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Nidetzky Bernd Griessler Richard Weinhausel Andreas Haltrich Dietmar Kulbe Klaus D. 《Applied biochemistry and biotechnology》1997,(1):159-172
Some important process properties of α-l,4-D-ghican phosphorylases isolated from the bacteriumCorynebacterium callunae and potato tubers (Solatium tuberosum) were compared. Apart from minor differences in their stability and specificity (represented by the maximum degree of maltodextrin
conversion) and a 10-fold higher affinity of the plant phosphorylase for maltodextrin (K
M of 1.3 g/L at 300 mM of orthophosphate), the performances of both enzymes in a continuous ultrafiltration membrane reactor
were almost identical. Product synthesis was carried out over a time course of 300–400 h in the presence or absence of auxiliary
pullulanase (increasing the accessibility of the glucan substrate for phosphorolytic attack up to 15–20%). The effect of varied
dilution rate and reaction temperature on the resulting productivities was quantitated, and a maximum operational temperature
of 40°C was identified. 相似文献
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The James constant for the <Emphasis Type="Italic">l</Emphasis><Subscript>3</Subscript> − <Emphasis Type="Italic">l</Emphasis><Subscript>1</Subscript> space
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In this note, the exact value of the James constant for the l3-l1 space is obtained, J(l3-l1)=1.5573…. This result improves the known inequality, J(l3-l1)≤4/3√10, which was given by Dhompongsa, Piraisangjun and Saejung. 相似文献
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研究了3-(2'-苯基-1', 2', 3'-连三唑-4'-基)-4-氨基-5-巯基-1, 2, 4-三唑(1)与取代苯甲酸和脂肪酸(2a-r)在POCl3催化下的反应, 共合成得到18个新的3-(2'-苯基-1', 2', 3'-连三唑-4'-基)-6-烷基/芳基-均三唑并[3, 4-b]-1, 3, 4-噻二唑(3a-r), 经元素分析,IR, 1H NMR和MS进行了结构确证。 相似文献
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二溴对甲基偶氮溴羧与钡显色反应的研究与应用 总被引:1,自引:0,他引:1
研究了新显色剂二溴对甲基偶氮溴羧与钡显色反应的条件。在磷酸介质中,试剂与钡形成2:1的络合物,最大吸收波长为610nm,摩尔吸光系数为2.13×10~4L·mol~(-1)·cm~(-1),钡量在0~20μg/25ml范围内符合比耳定律。两倍的锶和五倍的钛不干扰,钙的允许量较大,方法用于直接测定钛酸钡烧结物中微量钡,结果满意。 相似文献
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研究了salen型席夫结构的荧光探针N,N’-二(2-羟基-1-萘甲醛)-l,2-苯二胺(NAPPDIH)对Cr3+的响应。Cr3+能够使该探针的荧光猝灭。研究表明,在pH3.5(乙酸胺-盐酸)和DMSO/H2O(V/V,8:2)的条件下,8.0×10-6 mol/L的Cr3+可以导致NAPPDIH 65%的荧光猝灭。并且,Cr3+的浓度在5.0×10-7~8.0×10-6 mol/L的范围内,与荧光强度的变化值呈良好的线性关系,检出限为3.7×10-7 mol/L。方法可用于直接检测水样中的Cr3+。 相似文献
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Ingeborg Maier Johann Jurenitsch Franz Heresch Ernst Haslinger Gerhard Schulz Maximilian Pöhm Kurt Jentzsch 《Monatshefte für Chemie / Chemical Monthly》1981,112(12):1425-1439
In the transverse section of the seeds ofDatura stramonium L. var.stramonium a conspicuous sea-green fluorescence under UV-light (365 nm) can be observed. Thinlayer chromatography of a methanolic extract shows many blue and sea-green fluorescing substances, the main component being a polar, sea-green fluorescing compound. This substance is characteristic for all of the four varieties ofDatura stramonium L., and therefore of taxonomic interest. Isolation was tried by means of different chromatographic techniques. Combination of column chromatography and preparative thinlayer chromatography allowed the isolation of the main product, which was shown to consist of two substances (GF andGFa). Application of chemical and spectroscopic methods established the structure ofGF, named Fluorodaturatin, as 2,3,5,6-Tetrahydro-9-hydroxy-1H-pyrido-[1,2,3-l, m]--carboline-3-one. The second substanceGFa, called Homofluorodaturatin, was identified as analogue ofGF and the structure could be determined as 1,2,3,4,6,7-Hexahydro-10-hydroxyazepino-[1,2,3-l, m]--carboline-4-one.
Teil der DissertationI. Maier, Universität Wien, 1981; Auszugsweise vorgetragen bei der 2. Wissenschaftlichen Tagung der Österreichischen Pharmazeutischen Gesellschaft, 17. bis 19. Mai 1981, Graz. 相似文献
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压缩感知(compressed sensing,CS) 是一种全新的信息采集与处理的理论框架,借助信号内在的稀疏性或可压缩性,可以从小规模的线性、非自适应的测量中通过求解非线性优化问题重构原信号.块稀疏信号是一种具有块结构的信号,即信号的非零元是成块出现的.受YIN Peng-hang, LOU Yi-fei, HE Qi等提出的l1-2范数最小化方法的启发,将基于l1-l2范数的稀疏重构算法推广到块稀疏模型,证明了块稀疏模型下l1-l2范数的相关性质,建立了基于l1-l2范数的块稀疏信号精确重构的充分条件,并通过DCA(difference of convex functions algorithm) 和ADMM(alternating direction method of multipliers)给出了求解块稀疏模型下l1-l2范数的迭代方法.数值实验表明,基于l1-l2范数的块稀疏重构算法比其他块稀疏重构算法具有更高的重构成功率. 相似文献