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61.
In this paper, we establish new sufficient conditions for the infected equilibrium of a nonresident computer virus model to be globally asymptotically stable. Our results extend two kind of known results in recent literature. 相似文献
62.
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
63.
Ryuichi Iemura Tsuneo Kawashima Toshikazu Fukuda Keizo Ito Goro Tsukamoto 《Journal of heterocyclic chemistry》1987,24(1):31-37
Several types of benzimidazole derivatives were prepared and were screened for H 1-antihistaminic activity. Most of the compounds showed potent antihistaminic activity in vitro. Among them 2-[(1-piperazinyl)methyl]-benzimidazoles 14 and 2-[(1-homopiperazinyi)methyl]benzimidazoles 15 exhibited potent activity also in vivo. 相似文献
64.
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
65.
NMR and DFT studies on persistent carbocations derived from benzo[kl]xanthene,dibenzo[d,d′]benzo[1,2‐b:4,3‐b′]difuran,and dibenzo[d,d′]benzo[1,2‐b:4,5‐b′]difuran in superacidic media 下载免费PDF全文
Takao Okazaki Madoka Nakagawa Takeshi Futemma Toshikazu Kitagawa 《Journal of Physical Organic Chemistry》2016,29(2):107-111
Persistent carbocations generated by the protonation of hetero‐polycyclic aromatic compounds with oxygen atom(s) were studied by experimental NMR and density function theory calculations. Benzo[kl]xanthene ( 1 ), dibenzo[d,d′]benzo[1,2‐b:4,3‐b′]difuran ( 2 ), and dibenzo[d,d′]benzo[1,2‐b:4,5‐b′]difuran ( 3 ) were synthesized by the annulation of arenediazonium salts. Compound 1 in FSO3H‐SbF5 (4:1)/SO2ClF and 3 in FSO3H‐SbF5 (1:1)/SO2ClF ionized to 1aH+ with protonation at C(4) and to 3aH+ with protonation at C(6), and these cations were successfully observed by NMR at low temperatures. The density function theory calculations indicated that 1aH+ and 3aH+ were the most stable protonated carbocations and that 2 should ionize to 2aH+ with protonation at C(6). According to the changes in 13C chemical shifts (Δδ13C), the positive charge was delocalized into the naphthalene unit for 1aH+ , into one benzo[b,d]furan unit for 2aH+ , and into one benzo[b,d]furan unit for 3aH+ . Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
66.
Phase diagrams of d-wave superconductivity characterized by an order parameter Δ coexisting with charge-density waves (CDWs) characterized by an order parameter Σ were constructed for the two-dimensional Fermi surface (FS) appropriate to, e.g., cuprates. CDWs were considered as an origin of the pseudogap appearing at antinodal FS sections of the d(x2-y2) superconductor. Two types of the Σ-reentrance were found: with the temperature, T, and with the opening of the CDW sector, 2α. The angular plots in the momentum space for the resulting gap profile over the FS ('gap roses') were obtained. The gap patterns are rather involved, giving insight into the difficulties of the interpretation of photoemission spectra. It was shown that the Σ-Δ coexistence region exists even for the complete dielectric gapping due to the distinction between the superconducting and CDW order parameter symmetries. The checkerboard and unidirectional CDW configurations were examined, and both the phase diagrams and the behavior with T and α of the order parameters were found to differ. A more general case with a non-zero mismatch angle β between the superconducting lobes and the CDW sectors was analyzed, the case β = π/4 corresponding to the d(xy) symmetry of the superconducting order parameter. The phase diagrams were found to be sensitive to β-variations, showing that internal strains and external pressure can drastically affect the behavior of Σ(T) and Δ(T). 相似文献
67.
Nobutaka Takahashi Noboru Murofushi Saburo Tamura Nobuhide Wasada Hiroko Hoshino Toshikazu Tsuchiya Shin-Ichi Sasaki Tetsumi Aoyama Eiji Watanabe 《Journal of mass spectrometry : JMS》1969,2(7):711-722
Based on the element maps of twenty-two gibberellin methyl esters fragmentations are discussed, which are characteristic of the common structural features as well as structural modification in gibberellin homologues. 相似文献
68.
Kurosaki Hiromu Mueller Rebecca J. Lambert Susan B. Rao Govind R. 《Journal of Radioanalytical and Nuclear Chemistry》2017,311(1):323-329
Journal of Radioanalytical and Nuclear Chemistry - An alternate method of preparing actinide alpha counting sources was developed in place of electrodeposition or lanthanide fluoride... 相似文献
69.
H. Yoshioka H. Kurosaki H. Yoshioka 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(1):217-220
The aqueous solutions of 5,5-dimethyl-1-pyrroline N-oxide (DMPO) containing various amount of (-)-epigallocatechin gallate
(EGCg) were mixed with tritiated water, then frozen and β-ray irradiatedin situ for 90 days at −80°C. ESR spectra were measured as a function of time after melting the sample at room temperature. The intensity
of the hydroxyl (OH)_ radical adduct, DMPO-OH, was obtained by the extrapolation to zero time. The ratio of the reaction rate
constants of the OH radical with EGCg and DMPO,k
EGCg/k
DMPO, was obtained kinetically. The result was compared with the case of DNA and EGCg in tritiated water, in order to make clear
the mechanism of the protection of DNA from the radiation-induced scission with EGCg. 相似文献
70.
Ryota Seto Takashi Sato Takahiro Kojima Katsumoto Hosokawa Yasuhito Koyama Gen‐Ichi Konishi Toshikazu Takata 《Journal of polymer science. Part A, Polymer chemistry》2010,48(16):3658-3667
Syntheses of 2,2′‐bisalcoholic group‐substituted 9,9′‐spirobifluorene monomers 2 were performed by the reaction of 2,2′‐dihydroxy‐9,9′‐spirobifluorene 2a with haloalcohols. Polycarbonates consisting of 9,9′‐spirobifluorene skeleton in the main chain (PC 4 ) were synthesized by the polycondensation of 2,2′‐bisalcoholic monomers 2 and triphosgene or diphenyl carbonate. PC 4 showed good thermal stability: the 5% weight loss temperature was over 330 °C under both nitrogen and air atmospheres. The glass transition temperature was in a range of 16–269 °C estimated by differential scanning calorimetry, depending on the flexibility of the alkylene or oxyethylene chains of 2 . PC 4 showed high solubility toward ordinary organic solvents such as CHCl3, benzene, and THF, making possible the preparation of the flexible thin films. Very high refractive index in a range of 1.62–1.66 at 589 nm was observed although PC 4 consists only of C, H, and O atoms, whereas very low degree of birefringence was confirmed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3658–3667, 2010 相似文献