Growth and passivation of tunnels within Al foil by on-off controlling DC etching in 6 wt.% HCI solution has been investigated. It was found that, in a given etchant solution at a special temperature, the longest tunn...Growth and passivation of tunnels within Al foil by on-off controlling DC etching in 6 wt.% HCI solution has been investigated. It was found that, in a given etchant solution at a special temperature, the longest tunnel length was only a function of the turn-on interval of DC. The potential of Al foil broke at on-off controlling DC by the result from anode polarization curves and potential-time （E-t） responding curves. When DC was switched on, the potential increased abruptly over pitting potential, leading to nucleation of pits at the surface and the growth of tunnels at special length. When DC was switched off, the potential decreased rapidly to a passive value, leading to stoppage of nucleation and death of tunnels. By this way, the longest tunnel length can be controlled and a non-piercing layer can be obtained. Hence, etching of Al foil at this current is beneficial for maintaining a good mechanical strength.展开更多
The effects of trapped electrons on off-axis lower hybrid current drive （LHCD） in tokamaks are studied, A computer code for solving the Fokker-Planck equation in a toroidal geometry is developed and employed. The co...The effects of trapped electrons on off-axis lower hybrid current drive （LHCD） in tokamaks are studied, A computer code for solving the Fokker-Planck equation in a toroidal geometry is developed and employed. The code is suitable for various auxiliary heating and current drive schemes in tokamak plasmas. The influence of the resonance regime on the current drive efficiency as well as the influence of trapped particle fraction on the current drive efficiency are emphasized. It is shown that, as an electrostatic force, the lower hybrid wave causes some of the trapped electrons to be untrapped and lose their energy, which can cut the LHCD efficiency by about 30%. The ITER scaling law is also used to estimate the trapped electron effects.展开更多
In this paper, a novel junctionless field effect transistor（JLFET） is proposed. In the presence of a field plate between gate and drain, the gate-induced drain leakage（GIDL） effect is suppressed due to the decreas...In this paper, a novel junctionless field effect transistor（JLFET） is proposed. In the presence of a field plate between gate and drain, the gate-induced drain leakage（GIDL） effect is suppressed due to the decrease of lateral band-to-band tunneling probability. Thus, the off-state current Ioff, which is mainly provided by the GIDL current, is reduced. Sentaurus simulation shows that the Ioffof the new optimized JLFET is reduced by ～ 2 orders and its sub-threshold swing can reach76.8 mV/decade with little influence on its on-state current Ion, so its Ion/Ioff ratio is improved by 2 orders of magnitude compared with that of the normal JLFET. Optimization of device parameters such as Φfps（the work difference between field plate and substrate） and LFP（the length of field plate）, is also discussed in detail.展开更多
Domestic off-grid renewable energy systems have become common place in many areas of the world, as humanity seeks to keep abreast with global technological changes and advancements. This paper aims to present a cost-e...Domestic off-grid renewable energy systems have become common place in many areas of the world, as humanity seeks to keep abreast with global technological changes and advancements. This paper aims to present a cost-effective energy monitoring system which may be used to analyze and evaluate the operation of a domestic off-grid PV system. Parameters which are monitored include the output voltage and current from a 55 W polycrystalline PV panel. The output voltage and current from a power regulation circuit (which could be a DC-DC converter, solar charger or MPPT) is also monitored with this singular system which incorporates a data logging interface circuit, a data logger and a personal computer.展开更多
A novel fully-depleted dual-gate MOSFET with a hetero-material gate and a lightly-doped drain is proposed. The hetero-material gate, which consists of a main gate and two side-gates,is used to control the surface pote...A novel fully-depleted dual-gate MOSFET with a hetero-material gate and a lightly-doped drain is proposed. The hetero-material gate, which consists of a main gate and two side-gates,is used to control the surface potential distribution. The fabrication process and the device characteristics are simulated with Tsuprem-4 and Medici separately. Compared to a common DG fully depleted SO1 MOSFET,the proposed device has much higher on/off current ratio and superior sub-threshold slope. The on/off current ratio is about 10^10 and the sub-threshold slope is nearly 60mV/dec under a 0.18μm process.展开更多
基金This study was financially supported by Beijing Education Commission,China.
