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81.
Yoshiki Shimizu Takeshi Sasaki Tetsuya Kodaira Kenji Kawaguchi Kazuo Terashima Naoto Koshizaki 《Chemical physics letters》2003,370(5-6):774-780
We fabricated cone-shaped carbon nanotube assemblies, which align in a densely packed geometry like a cedar tree forest, on unpatterned nanocomposite substrate of Ni and Mo by the DC plasma assisted hot filament chemical vapor deposition. Carbon nanotubes initially grew on the nickel domains created during deposition, forming cone-shaped assemblies. These assemblies grew keeping their shape with decreasing their number density by merging together. The relationship between the mean volume and the number density of conical-shaped tree-like assemblies was similar to one of natural plant forest. 相似文献
82.
83.
Yutaka Tsuji Yoshinobu Morikawa Kozo Terashima 《International Journal of Multiphase Flow》1982,8(1):71-82
Experiment of fluid-dynamic interaction between two spheres was conducted to obtain basic information concerning the two-phase flow, especially in dense phase. Two or three spheres were set up in a water tunnel in the longitudinal or transverse direction with Reynolds numbers less than 103. The flow behind the sphere was visualized by the use of condense milk and change in vortex structure due to the interaction was observed in detail. Additionally, drag force on the sphere was measured by a pendulum method which was developed to detect small drag, and the range of distance in which the drag is affected by the interaction was shown. 相似文献
84.
85.
Hayama T Baldridge KK Wu YT Linden A Siegel JS 《Journal of the American Chemical Society》2008,130(5):1583-1591
Motivated by a greater bowl depth and barrier to bowl inversion in sym-1,3,5,7,9-pentamanisylcorannulene compared to corannulene, an experimental plan is developed to measure the effective hydrogen/deuterium steric kinetic isotope effect (KIE). Symmetry arguments are used to design orthogonal isotope labeling patterns so that the barrier for the CD3 compound can be measured in the presence of the CH3 compound. This scheme eliminates the differential uncertainty in the temperature measurement by allowing both barriers to be measure in the same sample, which in turn reduces the error in determining the differential barrier. Ab initio computations corroborate the structure and isotope effect found experimentally. The predicted and determined steric KIE at 250 K is 1.08 (modified QUIVER at M06-2X/cc-pVDZ) and 1.22 +/- 0.06 (VT-NMR), respectively. The results stem from differences in zero-point energy of the CH and CD motions; however, the phenomenology makes the CD3 group appear effectively "stickier" than CH3. The more the C-H...X interaction steepens the well, the "stickier" C-D should appear to be relative to C-H--an important consideration for molecular recognition and one supported by stronger binding constants for deuterated substrates. 相似文献
86.
Nemoto K Kubo T Nomachi M Sano T Matsumoto T Hosoya K Hattori T Kaya K 《Journal of the American Chemical Society》2007,129(44):13626-13632
We have developed a simple and effective molecular imprinting technique to target compounds with flexible structure. Domoic acid (DA), an amnesic shellfish poison, was used as the target compound while many acidic compounds (mono-, di-, and tricarboxylic acids) were used as template molecules for molecularly imprinted polymers (MIPs). Evaluation of selective recognition abilities using liquid chromatography revealed that the highest selective recognition ability for DA was found when pentane-1,3,5-tricarboxylic acid (1,3,5-PeTA) was used as the template. Computer modeling studies of the DA structure suggested that the observed selective recognition depended on the structural changes in DA at the recognition site of the MIPs as well as spatial distance between the COOH groups in DA and 1,3,5-PeTA. Using the 1,3,5-PeTA-MIP, we could easily purify DA from blue mussel extracts by solid-phase extraction. 相似文献
87.
Takahide Y Konoike T Enomoto K Nishimura M Terashima T Uji S Yamamoto HM 《Physical review letters》2007,98(11):116602
We report a large positive magnetoresistance ratio in insulating organic crystals theta-(ET)(2)CsZn(SCN)(4) at low temperatures at which they exhibit highly nonlinear current-voltage characteristics. Despite the nonlinearity, the magnetoresistance ratio is independent of the applied voltage. The magnetoresistance ratio depends little on the magnetic field direction and is described by a simple universal function of mu(B)B/k(B)T, where mu(B) is the Bohr magneton. The positive magnetoresistance may be caused by magnetic-field-induced parallel alignment of spins of mobile and localized electrons, and a resulting blockade of electrical conduction due to the Pauli exclusion principle. 相似文献
88.
A novel arylene-ethynylene molecule has been synthesized. This molecule is more stable in a coplanar form than in a twisted form as in the cases of typical arylene-ethynylene molecules. When the cationic charge was introduced into the pi-conjugated system, the perpendicularly twisted form became more stable than the coplanar state. The conformational change was controlled by introduction and removal of cationic charge, confirmed by the absorption and fluorescence spectroscopy and DFT calculation. 相似文献
89.
90.
Unique Separation Behavior of a C60 Fullerene‐Bonded Silica Monolith Prepared by an Effective Thermal Coupling Agent
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Dr. Takuya Kubo Yoshiki Murakami Madoka Tsuzuki Hiroshi Kobayashi Dr. Toyohiro Naito Dr. Tomoharu Sano Prof. Dr. Mingdi Yan Prof. Dr. Koji Otsuka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(50):18095-18098
Herein, we report a newly developed C60 fullerene‐bonded silica monolith in a capillary with unique retention behavior due to the structure of C60 fullerene. N‐Hydroxysuccinimide (NHS)‐conjugated C60 fullerene was successfully synthesized by a thermal coupling agent, perfluorophenyl azide (PFPA), and assigned by spectroscopic analyses. Then, NHS‐PFPA‐C60 fullerene was attached onto the surface of a silica monolith in a capillary. The capillary provided specific separation ability for polycyclic aromatic hydrocarbons in liquid chromatography by an effective π–π interaction. Furthermore, corannulene, which has a hemispherical structure, was selectively retained in the capillary based on the specific structural recognition due to the spherical C60 fullerene. This is the first report revealing the spherical recognition ability by C60 fullerene in liquid chromatographic separation. 相似文献