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991.
Sungmin Kang Jirakorn Thisayukta Hideo Takezoe Junji Watanabe Corresponding author Kumiko Ogino Takayuki Doi 《Liquid crystals》2013,40(10):1323-1336
Novel derivative series of the well known bent-shaped P-n-O-PIMB liquid crystal mesogens, referred to as ‘4Br-P-n-O-PIMB’, ‘4Cl-P-n-O-PIMB’ and ‘5Cl-P-n-O-PIMB’, having halogen atoms substituted on the phenyl ring in the central core, were synthesized by solution phase parallel synthesis based on a combinatorial approach. The mesomorphic behaviour and physical properties of all the new compounds were studied by means of optical microscopy, differential scanning calorimetry, X-ray and circular dichroism spectroscopy. We found interesting transitional behaviour for the 4Br-P-n-O-PIMB homologous series. The homologues with alkyl tails having carbon numbers of n=3–10, 12, 14 exhibit rather complicated mesomorphic behaviour, which is strongly sensitive to n. The chiral fluid smectic B2 phase with SmCAPA structure and unidentified smectic Bx phase were observed in the homologues with n=9, 10, 12, 14 and n=3–5, respectively. Interestingly, every member exhibits frustrated and/or helical ordered phases at low temperatures, designated as X1, X2, and X3 phases, which result from a spontaneous escape from a macroscopic polarization. The mesomorphic behaviour and mesophase structures differ remarkably from those of the parent P-n-O-PIMB homologues, suggesting that substitution of the halogen atoms at the central core essentially creates a particular interaction between molecules. 相似文献
992.
Dr. Takayuki Arai Keumhee Jang Dr. Yasuhito Koyama Dr. Shigeo Asai Prof. Toshikazu Takata 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(19):5917-5923
A supramolecular cross‐linked cross‐linker, capable of introducing rotaxane cross‐links to vinyl polymers, has been developed for the rational synthesis of polyrotaxane networks. The experimental results reveal that the combination of an oligocyclodextrin (OCD) and a terminal bulky group‐tethering macromonomer (TBM) forms a polymer‐network structure having polymerizable moieties through supramolecular cross‐linking. Radical polymerization of a variety of typical vinyl monomers in the presence of the vinylic supramolecular cross‐linker (VSC) afforded the corresponding vinyl polymers cross‐linked through the rotaxane cross‐links (RCP) as transparent stable films in high yields under both photoinitiated and thermal polymerization conditions. A poly(N,N‐dimethylacrylamide)‐based hydrogel synthesized by using VSC, RCPDMAAm, displayed a unique mechanical property. The small‐angle X‐ray scattering (SAXS) results, indicating patterns characteristic of a polyrotaxane network, clearly suggested the presence and role of the rotaxane cross‐links. The confirmation of the introduction of rotaxane‐cross‐links into vinyl polymers strongly reveals the significant usefulness of VSC. 相似文献
993.
A simple method to detect audible echoes is proposed as an objective criterion for room acoustics. This method evaluates the perceptibility of sound reflections that are generated by an impulsive sound source and identifies from reflectograms harmful reflections perceived as echoes. Particularly with this method, the masking effect of reverberation is taken into consideration, which cannot be treated sufficiently by the existing objective criteria. The applicability to room acoustical design is verified by evaluating the impulse responses measured in real halls where audible echoes occurred. It is shown that the proposed method detects audible echoes at an accuracy of more than 90% and would be suitable for practical use. 相似文献
994.
Yutaka Nishigaichi Takayuki Orimi Akio Takuwa 《Journal of organometallic chemistry》2009,694(24):3837-8723
Allyl- and benzyl-trifluoroborates can be applied to the photoreaction of carbonyl compounds to afford the corresponding alcoholic adducts in acceptable yields via a photo-induced single electron transfer pathway. The results were confirmed from the reaction selectivity and the negative free energy change for the electron transfer process. 相似文献
995.
996.
Three-dimensional numerical thrust performance analysis of hydrogen fuel mixture rotating detonation engine with aerospike nozzle 总被引:6,自引:0,他引:6
Nicolas Jourdaine Nobuyuki Tsuboi Kohei Ozawa Takayuki Kojima A. Koichi Hayashi 《Proceedings of the Combustion Institute》2019,37(3):3443-3451
The propulsive performance for an H2/O2 and H2/Air rotating detonation engine (RDE) with conic aerospike nozzle has been estimated using three-dimensional numerical simulation with detailed chemical reaction model. The present paper provides the evaluation of the specific impulse (Isp), pressure gain and the thrust coefficient for different micro-nozzle stagnation pressures and for two configurations of conic aerospike nozzle, open and choked aerospike. The simulations show that regardless of the nozzle, increase the micro-nozzles stagnation pressure increases the mass flow rate, the pre-detonation gases pressure and consequently the post-detonation pressure. This gain of pressure in the combustion chamber leads to a higher pressure thrust through the nozzle, improving the Isp. It was also found that the choked nozzle increases the chamber time-averaged static pressure by 50–60% compared with the open nozzle, inducing higher performance for the same reason explained before. 相似文献
997.
Abstract In [3] Dias and Figueira have reported that the square of the solution for the nonlinear Dirac equation satisfies the linear
wave equation in one space dimension. So the aim of this paper is to proceed with their work and to clarify a structure of
the nonlinear Dirac equation. The explicit solutions to the nonlinear Dirac equation and Dirac-Klein-Gordon equation are obtained.
Keywords: Nonlinear Dirac equation, Dirac-Klein-Gordon equation, Pauli matrix
Mathematics Subject Classification (2000): 35C05, 35L45 相似文献
998.
This paper describes the structure and characteristics of a deflecting mirror using electromagnetic actuation. We used a moving
magnet structure for mirror actuation and focused on designing a mirror structure with effective magnetic force (for low-power
operation) and a simple fabrication process (to achieve low manufacturing cost). In this design, the magnetic forces of attraction
and repulsion are simultaneously used for mirror deflection, allowing the mirror to be operated with low current. Moreover,
the structures of the yoke core and magnet bar have been designed to further reduce the operating current. Such a mirror structure
is simple and can be easily fabricated with a small number of components. This structure can be used not only for a one-dimensionally
deflecting mirror but also for a two-dimensionally deflecting mirror by attaching a second yoke core. 相似文献
999.
Hiroshi Hatano Tadafumi Sakata Kazuyuki Ogura Takayuki Hoshino Hiroaki Ueda 《Optical Review》2002,9(2):66-69
We proposed and developed a new solid immersion mirror (SIM) for near-field optical data storage. The SIM has some advantages, especially in manufacturing, because its shape is similar to a general plano-convex lens. Making an aperture of about 130 nm in diameter just on the focus area of the SIM, a bit-data recording onto a photochromic thin film was carried out. Minimum diameter of the written marks was estimated to be 180nm. We also demonstrated readout experiments where a recorded medium was rotating and a gap between the SIM and the disk was controlled with capacitance sensing. This is the first result of reading with a rotating disk using an SIM containing a small aperture.This paper was originally presented at the 10th Optical Near Field Workshop, which was held on June 27-28, 2001 at Osaka University, organized by the Optical Near Field Group, the Optical Society of Japan, an affiliate of the Japan Society of Applied Physics. 相似文献
1000.
Shin-ichi KusakaSuguru Dohi Takayuki DoiTakashi Takahashi 《Tetrahedron letters》2003,44(49):8857-8859
We achieved the total synthesis of macrosphelide A, as part of a combinatorial library of its analogues. The key intermediate, the seco-acid derivative, was prepared from the corresponding vinyl iodide using sequential carbonylative esterification. 相似文献