目的采用Box-Behnken效应面优化姜黄素长循环纳米结构脂质载体(mPEG2000-Cur-NLC)处方,并考察其理化性质。方法采用薄膜-超声法制备mPEG2000-Cur-NLC,以粒径、包封率和载药量为评价指标,以混合脂质的用量、乳化剂的用量和脂药质量比为...目的采用Box-Behnken效应面优化姜黄素长循环纳米结构脂质载体(mPEG2000-Cur-NLC)处方,并考察其理化性质。方法采用薄膜-超声法制备mPEG2000-Cur-NLC,以粒径、包封率和载药量为评价指标,以混合脂质的用量、乳化剂的用量和脂药质量比为考察对象,采用Box-Behnken效应面法筛选其最佳处方,并考察其粒径、包封率、zeta电位及体外释放。结果最优处方为混合脂质用量为质量分数2.5%、乳化剂的用量质量分数3.5%和脂药质量比40∶1,按最优处方制备的m PEG2000-Cur-NLC粒径为(135.33±2.52)nm、包封率为(96.70±0.146)%、载药量为(2.41±0.587)%,体外释放72h药物累积释放量为58.37%,呈缓释释放,Weibull方程拟合结果最好。结论 m PEG2000-Cur-NLC采用Box-Behnken效应面法优化是可行的,体外缓释效果良好。展开更多
Rock pillar is the key supporting component in underground engineering.During an earthquake,the key rock pillar must bear both the seismic load and the load transferred from other damaged pillars.This paper attempts t...Rock pillar is the key supporting component in underground engineering.During an earthquake,the key rock pillar must bear both the seismic load and the load transferred from other damaged pillars.This paper attempts to reveal the influence of the mainshock on damage evolution and failure characteristic of the key rock pillar during aftershocks by cyclic loading test of marble.Four levels of pre-damage stress(i.e.,10,30,50 and 70 MPa)in the first cycle were used to simulate the mainshock damage,and then cyclic stress with the same amplitude(namely 10 MPa)was conducted in the subsequent cycles to simulate the aftershock until rock failure.The results indicate that the presence of pre-damage has an obvious weakening effect on the bearing capacity and deformation resistance of rock materials during the aftershock process.Besides,the increase of pre-damage significantly changes the final failure pattern of the key rock pillar,and leads to an increase in the proportion of small-scale rock fragments.This study may contribute to understanding the seismic capacity of the unreinforced rock pillar during mainshock-aftershock seismic sequences and to optimizing the design of the key rock pillar in underground engineering.展开更多
Ni-based, Fe-based and Co-based oxygen carriers with perovskite oxides used as the supports were prepared by citric acid complexation method, The oxygen carriers were characterized by thermal analysis, H2-temperature-...Ni-based, Fe-based and Co-based oxygen carriers with perovskite oxides used as the supports were prepared by citric acid complexation method, The oxygen carriers were characterized by thermal analysis, H2-temperature-programmed reduction and X-ray diffraction methods. Performance tests were evaluated through Chemical-Looping Hydrogen Genera- tion in a fixed-bed reactor operating at atmospheric pressure. The characterization results showed that all samples were composed of metal oxides and perovskite oxides. Performance results indicated that CH4 conversion over the oxygen car- riers decreased in the lbllowing order： NiO/LaNiO3〉Co203/LaCoO3〉Fe203/LaFeO3. The ability of NiO/LaNiO3 and F%O3/ LaFeO3 to decompose water was stronger than that of Co203/LaCoO3 as evidenced by our experiments. H2 amounting to 80 mL upon reacting on methane in every cycle could be completely oxidized by NiO/LaNiO3 at 900℃ in the period from the third cycle to the eighth cycle.展开更多
文摘目的采用Box-Behnken效应面优化姜黄素长循环纳米结构脂质载体(mPEG2000-Cur-NLC)处方,并考察其理化性质。方法采用薄膜-超声法制备mPEG2000-Cur-NLC,以粒径、包封率和载药量为评价指标,以混合脂质的用量、乳化剂的用量和脂药质量比为考察对象,采用Box-Behnken效应面法筛选其最佳处方,并考察其粒径、包封率、zeta电位及体外释放。结果最优处方为混合脂质用量为质量分数2.5%、乳化剂的用量质量分数3.5%和脂药质量比40∶1,按最优处方制备的m PEG2000-Cur-NLC粒径为(135.33±2.52)nm、包封率为(96.70±0.146)%、载药量为(2.41±0.587)%,体外释放72h药物累积释放量为58.37%,呈缓释释放,Weibull方程拟合结果最好。结论 m PEG2000-Cur-NLC采用Box-Behnken效应面法优化是可行的,体外缓释效果良好。
基金Project(2022MD713784) supported by China Postdoctoral ScienceProject (1960321032) supported by the Research Start-up Fund Project for High-level Talents Introduction,ChinaProject (1609722058) supported by Xi’ an University of Architecture and Technology,China。
文摘Rock pillar is the key supporting component in underground engineering.During an earthquake,the key rock pillar must bear both the seismic load and the load transferred from other damaged pillars.This paper attempts to reveal the influence of the mainshock on damage evolution and failure characteristic of the key rock pillar during aftershocks by cyclic loading test of marble.Four levels of pre-damage stress(i.e.,10,30,50 and 70 MPa)in the first cycle were used to simulate the mainshock damage,and then cyclic stress with the same amplitude(namely 10 MPa)was conducted in the subsequent cycles to simulate the aftershock until rock failure.The results indicate that the presence of pre-damage has an obvious weakening effect on the bearing capacity and deformation resistance of rock materials during the aftershock process.Besides,the increase of pre-damage significantly changes the final failure pattern of the key rock pillar,and leads to an increase in the proportion of small-scale rock fragments.This study may contribute to understanding the seismic capacity of the unreinforced rock pillar during mainshock-aftershock seismic sequences and to optimizing the design of the key rock pillar in underground engineering.
基金supported by China Petrochemical Corporation(SINOPEC)(Contact No.106002000284)
文摘Ni-based, Fe-based and Co-based oxygen carriers with perovskite oxides used as the supports were prepared by citric acid complexation method, The oxygen carriers were characterized by thermal analysis, H2-temperature-programmed reduction and X-ray diffraction methods. Performance tests were evaluated through Chemical-Looping Hydrogen Genera- tion in a fixed-bed reactor operating at atmospheric pressure. The characterization results showed that all samples were composed of metal oxides and perovskite oxides. Performance results indicated that CH4 conversion over the oxygen car- riers decreased in the lbllowing order： NiO/LaNiO3〉Co203/LaCoO3〉Fe203/LaFeO3. The ability of NiO/LaNiO3 and F%O3/ LaFeO3 to decompose water was stronger than that of Co203/LaCoO3 as evidenced by our experiments. H2 amounting to 80 mL upon reacting on methane in every cycle could be completely oxidized by NiO/LaNiO3 at 900℃ in the period from the third cycle to the eighth cycle.
