HPLC-ELSD法测定烟草中单糖含量

为建立高效液相色谱-蒸发光散射检测法(HPLC-ELSD)同步定量测定烟草中果糖、葡萄糖的新方法,将烟草样品处理后,用水提取,用Kromasil NH2柱分离,以乙腈-水(80∶20,V/V)为流动相,流速1.0 m L/min,柱温为室温,进样量20μL,ELSD漂移管温度95℃,空气作载气,流速1.5 L/min,使用蒸发光散射检测器进行了单糖检测.结果表明:果糖、葡萄糖的线性范围分别为0.273~2.73 mg/m L,0.294~2.94 mg/m L,在线性范围内糖含量与峰面积线性关系良好;样品中糖的加标回收率范围为98.5%~102.8%,测得烟草样品中果糖、葡萄糖含量分别为10.44%、7.40%故该方法具有快速、有效、质量可控等优点,为烟草中糖含量的测定提供了一种行之有效的分析方法.     

苹果汁掺假检测及储藏过程中营养物质变化的研究

应用紫外光谱法结合主成分分析法,对掺入梨汁、甘蔗汁和葡萄糖、果糖及蔗糖溶液的掺假苹果汁进行了快速检测;同时,对苹果汁在室温储藏过程中营养物质的变化进行了研究.实验结果表明:紫外光谱法结合主成分分析法可以较好地检测出掺假的苹果汁,尤其是掺梨汁的苹果汁;苹果汁在室温储藏时,其可溶性固形物、维生素C、黄酮、总糖和还原糖的含量、pH值、抗氧化活性都呈降低的趋势,总酚含量则相对稳定.     

青龙衣多糖的提取及单糖组分和质量分数测定

提取青龙衣多糖,经纯化后,分析其单糖组分并测定其总糖质量分数.水提醇沉法提取粗多糖,酸性条件下离心脱色,Sevage法除蛋白,H2O2脱结合色素,高效毛细管电泳(HPCE)测定单糖组成,苯酚-硫酸法测定质量分数.青龙衣粗多糖提取率为38.07%,精制多糖为76.08%;主要单糖组分为半乳糖(Gal)、葡萄糖(G lu)、阿拉伯糖(Ara)、鼠李糖(Rha)、果糖(Fru),其百分比分别为42.998%、23.30%、16.03%、10.123%、7.549%.高效毛细管电泳分离度高,可用于单糖组分定量、定性分析;苯酚-硫酸法实验操作简便,准确可靠,可用于青龙衣多糖质量分数的测定.     

基于亲水色谱-电雾式检测器-电喷雾-飞行时间质谱技术的西洋参不同部位单糖组成的对比分析

采用亲水色谱-电雾式检测器-电喷雾-飞行时间质谱,测定西洋参不同部位(芦头、主根、参须)中多糖的单糖组成。采用超声辅助酸解法对西洋参多糖进行完全水解,应用Waters Xbridge Amide柱(4.6 mm×250 mm,5 μm),梯度洗脱(A为乙酸铵水溶液,B为乙腈),流速0.8 mL/min,柱温40 ℃,ESI-TOF/MS进行定性鉴别,CAD检测器(雾化器温度60 ℃,N₂压力8.8 kPa)进行定量测定,结合主成分分析对西洋参不同部位进行区分。该方法在一定质量浓度范围内具有良好的线性(相关系数>0.999 1),检出限为0.03~0.13 μg/mL,平均回收率为94.17%~107.15%。应用该方法测定了西洋参不同部位多糖水解产物中7种单糖(葡萄糖、果糖、阿拉伯糖、鼠李糖、木糖、岩藻糖、甘露糖)和2种糖醛酸(半乳糖醛酸、葡萄糖醛酸),主根中葡萄糖含量较高,其平均值为(2.123±0.070)mg/g;芦头中鼠李糖、阿拉伯糖、果糖、甘露糖、葡萄糖醛酸、半乳糖醛酸含量较高,其平均值分别为(0.037±0.006)mg/g、(0.179±0.023)mg/g、(0.158±0.028)mg/g、(0.036±0.006)mg/g、(0.069±0.007)mg/g、(0.376±0.096)mg/g;参须中岩藻糖含量较高,其平均值为(0.120±0.005)mg/g。该方法简单,灵敏度、重复性好,为西洋参单糖组成和不同药用部位开发利用提供了方法和数据支持。     

