For an electron microscopic study of the liver,expertise and complicated,time-consuming processing of hepatic tissues and cells is needed.The interpretation of electron microscopy(EM) images requires knowledge of the ...For an electron microscopic study of the liver,expertise and complicated,time-consuming processing of hepatic tissues and cells is needed.The interpretation of electron microscopy(EM) images requires knowledge of the liver fine structure and experience with the numerous artifacts in fixation,embedding,sectioning,contrast staining and microscopic imaging.Hence,the aim of this paper is to present a detailed summary of different methods for the preparation of hepatic cells and tissue,for the purpose of preserving long-standing expertise and to encourage new investigators and clinicians to include EM studies of liver cells and tissue in their projects.展开更多
We successfully grow high-quality wurtzite InAs nanowires on GaAs substrates. The influences of growth tem- perature and orientations of GaAs substrates on the morphology and microstructure of InAs nanowires are also ...We successfully grow high-quality wurtzite InAs nanowires on GaAs substrates. The influences of growth tem- perature and orientations of GaAs substrates on the morphology and microstructure of InAs nanowires are also investigated. We find that a low growth temperature （330℃） is beneficial to the synthesis of uniform defect-free InAs nanowires. Meanwhile, InAs nanowires along （ 111〉 B direction are always dominated despite the variation of GaAs substrate orientations.展开更多
The use of selective laser melting(SLM)to produce titanium matrix composites(TMCs)with high strength while retaining sufficient tensile ductility suitable for structural applications is emerging as an attractive oppor...The use of selective laser melting(SLM)to produce titanium matrix composites(TMCs)with high strength while retaining sufficient tensile ductility suitable for structural applications is emerging as an attractive opportunity in the field of advanced manufacturing.However,the presence of coarse ceramic reinforcements as well as difficulties in optimizing the SLM process is a barrier to the application of TMCs.In this study,we demonstrated the production of TMCs reinforced with in situ high aspect ratio Ti B nanowhiskers by selective laser melting using nanosized BN powder additions.Pure Ti with 2.5 vol.%nanosized BN powder showed promise for producing high performance TMCs with retained ductility.BN acted to produce Ti B nanowhiskers with diameter<50 nm.Further,by controlling post process furnace annealing Ti B retained a low diameter but exhibited a high aspect ratio,up to 400.In addition to Ti B refinement,nanosized BN addition promoted grain refinement during SLM,both acting as a solute to induce nucleation events and,as Ti B is formed,providing nucleation sites leading to an ultrafine grain structure in as printed samples and after annealing.The produced TMCs exhibit high tensile yield strength,up to1392 MPa,while retaining tensile ductility up to 10%.This study has shown how nanoscale design in powder bed fusion additive manufacturing techniques can be used to produce high performance TMCs through a combination of refined grain structure and high aspect ratio Ti B leading to TMCs with significant improvement in strength,isotropic properties and retained tensile ductility.展开更多
We have grown transition metal （Fe, Mn） doped GaN thin films on c-oriented sapphire by metal-organic chemical vapor deposition. By varying the flow of the metal precursor, a series of samples with different ion con-...We have grown transition metal （Fe, Mn） doped GaN thin films on c-oriented sapphire by metal-organic chemical vapor deposition. By varying the flow of the metal precursor, a series of samples with different ion con- centrations are synthesized. Microstructural properties are characterized by using a high-resolution transmission electron microscope. For Fe over-doped GaN samples, hexagonal Fe3N clusters are observed with Fe3N （0002） parallel to GaN （0002） while for Mn over-doped GaN, hexagonal Mn6N2.58 phases are observed with Mn6N2.58（0002） parallel to GaN （0002）. In addition, with higher concentration ions doping into the lattice matrix, the partial lattice orientation is distorted, leading to the tilt orGaN （0002） planes. The magnetization of the Fe over-doped GaN sam- ple is increased, which is ascribed to the participation of ferromagnetic iron and Fe3N. The Mn over-doped sample displays very weak ferromagnetic behavior, which probably originates from the Mn6N2.58.展开更多
文摘For an electron microscopic study of the liver,expertise and complicated,time-consuming processing of hepatic tissues and cells is needed.The interpretation of electron microscopy(EM) images requires knowledge of the liver fine structure and experience with the numerous artifacts in fixation,embedding,sectioning,contrast staining and microscopic imaging.Hence,the aim of this paper is to present a detailed summary of different methods for the preparation of hepatic cells and tissue,for the purpose of preserving long-standing expertise and to encourage new investigators and clinicians to include EM studies of liver cells and tissue in their projects.
