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131.
132.
In this paper we consider a nonstationary periodic review dynamic production–inventory model with uncertain production capacity and uncertain demand. The maximum production capacity varies stochastically. It is known that order up-to (or base-stock, critical number) policies are optimal for both finite horizon problems and infinite horizon problems. We obtain upper and lower bounds of the optimal order up-to levels, and show that for an infinite horizon problem the upper and the lower bounds of the optimal order up-to levels for the finite horizon counterparts converge as the planning horizons considered get longer. Furthermore, under mild conditions the differences between the upper and the lower bounds converge exponentially to zero. 相似文献
133.
Karim Kadir Tetsuo Sakai Itsuki Uehara Lars Eriksson 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):999-1000
Yttrium tricopper dialuminium, YCu3Al2, is isostructural with hexagonal CaCu5, in which each Cu atom at the 3g(½,0,½) position in space group P6/mmm (No. 191) is partially replaced by an Al atom. The hydrogen‐uptake properties are usually enhanced in other AB5 structures by aluminium substitution. YCu5 does not show any hydrogen absorption, and the goal of the present work is to investigate whether aluminium substitution could expand the metal‐atom lattice enough to provide better interstitial positions for hydrogen storage. However, no enthalpy change was observed up to 773 K under 3 MPa static H2 pressure by differential thermal analysis (DTA) for the title compound. The compound does not show any significant hydrogen absorption/desorption in the pressure‐composition isotherms (P–C–T diagrams) in the temperature range 298–673 K under 3.3 MPa H2 pressure. 相似文献
134.
In this note we give a simpler proof of Kato's inequality for the Weyl quantized relativistic HamiltonianH
A
m
of a spinless particle with a more singular vector potentialA(x) than in a previous paper of one of the authors.
This article was processed by the author using the Springer-Verlag TEX mamath macro package 1990 相似文献
135.
Jun Hosoi Tetsuo Oikawa Masao Inoue Yoshio Matsui Tadashi Endo 《Journal of Electron Spectroscopy and Related Phenomena》1982,27(3):243-254
An interband π plasmon and π* edge have been observed in the spectrum of hexagonal boron nitride (h-BN). This result is in good agreement with that 相似文献
136.
Neutron scattering measurements have been made of phonons in a Fe65Ni35 crystal at several temperatures. Marked softening of the [110] acoustic shear modes and a dip in the dispersion relation are found at low temperatures. Above the magnetic ordering temperature Tc, the frequency shift is removed completely, which suggests phonon perturbation by magnetoelastic coupling. 相似文献
137.
138.
L-Threonine was transformed, stereospecifically, to a versatile β-lactam (5a) in 3 steps. This β-lactam was further converted to a key intermediate (25) for the synthesis of thienamycin and its biologically active analogues. Furthermore, the compound 5a was changed to iodides (18 and 23), cyanides (19 and 24), chloromethylketone (26) and aldehydes (30 and 31) which appear to have a latent potential as precursors for the syntheses of the carbapenems. 相似文献
139.
140.
Tateaki Wakamiya Keiko Yamanoi Masahiro Nishikawa Tetsuo Shiba 《Tetrahedron letters》1985,26(39):4759-4760
Bulgecinine, a new proline type amino acid in bulgecins, was synthesized stereospecifically by use of D-glucose as a chiral precursor. 相似文献