As the Arctic Channel continues to be developed,collisions between polar navigation vessels and sea ice are inevitable,which will directly affect structural safety and vibration comfort.However,the numerical analysis ...As the Arctic Channel continues to be developed,collisions between polar navigation vessels and sea ice are inevitable,which will directly affect structural safety and vibration comfort.However,the numerical analysis method of ship-ice collision-induced vibration is not perfect,and the effect of fluid coupling is not typically considered.In this paper,a simplified numerical analysis method for ship-ice collision-induced vibration is proposed,in which a reliable ice load is obtained by first performing ship-ice-water-air coupled collision calculations,followed by ship-ice-water coupled vibration calculations to obtain the vibration response of the structure.In addition,this paper investigates the full coupling method and the modeling ranges and meshing sizes involved in the analysis ship-ice collision-induced vibration,and the computational efficiencies of the traditional ALE algorithm and S-ALE algorithm are compared.The results indicate that the simplified simulation analysis method and gradient meshing model improve the calculation accuracy and efficiency in ship-ice collision and vibration response analysis.Moreover,the modeling range of the water and air models cannot be less than 6 times the ship width,2 times the ship length,and 1 times the ship depth,and the S-ALE algorithm saves 47.86%time compared to the ALE algorithm.The research results in this paper can provide a reference for the numerical simulation of ship-ice collision-induced vibration.展开更多
Objective： To investigate the efficacy and mechanism of EGDT against NPC cell lines. Methods： M＇IT assay was used to assess cell proliferation inhibition of EGDT. The apoptotic induction and cell cycle arrest were ...Objective： To investigate the efficacy and mechanism of EGDT against NPC cell lines. Methods： M＇IT assay was used to assess cell proliferation inhibition of EGDT. The apoptotic induction and cell cycle arrest were detected by flow cytometry. Western blot was adopted to detect the protein levels. Quantitative Real-time PCR was used to determine the mRNA expressions. The NPC xenografts were established to evaluate the tumor growth inhibition of EGDT. Immunohistochemistry was applied to analyze the EGFR expression in the tumor tissues. Results： EGDT showed proliferation inhibition on the NPC cell, induced G0/G1 phase arrest and cell apop- tosis in vitro. EGDT decreased the protein and mRNA levels of EGFR and its downstream RAF/MEK/ERK and PI3K/AKT pathways in time- and dose-dependent manner. Furthermore, EGDT also showed a sound antitumnr activity in NPC xenograft in vivo. Conclusion： The treatment of EGDT displays EGFR and its mediated downstream signaling pathway block- ade through decreasing the protein and mRNA levels, suggesting a promising strategy in treating human NPC.展开更多
Electromigration in Cu has been extensively investigated as the root cause of typical breakdown failure in Cu interconnects. In this study Cu nanowires connected to Au electrodes are fabricated and observed using in s...Electromigration in Cu has been extensively investigated as the root cause of typical breakdown failure in Cu interconnects. In this study Cu nanowires connected to Au electrodes are fabricated and observed using in situ transmission electron microscopy to investigate the electro- and thermo-migration processes that are induced by direct current sweeps. We observe the dynamic evolution of different mass transport mechanisms. A current density on the order of 106 A/cm^2 and a temperature of approximately 400 ℃ are sufficient to induce electro- and thermo-migration, respectively. Observations of the migration processes activated by increasing temperatures indicate that the migration direction of Cu atoms is dependent on the net force from the electric field and electron wind. This work is expected to support future design efforts to improve the robustness of Cu interconnects.展开更多
Graphene has demonstrated its potential in several practical applications owing to its remarkable electronic and physical properties. In this study, we successfully fabricated a suspended graphene device with a width ...Graphene has demonstrated its potential in several practical applications owing to its remarkable electronic and physical properties. In this study, we successfully fabricated a suspended graphene device with a width down to 20 nm. The morphological evolution of graphene under various electric field effects was systematically examined using an in-situ transmission electron microscope （TEM）. The hourglass-shaped graphene sample instantly broke apart at 7.5 mA, indicating an impressive breakdown current density. The current-carrying capacity was calculated to be -1.6 × 10^9 A.cm-2, which is several orders higher than that of copper. The current-carrying capacity depended on the resistivity of graphene. In addition, atomic volume changes occurred in the multilayer graphene samples due to surface diffusion and Ostwald ripening （OR）, indicating that the breakdown mechanism is well approximated by the electric field. This study not only provides a theory to explain the breakdown behavior but also presents the effects on materials contacted with a graphene layer used as the transmission path.展开更多
