The coupling effects of electrical pulse,temperature,strain rate,and strain on the flow behavior and plasticity of 5182-O aluminum alloy were investigated and characterized.The isothermal tensile test and electrically...The coupling effects of electrical pulse,temperature,strain rate,and strain on the flow behavior and plasticity of 5182-O aluminum alloy were investigated and characterized.The isothermal tensile test and electrically-assisted isothermal tensile test were performed at the same temperature,and three typical models were further embedded in ABAQUS/Explicit for numerical simulation to illustrate the electroplastic effect.The results show that electric pulse reduces the deformation resistance but enhances the elongation greatly.The calibration accuracy of the proposed modified Lim−Huh model for highly nonlinear and coupled dynamic hardening behavior is not much improved compared to the modified Kocks−Mecking model.Moreover,the artificial neural network model is very suitable to describe the macromechenical response of materials under the coupling effect of different variables.展开更多
The electroplastic effect in AZ31B magnesium alloy sheet was investigated through uniaxial tensile tests. In order to show the athermal effect of the electrical pulses, two types of uniaxial tensile tests at the same ...The electroplastic effect in AZ31B magnesium alloy sheet was investigated through uniaxial tensile tests. In order to show the athermal effect of the electrical pulses, two types of uniaxial tensile tests at the same testing temperature were carried out： uniaxial tension in environmental cabinet and uniaxial tension with electrical pulses. In addition, the distribution of temperature field in the cross-section area during uniaxial tension with electrical pulses was simulated. The results show that the distribution of temperature field along the cross-section area is homogeneous. By comparing the true stress？true strain curves of AZ31B alloy under uniaxial tensile tests, the athermal effect with electrical pulses was confirmed. The microstructure evolution after the uniaxial tension was studied by optical microscopy. The results indicate that the electrical pulses induced dynamic recrystallization plays an important role in the decrease of flow stress. Finally, a flow stress model of AZ31B sheet taking the influence of electroplastic effect into account was proposed and validated. The results demonstrate that the calculated data fit the experimental data well.展开更多
Objective Fungal keratitis（FK） is a vision-threatening infection,whose treatment requires more effective and safer anti-fungal agent exploitation urgently.With this aim,we focused on the effect of an extracellular p...Objective Fungal keratitis（FK） is a vision-threatening infection,whose treatment requires more effective and safer anti-fungal agent exploitation urgently.With this aim,we focused on the effect of an extracellular polysaccharide on fungal adhesion to human corneal epithelial cells.Methods We performed the cytotoxicity assays of the extracellular polysaccharide EPS-II from an antarctic bacterium Pseudoaltermonas and evaluated its inhibitory effect on Candida albicans cells＇ adherence to human corneal epithelial cells（HCECs）.Results EPS-II,which displayed minor cytotoxicity but also promoted proliferation of HCECs,could inhibit the adherence of yeast cells to HCECs in a dose-dependent manner.EPS-II could also suppress the subsequent PI3K/AKT signaling pathway,and thereby decrease the expression of early inflammatory cytokines.Conclusions ExtracellularpolysaccharideEPS-IIwassuggestedasanewnaturalagentforattenuatingFK.展开更多
对掺膨胀石墨、碳纤维的EPS多孔水泥基复合材料在100 k Hz^1 500 MHz频率范围内的电磁屏蔽性能进行了实验研究,结果表明:复掺膨胀石墨、碳纤维可明显提高EPS多孔水泥基复合材料低频段的电磁屏蔽性能;当EPS掺量为0.5%,膨胀石墨和碳纤维...对掺膨胀石墨、碳纤维的EPS多孔水泥基复合材料在100 k Hz^1 500 MHz频率范围内的电磁屏蔽性能进行了实验研究,结果表明:复掺膨胀石墨、碳纤维可明显提高EPS多孔水泥基复合材料低频段的电磁屏蔽性能;当EPS掺量为0.5%,膨胀石墨和碳纤维掺量分别为1.0%和3%时,在200~1 500 MHz内试样的最低电磁屏蔽效能为13 d B,最大的屏蔽效能达到20 d B;且导热系数为0.22 W/(m·K)。复掺膨胀石墨、碳纤维的EPS多孔水泥基复合材料力学性能也比单纯的EPS水泥基复合材料有所提高。展开更多
基金the financial supports from the National Natural Science Foundation of China(Nos.52075423,U2141214).
