Preparation and characterization of TiO2 photoelectrode codoped with aluminum and boron and its application in dye-sensitized solar cell

Nanocrystalline titania films codoped with aluminum and boron were prepared by cathodic vacuum arc deposition. In the process, titanium alloy target was used under an O2/Ar atmosphere, and sensitization of films were carried out by natural dye-sensitized complex in anhydrous ethanol. The structure, surface morphology and UV-vis spectra of titania films codoped were measured by X-ray diffraction analysis, scanning electron microscopy and ultraviolet-visible spectrometer. Theas-deposited films are found to be amorphous. The films annealed were examinedto be of anatase structure with orientation along the (101) planes, the averagecrystal size is in the range between 41 and 45 nm. SEM results show that thereare some pores in the codoped titania films, the optical properties of the dye-sensitized films were also measured which reveals that the spectral responses of films shift to the visible region. Under simulated sunlight illumination, the overall energy conversion efficiency of dye-sensitized nanocrystalline solar cell is 0.9%.     

Einfluß des totvolumens auf die Al2O3-CVD-Abscheidung

The influence of the free gas volume around the substrate on the chemical vapor deposition of Al₂O₃ layers in the AlCl₃/H₂/CO₂ system at different pressures and temperatures has been studied. Through the water gas reaction which occurs homogeneously in the gas phase, the Al₂O₃ growth rate increases with increasing free gas volume until a certain volume is reached, after which it remains constant. For this ‘critical free gas volume’ a theoretical characteristic dimension L_max is introduced. It is defined as the normal distance from a substrate surface, at which the water molecules formed from the CO₂ + H₂ in the gas phase can no longer reach the substrate surface in the time available. The dependencies of L_max on pressure, temperature and gas flow rate deduced through this theoretical consideration show agreement with the experimental results.

Zusammenfassung

Der Einfluß des die Substrate umgebenden Totvolumens auf die Al₂O₃-CVD-Abscheidung im System AlCl₃/H₂/CO₂ wurde systematisch bei verschiedenen Drücken und Temperaturen untersucht. Durch die homogen in der Gasphase ablaufende Wassergasreaktion nimmt in allen Fällen die Abscheidungs-geschwindigkeit mit vergrößerten Totvolumen zuerst zu, bleibt aber ab einer bestimmten Totvolumensgröße konstant. Für diese “kritische Totvolumensgröße” wird die theoretische Kenngröße L_max eingeführt. Diese Größe ist als Normalabstand zur Substratoberfläche definiert, bei dem das in der Gasphase aus CO₂ + H₂ gebildeten Wasser in der zur Verfügung stehenden Zeit die mit AlCl₃ belegte Oberfläche der Substrate nicht mehr erreichen kann. Die aus dieser theoretischen Überlegung abgeleiteten Voraussagen über die Abhängigkeit des L_max von Druck, Temperatur und Gasströmungsgeschwindigkeit zeigten Übereinstimmung mit den Versuchsergebnissen.     

医用钴基合金的组织结构及耐腐蚀性能

以锻造CoNiCrMo，CoCrMo和CoCrMoC台会为研究对象，通过金相观察，XRD分析和耐腐蚀试验，研究了3组合金在不同热处理条件下的显微结构，相成分及在Hi同溶液中的耐腐蚀性能。结果表明：2组锻造合金的再结晶温度都是1000℃，且晶粒尺寸随着固溶温度升高和时效时间延长而逐渐变大。3组试样在NaCl溶液中为钴基合金典型的阳极极化曲线；在Hanks’溶液中均有一个二次钝化行为，且锻造CoNiCrMo合金的二次钝化区域较窄，而其他2组合金则较宽；在含柠檬酸三钠的溶液中过钝化电位降低，柠檬酸盐的存在降低了含金的耐腐蚀性能。热处理对合金的耐腐蚀性能影响不大。     

Influence of electroplating conditions on magnetic properties of Fe-36wt.% Ni alloy film

A Fe-Ni soft magnetic film was prepared in sulphate solution by electroplating. The influences of the molar ratio of n [Fe2+ ]/ n [Ni2+ ], current density, bath temperature, pH and L-ascorbic acid concentration on magnetic properties of Fe-Ni alloy film were investigated. The results show that the saturated flux density(BS) of the film increases initially and decreases after it reaches the specific value with the increase of n [Fe2+ ]/ n [Ni2+ ] molar ratio, current density, bath temperature and pH. However, the relationship between L-ascorbic acid concentration and B S keeps linear. It is observed that the coercive force( Hc) is enhanced with the increase of n [Fe2+ ]/ n [Ni2+ ] molar ratio, current density and pH. By comparison, when the bath temperature increases, Hc always decreases. With the increase of L-ascorbic acid concentration, the coercive force increases initially and then decreases.     

