We recently observed that the decanoylation of N-phenylthiocarbamoyl chitosan (2) with a mixture of decanoic anhydride and pyridine at 60 °C for 24 h afforded N,N-(decanoyl)phenythiocarbamoyl-/2-isothiocynato chitosan decanoate (3b) rather than the expected product N,N-(decanoyl)phenylthiocarbamoyl chitosan decanoate (3a). This result suggested that some of the N,N-(decanoyl)phenylthiocarmbamoyl groups had been converted to isothiocyanate groups during the decanoylation process. The subsequent reaction of compound 3b with aniline gave N,N-(decanoyl)phenylthiocarbamoyl/N-phenylthiocarbamoyl chitosan decanoate (4) in high yield. A solution of compound 4 in CHCl3 was then added to a solution of copper decanoate (5) in the same solvent, and the resulting mixture was cast onto a glass plate to give a cast film. The film was annealed at 200 °C in an oven to give a greenish film, which showed good near-infrared absorption characteristic in the range of 800–2200 nm. 相似文献
Fine particles of a blue emission phosphor Sr2CeO4 have been synthesized using a chemical co-precipitation technique, and the textual and luminescent properties were compared with the one synthesized by the conventional solid-state reaction method. Particle size and distribution of the Sr2CeO4 fine powder prepared by the co-precipitation process were smaller and narrower than those obtained by the samples prepared from the conventional one. The emission intensity of the fine particles was equal to that of the larger particles prepared from the solid-state reaction, on the contrary to the general tendency that emission intensity decrease with particle size reduction. Although no Ce3+ peaks were observed in EPR measurements, X-ray photoelectron spectra of the samples clearly elucidated the existence of Ce3+ only on the surface of Sr2CeO4. 相似文献
The Co/MFI(SiO2/Al2O3 = 30) were prepared by a precipitation method with NaOCl in alkali solutions exhibited high activities to N2 at 250 °C for the selective catalytic reduction (SCR) of NOx. These catalysts showed two UV–vis bands at 700 and 400 nm, indicating the presence of octahedral Co(III) as well as tetrahedral Co(II). The high SCR activity over such Co(III, II)/MFI(30) seems to come from Co(III)---O moieties. The Co(II)MFI(30) catalysts prepared from Co(II)Cl2 exhibited low SCR activities due to the presence of tetrahedral Co(II) ions in MFI. Less CO formation occurred over Co/MFI catalysts. The Fe/MFI(30) catalyst exhibited high activity due to the presence of some Fe---O species in MFI but more amount of CO were produced during SCR. H/MFI(30) catalyst exhibited a good SCR activity. However, more amount of carbonaceous deposits were produced on it. The correlation between acid concentration and SCR activity was discussed over H/MFIs. 相似文献
By using structural equations, we investigated the effect of chronic stress on salivary cortisol rhythm and proposed a causal model of chronic stress by using psychosocial and physiological data. First, 111 healthy workers (48 males, 63 females) completed questionnaires on chronic stress and lifestyle habits. Then, they provided saliva samples and answered questionnaires that were prepared to assess their psychological states 5 times (on waking up and at 10:00, 11:40, 14:00, and 16:00) on workdays. Structural equation modeling (SEM) revealed that chronic stress and longer commuting time resulted in sleep irregularities and this disrupted the cortisol circadian rhythm. This suggests that chronic stress disrupts the cortisol circadian rhythm even in healthy individuals, and sleep regularity mediates the effect of chronic stress on the cortisol rhythm.
This paper proposes a new belt drive control method for reducing a belt velocity-fluctuation that is caused by a belt thickness-variation in the circumferential direction. A belt driving system performs feedback control with a rotary encoder-output mounted on a driven roller. This proposed method correct the reference value of the feedback control for the purpose of the belt velocity regulation. The correction includes two steps. The first step acquires the encoder-output of the driven roller and calculates the rotational angular velocity-fluctuation with one cycle of the belt rotation. The second step converts from the velocity-fluctuation to the correction value of the feedback reference. The correction value cancels a detection error of the driven roller caused by the belt thickness-variation. After these steps, the belt driving system controls the belt velocity as compensating the belt velocity-fluctuation. Experimental result showed the significant fluctuation reduction on a typical tandem-engine printer. 相似文献
Isothermally forged TiAl-base alloys (Al-rich, Mn-containing, and Cr-containing TiAl) were heat-treated in various conditions,
and equiaxed grain structures consisting of γ and α2 or Β phases were obtained. The heat-treated alloys were tensile tested in vacuum and air at room temperature, and the environmental
effect on tensile elongation was studied. The ductility of the alloys consisting of equiaxed γ grains and a large amount of
α2 grains was not largely affected by laboratory air, and a decrease in the amount of α2 grains resulted in a large reduction of ductility in air. The Β phase in the Cr-containing alloy improved the ductility in
vacuum, but it resulted in a large reduction of ductility in air.
Formerly with Kougakuin University, Shinjyuku-ku, Tokyo,
Formerly with National Research Institute for Metals, Meguro-ku, Tokyo, 相似文献
The durability of a cold wall MHD generator consisting of metal electrodes and alumina-coated peg insulators was experimentally examined in the oil-fired MHD condition with the additive of SO2 corresponding to S = 0.54 wt%. The structure of the electrode wall and various anode and cathode materials were tested, with particular reference to developing long-life electrodes. It was clarified that Pt, SHOMAC (28.8 Cr−1.9 Mo) and SUS-304 as anodes and W---Cu (70 W−30 Cu) and WC---Ag (60 WC−40 Ag) alloys as cathodes were promising for durability and that the structure of an anode divided into two elements connected to each other with an SnO2 resistor was very useful for uniformity of the anode corrosion pattern and the inter-anode voltages. It is reasonable to expect, from the test results, that the lifetime of a cold wall MHD generator in an oil-fired commercial plant will be over 4000 h, and therefore, a foundation for its commercial use has been established. 相似文献
The restoration of the red colour of carthamine (photo-bleached in polymeric heterosaccharide gels) was investigated using sodium salts, potassium salts, and alkali. Ca-alginate gel was stained with carthamine, and the red-dish membranes were exposed to fluorescent light for 2·5, 4·0 and 20 h (at 28°C). The resulting orange-yellow gel membranes were treated with Na- or K-citrate solution and the restoration of the red colouration was followed spectrophoto-metrically. The results indicate that the red colour of carthamine can be retained within the gel membranes, while yellow-coloured compounds were removed and/or transformed by the alkaline salt solutions. 相似文献