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排序方式: 共有161条查询结果,搜索用时 15 毫秒
61.
62.
63.
We consider contributions to
c
+
, and
from excited states. The calculations are performed within the MIT-bag model and a heavy quark bag model. Because the mass of
c
+
is rather big compared to the strange baryons, excited baryon states with mass close to that of
c
+
in some cases give significant pole contributions to the decay amplitudes of
c
+
. 相似文献
64.
In this work, photovoltaic performance of Ga-doped ZnO thin film/Si NWs heterojunction diodes was investigated. Highly dense and vertically well-aligned Si NW arrays were successfully synthesised on a p-type (1?0?0)-oriented Si wafer through cost-effective metal-assisted chemical etching technique. Ga-doped ZnO thin films were deposited onto Si NWs via radio frequency magnetron sputtering to construct three-dimensional heterostructures. Photovoltaic characteristics of the fabricated diodes were determined with current density (J)–voltage (V) measurements under simulated solar irradiation of AM 1.5 G. The optimal open-circuit voltage, short-circuit current density, fill factor and power conversion efficiency were found to be 0.37 V, 3.30 mA cm?2, 39.00 and 0.62%, respectively. Moreover, photovoltaic diodes exhibited relatively high external quantum efficiency over the broadband wavelengths between 350 and 1100 nm interval of the spectrum. The observed photovoltaic performance in this study clearly indicates that the investigated device structure composed of Ga-doped ZnO thin film/Si NWs heterojunctions could facilitate an alternative pathway for optoelectronic applications in future, and be a promising alternative candidate for high-performance low-cost new-generation photovoltaic diodes. 相似文献
65.
A systematic study on the synthesis of 8‐aminoquinoline derivatives with an n‐butyl group at each alternate position of the quinoline ring was carried out. Skraup Reaction and its Doebner–von Miller variation were used to obtain most of the quinoline ring except for the 2‐butyl‐8‐aminoquinolines and 4‐butyl‐8‐aminoquinolines where the commercially available methylquinoline derivatives were used as precursors. The structures of the synthesized compounds were characterized by FTIR, 1H‐NMR, COSY, 13C‐NMR and HRMS spectra. 相似文献
66.
Recep Isci Dilara Gunturkun Ahsen Sare Yalin Turan Ozturk 《Journal of polymer science. Part A, Polymer chemistry》2021,59(1):117-123
Two novel copolymers of 4-thieno[3,2-b]thiophen-3-ylbenzonitrile (TT-CN), possessing electron withdrawing cyano moiety, with anthracene (P1) and biphenyl (P2) were prepared via Suzuki coupling. Optic, electronic, and thermal properties of the copolymers were investigated through UV–Vis spectroscopy, cyclic voltammetry, gel permeation chromatography, and thermal gravimetric analysis. The polymers with anthracene and biphenyl had electronic band gaps of 2.01 and 1.90 eV, respectively. Both polymers demonstrated excellent large Stokes shifts of 101 (anthracene) and 105 nm (biphenyl) as well as very good thermal properties. As they had good optical, electronic, and thermal properties, they are promising candidates for electronic applications. 相似文献
67.
Kaba Aziz Aygun Hakan Turan Onder 《Journal of Thermal Analysis and Calorimetry》2022,147(10):5913-5935
Journal of Thermal Analysis and Calorimetry - Aircraft must have reliable and sustainable sources of power systems and must use energy efficiently. Aircraft engine advances have dramatically... 相似文献
68.
69.
R. Turan B. Aslan O. Nur M.Y.A. Yousif M. Willander 《Applied Physics A: Materials Science & Processing》2001,72(5):587-593
We have studied the effect of the strain relaxation on the band-edge alignments in a Pt/p-Si1-xGex Schottky junction with x=0.14 by internal photoemission spectroscopy and current–voltage measurements. We have shown that
the variations in the band-edge alignments can be observed directly by measuring the optical and electrical properties of
a simple Schottky junction. The strain in the Si1-xGex layer has been partially relaxed by thermal treatments at two different temperatures. The degree of relaxation and other
structural changes have been determined by a high-resolution X-ray diffractometer. Both optical and electrical techniques
have shown that the barrier height of the Pt/Si0.86Ge0.14 junction increases with the amount of relaxation in the Si1-xGex layer. This shows that the valence-band edge of the Si1-xGex layer moves away from the Fermi level of the Pt/Si1-xGex junction. The band-edge movement results from the increase in the band gap of the Si1-xGex layer after the strain relaxation. This result agrees with the theoretical predictions for the strain-induced effects on
the Si1-xGex band structure.
Received: 18 October 2000 / Accepted: 19 December 2000 / Published online: 23 March 2001 相似文献
70.
A. Seyhan O. Karabulut B. G. Aknolu B. Aslan R. Turan 《Crystal Research and Technology》2005,40(9):893-895
Optical anisotropy of the layer semiconductor GaSe has been studied by photoluminescence (PL) and Fourier Transform Infrared Spectroscopy (FTIR). The PL spectra are dominated by two closely positioned emission bands resulting from the free exciton and the bound exciton connected direct band edge of GaSe. Photoluminescence and transmission spectra of GaSe crystals have been measured for two cases in which the propagation vector k is perpendicular (k ⟂ c) and parallel to the c‐axis (k // c). Peak position of the PL emission band and the onset of the transmission have been found to be significantly different for these two cases. This observed anisotropy is related to anisotropic band structure and the selection rules for the optical absorption in layered GaSe. FTIR transmission spectrum is in good agreement with PL results. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献