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61.
Dilute THF-solutions of different fractions of polymers of methyl, ethyl, n-propyl, n-, i- and t-butyl, n-hexyl, 2-ethylhexyl, and lauryl acrylate, prepared by solution polymerization in benzene, were studied by light scattering and viscosity methods. Poly(acrylic acid) was examined in dioxane. For the different polyacrylic esters the [η]-Mw-relations were established and the dependence of the radius of gyration <r2w> on the molecular weight was determined. 相似文献
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Erich Farber Professor Research Professor Ford L. Prescott Professor Emeritus 《Solar Energy》1965,9(4):175-176
This paper discusses the latest closed-cycle engine in the development of small solar engines being carried out at the Solar Energy Laboratory of the University of Florida. It describes the design and construction of the engine, gives the performance efficiency of the engine and demonstrates how pressurization improves the power output of the engine. 相似文献
65.
A new stage-to-stage method has been developed for the calculation of NXx absorption columns. Each stage of the absorption column is simulated as a combination of a bubble column reactor (absorption) and an adiabatic plug for reactor (oxidation). The bubble column reactor is modelled as two single stirred tank reactors, one as a gas-phase and one as a liquid-phase reactor, both coupled by mass and heat transfer. In this hydrodynamic model, a dynamic approach is adopted, in which the gas-phase transport of N2O4 is the limiting step for the absorption. A gas-phasepseudo-enhancement for factor for N2O4 is therefore introduced. The balance equations for a single phase of the bubble column are solved with a Newton-Raphson algorithm. The entire column calculation is divided into a gas and a liquid side. On both sides, the stage-to-stage method is applied in such way that the overall calculation is performed as a loop process. The direction of the loop calculation follows that of the flow: gas-side upwards and liquid-side downwards. 相似文献
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A Combined Surface Science and Electrochemical Study of Tungsten Carbides as Anode Electrocatalysts 总被引:1,自引:0,他引:1
Erich C. Weigert Michael B. Zellner Alan L. Stottlemyer Jingguang G. Chen 《Topics in Catalysis》2007,46(3-4):349-357
An effective anode electrocatalyst in direct methanol fuel cell (DMFC) should have high activity for the oxidation of methanol
and the decomposition of water, while remaining stable under the relatively harsh anode environment. Although the Pt/Ru bimetallic
alloy is currently the most effective anode electrocatalyst, both Pt and Ru are expensive due to limited supplies and both
are susceptible to CO poisoning. Consequently, the discovery of less expensive and more CO tolerant alternatives to the Pt/Ru
catalysts would help facilitate the commercialization of DMFC. In this paper we will discuss the possibility of using tungsten
carbides (WC) and Pt-modified WC as potential anode electrocatalysts in DMFC. We will provide an overview of our recent work,
using a combined approach of fundamental surface science studies and in-situ electrochemical evaluation of the activity and
stability of tungsten carbides. We will demonstrate the feasibility to bridge fundamental surface science studies on single
crystals with the electrochemical evaluation on polycrystalline WC films. We will also discuss the synergistic effect by supporting
low coverages of Pt on the WC substrate to further enhance the electrochemical performance of WC. 相似文献
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