A numerical study of bitubular tubes with diaphragms compared with single and bitubular tubes subjected to dynamic axial impact force was presented. At first, the energy absorption response of the composite structure ...A numerical study of bitubular tubes with diaphragms compared with single and bitubular tubes subjected to dynamic axial impact force was presented. At first, the energy absorption response of the composite structure under axial loading was analyzed by finite element simulation. The results show that the efficiency of energy absorption can be improved by introducing diaphragms to the double-walled columns. Then, the effect of the amount and location of diaphragms, the shape and the size of the inner tubes, and the thickness of the composite structures were also studied numerically. The collision performance of the composite structure is affected by the deformation of diaphragms, as well as the interaction of outer and inner tube. The non-uniform distribution of diaphragms can improve the energy absorption efficiency of structures for a constant number of diaphragms. The specific energy absorption of the hexagonal inner tube is the highest, followed by the circular, octagonal and square ones.展开更多
The paper designed a bionic woven tracheal stent and the stent was a multi-layer tubular structure with a transverse pipeline.Polydioxanone( PDO) monofilament and β-hydroxybutyrate and β-hydroxyvalerate copolymers/p...The paper designed a bionic woven tracheal stent and the stent was a multi-layer tubular structure with a transverse pipeline.Polydioxanone( PDO) monofilament and β-hydroxybutyrate and β-hydroxyvalerate copolymers/polylactic( PHBV/PLA) multifilament were chosen as the tissue engineering tracheal stent materials,and chitosan was chosen as the coating material. This study selected appropriate basic fabric structures and prepared the tracheal stent by setting reasonable weaving parameters,then treated the sample with coating and heat setting. Radical compression performances of the horizontal pipeline and longitudinal pipeline of this tracheal stent were investigated,and the experimental results showed that the stent had good performance on radial supporting force and elastic recovery,which meant it could supply adequate supports for cell growth and tissue regeneration of tracheal lesions; the horizontal pipeline could provide a good experimental foundation for reconstruction of the cartilage ring.展开更多
Graphene, a new two-dimensional carbon material, is a rising star of physics, chemistry and materials science. In this work, we report the recent experimental researches on the Raman spectra and the temperature-depend...Graphene, a new two-dimensional carbon material, is a rising star of physics, chemistry and materials science. In this work, we report the recent experimental researches on the Raman spectra and the temperature-dependent features of graphenes and car- bon nanoscrolls, which are evolved from graphene and have an open tubular structure. The layer-dependent Raman enhancing characteristics of n-layer graphenes for crystal violet, and the thickness-dependent morphologies of gold on n-layer graphenes are also systematically investigated. Meanwhile, the aggregations of ferromagnetic and paramagnetic atoms at edges of gra- phenes and graphite are observed and the mechanisms are discussed.展开更多
Light-weight and high-strength materials have attracted considerable attention owing to their outstanding properties, such as weight-reducing, acoustic absorption, thermal insulation, shock and vibration damping. Diam...Light-weight and high-strength materials have attracted considerable attention owing to their outstanding properties, such as weight-reducing, acoustic absorption, thermal insulation, shock and vibration damping. Diamond possesses specific stiffness and strength arising from its special crystal structure. In this work, inspired by the diamond crystal structure, hollow-tube nickel materials with the diamond structure were fabricated using a diamond structured polymer template based on the Stereo Lithography Appearance technology. The diamond structured template was coated with Ni-P by electroless plating. Finally, the template was removed by high temperature calcinations. The density of the hollow tube nickel materials is about 20 mg/cm3. The morphology and composition of the resultant materials were characterized by scanning electron microscope, energy-dispersive spectrometry, and X-ray diffraction. The results showed that the surface of the Ni film was uniform with the thickness of 4 gm. The mechanical property was also measured by stress and strain tester. The maximum compression stress can be reached to 40.6 KPa.展开更多
This article summarized the recent advance on the structural design and synthetic strategies of intramolec- ular charge-transfer compounds as well as their potential ap- plications in two-photon absorption chromophore...This article summarized the recent advance on the structural design and synthetic strategies of intramolec- ular charge-transfer compounds as well as their potential ap- plications in two-photon absorption chromophores, organic photovoltaics and organic light-emitting diodes.展开更多
Lithographically defined microporous templates in conjunction with the atomic layer deposition （ALD） technique enable remarkable control of complex novel nested nanotube structures. So far three-dimensional control ...Lithographically defined microporous templates in conjunction with the atomic layer deposition （ALD） technique enable remarkable control of complex novel nested nanotube structures. So far three-dimensional control of physical process parameters has not been fully realized with high precision resolution, and requires optimization in order to achieve a wider range of potential applications. Furthermore, the combination of composite insulating oxide layers alternating with semiconducting layers and metals can provide various types of novel applications and eventually provide unique and advanced levels of multifunctional nanoscale devices. Semiconducting TiO2 nanotubes have potential applications in photovoltaic devices. The combination of nanostructured semiconducting materials with nested metal nanotubes has the potential to produce novel multi functional vertically-ordered three-dimensional nanodevices. Platinum growth by ALD has been explored, covering the initial stages of the thin film nucleation process and the synthesis of high aspect ratio nanotube structures. The penetration depth of the Pt into porous templates having various pore sizes and aspect ratios has been investigated. Several multi-walled nested TiO2-Pt nanotubes in series have been successfully fabricated using microporous Si templates. These innovative nested nanostructures have the potential to produce novel multifunctional vertically-ordered three-dimensional nanodevices in photovoltaic and sensing technologies.展开更多
基金Projects(U1334208,51405516,51275532) supported by the National Natural Science Foundation of ChinaProject(2015ZZTS045) supported by the Fundamental Research Funds for the Central Universities of China
文摘A numerical study of bitubular tubes with diaphragms compared with single and bitubular tubes subjected to dynamic axial impact force was presented. At first, the energy absorption response of the composite structure under axial loading was analyzed by finite element simulation. The results show that the efficiency of energy absorption can be improved by introducing diaphragms to the double-walled columns. Then, the effect of the amount and location of diaphragms, the shape and the size of the inner tubes, and the thickness of the composite structures were also studied numerically. The collision performance of the composite structure is affected by the deformation of diaphragms, as well as the interaction of outer and inner tube. The non-uniform distribution of diaphragms can improve the energy absorption efficiency of structures for a constant number of diaphragms. The specific energy absorption of the hexagonal inner tube is the highest, followed by the circular, octagonal and square ones.
