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51.
Summary Analytical solutions are proposed for the stress and displacement fields in a quasi three-dimensional elastic anisotropic body containing an elliptic cavity or rigid inclusion. The directions of the principal elastic axes are allowed to be inclined arbitrarily with respect to the axes of the elliptic cavity. As an application, expressions for the stress intensity factors are formulated when the cavity reduces to a colinear crack. 相似文献
52.
Kosuke Nakashima Shin-ichi Hirashima Masahiro Kawada Yuji Koseki Norihiro Tada Akichika Itoh Tsuyoshi Miura 《Tetrahedron letters》2014
The novel pyrrolidine-diaminomethylenemalononitrile organocatalyst 7 promotes the asymmetric conjugate addition of a carbonyl compound to a nitroalkene to afford the corresponding adduct in high yield with up to 99% ee, under solvent-free conditions. 相似文献
53.
54.
Preparation of Porous Titania Film by Modified Sol-Gel Method and its Application to Photocatalyst 总被引:2,自引:0,他引:2
Yusuf Miah Muhammed Imai Hiroaki Hirashima Hiroshi 《Journal of Sol-Gel Science and Technology》2002,25(1):65-74
Sol-Gel derived mesoporous titania films with controlled pore sizes were prepared by surfactant templating. The coating sol was obtained by hydrolysis of Ti(OC4H9)4 in ethanol/HCl solution. The gel films, prepared by spin coating on glass substrate, were dried after immersion in surfactant solutions under an atmospheric pressure. The porous films of anatase with columnar and rectangular structure were obtained after annealing at 500°C. The annealed films are transparent and 80–140 nm in thickness. Refractive indices of the films with surfactant immersion were 10–20% lower than those of the films without immersion. The spacing between the columns or rectangular grains and the grain shape were found to depend on the surfactant species. The pohoto-catalytic activity of the films for the oxidation of NO
x
was improved by the surfactant modification. 相似文献
55.
Functional Sulfur‐Doped Buckybowls and Their Concave–Convex Supramolecular Assembly with Fullerenes
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Bo‐Wei Li Dr. Qian‐Yan Zhang Dr. Tsuneaki Sakurai Prof. Dr. Yuan‐Zhi Tan Prof. Dr. Shu Seki Prof. Dr. Su‐Yuan Xie Prof. Dr. Lan‐Sun Zheng 《Angewandte Chemie (International ed. in English)》2016,55(42):13047-13051
Buckybowls are fascinating components of supramolecular assemblies owing to their unique bowl‐shaped π‐surfaces. Herein we present a protocol for the functionalization of a sulfur‐doped buckybowl, trithiasumanene, via a brominated intermediate, from which thiolated trithiasumanenes were derived. The curved surface and electron‐donating properties of thiolated trithiasumanenes promote their ready assembly with fullerenes to form concave–convex complexes. The supramolecular assembly behavior in solution was investigated by NMR analysis. The structures of supramolecular complexes were unambiguously characterized by crystallography. The crystals of the concave–convex complexes showed high thermal stability and photoconductivity. 相似文献
56.
Fusing Porphyrins and Phospholes: Synthesis and Analysis of a Phosphorus‐Containing Porphyrin
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Dr. Tomohiro Higashino Tomoki Yamada Dr. Tsuneaki Sakurai Prof. Dr. Shu Seki Prof. Dr. Hiroshi Imahori 《Angewandte Chemie (International ed. in English)》2016,55(40):12311-12315
A phosphole‐fused porphyrin dimer, as a representative of a new class of porphyrins with a phosphorus atom, was synthesized for the first time. The porphyrin dimer exhibits remarkably broadened absorption, indicating effective π‐conjugation over the two porphyrins through the phosphole moiety. The porphyrin dimer possesses excellent electron‐accepting character, which is comparable to that of a representative electron‐accepting material, [60]PCBM. These results provide access to a new class of phosphorus‐containing porphyrins with unique optoelectronic properties. 相似文献
57.
The metrological effectiveness of an analytical method using the post-column reaction GC/FID system was evaluated. The SI-traceable certified reference material (CRM), the eight ester phthalates mixture standard solution, was used as a sample. We assigned specific value to n-eicosane and it was used as an internal standard. A known quantity of n-eicosane was added to the CRM, and the mixture was measured with the post-column reaction GC/FID system. Six phthalate esters were chromatographically separated and determined. The assigned values by our system are in good agreement with the certified values of the CRM, and the combined uncertainties of the measurements by the present system were better than those of the CRM. Our method is classified as a primary ratio method and the specific values of many organic compounds can be assigned very precisely by using a small number of reference materials. Also, the method can make it possible to avoid the purity determination of raw materials and directly to assign their specific values after the preparation of the standard mixture. Conclusively, this post-column reaction GC/FID system is very effective for the chemical metrology. 相似文献
58.
We present a mean-field theory to describe phase separations in mixtures of a nematic liquid crystal and a colloidal particle. The theory takes into account an orientational ordering of liquid crystals and a crystalline ordering of colloidal particles. We calculate phase diagrams on the temperature-concentration plane, depending on interactions between a liquid crystal and a colloidal surface and a coupling between nematic and crystalline ordering. We find various phase separation processes, such as a nematic-crystal phase separation and nematic-isotropic-crystal triple point. Inside binodal curves, we find new unstable and metastable regions which are important in phase ordering dynamics. We also find a stable nematic-crystalline (NC) phase, where colloidal particles dispersed in a nematic phase can form a crystalline structure. The coexistence between two NC phases with different concentrations can be appear though the coupling between nematic and crystalline ordering. 相似文献
59.
Takahashi K Matsuyama S Saito T Kato H Kinugasa S Yarita T Maeda T Kitazawa H Bounoshita M 《Journal of chromatography. A》2008,1193(1-2):146-150
The quantitativeness of an evaporative light-scattering detector (ELSD) for supercritical fluid chromatography (SFC) was evaluated by using an equimass mixture of uniform poly(ethylene glycol) (PEG) oligomers. Uniform oligomers, in which all molecules have an identical molecular mass, are useful for the accurate calibration of detectors. We calibrated the SFC-ELSD system for various concentrations and molecular masses by using an equimass mixture of PEG oligomers. ELSD not only showed a good linear response to the injected concentration over a wide concentration range, from 10(-4) to 10(-1)g/mL, but also showed a strong dependence on the molecular mass of the solute. By using chromatograms of the equimass mixture of uniform oligomers to calibrate SFC-ELSD, it was possible to determine exact values of not only the average mass but also the molecular-mass distribution for a PEG 1540 sample. The average molecular mass was shifted to a higher value by several percentage points after calibration of the ELSD. 相似文献
60.
Ohashi M Yagyu A Yamagata T Mashima K 《Chemical communications (Cambridge, England)》2007,(29):3103-3105
Treatment of the cisoid-capped complex [Pt(4)(micro-OCOCH(3))(6)(kappa(4)-N(4)-DAr'Bp)] (), which was obtained from the reaction of [Pt(4)(micro-OCOCH(3))(8)] (1) with Na(2)D(t)BuPhBp (D(t)BuPhBp = 1,3-bis(para-tert-butylphenylbenzamidinate)propane), with an equimolar amount of 1,1'-ferrocenedicarboxylic acid undergoes a stereoselective self-assembly to afford an indented-quadrangle tetramer [Pt(4)(micro-OCOCH(3))(4)(kappa(4)-N(4)-D(t)BuPhBp){Fe(C(5)H(4)COO)(2)}](4) as a single diastereomer. 相似文献