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101.
Selective Cell Adhesion and Biosensing Applications of Bio‐Active Block Copolymers Prepared by CuAAC/Thiol‐ene Double Click Reactions
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102.
In this article, we study the reduced bifurcation equations of the nonlinear delay differential equations with periodic delays, which models the machine tool chatter with continuously modulated spindle speed to determine the periodic solutions and analyze the tool motion. Analytical results show both modest increase of stability and existence of periodic solutions close to the new stability boundary. 相似文献
103.
The mathematical models representing machine tool chatter dynamics have been cast as differential equations with delay. The suppression of regenerative chatter by spindle speed variation is attracting increasing attention. In this paper, we study nonlinear delay differential equations with periodic delays which models the machine tool chatter with continuously modulated spindle speed. The explicit time-dependent delay terms, due to spindle speed modulation, are replaced by state dependent delay terms by augmenting the original equations. The augmented system of equations is autonomous and has two pairs of pure imaginary eigenvalues without resonance. The reduced bifurcation equation is obtained by making use of Lyapunov–Schmidt Reduction method. 相似文献
104.
Oznülüer T Erdogan I Demir U 《Langmuir : the ACS journal of surfaces and colloids》2006,22(9):4415-4419
Ultrathin films of ZnS were grown on Au (111) substrates using a novel, simple co-deposition method and characterized using X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and UV-visible spectroscopy. Cyclic voltammograms were used to determine approximate deposition potentials for co-deposition. XRD shows that the material growth is highly preferential with (111) orientation. Both AFM and XRD data indicate that the ZnS growth mechanism starts by the formation of rounded nanoparticles at the surface and then continues by lateral and vertical growth to form flat square crystallites of ZnS. UV-vis spectra taken for the ZnS thin films with various thicknesses, which is related to deposition time, shows that the band gap of the ZnS decreases as the film thickness increases. 相似文献
105.
Chemical characterisation has been carried out on 25 quarry marbles collected from Marmara, Aegean and Thrace regions of Turkey. Ten elements were determined by capillary electrophoresis (CE). Principal component analysis and cluster analysis techniques were utilised to define grouping of different marble samples. These techniques showed that the analysed marbles were differentiable mainly by provenance. Experimental conditions such as pH, applied voltage and concentration of α-hydroxyisobutyric acid (HIBA) were optimised to achieve the best separation of metal ions using central composite design. The optimum pH 3.7, applied voltage 15 kV and concentration of HIBA 10 mM were found to provide the best separation for all metal ions investigated. 相似文献
106.
Glutathione reductase was purified from chicken liver and some characteristics of the enzyme were investigated. The purification
procedure was composed of four steps: preparation of homogenate, ammonium sulfate precipitation, 2′,5′-ADP Sepharose 4B affinity
chromatography, and Sephadex G-200 gel filtration chromatography. Owing to the four consecutive procedures, the enzyme was
purified 1714-fold, with a yield of 38%. Specific activity at the final step was 120 enzyme unit (EU)/mg of protein. The purified
enzyme showed a single band on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weight
of the enzyme was found to be 100 kDa by Sephadex G-200 gel filtration chromatography, and the subunit molecular weight was
found to be 43 kDa by SDS-PAGE. Optimum pH, stable pH, optimum ionic strength, and optimum temperature were 7.0, 7.4, 0.75
M Tris-HCl buffer including 1 mM EDTA, and 50°C, respectively. K
M and V
max values for NADPH and glutathione disulfide (GSSG) substrates were also determined for the enzyme. 相似文献
107.
The oligomer of 4-(4-pyridylmethylideneimino)phenol was formed during oxidative polycondensation in aqueous alkaline medium
using oxygen as the oxidant. Optimum conditions of the oxidative polycondensation and the main parameters of the process were
found. The maximum yield of the oligomer was 52.4%. The product was characterized by elemental analysis, FT-IR spectroscopy,
UV-Vis spectroscopy, and 1H NMR spectroscopy. The molecular weight distribution was determined by size exclusion chromatography. Thermogravimetric and
differential thermal analyses were carried out for 4-(4-pyridylmethylideneimino)phenol and its oligomer.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1785–1788, October, 2006. 相似文献
108.
Ibrahim Demir Ertugrul Sahmetlioglu Gokcen Y. Celik Murat Unal 《Russian Journal of General Chemistry》2008,78(7):1458-1462
A novel ligand has been synthesized by the condensation of 1,3-diaminoprophane (HL) wıth isonitroso-p-chloroacetophenone. The complexes of cobalt(II), nicel(II), cupper(II) and zinc(II) with HL were prepared. All compounds
were characterized by spectroscopic techniques and its antibacterial activities were determined by the disc diffusion method
used against to those gram-positive and-negative bacteria. All compounds were investigated by cyclic voltammetry at 25°C.
The voltammograms were recorded with a potential scan of 100 mV s−1.
The text was submitted by the authors in English. 相似文献
109.
110.
T. M. Aliev D. A. Demir E. Iltan N. K. Pak 《Zeitschrift fur Physik C Particles and Fields》1995,69(1):481-484
Theg B*B? andg D*D? coupling constants are calculated at the intermediate momentum transfer interval 0.5 GeV2≤Q 2≤1.5 GeV2, in the context of QCD sum rules. Our predictions are in good agreement with those of the Vector Dominance Model 相似文献