Profile grinding is the most crucial method for the ultra-precision machining of special-shaped surfaces.However,profile grinding produces a unique machining profile,and many random factors in the machining process le...Profile grinding is the most crucial method for the ultra-precision machining of special-shaped surfaces.However,profile grinding produces a unique machining profile,and many random factors in the machining process lead to complex surface characteristics.In this study,the structural and probabilistic characteristics of the profile grinding of a special-shaped surface were analyzed,and a probabilistic algorithm for the forming and 3D characterization of special-shaped surfaces under profile grinding was developed.The forming process of a GH738 blade tenon tooth surface was considered as an example to demonstrate the algorithm.The comparison results showed that the simulation results had similar surface characteristics to the measurement results,and the relative error range of the 3D roughness parameter was 0.21%–19.76%,indicating an accurate prediction and characterization of the complex special-shaped surface under the action of multiple factors.展开更多
Damage assessments in three dimensional (3D) textile composites subjected to mechanical loading can be performed by non-destructive and destructive techniques.This paper applies the two techniques to investigate the f...Damage assessments in three dimensional (3D) textile composites subjected to mechanical loading can be performed by non-destructive and destructive techniques.This paper applies the two techniques to investigate the fracture behavior of 3D tufted textile composites.X-ray computed tomography as a non-destructive evaluation method is appropriate to detect damage locations and identify their progression in 3D textile composites.Destructive methods such as sectioning toward observing damage provide valuable information about damage patterns.The results of this research could be utilized to evaluate the initial cause of rupture in 3D tufted composites used in aerospace structures and analyze fracture modes and damage progression.展开更多
Purpose – In the process of robot shell design, it is necessary to match the shape of the input 3D originalcharacter mesh model and robot endoskeleton, in order to make the input model fit for robot and avoidcollisio...Purpose – In the process of robot shell design, it is necessary to match the shape of the input 3D originalcharacter mesh model and robot endoskeleton, in order to make the input model fit for robot and avoidcollision. So, the purpose of this paper is to find an object of reference, which can be used for the process ofshape matching.Design/methodology/approach – In this work, the authors propose an interior bounded box (IBB)approach that derives from oriented bounding box (OBB). This kind of box is inside the closed mesh model.At the same time, it has maximum volume which is aligned with the object axis but is enclosed by all the meshvertices. Based on the IBB of input mesh model and the OBB of robot endoskeleton, the authors can completethe process of shape matching. In this paper, the authors use an evolutionary algorithm, covariance matrixadaptation evolution strategy (CMA-ES), to approximate the IBB based on skeleton and symmetry of inputcharacter mesh model.Findings – Based on the evolutionary algorithm CMA-ES, the optimal position and scale informationof IBB can be found. The authors can obtain satisfactory IBB result after this optimization process.The output IBB has maximum volume and is enveloped by the input character mesh model as well.Originality/value – To the best knowledge of the authors, the IBB is first proposed and used in the field ofrobot shell design. Taking advantage of the IBB, people can quickly obtain a shell model that fit for robot.At the same time, it can avoid collision between shell model and the robot endoskeleton.展开更多
Interleukin-10 (IL-10) is an important cytokine that plays a pivotal role in natural and adaptive immune systems. However, in lower vertebrates, especially in teleost the receptor of this cytokine is still largely unk...Interleukin-10 (IL-10) is an important cytokine that plays a pivotal role in natural and adaptive immune systems. However, in lower vertebrates, especially in teleost the receptor of this cytokine is still largely unknown. This paper described the cloning and characterization of grass carp interleukin-10 receptor 1 (gcIL10R1) and the 3D structure of its extracellular domain was predicted. The gcIL10R1 cDNA included 180 bp5’ untranslated region (UTR), 870 bp3’ UTR and an open reading frame (ORF) of 1632 bp. The ORF was found to encode a 543 amino acid protein with a putative JAK1 binding site, one STAT3 binding site. The phylogenetic analysis clusters gcIL10R1 with other teleost IL10R1s but independently of the amphibian, avian and mammalian IL10R1s. The 3D structure of its extracellular domain was the first homology model of a fish IL10R1 that revealed a high similarity with its mammalian and avian counterparts.展开更多
