The deoxidation behaviors of alloys bearing barium in pipe steel were researched with MgO crucible under argon atmosphere in MoSi 2 furnace at 1 873 K. The total oxygen contents of molten steel, the distribution, siz...The deoxidation behaviors of alloys bearing barium in pipe steel were researched with MgO crucible under argon atmosphere in MoSi 2 furnace at 1 873 K. The total oxygen contents of molten steel, the distribution, size and morphology of deoxidation products in the steel were surveyed. The metamorphic mechanism for deoxidation products of alloy bearing barium was also discussed. The results show that applying alloy bearing barium to the pipe steel, very low total oxygen contents can be obtained, and deoxidation products, which easily float up from molten steel, can be changed into globular shape and uniformly distributed in steel. The equilibrium time of total oxygen is about 25 min, and the terminal total oxygen contents range from 0 002 0 % to 0 002 2 % after treating with SiCa wire. The best deoxidizers are SiAlBaCa and SiAlBaCaSr.展开更多
The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre-melted CaO-based slag was carried out.For pre-treatment of hot metal,both desulphurization and dephos...The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre-melted CaO-based slag was carried out.For pre-treatment of hot metal,both desulphurization and dephosphorization are improved with the increase of CaO in slag,but deteriorated with the increase of CaF2 in slag.The average desulphurization and dephosphorization rate is 68.83 % and 78.46 %,respectively.For molten steel,the substitution of BaO for CaO in slag has minor effect on simultaneous desulphurization and dephosphorization.The desulphurization and dephosphorization rate is higher than 90% and 50% respectively with the lowest final sulfur and phosphorus mass percent being 0.001 2% and 0.010%,respectively.The overall effect of simultaneous desulphurization and dephosphorization of molten steel is better than that of hot metal.展开更多
The effect of top slag basicity on quality of steel treated with SiFe and SiCaBa alloy as exothermic agent in chemical heating was studied.These experiments were carried out in MoSi_2 laboratory furnace with 0.2 kg mo...The effect of top slag basicity on quality of steel treated with SiFe and SiCaBa alloy as exothermic agent in chemical heating was studied.These experiments were carried out in MoSi_2 laboratory furnace with 0.2 kg molten steel for equilibrium test and 2 kg molten steel for simulation test respectively.These results showed that the adjusting basicity of top slag with CaO is effective to prevent rephosphorization and resulphurization,and it is possible to dephosphorize and desulphurize and remove the inclusions from molten steel when basicity R of the top slag is adjusted to 2.0 — 3.10,and SiCaBa alloy is better than SiFe alloy in this relation.展开更多
[目的]探讨SPRED1在结肠癌中的表达,及其与结肠癌患者预后的相关性,以及对结肠癌细胞增殖、迁移和凋亡的影响。[方法]采用实时荧光定量聚合酶链反应(qRT-PCR)检测SPRED1 m RNA在结肠癌细胞和组织标本中的表达,免疫组织化学技术检测SPRED...[目的]探讨SPRED1在结肠癌中的表达,及其与结肠癌患者预后的相关性,以及对结肠癌细胞增殖、迁移和凋亡的影响。[方法]采用实时荧光定量聚合酶链反应(qRT-PCR)检测SPRED1 m RNA在结肠癌细胞和组织标本中的表达,免疫组织化学技术检测SPRED1蛋白在结肠癌组织中的表达。使用小干扰RNA(siRNA)干扰结肠癌细胞内SPRED1表达后,CCK-8试剂盒检测结肠癌细胞增殖能力变化,Transwell小室检测结肠癌细胞迁移能力变化,Annexin V-FITC/PI凋亡试剂盒检测细胞凋亡水平。[结果] SPRED1 mRNA在结肠癌细胞株和结肠癌组织中表达水平均显著上调(P均<0.001),高表达SPRED1患者的总生存期短于低表达SPRED1患者(HR=2.326,95%CI:1.340~4.062,P<0.05)。干扰SPRED1后,干扰组结肠癌SW480和SW620细胞在36h和48h后增殖能力显著下降(P<0.05),侵袭能力显著下降(SW480:t=42.05,P<0.0001;SW620:t=12.91,P=0.0002),且凋亡水平显著上升(SW480:t=18.46,P<0.05;SW620:t=18.52,P<0.0001)。[结论]SPRED1在结肠癌中表达上调,促进结肠癌的增殖和侵袭。展开更多
基金Item Sponsored by National Natural Science Foundation of China(59874014)Foundation of Science and Technology for Excellent Youth of Anhui Province of China
文摘The deoxidation behaviors of alloys bearing barium in pipe steel were researched with MgO crucible under argon atmosphere in MoSi 2 furnace at 1 873 K. The total oxygen contents of molten steel, the distribution, size and morphology of deoxidation products in the steel were surveyed. The metamorphic mechanism for deoxidation products of alloy bearing barium was also discussed. The results show that applying alloy bearing barium to the pipe steel, very low total oxygen contents can be obtained, and deoxidation products, which easily float up from molten steel, can be changed into globular shape and uniformly distributed in steel. The equilibrium time of total oxygen is about 25 min, and the terminal total oxygen contents range from 0 002 0 % to 0 002 2 % after treating with SiCa wire. The best deoxidizers are SiAlBaCa and SiAlBaCaSr.
基金Sponsored by Provincial Natural Science Foundation of Anhui of China
文摘The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre-melted CaO-based slag was carried out.For pre-treatment of hot metal,both desulphurization and dephosphorization are improved with the increase of CaO in slag,but deteriorated with the increase of CaF2 in slag.The average desulphurization and dephosphorization rate is 68.83 % and 78.46 %,respectively.For molten steel,the substitution of BaO for CaO in slag has minor effect on simultaneous desulphurization and dephosphorization.The desulphurization and dephosphorization rate is higher than 90% and 50% respectively with the lowest final sulfur and phosphorus mass percent being 0.001 2% and 0.010%,respectively.The overall effect of simultaneous desulphurization and dephosphorization of molten steel is better than that of hot metal.
基金Sponsored by National Natural Science Foundation(59874014)
文摘The effect of top slag basicity on quality of steel treated with SiFe and SiCaBa alloy as exothermic agent in chemical heating was studied.These experiments were carried out in MoSi_2 laboratory furnace with 0.2 kg molten steel for equilibrium test and 2 kg molten steel for simulation test respectively.These results showed that the adjusting basicity of top slag with CaO is effective to prevent rephosphorization and resulphurization,and it is possible to dephosphorize and desulphurize and remove the inclusions from molten steel when basicity R of the top slag is adjusted to 2.0 — 3.10,and SiCaBa alloy is better than SiFe alloy in this relation.
