Abstract: In this study, a thixotropic agent was applied to improve the aspect ratio of the silicone rubber gasket and the resulting obtained through modification showed an increase in aspect ratio from 0.26 to 0.91 with the relative to the gasket without thixotropic agent. Compared with the silicone rubber without thixotropic agent, the mechanical properties of the silicone rubber with thixotropic agent were discussed and the results revealed that the shift was very small. In addition, using Ag-coated Cu dendritic powder as conductive fillers, conductive silicone rubber with the resistivity (0.004Ω·cm) was prepared comparable to the relative commercial products can be used for electro-magnetic interference (EMI). The reliability of the conductive composites under aging at 85°C and 85% room humidity (RH) in a temperature/humidity chamber for 48 h was also discussed and the results showed that the shift of the volume resistivity was almost negligible which can meet the actual needs completely.
Abstract: We have studied the anodization behavior of an Al film electrodeposited on the 316L stainless steel (316L SS) substrate and demonstrated an effective approach to fabricate the micro-cavities on the conducting substrate through anodic aluminum oxide (AAO) template. The morphologies and composition of the electroplating aluminum layers and the micro-cavities were evaluated by SEM and energy dispersive X-ray analysis (EDXA) respectively. The results indicated that different shapes of cavities with size ranging from 0.6 to 2 mm were come into being directly on 316L SS substrates. The size of cavities could be controlled by adjusting the anodizing voltage and time. And the morphologies of the initial aluminum films were found to be critical factors for successfully anodizing the Al film on 316L SS surface.
Abstract: Hexa-peri-Hexabenzocoronene (HBC), as the smaller graphene fragment consisting of 13 fused benzene rings, possesses a strong tendency to stack together via π-electronic interaction. In this paper, the 1,2-(4-bromomethyl-1-yl) acetylene was alkylated by Grignard reagent to form corresponding 1,2-bis(p-pentadecanylphenyl)acetylene. Cobalt(0)-catalyzed cyclotrimerization was carried out to give hexaphenylbenzene analogue. This step was followed by intramolecular cyclodehydrogenation to yield the desired product HBC-C15. The identity and purity of the new compound was confirmed by UV-vis spectrometer and 1H NMR spectrum. Its thermal behavior and self-assembly were studied by differential scanning calorimetry and polarizing optical microscopy.
Abstract: The Ni-P/ BN(h) composite coatings were prepared by pulse electroplating,and were heat treated at temperature of 200～400°C.The microstructure of the composite coatings was identified by X-ray diffraction,the corrosion behavior of the composite coatings in 3.5%NaCl and 10%H2SO4 solutions was investigated by the linear polarization measurements and scanning electron microscope (SEM).The results show that the as-deposited is an amorphous structure,the precipitated phases are Ni12P5 and Ni5P2 metastable state phases when heat treatment temperature is below 300°C,the precipitated phases is Ni3P stable state phase heat-treated at 400°C，the composite coating was crystallized in great degree.Both the as-deposited and heat treated composite coatings revealed best corrosion resistance in 3.5%NaCl and 10%H2SO4 solutions.
Abstract: The chemical composition and the antimicrobial activity of the essential oil from Illicium wardii A. C. Smith seed were evaluated.The oil which was analyzed by GC and GC/MS was found to contain limonene (18.8%), dihydrocarveol(16.6%),menthatriene(4.6%),caryophylleneoxide(3.9%),β- pinene (3.6%) as major components . Illicium wardii oil displayed a high inhibitory activity against B.subtilis and S.aureus.
Abstract: The corrosion characteristics of steel bar in concrete are decided by the corrosion current distribution along the circumference of the steel bar. It is a general assumption that carbonation lead to a general corrosion on the rebar. However, the destruction of a large number of specimens indicated that before corrosion cracking, the carbonation-induced corrosion mainly distributes on the surface of the steel bar facing the concrete cover. This paper examined the corrosion mechanism from fundamental electrochemical principles and experimental verification. It was illustrated that the macrocell corrosion must co-exist with microcell corrosion, both macrocell and microcell corrosion mechanisms could play significant roles, and the total corrosion could be underestimated if each of two is overlooked.
Abstract: Online roller punching is required for many cold forming sectional steel products, and the productive efficiency of punching is significantly affected by uncoordinated speed between the traditional punching and the cold roll forming. Based on the analysis of the mechanical structure and the mould structure of the equipment, a new roller punching equipment has been developed for continuous high-speed punching process of steel strips with thickness of less than 1mm.