Conventional electron and optical microscopy techniques require the sample to be sectioned, polished or etched to expose the internal surfaces for imaging. However, such sample preparation techniques have traditionall...Conventional electron and optical microscopy techniques require the sample to be sectioned, polished or etched to expose the internal surfaces for imaging. However, such sample preparation techniques have traditionally prevented the observation of the same sample over time, under realistic three-dimensional geometries and in an environment representative of real-world operating conditions. X-ray microscopy (XRM) is a rapidly emerging technique that enables non-destructive evaluation of buried structures within hard to soft materials in 3D, requiring little to no sample preparation. Furthermore in situ and 4D quantification of microstructural evolution under controlled environment as a function of time, temperature, chemistry or stress can be done repeatable on the same sample, using practical specimen sizes ranging from tens of microns to several cm diameter, with achievable imaging resolution from submicron to 50 nm. Many of these studies were reported using XRM in synchrotron beamlines. These include crack propagation on composite and construction materials; corrosion studies; microstructural changes during the setting of cement; flow studies within porous media to mention but a few.展开更多
目的探究3D打印多孔结构陶瓷材料外科植入物孔隙结构的宏微观特征分析及评价方法。方法基于微米X射线CT(Micro-CT)扫描获取的多孔样品图像数据,利用VG Studio MAX 3.0软件及Mimics 16.0软件的多孔结构分析功能,对多孔结构的宏观结构特...目的探究3D打印多孔结构陶瓷材料外科植入物孔隙结构的宏微观特征分析及评价方法。方法基于微米X射线CT(Micro-CT)扫描获取的多孔样品图像数据,利用VG Studio MAX 3.0软件及Mimics 16.0软件的多孔结构分析功能,对多孔结构的宏观结构特征包括总孔隙率、宏孔孔径、内连接、开/闭孔率等进行测量和分析;同时,采用扫描电子显微镜对样品表面微观多孔形貌进行特征分析和评价。结果基于Micro-CT和SEM扫描及影像学分析实现了针对3D打印多孔结构陶瓷样件的孔隙结构的宏微观特征表征和统计分析,并验证了其可行性和准确性,形成了一套面向3D打印多孔结构陶瓷材料外科植入物形貌宏微结构尺寸特征的有效的测量和评价方法。结论本文提出的基于Micro-CT和SEM扫描成像进行3D打印多孔结构陶瓷样件的孔隙结构的宏微观特征表征和分析的统计方法,有利于实现多孔结构宏微观特征的相关测试内容和试验过程的规范统一,确保测试过程方法有据可依,结果评价准确有效,有利于提升产品的加工精度,便于不同企业同种工艺制造的多孔结构特征参数之间等同比较,为医疗器械行业多孔结构宏微观特征的数据积累奠定基础,有利于提高与人体生命安全息息相关的外科植入物产品的研发和制造水平。展开更多
基金sponsored by the National Natural Science Foundation of China(Grant No.51905442)the National Major Science and Technology Projects of China(Grant No.2017-VII-0002-0095).
文摘Profile grinding is the most crucial method for the ultra-precision machining of special-shaped surfaces.However,profile grinding produces a unique machining profile,and many random factors in the machining process lead to complex surface characteristics.In this study,the structural and probabilistic characteristics of the profile grinding of a special-shaped surface were analyzed,and a probabilistic algorithm for the forming and 3D characterization of special-shaped surfaces under profile grinding was developed.The forming process of a GH738 blade tenon tooth surface was considered as an example to demonstrate the algorithm.The comparison results showed that the simulation results had similar surface characteristics to the measurement results,and the relative error range of the 3D roughness parameter was 0.21%–19.76%,indicating an accurate prediction and characterization of the complex special-shaped surface under the action of multiple factors.
基金supported by the National Natural Science Foundation of China (No.12202190)Outstanding Postdoctoral Program in Jiangsu Province (No.2022ZB233)Research Start-up Funding from Nanjing University of Aeronautics and Astronautics (No.90YAH21131)。
文摘Damage assessments in three dimensional (3D) textile composites subjected to mechanical loading can be performed by non-destructive and destructive techniques.This paper applies the two techniques to investigate the fracture behavior of 3D tufted textile composites.X-ray computed tomography as a non-destructive evaluation method is appropriate to detect damage locations and identify their progression in 3D textile composites.Destructive methods such as sectioning toward observing damage provide valuable information about damage patterns.The results of this research could be utilized to evaluate the initial cause of rupture in 3D tufted composites used in aerospace structures and analyze fracture modes and damage progression.
基金This research,which is carried out at BeingThere Centre,collaboration among IMI of Nanyang Technological University(NTU)Singapore,ETH Zurich and UNC Chapel Hill,is supported by the Singapore National Research Foundation(NRF)under its International Research Centre@Singapore Funding Initiative and administered by the Interactive Digital Media Programme Office(IDMPO).The author Shihui Guo is supported by Chinese Post-doctoral Science Foundation 2016M600506.
