γ-Fe2O3/Au核壳型纳米粒子制备与表征

以化学还原法制备得到了γ-Fe2O3/Au核壳型纳米粒子,采用紫外可见吸收光谱、X射线衍射和透射电镜对复合纳米粒子的光学性质和形态进行表征,同时利用小角X射线散射技术分析了粒子的粒径与界面结构.     

纳米Fe_2O_3/石墨烯复合材料的制备及其对NaNO_2的电化学传感研究

本文利用水热合成法制备了Fe2O3纳米粒子(Fe2O3NPs)和纳米Fe2O3/石墨烯(rGO-Fe2O3NPs)复合材料,分别用于修饰电极,制备了检测亚硝酸钠(NaNO2)的电化学传感器,并详细考察了其性能指标.X射线衍射(XRD)和扫描电子显微镜(SEM)实验结果表明制备的rGO-Fe2O3NPs分布均匀,Fe2O3NPs与rGO直接混合可以实现Fe2O3纳米粒子在rGO表面的负载,混合后其形貌发生了较大的改变.通过实验检测,结果表明氧化铁纳米粒子的修饰电极表现出较好的传感器效果,掺杂石墨烯材料的传感性能略提高一些.     

Bi2O3/Cu-O-Cr核壳结构纳米复合物的合成

采用沉淀法制得球形单分散Bi2O3纳米粒子；通过共沉淀法制备球形单分散Bi2O3／Cu-O-Cr核壳结构复合纳米材料,通过X射线衍射、透射电镜、能谱分析和红外光谱等技术表征所合成材料的成分组成、晶体结构、微现形貌以及颗粒尺寸，并对Bi2Oa／Cu-O-Cr核壳结构的复合纳米粒子的形成机理进行研究。研究结果表明：在包覆前先对Bi2O3粒子进行表面铵离子（NH4^＋）功能化是形成均匀核壳纳米结构的关键；铜铬包覆层以氨配合物的形式包在Bi2O3粒子表面，形成棱壳结构的复合粒子，复合粒子的平均粒度为78nm．核厚为60nm．     

ZnFe2O4@SiO2纳米核壳结构的合成及磁性随退火温度的演化

采用水热法合成了直径为10~15 nm的ZnFe2O4磁性纳米颗粒,将ZnFe2O4磁性纳米粒子添加到TEOS中,水解后得到ZnFe2O4@SiO2核壳结构的纳米复合材料,TEM图像证实了复合材料具有直径约为20 nm的核壳结构.制备出的ZnFe2O4磁性纳米粒子和ZnFe2O4@SiO2核壳结构纳米复合材料都表现出了顺磁性,温度低于800 ℃时ZnFe2O4磁性纳米粒子仍然具有顺磁性,温度高达580 ℃时ZnFe2O4@SiO2核壳结构纳米复合材料还是显示出了超顺磁性,这意味着ZnFe2O4和ZnFe2O4@SiO2磁性纳米粒子具有良好的磁稳定性.由于SiO2壳具有很好的亲水性和抗酸性,ZnFe2O4@SiO2核壳结构纳米复合材料未来可应用于磁疗法治疗癌症.     

TiO2纳米刺球制备和表征

采用溶胶-凝胶法制备出球形TiO2纳米粒子,通过离心的方法将TiO2纳米粒子从乙醇中转移到水中.在60℃下,将分散剂聚乙烯吡咯烷酮(PVP)和刻蚀剂NaBH4加入到TiO2纳米粒子水分散体系中,经61h的恒温刻蚀反应,制备出TiO2纳米刺球.此外,该刻蚀方法同样被应用于Au@SiO2@TiO2纳米刺球的制备.用扫描电子显微镜(SEM)、动态光散射(DLS)、透射电镜(TEM)及X射线衍射实验(XRD)等方法对TiO2纳米粒子和Au@SiO2@TiO2纳米粒子及其纳米刺球进行表征,进而探索NaBH4刻蚀TiO2的机理.该刻蚀方法所需的设备和实验步骤相对简单,反应条件温和可控,较易实现大批量的TiO2纳米刺球的合成并且也适用于外壳层为TiO2的复合核壳结构纳米刺球的制备.     