云南普洱茶产地土壤理化性状分析

选择云南省普洱茶产地普洱市、临沧市和西双版纳州为研究区,对不同的土壤类型和土壤各层的理化性质进行分析,并结合茶园的生长情况,研究了土壤理化性质的适宜性.结果表明:1)普洱茶主产区各种土壤类型中,赤红壤的N、P、K的质量分数(w)均偏低,对茶树生长的限制因素较多.黄壤的全P、全K含量丰富,适合茶树生长的有利条件较多.其他土壤类型中,K和P是茶树生长的主要限制因子;2)表、心、底土层的质地一般为粉砂质壤土,是pH范围为4~5的微酸性土壤,存在土壤表层酸化的趋势;3)土壤有机质层深厚,w(全N)达到1%~2%;w(速效P)较低,且从表、心、底土层逐渐减少.w(K)较高,w(全K)平均值在0.6%~1.0%,w(有效K)在土壤表层的积累较明显;微量元素中,Fe、Mn元素w较高;4)有效P、有效K及微量元素Fe和Mn对普洱茶茶叶的生长有重要的作用.     

山楂多糖的成分测定及其单糖组分分析研究

目的:研究山楂多糖的总多糖含量及单糖组分构成.方法:用苯酚-硫酸法测定山楂多糖中的中性多糖含量,用间羟基联苯法测山楂多糖中糖醛酸含量,用红外光谱法初步探究山楂多糖官能团,用气相色谱法分析山楂多糖中单糖组分.结果:山楂多糖中中性多糖的含量为72.00%;糖醛酸的含量为14.98%;红外光谱分析表明山楂多糖可能为一种氨基多糖;气相色谱法分析得山楂多糖的单糖组成为木糖、核糖、阿拉伯糖、鼠李糖、果糖、葡萄糖、半乳糖,其质量分数分别为5.53%、13.85%、14.26%、9.29%、8.37%、19.91%、21.93%.结论:该方法比较便捷,重复性好,可用于山楂多糖中单糖的组成成分分析.     

餐厨垃圾和污泥联合好氧堆肥中的氮素转化及损失

采用强制通风静态好氧堆肥工艺,对餐厨垃圾和污泥进行联合堆肥化处理,探究二者不同配比对堆肥氮素转化及氮素损失的影响.以w(C)/w(N)=15~40的5组餐厨垃圾和污泥作为堆肥基质,以木屑作为调理剂进行堆肥试验.结果表明:所有堆体温度均先升高后降低,最高温度为78℃,w(C)/w(N)越高,堆体的最高温度越低,且达到最高温度的时间越长,pH先降低后升高至8.5趋于平缓,总有机碳质量分数不断降低.各堆体全氮和有机氮质量分数先升高后显著降低,铵态氮质量分数先增加后略有减少,硝态氮质量分数很低且变化不大.二者联合堆肥中氮损失27.8%~48.4%,且与投加的污泥含量呈正相关关系,氨挥发占氮损失的52.6%~80.4%,氨挥发是氮损失的主要途径,且随着堆体w(C)/w(N)的增加呈减少趋势.     

气相色谱法分析大麻药多糖成分中单糖组成

为研究大麻药多糖成分中单糖的组成,用3 mol·L-1三氟乙酸将大麻药多糖水解成单糖,再与盐酸羟胺进行衍生化反应,用气相色谱法分析了其单糖组成,结果表明:鼠李糖、阿拉伯糖、果糖、葡萄糖、阿洛糖和半乳糖为大麻药多糖成分中的单糖组成,其质量分数依次为15.86%,20.37%,6.62%,14.24%,8.38%和14.15%.此方法简便、快速,重现性好,可用于大麻药多糖成分中单糖的组成分析.     

