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91.
92.
Shundo A Nakashima R Fukui M Takafuji M Nagaoka S Ihara H 《Journal of chromatography. A》2006,1119(1-2):115-119
Poly(octadecylacrylate) having plural trimethoxysilyl groups in the side chain (co-ODA(n)) was newly synthesized and immobilized onto silica through these groups. The liquid chromatographic behavior of silica-supported co-ODA(n) (Sil-co-ODA(n)) was investigated and compared with that of Sil-ODA(n), in which poly(octadecylacrylate) was immobilized through a terminal trimethoxy group at one side of the polymer main chain. Sil-co-ODA(n) showed higher selectivity for molecular shape, especially molecular planarity of PAHs than Sil-ODA(n). 相似文献
93.
Suzuki S Morita Y Fukui K Sato K Shiomi D Takui T Nakasuji K 《Journal of the American Chemical Society》2006,128(8):2530-2531
We have demonstrated the first MS and NMR observation of a face-to-face pi-bonded dimer of an organic radical (pancake-bonded dimer coined by R. S. Mulliken) in solution, using tri-tert-butylated phenalenyl radical 1, a 3-fold symmetric neutral hydrocarbon. In addition to the direct detection of the dimer signal by cold-spray ionization mass spectrometry (CSI-MS), 1H and 13C NMR spectra in solution gave definitive evidence of a well-defined D3d dimer structure with a 12-center-2-electron-long C-C bond formation, which is the same symmetry as seen in the crystalline state. On the basis of the NMR peaks of the dimer in the aromatic region (6.47 ppm for 1H NMR and 120-143 ppm for 13C NMR), we carried out nucleus-independent chemical shift (NICS) analysis, which showed that the ring center of the dimer became more aromatic (-7.1 ppm) than that of the monomer (-3.8 ppm). The trend of aromaticity generation was more pronounced in the interior of the dimer, which has been interpreted by the negative electron density induced in the bonding region as seen in the electrostatic potential surface. 相似文献
94.
Koji Morinishi Tomohiro Fukui 《International Journal of Computational Fluid Dynamics》2016,30(5):363-369
This paper describes parallel computing approach for simulating turbulent flows using a moment base lattice Boltzmann method. The distribution functions of the lattice Boltzmann method are expressed by corresponding moments. Choosing proper relaxation times for higher order moments, a minimum numerical dissipation is implicitly added to stabilise the method at high Reynolds numbers. Validation of the method is made by computing free decaying periodic turbulent flows and fully developed turbulent channel flows on a GPU platform. Though the present method requires additional work to calculate the higher order moments, it is shown that additional computational cost is negligible in the GPU computing. The numerical results stably obtained for the turbulent flows are in good agreement with those of a pseudo-spectral method and corresponding DNS database. 相似文献
95.
We developed a method, called RNA Assembler using Secondary Structure Information Effectively (RASSIE), for predicting RNA tertiary structures using known secondary structure information. We attempted a fragment assembly-based method that uses a secondary structure-based fragment library. For several typical target structures such as stem-loops, bulge-loops, and 2-way junctions, our method provided numerous good quality candidate structures in less computational time than previously proposed methods. By using a high-resolution potential energy function, we were able to select good predicted structures from candidate structures. This method of efficient conformational search and detailed structure evaluation using high-resolution potential is potentially useful for the tertiary structure prediction of RNA. 相似文献
96.
Nishikimi A Uruno T Duan X Cao Q Okamura Y Saitoh T Saito N Sakaoka S Du Y Suenaga A Kukimoto-Niino M Miyano K Gotoh K Okabe T Sanematsu F Tanaka Y Sumimoto H Honma T Yokoyama S Nagano T Kohda D Kanai M Fukui Y 《Chemistry & biology》2012,19(4):488-497
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97.
