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521.
522.
Assignment games with stable core 总被引:1,自引:0,他引:1
We prove that the core of an assignment game (a two-sided matching game with transferable utility as introduced by Shapley
and Shubik, 1972) is stable (i.e., it is the unique von Neumann-Morgenstern solution) if and only if there is a matching between
the two types of players such that the corresponding entries in the underlying matrix are all row and column maximums. We
identify other easily verifiable matrix properties and show their equivalence to various known sufficient conditions for core-stability.
By these matrix characterizations we found that on the class of assignment games, largeness of the core, extendability and
exactness of the game are all equivalent conditions, and strictly imply the stability of the core. In turn, convexity and
subconvexity are equivalent, and strictly imply all aformentioned conditions.
Final version: April 1, 2001 相似文献
523.
Arun Singh Chouhan Naga Prathibha Jasti Shreyash Hadke Srinivasan Raghavan Sushobhan Avasthi 《Current Applied Physics》2017,17(10):1335-1340
Spin coated perovskite thin films are known to have an issue of pinholes & poor morphology control which lead to poor device-to-device repeatability, that is an impediment to scale-up. In this work, Methylamine vapor annealing process is demonstrated which consistently leads to high-quality perovskite thin-films with an average grain-size of 10–15 μm. The improvement in film morphology enables improvement in effective carrier recombination lifetime, from 21 μs in as-deposited films to 54 μs in vapor-annealed films. The annealed films with large-grains are also more stable in ambient conditions. Devices made on annealed perovskite films are very consistent, with a standard deviation of only 0.7%. Methylamine vapor annealing process is a promising method of depositing large-grain CH3NH3PbI3 films with high recombination lifetime and the devices with improved performance. 相似文献
524.
Quantum communication with terahertz (THz) frequency signals has many advantages like reduced attenuation and scintillation effects in certain atmospheric conditions along with very high level of data security. In this work, we propose a scheme to realize Quantum Memory (QM) for efficient storage of terahertz (THz) frequency signals using Electromagnetically Induced Transparency (EIT) in an ultracold atomic medium of 87Rb Rydberg atoms prepared in a Two Dimensional Magneto Optical Trap (2D-MOT). The uniqueness of our scheme lies in the choice of the energy levels involved in the EIT process, all three of which have been chosen to be the Rydberg levels (enabling signal beam to be in THz) in a lambda type arrangement. This first of its kind proposal reveals that atomic media are a potential candidate for devising QMs which can store THz frequency signals. We have estimated that the Optical Depth (OD) in our scheme can reach a very high value of 690, very high maximum obtainable storage efficiency (η) of ~99%, the group velocity () can be as low as 5.07 × 103 m/s, and the Delay Bandwidth Product (DBP) can be as high as 9.5. All of these estimates emphasize the feasibility of our scheme as a QM device for efficient storage of THz pulses. 相似文献
525.
A convergent synthesis of bullatanocin is envisaged by the union of C18–C34, C3–C17 and the butenolide subunits. The synthesis of the C3–C17 and C18–C34 subunits is disclosed that takes advantage of the chirality of tartaric acid for 1,2-asymmetric induction, chloro sulfides for carbon chain elongation and [2,3] sigmatropic shift for the preparation of 1,4-diol moiety via efficient 1,3-chirality transfer. The THF ring is elaborated by intramolecular displacement. 相似文献
526.
Analysis of carcinogenic substances is a high-priority area. Carcinogenic arylamines draw the analyst's attention because dyes and pigments are in production and used in large volumes. Identification of carcinogenic isomers of arylamines employing micellar electrokinetic chromatography (MEKC), a mode of capillary electrophoresis was studied as it offers better scope for separation science. Mixed micellar modes of MEKC techniques were employed to achieve acceptable analyses. Success of this analytical method was proved by real-sample analysis, which confirmed that this is a promising technique for the arylamine species. 相似文献
527.
528.
Raghavan Narasimhan 《Mathematische Annalen》1962,146(3):195-216
529.
The breakdown into turbulent spots is the least understood stage of the laminar-turbulent transition process. With cellular-automaton stochastic simulations and stability analysis, we show that the pattern of breakdown in boundary-layer flow bears a connection to laminar instability and may be reconstructed using macroscopic properties of the transition zone, such as persistence times and transitional intermittency. We propose experimental tests of our ideas. 相似文献
530.
Sivaguru J Sunoj RB Wada T Origane Y Inoue Y Ramamurthy V 《The Journal of organic chemistry》2004,69(17):5528-5536
Photochemistry of optically pure trans-2,3-diphenyl-1-benzoylcyclopropane has been examined in isotropic solution and within zeolites. Results suggest that it isomerizes by cleavage of either the C1-C2 or C1-C3 bond. From the perspective of chiral induction, photoisomerization of cis-2,3-diphenyl-1-benzoylcyclopropane derivatives with chiral auxiliaries placed at the meta and para positions of the benzoyl group have been examined both in isotropic solution and within zeolites. Whereas in isotropic solution the chiral auxiliaries placed at the meta position exhibit very little influence during the conversion of triplet cis-2,3-diphenyl-1-benzoylcyclopropane derivatives, they have significant influence within zeolites. For example, alpha-methyl benzylamine placed at the meta position of the benzoyl group (via an amide bond) yields the trans isomer with a diastereoselectivity (de) of 71% within NaY zeolite, whereas in solution no de is obtained. The chiral induction process within zeolites depends on the nature of the alkali ion and on the presence of water. Results suggest that the chiral auxiliary is able to control the bond being cleaved (C1-C2 vs. C1-C3 bond) within a zeolite, but it is unable to do so in an isotropic solution. 相似文献