In the present study,we aimed to observe the effects of ethanol extract of Oxalis corniculata L.on bleeding time(BT)and coagulation time(CT)and determine its acute toxicity in mice.Firstly,the ethanol extract of O.cor...In the present study,we aimed to observe the effects of ethanol extract of Oxalis corniculata L.on bleeding time(BT)and coagulation time(CT)and determine its acute toxicity in mice.Firstly,the ethanol extract of O.corniculata was administered to 40 mice,which were randomly divided into the normal control group,Yunnan Baiyao control group,low-dose group,and high-dose group.The low-dose(0.6 g/kg)and high-dose(1.2 g/kg)groups received ethanol extract of O.corniculata by gavage,and the BT and CT of the mice were measured by the slide method and tail clipping method,respectively.Secondly,the median lethal dose method was used with 50 mice to observe the physiological state,poisoning reaction,and death of the mice after intragastric administration.Finally,on the 14th day of the experiment,a necropsy was performed to observe any abnormality of the organs.In conclusion,in the coagulation and hemostasis tests,there were no statistical differences between the groups(P>0.05),while there was a significant dose-response relationship,and the BT and CT were significantly shorter than those of the negative control group,which were comparable to the Yunnan Baiyao control group.Moreover,in the acute toxicity test,the median lethal dose of ethanol extract of O.corniculata was 6.0291 g/kg,with a 95%confidence interval of 5.3065–6.7829 mg/kg.展开更多
In this paper,we report a full account of the synthesis of dimeric hexahydropyrroloindole alkaloids and its analogues.The key feature of our new strategy is the novel catalytic copper(10%)mediated intramolecular aryla...In this paper,we report a full account of the synthesis of dimeric hexahydropyrroloindole alkaloids and its analogues.The key feature of our new strategy is the novel catalytic copper(10%)mediated intramolecular arylations of o-haloanilides followed by intermolecular oxidative dimerization of the resulting oxindoles in one pot.This sequential reaction leads to the key intermediates for the synthesis of(+)-chimonanthine,(+)-folicanthine,(-)-calycanthine and(-)-ditryptophenaline.Graphical Abstract In the presence of catalytic amount of cuprous iodide(10%),an intramolecular arylation of ohaloanilides followed by an intermolecular oxidative dimerization of the resulting oxindoles leads to a commonintermediate for the synthesis of(+)-chimonanthine,(+)-folicanthine and(-)-calycanthine.Based on this cascade sequence,we also developed a flexible strategy towards the asymmetric syntheses of dimeric HPI alkaloids(-)-ditryptophenaline and its analogues.展开更多
Classical molecular dynamics simulation has been widely used to study the rapid cooling process of preparing amorphous alloys.However,the simulated cooling rate is several orders of magnitude higher than the experimen...Classical molecular dynamics simulation has been widely used to study the rapid cooling process of preparing amorphous alloys.However,the simulated cooling rate is several orders of magnitude higher than the experimental cooling rate.In this paper,Zr_(55)Cu_(35)Al_(10)alloy was taken as an example.It is found that adding isothermal annealing at a temperature slightly lower than Tand prolonging isothermal annealing time could effectively reduce the cooling rate.The glassy sample prepared in this way demonstrates significant energetic stability and well-developed short-range and medium-range order.展开更多
Classical molecular dynamics(MD)were conducted to study the structure and energy distribution of Zr_(x)Cu_(90-x)Al_(10)(x=20,30,40,50,60,70)ternary alloys.When the Zr composition is 30%,the glass transition temperatur...Classical molecular dynamics(MD)were conducted to study the structure and energy distribution of Zr_(x)Cu_(90-x)Al_(10)(x=20,30,40,50,60,70)ternary alloys.When the Zr composition is 30%,the glass transition temperature reaches the maximum value and the Zr_(30)Cu_(60)Al_(10)owns high glass forming ability(GFA).Analysis of the short⁃range structure shows that there are more low⁃energy Zr⁃centered polyhedron with high coordination number(CN)and Cu and Al⁃centered coordination polyhedron with CN=12 in Zr_(30)Cu_(60_Al_(10)alloy.As the medium⁃range structure is concerned,Zr_(30)Cu_(60_Al_(10)alloy has the largest number of coordination polyhedron connection sharing three atoms and connection in this way presenting the lowest energy.These low⁃energy and stable short and medium⁃range structures contribute to the high GFA of Zr_(30)Cu_(60_Al_(10).展开更多
