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171.
Motivated by the study of self-cleaning surfaces, the interaction between a spherical solid particle and a water droplet is studied on the microsale level, in terms of the balance forces and the surface properties. To define the forces acting on the solid-liquid interface, the meniscus depression is computed from the Young-Laplace equation, using a non-linear finite element formulation. The equilibrium force is derived in terms of the contact angle, particle size, and the penetration. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
172.
173.
174.
3-Ethoxycarbonyl-5-methyl-1-(4-methylphenyl)-4-pyrazoloylhydroximoyl chloride (1) reacted with o-phenylenediamine, o-aminothiophenol, o-aminophenol and methyl anthranilate to afford 3-nitrosoquinoxaline, benzothiadiazine, benzoxadiazine, and 3-hydroxyquinazoline, respectively. Imidazo[1,2-a]pyridine, imidazo[1,2-a]pyrimidine and isoxazole derivatives were obtained via the reaction of 1 with 2-aminopyridine, 2-aminopyrimidine and the appropriate active methylene compounds, respectively. Pyrazolo[3,4-d]pyridazines, and pyrrolidino[3,4-d]isoxazolines derivatives were also synthesized. The structures of the newly synthesized compounds were established on the basis of spectral data and alternate synthesis whenever possible. 相似文献
175.
The effect of B2O3 addition to the microstructure and magnetic properties of Ni0.4Zn0.6Fe2O4 ferrite
Berat Yuksel Sebahattin Kirtay T. Osman Ozkan Engin Acikalin Hilkat Erkalfa 《Journal of magnetism and magnetic materials》2008
The effects of 0.01 and 0.1 mol B2O3 addition to the microstructure and magnetic properties of a Ni–Zn ferrite composition expressed by a molecular formula of Ni0.4Zn0.6Fe2O4 were investigated. The toroid-shaped samples prepared by pressing the milled raw materials used in the preparation of the composition were sintered in the range of 1000–1300 °C. The addition of 0.01 mol B2O3 increased the grain growth and densification giving rise to reduced intergranular and intragranular porosity due to liquid-phase sintering. The sintered toroid sample at 1300 °C gave the optimum magnetic properties of Br=170 mT, Hc=0.025 kA/m and a high initial permeability value of μi=4000. The increment of the B2O3 content to 0.1 mol resulted in a pronounced grain growth and also gave rise to large porosity due to the evaporation of B2O3 at higher sintering temperatures. Hence, it resulted in an air-gap effect in the hysteresis curves of these samples. 相似文献
176.
Photoinitiated graft copolymerization of acrylamide onto chitosan under heterogeneous conditions and in the absence of a photo initiator was investigated. The effect of irradiation time, the amount of chitosan and monomer concentration on the extent of grafting was examined. The maximum grafting percentage obtained was 294%. The copolymer was characterized using carbon-13 nuclear magnetic resonance (13C-NMR) spectroscopy, X-ray diffraction analysis (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The system designed allows synthesis of grafted chitosan with free amine groups which are otherwise possible only by chemical protection. The swelling properties of copolymer were followed in aqueous solution. 相似文献
177.
The synthesis of 3-alkyl(aryl)-4-(3-ethoxy-4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones 3 from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones 2 with 3-ethoxy-4-hydroxybenzaldehyde is described.The acetylation and methylation reactions of the compounds 3 giving compounds of type 4 and 5, respectively, were investigated. The newly synthesized compounds were characterized using elemental analyses and IR, (1)H-NMR, (13)C-NMR and UV spectral data.In addition, to investigate the effects of solvents and molecular structure upon acidity,compounds 3 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents (isopropyl alcohol, tert-butyl alcohol, acetonitrile and N,N-dimethylformamide). The half-neutralization potential values and the corresponding pKa values were determined for all cases. 相似文献
178.
Osman Dayan Namk
zdemir Muharrem Diner Bekir etinkaya 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(6):m264-m266
The title compound, [RuCl2(C25H29N5)(C18H15P)], a transfer hydrogenation catalyst, is supported by an N,N′,N′′‐tridentate pyridine‐bridged ligand and triphenylphosphine. The RuII centre is six‐coordinated in a distorted octahedral arrangement, with the two Cl atoms located in the axial positions, and the pyridine (py) N atom, the two imino N atoms and the triphenylphosphine P atom located in the equatorial plane. The two equatorial Ru—Nimino distances (mean 2.093 Å) are substantially longer than the equatorial Ru—Npy bond [1.954 (4) Å]. It is observed that the Nimino—M—Npy bond angle for the five‐membered chelate rings of 2,6‐bis(imino)pyridine‐based complexes is inversely related to the magnitude of the M—Npy bond. The title structure is stabilized by intra‐ and intermolecular C—H...Cl hydrogen bonds, as well as by intramolecular π–π stacking interactions between the aromatic rings belonging to the triphenylphosphine ligand and the dimethylaminophenyl fragment. The intermolecular hydrogen bonds form an R22(12) ring and a zigzag chain of fused centrosymmetric rings running parallel to the [100] direction. 相似文献
179.
180.
The magnetic properties of an anti-ferromagnetic and ferrimagnetic mixed spin-1/2 and spin-5/2 Ising model with a crystal field in a longitudinal magnetic field on the honeycomb (z=3) and square lattice (z=4) are studied by using the effective-field theory with correlations. The ground state phase diagram of the model is obtained in the longitudinal magnetic field (h) and a single-ion potential or crystal-field interaction (Δ) plane. We also investigate the thermal variations of the sublattice and total magnetizations, and present the phase diagrams in the (Δ/|J|, ) plane. The phase diagrams have one, two or even three compensation temperatures depending on the values of the crystal-field interaction. Moreover, the susceptibility, internal energy and specific heat of the system are numerically examined, and some interesting phenomena in these quantities are found due to the applied longitudinal magnetic field. 相似文献