The growth mechanism of paramorphic SiC whisker (SiCw) and SiC particle (SiCp) produced from rice bulls under the catalytic actions is studied. The results indicate that the growtb mechanism of the SiCw is vapour-liqu...The growth mechanism of paramorphic SiC whisker (SiCw) and SiC particle (SiCp) produced from rice bulls under the catalytic actions is studied. The results indicate that the growtb mechanism of the SiCw is vapour-liquid-solid (VLS) , while the crystalline structure of the SiCw is β-SiC. Some SiCp will be formed during the production of the SiCw. Under the pilot-plant condition, the grade of SiCw is over 20%, and SiCp is over 50%. The micron-grade of SiCw and SiCp are separated successfully by flotation and other traditional mineral separation and purification technology. So the grade of the high purity SiCw is over 95 %.展开更多
Impact diamond is one of perspective natural type of superhard carbon materials,forming huge resources sometimes,such as Popigai impact structure counting the largest diamond storage on the Earth.By present,there are ...Impact diamond is one of perspective natural type of superhard carbon materials,forming huge resources sometimes,such as Popigai impact structure counting the largest diamond storage on the Earth.By present,there are two known types of impact diamonds-after-graphitic and after-coal varieties formed from different carbon precursors.Here we present for the first time a new impact diamond type-diamond fossils,named by "karite",formed about 70 Ma from unmetamorphosed organics in the giant Kara impact crater(Pay-Khoy,Russia).A full complex of the diamond fossil characteristics is described proving its nature and phase state.Karite is presented with supernanocrystalline diamond aggregates,nicely preserves tiny cell morphology and relict features of lignin and cellulose.The diamond fossils are spread widely through the Kara impactites,point to possible wider distribution of impact diamonds within large impact occurrences around the world,can be used for impact modeling,astrobiological and material studies.展开更多
Section Z of Meishan in Changxing of Zhejiang, known as the stratotype section of the Permain-Triassic boundary in South China, is also one of the candidate stratotype sections of the same boundary in the world. Here ...Section Z of Meishan in Changxing of Zhejiang, known as the stratotype section of the Permain-Triassic boundary in South China, is also one of the candidate stratotype sections of the same boundary in the world. Here the strata crossing the Permian-Triassic boundary are well exposed. The Upper Permian Changhsingian is展开更多
文摘The growth mechanism of paramorphic SiC whisker (SiCw) and SiC particle (SiCp) produced from rice bulls under the catalytic actions is studied. The results indicate that the growtb mechanism of the SiCw is vapour-liquid-solid (VLS) , while the crystalline structure of the SiCw is β-SiC. Some SiCp will be formed during the production of the SiCw. Under the pilot-plant condition, the grade of SiCw is over 20%, and SiCp is over 50%. The micron-grade of SiCw and SiCp are separated successfully by flotation and other traditional mineral separation and purification technology. So the grade of the high purity SiCw is over 95 %.
基金The work has been supported by the RFBR Project#17-0500516 for diamond fossils studiesthe frame of NIR#AAA-A17-117121270036-7the Russian Science Foundation Project#17-17-01080
文摘Impact diamond is one of perspective natural type of superhard carbon materials,forming huge resources sometimes,such as Popigai impact structure counting the largest diamond storage on the Earth.By present,there are two known types of impact diamonds-after-graphitic and after-coal varieties formed from different carbon precursors.Here we present for the first time a new impact diamond type-diamond fossils,named by "karite",formed about 70 Ma from unmetamorphosed organics in the giant Kara impact crater(Pay-Khoy,Russia).A full complex of the diamond fossil characteristics is described proving its nature and phase state.Karite is presented with supernanocrystalline diamond aggregates,nicely preserves tiny cell morphology and relict features of lignin and cellulose.The diamond fossils are spread widely through the Kara impactites,point to possible wider distribution of impact diamonds within large impact occurrences around the world,can be used for impact modeling,astrobiological and material studies.
基金Project partly supported by the National Natural Science Foundation of China.
文摘Section Z of Meishan in Changxing of Zhejiang, known as the stratotype section of the Permain-Triassic boundary in South China, is also one of the candidate stratotype sections of the same boundary in the world. Here the strata crossing the Permian-Triassic boundary are well exposed. The Upper Permian Changhsingian is
