La~(3+)掺杂Ca_(1-x)La_xCu_3Ti_4O_(12)陶瓷的制备及性能研究

采用固相反应法制备了La~(3+)掺杂的Ca_(1-x)La_xCu_3Ti_4O_(12)(CCTO)陶瓷,研究了La~(3+)掺杂量对Ca1-xLaxCu3Ti4O12(x=0%,1%,3%,5%,7%)陶瓷物相结构、微观形貌和介电性能影响,对La~(3+)掺杂影响CCTO陶瓷介电性能的机理进行了分析。结果表明:x为3%时,开始出现杂相;x高于5%时,陶瓷晶粒开始细化;La~(3+)掺杂可以显著提高Ca_(1-x)La_xCu_3Ti_4O_(12)陶瓷的介电常数,同时介电损耗在高频段也相应降低,从而有助于CCTO陶瓷的综合介电性能的提升。     

热带对流活动日变化的模拟研究

利用一个云分辨与海洋的耦合模式，模拟研究了热带对流活动的日变化.通过对模拟结果的分析，揭示了热带地区不同海温日变化条件下，对流活动的云物理特征.利用热带海洋与全球大气响应观测实验（TOGA COARE）的观测资料作为模式的初始与边界场，来驱动耦合模式.对热带海表温度按照其日变化幅度的大小进行了分类，分为强、弱海表温度日变化两种类型，并在此基础上进行了合成分析.结果表明：1）在弱的海表温度日变化下，云中的云冰含量大于云水含量，说明云中以层状云为主；而在强的海温日变化下，云中的云水含量大于云冰含量，说明云中以 关键词： 热带对流日变化 地面降水率 云冰含量 云水含量     

湿过程对多平衡态及副热带流型的影响

本文提出一个两层,β平面,带有海陆分布的低谱准地转湿模式;模式的湿度变量为全露点温度。模式过程包含蒸发、降水以及云和水汽对辐射的作用。用该模式实施的数值试验表明,湿过程使模拟的副热带高压显著增强,流型的经向度加大。在一定的参数集合,湿模式大气可以显示出双平衡态,结果与夏半年对流上层副热带高压东部型和西部型的观测事实相似。     

6月和10月大气环流突变的非线性机制

本文用低谱途径,研究了正压大气中环流的突变。在一定的参数集合,随着外部热力强迫的渐变,激发出了谱系数的准Cusp型突变与西风急流位置的突变,结果与6月、10月南支急流突然北跳与建立的图象相似。依赖于参数集合的变化,突变可被单稳态的渐变或多平衡态的分支所代替。环流突变的机制,是一个有多种加热强迫、有耗散、有热力动力共同作用的非线性机制。     

氢退火的BZO前电极对非晶硅薄膜太阳能电池性能的影响

采用低压化学气相沉积方法在玻璃衬底上制备了B掺杂的ZnO（BZO）薄膜，通过氢退火对BZO进行处理，然后作为前电极进行了非晶硅薄膜太阳能电池的制备及性能研究。结果表明：在氢气气氛下退火后，BZO薄膜的载流子浓度基本无变化，但Hall迁移率显著提高，这使得BZO薄膜的导电能力提高；当采用厚度较小、透光率较高的BZO薄膜进行氢退火后作为前电极结构时，非晶硅薄膜太阳能电池的短路电流密度提高0.3~0.4 mA/cm²，电池的转化效率提高0.2%。实验结果可为通过优化前电极结构来提高非晶硅薄膜太阳能电池转化效率提供一种简易的方法。     

POSSIBLE CAUSES OF COUNTERCLOCKWISE LOOP OF TROPICAL CYCLONES

The counterclockwise loop of a moving tropical cyclone in the model atmosphere is clearly shown in the numerical experiment by six sets of time integrations over periods longer than seven days in terms of a barotropical quasi-geostrophic model containing terms of environmental heating and dissipation. Numerical investigation is performed of the dependence of the abnormal path stability upon the computational domain size and the disturbance of the heat source, initial value and iterative precision, indicating that this type of path is a stabler form of motion for the cyclone in the model atmosphere. And the possible causes are presented.     

湿过程对北半球夏季大气环流低频振荡的影响

本文在Lorenz低谱湿模式中引进积云对流参数化。模拟的对流上层副热带高压的位置及南亚区域的降水量均显示出准三周的低频振荡。对比试验及能量学参数的计算表明,湿过程对于准三周振荡的激发和维持起着重要的作用。同时,积云对流缩短了低频振荡的周期,这与作者另一篇论文理论分析的结果是一致的。     

Statistical characteristics of meso-scale vortex effects on the track of a tropical cyclone

This paper examines initial meso-scale vortex effects on the motion of a tropical cyclone (TC) in a system where coexisting two components of TC and meso-scale vortices with a barotropic vorticity equation model. The initial meso-scale vortices are generated stochastically by employing Reinaud’s method. The 62 simulations are performed and analysed in order to understand the statistical characteristics of the effects. Results show that the deflection of the TC track at t=24 h induced by the initial meso-scale vortices ranges from 2km to 37 km with the mean value of 13.4 km. A more significant deflection of the TC track can be reduced when several initial meso-scale vortices simultaneously appear in a smaller TC circulation area. It ranges from 22 km to 37 km with the mean value of 28 km,this fact implies that the initial meso-scale vortices-induced deflection may not be neglected sometimes.     

氢退火对LPCVD生长的ZnO薄膜光学和电学性能的影响

采用低压化学气相沉积(LPCVD)在玻璃衬底上制备了B掺杂ZnO(BZO)薄膜,研究了氢气气氛退火对BZO薄膜光学性能和电学性能的影响。结果表明:在氢气气氛下退火后,BZO薄膜的物相结构和透光率基本无变化,但BZO薄膜的导电能力却明显提高。Hall测试结果表明:在氢气下退火时载流子浓度基本保持不变,但迁移率却明显提高。实验结果可为进一步提高BZO薄膜的光学电学综合性能提供借鉴。     

A NUMERICAL STUDY ON THE MECHANISM OF BLOCKING HIGH FORMATION

Numerical integration is performed of the KDV equation of the forced dissipation with the result that it takes about 10 days to transform a high-index circulation into a blocking pattern, in whose establishment and maintenance the thermal forcing and dissipation, nonlinoear advection, and linear dispersion are equally important and serve as three factors of essentiality.