酶脱支处理对颗粒态缓慢消化淀粉形成的影响

以玉米淀粉为原料,研究了低于淀粉糊化温度条件下酶脱支处理对直链淀粉溶出及缓慢消化淀粉形成的影响。选取不同条件产物,采用Guraya法测定酶脱支处理后的缓慢消化淀粉含量的变化,从而研究酶脱支处理过程上清液中溶出的直链淀粉与沉淀淀粉颗粒态缓慢消化淀粉含量之间的关系。并利用扫描电子显微镜、X-射线衍射仪、差示扫描量热仪等进一步研究酶脱支淀粉的颗粒形貌、结晶特性、热焓特性。结果表明,直链淀粉溶出量与缓慢消化淀粉形成具有相关性;低于糊化温度下通过酶脱支制备缓慢消化淀粉能提高淀粉颗粒表面的疏松度;相对于结晶的数量,结晶的质量对淀粉消化性影响更大;酶脱支处理后,淀粉糊化的起始温度、峰值温度、终止温度均有所增加,糊化温度区间变小,糊化焓降低。     

淀粉特性粘度与链淀粉含量的关系

本文研究了马铃薯淀粉、链淀粉、支淀粉和链一支淀粉混合物在9∶1二甲亚砜—水溶剂中的特性粘度,并推导出了原淀粉的特性粘度与链淀粉含量的关系表达式。     

改性高链玉米淀粉的生物降解性能

利用微生物群在半生物体内模型中分解底物的模拟人体消化的方法,研究了不同链淀粉含量的玉米淀粉及其改性淀粉的生物降解性能、结果表明,玉米淀粉及其改性淀粉的生物降解性能与其链淀粉含量有关,链淀粉含量为50％的高链玉米淀粉最难降解,普通玉米淀粉(链淀粉含量为26％)最易被降解,链淀粉含量为70％的高链玉米淀粉的降解性能居中;普通玉米淀粉和链淀粉含量高的玉米淀粉经交联变性可抑制其生物降解性能,而羧甲基化变性将会加速其降解.     

细胞膜淀粉酶的纯化和分析(英文)

一种Ruminobacteramylophilus70细胞膜联的新支连淀粉酶被4%TritonX 100提取.其新支连淀粉酶活性存在于70%的硫酸铵沉淀组分中.通过等电聚焦纯化,根据SDS凝胶电泳测定,其新支连淀粉酶的分子量是91 2kDa,其等电点是5 8～5 9.根据另一种淀粉酶活性凝胶电泳的方法测定,其新支连淀粉酶的分子量大约是92 6kDa.在R.amylophilus70细胞中存在着两种类型的淀粉酶(可溶性淀粉酶和膜联淀粉酶,比如新支连淀粉酶)共同承担分解淀粉的作用.     

淀粉—聚乙烯薄膜的研究

探讨了几种淀粉和LDPE共混体系的性能,结果表明,淀粉经过变性,降低了数均分子量和链之间的缠绕程度,提高了在高聚物共混体系中的分散性;加入增容剂,又进一步改善了淀粉表面的性质,缩小了共混体系组份间的性质差异;共混后,可得到相态稳定、分散均匀、界面粘结力强的共混膜料。对不同配方试片的力学性能、流变学性质以及形态进行了比较,研制出了较为理想的可降解的农用覆盖膜和包装材料用膜。     

羧甲基淀粉醚的抗酶降解机理和取代基在分子链上的分布

引用未被取代的葡萄糖单元的序列长度分布的概念,对羧甲基淀粉醚在α-淀粉酶和葡萄糖淀粉酶的混合酶试剂作用下,发生的酶降解的准确位置进行了数学推算。结果表明酶降解只发生在两个相邻的未被取代的葡萄糖单元之间,用酶降解前后1000个葡萄糖单元的分子链数之差(△1000/(?)_n)和降解后生成的葡萄糖占未被取代的葡萄糖单元数的百分含量(GI)可表征取代基在分子链上的分布。此外还对取代度和取代基在分子链上的分布与抗酶降解性的关系进行了研究。     

Ruminobacter amylophilus 70细胞膜淀粉酶的纯化和分析

一种Ruminobacter amylophilus 70细胞膜联的新支连淀粉酶被4％ Triton X-100提取．其新支连淀粉酶活性存在于70％的硫酸铵沉淀组分中．通过等电聚焦纯化，根据SDS凝胶电泳测定，其新支连淀粉酶的分子量是91．2kDa，其等电点是5．8-5.9.根据另一种淀粉酶活性凝胶电泳的方法测定，其新支连淀粉酶的分子量大约是92．6kDa．在R.amylophilus 70细胞中存在着两种类型的淀粉酶(可溶性淀粉酶和膜联淀粉酶，比如新支连淀粉酶)共同承担分解淀粉的作用．     

麦芽——异麦芽低聚糖制备工艺的优化研究

本文应用生物降解技术，探讨了以马铃薯淀粉和α－淀粉酶为原料制备麦芽——异麦芽低聚糖的工艺，用正交试验和统计分析，确定了一组优化实验条件。     

改性豌豆淀粉用于改进玻纤浸润剂的性能

以豌豆淀粉为原料, 先用异淀粉酶处理, 再将酶化的淀粉进行醚化反应, 研究淀粉成膜剂的制备条件. 考察酶解时间、 环氧丙烷用量、 醚化
时间、 反应温度和氢氧化钠用量对成膜剂的性能影响. 通过正交试验得到制备淀粉成膜剂的最优条件： 酶解时间12 h, 环氧丙烷用量4 g, 醚化时间16 h, 反应温度45 ℃, 氢氧化钠用量0.4 g. 拉丝实验结果表明, 改性淀粉作为成膜剂用于玻璃纤维浸润剂, 可保证拉丝工艺顺利完成.     

抗消化淀粉体外的评价方法

采用体外模拟方法，研究了胃蛋白酶处理条件、α-淀粉酶消化条件等对抗消化淀粉含量测定的影响，结果表明，用2%胃蛋白酶在30℃条件下对淀粉样品处理70min，可有效除去淀粉中的蛋白质组分，当淀粉酶处于最高活性条件下，pH值为6.3～7，作用时间为20min,可以模拟体内淀粉酶对淀粉的消化过程，基本上除去了可消化淀粉部分，剩余部分即为抗消化淀粉。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with