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901.
902.
A 40 Gbit/s 1V limiting output buffer for an AC-coupled 50 /spl Omega/ load with a differential output swing of 660 mV and a gain of 18 dB is presented. A power consumption of only 24 mW and a simulated risetime of 11 ps are achieved by means of a systematic buffer optimisation. 相似文献
903.
904.
In this work, we report new optically pumped far-infrared (FIR) laser lines from CHD/sub 2/OH. A waveguide CO/sub 2/ laser of wide tunability (290 MHz) was used as pump source, and a Fabry-Pe/spl acute/rot open cavity was used as a FIR laser resonator. Optoacoustic absorption spectra were used as a guide to search for new FIR laser lines. We could observe 15 new laser lines in the range from 116.4 to 401.4 /spl mu/m. The lines were characterized according to wavelength, relative polarization, relative intensity, and optimum working pressure. The transferred Lamb-dip technique was used to measure the frequency absorption transition both for the new and previously reported laser lines. 相似文献
905.
Goni O. Hossain F. Yusuf S.U. Rahman M. Kaneko E. Takahashi H. 《Power Delivery, IEEE Transactions on》2006,21(4):1778-1786
Simulation of very fast surge phenomena in a three-dimensional (3-D) structure requires a method based on Maxwell's equations, such as the finite-difference time-domain (FDTD) method or the method of moments, because circuit-equation-based methods cannot handle the phenomena. This paper uses a method of thin-wire representation of the vertical conductor system for the FDTD method which is suitable for the 3-D surge simulation. The thin-wire representation is indispensable to simulate electromagnetic surges on wires or steel frames in which the radius is smaller than a discretized space step used in the FDTD simulation. In this paper, a general surge analysis program named the virtual surge test lab based on the Maxwell's equations formulated by the FDTD method, is used to simulate the surge phenomena of a vertical conductor, including the effects of horizontal wave incidence and vertical wave incidence. Experimental results on the reduced scale model have been presented in order to compare among the simulation results by the FDTD method and the results using numerical electromagnetic code based on the MoM. 相似文献
906.
A. Koblischka-Veneva M. R. Koblischka K. Ogasawara F. Mücklich M. Murakami 《Journal of Superconductivity》2005,18(4):469-474
Local orientations of superconducting YBa2Cu3O
x
(123) and embedded Y2BaCuO5 (211) particles within bulk, melt-textured 123 samples are studied on a local scale by means of electron backscatter diffraction
(EBSD). The embedded Y2BaCuO5 (211) particles do not show any preferred texture, but their presence within the 123-matrix alters the growth of the 123-phase,
independent of the orientation. EBSD enables to analyse the interactions between the 123- and 211-phases in detail. 相似文献
907.
Paulo S. André António L. Teixeira Armando N. Pinto Lara P. Pellegrino Berta B. Neto José F. Rocha Joäo L. Pinto Paulo N. Monteiro 《ETRI Journal》2006,28(2):257-259
In this letter, we will evaluate the performance degradation of a 40 km high‐speed (40 Gb/s) optical system, induced by optical fiber variations of the chromatic dispersion induced by temperature changes. The chromatic dispersion temperature sensitivity will be estimated based on the signal quality parameters. 相似文献
908.
The aim of this study was to determine the tocopherol contents of wine by-products including grape seed, pomace (seed, skin and stem) and bagasse (skin and stem) by using two different extraction methods in order to evaluate the possibilities of them as natural non-polar antioxidants. Cold extraction appeared to give more tocopherol contents in seeds than hot extraction. But hot extraction was found more suitable for pomace and bagasse. α-Tocopherol was the most abundant tocopherol in the grape seed, pomace and bagasse. Although γ- and δ-tocopherols were found in the samples with low concentrations, β-tocopherol was not detected in the samples. Kalecik karası had the highest α and total tocopherol compared to the other cultivars. On the other hand, hot extracted bagasse in all cultivars gave the highest tocopherol contents. As a conclusion, wine by-products, a large scale wastes, can be evaluated both to get natural tocopherol source and to obtain economical gain. 相似文献
909.
Y. Xun R. Rodriguez E. J. Lavernia F. A. Mohamed 《Metallurgical and Materials Transactions A》2005,36(10):2849-2859
The present article deals with the processing and microstructural evolution of powder metallurgy (PM) Zn-22Al pct eutectoid
alloy. The powder material was produced through inert gas atomization and then cryomilled in liquid nitrogen. The milled powder
particles were consolidated by hot isostatic pressing (“hipping”) followed by thermomechanical treatment, resulting in a two-phase
microstructure. The microstructures were characterized using scanning electron microscopy (SEM) and transmission electron
microscopy (TEM). The principal processing factors and microstructural characteristics associated with the major processing
steps, including spray atomization, mechanical milling (MM), consolidation, and heat treatment, were evaluated and discussed.
Hot isostatic pressing and extrusion followed by heat treatment to produce the superplastic structure (Al-rich phase and Zn-rich
phase) are effective in elimination porosity. A TEM examination of the microstructure of the alloy after processing reveals
the presence of nanodispersion particles that are not uniformly distributed. The formation of the dispersions was attributed
to the interaction between the powder material (primarily Al phase) and environmental elements such as oxygen and nitrogen
during milling. Moreover, the size and distribution of the dispersions present in the bulk material met the anticipated requirements
for serving as inhibitors for grain growth and barriers for dislocation movement. The TEM observations on crept specimens
reveal extensive dislocation/dispersion interactions. 相似文献
910.
K.F. Chan C.K. Wan K.N. Yu 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2007,262(1):128-134
In the present work, we have studied the feasibility of a method based on polyallyldiglycol-carbonate (PADC) films to investigate the effects of alpha particles on HeLa cervix cancer cells. Thin PADC films with thickness of about 20 μm were prepared from commercially available CR-39 films by chemical etching to fabricate custom-made petri dishes for cell culture, which could accurately record alpha particle hit positions. A special method involving “base tracks” for aligning the images of cell nuclei and alpha particle hits has been proposed, so that alpha particle transversals of cell nuclei can be visually counted. Radiobiological experiments were carried out to induce DNA damages, with the TdT-mediated dUTP Nick-End Labeling (TUNEL) fluorescence method employed to detect DNA strand breaks. The staining results were investigated by flow cytometer. The preliminary results showed that more strand breaks occurred in cells hit by alpha particles with lower energies. Moreover, large TUNEL positive signals were obtained even with small percentages of cells irradiated and TUNEL signals were also obtained from non-targeted cells. These provided evidence for the bystander effect. 相似文献