热处理温度及冷却速度对ZnO:Al薄膜性能的影响

采用溶胶一凝胶法在普通玻璃衬底上制备出了Al3+离子掺杂的ZnO(ZnO:Al)透明导电薄膜.利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、四探针法及紫外-可见分光光度计(UV-VIS)等分析方法对制备的薄膜进行了表征,研究了热处理温度及冷却速度对ZnO:Al薄膜结晶状况、电阻率、可见光透过率的影响.研究发现:制备的薄膜为具有沿(002)晶面择优取向的ZnO六角纤锌矿结构,适当的热处理温度和冷却速度有利于改善ZnO:Al薄膜的导电性,并且当采用快速冷却时薄膜的导电性明显增强,而透光率略微减小.500℃热处理1 h后,-15℃环境中快速冷却相对于随炉冷却和空气中冷却制备的薄膜电阻率有大幅度的降低,达到0.22Ω·cm,透光率大于80%.     

热处理温度对TiO2光催化膜性能的影响

用溶胶凝胶法在玻璃纤维网上制备TiO2膜,采用热重仪/差式扫描量热仪(TG/DSC)、负载量测定、X射线仪(XRD)、扫描电子显微镜(SEM)等手段,较为系统地描述了不同热处理温度条件下膜的形貌特点和结构特征;以光催化降解水中苯酚作为探针反应,考察了热处理温度对催化剂降解活性的影响.结果表明,在所采用的焙烧温度范围(350,400,450,500 ℃),500 ℃时锐钛矿TiO2的含量达到最高,晶粒达到最大.随热处理温度的升高,膜催化剂的单层负载量逐渐增大,膜催化剂降解水中苯酚的能力逐渐提高.当苯酚初始质量浓度为2 mg·L-1,反应2 h,4个焙烧温度条件下制得的TiO2膜催化剂对苯酚的去除率都可达90%以上.     

纳米二氧化钛光催化剂膜分解甲基橙

采用溶胶—凝胶法，以普通载玻片为基底材料，制备了纳米二氧化钛薄膜。通过扫描电子显微镜(SEM)、透射电子显微镜(TEn)、X射线衍射仪(XRD)对TiO2薄膜进行晶相结构和薄膜结构表征。利用制备的TiO2薄膜光催化分解甲基橙溶液。实验结果表明：焙烧温度500℃时，制备的TiO2薄膜牢固、透光性能好、光催化活性强。随着紫外光照射时间的延长，镀膜次数达5次时，光催化效率较高。     

掺氮可见光响应TiO2-xNx光催化薄膜的制备及性能初探

采用反应磁控溅射法在玻璃基片上制备N掺杂TiO2-xNx薄膜和纯TiO2薄膜,并且对两种薄膜样品分别进行了300、400和500℃的退火处理.采用X射线光电子能谱仪(XPS)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)和紫外-可见光光度计(UV-Vis)对经过退火处理的样品进行了表征.结果表明:成功制备了N掺杂TiO2-xNx薄膜,部分N进入了TiO2薄膜晶格,并且以N-O键形式存在;N掺杂TiO2-xNx薄膜和纯TiO2薄膜相对比,晶型和表面形貌没有什么太大的区别,但通过紫外-可见光吸收谱图可以发现经过400℃退火处理的N掺杂TiO2-xNx薄膜吸收带边从纯TiO2薄膜的400 nm红移到455 nm.     

La掺杂对纳米TiO2薄膜晶体结构和光催化性能的影响

采用溶胶一凝胶法在玻璃表面制备La掺杂纳米TiO2薄膜;利用X射线衍射仪(XRD)和原子力显微镜(AFM)对其结构和形貌进行表征;通过对紫外光照射下亚甲基蓝溶液的光催化降解率评价其光催化性能;研究不同掺杂量、热处理温度以及pH值对La掺杂纳米TiO2薄膜光催化性能的影响,并对其光催化的影响机制进行探讨.研究结果表明:适量La掺杂能抑制TiO2由锐钛矿相向金红石相的转变,引起晶格膨胀,导致晶格畸变;La掺杂使TiO2的吸收光谱发生红移,扩展TiO2的光谱吸收范围,有效地提高纳米TiO2薄膜的光催化性能,且光催化反应符合一级动力学方程:La掺杂量(摩尔分数)为0.5%的纳米TiO2薄膜在400℃热处理2 h后具有最大的光催化效率98.2%,其光催化效率比纯TiO2薄膜的光催化效率提高约40%.     

