Papers by Author: Chao Liu

Abstract: The present study was designed to investigate the effects of hydrolyzed fish collagen (HFC) on the cytokine production of lipopolysaccharide (LPS)-induced human umbilical vein endothelial cells (HUVECs). The in vitro inflammation model was established using LPS-induced HUVECs.The cell viability of HUVECs and the secretion level of inflammatory cytokines,IL-6, IL-8, and TNF-α from LPS-treated HUVECs exposed to HFC were determined respectively using MTT and ELISA assays. Our results indicate that HFC promoted HUVECs proliferation, and significantly reduced IL-6, IL-8, and TNF-α production in LPS-stimulated HUVECs. It suggested that HFC had a prominent anti-inflammatory property, HFC could be considered as a promising candidate for anti-inflammatory wound dressing.

Abstract: Microstructure and dielectric properties of Ba0.62Sr0.38TiO3 ceramics doped with x mol% (x=0.2~0.6) Y2O3 were investigated. SEM showed that Y3+ can accelerate growth of the grains at first, then turn to inhabit growth of the grains with further addition of Y3+ above 0.8mol%. The experimental results showed that the dielectric constants were improved with the additive amount of Y3+ increasing, if the amount of Y3+ increased continuously, the dielectric constants will drop, whereas the dielectric losses of the samples descended rapidly in the beginning, then went up obviously with further addition of Y3+ above 1.0mol%, the optimal dielectric constant and dielectric loss could reach 6700 and 0.0015 in the room temperature, respectively.

Abstract: Ferroelectric properties of (Bi1/2Na1/2) TiO3-SrTiO3 were studied. The dielectric properties were measured at 1KHz. It was found that the dielectric constants are improved with the increase of additive amount of BNT. If the amount continues increasing, the properties become worse, the optimum dielectric constant of the samples can reach 4300. When the proportion of (Bi1/2Na1/2)TiO3: SrTiO3 is 65:35, with the increase of additive amount of MnCO3, the Curie temperature descends obviously. The dielectric constant increased at beginning and dropped sharply when the amount of MnCO3 exceeds 1.1wt%.

Abstract: The grinding fluid is typically used to provide functions such as lubrication and cooling in order to reduce surface grinding temperatures effectively in order to achieve better work-piece surface integrity and higher wheel life. This paper investigates the convection heat transfer coefficient of fluid based on the fluid dynamic and thermal modelling within the grinding zone under different grinding condition. This work makes it possible to determine a suitable value of the useful flowrate fluid through the grinding contact arc under optimization of the wheel speed, work speed and jet velocity of nozzle. Its simplicity and accuracy allow application to a wide range of grinding situations from shallow to high efficiency deep grinding.