The existing interventional therapy robots for the microwave ablation of liver tumors have a poor clinical applicability with a large volume, low positioning speed and complex automatic navigation control. To solve ab...The existing interventional therapy robots for the microwave ablation of liver tumors have a poor clinical applicability with a large volume, low positioning speed and complex automatic navigation control. To solve above problems, a composite configuration interventional therapy robot with passive and active joints is developed. The design of composite configuration reduces the size of the robot under the premise of a wide range of movement, and the robot with composite configuration can realizes rapid positioning with operation safety. The cumulative error of positioning is eliminated and the control complexity is reduced by decoupling active parts. The navigation algo- rithms for the robot are proposed based on solution of the inverse kinematics and geometric analysis. A simulation clinical test method is designed for the robot, and the functions of the robot and the navigation algorithms are verified by the test method. The mean error of navigation is 1.488 mm and the maximum error is 2.056 mm, and thepositioning time for the ablation needle is in 10 s. The experimental results show that the designed robot can meet the clinical requirements for the microwave ablation of liver tumors. The composite configuration is proposed in development of the interventional therapy robot for the microwave ablation of liver tumors, which provides a new idea for the structural design of medical robots.展开更多
The climate has an impact on the urban thermal environment,and the magnitude of the surface urban heat island(SUHI)and urban cool island(UCI)vary across the world’s climatic zones.This literature review investigated:...The climate has an impact on the urban thermal environment,and the magnitude of the surface urban heat island(SUHI)and urban cool island(UCI)vary across the world’s climatic zones.This literature review investigated:1)the variations in the SUHI and UCI intensity under different climatic backgrounds,and 2)the effect of vegetation types,landscape composition,urban configuration,and water bodies on the SUHI.The SUHI had a higher intensity in tropical(Af(tropical rainy climate,Köppen climate classification),Am(tropical monsoon climate),subtropical(Cfa,subtropical humid climate),and humid continental(Dwa,semi-humid and semi-arid monsoon climate)climate zones.The magnitude of the UCI was low compared to the SUHI across the climate zones.The cool and dry Mediterranean(Cfb,temperate marine climate;Csb,temperate mediterranean climate;Cfa)and tropical climate(Af)areas had a higher cooling intensity.For cities with a desert climate(BWh,tropical desert climate),a reverse pattern was found.The difference in the SUHI in the night-time was greater than in the daytime for most cities across the climate zones.The extent of green space cooling was related to city size,the adjacent impervious surface,and the local climate.Additionally,the composition of urban landscape elements was more significant than their configuration for sustaining the urban thermal environment.Finally,we identified future research gaps for possible solutions in the context of sustainable urbanization in different climate zones.展开更多
In the study,it is proposed that a coordinate-parametric matrix model is performed to a square-conjoint pattern of cross woven(SCPCW)in the bamboo mat.The patterns of SCPCW are firstly detected according to the perspe...In the study,it is proposed that a coordinate-parametric matrix model is performed to a square-conjoint pattern of cross woven(SCPCW)in the bamboo mat.The patterns of SCPCW are firstly detected according to the perspective of configuration,which is divided into the basic-monomer shape and the basic combination shape.Secondly,the compositions of design patterns in SCPCW are analyzed to attain the trend of curve shape.Based on the coordinate-parametric matrix model,the specimens of SCPCW are subsequently accomplished to elaborate the woven logic of bamboo mats.The digital innovation of SCPCW,defined by a mathematical resolution,is implemented by the software of Grasshopper(GH),which plays a crucial role in capturing image information by the Image Sampler component.Successively,the weaving logic of coordinated matrix is referred to apply in the computing component of Grasshopper software.Finally,the computer simulation could demonstrate that the coordinate-parametric matrix model of SCPCWwould be realized to analyze the micro-weaving structure and overall weaving effect in the bamboo mat.展开更多
Owing to its distinguished mechanical stiffness and strength, graphene has become an ideal reinforcing material in kinds of composite materials. In this work, the graphene(reduced graphene oxide) reinforced aluminum...Owing to its distinguished mechanical stiffness and strength, graphene has become an ideal reinforcing material in kinds of composite materials. In this work, the graphene(reduced graphene oxide) reinforced aluminum(Al)matrix composites were fabricated by flaky powder metallurgy. Tensile tests of pure Al matrix and graphene/Al composites with bioinspired layered structures are conducted.By means of an independently developed Python-based structural modeling program, three-dimensional microscopic structural models of graphene/Al composites can be established, in which the size, shape, orientation, location and content of graphene can be reconstructed in line with the actual graphene/Al composite structures. Elastoplastic mechanical properties, damaged materials behaviors, grapheneAl interfacial behaviors and reasonable boundary conditions are introduced and applied to perform the simulations. Based on the experimental and numerical tensile behaviors of graphene/Al composites, the effects of graphene morphology,graphene-Al interface, composite configuration and failure behavior within the tensile mechanical deformations of graphene/Al composites can be revealed and indicated, respectively.From the analysis above, a good understanding can be brought to light for the deformation mechanism of graphene/Al composites.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.2013BAI01B01)Science and Technology Planning Project of Beijing Education Commission of China(Grant No.KM201310017002)
文摘The existing interventional therapy robots for the microwave ablation of liver tumors have a poor clinical applicability with a large volume, low positioning speed and complex automatic navigation control. To solve above problems, a composite configuration interventional therapy robot with passive and active joints is developed. The design of composite configuration reduces the size of the robot under the premise of a wide range of movement, and the robot with composite configuration can realizes rapid positioning with operation safety. The cumulative error of positioning is eliminated and the control complexity is reduced by decoupling active parts. The navigation algo- rithms for the robot are proposed based on solution of the inverse kinematics and geometric analysis. A simulation clinical test method is designed for the robot, and the functions of the robot and the navigation algorithms are verified by the test method. The mean error of navigation is 1.488 mm and the maximum error is 2.056 mm, and thepositioning time for the ablation needle is in 10 s. The experimental results show that the designed robot can meet the clinical requirements for the microwave ablation of liver tumors. The composite configuration is proposed in development of the interventional therapy robot for the microwave ablation of liver tumors, which provides a new idea for the structural design of medical robots.
