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541.
Noriyuki Suzuki Taiga Takabe Yoshiko Yamauchi Shun Koyama Rina Koike Masahiro Rikukawa Wei-Ting Liao Wen-Sheng Peng Fu-Yu Tsai 《Tetrahedron》2019,75(10):1351-1358
Palladium-catalyzed Mizoroki-Heck reactions were carried out in water using thermoresponsive polymer micelles. The micelles were generated from thermoresponsive block copolymers consisting of a poly(N-isopropylacrylamide) (PNIPAAm) segment and a hydrophilic segment such as nonionic poly(ethylene glycol) (PEG) (2) and anionic poly(sodium p-styrenesulfonate) (PSSNa) (9). These copolymers exhibited lower critical solution temperature (LCST) behavior at ca. 40–50?°C and showed thermal stimuli-induced formation and dissociation of micelles. The copolymers formed micelles in aqueous solution at higher temperature, where catalytic reactions proceeded. At lower temperature, the micelles dissociated to form a clear solution, enabling efficient extraction of the products from aqueous reaction mixture. In the presence of these copolymers, palladium complexes catalyzed the coupling reactions between aryl iodides and alkene compounds inside the hydrophobic micelle cores in water under relatively milder conditions. Extraction of the products from the aqueous solution of 2 or 9 was found to be efficient enough in comparison with conventional surfactants. 相似文献
542.
Yoshinori Yamanoi Tsukasa Usuki Kenichiro Omoto Masaki Shimada Hikaru Koike Munetaka Iwamura Koichi Nozaki Daisuke Saito Masako Kato Hiroshi Nishihara 《Tetrahedron letters》2019,60(16):1108-1112
Planar chiral dioxacyclophanes were designed and synthesized as a key scaffold for materials with circularly polarized luminescence (CPL). Representative planar chiral 1,12-dioxa[12](1,4)naphthaleneophane-derived organosilane compounds (?)-(R)-1, (+)-(R)-2, and (?)-(R)-3 were prepared by (+)-sparteine-mediated aryl metalation and an electrophilic reaction with chlorosilanes. The absolute configurations of the planar chirality were determined in the R form by single-crystal X-ray analysis. Optically active compound (+)-(R)-2 exhibited blue fluorescence and a CPL signal with a dissymmetry factor (glum value) of 0.001 in solution. The electronic structure was corroborated by DFT and TD-DFT calculations rationalizing the observed spectroscopic properties. 相似文献
543.
Akira Sasaki Atsushi Sunahara Hiroyuki Furukawa Katsunobu Nishihara Takeshi Nishikawa Fumihiro Koike Hajime Tanuma 《High Energy Density Physics》2009,5(3):147-151
We present the development of population kinetics models for tin plasmas that can be employed to design an EUV source for microlithography. The atomic kinetic code is constrained for the requirement that the model must be able to calculate spectral emissivity and opacity that can be used in radiation hydrodynamic simulations. Methods to develop compact and reliable atomic model with an appropriate set of atomic states are discussed. Specifically, after investigation of model dependencies and comparison experiment, we improve the effect of configuration interaction and the treatment of satellite lines. Using the present atomic model we discuss the temperature and density dependencies of the emissivity, as well as conditions necessary to obtain high efficiency EUV power at λ = 13.5 nm. 相似文献
544.
Taconis oscillation in a closed long tube with large thermal gradient is studied by numerical calculation of the 2D compressible Navier-Stokes equations. The both ends of tube are hot (T = TH), and the center of side wall is cold (T = TC). We analyze the pressure amplitude pamp and the time averaged temperature Tm in the closed tube. pamp is almost homogenous in the tube cross section, however, Tm is not homogenous in the central cold region. We also observe two steady states at the same temperature ratio θ = TH/TC. It is important to analyze the effects of the boundary layer in this cold region on Taconis oscillations. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
545.
