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971.
972.
C60-doped silicon oxide thin films were prepared by spin-coating a viscous solution formed upon soaking at 40°C an acidic toluene/ethanol solution of C60, phenyltriethoxysilane, and tetraethoxysilane with a C60–to–Si molar ratio of 2.5 × 10–3. The films were submitted to annealing at 300–500°C in Ar to investigate variation in the size of C60 clusters embedded in the films by photoluminescence spectroscopy. The film before annealing was found to contain the clusters consisting of ca. 60 C60 molecules, suggesting that C60 is present well-dispersed in the film. The molecules in the film aggregated to increase the size with increasing annealing temperature, indicating that the molecules diffuse easily in the film upon heating and therefore the size of the clusters is controllable with the annealing temperature. 相似文献
973.
Isao Kaetsu Kumao Uchida Kouichi Sutani Shoei Sakata 《Radiation Physics and Chemistry》2000,57(3-6):465-469
An intelligent biomembrane for environment-responsive feedback releases has been developed using radiation techniques. Various fine-porous base membranes (polyester, polycarbonate, silicon) were prepared by hole fabrication techniques with excimer-laser, ion-beam etching and photo-lithography etching. Then, various monomeric mixture of stimuli-sensitive hydrogels with or without immobilized enzymes were coated and polymerized on the porous membrane by UV, γ-ray or electron beam. The product showed the intelligent feedback release functions of model substance (methylene blue) in response to the on–off switching of signals such as pH changes and introduction of electric field. The responsiveness was remarkably improved by radiation induced IPN (interpenetrating polymer network) formation. Intelligent release controlled by a computer program was also studied and proved. 相似文献
974.
Thomas Höllerhage Danny Schuhknecht Alisha Mistry Dr. Thomas P. Spaniol Yan Yang Prof. Dr. Laurent Maron Prof. Dr. Jun Okuda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(9):3002-3007
The fifteen-membered NNNNN macrocycle Me5PACP (Me5PACP=1,4,7,10,13-pentamethyl-1,4,7,10,13-pentaazacyclopentadecane) stabilized the [CaH]+ fragment as a dimer with a distorted pentagonal bipyramidal coordination geometry at calcium. The hydride complex was prepared by protonolysis of calcium dibenzyl with the conjugate acid of Me5PACP followed by hydrogenolysis or treating with nOctSiH3 of the intermediate calcium benzyl cation. The calcium hydride catalyzed the hydrogenation and hydrosilylation of unactivated olefins faster than the analogous calcium complex stabilized by the twelve-membered NNNN macrocycle Me4TACD (Me4TACD=1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane). Kinetic investigations indicate that higher catalytic efficiency for the Me5PACP stabilized calcium hydride is due to easier dissociation of the dimer in solution when compared to the Me4TACD analogue. 相似文献
975.
Raju Chambenahalli R. M. Bhargav Karl N. McCabe Alex P. Andrews Florian Ritter Prof. Jun Okuda Prof. Laurent Maron Dr. Ajay Venugopal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(26):7391-7401
Zinc has been an element of choice for carbon dioxide reduction in recent years. Zinc compounds have been showcased as catalysts for carbon dioxide hydrosilylation and hydroboration. The extent of carbon dioxide reduction can depend on various factors, including electrophilicity at the zinc center and the denticity of the ancillary ligands. In a few cases, the addition of Lewis acids to zinc hydride catalysts markedly influences carbon dioxide reduction. These factors have been investigated by exploring elementary reactions of carbon dioxide hydrosilylation and hydroboration by using cationic zinc hydrides bearing tetradentate tris[2-(dimethylamino)ethyl]amine and tridentate N,N,N′,N′′,N′′-pentamethyldiethylenetriamine in the presence of triphenylborane and tris(pentafluorophenyl)borane. 相似文献
976.
Isao Okamura 《Colloid and polymer science》1933,65(2):175-178
Zusammenfassung Um die Wärmetönung und Arbeitsleistung bei der Verdünnung lyophiler Sole zu vergleichen, wurden Verdünnungswärme und osmotischer Druck an den Lösungen von Zellulosederivaten gemessen. Es ergibt sich, daß die differentiale Quellungsarbeit größer ist als die differentialeVerdünnungswärme. Dabei konnte eine Definition der Quellungsarbeit im Sinne der Ostwaldschen Zerlegung des osmotischen Druckes zugrunde gelegt werden.Den Herren Dr. Burgeni und Dr. Kudar, die die in dem allgemeinen Teil berührten Zusammenhänge diskutiert haben, möchte ich an dieser Stelle herzlich danken! 相似文献
977.
Akane Fujii Dr. Osamu Nakagawa Yuki Kishimoto Takumi Okuda Yusuke Nakatsuji Natsumi Nozaki Dr. Yuuya Kasahara Prof. Dr. Satoshi Obika 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(31):7443-7448
Metal-mediated base pairs (MMBPs) formed by natural or artificial nucleobases have recently been developed. The metal ions can be aligned linearly in a duplex by MMBP formation. The development of a three- or more-metal-coordinated MMBPs has the potential to improve the conductivity and enable the design of metal ion architectures in a duplex. This study aimed to develop artificial self-bases coordinated by three linearly aligned AgI ions within an MMBP. Thus, artificial nucleic acids with a 1,3,9-triaza-2-oxophenoxazine (9-TAP) nucleobase were designed and synthesized. In a DNA/DNA duplex, self-base pairs of 9-TAP could form highly stable MMBPs with three AgI ions. Nine equivalents of AgI led to the formation of three consecutive 9-TAP self-base pairs with extremely high stability. The complex structures of 9-TAP MMBPs were determined by using electrospray ionization mass spectrometry and UV titration experiments. Highly stable self-9-TAP MMBPs with three AgI ions are expected to be applicable to new DNA nanotechnologies. 相似文献
978.
979.
Details of light-induced annealing of hole trap state in undoped hydrogenated amorphous silicon (a-Si:H) have been studied; it has been found that prolonged illumination significantly reduces the density of hole trap states in the energy range deeper than 0.5 eV, and subsequent thermal annealing increases the density of hole trap states and restored the sample to the initial state before the illumination. We can speculate, from the experimental results and discussion in this work, that defect conversion processes are taking place during the long exposure to light; Si dangling bonds are generated from the precursors or latent sites which manifested as hole trap states located between 0.5 and 0.7 eV from the top of the valence band. 相似文献
980.
Nadaoka I Watanabe K Yasue M Sami M Kitagawa Y Mimaki Y 《Natural product communications》2012,7(1):15-18
Dried rhizomes of Cimicifuga racemosa (CR), known as black cohosh, have been widely used as a herbal dietary supplement in the treatment of menopausal symptoms. Here we used experimental mouse stress models to investigate the role of anti-stress food factors, and found that a CR extract had stress-relieving effects. A single oral administration of CR extract (1,000 mg/kg) significantly attenuated plasma corticosterone and aspartate aminotransferase (AST) levels that had increased as a result of enforced immobilization. Bioassay-guided fractionation of the CR extract resulted in the isolation of 10 triterpenes, among which actein, 23-epi-26-deoxyactein, and cimiracemoside F (100 mg/kg, per os) were shown to contribute to the anti-stress effects. Furthermore, the CR extract significantly prevented the development of water immersion stress-induced gastric mucosal ulcers in rats. We propose that the CR extract might be suitable for the prevention and treatment of stress-related disorders. 相似文献