The support designs of the triply even binary codes of length 48

In this paper, we present examples of codes all of whose weight classes support 1‐designs, with duals whose classes include two that support 2‐designs. We can find these examples in the triply even binary codes of length 48, which have been classified by Betsumiya and Munemasa.     

α‐ZrP/Uracil/Cu2+ nanoparticles as an efficient catalyst in the Morita‐Baylis‐Hillman reaction

A facile synthesis of uracil‐Cu²⁺ nanoparticles immobilized on alpha‐zirconium hydrogen phosphate (α‐ZrP), abbreviated as α‐ZrP/Uracil/Cu²⁺, was presented. This compound was synthesized by the thermal method and used as a reusable catalyst for the Morita‐Baylis‐Hillman reaction without any additives. First, (3‐ iodopropyl) trimethoxysilane as a linker is reacted with α‐ZrP support to give the α‐ZrP/IPTMOS. Addition of uracil and then the addition of copper (II) acetate to α‐ZrP/IPTMOS results in the production of selected catalyst. The Morita‐Baylis‐Hillman reaction catalyzed by α‐ZrP/Uracil/Cu^{2 +} demonstrated high product yield, short reaction time and a straightforward work‐up. The catalyst with enough outside surface was easily recovered using centrifugation and reused five times without a significant reduction in its activity.     

基于工作电流分析的回转副摩擦状态识别实验研究

回转副摩擦状态的变化对机械设备的运行有着重要影响. 针对回转副摩擦状态的识别问题, 设计了以回转副工作电流为摩擦特征来源的实验方案. 通过采集摩擦过程的回转副驱动电机工作电流信号, 分析实验信号的频域和时频域特征, 建立工作电流的摩擦特征库, 用于训练多分类支持向量机分类器, 并在分类器上完成摩擦状态的识别. 实验结果表明, 经特征提取与降维处理后建立的多分类支持向量机分类器具有近90%的识别正确率, 所提出的实验方案有利于实现远距离信号的采集, 适用实际生产加工.     

铈铝复合载体对钼基催化剂耐硫甲烷化催化性能的研究

采用共沉淀法、浸渍法和沉积沉淀法制备了CeO₂-Al₂O₃复合载体,比较了不同复合载体浸渍钴钼后的耐硫甲烷化催化性能,并优化了复合载体中CeO₂的含量。结合N₂物理吸附、XRD、H₂-TPR等表征手段对复合载体及其负载的钴钼催化剂进行物相和结构分析发现,在Al₂O₃中添加CeO₂可以明显提高合成气的耐硫甲烷化活性,其中,沉积沉淀法制备的25% CeO₂-Al₂O₃复合载体负载钴钼后具有最佳催化活性。     

Prediction of thermal conductivity of polymer-based composites by using support vector regression

Support vector regression (SVR) combined with particle swarm optimization (PSO) for its parameter optimization, was proposed to establish a model to predict the thermal conductivity of polymer-based composites under different mass fractions of fillers (mass fraction of polyethylene (PE) and mass fraction of polystyrene (PS)). The prediction performance of SVR was compared with those of other two theoretical models of spherical packing and flake packing. The result demonstrated that the estimated errors by l...     

A simple zero length surface-modification approach for preparing novel bifunctional supports for co-immobilisation studies

A straightforward method of creating a bifunctional support possessing pre-defined ratios of amine and chloromethyl groups based upon a controlled conversion of standard Merrifield resin is presented. It avoids the extensive optimisation of reactant concentrations and reaction conditions required by existing methods. Furthermore, it avoids increases in the spacer/linker length that lead to detrimental reductions in the rigidity of the grafted layer. The method will allow for efficient, predictable and reproducible co-immobilisation of molecular species.     

Synthesis of Methyl N‐Aryl Oxamate Using Soluble Polymer Support

A variety of methyl N‐aryl oxamates were synthesized using poly(ethylene glycol) (PEG) as a soluble polymer support and a monoproctection group with excellent yields.     

含氟体系中高性能T型分子筛膜的合成

含氟体系中,在负载晶种的大孔莫来石支撑体表面快速合成了高性能且取向生长的T型分子筛膜。采用XRD、SEM和MASNMR等手段对分子筛膜层和粉末进行表征。讨论了添加物、氟硅比、合成温度和合成时间等条件对膜生长与分离性能的影响,并阐述了含氟体系中T型分子筛膜快速晶化的机理。碱金属氟盐的加入促进了T型分子筛晶体层的晶化速率,并对晶体层形貌产生了一定的影响。膜应用于75℃、水/异丙醇（10：90,w/w）体系的平均渗透通量和分离因子分别为（4.91±0.18）kg·m^-2·h^-1和7060±1130。     

基于支座反力影响线曲率差分的等截面连续梁损伤识别方法

为了实现仅采用损伤状态信息对等截面连续梁进行损伤识别,通过推导三跨不等跨连续梁在移动荷载作用下的支座反力影响线,发现支座反力影响线求曲率并作差分后的曲线在损伤位置会发生突变,基于该现象提出了一种损伤定位方法,进一步建立了损伤程度计算方法,可对损伤程度进行较精确的定量。通过一三跨连续梁和一四跨连续梁工程实例的仿真分析,证明了支座反力影响线曲率差分指标损伤定位和相应的损伤程度定量方法对等截面连续梁损伤识别具有可行性。