[Objective] This study aimed to investigate the submicroscopic structure and morphological characteristics of mulberry pollen. [Method] Mulberry pollen of seven cultivars were treated by glutaraldehyde fixing, alcohol...[Objective] This study aimed to investigate the submicroscopic structure and morphological characteristics of mulberry pollen. [Method] Mulberry pollen of seven cultivars were treated by glutaraldehyde fixing, alcohol gradient dehydration, freeze-drying and metal plating to observe the size and surface ornamentation under the scanning electron microscope （SEM）. [Result] The pollen surface characteristics and ornamentation were clearly visible, indicating that this method is suitable for SEM observation of mulberry pollen; experimental mulberry pollen was nearly spher- ical, with two germination apertures and processes on aperture membrane; polar axis was 15.99-22.63 μm long, and equatorial axis was 14.98-20.78 μm long; the pollen volume of ＂Yu No.2＇ was the maximum, while that of ＂Jinxuan No.7＇ was the minimum; the surface of mulberry pollen showed smooth and tumor-like protuberance ornamentations, covered with different densities of particles. [Conclusion] Glutaralde- hyde fixative-alcohol gradient dehydration is an ideal method for morphological char- acteristics of mulberry pollen. This study may provide useful information for palynology identification of Morus plants or even species-level systematic classification.展开更多
Ti-coated SiCp particles were developed by vacuum evaporation with Ti to improve the interfacial bonding of SiCp/Al composites.Ti-coated SiC particles and uncoated SiC particles reinforced Al 2519 matrix composites we...Ti-coated SiCp particles were developed by vacuum evaporation with Ti to improve the interfacial bonding of SiCp/Al composites.Ti-coated SiC particles and uncoated SiC particles reinforced Al 2519 matrix composites were prepared by hot pressing,hot extrusion and heat treatment.The influence of Ti coating on microstructure and mechanical properties of the composites was analyzed by scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).The results show that the densely deposited Ti coating reacts with SiC particles to form TiC and Ti5Si3 phases at the interface.Ti-coated SiC particle reinforced composite exhibits uniformity and compactness compared to the composite reinforced with uncoated SiC particles.The microstructure,relative density and mechanical properties of the composite are significantly improved.When the volume fraction is 15%,the hardness,fracture strain and tensile strength of the SiCp reinforced Al 2519 composite after Ti plating are optimized,which are HB 138.5,4.02%and 455 MPa,respectively.展开更多
基金Supported by National Science Foundation for Young Scholars of China(31000308)Outstanding Young Scientist Research Award Fund of Shandong Province(BS2010NY006)~~
文摘[Objective] This study aimed to investigate the submicroscopic structure and morphological characteristics of mulberry pollen. [Method] Mulberry pollen of seven cultivars were treated by glutaraldehyde fixing, alcohol gradient dehydration, freeze-drying and metal plating to observe the size and surface ornamentation under the scanning electron microscope （SEM）. [Result] The pollen surface characteristics and ornamentation were clearly visible, indicating that this method is suitable for SEM observation of mulberry pollen; experimental mulberry pollen was nearly spher- ical, with two germination apertures and processes on aperture membrane; polar axis was 15.99-22.63 μm long, and equatorial axis was 14.98-20.78 μm long; the pollen volume of ＂Yu No.2＇ was the maximum, while that of ＂Jinxuan No.7＇ was the minimum; the surface of mulberry pollen showed smooth and tumor-like protuberance ornamentations, covered with different densities of particles. [Conclusion] Glutaralde- hyde fixative-alcohol gradient dehydration is an ideal method for morphological char- acteristics of mulberry pollen. This study may provide useful information for palynology identification of Morus plants or even species-level systematic classification.
基金Project(CXZZ20140506150310438)supported by the Science and Technology Program of Shenzhen,ChinaProject(2017GK2261)supported by the Science and Technology Program of Hunan Province,ChinaProject(2017zzts111)supported by the Fundamental Research Funds for the Central Universities of Central South University,China。
文摘Ti-coated SiCp particles were developed by vacuum evaporation with Ti to improve the interfacial bonding of SiCp/Al composites.Ti-coated SiC particles and uncoated SiC particles reinforced Al 2519 matrix composites were prepared by hot pressing,hot extrusion and heat treatment.The influence of Ti coating on microstructure and mechanical properties of the composites was analyzed by scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).The results show that the densely deposited Ti coating reacts with SiC particles to form TiC and Ti5Si3 phases at the interface.Ti-coated SiC particle reinforced composite exhibits uniformity and compactness compared to the composite reinforced with uncoated SiC particles.The microstructure,relative density and mechanical properties of the composite are significantly improved.When the volume fraction is 15%,the hardness,fracture strain and tensile strength of the SiCp reinforced Al 2519 composite after Ti plating are optimized,which are HB 138.5,4.02%and 455 MPa,respectively.
