This paper proposed a discrete operation mode for a punchthrough（PT） phototransistor,which is suitable for low power application,since the bias current is only necessary during the read-out phase.Moreover,simulation...This paper proposed a discrete operation mode for a punchthrough（PT） phototransistor,which is suitable for low power application,since the bias current is only necessary during the read-out phase.Moreover,simulation results show that with the new operation mode,the photocurrent is much larger than that of continuous operation mode.An ultra-high responsivity of 2×10~7A/W at 10^（-9） W/cm^2 is obtained with a small detector size of 1μm^2.In CMOS image sensor applications,with an integration time of 10 ms,a normalized pixel responsivity of 220 V·m^2/W·s·μm^2 is obtained without any auxiliary amplifier.展开更多
An integrated dynamic model of China＇s deep ocean mining system is developed and the fast simulation analysis of its longitudinal reciprocating motion operation processes is achieved. The seafloor tracked miner is bu...An integrated dynamic model of China＇s deep ocean mining system is developed and the fast simulation analysis of its longitudinal reciprocating motion operation processes is achieved. The seafloor tracked miner is built as a three-dimensional single-body model with six-degree-of-freedom. The track-terrain interaction is modeled by partitioning the track-terrain interface into a certain number of mesh elements with three mutually perpendicular forces, including the normal force, the longitudinal shear force and the lateral shear force, acting on the center point of each mesh element. The hydrodynamic force of the miner is considered and applied. By considering the operational safety and collection efficiency, two new mining paths for the miner on the seafloor are proposed, which can be simulated with the established single-body dynamic model of the miner. The pipeline subsystem is built as a three-dimensional multi-body discrete element model, which is divided into rigid elements linked by flexible connectors. The flexible connector without mass is represented by six spring-damper elements. The external hydrodynamic forces of the ocean current from the longitudinal and lateral directions are both considered and modeled based on the Morison formula and applied to the mass center of each corresponding discrete rigid element. The mining ship is simplified and represented by a general kinematic point, whose heave motion induced by the ocean waves and the longitudinal and lateral towing motions are considered and applied. By integrating the single-body dynamic model of the miner and the multi-body discrete element dynamic model of the pipeline, and defining the kinematic equations of the mining ship, the integrated dynamic model of the total deep ocean mining system is formed. The longitudinal reciprocating motion operation modes of the total mining system, which combine the active straight-line and turning motions of the miner and the ship, and the passive towed motions of the pipeline, are proposed and simulated wi展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.61076046,61274023)the New Century Excellent Talents Support Program of the Ministry of Educationthe Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory(No.ZHD201204)
文摘This paper proposed a discrete operation mode for a punchthrough（PT） phototransistor,which is suitable for low power application,since the bias current is only necessary during the read-out phase.Moreover,simulation results show that with the new operation mode,the photocurrent is much larger than that of continuous operation mode.An ultra-high responsivity of 2×10~7A/W at 10^（-9） W/cm^2 is obtained with a small detector size of 1μm^2.In CMOS image sensor applications,with an integration time of 10 ms,a normalized pixel responsivity of 220 V·m^2/W·s·μm^2 is obtained without any auxiliary amplifier.
基金supported by the National Natural Science Foundation of China(Grant No.51105386)the National Deep-Sea Technology Project of Development and Research(Grant No.DYXM-115-04-02-01)the Fundamental Research Funds for the Central Universities(Grant No.2011QNZT058)
文摘An integrated dynamic model of China＇s deep ocean mining system is developed and the fast simulation analysis of its longitudinal reciprocating motion operation processes is achieved. The seafloor tracked miner is built as a three-dimensional single-body model with six-degree-of-freedom. The track-terrain interaction is modeled by partitioning the track-terrain interface into a certain number of mesh elements with three mutually perpendicular forces, including the normal force, the longitudinal shear force and the lateral shear force, acting on the center point of each mesh element. The hydrodynamic force of the miner is considered and applied. By considering the operational safety and collection efficiency, two new mining paths for the miner on the seafloor are proposed, which can be simulated with the established single-body dynamic model of the miner. The pipeline subsystem is built as a three-dimensional multi-body discrete element model, which is divided into rigid elements linked by flexible connectors. The flexible connector without mass is represented by six spring-damper elements. The external hydrodynamic forces of the ocean current from the longitudinal and lateral directions are both considered and modeled based on the Morison formula and applied to the mass center of each corresponding discrete rigid element. The mining ship is simplified and represented by a general kinematic point, whose heave motion induced by the ocean waves and the longitudinal and lateral towing motions are considered and applied. By integrating the single-body dynamic model of the miner and the multi-body discrete element dynamic model of the pipeline, and defining the kinematic equations of the mining ship, the integrated dynamic model of the total deep ocean mining system is formed. The longitudinal reciprocating motion operation modes of the total mining system, which combine the active straight-line and turning motions of the miner and the ship, and the passive towed motions of the pipeline, are proposed and simulated wi
