为提高热轧态0Cr21A16合金板材的组织均匀性和塑性,以改善其高温性能及冷加工特性,分析研究了不同温度的热处理试验及组织性能。采用光学显微镜、X射线衍射仪、Gleeble高温热拉伸实验、扫描电镜和纳米压痕仪等研究了热处理前后0Cr21Al6...为提高热轧态0Cr21A16合金板材的组织均匀性和塑性,以改善其高温性能及冷加工特性,分析研究了不同温度的热处理试验及组织性能。采用光学显微镜、X射线衍射仪、Gleeble高温热拉伸实验、扫描电镜和纳米压痕仪等研究了热处理前后0Cr21Al6合金板材的显微组织和力学性能。结果表明,通过热处理的方式改善0Cr21Al6合金板材的组织均匀性,在960℃保温6 min 40 s后快速冷却,晶粒平均尺寸为42μm,整体的晶粒尺寸相对于940、980、1000、1020℃热处理后较为均匀、细小,硬度和塑性达到最佳匹配,断裂韧度KIC在960℃处理下达到最佳,拥有最佳的综合性能,可有效避免生产过程中材料的脆性断裂问题。另外Gleeble实验显示1000℃以上的热处理温度不再适合于热加工。展开更多
BACKGROUND： Previous studies have confirmed the neuroprotective effect of mild hypothermia on ischemic brain injury. OBJECTIVE： To investigate the effects of mild hypothermia on intercellular adhesion molecule-1 exp...BACKGROUND： Previous studies have confirmed the neuroprotective effect of mild hypothermia on ischemic brain injury. OBJECTIVE： To investigate the effects of mild hypothermia on intercellular adhesion molecule-1 expression and serum interleukin-6 levels in ischemic brain tissues of focal brain ischemia rats, and to explore the neuroprotective effects of mild hypothermia on ischemic brain injury. DESIGN, TIME AND SETTING： A randomized, controlled, neurobiological experiment was performed at the Central Laboratory, First Affiliated Hospital, Xinxiang Medical College, China from February to July 2006. MATERIALS： Thirty healthy, adult, Sprague Dawley rats were used to establish middle cerebral artery occlusion models using the suture method, The immunohistochemistry （streptavidin-biotin-peroxidase complex method） kit was purchased from Boster, China. Interleukin-6 radioimmunoassay was supplied by Institute of Radioimmunity, Technology Development Center, General Hospital of Chinese PLA. METHODS： The rats were equally and randomly assigned into mild hypothermia and control groups, and middle cerebral artery occlusion models were established. The rectal temperature was maintained at （37 ±0.5）℃ in the control group. In the mild hypothermia group, the rectal temperature was maintained at （33±1）℃. MAIN OUTCOME MEASURES： At 12 hours after model establishment, the ischemic brain hemispheres were coronally sliced at the level of the optic chiasm. The number of intercellular adhesion molecule-1-positive vessels per high-power field was observed with an optical microscope. Serum interleukin-6 levels were measured by radioimmunoassay. RESULTS： Compared with the control group, intercellular adhesion molecule-1 and serum interleukin-6 expressions were significantly decreased in ischemic brain tissues of the mild hypothermia group （P 〈 0.01）. CONCLUSION： Mild hypothermia exhibits a neuroprotective effect by reducing serum interleukin-6 and intercellular adhesion molecule-1 expression following cerebral ischemia.展开更多
Based on the density functional theory with generalized gradient approximation, the stable geometrical structures of one or more CO molecules adsorbed on the Al6Si cluster are investigated and the corresponding adsorp...Based on the density functional theory with generalized gradient approximation, the stable geometrical structures of one or more CO molecules adsorbed on the Al6Si cluster are investigated and the corresponding adsorption energies are also calculated. It is found that the cluster Al6Si can adsorb six CO molecules. The thermal stability of the（CO）6@Al6Si complexes is examined using the atom centered density matrix propagation molecular dynamics calculations at 373 K. The results show that two isomers of Al6Si cluster can solidly adsorb six CO molecules, and the other isomer adsorbs four ones. Therefore, the Al6Si cluster is a promising candidate for eliminating CO effectively.展开更多
