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61.
The DNA base thymine is deposited at 100?K on Cu(111) and investigated and manipulated by low-temperature scanning tunneling microscopy at 5?K. At submonolayer coverage paired rows are observed. At monolayer coverage a hexagonal commensurate self-assembled layer with the methyl group pointing away from the surface forms. A reversible local manipulation of molecules within the self-assembled layer is demonstrated. This manipulation is interpreted as an out-of-plane relaxation of molecules within the layer induced by the change of the adsorption geometry of individual molecules between two meta-stable orientations. A positive field of 2-4?V leads to this local change in the molecular arrangement, while a field larger than 4?V restores the original geometry. 相似文献
62.
Fatih Bayazit 《Positivity》2012,16(4):653-684
We study nonautonomous linear difference equations via the corresponding abstract Cauchy problem. The domains of the associated operators are time dependent and do not contain a common core, so we have to prove wellposedness by a direct approach. In the periodic case we then investigate the asymptotics (in different topologies) of the corresponding evolution families using the Perron?CFrobenius theory for positive matrices combined with spectral decomposition methods. Finally, we show how flows in time-dependent networks can be treated within this framework. 相似文献
63.
Fatih Ecevit 《PAMM》2007,7(1):1022701-1022702
We have recently uncovered the convergence characteristics of multiple scattering iterations for “two-dimensional” as well as “three-dimensional scalar (acoustics)” scattering models in the high-frequency regime. As we have demonstrated, a most distinctive property of these latermodels, compared to their two-dimensional counterparts, is the dependence of corresponding asymptotic expansions on the relative angle of rotation between the principal axes of the successive reflection points of the optical rays. Concerning the case of fully “three-dimensional vector (electromagnetic)” scattering problems, here we show that the vectorial nature of the problem, in turn, gives rise to new additional complex structure. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
64.
Muhammet Yürüsoy Hüseyin Bayrakçeken Mehmet Kapucu Fatih Aksoy 《International Journal of Non》2008,43(7):588-599
The steady-state flow of a third grade fluid between concentric circular cylinders is considered and entropy generation due to fluid friction and heat transfer in the annular pipe is examined. Depending upon the fluid viscosity, entropy generation in the flow system varies. The third grade fluid is employed to account for the non-Newtonian effect while Vogel model is accommodated for temperature-dependent viscosity. The analysis is based on perturbation technique. The closed form solutions for velocity, temperature and entropy fields are presented. Entropy generation due to fluid friction and heat transfer in the flow system is formulated. The influence of viscosity parameters A and B on the entropy generation number is investigated. It is found that entropy generation number reduces with increasing viscosity parameter A, which is more pronounced in the region close to the annular pipe inner wall and opposite is true for increasing viscosity parameter B. 相似文献
65.
Bilici Sevim Külahcı Fatih Bilici Ahmet 《Journal of Radioanalytical and Nuclear Chemistry》2019,322(2):431-454
Journal of Radioanalytical and Nuclear Chemistry - Determination of radionuclides transport characteristics is among the most significant research topics, which require extensive multidisciplinary... 相似文献
66.