低成本改造焊管定尺锯切系统

介绍了一项低成本改造焊管定尺锯切系统的技术。该技术以PLC为控制中心,旋转编码器、接近开关为检测元件,采用机电结合的方法,解决了老式焊管定尺锯切系统普遍存在的定尺不准、可靠性差等问题。新系统控制可靠,工作稳定,定尺误差为±5mm,改造成本2万元左右,能够满足生产的需要。     

Measurement of drill point geometry by using laser sensor

Accurate measurement for the drill geometry is essential to drill design and reconditioning. In recent years, a number of non-contact drill measuring instruments, using CCD camera are reported in the literature. But these systems are not suitable in measuring three-dimensional surface, especially the concave ones. As an effectual remedy, a geometry measurement instrument using laser sensor is developed. This paper describes its configuration and calibration. In addition, the measurement method for a drill flute is detailed. Validity of the system and proposed method are demonstrated by an example. The deviations of the data measured from that inspected by using a microscope are no more than 0.0061 mm.     

Effect of surface modification of metal hydride electrode on performance of MH/Ni batteries

A novel method was applied to the surface modification of the metal hydride(MH)electrode of MH/Ni batteries.Both sides of the electrode were plated with a thin silver film about 0.1μm thick using vacuum evaporation plating technology,and the effect of the electrode on the performance of MH/Ni batteries was examined.It is found that the surface modification can enhance the electrode conductivity and decrease the battery ohimic resistance.After surface modification,the discharge capacity at 5C(7.5A)is increased by 212 mA.h and the discharge voltage is increased by 0.11 V,the resistance of the batteries is also decreased by 32%.The batteries with modified electrode exhibit satisfactory durability.The remaining capacity of the modified batteries is 89%of the initial capacity even after 500 cycles.The inner pressure of the batteries during overcharging is lowered and the charging efficiency of the batteries is improved.     

转轮体铸造工艺的优化设计

本文重点总结了水轮机的重要部件转轮体常发生的主要铸造质量问题,分析了产生缩孔缩松、裂纹、尺寸超差等质量问题的主要直接原因,并提出了铸造工艺优化设计方案。     

Some Results for Pythagorean Fuzzy Sets

Pythagorean fuzzy sets (PFSs), originally proposed by Yager (Yager, Abbasov. Int J Intell Syst 2013;28:436–452), are a new tool to deal with vagueness considering the membership grades are pairs satisfying the condition . As a generalized set, PFSs have close relationship with intuitionistic fuzzy sets (IFSs). PFSs can be reduced to IFSs satisfying the condition . However, the related operations of PFSs do not take different conditions into consideration. To better understand PFSs, we propose two operations: division and subtraction, and discuss their properties in detail. Then, based on Pythagorean fuzzy aggregation operators, their properties such as boundedness, idempotency, and monotonicity are investigated. Later, we develop a Pythagorean fuzzy superiority and inferiority ranking method to solve uncertainty multiple attribute group decision making problem. Finally, an illustrative example for evaluating the Internet stocks performance is given to verify the developed approach and to demonstrate its practicality and effectiveness.     

栅元有效共振积分的CUDA算法设计与实现

核反应堆中需要实时精确地计算堆芯和增殖材料的有效共振积分或群截面来实现反应堆的安全控制。整个计算过程因为涉及大量的积分运算和庞大的核素截面数据,采用常规的计算方法,计算时耗相当大。基于统一计算设备架构(CUDA)平台,利用图形处理器(GPU)的计算能力,对整个计算过程进行并行化分解,多线程同时运算,大幅度提升计算速度,降低时耗。实验结果表明,在GPU上并行计算所得结果与原始数据没有明显差异,且加速效果显著。