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621.
Negishi Y Kurashige W Kamimura U 《Langmuir : the ACS journal of surfaces and colloids》2011,27(20):12289-12292
We report the isolation and structural characterization of an octaneselenolate-protected Au(25) cluster ([Au(25)(SeC(8)H(17))(18)](-)). Isolated [Au(25)(SeC(8)H(17))(18)](-) was characterized by various analytical techniques. The results strongly suggest that [Au(25)(SeC(8)H(17))(18)](-) possesses a similar geometric structure to the well-studied thiolate (RS)-protected Au(25) cluster ([Au(25)(SR)(18)](-)) and that the charge transfer between the metal atoms and ligands in [Au(25)(SeC(8)H(17))(18)](-) is lower than that in [Au(25)(SR)(18)](-). To the best of our knowledge, this is the first report of the isolation of a selenolate-protected gold cluster. [Au(25)(SeC(8)H(17))(18)](-) is an ideal compound for determining how changing the ligand from thiolate to selenolate affects the fundamental properties of a cluster. 相似文献
622.
Naoto Tsutsumi Akihito Dohi Asato Nonomura Wataru Sakai 《Journal of Polymer Science.Polymer Physics》2011,49(6):414-420
We present the enhanced photorefractive performance of high molecular weight poly(N‐vinyl carbazole) (PVCz)‐based composites. Higher diffraction efficiency with faster speed of grating build‐up was obtained by optimizing the composition of the PVCz composites. At relatively low applied electric field of E = 45 V μm?1, diffraction efficiency of 26% for p‐polarized probe beam and corresponding that of 5.1% for s‐polarized probe beam were measured with faster grating build‐up speed of 48.3 s?1 for the composite with 2,4,7‐trinitrofluorenone (TNF) as a sensitizer. Fastest speed of grating build‐up of 100 s?1 and large optical gain up to 110 cm?1 were measured at E = 80 V μm?1 for the composite with fullerene derivative of PCBM as a sensitizer. These improved performances are due to a large orientational enhancement effect with faster response speed in addition to Pockels effect for the samples with appropriate glass transition temperature. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 相似文献
623.
Aerobic oxidation of thiols is efficiently catalyzed by diaryl tellurides such as bis(4-methoxyphenyl) telluride under photosensitized conditions to give the corresponding disulfides in good to excellent yields. In this catalytic system, the tellurone oligomer, produced by the reaction of a telluride with singlet oxygen, is assumed to be the active species and is capable of oxidizing 4 equiv of a thiol. 相似文献
624.
A planar near-field optical head with a high optical efficiency of 12.9% (3.2 times higher than that of our previous design)
for laser-assisted magnetic recording is described. In this head, a slab-type waveguide with a narrow core is butt-coupled
into a one-sided multilayer thin-film stack. Metal cladding is used in the core because of its high optical efficiency due
to surface plasmon excitation. To keep production costs low, we use only two layers for the side part, which act as a two-index-step
lens that couples light in the side part into a core of the central part. We optimized the parameters of this optical head
and recording medium by means of an optical simulator using the finite-difference time-domain method and a thermal simulator.
The calculated full width half maximum (FWHM) optical spot size on the recording medium is 24 × 47 nm2 and the thermal spot size is 80 × 88 nm2 (FWHM). 相似文献
625.
Natsumi Fukushi Miku Yoshizawa Shota Onosato Motohiro Hanada Wataru Takarada 《Journal of Macromolecular Science: Physics》2018,57(2):110-128
Multiple melting behavior of high-speed melt-spun polylactide (PLA) fibers was investigated by temperature modulated differential scanning calorimetry (TMDSC) in the heating process with various modulation periods in the calorimeter. In the case of the as-spun PLA fibers taken-up at 1 km/min, a melting endothermic peak and a recrystallization exothermic peak appeared at the same peak temperature of 151°C in the reversing and non-reversing heat flows (RHF and NRHF), respectively, whereas at 168°C, an endothermic peak was observed in both the RHF and NRHF. On the other hand, the as-spun PLA fibers taken-up at a high-speed of 6 km/min showed the melting in both the RHF and NRHF, but the recrystallization behavior was not obvious in the NRHF at the shorter modulation period conditions. The obtained data were analyzed based on the kinetic modeling of melting proposed by Toda et al. The real and imaginary parts of the complex apparent heat capacity in the melting region showed a strong modulation period dependence for both the low- and high-speed spun fibers. The endothermic heat flow of melting was separated by extrapolating the frequency to zero. For the PLA fibers spun at 1 km/min, a set of melting and recrystallization peaks in the RHF and NRHF appeared even for the melting at 168°C. In other words, the simultaneous occurrence of melting and recrystallization was confirmed through this extrapolation. For the 6 km/min PLA fibers, the presence of an exothermic heat of recrystallization was clearly confirmed at a peak temperature of 164°C. 相似文献
626.
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628.
Dr. Wataru Kosaka Yoshie Hiwatashi Naoka Amamizu Prof. Dr. Yasutaka Kitagawa Prof. Dr. Jun Zhang Prof. Dr. Hitoshi Miyasaka 《Angewandte Chemie (International ed. in English)》2023,62(48):e202312205
Partial charge fluctuations in the charge-ordered state of a material, often triggered by structural disorders and/or defects, can significantly alter its physical characteristics, such as magnetic long-range ordering. However, it is difficult to post-chemically fix such accidental partial fluctuations to reconstruct a uniform charge-ordered state. Herein, we report CO2-aided charge ordering demonstrated in a CO2-post-captured layered magnet, [{Ru2(o-ClPhCO2)4}2{TCNQ(OMe)2}] ⋅ CO2 ( 1⊃CO2 ; o-ClPhCO2−=ortho-chlorobenzoate; TNCQ(OMe)2=2,5-dimethoxy-7,7,8,8-tetracyanoquinodimethane). Pristine porous layered magnet 1 had a partially charge-fluctuated ordered state, which provided ferrimagnetic ordering at TC=65 K. Upon loading CO2, 1 adsorbed one mole of CO2, forming 1⊃CO2 , and raising TC to 100 K. This was because of the vanishing charge fluctuations without significantly changing the framework structure. This research illustrates the post-accessible host–guest chemistry delicately combined with charge, spin, and lattice ordering in a spongy magnet. Furthermore, it highlights how this innovative approach opens up new possibilities for technology and nanoscale magnetism manipulation. 相似文献