The in situ formation of magnetoplumbite-type (M-type) hexaferrites within a 3Y-TZP matrix was examined for the La2O3–ZnO–Fe2O3 and BaO–Fe2O3 systems. The formation of barium hexaferrite (Ba-M) was rapid enough at a temperature of 1300°C for 2 h to result in a uniform dispersion of fine Ba-M particles in a tetragonal zirconia polycrystal (TZP) matrix. However, the formation of lanthanum-substituted hexaferrite (La-M) was rather sluggish, despite the existence of a charge-compensating divalent oxide. The 3Y-TZP/20-wt%-BaFe12O19 in situ composite possessed good magnetic properties, as well as moderately good mechanical properties. 相似文献
We report simultaneous all-optical switching of multiple wavelengths using an optical loop mirror with an asymmetrically placed semiconductor optical amplifier. Switching is shown for 14-wavelength channels (across 14-nm bandwidth) with switching contrast of 10-23 dB 相似文献
To improve alkaline resistance, a newly mixed powder coating film using thermoplastic polyethylene terephthalate (PET) was investigated. Two kinds of polyvinyl butyral (PVB) and two kinds of polyamide (PA) were chosen as the secondary polymer. The melting temperatures (Tms) of these materials were lower than that of primary PET polymer so the mixed powder coating was able to form a dual phase film through a fluidized bed coating process. Microscope and Fourier transform infrared spectroscopy (FTIR) observations revealed that the dual phase structure was indeed successfully formed and there was a secondary layer over the entire surface area of the film. This mixed powder coating film significantly enhanced the alkaline resistance to an environment filled with NaOH solution at 40°C in which a secondary material would be effective in protecting the film. With regard to both alkaline resistance and film formability, PET/PVB was superior to the PET/PA mixture. 相似文献
A reduced–order model for a multi–input single–output or a single–input multi–output continuous system is proposed. The model is especially suitable for the case where accuracy in the high-frequency region is important. It also satisfies basic conditions for reduced-order models, such as uniqueness, stability, and a simple calculation requirement. Chained aggregation with the minimization of truncation errors introduces an internal system representation characterized by a system matrix of Hessenberg form and a diagonalized covariance matrix. 相似文献
This paper describes the Alternate Lighting of Surfaces (ALIS) method as a promising drive technology which can lead to high‐resolution plasma‐display panels (PDPs). This technology provides a resolution of more than 1000 scanning lines without lowering luminance, thus enabling the essential requirements of HDTV. Moreover, it allows the number of scanning electrodes to be halved in comparison with the conventional method, as well as the circuit scale to be minimized due to the use of the single scanning drive. The ALIS method is expected to be a key technology that will help PDPs penetrate the TV market. 相似文献
Dislocation-free and low dislocation densityn-type conductive GaAs crystals, 50 mm in diameter, were grown by the In and Si co-doping LEC technique. Two-dimensional LED
arrays were fabricated on substrates obtained from these crystals by the MOCVD technique and the influence of the In doping
on the LED characteristics was examined. The light output power of LEDs fabricated on co-doped substrate with an In concentration
of 1 ×1020atoms/cm3 are low and are non-uniformly distributed, as compared with the boat-grown substrate, even though the co-doped substrate
is dislocation-free. However, the LED properties of a substrate with an In concentration of 2 × 1018atoms/cm3 are the same as those of a boat-grown substrate. The light output power of the LEDs becomes higher as the In concentration
in the substrate decreased. 相似文献
A three‐component reaction of 3‐(tri‐n‐butylstannyl)allyl acetates, aldehydes, and triorganoboranes in the presence of a palladium‐Xantphos catalyst system predominately gave (E)‐anti‐homoallylic alcohols with high diastereoselectivity and good to high levels of alkene stereocontrol. An efficient chirality transfer was observed when an enantioenriched substrate was employed. The reaction was initiated by the formation of an allylic gem‐palladium/stannyl intermediate, which subsequently underwent allylation of the aldehyde by an allyltributyltin followed by a coupling reaction of the in‐situ‐generated (E)‐vinylpalladium acetate with the triorganoborane.
The effects of morphology on mechanism of plastic deformation are investigated for binary blends of isotactic polypropylene and rubbery ethylene-1-hexene copolymers. In this work, plastic deformation developed during elongation is investigated by measuring light transmittance, electron microscopy, and ultrasonic propagation in the temperature region between 298 K and 353 K. It is found that the compatible blends hardly show stress-whitening at any temperature, whereas the incompatible blends show distinct stress-whitening below 333 K. Furthermore, microscopic defects such as microvoids and crystalline defects are found to be precursors for crazing which are origin of the stress-whitening. 相似文献