基金Supported by the National Natural Science Foundation of China under Grant Nos 091021015 and 61376015, the Key Basic Research Programs of Shanghai under Grant No 13JC1405900, and the Australian Research Council.
文摘We successfully grow high-quality wurtzite InAs nanowires on GaAs substrates. The influences of growth tem- perature and orientations of GaAs substrates on the morphology and microstructure of InAs nanowires are also investigated. We find that a low growth temperature （330℃） is beneficial to the synthesis of uniform defect-free InAs nanowires. Meanwhile, InAs nanowires along （ 111〉 B direction are always dominated despite the variation of GaAs substrate orientations.
基金support of the School of Mechanical and Mining Engineering and the Queensland Center for Advanced Materials Processing and Manufacturing through the ARCresearch hub IH150100024。
文摘The use of selective laser melting(SLM)to produce titanium matrix composites(TMCs)with high strength while retaining sufficient tensile ductility suitable for structural applications is emerging as an attractive opportunity in the field of advanced manufacturing.However,the presence of coarse ceramic reinforcements as well as difficulties in optimizing the SLM process is a barrier to the application of TMCs.In this study,we demonstrated the production of TMCs reinforced with in situ high aspect ratio Ti B nanowhiskers by selective laser melting using nanosized BN powder additions.Pure Ti with 2.5 vol.%nanosized BN powder showed promise for producing high performance TMCs with retained ductility.BN acted to produce Ti B nanowhiskers with diameter<50 nm.Further,by controlling post process furnace annealing Ti B retained a low diameter but exhibited a high aspect ratio,up to 400.In addition to Ti B refinement,nanosized BN addition promoted grain refinement during SLM,both acting as a solute to induce nucleation events and,as Ti B is formed,providing nucleation sites leading to an ultrafine grain structure in as printed samples and after annealing.The produced TMCs exhibit high tensile yield strength,up to1392 MPa,while retaining tensile ductility up to 10%.This study has shown how nanoscale design in powder bed fusion additive manufacturing techniques can be used to produce high performance TMCs through a combination of refined grain structure and high aspect ratio Ti B leading to TMCs with significant improvement in strength,isotropic properties and retained tensile ductility.
基金supported by the Special Funds for Major State Basic Research Project,China(No.2011CB301900)the Hi-Tech Research Project,China(No.2009AA03A198)+2 种基金the National Natural Science Foundation of China(Nos.60990311,60820106003,608201060,60906025,60936004,61106009)the Natural Science Foundation of Jiangsu Province,China(Nos.BK2008019,K2009255,BK2010178, BK2010385)the Research Funds from NJU-Yangzhou Institute of Opto-Electronics
文摘We have grown transition metal （Fe, Mn） doped GaN thin films on c-oriented sapphire by metal-organic chemical vapor deposition. By varying the flow of the metal precursor, a series of samples with different ion con- centrations are synthesized. Microstructural properties are characterized by using a high-resolution transmission electron microscope. For Fe over-doped GaN samples, hexagonal Fe3N clusters are observed with Fe3N （0002） parallel to GaN （0002） while for Mn over-doped GaN, hexagonal Mn6N2.58 phases are observed with Mn6N2.58（0002） parallel to GaN （0002）. In addition, with higher concentration ions doping into the lattice matrix, the partial lattice orientation is distorted, leading to the tilt orGaN （0002） planes. The magnetization of the Fe over-doped GaN sam- ple is increased, which is ascribed to the participation of ferromagnetic iron and Fe3N. The Mn over-doped sample displays very weak ferromagnetic behavior, which probably originates from the Mn6N2.58.
