ASA中性施胶剂在文化用纸生产中的应用

结合烯基琥珀酸酐（ASA）在岳阳纸业股份有限公司9#纸机上的应用实例,就ASA现场乳化、施胶稳定性及控制水解等方面进行了深入探讨,并就ASA替代AKD施胶,在控制假施胶方面进行比较。     

球磨法制备超微细蒽醌及其表征

介绍了超微细蒽醌制备方法和表征手段。该法首先是利用球磨机将商品蒽醌球磨成细小蒽醌;然后,在十二烷基苯磺酸钠的作用下使制得的蒽醌颗粒悬浮液通过物理沉降,将较大颗粒的蒽醌分离,从而获得了超微细蒽醌的悬浮液;最后分别用可见分光光度计及马尔文粒度分析仪对超微细蒽醌悬浮液中蒽醌含量及粒度分布进行测定与表征。结果表明,用本实验的球磨机制备超微细蒽醌的适宜条件为:球磨时间12 h、十二烷基苯磺酸钠用量10%。对超微细蒽醌悬浮液中蒽醌含量及粒度分布进行测定时应充分搅拌后将悬浮液静置30 min时取样为宜。本方法可制备含量高、粒径小、粒度分布均一的超微细蒽醌悬浮液。     

激光烧蚀制备纳米Si晶粒尺寸均匀性与靶衬间距的关系

为了对纳米Si薄膜中晶粒尺寸的分布进行定量研究,首次提出“晶粒尺寸均匀度”的概念,并对Lowndes等人采用脉冲激光烧蚀方法制备纳米Si薄膜的实验结果进行了定量分析。结果表明,随着靶衬间距的增大,晶粒尺寸均匀度先减小后增大,也就是说,存在靶衬间距的最佳值,使所制备的纳米Si晶粒的尺寸均匀性最好。MonteCarlo模拟结果对这一结论进行了解释。     

Wear characteristics of some internally lubricated and reinforced engineering polymer composites

An interesting characteristic of abrasion is the dependence of the wear rate on the particle size of the abrasive grits used to lubricate the abrasive papers. Three types of polymers, PTFE, PA, PI, several of their composites, and three metals were selected for studying the effect of particle size on wear rate. The pins were abraded against Sic abrasive papers of various mesh sizes under constant loading in multi-pass conditions. For some of the polymers and their composites (PA and PEI) the size effect on wear rate was similar to that for the metals. Beyond a critical particle size, no increase in wear was found with increasing particle size. On the other hand, PTFE, PI, and their composites showed the opposite effect. SEM and EDAX were used to investigate the related mechanisms.     

TAPPI JOURNAL 2018年第10期目次

本实验建立在之前对含淀粉乳胶涂料的流变特性和动态保水性的研究成果基础之上。前期研究表明,淀粉胶乳的流变性和动态保水性不同于传统熟化涂布淀粉。本实验采用血清置换法研究了水膨胀淀粉纳米粒子的基本性能及其胶体行为。结果表明,淀粉胶乳是由微粒和少量可溶性聚合物组成的复杂体系。提高交联度会减少可溶性组分,并降低分散黏度。实验室圆柱形涂布机形成的涂层显示,丁苯胶乳具有可塑性,在压光过程中起到润滑剂的作用,有助于提高纸张光泽度。将生物胶乳与羟乙基淀粉（接枝聚合物）交联可以提高涂料的保水性,但是低交联Bio-A的使用则会降低涂布纸的光泽度。     

基于计算机视觉的纸张填料粒径分析方法

针对现有纸张填料粒径分析过程中使用的激光衍射法存在的缺点,提出一种基于计算机视觉的纸张填料粒径分析方法。将获取到的扫描电子显微镜图像进行预处理,去除噪声等影响统计粒径分布的因素,对图像中存在的填料颗粒粘连比较严重的部分采用改进的分水岭算法进行图像分割,进而利用快速连通域标记及欧拉数算法确定填料颗粒的粒径分布。最后将采用计算机视觉方法计算的填料颗粒粒径分布结果与采用激光衍射法得到的结果进行对比。在放大1500倍沉淀碳酸钙填料颗粒图像上的实验结果表明,采用计算机视觉方法计算的纸张填料粒径分布与激光衍射法测得的结果基本一致,中位径误差小于1%,累计粒度分布数达到85%时,误差在6%左右。     

航空用夹布橡胶薄膜高精度尺寸孔的优化加工方法

提出了利用预制底孔来减小橡胶零件冲制时自然收缩量波动范围的工艺方案.解析了夹布橡胶薄膜高精度尺寸孔的加工工艺参数设计方法.生产实践证明:采用预冲底孔的方法冲制夹布橡胶薄膜,尺寸波动小于0.02 mm,而用原工艺加工的尺寸孔的波动达到0.15 mm.     

