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31.
Melt viscosity and flow birefringence of bisphenol A-type polycarbonate were measured and analyzed by the application of rubber-like photoelastic theory. The melt viscosity in the Newtonian flow region increased with the molecular weight to the power of 3.4. In polycarbonate, the shear stress of the Newtonian flow region was to 106 dyn/cm2, whereas in PMMA it was at most 3 = 105 dyn/cm2. The flow birefringence δn has a linear relation with shear stress S, that is δn = 5.7 × 10?10 S. The principal polarization difference of flow unit α1 – α2 was 1.62 × 10?23 cm3, which was obtained by the application of the rubber-like elastic theory. In PMMA, it was 3.9 = 10?25 cm3; about 1/40 of that was polycarbonate. The anisotropy of polarizability of the flow unit of polycarbonate was also about 40 times larger than that of PMMA. So the anisotropy reflected the large flow birefringence of the polycarbonate. 相似文献
32.
A study on capacity fading of lithium-ion battery with manganese spinel positive electrode during cycling 总被引:3,自引:0,他引:3
The capacity fading mechanism of lithium-ion cell was studied by disassembling the charge-discharged cells and analyzing their electrodes using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), etc. Cu ion dissolved from current collector of anode and Mn ion dissolved from LiMn2O4 spinel (cathode) were all existing in solid electrolyte interface (SEI) layer on carbon anode as Cu2O and MnO or MnO2, respectively. These depositions of Cu and Mn oxides did not uniformly deposited on the anode side, and most of them were detected on the carbon surface nearby to the separator side. The SEI layer is hard and about 0.3 μm in thickness. Furthermore, the cycling performance of the cells can be improved by adding 1,2,3-benzotrazole (a corrosion inhibitor of Cu) before assembling the cell, it then coordinates strongly with Cu ions into the electrolyte. From the results, it is obvious that the existing of Cu oxide as well as Mn oxide in the SEI layer, which blocks the normal intercalation of the lithium ions, is one of the factors for the capacity fading of the cells. 相似文献
33.
S. Watanabe S. Nakasato S. Hayano H. Kuwamura T. Nagai M. Negishi Y. Sasamoto H. Seino S. Shiraishi 《Journal of the American Oil Chemists' Society》1973,50(9):360-363
In this study known mixtures of four or five fatty acid methyl esters were analyzed collaboratively by gas chromatography
with flame ionization detectors. The experimental data was treated statistically to examine inter- and intralaboratory scattering.
More-over the effect of the use of correction factors was investigated. Even if only the specific analytical values that scattered
a little were chosen, the averages of such values did not always approach the actual values. In some laboratories a sort of
regularity was observed in the deviation of analytical values from real values throughout the analyses of four samples. The
application of correction factors to the analytical values obtained by these laboratories resulted in a considerable decrease
of interlaboratory scattering and deviation from the real values. When a constant amount of sample was injected, intralaboratory
scattering was decreased, whereas interlaboratory scattering was not. Injection of large sample sizes caused deviation. From
this collaborative study it was recommended that 0.5–1.0 μl of 20% solution be injected.
Presented at the JOCS-AOCS Joint Meeting, Los Angeles, April 1972. 相似文献
34.
1 INTRODUCTION Since Cu-ZSM-5 was reported as an effective catalyst for the selective catalytic reduction (SCR) of NO by hydrocarbons in the presence of excess oxygen, the SCR of NOx has received much attention as a kind of potential technology for cleaning NOx in various oxygen-rich exhausts of diesel engine, lean burning gasoline engine and gas engine. Although a number of catalysts have been tested, to date, it still seems to be difficult to find a catalyst that is completely suit… 相似文献
35.
36.
