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71.
Use of alginate as a free bioligand incorporated in an aqueous two-phase system of polyethylene glycol 6000-salt resulted in considerable purification of wheat germ alpha-amylase and sweet potato beta-amylase from their crude extracts. The elution of the enzyme from the free bioligand was facilitated by exploiting the fact that alginate can be reversibly precipitated in the presence of Ca2+. alpha-Amylase could be purified 42-fold with 92% activity recovery. beta-Amylase on the other hand could be purified 43-fold with 90% recovery. Both purified enzymes showed a single band on sodium dodecylsulfate-polyacrylamide gel electrophoresis. 相似文献
72.
A new colchicine glycoside, 3-O-demethylcolchicine-3-O-alpha-D-glucopyranoside, has been isolated from Gloriosa superba seeds. The assigned structure has been corroborated by spectroscopic data and enzymatic hydrolysis. 相似文献
73.
Sen Gupta JG 《Talanta》1985,32(1):1-6
An improved graphite furnace atomic-absorption method has been developed for the determination of Sc, Y and the rare-earth elements in silicate rocks and related materials. The method, which involves the separation of the lanthanides by ion-exchange followed by their determination by electrothermal atomization, with use of an automatic sampling device, is more rapid than a previous method based on separation by co-precipitation with calcium oxalate and hydrous ferric oxide followed by normal injection of the solution into the furnace. Greater sensitivity (~ 10-40-fold) for La, Ce, Pr, Gd, Tb and Lu is also achieved by using a tantalum foil-lined graphite furnace instead of a pyrolytically-coated furnace. Results obtained for five international reference rock samples, NIM-G, SCo-1, MAG-1, SDC-1 and BHVO-1, are compared with those obtained previously by the oxalate-hydrous oxide co-precipitation method and with other published values. Results are given for four new Canadian iron-formation reference materials, FeR-1 to FeR-4. 相似文献
74.
V. K. Gupta P. K. R. Nair K. Srinivasulu 《Reaction Kinetics and Catalysis Letters》1982,18(1-2):45-49
Uncatalyzed and catalyzed oscillatory behavior in the redox potential in the oxidation of 3-alizarin-sulfonic acid sodium salt with acidid (H2SO4) bromate is reported. Optimum and boundary conditions for each reactant exhibiting oscillatory behavior have been studied and a probable mechanism is suggested.
- 3-- (H2SO4) . , .相似文献
75.
Algebras and Representation Theory - We introduce the concept of a prime band in a string algebra Λ and use it to associate to Λ its finite bridge quiver. Then we introduce a new... 相似文献
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T. T. Nguyen A. K. Gupta Y. Wang 《Annals of the Institute of Statistical Mathematics》1996,48(3):573-576
For independent random variables X and Y, define % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbfv3ySLgzGueE0jxyaibaiGc9yrFr0xXdbba91rFfpec8Eeeu0x% Xdbba9frFj0-OqFfea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs% 0dXdbPYxe9vr0-vr0-vqpWqaaeaabiGaciaacaqabeaadaqaaqGaaO% qaaiaabofaruWrL9MCNLwyaGqbciaa-bcacqGHHjIUcaWFGaGaa8hw% aiaa-TcacaWFzbaaaa!4551!\[{\rm{S}} \equiv X + Y\]. When the conditional expectations % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbfv3ySLgzGueE0jxyaibaiGc9yrFr0xXdbba91rFfpec8Eeeu0x% Xdbba9frFj0-OqFfea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs% 0dXdbPYxe9vr0-vr0-vqpWqaaeaabiGaciaacaqabeaadaqaaqGaaO% qaaiaadweacaGGBbqefCuzVj3zPfgaiuGajaaqcaWFNbGccaGGOaGa% amiwaiaacMcacaGG8bGaam4uaiaac2facqGHHjIUcaWGHbGaaiikai% aadofacaGGPaaaaa!4BC4!\[E[g(X)|S] \equiv a(S)\]and % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbfv3ySLgzGueE0jxyaibaiGc9yrFr0xXdbba91rFfpec8Eeeu0x% Xdbba9frFj0-OqFfea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs% 0dXdbPYxe9vr0-vr0-vqpWqaaeaabiGaciaacaqabeaadaqaaqGaaO% qaaiaadweacaGGBbGaamiAaiaacIcacaWGybGaaiykaiaacYhacaWG% tbGaaiyxaiabggMi6kaadkgacaGGOaGaam4uaiaacMcaaaa!4894!\[E[h(X)|S] \equiv b(S)\]are given, then under certain assumptions, the density function of X has the form of u(x)k()eax, where u(x) is uniquely determined by the functions a(·) and b(·). 相似文献