文摘As the Arctic Channel continues to be developed,collisions between polar navigation vessels and sea ice are inevitable,which will directly affect structural safety and vibration comfort.However,the numerical analysis method of ship-ice collision-induced vibration is not perfect,and the effect of fluid coupling is not typically considered.In this paper,a simplified numerical analysis method for ship-ice collision-induced vibration is proposed,in which a reliable ice load is obtained by first performing ship-ice-water-air coupled collision calculations,followed by ship-ice-water coupled vibration calculations to obtain the vibration response of the structure.In addition,this paper investigates the full coupling method and the modeling ranges and meshing sizes involved in the analysis ship-ice collision-induced vibration,and the computational efficiencies of the traditional ALE algorithm and S-ALE algorithm are compared.The results indicate that the simplified simulation analysis method and gradient meshing model improve the calculation accuracy and efficiency in ship-ice collision and vibration response analysis.Moreover,the modeling range of the water and air models cannot be less than 6 times the ship width,2 times the ship length,and 1 times the ship depth,and the S-ALE algorithm saves 47.86%time compared to the ALE algorithm.The research results in this paper can provide a reference for the numerical simulation of ship-ice collision-induced vibration.
基金supported by the Youth Research Project of Health and Family Planning Commission of Fujian Province (2015-2-37)
文摘Objective： To investigate the efficacy and mechanism of EGDT against NPC cell lines. Methods： M＇IT assay was used to assess cell proliferation inhibition of EGDT. The apoptotic induction and cell cycle arrest were detected by flow cytometry. Western blot was adopted to detect the protein levels. Quantitative Real-time PCR was used to determine the mRNA expressions. The NPC xenografts were established to evaluate the tumor growth inhibition of EGDT. Immunohistochemistry was applied to analyze the EGFR expression in the tumor tissues. Results： EGDT showed proliferation inhibition on the NPC cell, induced G0/G1 phase arrest and cell apop- tosis in vitro. EGDT decreased the protein and mRNA levels of EGFR and its downstream RAF/MEK/ERK and PI3K/AKT pathways in time- and dose-dependent manner. Furthermore, EGDT also showed a sound antitumnr activity in NPC xenograft in vivo. Conclusion： The treatment of EGDT displays EGFR and its mediated downstream signaling pathway block- ade through decreasing the protein and mRNA levels, suggesting a promising strategy in treating human NPC.
文摘Electromigration in Cu has been extensively investigated as the root cause of typical breakdown failure in Cu interconnects. In this study Cu nanowires connected to Au electrodes are fabricated and observed using in situ transmission electron microscopy to investigate the electro- and thermo-migration processes that are induced by direct current sweeps. We observe the dynamic evolution of different mass transport mechanisms. A current density on the order of 106 A/cm^2 and a temperature of approximately 400 ℃ are sufficient to induce electro- and thermo-migration, respectively. Observations of the migration processes activated by increasing temperatures indicate that the migration direction of Cu atoms is dependent on the net force from the electric field and electron wind. This work is expected to support future design efforts to improve the robustness of Cu interconnects.
文摘Graphene has demonstrated its potential in several practical applications owing to its remarkable electronic and physical properties. In this study, we successfully fabricated a suspended graphene device with a width down to 20 nm. The morphological evolution of graphene under various electric field effects was systematically examined using an in-situ transmission electron microscope （TEM）. The hourglass-shaped graphene sample instantly broke apart at 7.5 mA, indicating an impressive breakdown current density. The current-carrying capacity was calculated to be -1.6 × 10^9 A.cm-2, which is several orders higher than that of copper. The current-carrying capacity depended on the resistivity of graphene. In addition, atomic volume changes occurred in the multilayer graphene samples due to surface diffusion and Ostwald ripening （OR）, indicating that the breakdown mechanism is well approximated by the electric field. This study not only provides a theory to explain the breakdown behavior but also presents the effects on materials contacted with a graphene layer used as the transmission path.
