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It is common to schedule project activities first, then the utilization of equipment and its operating crew is planned based on such schedule. Real world experiences indicate that activity scheduling can be heavily impacted by the resources needed. In particular, if a project requires highly specialized and expensive equipment type, then one needs to take into account the schedule and cost of such resources in developing the project schedule. 相似文献
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It is shown theoretically that ultrashort terahertz electromagnetic pulses can be generated in resonant systems containing a quantum semiconductor superlattice. This effect is due to the compression of radiation incident on a cavity as a result of ultrafast self-modulation of the cavity Q factor upon cyclic switching of the superlattice from the screening to the transparent state in a pump field. 相似文献
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Intense laser waves can form a time-dependent gate, which transmits or reflects particles depending on their initial phases. When faced by a relativistic electron beam, such a barrier slices it by randomly scattering all but some particles, which nearly conserve their velocity. Subfemtosecond or attosecond periodic electron bunches are then formed downstream and can be used, for example, to generate coherent x rays via Thomson backscattering of the laser light. 相似文献
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L. Seetha Lakshmi V Sridharan DV Natarajan V Sankara Sastry T S Radhakrishnan 《Pramana》2002,58(5-6):1019-1026
Mn site is substituted with closed shell ions (Al, Ga, Ti, Zr and a certain combination of Zr and Al) and also with Fe and
Ru ions carrying the magnetic moment (S=5/2 and 2 respectively) at a fixed concentration of 5 at %. Substitution did not change either the crystal symmetry or the
oxygen stoichiometry. All substituents were found to suppress both the metal-insulator and ferromagnetic transition temperatures
(T
p(ρ) and T
C, respectively) to varied extents. Two main contributions identified for the suppression are the lattice disorder arising
due to difference in the ionic radii between the substituent (r
M) and the Mn3+ ion (r
Mn
3+) and in the case of the substituents carrying a magnetic moment, the type of magnetic coupling between the substituent and
that of the neighboring Mn ion. 相似文献
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We show that dynamical localization of electrons in a thin semiconductor superlattice irradiated by a TM electromagnetic wave can lead to the formation of multistable states of the high-frequency field, which is accompanied by significant distortions of the reflection characteristics of superlattices. This effect is caused by the phenomenon of nonlinear plasma resonance and the related significant increase in the component of an alternating electric field, parallel to the superlattice axis, in the case where the real part of the corresponding component of the tensor of nonlinear dielectric permittivity becomes zero. It is found that the generation efficiency of odd harmonics of the radiation increases considerably under resonance conditions. 相似文献
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A Supply Chain (SC) requires undertaking considerable number of activities covering the flow of information and goods among multiple production and distribution cells over several tiers. The successful implementation of a SC hinges on the optimum integration and synchronization of these activities. 相似文献