We present a leading order (LO) estimate for the longitidinal-transverse spin asymmetry (A
) in the nucleon-nucleon polarized Drell-Yan process at RHIC and
energies in comparison with A
and A
. A
receives contribution from g1, the transversity distribution h1, and the twist-3 distributions g
and h
. For the twist-3 contribution we use the bag model prediction evolved to a high energy scale by the large-Nc evolution equation. We found that A
(normalized by the asymmetry in the parton level) is much smaller than the corresponding A
. Twist-3 contribution given by the bag model turned out to be negligible. 相似文献
546.
547.
C. Petrascu S. Bianco A.M. Bragadireanu F.L. Fabbri C. Guaraldo M. Iliescu T.M. Ito V. Lucherini M. Bregant E. Milotti A. Vacchi E. Zavattini M. Augsburger D. Chatellard P. Knowles F. Mulhauser L.A. Schaller L. Schellenberg H. Schneuwly J.-P. Egger D. Varidel W.H. Breunlich M. Cargnelli B. Gartner R. King B. Lauss J. Marton J. Zmeskal T. Ponta S.N. Nakamura T. Koike R.S. Hayano M. Hori T. Ishikawa T. Ishiwatari M. Iwasaki Y. Akaishi G. Beer A.C. Sanderson R. Seki 《Hyperfine Interactions》1999,118(1-4):53-57
The DEAR (DAΦNE Exotic Atom Research) experiment at the new φ-factory DAΦNE of Laboratori Nazionali di Frascati aims for a
1% measurement of the line shift of the K-complex due to strong interaction in kaonic hydrogen. This presentation is meant to prove that the high statistics and good
resolution obtainable with DEAR will be able to disentangle the kaonic hydrogen K-complex lines (a cascade unconstrained fit), obtaining in this way constraints for what concerns the cascade parameters and,
consequently, information regarding the physical processes involved in the kaonic hydrogen atomic cascade.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
548.
Six new acylated triterpenoid saponins, bellisosides A-F (1-6), were isolated from the roots of Bellis perennis (Compositae) together with a known saponin, bellissaponin BS2 (7). These saponins which bear polygalacic acid as sapogenin, are bisdesmosidic glycosides. The structures were elucidated on the basis of chemical and physicochemical evidence. The cytotoxic activities of 1-7 against HL-60 human promyelocytic leukemia cells are also reported. 相似文献
549.
Naoyuki Koike 《Results in Mathematics》2002,42(1-2):81-106
For an equiaffine immersion of general codimension, we recently defined the Lipschitz-Killing curvature, where we fix a transversal bundle and a transversal volume element. The main purpose of this paper is to show that the integration of the absolute value of the Lipschitz-Killing curvature is independent of the choices of a transversal bundle and a transversal volume element. 相似文献
550.
In practical cardiology, a stethoscope based auscultation has been used to reveal the patient's clinical status. Recently, several hand-held echo devices are going on market and they are expected to play a role as "visible" auscultation instead of stethoscope. We have developed a portable and inexpensive echo device which can be used for screening of cardiac function. Two single element transducers were attached 180 degrees apart to a rotor with 14-mm diameter. The mechanical scanner, integrated circuits for transmitting and receiving ultrasonic signals and an A/D converter were encapsulated in a 150 x 40 mm probe weighing 200 g. The scan was started and the image was displayed on a Windows based personal computer (PC) as soon as the probe was connected to USB 2.0 port of the PC. The central frequency was available between 2.5 and 7.5 MHz, the image depth was 15 cm and the frame rate was 30/s. The estimated price of this ultra-portable ultrasound is about 3000 US dollars with software. For 69 cardiac patients with informed consent, image quality was compared with those obtained with basic range diagnostic echo machines. Left ventricular ejection fraction (EF) derived from normal M-mode image of standard machines (EFm) were compared with visual EF of the ultra-portable ultrasound device (EFv). The image quality was comparable to the basic range diagnostic echo machines although short axis view of aortic root was not clearly visualized because the probe was too large for intercostal approach. EFv agreed well with EFm. The ultra-portable ultrasound may provide useful information on screening and health care. 相似文献