文摘Purpose – In the process of robot shell design, it is necessary to match the shape of the input 3D originalcharacter mesh model and robot endoskeleton, in order to make the input model fit for robot and avoidcollision. So, the purpose of this paper is to find an object of reference, which can be used for the process ofshape matching.Design/methodology/approach – In this work, the authors propose an interior bounded box (IBB)approach that derives from oriented bounding box (OBB). This kind of box is inside the closed mesh model.At the same time, it has maximum volume which is aligned with the object axis but is enclosed by all the meshvertices. Based on the IBB of input mesh model and the OBB of robot endoskeleton, the authors can completethe process of shape matching. In this paper, the authors use an evolutionary algorithm, covariance matrixadaptation evolution strategy (CMA-ES), to approximate the IBB based on skeleton and symmetry of inputcharacter mesh model.Findings – Based on the evolutionary algorithm CMA-ES, the optimal position and scale informationof IBB can be found. The authors can obtain satisfactory IBB result after this optimization process.The output IBB has maximum volume and is enveloped by the input character mesh model as well.Originality/value – To the best knowledge of the authors, the IBB is first proposed and used in the field ofrobot shell design. Taking advantage of the IBB, people can quickly obtain a shell model that fit for robot.At the same time, it can avoid collision between shell model and the robot endoskeleton.
文摘Interleukin-10 (IL-10) is an important cytokine that plays a pivotal role in natural and adaptive immune systems. However, in lower vertebrates, especially in teleost the receptor of this cytokine is still largely unknown. This paper described the cloning and characterization of grass carp interleukin-10 receptor 1 (gcIL10R1) and the 3D structure of its extracellular domain was predicted. The gcIL10R1 cDNA included 180 bp5’ untranslated region (UTR), 870 bp3’ UTR and an open reading frame (ORF) of 1632 bp. The ORF was found to encode a 543 amino acid protein with a putative JAK1 binding site, one STAT3 binding site. The phylogenetic analysis clusters gcIL10R1 with other teleost IL10R1s but independently of the amphibian, avian and mammalian IL10R1s. The 3D structure of its extracellular domain was the first homology model of a fish IL10R1 that revealed a high similarity with its mammalian and avian counterparts.
文摘Conventional electron and optical microscopy techniques require the sample to be sectioned, polished or etched to expose the internal surfaces for imaging. However, such sample preparation techniques have traditionally prevented the observation of the same sample over time, under realistic three-dimensional geometries and in an environment representative of real-world operating conditions. X-ray microscopy (XRM) is a rapidly emerging technique that enables non-destructive evaluation of buried structures within hard to soft materials in 3D, requiring little to no sample preparation. Furthermore in situ and 4D quantification of microstructural evolution under controlled environment as a function of time, temperature, chemistry or stress can be done repeatable on the same sample, using practical specimen sizes ranging from tens of microns to several cm diameter, with achievable imaging resolution from submicron to 50 nm. Many of these studies were reported using XRM in synchrotron beamlines. These include crack propagation on composite and construction materials; corrosion studies; microstructural changes during the setting of cement; flow studies within porous media to mention but a few.
文摘目的探究3D打印多孔结构陶瓷材料外科植入物孔隙结构的宏微观特征分析及评价方法。方法基于微米X射线CT(Micro-CT)扫描获取的多孔样品图像数据,利用VG Studio MAX 3.0软件及Mimics 16.0软件的多孔结构分析功能,对多孔结构的宏观结构特征包括总孔隙率、宏孔孔径、内连接、开/闭孔率等进行测量和分析;同时,采用扫描电子显微镜对样品表面微观多孔形貌进行特征分析和评价。结果基于Micro-CT和SEM扫描及影像学分析实现了针对3D打印多孔结构陶瓷样件的孔隙结构的宏微观特征表征和统计分析,并验证了其可行性和准确性,形成了一套面向3D打印多孔结构陶瓷材料外科植入物形貌宏微结构尺寸特征的有效的测量和评价方法。结论本文提出的基于Micro-CT和SEM扫描成像进行3D打印多孔结构陶瓷样件的孔隙结构的宏微观特征表征和分析的统计方法,有利于实现多孔结构宏微观特征的相关测试内容和试验过程的规范统一,确保测试过程方法有据可依,结果评价准确有效,有利于提升产品的加工精度,便于不同企业同种工艺制造的多孔结构特征参数之间等同比较,为医疗器械行业多孔结构宏微观特征的数据积累奠定基础,有利于提高与人体生命安全息息相关的外科植入物产品的研发和制造水平。