Keggin型多金属氧酸盐Cs3PMo12O40·12H2O纳米粒子的微乳液法的制备

在二(2-乙基己基)磺基琥珀酸钠/ n-C7H16H2O(AOT)微乳液体系中制备出Keggin型多金属氧酸盐Cs3PMo12O40·12H2O纳米粒子,由透射电镜照片观察到这种球形纳米粒子的平均尺寸为60 nm.当杂多酸阴离子PMo12O3-40的浓度增大到50 mol/ m3时,粒子直径增加到200 nm.IR光谱和X射线粉末衍射测定结果表明:纳米粒子中的PMo12O3-40阴离子仍然保持Keggin结构,并且这些纳米粒子的固相为结晶态.     

ZnO纳米片的水热合成及其光催化性能

目的以Zn(CH_3COO)_2·2H_2O和NaOH为原料,制备ZnO纳米粒子,并研究ZnO纳米材料的形貌对其光催化性能的影响。方法采用一步水热法合成ZnO片状纳米粒子,通过X-射线粉末衍射(XRD),场发射扫描电镜(FE-SEM)和拉曼光谱(Raman)等分析手段对合成产物的结构和形貌进行表征,探讨反应物摩尔比、水热温度和水热时间等合成条件对形成的ZnO纳米粒子形貌的影响,以及形貌演变机理。通过光催化分解水实验对所制备的ZnO纳米粒子的光催化性能进行测试。结果 Zn~(2+)/OH~-摩尔比为1∶4时,在100℃反应6h,可制得片状的纳米ZnO,其产氢量为313μmol·h~(-1)·g~(-1)。结论在本文制备的ZnO纳米材料中,ZnO纳米片的光催化性能优于短棒状和纤维状的ZnO粒子。     

TOPO包裹单晶体α-Fe2O3纳米粒子的合成与表征

在不锈钢高压反应釜中,应用水热合成和相转移技术,经过反应条件的筛选和优化,成功制备了TOPO(Trioctylphosphine Oxide,[CH3(CH2)6CH2]3P＝O)键合包裹的单晶α-Fe2O3纳米粒子.X-射线粉末衍射确定固体晶相为单晶α-Fe2O3.透射电镜(TEM)观测其所制得的纳米粒子的粒径分布很均匀,在(6.5±0.5)nm左右.其纳米粒子可以很均匀地分散在非极性有机溶剂中,可望作为磁性液体和颜料.     

利用聚乙烯吡咯烷酮制备银纳米粒子

利用聚乙烯吡咯烷酮(PVP)的还原性,通过水热法还原Ag2O制备了Ag纳米粒子,并初步探讨了PVP作为还原剂的还原机理.利用X-ray粉末衍射(XRD)、透射电子显微镜(TEM)和选区电子衍射(SAED)对Ag纳米粒子进行了表征分析.实验结果发现,PVP在制备Ag纳米粒子的过程中可同时起到还原剂和表面活性剂的双重作用.     

无定型二氧化硅包裹的Au纳米棒(Aunanorod@mSiO2)的合成条件优化

目的 合成Au纳米棒,并以Au纳米棒为核心,合成复合纳米结构(Au_nanorod@mSiO_2)并优化合成条件。方法 首先采用种子生长法制备Au纳米棒,合成的长径比为4.8;然后,将正硅酸乙酯在碱性条件下进行水解,在常温下,调节pH值在9~10之间,低速搅拌的条件下,借助于自组装技术,在Au纳米棒表面可以形成不同厚度二氧化硅层。利用透射电镜（TEM）,X射线衍射（XRD）和紫外吸收光谱表征复合纳米粒子。结果 所合成的纳米粒子经TEM表征,展示了层次分明的核壳结构,Au作为核心,二氧化硅层作为外壳层。XRD表明复合结构中存在Au的衍射峰与二氧化硅衍射峰。通过紫外吸收光谱表明,随着二氧化硅层厚度的增加,吸收峰发生红移现象。结论 在优化条件下可合成不同二氧化硅层厚度的复合纳米粒子Au_nanorod@mSiO_2。     

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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