The hot-section parts easily occur the creep-fatigued interaction under the condition of mechanicalthermal coupled load during the period of service, which may lead to the damage of the parts, and therefore, the measu...The hot-section parts easily occur the creep-fatigued interaction under the condition of mechanicalthermal coupled load during the period of service, which may lead to the damage of the parts, and therefore, the measurement and characterization of thermal-deformed fields of the parts are important to understand its damage process. Aiming at relevant demand, the bilateral telecentric-multispectral imaging system was established, the research of synchronous measurement technique of the temperature and deformation fields was developed. On the one hand, the measurement technology for surface temperature of the object was developed using the two-color images captured by the multispectral camera with bilateral telecentric lens and combined with colorimetric method. On the other hand, the 2 D-DIC measurement technique of the multispectral camera was developed by conducting digital image correlation analysis using the blue light images before and after deformation, which can measure the high temperature deformation field of the object(the blue light images were filtered by multispectral camera).Results showed that the bilateral telecentric lens is used to replace the ordinary optical lens for imaging,which can effectively eliminate the distortion of the multispectral imaging system. Since the temperature measurement process of this measurement system is little affected by the emissivity of the object, therefore, it has excellent robustness. The thermal expansion coefficients of the nickel alloys are evaluated at the temperature ranges of 700–1000℃, indicating this system can achieve the synchronous and precise measurement of the temperature and deformation fields of the object.展开更多
[Objectives]To determine the kaempferol content in Yao medicine Lysimachia foenum-graecum Hance.[Methods]The high performance liquid chromatography(HPLC)method was used.The chromatographic column:Inertsil ODS-3 C18 co...[Objectives]To determine the kaempferol content in Yao medicine Lysimachia foenum-graecum Hance.[Methods]The high performance liquid chromatography(HPLC)method was used.The chromatographic column:Inertsil ODS-3 C18 column(4.60 mm×250 mm,5μm);mobile phase:acetonitrile-0.1%glacial acetic acid;flow rate:1.0 mL/min;column temperature:30℃;detection wavelength:360 nm;sample injection volume:10μL.[Results]The kaempferol content in Yao medicine L.foenum-graecum was determined,Y=20652X-151098(R=0.9997)shows a good linear relationship within the linear range of 9.80-156.8μg/mL.[Conclusions]The high performance liquid chromatography(HPLC)method was established for determining the kaempferol content in Yao medicine L.foenum-graecum.This method is expected to provide a scientific basis for the formulation of quality control methods for L.foenum-graecum.展开更多
A variety of soft wall-climbing robots have been developed that can move in certain patterns.Most of these soft robots can only move on conventional surfaces and lack adaptability to complex surfaces.Improving the ada...A variety of soft wall-climbing robots have been developed that can move in certain patterns.Most of these soft robots can only move on conventional surfaces and lack adaptability to complex surfaces.Improving the adaptability of soft robots on complex surfaces is still a challenging problem.To this end,we study the layered structure of the starfish tube foot and the valve flap structure in the water vascular system,and use an ultrasonic stress detector to study the stiffness distribution of the arm structure.Inspired by the motion of the starfish,we present a bionic soft wall-climbing robot,which is driven by two groups of pneumatic feet and achieves body bending through active adaptation layers.We design the structure of the foot to flex to provide driving force,and there are suction cups at the end of the foot to provide suction.The soft foot has a simple structure design,adapts to a variety of surfaces,and does not damage the surface of the substrate.Variable stiffness layers achieve stiffness changes by the principle of line blocking.The Central Pattern Generator theory is introduced to coordinately control the multiple feet of the robot.After experiments,we verify the adaptability of the soft robot to curved surfaces.The research may provide a reference for the design and development of crawling soft robots on complex surfaces.展开更多
With the development of power electronic technologies and distributed power generation,DC distribution networks attract increasing attention due to their various advantages compared with traditional AC distribution ne...With the development of power electronic technologies and distributed power generation,DC distribution networks attract increasing attention due to their various advantages compared with traditional AC distribution networks.However,DC fault protection is one of the major issues in DC distribution networks.To improve their reliability and protect the semiconductor devices under DC faults,a current-limiting and energy-transferring DC circuit breaker topology is proposed in this paper.By applying passive components and thyristors,the proposed topology is capable of quickly limiting the fault current and transferring the faulty energy.The working principle,mathematical model and parameter designing method of the proposed topology are presented in this paper.The simulation results verify that the proposed DC circuit breaker could effectively limit the fault current and quickly interrupt the fault current.Cost and conduction power loss evaluation proves the practicality of the proposed topology in medium-voltage DC distribution networks.展开更多
基金the National Natural Science Foundation of China(Grant Nos.12032013 and 11972209)the National Key Research and Development Program of China(Grant No.2017YFB1103900)the National Science and Technology Major Project(Grant No.2017-VⅠ-0003-0073).
