TiO2-SiO2复合半导体气凝胶制备及光催化活性研究

ＴｉＯ２－ＳｉＯ２复合半导体气交是一种新型纳米光催化氧化剂。本文以正硅酸乙酯、钛酸丁酯为原料,用溶胶－凝胶法经超临界干燥制备出了ＴｉＯ２－ＳｉＯ２复合半导体气凝胶。研究了ＴｉＯ２：ＳｉＯ２不同配比对溶胶－凝胶过程的影响;用ＢＥＴ、ＸＲＤ、ＳＥＭ、ＴＥＭ等测试方法对其结构进行了表征;以苯酚为探针考察了ＴｉＯ２－ＳｉＯ２复合半导体气凝胶的光催化氧化活性,并与普通锐钛矿型钛白粉光催化剂进行了对比结果表明     

以正钛酸为原料制备纳米TiO2光催化剂

以正钛酸为原料,通过直接水解法制备纳米ＴｉＯ_２;并对样品分别进行了差热分析、Ｘ射线衍射分析和透射电子显微镜分析．结果表明,样品粒子为混晶型纳米ＴｉＯ_２,单分散性良好,粒径分布范围狭窄．当它应用于阴离子表面活性剂十二烷基苯磺酸钠的光催化降解时,与Ｐ－２５光催化剂相比,具有较好的催化活性．同时,我们用Ａｌ_２Ｏ_３陶瓷膜回收纳米ＴｉＯ_２循环再利用;这为纳米ＴｉＯ_２在环保方面的大规模应用创造了条件．     

铁、铬离子掺杂对TiO_2薄膜光催化活性的影响

采用溶胶－凝胶法在釉面砖表面制备了均匀的ＴｉＯ２薄膜,并研究了铁、铬离子掺杂对ＴｉＯ２光催化性能影响．对罗丹明Ｂ的光降解实验表明,适量的铁、铬离子掺杂均可提高ＴｉＯ２薄膜的光催化活性,铁离子的掺杂效果明显高于铬离子,而铬离子的掺杂方式影响ＴｉＯ２薄膜的光催化活性,这主要基于它们不同的掺杂机理     

Y^3＋掺杂TiO2复合粒子的光催化活性研究

以钛酸丁酯和氧化钇为原料,采用溶胶－凝胶法研究了Ｙ＾３＋掺杂对ＴｉＯ２光催化活性的影响,通过红外光谱（ＩＲ）分析了ＴｉＯ２复合粒子的结构,结果表明：Ｙ＾３＋掺杂能够显著提高ＴｉＯ２粒子的光催化活性,当掺杂比为１００∶１．５（Ｙ＾３＋外加１．５％）时光催化活性最高,分析了Ｙ＾３＋掺杂ＴｉＯ２粒子光催化活性提高的原因。     

纳米TiO2光催化降解水中有机污染物的研究与发展

光催化降解水中有机污染物是一项新兴的颇有发展前任的废水处理技术,纳米Ｔｉｏ２因其活性高,稳定性好而在该领域广泛被用作光催化剂。本文系统介绍了纳米ＴｉＯ２的制备,光催化降解水中有机污染物的机理,动力学规律及其研究现状和发展方向。     

溶胶—凝胶法制备TiO2／Pt／glass纳米薄膜及其光电催化性能

本文采用Ｓｏｌ－ｇｅｌ法制备了ＴｉＯ２／Ｐｔ／ｇｌａｓｓ纳米光催化薄膜，并进行了结构和乐电催化性能的测试。薄膜对染料溶液的光电催化降解结果表明，当输入正向偏压后，ＴｉＯ２／Ｐｔ／ｇｌａｓｓ薄膜的光催化性能有一定提高，且随着偏压增大而增强。同时，薄膜的中间层Ｐｔ及光源强度对薄膜的光电催化活性也有较大影响。     

纳米TiO2粉体的制备及应用进展

纳米ＴｉＯ２粉体在催化、功能陶瓷、化妆品、化纤及环境工程等领域具有广阔和潜在的应用。本文根据国内外研究者的报道及作者近期对纳米ＴｉＯ２的制备研究,介绍了纳米ＴｉＯ２的合成及应用。     

纳米 TiO2的高分子"锚定位"包覆

通过多组分溶液的原位合成方法,成功地制备了ＴｉＯ２／聚苯乙烯－马来酸酐（ＰＳＭＡ）纳米复合材料．红外普图（ＩＲ）分析了这种材料的化学构成,证明纳米ＴｉＯ２与高分子是以共价键的形式存在．随着反应条件的改变,透射电镜（ＴＥＭ）观察到了纳米ＴｉＯ２在复合物中有规律的形貌变化．综合实验结果,提出高分子“锚定位”包覆的作用模型,形象地说明了这种材料以三维网络、纳米晶ＴｉＯ２微相分离的形式存在,同时ＴｉＯ２颗粒的团聚几率在相当大程度上得以降低．结合Ｘ射线衍射,还确定出了复合物中纳米ＴｉＯ２的锐钛矿型结构．     

