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871.
Veara Loha Aleš Prokop Liping Du Robert D. Tanner 《Applied biochemistry and biotechnology》1999,79(1-3):701-712
Foam fractionation isone of the low operating-cost techniques for removing proteins from a dilute solution. The initial bulk
solution pH and air superficial velocity play an importantrole in the foam-fractionation process. Denaturation of proteins
(enzymes) can occur, however, during the foamfractionation process from the shear forces resulting from bursting air bubbles.
At the extreme bulk solution pHs (lower than 3.0 and higher than 10.0), the en zymatic activity of cellulase in the foamate
phase drops significantly. Within these two pH boundsan increase in the air superficial velocity, Vo, and a decrease in the bulk solution pH leads to a decrease in the separation ratio (SR), defined as theratio of the protein
concentration in the foamate to the protein concentration in the residue. On the other hand, an increase in Vo provides a higher foamate-protein recovery. The process efficiency is defined as the product of foamate-protein recovery
times the SR times the cellulase activity. The optimal operating condition of the cellulase foamfractionation process is taken
into account at the maximum value of the processefficiency. In this study, that optimal condition is atan air superficial
velocity of 32 cm/min and a bulk-solution pH of 10.0. At this condition, the recovered foamate is about 80% of the original
protein mass, the SR is about 12, and the en zymatic activity is about 60% of the original cellulase activity. 相似文献
872.
873.
874.
We introduce a marker-particle method for the computation of three-dimensional solid surface morphologies evolving by surface diffusion. The method does not use gridding of surfaces or numerical differentiation, and applies to surfaces with finite slopes and overhangs. We demonstrate the method by computing the evolution of perturbed cylindrical wires on a substrate. We show that computed growth rates at early times agree with those predicted by the linear stability analysis. Furthermore, when the marker particles are redistributed periodically to maintain even spacing, the method can follow breakup of the wire. 相似文献
875.
Hai-lin Su ;Shao-long Tang ;Rui-long Wang ;Yi-qing Chen ;Chong Jia ;You-wei Du 《化学物理学报(中文版)》2009,(1):82-86
The effects of magnetic field annealing on the properties of Fe48Co52 alloy nanowire arrays with various interwire distances (Di=30-60 nm) and wire diameters (Dw=22-46 nm) were investigated in detail. It was found that the array's best annealing temperature and crys- talline structure did not show any apparent dependence on the treatment of applying a 3 kOe magnetic field along the wire during the annealing process. For arrays with small Dw or with large Di, the treatment of magnetic field annealing also had no obvious influence on their magnetic performances. However, such a magnetic field annealing constrained the shift of the easy magnetization direction and improved the coercivity and the squareness obviously for arrays with large Dw or with small Di. The difference in the intensity of the effective anisotropic field within the arrays was believed to be responsible for this different variation of the array's magnetic properties after magnetic field annealing. 相似文献
876.
877.
Shaozhi Pu Chunfeng Hou Kaiyun Zhan Chengxun Yuan Yanwei Du 《Optics Communications》2012,285(17):3631-3635
We theoretically investigate the dynamics of dark solitons as well as their interaction in nonlocal media. Approximate equations describing the evolution of the beams are obtained via suitable trial functions of amplitude u and refractive index n in an averaged Lagrangian. Our results reveal that out-of-phase dark solitons can evolve into stable bound states in nonlocal materials. Moreover, it is found that the separations in the bound state monotonically increase with the degree of nonlocality in nonlocal limit. These results are in excellent agreement with the numerical simulations. 相似文献
878.
879.
Xiaoyan Zhao Zhiyi Wei Fangling Du Junqing Zhu 《Applied biochemistry and biotechnology》2010,162(7):2087-2097
Suitability of reverse micelles of anionic surfactant sodium bis(2-ethyl hexyl) sulfosuccinate (AOT) and sodium dodecyl sulfate
(SDS), cationic surfactant hexadecyl trimethyl ammonium bromide (CTAB) and nonionic surfactant polyoxyethylene p-t-octylphenol (TritonX-100) in organic solvent isooctane for extraction of soy isoflavone-enriching proteins was investigated.
The results showed that the order of combined isoflavone contents was SDS>CTAB>Triton X-100>AOT, while the order of protein
recovery was SDS>AOT>TritonX-100>CTAB. As compared with ACN-HCl extraction, the total amount of isoflavones was lower than
reverse micellar extraction. Ion strength was one of the important conditions to control extraction of isoflavone-enriching
proteins with AOT reversed micelles. For the six salt systems, KNO3, KCl, MgCl2, CaCl2, NaCl, and Na2SO4, extracted fraction of isoflavone-enriching proteins was measured. Salt solutions greatly influenced the extraction efficiency
of isoflavones in an order of KNO3>MgCl2>CaCl2>KCl>NaCl>Na2SO4, while protein in an order of MgCl2>CaCl2>NaCl>KNO3>Na2SO4>KCl. 相似文献
880.