暴露锐钛矿高能晶面的异质结TiO_2/SrTiO_3光电化学性能研究

通过两步阳极氧化法结合水热法,制备不同水热反应时间条件下的异质结TiO_2/SrTiO_3纳米管阵列,利用X射线衍射(XRD)、场发射扫描电子显微镜(FE-SEM)、场发射投射电镜(FE-TEM)表征手段对异质结TiO_2/SrTiO_3材料进行表征,并通过开路电压谱和瞬态光电流图谱分析对异质结光催化材料的光电化学特性进行了研究,同时紫外光下降解罗丹明B(Rh.B)来研究异质结TiO_2/SrTiO_3材料的光电催化活性和耐光腐蚀稳定性.实验研究表明,TiO_2表面发生原位取代形成Sr TiO_3晶体颗粒,并促使TiO_2锐钛矿(004)晶面的趋向生长.水热1~5,h的异质结TiO_2/SrTiO_3纳米管阵列仍具有较好的催化活性.通过光电性能测试,水热反应2,h后的异质结材料表现出最好的光电化学特性.此外,光电催化结果表明,光电催化200,s、水热反应2,h的异质结材料的降解率是纯TiO_2纳米管的1.71倍,且表现出较好的耐光腐蚀稳定性.     

铁掺杂TiO2纳米管阵列的制备及可见光光催化性能

以硝酸铁为铁源,采用阳极氧化法一步合成Fe3+掺杂的TiO2纳米管阵列.用扫描电镜(SEM)、X-射线能谱仪(EDS)、X射线衍射(XRD)和紫外-可见漫反射吸收光谱(UV-VIS)等测试方法对催化剂进行表征,并通过可见光光催化降解甲基橙溶液,测定其光催化活性.结果表明:高度致密,规整有序的纳米管阵列垂直生长在钛基底表...     

Ti/TiO_2界面的整流特性研究

采用电化学阳极氧化法在钛片表面构筑了一层结构有序、纳米级的TiO2纳米管阵列膜层,考察了制备电压对TiO2纳米管阵列形貌和尺寸的影响,应用扫描电子显微镜(SEM)对膜层的形貌进行了表征,测量了Ti/TiO2界面的整流特性,研究了TiO2纳米管阵列膜层结构与Ti/TiO2界面的整流特性的关系。结果表明:制备电压对TiO2纳米管阵列的结构起到关键的作用,二氧化钛纳米管之所以具有整流特性是由于Ti/TiO2界面具有类似p-n结的性质。利用二氧化钛纳米管的整流特性,人们可以制备出各种性能优良的材料和器件。     

阳极氧化法制备氧化钛纳米管阵列及光催化降解氯胺磷

采用阳极氧化法在氢氟酸+冰醋酸+聚乙二醇水溶液恒压处理钛箔,制备结构规整有序的高密度TiO2纳米管阵列.利用电子扫描电镜(SEM)和X线衍射仪(XRD)对纳米管形貌和结构进行表征,考察氧化时间对纳米管阵列形貌和尺寸的影响,绘制并分析电流-时间曲线.选用有机磷药氯胺磷为光催化降解对象,利用钼锑抗分光光度法测量并计算降解率,研究不同热处理温度和阳极氧化时间对光催化降解效果的影响,并采用溶胶-凝胶法制备TiO2纳米薄膜进行光催化对比实验.     

TiO2纳米管阵列的制备及其光催化效率研究

以质量分数（下同）0.3%NH4F＋ethylene glycol＋1%H2O为电解液采用阳极氧化法制备了TiO2纳米管,研究了阳极氧化时间和退火温度对TiO2纳米管表面形貌、晶体结构和光催化效率的影响,比较了不同电解液制备的TiO2纳米管和溶胶凝胶法制备的TiO2薄膜的光催化效率.应用X射线衍射（XRD）和场发射扫描电镜（FESEM）对TiO2纳米管的形貌和结构进行了分析.结果表明：在阳极氧化恒电压50 V、阳极氧化48 h、450℃退火4 h条件下制备的TiO2纳米管具有最高的光催化效率,其光催化效率明显高于溶胶凝胶法制备的TiO2薄膜（4.4倍）,也高于0.5%HF电解液和弱酸水溶性电解液（0.5%HF＋1 mol/L NH4H2PO4）制备的TiO2纳米管的光催化效率.     

