The vibration pretreatment-microwave curing process is an efficient,low energy consumption,and high-quality out-of-autoclave curing process for carbon fiber resin matrix composites.This study aims to investigate the i...The vibration pretreatment-microwave curing process is an efficient,low energy consumption,and high-quality out-of-autoclave curing process for carbon fiber resin matrix composites.This study aims to investigate the impact of vibration pretreatment temperature on the fiber weight content,microscopic morphology and mechanical properties of the composite laminates by using optical digital microscopy,universal tensile testing machine and thermo-gravimetric analyzer.Additionally,the combined mode of Bragg fiber grating sensor and temperature measurement fiber was employed to explore the effect of vibration pretreatment on the strain process during microwave curing.The study results revealed that the change in vibration pretreatment temperature had a slight impact on the fiber weight content when the vibration acceleration remained constant.The metallographic and interlaminar strength of the specimen formed at a vibration pretreatment temperature of 80℃ demonstrated a porosity of 0.414% and a 10.69% decrease in interlaminar shear strength compared to autoclave curing.Moreover,the introduction of the vibration energy field during the microwave curing process led to a significant reduction in residual strain in both the 0°and 90°fiber directions,when the laminate was cooled to 60℃.展开更多
The creep strain of conventionally treated 2195 alloy is very low,increasing the difficulty of manufacturing Al-Cu-Li alloy sheet parts by creep age forming.Therefore,finding a solution to improve the creep formabilit...The creep strain of conventionally treated 2195 alloy is very low,increasing the difficulty of manufacturing Al-Cu-Li alloy sheet parts by creep age forming.Therefore,finding a solution to improve the creep formability of Al-Cu-Li alloy is vital.A thorough comparison of the effects of cryo-deformation and ambient temperature large pre-deformation(LPD)on the creep ageing response in the 2195 alloy sheet at 160℃with different stresses has been made.The evolution of dislocations and precipitates during creep ageing of LPD alloys are revealed by X-ray diffraction and transmission electron microscopy.High-quality 2195 alloy sheet largely pre-deformed by 80%without edge-cracking is obtained by cryo-rolling at liquid nitrogen temperature,while severe edge-cracking occurs during room temperature rolling.The creep formability and strength of the 2195 alloy are both enhanced by introducing pre-existing dislocations with a density over 1.4×10^(15)m^(−2).At 160℃and 150 MPa,creep strain and creep-aged strength generally increases by 4−6 times and 30−50 MPa in the LPD sample,respectively,compared to conventional T3 alloy counterpart.The elongation of creep-aged LPD sample is low but remains relevant for application.The high-density dislocations,though existing in the form of dislocation tangles,promote the formation of refined T1 precipitates with a uniform dispersion.展开更多
目的分析利司那肽联合甘精胰岛素治疗口服降糖药血糖控制不佳的2型糖尿病(T2DM)患者的疗效及安全性。方法100例口服降糖药控制不佳的T2DM患者,随机分为观察组和对照组,每组50例。观察组于早餐前皮下注射利司那肽联合甘精胰岛素,对照组...目的分析利司那肽联合甘精胰岛素治疗口服降糖药血糖控制不佳的2型糖尿病(T2DM)患者的疗效及安全性。方法100例口服降糖药控制不佳的T2DM患者,随机分为观察组和对照组,每组50例。观察组于早餐前皮下注射利司那肽联合甘精胰岛素,对照组于早晚餐前皮下注射精蛋白人胰岛素混合注射液。比较两组患者血糖控制达标时间、低血糖发生率以及治疗前后体质量指数、血糖指标[空腹血糖(FBG)、餐后2 h血糖(2 h PBG)、糖化血红蛋白(HbA1c)]、空腹C肽(FCP)、餐后2 hC肽(PCP)、血脂指标[总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)]水平。结果治疗后,观察组血糖控制达标时间(9.96±0.87)d短于对照组的(14.17±1.45)d,体质量指数(22.05±1.07)kg/m^(2)小于对照组的(24.37±1.65)kg/m^(2),差异均具有统计学意义(P<0.05)。治疗后,观察组患者FBG(6.49±0.75)mmol/L、2 h PBG(8.53±1.28)mmol/L、HbA1c(5.89±0.42)%低于对照组的(8.04±1.19)mmol/L、(10.96±2.37)mmol/L、(7.82±0.97)%,差异均具有统计学意义(P<0.05)。治疗后,观察组患者FCP(551.39±72.18)pmol/L、PCP(1824.56±215.61)pmol/L均高于对照组的(513.46±48.94)、(1427.89±199.63)pmol/L,差异均具有统计学意义(P<0.05)。治疗后,观察组患者TC(4.12±0.34)mmol/L、TG(1.69±0.12)mmol/L、LDL-C(2.37±0.17)mmol/L均低于对照组的(5.48±0.51)、(2.52±0.25)、(3.52±0.32)mmol/L,HDL-C(1.27±0.33)mmol/L高于对照组的(1.09±0.17)mmol/L,差异均具有统计学意义(P<0.05)。观察组低血糖发生率2.00%低于对照组的14.00%,差异具有统计学意义(χ^(2)=4.891,P=0.027<0.05)。结论与预混胰岛素相比,利司那肽联合甘精胰岛素可更好改善T2DM患者血糖水平及体质量指数,还能调节血脂水平,减少低血糖的发生,值得应用。展开更多
基金Projects(52175373,52005516)supported by the National Natural Science Foundation of ChinaProject(2018YFA0702800)supported by the National Key Basic Research Program,ChinaProject(ZZYJKT2021-03)supported by the State Key Laboratory of High Performance Complex Manufacturing,Central South University,China。
文摘The vibration pretreatment-microwave curing process is an efficient,low energy consumption,and high-quality out-of-autoclave curing process for carbon fiber resin matrix composites.This study aims to investigate the impact of vibration pretreatment temperature on the fiber weight content,microscopic morphology and mechanical properties of the composite laminates by using optical digital microscopy,universal tensile testing machine and thermo-gravimetric analyzer.Additionally,the combined mode of Bragg fiber grating sensor and temperature measurement fiber was employed to explore the effect of vibration pretreatment on the strain process during microwave curing.The study results revealed that the change in vibration pretreatment temperature had a slight impact on the fiber weight content when the vibration acceleration remained constant.The metallographic and interlaminar strength of the specimen formed at a vibration pretreatment temperature of 80℃ demonstrated a porosity of 0.414% and a 10.69% decrease in interlaminar shear strength compared to autoclave curing.Moreover,the introduction of the vibration energy field during the microwave curing process led to a significant reduction in residual strain in both the 0°and 90°fiber directions,when the laminate was cooled to 60℃.
