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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.
Dr. Yogesh Kumar Maurya Dr. Pingchun Wei Takahide Shimada Dr. Kazuhisa Yamasumi Dr. Shigeki Mori Prof. Dr. Ko Furukawa Dr. Hajime Kusaba Prof. Dr. Tatsumi Ishihara Prof. Dr. Yongshu Xie Dr. Masatoshi Ishida Prof. Dr. Hiroyuki Furuta 《化学:亚洲杂志》2021,16(7):743-747
A facile synthetic strategy towards conformationally stable chiral chromophores based on dimeric porphyrinoids has been established. A peculiar class of face-to-face intramolecularly interlocked corrole dimers were formed by the oxidative C−C coupling linked at the inner carbon sites upon simple treatment of copper(II) ions. Their intrinsic electronic structures were modulated by the peripheral corrole ring annulations, which lead to distinct optical properties and redox profiles. The stereogenic carbon centers implemented in the confused corrole skeleton provided a rationale for designing novel chiral materials. 相似文献
4.
In this study we examined the unsteady and chaotic characteristics of the natural convection field in vertical slots at large
Prandtl number. In the computation, temperature dependence of viscosity was partially taken into consideration. As a result
we discovered that the spatial region where a significant temperature fluctuation is detected corresponds to the spatial region
where the secondary cells exist. The largest Lyapunov exponents calculated from the temperature on the center line have a
local maximum at the lower region of the enclosure when the viscosity change was considered. These characteristics agree well
with the experimental ones that have been observed by authors (Ishida, Kure and Kimoto 2001). 相似文献
5.
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
6.
Shuichi Ishida Keiki Takeda Atsushi Okamoto Ichiro Shibasaki 《Physica E: Low-dimensional Systems and Nanostructures》2004,20(3-4):255
Magnetoresistance (MR) effects have been investigated in perpendicular and parallel magnetic fields at 300, 80 K and liquid He temperatures for undoped InSb thin films 0.1–2.3 μm thick grown on GaAs(1 0 0) substrates by MBE. At high temperatures, the intrinsic carriers show the parabolic negative MR observable only in magnetic fields parallel to the film. The skipping-orbit effect due to surface boundary scattering in the classical orbits in the plane vertical to the film has been argued to be responsible for the negative MR. At low temperatures (T=80 K), the transport is dominated by the two-dimensional (2D) electrons in the accumulation layers at the InSb/GaAs(1 0 0) hetero interface; MR is positive and shows a logarithmic increase with anisotropy between parallel and perpendicular field orientation, arising from the 2D weak anti-localization (WAL) that reflects the interplay between the spin-Zeeman effect and strong spin–orbit interaction caused by the asymmetric potential at the interface (Rashba term). The zero-field spin splitting energy of Δ013 meV, the electron effective mass of m*0.10m0 seven times of the band edge mass in bulk InSb and the effective g-factor of |g*|15 in the accumulation layer have been inferred from fits of MR for the 0.1 μm thick film to the 2D WL theory. 相似文献
7.
The potential of an N-Troc-protected sialic acid donor, equipped with phenylsulfenyl functionality as a leaving group, has been explored. As a result, the entitled donor was proven to be highly reactive and to have broad applicability toward the synthesis of variant sialo-glycans, which have N-glycolyl, de-N-acetyl, 1,5-lactam and 8-O-sulfo sialic acid analogs. 相似文献
8.
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
9.
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
10.