阳极氧化法制备有序TiO_2纳米管阵列

以NH4F/乙二醇为电解液对Ti箔进行阳极氧化,通过对溶液中水的含量、氧化电压、时间等参数的控制,制备了高度有序TiO2纳米管.分别利用XRD和SEM对TiO2纳米管阵列的物相组成和形貌结构进行了表征,结合氧化过程电流密度变化探讨了TiO2纳米管的生长机理.研究结果表明:TiO2纳米管阵列的形成须经历致密氧化层的形成、多孔层的形成以及纳米管的形成与稳定生长3个阶段的演化.     

ZnO纳米颗粒沉积增强TiO_2纳米管光催化活性

采用阳极氧化法制备TiO2纳米管,用光化学沉积法、将纳米管浸没在硝酸锌(Zn(NO3)2)溶液中,在纳米管表面沉积ZnO纳米颗粒.对样品进行了Raman谱、XRD和SEM表征.结果显示,TiO2纳米管为锐钛矿相,沉积ZnO没有改变TiO2的相结构.用甲基橙在紫外光辐照下的降解速率来评价ZnO/TiO2纳米管的催化活性.结果表明,Zn(NO3)2浓度为10-4 mol.L-1时制备的ZnO/TiO2纳米管,其降解甲基橙的活性最高,效率提高40.7%.     

TiO_2纳米管的制备及其在染料敏化太阳能电池中的应用

以氟化铵的乙二醇溶液为电解液,采用电化学阳极氧化法在钛片表面构筑了一层结构有序、纳米级的TiO_2纳米管阵列膜层,应用扫描电子显微镜(SEM)对膜层的形貌进行了表征,利用X射线衍射(XRD)研究了样品的晶相、结构,并分析了阳极氧化电压对TiO_2纳米管尺寸和结构的影响。结果表明:阳极氧化电压对TiO_2纳米管阵列的结构起到关键的作用,随着纳米管的管径和长度的增加,表面积增大。研究了TiO_2纳米管阵列膜层结构对染料敏化太阳能电池(DSSC)性能的影响。结果表明:二氧化钛纳米管阵列薄膜的管径对电池的效率有显著影响,当管径越大时,填充因子变大,DSSC的开路电压降低,而短路电流变大,光电转换效率也随之提高。     

TiO2纳米管的制备方法研究

研究了目前常用的TiO2纳米管阵列的制备方法:模板法,水热合成法和阳极氧化法,对阳极氧化法经常采用的几个电解液体系也做了相应的讨论.本文通过对比不同制备方法所需的实验条件以及所得到的纳米管的形貌,优选出更适合进一步研究的制备方法.阳极氧化法制备的 TiO2 纳米管具有高度有序的纳米阵列结构,并且制备方法简单易行,其缺点在于成本较高.     

TiO2纳米管阵列制备及机理研究进展

TiO2是一种重要的无机功能材料,TiO2纳米管阵列在许多技术领域具有广阔的应用前景.本文综述了TiO2纳米管阵列的制备方法如模板法和阳极氧化法,以及不同制备条件得到的纳米管阵列的形貌特征,通过讨论当前对TiO2纳米管阵列形成机理的不同研究结果,说明TiO2纳米管阵列形成过程中阳极氧化电流随时间的变化趋势,以及这种变化对纳米管阵列微结构的影响因素.最后对TiO2纳米管阵列的应用、发展趋势和需要解决的问题作了简要的阐述.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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     

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