磷钼杂多酸光度法测定水果、蔬菜、药物中抗坏血酸

研究了抗坏血酸磷钼蓝的显色反应体系 ,考察测定最佳条件 ,建立了一种测定水果、蔬菜、药物中抗坏血酸含量的方法 .该法检测限为 1 .0× 1 0 - 7g/m L,抗坏血酸质量浓度 0 .0 1 0～1 .5 0 0 mg/5 0 m L范围内服从比尔定律 .已用于水果蔬菜中抗坏血酸的测定 .     

二氧化钛光催化还原银离子探针反应的研究

探讨了以微量银离子为光化学反应的探针,依据金属离子光催化还原反应评价催化剂的光催化活性的方法.选择晶粒度为25nm的锐钛矿二氧化钛为研究对象,研究了紫外光照射下此催化还原反应的反应动力学特性,考察了二氧化钛浓度和银离子浓度对光催化反应速率的影响,确定了适合该评价方法的优化操作条件,并通过TEM和XRD等手段对反应后的固体颗粒物进行了表征.结果表明,在254nm的紫外光照射下,二氧化钛光催化还原银离子具有一级反应动力学特征,水溶液中的银离子在二氧化钛表面发生还原生成单质银.评价二氧化钛活性的优化操作条件为二氧化钛浓度为0.4g/L,银离子初始浓度为10~15mg/L时.检测了4种不同粒径二氧化钛的光催化活性,结果表明银离子适合作为光催化反应的探针.     

紫外光催化氧化消解-氢化物发生-原子荧光光谱法测定人发中Se

采用紫外光催化氧化消解试样,氢化物发生-原子荧光光谱法测定人发中Se含量的方法.探讨了消解条件、原子荧光光度计工作条件及氢化物发生反应条件,对比沸水浴加热和紫外光加热2种将Se (Ⅵ)还原为Se (Ⅳ)的方法,研究氨基磺酸消除氮氧化物干扰的最佳条件.在最佳实验条件下测定人发标准参考物质和人发试样中Se的含量,方法的检出限为0.08 μg/L (相对标准偏差为2.1%),荧光强度与Se (Ⅳ)的质量浓度在0～10 μg/L范围内呈线性关系.研究结果表明,人发标准参考物质中Se的测定值与标示值相吻合.人发试样中Se的质量分数与文献值(0.4～0.9 μg/g)一致.     

渗透性反应墙去除地下水中硝酸盐的试验研究

通过柱试验模拟地下水环境,研究了在最适温度条件下,利用混合碳源为介质的生物反应墙与模拟沸石墙串联的组合反应器,考察其对地下水中硝酸盐氮的去除效果,为受硝酸盐污染的地下水提供经济有效的修复方法.结果表明,在30℃条件下,通入硝态氮浓度为65 mg/L的地下水,以锯末和玉米秸秆的混合物作为碳源,沸石作为进一步的修复反应能有效的去除模拟地下水中的硝酸盐.在15 d的运行时间内,模拟装置对水中的硝态氮去除率为90%以上,试验过程中出现亚硝酸盐和氨氮的积累,其中出水中亚硝酸盐氮浓度为0.020~0.120 mg/L,氨氮浓度为0.7~2.5 mg/L,出水p H值介于6.7~7.7之间.     

大气中二氧化硫的分析

采用还原分光光度法对大气中的二氧化硫进行了测定.通过一系列单一条件实验确定了还原反应发生的最佳体系.在反应体系中微量二氧化硫能迅速还原三价铁为二价铁,使邻二氮菲-铁(Ⅱ)配合物浓度增加,以此测定二氧化硫的含量.实验发现邻二氮菲-铁(Ⅱ)红色配合物经有机溶剂异戊醇萃取后,其吸光度增大,测定的灵敏度提高,最大摩尔吸光系数(ε)由原来的9.93×104L(cm.mol)-1增大到1.13×105L(cm.mol)-1.检出限为0.008 6μg/mL,RSD为1.6%.方法简便灵敏,精密度高,线性关系达0.999.将该法用于大气中二氧化硫的测定,获得满意的结果.     

甾体5α-还原酶抑制剂的高效液相色谱法体外筛选模型

报道了一种用高效液相色谱法(HPLC)筛选甾体5α-还原酶抑制剂的体外模型.将甾体5α-还原酶液、睾酮溶液、辅酶(NADPH)与5α-还原酶抑制剂(非那甾胺和爱普列特)在37℃下反应30 min,反应终止后,通过HPLC测定反应前后底物睾酮量的变化来分析酶的活性,进而由酶活性的降低来判断抑制剂对5α-还原酶的抑制作用.将实验数据按Lineweaver-Burk倒数作图,求得甾体类抑制非那甾胺抑制常数Ki=4.32±0.38μmol/L,爱普列特抑制常数Ki=1.14±0.23μmol/L.实验所得的数据和图形均说明了本实验所采用的高效液相色谱法作为一种甾体5α-还原酶抑制剂体外筛选模型是简便可行的.     

