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991.
Reactive molecular dynamics (MD) simulation is performed using a reactive force field (ReaxFF). To this end, we developed a new method to optimize the ReaxFF parameters based on a machine learning approach. This approach combines the k-nearest neighbor and random forest regressor algorithm to efficiently locate several possible ReaxFF parameter sets. As a pilot test of the developed approach, the optimized ReaxFF parameter set was applied to perform chemical vapor deposition (CVD) of an α-Al2O3 crystal. The crystal structure of α-Al2O3 was reasonably reproduced even at a relatively high temperature (2000 K). The reactive MD simulation suggests that the (110) surface grows faster than the (0001) surface, indicating that the developed parameter optimization technique could be used for understanding the chemical reaction in the CVD process. © 2019 Wiley Periodicals, Inc. 相似文献
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995.
H. Seyama Y. Soma M. Soma S. Takao T. Sakurai S. Tagami 《Fresenius' Journal of Analytical Chemistry》1991,341(10):619-624
Summary Secondary ion mass spectrometry (SIMS) was applied for the analysis of asbestos fibers. It was possible to identify the asbestos fibers by the pattern of the positive secondary ion mass spectrum. The image of the asbestos fibers was measurable by use of any major positive secondary ions. The smallest size of detectable asbestos fiber was about 5 and 1 m in length and diameter, respectively. Using a fast atom bombardment (FAB) source instead of primary ion beam, asbestos fibers collected on a membrane filter were easily detected without any pretreatment. 相似文献
996.
Satoshi Tsutsui Yoshiharu Sakurai Dai Aoki Yoshiya Homma Akio Nakamura Yoshichika ōnuki 《Journal of Physics and Chemistry of Solids》2007,68(11):2099-2102
We have carried out the magnetic Compton scattering of NpNiGa5. The signs of the magnetic effects in both ordered states are negative. These facts demonstrate that the contribution of the Np 5f electrons is dominant in the ordered states of NpNiGa5. The magnetic Compton profile shows significant change across the successive transitions. This suggests that the successive transitions are correlated with the 5f quadrupolar degrees of freedom and/or the change of the quantized axis. 相似文献
997.
Yoshihiro Ohba Kazuaki Ito Tomomi Nagasawa Shinya Sakurai 《Journal of heterocyclic chemistry》2000,37(5):1071-1076
A series of new types of sulfur‐bridged Lewis acids were synthesized. The ligands that contained the sulfoxide or sulfone as the joint moieties of two phenols were found to quantitatively give Lewis acids. These obtained Lewis acids also have good discrimination properties of some epoxides. The reaction prop erties of the Lewis acids were studied using the rearrangement of the epoxides to carbonyl compounds. 相似文献
998.
H. Erdmann M. v. Unruh Weinhold und Sakurai 《Fresenius' Journal of Analytical Chemistry》1904,43(4):239-242
Ohne Zusammenfassung 相似文献
999.
Katsumi Hagita Takashi Arai Hiroyuki Kishimoto Norimasa Umesaki Hiroya Suno Yuya Shinohara Yoshiyuki Amemiya 《Rheologica Acta》2008,47(5-6):537-541
Two-dimensional pattern reverse Monte Carlo method is applied to investigate structural changes of silica particle filler in uniaxially elongat ed rubber. We calculated three-dimensional confor mations of spherical silica particles using a series of two-dimensional patterns of structure factors during elongation. The structure factors we used are inter polated from experimentally observed structure factors for the elongation ratio ε?=?0.0, 0.5, 1.0, and 1.5. To make a continuous motion of particles, we set the elongation ratio with small interval Δε?=?0.001. It is found that the structural change of the particles seem to be reliable at least for small ε regions because spurious motions like the Brownian motions are not observed. 相似文献
1000.
Naohiko Shimada Tadashi Okobira Yoichi Takeda Seiji Shinkai Kazuo Sakurai 《Journal of polymer science. Part A, Polymer chemistry》2008,46(4):1440-1448
Schizophyllan (SPG) is a natural β‐1,3‐glucan that forms a triple helix (t‐SPG) in neutral aqueous solutions and t‐SPG can be denatured to single chains (s‐SPGs) in DMSO or alkaline solutions. Exchanging the denatured solutions for neutral water leads the renaturation of the triple helix. We have reported that hydrophobic molecules can form a complex with s‐SPG when they are present in the renaturation process. Some of these, for example poly(dA) and polyaniline, were found to have aromatic amino moieties. This report demonstrates whether s‐SPG can interact with other aromatic amino compounds such as anilinonaphthalene sulfonic acid (ANS) derivatives. Enhanced fluorescence intensity and red‐shifted UV absorption spectra were observed in the mixture of s‐SPG and 2,6‐ANS or 2,6‐TNS. In the circular dichroism measurement, the positive Cotton effects appeared after mixing 2, 6‐ANS with s‐SPG. When the amino proton was replaced by the methyl group or used in intramolecular hydrogen bonds, any spectral changes were not observed. These results indicate that amino proton in the ANS derivatives plays a key role in the complexation. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1440–1448, 2008 相似文献