低能量沥青温拌技术的应用与实践

低能量沥青温拌技术作为沥青混合料泡沫温拌技术的一种,其生产、施工过程中不需要添加任何温拌剂,因没有温拌剂生产过程的能耗与排放,系统能耗更低,并且在节约成本方面具有明显优势,这使得低能量沥青温拌技术迅猛发展,成为当前世界各国最感兴趣的温拌技术之一。笔者通过其与热拌沥青混合料的对比,介绍了低能量沥青温拌技术在欧洲的应用和实践,提出了低能量沥青温拌技术推广应用需要解决的关键性问题。     

运转中回转窑大直径在线测量仪

为确保回转窑安全正常运行,需要定期对回转窑中心线、支承托轮及轮带直径进行在线测量,根据测量结果调整回转窑的位置。本文介绍一种采用双滚轮结构的在线回转窑大直径测量仪,它主要由摩擦滚轮、滚轮轴、编码器、支撑及弹簧预压力机构和单片机控制系统等组成。该仪器的双滚轮结构和滚轮外圆直径表面防滑纹特殊处理以及跟随装置能够保证滚轮与被测回转体表面平行,能够有效避免和减小滚轮打滑引起的测径误差。该仪器能够实时自动修正滚轮直径热膨胀误差,它对轮带及托轮的动态直径测量总误差小于0.5mm,具有推广应用价值。     

Synthesis and optimization of high-performance amine-based polymer for CO2 separation

Membrane technology features inspiring excellence from numerous separation technologies for CO₂ capture from post-combustion gas. Polyvinylamine (PVAm)-based facilitated transport membranes show significantly high separation performance, which has been proven promising for industrial scale-up. However, commercialized PVAm with low molecular weight and excessive crystallinity is not available to prepare high-performance membranes. Herein, the synthesis process of PVAm was optimized by regulating polymerization and acidic hydrolytic conditions. The membranes based on PVAm with a molecular weight of 154 kDa and crystallinity of 11.37% display high CO₂ permeance of 726 GPU and CO₂/N₂ selectivity of 55 at a feed gas pressure of 0.50 MPa. Furthermore, we established a PVAm synthesis reactor with an annual PVAm solution (1%(mass)) capacity of over 7000 kg and realized the scaled-up manufacture of both PVAm and composite membranes.     

Differentiated Electric Behaviors of La2/3Cu3Ti4O12 Ceramics Prepared by Different Methods

Microstructure and electric behaviors of La_2/3Cu₃Ti₄O₁₂ (LCTO) ceramics prepared by the sol‐gel method (SG) and solid‐state method (SS) have been systemically investigated. The results indicated that LCTO‐SG ceramics sintered at 1105°C for 15 h showed larger grain size, higher density, and especially higher dielectric constant up to about 0.9–1.6 × 10⁴ at 10²~10⁵ Hz compared to LCTO‐SS ceramics. The higher dielectric constant of the LCTO‐SG ceramics might be due to the stronger internal barrier layer capacitor (IBLC) effect. More notably, compared with LCTO‐SS ceramics, two kinds of dielectric anomalies, one conduction activation energy value and same activation energies for the conduction and relaxation process in LCTO‐SS ceramics, the LCTO‐SG ceramics showed three kinds of dielectric anomalies, two values of conduction activation energy, and decrease in conduction activation energy with increasing temperature. The activation energies for the conduction and relaxation process in LCTO‐SG ceramics showed great difference below about 210°C, suggesting that the mechanism of electrical conduction and dielectric relaxation seem to be different in LCTO‐SG ceramics. These remarkable differences in electric behaviors of LCTO ceramics prepared by sol‐gel and solid‐state methods were firstly found and analyzed.     

Polymerization kinetics of polyurethane and vinyl ester resin interpenetrating polymer networks by using fourier transform infrared spectroscopy

Fourier transform infrared spectroscopy (FTIR) was applied to the study of polymerization kinetics of simultaneous interpenetrating polymer networks (SINs) composed of polyurethane (PU) and vinyl ester resin (VER), in which the pendent hydroxyl groups were capped with acetyl groups to minimize the possibility of chemical binding between the two networks. It was found that during the course of synthesis the two pairs of reactants interfere with each other in the SIN systems, giving rise to depressed reaction rates, although they follow different polymerization mechanisms. Increasing the reaction temperature could be more effective than increasing the free-radical initiator level with regard to the final conversions of both components. The reaction sequence could be varied through the amount of the step-growth polymerization catalyst and free-radical initiator as well as the reaction temperature adjustment. Using VER containing pendent hydroxyl groups could strongly affect the reaction kinetics of such SINs and lead to hybrid structures. The quick formation of one network would always depress the conversion of the other network in all SINs studied. © 1996 John Wiley & Sons, Inc.     

钌基析氢电催化剂的研究进展

能源消耗持续增长以及化石燃料燃烧带来的能源安全与环保问题日益突出,开发安全、清洁、高效的新能源是人类可持续发展的重要课题。氢气具有能量密度高、无污染、资源丰富的优点,被视为最具发展潜力的石油与天然气的替代清洁能源。制氢最常用的方法是电解水,为实现高效制氢,通常需要添加催化剂（钌及钌基材料）提高析氢效果。本文详细介绍了铂（Pt）族元素中最便宜的金属元素钌（Ru）和钌基材料作为高效电催化剂的制备方法,阐明了析氢促进机理以及析氢效果,并提出了钌基析氢电催化剂的未来发展方向。     

微波高温烧结自动控制系统设计

为了防止微波高温烧结过程中,升温十分迅速,发生局部过烧,用单片机设计高温烧结微波炉的自动控制系统。介绍了其工作原理、组成框图、硬件设计以及软件程序流程;并详细说明电路设计。该系统已正常运行于所开发的YC-Ⅱ型微波高温烧结炉上。     

基于PI荧光图像计数的乳制品荧光性质分析

为分析添加PI染料时乳制品中不同的荧光成分如酪蛋白、黄油、维生素B1、维生素B2、维生素C等对荧光图像观察的影响,探究了不同乳制品及其成分在PI染色观察条件下的荧光性质,并以酿酒酵母为目标菌,研究了10种乳制品中酿酒酵母PI荧光图像计数结果。结果表明,酪蛋白、黄油、维生素B1、维生素B2、维生素C等成分及10种乳制品在发射光615 nm均可产生荧光,但不影响PI染色的酿酒酵母荧光计数的观察结果。使用荧光显微镜对添加105~107 CFU/mL酿酒酵母菌液的10种乳制品进行PI染色计数,并将荧光图像计数结果与平板计数结果进行比较。其中经荧光图像计数后得到的菌液浓度对数值分别在5.69~5.93、6.18~6.28、7.13~7.21之间,对应平板计数结果的对数值分别5.49~5.63、6.02~6.06、7.02~7.06之间,二者结果一致。使用 PI 进行荧光图像计数时,乳制品荧光虽然存在但不会对酿酒酵母荧光图像观察与计数造成影响。