction solar cells,the fill factor,photoelectric conversion efficiency,open-circuit voltage,and short-circuit current density of the devices prepared in this study can be significantly improved,reaching up to 70.98%,15.17%,652 mV and 32.8 mA/cm^(2),respectively.This research provides a promising and effective method for improving the photoelectric conversion performance of PEDOT:PSS/Si heterojunction solar cells,which enables the application of V_(2)O_(5)in Si solar cells.

Synthesis of three-dimensionally ordered porous perovskite type LaMnO_3 for Al-air battery

LaMnO3 catalysts with three-dimensionally ordered holes perovskite structure were prepared via closepacked SiO2 template synthesized by Stober-Frink method. SEM, XRD and BET were employed to characterize the microstructure, phases and specific surface area. CV method was used to the oxygen electrode beha-vior of catalysts. Diameter of the holes was about 330 nm, corresponding to the size of SiO2 template. Full-cell discharge tests were performed on aluminum-air battery fabricated by porous LaMnO3.Results showed that the discharge performance of porous LaMnO3 were 1.54 V, 1.42 V and 1.24 V respectively when the discharge currents were set at 5 mA/cm^2,10 mA/cm^2 and 20 mA/cm^2, respectively, which were higher than that of LaMnO3 prepared by coprecipitation method（1.33 V, 1.09 V, 0.63 V, respectively）.

Enhanced efficiency of graphene-silicon Schottky junction solar cell through inverted pyramid arrays texturation

Nanostructures of silicon are gradually becoming hot candidate due to outstanding capability for trapping light and improving conversion efficiency of solar cell. In this paper, silicon nanowires（SiNWs） and silicon inverted pyramid arrays（SiIPs） were introduced on surface of Gr-Si solar cell through silver and copper-catalyzed chemical etching, respectively. The effects of SiNWs and SiIPs on carrier lifetime, optical properties and efficiency of Gr-SiNWs and Gr-SiIPs solar cells were systematically analyzed. The results show that the inverted pyramid arrays have more excellent ability for balancing antireflectance loss and surface area enlargement. The power conversion efficiency（PCE） and carrier lifetime of Gr-SiIPs devices respectively increase by 62% and 34% by comparing with that of Gr-SiNWs solar cells. Finally, the Gr-SiIPs cell with PCE of 5.63% was successfully achieved through nitric acid doping. This work proposes a new strategy to introduce the inverted pyramid arrays for improving the performance of Gr-Si solar cells.

Martensitic Transformation Eflfect on the Dislocation Emission from a Semi-infinite Crack Tip in Nano composites

A theoretical model is established to investigate the effect of martensitic transformation particle on the dislocation emission from a crack tip in ceramic-matrix nanocomposites. Using the model of dislocation-based strain nucleus and the Green's function met hod, the expressions of complex potentials and stress fields are derived in closed form. The critical stress intensity factors for the first-lattice dislocation emission and the maximum number of emitted dislocations are well calculated. The effects of important parameters such as the size of transformation particle, the dislocation emission angle and the distance from the crack tip to the transformation particle on dislocation emission are discussed in detail. The results reveal that the transformation particle shows a significant shielding effect on the dislocation emission from the crack tip, and the shielding effect enhances with an increase in the size of transformation particle. On the other hand, the results also imply that the emission of edge dislocations is closely related with the dislocation emission angle, and there exists a probable angle |θ|≈ 74° making the dislocation emission easiest. Besides, the remarkable crack blunting induced by the dislocation emission is quite difficult for small grain size but easy for the growth of crack.

Graphene Quantum Dots Open Up New Prospects for Interfacial Modifying in Graphene/Silicon Schottky Barrier Solar Cell

Graphene/silicon(Gr/Si)Schottky barrier solar cells(SBSCs)are attractive for harvesting solar energy and have been gaining grounds for its low-cost solution-processing.The interfacial barrier between graphene and silicon facilitates the reducing excessive carrier recombination while accelerating the separation processes of photo-generated carriers at the interface,which empowers the performance of Gr/Si SBSCs.However,the difficulty to control the interface thickness prevents its application.Here,we introduce the graphene oxide quantum dots(GOQDs)as a unique interfacial modulation species with tunable thickness by controlling the GOQDs particle size.The power conversion efficiency(PCE)of 13.67%for Gr/Si-based SBSC with outstanding stability in the air is obtained with the optimal barrier thickness(26 nm)and particle size(4.15 nm)of GOQDs.The GOQDs in Gr/Si-based SBSCs provide the extra band bending which further enhances the PCE for its photovoltaic applications.