频率响应法研究噻吩和苯在NiY分子筛上的吸附行为

The adsorption behavior of thiophene and benzene on NiY zeolite has been investigated by the frequency response(FR) method.The FR spectra of thiophene and benzene on NiY zeolite were recorded at 302—335 K in a pressure range of 26.6—266 Pa.The results showed that adsorption was found to be the rate-controlling process for the thiophene/NiY zeolite system,and there were two different adsorption processes.Two kinds of adsorption models have been proposed,namely:the S-M interaction(low frequency adsorption) an...     

海洋工程大直径长桩自由入泥深度计算研究

海洋工程大直径长桩在就位后置锤的瞬间会发生自沉,校核土面以上部分的桩段在锤和桩的自重作用下发生屈曲失稳的可能性是桩可打入性分析的一个重要步骤。文章根据土力学的极限承载力理论,在分别介绍了桩自由入泥深度计算方法、桩端阻力计算方法、桩自由入泥深度判断方法的基础上,提出了计算桩自由下沉深度的评估方法。工程实例计算表明,该评估方法与实测数据吻合较好,可用于指导工程设计。     

液晶聚酯的研究概况

概述了聚酯类液晶高分子材料的发展,对其分子设计、合成方法、应用及发展前景进行了比较详细的分析。     

电吸附除盐技术的研究与应用进展

电吸附是一种利用电势差为驱动力,促使离子被吸附到带电电极表面的除盐技术,具有低能耗、不添加化学试剂、环境友好等显著特点.从电吸附理论、电极材料、电吸附装置等方面综述了电吸附除盐技术的研究和应用进展,并展望了电吸附技术在水处理除盐领域的研究方向和应用前景.     

载流条件下铜基粉末冶金滑板材料的电弧侵蚀防护

以粉末冶金/铬青铜为摩擦副,在销-盘式摩擦磨损试验机上进行了载流摩擦学特性研究,结果显示:电流对电弧能量的大小有影响,载荷、速度对电弧能量有显著影响;可以找出一组电流、速度、载荷的最接近最佳匹配的数据,把电弧对粉末冶金滑板材料侵蚀程度减到最小;在水雾条件下,低速可以减小铜基粉末冶金滑板材料的质量磨损率.在最佳的表面粗糙度下电弧能量、质量磨损率最小;摩擦副材料的匹配性可以减小滑板材料的质量磨损率.     

PET／60PABA 热致型液晶共聚酯的合成与表征

将对羟基苯甲酸（PHB）的乙酰化产物对乙酰氧基苯甲酸（PABA）引入聚酯（PET）分子主链结构中,成功制备出共聚酯 PET /60PABA,研究了聚合温度和催化剂浓度对共聚酯合成的影响。通过差示扫描量热（DSC）、X 射线衍射（XRD）、超导核磁共振（NMR）、凝胶渗透色谱（GPC）、偏光显微镜（POM）和毛细管流变仪等手段对共聚酯的分子结构与液晶形态进行表征,结果表明,共聚酯 PET /60PABA 几乎为完全无规共聚,熔融状态下具有向列型热致液晶聚合物的典型特征。     

PET/60PABA热致型液晶共聚酯的合成与表征

将对羟基苯甲酸(PHB)的乙酰化产物对乙酰氧基苯甲酸(PABA)引入聚酯(PET)分子主链结构中,成功制备出共聚酯PET/60PABA,研究了聚合温度和催化剂浓度对共聚酯合成的影响。通过差示扫描量热(DSC)、X射线衍射(XRD)、超导核磁共振(NMR)、凝胶渗透色谱(GPC)、偏光显微镜(POM)和毛细管流变仪等手段对共聚酯的分子结构与液晶形态进行表征,结果表明,共聚酯PET/60PABA几乎为完全无规共聚,熔融状态下具有向列型热致液晶聚合物的典型特征。     

烃类异构化催化剂的研究进展

介绍了烃类异构化催化剂的研究现状,详细阐述了硅铝分子筛基催化剂、磷酸硅铝分子筛基催化剂、介孔分子筛基催化剂和复合分子筛基催化剂在烃类异构化方面的研究进展.并对烃类异构化催化剂的发展前景进行展望,指出微孔-微孔和微孔-介孔复合的分子筛基催化剂是烃类异构化催化剂今后发展的方向.     

Hollow Co3O4 Nanosphere Embedded in Carbon Arrays for Stable and Flexible Solid‐State Zinc–Air Batteries

Highly active and durable air cathodes to catalyze both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are urgently required for rechargeable metal–air batteries. In this work, an efficient bifunctional oxygen catalyst comprising hollow Co₃O₄ nanospheres embedded in nitrogen‐doped carbon nanowall arrays on flexible carbon cloth (NC‐Co₃O₄/CC) is reported. The hierarchical structure is facilely derived from a metal–organic framework precursor. A carbon onion coating constrains the Kirkendall effect to promote the conversion of the Co nanoparticles into irregular hollow oxide nanospheres with a fine scale nanograin structure, which enables promising catalytic properties toward both OER and ORR. The integrated NC‐Co₃O₄/CC can be used as an additive‐free air cathode for flexible all‐solid‐state zinc–air batteries, which present high open circuit potential (1.44 V), high capacity (387.2 mAh g^?1, based on the total mass of Zn and catalysts), excellent cycling stability and mechanical flexibility, significantly outperforming Pt‐ and Ir‐based zinc–air batteries.     

Pt and Ru dispersed on LiCoO2 for hydrogen generation from sodium borohydride solutions

Nano-sized platinum and ruthenium dispersed on the surface LiCoO₂ as catalysts for borohydride hydrolysis are prepared by microwave-assisted polyol process. The catalysts are characterized by transmission electron microscopy (TEM), X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). Very uniform Pt and Ru nanoparticles with sizes of <10 nm are dispersed on the surface of LiCoO₂. XRD patterns show that the Pt/LiCoO₂ and Ru/LiCoO₂ catalysts only display the characteristic diffraction peaks of a LiCoO₂ crystal structure. Results obtained from XPS analysis reveal that the Pt/LiCoO₂ and Ru/LiCoO₂ catalysts contain mostly Pt(0) and Ru(0), with traces of Pt(IV) and Ru(IV), respectively. The hydrogen generation rates using low noble metal loading catalysts, 1 wt.% Pt/LiCoO₂ and 1 wt.% Ru/LiCoO₂, are very high. The hydrogen generation rate using Ru/LiCoO₂ as a catalyst is slightly higher compared with that of Pt/LiCoO₂.