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951.
Ohno H Oyabu I Iizuka Y Hondoh T Narita H Nagao J 《The journal of physical chemistry. A》2011,115(32):8889-8894
The dissociation of C(2)H(6) hydrate particles by slow depressurization at temperatures slightly below the ice melting point was studied using optical microscopy and Raman spectroscopy. Visual observations and Raman measurements revealed that ethane hydrates can be present as a metastable state at pressures lower than the dissociation pressures of the three components: ice, hydrate, and free gas. However, they decompose into liquid water and gas phases once the system pressure drops to the equilibrium boundary for supercooled water, hydrate, and free gas. Structural analyses of obtained Raman spectra indicate that structures of the metastable hydrates and liquid water from the hydrate decay are fundamentally identical to those of the stable hydrates and supercooled water without experience of the hydration. These results imply a considerably high energy barrier for the direct hydrate-to-ice transition. Water solidification, probably induced by dynamic nucleation, was also observed during melting. 相似文献
952.
Akhtaruzzaman M Islam A Yang F Asao N Kwon E Singh SP Han L Yamamoto Y 《Chemical communications (Cambridge, England)》2011,47(45):12400-12402
A novel donor-π-spacer-acceptor type organic dye (AK01) bearing a phenylenevinylene-conjugated system and a derivative of indoline donor was synthesized for dye-sensitized solar cells. AK01 showed panchromatic TiO(2) sensitization with high overall conversion efficiency of 6.2% under AM 1.5 illumination (100 mW cm(-2)). 相似文献
953.
Kashida H Kondo N Sekiguchi K Asanuma H 《Chemical communications (Cambridge, England)》2011,47(22):6404-6406
Here, we synthesized fluorescent DNA probes labeled with two perylene derivatives for the detection of a three-base deletion mutant. One such probe discriminated the three-base deletion mutant from the wild-type sequence by exciplex emission, and the deletion mutant was identifiable even by the naked eye. 相似文献
954.
Nakashima Y Suzuki S Yamazaki M Inoue Y Fukatsu Y Yamamoto A 《Analytical sciences》2011,27(9):889-892
A quantitative analysis was developed for eight acidic and neutral preservatives in foods and daily necessities using the inline dialysis-IC combined with hydrophobic anion-exchange separation. The eight preservatives were dialyzed by inline dialysis and separated on a hydrophobic anion exchange column. Under the optimized separation conditions, the detection limits (S/N = 3) for the eight preservatives were from 0.08 to 0.66 mg L(-1), moreover, a good linearity (R(2) > 0.998) for each preservative was obtained in the range to 100 mg L(-1). Although the dialysis rate of the neutral preservatives was not so high, a good repeatability (RSD, n = 8) of less than 1.5% for the eight preservatives was obtained. The inline dialysis-IC method was applied to the determination of the preservatives in foods and daily necessities. The preservatives were quantified without any interference. The proposed method will be useful for the determination of the preservatives in foods and daily necessities containing high concentration matrices. 相似文献
955.
A novel hydrophilic stationary phase bonded with a zwitter-ionic polymer for HPLC was synthesized. The stationary phase, in combination with a mobile phase containing various salts, was evaluated for its ability to separate water-soluble compounds, such as nucleobases, nucleosides and glycosides. The retention of a large majority of the solutes, except for cytosine, was increased by adding anti-chaotropic ions to the mobile phase. These results suggested that the retention of solutes depended on the thickness of the hydration layer on the stationary phase. In the zwitter-ionic polymer adsorbent, the formation of the hydration layer and the ionicity of the zwitter-ionic group on the stationary phase will be controlled by the properties of the ions added to the mobile phase. 相似文献
956.
Zheng Y Hashidzume A Takashima Y Yamaguchi H Harada A 《Langmuir : the ACS journal of surfaces and colloids》2011,27(22):13790-13795
Macroscopic molecular recognition observations were realized using polyacrylamide-based gels modified with α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), 1-naphthylmethyl (1Np), and 2-naphthylmethyl (2Np) moieties, which are denoted as αCD(x)-gel, βCD(x)-gel, 1Np(y)-gel, and 2Np(y)-gel, where x and y indicate the mol % of CD and Np moieties, respectively. The αCD(5)-gel did not adhere to either the 1Np(5)-gel or 2Np(5)-gel, whereas the βCD(5)-gel interacted with both to form alternating or checkered assemblies. Although the difference in the association constants of β-CD for the model polymers was small, the βCD(x)-gel successfully discriminated between 1Np(y)-gel and 2Np(y)-gel at the appropriate x and y. 相似文献
957.
Yamamoto Y 《Chemical communications (Cambridge, England)》2012,48(38):4525-4526
958.
Inamoto K Kawasaki J Hiroya K Kondo Y Doi T 《Chemical communications (Cambridge, England)》2012,48(36):4332-4334
A novel catalytic method for synthesizing 4-aryl-2-quinolinones is reported. The process involves two mechanistically independent, sequential Pd(II)-catalyzed reactions--the oxidative Heck reaction and the intramolecular C-H amidation--both of which smoothly proceed in the presence of a single catalytic system in a one-pot manner. 相似文献
959.
The mechanisms of suppression and enhancement of photocurrent/conversion efficiency (performance) in dye-sensitized solar cells, using carotenoid and chlorophyll derivatives as sensitizers, were compared systematically. The key factor to enhance the performance was found to be how to minimize interaction among the excited-state dye-sensitizer(s). In a set of retinoic-acid (RA) and carotenoic-acid (CA) sensitizers, having n conjugated double bonds, CA7 gave rise to the highest performance, which was reduced toward RA5 and CA13. The former was ascribed to the generation of triplet and the resultant singlet-triplet annihilation reaction, while the latter, to the intrinsic electron injection efficiency. In a set of shorter polyene sensitizers having different polarizabilities, the one with the highest polarizability (the highest trend of aggregate formation) exhibited the higher performance toward the lower dye concentration and the lower light intensity, contrary to our expectation. This is ascribed to a decrease in the singlet-triplet annihilation reaction. The performance of cosensitization, by a pair of pheophorbide sensitizers without and with the central metal, Mg or Zn, was enhanced by the light absorption (complementary rather than competitive), the transition-dipole moments (orthogonal rather than parallel) and by the pathways of electron injection (energetically independent rather than interactive). 相似文献
960.
Horikawa Y Imai T Takada R Watanabe T Takabe K Kobayashi Y Sugiyama J 《Applied biochemistry and biotechnology》2012,166(3):711-721
In this paper, we report the combination of a near-infrared (NIR) spectroscopic method with multivariate analysis in order
to develop a calibration model of the saccharification ratio of chemically pretreated Erianthus. The regression models clearly depend on the NIR spectral regions, and the information of CH and aromatic framework vibrations
contributed most effectively to the alkaline dataset. From interpretations of the regression coefficient, lignin and cellulose
were negatively and positively correlated with the saccharification ratio, respectively, and this result was supported by
the data from wet chemical analysis. A more complex dataset was obtained from varied chemical pretreatments; here, the saccharification
ratio was either small or had no linear correlation with each structural monocomponent. These results enabled the successful
construction of the PLS regression model. NIR spectroscopy can be a rapid screening method for the saccharification ratio,
and furthermore, can provide information of the key factors influencing the realization of more efficient enzymatic accessibility. 相似文献