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31.
A distributed environment that supports multimedia interfaces, Shastra strengthens collaboration in scientific and engineering design. Implemented on a desktop system, it provides an infrastructure for user- and application-level cooperation. We describe the Shastra architecture and tools, then walk through a scenario that shows how it enhances collaborative problem solving 相似文献
32.
Single crystals of EuB6 were prepared by the floating-zone method. Magnetic and electric measurements on these crystals in the temperature range 1.6–300 K revealed that the pure EuB6 is an antiferromagnet with a Néel temperature of 5–6 K and has a carrier concentration of 4.2 × 1020 cm-3. It was found that in polycrystalline sample, defects of Eu ions reduce the carrier concentration and make the sample ferromagnetic. It is suggested that the conduction electrons in pure EuB6 originate from the overlap of the 4f band tail and the conduction band. 相似文献
33.
Chanderjit Bajaj 《Discrete and Computational Geometry》1988,3(1):177-191
In this paper we apply Galois methods to certain fundamentalgeometric optimization problems whose exact computational complexity has been an open problem for a long time. In particular we show that the classic Weber problem, along with theline-restricted Weber problem and itsthree-dimensional version are in general not solvable by radicals over the field of rationals. One direct consequence of these results is that for these geometric optimization problems there existsno exact algorithm under models of computation where the root of an algebraic equation is obtained using arithmetic operations and the extraction ofkth roots. This leaves only numerical or symbolic approximations to the solutions, where the complexity of the approximations is shown to be primarily a function of the algebraic degree of the optimum solution point. 相似文献
34.
Il Nuovo Cimento D - We have calculated the binding energies of excitons in quantum well structures based on ionic semiconductors by including the electron-hole interactions with the... 相似文献
35.
A general analysis of the renormalisation corrections to the unification results for the coupling constants of strong and electroweak interactions is attempted. In particular, the effects of introducing an energy scale intermediate between the unification energy and the low-energy regions are studied and found to be important. This analysis is applied to unification schemes of both kinds, namely, unification at superhigh energies, and unification at accessible energies. 相似文献
36.
D. B. Parihar Om Prakash Indira Bajaj R. P. Tripathi K. K. Verma 《Mikrochimica acta》1971,59(3):393-398
Summary High explosives having the sameR
f
values on a thin-layer chromatogram and difficult to separate are readily resolved as their coloured -complexes with aromatic amines. After liberation from their complexes on the plate, up to 1.5 g of the explosives can be conveniently estimated at their characteristic absorption maxima.
Zusammenfassung Hochexplosive Substanzen mit gleichenR f -Werten auf Dünnschichtchromatogrammen, die sich schlecht trennen lassen, werden als gefärbte -Komplexe mit aromatischen Aminen gut voneinander getrennt. Nach Freisetzung aus den Komplexen auf der Platte können bis zu 1,5 g der Explosivstoffe bei ihrem charakteristischen Absorptionsmaximum auf übliche Weise bestimmt werden.相似文献
37.
R. J. Almassy D. C. Reynolds C. W. Litton K. K. Bajaj D. C. Look 《Journal of Electronic Materials》1978,7(2):263-277
Magneto-optical analysis of prominent photoluminescence lines from GaAs FET structures has been performed. Fifteen samples
were investigated. Each consisted of a sulfur doped active layer on a high resistivity buffer layer (both epitaxially grown
films) on a chromium doped GaAs substrate. The active layers were generally 2μm thick or less, except for two thicker layers
(4 and 5μm) grown especially for this study. Buffer layer thicknesses ranged from 1.5 to 26μm. A model based on carrier diffusion
through the active layer has been used to interpret the spectra as originating from the active-buffer interface region. All
spectra contain strong-evidence of two donorbound exciton complexes associated with sulfur (1.51417eV) and silicon (1.51412eV).
Other sharp spectral features included up to six lines associated with more complicated complexes. Linear Zeeman and quadratic
diamagnetic behavior of the lines in applied magnetic fields are discussed.
Supported under AF Contract F33615-77-C-5003
Supported under AF Contract F33615-76-C-1207 相似文献
38.
Wave propagation in a rarefied two-component plasma immersed in a uniform constant magnetic field has been discussed wherein the plasma pressure is assumed to be anisotropic owing to finite Larmor radius effect. It is shown that, for propagation along the external magnetic field, there exist two modes of wave propagation, namely, the gravitational mode and the hydromagnetic mode. The former is found to be independent of the magnetic field and hence of the Larmor radius, while the latter is appreciably influenced by the finite Larmor radius. On the other hand, for transverse propagation, there are three modes of wave propagation viz. the ion-sound mode, the electron-sound mode and the electromagnetic mode. It is shown that only the lowfrequency ion-sound mode is affected by the finite Larmor radius. 相似文献
39.
D.C. Reynolds K.K. Bajaj G. Peters C. Leak W.M. Theis P.W. Yu H. Morkoc K. Alavi C. Colvard I. Shidlovsky 《Superlattices and Microstructures》1988,4(6)
Sharp-line structure associated with both the light-hole free exciton (LHFE) and heavy-hole free exciton (HHFE) transitions has been observed in multi-quantum-well (MQW) structures of four well sizes in photoluminescence (PL) and reflection spectra. These spectra have been deconvulated using photoluminescence excitation spectroscopy (PLE). The LHFE and HHFE sharp-line structure is associated with interface structure composed of growth islands at the interface between the barriers and the wells. Estimates of the average interface island sizes for the four different MQW structures are made based on theoretical modelling. A correlation is established between particular LHFE fine structure components and specific HHFE fine structure components. A model is developed to account for the LHFE and HHFE fine structure based on a non-random distribution of the interface structure. The physical location of the excitons is demonstrated to be in regions of the wells with essentially identical interfacial microstructure. Evidence for diffusion of excitons from effectively narrow well regions to wider well regions is presented. 相似文献
40.
Ashok G. Bajaj Sukh Dev Edward Arnold Bruce Tagle Jon Clardy 《Tetrahedron letters》1981,22(46):4623-4626
The steroechemistry of guggulsterol-1, a component of the exudate of , is shown to be 20(R), 22(R)(). 相似文献