城市空中交通(urban air mobility, UAM),是近期解决当前地面交通拥堵困境的有效方法。因此,研究飞行汽车典型飞行任务剖面下的动力系统工作特性至关重要。由于电池能量密度的限制以及纯电动飞行汽车的里程限制,因此使用油电混合作为飞...城市空中交通(urban air mobility, UAM),是近期解决当前地面交通拥堵困境的有效方法。因此,研究飞行汽车典型飞行任务剖面下的动力系统工作特性至关重要。由于电池能量密度的限制以及纯电动飞行汽车的里程限制,因此使用油电混合作为飞行汽车的动力系统更为合理。总结垂直起降飞行汽车(vertical takeoff and landing, VTOL)任务剖面下混动系统运行性能的相关研究。基于MATLAB Simulink,提出一种混合动力的协调方法,其中同时考虑两种操作模式。根据实际操作条件,预设垂直起降和平飞两种工况下不同的操作模式。在此基础上,研究作为主要电源的增程器调节功率流和提高增程器工作效率的电池协调。直流母线电压由DC/DC转换器调节,有利于电池组的整体寿命,实现了充电和放电状态期间的功率共享。仿真结果表明:可以很好地控制直流母线电压,并且增程器和电池之间的功率共享遵循设计。展开更多
The Yellow River is usually assumed to record tectonic activities and climatic changes;however,a systematic study was lack in the sedimentology,stratigraphy,geomorphology and geochronology for the entire Yellow River ...The Yellow River is usually assumed to record tectonic activities and climatic changes;however,a systematic study was lack in the sedimentology,stratigraphy,geomorphology and geochronology for the entire Yellow River though various geologic scholars have conducted numerous works in individual basins.This review focused on well-preserved fluvial terrace sequences that formed along this river on northeastern(NE)Tibetan Plateau and Ordos Block over the past 2.6 Ma.After comparing numerous initial incision ages at different segments along the Yellow River,we found out that the youngest initial incision may occur at ca.150 ka at the Longyang Gorge.The Yellow River may transit from multiple separated endorheic drainages to an entire external drainage after 150 ka,which may cause differentiations in the apparent incision rates before and after 150 ka;thus apparent net incision rates were calculated respectively for the Yellow River before 150 ka and the drainage network post 150 ka.Apparent net incision rates prior to 0.15 Ma were calculated as 0.15,0.29,0.10,0.12 and 0.03 mm/a respectively in Tongde-Xunhua,Lanzhou-Linxia basins,Heishan,Jinshan and Fenwei-Sanmen Gorges in this review,which mainly reflected Kunhuang-Gonghe Tectonic Event,generated by the Indo-Asian collision and diminishing as the NE Tibetan Plateau eastward extruding at ca.1.8-0.15 Ma.Apparent net incision rates post 0.15 Ma were calculated respectively for NE Tibetan Plateau and Ordos Block,considering their different base level.On NE Tibetan Plateau,four fluvial degradational phases were identified between ca.105~70,53~40,25~16 and 12~6 ka associated with terrace levels respectively,at average elevations of 96,40,20 and 10.5 meters above the current river level(m arl)within a range of 5~96 m arl;and four broad periods in the last 150 ka on Ordos Block:possibly marine oxygen isotope stage(MIS)5,ca.118 to 72 ka,most of MIS 3,ca.44~28 ka,transition from LGM to last deglacial ca.20 to 16 ka,and 4~3 ka at average elevations of 67.5,26,19 and 11.5 m arl.These degradational phases post 0.15 Ma were associated with multiple processes including enhanced fluvial discharge with an increase in monsoonal precipitation and/or melt water in deglaciation.展开更多
本文首先简要回顾了启发式教学法,从苏格拉底的助产术到孔子的温故而知新谈到了现代数学教学模式MM(Methodology of Mathematics)教学法。根据当前教学现状,我们将大学数学教学模式划分为三类形式,即照本宣科模式、小启发模式(简称小启...本文首先简要回顾了启发式教学法,从苏格拉底的助产术到孔子的温故而知新谈到了现代数学教学模式MM(Methodology of Mathematics)教学法。根据当前教学现状,我们将大学数学教学模式划分为三类形式,即照本宣科模式、小启发模式(简称小启发)和大启发模式(简称大启发)。特别地指出了大启发不仅是教学创新模式,也是科研创新的思想方法。为了贯彻大启发教学,最后提出了大学数学教师应有的基本教学素质。展开更多
