Structure de la Nor-Mycosporine Glutamine,nouvelle substance isolee de Pyronema omphalodes (Bull ex Fr.) fuckel.

Nor-Mycosporin Glutamin, a new unstable compound isolated from sporulating cultures of $\text{Pyronema omphalodes}$, has the structure (I).     

Elucidation of the structure of a highly efficient blue emitting lithium boron 2-(2-hydroxyphenyl) benzoxazole

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].     

Intensity ratios of forbidden coronal lines of Fe XI at 7892 Å and 3987 Å

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.     

Calixarenes. II. The isolation and characterization of the calix[4]arene and the bishomooxacalix[4]arene from A p-t-butylphenol-formaldehyde condensation product

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).     

Concerning high-spin negative parity states in 20Ne

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.     

Static moments of 54Fem and perturbed angular distributions with combined dipole and quadrupole interactions

The static moments of a new I^π = (10⁺) isomer in ⁵⁴Fe (E_x = 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.     

HT20—40铸铁中碳的光电光谱分析

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。     

Viability in dynamic social networks

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.     

Static and dynamic behaviour of nonlocal elastic bar using integral strain-based and peridynamic models

The static and dynamic behaviour of a nonlocal bar of finite length is studied in this paper. The nonlocal integral models considered in this paper are strain-based and relative displacement-based nonlocal models; the latter one is also labelled as a peridynamic model. For infinite media, and for sufficiently smooth displacement fields, both integral nonlocal models can be equivalent, assuming some kernel correspondence rules. For infinite media (or finite media with extended reflection rules), it is also shown that Eringen's differential model can be reformulated into a consistent strain-based integral nonlocal model with exponential kernel, or into a relative displacement-based integral nonlocal model with a modified exponential kernel. A finite bar in uniform tension is considered as a paradigmatic static case. The strain-based nonlocal behaviour of this bar in tension is analyzed for different kernels available in the literature. It is shown that the kernel has to fulfil some normalization and end compatibility conditions in order to preserve the uniform strain field associated with this homogeneous stress state. Such a kernel can be built by combining a local and a nonlocal strain measure with compatible boundary conditions, or by extending the domain outside its finite size while preserving some kinematic compatibility conditions. The same results are shown for the nonlocal peridynamic bar where a homogeneous strain field is also analytically obtained in the elastic bar for consistent compatible kinematic boundary conditions at the vicinity of the end conditions. The results are extended to the vibration of a fixed–fixed finite bar where the natural frequencies are calculated for both the strain-based and the peridynamic models.