诱发IAF夹杂物与原晶粒的尺寸匹配关系

 对于氧化物冶金船板钢而言,细小弥散分布的夹杂物会对其原始晶粒产生钉扎和诱发晶内铁素体的双重作用,且研究发现诱发晶内铁素体的夹杂物尺寸与原始奥氏体晶粒尺寸存在一定的匹配关系。围绕上述问题进行了系统的分析研究和数据统计,结果表明,不同晶粒尺寸下,诱发晶内铁素体的夹杂物尺寸与原奥氏体晶粒度间存在近似线性关系,且随着奥氏体晶粒度的增大,诱发晶内铁素体的夹杂物尺寸则相应减小。     

稀土Y对气雾化制备PH13-8Mo钢粉末特性的影响

摘要：研究了不同含量的稀土Y对选区激光熔化技术(SLM)用PH13 8Mo钢粉末特性的影响,并通过Thermo-Calc热力学软件、粉体综合特性测试仪、霍尔流速计、激光粒度分析仪、扫描电镜和电子探针等方法对不同Y含量的PH13-8Mo钢粉末特性的变化规律进行研究。结果表明,随着金属粉末中Y含量的增加,金属粉末的松装密度从3.73提高到3.93g/cm3,50g粉末的自由流动时间从25.44减小到25.11s,粉末的流动性变好。同时,PH13 8Mo钢粉末的平均粒径从37.29减小到30.99μm,粉末的粒度分布区间变窄。研究还发现,不含Y的PH13-8Mo钢粉末的组织由树枝晶和等轴晶组成,而Y质量分数为0.080%的PH13 8Mo钢粉末的组织均由等轴晶组成。综上,在PH13.8Mo钢粉末中加入稀土Y,粉末的特性得到优化。     

Impact of grain size,Pr~(3+) concentration and host composition on non-contact temperature sensing abilities of polyphosphate nano- and microcrystals

In this article,varied praseodymium polyphosphate hosts:M~I(Li,Na K)Pr(PO_3)_4 microcrystals and LiLa_(1-x)Pr_x(PO_3)_4(x = 0.01-1)nanocrystals were successfully synthesized by the flux method and the coprecipitation technique,respectively.The size of stoichiometric nanocrystals of LiPr(PO_3)_4 was tuned by the te mpe rature of thermal treatment in range of 35-145 nm.In order to dete rmine the most suitable material for the non-contact optical thermometric applications,the temperature sensing measurements were carried out by using luminescence intensity ratio(LIR)of emission bands corresponding to the ~3 P_1→~3H_5 and ~3P_0→~3 H_5 electronic transitions of Pr~(3+) ions into the 123-423 K temperature range.The influence of the host material composition of M~Ⅰ(Li,Na,K)Pr(PO_3)_4 microcrystals on the sensitivity of luminescent thermometers was studied.It is found that the sensitivity of lithium praseodymium polyphosphate is the highest of all micropowders under investigation.Moreover,it is found that the nanocrystals reveal much higher relative sensitivity in respect to the microcrystalline counterparts.The highest sensitivity of LIR temperature sensing is found for LiPr(PO_3)_4 nanocrystals(35 nm grain size)in the whole temperature range,reaching 0.283%/K at 164 K.The impact of the average grain size on the sensitivity of LIR based thermometers of LiPr(PO_3)_4 nanocrystals was investigated.It is found that the reduction of the grain size from 145 to 35 nm results in the enhancement of the relative sensitivity from0.156 to 0.240%/K at 223 K.Additionally it is found that the high dopant concentration possesses favorable influence on the relative sensitivity of LiLa_(1-x)Pr_x(PO_3)_4 nanocrystalline luminescent thermometers.