甲苯胺蓝-果糖二磷酸钠体系的褪色反应及其分析应用

在pH4.0的BR缓冲体系中，甲苯胺蓝与果糖二磷酸钠作用，形成离子缔合物，溶液颜色发生改变。其最大褪色波长位于628处，在最大褪色波长处，溶液的褪色与果糖二磷酸钠的浓度呈良好的线性关系，果糖二磷酸钠的浓度在0.19~25.0μg•mL-1范围内遵守比尔定律，相关系数分别为r=0.9994，摩尔吸光系数为1.02×104 L•mol-1.•cm-1，检出限为0.058ug•mL-1。该法快速、灵敏、操作简便，用于片剂中果糖二磷酸钠的分析测定，结果满意。     

不同水果对啶虫脒和阿维菌素的吸附残留

采用静态暴露法,将芦柑、香蕉、苹果暴露在12.5和25μg·mL~(-1)啶虫脒溶液中,将梨子暴露在4.25和9.5μg·mL~(-1)阿维菌素溶液中,研究农药在水果果皮及果肉中的残留情况。结果表明,经过24 h的暴露后,当暴露浓度为25μg·mL~(-1)时,啶虫脒在苹果、香蕉、芦柑果皮上的残留量平均值分别为0.34、0.40和0.64μg·mL~(-1);当暴露浓度为12.5μg·mL~(-1)时,啶虫脒残留量分别为0.16、0.13和0.23μg·mL~(-1)。而在果肉上的残留量为零或者低于检出限。阿维菌素在梨子皮和果肉上均未检测到残留。试验表明啶虫脒类农药容易残留在水果表面,而阿维菌素类农药不容易残留。     

紫草素体外抗菌活性的实验研究

目的:本文主要研究紫草主要成分紫草素体外抗菌活性及其抗菌谱.方法:用琼脂平板法测定紫草素的抗菌谱;以左氧氟沙星为阳性对照药,通过试管二倍稀释法检测紫草素最低抑菌浓度(MIC)和最低杀菌浓度(MBC).结果:紫草素对多种常见菌株包括革兰阳性菌、革兰阴性菌以及真菌显示出抗菌作用,对金黄色葡萄球菌(MIC为6.25μg·mL~(-1),MBC为25.0μg·mL~(-1))、大肠埃希菌菌(MIC为12.5μg·mL~(-1),MBC为25.0μg·mL~(-1))、白色念珠菌(MIC为1.563μg·mL~(-1),MBC为3.125μg·mL~(-1))、蜡状芽孢杆菌(MIC为1.563μg·mL~(-1),MBC为6.25μg·mL~(-1))、沙门氏菌(MIC为25.0μg·mL~(-1),MBC100.0μg·mL~(-1))的生长有显著的抑制作用.抗菌能力与左氧氟沙星相当.结论:紫草素具有良好的抗菌作用,具有成为抗菌药物先导化合物的条件.     

纳米银与富里酸对AL细胞增殖及产生RNS/ROS的影响

利用ALamar Blue法和RNS/ROS荧光特异性探针,探讨不同浓度纳米银(nAg,0.1~5μg·mL~(-1))、银离子(Ag+,0.01~0.5μg·mL~(-1))及纳米银与富里酸(FA,10μg·mL~(-1))协同作用对人鼠杂交瘤(AL)细胞增殖及活性氮/活性氧自由基产生的影响及在这一过程中的作用.结果显示:在低浓度(小于等于1μg·mL~(-1))情况下,nAg对AL细胞的毒性作用主要来自于nAg释放的银离子(Ag~+),Ag~+通过诱导胞内RNS的产生,进而产生增殖抑制作用;在高浓度(5μg·mL~(-1))情况下,nAg对AL细胞的毒性主要来自于Ag~+诱导的RNS和nAg本身诱导的ROS二者共同的作用.模拟水环境中存在的FA(10μg·mL~(-1))能够显著降低nAg和Ag~+对AL细胞增殖的抑制作用,并且能显著降低nAg和Ag~+引起的A_L细胞内RNS和ROS的升高作用.     

