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71.
72.
The repression of glucose oxidase (GOD) biosynthesis by catabolites during fermentation can be alleviated through membrane dialysis fermentation (MDF). The results show that the volumetric enzyme productivity of MDF was two times higher than that of the control (fermentation without dialysis), and its total enzyme activity was increased by 30–50%. The operation conditions of MDF, such as pore size of the membrane, initiating time for membrane dialysis, and volume of dialysate used, were optimized. The content of amino acids and organic acids in the fermentation broth and the dialysate in the reservoir were assessed by amino acid analyzer and ionic chromatography, respectively. The relationship among the contents of pyruvic acid, gluconic acid, and enzyme activity during fermentation was analyzed quantitatively. Furthermore, the effect of membrane dialysis technology applied to the low-yield strain was found to be more effective than that applied to the high-yield strain. 相似文献
73.
Wieczorek-Ciurowa K. Gamrat K. Shirokov Ju. G. 《Journal of Thermal Analysis and Calorimetry》2003,72(1):323-328
A catalytic action of the mechanochemical products of copper hydroxocarbonate with calcium carbonate was investigated in n-butyl
alcohol oxidation tests. The solid products of high-energy milling were identified using thermogravimetry supplemented by
X-ray diffraction method. It was shown that the mechanical activation induces more effective tested catalyst because it promotes
the alcohol conversion at lower temperatures than that unmilled one.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
74.
Ju Wang Zuo Yin Yang Xiu Li Wang Jing Chang Zhang Wei Liang Cao State Key Laboratory of Chemical Resource Engineering Faculty of Science Beijing University of Chemical Technology Beijing China 《中国化学快报》2007,18(2):244-246
The conformational conversion of 1,3-dioxane guest encapsulated inside a cylindrical capsular host was investigated with PM3 method and single point energies were evaluated by B3LYP method. When entrapped in the capsule, the guest tumbles were slower than that in the free condition. The influences of the inner phase of the capsule on the guest conformational conversion were discussed in detail. 相似文献
75.
Asymmetric silyl nitronate cycloadditions with N-acryloyl (2R)-bornane-10,2-sultam, N-acryloyl (2S)-bornane-10,2-sultam, and N-methacryloyl (2R)-bornane-10,2-sultam have been studied. The asymmetric silyl nitronate cycloaddidon/elimination methodology provides a general route for the asymmetric synthesis of 2-isoxazolines. 相似文献
76.
A novel organic/inorganic compound [Hbenzimi]4[(benzimi)2Mo8O26] · 2H2O (1) has been prepared hydrothermally and characterized by elemental analyses, i.r., x.p.s., t.g. and single crystal X-ray diffraction.
The single crystal X-ray diffraction analysis reveals that compound (1) consists of the [Mo8O26]4− cluster as the structural motif covalently linked by benzimidazole molecules and protonated benzimidazole molecules as charge
compensation cations. It is interesting that the benzimidazole molecules were synthesized from 1,2-phenylenediamine and oxalic
acid. The [Mo8O26]4− polyoxoanions and organic ligands in compound (1) interact with each other via extensive hydrogen bonds to form a three-dimensional supramolecular framework. 相似文献
77.
[reaction: see text]. The reactions of aryl aldehydes with 2 equiv of arylacetylenes in the presence of boron trichloride yield (E,Z)-1,3,5-triaryl-1,5-dichloro-1,4-pentadienes. Reactions carried out in the presence of boron tribromide generate the corresponding (Z,Z)-1,3,5-triaryl-1,5-dibromo-1,4-pentadienes. 相似文献
78.
聚丙烯酰胺凝胶结构非均匀性的动态光散射研究 总被引:3,自引:0,他引:3
利用动态光散射技术研究了聚丙烯酰胺 (PAAm)凝胶结构的非均匀性 ,分析了PAAm凝胶结构非均匀性的形成原因及凝胶动态光散射的数据处理方法和分析结果的物理意义 .研究结果表明 ,PAAm凝胶中含有动态相关长度 (LC)不同的两相 ,其中 ,LC 为 10~ 2 0nm的区域是聚合物稀疏相 ,LC 为 85nm左右的区域是聚合物密集相 ,两相的不均匀分布形成了PAAm凝胶结构的非均匀性 .分析表明 ,PAAm凝胶存在两相主要是由于单体和交联剂的溶解度存在差异所致 .随交联度增大 ,PAAm凝胶结构的非均匀性显著增强 相似文献
79.
This review aims to provide a summary of the progress in organic small molecular fluorescent dyes for photodynamic therapy in recent years and it is classified according to the structures of dyes including cyanines, phthalocyanine, BODIPYs and other agents. 相似文献
80.