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981.
982.
V. G. Baklykov V. N. Charushin O. N. Chupakhin V. N. Drozd 《Chemistry of Heterocyclic Compounds》1987,23(4):465-469
Thiobenzhydrazides undergo cyclization with N-alkyl-quinoxalinium salts to give 5-alkyl-substituted 1,4,4a,5,10,10a-hexahydro-1,3,4-thiadiazino[5,6-b]quinoxalines, which undergo isomerization to 10-alkyl-substituted thiadiazinoquinoxalines when they are heated in ethanol or in the presence of acids.See [1] for Communication 20.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 557–561, April, 1987. 相似文献
983.
984.
985.
986.
In this paper, an adaptive FE analysis is presented based on error estimation, adaptive mesh refinement and data transfer for enriched plasticity continua in the modelling of strain localization. As the classical continuum models suffer from pathological mesh-dependence in the strain softening models, the governing equations are regularized by adding rotational degrees-of-freedom to the conventional degrees-of-freedom. Adaptive strategy using element elongation is applied to compute the distribution of required element size using the estimated error distribution. Once a new mesh is generated, state variables and history-dependent variables are mapped from the old finite element mesh to the new one. In order to transfer the history-dependent variables from the old to new mesh, the values of internal variables available at Gauss point are first projected at nodes of old mesh, then the values of the old nodes are transferred to the nodes of new mesh and finally, the values at Gauss points of new elements are determined with respect to nodal values of the new mesh. Finally, the efficiency of the proposed model and computational algorithms is demonstrated by several numerical examples. 相似文献
987.
Agrachev A. A. Gamkrelidze R. V. 《Proceedings of the Steklov Institute of Mathematics》2006,253(1):S4-S12
Proceedings of the Steklov Institute of Mathematics - 相似文献
988.
In this note we study uncertainty sequencing situations, i.e., one-machine sequencing situations in which no initial order
is specified. We associate cooperative games with these sequencing situations, study their core, and provide links with the
classic sequencing games introduced by Curiel et al. (Eur J Oper Res 40:344–351, 1989). Moreover, we propose and characterize
two simple cost allocation rules for uncertainty sequencing situations with equal processing times. 相似文献
989.
V. N. Sorokoumov S. N. Morozkina I. A. Balova 《Chemistry of Heterocyclic Compounds》2006,42(5):615-624
An investigation of the reaction of 1-lithio-1,3-diynes, generated in situ, with nitriles has been carried out. In the case
of aromatic nitriles 1-arylalk-1-ene-3,5-diynylamines are formed, which undergo dimerization and cyclization on isolation,
giving 3-(alka-1,3-diynyl)-4-(alk-2-ynyl)-2,6-diarylpyridines. The effect of the nature of the substituent in the benzonitrile
molecule on the selectivity of the reaction and the yield of the products has been determined. A scheme is proposed for the
conversions and the structures of the intermediates have been established.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 701–710, May, 2006. 相似文献
990.
C.E. Allmond V.P. Oleshko J.M. Howe J.M. Fitz-Gerald 《Applied Physics A: Materials Science & Processing》2006,82(4):675-678
Nanostructured powders have shown great promise for a variety of applications including chemical gas sensors, high surface
area supports for catalysis, tribology, chemical mechanical polishing, and optoelectronics. In this report, highly dispersed
Pd nanoparticles with a narrow size distribution, and mean diameter of 2±0.2 nm, were deposited at room temperature onto amorphous
carbon and oxide supports (TiO2, Al2O3) by pulsed-laser ablation of a Pd sputtering target. Depositions were performed in Ar at a back-fill pressure of 3 mTorr
after reaching a base pressure of 10-7 Torr. Populations of uniformly dispersed particles with an interparticle spacing of 3 to 10 nm were observed by high-resolution
transmission electron microscopy with little evidence of nanoparticle aggregation. The chemical compositions of individual
nanoparticles were confirmed by high spatial resolution energy-dispersive X-ray spectroscopy. 相似文献