文摘The hot-section parts easily occur the creep-fatigued interaction under the condition of mechanicalthermal coupled load during the period of service, which may lead to the damage of the parts, and therefore, the measurement and characterization of thermal-deformed fields of the parts are important to understand its damage process. Aiming at relevant demand, the bilateral telecentric-multispectral imaging system was established, the research of synchronous measurement technique of the temperature and deformation fields was developed. On the one hand, the measurement technology for surface temperature of the object was developed using the two-color images captured by the multispectral camera with bilateral telecentric lens and combined with colorimetric method. On the other hand, the 2 D-DIC measurement technique of the multispectral camera was developed by conducting digital image correlation analysis using the blue light images before and after deformation, which can measure the high temperature deformation field of the object(the blue light images were filtered by multispectral camera).Results showed that the bilateral telecentric lens is used to replace the ordinary optical lens for imaging,which can effectively eliminate the distortion of the multispectral imaging system. Since the temperature measurement process of this measurement system is little affected by the emissivity of the object, therefore, it has excellent robustness. The thermal expansion coefficients of the nickel alloys are evaluated at the temperature ranges of 700–1000℃, indicating this system can achieve the synchronous and precise measurement of the temperature and deformation fields of the object.
基金Scientific Research and Technological Development Program Project of Hezhou City(He Ke Ji 20047)Scientific Research Program of Guangxi International Zhuang Medicine Hospital in 2020(GZ202001)+1 种基金Preparation Quality Improvement Project of Traditional Chinese Medicine Zhuang and Yao Medicine Hospital of Traditional Chinese Medicine Administration of Guangxi Zhuang Autonomous Region(GZZJ202013&GZZJ202015)Zhuang and Yao Medicine Research Laboratory of Guangxi International Zhuang Medicine Hospital.
文摘[Objectives]To determine the kaempferol content in Yao medicine Lysimachia foenum-graecum Hance.[Methods]The high performance liquid chromatography(HPLC)method was used.The chromatographic column:Inertsil ODS-3 C18 column(4.60 mm×250 mm,5μm);mobile phase:acetonitrile-0.1%glacial acetic acid;flow rate:1.0 mL/min;column temperature:30℃;detection wavelength:360 nm;sample injection volume:10μL.[Results]The kaempferol content in Yao medicine L.foenum-graecum was determined,Y=20652X-151098(R=0.9997)shows a good linear relationship within the linear range of 9.80-156.8μg/mL.[Conclusions]The high performance liquid chromatography(HPLC)method was established for determining the kaempferol content in Yao medicine L.foenum-graecum.This method is expected to provide a scientific basis for the formulation of quality control methods for L.foenum-graecum.
文摘A variety of soft wall-climbing robots have been developed that can move in certain patterns.Most of these soft robots can only move on conventional surfaces and lack adaptability to complex surfaces.Improving the adaptability of soft robots on complex surfaces is still a challenging problem.To this end,we study the layered structure of the starfish tube foot and the valve flap structure in the water vascular system,and use an ultrasonic stress detector to study the stiffness distribution of the arm structure.Inspired by the motion of the starfish,we present a bionic soft wall-climbing robot,which is driven by two groups of pneumatic feet and achieves body bending through active adaptation layers.We design the structure of the foot to flex to provide driving force,and there are suction cups at the end of the foot to provide suction.The soft foot has a simple structure design,adapts to a variety of surfaces,and does not damage the surface of the substrate.Variable stiffness layers achieve stiffness changes by the principle of line blocking.The Central Pattern Generator theory is introduced to coordinately control the multiple feet of the robot.After experiments,we verify the adaptability of the soft robot to curved surfaces.The research may provide a reference for the design and development of crawling soft robots on complex surfaces.
基金This work is supported by National Key R&D Program(2018YFB0904600).
文摘With the development of power electronic technologies and distributed power generation,DC distribution networks attract increasing attention due to their various advantages compared with traditional AC distribution networks.However,DC fault protection is one of the major issues in DC distribution networks.To improve their reliability and protect the semiconductor devices under DC faults,a current-limiting and energy-transferring DC circuit breaker topology is proposed in this paper.By applying passive components and thyristors,the proposed topology is capable of quickly limiting the fault current and transferring the faulty energy.The working principle,mathematical model and parameter designing method of the proposed topology are presented in this paper.The simulation results verify that the proposed DC circuit breaker could effectively limit the fault current and quickly interrupt the fault current.Cost and conduction power loss evaluation proves the practicality of the proposed topology in medium-voltage DC distribution networks.