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101.
Nor-Mycosporin Glutamin, a new unstable compound isolated from sporulating cultures of , has the structure (I). 相似文献
102.
103.
Elucidation of the structure of a highly efficient blue emitting lithium boron 2-(2-hydroxyphenyl) benzoxazole 总被引:1,自引:0,他引:1
Jung Eun Lee Gyu Chul Choi No Gill Park Yun Kyoung Ha Young Sik Kim 《Current Applied Physics》2004,4(6):675-678
We have studied the new blue electroluminescent material (compound 1) synthesized from the reaction of 2-(2-hydroxyphenyl)benzoxazole with LiBH4 according to Tao's procedure [J. Am. Chem. Soc. 121 (1999) 9447; Appl. Phys. Lett. 75 (1999) 1665] Compound 1 showed the UV and the PL peak at 366 and 432 nm, respectively. The manufactured device (ITO/compound 1(600 Å)/Al) showed the EL peak at 412 nm. However, the structure of compound 1 was not fully identified as examined by experiment. In order to disclose the structure of compound 1, we proposed several possible compounds and calculated each compound, using the following methods. Hartree–Fock with the 3-21G(d) basis set was used for energy calculation and geometry optimizations of those compounds. Excitation energies were obtained from time-dependent density functional theory (TD-DFT) using the B3LYP functional with the 3-21G(d) basis set. As a result, [(box)(boxH)Li]2 was found to be one of the possible compounds which had the most stable geometry structure. Its optical properties showed remarkably good agreement with the characterization data of compound 1. In addition, the structure of [(box)(boxH)Li]2 was also compared well with that of LiBq4 which was reported by the groups of Tao and was argumentatively asserted by Radu and coworkers [J. Am. Chem. Soc. 125 (2003) 880]. 相似文献
104.
J.P. Rozelot J.C. Noëns 《Journal of Quantitative Spectroscopy & Radiative Transfer》1975,15(5):379-384
The excitation of the lowest (3s23p4) configuration of Fe XI is discussed and theoretical values for the relative intensities of the Fe XI lines at 7892 Å and 3987 Å are presented. Particular attention has been paid to the quality of the atomic parameters involved and, in spite of probably inaccurate rates involving complex configurations (such as 3p34p), it is shown that the predicted intensity ratio obtained is more nearly consistent with available observations that previously published results. 相似文献
105.
The base-catalyzed condensation of p-tbutylphenol and formaldehyde, which yields a cyclic octamer (I, n=8) as the major product, has been shown to also yield a cyclic tetramer (I, n=4) and a bischomooxa cyclic tetramer (II). 相似文献
106.
Unambiguous spin and parity assignment have been made from angular correlation measurements to states in 20Ne at 15.18 MeV (6+) and 17.40 MeV (9?). Our results are in disagreement with an earlier 9? assignment to the 15.18 MeV state. The 17.40 MeV state is assigned to the K = 2? rotational band based on the 2? state at 4.97 meV. 相似文献
107.
The static moments of a new Iπ = (10+) isomer in 54Fe (Ex = 6528keV; τ = 525 ± 10ns) were measured by the perturbed angular distribution method with the results g = +0.778 ± 0.010, |Q| = 72 ± 7efm2. The isomer was then used to study the combined interaction produced by weak randomly-oriented electric field gradients in the presence of a strong magnetic field. 相似文献
108.
HT20—40铸铁中碳的光电光谱分析 总被引:1,自引:0,他引:1
冯继承 《光谱学与光谱分析》1992,12(1):86-88
本文主要论述HT20-40铸铁中碳的光电光谱分析。由于薄片样急冷快,白口化好,这样解决了铸铁样品难以白口化的问题。为了加工薄片样,设计了磁钢磨具。解决了加工薄片样非常困难的问题。实践证明,只要严格控制铸铁样分析条件,碳的光电光谱分析结果完全达到了要求。 相似文献
109.
Archilla JF Cuevas J Alba MD Naranjo M Trillo JM 《The journal of physical chemistry. B》2006,110(47):24112-24120
Reconstructive transformations in layered silicates need a high temperature in order to be observed. However, very recently, some systems have been found where transformation can be studied at temperatures 600 degrees C below the lowest experimental results previously reported, including sol-gel methods. We explore the possible relation with the existence of intrinsic localized modes, known as discrete breathers. We construct a model for nonlinear vibrations within the cation layer, obtain their parameters, and calculate them numerically, obtaining their energies. Their statistics show that, although there are far less breathers than phonons, there are much more above the activation energy, making them good candidates to explain the reconstructive transformations at low temperatures. 相似文献
110.
Noël Bonneuil 《The Journal of mathematical sociology》2013,37(3):175-192
Two examples, Sampson's monks and Padgett and Ansell’ Florentines, illustrate the viability approach of dynamic networks. Notably, the relationship with centrality is studied. Historical processes involving networks are discussed. Networks are presented as controls in controlled dynamic systems. Viability is the property for a state x that there exists a trajectory starting from x and satisfying the constraints until the time horizon. To obtain this, connection matrices must be selected at each time and each visited state among a specific set, the regulation map, which is carefully defined and built. 相似文献