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521.
We experimentally demonstrate the direct measurement of net group and reshaping delays for arbitrary optical pulses in dispersive media, verifying the earlier prediction of Peatross et al. [Phys. Rev. Lett. 84, 2370 (2000)]. Incoherent pulse propagation in an absorptionless system is well described by net group delay; even the medium causes a great deal of deformation in the transmitted pulse. However, in the case of phase modulated chirping pulses in a resonant absorber, the so-called superluminal or subluminal propagation velocity is strongly influenced by the reshaping delay. 相似文献
522.
A. Z. M. Shaifullah Chowdhury Yasuyuki Shibata Masatoshi Morita Kunimitsu Kaya Kazuhisa Hiratani 《Journal of heterocyclic chemistry》2001,38(5):1173-1177
Reaction of 2-aminopyrazine 1 with isothiocyanate, isocyanate or dithioketal reagent furnished pteridines 3,4 in good yield. Thioxo compound 3a was chlorinated, methylated and subsequently displaced by amines. A simple one-step synthesis of heterocondensed pteridines 8–13 by reaction of 2-aminopyrazine with various imino thioacetals was described 8–13 . 相似文献
523.
J.-L. Lu S. Kaya T.K. Todorova J. Sauer S. Shaikhutdinov H.-J. Freund 《Surface science》2006,600(13):L164
We have observed formation of one-dimensional silica structures of 0.5 nm in width on Mo(1 1 2) single crystal surface. Combination of high-resolution scanning tunneling microscopy, photoelectron and infrared spectroscopy, and density functional theory provides strong evidence for formation of paired rows of corner sharing [SiO4] tetrahedra chemisorbed on a metal substrate. 相似文献
524.
Kiyoshi Kikukawa Takatoshi Totoki Fumio Wada Tsutomu Matsuda 《Journal of organometallic chemistry》1984,270(3):283-287
Arenediazonium tetrafluoroborates (ArN2BF4 where Ar = X-C6H4; X = H, 2-Me, 3-Me, 4-Me, 4-MeO, 4-MeCO, 4-EtOCO, 2-Ph, 2-Cl, 3-Cl, 4-Cl, 4-Br, 4-I, 3-NO2 and 4-NO2) were easily converted to aromatic aldehydes (ArCHO) in good yields through the palladium-catalyzed reaction with CO and Et3SiH or polymethylhydrosiloxane (PMHS) at room temperature. 相似文献
525.
The S1← So electronic transitions of toluene involving also some internal rotational levels were observed for the first time in the multiphoton ionization spectrum in a supersonic jet. A large population in several low-lying internal rotational levels and a strong coupling between electronic motion and the internal rotation are suggested. 相似文献
526.
Central European Journal of Operations Research - Production capacity decision under random demand is an important factor that significantly effects supply chain profits. It is realized in... 相似文献
527.
Mehmet Baha Karan Aydın Ulucan Mustafa Kaya 《Central European Journal of Operations Research》2013,21(2):479-494
Our paper presents a comparative study applying logistic regression and multiple criteria decision analysis tools to the operations of wholesalers to assess the credit risk of their retailers using payment history data and to cluster the risky customers by ranking their risk levels. Our sample comprises approximately 6,000 retailer customers and 600.000 transactions of one of the major wholesalers of Turkey. Our findings emphasize the importance of using payment history and some non-financial factors data for predicting the creditworthiness of a firm. 相似文献
528.
In this study, laminar boundary layer flow over a flat plate embedded in a fluid-saturated porous medium in the presence of
viscous dissipation, inertia effect and suction/injection is analyzed using the Keller box finite difference method. The flat
plate is assumed to be held at constant temperature. The non-Darcian effects of convection, boundary and inertia are considered.
Results for the local heat transfer parameter and the local skin friction parameter as well as the velocity and temperature
profiles are presented for various values of the governing parameters. The non-Darcian effects are shown to decrease the velocity
and to increase the temperature. It is also shown that the local heat transfer parameter and the local skin friction parameter
increase due to suction of fluid while injection reverses this trend. It is disclosed that the effect of the viscous dissipation
for negative values of Ec (T
w
< T
∞) is to enhance the heat transfer coefficient while the opposite is true for positive values of Ec (T
w
> T
∞). The results are compared with those available in the existing literature and an excellent agreement is obtained. 相似文献
529.
S. Nonose Y. Sone K. Kaya 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1991,19(4):357-359
Using two independent vaporization lasers, bimetallic clusters composed of transition elements and A1 were generated by the laser vaporization method. Reactivity toward hydrogen adsorption of bimetallic clusters was compared with genuine clusters. It was found that A1 which has no reactivity toward hydrogen plays a role of either inhibitor or accelerator of the reaction when A1 is mixed with Nb or Co. Unusual stability of Co12 V1 in contrast to the high reactivity of Co12–13 is attributed to the rigid geometric structure where V occupies the central position. 相似文献
530.
Nahid Banihashemi C. Yalçın Kaya 《Journal of Optimization Theory and Applications》2013,156(3):726-760
The Inexact Restoration method for Euler discretization of state and control constrained optimal control problems is studied. Convergence of the discretized (finite-dimensional optimization) problem to an approximate solution using the Inexact Restoration method and convergence of the approximate solution to a continuous-time solution of the original problem are established. It is proved that a sufficient condition for convergence of the Inexact Restoration method is guaranteed to hold for the constrained optimal control problem. Numerical experiments employing the modelling language AMPL and optimization software Ipopt are carried out to illustrate the robustness of the Inexact Restoration method by means of two computationally challenging optimal control problems, one involving a container crane and the other a free-flying robot. The experiments interestingly demonstrate that one might be better-off using Ipopt as part of the Inexact Restoration method (in its subproblems) rather than using Ipopt directly on its own. 相似文献