硬脂酸法制备纳米TiO_2及微结构控制

采用硬脂酸法制备了不同掺杂量的ＴｉＯ２纳米晶．通过ＦＴＩＲ、ＸＲＤ和ＴＥＭ等实验手段对所得纳米ＴｉＯ２进行分析和表征,并对反应历程进行了初步探讨．实验结果表明,利用硬脂酸法,金红石型ＴｉＯ２能在５００℃获得,掺杂Ｎａ＋和Ｋ＋后则得到锐钛矿型ＴｉＯ２,且随着掺杂量的增加,ＴｉＯ２的粒径减小．     

纳米TiO2的高分子锚定位包覆

通过多组分溶液的原位合成方法,成功地制备了ＴｉＯ２／聚苯乙烯－马来酸酐纳米复合材料,红外谱图分析了这种材料的化学构成,证明纳米米ＴｉＯ２与高分子是以共价 形式存在。随着反应条件的改变,透射电镜观察到了纳米ＴｉＯ２在复合物中有规律的形貌变化。     

环保型TiO2薄膜玻璃性能的研究

采用溶胶－凝胶法在玻璃表面制备了TiO2薄膜和掺杂铈或镧TiO2薄膜，利用高效液相色谱仪（HPLC）、紫外－可见分光光度计、扫描电镜（SEM）等测试手段，研究了不同气氛条件下热处理的TiO2薄膜对油酸光催化降解的影响，TiO2薄膜中掺杂稀土铈或稀土镧对油酸光催化降解的影响，薄膜内TiO2晶粒的分布及形态，薄膜表面化学稳定性等。结果表明空气气氛下处理的TiO2薄膜光催化效率最高。掺杂铈或镧有利于提高TiO2薄膜的光催化降解效率，涂层有利于提高玻璃的化学稳定性，但提高的程度不一。     

太平洋牡蛎(Crassostrea gigas)鳃氯细胞的超微形态研究

利用透射电子显微镜研究了太平洋牡蛎鳃氯细胞的超微结构。氯细胞主要分布于鳃小叶的基部,呈口袋状,细胞个体较大,在鳃表面有一凹隐的分泌腔。细胞中,细胞核多位于基部,体积较小;具有发达的微细小管系统,但小管的分支程度低;线粒体数量较少且结构不够发达;可见少量的高尔基体,未见内质网。鳃氯细胞是太平洋牡蛎鳃渗透压调节的重要细胞系统。     

2003年SARS对中国交通客运量影响的后评价研究——基于本底趋势线全国28个省(市)自治区的分析与估算

2003年SARS是中国公众健康的“灾难”，交通旅客运输因此蒙受巨大损失。依据本底趋势线理论，对此次危机的交通客运量损失进行了定量估算。结果显示：2003年SARS共造成交通旅客损失10．07亿人次，其中，公路损失8．88亿人次，铁路损失1．05亿人次，航空损失1611．7万人次，水运损失1943万人次；危机的生命周期从2003年4月开始，5～6月全面爆发，7～8月消减衰退，11～12月有一定的补偿；由于交通区位和SARS疫情的差异．全国28个省（市）自治区客运量损失可划分为4个等级，其中，广东、四川、河北3省客运量损失超过l亿人次；以28个省（市）自治区客运量损失与2003年本底值、SARS确诊人数建立空间预报模型，结果显示，客运量本底值边际系数为0．78846，SARS确诊人数边际系数为0．075868。     

Brain tumor detection and diagnosis using ANFIS classifier

In this article, the segmented brain tumor region is diagnosed into mild, moderate, and severe case based on the presence of tumor cells in the brain components such as Gray Matter (GM), White Matter (WM), and cerebrospinal fluid (CSF). The modified spatial fuzzy c mean algorithm is used to segment brain tissues. The feature Local binary pattern is extracted from segmented tissues, which is trained and classified by ANFIS Classifier. The performance of the proposed brain tissues segmentation system is analyzed in terms of sensitivity, specificity, and accuracy with respect to manually segmented ground truth images. The severity of brain tumor is diagnosed into mild case if the segmented brain tumor is present in the grey matter. The severity of brain tumor is diagnosed into moderate case if the segmented brain tumor is present in the WM. The severity of brain tumor is diagnosed into severe case if the segmented brain tumor is present in the CSF region. The immediate surgery is required for severe case and medical treatment is preferred for mild and moderate case.     

