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991.
992.
A new pinhole-plate ultrasonic atomizer has been proposed and developed. A pinhole-plate having one or more pinholes is joined to a cavity filled with liquid and is vibrated by a circular ring piezoelectric element bonded onto it. The vibrating plate generates ultrasonic waves only in the vicinity of the pinholes to jet and atomize the liquid from them. The atomizer is very simple and compact, and extremely low in power consumption. 相似文献
993.
K Yamamoto N Oyamada M Mizutani Z An N Saito M Yamaguchi M Kasuya K Kurihara 《Langmuir : the ACS journal of surfaces and colloids》2012,28(32):11939-11947
Two-component gels formed from pseudoenantiomeric ethynylhelicene oligomers in toluene exhibited two different properties depending on difference in numbers of helicenes in the two components. The combinations (M)-5/(P)-4, (M)-6/(P)-4, and (M)-7/(P)-4, which contained oligomers with comparable numbers of helicenes, formed transparent gels (Type I gels). The combinations (M)-6/(P)-3, (M)-7/(P)-3, and (M)-8/(P)-3, which contained oligomers with considerably different numbers of helicenes, formed turbid gels (Type II gels). Negative Cotton effects were observed for the Type I gels in the region between 350 and 450 nm, and were positive for the Type II gels, despite the use of (M)-oligomers for the longer components. UV/vis exhibited absorption maxima at 350 nm for the Type I gels and at 338 nm for the Type II gels. Different behaviors in gel formation processes were observed by fluorescence studies. Atomic force microscopy analysis showed fiber structures of 25-50 nm diameter for Type I gels and bundles of 100-150 nm diameter for Type II gels. The stoichiometry in gel formation also differed: The Type I gels showed 1:1 stoichiometry of the two components; the Type II gels showed no 1:1 stoichiometry, likely 1:2 stoichiometry. Using the Type I and II gels, two-layer gel systems were constructed. 相似文献
994.
Osamu Yamamoto Kikuko Hayamizu Masaru Yanagisawa 《Journal of organometallic chemistry》1974,73(1):17-25
The kinetic parameters of the bridge-terminal interconversion of triethylaluminum (TEA) in cyclopentane and in toluene as well as of tri-n-propylaluminum (TPA) in cyclopentane are obtained from the total line shape analysis of 13C NMR spectra with proton-decoupling. The enthalpies and entropies of activation of these aluminum alkyls and of trimethylaluminum (TMA) in both solvents are nearly the same, but the interconversion is faster in toluene than in cyclopentane, and also becomes faster as the alkyl chain of the aluminum compounds becomes longer. From these data and the heats of dissociation obtained thermochemically by M.B. Smith [J. Phys. Chem., 71 (1967) 365; J. Organometal. Chem., 21 (1970) 273, 46 (1972) 31 and 211], a possible mechanism of the bridge-terminal exchange is elucidated, in which the exchange proceeds “intramolecularly” for TMA and presumably TEA in cyclopentane. For the aluminum alkyls in toluene and for TPA in cyclopentane, on the other hand, the exchange may proceed “intermolecularly” with only a little contribution from an “intramolecular process”. 相似文献
995.
Holographic data storage is being widely studied for the purpose of developing next-generation large optical memories. A prospective
use of this type of memory is in building image archives in large-scale data centers. In particular, demand for energy conservation
at data centers, and therefore for holographic data storage, is growing. In holographic data storage, interference between
bits occurs owing to wave aberration in the optical system, shrinkage of the medium, and crosstalk noise from neighboring
holograms during multiplex recording; as a result of the interference, the reproduced image deteriorates and the bit error
rate (BER) increases. In this study, to reduce the BER in both off-axis-type recording and coaxial-type recording, a two-dimensional
finite impulse response (FIR) filter is applied to a reproduced image that has been recorded by angle multiplex recording
and shift multiplex recording. First, for the optimization of the FIR filter coefficients, the linear minimum mean square
error (LMMSE) method is applied; this method optimizes the coefficients by reducing the BER. Furthermore, for evaluating the
optimization performance of the LMMSE method, the optimization performance is compared with that of the real-coded genetic
algorithm (RCGA), which has the capability to search a wide range of coefficients. The optimization by the LMMSE method has
been found to be excellent for off-axis-type recording but not for coaxial-type recording. It is speculated that this is because
of the brightness irregularity in the reproduced image, resulting from crosstalk. On the other hand, a marked reduction in
the BER is observed using the RCGA, despite the brightness irregularity. In this study, the effectiveness of the LMMSE method
for signals recorded by coaxial-type recording, in which large brightness irregularity is expected, is examined using automatic
gain control (AGC). It is found that the application of AGC reduces the BER even in the case of coaxial-type recording. 相似文献
996.
