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1.
An efficient method for preparation of semiconductor quantum rod films for robust lasing in a cylindrical microcavity is reported. A capillary tube, serving as the laser cavity, is filled with a solution of nanocrystals and irradiated with a series of intense nanosecond laser pulses to produce a nanocrystal film on the capillary surface. The films exhibit intense room‐temperature lasing in whispering‐gallery modes that develop at the film–capillary interface as corroborated from the spacing detected for the lasing modes. Good lasing stability is observed at moderate pump powers. The method was applied successfully to several quantum‐rod samples of various sizes. 相似文献
2.
3.
Arnon Arazi Eshel Ben-Jacob Uri Yechiali 《Mathematical Methods of Operations Research》2005,62(3):453-466
We consider a Jackson-type network comprised of two queues having state-dependent service rates, in which the queue lengths
evolve periodically, exhibiting noisy cycles. To reduce this noise a certain heuristic, utilizing regions in the phase space
in which the system behaves almost deterministically, is applied. Using this heuristic, we show that in order to decrease
the probability of a customers overflow in one of the queues in the network, the server in that same queue – contrary to intuition
– should be shut down for a short period of time. Further noise reduction is obtained if the server in the second queue is
briefly shut down as well, when certain conditions hold. 相似文献
4.
We study property (T) and the fixed-point property for actions on L
p
and other Banach spaces. We show that property (T) holds when L
2 is replaced by L
p
(and even a subspace/quotient of L
p
), and that in fact it is independent of 1≤p<∞. We show that the fixed-point property for L
p
follows from property (T) when 1<p< 2+ε. For simple Lie groups and their lattices, we prove that the fixed-point property for L
p
holds for any 1< p<∞ if and only if the rank is at least two. Finally, we obtain a superrigidity result for actions of irreducible lattices
in products of general groups on superreflexive spaces.
Bader partially supported by ISF grant 100146; Furman partially supported by NSF grants DMS-0094245 and DMS-0604611; Gelander
partially supported by NSF grant DMS-0404557 and BSF grant 2004010; Monod partially supported by FNS (CH) and NSF (US). 相似文献
5.
The analysis in this paper looks at two important elements in modelling the market for timber in the United States. First, the issue of directional causality between price and quantity and its implications in a modelling effort is investigated. Second, the extent of the geographic market for timber is discussed and a method of detecting it is suggested. The method for detecting the extent of the geographical market is tractable and can be applied in a straightforward way. Both considerations are applied to the softwood lumber market in the United States. 相似文献
6.
We obtain the one-loop quantum corrections to the Kählerian and superpotentials in the generic chiral superfield model on the nonanticommutative superspace. Unlike all previous works, we use a method which does not require to rewrite a star-product of superfields in terms of ordinary products. In the Kählerian potential sector the one-loop contributions are analogous to ones in the undeformed theory while in the chiral potential sector the quantum corrections contain a deformation parameter. 相似文献
7.
Uri Golik 《Journal of heterocyclic chemistry》1972,9(1):21-24
Malonimidoacetic acid derivatives (VIII, XIII) were synthesized as a potential penicillin analogs, hut they failed to inhibit the growth of bacteria when tested in vitro against a range of Gram-positive and Gram-negative microorganisms. 相似文献
8.
We describe an algorithm for selecting the n-th largest element (where 0<<1), from a totally ordered set ofn elements, using at most (1+(1+o(1))H())·n comparisons whereH() is the binary entropy function and theo(1) stands for a function that tends to 0 as tends to 0. For small values of this is almost the best possible as there is a lower bound of about (1+H())·n comparisons. The algorithm obtained beats the global 3n upper bound of Schönhage, Paterson and Pippenger for <1/3. 相似文献
9.
Uri Dinur 《Chemical physics letters》1982,93(3):253-259
Asymmetrical vibrations induce small oscillating dipole moments in the ground states of linear all-trans polyenes. Upon vertical excitation into one of the two low-lying valence excited states the induced in-plane dipole moments are increased 3 times and more. The rms dipole moments increase with the chain length. The inducing modes are the CCC skeletal bending and the CC stretching vibrations. CH stretching vibrations are also found to contribute non-negligible polarization. 相似文献
10.
Uri Cohen 《Journal of Electronic Materials》1977,6(6):607-643
Electrodeposition of both epitaxial and polycrystalline continuous films of dense, coherent, and well-adherent silicon coatings
was achieved from molten fluorides. A dissolving Si anode and an operating temperature of about 750 C were utilized. Silicon
electrocrystallization epitaxy (ECE) produced films with the (111) orientation on Si substrates of the same orientation. The
unintentionally doped films were of p-type character with a resistivity in the range 0.05 - 0.10 Ω-cm. Polycrystalline Si
films were similarly electroplated onto various polycrystalline metal substrates. Uniform coherent, and well-adherent coatings
with grain diameters as large as 40 – 50 μm were obtained. The useful rate of electrodeposition of Si could be significantly
increased by the application of an alternating square wave pulse (ASWP)2technique. Cathodic current pulses as high as 300 mA/cm2 (growth rate of about 5 μm/min) were demonstrated. The cathodic current efficiencies, for all modes of growth, were about
70 – 100%. The effects of the various operating parameters, and some prospective applications to the fabrication of solar
cells, are discussed.
This was paper A-6 in the 18th Annual Electronic Materials Conference, Salt Lake City, June 23–25, 1976. 相似文献