基于卷积神经网络的煤泥浮选泡沫图像分类方法

当前煤泥浮选泡沫分类研究多针对光照充足条件下泡沫图像,对于夜晚车间光照不足的暗淡图像效果不好。针对这一问题,引入一种利用深度学习的有效浮选泡沫分类方法,建立了一个深度卷积神经网络同时执行特征学习与泡沫分类,逐层运算抽取图像本质信息,过滤光线影响。实验结果表明,在白天强光和夜晚弱光下,无需图像增强等预处理均获得很高的准确率,实现浮选泡沫端到端分类,提高了识别的抗干扰能力。     

天然橡胶接枝甲基丙烯酸羟乙酯的合成与表征

以甲基丙烯酸羟乙酯(HEMA)为接枝单体,过氧化二苯甲酰(BPO)为引发剂,合成了天然橡胶(NR)接枝聚甲基丙烯酸羟乙酯(NR-g-HEMA)。研究了BPO和HEMA用量、反应温度、反应时间以及NR塑炼时间对单体转化率、接枝率和接枝效率的影响,并采用红外光谱对接枝产物进行了表征。结果表明:当BPO用量为3%,HEMA用量为30%,反应温度为80℃,反应时间和NR塑炼时间分别为4h和30min时,NR-g-HEMA的接枝率达16%。     

KH-570改性纳米二氧化钛的制备及其分散性研究

以乙醇为分散介质,采用γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)对纳米二氧化钛进行化学改性,研究了KH-570用量、反应时间和反应温度对TiO2接枝率和亲油化度的影响;采用红外光谱(FT-IR)和激光粒径分析(DLS)等手段表征了KH-570改性TiO2粒子的结构及其分散性.结果表明:KH-570成功接枝到TiO2表面.当KH-570用量为TiO2的15％(质量分数),反应温度为60℃,反应时间为6h时,改性效果最好:接枝率达到8.9％,亲油化度达到56％;与未改性的TiO2相比,KH-570改性TiO2的平均粒径明显减小,分布变窄.     

纳米二氧化钛/丙烯酸酯复合乳液的制备及反应稳定性研究

采用预乳化及种子乳液聚合方法制备了纳米二氧化钛/丙烯酸酯复合乳液,研究了丙烯酸(AA)、过硫酸钾(KPS)、乳化剂及纳米二氧化钛用量对聚合反应稳定性的影响,并采用红外光谱对复合乳胶膜的结构进行了表征。结果表明:当AA、KPS、乳化剂和纳米二氧化钛的用量分别为3.0%,0.5%,3.3%和2.0%时,体系中的凝胶较少,具有良好的聚合反应稳定性。     

原位乳液聚合制备聚合墨粉用含蜡苯丙复合乳液及其性能研究

采用核壳乳液聚合的方法,以苯乙烯、丙烯酸丁酯和丙烯酸为共聚单体,原位制备了聚合墨粉用含蜡苯丙复合乳液。探讨了巴西棕榈蜡用量对单体转化率、凝聚率、复合乳液粒径及其分布、Zeta电位、共聚物的玻璃化转变温度以及相对分子质量及其分布的影响。结果表明,巴西棕榈蜡的加入对聚合稳定性影响不大;随着其用量的增加,乳液粒径、Zeta电位、聚合物玻璃化转变温度降低,而相对分子质量增大。当其用量为3%(wt)时,聚合物具有较适宜的Tg和相对分子质量,分别为65.9℃和89,000。     

跟踪系统在剪切线中应用

从钢板运输、定位到剪切全是在跟踪系统中完成,通过对一级和二级之间跟踪讲解和跟踪优化,满足了工艺要求,提高了剪切线的精确剪切和稳定运行。     

Synthesis and properties of UV curable polyurethane acrylates based on two different hydroxyethyl acrylates