MOVPE growth of InN on sapphire substrates is compared using two different designs of horizontal reactor. The major difference between the two designs is a variation in the reactant-gas flow-spacing between the substrate and the ceiling of the quartz chamber: 33 mm for the Type A reactor and 14 mm for Type B. Compared with the Type A reactor, the Type B reactor brings about InN films with a larger grain size. This is especially true when InN is grown at 600°C using the Type B reactor, in which case the two-dimensional (2D) growth of InN is found to be extremely enhanced. An investigation of the NH3/TMIn molar ratio dependence of the surface morphology of grown InN films using the two reactors suggests that the enhanced 2D growth is attributed to the decrease in the effective NH3/TMIn ratio in the growth atmosphere. Even using the Type A reactor, a film with enhanced 2D growth can be obtained when the NH3/TMIn ratio is considerably low (1.8×104). The enhanced 2D growth results in a smaller XRC-FWHM (full-width at half maximum of the X-ray rocking curve) (1500 arcsec), than that for a 3D-grown film (5000 arcsec). 相似文献
997.
Hirai H Komatsu K Honda M Kawamura T Yamamoto Y Yagi T 《The Journal of chemical physics》2010,133(12):124511
High pressure and low temperature experiments with CO(2) hydrate were performed using diamond anvil cells and a helium-refrigeration cryostat in the pressure and temperature range of 0.2-3.0 GPa and 280-80 K, respectively. In situ x-ray diffractometry revealed that the phase boundary between CO(2) hydrate and water+CO(2) extended below the 280 K reported previously, toward a higher pressure and low temperature region. The results also showed the existence of a new high pressure phase above approximately 0.6 GPa and below 1.0 GPa at which the hydrate decomposed to dry ice and ice VI. In addition, in the lower temperature region of structure I, a small and abrupt lattice expansion was observed at approximately 210 K with decreasing temperature under fixed pressures. The expansion was accompanied by a release of water content from the sI structure as ice Ih, which indicates an increased cage occupancy. A similar lattice expansion was also described in another clathrate, SiO(2) clathrate, under high pressure. Such expansion with increasing cage occupancy might be a common manner to stabilize the clathrate structures under high pressure and low temperature. 相似文献
998.
Transition metal-catalysed acylation of alpha,beta-unsaturated carbonyl compounds with acylstannanes
Shirakawa E Yamamoto Y Nakao Y Tsuchimoto T Hiyama T 《Chemical communications (Cambridge, England)》2001,(19):1926-1927
Acylstannanes were found to add to such alpha,beta-unsaturated carbonyl compounds as enones or ynoates in the presence of a nicel or palladium catalyst to give 2-stannyl-4-oxoalk-2-enoates or 1,4-diketones, whereas the three component coupling between acylstannanes, enones and aldehydes provided 2-hydroxymethyl 1,4-diketones. 相似文献
999.
Dr. Takuya Nakashima Kazuhiko Imamura Kyohei Yamamoto Yuka Kimura Shohei Katao Yuichiro Hashimoto Prof. Tsuyoshi Kawai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(42):13722-13729
α,β‐Linked oligothiazoles with head‐to‐tail connectivity are presented as a new family of helical scaffolds. Combinations of palladium‐catalyzed cross‐coupling reactions at the 5‐ and 4‐positions of 2‐phenylthiazole led to the synthesis of oligo(2‐phenylthiazoles) with ortho linkages with a variety of defined sequences. The secondary structures of the α,β‐linked oligo(2‐phenylthiazoles) showed a clear dependence on their sequences. X‐ray crystallography of the trimer, tetramer, and hexamer with head‐to‐tail connection revealed the formation of a helical structure, which was stabilized by a combination of intramolecular forces, including interheteroatom (S???N), CH–π, and π–π interactions. The introduction of a chiral end‐group successfully led to the induction of chirality into the helical conformations. Programmable sequences for controlled geometries and photofunctions have been demonstrated through the manifold connection pathways in α,β‐linked oligothiazoles. 相似文献
1000.
Inokuchi T Takiuchi H Moriwaki Y Ka T Takahashi S Tsutsumi Z Shima H Hirota S Yamamoto T 《Magnetic resonance imaging》2006,24(10):1389-1393
A 35-year-old woman was referred to our institution for additional examinations to evaluate bilateral suprarenal masses incidentally found on abdominal ultrasonographic images obtained during an annual medical health checkup. Our computed tomographic scans showed bilateral and well-circumscribed low-density suprarenal masses, while MRI revealed the tumors to be heterogeneous with low intensity on T1-weighted images and high intensity on T2-weighted images. A laparoscopic adrenalectomy was performed under the suspicion of a malignant tumor, such as a malignant fibrous histiocytoma. Pathologic findings indicated a retroperitoneal ancient schwannoma of two histologic types: Antoni A and Antoni B. We considered that elucidation of the characteristic features of a schwannoma would provide helpful preoperative information for diagnosis. 相似文献