熔覆电流对高钼高钒铁基硬质涂层组织结构与性能的影响

刃板的磨损失效往往导致整个挖斗报废,为了提高其耐磨性能,采用等离子熔覆技术在刃板材料Q345B表面制备高钼高钒铁基耐磨涂层,研究熔覆电流(120、140、160 A)对涂层组织结构的影响,考察涂层的显微硬度、摩擦磨损与耐冲击性能。结果表明,电流大小对涂层的组织结构与界面状态影响较大,涂层组织主要由马氏体基体、弥散分布的细小球形碳化钒(VC)、多边形块状硼化钼(Mo_(2)B)和层片状复合硼碳化物(M_(2)(B,C))组成。120 A下制备的涂层与基材界面处存在局部未熔合区,增大电流导致涂层中VC的尺寸和分布间距变大,Mo_(2)B消失,M_(2)(B,C)增多且尺寸增大。涂层的平均显微硬度约为920 HV0.1,是耐磨钢NM400的2倍多,同等条件下的磨损失重仅为NM400的1/20,表现出优异的耐磨性能。带基材的涂层具有良好的耐冲击性能,且平行熔覆纹路的耐冲击性能优于垂直熔覆纹路的。

基质相容性溶胶-凝胶固相微萃取涂层直接萃取柑橘中农药残留

为了开发新的可利用的基质相容性固相微萃取(solid phase microextraction,SPME)涂层,促进活体SPME采样技术的发展。本研究评价了溶胶-凝胶聚二甲基硅氧烷萃取头在柑橘基质中的基质相容性,建立了直接SPME-气相色谱法检测柑橘果浆中有机磷农药的方法。结果表明:在柑橘果肉匀浆并添加同样质量的水,调节pH至1.84、50℃萃取60min、搅拌速度为1200r/min条件下,5种有机磷农药在线性范围内具有良好的线性关系,R2≥0.999,检测限为0.002~0.046μg/kg,加标回收率为71.0%~125.3%,相对标准偏差为0.5%~15.6%。该萃取头在柑橘活体基质中可以连续使用50次以上。

多孔BCP支架及其仿ECM涂层对MG63细胞功能的影响

通过改良冰模板法制备一种由内向外呈放射状排列、全开孔板层状多孔结构的仿生多孔双相磷酸钙(BCP)支架,并在支架表面制备不同的仿细胞外基质(ECM)涂层。通过体外细胞实验,评价支架结构及表面4 种仿ECM生物涂层对人成骨肉瘤MG63 细胞(MG63)的细胞功能影响。研究结果表明:支架及其仿ECM涂层均无细胞毒性,仿生ECM涂层支架对MG63 细胞功能的作用优于未涂层支架,且明胶?透明质酸复合涂层试样对MG63 细胞功能的作用优于单一涂层,明胶?透明质酸?掺RGD涂层试样对MG63 细胞增殖、黏附、分化功能的作用均优于其他各涂层组。

纸制品包装物涂蜡方法及设备

纸制品包装物涂蜡方法有干法涂蜡（Dry-waxed）和湿法涂蜡（Wet-waxed）两种。干法涂蜡是用低粘度蜡液浸透,并使蜡液进入纸纤维内部,表面没有明显蜡层的方法;湿法涂蜡是将石蜡及其调和物（Wax Blends）涂于纸张表面,不使蜡液进入纸张纤维内部而在纸张表面形成一层蜡膜的方法。

Study of Wetting Properties of Carbon Nanofiber Coatings on Various Substrates

The role of roughness and composition on the wetting characteristics of a series of carbon nanofiber based coatings were studied in order to evaluate its superhydrophobic properties. In this study, idealized surfaces were created from a smooth stainless steel and aluminium sheets and two other stainless steel sheets with different textured surfaces. All surfaces were coated with carbon nanofiber alcohol solutions in order to generate coatings of variable compositions using mixtures of isopropanol, water and a commercial carbon nanofibre. The optimum concentration of carbon nanofiber in coatings was obtained to produce superhydrophobic surfaces. A general trend of increasing hydrophobicity was observed for coated surfaces as compared to the bare substrate. Individual contact angles were dependent on the nature of the underlying substrate, relative surface pattern, and roughness. Overall wetting properties were dependent upon composition and micro scale roughness of the coatings.