TiO2薄膜的半导体和气敏特性

溶胶-凝胶法制备了添加聚乙二醇和Al3 的TiO2薄膜,研究了薄膜的半导体特性和气敏性.添加聚乙二醇使TiO2薄膜的荧光发射峰从未添加的650 nm蓝移至600 nm处.添加聚乙二醇(相对分子质量2000)2.0 g/100mL的TiO2薄膜在还原性气氛中电阻值增大,在350℃下薄膜对1.0×10-3(体积分数)CO的灵敏度约为3.4;进而掺杂离子半径较小的Al3 ,能够提高薄膜对CO的气敏性:在350℃时添加聚乙二醇且Al3 摩尔分数为50/0、100/0的薄膜对1.0×10-3(体积分数)CO的灵敏度分别为5.0和20.4.X射线光电子能谱表征说明,由于Al3 的晶格替代和氧间隙原子使添加有聚乙二醇和Al3 的TiO2薄膜产生以空穴为主的传导机制,表现出P型半导体特性.该研究结果对于研发TiO基的气敏传感器、新型太阳能电池具有重要意义.     

TiO_2/ITO负载型催化剂的制备与表征

采用溶胶凝胶法制备出ITO导电玻璃负载的TiO2薄膜光催化剂.利用XRD、Raman和SEM等手段对催化剂进行表征,结果表明:经500℃焙烧1h的TiO2/ITO薄膜光催化剂,以锐钛矿晶型存在;镀膜4次的TiO2薄膜表面均匀,对紫外光吸收强烈.乙酸的降解实验表明:TiO2/ITO薄膜与等负载量的TiO2粉末相比具有较高的光催化活性.     

TiO2-PVP纳米复合材料的制备、表征及其性能

文章通过在PVP的存在下水解TiCl4,再经过高压釜分别于140 ℃和180℃处理8 h制备TiO2-PVP纳米复合材料,并用红外光谱(IR)、X-Ray衍射(XRD)、透射电子显微镜(TEM)对其进行表征.结果表明,PVP是通过C=O键中的氧原子吸附在TiO2上, TiO2-PVP中的TiO2是锐钛矿型.紫外可见吸收光谱表明,经过胶溶并用高压釜在140 ℃下处理得到的TiO2-PVP制成的薄膜在紫外区有较强的吸收.     

纳米TiO_(2-x)N_x光催化薄膜的制备及其性能表征

采用溶胶-凝胶法制备TiO2溶胶,负载于玻璃微珠表面,并采用NH3气氛焙烧法制得掺氮纳米TiO2薄膜.运用X射线粉末衍射仪、扫描电镜和紫外-可见漫反射吸收光谱等技术,考察不同焙烧温度和负载次数对掺氮的TiO2样品性能的影响.研究结果表明,350,400,450℃热处理的样品的晶相为锐钛矿相,而在500℃时开始出现金红石相,且随温度的进一步升高,金红石相的含量逐渐增多;掺氮的TiO2样品具有可见光吸收性能,450℃热处理的样品达到最佳,其吸收边红移至约720 nm.另外,薄膜的厚度对样品的光催化性能影响显著,负载3次后,样品对罗丹明B的光催化活性最高.     

连续片状纳米TiO2薄膜的制备和表征

采用溶胶-凝胶法，通过在制备过程中加入丙烯酸对纳米TiO2胶体颗粒进行表面修饰以及加入引发剂偶氮双异丁腈(AIBN)引发丙烯酸聚合，利用提拉法在载玻片表面制备了纳米TiO2薄膜；采用热分析仪考察了纳米TiO2胶体颗粒中有机物的热解行为，并用X射线衍射仪测定了经不同温度下焙烧后的纳米TiO2粉体的晶体结构；采用原子力显微镜和透射电子显微镜观察分析了薄膜的微观结构；在对不同制备条件下制备的纳米。TiO2干胶进行红外光谱分析的基础上，初步考察了薄膜成膜机理，结果表明，所制备的TiO2薄膜经400℃烧结处理后形成连续、片状、由粒径为6-8nm的纳米TiO2组成的薄膜材料。     

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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