碳源体积分数对BDD薄膜制备和性能的影响

以丙酮为碳源,采用热丝化学气相沉积(HFCVD)技术在钽衬底上制备p型硼掺杂金刚石(BDD)薄膜电极。在BDD电极制备过程中,碳源体积分数对它的质量和性能影响很大。利用AFM和XRD分析了丙酮体积分数对BDD电极表面形态和成膜质量的影响。利用循环伏安法研究了采用不同体积分数的丙酮沉积的BDD电极对电化学窗口和背景电流的影响。分别采用BDD电极和不锈钢片作阳极和阴极电解K2SO4溶液,并利用KMnO4滴定法检测BDD电极的氧化效率。结果表明,优化丙酮体积分数可以提高BDD的均匀性和附着力。合适的丙酮体积分数所制备的BDD电极具有电化学窗口宽、背景电流低和电极氧化效率高等特点,有很好的应用前景。     

电压和电极间距对BDD电极电化学氧化效率的影响

掺硼金刚石(BDD)薄膜电极具有很宽的电势窗口、很小的背景电流、很高的电化学稳定性、其电化学响应在很长时间内保持稳定以及耐腐蚀等优点。采用热丝化学气相沉积(HFCVD)方法制备掺硼金刚石薄膜,并用金相显微镜、原子力显微镜(AFM)、X射线衍射(XRD)这三种测试方式进行表征。BDD薄膜电极在电解过程中消耗很多能量。从提高氧化效率来降低能耗的角度出发,研究了电压及电极间距对BDD薄膜电极电化学氧化效率的影响。通过实验得出电压在5~13 V时电化学氧化效率会随着电压的升高而升高;电极间距在0.5~4 cm时电化学氧化效率随着电极间距的增大而降低。     

中专物理课程改革向何处去

中专物理课程改革向何处去程川吉，中惠英（九江船舶工业学校３３２００７）目前，有的中专校把物理课程内容分解，分别讲人力学和电工学，又有学校要求物理课程教学参加普通高中会考．种种迹象表明，中专物理课程的重大变革正在蕴酿之中．改革应向何处去？本文抛砖引玉，...     

混合粒子群优化算法及其收敛性分析

为解决标准粒子群优化算法不能保证全局收敛、寻优精度低等问题,提出一种融合Kent混沌映射、云模型和布谷鸟搜索,并采用混沌初始化、全局及局部均衡搜索、多子种群协同进化等策略的混合粒子群优化算法(CPSO),同时对其收敛性和复杂度进行分析。经典的benchmark测试函数的实验统计结果表明,CPSO算法在收敛性、寻优精度、稳定性等方面均优于经典算法。     

环和纳米管径向呼吸振动模式的一个简单理论模型

用密度泛函方法在B3LYP/6-31G(d)基组下计算了(MgO)n和(BeO)n环(n=3-10)的径向呼吸振动. 大环的径向呼吸振动频率正比于环直径的倒数, 但键长的变化导致频率偏离了这种线性关系. 随着环直径的减小, 直径倒数的三次方和键长的变化将导致频率更大地偏离线性行为. 从化学键的角度出发利用一维谐振子及弹簧的串并联思想, 解释了这种线性关系和偏离现象. 这种模型还可以用于研究纳米管的径向呼吸振动频率.     

对象存储系统中的数据分布及在线重构算法研究

重点解决了对象存储系统在线状态下的可扩展性问题,提出了一种在对象存储的数据分布及在线重构算法来实现可用性、性能和可扩展性的平衡,描述了数据分布策略和在线重构算法,并进行了实验分析和总结。     

金刚石膜电极电化学过程阴极被氧化的研究

掺杂金刚石薄膜材料(BDD)具有优良的电化学催化氧化特性,研究发现,金刚石薄膜作为阳极的电化学氧化过程在一定条件下,能将阴极材料氧化.本文研究了电化学过程中电解液氧化浓度变化并对阴极材料进行XRD检测,经分析是金刚石薄膜电化学氧化在特定条件下氧化能力提升而导致阴极被氧化.     

城域网PBT技术中OAM的实现

主要介绍了OAM技术在PBT中的实现。首先说明了PBT相关技术,然后阐述了基于IEEE802．1ag和ITU—T Y．1731的OAM功能。分析研究了OAM技术在PBT上的实现。     

二氧化硅纳米结构径向呼吸振动的理论研究

运用密度泛函理论的B3LYP方法,在6-31G(d)基组水平上,计算了由Si₂O₂二元环组成的准一维SiO₂纳米链及三元环(3MR)、四元环(4MR)、六元环(6MR)和八元环(8MR)组成的SiO₂纳米管的Raman振动光谱。从Raman光谱发现纳米链和纳米管的径向呼吸振动频率随链或管长的增加而频率移动相反,即分别发生红移和蓝移,但随着链和管趋于无限长频率趋近稳定值;同时,随着直径的增大,振动频率减小。在小尺寸时,由于结构内部的应力影响使频率移动更明显,进一步对键长和键角分析说明,结构应力的作用使频率随尺寸变化发生移动。     

基于SiO2溶胶的稳定性的Cu/SiO2催化体系在化学机械抛光中的应用研究

There is a lot ofhydroxyl on the surface ofnano SiO2 sol used as an abrasive in the chemical mechanical planarization （CMP） process, and the chemical reaction activity of the hydroxyl is very strong due to the nano effect. In addition to providing a mechanical polishing effect, SiO2 sol is also directly involved in the chemical reaction. The stability of SiO2 sol was characterized through particle size distribution, zeta potential, viscosity, surface charge and other parameters in order to ensure that the chemical reaction rate in the CMP process, and the surface state of the copper film after CMP was not affected by the SiO2 sol. Polarization curves and corrosion potential of different concentrations of SiO2 sol showed that trace SiO2 sol can effectively weaken the passivation film thickness. In other words, SiO2 sol accelerated the decomposition rate of passive film. It was confirmed that the SiO2 sol as reactant had been involved in the CMP process of copper film as reactant by the effect of trace SiO2 sol on the removal rate of copper film in the CMP process under different conditions. In the CMP process, a small amount of SiO2 sol can drastically alter the chemical reaction rate of the copper film, therefore, the possibility that Cu/SiO2 as a catalytic system catalytically accelerated the chemical reaction in the CMP process was proposed. According to the van＇t Hoff isotherm formula and the characteristics of a catalyst which only changes the chemical reaction rate without changing the total reaction standard Gibbs free energy, factors affecting the Cu/SiO2 catalytic reaction were derived from the decomposition rate of Cu （OH）2 and the pH value of the system, and then it was concluded that the CuSiO3 as intermediates of Cu/SiO2 catalytic reaction accelerated the chemical reaction rate in the CMP process. It was confirmed that the Cu/SiO2 catalytic system generated the intermediate of the catalytic reaction （CuSiO3） in the CMP process through the removal rate of copper film, infrared spectrum and AFM diagrams in different pH conditions. FinalLy it is concluded that the SiO2 sol used in the experiment possesses stable performance; in the CMP process it is directly involved in the chemical reaction by creating the intermediate of the catalytic reaction （CuSiO3） whose yield is proportional to the pH value, which accelerates the removal of copper film.