Objective:This study is aimed to explore the effect of triazole fungicide tebuconazole(TEB)exposure on the oral absorption behavior of atenolol(AT),based on the homeostasis of bile acids(BAs).Methods:TEB was daily gav...Objective:This study is aimed to explore the effect of triazole fungicide tebuconazole(TEB)exposure on the oral absorption behavior of atenolol(AT),based on the homeostasis of bile acids(BAs).Methods:TEB was daily gavaged to rats with 3 mg/kg dose for 28 days to establish the TEB-exposure rat model.The amounts of glycocholic acid,glycochenodeoxycholic acid,taurocholic acid and taurine deoxycholic acid in the small intestine contents of normal and TEB-exposure rats were detected by LC-MS/MS.AT(10 mg/kg)were gavaged to the normal and TEB-exposure rats,and then blood were collected from orbital venous plexus at predetermined time-points.The concentration of AT in plasma was detected by LC-MS/MS,and the pharmacokinetic parameters were calculated by the DAS pharmacokinetic software.An intestinal circulation perfusion model was established in normal rats,and perfused with the perfusates containing the model drug of fluorescein and the BAs with the same compositions as the normal/TEB-exposure rats.After perfusion,the absorption and permeability of fluorescein in intestine were detected,as well as the oxidative stress status and ZO-1 expression level in the intestinal tissues.Results:Compared with normal rats,TEB-exposure increased the amounts of glycocholic acid,glycochenodeoxycholic acid,taurocholic acid and taurine deoxycholic acid in intestine significantly(P<0.001).In TEB-exposure rats,the maximum plasma concentration and area under the curve of AT were increased significantly than those of normal rats(P<0.05),and the peak time was significantly delayed(P<0.05).The TEB-induced BAs homeostasis perturbance increased intestinal permeability,and this effect was associated with the elevation of oxidative stress and the down-regulation of intercellular tight junction proteins in intestinal tissues.Conclusion:TEB-exposure can affect the oral absorption behavior of AT,which is probably related with the intestinal BAs homeostasis perturbance,thus it might affect the clinical efficacy and safety of this drug.展开更多
文摘城市空中交通(urban air mobility, UAM),是近期解决当前地面交通拥堵困境的有效方法。因此,研究飞行汽车典型飞行任务剖面下的动力系统工作特性至关重要。由于电池能量密度的限制以及纯电动飞行汽车的里程限制,因此使用油电混合作为飞行汽车的动力系统更为合理。总结垂直起降飞行汽车(vertical takeoff and landing, VTOL)任务剖面下混动系统运行性能的相关研究。基于MATLAB Simulink,提出一种混合动力的协调方法,其中同时考虑两种操作模式。根据实际操作条件,预设垂直起降和平飞两种工况下不同的操作模式。在此基础上,研究作为主要电源的增程器调节功率流和提高增程器工作效率的电池协调。直流母线电压由DC/DC转换器调节,有利于电池组的整体寿命,实现了充电和放电状态期间的功率共享。仿真结果表明:可以很好地控制直流母线电压,并且增程器和电池之间的功率共享遵循设计。
基金supported by the National Natural Science Foundation of China(Grant No.41472155),Grant No.ZR2022QD083,LYHZW202248 and NSFC 417644073Cultivating Young Talents in the Universities of Shandong Province(LUJIAOKEHAN2021-51,granted to L.Yu)。
文摘The Yellow River is usually assumed to record tectonic activities and climatic changes;however,a systematic study was lack in the sedimentology,stratigraphy,geomorphology and geochronology for the entire Yellow River though various geologic scholars have conducted numerous works in individual basins.This review focused on well-preserved fluvial terrace sequences that formed along this river on northeastern(NE)Tibetan Plateau and Ordos Block over the past 2.6 Ma.After comparing numerous initial incision ages at different segments along the Yellow River,we found out that the youngest initial incision may occur at ca.150 ka at the Longyang Gorge.The Yellow River may transit from multiple separated endorheic drainages to an entire external drainage after 150 ka,which may cause differentiations in the apparent incision rates before and after 150 ka;thus apparent net incision rates were calculated respectively for the Yellow River before 150 ka and the drainage network post 150 ka.Apparent net incision rates prior to 0.15 Ma were calculated as 0.15,0.29,0.10,0.12 