Two kinds of UV curable polyurethane acrylate oligomers (PUPA and PUCA) were synthesized via the addition reaction between isophorone diisocyanate (IPDI) and polyethylene glycol monoacrylate (PEA₆) or polycaprolactone modified hydroxyethyl acrylate (PCLA₂). The structures of PUPA and PUCA were characterized by Fourier transform infrared spectroscopy (FT-IR), ¹H nuclear magnetic resonance (¹H NMR), gel permeation chromatography (GPC) and differential scanning calorimeter (DSC), and the thermal stability and dynamic mechanical thermal properties of their cured films were measured by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA), respectively. The viscosity of the oligomers and mechanical properties of the cured films were also studied. The results show that both oligomers have narrow molecular weight distribution. The viscosity of PUPA is 2.310 Pa·s at 25 °C, while that of PUCA is up to 3.980 Pa·s. The UV cured PUPA and PUCA films have homogeneous phase structure, and the PUCA film shows higher glass transition temperature and storage modulus. Furthermore, the PUCA film possesses better mechanical properties than PUPA, while the latter shows better alkali resistance.     

水性UV固化聚氨酯丙烯酸酯涂料的制备及其合成工艺的研究

采用分步加料法,以甲苯二异氰酸酯(TD I)、聚乙二醇(PEG)、二羟甲基丙酸(DMPA)以及甲基丙烯酸β-羟乙酯(HEMA)为原料合成了光固化水性聚氨酯丙烯酸酯(PUA)预聚体。产物经三乙胺中和后自乳化分散于水中,体系固含量达到36%。比较了一步加料法和分步加料法对体系稳定性及涂膜性能的影响,并研究了PEG与DMPA物质的量的比对涂膜性能及固化时间的影响。结果表明,分步加料法制得的体系的稳定性要优于一步加料法;随着n(PEG)∶n(DMPA)的减小,涂膜的吸水率先减小后增大,而光泽和固化速度有所降低。另外,在同一预聚体的体系中,光引发剂的含量对涂膜固化时间的影响较大。     

Epoxidation of styrene-isoprene-styrene block copolymer and research on its reaction mechanism

Styrene-isoprene-styrene(SIS) block copolymer was modified into epoxidized styrene-isoprene-styrene(ESIS) block copolymer with performic acid generated in situ from hydrogen peroxide and formic acid.The structure and property of ESIS were characterized by Fourier transform infrared(FT-IR) spectroscopy,gel permeation chromatography(GPC),thermogravimetric/differential thermogravimetric(TG/DTG),melt flow rate(MFR) and dynamic mechanical analysis(DMA),and the reaction mechanism in the process of epoxidation was analyzed.The results showed that C=C double bonds of 1,4-structure were more active than that of 3,4-structure in polyisoprene chains.With epoxidation reaction proceeding,the whole tendency of molecular weight increased and molecular weight distribution widened,and MFR firstly increased and latterly decreased.The heat resistance of ESIS was superior to that of SIS.When SIS was changed into ESIS with 15.3% of mass fraction of epoxide groups,Tg of polyisoprene chains increased from-45.3 ℃ to 10.9 ℃.In the earlier period of epoxidation,some molecular chains ruptured and new substances with low molecular weight formed.However,in the latter period,crosslinking reaction between molecular chains which was initiated by epoxide groups or C=C double bonds occurred and crosslinked insoluble substances came into being.     

超亲水表面的研究及应用进展

超亲水表面与水具有很强的相互作用力,将水滴滴在上面能够在较短时间内完全铺展开,使接触角等于或接近于0°,在自清洁、防雾、防污、油水分离等众多领域均有着十分广阔的应用前景,是当前研究的热点之一。该文首先介绍了超亲水表面的定义,并简单回顾了其研究背景;其次对超亲水表面的亲水机理进行了总结和归纳,其一是在高表面能物质的表面上构造粗糙度实现超亲水,其二是光致实现超亲水;进一步地,重点阐述了目前超亲水表面的主要制备方法及其研究进展,如溶胶-凝胶法、气相沉积法、模板法、相分离法和层层自组装法等,并对比了其优缺点;此外,介绍了超亲水表面在自清洁与防雾、油水分离及其它方面的主要应用进展;最后,指出了目前制备超亲水表面存在的一些问题,如需要采用昂贵的仪器设备或复杂的工艺流程、易受外界条件(光、热、氧等)的影响、使用的持久性差、应用领域仍有待于发展等,并认为环保型、功能性和耐久性是超亲水表面未来的主要发展方向。