过氧乙酸的现场电化学转换及其化学发光法测定

通过碳糊电极上过氧乙酸的现场电化学转换及其原位化学发光检测,研究了过氧乙酸对鲁米诺在硼砂介质中弱电化学还原发光信号的强增敏作用,据此建立了一种新的过氧乙酸电化学发光分析方法.结果表明,在实验条件下相对电化学发光强度和过氧乙酸的浓度在8 X 10-9～2 X10-6 mol/L范围内呈线性关系,检出限为2.7×10-9 mol/L(σ=3).对浓度为8 X 10-8 mol/L的过氧乙酸平行测定11次,相对标准偏差为0.3%.此方法可用于医用过氧乙酸消毒液中过氧乙酸的含量测定.     

小球藻培养基优化及脱氮效果

为了得到有利于小球藻生长的最佳培养基,采用单因子实验和正交实验方法,在无菌条件和开放培养条件下对小球藻的培养基进行优化和放大,并考察小球藻对氨氮和硝酸盐氮的脱氮效果.结果表明,在无菌条件下利于小球藻生长的培养基组成为:0.2 g/L(NH_2)_2CO,0.5 g/L NH_4Cl,0.75 g/L NaHCO_3,0.03 g/L KH_2PO_4,5 g/L葡萄糖,0.3 g/L MgSO_4·7H_2O,0.008 g/L FeSO_4·7H_2O.在此培养基中培养4 d小球藻的浓度可达2.15×10~8 CFU/mL,为优化前的26.7倍.在开放培养条件下,当葡萄糖质量浓度为0.3 g/L,其他成分与无菌条件相同时,小球藻细胞浓度可达9.9×10~7 CFU/mL,并在1 000 L的容器中得到成功放大.小球藻对氨氮和硝酸盐氮的绝对去除速率随着底物浓度的升高而增大,当底物质量浓度为1 000 mg/L时,小球藻对氨氮和硝酸盐氮的去除速率分别达到16.4 mg/(L·h)和17.8 mg/(L·h).     

表面活性剂增敏苏丹红B褪色反应光度法测定亚硝酸根

构建了一种测定亚硝酸根的催化动力学光度法.基于稀硫酸介质中,阳离子表面活性剂十六烷基三甲基溴化铵对亚硝酸根催化溴酸钾氧化苏丹红B褪色反应的增敏作用,建立了测定亚硝酸根的表面活性剂增敏催化动力学光度法.通过实验条件的优化,在30℃,反应时间从反应开始到3min为止,495nm处用分光光度法测定反应体系吸光度的减少值,从而测定其反应速率.实验结果表明,加入十六烷基三甲基溴化铵后,非催化体系吸光度A0和催化体系吸光度A的差值ΔA(=A0-A)增大约1倍.研究了催化反应的动力学条件,测定了反应的表观速率常数k为3.07×10-4s-1和表观活化能Ea为57.44kJ/mol.体系ΔA值与亚硝酸根的浓度在0.01~0.2mg/L范围内呈良好的线性关系,检测限为5.0μg/L.用于泡椒鲜竹食品中亚硝酸根的测定,结果满意.     

黄钾铁矾渣浸出液还原和深度净化

以热酸直接浸出黄钾铁矾渣的浸出液为原料,采用单因素法对浸出液还原、硫化沉淀除隔和氟化沉淀除钙除镁的工艺进行研究.浸出液还原实验结果表明:在反应温度80℃,时间2 h,搅拌速度150~200 r/min,铁粉加入量为理论量1.15倍的条件下,浸出液中Fe3+全部被还原,铁锌比接近低功耗锰锌铁氧体的理论配方,杂质Cu2+的质量浓度降到1 mg/L,去除率在99%以上,Cd2+的去除率为17%.硫化沉淀除隔实验结果表明:浸出液还原反应完成后,直接在其中加入理论量1.4倍的(NH4)2S,反应时间为30 min,溶液中杂质Cd2+的质量浓度降到1 mg/L以下,去除率在98%以上.氟化沉淀除钙除镁综合实验研究中,溶液中Mg2+、Ca2+的除去率分别为96.73%和76.67%.     

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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