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131.
Fujiwara H Kimura A Yanagawa Y Kamiya T Hattori M Hiraga T 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2001,150(2):156-160
Size dependency of the relaxation time T(1) was measured for laser-polarized (129)Xe gas encapsulated in different sized cavities made by glass bulbs or gelatin capsules. The use of laser-polarized gas enhances the sensitivity a great deal, making it possible to measure the longer (129)Xe relaxation time in quite a short time. The size dependency is analyzed on the basis of the kinetic theory of gases and a relationship is derived in which the relaxation rate is connected with the square inverse of the diameter of the cavity. Such an analysis provides a novel parameter which denotes the wall effect on the relaxation rate when a gas molecule collides with the surface once in a second. The relaxation time of (129)Xe gas is also dependent on the material which forms the cavity. This dependency is large and the relaxation study using polarized (129)Xe gas is expected to offer important information about the state of the matter of the cavity wall. 相似文献
132.
Measurement Accuracy in Phase-Shifting Point Diffraction Interferometer with Two Optical Fibers 总被引:1,自引:0,他引:1
Toshiaki Matsuura Satoru Okagaki Takaaki Nakamura Yasushi Oshikane Haruyuki Inoue Motohiro Nakano Toshihiko Kataoka 《Optical Review》2007,14(6):401-405
A phase-shifting point diffraction interferometer (PS/PDI) with point sources of two single mode optical fibers has been developed,
which will be appropriate for the surface figure measurement of large aperture optics on a sub-nanometer scale. To reduce
the measurement error factors, a fiber optic plate (FOP) is used as a projection plane for interference pattern. Errors caused
by imperfection of optical alignment, such as position of point sources and tilt of FOP, are minimized by analyzing the measured
phase data with an original method. Measurement accuracy in the PS/ PDI is estimated with the interference pattern produced
by the two optical fiber sources. If inhomogeneity of the FOP and a systematic error of the PS/PDI are eliminated, the measurement
accuracy of the present system is estimated to be less than 4nm P-V and 0.7nm rms, respectively, at a measurement wavelength
of 632.8 nm. 相似文献
133.
The lithium ion conducting solid polymer electrolytes (SPE) based on PVAc-LiClO4 of various compositions were prepared by solution casting technique. Structure and surface morphology characterization were studied by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) measurements, respectively. Thermal and conductivity behavior of polymer-salt complexes were studied by employing differential scanning calorimetry (DSC) and ac impedance measurements, respectively. XRD and SEM analyses indicate the amorphous nature of the polymer-salt complexes. DSC measurements show decrease in Tg with the increase in LiClO4 concentrations. The bulk conductivity of the PVAc:LiClO4 polymer electrolytes was found to vary between 7.6×10−7 and 6.2×10−5 S cm−1 at 303 K with the increase in salt concentration. The temperature dependence of the polymer electrolyte complexes appear to obey Arrhenius law. 相似文献
134.
135.
Keiko Takahashi Sayo Morimoto Hiroto Nakamura Toshiaki Narusawa Taizo Seki Masahiko Ooe Keigo Aoi Akiyoshi Takada 《Journal of inclusion phenomena and macrocyclic chemistry》2011,70(3-4):389-396
2-Hydroxypropyl-??-cyclodextrin (HP-??-CyD) includes all-trans retinoic acid (RA), covering the double-bond area of RA with substituted hydroxypropyl groups on CyD ring, as proved by the nuclear Overhauser effect (NOE) between methylene protons on the hydroxypropyl groups and the proton on RA. The formation of an inclusion complex results in hydrophilicity and stability. The effect of RA/HP-??-CyD and that of RA without HP-??-CyD on wrinkle scores and skin elasticity during skin treatment were identical, and the cutaneous stimulus was reduced comparing with RA. The results indicated that the RA/HP-??-CyD complex should help to realize new approaches in skin rejuvenation therapy. 相似文献
136.
In this study, water penetration and the interaction between water and a pharmaceutical excipient in a tablet were investigated using near-infrared (NIR) spectroscopy and perturbation-correlation moving-window two-dimensional correlation spectroscopy (PCMW-2DCS). The penetration rate of water into a tablet was mainly dependent on the porosity of the tablet and was less dependent on the type of excipient. This behavior was well described by the Lucas–Washburn theory. The PCMW-2DCS technique revealed that there are two-staged interaction changes in NIR spectra of the water–powder interactions. The first and second changes corresponded to the water–solid interaction and the dissolution of the solid, respectively. The diffusion-controlled dissolution model by Nernst well explained these results. 相似文献
137.
Toshiaki Shirakawa Hajime Ichimura Isao Ikemoto 《Molecular Crystals and Liquid Crystals》2013,570(1-4):101-107
Pressure-volume isotherms for 4-(trans-4-butylcylohexyl)benzonitrile were measured by means of piston-cylinder method. This substance has a monotropic nematic phase at atmospheric pressure. But over a pressure, the nature of isotropic to nematic phase transition changed from monotropic to enantiotropic phase transition. It is the first observation in P-V-T experiments that the monotropic isotropic-nematic transition changes enantiotropic under pressure. 相似文献
138.
We show that the transfinite inductive dimensions modulo PP-trind and P-trInd introduced in M.G. Charalambous (1997) [2] differ by simple spaces, where P is the absolutely additive Borel class A(α) or the absolutely multiplicative Borel class M(α), 0?α<ω1. 相似文献
139.
Effect of tea polyphenols on glucan synthesis by glucosyltransferase from Streptococcus mutans 总被引:3,自引:0,他引:3
M Hattori I T Kusumoto T Namba T Ishigami Y Hara 《Chemical & pharmaceutical bulletin》1990,38(3):717-720
In the course of our studies on the development of anti-plaque agents for prevention of dental caries, we investigated effects of some of tea preparations and their individual components on the glucan synthesis catalyzed by glucosyltransferase (GTF) from Streptococcus mutans. Extracts of green tea and black tea, and polyphenol mixtures showed appreciable inhibition in the synthesis of insoluble glucan. Among the components isolated from tea infusions, theaflavin and its mono- and digallates had potent inhibitory activities at concentrations of 1-10 mM against GTF. (+)-Catechin, (-)-epicatechin and their enantiomers had moderate inhibitory activities at these concentrations, while galloyl esters of (-)-epicatechin, (-)-epigallocatechin and (-)-gallocatechin had increased inhibitory activities. 相似文献
140.