胭脂红与dsDNA相互作用在有无纳米TiO_2掺杂的碳糊电极上的比较研究及其应用(英文)

与裸碳糊电极相比,胭脂红与dsDNA的嵌插作用在TiO_2掺杂的碳糊电极上得到增强.这是由于纳米TiO_2的存在,增加了胭脂红的电子传递速率.基于胭脂红与dsDNA的强嵌插作用,当dsDNA的浓度在21.24~127.44μg·mL~(-1)时,胭脂红的氧化还原峰电流下降值与dsDNA的浓度成正比,检测限为16.04μg·mL~(-1).而在裸电极上,dsDNA的浓度范围为31.76~74.34μg·mL~(-1),检测限只有30.32μg·mL~(-1).对于这两种电极,胭脂红与dsDNA的结合常数分别是4.92×10~8,6.41×10~7L·mol~(-1),结合比均为1∶2.因此,胭脂红与dsDNA在纳米TiO_2掺杂的碳糊电极嵌插作用被用于测定合成样品中的dsDNA,平均回收率在96.02%~102.5%.     

铬天青S褪色分光光度法测定水中溴酸根

在盐酸介质中,依据溴酸根离子氧化铬天青褪色的原理提出了测定水中溴酸根含量的新方法,研究了测定的最佳条件.最大吸收波长λmax为480nm,BrO3-浓度在5 ～40μg·mL-1浓度范围内,其浓度与吸光度呈良好线性关系,线性回归方程为A480 =0.09786 C(μg·mL-1)-0.006930,相关系数为0.9976,表观摩尔吸光系数为1.25 ×104cm-1·mol-1·L.该法用于水中微量溴酸根测定,结果满意.     

Fe~(3+)-水合红菲绕啉二磺酸钠分光光度法测定异烟肼

基于异烟肼分子结构中的酰肼基具有较强的还原性,可将Fe~(3+)还原为Fe~(2+),选择水合红菲绕啉二磺酸钠作为Fe~(2+)的显色剂,建立了可见分光光度法测定异烟肼的新方法.在最佳实验条件下,异烟肼的浓度在0.04~3.2μg·mL-1范围内符合比尔定律,表观摩尔吸光系数ε=1.14×104 L·mol~(-1)·cm~(-1),检测限为0.033μg·mL~(-1).方法可用于异烟肼片剂和尿样中异烟肼含量的测定.     

催化还原褪色光度法测定粉煤灰中微量锡

在浓度为0.05mol/LH3PO4介质中痕量Sn(Ⅱ)对NaH2PO2还原罗丹明B(RhB)褪色反应有催化作用,褪色程度与Sn(Ⅱ)含量线性相关,借此建立了测定痕量Sn(Ⅱ)的分光光度法.实验表明,溶液的最大吸收波长为555nm,方法检出限为0.035μg/L,吸光度变化与Sn(Ⅱ)的质量浓度在0～1.0μg/50mL范围内符合比耳定律.本法可用于测定粉煤灰中的微量锡.图1,表1,参7.     

HPLC法同时测定外感风痧颗粒中4种成分

本文建立同时测定外感风痧颗粒中原儿茶酸、原儿茶醛、绿原酸、咖啡酸4种成分的HPLC方法。色谱柱为依利特Hypersil C18柱(250 mm×4.6 mm,5μm);流动相为乙腈-0.2%磷酸,梯度洗脱,流速1.0mL·min~(-1);柱温25℃。结果显示:4种指标成分分离效果良好,原儿茶酸在3.672～33.048μg·mL~(-1)、原儿茶醛在1.236～11.124μg·mL~(-1)、绿原酸在9.2～82.8μg·mL~(-1)、咖啡酸在1.488～13.392μg·mL~(-1)线性关系良好;平均加样回收率均为97.6%～103.3%。本方法准确、灵敏、可靠,重现性较好,可用于外感风痧颗粒的质量控制。     

二溴羧基偶氮胂褪色光度法测定痕量铈

研究了稀土元素铈对二溴羧基偶氮胂的褪色作用.结果表明,在0.05mol·L-1H2SO4介质中,Ce(Ⅳ)对二溴羧基偶氮胂具有很强的氧化褪色作用,且有色溶液的褪色程度与Ce(Ⅳ)量在0.25～10.00μg/25mL范围内符合比耳定律,最大吸收波长为530nm,表观摩尔吸光系数为7.2×106L·mol-1·cm-1,检出限为4.5μg·L-1.据此建立了一种测定痕量Ce(Ⅳ)的新方法,该法可直接用于红豆、土豆等农副产品中痕量铈的测定,加标回收率为92%～102%,样品不需预处理,结果令人满意.     

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