一种提取聚-β-羟基丁酸酯的新方法

介绍了一种用十二烷基磺酸钠（SDS）结合乙二胺四乙酸（EDTA）从圆褐固氮菌G－3细胞中分离聚－β－羟基丁酸酯（PHB）的方法，并与SDS单独作用菌体分离PHB的方法作了比较，实验发现，前种方法具有更高的效率。主要研究了在不同试剂用量、作用时间、作用温度和pH值等条件下，SDS和EDTA提取PHB的效果，并对分离条件进行了优化。结果表明，在50℃，pH值为7的条件下，用10g/L的EDTA和7g/L的SDS共同作用菌体（含PHB 66％）15min，可使PHB的纯度达到98．75％。     

超声波和微波辅助法提取茵陈总黄酮的条件研究

以70%乙醇为提取溶剂,分别用超声波和微波辅助法提取茵陈黄酮类化合物,以总黄酮提取率为考察指标,通过正交实验设计优选最佳工艺条件.结果表明:超声波辅助提取的最佳条件为提取时间60min、温度60℃、5g原料使用溶剂125mL、超声波功率200W;微波辅助提取的最佳条件为提取时间24 min、5g原料使用溶剂125mL、微波功率350W.最佳提取条件下,超声波辅助提取率(3.29%)略高于微波辅助提取率(3.09%),微波辅助提取法能明显节省提取时间.     

半仿生及超声波辅助半仿生法提取杜仲叶黄酮

探讨半仿生法及超声波辅助半仿生法提取杜仲黄酮的实验条件.半仿生法考察提取温度、提取时间、料液比对黄酮提取率的影响.以半仿生法提取在超声波协同作用的基础上,采用正交试验、单因素考察超声时间、超声温度、料液比对黄酮提取率的影响.结果表明,半仿生法在提取时间1.5 h,提取温度60 ℃,料液比1∶20（g∶mL）时,黄酮提取率高达325.0 mg/g;超声波辅助法提取的最佳条件为时间50 min,温度65 ℃,料液比1∶40（g∶mL）,黄酮提取率为264.4 mg/g.     

甘草酸的热回流提取工艺研究

采用热回流提取法,经过粉碎、热回流提取、浓缩、酸沉、过滤等实验过程从甘草中提取粗提甘草酸。以甘草酸的提取率为指标,通过正交实验设计考察乙醇浓度、NaHCO_3添加量、液料比、提取时间和提取温度对甘草酸提取率的影响。结果表明,甘草酸的最佳提取条件为:乙醇浓度60%、NaHCO_3添加量0. 4%、液料比15∶1、提取时间2. 5 h、提取温度60℃。在最佳条件下甘草酸的平均提取率为33. 27%。     

从中华根瘤菌中萃取聚羟基丁酸的研究

以氯仿为萃取剂、发酵所得的费氏中华根瘤菌干细胞为原料,研究并建立了聚羟基丁酸（PHB）的三级错流萃取法,考察了萃取剂的最佳用量、温度及时间等对纯度及收率的影响,确立了最佳的萃取工艺条件,PHB收率可达96.36%,纯度可达99%以上.     

甘草中甘草酸的多级逆流提取技术研究

研究利用多级逆流技术提取甘草酸的新方法.采用正交试验考察提取温度、提取时间、级数和液固比对提取效率的影响,确定多级逆流提取甘草酸的最佳工艺条件;在优选出的最佳工艺条件下,考察了提取溶剂对提取率的影响,并与室温冷浸法、超声波法、索氏提取法和微波提取法做了比较.结果表明:多级逆流提取甘草酸的最佳条件为提取温度70℃,单级提取时间60 min,液比6,提取级数为5.在此最佳条件下,多级逆流提取的提取率高于室温冷浸44.3 h、超声波提取40 min、索氏提取4 h、微波萃取54 min的提取率.多级逆流提取具有快速、高效、节能、节约溶剂的特点,用于中草药有效成分的提取,值得推广应用.     

蓝莓花色苷超声辅助提取工艺优化及组分分析

通过单因素和Box-Behnken设计优化了最佳提取料液比、温度、时间条件,同时比较了最佳工艺条件下的超声辅助提取、传统酶法提取和静置提取的花色苷提取率及花色苷吸收光谱,并采用高效液相色谱（HPLC）分析了3种提取方法对花色苷组分的影响.结果表明：超声辅助提取最佳条件为提取时间119min,提取温度69.7℃,超声时间45.8min,稀释倍数7.8,预测得到花色苷的最大提取率为58.83±1.78%.在最优条件下,花色苷的提取率为58.64±0.32%,相对误差仅为0.95%,模型准确度高.超声辅助提取比传统酶法提取的花色苷提取率高12.96%.经HPLC分析,超声辅助提取提高了花色苷组分的提取率.     

乙醇-硫酸铵双水相体系提取柠檬渣中总黄酮研究

以低温烘干的柠檬渣为原料,利用乙醇-硫酸铵双水相体系提取柠檬渣中的总黄酮,通过单因素实验和正交实验考察了乙醇浓度、料液比、硫酸铵用量、提取温度和提取时间对提取率的影响,结果表明乙醇体积浓度为60%、料液比为1∶20g/mL、硫酸铵用量为24g、提取温度为55℃、提取时间为30min时,提取率最高.在此条件下进行了5次平行实验,平均提取率可达1.58%,而且实验重现性好.     

超声法提取香椿叶多糖条件优化

以香椿老叶为原材料,通过正交实验优化方法,探讨了超声时间、超声功率、温度对香椿叶粗多糖提取的影响．结果表明,香椿叶多糖超声提取最优工艺条件为超声时间45min、超声功率240W、温度60℃,此条件下香椿老叶多糖提取率为5．49％．该工艺较一般传统工艺香椿老叶粗多糖提取率有所提高．     

氧化法去除废淡盐水中苯胺的研究

采用次氯酸钠和过氧化氢为氧化剂氧化废淡盐水中的苯胺,考察了氧化剂加入量、pH、温度、时间等因素对苯胺氧化效果的影响.实验结果表明,次氯酸钠的氧化效果好于过氧化氢,在最佳工艺条件下,苯胺的去除率可达97.5%,处理后的废淡盐水可回收利用.     

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     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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