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Distinguished from conventional inductive or resonant method, this paper presents a novel high radiation gain and narrower half-power beamwidth microstrip patch antenna (MPA) array loading with modified-I-shaped(MIS) electromagnetic metamaterials(MTM) to apply in the microwave wireless power transmission(MWPT). The MIS MTM unit cell is simulated in HFSS and the effective parameters of the meta-atom is extracted by homogenization retrieval method. Detailed single MPA numerical computing and modeled simulation is proposed step by step and optimetrics procedure in HFSS is conducted to optimize the design parameters for optimum performance. To better take advantages of the higher directive radiation gain and planer structure, a 6 × 10 × 1 MIS MTM array acting as superstrate is placed above a 2 × 2 MPA array with delicate feeding network and power distribution system. Experiment investigation indicates that the MPA array with superstrate obtained the peak value gain of 17.66 dB compared to original 13.18 dB in the operating frequency of 10 GHz. The half-power beamwidth decreased from 36.775° to 18.645° for the E-plane and reduced to 19.958° from 38.649° for the H-plane respectively. The measured results of the fabricated prototype are consistent with the simulation ones with slight discrepancy. This method offers valuable guidance for designing high efficiency transmitting antenna system in application of MWPT.

High-efficient silicon heterojunction (SHJ) solar cells are ideal bifacial devices. In this application context, Na+ ions induced degradations from encapsulation soda-lime glass are of significance. We conducted accelerated Na+ ions aging experiments at 85 °C, 85% relative humidity without encapsulation to simulate damp heat test in soda-lime glass for SHJ solar cells. It is found that Na+ ions accelerated the formation of metal In and In(OH)3 or InOOH in damp heat condition, which destroyed the capping metal oxide, i.e., tungsten doped indium oxide (IWO). Interestingly, it demonstrates that the device stability is highly dependent on the crystallinity of IWO films. IWO films with large grains are more resistive to Na+ ions erosion, and consequently, account for the enhanced device stability of SHJ solar cells. We believe this work provides a guide for designing more reliable bifacial SHJ solar cells installed in hot climates and coastal areas.

This paper proposes a novel approach to enhance the aperture efficiency of the transmitting microstrip patch antenna (MPA) by designing a new inclusion of double-cross-shaped metamaterial (DCSM) superstrate applied in microwave wireless power transmission(WPT). Overall WPT model and transmitting antenna selection are briefly introduced and numerical simulation is conducted in HFSS. Homogenization retrieval method based on transmission and reflection coefficients is utilized to calculate the effective parameters of the DCSM unit cell, electric field and surface current distribution are displayed to qualitatively explain the occurrence of negative permittivity and permeability. The Matlab2008a script is also presented to calculate the geometry dimensions of the corresponding conventional patch antenna operating at desired resonant frequency. Simulation results indicate that the gain of the transmitting antenna increases from 7.46 dB to 12.35 dB after loading with the 6 × 3 × 1 array DCSM MTM as the superstrate, the measured gain increases from 7.1 dB to 12.21 dB thus an enhancement of 184% for the transmitting antenna's aperture efficiency is obtained which is of significant value for the whole WPT system. For the last section of our paper, electric field of the transmitting MPA before and after loading with DCSM superstrate are illustrated to gain insight physical mechanism of the gain enhancement.

This paper presents a novel multiple splits octagon-shaped metamaterial which exhibits double left-handed frequency bands roughly from 9.25 GHz to 9.68 GHz and from 15.28 GHz to 15.36 GHz derived from the transmission characteristics by homogenization retrieval method. Two conventional microstrip patch antennas whose resonance frequency bands are located at the first left-handed frequency band and the second one respectively are designed to further investigate the influence by loading the proposed metamaterial as its superstrate. HFSS simulation numerical results indicate that the far field radiation directivity half-power bandwidth(HPBW) of the E-plane and H-plane have reduced by 64%, 63.7% and 59.4%, 59%, and the maximal gain increases from 8.251 dB to 11.024 dB and from 8.5432 dB to 11.9653 dB respectively after loading with the multiple splits octagonal metamaterial superstrate.

As a material that exhibits a high refractive index and an excellent chemical stability, Ta2O5 is widely used in the microelectronics and chemical industries. In this study, we analyzed the effect of plasma shock waves on Ta2O5 thin films. The experimental results showed that the damage characteristics of the film include thermal ablation, surface cracks, and peeling off from the substrate owing to the repeated action of the pulse. Coating characterization before and after exposure to laser plasma was performed using UV-Vis spectroscopy, energy dispersive spectroscopy (EDS), Raman spectroscopy, and X-ray diffraction. With the increase in the light absorbed by the ablated products, the transmittance of the film decreased after damage, and the Raman spectrum and X-ray diffraction pattern of the sample indicated that the film changes from an amorphous to a crystalline structure owing to the action of the high-temperature and high-pressure plasma. The EDS analysis results indicated that the oxygen content in the film decreases because of the damage inflicted to its structure.

Strain-hardening mechanism of high strain line pipe was investigated and discussed in terms of microstructure and grain orientation. It is concluded that X70 high strain line pipe does not fit to the Hollimon formula in the entire deforming process, but the normal X70 line pipe does. At the beginning of plastic deformation, the strain-hardening capacity of X70 high strain line pipe is excellent. It decreases rapidly as the stain increases, then becomes stable after 2.0% total strain. The high strain line pipe is composed of soft phase (polygonal ferrite) and hard phase (bainite). When plastic deformation initiates, the strain-hardening capacity of high strain line pipe is better because of the ferrite deformation firstly ahead of the bainite, due to strain-hardening capacity of the ferrite is much better than that of the bainite. With ferrite deformation decreasing and bainite deformation increasing, the strain-hardening capacity declines until the micro-deformation is homogeneous. Besides, it is obvious that the large angle grain boundaries of more than 15° are in the majority of the microstructure of high strain line pipe without deformation, so the strain-hardening capacity is highest at the beginning of plastic deformation. As strain

Strain-hardening capacity is the most effective way to improve the deformability of line pipe. In this paper, four kinds of new X70 high strain line pipe have been produced by four manufactures respectively. Microstructure, strain-hardening capacity, and characterization of the X70 high strain line pipe have been analyzed. It is concluded that X70 high strain line pipe steel does not fit to the Hollimon formula in the entire deforming process, and a stable strain-hardening exponent is not available. At the beginning of plastic deformation, the strain-hardening capacity of X70 high strain line pipe steel is excellent. It decreases rapidly as the stain increases then becomes stable after 2.0% total strain. The stress ratios of Rt₁.₅/Rt₀.₅, Rt₂.₀/Rt₁.₀ and Rt₅.₀/Rt₁.₀ are proved to characterize the strain-hardening capacity of X70 high strain line pipe steel. When Rt₁.₅/Rt₀.₅≥1.070, Rt₂.₀/Rt₁.₀≥1.025, and Rt₅.₀/Rt₁.₀≥1.050, the average strain over the gauge length of 2 times the outer diameter, centered at the wrinkle on intrados peak, is above 1.3%.