Besides carbon solubility, the carbide formation possibility is another important factor to differentiate various substrate materials in graphene growth. A recent experiment indicates that the formation of transition ...Besides carbon solubility, the carbide formation possibility is another important factor to differentiate various substrate materials in graphene growth. A recent experiment indicates that the formation of transition metal carbides （TMCs） can suppress carbon precipitation. In this study, Mo2C, a representative of TMCs, is used to study the effects of carbide formation in graphene growth from first principles. Carbon diffusion in Mo2C bulk turns out to be very difficult and it becomes much easier on the Mo2C（001） surface. Therefore, carbon precipitation suppression and graphene growth can be realized simultaneously. A direction depended diffusion behavior is observed on the Mo2C（101） surface, which makes it less favorable for graphene growth compared to the （001） surface.展开更多
Oplegnathusfasciatus （rock bream） is a commercial rocky reef fish species in East Asia that has been considered for aquaculture. We estimated the population genetic diversity and population structure of the species ...Oplegnathusfasciatus （rock bream） is a commercial rocky reef fish species in East Asia that has been considered for aquaculture. We estimated the population genetic diversity and population structure of the species along the coastal waters of China using fluorescent-amplifed fragment length polymorphisms technology. Using 53 individuals from three populations and four pairs of selective primers, we amplified 1 264 bands, 98.73% of which were polymorphic. The Zhoushan population showed the highest Nei＇s genetic diversity and Shannon genetic diversity. The results of analysis of molecular variance （AMOVA） showed that 59.55% of genetic variation existed among populations and 40.45% occurred within populations, which indicated that a significant population genetic structure existed in the species. The pairwise fixation index Fst ranged from 0.20 to 0.63 and were significant after sequential Bonferroni correction. The topology of an unweighted pair group method with arithmetic mean tree showed two significant genealogical branches corresponding to the sampling locations of North and South China. The AMOVA and STRUCTURE analyses suggested that the O.fasciatus populations examined should comprise two stocks.展开更多
文摘Besides carbon solubility, the carbide formation possibility is another important factor to differentiate various substrate materials in graphene growth. A recent experiment indicates that the formation of transition metal carbides （TMCs） can suppress carbon precipitation. In this study, Mo2C, a representative of TMCs, is used to study the effects of carbide formation in graphene growth from first principles. Carbon diffusion in Mo2C bulk turns out to be very difficult and it becomes much easier on the Mo2C（001） surface. Therefore, carbon precipitation suppression and graphene growth can be realized simultaneously. A direction depended diffusion behavior is observed on the Mo2C（101） surface, which makes it less favorable for graphene growth compared to the （001） surface.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A413-1)the STS(No.KFJ-EW-STS-060-STS)+5 种基金the Natural Science Foundation of Jiangsu Province(No.BK2012222)the Key Laboratory of East China Sea&Oceanic Fishery Resources Exploitation and Utilization,Ministry of Agriculture,China(No.K201204)the Promotive Research Fund for Excellent Young and Middle-Aged Scientists of Shandong Province(No.BS2012HZ025)the National Natural Science Foundation of China(No.41506170)the Technology Foundation for Selected Overseas Chinese ScholarMinistry of Personnel of China(No.2013.01)
文摘Oplegnathusfasciatus （rock bream） is a commercial rocky reef fish species in East Asia that has been considered for aquaculture. We estimated the population genetic diversity and population structure of the species along the coastal waters of China using fluorescent-amplifed fragment length polymorphisms technology. Using 53 individuals from three populations and four pairs of selective primers, we amplified 1 264 bands, 98.73% of which were polymorphic. The Zhoushan population showed the highest Nei＇s genetic diversity and Shannon genetic diversity. The results of analysis of molecular variance （AMOVA） showed that 59.55% of genetic variation existed among populations and 40.45% occurred within populations, which indicated that a significant population genetic structure existed in the species. The pairwise fixation index Fst ranged from 0.20 to 0.63 and were significant after sequential Bonferroni correction. The topology of an unweighted pair group method with arithmetic mean tree showed two significant genealogical branches corresponding to the sampling locations of North and South China. The AMOVA and STRUCTURE analyses suggested that the O.fasciatus populations examined should comprise two stocks.
