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2.
Inside Cover: Photoinduced Formation of an Azobenzene‐Based CD‐Active Supramolecular Cyclic Dimer (Chem. Eur. J. 18/2015) 下载免费PDF全文
3.
Masashi Ohkawa Yuki Shirai Takeshi Goto Seishi Sekine Takashi Sato 《Fiber and Integrated Optics》2002,21(2):105-113
In this paper, a silicon-based integrated optic pressure sensor using an intermodal interference between the fundamental TM-like and TE-like modes is described. The sensor consists of a micromachined rectangular diaphragm and a straight polystyrene optical waveguide passing over the diaphragm. Its sensitivity is theoretically known to be strongly dependent on the position of the waveguide over the diaphragm. To experimentally investigate such dependence, we fabricated a sensor with a 1.2 mm ×10 mm ×20 μm diaphragm, over which waveguides were placed at 50 μm intervals. The measured phase sensitivity was 98 mrad/kPa for the waveguide nearest to the diaphragm edge. The measurement was also carried out for the other waveguides. As theoretically expected, the largest sensitivity was obtained for the waveguide nearest to the edge. 相似文献
4.
N Murakami T Morimoto H Imamura T Ueda S Nagai J Sakakibara N Yamada 《Chemical & pharmaceutical bulletin》1991,39(9):2277-2281
Seven new monogalactosyl diacylglycerols (1-7) and six new digalactosyl diacylglycerols (11-16) were isolated from an axenically cultured cyanobacterium, P. tenue. Their structures were elucidated on the basis of physicochemical evidence and the results of enzymatic hydrolysis using a lipase (from Rhizopus arrhizus). Comparison of antialgal activity for P. tenue between monogalactosyl diacylglycerols (1-8) and digalactosyl diacylglycerols (11-19) revealed that the former showed more potent activity than the latter. 相似文献
5.
Squier (1987) showed that if a monoid is defined by a finite complete rewriting system, then it satisfies the homological
finiteness condition FP3, and using this fact he gave monoids (groups) which have solvable word problems but cannot be presented by finite complete
systems. In the present paper we show that a monoid cannot have a finite complete presentation if it contains certain special
elements. This observation enables us to construct monoids without finite complete presentation in a direct and elementary
way. We give a finitely presented monoid which has (1) a word problem solvable in linear time and (2) linear growth but (3)
no finite complete presentation. We also give a finitely presented monoid which has (1) a word problem solvable in linear
time, (2) finite derivation type in the sense of Squier and (3) the property FP∞, but (4) no finite complete presentation. 相似文献
6.
Linear and nonlinear optical properties of racemic (±)2-(α-methylbenzylamino)-5-nitropyridine ((±)MBANP) single crystals have been comprehensively investigated and compared with those of the enantiomorph (–)2-(α-methylbenzylamino)-5-nitropyridine ((–)MBANP) crystals. (±)MBANP crystal exhibits very high chemical and physical stability, but relatively small nonlinear optical coefficients (d31 = 6.8 pm/V, d32 = 4.7 pm/V, d33 = 0.84 pm/V). A comparison between the nonlinear optical coefficients of (±)MBANP and (–)MBANP demonstrates the validity of the oriented-gas model in molecular crystals that neglects all the contributions from intermolecular interaction. 相似文献
7.
The rate coefficient for the reaction of CCl3 radicals with ozone has been measured at 303 ± 2 K. The CCl3 radicals were generated by the pulsed laser photolysis of carbon tetrachloride at 193 nm. The time profile of CCl3 concentration was monitored with a photoionization mass spectrometer. Addition of the O3–O2 mixture to this system caused a decay of the CCl3 concentration because of the reactions of CCl3 + O3 → products (5) and CCl3 + O2 → products (4). The decay of signals from the CCl3 radical was measured in the presence and absence of ozone. In the absence of ozone, the O3–O2 mixture was passed through a heated quartz tube to convert the ozone to molecular oxygen. Since the rate coefficient for the reaction of CCl3 + O2 could be determined separately, the absolute rate coefficient for reaction ( 5 ) was obtained from the competition among these reactions. The rate coefficient determined for reaction ( 5 ) was (8.6 ± 0.5) × 10?13 cm3 molecule?1 s?1 and was also found to be independent of the total pressure (253–880 Pa of N2). This result shows that the reaction of CCl3 with O3 cannot compete with its reaction with O2 in the ozone layer. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 310–316, 2003 相似文献
8.
In photochemical vapor deposition of aluminum film on silicon using dimethylaluminum hydride, (CH3)2AlH, a surface reaction dominated below a (CH3)2AlH pressure of 0.3 m Torr at 200°C, which was induced only with the 160 nm band emitted from a deuterium lamp. A gas-phase reaction occurred above 0.3 mTorr at 200°C, which could be induced by both 160 nm and 240 nm emission bands from the lamp. To distinguish between surface ad gas-phase reactions, a thickness profile was used. At 240°C the surface reaction could be induced even by the 240 nm band, while the deposits formed under illumination of the two bands were thinner than those obtained with only the 240 nm band, indicating occurrence of vacuum ultraviolet (VUV)-enhanced desorption. The mechanism responsible for the observed wavelength dependence in unclear. The electrical resistivity of the films deposited at 200°C was 4.5 μΩ cm, which did not change with wavelength. 相似文献
9.
Recently, we have developed a new tight-binding quantum chemical molecular dynamics program “Colors” for combinatorial computational chemistry approach. This methodology is based on our original tight-binding approximation and realized over 5000 times acceleration compared to the conventional first-principles molecular dynamics method. In the present study, we applied our new program to the simulations on various realistic large-scale models of the automotive three-way catalysts, ultrafine Pt particle/CeO2(111) support. Significant electron transfer from the Pt particle to the CeO2(111) surface was observed and it was found to strongly depend on the size of the Pt particle. Furthermore, our simulation results suggest that the reduction of the Ce atom due to the electron transfer from the Pt particle to the CeO2 surface is a main reason for the strong interaction of the Pt particle and CeO2(111) support. 相似文献
10.
S. Takahashi T. Yamashita H. Imamura S. Maekawa 《Journal of magnetism and magnetic materials》2002,240(1-3):100-102
The effect of spin relaxation on tunnel magnetoresistance (TMR) in a ferromagnet/superconductor/ferromagnet (FM/SC/FM) double tunnel junction is theoretically studied. The spin accumulation in SC is determined by balancing of the spin-injection rate and the spin-relaxation rate. In the superconducting state, the spin-relaxation time τs becomes longer with decreasing temperature, resulting in a rapid increase of TMR. The TMR of FM/SC/FM junctions provides a useful probe to extract information about spin-relaxation in superconductors. 相似文献