基金Under the auspices of the National Natural Science Foundation of China(No.41590841)the National Key Research and Development Program of China(No.2016YFC0503000)the Research Funds of the Chinese Academy of Sciences the Chinese Academy of Sciences(CAS)-the World Academy of Sciences(TWAS)President’s Fellowship。
文摘The climate has an impact on the urban thermal environment,and the magnitude of the surface urban heat island(SUHI)and urban cool island(UCI)vary across the world’s climatic zones.This literature review investigated:1)the variations in the SUHI and UCI intensity under different climatic backgrounds,and 2)the effect of vegetation types,landscape composition,urban configuration,and water bodies on the SUHI.The SUHI had a higher intensity in tropical(Af(tropical rainy climate,Köppen climate classification),Am(tropical monsoon climate),subtropical(Cfa,subtropical humid climate),and humid continental(Dwa,semi-humid and semi-arid monsoon climate)climate zones.The magnitude of the UCI was low compared to the SUHI across the climate zones.The cool and dry Mediterranean(Cfb,temperate marine climate;Csb,temperate mediterranean climate;Cfa)and tropical climate(Af)areas had a higher cooling intensity.For cities with a desert climate(BWh,tropical desert climate),a reverse pattern was found.The difference in the SUHI in the night-time was greater than in the daytime for most cities across the climate zones.The extent of green space cooling was related to city size,the adjacent impervious surface,and the local climate.Additionally,the composition of urban landscape elements was more significant than their configuration for sustaining the urban thermal environment.Finally,we identified future research gaps for possible solutions in the context of sustainable urbanization in different climate zones.
基金financial support from the Hunan Provincial Key Research and Development Program(2020WK2018)the Arts Crafts Industrial Design Center of Hunan Province(No.2022GYMSZ2)the Scientific Innovation Fund for Post-Graduates of Central South University of Forestry and Technology(No.2022CX02079).
文摘In the study,it is proposed that a coordinate-parametric matrix model is performed to a square-conjoint pattern of cross woven(SCPCW)in the bamboo mat.The patterns of SCPCW are firstly detected according to the perspective of configuration,which is divided into the basic-monomer shape and the basic combination shape.Secondly,the compositions of design patterns in SCPCW are analyzed to attain the trend of curve shape.Based on the coordinate-parametric matrix model,the specimens of SCPCW are subsequently accomplished to elaborate the woven logic of bamboo mats.The digital innovation of SCPCW,defined by a mathematical resolution,is implemented by the software of Grasshopper(GH),which plays a crucial role in capturing image information by the Image Sampler component.Successively,the weaving logic of coordinated matrix is referred to apply in the computing component of Grasshopper software.Finally,the computer simulation could demonstrate that the coordinate-parametric matrix model of SCPCWwould be realized to analyze the micro-weaving structure and overall weaving effect in the bamboo mat.
基金financial supports by the National Natural Science Foundation (51501111, 51131004)the Ministry of Science and Technology of China (2016YFE0130200)+1 种基金Science & Technology Committee of Shanghai (14DZ2261200, 1452 0710100 and 14JC14033 00)111 Project (B16032)
文摘Owing to its distinguished mechanical stiffness and strength, graphene has become an ideal reinforcing material in kinds of composite materials. In this work, the graphene(reduced graphene oxide) reinforced aluminum(Al)matrix composites were fabricated by flaky powder metallurgy. Tensile tests of pure Al matrix and graphene/Al composites with bioinspired layered structures are conducted.By means of an independently developed Python-based structural modeling program, three-dimensional microscopic structural models of graphene/Al composites can be established, in which the size, shape, orientation, location and content of graphene can be reconstructed in line with the actual graphene/Al composite structures. Elastoplastic mechanical properties, damaged materials behaviors, grapheneAl interfacial behaviors and reasonable boundary conditions are introduced and applied to perform the simulations. Based on the experimental and numerical tensile behaviors of graphene/Al composites, the effects of graphene morphology,graphene-Al interface, composite configuration and failure behavior within the tensile mechanical deformations of graphene/Al composites can be revealed and indicated, respectively.From the analysis above, a good understanding can be brought to light for the deformation mechanism of graphene/Al composites.