基金Projects(52274404,52305441,U22A20190)supported by the National Natural Science Foundation of ChinaProjects(2022JJ20065,2023JJ40739)supported by the Natural Science Foundation of Hunan Province,China+2 种基金Project(2022RC1001)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(2023ZZTS0972)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2021YFB3400903)supported by the National Key R&D Program of China。
文摘The creep strain of conventionally treated 2195 alloy is very low,increasing the difficulty of manufacturing Al-Cu-Li alloy sheet parts by creep age forming.Therefore,finding a solution to improve the creep formability of Al-Cu-Li alloy is vital.A thorough comparison of the effects of cryo-deformation and ambient temperature large pre-deformation(LPD)on the creep ageing response in the 2195 alloy sheet at 160℃with different stresses has been made.The evolution of dislocations and precipitates during creep ageing of LPD alloys are revealed by X-ray diffraction and transmission electron microscopy.High-quality 2195 alloy sheet largely pre-deformed by 80%without edge-cracking is obtained by cryo-rolling at liquid nitrogen temperature,while severe edge-cracking occurs during room temperature rolling.The creep formability and strength of the 2195 alloy are both enhanced by introducing pre-existing dislocations with a density over 1.4×10^(15)m^(−2).At 160℃and 150 MPa,creep strain and creep-aged strength generally increases by 4−6 times and 30−50 MPa in the LPD sample,respectively,compared to conventional T3 alloy counterpart.The elongation of creep-aged LPD sample is low but remains relevant for application.The high-density dislocations,though existing in the form of dislocation tangles,promote the formation of refined T1 precipitates with a uniform dispersion.
基金Projects(U22A20190, 52175373, 52005516) supported by the National Natural Science Foundation of ChinaProject(ZZYJKT2021-03) supported by the State Key Laboratory of High Performance Complex Manufacturing,Central South University,ChinaProject(2020RC4001) supported by the Science and Technology Innovation Program of Hunan Province,China。
基金Projects(52175373,52005108,52275096)supported by the National Natural Science Foundation of ChinaProject(2018YFA0702800)supported by the National Key Research and Development Program of ChinaProject(2022HZ024005)supported by the Fujian Provincial Major Research Project,China。
文摘目的分析利司那肽联合甘精胰岛素治疗口服降糖药血糖控制不佳的2型糖尿病(T2DM)患者的疗效及安全性。方法100例口服降糖药控制不佳的T2DM患者,随机分为观察组和对照组,每组50例。观察组于早餐前皮下注射利司那肽联合甘精胰岛素,对照组于早晚餐前皮下注射精蛋白人胰岛素混合注射液。比较两组患者血糖控制达标时间、低血糖发生率以及治疗前后体质量指数、血糖指标[空腹血糖(FBG)、餐后2 h血糖(2 h PBG)、糖化血红蛋白(HbA1c)]、空腹C肽(FCP)、餐后2 hC肽(PCP)、血脂指标[总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)]水平。结果治疗后,观察组血糖控制达标时间(9.96±0.87)d短于对照组的(14.17±1.45)d,体质量指数(22.05±1.07)kg/m^(2)小于对照组的(24.37±1.65)kg/m^(2),差异均具有统计学意义(P<0.05)。治疗后,观察组患者FBG(6.49±0.75)mmol/L、2 h PBG(8.53±1.28)mmol/L、HbA1c(5.89±0.42)%低于对照组的(8.04±1.19)mmol/L、(10.96±2.37)mmol/L、(7.82±0.97)%,差异均具有统计学意义(P<0.05)。治疗后,观察组患者FCP(551.39±72.18)pmol/L、PCP(1824.56±215.61)pmol/L均高于对照组的(513.46±48.94)、(1427.89±199.63)pmol/L,差异均具有统计学意义(P<0.05)。治疗后,观察组患者TC(4.12±0.34)mmol/L、TG(1.69±0.12)mmol/L、LDL-C(2.37±0.17)mmol/L均低于对照组的(5.48±0.51)、(2.52±0.25)、(3.52±0.32)mmol/L,HDL-C(1.27±0.33)mmol/L高于对照组的(1.09±0.17)mmol/L,差异均具有统计学意义(P<0.05)。观察组低血糖发生率2.00%低于对照组的14.00%,差异具有统计学意义(χ^(2)=4.891,P=0.027<0.05)。结论与预混胰岛素相比,利司那肽联合甘精胰岛素可更好改善T2DM患者血糖水平及体质量指数,还能调节血脂水平,减少低血糖的发生,值得应用。