Ilknur Babahan Ali Özmen Mehran Aksel Mehmet Dincer Bilgin Rukiye Gumusada Muhammet Emin Gunay Fatih Eyduran 《应用有机金属化学》2020,34(7):e5632
In this study, a novel bidentate ligand containing oxime, hydrazone, and indole moieties and its BF2+-bridged transition metal complexes [Ni(II), Cu(II), and Co(II)] were synthesized and their cytotoxic activities against prostate and breast cancer cells were investigated. The vic-dioxime ligand bearing indole–hydrazone side groups was synthesized by reacting antiglyoximehydrazine (GH2) with 3-methoxy indole. The ligand forms mononuclear complexes with a metal-to-ligand ratio of 1:2 with M = Co(II)(H2O)2, Ni(II), and Cu(II). These metal complexes were then reacted with BF3(C2H5)2O to obtain BF2+-bridged transition metal complexes. The Co(II) complex of the ligand is proposed to be octahedral with water molecules as axial ligands, whereas the Ni(II) and Cu(II) complexes are proposed to be square planar. Spectral studies showed that the ligand bonded to the metal ion in a neutral bidentate fashion through the azomethine nitrogen atom and the imine oxime group. Structural assignments are supported by a combination of 1H nuclear magnetic resonance (NMR), 13C NMR, Fourier-transform infrared, LC/MS, elemental analyses, and magnetic susceptibility testing. For determining the cytotoxic effects of the novel anticancer products, cancer cells were cultured. The antiproliferative effects were determined using the MCF-7 breast cancer and PC-3 prostate cancer cell lines. The antiproliferative effects of the products were analyzed and their apoptotic or necrotic effects were determined with the Hoechst/propidium iodide double staining method in both cancer cell lines. Paclitaxel was used as the positive control (1 μm ). The results indicated that the newly synthesized compounds are effective on both cell lines between concentrations of 5 and 40 μm and show their effects by apoptotic mechanisms. Besides, these products were found to be more effective on the MCF-7 cell line. The cytotoxic efficiency of the newly synthesized products was more than that of paclitaxel (depending on concentration), which is a chemotherapeutic agent used in cancer therapy. 相似文献
67.
Selimefendigil Fatih Öztop Hakan F. 《Journal of Thermal Analysis and Calorimetry》2021,143(2):1485-1501
Journal of Thermal Analysis and Calorimetry - Forced convection of hybrid Ag–MgO/water nanofluid in a three-dimensional T-shaped vented cavity with multiple ports under the effects of a inner... 相似文献
68.
Selimefendigil Fatih Oztop Hakan F. Abu-Hamdeh Nidal H. 《Journal of Thermal Analysis and Calorimetry》2019,135(1):341-355
Journal of Thermal Analysis and Calorimetry - Analysis of mixed convection due to a rotating inner cylinder in a corrugated three-dimensional cavity filled with carbon nanotube-water nanofluid was... 相似文献
69.
Let F be an arbitrary family of subsets of U and f be a mapping: F→{0,1}, how can we tell whether fz=f for some subset Z of U and how can we construct this Z (or the equivalence class of such Zs)? Here fz:?T∈F,(?).This problem was recognized by D. G. Kendall and the largest element of such Z' s had been established at the same time. In this paper, we shall obtain a class of the minimums and a complete consequence of such Z's by means of F-atom, contacta-bility and relation equation. 相似文献
70.
Ihor Pavlov Andrey Rybak Andrii Dobrovolskiy Viktor Kadan Ivan Blonskiy Fatih Ö. Ilday 《Liquid crystals》2018,45(9):1265-1271
It is well known that the alignment of liquid crystals (LCs) can be realised by rubbing or photoalignment technologies. Recently, nonlinear laser lithography (NLL) was introduced as a fast, relatively low-cost method for large area nano-grating fabrication based on laser-induced periodic surface structuring. In this letter for the first time, the usage of the NLL as a perspective method of the alignment of nematics was presented. By NLL, nanogrooves with about 0.92 μm period were formed on Ti layer. The nanostructured Ti layer (NSTL) was coated with oxidianiline-polyimide film with annealing of the polymer followed without any further processing. Aligning properties of NSTLs were examined with combined twist LC cell. The dependencies of the twist angle of LC cells and azimuthal anchoring energy (AE) of layers on scanning speed and power of laser beam during processing of the Ti layer were the focus of our studies as well. The maximum azimuthal AE, obtained for pure NSTL, is comparable with photoalignment technology. It was found that the deposition of polyimide film on NSTL leads to the gain effect of the azimuthal AE. Also, atomic force microscopy (AFM) study of aligning surfaces was carried out. 相似文献