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671.
V. Antonucci J. Kelly L. Wright N. Yasuda M. Jensen C. Yang R. Reamer 《Journal of chromatography. A》1999,840(2):563-223
Simple and robust derivatization methods for monitoring the formation of (tributylstannyl)methanol from tributyltin hydride via unstable lithiated intermediates have been developed and validated. These analytes present both chromatographic and detection difficulties in their native states due to low volatility, poor aqueous solubility/stability, and lack of a chromophore. Derivatization of these analytes to trimethylsilyl analogues for gas chromatographic analysis or to benzenesulfonyl urethane analogues for reversed-phase liquid chromatographic analysis was evaluated. The derivatization/gas chromatographic methods developed were demonstrated to be more specific and sensitive for impurity monitoring during (tributylstannyl)methanol preparation. 相似文献
672.
M. Yamamoto N. Yasuda Y. Kaizuka M. Yamagishi T. Kanai N. Ishigure A. Furukawa M. Kurano N. Miyahara M. Nakazawa T. Doke K. Ogura 《Radiation measurements》1997,28(1-6):227-230
Preliminary results of feasibility study to apply atomic force microscope (AFM) to the quantitative analysis for minute etch pits on CR-39 are reported comparing with the optical microscope observation. The growth curves of the Si track diameter and length obtained by both technqiues were discussed in relation to the track sensitivity and the etch induction time. 相似文献
673.
A method for measuring longitudinal atom density distributions in a graphite tube furnace using coherent forward scattering is proposed. A transverse magnetic field is locally applied to the atomic vapor in a graphite tube. Relative atom density distributions for the elements Cd, Cu, Mn, Ni and Pb are measured. 相似文献
674.
675.
Magnetoresistance anisotropies, differing from those of bulk p-type Si, have been observed on p-type Si film on sapphire (SOS). They may arise from the valence band split and deformed by a large compressive strain due to thermal expansion coefficient difference between Si and sapphire. 相似文献
676.
S. Lucht D. Neher T. Miteva G. Nelles A. Yasuda R. Hagen S. Kostromine 《Liquid crystals》2003,30(3):337-344
We demonstrate reversible photoinduced in situ reorientation of low molecular mass liquid crystals (LCs) by means of photoaddressable polymers (PAPs). These polymers contain mesogenic azobenzene side chains optimized to reorient cooperatively and effectively upon illumination with polarized light. Various low molecular mass LCs were introduced between two PAP layers and these sandwich devices were tested with respect to stability and reversibility of photoinduced orientation. Dissolution of the PAP layer by the low molecular mass LC was observed for several material combinations and systematically investigated. Different anisotropic dyes were added as fluorescence markers in order to monitor the photoinduced LC orientation. With an optimized material combination, more than 10 reversible reorientation processes could be realized with polarized light of either 514 or 405 nm wavelength, without any reduction in alignment quality. Further, microscopic polarized fluorescence patterns could be produced and erased within short exposure times. 相似文献
677.
Improvement of primer adhesion to thermoplastic olefins (TPOs) by methane plasma polymerization with a low‐temperature cascade arc discharge was investigated. Methane plasma with a low‐temperature cascade arc plasma torch can be used for improving the primer adhesion to TPOs. Tape‐adhesion tests (ASTM 3359‐92a method) demonstrated this improvement, with a rating of 0 for untreated TPOs and 5 for methane plasma‐polymerized TPOs at certain plasma conditions even for aging at 60 °C and 80% relative humidity for 5 days. The adhesion to primer for the soft, flexible TPOs (ETA‐3041c and ETA‐3101) was easily enhanced. The adhesion to primer for the hard and brittle TPOs (ETA‐3183) needs to optimize the plasma conditions to pass the dry‐ and wet‐adhesion test with methane plasmas. To relate the surface characteristics of methane plasma‐polymerized TPOs to adhesion performance with primer, the wettability and polarity of TPOs were evaluated by the contact‐angle measurements of primer and deionized water to TPOs. TPO surface morphology was evaluated with scanning electron microscopy. The surface composition was characterized with electron spectroscopy for chemical analysis. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2004–2021, 2003 相似文献
678.
H. Yasuda Toshihiro Hirotsu 《Journal of polymer science. Part A, Polymer chemistry》1978,16(2):313-326
The effects of relative positions of the monomer inlet and the r.f. coil, and of the inlet and outlet, on the distribution of polymer deposition in plasma polymerization of ethylene were investigated using an electrodeless glow discharge by a 13.5-MHz radiofrequency source. The diffusional transport of active species created under the r.f. coil, diffusional transport of polymer forming species, and flow of gas in the system are important factors that determine the distributions of polymer deposition observed in plasma polymerization of ethylene. The mechanisms of polymer deposition are discussed in conjunction with postulated plasma polymerization mechanisms. 相似文献
679.
Osamu Yasuda 《Nuclear Physics B》1984,246(1):170-188
Classical stability of Einstein spaces Sd1 ×?×Sdn(dj ? 2) against all fluctuations is investigated in euclidean gravity with a cosmological constant. It is shown that Sd is classically stable, while Sd1 ×?× Sdn(n ? 2) is classically unstable. As a generalization of this analysis it is proved that a compact Einstein space B1 ×?× Bn(n ? 2) which is a direct product of each Einstein space is classically unstable. Non-Einstein spaces M2 × S4 (M2 × S2 × S2) are also considered in six- dimensional Einstein-Maxwell theory and are shown to be classically stable (unstable). 相似文献
680.
Masayoshi Tonouchi Akihiko Itoh Takashi Yasuda Hisashi Shimakage Zhen Wang Shuzo Takano 《Czechoslovak Journal of Physics》1996,46(Z3):1275-1276
We fabricatedc-axis oriented meas on YBa2Cu3O7−δ thin films. Columnar structures with an area of 20×20 μm2 and a depth of 0.1 μm were formed on oxygen deficient films with a critical temperature (T
c
) of 64 K or less. The devices showed hysteretic I–V curves without any branches. The dependence of the critical current density
on the temperature nearT
c
is explained by the Ambegaokar-Baratoff relation. 相似文献