基金Biomedical Textile Materials Science and Technology(111 Project),China(No.B07024)National Natural Science Foundation of China(No.H0106)Shanghai Pujiang Program,China(No.2015PJC0002)
文摘The paper designed a bionic woven tracheal stent and the stent was a multi-layer tubular structure with a transverse pipeline.Polydioxanone( PDO) monofilament and β-hydroxybutyrate and β-hydroxyvalerate copolymers/polylactic( PHBV/PLA) multifilament were chosen as the tissue engineering tracheal stent materials,and chitosan was chosen as the coating material. This study selected appropriate basic fabric structures and prepared the tracheal stent by setting reasonable weaving parameters,then treated the sample with coating and heat setting. Radical compression performances of the horizontal pipeline and longitudinal pipeline of this tracheal stent were investigated,and the experimental results showed that the stent had good performance on radial supporting force and elastic recovery,which meant it could supply adequate supports for cell growth and tissue regeneration of tracheal lesions; the horizontal pipeline could provide a good experimental foundation for reconstruction of the cartilage ring.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10774032, 90921001, 50825206)
文摘Graphene, a new two-dimensional carbon material, is a rising star of physics, chemistry and materials science. In this work, we report the recent experimental researches on the Raman spectra and the temperature-dependent features of graphenes and car- bon nanoscrolls, which are evolved from graphene and have an open tubular structure. The layer-dependent Raman enhancing characteristics of n-layer graphenes for crystal violet, and the thickness-dependent morphologies of gold on n-layer graphenes are also systematically investigated. Meanwhile, the aggregations of ferromagnetic and paramagnetic atoms at edges of gra- phenes and graphite are observed and the mechanisms are discussed.
基金support of the National Basic Research Program of China(2010CB934700)the National Natural Science Foundation of China(51372010)
文摘Light-weight and high-strength materials have attracted considerable attention owing to their outstanding properties, such as weight-reducing, acoustic absorption, thermal insulation, shock and vibration damping. Diamond possesses specific stiffness and strength arising from its special crystal structure. In this work, inspired by the diamond crystal structure, hollow-tube nickel materials with the diamond structure were fabricated using a diamond structured polymer template based on the Stereo Lithography Appearance technology. The diamond structured template was coated with Ni-P by electroless plating. Finally, the template was removed by high temperature calcinations. The density of the hollow tube nickel materials is about 20 mg/cm3. The morphology and composition of the resultant materials were characterized by scanning electron microscope, energy-dispersive spectrometry, and X-ray diffraction. The results showed that the surface of the Ni film was uniform with the thickness of 4 gm. The mechanical property was also measured by stress and strain tester. The maximum compression stress can be reached to 40.6 KPa.
基金supported by AcRF Tier 1(RG 8/16,RG 133/14 and RG 13/15)from MOE,SingaporeSTU Scientific Research Foundation for Talents(NTF15005)+1 种基金STU Youth Research Fund(YR15001)the Foundation for Young Talents in Higher Education of Guangdong(2015KQNCX042)
文摘This article summarized the recent advance on the structural design and synthetic strategies of intramolec- ular charge-transfer compounds as well as their potential ap- plications in two-photon absorption chromophores, organic photovoltaics and organic light-emitting diodes.
文摘Lithographically defined microporous templates in conjunction with the atomic layer deposition （ALD） technique enable remarkable control of complex novel nested nanotube structures. So far three-dimensional control of physical process parameters has not been fully realized with high precision resolution, and requires optimization in order to achieve a wider range of potential applications. Furthermore, the combination of composite insulating oxide layers alternating with semiconducting layers and metals can provide various types of novel applications and eventually provide unique and advanced levels of multifunctional nanoscale devices. Semiconducting TiO2 nanotubes have potential applications in photovoltaic devices. The combination of nanostructured semiconducting materials with nested metal nanotubes has the potential to produce novel multi functional vertically-ordered three-dimensional nanodevices. Platinum growth by ALD has been explored, covering the initial stages of the thin film nucleation process and the synthesis of high aspect ratio nanotube structures. The penetration depth of the Pt into porous templates having various pore sizes and aspect ratios has been investigated. Several multi-walled nested TiO2-Pt nanotubes in series have been successfully fabricated using microporous Si templates. These innovative nested nanostructures have the potential to produce novel multifunctional vertically-ordered three-dimensional nanodevices in photovoltaic and sensing technologies.