文摘Growth and passivation of tunnels within Al foil by on-off controlling DC etching in 6 wt.% HCI solution has been investigated. It was found that, in a given etchant solution at a special temperature, the longest tunnel length was only a function of the turn-on interval of DC. The potential of Al foil broke at on-off controlling DC by the result from anode polarization curves and potential-time （E-t） responding curves. When DC was switched on, the potential increased abruptly over pitting potential, leading to nucleation of pits at the surface and the growth of tunnels at special length. When DC was switched off, the potential decreased rapidly to a passive value, leading to stoppage of nucleation and death of tunnels. By this way, the longest tunnel length can be controlled and a non-piercing layer can be obtained. Hence, etching of Al foil at this current is beneficial for maintaining a good mechanical strength.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10675043, 10575031 and 10675042）.
文摘The effects of trapped electrons on off-axis lower hybrid current drive （LHCD） in tokamaks are studied, A computer code for solving the Fokker-Planck equation in a toroidal geometry is developed and employed. The code is suitable for various auxiliary heating and current drive schemes in tokamak plasmas. The influence of the resonance regime on the current drive efficiency as well as the influence of trapped particle fraction on the current drive efficiency are emphasized. It is shown that, as an electrostatic force, the lower hybrid wave causes some of the trapped electrons to be untrapped and lose their energy, which can cut the LHCD efficiency by about 30%. The ITER scaling law is also used to estimate the trapped electron effects.
基金supported by the National Natural Science Foundation of China(Grant No.61704130)the Fundamental Research Funds for the Central Universities,China(Grant No.20101166085)the Opening Project of Key Laboratory of Microelectronic Devices&Integrated Technology from Institute of Microelectronics,Chinese Academy of Sciences(Grant No.90109162905)
文摘In this paper, a novel junctionless field effect transistor（JLFET） is proposed. In the presence of a field plate between gate and drain, the gate-induced drain leakage（GIDL） effect is suppressed due to the decrease of lateral band-to-band tunneling probability. Thus, the off-state current Ioff, which is mainly provided by the GIDL current, is reduced. Sentaurus simulation shows that the Ioffof the new optimized JLFET is reduced by ～ 2 orders and its sub-threshold swing can reach76.8 mV/decade with little influence on its on-state current Ion, so its Ion/Ioff ratio is improved by 2 orders of magnitude compared with that of the normal JLFET. Optimization of device parameters such as Φfps（the work difference between field plate and substrate） and LFP（the length of field plate）, is also discussed in detail.
文摘Domestic off-grid renewable energy systems have become common place in many areas of the world, as humanity seeks to keep abreast with global technological changes and advancements. This paper aims to present a cost-effective energy monitoring system which may be used to analyze and evaluate the operation of a domestic off-grid PV system. Parameters which are monitored include the output voltage and current from a 55 W polycrystalline PV panel. The output voltage and current from a power regulation circuit (which could be a DC-DC converter, solar charger or MPPT) is also monitored with this singular system which incorporates a data logging interface circuit, a data logger and a personal computer.
文摘A novel fully-depleted dual-gate MOSFET with a hetero-material gate and a lightly-doped drain is proposed. The hetero-material gate, which consists of a main gate and two side-gates,is used to control the surface potential distribution. The fabrication process and the device characteristics are simulated with Tsuprem-4 and Medici separately. Compared to a common DG fully depleted SO1 MOSFET,the proposed device has much higher on/off current ratio and superior sub-threshold slope. The on/off current ratio is about 10^10 and the sub-threshold slope is nearly 60mV/dec under a 0.18μm process.