Naoko Asakuma Toshimi Fukui Mamoru Aizawa Motoyuki Toki Hiroaki Imai Hiroshi Hirashima 《Journal of Sol-Gel Science and Technology》2000,19(1-3):333-336
Structural changes stimulated by ultraviolet (UV) laser irradiations of sol-gel derived inorganic oxide films were investigated. Dried gel films of TiO2, Nb2O5, Ta2O5, SrTiO3 and Pb(Zr
x
Ti1–x
)O3 (PZT) were found to be crystallized by the laser irradiation. On the other hand, the photo-induced change in gel films of BaTiO3, LiNbO3 and LiTaO3 was not observed although the laser beams were absorbed in the films. These sol-gel films were thermally crystallized at almost the same temperature around 600–700°C except TiO2. Thus, the UV-laser-induced crystallization is not directly ascribed to a simple thermal effect with the irradiation. Photochemical properties of the cations are assumed to be important for the change in sol-gel films. 相似文献
98.
Y. Asakuma M. Nishimura M. Kimura H. M. Ang M. O. Tade K. Maeda K. Fukui 《Crystal Research and Technology》2007,42(5):424-431
The impurity effect by trivalent metal ion such as Al3+, Fe3+ and Cr3+ during crystal growth of KDP is reasonably well documented. If a metal ion is adsorbed onto the crystal surface, it prevents the step propagation relevant to the crystal growth rate. However, this impurity adsorption mechanism is still not well understood. Recently, in our work on the addition of chelate agents, a recovery effect of the metal ion adsorption was discovered. However, its recovery mechanism is not clearly understood both theoretically and phenomenally. In this research, ethylene‐diamine‐tetra‐acetic acid, EDTA, which is the most common chelate agent, was used as a recovery agent. The recovery mechanism was considered from the correlation of experimental data and the interfacial distribution model that we proposed in our former study. Furthermore, quantum calculation of EDTA metal complex can explain the relaxation of impurity adsorption by the addition of EDTA. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
99.
Keigo Matsuyama Akito Fukui Kohei Miura Hisashi Ichimiya Yuki Aoki Yuki Yamada Prof. Atsushi Ashida Prof. Takeshi Yoshimura Prof. Norifumi Fujimura Prof. Daisuke Kiriya 《ChemistryOpen》2019,8(7):908-914
Transition metal dichalcogenides (TMDCs) have received attention as atomically thin post-silicon semiconducting materials. Tuning the carrier concentrations of the TMDCs is important, but their thin structure requires a non-destructive modulation method. Recently, a surface-charge transfer doping method was developed based on contacting molecules on TMDCs, and the method succeeded in achieving a large modulation of the electronic structures. The successful dopant is a neutral benzyl viologen (BV0); however, the problem remains of how to effectively prepare the BV0 molecules. A reduction process with NaBH4 in water has been proposed as a preparation method, but the NaBH4 simultaneously reacts vigorously with the water. Here, a simple method is developed, in which the reaction vial is placed on a hotplate and a fragment of air-stable metal is used instead of NaBH4 to prepare the BV0 dopant molecules. The prepared BV0 molecules show a strong doping ability in terms of achieving a degenerate situation of a TMDC, MoS2. A key finding in this preparation method is that a convection flow in the vial effectively transports the produced BV0 to a collection solvent. This method is simple and safe and facilitates the tuning of the optoelectronic properties of nanomaterials by the easily-handled dopant molecules. 相似文献
100.
A. Uedono T. Ohdaira R. Suzuki T. Mikado S. Fukui S. Kimura H. Miyamoto H. Nemoto 《Journal of Polymer Science.Polymer Physics》2004,42(2):341-346
The volume and depth distributions of open spaces in photoresist films designed for ArF‐excimer laser light exposure were studied with monoenergetic positron beams. We measured the Doppler broadening spectra of the annihilation radiation and lifetime spectra of positrons for acrylate and cyclic olefin‐co‐maleic anhydride (COMA) polymers spin‐coated onto Si wafers with methyl amyl ketone, cyclohexanone, and propylene glycol methyl ether acetate solvents. The volume of open spaces in both prebaked acrylate and COMA films was estimated to be 0.12 nm3. The volume of open spaces in acrylate films decreased up to 20% by postexposure baking, but no large change was observed for COMA films. The decrease in the open volume was attributed to the removal of large molecules (adamantyl) from flexible main chains after the chemically amplified reaction of acrylate. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 341–346, 2004 相似文献