Water Content Distribution in the Surface Layer of Maoping Slope

The water content distribution in the surface layer of Maoping slope has been studied by testing the water content at 31 control sites. The water content profiles at these sites have also been determined. The water content distributions at different segments have been obtained by using the Kriging method of geostatistics. By comparing the water content distributions with the landform of the slope, it was shown that the water content is closely dependent on the landform of the slope. The water content distribution in the surface layer provided a fundamental basis for landslide predication and treatment.

Self-assembled quasi-periodic voids in glass induced by a tightly focused femtosecond laser

Multiple refocusing of a tightly focused femtosecond laser due to the dynamic transformation between self-focusing and self-defocusing is employed to provide a novel method to produce quasi-periodic voids in glass. It is found that the diameter or the interval of the periodic voids increases with the increasing pulse energy of the laser. The detailed course for producing periodic voids is discussed by analysing the damaged track induced by the tightly focused femtosecond laser pulses. It is suggested that this periodic structure has potential applications in fabrication of three-dimensional optical devices.

一种基于编码孔径成像原理的三维成像方法

三维成像技术因其应用广泛而备受关注。根据编码孔径成像的基本原理，提出了一种非相干可见光三维成像方法。这种两步成像方法的第一步采用空间位置编码的照相机阵列对物体拍照，在第二步中，首先将照相机阵列拍照得到的物体照片根据拍照时的位置关系合成为一幅图像，然后采用计算机程序模拟光学反投影解码方法解码再现出物体不同深度的表面分层图像。设计了初步的实验，该实验采用1部照相机依次在各编码位置对物体模型拍照，编码形式是包含9个点的无冗余阵列形式，物体模型只包含2个深度层次，布置在距离照相机阵列1．5m的地方。实验得到了信噪

复合垂直流人工湿地对氮的净化效果

采用复合垂直流人工湿地处理武汉东湖污染水的中试结果表明 ,出水中NH+ 4-N、NO- 2 -N和凯氏氮 (KN)浓度均显著降低 ,而NO- 3-N含量有所上升 ;系统最佳运行水力负荷为 80 0mm/d ,超过此负荷后系统净化效果随负荷增加而下降 ;在东湖现有的污染负荷下 ,处理系统仍呈现出继续承载污染量的潜力 ;就基质中KN的分布而言 ,水平方向为下行流池含量高于上行流池 ,垂直方向为上层 >中层 >下层 ,而在植物体内的分布则为叶片中含量最高。

签密方案在分布式协议中的应用

该文基于可验证秘密共享思想和对Zheng的签密方案的必要修改，首次构造了一种不需要可信中心的门限签密方案．它能同时达到门限签名和加密的双重目的，实现代价仅和门限签名相当，并具有非否认性质．该文对当前一些分布式密钥分配协议做了分析，并基于Naor的基本思想，重点利用签密方案设计了协议SC—DKDS．与其它协议相比，该协议在减低实现成本等方面更为有效，因为它不需要认证信道、秘密信道及复杂的零知识证明等．该文还在RO（Random Oracle，随机预言）模型中给出了以上协议的安全性证明．