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81.
Günister E Işçi S Oztekin N Erim FB Ece OI Güngör N 《Journal of colloid and interface science》2006,303(1):137-141
In this study, the adsorption, bridging, and intercalation effects of a cationic surfactant, benzyldimethyltetradecyl ammonium chloride (BDTDACl), on bentonite clay suspensions was investigated. The adsorption, rheological behaviors, and colloidal properties of the clay dispersions were determined as a function surfactant concentration. Adsorption isotherms were obtained using the batch-equilibrium technique. The rheological behavior of the clay suspensions was obtained by shear stress-shear rate measurements within 0-350 s-1 shear rates. The structure of the composite particles was analyzed by using X-ray diffraction analysis and it was found that the expansions of basal d-spacings are less than 16.80 A, suggesting a monolayer structure. 相似文献
82.
We study hypersurfaces in Euclidean space
whose position vector x satisfies the condition L
k
x = Ax + b, where L
k
is the linearized operator of the (k + 1)th mean curvature of the hypersurface for a fixed
,
is a constant matrix and
is a constant vector. For every k, we prove that the only hypersurfaces satisfying that condition are hypersurfaces with zero (k + 1)th mean curvature and open pieces of round hyperspheres and generalized right spherical cylinders of the form
, with
. This extends a previous classification for hypersurfaces in
satisfying
, where
is the Laplacian operator of the hypersurface, given independently by Hasanis and Vlachos [J. Austral. Math. Soc. Ser. A
53, 377–384 (1991) and Chen and Petrovic [Bull. Austral. Math. Soc. 44, 117–129 (1991)].
相似文献
83.
Uras-Aytemiz N Devlin JP Sadlej J Buch V 《The journal of physical chemistry. B》2006,110(43):21751-21763
Condensed-phase solvation of HCl on and within methanol nanoparticles was investigated by Fourier transform infrared (FTIR) spectroscopy, on-the-fly molecular dynamics as implemented in the density functional code Quickstep (which is part of the CP2K package), and ab initio calculations. Adsorption and solvation stages are identified and assigned with the help of calculated infrared spectra obtained from the simulations. The results have been further checked with MP2-level ab initio calculations. The range of acid solvation states extends from the single-coordinated slightly stretched HCl to proton-sharing with Zundel-like methanol O...H+...X- states, and finally to MeOH2+...Cl- units with full proton transfer. Furthermore, once the proton moves to methanol, it is mobilized along methanol molecular chains. Since the proton dynamics reflects the evolving local structures, the "proton" spectra display broad bands usually with underlying continua. 相似文献
84.
Karaböcek Serdar Değirmencioğlu İsmail Karaböcek Nevin Serbest Kerim 《Transition Metal Chemistry》2003,28(5):529-533
1,9-Dioxa-3,6-dithiacyclotridecane-10,12-dione (L1), and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione, (L2), two novel ligands, and their mono- and di-nuclear copper(II) and/or nickel(II) complexes have been prepared and characterized by elemental analyses, 1H- and 13C-n.m.r., i.r., magnetic moments and mass spectral studies. Elemental analyses, stochiometric and spectroscopic data on the complexes indicate that the metal ions are coordinated to the nitrogen, oxygen and sulphur atoms and the data support the proposed structure for the diones and their mono–dinuclear copper(II) complexes. Moreover, copper(II) complexes of the dione ligands have a 1:1 metal:ligand ratio. 相似文献
85.
Nevin Arslan 《Phosphorus, sulfur, and silicon and the related elements》2020,195(8):628-637
AbstractThe interaction of [Ru(η6-arene)(μ-Cl)Cl]2 and Ir(η5-C5Me5)(μ-Cl)Cl]2 with a new Ionic Liquid-based phosphinite ligand, [(Ph2PO)-C6H9N2Ph]Cl, (2) gave [Ru((Ph2PO)-C6H9N2Ph)(η6-p-cymene)Cl2]Cl (3), [Ru((Ph2PO)-C6H9N2Ph)(benzene)Cl2]Cl (4) and [Ir((Ph2PO)-C6H9N2Ph)(C5Me5)Cl2]Cl (5), complexes. All the compounds were characterized by a combination of multinuclear NMR and IR spectroscopy as well as elemental analysis. Furthermore, the Ru(II) and Ir(III) catalysts were applied to asymmetric transfer hydrogenation of acetophenone derivatives using 2-propanol as a hydrogen source. The results showed that the corresponding alcohols could be obtained with good activity (up to 55% ee and 99% conversion) under mild conditions. Notably, [Ir((Ph2PO)-C6H9N2Ph)(C5Me5)Cl2]Cl (5) is more active than the other analogous complexes in the transfer hydrogenation (up to 81% ee). 相似文献
86.
In this study, we have prepared pH/temperature-sensitive imprinted ionic poly(N-tert-butylacrylamide-co-acrylamide/maleic acid) [P(TBA-co-AAm/MA)] hydrogels for bovine serum albumin (BSA) by using molecular imprinting method. BSA adsorption from aqueous BSA solutions was investigated with two types of hydrogel systems prepared by non-imprinted and imprinted methods. Hydrogels imprinted with BSA showed higher adsorption capacity and specificity for BSA than hydrogels prepared by the usual procedure. At all studied conditions, the highest BSA adsorption was observed in the hydrogel imprinted with 8.63 wt.-% BSA. In addition, the imprinted hydrogels exhibited both for good selectivity BSA and high adsorption rate depending on the number of BSA-sized cavities. Adsorption studies showed that other stimuli, such as pH, temperature and initial BSA concentration also influenced the BSA adsorption capacity of both non-imprinted and imprinted hydrogels. 相似文献
87.
A. Turan Gürkanl 《数学物理学报(B辑英文版)》2007,27(1):107-116
Let G be a locally compact abelian group. The main purpose of this article is to find the space of multipliers from the Lorentz space L(p1, q1)(G) to L(p21,q21)(G). For this reason, the authors define the space Ap1,q1p2,q2(G), discuss its properties and prove that the space of multipliers from L(p1,q1)(G) to L(p21,q21)(G) is isometrically isomorphic to the dual of Ap1,q1p2q2(G). 相似文献
88.
Within the framework of a piecewise homogeneous body model, by utilizing the three-dimensional linearized theory of elasticity,
the problem of opening of interface cracks in an initially stressed sandwich plate-strip is studied. To solve the corresponding
boundary-contact problem, the FEM is employed. Numerical results for the influence of the initial stresses on the energy release
rate (ERR) at various values of problem parameters are presented and discussed. In particular, it is established that the
ERR in creases (de creases) with growing initial tension (compression) of the plate-strip. 相似文献
89.
90.
We explore the consequences that follow if the dark energy is phantom energy, in which the sum of the pressure and energy density is negative. The positive phantom-energy density becomes infinite in finite time, overcoming all other forms of matter, such that the gravitational repulsion rapidly brings our brief epoch of cosmic structure to a close. The phantom energy rips apart the Milky Way, solar system, Earth, and ultimately the molecules, atoms, nuclei, and nucleons of which we are composed, before the death of the Universe in a "big rip." 相似文献