Modification of CdX (X=S, Se) on TiO2 Nanotubular Array Film and Its Photoelectric Performance in Photogenerated Cathodic Protection and Sensitized Solar Cells

二氧化钛(TiO2)是一种重要的无机半导体功能材料，已被广泛应用于太阳能转换等领域。但由于TiO2禁带宽度较宽(3.2eV)，仅能被能量较高的紫外光激发，且光生电子-空穴对快速复合，导致其对太阳光的利用效率较低。通过在TiO2表面复合窄禁带半导体材料，利用半导体能级的交叠，可有效地扩展光响应范围，同时抑制光生电子-空穴对的复合，提高量子产率。 本论文首先在钛金属表面制备高度有序的TiO2纳米管阵列，并以此为基底沉积窄禁带的半导体材料(CdS、CdSe)，制备CdX(X=S，Se)@TiO2复合光阳极。利用扫描电子显微镜、透射电子显微镜、X-射线电子能谱、紫外-可见-近红外分光光度计等对制得的...Titanium dioxide (TiO2) has been proved to be one of the most important semiconductors in various attractive applications based on solar light conversion. However, the fast recombination rate of photogenerated electron-hole pairs in the pure TiO2 and the wide bandgap (3.2 eV) severely hinder its industrial applications. Surface modification of TiO2 with narrow bandgap semiconductors is a promising...学位：理学硕士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：2052008115171

一种高速缓存优化的并行连接算法

连接查询操作是主存数据库中一种较为重要的查询操作。随着计算机芯片技术的发展，中央处理器和内存速度之间的差距越来越大，极大地影响了连接算法的性能。本文通过高速缓存优化技术，提出了一种基于缓冲的高速缓存参数无关的嵌套循环并行连接算法。分析以及实验结果表明，高速缓存优化后的串行连接算法的性能是原来的2倍，其并行算法效果近似线形加速比。中国计算机学

cache optimized parallel join algorithm

由于嵌套循环连接操作过程中存在较大的高速缓存缺失,严重影响了连接查询的性能。提出了一种基于缓冲的高速缓存参数无关的嵌套循环并行连接算法。通过高速缓存参数无关和缓冲技术,提高了连接算法的空间局部性和时间局部性。理论分析和实验结果表明,高速缓存优化后的串行连接算法的性能是原来的2倍,其并行算法效果近似线性加速比

A Study on Co-Doped TiO_2 Nanotube Arrays for Photogenerated Cathodic Protection of Stainless Steel

应用电化学阳极氧化法在纯钛箔表面构筑TIO2纳米管阵列膜,借助离子交换法对纳米管阵列膜作钴离子(CO2+)掺杂.扫描电子显微镜(SEM)、X-射线衍射(Xrd)观察膜层的形貌和晶型,紫外-可见吸收光谱(uV-VIS)、光电化学分别测试CO2+掺杂TIO2纳米管阵列在不同波长范围内的光电响应特性和光生阴极保护行为,考察CO2+掺杂量对TIO2纳米管阵列几何尺寸、形貌和光电性能的影响.结果表明,掺杂适量CO2+形成的杂化能级可有效窄化TIO2带隙宽度,并使光响应扩展至可见光区.CO2+掺杂TIO2纳米管阵列膜在400~650 nM波长范围有较强的光吸收,对403不锈钢光生阴极保护作用明显.A highly ordered Co2 + doped TiO2 nanotube layer was fabricated by potentiostatic anodization of pure titanium in fluorinated electrolyte solutions followed by ion-exchange method.The structure and composition of the as-prepared Co2 + doped TiO2 nanotube layer were characterized by SEM,XRD,UV-Vis,and XPS.The effects of dopant content on the morphologies,structural and photochemical properties of the TiO2 nanotube arrays were investigated.The performances of photogenerated cathodic protection and the photoelectrochemical response for the Co-doped TiO2 nanotube arrays under illumination and dark conditions were evaluated through the electrochemical measurements.The Co-doped TiO2 nanotubes showed a stronger absorption in the visible light range,due to a low recombination of photogenerated hole-electron.The open-circuit potentials of 403 SS(stainless steel) coupled with the Co-doped TiO2 nanotube arrays shifted negatively under visible light irradiation.It was indicated that the Co-doped TiO2 nanotube arrays were able to provide an effective photogenerated cathodic protection for metals under regular sunlight conditions.国家自然科学基金项目(51072170;50731004;21021002);国家863计划项目(2009AA03Z327)资

P-QuantWiz:一种基于质谱的并行非标记定量软件

本文设计并实现了基于质谱的非标记定量软件QuantWiz,通过改变肽段定量的顺序,提高了定量软件的时间局部性和质谱数据缓存的命中次数。分析了QuantWiz的多种数据并行策略,设计并实现了按保留时间划分的并行定量软件P-QuantWiz。通过实验验证P-QuantWiz具有良好的并行效率,当进程数为32时,并行效率为63%

Rapid determination of dicofol in Chinese teas by GC/ECD using microwave-assisted extraction associated with solid phase microextraction

