Thickness Dependence of Resistivity and Optical Reflectance of ITO Films

Indium-tin-oxide （ITO） films deposited on crystalline silicon wafer and Corning glass are prepared by directcurrent magnetron sputtering method at room temperature with various thicknesses. The thickness dependences of structure, resistance and optical refectance of ITO films are characterized. The results show that when the film thickness is less than 40 nm, the resistivity and optical reflectance of the ITO film changes remarkably with thickness. The optoelectrical properties trend to stabilize when the thickness is over 55 nm. The GXRD result implies that the ITO film begins to crystallize if only the thickness is large enough.     

Substrate Dependence of Properties of Sputtered ITO Films

High-quality indium-tin-oxide (ITO) films are deposited on p-type Czochralski silicon and 7059 Coming glass by direct-current magnetron sputtering at various temperatures. The structural, electrical and optical properties of the ITO films are investigated as functions of the substrate temperature. A comparison between the characteristics of the ITO films on silicon and Coming glass is presented. The results show that for the ITO film on silicon,the nucleation begins from room temperature; the resistivity reaches a maximum value at 75℃; the reflectivity increases with increasing temperature; when temperature is above 125℃, the ITO grows in a three-dimensional manner and forms a granular structure. However, for the ITO film on glass, it is still in an amorphous state at 75℃. Moreover, both the resistivity and the reflectivity decrease with increasing temperature. Above 125℃, the ITO grows in a two-dimensional manner and forms a domain structure.     

沸石咪唑酯骨架结构材料ZIF-71用于低浓度生物基2，3-丁二醇/1，3-丙二醇的吸附分离性能

1,3-丙二醇是一种重要的化工原料,生物发酵法生产1,3-丙二醇往往会产生副产物2,3-丁二醇,限制了生物基1,3-丙二醇的进一步工业化应用。1,3-丙二醇与2,3-丁二醇亲水性强,导致其在低浓度发酵液中分离困难。基于2,3-丁二醇比1,3-丙二醇具有长的碳链和大的极化率,本文采用含有―Cl基团（憎水且具有大的极化率）的ZIF-71吸附分离水中低浓度的2,3-丁二醇/1,3-丙二醇。结果表明,ZIF-71对双组分2,3-丁二醇/1,3-丙二醇（50 g/L,50 g/L）中2,3-丁二醇的静态竞争吸附容量为123.6 mg/g,对2,3-丁二醇/1,3-丙二醇分离选择性高达7.6,分离效果优于沸石材料Beta。在3次循环吸附-解吸实验中ZIF-71依旧保持着稳定的结构和对2,3-丁二醇的选择性吸附能力。通过分子模拟,揭示了ZIF-71对1,3-丙二醇和2,3-丁二醇的吸附分离机制。ZIF-71与1,3-丙二醇之间主要通过弱的范德华力作用;而ZIF-71与2,3-丁二醇之间则是通过强的范德华力与弱的氢键协同作用,从而对2,3-丁二醇产生选择性吸附。可以看出, ZIFs材料有望成为选择性吸附分离低浓度副产物2,3-丁二醇的吸附剂,推动生物法制1,3-丙二醇的工业化发展。     

Effect of Annealing Conditions on Properties of Sol-Gel Derived Al-Doped ZnO Thin Films

Transparent conductive Al-doped ZnO （AZO） thin films are prepared on normal glass substrates by the sol-gel spin coating method. The effects of drying conditions, annealing temperature and cooling rate on the structural, electrical and optical properties of AZO films are investigated by x-ray diffraction, scanning electron microscopy, the four-point probe method and UV-VIS spectrophotometry, respectively. The deposited films show a hexagonal wurtzite structure and high preferential c-axis orientation. As the drying temperature increases from 100℃ to 300℃ the resistivity of AZO films decreases dramatically. In contrast to the annealed films cooled in a furnace and in air, the resistivity of the annealed film which is cooled at -15℃is greatly reduced. Increasing the cooling rate dramatically increases the electrical conductivity of AZO films.     

Al^＋注入316奥氏体不锈钢表面改性的研究

利用６０ｋｅｖ的Ａｌ＋以４×１０￣（１７）ｉｏｎｓ／ｃｍ￣２的剂量对３１６奥氏体不锈钢进行了离子注入，并对注入前后之试样的显微硬度、摩擦磨损性能和电化学腐蚀性能进行了试验研究，还对Ａｌ”注入表面改性的机理作了探讨。结果发现，Ａｌ￣＋注入对３１６奥氏体不锈钢表面改性的效果很好，可以使其显微硬度提高４３．７％，摩擦系数降低约５０％，耐磨性能也有明显提高，同时还能使这种材料的腐蚀电流密度和腐蚀速率分别降低３个数量级和９个数量级。微观分析表明，注入的Ａｌ￣＋主要以替代方式存在于奥氏体结构中，改性层内大量替代式缺陷和空位型缺陷的存在造成了较大的晶格畸变，从而增强了固溶强化的效果。另外，由于铝和氧的亲和力很强，不仅容易在不锈钢表面形成氧化膜，而且还有助于磨损过程中氧化膜的形成与修复，因此，Ａｌ￣＋的注入能使３１６奥氏体不锈钢由粘着磨损转变为以氧化磨损为主的磨损机制。     

单摆近似周期的新形式及构造分析

通过对比单摆严格周期的级数展开式,给出了一个新的单摆周期近似公式及其修正形式.在振幅小于114°(136°)的范围内,近似公式(修正形式)的计算结果相对于严格周期的数值计算结果相对误差小于1‰.同时,对单摆近似周期的构造进行了分析.     

基于甲苯模板合成的ZIF-93及其对1,3-丙二醇和2,3-丁二醇的吸附分离性能

生物基1,3-丙二醇原液预处理后主要是由低浓度水溶液、1,3-丙二醇和2,3-丁二醇组成。1,3-丙二醇和2,3-丁二醇均是二元醇，含有2个羟基能与水形成强的氢键，增加了分离的难度。然而仅具有范德华作用的传统疏水吸附剂通过动态柱吸附无法实现有效分离二元醇。因此，选择具有范德华作用基团—CH3和氢键作用基团—CHO的ZIF-93研究其对低浓度2,3-丁二醇/1,3-丙二醇的静态和动态柱吸附分离性能。首先，在ZIF-93合成中引入甲苯作为溶剂和模板剂，利用甲苯与咪唑基配体以及甲苯分子之间的π-π相互作用模板支撑ZIF-93的结构单元lta笼，有效提高ZIF-93的BET比表面积和微孔孔容。结果表明，ZIF-93对2,3-丁二醇(50 g/L)/1,3-丙二醇(50 g/L)的动态柱吸附量为69.9和17.3 mg/g，对2,3-丁二醇/1,3-丙二醇的选择性为4.0。相对于传统疏水吸附剂，具有氢键作用基团的ZIF-93穿透曲线斜率增大，传质区间缩短，穿透时间提高，从而提高吸附床层的有效利用率，利于工业上连续分离操作。通过模拟揭示了ZIF-93的-CHO与2,3-丁二醇的―OH和―CH