The simplified expressions for the electromagnetic field of the near zone from the magnetic frill are derived. In these formulas,E_{rho}andH_{phi}are expressed as a single integration of the complete elliptical integrals of the first and second kinds. Furthermore the closed form ofE_{z}is obtained approximately. Their accuracy is checked numerically by comparing with Tsai's, and significant improvement in efficiencies is obtained. 相似文献
The efficiency of power dissipation (η) in a dynamic material model has been conventionally used for qualitative predictions to estimate the hot working conditions at which dynamic recrystallization (DRX) is dominant. However, predicting the quantitative value of the DRX fraction (XDRX) from η remains a challenge. In this paper, a constitutive equation is proposed to quantitatively predict XDRX using η. The proposed equation for describing XDRX is derived from the reaction rate equation using the assumption that the DRX rate depends on η. The proposed equation is verified via hot compression tests of equiaxed Ti–6Al–4V ELI alloys (Ti-64) in the (α + β) region. The predicted and experimental XDRX values are found to be generally consistent with one another, exhibiting an average absolute error of 0.05. Furthermore, the proposed equation provides the same level of prediction accuracy as the conventional Johnson–Mehl–Avrami–Kolmogorov (JMAK) equation. Therefore, the proposed equation can be used to quantitatively predict XDRX following hot compression tests of equiaxed Ti-64. Moreover, compared with the JMAK equation, the proposed equation is expressed in fewer parameters and constant terms. It is, thus, expected to facilitate the quantitative prediction of XDRX.
The thermal diffusivity of AlN ceramics was significantly decreased by the addition of SiO2. The AlN ceramics with 4 wt% SiO2 could not be densified by pressureless sintering in the temperature range 1400° to 1800°C. The thermal diffusivity of these samples was very low because of their porous structure. The AlN ceramics containing 2, 4, and 8 wt% SiO2 were densified by hot-pressing and also had low thermal diffusivity. In these samples, the grains of the 27R polytype that resulted from the reaction between AlN and SiO2 were dispersed, obstructing the conduction of heat. The relation between the amount of 27R polytype and the thermal diffusivity of the AlN ceramics was determined. 相似文献
Beneficial effects of dietary phytic acid (myo-inositol hexaphosphate; IP6) have often been explained by its strong iron ion-chelating ability, which possibly suppresses iron ion-induced oxidative
damage in the gastrointestinal tract. Because phytic acid is hydrolyzed during digestion, this work aimed to know whether
its hydrolysis products (IP2′ IP3′, IP4′ and IP5) could still prevent iron ion-induced lipid peroxidation. Studies using liposomal membranes demonstrated that hydrolysis
products containing three or more phosphate groups are able to inhibit iron ion-induced lipid peroxidation although their
effectiveness decreased with dephosphorylation. Similarly, they also prevented iron ion-induced decomposition of phosphatidylcholine
hydroperoxide. These results demonstrate that intermediate products of phytic acid hydrolysis still possess iron ion-chelating
ability, and thus they can probably prevent iron ion-induced lipid peroxidation in biological systems. 相似文献
The H2 evolution reaction from an aqueous Na2SO3 solution proceeded with 3.7% quantum yield under visible light irradiation (λ > 420 nm) on a Zn0.957Cu0.043S solid solution photocatalyst without co‐catalysts such as Pt.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
Microporous carbons have been synthesized by the carbonization of cationic surfactant-resorcinol/formaldehyde (RF) composites, which were themselves formed by electrostatic organic-organic interaction. The porous structure produced by the decomposition of the surfactant plays an important role for the gasification of the RF polymer at higher temperatures. The pore size of the carbon prepared from tetrapropylammonium bromide (TPAB)-RF, cetyltrimethylammonium bromide (C16TAB)-RF and decyltrimethylammonium bromide (C10TAB)-RF mixtures can be estimated as 0.53 nm from the Horvath-Kawazoe method using N2 adsorption isotherms. Their pore size distributions were very narrow, showing that the microporous carbons derived from surfactant-RF mixture may have promise as adsorbents and membrane materials. 相似文献
The liver lipogenic enzymes are compared among rats, chickens, frogs and fish. Although the apparent Km values of glucose-6-phosphate
dehydrogenase for glucose-6-phosphate are not much different among all the species, those of malic enzyme for malate are much
higher in chickens and fish than in rats and frogs. Glucose-6-phosphate dehydrogenase showed very high activities compared
with malic enzyme in fish liver, and malic enzyme showed high activities in chicken liver. Although the apparent Km values
of acetyl-CoA carboxylase and fatty acid synthetase for substrates are in the same range among all the animals, the activity
of acetyl-CoA carboxylase seems to be extremely low in fish and frog livers, and that of fatty acid synthetase is low in frog
livers only. In addition, the apparent Km values of α-glycerophosphate acyltransferase of fish liver are very high, and the
enzyme activity appears to be extremely low compared to the others. Therefore, the enzymes at the first steps of both fatty
acid and glycerolipid syntheses of poikilothermos animals appear to be very low. On the other hand, the Ouchterlony double-diffusion
patterns showed that the lipogenic enzymes of chickens, frogs and fish are immunologically different from those of rats, with
the exception of acetyl-CoA carboxylase in chickens. Therefore, it is suggested that the fatty acid and glycerolipid forming
systems of poikilothermos animals are quite different from those of homoiothermos and the lipogenesis is very low in poikilothermos. 相似文献
Multiply-accumulate operation is the most fundamental operation in digital signal processing for image processing, robotics and automatic control. In this paper, a novel architecture of dynamically reconfigurable fused multiply-adder (FMA) is proposed.
Methods
Dynamic reconfiguration is a method that can change the circuit configuration without stop of operation. The proposed circuit provides the following four calculation modes by dynamic reconfiguration: (1) complex number FMA mode, (2) real number FMA mode, (3) complex number parallel calculation mode, and (4) real number parallel calculation mode. The data format is single precision floating point format based on IEEE754. The proposed circuit was designed using Verilog-HDL. It was simulated by logic circuit simulator, and implemented on FPGA.
Result
As a result of circuit synthesis, we confirmed the reduction of resource in the proposed circuit. Furthermore, we confirmed proper result for each calculation mode by logic simulation and experiment on FPGA.
Conclusion
The proposed circuit provides the four calculation modes by dynamic reconfiguration. We confirmed the reduction of resource and proper result for each calculation mode. 相似文献