弹性变形对三维弹性液箱内晃荡波面的影响

弹性液舱舱壁在大幅晃荡液体的作用下会发生弹性变形,从而会对液舱内液体晃荡的水动力特性产生一定的影响.文中通过物理模型实验研究了水弹性效应对弹性方形液舱内液面晃动的影响.实验水深比h/L(h为液深,L为液舱长度)为0.167,激励频率在最低阶自振频率附近.由于液舱结构变形的影响,弹性液舱内液体的最低阶自振频率与同尺寸的刚性液舱略有差别.实验中分别对刚性和弹性两个方形液舱在不同频率的简谐纵向激励作用下的波动形态进行了分类分析,并比较了对应不同二维行波、过渡状态和三维共振以及二阶次共振等不同波动形态时弹性液舱和刚性液舱内的波面高度.     

Trend in the atmospheric heat source over the central and eastern Tibetan Plateau during recent decades: Comparison of observations and reanalysis data

The trend in the atmospheric heat source over the central and eastern Tibetan Plateau (CE-TP) is quantitatively estimated using historical observations at 71 meteorological stations, three reanalysis datasets from 1980-2008, and two satellite radiation datasets from 1984-2007. Results show that a weakening of sensible heat (SH) flux over the CE-TP continues. The most significant trend occurs in spring, induced mainly by decelerated surface wind speeds. The ground-air temperature difference shows a notable increasing trend over the last 5 years. Trends in net radiation flux of the atmospheric column over the CE-TP, evaluated by two satellite radiation datasets, are clearly different. Trends in the atmospheric heat source calculated by the three reanalysis datasets are not completely consistent, and even show opposite signals. Results from the two datasets both show a weakening of the heat source but the magnitude of one is significantly stronger, whereas an increase is indicated by the other data. Therefore, it is challenging to accurately calculate the trend in the atmospheric heat source over the CE-TP, particularly from the estimates of the reanalysis datasets.     

基于神经网络数据融合方法的模拟电路故障诊断

根据模拟系统故障检测原理，采用神经网络与数据融合相结合的方法进行模拟电路故障诊断，提出了一种新型的基于D-S证据神经网络的故障检测与诊断方法．应用D-S证据理论对径向基函数网络进行了修正，用具有一个输入层、两个隐含层和一个输出层的神经网络实现．各个证据体的基本概率赋值的获取是D—S证据理论在实际应用中的难点问题，本方法中采用的是根据输入模式与原型模式之间的相似度以及原型模式的类别隶属度来确定基本概率赋值．借助神经网络自学习的功能，实现对类别隶属度的最优化．结果表明该方法能快速有效地进行故障诊断中大量数据的处理，具有很强的鲁棒性．     

前处理对CdS敏化TiO2纳晶复合半导体电极光电化学性能的影响

将TiO₂纳晶薄膜在尿素及聚乙二醇（PEG）的混合水溶液中进行前处理，并采用连续离子吸附反应技术制备了具有多孔结构的纳米复合CdS/TiO₂薄膜电极。利用表面分析及光电化学方法研究了前处理对复合电极材料的结构、光学及光电化学性能的影响。结果表明，前处理能有效地提高CdS在TiO₂表面的沉积量，在400～500nm处提高了复合电极材料的光吸收效率。光电化学性能结果表明，前处理对复合电极的光电流及光电压没有产生明显的影响，但有效地提高了太阳能电池填充因子，因此有利于提高太阳能电池的光电转换效率。     

Macrocyclic compound as ionophores in lead（Ⅱ） ion-selective electrodes with excellent response characteristics

Macrocyclic compounds, such as crown ethers, azacrown ethers, thiacrown ethers, calixarenes and porphyrins, which act as ionophores in lead（Ⅱ） ion-selective electrodes, are systematically summarized based on the latest literatures. The molecular structure characteristics of the ionophores are generalized. The modification regulations for the substituted ionophores are elaborated with the purpose of improving the response features of the lead（Ⅱ） ion-selective electrodes assembled by them. It is pointed out that the introduction of pendant moieties which contain soft base coordination centers like N, S and P atoms is in favor of adjusting the cavity size and conformation of the macrocyclic com- pounds. Furthermore, there is synergic effect between the cavity and the donor sites of the ligand and thus the selective complexation of lead ions is easily realized, resulting in significant avoidance of the interference from other metal ions. The macrocyclic ionophore having the best response characteristics thus far was found to be N,N＇-dimethylcyanodiaza-18-crown-6 with the detection limit of 7.0×10^8 （14.5 μg/L）, which is one of the uncommon ionophores that can really eliminate the interference from silver and mercury ions. The selectivity coefficients of the ionophore for lead ions over other metal ions, such as alkali, alkaline earth and transition metal ions are in the order of 10^-4 or smaller, where the selectivity coefficient of lead（Ⅱ） over mercury（Ⅱ） ions is much lower, down to 8.9×10^4, The structure design idea for high-performance ionophore is proposed according to present results. The incorporation of nitrogen atom, especially cyano group or thiocyano group or amino/imino groups, rather than thio atom alone could result in new excellent lead ionophores. The aborative design for metacyclophanes containing aromatic nitrogen atoms with the aim of creating excellent ionophores would also become a potential research trend. The lead（Ⅱ） ion-selective electrodes have shown wid