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31.
In this study, large-solid-core photonic crystal fibers with fixed air-hole diameter d = 0.84 μm and with fixed pitch length Λ = 4.2 μm are investigated for different d/Λ ratios. The dispersions and the effective mode-areas are obtained and compared for both the structures. It is seen that the dispersion management is easier by using the fixed d structures, but for working around the same zero dispersion points in a large interval of d/Λ the fixed Λ structures are more available. The Aeff values larger than 100 μm2 are obtained with d/Λ smaller than 0.2 for both the two structures. Aeff increases rapidly with decreasing d/Λ to 0.1 and then reaches to Aeff value of 500 μm2 at the d/Λ = 0.1 for the fixed d structures. The single-mode regime for the two structures is also discussed. 相似文献
32.
Lamia Boubakri Khaireddine Dridi Abdullah Sulaiman Al-Ayed İsmail Özdemir Sedat Yasar 《Journal of Coordination Chemistry》2019,72(3):516-527
New palladium complexes were efficiently synthesized from the reaction of benzimidazolium salts 2a–e, potassium carbonate (K2CO3) and palladium chloride (PdCl2) in pyridine (for 3a–e). The catalytic activity of these complexes in a catalytic system including palladium complexes and K2CO3 in DMF-H2O was evaluated in Suzuki–Miyaura cross-coupling reactions of aryl bromides and chlorides with phenylboronic acid. Our novel complexes show excellent catalytic activities with high turnover numbers (TON) and high turnover frequencies (TOF) (e.g. for the Suzuki–Miyaura reaction: TON up to 370 and TOF up to 123.3?h?1). Both benzimidazolium salts 2a–e and complexes 3 have been characterized using spectroscopic data and elemental analysis. The antimicrobial activity of the N-heterocyclic carbene palladium complexes 3a–e varies with the nature of the ligands. Also, the IC50 values of both, complexes (3a–e) and benzimidazoles 2a–e, have been determined. In addition, the new palladium complexes were screened for their antitumor activity. Complexes 3e and 3d exhibited the highest antitumor effect with IC50 values 6.85?μg/mL against MCF-7 and 10.75?μg/mL against T47D, respectively. 相似文献
33.
Arif Sanli Ozlem Celebi Mehmet Eken Alev Oktay Sedat Aydin Emin Ayduran 《Journal of voice》2008,22(2):238-244
SUMMARY: Visualization of enlarged laryngeal lesions is the most important factor in choosing a surgical technique, especially for partial surgery. For this reason standard microlaryngoscopy, a computed tomography (CT) scan of the larynx, and 30 degrees telescopic microlaryngoscopy were compared during evaluation of the laryngeal ventricul and sub-glottic area. The histopatholgoical findings of the specimens collected under each modality were simultaneously compared. Comparison of the histopathological findings, which corresponded to inspection with the 30 degrees telescopic method, was more significant than with the use of standard microlaryngoscopy or the CT scan. The aim of the current study therefore was to determine the importance of the 30 degrees telescopic microlaryngoscopic method for the evaluation of the laryngeal ventricle and subglottic area. 相似文献
34.
Christopher P. Falshaw Trevor J. King Sedat Imre Sezen Islimyeli Ronald H. Thomson 《Tetrahedron letters》1980,21(51):4951-4954
Laurenyne, a new chloroacetylene from the red form of the alga Laurencia obtusa has been identified and its crystal structure determined. 相似文献
35.
A very simple pathway for the preparation of amphiphilic analogues of natural bioactive peptidoamines such as carnosine (β-alanylhistidine) or carcinine (β-alanylhistamine), is presented. The strategy makes it possible to synthesise original bialkylchain or trialkylchain perfluorinated surfactants with or without perhydrogenated chains. 相似文献
36.
Two‐center overlap integrals over Slater type orbitals (STOs) have been expressed in terms of the well‐known Mulliken's integrals Bn(pt) using Rodrigues's formula for normalized associated Legendre functions. A computer program is written in Mathematica 4.0 for the evaluation of two‐center overlap integrals over STOs. Using this computer program, symbolic tables are presented for two‐center overlap integrals up to quantum numbers 1 ≤ n,n′ ≤ 3, 0 ≤ l,l′ ≤ 2, ?2 ≤ m,m′ ≤ 2. Numerical results of this work, for some quantum sets, have also been compared with prior literature and best agreement achieved with recent works of Barnett while some discrepancies were obtained with works of Öztekin et al. and Guseinov et al. 相似文献
37.
The temperature dependence of the saturated signal power for the 4I13/2 → 4I15/2 transition in erbium-doped fiber amplifiers (EDFAs) pumped at 980 nm and 1480 nm pumping wavelengths within a temperature range from −20 to 60°C are investigated by a novel approach. This approach is based on the temperature dependence of the saturated signal power. The influence of pump excited-state absorption (ESA) is inserted into the rate equations so as to investigate a generally situation. For 1480 nm pumping regime, it is seen that the saturated signal power increases more quickly than that of 980 nm pumping regime, with the increasing temperature. The variation in the saturated signal power with temperature is nearly constant at 980 nm pumping regime. In addition, the population inversion with respect to the increasing normalized signal power is examined and it is seen that it is independent temperature for 980 nm but it strongly depends on temperature for 1480 nm especially at lower normalized signal powers. 相似文献
38.
A series of novel quasi‐scorpionate CNC donor ligands, MeC(2‐C5H4N){CH2(imidazole‐R)} (R = methyl, n‐butyl, n‐propenyl), in which a chelating bis(NHC) core is supplemented by a hemi‐labile pyridyl donor, were prepared. The coordination chemistry of these ligands was investigated with silver, palladium, rhodium and iridium. The single crystal X‐ray structures of [Rh(NC2Me)(COD)]Cl 8a and [Ir(NC2Pr)(COD)]Br 9b were determined. The catalytic potential of the rhodium and iridium complexes was assessed in the transfer hydrogenation of ketones; the iridium complexes, which show superior performance, form very effective and stable catalysts. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
39.
I. Sedat Gunes Feina Cao Sadhan C. Jana 《Journal of Polymer Science.Polymer Physics》2008,46(14):1437-1449
The effects of thermal expansion on shape memory performance of shape memory polyurethanes and their nanocomposites with organoclay, carbon nanofiber (CNF), silicon carbide (SiC), and carbon black (CB) were evaluated. The shape memory test cycle involved tensile deformation at above the trigger temperature to initiate shape memory function, cooling to room temperature to fix the shape, and shape recovery induced by heating to above the trigger temperature. Phenomenological models were used to interpret the experimental data on coefficient of thermal expansion (CTE). It was found that Kerner model showed good fit for composites of SiC and CB, and Halpin model gave better fit for composites of organoclay and CNF. It was observed that thermal expansion exerts negative effect on recovered strain, the extent of which depends on the magnitude of temperature gradient, CTE, and the level of tensile strain. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1437–1449, 2008 相似文献
40.
A new series of bis‐N‐heterocyclic carbene precursors, LHX ( 3a–d ), have been synthesized and characterized by appropriate spectroscopic techniques and microanalyses. In situ prepared Pd(OAc)2/bis‐N‐heterocyclic carbene precursors catalysts have catalyzed unactivated aryl chlorides on the Suzuki cross‐coupling reaction under mild reaction conditions in aqueous media. 相似文献