Design and application of functional absorbers

This paper gives an overview of the research at Institute of Acoustics, Tongji University, on functional absorbers and experience acquired in practical applications over the past three decades. Experiments and analysis of the absorption characteristics of three different geometrical forms of functional absorbers, i.e., panels, cubes and tubes, were conducted with different arrangements. The resulting esthetical effects are illustrated with pictures. Several non-fiber materials are used to compose functional absorbers with advantages both in acoustic properties and in architectural features. Cost effectiveness analysis is also given in order to provide design guidelines.     

Improving Thermal Stability of BaMgAl10O17:Eu Phosphor

Heterogeneous precipitation method was used to prepared surface coating on self-made BaMgAl10O17:Eu phosphor. Results illustrate that the coating film can be silicon dioxide in amorphous state with 50 nm in thickness. Photoluminescence results indicate that the coating layer presents an observable improved effect on the enhancement of thermal stability. When baked at 600 ℃ for 1 h, the luminance of coated BAM keeps at 92% higher than that of uncoated BAM by 23%. This protective effect can be attributed to the high compact degree and uniformity of this amorphous SiO2 coating film which is served as a diffusion block layer to inbreak oxygen atom, thus releases the oxidation extent of Eu2 effectively.     

WF40防腐蚀涂料在原料水罐上的应用

中国石化股份有限公司洛阳分公司炼油厂污水汽提装置的原料水罐(V303)由于接触的污水中含有H2S,NH3,CO2,CN-,酚等多种腐蚀介质因此经常发生腐蚀泄漏事故。经涂刷WF40玻璃鳞片防腐蚀涂料后,已平稳运行两年。2002年检修检查,涂层完好,仍在继续使用。WF40涂料为环氧型玻璃鳞片涂料,其热膨胀系数与钢质基体接近,因此具有耐热冲击性强等优点。待涂罐体经喷砂除锈到Sa2.5级后,涂底漆2道,中间涂层2道、面漆2道,使干膜厚度达到350μm,可有效防止腐蚀性介质的渗透。     

石墨电极高温抗氧化技术研究现状

概述石墨电极抗氧化技术的研究现状，重点介绍选择抗氧化涂层体系的要求及涂层制备方法，包括包埋浸渗法、化学气相沉积法、等离子喷涂法及溶胶--凝胶法．展望了石墨电极材料高温抗氧化涂层研究的方向．     

石英砂在菱苦土磨具中的作用机理

本文利用物质结构与化学键的有关理论对石英砂的菱苦土磨具中的作用机理进行分析，并以实验对分析结果进行验证。结果表明：金刚砂晶体中Si-C共价键的离子性百分数仅为9％，石英晶体中Si-O共价键的离子性百分数为47％，因此，石英与主要以离子键结合的菱苦土结合剂之间有较强的静电作用力，石英与菱苦土的结合力强于金刚砂，可提高菱苦土磨具的耐磨性。     

The application of microencapsulated phase‐change materials to nylon fabric using direct dual coating method

The fabrication of functional textiles able to provide thermal regulation and comfort for the body has attracted increasing interest in recent years. This research investigated fabric coatings containing energy absorbing, temperature stabilizing, phase‐change material microcapsules (PCMMcs), and their methods of application. Specifically, a coated fabric was directly prepared by a dual‐type coating method, in which the PCMMcs were dispersed in a polyurethane coating solution with no binder. The thermal performances of the dual‐coated samples were evaluated by differential scanning calorimetry, and their physical characteristics were examined by scanning electron microscopy, thermal vision camera, porosity, water vapor transmission rate (WVTR), and water entry pressure (WEP) analyses. Furthermore, the microclimate characteristics of the thermally enhanced fabrics were investigated under experimental conditions using a human‐clothing‐environment (HCE) simulator system. The study results confirmed the superior performance of the dual‐coated fabrics in terms of thermal regulation and body comfort, compared with those coated by the dry or wet coating method, because of the improved WEP, WVTR, and thermal performance. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Functional copolymer of geraniol and acrylonitrile: Synthesis and characterization

The radical copolymerization of acyclic terpene namely geraniol [GER] with acrylonitrile [AN] in DMF at (70 ± 0.1)°C for 1 h, using benzoylperoxide (BPO) as an initiator has been carried out under inert atmosphere of nitrogen. The kinetic expression for reaction is R_p ∝ [BPO]^0.5 [AN]^1.0 [GER]^1.0. The IR spectrum of the copolymer shows bands at 3432 and at 2244 cm^?1 due to ? OH group of GER and ? CN group of AN, respectively. The ¹³C‐NMR spectrum shows peaks at 73–75 δ ppm and 116–120 δ ppm due to ? OH group of GER and ? CN group of AN, respectively. The thermogravimetric analysis and differential scanning calorimetry study shows that copolymer is thermally stable up to 407°C and has glass transition temperatures (T_g) 56°C. The reactivity ratios r₁ (AN) and r₂ (GER) have been calculated as 0.05 and 0.005, respectively. The Alfrey‐Price Q‐e parameter for GER has been calculated as 0.094 and ?2.0, respectively. The molecular weights of the copolymers have been evaluated by gel‐permeation chromatography. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

高性能磁性液体材料研究进展

解决纳米磁性粒子的耐氧化问题对制备高性能磁性液体具有重要意义。系统介绍了金属磁性液体和氮化铁磁性液体的制备方法，并对各种制备方法进行了评述。综述了磁性液体的耐氧化研究进展，主要是纳米金属粒子的无机物包覆和氮化铁磁性液体的抗氧化剂添加；展望了高性能磁性液体在耐氧化方面的研究趋势。     

Distinctive Features of Minimization of a Risk Functional in Mass Data Sets

A statistical learning model is considered within the framework of the theory of uniform convergence of frequencies of errors in the case where the convergence is violated as a result of increasing the informativeness of training examples. Drawbacks of nonconstructive refinements of Vapnik-Chervonenkis estimates based on an assumption on the distribution law of violations are shown. A new approach to obtaining constructive estimates for mass data sets is proposed.     

一种中温C/C复合材料抗氧化涂层的制备及其性能

制备了一种工作温度约1 173 K的C/C复合材料抗氧化复合涂层,它由磷酸盐过渡层和陶瓷相阻挡层构成,通过与单一陶瓷相涂层的对比试验研究了它的抗氧化机理。涂覆有该复合涂层的C/C复合材料试样,在空气中1 173 K时氧化10 h的失重率为11.25％,氧化失重率为9.84×10~(-5)g/(cm~2·min),而且其氧化失重率随氧化时间延长而降低;4 h内经过30次从1 173 K至室温急冷急热循环后,失重率为6.38％,涂层基本完好,说明涂层在温度不超过1 173 K时具有良好的抗氧化性和抗热震性。该种涂层适合于中温下C/C复合材料的抗氧化保护。