Templated ceramic microstructures by using the breath-figure method

We describe the synthesis of two cyclobutadiene(cyclopentadienyl)cobalt-containing poly(p-phenylene ethynylene)s (PPEs) and their use as precursors for stable ceramic surface coatings. Organometallic PPEs were shaped into hexagonally ordered assemblies by using the breath-figure method. Such breath figures can be washed away with an appropriate solvent. Upon pyrolysis at 500 degrees C under either nitrogen or air, the bubble arrays persist as ceramics and are insoluble in organic solvents or water. The formed pyrolyzed bubble arrays were analyzed by optical and scanning electron microscopy, as well as energy dispersive X-ray microanalysis (EDX). The composition of the ceramic materials is discussed based on EDX and IR data.     

Information for Authors

Chinese Optics Letters is a short-article journal for the rapid dissemination of new, important results in all branches of optical science and technology and related fields, published monthly by Chinese Laser Press and distributed abroad by the Optical Society （OSA）.     

Instructions for Authors

<正>Chinese Physics B(Chin.Phys.B),formerly titled Chinese Physics,is an international comprehensive academic journal,aiming to publish original papers and rapid communications reflecting creative and innovative achievements in physics,as well as review papers about important accomplishments in frontier of physics.The journal is published monthly in English by the Chinese Physical Society(CPS)and the IOP Publishing.Chin.     

Chinese Journal of Polymer Science

正Aims and Scope Chinese Journal of Polymer Science(CJPS)is a monthly journal published in English and sponsored by the Chinese Chemical Society and the Institute of Chemistry,Chinese Academy of Sciences.CJPS is edited by a distinguished Editorial Board headed by Professor Fosong Wang and supported by an International Advisory Board in which many famous active polymer scientists all over the world are included.The journal was first published in 1983 under the title     

Dynamic behaviors of ferroelectric liquid crystal molecules under an applied electric field

The dynamic changes in ferroelectric liquid crystal (FLC) molecular alignments under an applied electric field are examined by observing the formation of conoscopic figures with a time resolution of 0.1 ms. Close agreements between observed and simulated conoscopic figures under low voltage (30 V) were obtained. Under high voltage (120 V), however, the observed conoscopic figures became blurred between 0.8 ms and 1.1 ms after reversal of the electric field. The light scattering producing the blurriness occurred due to the development of fast transient molecular alignments during the switching transition above the applied voltage 70 V.     

Preparation of honeycomb porous La0.6Sr0.4Co0.2Fe0.8O3−δ-Gd0.2Ce0.8O2−δ composite cathodes by breath figures method for solid oxide fuel cells

Honeycomb porous La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ-Gd_0.2Ce_0.8O_2−δ (LSCF-GDC) composite cathodes are prepared using the breath figures (BFs) method with nontoxic and easily available water droplets as templates. The fabrication of honeycomb porous membranes is realized in a relatively humid environment, using a volatile solvent. The microstructure and morphology of the membranes produced are investigated by scanning electron microscopy (SEM). The SEM micrographs suggest that experimental conditions, such as ambient temperature, relative humidity, and concentration of polymer and LSCF-GDC powder, which have direct influence on the solvent evaporation affects the pore structure of the porous membranes. Electrochemical impedance spectroscopy (EIS) is used to evaluate the polarization resistance of LSCF-GDC composite cathodes prepared at different experimental conditions. The honeycomb porous LSCF-GDC composite cathode showing average pore diameter of 10 μm illustrates the lowest polarization resistance.     

分析化学有效数字教学中常见问题及分析

Analytical chemistry often involves a large amount of experimental data, and the reliability and accuracy of the experimental results are related to whether the original data can be properly recorded and calculated. In this paper, starting from the importance of significant figures, analyzing the frequently encountered problems related to the significant figures in teaching process, and giving some solutions, we try to help students to learn and master the concept of significant figures, rounding off numerical values, rule of operation and data processing.     

Formation of ⊥c texture of tungsten disulfide thin films with nickel

The formation of ⊥c texture of WS₂ thin films by solid state reaction between the spray deposited WO₃ and gaseous sulfur vapours with Ni interfacial layer has been reported. X-ray diffraction technique has been used to measure the degree of preferred orientation and texture of WS₂ films. Scanning electron microscopy, transmission electron microscopy and atomic force microscopy have been used to characterize the microstructure and morphology. The electronic structure and chemical composition was studied using X-ray photoelectron spectroscopy. The WS₂ films comprise single crystalline quality hexagonal crystallites of 15 μm × 15 μm size with their basal planes parallel to the substrate. The film consists of turbostratic stacking sequence of 2H and 3R polytypes of WS₂. The tungsten-to-sulfur ratio was estimated to be 1:1.8. The various qualitative models used to explain promotional effects are briefly outlined and the plausible underlying mechanism of formation of ⊥c texture with nickel, in this study, is given.     

Obtaining Fourier series graphically from large amplitude oscillatory shear loops

Large amplitude oscillatory shear (LAOS) flow has been used to characterize the nonlinear viscoelasticity of polymer melts and solutions. Results are frequently reported with shear stress versus strain loops, or with shear stress versus shear rate loops. A Fourier analysis of the stress response to LAOS is often desired for comparison with theory, or for quantitative comparison between resins. A method is presented which employs the discrete Fourier transform to obtain the Fourier series coefficients from LAOS loops.     

物理仿真实验系统的设计与实现

以LabVIEW软件为开发平台设计制作了物理仿真实验系统,并以李莎如图实验为例详细介绍了仿真实验的制作过程。仿真实验能够以逼真的实验场景和生动的现象帮助学生理解复杂的物理原理,并激发学生的学习兴趣。该课题的研究能够促进仿真实验在物理课堂的普及和推广,并对新课程体系下人才的培养具有一定的借鉴作用和参考价值。