PIV is one of the most popular measurement techniques in hydraulic engineering as well as in fluid sciences. It has been applied to study various turbulent phenomena in laboratory experiments related to natural rivers, e.g., bursting phenomena near the bed, mixing layers observed at confluences, wake turbulence around dikes and piers, and so on. In these studies, PIV plays important roles in revealing the space-time structure of velocity fluctuations and coherent vortices. This review article focuses particularly on the applications of PIV to turbulent open-channel flows, which have been conducted for the past decade in Hydraulics Laboratory of Kyoto University. In Section 2, we introduce our experimental setup and PIV/PTV algorithm. In Section 3, we apply the PIV measurements to reveal turbulence characteristics and coherent structures in open-channel flows as well as in vegetated canopy flows. For complex flow situations, various applications of PIV to compound open-channel flows and wind-induced water waves are considered to reveal coherent vortices. In Section 4, we discuss some advanced PIV measurements in open-channel flows. The free-surface-elevation fluctuations and velocity components were measured simultaneously with two sets of cameras to examine phase-averaged parameters of turbulence. A multi-layer scanning PIV was developed to reveal 3D turbulence structure in compound open-channel flows. Our discriminator PIV/PTV was applied successfully to sediment-laden open-channel flows and revealed the fluid/particle interaction and the relationship between coherent structures and sediment concentration. Finally, we conducted simultaneous measurements of velocity and dye concentration with a combination of PIV and LIF in vegetated open-channel flow, which enables us to examine turbulent scalar flux of a passive contaminant. 相似文献
37.
Hiroki Kikuchi Shigeki Hashimoto Shinichiro Tajiri Tsuneo Hayashi Yutaka Sugawara Michio Oka Yoshiyuki Akiyama Akira Nakamura Naoya Eguchi 《Journal of the Society for Information Display》2009,17(3):263-269
Abstract— A high‐pixel‐rate, high‐contrast (30,000:1) wide‐color‐gamut grating‐light‐valve laser projector is reported. A new optical engine enabling high‐frame‐rate (240 Hz) scan projection is employed. Panoramic wide‐angle‐scan projection with a 64:9 aspect ratio was also developed. Speckle noise is eliminated using a simple but highly efficient technique. The optical throughput efficiency of the grating‐light‐valve laser projector is reviewed. 相似文献
38.
Robust control method for the inverted pendulum system with structured uncertainty caused by measurement error 总被引:1,自引:1,他引:0
In this article, we propose a design method for an inverted pendulum system with a structured uncertainty. We consider that
such an uncertainty is caused by a measurement error in the rotation angle of the pendulum and effects on the system structure
that cannot be included in the nominal elements. For the uncertain system obtained, we apply an integral tracking control
and the guaranteed cost control to design a robust, stable, tracking control system. Finally, we show the effectiveness of
our method through a numerical example. 相似文献
39.
We developed equipment and methods for measuring quantitatively the local Young's modulus of solids. It consists of an electrodeless langasite oscillator and line antennas, and oscillator vibrations are generated and detected contactlessly. A constant biasing force results from oscillator mass and is independent of surface roughness. The effect of material anisotropy on the measured stiffness is theoretically discussed for studying the limitation of the quantitative measurement. The microscopy has been applied to polycrystalline copper, and the measured modulus is compared to calculations based on electron-backscatter-diffraction measurements. Also, we applied it to a duplex stainless steel and an embedded silicon-carbide fiber. The results reveal textured regions, defects with high sensitivity, and even stiffness distribution in a single grain. 相似文献
40.
M. Nakao Y. Hatamura T. Sato K. Koyano K. Ichiki H. Sangu M. Hatakeyama T. Kobata K. Nagai 《Microsystem Technologies》1995,1(3):124-128
In order to make micro 3-D structures, we are designing a table-sized factory, namely Nano Manufacturing World (NMW). In NMW, we challenged to use a new process fused by semiconductor process for preciseness and machine process for 3-dimensionality. In order to realize the new process, we designed three new mechanisms in this paper: multi-face shape making beam, co-focus rotational robot and micro mechanical tools. Through an evaluation to actually make a micro Gojunoto with the mechanisms, we confirmed their validities for functions of integration of 3-D shape construction and assembly. 相似文献