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71.
Structures and IR absorption spectra of the conformational isomers of perfluorinated aldehyde hydrates, n-CxF2x+1CH(OH)2, (x = 1-4) have been calculated using density functional theory (DFT) and compared to experimental FT-IR measurements. Two absorption peaks around 3600-3700 cm−1 were observed and are assigned to OH stretching modes of OH groups with, and without, intramolecular hydrogen bonding. For n-C3F7CH(OH)2, two absorption bands around 900-1000 cm−1 were observed in the experimental spectra, whereas only a single in-phase stretching mode of the (CF3)(C2F4CH(OH)2) and (C3F7)(CH(OH)2) bonds was calculated for each conformer. The experimental spectra were well described by composite spectra of the thermal equilibrium mixture of different conformational isomers of n-CxF2x+1CH(OH)2 calculated by DFT. 相似文献
72.
A reagent tablet for determination of fluoride ion has been prepared using ethylenediamine-N,N,N′,N′-tetraacetate complex of zirconium (Zr-EDTA), 3-hydroxy-2′-flavone (FS) and an appropriate pH buffer. Dissolving of the tablet into water exhibits an intense blue fluorescence (λmax = 460 nm) upon excitation at 377 nm and the fluorescence intensity decreases with the presence of fluoride ion. Hence, a simple fluorescent detection procedure for fluoride ion in aqueous media was successfully constructed with this tablet. The principle of this detection system is the ligand exchange reaction of FS bound to Zr-EDTA with fluoride ion. The present system provides an easy, rapid and selective determination method of fluoride ion ranging from 5 × 10−6 to 1 × 10−3 mol dm−3. The measurement of real samples with this tablet showed the similar results as those by the common method with the Alfusone reagent. 相似文献
73.
Marine Cuisinier Jean-Frédéric Martin Nicolas Dupré Atsuo Yamada Ryoji Kanno Dominique Guyomard 《Electrochemistry communications》2010,12(2):238-241
The impact of air exposure on LiFePO4–C nanocomposites has been investigated at moderate temperature. We show here that the storage in 120 °C hot air for 30 days leads not only to the material delithiation but also to the formation of an amorphous ferric phosphate side-phase, accounting for 38% of the total iron. The formed phase is found to be partially hydrated, suggesting a water-driven aging mechanism and a proposed hypothetic formula: LixFePO4(OH)x. The side-phase displays new electrochemical activity but poor cyclability and the overall battery performance is thus deteriorated. The regeneration of pristine structure, together with the performance recovery can be achieved by a simple thermal treatment under inert atmosphere. 相似文献
74.
Vibe B. Jakobsen Elzbieta Trzop Laurence C. Gavin Emiel Dobbelaar Shalinee Chikara Xiaxin Ding Kane Esien Helge Müller‐Bunz Solveig Felton Vivien S. Zapf Eric Collet Michael A. Carpenter Grace G. Morgan 《Angewandte Chemie (International ed. in English)》2020,59(32):13305-13312
Domain wall motion is detected for the first time during the transition to a ferroelastic and spin state ordered phase of a spin crossover complex. Single‐crystal X‐ray diffraction and resonant ultrasound spectroscopy (RUS) revealed two distinct symmetry‐breaking phase transitions in the mononuclear Mn3+ compound [Mn(3,5‐diBr‐sal2(323))]BPh4, 1. The first at 250 K, involves the space group change Cc→Pc and is thermodynamically continuous, while the second, Pc→P1 at 85 K, is discontinuous and related to spin crossover and spin state ordering. Stress‐induced domain wall mobility was interpreted on the basis of a steep increase in acoustic loss immediately below the the Pc‐P1 transition 相似文献
75.
Raman spectral changes associated with vitrification were measured for ZnCl2·4OROH solutions (ROH=methanol, ethanol and 1-propanol). Solvated ZnCl2 is the only major Zn-species in these solutions at room temperature while the dominant Zn-species stabilized in the glassy alcoholic solutions are ZnCl
3
–
, ZnCl
4
2–
and [Zn(MeOH)6]2+ for the methanol solution, ZnCl2 and ZnCl
3
–
for the ethanol solution and ZnCl2 for the 1-propanol solution. Together with Raman data for aqueous ZnCl2 solutions, the differences in the dominant Zn-species in the glassy alcoholic solutions are discussed in terms of the dielectric constants of solvents (water and alcohols). 相似文献
76.
Akiyoshi Osaka Kanji Tsuru H. Iida Chikara Ohtsuki Satoshi Hayakawa Yoshinari Miura 《Journal of Sol-Gel Science and Technology》1997,8(1-3):655-661
Apatite derived by sol-gel routes through an amorphous state or derived biomimetically is likely to provide chemically and
biologically active surfaces. Thus apatite or apatite-composite particles were prepared by spray-pyrolysis of several solutions
as they were applicable to medical treatment. Calcium lactate and ammonium dihydrogen phosphate aqueous solutions stabilized
with ethylenediaminetetraacetic acid were sprayed ultrasonically and pyrolysed at 600°C to yield amorphous particles of apatite
while apatite-ferric oxide composite powders were prepared from the solutions of calcium lactate and ferric nitrate. Solutions
of calcium nitrate and titanium ethoxide in 0.5 N HNO3 were also spray-pyrolysed at 600°C to prepare calcium titanate and titanium oxide particles trapped on a Ti substrate. Apatite
could biomimetically be developed on the calcium titanate particles when they were soaked in an acellular simulated body fluid. 相似文献
77.
78.
79.
Chihiro Moriguchi Akihiro Ohta Chikara Egami Yoshimasa Kawata Susumu Terakawa Masaaki Tsuchimori Osamu Watanabe 《Optical Review》2006,13(4):215-217
We present an analysis of the properties of an imaging based on a near-field recording technique in comparison with simulation
results. In the system, the optical field distributions localized near the specimens are recorded as the surface topographic
distributions of a photosensitive film. It is possible to observe both soft and moving specimens, because the system does
not require a scanning probe to obtain the observed image. The imaging properties are evaluated using fine structures of paramecium,
and we demonstrate that it is possible to observe minute differences of refractive indices. 相似文献
80.
S. Kanno H. Rai T. Ohya Y. Hayashi K. Tanoi T. M. Nakanishi 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(3):565-570
We developed a quantitative, real-time imaging system of labeled compounds in a living plant. The system was composed of CsI
scintillator to convert β-rays to visible light and an image intensifier unit (composed of GaAsP semiconductor and MCP; micro
channel plate) to detect extremely weak light. When the sensitivity and resolution of the image of our system was compared
with that of an imaging plate (IP), the sensitivity of our system (with 20 minutes) was higher than that of an IP, with similar
quality to that of an IP. Using this system, the translocation of 32P in a soybean plant tissue was shown in successive images.
Shared first authors. 相似文献