改性三氧化二锑协效二乙基次磷酸铝阻燃PA6研究

采用硅烷偶联剂（KH560）对三氧化二锑（Sb₂O₃）进行表面改性处理，并将其协效二乙基次磷酸铝（ADP）应用于聚酰胺6（PA6）阻燃研究。采用傅里叶变换红外光谱和热失重分析对改性Sb₂O₃进行表征，运用垂直燃烧、氧指数、锥形量热仪、热分析以及扫描电子显微镜和拉曼光谱等对阻燃PA6进行了阻燃性能及机理分析。结果表明，改性 Sb₂O₃与Sb₂O₃相比，与ADP具有更好的协同阻燃效应，其作用机制主要是在气相发挥阻燃作用；当ADP含量为8 %，改性Sb₂O₃含量为2 %时，阻燃PA6复合材料的UL 94等级达到V?0级，极限氧指数达到33.8 %。     

Excellent Mechanical and Transparency Properties of Cationic Waterborne Polyurethane Films Modified by Boehmite Sol

The strategies for nanosol from metal alkoxide have enabled production of ultratransparent and mechanically robust polymer nanocomposites at extremely high loading. Herein, a simple approach to fabricate high‐performance polyurethane‐based nanocomposites via unmodified boehmite nanoparticles is reported. Evaluating their physical properties, the uniform dispersion of boehmite in the matrix caused nanocomposites retains ultrahigh transparency. Hydrogen bonding and intermolecular entanglement between boehmite and polyurethane brings about the mechanical properties of the nanocomposites material enhanced, i.e., strength, stiffness, and toughness. Optimized strength, stiffness, and toughness of Boehmite/Cationic waterborne polyurethane at 40 wt% (BNC40) are up to 58.1 MPa, 1096.7 MPa, 249.5 MJ m^?3, respectively. Furthermore, the feasibility and mechanism of polymer strengthening and toughening by inorganic rigid nanoparticles is explored from the aspects of crystallinity and micromorphology.     

机床结构轻量化设计研究进展

对机床进行优化的结构构型设计,使得材料在机床结构空间内更加合理地分布和有效地利用,一直都是机床设计工作者追求探索的目标。论述机床构型和结构件轻量化设计的研究历程和技术发展,对机床结构轻量化设计中常用的现代设计方法:参数优化、结构拓扑优化、多方法综合结构设计、仿生优化设计方法进行具体技术介绍和综合评述,并对近年兴起的仿生优化设计方法进行从方法、实现手段和轻量化效果等方面重点分析和评述,对机床构型和结构件轻量化设计研究的未来发展提出展望。     

焊缝表面缺陷激光扫描三维重构测量

为检测工件焊缝表面缺陷，采用点激光位移传感测距法和数据拟合技术进行焊缝表面缺陷检测试验研究. 首先采集缺陷表面轮廓数据点，利用高斯滤波对原始数据降噪处理. 再对处理后的数据点进行Delaunay三角剖分，使散乱点连接并结合其空间坐标重构出缺陷的三维模型. 结果表明，基于点激光位移传感测距技术及焊缝表面缺陷三维重构方法可以准确判断焊缝成形情况.     

A Dual Inhibitor of DYRK1A and GSK3β for β-Cell Proliferation: Aminopyrazine Derivative GNF4877

Loss of β-cell mass and function can lead to insufficient insulin levels and ultimately to hyperglycemia and diabetes mellitus. The mainstream treatment approach involves regulation of insulin levels; however, approaches intended to increase β-cell mass are less developed. Promoting β-cell proliferation with low-molecular-weight inhibitors of dual-specificity tyrosine-regulated kinase 1A (DYRK1A) offers the potential to treat diabetes with oral therapies by restoring β-cell mass, insulin content and glycemic control. GNF4877, a potent dual inhibitor of DYRK1A and glycogen synthase kinase 3β (GSK3β) was previously reported to induce primary human β-cell proliferation in vitro and in vivo. Herein, we describe the lead optimization that lead to the identification of GNF4877 from an aminopyrazine hit identified in a phenotypic high-throughput screening campaign measuring β-cell proliferation.     

煤矿新型让压锚杆研究及应用

针对高应力软岩巷道围岩的大变形特征,设计了一种煤矿新型让压锚杆,主要运用钢套管内部约束热固性聚氨酯弹性材料来达到大变形让压的目的。试验表明,该锚杆与传统让压锚杆相比,具有让压距离大(为传统让压锚杆的3倍)、让压后承载性能稳定的显著特点。工程应用表明,该锚杆对深部高应力软岩巷道围岩稳定性能起到较好的控制作用。     

正压给水的主排水泵启动特性仿真分析研究

峰峰集团某矿排水系统在采用正压给水方式后主排水泵泵效明显提高,为了研究排水系统的启动特性,利用Flowmaster软件建立了离心泵串联系统模型。根据水力机械试验室的设备参数进行了仿真,分析了正压给水条件下主泵定量启动前由单泵和双泵组成的排水系统特性。在此基础上,得到了离心泵瞬时启动转速和功率的特性曲线。结果表明,在正压给水条件下,主泵启动功率的影响基本消除,主泵功率达到稳定值的时间缩短。提高了主排水泵的效率,提高了排水系统的综合效率。     

CNG-电混动公交车道路行驶工况与排放特性研究

CNG-电公交车以天然气作为发动机燃料,辅以电机共同驱动的混合动力车辆,车辆行驶速度低、启动频繁等特性,发动机实际运行工况与型式检验工况具有较大差异。为研究其实际行驶工况与排放特性,选取4辆国V排放标准的CNG-电混合动力公交车,往返于市区与城郊,使用PEMS(portable emission measurement system)实时收集车辆行驶及NO_X排放数据。结果表明,发动机运行工况集中于中低功率段,与型式检验工况差异较大,污染物排放集中于发动机切入车辆传动系统的临界车速附近。     

Headspace fingerprinting approach to identify the major pathway influencing volatile patterns of vinasse-cured duck processed by high pressure,as well as its impact on physicochemical and sensory attributes

As a decisive attribute, flavour could be influenced by HP treatments through multiple physical and chemical pathways within the high pressure (HP)-assisted meat curing process. This investigation aimed to identify the major pathway influencing volatile flavour patterns of two representative vinasse-cured duck (VCD) products with HP treatments (150–300 MPa/15 min), including wet and dry types, by employing headspace fingerprinting as an untargeted approach. Results suggested that HP treatments greatly lowered moisture contents and increased Warner-Bratzler shear force and thiobarbituric acid reactive substances of the cured samples. According to multivariate models, the volatile flavour patterns of the HP-processed VCD could be clearly separated from the unprocessed samples, but the VCD pressurised at different intensities represented similar volatile fingerprinting, which was validated by e-nose analysis. The discriminant analysis (OPLS-DA) model outlined vinasse-derived ethanol, acetic acid, 3-methyl-1-butanol, 2-methyl-1-butanol, phenethyl alcohol and 2-methyl-3-octanone as the major discriminant aromas across the unpressurised and pressurised samples.     

喷雾干燥法制备材料论文的指导方案

喷雾干燥技术的突出特点是将液态物料瞬时干燥成固体粉末或者颗粒。我们课题组在指导本科生毕业论文中采用了喷雾干燥法制备碳包覆铌酸钛材料的实验,在实验过程中我们发现了一些问题,如喷雾干燥机需要适当预热、喷头容易堵赛和收集原料不干等问题。我们就以上问题进提出了相应的对策,这加深了本科生对喷雾干燥实验的体会和认识,培养了学生在独自实验时面对问题解决问题的能力。