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991.
Tatsuro Tominaga Koki Fukuda Dr. Kazutaka Koga Dr. Makoto Fukudome Prof. Dr. De-Qi Yuan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(8):e202103940
Miniature models of acyl-transfer systems in cells, which were composed by replacing the protein, coenzyme, and substrate with CD, functional group, and CD, respectively, and combining them all together in one, displayed definite role-sharing and exact cooperation of the functional groups and hydrophobic cavity, and thus enabled the regio-specific reaction. 相似文献
992.
Dr. Ryu Yamasaki Kento Morita Hiromi Iizumi Dr. Ai Ito Dr. Kazuo Fukuda Prof. Dr. Iwao Okamoto 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(43):10118-10122
Activated amide bonds have been attracting intense attention; however, most of the studied moieties have twisted amide character. To add a new strategy to activate amide bonds while maintaining its planarity, we envisioned the introduction of an alkynyl group on the amide nitrogen to disrupt amide resonance by nN→Csp conjugation. In this context, the conformations and properties of N-ethynyl-substituted aromatic amides were investigated by DFT calculations, crystallography, and NMR spectroscopic analysis. In contrast to the cis conformational preference of N-ethyl- and vinyl-substituted acetanilides, N-ethynyl-substituted acetanilide favors the trans conformation in the crystal and in solution. It also has a decreased double bond character of the C(O)−N bond, without twisting of the amide. N-Ethynyl-substituted acetanilides undergo selective C(O)−N bond or N−C(sp) bond cleavage reactions and have potential applications as activated amides for coupling reactions or easily cleavable tethers. 相似文献
993.
ABSTRACTWe have isolated several poly 3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBH) degradable bacteria from the deep-sea sediment samples. The isolated microbes were involved into α-, γ- Proteobacteria group and the phylum Firmicutes, which were commonly diverged in the ocean environment. Four bacterial strains, Bacillus sp. MH10, Alteromonas sp. MH53, Psychrobacillus sp. PL87 and Rheinheimera sp. PL100, were selected as more active strains for the PHBH bio-degradation at high pressure and cold temperature conditions, and showed that those strains were piezotolerant up to 20–30?MPa. Our findings indicated that the PHBH could be well degraded not only in the ocean environment, but also at the deep-sea bottom, by means of those marine microorganisms. 相似文献
994.
Yuya Ishii Shota Satozono Keisho Omori Mitsuo Fukuda 《Journal of Polymer Science.Polymer Physics》2016,54(13):1237-1244
Dye‐doped submicron poly(N‐vinylcarbazole) fibers having mean diameters of 290–430 nm were fabricated via electrospinning and their waveguiding properties were investigated. The middle of each fiber's length was excited with UV light and guided photoluminescence (PL) was measured at the end of each of the fibers for different propagation lengths. The spectral shapes of the guided PL differed depending on the fiber diameter because of leakage of light into the substrate. We propose a model that reproduces the PL attenuation with increasing propagation lengths and includes the temporal PL decay due to photobleaching and the size of the excitation area. The calculated propagation loss coefficient in the fibers was 6.3 × 10?3?1.4 × 10?1 µm?1 with λ = 430–500 nm. The propagation loss was inherent in the fiber itself because the re‐absorption loss coefficient of the doped dye was <1.3% of the propagation loss coefficient. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1237–1244 相似文献
995.
Shingo Sato Takeshi Watanabe Hironobu Kumagai Nobuo Kitamura Shigeru Matsuba Toshihiro Kumazawa Jun-Ichi Onodera Masanobu Suzuki 《Journal of heterocyclic chemistry》1999,36(5):1189-1193
Condensation of 2-hydroxyacetophenone with benzaldehyde in the presence of 70% perchloric acid in ethyl orthoformate gave the corresponding 4-ethoxyflavylium perchlorate, which was treated with aqueous ammonia or methylamine solution to afford 1,6,7,8-substituted 2-(3′,4′-substituted-phenyl)-4-quinolone in fair to good yield. 相似文献
996.
997.
Y. Urata K. Akagawa S. Wada H. Tashiro S. J. Suh D. H. Yoon T. Fukuda 《Crystal Research and Technology》1999,34(1):41-45
Thulium-doped gadolinium vanadate (Tm:GdVO4) single crystal has been successfully grown by a modified Czochralski (CZ) technique. Effective distribution coefficient of Tm was determined to be 0.74. Absorption characterization was performed in the 800 nm region and the maximum absorption peak was found at 799 nm for p polarization. Fluorescence spectra for tuning at the maximum absorption were obtained around 1.8-2.0µm region with 100 nm bandwidth. This suggests that a Tm:GdVO4 crystal is expected as a new promising LD pumped solid-state laser in the 2µm region. 相似文献
998.
Wu Pinga Tian Yali Jiang Enyong Tang Wenchao Hiroki Fukuda Teiichi Ando 《化学物理学报(中文版)》2004,17(4):471-475
The Sn-5%Pb droplets with sizes of 150 and 185 μm were generated by Uniform Droplet Spray(UDS) under N2 atmosphere with 1. 36 μmol / L oxygen. The appearance of Sn-5%Pb droplets under the optical microscope showed that the droplets are uniform and spherical. The method employed non-adiabatic calorimetry to determine the nucleation point and undercooling of droplets. The fraction covered by oxide was calculated as a function of time and temperature. The model for heterogeneous nucleation catalyzed by oxidation on the droplet surface was developed,which was a reasonable expression of the heterogeneous nucleation and solidification behavior of Sn-Pb droplets. The CCT curves were computed using above experimental results under the heterogeneous surface nucleation of droplet. The same model can be applied to predict the heterogeneous nucleation behavior of the droplets for any type of cooling schedule. The calculation results are very reliable based on the experimental data. 相似文献
999.
Peter Fulde Patrick Unger Jun-Ichi Igarashi 《International journal of quantum chemistry》1997,63(3):645-653
Until now, solids with strongly correlated electrons can be treated only by model Hamiltonians. Even then a calculation of spectral densities is not simple, because the strong Coulomb interactions prevent us from treating correlations perturbatively. We show that projection and partitioning techniques are a very valuable tool here. The method is applied to computations of the density of states of transition metals, in particular, Ni. Here, the band narrowing and the sattlite peak at 6 eV due to correlations are reproduced. A second application concerns the spectral density of doped and undoped Cu(SINGLE BOND)O planes which are part of the high-Tc superconducting materials. © 1997 John Wiley & Sons, Inc. J Quant Chem 63: 645–653, 1997 相似文献
1000.
The automatic diameter control system with two ways of the crystal diameter determination is described. The correction of temperature oscillations during the growth process is applied in the describing system. Also, it allows to estimate the crystal quality already during the growth process. The control system is intended for the growth of crystals with different physical properties. 相似文献