The aerodynamics and heat transfer performance in the rear-mounted automobile cabin have an important influence on the engine’s safety and the operational stability of the automobile.The article uses STARCCM and GT-C...The aerodynamics and heat transfer performance in the rear-mounted automobile cabin have an important influence on the engine’s safety and the operational stability of the automobile.The article uses STARCCM and GT-COOL software to establish the 3D wind tunnel model and engine cooling system model of the internal combustion engine.At the same time,we established a 3D artificial coupling model through parameter transfer.The research results show that the heat transfer coefficient decreases with the increase of the comprehensive drag coefficient of the nacelle.This shows that the cabin flow field has an important influence on the heat transfer coefficient.Themainstream temperature rise of the engine room increases with the increase of the engine load.It is proved that vehicle speed affects the amount of heat dissipation of the engine room internal combustion engine under certain load conditions.The article provides a more effective and fast calculation method for the research on the heat dissipation of the internal combustion engine and the optimization of the cooling system equipment.展开更多
The present paper studies the sources of economic growth and the nature of structural change in the Chinese economy from 1987 to 2008. Using a methodology that evaluates the contribution o fan industry to economic gro...The present paper studies the sources of economic growth and the nature of structural change in the Chinese economy from 1987 to 2008. Using a methodology that evaluates the contribution o fan industry to economic growth, the present paper shows that the post-2000 subperiod marked an increased reliance on the services sector as a source of growth in the Chinese economy. Much of the acceleration in real GDP or aggregate labor productivity growth in China in the post-2000 subperiod compared to the pre-2000 period can be traced to an increased contribution from service-producing and high-technology exporting manufacturing industries. The evidence indicates that the Chinese economy has been rebalancing toward domestic consumption and shifting its export sector toward high- technology manufacturing industries.展开更多
基金Yunnan Province Education Department Scientific Research Fund Project(Grant No.2022J1683)。
文摘In the present study,we aimed to observe the effects of ethanol extract of Oxalis corniculata L.on bleeding time(BT)and coagulation time(CT)and determine its acute toxicity in mice.Firstly,the ethanol extract of O.corniculata was administered to 40 mice,which were randomly divided into the normal control group,Yunnan Baiyao control group,low-dose group,and high-dose group.The low-dose(0.6 g/kg)and high-dose(1.2 g/kg)groups received ethanol extract of O.corniculata by gavage,and the BT and CT of the mice were measured by the slide method and tail clipping method,respectively.Secondly,the median lethal dose method was used with 50 mice to observe the physiological state,poisoning reaction,and death of the mice after intragastric administration.Finally,on the 14th day of the experiment,a necropsy was performed to observe any abnormality of the organs.In conclusion,in the coagulation and hemostasis tests,there were no statistical differences between the groups(P>0.05),while there was a significant dose-response relationship,and the BT and CT were significantly shorter than those of the negative control group,which were comparable to the Yunnan Baiyao control group.Moreover,in the acute toxicity test,the median lethal dose of ethanol extract of O.corniculata was 6.0291 g/kg,with a 95%confidence interval of 5.3065–6.7829 mg/kg.
基金This work was supported by Grants from Natural Science Foundation of China(20925205 and 21332007)the Program for Changjiang Scholars and Innovative Research Team in University(IRT13095)+1 种基金Yunnan Provincial Science and Technology Department(2010GA014)the Program for Yunling Scholars.Dr.Xiaonian Li of the Kunming Institute of Botany is gratefully acknowledged for X-ray crystallographic analysis of compound 23.CCDC 1409209(23).
