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991.
Inumaru K Kasahara T Yasui M Yamanaka S 《Chemical communications (Cambridge, England)》2005,(16):2131-2133
Well-crystallised TiO2 particles (P-25, 20-30 nm in diameter) were directly incorporated into surfactant-templated mesoporous silica particles (pore diameter: 2.7 nm), and the composite material with a high TiO2 content (60 wt%) showed molecular selective and enhanced photocatalysis for decomposition of 4-nonylphenol. 相似文献
992.
Uchiyama T Miyoki S Telada S Yamamoto K Ohashi M Agatsuma K Arai K Fujimoto MK Haruyama T Kawamura S Miyakawa O Ohishi N Saito T Shintomi T Suzuki T Takahashi R Tatsumi D 《Physical review letters》2012,108(14):141101
The thermal fluctuation of mirror surfaces is the fundamental limitation for interferometric gravitational wave (GW) detectors. Here, we experimentally demonstrate for the first time a reduction in a mirror's thermal fluctuation in a GW detector with sapphire mirrors from the Cryogenic Laser Interferometer Observatory at 17 and 18 K. The detector sensitivity, which was limited by the mirror's thermal fluctuation at room temperature, was improved in the frequency range of 90 to 240 Hz by cooling the mirrors. The improved sensitivity reached a maximum of 2.2×10(-19) m/√Hz at 165 Hz. 相似文献
993.
Hatano M Ikeno T Miyamoto T Ishihara K 《Journal of the American Chemical Society》2005,127(31):10776-10777
A highly enantioselective cyanohydrin synthesis with aromatic aldehydes using chiral lithium binaphtholate aqua or alcohol complexes has been developed and is a simple and inexpensive catalyst suitable for process chemistry to give gram-scale cyanohydrins successfully. Dramatic improvements in enantiomeric excess have been realized along with an interesting changeover in absolute stereochemistry of cyanohydrin product against the thoroughly "dry" catalytic systems. 相似文献
994.
Takashi Koda 《Annals of Global Analysis and Geometry》1993,11(4):323-329
Bérard-Bergery has constructed a non-Kähler Einstein Hermitian metricg with positive scalar curvature on
. We prove thatg is a weakly *-Einstein metric with nonconstant positive *-scalar curvature.This research is partially supported by the Grand-in-Aid for Scientific Research (No. 03740022), the Ministry of Education, Science and Culture. 相似文献
995.
996.
Prof. Arivazhagan Rajendran Kirankumar Krishnamurthy Seojeong Park Prof. Eiji Nakata Prof. Youngjoo Kwon Prof. Takashi Morii 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(22):e202200108
DNA minicircles exist in biological contexts, such as kinetoplast DNA, and are promising components for creating functional nanodevices. They have been used to mimic the topological features of nucleosomal DNA and to probe DNA-protein interactions such as HIV-1 and PFV integrases, and DNA gyrase. Here, we synthesized the topologically-interlocked minicircle rotaxane and catenane inside a frame-shaped DNA origami. These minicircles are 183 bp in length, constitute six individual single-stranded DNAs that are ligated to realize duplex interlocking, and adopt temporary base pairing of single strands for interlocking. To probe the DNA-protein interactions, restriction reactions were carried out on DNAs with different topologies such as free linear duplex or duplex constrained inside origami and free or topologically-interlocked minicircles. Except the free linear duplex, all tested structures were resistant to restriction digestion, indicating that the topological features of DNA, such as flexibility, curvature, and groove orientation, play a major role in DNA-protein interactions. 相似文献
997.
Chikako Matsuda Ryo Igarashi Prof. Dr. Hiroshi Katagiri Dr. Takashi Murase 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(19):e202200132
Tri- and tetra-fluorinated [7]helicenes are photolabile and undergo a double fluorine atom transfer. Herein, we show that the transferred product further undergoes a skeletal transformation on silica gel. The transformation begins with activation of the allylic C−F bond on the silanol surface. Then, the resulting carbocation readily undergoes a regioselective nucleophilic aromatic substitution with water, depending on the position of the fluorine substituents. Hexafluoro-2-propanol also activated the allylic C−F bond and acted as a nucleophile. These findings support the generation of a highly reactive cationic electrophilic intermediate in the successive transformations involving fluorine atoms. 相似文献
998.
Experimental and numerical approaches have been used to study the effect of the radial rim-shroud gap on the flow structures found around a rotating disk in a finite cylindrical casing. When the radius of the disk and the inner radius of the casing are comparable and there is no radial gap, instabilities bring spiral rolls with a positive front angle in the Bödewadt layer on the end wall of the stationary casing. When the disk radius is smaller than the inner radius of the casing, vortex flows appear within the radial gap between the disk rim and the side wall of the casing. If the disk is thin, but not too thin, disturbances generated by these vortex flows proceed inward and the spiral rolls with a negative front angle appear in the Bödewadt layer. In the case of a thick disk, wavy Taylor vortex-like flow appears in the radial gap. The disturbances formed by the vortex flow do not well propagate into the inner region, and a flow pattern of bead-like vortices or a chain of vortices consisting of a series of small vortices are found around the disk in the visualized figure parallel to the disk. 相似文献
999.
Takashi Ikeda Dr. Keishiro Tahara Dr. Ryoichi Ishimatsu Prof. Toshikazu Ono Dr. Luxia Cui Momoka Maeda Prof. Yoshiki Ozawa Prof. Masaaki Abe 《Angewandte Chemie (International ed. in English)》2023,62(21):e202301109
This study reports an effective peripheral decoration of organic donor-acceptor diads with B(C6F5)3 for stabilizing electrogenerated radical ions. By employing a common p-type organic semiconductor benzothienobenzothiophene (BTBT) as the donor, tetracoordinate boron complexes showed improved solution electrochemiluminescence (ECL) intensity, reaching a 156-fold increase compared to that of the parent diad. The unprecedented Lewis-pairing-induced ECL enhancement is attributed to the multiple roles of B(C6F5)3: 1) redistributing frontier orbitals, 2) facilitating electrochemical excitation, and 3) restricting molecular motions. Furthermore, B(C6F5)3 converted the molecular arrangement of BTBT from conventional 2D herringbones into 1D π-stacks. This robust, highly ordered columnar nanostructure allowed red-shifting of the crystalline film ECL with electrochemical doping through the electronic coupling pathways of BTBT. Our approach will facilitate the development of elaborate metal-free ECL systems. 相似文献
1000.
A cationic coordination cage dramatically accelerates the Knoevenagel condensation of aromatic aldehydes in water under neutral conditions. The addition of a nucleophile to the aldehyde to generate anionic intermediates seems to be facilitated by the cationic environment of the cavity. The products are ejected from the cage as a result of the host-guest size discrepancy. As a result, the condensation is promoted by a catalytic amount of the cage. 相似文献