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81.
S. Sakiroglu U. Yesilgul F. Ungan C.A. Duque E. Kasapoglu H. Sari I. Sokmen 《Journal of luminescence》2012,132(6):1584-1588
We perform theoretical calculations for the band structure of semiconductor superlattice under intense high-frequency laser field. In the frame of the non-perturbative approach, the laser effects are included via laser-dressed potential. Results reveal that an intense laser field creates an additional geometric confinement on the electronic states. Numerical results show that when tuning the strength of the laser field significant changes come in the electronic energy levels and density of states. 相似文献
82.
Ayhan Usta Mehmet Birey Nursen Sari Aliye Altundas Dilek Nartop 《Journal of Physical Organic Chemistry》2012,25(4):309-313
Ethyl 2‐amino‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐3‐carboxylate [C11H15NO2S] was synthesized by the Gewald method. Its single crystals were grown from an alcohol/ethyl acetate solution at 15 °C and characterized using IR and 1H‐NMR. These single crystals were irradiated for 72 h at 298 K by a 60Co gamma source with a dose speed of 0.864 kGy/h. After irradiation, electron spin resonance (ESR) measurements were carried out to study radiation‐induced radicals in the temperature range from 120 to 450 K. Additionally, for the single crystal, ESR angular dependencies were measured in the xy, xz and yz planes of the substance. This irradiated single crystal was analyzed based on the ESR spectra. Analysis of the spectra revealed that the radical was formed by a C–H bond fission at the carbon end of the substance. It was also observed that the color of the sample changed after irradiation. The hyperfine and g parameters were determined from the experimental spectra. It was inferred from these results that the hyperfine parameters and g value exhibited anisotropic behavior. The average values of these parameters were calculated as follows: g = 2.0088, AH1=H2 = 20.70 G, AH3=H4 = 10.80 G, AHa = 4.59 G, AHb = 3.24 G and, AN = 6.10 G. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
83.
We have studied the magnetic field effects on the diamagnetic susceptibility and binding energy of a hydrogenic impurity in a quantum well-wire by taking into account spatially dependent screening. Using the effective-mass approximation within a variational scheme, binding energy and diamagnetic susceptibility of donor are obtained as a function of the magnetic field, length of the square quantum well-wire for different impurity positions. It is shown that the magnetic field effects on diamagnetic susceptibility can be more important for donors in quantum well-wires over a large range of wire dimensions. 相似文献
84.
Nicolas A. Frank Mri Szles Sergi H. Akone Sari Rasheed Stephan Hüttel Simon Frewert Mostafa M. Hamed Jennifer Herrmann Sren M. M. Schuler Anna K. H. Hirsch Rolf Müller 《Molecules (Basel, Switzerland)》2021,26(16)
Myxobacteria represent a viable source of chemically diverse and biologically active secondary metabolites. The myxochelins are a well-studied family of catecholate-type siderophores produced by various myxobacterial strains. Here, we report the discovery, isolation, and structure elucidation of three new myxochelins N1–N3 from the terrestrial myxobacterium Corallococcus sp. MCy9049, featuring an unusual nicotinic acid moiety. Precursor-directed biosynthesis (PDB) experiments and total synthesis were performed in order to confirm structures, improve access to pure compounds for bioactivity testing, and to devise a biosynthesis proposal. The combined evaluation of metabolome and genome data covering myxobacteria supports the notion that the new myxochelin congeners reported here are in fact frequent side products of the known myxochelin A biosynthetic pathway in myxobacteria. 相似文献
85.
Junko Fujimoto Sari Hayashi Hideyuki Kainuma Kazuhiro Manseki Taro Udagawa Hidekazu Miyaji 《化学:亚洲杂志》2019,14(15):2567-2572
Artificial antenna complexes of metal‐coordinated bis(8‐hydroxyquinoline)‐substituted porphyrin networks that mimic antenna chromophores in plants were organized on titanium dioxide electrodes in photoelectrochemical cells. The generated photocurrents can be optimized according to the two ways of porphyrin self‐assembly due to the “antenna effect”: changing the number of assembled porphyrin monolayers and the number of generations of the metal‐coordinated porphyrin networks. 相似文献
86.
Y. Karaaslan B. Gisi S. Sakiroglu E. Kasapoglu H. Sari I. Sokmen 《Physics letters. A》2018,382(7):507-515
We study the influence of electric field on the electronic energy band structure, zero-temperature ballistic conductivity and optical properties of double quantum wire. System described by double-well anharmonic confinement potential is exposed to a perpendicular magnetic field and Rashba and Dresselhaus spin-orbit interactions. Numerical results show up that the combined effects of internal and external agents cause the formation of crossing, anticrossing, camel-back/anomaly structures and the lateral, downward/upward shifts in the energy dispersion. The anomalies in the energy subbands give rise to the oscillation patterns in the ballistic conductance, and the energy shifts bring about the shift in the peak positions of optical absorption coefficients and refractive index changes. 相似文献
87.
88.
Huseyin Sari Esin Kasapoglu Unal Yesilgul Serpil Sakiroglu Fatih Ungan Ismail Sökmen 《The European Physical Journal B - Condensed Matter and Complex Systems》2017,90(9):162
The effect of non-resonant intense laser field on the intersubband-related optical absorption coefficient and refractive index change in the asymmetric n-type double δ-doped GaAs quantum well is theoretically investigated. The confined energy levels and corresponding wave functions of this structure are calculated by solving the Schrödinger equation in the laser-dressed confinement potential within the framework of effective mass approximation. The optical responses are reported as a function of the δ-doped impurities density and the applied non-resonant intense laser field. Additionally, the calculated results also reveal that the non-resonant intense laser field can be used as a way to control the electronic and optical properties of the low dimensional semiconductor nano-structures. 相似文献
89.
90.
Sari Kiviniemi Maija Nissinen Tanja Kolli Jorma Jalonen Kari Rissanen Jouni Pursiainen 《Journal of inclusion phenomena and macrocyclic chemistry》2001,40(1-2):153-159
Crown ether complexes of six-membered N-heteroaromatic cations and the closely related bicyclic purinium cation (6) have been studied by 1H NMR, mass spectrometric and crystallographic methods. The stability constants for the complexes were determined by 1H NMR titration in acetonitrile solution and the complexation stoichiometry by 1H NMR and ESI mass spectrometric methods. Altogether six crystal structures of complexes were determined to study the complexation in the solid state. Hydrogen bonding was observed to be the most important interaction for the complexation both in solution and in the solid state but – interactions also contribute to it. All crystal structures of the DB18C6 complexes with six-membered N-heteroaromatic cations, except for 4-hydroxypyridinium, are isomorphous to previously studied five-membered N-heteroaromatic cations and pyridinium complexes. Such a close resemblance is not observed in B18C6 and 18C6 complexes or DB18C6purinium (6). 相似文献