Indian composites industry set to take off

The composites industry in India is in an optimistic mood and is looking forward to continued growth this year. Amanda Jacob reports on the ICERP 2004 International Conference and Exhibition on Reinforced Plastics, which took place in Chennai on 12-14 February.     

烟蚜的抗药性现状及其综合治理

烟蚜作为烟田的重要害虫之一,不仅直接为害烟草叶片,使烟叶的品质下降,而且还可传播多种病毒病。目前主要以化学防治为主来控制烟蚜及其传播烟草病毒病,但是随着农药的广泛使用,烟蚜的抗药性己成为当前烟蚜防治中所面临的一场严峻挑战。因此,烟蚜抗药性的研究对烟草生产具有重要意义。本文就烟蚜的抗药性现状,抗药性综合治理等方面进行了论述。     

High speed electron spin resonance techniques applied to polymer fracture

Mechanical fracture of nylon 6 produces free radicals as a direct result of bond-breaking; these initial free radicals rapidly decay into secondary free radicals at room temperature. Aromatic nitro-compounds react with the initial, but not the secondary, free radicals. The rate of reaction is sufficiently fast to compete with the usual initial radical decay process, even at room temperature. Considerations involved in applying high speed (microsecond) electron spin resonance techniques are discussed.     

Viscoelastic response of unidirectionally reinforced thermoplastic composites to off axis deformation

Measurements of dynamic viscoelastic in-plane shear modulus have been made for unidirectional carbon fiber composites with amorphous engineering thermoplastics as the binder resins. The viscoelastic response is modeled by a three-phase, finite-element model in which fiber placement in the plane perpendicular to the fiber axes is largely disordered. In the model, fibers tend to chain with the distance of closest approach dictated by several factors, including the tendency for the resin to wet the entire fiber surface. Polished section microscopy supports the assumed microstructure. The model includes an adsorbed primer layer at the fiber interface with perturbed viscoelastic response. The model is useful throughout the temperature range up to and including the glass transition of the binder resin.     

气动执行器在高危泵切断阀上的应用

通过对PTA生产工艺中易燃、有毒、有害类物料泄漏造成的危害分析,制定出高危泵入口和出口阀改造方案,比较几种方案的优势,确定使用气动执行器改造切断阀,提高阀门的切断速度,在发生泄漏等故障时,迅速切断进料和出料,以避免事故扩大。