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排序方式: 共有175条查询结果,搜索用时 609 毫秒
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A wetting/dewetting process was utilized to prepare self-organized organic dye particles of micrometer and submicrometer size.
Near-field scanning optical microscopy successfully identified near-field excited near-field fluorescence from single particles.
The majority of the small particles with diameters around 2 mm or less, however, did not show fluorescence under near-field
observation. In contrast, far-field fluorescence, when excited by a polarized evanescent field, was observed, with the intensity
depending on the excitation polarization, indicating that molecules' transition moment within dye particles was oriented parallel
to the substrate surface. Single particle fluorescence spectrum consistently showed an identical sharp peak with a large redshift,
indicating that the particles were composed of identical dye aggregates similar to J-aggregates. These observations suggest
that the near-field at the probe tip was polarized parallel to the probe axis. Another observation, that molecules were oriented
in a similar direction among adjacent particles, suggests that the dewetting process contributed to the alignment of the molecular
direction among adjacent particles, which further proves that the present specimen was formed by a self-organizing mechanism. 相似文献
3.
Zhi-Hui Su Munehiro Okamoto Osamu Tominaga Katsumi Akita Noboru Kashiwai Y?ki Imura Tooru Ojika Yoshiyuki Nagahata Syozo Osawa 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2006,82(7):232-250
An approach to deduce the mechanism of stabilization of the hybrid-derived populations in the Ohomopterus ground beetles has been made by comparative studies on the phylogenetic trees of the mitochondrial and nuclear DNA. A phylogenetic tree based on the internal transcribed spacer (ITS) of nuclear ribosomal gene roughly reflects the relations of morphological species group, while mitochondrial NADH dehydrogenase subunit 5 (ND5) gene shows a considerable different topology on the tree; there exist several geographically-linked lineages, most of which consist of more than one species. These results suggest that the replacement of mitochondria has occurred widely in the Ohomopterus species. In most cases, hybridization is unidirectional, i.e., the species A (♂) hybridized with another species B (♀) and not vice versa, with accompanied replacement of mitochondria of A by those of B. The results also suggest that partial or complete occupation of the distribution territory by a hybrid-derived morphological species. The morphological appearance of the resultant hybrid-derivatives are recognized as that of the original species A. Emergence of a morphological new species from a hybrid-derived population has been exemplified. 相似文献
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Y. Akishige H. Shigematsu T. Tojo H. Kawaji T. Atake 《Journal of Thermal Analysis and Calorimetry》2005,81(3):537-540
Summary Specific heats on the single crystals of Sr2Nb2O7, Sr2Ta2O7 and (Sr1-xBax)2Nb2O7 were measured in a wide temperature range of 2-600 K. Heat anomalies of a λ-type were observed at the incommensurate phase transition of TINC (=495 K) on Sr2Nb2O7 and at the super-lattice phase transition of TSL (=443 K) on Sr2Ta2O7; the transition enthalpies and the transition entropies were estimated. Furthermore, a small heat anomaly was observed at the low temperature ferroelectric phase transition of TLOW (=95 K) on Sr2Nb2O7. The transition temperature TLOW decreases with increasing Ba content x and it vanishes for samples of x>2%. 相似文献
6.
Hirose H Sano H Mizutani G Eguchi M Ooya T Yui N 《Langmuir : the ACS journal of surfaces and colloids》2004,20(7):2852-2854
The effect of the mobility of ligands (maltose groups) in the polyrotaxanes (pRXs) on the structure of the surrounding water molecules was investigated. Raman spectra of collective OH stretching vibration of water molecules in aqueous solutions of maltose-pRX conjugates with different alpha-cyclodextrin (alpha-CD) threading on a poly(ethylene glycol) (PEG) chain was measured. The mobility of maltose groups was estimated by measuring the relaxation time T2 of the C1 protons in maltose groups bound on alpha-CD by NMR experiment. A positive correlation between the Raman intensity of the collective band and the relaxation time T2 was obtained. This result indicates that the degree of order of the water clusters is higher as the mobility of maltose groups increases in these conjugate solutions. It is suggested that rapid motion of maltose groups in the pRX conjugate can contribute to preserving ordered structure of the bulk water clusters. 相似文献
7.
The thermal properties and gas Chromatographie behaviour of manganese(II) and manganese(III) trifluoroacetylacetonates (TFA) were investigated by using the ligand vapour technique. The two chelates, Mn(TFA); and Mn(TFA)3, can be quantitatively eluted on a mixed-liquid phase (1.9% OV-17 ÷ 0.1% PEG-20M) at column temperatures above 210°C and 130–150°C, respectively; Mn(TFA)3 is completely converted to Mn(TFA)2 by thermal dissociation at column temperatures above 180°C and completely eluted as Mn(TFA)2 above 210°C. The chelates can be determined separately within errors of about 1% after a preliminary extraction. 相似文献
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Tooru Ooya Hideharu Mori Minoru Terano Nobuhiko Yui 《Macromolecular rapid communications》1995,16(4):259-263
A novel design of a biodegradable carrier for drug delivery was established by constructing a supramolecular assembly of drugs and polymer backbones without any covalent bonds. A biodegradable polyrotaxane was synthesized in which α-cyclodextrins (α-CDs) as drug carriers were threaded onto poly(ethylene glycol) chains which then were capped at each chain end by L -phenylalanine via peptide linkages. The release of α-CDs was observed only when the terminal peptide linkages were degraded. 相似文献
10.
研究了离子液体镀液中Co、Zn的共沉积行为。ZnCl2-EMIC -CoCl2电解液的循环伏安曲线上出现了三个电流峰,对应的电极电位分别为250mV、50mV、-200mV(vs. Zn2+/Zn)。结合EDS成分分析,可断定这三个电流峰分别对应着Co的电沉积、Co电极上Zn的欠电位沉积和Co-Zn合金的电沉积。恒电位沉积表明,当控制阴极电位在100 mV(vs. Zn2+/Zn)左右时,可得到高纯度的钴镀层;若进行恒电流沉积,则当电流密度为85mA/cm2左右时能够得到高纯度的钴镀层。对Co、Zn的共沉积机理研究表明,Co的电沉积过程和Zn 在Co上的欠电位沉积过程均受扩散过程控制。 相似文献