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排序方式: 共有216条查询结果,搜索用时 734 毫秒
101.
J. T. King R. G. Place Graham Edgar R. B. Purdum L. Bertiaux A. Lassieur A. Kling W. Böttger G. Meillère A. Eilert W. G. France T. S. Eckert A. de Meeus E. Lasala E. Fernandez-Espina I. Guiteras T. Callan G. W. Monier-Williams F. G. Hawley F. Glaser L. M. Dennis G. Krüss Th. P. McCutcheon Jr. P. A. van der Meulen A. B. Ray J. S. Goldbaum J. H. Reedy G. Schay Schleicher 《Analytical and bioanalytical chemistry》1925,67(9):356-368
102.
G. de France 《Zeitschrift für Physik A Hadrons and Nuclei》1997,358(2):243-247
The identical bands phenomenon has been studied in detail both experimentally and theoretically. A first step has been done by analysing the distributions of the fractional changes in the dynamical moments of inertia of superdeformed nuclei. They showthat there is a clear excess of identical bands in superdeformed nuclei compared to normally-deformed nuclei at low spin. Furthermore, this difference can be traced back to some special properties of superdeformed bands. The second step consists in the precise lifetime measurements that have been performed in superdeformed nuclei of the rare earth region. The derived quadrupole moments support the picture that alignments and deformation effects cancel in identical bands. 相似文献
103.
104.
105.
F. Hannachi A. Lopez-Martens A. Korichi C. Schück E. Gueorguieva Ch. Vieu B. Haas R. Lucas A. Astier G. Baldsiefen M. Carpenter G. de France R. Duffait L. Ducroux Y. Le Coz Ch. Finck A. Gorgen H. Hübel T.L. Khoo T. Lauritsen M. Meyer D. Prévost N. Redon C. Rigollet H. Savajols J.F. Sharpey-Schafer O. Stezowski Ch. Theisen U. Van Severen J.P. Vivien A.N. Wilson 《Zeitschrift für Physik A Hadrons and Nuclei》1997,358(2):183-184
The EUROGAMarray has been used to investigate the decay out of the yrast superdeformed (SD) band in 194Pb. Eigth single step decays from the lowest observed SD states to low-lying states at normal deformation (ND) have been identified. From this observation, the excitation energy (4877 ± 1.5 keV) and the spin (6+) of the lowest observed SD state in 194Pb are established. 相似文献
106.
A Catalytic Diastereoselective Formal [5+2] Cycloaddition Approach to Azepino[1,2‐a]indoles: Putative Donor–Acceptor Cyclobutanes as Reactive Intermediates
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Raynold Shenje M. Cynthia Martin Prof. Dr. Stefan France 《Angewandte Chemie (International ed. in English)》2014,53(50):13907-13911
A catalytic formal [5+2] cycloaddition approach to the diastereoselective synthesis of azepino[1,2‐a]indoles is reported. The reaction presumably proceeds through a Lewis acid catalyzed formal [2+2] cycloaddition of an alkene with an N‐indolyl alkylidene β‐amide ester to form a donor–acceptor cyclobutane intermediate, which subsequently undergoes an intramolecular ring‐opening cyclization. Azepine products are formed in up to 92 % yield with high degrees of diastereoselectivity (up to 34:1 d.r.). 相似文献
107.
Jan Kuliga Stephen Massicot Rajan Adhikari Michael Ruppel Prof. Dr. Norbert Jux Prof. Dr. Hans-Peter Steinrück Dr. Hubertus Marbach 《Chemphyschem》2020,21(5):423-427
The adsorption behavior and the mobility of 2H-Tetranaphthylporphyrin (2HTNP) on Cu(111) was investigated by scanning tunneling microscopy (STM) at room temperature (RT). The molecules adsorb, like the structurally related 2HTPP, in the “inverted” structure with the naphthyl plane restricted to an orientation parallel to the Cu surface. The orientation of the four naphthyl groups yields altogether 16 possible conformations. Due to the existence of rotamer pairs, 10 different appearances are expected on the surface, and all of them are identified by STM at RT. Most interestingly, the orientation of the naphthyl groups significantly influences the diffusion behavior of the molecules on Cu(111). We identify three different groups of conformers, which are either immobile, medium or fast diffusing at RT. The mobility seems to decrease with increasing size of the footprint of the conformers on the surface. 相似文献
108.
109.
望远镜干涉阵中光程调制的研究 总被引:4,自引:2,他引:2
提出了在单模光纤联接的望远镜干涉阵中通过拉伸红外单模光纤实现光程调制的方法。简要分析了该方法的机理及存在的问题,如偏振效应,色散等,用少模光纤和单模光纤分别代替马赫-陈德尔(Mach-Zehnder)干涉仪的两个臂,并且其中一臂的光纤缠在直径为6cm的PZT圆柱上,给PZT圆柱施加三角皮电压后,首次得到干涉条纹,并证明了方法的可行性。 相似文献
110.
T. Kikuchi T. Motobayashi N. Iwasa Y. Ando M. Kurokawa S. Moriya H. Murakami T. Nishio J. Ruan S. Shirato S. Shimoura T. Uchibori Y. Yanagisawa T. Kubo H. Sakurai T. Teranishi Y. Watanabe M. Ishihara M. Hirai T. Nakamura S. Kubono M. Gai R.H. France III K.I. Hahn T. Delbar P. Lipnik C. Michotte 《The European Physical Journal A - Hadrons and Nuclei》1998,3(3):213-215
We have measured the dissociation of 8B in the Coulomb field of 208Pb at Ein=51.9 MeV/nucleon and extracted the cross section of the 7Be(p,γ)8B reaction at 0.4 ≤ Erel≤ 3 MeV, which is of importance for the 8B solar-neutrino production rate. The extracted astrophysical S17 factors are consistent with our earlier Coulomb dissociation measurement, and agree with the values deduced from the direct
capture measurements by Filippone et al., Vaughn et al. and Hammache et al. The S factor at zero energy was extracted to be
18.9±1.8 eV-b with the help of theoretical energy-dependence.
Received: 15 August 1998 相似文献