巴戟天多糖的分级纯化及结构分析

对巴戟天多糖的柱层析分级纯化和一级结构进行了研究．采取热水浸提、乙醇沉淀的工艺获得巴戟天粗多糖MOHP,经离子交换和凝胶柱层析得到了MOHP-I,MOHP-Ⅱ,MOHP－Ⅲ和MOHP－Ⅳ4　个组分,通过红外光谱、液相和气相色谱等分析手段对分级后的MOHP－Ⅰ和MOHP-Ⅲ进行了初步的结构分析．结果表明：MOHP—Ⅰ的单糖组成为葡萄糖和果糖,分子质量约为2ku,呋喃糖环结构;MOHP-Ⅲ是一种均一的糖蛋白物质,其组成单糖为阿拉伯糖、木糖、葡萄糖、果糖以及半乳糖,分子质量约为35ku;高效凝胶渗透色谱显示两组分均达到了较高的纯度．     

食品真实属性表征和品质识别新技术研究

在食品真实属性表征生物识别新技术研究方面,采用分子生物学技术,针对燕窝、王浆、海参等常见高附加值食品建立真伪鉴别新方法,为政府监管,企业质控提供技术保障,包括:采用免疫检测、酶活检测、毛细管电泳等技术,建立蜂王浆品质识别方法,收集不同产地和蜜源的王浆样品,初步建立了王浆属性表征数据库,进一步为王浆真伪鉴别和品质评价的应用奠定了基础;针对银耳、红藻、猪皮、蛋清等燕窝掺假物,建立燕窝真伪鉴别实时荧光PCR检测方法研究,开发燕窝真伪鉴别液相芯片检测方法,提高检测通量。采用双向电泳技术开展不同产地和级别燕窝样品的蛋白质组比较,为燕窝产品品质识别积累了基础数据。在蜂蜜蜜源品种溯源方面,建立8种蜂蜜蜜源植物的实时荧光PCR检测方法,可以灵敏检测不同蜜源蜂蜜混杂的产品。在鲑鱼和海参等海产品真伪检测方面,建立鲑鱼和海参真伪鉴别实时荧光PCR方法。在食品感官品质仿生识别技术研究与设备开发方面,开发了食品感官品质多通道识别信息融合技术与质量决策系统,采用传感器电子鼻、可视化电子鼻、电子舌等现代智能感官分析技术及气相色谱-质谱技术,针对普洱茶、绿茶、蜂蜜等食品建立品质识别新方法,为规范市场提供科学手段,包括:初步建立多种信息融合模式下的产品质量检测模型,开展了智能化电子舌传感器清洗、漂移校正、系统集成、标准操作应用方法学等产业化关键技术的研究,开发了利用4种天然植物色素作为气体敏感材料的可视化电子鼻技术,进行猪肉新鲜度检测应用研究,针对普洱茶品质和产地、绿茶产地、食用油品种等建立电子鼻品质识别方法。在食品质量属性分子识别技术及装备研究方面,重点针对组胺分子印迹技术、癸烯酸仿生免疫技术、蜂蜜红外光谱检测技术、杂胺免疫检测技术开展研究,包括:在前期组胺分子印迹聚合物合成的基础上,进一步优化构建了组胺分子印迹压电石英微天平传感器,并将其应用于实际样品的测定。建立了10-羟基-癸烯酸仿生免疫层析和高效液相色谱仪联用的检测方法来检测蜂王浆及其制品中蜂王酸的含量。采用近红外光谱技术结合化学计量学方法对掺入不同质量分数果葡糖浆的掺假蜂蜜进行定性和定量分析。在杂环胺半抗原合成、抗体制备的基础上优化建立了竞争ELISA方法,并优化建立了样品基质消除方法,对实际样品进行检测,并与仪器分析方法进行了比对。     

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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