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591.
A model of the absorption process in a vertical tubular bubble absorber working with R22-DMF, R22-DMA, R22-DMETEG, R22-DMEDEG and R22-NMP is developed using finite element method employing Galerkin's technique. The objective of this paper is to study the influence of the liquid and gas properties on the volumetric mass transfer coefficient. Analysis have also been done using ammonia-water as working fluid, the results obtained are compared with those in the literature and the agreement is found to be good. A correlation for mass transfer coefficient is proposed as a function of Reynolds number, Schmidt number and length to diameter ratio. The correlation can be used either in estimating the mass transfer rates or in fixing up any of the major design parameters namely length required for complete absorption and diameter. 相似文献
592.
The 6-acetoxy, tosyloxy, and p-nitrobenzoyloxy derivatives of fulvene undergo [6+4] cycloadditions with 1-diethylaminobutadiene to give azulene in 12, 14, and 68% yield, respectively. The p-nitrobenzoyloxyfulvene is a crystalline, stable substance which is highly reactive towards nucleophilic dienes. 相似文献
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It is the main purpose of this paper to determine the extremal values of the Euler characteristic of unions of at most n polytopes, disregarding the dimension d of the space in which they lie. 相似文献
596.
Electrocatalytic oxidative cyclization of dithiothreitol (DTT(SH)2) to a disulfide product was demonstrated on a Nafion/lead-ruthenium oxide pyrochlore chemically modified electrode (NPyCME). The process at the NPyCME with DTT(SH)2 is similar to the behaviour of protein in a disulfide linkage, which can be demonstrated by product analysis using HPLC coupled with UV spectroscopy. A possible electrocatalytic mechanism for DTT(SH)2 oxidation to dihydroxydithiane [i.e. cyclized DTT(S-S)] on the NPyCME was proposed in terms of Py-Ru(IV)/Py-Ru(VI) redox active sites. This physical aspect was further utilized for high precision analytical assays using flow injection analysis (FIA), with a linearity up to 50 microM and a detection limit (S/N = 3) of 28 nM (8.64 pg) in a 20 microL sample loop. This is the most sensitive method ever reported for DTT(SH)2 detection assays. The interference from dissolved oxygen, disulfide and glucose is almost negligible. The present method offers an easy route for extension to redox-related protein studies. 相似文献
597.
The generation of laser pulses with energies of >40 mJ at 25 Hz and durations variable from 15 ps to 45 ps using an Nd:yttrium aluminum garnet laser mode-locked with a Stankov nonlinear mirror is demonstrated. This laser is used to pump an optical parametric generator-amplifier, which is tunable in the visible spectral range. 相似文献
598.
I. Felner I. Nowik S. Balamurugan E. Takayama-Muromachi 《Hyperfine Interactions》2008,184(1-3):111-115
57Fe (1%) doped SrCoO3 obtained by high-pressure method, has been investigated by magnetization and Mössbauer spectroscopy studies (MS) in the temperature range 4.2 K to 300 K. The ferromagnetic ordering temperature T C obtained is 272(2) K. Isothermal magnetization curves have been measured at various temperatures, from which the saturation moments (M sat) have been deduced. The 57Fe MS spectra display standard six-line patterns with an isomer shift typical of Fe3?+? and a very small quadrupole splitting (QS = 0.14(1) mm/s above T C). The magnetic hyperfine field at 4.2 K is 276(1) kOe. The temperature dependencies of the iron hyperfine field and M sat (1.83 µ B at 5 K) are almost identical. This shows that the Fe3?+? is replacing Co4?+?, both of the same electronic configuration. They also interact similarly, namely the Fe–Co exchange is almost identical to the Co–Co exchange. 相似文献
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600.
Saloua Mani Aouadi Christine Bernardi Jamil Satouri 《Numerical Methods for Partial Differential Equations》2014,30(1):44-73
The Stokes problem in a tri‐dimensional axisymmetric domain results into a countable family of two‐dimensional problems when using the Fourier coefficients with respect to the angular variable. Relying on this dimension reduction, we propose and study a mortar spectral element discretization of the problem. Numerical experiments confirm the efficiency of this method. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 44–73, 2014 相似文献