and 0.03 mm/a respectively in Tongde-Xunhua,Lanzhou-Linxia basins,Heishan,Jinshan and Fenwei-Sanmen Gorges in this review,which mainly reflected Kunhuang-Gonghe Tectonic Event,generated by the Indo-Asian collision and diminishing as the NE Tibetan Plateau eastward extruding at ca.1.8-0.15 Ma.Apparent net incision rates post 0.15 Ma were calculated respectively for NE Tibetan Plateau and Ordos Block,considering their different base level.On NE Tibetan Plateau,four fluvial degradational phases were identified between ca.105~70,53~40,25~16 and 12~6 ka associated with terrace levels respectively,at average elevations of 96,40,20 and 10.5 meters above the current river level(m arl)within a range of 5~96 m arl;and four broad periods in the last 150 ka on Ordos Block:possibly marine oxygen isotope stage(MIS)5,ca.118 to 72 ka,most of MIS 3,ca.44~28 ka,transition from LGM to last deglacial ca.20 to 16 ka,and 4~3 ka at average elevations of 67.5,26,19 and 11.5 m arl.These degradational phases post 0.15 Ma were associated with multiple processes including enhanced fluvial discharge with an increase in monsoonal precipitation and/or melt water in deglaciation.
文摘本文首先简要回顾了启发式教学法,从苏格拉底的助产术到孔子的温故而知新谈到了现代数学教学模式MM(Methodology of Mathematics)教学法。根据当前教学现状,我们将大学数学教学模式划分为三类形式,即照本宣科模式、小启发模式(简称小启发)和大启发模式(简称大启发)。特别地指出了大启发不仅是教学创新模式,也是科研创新的思想方法。为了贯彻大启发教学,最后提出了大学数学教师应有的基本教学素质。
基金supported by National Natural Science Foundation of China(81874348)Academic Support Program for Top Talents of Higher Education in Anhui Province(GXBJZD2022027)Science and Technology Innovation Project of Anhui Drug Administration(AHYJ-KJ-202110)。
文摘Objective:This study is aimed to explore the effect of triazole fungicide tebuconazole(TEB)exposure on the oral absorption behavior of atenolol(AT),based on the homeostasis of bile acids(BAs).Methods:TEB was daily gavaged to rats with 3 mg/kg dose for 28 days to establish the TEB-exposure rat model.The amounts of glycocholic acid,glycochenodeoxycholic acid,taurocholic acid and taurine deoxycholic acid in the small intestine contents of normal and TEB-exposure rats were detected by LC-MS/MS.AT(10 mg/kg)were gavaged to the normal and TEB-exposure rats,and then blood were collected from orbital venous plexus at predetermined time-points.The concentration of AT in plasma was detected by LC-MS/MS,and the pharmacokinetic parameters were calculated by the DAS pharmacokinetic software.An intestinal circulation perfusion model was established in normal rats,and perfused with the perfusates containing the model drug of fluorescein and the BAs with the same compositions as the normal/TEB-exposure rats.After perfusion,the absorption and permeability of fluorescein in intestine were detected,as well as the oxidative stress status and ZO-1 expression level in the intestinal tissues.Results:Compared with normal rats,TEB-exposure increased the amounts of glycocholic acid,glycochenodeoxycholic acid,taurocholic acid and taurine deoxycholic acid in intestine significantly(P<0.001).In TEB-exposure rats,the maximum plasma concentration and area under the curve of AT were increased significantly than those of normal rats(P<0.05),and the peak time was significantly delayed(P<0.05).The TEB-induced BAs homeostasis perturbance increased intestinal permeability,and this effect was associated with the elevation of oxidative stress and the down-regulation of intercellular tight junction proteins in intestinal tissues.Conclusion:TEB-exposure can affect the oral absorption behavior of AT,which is probably related with the intestinal BAs homeostasis perturbance,thus it might affect the clinical efficacy and safety of this drug.
