A quasi-discrete Hankel transform (QDHT) is presented as a new and efficient framework for numerical evaluation of the zero-order Hankel transform. A discrete form of Parseval's theorem is obtained for the first time to the authors' knowledge, and the transform matrix is discussed. It is shown that the S factor, defined as the products of a truncated radius, is critical to building the QDHT.

Increasing atmospheric CO 2 can decrease seawater pH and carbonate ions, which may adversely affect the larval survival of calcareous animals. In this study, we simulated future atmospheric CO 2 concentrations (800, 1500, 2000 and 3000 ppm) and examined the effects of ocean acidification on the early development of 3 mollusks (the abalones Haliotis diversicolor and H. discus hannai and the oyster Crassostrea angulata). We showed that fertilization rate, hatching rate, larval shell length, trochophore development, veliger survival and metamorphosis all decreased significantly at different pCO 2 levels (except oyster hatching). H. discus hannai were more tolerant of high CO 2 compared to H. diversicolor. At 2000 ppm CO 2 , 79.2% of H. discus hannai veliger larvae developed normally, but only 13.3% of H. diversicolor veliger larvae. Tolerance of C. angulata to ocean acidification was greater than the 2 abalone species; 50.5% of its D-larvae developed normally at 3000 ppm CO 2 . This apparent resistance of C. angulata to ocean acidification may be attributed to their adaptability to estuarine environments. Mechanisms underlying the resistance to ocean acidification of both abalones requires further investigation. Our results suggest that ocean acidification may decrease the yield of these 3 economically important shellfish if increasing CO 2 is a future trend.

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Dispersion stability of nanoparticles in the liquid media is of great importance to the utilization in practice. This study aims to investigate the effects of mechanical dispersion method on the dispersibility of functionalized TiO2 nanoparticles in the transformer oil. Dispersion methods, including stirring, ultrasonic bath, and probe processes, were systematically tested to verify their versatility for preparing stable nanofluid. The test results reveal that the combination of ultrasonic bath process and stirring method has the best dispersion efficiency and the obtained nanofluid possesses the highest AC breakdown strength. Specifically, after aging for 168 h, the size of nanoparticles in the nanofluid prepared by the combination method has no obvious change, while those obtained by the other three paths are increased obviously.

This paper focuses on the effect of nanoparticle surface modification on the charge transport characteristics in XLPE/SiO 2 nanocomposites. A titanate coupling agent (TC9) and a 3-(Methacryloyloxy)propyltrimethoxysilane (KH570) were used for the surface modification of SiO 2 nanoparticles. It was found that both KH570 and TC9 coupling agents improve the nanoparticle dispersion compared with unmodified SiO 2 nanoparticles. The improvement in dispersion was found to be due to increased surface hydrophobicity of the treated SiO 2 nanoparticles. In addition, it was found that the surface modification improved the DC conductivity, dielectric characteristics, and space charge properties as compared to XLPE or XLPE/SiO 2 nanocomposites without surface modification. The results of the TSC measurements showed that the introduction of SiO 2 nanoparticles into XLPE increased the trap density and produced more trap energy levels. Improving the nanoparticle dispersion was found to further increase the corresponding trap depth and trap density. The trapped homocharge formed an independent electric field and reduced the effective electric field, which reduced charge injection and increased the charge injection barrier height. Therefore, the space charge formation in the material bulk was suppressed.

We derive the integral representation of a fractional Hankel transform (FRHT) from a fractional Fourier transform. Some basic properties of the FRHT such as Parseval's theorem and its optical implementation are discussed qualitatively.

In this paper, the alignment of the average bonding-antibonding energy Em between the two sides of heterojunctions and other relevant behaviour have been investigated. This study is based on the peculiarity of the atomic sphere approximation in the linear muffin-tin orbital band-structure calculation. Using Em as an energy reference, the authors have determined the valence band offset Delta Ev-values for 16 heterojunctions. The calculated results are in excellent agreement with the available experimental data, and the computational effort required is very small.

Space charge is a threat to insulation materials and oil-paper insulation gradually degrades in service. The degradation of cellulose affects space charge formation, accumulation and dissipation, and the presence of space charge affects the performance of dielectric. In this paper, the effect of thermal aging on space charge behaviors and other properties including permittivity, conductivity, and tensile strength was investigated. Oil-paper samples were aged at a hot spot temperature (180℃). During thermal aging, space charge distribution was measured at a regular interval at room temperature. And the pulse electro-acoustic (PEA) method was used for space charge measurement. The results showed that the thermal aging at hot spot temperature caused increase of conductivity and tensile strength degradation. The permittivity increased at the beginning but then it decreased, while dissipation factor showed an upward trend. Besides these, trap distribution and carriers characteristics were also affected. The formations of space charge of unaged and aged oil paper were consequently different under low electric field. Due to the generation of traps by the degradation of cellulose, more charge, especially positive charge was trapped, but the increased traps mostly were shallow traps. Based on the Schottky model, a correlation between space charge injection and the permittivity was drawn. This, together with the appearance of positive bulk charge could be used for oil paper aging status diagnosis.