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921.
Ezra Einy Ori Haimanko Ram Orzach Aner Sela 《International Journal of Game Theory》2002,30(3):405-419
In a general model of common-value second-price auctions with differential information, we show equivalence between the following
characteristics of a bidder: (i) having a dominant strategy; (ii) possessing superior information; (iii) being immune from
winner's curse. When a dominant strategy exists, it is given by the conditional expectation of the common value with respect
to bidder's information field; if the dominant strategy is used, other bidders cannot make a profit.
Final version November 2001 相似文献
922.
Surface sensitive probe of the morphological and structural aspects of CdSe core-shell nanoparticles
Himani Sharma Shailesh N. Sharma Ram Kishore S.M. Shivaprasad 《Applied Surface Science》2007,253(12):5325-5333
The promising technological applications of colloids of CdSe nanoparticles in solid state devices is hampered due to issues related to their stoichiometry, agglomeration effects and core-shell relationship. Due to the short inelastic mean free path of core-level electrons, X-ray photoelectron spectroscopy is the most reliable method for analysis at the nanometer depth scale, and in conjunction with layer by layer ion beam erosion it can provide valuable information regarding distribution of elements along the depth of the sample. In this work, we address the issue of synthesis of CdSe nanoparticles and probing them by XPS and conventional techniques such as like transmission electron microscopy (TEM) and X-ray diffraction (XRD). Cd/Se input precursor ratio is varied to form colloidal TOP/TOPO capped CdSe nanoparticles. An optimum input precursor ratio is determined where stoichiometric yield, efficiently capped smallest sized (∼5 nm) CdSe nanoparticles with superior optical, structural and morphological properties are obtained. Electron diffraction and deconvolution of XPS-core-levels enables the identification of the different compositional regimes of CdSe nanocrystallites. For non-optimal precursor ratios, the presence of Cd- and Se-related oxides are observed. This multi-technique approach has enabled us to pictorially model the compositional, structural and morphological aspects of TOP/TOPO capped CdSe nanoparticles. 相似文献
923.
José Ramón Salgueiro David Olivieri Humberto Michinel 《Optical and Quantum Electronics》2007,39(3):239-260
In this paper we describe efficient methods to obtain the stationary states of linear and nonlinear photonic systems, which
have gained particular interest in the field of integrated and nonlinear optics. While the methods presented are directly
applicable to optical physics, they are also general and should be of interest in a broad range of phenomena presently under
study in other areas of physics and engineering. The strategy consists in combining the use of classical methods, such as
inverse iteration or the Newton method, together with modern, nonstationary linear solvers, such as SYMMLQ or GMRES, in order
to obtain efficient numerical computations to problems involving large matrices. We have selected several example problems
in order to discuss the practical implementation details, not normally described in the present literature. Moreover, the
problems we have selected provide a backdrop to contrast and motivate the use of different methods for systems which are symmetric
and non-symmetric, single and multi-component, and also real and complex. Information relative to numerical performance of
the different algorithms, including a survey for a nonsymmetric problem, which requires the adjustment of a restarting parameter
for the GMRES algorithm, is also presented. 相似文献
924.
[Chemical reaction: see text] The reactions of a series of urea- and amide-substituted olefins with Grubbs' catalysts are presented. Depending on the substrate's nature, the formation of either cross-metathesis or isomerization products is observed. To favor the cross-metathesis products, the reactions have been carried out using a wide range of experimental conditions. Upon addition of monophenyl phosphoester to these reactions, the isomerization of the olefins is completely suppressed and the cross-metathesis products are obtained in up to 60% yield. 相似文献
925.
Ros-Lis JV Martínez-Máñez R Soto J 《Chemical communications (Cambridge, England)》2005,(42):5260-5262
The use of a subphthalocyanine derivative as a selective chromo-fluorogenic reporter for the anion cyanide in mixed aqueous solutions is reported. 相似文献
926.
Schelter EJ Shatruk M Heintz RA Galán-Mascarós JR Dunbar KR 《Chemical communications (Cambridge, England)》2005,(11):1417-1419
The homoleptic, triphenylborane adduct of the hexacyanochromate anion was structurally characterized and found to be a product in which all six cyanide ligands have undergone isomerization to nitrile groups. 相似文献
927.
Alarcón-Angeles G Corona-Avendaño S Rojas-Hernández A Romero-Romo MA Ramírez-Silva MT 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(1-2):313-319
The time stability of the azomethine-H species was determined not to be better than 10 min in the absence of oxygen and light, however under phosphate buffered conditions the azomethine-H species remained stable for longer periods, as indicated by the spectrophotometric behaviour. Nevertheless, the analysis time still exceeded the stability allowance. Therefore, the determination of the acidity constants of the Azomethine-H species was studied by means of UV-vis spectrophotometry in buffered media by means of the point-by-point analysis and data processing with SQUAD to refine the resulting constants, which were: pK(a1) = 3.39, pK(a2) 7.36 and pK(a3) 8.73. The latter were associated to the corresponding acid-base equilibria of the amine and hydroxy groups constituting the molecule. 相似文献
928.
J.?Rogan R.?Ramírez A.?H.?Romero M.?KiwiEmail author 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2004,28(2):219-228
Collision processes between two gold clusters are investigated using classical molecular dynamics in combination with embedded atom (EA) potentials, after checking the reliability of the EA results by contrasting them with first principles calculations. The Au projectiles considered are both single atoms (N = 1) and clusters of N = 2, 12, 13 and 14 atoms. The targets contain N = 12, 13 and 14 gold atoms. The collision energy E and impact parameter b are chosen within a range such that the three regimes we are interested in studying (fusion, scattering and fragmentation) are realized. The results of the collision processes are described and analyzed in detail, and compared with previous work. 相似文献
929.
The emission spectrum of VCl has been investigated at high resolution in the 3000-19 400 cm−1 region using a Fourier transform spectrometer. The bands were excited in a high temperature carbon tube furnace by the reaction of vanadium metal vapor and a trace of BCl3 as well as in a microwave discharge lamp by the reaction of VOCl3 vapor with active nitrogen. The spectra were recorded using the Fourier transform spectrometer associated with the McMath-Pierce telescope of the National Solar Observatory at Kitt Peak. The analysis of the system of VCl (previously labeled as ) has been extended by analyzing the rotational structure of some additional bands. A rotational analysis of the , , and subbands of the 0-2, 0-1, 0-0, and 1-0 bands, and the subband of the 0-1 and 0-0 bands has been obtained and molecular constants have been extracted. The subband was not identified in any of the assigned bands. The spectroscopic properties of the low-lying electronic states of VCl have been predicted by CASSCF/CMRCI ab initio calculations and the experimental assignments are supported by the ab initio results. 相似文献
930.
Sampedro B Crespo P Hernando A Litrán R Sánchez López JC López Cartes C Fernandez A Ramírez J González Calbet J Vallet M 《Physical review letters》2003,91(23):237203
The onset of ferromagnetism has been experimentally observed in small Pd particles of average diameter 2.4 nm. High-resolution studies reveal that a high percentage of the fcc particle exhibits single and multiple twinning boundaries. The spontaneous magnetization close to 0.02 emu/g seems to indicate that only a small fraction of atoms holds a permanent magnetic moment and contributes to ferromagnetism. The possible origin of ferromagnetism is briefly discussed according to different models recently reported. 相似文献