船舶锚泊作业对海底管线的拖拽损害

针对渤海海域近年来频繁发生的由于抛锚导致海底管线损害故障,对锚和锚链拖拽力进行分析,选取实际船舶计算抛锚作业对海底管线的拖拽力,分析锚泊作业对海底管线的拖拽损害,可为船舶抛锚作业对海底管线损害的风险评估提供依据.     

The influence of electronic transport across interface junction between Si substrate and the root of ZnO micro-prism on field emission performance

ZnO micro-prisms are prepared on the p-type and n-type Si substrates, separately. The $I$--$V$ curves analysed by AFM show that the interface junctions between the ZnO micro-prisms and the p-type substrate and between the ZnO micro-prisms and the n-type Si substrate exhibit p--n junction behaviour and ohmic contact behaviour, respectively. The formation of the p--n heterojunction and ohmic contact is ascribed to the intrinsic n-type conduction of ZnO material. Better field emission performance (lower onset voltage and larger emission current) is observed from an individual ZnO micro-prism grown on the n-type Si substrate. It is suggested that the n-Si/n-ZnO interfacial ohmic contact benefits the electron emission; while the p-Si/n-ZnO interface heterojunction deteriorates the electron emission.