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901.
Isao Kaetsu Akihiko Ito Koichiro Hayashi 《Journal of polymer science. Part A, Polymer chemistry》1973,11(8):1811-1818
The effect of temperature and composition on the inflection point in the time–conversion curve and the saturated conversion was investigated in the radiation-induced radical polymerization of binary systems consisting of a glass-forming monomer and a solvent. In the polymerization of completely homogeneous systems such as glycidyl methacrylate (GMA)–triacetin and hydroxyethyl methacrylate (HEMA)–propylene glycol systems, the time–conversion curve has an inflection point at polymerization temperatures between Tvm (Tv of monomer system) and Tvp (Tv of polymer system). Such conversions at the inflection point changed monotonically between 0 and 100% in this temperature range. Tv was found to be 30–50°C higher than Tg (glass transition temperature) and a monotonic function of composition (monomer–polymer–solvent). The acceleration effect continued to 100% conversion above Tvp, and no acceleration effect was observed below Tvm. The saturated conversion in homogeneous systems changed monotonically between 0 and 100% for polymerization temperatures between Tgm (Tg of monomer system) and Tgp (Tg of polymer system). Tg was also a monotonic function of composition. No saturation in conversion was observed above Tgp, and no polymerization occurred below Tgm. In the polymerization of completely heterogeneous systems such as HEMA–dioctyl phthalate, no acceleration effect was observed at any temperature and composition. The saturated conversion was 100% above Tg of pure HEMA, and no polymerization occurred below this temperature in this system. 相似文献
902.
Surface morphology and biological activity of protein thin films produced by electrospray deposition
Uematsu I Matsumoto H Morota K Minagawa M Tanioka A Yamagata Y Inoue K 《Journal of colloid and interface science》2004,269(2):336-340
Protein thin films were prepared by the electrospray deposition (ESD) method from aqueous solutions of alpha-lactalbumin (alpha-LA) at different concentrations, and their surface morphologies and biological activities were characterized. The surface morphologies of the deposited films were observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The SEM and AFM images showed that the film surfaces had a fine porous structure, in which the pore diameters ranged from 40 to 600 nm. The biological activities of the cross-linked protein films were tested by the mechanochemical method. The response to calcium ion (Ca(2+)) demonstrated that the biological activity of the films was preserved. These results indicate that the ESD method is potentially useful for the fabrication of active protein thin films. The freestanding protein thin films prepared by ESD and postdeposition cross-linking provide novel options for protein-based biomaterials. 相似文献
903.
In this study, we examined the dielectric properties of an intermediate layer in a bipolar membrane, which is composed of a negatively charged layer and a positively charged layer joined in series. As a result of the time-dependent impedance measurements of charged membranes, the negative increment in electric conductivity and the positive increment in electric capacity were observed only in the case of a bipolar membrane under the application of reverse-biased voltages, which were quite different from the behavior of both monopolar membranes and of a bipolar membrane under forward-biased voltages. Further, the observed shifts showed a nearly constant value against the reverse-biased voltage. It is concluded that these characteristics coincide with the process of ion exclusion in the intermediate layer and are attributed to the water splitting mechanism. 相似文献
904.
Ab initio SCF MO calculations (with the 4-31G basis set) have been carried out to determine the equilibrium geometry, vibrational frequencies, dipole-moment derivatives, and force constants for intermolecular modes of the formamide dimer and its d4 and d6 derivatives. The results are correlated with monomer calculations and experimental data for crystalline formamide. 相似文献
905.
906.
907.
Akihiko Yukie 《Transactions of the American Mathematical Society》1998,350(12):5067-5094
In this paper we consider an analogue of the zeta function for not necessarily prehomogeneous representations of and compute some of the poles.
908.
Fumio Hamada Yoshihiko Kondo Kyoko Ishikawa Hideaki Ito Iwao Suzuki Tetsuo Osa Akihiko Ueno 《Journal of inclusion phenomena and macrocyclic chemistry》1994,17(3):267-275
Sodium anthranilate-modified-cyclodextrin (1) has been prepared as a sensor for detecting organic compounds including terpenoids and steroids.1 shows a pure monomer fluorescence whose intensity is increased or decreased upon addition of the guest species examined. In this system, the sodium anthranilate moiety acts either as a spacer, which enables the cyclodextrin to form a 11 guest complex by narrowing the-cyclodextrin cavity or acts as a hydrophobic cap.1 shows a higher sensitivity for terpenoids than for steroids, but has a higher selective molecular recognition ablity for steroids than for terpenoids. 相似文献
909.
Hiroshi Fukumura Daizo I-I Hiroshi Uji-I Satoru Nishio Hitoshi Sakai Akihiko Ohuchi 《Chemphyschem》2005,6(11):2383-2388
The structures of self-assembled monolayers of dioctadecyl selenide (CH3(CH2)17)2Se and dioctadecyl telluride (CH3(CH2)17)2Te, as well as dioctadecyl ether (CH3(CH2)17)2O and dioctadecyl sulfide (CH3(CH2)17)2S, on graphite at the liquid-solid interface were systematically investigated by scanning tunneling microscopy (STM). Both dioctadecyl selenide and telluride formed monolayer structures in which the tilt angle between the molecular axis of the alkyl chain and the lamellae axis was 90 degrees , while dioctadecyl ether assembled with a tilt angle of 60 degrees . Dioctadecyl sulfide was found to make two different self-assembled structures having tilt angles of 60 and 90 degrees . When selenide was embedded in ether compounds in mixed self-assembled monolayers, the alkyl chains of the selenide became blurred, implying that the alkyl chains in the monolayers were unstable. This is in contrast with the structure of co-adsorbed monolayers of the ether and sulfide compounds, where the images of all alkyl chains had high spatial resolution. For the co-adsorbed monolayers, the image contrast of chalcogen atoms was normalized compared with that of alkyl chains of the ether compound in the same image frame. The normalized image contrast was found to be independent of the measurement conditions involving tip shapes, having the following trend, Te>Se>S>C>O. The difference in the normalized image contrast among chalcogen atoms are discussed based on fundamental parameters like polarizability and atomic radii. 相似文献
910.
Xiaomao Xie Noriyuki Ohnishi Akihiko Kondo 《Journal of magnetism and magnetic materials》2009,321(10):1686-1688
The magnetic nanoparticles (MNPs) Therma-Max™ were used as a carrier to develop an automated sandwich chemiluminescent enzyme immunoassay (CLEIA) to detect thyroid-stimulating hormone (TSH) in a sensitive and specific way. The Therma-Max™ particles allow for automation because, unlike magnetic microspheres, they are completely dispersed in aqueous solution and allow for accurate automatic handling. Signal intensities detected with MNPs were 8-fold higher than those found with conventional micron-sized magnetic particles. A reproducibility study suggests that these particles allow for a stable detection method, as the coefficient of variation (CV) is less than 6% (n=10). 相似文献