文摘In this paper,we report a full account of the synthesis of dimeric hexahydropyrroloindole alkaloids and its analogues.The key feature of our new strategy is the novel catalytic copper(10%)mediated intramolecular arylations of o-haloanilides followed by intermolecular oxidative dimerization of the resulting oxindoles in one pot.This sequential reaction leads to the key intermediates for the synthesis of(+)-chimonanthine,(+)-folicanthine,(-)-calycanthine and(-)-ditryptophenaline.Graphical Abstract In the presence of catalytic amount of cuprous iodide(10%),an intramolecular arylation of ohaloanilides followed by an intermolecular oxidative dimerization of the resulting oxindoles leads to a commonintermediate for the synthesis of(+)-chimonanthine,(+)-folicanthine and(-)-calycanthine.Based on this cascade sequence,we also developed a flexible strategy towards the asymmetric syntheses of dimeric HPI alkaloids(-)-ditryptophenaline and its analogues.
文摘Classical molecular dynamics simulation has been widely used to study the rapid cooling process of preparing amorphous alloys.However,the simulated cooling rate is several orders of magnitude higher than the experimental cooling rate.In this paper,Zr_(55)Cu_(35)Al_(10)alloy was taken as an example.It is found that adding isothermal annealing at a temperature slightly lower than Tand prolonging isothermal annealing time could effectively reduce the cooling rate.The glassy sample prepared in this way demonstrates significant energetic stability and well-developed short-range and medium-range order.
文摘Classical molecular dynamics(MD)were conducted to study the structure and energy distribution of Zr_(x)Cu_(90-x)Al_(10)(x=20,30,40,50,60,70)ternary alloys.When the Zr composition is 30%,the glass transition temperature reaches the maximum value and the Zr_(30)Cu_(60)Al_(10)owns high glass forming ability(GFA).Analysis of the short⁃range structure shows that there are more low⁃energy Zr⁃centered polyhedron with high coordination number(CN)and Cu and Al⁃centered coordination polyhedron with CN=12 in Zr_(30)Cu_(60_Al_(10)alloy.As the medium⁃range structure is concerned,Zr_(30)Cu_(60_Al_(10)alloy has the largest number of coordination polyhedron connection sharing three atoms and connection in this way presenting the lowest energy.These low⁃energy and stable short and medium⁃range structures contribute to the high GFA of Zr_(30)Cu_(60_Al_(10).
基金The study was partly supported by the Grant SC2021ZX05A0013 of the Heilongjiang Province“hundred,thousand,thousand”Engineering Science and Technology Major Special Project.
文摘The aerodynamics and heat transfer performance in the rear-mounted automobile cabin have an important influence on the engine’s safety and the operational stability of the automobile.The article uses STARCCM and GT-COOL software to establish the 3D wind tunnel model and engine cooling system model of the internal combustion engine.At the same time,we established a 3D artificial coupling model through parameter transfer.The research results show that the heat transfer coefficient decreases with the increase of the comprehensive drag coefficient of the nacelle.This shows that the cabin flow field has an important influence on the heat transfer coefficient.Themainstream temperature rise of the engine room increases with the increase of the engine load.It is proved that vehicle speed affects the amount of heat dissipation of the engine room internal combustion engine under certain load conditions.The article provides a more effective and fast calculation method for the research on the heat dissipation of the internal combustion engine and the optimization of the cooling system equipment.
文摘The present paper studies the sources of economic growth and the nature of structural change in the Chinese economy from 1987 to 2008. Using a methodology that evaluates the contribution o fan industry to economic growth, the present paper shows that the post-2000 subperiod marked an increased reliance on the services sector as a source of growth in the Chinese economy. Much of the acceleration in real GDP or aggregate labor productivity growth in China in the post-2000 subperiod compared to the pre-2000 period can be traced to an increased contribution from service-producing and high-technology exporting manufacturing industries. The evidence indicates that the Chinese economy has been rebalancing toward domestic consumption and shifting its export sector toward high- technology manufacturing industries.
