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41.
Y. Hatsukawa Y. Miyamoto Y. Toh M. Oshima M. Hosein Mahmudy Gharaie K. Goto K. Toyoda 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(2):273-276
In this study, using neutron activation analysis with multi-parameter coincidence method which was developed at Japan Atomic
Energy Agency (JAEA), a non-destructive, ultra-high sensitive multi-elemental determination has been realized. The multi-parameter
coincidence method is carried out with an array of 19 germanium detectors, GEMINI-II. Using this system, very weak γ-rays
emitted from trace amounts of elements can be detected. The iridium concentration has been determined by means of neutron
activation analysis with multi-parameter coincidence method for Cuban sediment samples across the K/T boundary strata. 相似文献
42.
A novel dicyanoheptafulvene 9 annulated by two spiro[4,5]deca-1,3-dienes was synthesized by the reaction of dispirocyclopentaazulenium cation 8 with bromomalononitrile. Although 9 was found to have a nonplanar heptafulvene structure by its X-ray crystallographic analysis, it is still capable of π-conjugation and thus shows appreciable contribution of the dipolar resonance form 9B based on its spectroscopic data. The degree of the contribution was further evaluated for various dicyanoheptafulvenes in terms of the partial sum of atomic charges of the dicyanomethylene group in the calculated structures besides the interplanar angles of the heptafulvene part and the length of the exocyclic double bond in the crystal structures. 相似文献
43.
44.
Haruki Toyoda Shigefumi Naka Akiyuki Kinouchi 《Czechoslovak Journal of Physics》2006,56(10-11):1305-1310
We study a way ofq-deformation of the bi-local system, the two-particle system bounded by a relativistic harmonic-oscillator type of potential, from both points of view of mass spectra and the behavior of scattering amplitudes. In our formulation, the deformation is done so thatP 2, the square of center-of-mass momentum, enters into the deformation parameters of relative coordinates. As a result, the wave equation of the bi-local system becomes nonlinear with respect toP 2; then, the propagator of the bi-local system suffers significant change so as to get a convergent self energy to the second order. The study is also made on the covariantq-deformation in four-dimensional spacetime. 相似文献
45.
46.
We propose a conformational search method to find a global minimum energy structure for protein systems. The simulated annealing is a powerful method for local conformational search. On the other hand, the genetic crossover can search the global conformational space. Our method incorporates these attractive features of the simulated annealing and genetic crossover. In the previous works, we have been using the Monte Carlo algorithm for simulated annealing. In the present work, we use the molecular dynamics algorithm instead. To examine the effectiveness of our method, we compared our results with those of the normal simulated annealing molecular dynamics simulations by using an α-helical miniprotein. We used genetic two-point crossover here. The conformations, which have lower energy than those obtained from the conventional simulated annealing, were obtained. 相似文献
47.
48.
Takayuki Toyoda Hisakazu Mihara Akihiko Ueno 《Macromolecular rapid communications》2002,23(15):905-908
Peptides bearing β‐cyclodextrin and 4‐(N,N‐dimethylamino)benzoyl (DMAB) units in the peptide side chains were prepared as chemosensors for molecule detection. The DMAB unit was expected to be included into the cyclodextrin cavity intramolecularly. However, these peptides exhibited no twisted intramolecular charge transfer fluorescence and the normal fluorescence intensity decreased upon the addition of 1‐adamantanol as an exogenous guest, indicating that the DMAB units are shallowly included in the cyclodextrin cavities. 相似文献
49.
50.
Direct photoetching of single crystal SiC by VUV-266 nm multiwavelength laser ablation 总被引:1,自引:0,他引:1
J. Zhang K. Sugioka S. Wada H. Tashiro K. Toyoda 《Applied Physics A: Materials Science & Processing》1997,64(4):367-371
2 O2:H2O and HF:H2O. The analysis of the etched samples by scanning electron microscopy (SEM) and scanning probe microscopy (SPM) indicates
that an array of square holes having well-defined patterned structures and clean substrate surfaces were obtained. The X-ray
photoelectron spectroscopy (XPS) analysis indicates that the SiC samples etched by VUV-266 nm multiwavelength laser have a similar
stoichiometry after chemical post-treatment as the virgin SiC. The mechanism of high-quality ablation using VUV-266 nm multiwavelength
laser is discussed in comparison with ablation using 266 nm single wavelength. The chemical post-treatment contributes to
removing the residues from the laser photolysis of SiC.
Received: 26 August 1996/Accepted: 17 October
1996 相似文献