The as-cast and as-extruded Mg–9Li–1Al–xCa alloys(x=0,0.2;wt%)were prepared by a simple alloying process followed by hot extrusion with an extrusion ratio of 28.2.The microstructures of the as-cast and as-extruded...The as-cast and as-extruded Mg–9Li–1Al–xCa alloys(x=0,0.2;wt%)were prepared by a simple alloying process followed by hot extrusion with an extrusion ratio of 28.2.The microstructures of the as-cast and as-extruded Mg–9Li–1Al–xCa alloys were observed to investigate the effect of calcium(Ca)element on the Mg–9Li–1Al(LA91)alloy,and the crystallographic calculations between Al_(2)Ca and the matrix(α-Mg andβ-Li phases)were examined on the basis of the edge-to-edge matching model.The experimental results indicate that the addition of 0.2 wt%Ca into LA91 alloy reduce the size of theα-Mg phases in the as-cast alloy and that ofβ-Li phases in the as-extruded alloy due to the Al_(2)Ca particles distributed inside the matrix.Crystallographic calculation results suggested that there is a good crystallographic matching between the matrix and Al_(2)Ca,which confirmed that Al_(2)Ca particles can act as a heterogeneous nucleation site for bothα-Mg andβ-Li phases and were effective grain refiners for LA91 alloy.展开更多
目的：研究黎药除湿祛风汤对鸡Ⅱ型胶原蛋白诱导关节炎模型大鼠的保护作用。方法：将60只大鼠随机分为正常组、模型组、阳性组和除湿祛风汤高、中、低剂量组[45.9、22.95、11.48 g（生药）/kg],除正常组外,其余各组大鼠均以鸡Ⅱ型胶原...目的：研究黎药除湿祛风汤对鸡Ⅱ型胶原蛋白诱导关节炎模型大鼠的保护作用。方法：将60只大鼠随机分为正常组、模型组、阳性组和除湿祛风汤高、中、低剂量组[45.9、22.95、11.48 g（生药）/kg],除正常组外,其余各组大鼠均以鸡Ⅱ型胶原蛋白诱导关节炎模型。建模后,除湿祛风汤各剂量组大鼠ig相应药物,正常组和模型组大鼠ig生理盐水,每天1次,连续给药12 d;阳性组大鼠实验1-3 d ig来氟米特4.5 mg/kg,4-12 d ig来氟米特1.8 mg/kg,每天1次。观察大鼠关节病变程度并进行评分,测定关节肿胀度和血清中肿瘤坏死因子α（TNF-α）、白细胞介素1β（IL-1β）和Ⅱ型胶原蛋白抗体水平。结果：与正常组比较,模型组大鼠关节炎指数评分、关节肿胀度及血清中TNF-α、IL-1β、Ⅱ型胶原蛋白抗体水平显著升高（P〈0.01）。与模型组比较,阳性组和除湿祛风汤高剂量组大鼠病理评分显著降低,各给药组大鼠血清中TNF-α、IL-1β、Ⅱ型胶原蛋白抗体水平显著降低（P〈0.05或P〈0.01）。结论：黎药除湿祛风汤对鸡Ⅱ型胶原蛋白诱导模型大鼠具有一定的保护作用。展开更多
基金Project(50725413)supported by the National Natural Science Foundation of ChinaProject(2010CSTC-BJLKR)supported by Chongqing Science and Technology Commission, ChinaProject(CDJXS10132203)supported by the Fundamental Research Funds for the Central Universities,China
文摘以改善冷轧Mg-Li系合金的变形能力为目的,系统研究了冷轧变形后的Mg-9Li-1Zn合金的退火热处理工艺,分析了退火温度和退火时间对合金组织和性能的影响.研究结果表明：Mg-9Li-1Zn合金适宜的退火温度为280~300℃,退火温度过高会出现晶粒长大,表面脱锂等现象.300℃退火60 min后,合金的维氏硬度值为426.7 MPa,充分完成再结晶软化的合金在后续冷轧时总变形率可达70%.合金的退火时间以保证α相的充分球化及组织的均匀化为准则,实验中确定的最佳退火制度为300℃保温60 min.
基金The authors are grateful for the financial supports from National Natural Science Foundation of China(51171212)Chongqing Science and Technology Commission(CSTC2012JJJQ50001,CSTC2013jcyjC60001,cstc2012ggB 50003)+1 种基金The National Science and Technology Program of China(2013DFA71070)the Fundamental Research Funds for the Central Universities(CDJZR13138801).
文摘The as-cast and as-extruded Mg–9Li–1Al–xCa alloys(x=0,0.2;wt%)were prepared by a simple alloying process followed by hot extrusion with an extrusion ratio of 28.2.The microstructures of the as-cast and as-extruded Mg–9Li–1Al–xCa alloys were observed to investigate the effect of calcium(Ca)element on the Mg–9Li–1Al(LA91)alloy,and the crystallographic calculations between Al_(2)Ca and the matrix(α-Mg andβ-Li phases)were examined on the basis of the edge-to-edge matching model.The experimental results indicate that the addition of 0.2 wt%Ca into LA91 alloy reduce the size of theα-Mg phases in the as-cast alloy and that ofβ-Li phases in the as-extruded alloy due to the Al_(2)Ca particles distributed inside the matrix.Crystallographic calculation results suggested that there is a good crystallographic matching between the matrix and Al_(2)Ca,which confirmed that Al_(2)Ca particles can act as a heterogeneous nucleation site for bothα-Mg andβ-Li phases and were effective grain refiners for LA91 alloy.
文摘目的：研究黎药除湿祛风汤对鸡Ⅱ型胶原蛋白诱导关节炎模型大鼠的保护作用。方法：将60只大鼠随机分为正常组、模型组、阳性组和除湿祛风汤高、中、低剂量组[45.9、22.95、11.48 g（生药）/kg],除正常组外,其余各组大鼠均以鸡Ⅱ型胶原蛋白诱导关节炎模型。建模后,除湿祛风汤各剂量组大鼠ig相应药物,正常组和模型组大鼠ig生理盐水,每天1次,连续给药12 d;阳性组大鼠实验1-3 d ig来氟米特4.5 mg/kg,4-12 d ig来氟米特1.8 mg/kg,每天1次。观察大鼠关节病变程度并进行评分,测定关节肿胀度和血清中肿瘤坏死因子α（TNF-α）、白细胞介素1β（IL-1β）和Ⅱ型胶原蛋白抗体水平。结果：与正常组比较,模型组大鼠关节炎指数评分、关节肿胀度及血清中TNF-α、IL-1β、Ⅱ型胶原蛋白抗体水平显著升高（P〈0.01）。与模型组比较,阳性组和除湿祛风汤高剂量组大鼠病理评分显著降低,各给药组大鼠血清中TNF-α、IL-1β、Ⅱ型胶原蛋白抗体水平显著降低（P〈0.05或P〈0.01）。结论：黎药除湿祛风汤对鸡Ⅱ型胶原蛋白诱导模型大鼠具有一定的保护作用。