文摘The coupling effects of electrical pulse,temperature,strain rate,and strain on the flow behavior and plasticity of 5182-O aluminum alloy were investigated and characterized.The isothermal tensile test and electrically-assisted isothermal tensile test were performed at the same temperature,and three typical models were further embedded in ABAQUS/Explicit for numerical simulation to illustrate the electroplastic effect.The results show that electric pulse reduces the deformation resistance but enhances the elongation greatly.The calibration accuracy of the proposed modified Lim−Huh model for highly nonlinear and coupled dynamic hardening behavior is not much improved compared to the modified Kocks−Mecking model.Moreover,the artificial neural network model is very suitable to describe the macromechenical response of materials under the coupling effect of different variables.
基金Projects(50975174,51275297)supported by the National Natural Science Foundation of ChinaProject(20100073110044)supported by the Education Ministry of China
文摘The electroplastic effect in AZ31B magnesium alloy sheet was investigated through uniaxial tensile tests. In order to show the athermal effect of the electrical pulses, two types of uniaxial tensile tests at the same testing temperature were carried out： uniaxial tension in environmental cabinet and uniaxial tension with electrical pulses. In addition, the distribution of temperature field in the cross-section area during uniaxial tension with electrical pulses was simulated. The results show that the distribution of temperature field along the cross-section area is homogeneous. By comparing the true stress？true strain curves of AZ31B alloy under uniaxial tensile tests, the athermal effect with electrical pulses was confirmed. The microstructure evolution after the uniaxial tension was studied by optical microscopy. The results indicate that the electrical pulses induced dynamic recrystallization plays an important role in the decrease of flow stress. Finally, a flow stress model of AZ31B sheet taking the influence of electroplastic effect into account was proposed and validated. The results demonstrate that the calculated data fit the experimental data well.
基金partially supported by the National Natural Scientific Foundation (81000369)the Doctor Foundation of Shandong Province (BS2009SW018)
文摘Objective Fungal keratitis（FK） is a vision-threatening infection,whose treatment requires more effective and safer anti-fungal agent exploitation urgently.With this aim,we focused on the effect of an extracellular polysaccharide on fungal adhesion to human corneal epithelial cells.Methods We performed the cytotoxicity assays of the extracellular polysaccharide EPS-II from an antarctic bacterium Pseudoaltermonas and evaluated its inhibitory effect on Candida albicans cells＇ adherence to human corneal epithelial cells（HCECs）.Results EPS-II,which displayed minor cytotoxicity but also promoted proliferation of HCECs,could inhibit the adherence of yeast cells to HCECs in a dose-dependent manner.EPS-II could also suppress the subsequent PI3K/AKT signaling pathway,and thereby decrease the expression of early inflammatory cytokines.Conclusions ExtracellularpolysaccharideEPS-IIwassuggestedasanewnaturalagentforattenuatingFK.
文摘对掺膨胀石墨、碳纤维的EPS多孔水泥基复合材料在100 k Hz^1 500 MHz频率范围内的电磁屏蔽性能进行了实验研究,结果表明:复掺膨胀石墨、碳纤维可明显提高EPS多孔水泥基复合材料低频段的电磁屏蔽性能;当EPS掺量为0.5%,膨胀石墨和碳纤维掺量分别为1.0%和3%时,在200~1 500 MHz内试样的最低电磁屏蔽效能为13 d B,最大的屏蔽效能达到20 d B;且导热系数为0.22 W/(m·K)。复掺膨胀石墨、碳纤维的EPS多孔水泥基复合材料力学性能也比单纯的EPS水泥基复合材料有所提高。
