连铸保护渣组分对熔渣表面张力的影响

保护渣的表面张力是研究钢渣界面反应的重要参数,其大小直接影响钢渣分离和液渣吸收夹杂物的能力.采用拉筒法测定了板坯连铸保护渣的表面张力,研究结果表明:在本实验条件下,碱度降低,保护渣体系表面张力随之降低;相反,碱度升高,体系表面张力随之增大;Al2O3能使熔渣的表面张力升高,为非表面活性物质;Na2O,F-能降低熔渣的表面张力,为表面活性物质.     

浅谈纳米技术在纺织中的应用

本文根据纳米技术发展状况及纳米材料的特性 ,提出了在纺织产品开发中应用纳米技术及材料的一些思路 ,介绍了一些利用纳米材料开发的高性能纺织品。     

Fabrication and experimental characterization of d31 telescopic piezoelectric actuators

A popular and useful piezoelectric actuator is the stack. Unfortunately with this type of actuation architecture the long lengths normally required to obtain necessary displacements can pose packaging and buckling problems. To overcome these limitations, a new architecture for piezoelectric actuators has been developed called telescopic. The basic design consists of concentric shells interconnected by end-caps which alternate in placement between the two axial ends of the shells. This leads to a linear displacement amplification at the cost of force; yet the force remains at the same magnitude as a stack and significantly higher than bender type architectures. This paper describes the fabrication and experimental characterization of three different telescopic prototypes. The actuator prototypes discussed in this paper mark a definitive step forward in fabrication techniques for complex piezoceramic structures. Materials Systems, Inc. has adapted injection molding for the fabrication of net shape piezoceramic actuators. Injection molding provides several advantages over conventional fabrication techniques, including: high production rate, uniform part dimensions, uniform piezoelectric properties, and reduced fabrication and assembly costs. Acrylate polymerization, developed at the University of Michigan, is similar to gelcasting, but uses a nonaqueous slurry which facilitates the production of large, tall, complex components such as the telescopic actuator, and is ideal for the rapid manufacture of unique or small batch structures. To demonstrate these fabrication processes a five tube telescopic actuator was injection molded along with a very tall three tube actuator that was cast using the acrylate polymerization method. As a benchmark, a third actuator was built from off-the-shelf tubes that were joined with aluminum end-caps. Each prototype's free deflection behavior was experimentally characterized and the results of the testing are presented within this paper.     

Water consumption of the early-age paste and the determination of “time-zero” of self-desiccation shrinkage

Self-desiccation shrinkage (SDS) is closely related to the interior water consumption and the relative humidity (IRH) drop in the cement paste. Substantial self-desiccation shrinkage has been observed at very early-age for high performance concrete. However, it is difficult to investigate the IRH by conventional method of hygrometer at this time because the materials are still in the superhygroscopic range. In this paper, an automatically measuring system of meniscus depression is developed on the base of the mechanism of tensiometer and Laplace formula. The interior water consumption and the IRH changing within the paste could be automatically monitored at the very early-age (here specially refers to the stage from the beginning of casting till several hours after final setting). By using this system, the effects of water to binder ratio and replacement of cement by fly ash and ground granulated blast furnace slag on the self-desiccation were investigated for the very early-age cement paste. Experimental results could potentially explain the mechanism of the SDS at very early-age as well as determine the “time-zero” of SDS corresponding to its definition.     

糯扎渡水电站地下引水发电系统的施工方法

糯扎渡水电站地下引水发电系统不仅施工难度大，而且施工工期长、干扰多。对其施工通道布置、主要洞室施工方法及施工期通风等施工关键技术进行了分析研究，进而探讨了大型地下洞室群施工的施工方法。     

Preparation and properties of polymer/LDH nanocomposite used for UV curing coatings

The thermal and mechanical properties of UV curing coatings consisted of urethane acrylates as an oligomer and a diacrylate monomer were reinforced by using layered double hydroxide (LDH). The LDH was organically modified by an ion-exchange process, in which the nitrate anions were replaced by long alkyl sulfate anions. With organic modification, the d-spacing of inorganic LDH layers was greatly enlarged to 2.75 from 0.78 nm, leading the LDH to be organophilic. During in situ photopolymerization process, the d-spacing of LDH layers was further enlarged to 4.29 nm, indicating the intercalation of polymer chains. For comparison, polymer/LDH nanocomposite filled with un-modified LDH was also prepared, and showed less enhancement in thermal and mechanical properties.     

瓷石尾砂玻璃马赛克的研制

根据瓷石尾砂的矿物工艺特性，采用合理科学的配方和相应的熔融法生产工艺技术，以瓷石尾砂为主要原料，取代石英砂和部分熔剂原料，成功地研制出尾砂玻璃马赛克，产品性能按国标ＧＢ７６９７－８７检测，各项指标完全达到要求。研究成果为瓷石尾砂的综合利用开辟了新领域。