In the present work, the effects of chemical compositions on the hydrogen blistering and hydrogen induced cracking of A350LF2 steel with different S contents were studied. Four types of A350LF2 steels were evaluated b...In the present work, the effects of chemical compositions on the hydrogen blistering and hydrogen induced cracking of A350LF2 steel with different S contents were studied. Four types of A350LF2 steels were evaluated by immersing samples in H2S-saturated NACE solution. The hydrogen blistering, crack length rate(CLR), crack thickness rate(CTR) and crack sensitivity rate(CSR) were evaluated. The results show that there are many hydrogen blisters on the sample surface with S content of 0.021%, a few on the sample surface with S content of 0.019% and 0.012% and no one on the surface with S content of 0.002%. There were 12, 2 and 1 strips of cracks of longer than 0.3 mm on the evaluated cross sections with S content of 0.021%, 0.019% and 0.012%, respectively. There was no any crack in the sample with 0.002% S. The corrosion rate was also evaluated. The S content has no obvious influence on the corrosion rate.展开更多
The effect of evolution of polycrystalline texture on normal anisotropy coefficient r-value of aluminum alloy sheet was investigated. For this purpose, the textures under different elongation of LF2 aluminum alloy wer...The effect of evolution of polycrystalline texture on normal anisotropy coefficient r-value of aluminum alloy sheet was investigated. For this purpose, the textures under different elongation of LF2 aluminum alloy were measured and analyzed. The result indicates that the initial texture of LF2 aluminum alloy has the typical rolling texture, and the main components include Brass {011} <211>,Copper {112}<111>and S{123}<634>. These three main components exhibit different transformation tendencies when the material specimens are stretched along the different direction. Based on Taylor model and Minor Work principle, the normal anisotropy coefficient r-values of polycrystalline aluminum alloy under various strain states were calculated. The result indicates that the r-values of LF2 aluminum alloy vary with tensile direction and the amount of deformation. The deformability on rolling direction is superior to the other direction because an enhancement tendency of r0 appears in tension process along rolling direction.展开更多
This study was carried out explore the mechanism underlying the inhibition of platelet activation by kelp fucoidans in deep venous thrombosis(DVT)mouse.In the control and sham mice,the walls of deep vein were regular ...This study was carried out explore the mechanism underlying the inhibition of platelet activation by kelp fucoidans in deep venous thrombosis(DVT)mouse.In the control and sham mice,the walls of deep vein were regular and smooth with intact intima,myometrium and adventitia.The blood vessel was wrapped with the tissue and there was no thrombosis in the lumen.In the DVT model,the wall was uneven with thicken intima,myometrium and adventitia.After treated with fucoidans LF1 and LF2,the thrombus was dissolved and the blood vessel was recanalized.Compared with the control group,the ROS content,ET-1 and VWF content and the expression of PKC-βand NF-κB in the model were significantly higher(P<0.05);these levels were significantly reduced following treatments with LF2 and LF1.Compared with H_(2)O_(2)treated-HUVECs,combined LF1 and LF2 treatment resulted in significant decrease in the expression of PKC-β,NF-κB,VWF and TM protein(P<0.05).It is clear that LF1 and LF2 reduces DVT-induced ET-1,VWF and TM expressions and production of ROS,thus inhibiting the activation of PKC-β/NF-κB signal pathway and the activation of coagulation system and ultimately reducing the formation of venous thrombus.展开更多
文摘In the present work, the effects of chemical compositions on the hydrogen blistering and hydrogen induced cracking of A350LF2 steel with different S contents were studied. Four types of A350LF2 steels were evaluated by immersing samples in H2S-saturated NACE solution. The hydrogen blistering, crack length rate(CLR), crack thickness rate(CTR) and crack sensitivity rate(CSR) were evaluated. The results show that there are many hydrogen blisters on the sample surface with S content of 0.021%, a few on the sample surface with S content of 0.019% and 0.012% and no one on the surface with S content of 0.002%. There were 12, 2 and 1 strips of cracks of longer than 0.3 mm on the evaluated cross sections with S content of 0.021%, 0.019% and 0.012%, respectively. There was no any crack in the sample with 0.002% S. The corrosion rate was also evaluated. The S content has no obvious influence on the corrosion rate.
基金Project(50225520) supported by the National Natural Science Foundation of China
文摘The effect of evolution of polycrystalline texture on normal anisotropy coefficient r-value of aluminum alloy sheet was investigated. For this purpose, the textures under different elongation of LF2 aluminum alloy were measured and analyzed. The result indicates that the initial texture of LF2 aluminum alloy has the typical rolling texture, and the main components include Brass {011} <211>,Copper {112}<111>and S{123}<634>. These three main components exhibit different transformation tendencies when the material specimens are stretched along the different direction. Based on Taylor model and Minor Work principle, the normal anisotropy coefficient r-values of polycrystalline aluminum alloy under various strain states were calculated. The result indicates that the r-values of LF2 aluminum alloy vary with tensile direction and the amount of deformation. The deformability on rolling direction is superior to the other direction because an enhancement tendency of r0 appears in tension process along rolling direction.
基金supported by the Special Fund for Clinical Scientific Research of Shandong Medical Association(No.YXH2020ZX058).
文摘This study was carried out explore the mechanism underlying the inhibition of platelet activation by kelp fucoidans in deep venous thrombosis(DVT)mouse.In the control and sham mice,the walls of deep vein were regular and smooth with intact intima,myometrium and adventitia.The blood vessel was wrapped with the tissue and there was no thrombosis in the lumen.In the DVT model,the wall was uneven with thicken intima,myometrium and adventitia.After treated with fucoidans LF1 and LF2,the thrombus was dissolved and the blood vessel was recanalized.Compared with the control group,the ROS content,ET-1 and VWF content and the expression of PKC-βand NF-κB in the model were significantly higher(P<0.05);these levels were significantly reduced following treatments with LF2 and LF1.Compared with H_(2)O_(2)treated-HUVECs,combined LF1 and LF2 treatment resulted in significant decrease in the expression of PKC-β,NF-κB,VWF and TM protein(P<0.05).It is clear that LF1 and LF2 reduces DVT-induced ET-1,VWF and TM expressions and production of ROS,thus inhibiting the activation of PKC-β/NF-κB signal pathway and the activation of coagulation system and ultimately reducing the formation of venous thrombus.