文摘为提高热轧态0Cr21A16合金板材的组织均匀性和塑性,以改善其高温性能及冷加工特性,分析研究了不同温度的热处理试验及组织性能。采用光学显微镜、X射线衍射仪、Gleeble高温热拉伸实验、扫描电镜和纳米压痕仪等研究了热处理前后0Cr21Al6合金板材的显微组织和力学性能。结果表明,通过热处理的方式改善0Cr21Al6合金板材的组织均匀性,在960℃保温6 min 40 s后快速冷却,晶粒平均尺寸为42μm,整体的晶粒尺寸相对于940、980、1000、1020℃热处理后较为均匀、细小,硬度和塑性达到最佳匹配,断裂韧度KIC在960℃处理下达到最佳,拥有最佳的综合性能,可有效避免生产过程中材料的脆性断裂问题。另外Gleeble实验显示1000℃以上的热处理温度不再适合于热加工。
文摘BACKGROUND： Previous studies have confirmed the neuroprotective effect of mild hypothermia on ischemic brain injury. OBJECTIVE： To investigate the effects of mild hypothermia on intercellular adhesion molecule-1 expression and serum interleukin-6 levels in ischemic brain tissues of focal brain ischemia rats, and to explore the neuroprotective effects of mild hypothermia on ischemic brain injury. DESIGN, TIME AND SETTING： A randomized, controlled, neurobiological experiment was performed at the Central Laboratory, First Affiliated Hospital, Xinxiang Medical College, China from February to July 2006. MATERIALS： Thirty healthy, adult, Sprague Dawley rats were used to establish middle cerebral artery occlusion models using the suture method, The immunohistochemistry （streptavidin-biotin-peroxidase complex method） kit was purchased from Boster, China. Interleukin-6 radioimmunoassay was supplied by Institute of Radioimmunity, Technology Development Center, General Hospital of Chinese PLA. METHODS： The rats were equally and randomly assigned into mild hypothermia and control groups, and middle cerebral artery occlusion models were established. The rectal temperature was maintained at （37 ±0.5）℃ in the control group. In the mild hypothermia group, the rectal temperature was maintained at （33±1）℃. MAIN OUTCOME MEASURES： At 12 hours after model establishment, the ischemic brain hemispheres were coronally sliced at the level of the optic chiasm. The number of intercellular adhesion molecule-1-positive vessels per high-power field was observed with an optical microscope. Serum interleukin-6 levels were measured by radioimmunoassay. RESULTS： Compared with the control group, intercellular adhesion molecule-1 and serum interleukin-6 expressions were significantly decreased in ischemic brain tissues of the mild hypothermia group （P 〈 0.01）. CONCLUSION： Mild hypothermia exhibits a neuroprotective effect by reducing serum interleukin-6 and intercellular adhesion molecule-1 expression following cerebral ischemia.
基金supported by the National Natural Science Foundation of China(Nos.NSFC-11574125 and NSFC-11374132)the Taishan Scholar Project of Shandong Province(ts201511055)
文摘Based on the density functional theory with generalized gradient approximation, the stable geometrical structures of one or more CO molecules adsorbed on the Al6Si cluster are investigated and the corresponding adsorption energies are also calculated. It is found that the cluster Al6Si can adsorb six CO molecules. The thermal stability of the（CO）6@Al6Si complexes is examined using the atom centered density matrix propagation molecular dynamics calculations at 373 K. The results show that two isomers of Al6Si cluster can solidly adsorb six CO molecules, and the other isomer adsorbs four ones. Therefore, the Al6Si cluster is a promising candidate for eliminating CO effectively.
