浅谈影响纸面石膏板不粘纸的因素及解决方法

从纸和板两个方面探讨了纸面石膏板不粘纸的原因,分析了影响石膏板粘结的各种因素。研究发现:护面纸吸水性过高或过低、透气度过低以及强度过低都会对纸面石膏板的粘结产生不利影响;提高石膏粉品位、均化程度和细度,减少有害离子含量有利于纸面石膏板的粘结;合理添加水和外加剂有利于石膏板的粘结。     

Plasma-polymerized coatings for bio-MEMS applications

Coatings that provide either hydrophobic, hydrophilic, cell adhesive or cell non-adhesive functionalities have been deposited using three-phase low energy plasma-polymerization. The cell adhesive/non-adhesive coatings were tested using E. coli k-12. The four plasma-polymerized coatings are: para-xylene (PX), 1-vinyl-2-pyrrolidinone (VP), polyvinyldifluoride (PVDF) and phosphorous glass (SiPOC), respectively. In addition, micropatterning of PX and VP has been performed on the same silicon substrate. Feature sizes down to 2 μm and precise alignment were obtained using lift-off and cleanroom photolithography techniques. The patterning process used did not influence the wetability of the coatings. The simplicity of the lift-off technique and the sturdiness and versatility of the plasma-polymerized coatings, make this ideal for MEMS, bio-MEMS and microfluidic applications, where patterned surfaces with different functionalities are required on for instance the same microchip.     

非粘接型耐高温有机硅密封材料的性能研究

以聚硅氮烷为基体树脂,硅氧烷为增韧剂和浸润剂,云母粉、硅藻土、碳化硼为填料,制备了耐600℃高温的非粘接型密封材料,该密封材料经室温～600℃热循环24次后,密封压力达到4 MPa;以聚硅氮烷为基体树脂,二硅化钼、云母粉、滑石粉、二氧化硅为填料,制备了耐800℃高温的非粘接型密封材料,该密封材料经室温～800℃热循环24次后,密封压力达到4 MPa。     

Interfacial and Bulk Contributions to Peeling Energy

Thin polyurethane films, having low adhesion to dried protein, were developed as candidate materials for non-adhesive surgical dressings. In order to model wound-adhesion, gelatine was cast from solution on to the film and allowed to dry. The film was peeled from the gelatine at 180° peel angle, and the peel force measured as a function of the temperature of test. The dynamic mechanical properties of the films were measured over the range -90°C to 110°C and values of tan δ were determined at the temperatures employed for peeling. Thus, a correlation was obtained between peeling energy and tan δ for each of eight films.

The generalised theory of fracture mechanics states that the adhesive failure energy is given by the product of an interfacial energy term and a “loss function” involving the hysteresis ratio of the material. If the strains are small the hysteresis ratio is proportional to tan δ. The experimental results show excellent agreement with the theory, but the interfacial term turns out to be much greater than the true interfacial energy (or thermo-dynamic work of adhesion). The reason for this result is discussed.     

不粘性涂料

论述了不粘性涂料的特点与应用；介绍了常用的氟树脂和硅树脂不粘性涂料；提出了不粘性涂料的发展方向．     

无粘结预应力楼板的施工及质量控制

提出加强预应力施工质量控制的必要性,介绍无粘结预应力楼板的施工过程及技术准备工作,阐述了应从进场材料、预应力筋的制作和安装、混凝土浇筑、预应力张拉、封锚保护等5个方面对其质量进行控制。     

50m直径预应力混凝土沉淀池施工技术

介绍了50m直径沉淀池施工工艺和池壁预应力混凝土采用二次张拉新技术,为防止施工过程中池壁产生温度和收缩裂缝提供了经验,可供同类型预应力工程施工参考。