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91.
We show that the numbers of vertices of a given degree k ≥ 1 in several kinds of series‐parallel labeled graphs of size n satisfy a central limit theorem with mean and variance proportional to n, and quadratic exponential tail estimates. We further prove a corresponding theorem for the number of nodes of degree two in labeled planar graphs. The proof method is based on generating functions and singularity analysis. In particular, we need systems of equations for multivariate generating functions and transfer results for singular representations of analytic functions. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2010 相似文献
92.
A self-adaptive global best harmony search algorithm for continuous optimization problems 总被引:3,自引:0,他引:3
This paper presents a self-adaptive global best harmony search (SGHS) algorithm for solving continuous optimization problems. In the proposed SGHS algorithm, a new improvisation scheme is developed so that the good information captured in the current global best solution can be well utilized to generate new harmonies. The harmony memory consideration rate (HMCR) and pitch adjustment rate (PAR) are dynamically adapted by the learning mechanisms proposed. The distance bandwidth (BW) is dynamically adjusted to favor exploration in the early stages and exploitation during the final stages of the search process. Extensive computational simulations and comparisons are carried out by employing a set of 16 benchmark problems from literature. The computational results show that the proposed SGHS algorithm is more effective in finding better solutions than the state-of-the-art harmony search (HS) variants. 相似文献
93.
In this study, we have investigated the effect of the buffer layers on the electronic and optical properties of an exciton (X) and a biexciton (XX) in a type-II CdTe/CdSe quantum dot nanocrystal. In an experimental study, it has been reported that when a CdTe/CdSe quantum dot nanocrystal is coated by a ZnTe material as a buffer layer, the photoluminescence quantum yield is growing from 4 to 20%. We have confirmed theoretically this improvement and extended the calculations to an XX structure. In the calculations, two different semiconductor materials, CdS and ZnTe, have been considered for the buffer layer. We have theoretically shown that the buffer layer causes an increase in the radiative oscillator strength of both X and XX. When the ZnTe is used as the buffer layer, the oscillator strength becomes stronger when compared to CdSe buffer material because of higher conduction band offset between CdSe and ZnTe. 相似文献
94.
Uğur Parlatan Günay Başar Nima Bavili Harika Yumru Fatih Sag Sibel Bulgurcuoglu 《光谱学快报》2013,46(7):458-463
ABSTRACTEmbryo viability quantification is an important topic for in vitro fertilization researchers. This study suggests Raman spectroscopy as a candidate method to find an objective measure of embryo viability. Raman spectra of 31 spent embryo culture samples (16 nonpregnant, 15 pregnant) from 31 patients were analyzed with band component analysis. The band area ratio of 902 to 943 cm?1 was found to be the most discriminatory. These bands are related to glutamine, glycine, proline, aspartic acid, and valine. According to the pregnancy outcome the sensitivity and specificity of Raman analysis were found to be 93% and 77%, respectively. 相似文献
95.
Ion chromatography–inductively coupled plasma-mass spectrometry (IC–ICP-MS) was used for the identification and quantification of chromium species. Chromium(III) and chromium(VI) were separated and determined by IC–ICP-MS. The separation was achieved using an anion exchange column with 0.55?M HNO3 as mobile phase. It was a particular goal of this work to exclusively use nitric acid for elution in order to reduce interferences in the ICP-MS system. Analytical figures of merit were calculated under the optimum conditions by developing calibration plots in a concentration range of 0.50–250?µg/L for both species. The detection limits for Cr(III) and Cr(VI) were 0.09 and 0.03?µg/L, respectively. Spiked recovery tests were used to evaluate the applicability of the analytical method in environmental samples, and the recoveries ranged between 97 and 103% for both analytes. The accuracy of the method for total chromium content was validated through the analysis of a spring water-certified reference material (UME 1201), and the obtained results were in good agreement with the certified value. Lettuce seedlings were cultivated to evaluate the intake levels of these species. In addition, the bioaccessibility of Cr(III) and Cr(VI) from the lettuce seedlings in simulated gastric and intestinal fluids media was examined. 相似文献
96.
Selimefendigil Fatih Oztop Hakan F. Chamkha Ali J. 《Journal of Thermal Analysis and Calorimetry》2019,135(1):325-340
Journal of Thermal Analysis and Calorimetry - In this study, fluid flow and heat transfer in a vertical lid-driven CuO–water nanofluid filled square cavity with a flexible fin attached to its... 相似文献
97.
Control of four-wave mixing phase-matching condition using the Brillouin slow-light effect in fibers
All-optical control of the phase-matching condition in four-wave mixing (FWM) processes is demonstrated using the Brillouin slow-light effect in optical fibers. A counterpropagating stimulated Brillouin scattering (SBS) pump has been used to control the phase velocity of the FWM pump in a wavelength conversion scheme. Both experimental results and theoretical simulations show an SBS-controlled 20 dB difference on the wavelength conversion efficiency. 相似文献
98.
Hong KH Siddiqui A Moses J Gopinath J Hybl J Ilday FO Fan TY Kärtner FX 《Optics letters》2008,33(21):2473-2475
We generate linearly polarized, 287 W average-power, 5.5 ps pulses using a cryogenically cooled Yb:YAG amplifier at a repetition rate of 78 MHz. An optical-to-optical efficiency of 41% is obtained at 700 W pump power. A 6 W, 0.4 nm bandwidth picosecond seed source at 1029 nm wavelength is constructed using a chirped-pulse fiber amplification chain based on chirped volume Bragg gratings. The combination of a fiber amplifier system and a cryogenically cooled Yb:YAG amplifier results in good spatial beam quality at large average power. Low nonlinear phase accumulation as small as 5.1 x 10(-3) rad in the bulk Yb:YAG amplifier supports power scalability to a > 10 kW level without being affected by self-phase modulation. This amplification system is well suited for pumping high-power high-repetition-rate optical parametric chirped-pulse amplifiers. 相似文献
99.
Aidaoui Lakhdar Lasbet Yahia Selimefendigil Fatih 《Journal of Thermal Analysis and Calorimetry》2022,147(10):5865-5882
Journal of Thermal Analysis and Calorimetry - This work aims to characterize the heat exchange system efficiency and entropy generation of nanofluid forced convection flow with chaotic... 相似文献
100.
Omer Lustgarten Raanan Carmieli Leila Motiei David Margulies 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(1):190-194
A method for implementing a secret sharing scheme at the molecular level is presented. By creating molecular code generators that are self‐assembled from several molecular components, we established a means for distributing distinct code‐activating elements among several participants. In this way, an authorization code can only be generated when all the participants are present, which ensures that highly secured systems cannot be operated by unauthorized individuals or disloyal users. Additional layers of protection result from the ability to program the security code by replacing one or several molecular components and by subjecting the system to distinct chemical inputs. 相似文献