基于双寡头竞争的航空客运模糊销售定价决策

针对近年来航空公司机票销售领域流行的模糊分销模式,利用Hotelling模型建立了季末单一模糊销售以及直销与模糊销售共存的双寡头竞争模型,求解供大于求和供小于求下两种销售模式各利益主体的均衡价格及收益,旨在发现哪种销售模式更有利于提高航空公司的收益。研究表明,当市场竞争激烈时,模糊分销模式存在,且季末共同销售策略下航空公司的期望总收益高于单一模糊销售,同时模糊中介商有动力实施该模式,凸显了双渠道同期销售对市场需求的引导作用。该研究结果可为航空公司竞争环境下的均衡定价决策和销售模式选择提供理论参考。     

An inverse problem technique for detecting irregular cavities in circular cylinders by infrared scanning

An inverse problem technique has been developed for detecting irregular cavities in circular cylinders. In this method, the cavity is considered a part of the unknown geometry of the investigated system, and the evaluated temperature is used to locate this geometry. An auxiliary problem is introduced in the solution of this problem; and in the solution, the cavity wall is located by forcing the temperature to satisfy the condition imposed at the cavity. The new methodology is validated by an experiment presented in this paper, and the test results indicate that this method is highly successful in locating cavities. The accuracy of the method is closely related to the accuracy of the temperature that can be measured at the surface. A small error in the surface temperature results in a slight cavity error for deep cavities, while a shallow cavity is not severely affected by a surface temperature error. This method is particularly attractive in detecting shallow cavities in nondestructive evaluation.     

Influence of vanadium on grain boundary segregation of phosphorus in iron and iron-carbon alloys

The influence of vanadium on grain boundary segregation of phosphorus has been studied in iron and iron-carbon alloys by means of fracture experiments in a scanning Auger microprobe. The emphasis here is to study the effects of vanadium on the interaction processes operative under circumstances when structure in the interior of the grain (in the present case carbide formation) and grain boundary segregation form simultaneously. It is emphasized that to predict and analyse the behaviour of an alloy, it is important to consider atomic interactions both at the grain boundaries and in the grain interior and that between the constituents and the grain boundaries. The study suggests that the principal determining factor in the scavenging or retardation of migration of phosphorus to the grain boundaries is whether vanadium is present in the combined form (say, carbide) or is available in solid solution form. When vanadium is present in solid solution form, grain boundary segregation of phosphorus is low because of the chemical interaction of vanadium and phosphorus. However, as carbon is increasingly introduced in the alloy, vanadium now preferentially reacts with carbon in view of higher interaction for carbon as compared to phosphorus. A consequence of this is the increase in the grain boundary concentration of phosphorus. In such a situation the presence of excess carbon in addition to what is stoichiometrically required to precipitate the entire vanadium as vanadium carbides, serves as a palliative with regard to the reduction in the intergranular concentration of phosphorus. This palliative behaviour is explained in terms of the sitecompetition model. An effort is also made to examine the behaviour of segregating elements in terms of whole range of probable interactions (both at the grain boundaries and in the grain interior) and chemical interaction energies.     

基于霍尔效应的感应式瞬时旋转角速度传感器

设计了一种基于霍尔效应的感应式瞬时旋转角速度传感器,主要包括定子铁心及绕组、霍尔元件和永磁转子3大部分,且永磁转子的磁通在空间气隙中呈正弦规律分布。传感器工作时,永磁转子与被测旋转设备同轴连接,永磁转子的磁场与定子绕组匝链耦合,绕组中产生与瞬时旋转角速度呈对应关系的感应电动势。由于定子绕组与霍尔元件的控制端直接连接,则霍尔元件中存在电流,在永磁转子磁场的作用下,霍尔元件产生与瞬时旋转角速度成正比的直流霍尔电势。推导了传感器的输出特性,并对传感器进行了特性测定实验,结果表明其灵敏度系数约为203 mV/(rad·s^-1),线性误差约为0.5%。     

用ObjectARX实现设计图纸的管理

对制造业中设计人员最关心的设计图纸的计算机管理问题进行了研究和开发。对AutoCAD中的ObjectARX技术的功能和特点进行了概述，提出了对设计图纸的图形文件采用以设计号为基础的树型管理方式，并通过ObjectARX技术，以AutoCAD为背景，实现对设计图纸的自动化管理；同时介绍了图纸数据库的存储模式，并对于如何在数据库中定义存储过程和使用触发器给出了程序实现方法。