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81.
《ournal of non Newtonian Fluid Mechanics》2006,133(1):57-62
Several methods based on the measured rheological properties in steady shear show are suggested to determine the average droplet size in dilute, Newtonian and immiscible emulsions. Steady interfacial shear stress and first normal stress difference are used to extract droplet size. The average droplet size obtained from these steady methods is compared with literature results obtained via the dynamic method and also from experiments in steady state using online optical observations. The agreement between experimental results and theoretical predictions is fairly good. The method is however suited only for systems, where morphology is not controlled by coalescence. 相似文献
82.
83.
84.
Deng S Fulghum TM Krueger G Patton D Park JY Advincula RC 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(32):8929-8940
A series of hybrid Au-nanoparticle-dendrimer materials: nanoparticle-cored thiophene dendrimers (NCTDs) were synthesized, characterized, and investigated for their energy-transfer properties. These hybrid nanoparticles were obtained by the simultaneous and in situ reduction of gold(III) chloride and self-assembly of the thiol-containing thiophene dendritic ligands. The dendron ligands were radially attached to the gold nanoparticles and were analyzed by TEM, UV/Vis, (1)H NMR, and FTIR spectroscopies. The solution fluorescence of the attached thiophene dendrons are quenched progressively. Both alkyl-chain length and dendron size have significant influence on the energy-transfer efficiency, as well as on core sizes and size distribution of the Au nanoparticles. In spite of the phenomenon's dependence on nanoparticle size, the energy transfer generally follows the 1/d(2) distance dependence. Single NCTD nanoparticles were also adsorbed on highly ordered pyrolytic graphite (HOPG) and uniform aggregates were observed on mica flat substrates. 相似文献
85.
Kyung Hoon Han 《Journal of Functional Analysis》2011,261(4):999-386
We prove that an operator system S is nuclear in the category of operator systems if and only if there exist nets of unital completely positive maps φλ:S→Mnλ and ψλ:Mnλ→S such that ψλ°φλ converges to idS in the point-norm topology. Our proof is independent of the Choi-Effros-Kirchberg characterization of nuclear C?-algebras and yields this characterization as a corollary. We give an explicit example of a nuclear operator system that is not completely order isomorphic to a unital C?-algebra. 相似文献
86.
Mark Tomforde 《Journal of Pure and Applied Algebra》2011,215(4):471-484
Given a directed graph E we describe a method for constructing a Leavitt path algebra LR(E) whose coefficients are in a commutative unital ring R. We prove versions of the Graded Uniqueness Theorem and Cuntz-Krieger Uniqueness Theorem for these Leavitt path algebras, giving proofs that both generalize and simplify the classical results for Leavitt path algebras over fields. We also analyze the ideal structure of LR(E), and we prove that if K is a field, then LK(E)≅K⊗ZLZ(E). 相似文献
87.
Santos CM Tria MC Vergara RA Ahmed F Advincula RC Rodrigues DF 《Chemical communications (Cambridge, England)》2011,47(31):8892-8894
The first report on the fabrication and application of a nanocomposite containing poly-N-vinyl carbazole (PVK) polymer and graphene oxide (GO) as an antimicrobial film was demonstrated. The antimicrobial film was 90% more effective in preventing bacterial colonization relative to the unmodified surface. More importantly, the nanocomposite thin film showed higher bacterial toxicity than pure GO-modified surface. 相似文献
88.
Deng S Sriwichai S Taranekar P Krueger G Mays JW Advincula RC 《Chemical communications (Cambridge, England)》2011,47(31):8805-8807
A series of thiophene dendrons and dendrimers with peripheral functional groups were designed and synthesized. Two methodologies using thiophene dendrons and dendrons as synthetic building blocks, namely, (1) periphery functionalization; (2) a combination of focal and periphery functionalization have been demonstrated. 相似文献
89.
Synthesis of polymer catenanes via a living radical polymerization and supramolecular template approach are demonstrated. The ring closure was performed via atom transfer radical cross coupling (ATRC) to obtain polymer catenanes from the linear polymer metal complex precursor. 相似文献
90.
Manoj Yadav Wenquan Gong Allan J. Jacobson 《Journal of Solid State Electrochemistry》2011,15(2):293-301
Oxygen gas can be electrochemically separated from ambient air with very high purity and compressed by using a solid-electrolyte
ion-transport membrane. An electrolyte with high ionic conductivity such as gadolinium-doped ceria (CGO) and mixed conducting
electrodes are used to construct the electrochemical cell. To achieve high oxygen flux, the electrodes must exhibit very fast
electrode kinetics. Here, we report the performances of mixed conducting PrBaCo2O5 + x
and NdBaCo2O5 + x
electrodes in oxygen separation in a planar CGO electrolyte-supported cell. The properties of the electrode materials were
evaluated using potentiostatic and potentiodynamic measurements and alternating current impedance spectroscopy. The oxygen
flux was also measured using gas chromatography to confirm the absence of gas leaks. The electrodes demonstrated very low
polarization resistances as a result of very high cathodic and anodic reaction rates at temperatures of 600–800 °C. High oxygen
gas flow rates were observed on applying potentials up to 1 V with an almost linear relationship between the applied potential
and the molar flow rate of oxygen gas. 相似文献