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排序方式: 共有327条查询结果,搜索用时 359 毫秒
81.
82.
Matsuta K. Fukuda M. Tanigaki M. Minamisono T. Nojiri Y. Akai H. Izumikawa T. Nakazato M. Mihara M. Yamaguchi T. Harada A. Sasaki M. Miyake T. Onishi T. Minamisono K. Fukao T. Sato K. Matsumoto Y. Ohtsubo T. Fukuda S. Yoshida K. Ozawa A. Momota S. Kobayashi T. Tanihata I. Alonso J. R. Krebs G. F. Symons T. J. M. 《Hyperfine Interactions》1996,97(1):501-508
The spin relaxation timeT
1 for short-lived beta emitters13O and23Mg implanted in Pt have been measured for the first time;T
1T13O) = 2.90 ±0.65 Ks andT
1
T(23Mg) = 1665 ±140 Ks. The Knight shift for13O in Pt was measured at 300 K to beK(13O) = +(4.23 ±0.14) × 10–3. In the case of13O, the Knight shift is unusually large and the relaxation time is unusually fast compared with other interstitial impurities in Pt. A KKR band-structure calculation reproduces the present large Knight shift fairly well. 相似文献
83.
Akira Onishi Makoto Endo Shigeki Uchino Naoto Harashima Naoki Oguri 《Journal of separation science》1993,16(6):353-357
A new multichannel autosampler which can automatically analyze up to twenty samples in sequence has been developed for Curie point pyrolysis – capillary GC. Compared with a previous system [1] the transfer line between the pyroysis unit and chromatograph is shorter, and thus has less dead volume, and can be operated at a higher temperature (300 °C). The relative yields of higher boiling point, highly polar, and thermally labile pyrolysates generated from polymers, and the reproducibility, were better than those obtained from the previous autosampler. To facilitate rapid operation an additional flow controller is installed on the new device to shorten the time taken to purge air from the sampler. 相似文献
84.
Ayaka Hibi 《Tetrahedron letters》2009,50(34):4888-9921
A highly efficient palladium-catalyzed oxidative cyclization of olefinic keto and/or lactone esters, which features a catalytic cyclization employing one atmosphere of oxygen as a reoxidizing agent, is developed. 相似文献
85.
Jinxiang Li Ayaka Ogasawara Tamao Odake Tomonari Umemura Kin-ichi Tsunoda 《Analytical sciences》2004,20(12):1673-1679
A new isoelectric focusing (IEF) system for two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) has been proposed. In this system, a super-soft and tough IEF gel was achieved by casting polyacrylamide gel down to 2.0% T using a loose multifilament string (LMS) of nylon as a gel support. The IEF apparatus for the LMS-gel, fabricated from acrylic boards, had a cooling water chamber, and eliminated the need of electrode solutions by directly connecting the two ends of individual gels to platinum electrodes. The carrier ampholyte-generated pH gradients using the new IEF system was stable over a long duration of time and a wide range of voltages, and the IEF time became shorter using a 2.0% T gel than using a 4.0% T gel. Also, the LMS-gels prepared in different runs exhibited excellent reproducibility. The new IEF system was applied to 2-D PAGE of a chicken skeletal muscle extract, and it was found that the protein loading capacity, protein entry into the LMS-gels, and protein transfer efficiency from the first-dimensional to the second-dimensional gels were significantly improved by using a low-concentration (2.5% T) gel. Also, proteins of high molecular weight of more than 200 kDa were observed in the 2-D maps, and therefore the new IEF system has a very good potential to be applied for fast 2-D PAGE of high molecular-weight proteins. 相似文献
86.
Masakazu Anpo Takaiki Nomura Junko Kondo Kazunari Domen Ken-Ichi Maruya Takaharu Onishi 《Research on Chemical Intermediates》1990,13(3):195-202
Photoluminescence and FT-IR studies of the adsorption of H2 on ZrO2 catalysts have been performdd to clarify the true natuee of active surface sites for the activaiion of H2 in connection with the CO — H2 reaction on the catalyst. The results indicate that the coordinatively unsaturated surface sites with different coordination
numbers are generated on the surfaces by evacuation at temperatures higher than 600 K. These surface sites of lower coordination
play a significant role in the reversible and irreversible dissociative adsorption of H2 on the active ZrO2 catalyst. The former seems to act as active hydrogen species for the CO — H2 reaction to form branched hydrocarbons on the ZrO2 catalyst. 相似文献
87.
Scanning tunneling microscopy luminescence (STML) was induced from the nanometer scale surfaces of cleaved n-type and p-type GaAs(1 1 0) wafers by using of an ITO-coated optical fiber probe in an ultrahigh-vacuum chamber. The STML from n-type GaAs(1 1 0) surface was induced under negative sample bias when the applied bias exceeds a threshold voltage around −1.5 V. Whereas the STML from p-type GaAs(1 1 0) surface was induced under positive sample bias when the applied bias exceeds a threshold voltage around +1.5 V. The excitation energies at the threshold voltages are consistent with the band gap of GaAs (1.42 eV) at 295 K. The typical quantum efficiencies for n-type and p-type GaAs are about 3 × 10−5 and 2 × 10−4 photons/electron, respectively. The observed STML from are attributed to a radiative recombination of electron-hole pairs generated by a hole injection for n-type GaAs under negative sample bias and an electron injection for p-type GaAs under positive sample bias, respectively. 相似文献
88.
The most serious problems for the matrix projection exposure using a liquid crystal display (LCD) panel in place of a reticle
are largely solved by a new breakthrough method. LCD matrix exposure is effective for small volume productions of print circuits,
screen masks, micromachine parts, and other items. Since no reticles are needed, all reticle costs are saved, and turnaround
times required for changing the patterns are greatly shortened. However, in the conventional method, pattern widths and positions
were strictly restricted depending on the geometric size and pitch of the liquid crystal cells. In this paper, a new concept
appointing the cell brightness grades continuously using an analogue interface LCD panel is proposed. Calculating the image
intensity distributions for various appointments of cell brightness balances to print same wide patterns, it is clarified
that the pattern widths and positions are not much different if the pattern widths are wider than 2 cell pitches of the LCD
panel. Maximum width and position variations are less than ± 10% even when the patterns are printed at arbitrary positions,
of course including halfway ones. The calculated results are proved by experiments using an analogue LCD panel with a cell
pitch of 15 μm. Though the cell size are 13 × 10 μm2, and different in x and y directions, almost same wide line-and-space patterns are successfully printed at all positions
by only one exposure. It is not necessary to shift the reticle for overlapping exposures to print smooth patterns. Oblique
patterns and complicated Chinese character patterns are also printed at arbitrary positions. The new breakthrough technology
will make the LCD matrix exposure promising for wide uses of printing various rough patterns easily at small costs. 相似文献
89.
90.
Low temperature bis-metal—halogen exchange on a platinacyclic moietyis reported to occur without cleavage of the zero-valent platinumalkyne bond(s). The metallation procedure affords a convenient, mild route to metalate, dehalogenate, label, and/or functionalize metallacycles. 相似文献