Two-dimensional non-spatial filtering based on holographic Bragg gratings

The filter made up of two gratings performs as a two-dimensional non-spatial filtering. This paper reports that the volume Bragg gratings are fabricated by interfering two collimated coherent laser beams in photopolymer. Diffraction efficiency of a single grating is up to 78% in Bragg's condition, then a two-dimensional non-spatial filter, which consists of two volume Bragg gratings and a half-wave plate, enables the laser beam filtered in two dimensions with the diffraction efficiency of 54%. The Bragg's condition and effect of polarisation on performances of the two-dimension filter are also discussed.     

液体透镜发展现状

文章介绍了液体变焦透镜的发展现状.从压力型液体透镜到纯电力控制的液体-空气界面的透镜,再到操作较为灵便的运用"电浸润"方法控制的封闭式液-液界面透镜,最后到能自动调节光轴的改进型透镜,文章均进行了介绍,其中着重介绍了改进型液体透镜的结构、运作机理、自动调节光轴的功能及其他优异的性能.     

Quantum Mechanics Helps in Learning for More Intelligent Robots

A learning algorithm based on the state superposition principle is presented. The theoretical analysis shows that the needed fundamental transformations to realize this algorithm are the same as those needed in the Grover algorithm and are within current state-of-the-art technology. The simulated experiment shows that the quantum learning algorithm can help robots to learn faster and to become more intelligent.     

苯并螺环β-溴代酮Wagner-Meerwein重排反应研究及其在(±)-Colchicine形式合成中的应用

报道了在AgBF₄促进下苯并螺环β-溴代酮的Wagner-Meerwein重排反应, 从而发展了一条简捷新颖的构筑天然产物中广泛存在的n,7,6-三环骨架的方法. 作为该反应的应用, 合成了(±)-colchicine的7,7,6-三环母核, 完成了(±)-colchicine的形式合成.     

Arylation and vinylation of alkenes based on unusual sequential semipinacol rearrangement/Grob fragmentation of allylic alcohols

Alkenes can be stereoselectively arylated and vinylated without transition-metal catalyst under mild conditions through an interesting NBS-promoted semipinacol rearrangement and a subsequent unusual NaOH-mediated Grob fragmentation.     

苯并螺环β-溴代酮Wagner-Meerwein重排反应研究及其在（±）-Colchicine形式合成中的应用

报道了在AgBF4促进下苯并螺环β-溴代酮的Wagner-Meerwein重排反应,从而发展了一条简捷新颖的构筑天然产物中广泛存在的n,7,6-三环骨架的方法.作为该反应的应用,合成了（±）-colchicine的7,7,6-三环母核,完成了（±）-colchicine的形式合成.