Alignment of a Perylene‐Based Ionic Self‐Assembly Complex in Thermotropic and Lyotropic Liquid‐Crystalline Phases

The thermotropic and lyotropic liquid‐crystalline (LC) phases of the ionic self‐assembled complex N,N′,‐bis(2‐(trimethylammonium)ethylene)‐perylene‐3,4,9,10‐tetracarboxyldiimide‐bis(2‐ethylhexyl)sulfosuccinate have been studied using polarizing microscopy, differential scanning calorimetry (DSC), and X‐ray scattering techniques. A two‐dimensional (2D) columnar thermotropic LC phase with π–π stacking of the perylene tectonic units and a lyotropic LC phase in dimethyl sulfoxide (DMSO) have been found. Different techniques have been applied to align both systems and included: surface interactions, electric and magnetic fields, shear force, and controlled domain formation at the LC–isotropic phase‐transition front (PTF). Characterization of the alignment in films has been performed using polarized UV‐vis spectroscopy and transmission null‐ellipsometry. The best results have been obtained for alignment of the material in a lyotropic phase by controlled domain formation at the PTF of the LC–isotropic phase transition. In this case, a dichroic ratio of 18 is achieved with packing of columns of perylenediimide tectons perpendicular to the PTF.     

卫星电视接收天线的调整和日常维护

本文按照卫星电视接收天线的不同类别和可能出现的问题 ,简要介绍了天线的一般性调整方法和维护措施     

Reconstruct: a free editor for serial section microscopy

Many microscopy studies require reconstruction from serial sections, a method of analysis that is sometimes difficult and time-consuming. When each section is cut, mounted and imaged separately, section images must be montaged and realigned to accurately analyse and visualize the three-dimensional (3D) structure. Reconstruct is a free editor designed to facilitate montaging, alignment, analysis and visualization of serial sections. The methods used by Reconstruct for organizing, transforming and displaying data enable the analysis of series with large numbers of sections and images over a large range of magnifications by making efficient use of computer memory. Alignments can correct for some types of non-linear deformations, including cracks and folds, as often encountered in serial electron microscopy. A large number of different structures can be easily traced and placed together in a single 3D scene that can be animated or saved. As a flexible editor, Reconstruct can reduce the time and resources expended for serial section studies and allows a larger tissue volume to be analysed more quickly.     

A fortran 77 program for automatic stratigraphic correlation

A program that performs automatic stratigraphic correlation is described. The algorithm used is a modification of the Smith and Waterman (1980) technique. It allows for gaps in the strata and the simultaneous matching of one strata to a number of others. The method obtains the best match of two sequences by the minimization of a mathematical distance or difference between them.     

Inside Front Cover: A Supramolecular Approach to Optically Anisotropic Materials: Photosensitive Ionic Self‐Assembly Complexes (Adv. Mater. 16/2006)

Application of the supramolecular synthesis strategy ionic self‐assembly for the facile production of low‐molecular‐weight photosensitive materials is presented on p. 2133 by Stumpe, Faul, and Zakrevskyy. The materials so synthesized possess good film‐forming properties, are capable of undergoing light‐induced generation of optical anisotropy, and possess dichroic ratios of approximately 50.     

Compiler testing using a sentence generator

A system for assisting in the testing phase of compilers is described. The definition of the language to be compiled drives an automatic sentence generator. The language is described by an extended BNF grammar which can be augmented by actions to ensure contextual congruence, e.g. between definition and use of identifiers. For deep control of the structure of the produced sample the grammar can be described by step-wise refinements: the generator is iteratively applied to each level of refinement, producing at last compilable, complete programs. The implementation is described and some experimental results are reported concerning PLZ, MINIPL and some other languages.     

城市文化资本的挖掘与提升——上海市宝山绿色步道规划设计

以城市文化资本的挖掘和提升为主线,阐述上海市宝山绿色步道规划设计过程中城区风貌资源调查与空间文化特色分析、绿色步道选线规划、区段文化主题定位与分期建设、绿色步道详细设计等核心环节。建设实践表明:城市风貌是城市文化资本的重要载体,兼具大众游憩和文化展示功能的上海市宝山绿色步道建设不仅提升城市形象,改善生态环境,而且进一步整合和积累城市文化资本,促进城市和谐发展。