Ferroelectric relaxor as a critical state

After revisiting models for the ferroelectric relaxors,we notice that the models can be classified into two categories.One group models are directly based upon the compositional fluctuations,such as Smolenskii's theory and SRBRF model.The other models are experimental phenomenon oriented,such as macro-micro domain crossover and superparaelectric state. The later explanations imply that the ferroelectric relaxor is in a critical state.The unusual field induced phase transition in ferroelectric relaxor also s...     

面向21世纪的我国天文学学科发展与优先重点领域

本文讨论了当前国际天文学研究的发展状况与趋势，在对我国天文学研究的现状、特点和优势分析的基础上，提出了面向21世纪的我国天文学学科发展的方向、优先重点领域和相关政策措施。     

State of water and its implications for supersaturated structures in Mg(NO_3)_2 aerosols

One technique based on the difference spectra was developed to study the state of water in supersaturated Mg(NO3)2 aerosols. The technique could be derived from the observation that the Raman scattering and infrared absorbance cross sections of molecular vibrations of interest remain practically constant from diluted solutions to supersaturated aerosols. The spectra of solvated water were obtained and primarily related to the first hydration layers of solute molecules in supersaturated Mg(NO3)2 aerosols. Ba...     

螺旋结构手性材料的手性参数实验研究

利用微波圆波导测量系统，在８．５～１１．５ ＧＨｚ 频段内测量了螺旋结构手性材料的手性参数．研究了手性掺杂体的螺径、螺距和线径对手性参数的影响．结果表明，随着螺旋体结构参数的变化，有Ｃｏｔｔｏｎ 效应出现． 实验结果为手性材料的设计提供了实验依据．     

推帚式TDI-CCD相机应用分析

简要介绍了推帚式TDI-CCD相机及TDI-CCD像感器的工作原理，对引起相机调制传递函数退化的几个因素进行了详细分析，这些因素包括几何尺寸、电荷转移损失、速度失配、电荷分立运动，而且对离散空间域的线阵静态扫描MTF进行了分析研究，阐述了TDI-CCD级数与速度同步性、信噪比、动态范围的关系。     

Reconstructed index of summer monsoon dry-wet modes in East Asia for the last millennium

Monthly precipitation datasets collected at 160 stations in China as well as the monthly winds and humidity data derived from the US National Centers for Environmental Prediction (NCEP) were used to construct the relationship between six summer dry-wet modes in eastern China and the summer monsoon airflow northward advance in East Asia. A millennial series of the monsoon dry-wet index (MDWI) was reconstructed based on Wang’s six summer dry-wet modes in eastern China since 950 AD. A high (low) index indicate...     

自适应有源消声耳罩

提出了设计参数与具体配戴无关的双传声器自适应有源消声耳罩，给出了有源消声耳罩的结构和原理，理论和实验表明，其在较宽频率范围有较好消声效果，且具有不依赖具体佩戴状态的良好适应性．     

环形Hartmann势的Schrdinger方程束缚态的精确解

将环形Hartmann势的Schrdinger方程在球坐标系中进行变量分离,然后求解角向方程和径向方程,得出了精确的能谱方程,获得了归一化的角向和径向波函数,并给出了Hartmann势的径向矩阵元和径向平均值的通项表示式.     

SnO_2(F)、Fe_2O_3和ZnSe(Fe)薄膜厚度的测量

用RBS技术、椭偏法和微量天平称重法测量了掺氟SnO_2(FTO)透明导电膜、掺铁ZnSe磁性半导体膜和Fe_2O_3气敏元件膜的薄膜厚度.实验结果表明,RBS技术的测量数值与椭偏法以及微量天平称重法测得的结果符合得较好。