红茶菌发酵液中多糖提取及测定条件优化

采用乙醇沉淀法提取红茶菌粗多糖.结果表明,当乙醇终浓度为90%(V/V)时,粗多糖得率为6.1 g.L-1发酵液;并从检测波长、浓硫酸和苯酚用量、显色温度和时间等方面对苯酚-硫酸法进行优化,优化后的苯酚-硫酸法测定条件为苯酚用量1 mL、浓硫酸用量4 mL,60℃显色15 min,检测波长484 nm.该方法显色稳定,重现性好,平均加样回收率R=85.70%,RSD=1.65%(n=5).     

冠突散囊菌发酵液多糖测定条件优化研究

选取茯砖茶中优势微生物冠突散囊菌,进行液体发酵培养,利用水提醇沉淀法提取发酵液中多糖.以苯酚-硫酸法测定总多糖含量,探寻操作过程中苯酚用量、硫酸用量以及显色时间对多糖含量测定的影响,并在单因素试验结果的基础上进行正交试验优化.研究结果表明,3个因素对冠突散囊菌发酵液多糖含量测定的影响程度依次为:浓硫酸用量显色时间苯酚用量,当5%苯酚用量为0.6 m L、浓硫酸用量为7.0 m L、显色时间为40 min时,可以获得苯酚-硫酸法对冠突散囊菌发酵液中多糖含量的最佳测定效果.     

米糠多糖的提取及其含量的测定

对米糠中的多糖进行提取与测定,采用水提醇沉法对米糠中的多糖进行提取,并采用苯酚—硫酸法测定其多糖含量,以正交实验优化显色条件。确定检测波长为490nm,确定6%苯酚用量为1.0mL,浓硫酸用量7.5mL,反应时间为30min。在(0.0025—0.030)mg/mL范围内,呈良好的线性关系。平均回收率为97.8%,RSD=3.89%(n=6)。测得米糠粗多糖含量为20.2%。结果表明方法简单、准确,为继续研究开发提供一定的参考依据。     

山茱萸多糖含量测定方法的研究

采用苯酚-硫酸法测定山茱萸中多糖的含量,正交实验优化显色条件,确定5%苯酚用量1.2 mL,浓硫酸用量7.0 mL,反应时间20 min。标准曲线回归方程为A=6.0393C－0.0148,r=0.9994（n=6）,在10~100 μg/mL范围内呈良好线性关系。平均回收率为104.93%,RSD=1.87%（n=6）。测得多糖平均含量为45.2%,RSD=1.72%（n=6）。该法快速、准确、灵敏,可为山茱萸中多糖的测定、开发利用和质量评估提供参考。     

牛膝多糖的提取与含量测定

以水提醇沉法从牛膝中提取得到牛膝多糖,采用苯酚-硫酸法测定其多糖含量,以正交实验优化显色条件.确定5%苯酚用量1.0mL,浓硫酸用量7.5 mL,反应时间30 min.标准曲线回归方程为A=0.057 2C-0.006 9,r=0.9991(n=7),在2.5～30.0mg/L范围内呈良好线性关系.平均回收率为97.5%,RSD=1.69%(n=5).测得多糖平均含量为29.4%,RSD=1.84%(n=6).该法简单、准确、稳定,可为其继续研究开发及应用提供参考依据.     

京大戟多糖的提取及苯酚-硫酸法测定其多糖含量的研究

对京大戟多糖的提取条件和多糖的测定方法进行探索,以期优化京大戟多糖的提取条件和测定方法。采用热水浸提法提取京大戟多糖,同时采用苯酚-硫酸法测定其多糖含量。结果显示:(1)京大戟多糖最佳提取条件为液料比30∶1、提取次数为2、提取温度为80℃、提取时间为2 h;(2)苯酚-硫酸法测定京大戟多糖含量的最佳条件为:苯酚浓度为5%、浓硫酸用量为5 m L、反应温度为100℃、显色时间为30 min,在此条件下,测得京大戟中含糖量为22.09%。苯酚-硫酸法的精密度和重现性的RSD为1.38%、稳定性RSD为1.78%、加标回收率为98.35%,表明该实验获得的提取条件和测定方法均可有效用于京大戟多糖的提取和测定。     

苯酚-硫酸显色法测定生菜中的多糖含量

采用苯酚-硫酸显色法测定了生菜中多糖的含量,讨论了反应温度、反应时间、测定波长、苯酚及硫酸的用量等因素对显色反应的影响.在优化条件下,用分光光度法测量其吸光度.根据标准曲线回归方程A=9.770 51C+0.003 3(r=0.998 6)求出多糖含量.结果表明,生菜中多糖的含量为70.21 mg/g,平均回收率为98.0%,相对标准偏差RSD为1.16%,准确度高.该法可为蔬菜中多糖含量的测定提供一种快速简便的技术.     

浸矿细菌胞外聚合层中多糖含量的测定

以稳定期的浸矿细菌菌液为研究对象,探讨苯酚-硫酸法测定浸矿细菌胞外聚合层中多糖含量的最佳条件,并用红外光谱检测浸矿细菌胞外聚合层中多糖的结构组成。研究结果表明,苯酚-硫酸法测定浸矿细菌胞外聚合层中多糖含量的最佳条件为:最大吸收波长490 nm,浓硫酸用量5 mL,苯酚溶液质量分数5%;在最佳条件下测得的浸矿细菌胞外多聚合层中的多糖质量浓度为12 mg/L;由红外光谱分析浸矿细菌胞外聚合层中的多糖,发现其结构中含有O—H,C=C,—CH3和C—H键。     

美洲大蠊抗肝纤维化活性提取物ML-D中粘多糖的含量测定

目的:建立美洲大蠊抗肝纤维化活性提取物ML-D中粘多糖的含量测定方法。方法:采用苯酚-硫酸法测定粘多糖的含量,采用正交试验设计考察ML-D中粘多糖的水解工艺和显色条件,采用单因素试验考察加热显色时间、苯酚和硫酸的用量。结果:ML-D中粘多糖的最佳水解工艺为:盐酸浓度6 mol/L,固液比为1∶1,水解时间1 h;最佳显色条件:苯酚2 mL,硫酸20 mL,加热显色时间10 min。结论:该法操作简便,精密度高,重复性好,可作为美洲大蠊抗肝纤维化活性提取物ML-D中粘多糖含量的测定方法。     

苯酚-硫酸法测定花椒叶多糖含量

建立了一种灵敏、特异、精确定量分析花椒叶多糖的苯酚-硫酸法,采用该方法测定了陕西大红袍花椒叶中多糖的含量.该方法选择半乳糖作为标准单糖,484 nm为工作波长.通过单因素实验和正交试验优化得到了较佳显色反应条件是加样次序为苯酚-样品-浓硫酸,显色温度为25℃,质量分数为5％的苯酚添加量为0.3mL,浓硫酸添加量为3.5 mL,显色时间为30 min.系统适应性实验显示该方法的标准曲线方程为y =0.0127x-0.0076(R2=0.997),线性范围为10.00～60.00 μg/mL,LOD和LOQ分别为2.08 μg/mL和6.30 μg/mL,日内、日间精密度分别在0.49％～3.64％,5.17％ ～6.05％之间,平均回收率为101.19％.样品溶液在显色反应后的2h内稳定性较好.测定发现陕西大红袍花椒叶中w(多糖)在8.11～8.89mg/g之间.该方法为花椒叶多糖的定量分析和花椒叶资源的开发利用提供了参考.     

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