建立了微波辅助萃取-固相微萃取-气相色谱/电子捕获检测法快速测定茶叶中三氯杀螨醇的方法。采用自制的PDMS萃取头,优化了萃取溶剂的种类,微波辐射时间和微波功率等微波辅助萃取条件;研究了SPME萃取时间、搅拌速度、离子强度、解吸温度和解吸时间对萃取效率的影响。方法对三氯杀螨醇的检出限为0.048 ng/mL,线性范围为0.2~200 ng/mL。在优化的实验条件下,对乌龙茶进行添加回收试验,平均回收率为61.3%~72.8%,相对标准偏差为8.0%~16.3%。本方法适合于茶叶中痕量三氯杀螨醇快速检测。A microwave-assisted extraction(MAE) associated with solid phase microextraction(SPME) followed by gas chromatography-electron capture detector(GC-ECD) was developed for the determination of dicofol in tea samples.We used the homemade PDMS fiber as the SPME material in the experiment.The MAE conditions,such as the extraction type,irradiation time and irradiation power were optimized.Several factors influencing the SPME extraction efficiency such as extraction time,stir speed,ionic strength,desorption temperature and desorption time were investigated.The linear range of the method was from 0.2 to 200 ng/mL,and the detection limit was 0.048 ng/mL.Spiked tea samples were analyzed under the optimum MAE and SPME conditions.Recoveries of this method were between 61.3% and 72.8%,and the repeatability was found to be 8.0%～16.3%.The processed approach provides a simple and sensitive method for the rapid determination of dicofol in tea samples.福建省科技重点(2005I-030,2006Y005)项目资

Photogenerated Cathodic Protection of Stainless Steel

应用电化学阳极氧化法在纯钛箔表面构筑TiO2纳米管阵列膜，借助离子交换法向纳米管阵列膜作钴离子(Co2+)掺杂. 扫描电子显微镜(SEM)、X-射线衍射(XRD)观察膜层的形貌和晶型, 紫外-可见吸收光谱(UV-Vis)、光电化学分别测试Co2+掺杂TiO2纳米管阵列在不同波长范围内的光电响应特性和光生阴极保护行为, 考察Co2+掺杂量对TiO2纳米管阵列几何尺寸、形貌和光电性能的影响. 结果表明，掺杂适量Co2+形成的杂化能级可有效窄化TiO2带隙宽度，并使光响应扩展至可见光区，Co2+掺杂TiO2纳米管阵列膜在400-650 nm波长范围有较强的光吸收, 对403不锈钢光生阴极保护作用明显.A highly ordered Co-doped TiO2 nanotube layers were fabricated by potentiostatic anodization of pure titanium in fluorinated electrolyte solutions followed by ion-exchange method. The structure and composition of the as-prepared Co-doped TiO2 nanotube layers were characterized by SEM, XRD, UV-Vis, and XPS. The effects of dopant content on the morphologies, structural and photochemical properties of the TiO2 nanotube arrays were investigated. The performances of photogenerated cathodic protection and the photoelectrochemical response for the Co-doped TiO2 nanotube arrays under illumination and dark conditions were evaluated through the electrochemical measurements. The Co-doped TiO2 nanotubes showed a stronger absorption in the visible light range due to a low recombination of photogenerated hole-electron. The open-circuit potentials of 403 stainless steel coupled with the Co-doped TiO2 nanotube arrays shifted negatively under visible light irradiation. It was indicated that the Co-doped TiO2 nanotube arrays were able to provide an effective photogenerated cathodic protection for metals under regular sunlight conditions.国家自然科学基金 (51072170, 50731004, 21021002), 国家863计划项目(2009AA03Z327)作者联系地址：厦门大学化学化工学院，固体表面物理化学国家重点实验室，福建 厦门361005Author's Address: State Key Laboratory for Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China通讯作者E-mail：[email protected]

A highly efficient ZnS/CdS@TiO2 photoelectrode for photogenerated cathodic protection of metals

Shell-core nanostructured ZnS/CdS quantum dots (QDs) were assembled uniformly on the surface of TiO2 nanotube arrays by sequence chemical bath deposition (CBD) of CdS and ZnS in alcohol solution system The morphology and chemical composition of the obtained composite thin films were characterized by scanning electron microscopy transmission electron microscopy and energy dispersive X-ray spectroscopy The effect of solvent and immersion cycles for the photoanode preparation on the photoelectrochemical activity and photogenerated cathodic protection property was investigated It is found that the nanostructured CdS QDs (20 cycles) coated on TiO2 nanotube arrays show a remarkably enhanced photoelectrochemical activity The coating of ZnS QD shells (5 cycles) is able to improve the stability of the CdS@TiO2 photoanode under white-light irradiation After the irradiation light is turned off the photogenerated cathodic protection of 403 stainless steel (403SS) can be remained for several hours (C) 2010 Elsevier Ltd All rights reservedNational Natural Science Foundation of China [20773100, 50731004, 20620130427]; National High-Tech development Program of China [2009AA03Z327