Effects of KI encapsulation in single-walled carbon nanotubes by Raman and optical absorption spectroscopy.

The effect of KI encapsulation in narrow (HiPCO) single-walled carbon nanotubes is studied via Raman spectroscopy and optical absorption. The analysis of the data explores the interplay between strain and structural modifications, bond-length changes, charge transfer, and electronic density of states. KI encapsulation appears to be consistent with both charge transfer and strain that shrink both the C-C bonds and the overall nanotube along the axial direction. The charge transfer in larger semiconducting nanotubes is low and comparable with some cases of electrochemical doping, while optical transitions between pairs of singularities of the density of states are quenched for narrow metallic nanotubes. Stronger changes in the density of states occur in some energy ranges and are attributed to polarization van der Waals interactions caused by the ionic encapsulate. Unlike doping with other species, such as atoms and small molecules, encapsulation of inorganic compounds via the molten-phase route provides stable effects due to maximal occupation of the nanotube inner space.

Statistical image modelling using interscale phase relationships of complex wavelet coefficients

A novel method for modelling the statistics of 2D photographic images useful in image restoration is defined. The new method is based on the Dual Tree Complex Wavelet Transform (DT-CWT) but a phase rotation is applied to the coefficients to create complex coefficients whose phase is shift-invariant at multiscale edge and ridge features. This is in addition to the magnitude shift invariance achieved by the DT-CWT. The increased correlation between coefficients adjacent in space and scale provides an improved mechanism for signal estimation. © 2006 IEEE.

猕猴（M．mulatta）输精管安置铜节育器后的不育观察

为探讨铜串珠节育器在人类临床上的应用前景，选健康有生育史的雌、雄猴６３只，分设实验组（ｎ＝２８：＝１：３）与对照组（ｎ＝２５：＝３～４）进行比较研究。实验组雄猴在距副率４～６公分处的输精管内置入铜串珠节育器。术后２５ｄ按上述比例进行不育性试验观察。结果：第一年不育率７５．７％；第二年、第三年分别为５７．１％、５６．４％。但实验组不育效果在个体之间有很大差异，有四只雄猴（占５７．１％）置器后第三年仍处于不育水平。试验中发现许多问题，有待深入研究探讨。