A new type water-cooled heat dissipater for multiple high-power thyristors in explosion-proof shell used in coal mine was designed, and then, the numerical computation of the three-dimensional steady-state temperature...A new type water-cooled heat dissipater for multiple high-power thyristors in explosion-proof shell used in coal mine was designed, and then, the numerical computation of the three-dimensional steady-state temperature distributions under different working conditions for cooling core was conducted in order to understand in detail the heat transfer performance. Based on the computation results, the temperature differences and the maximum heat transfer rates were given. These results of the study on the heat dissipater lay a basis for optimising its structure design and guiding its operation.展开更多
Transparent metal oxide nanowires (NWs) have attracted intense research interest in recent years. We report here the synthesis of interesting ladder-like metal oxide NWs, including In2O3, SnO2, ZnO, and Ga2O3, via a...Transparent metal oxide nanowires (NWs) have attracted intense research interest in recent years. We report here the synthesis of interesting ladder-like metal oxide NWs, including In2O3, SnO2, ZnO, and Ga2O3, via a facile chemical vapor deposition (CVD) method. Their structural features and growth mechanism are demonstrated in detail by using the ladder-like In2O3 NWs as an example. Single ladder-like NW-based field-effect transistors (FETs) and photodetectors (PDs) of SnO2 were fabricated in order to investigate their electrical transport and light absorption properties. Compared with straight NW-based FETs which operate in an enhancement mode (E-mode), FETs build on ladder-like NWs operate in a depletion mode (D-mode). The ladder-like NWs also give higher carrier concentrations than conventional single nanowires. Finite-difference time-domain (FDTD) simulations have been performed on the ladder-like NWs and the results reveal a great enhancement of light absorption with both transverse-electric (TE) and transverse-magnetic (TM) polarization modes, which is in good agreement with the experimental results.展开更多
Intrinsic carrier transport properties of single-walled carbon nanotubes have been probed by two parallel methods on the same individual tubes: The contactless dielectric force microscopy (DFM) technique and the co...Intrinsic carrier transport properties of single-walled carbon nanotubes have been probed by two parallel methods on the same individual tubes: The contactless dielectric force microscopy (DFM) technique and the conventional field-effect transistor (FET) method. The dielectric responses of SWNTs are strongly correlated with electronic transport of the corresponding FETs. The DC bias voltage in DFM plays a role analogous to the gate voltage in FET. A microscopic model based on the general continuity equation and numerical simulation is built to reveal the link between intrinsic properties such as carrier concentration and mobility and the macroscopic observable, i.e. dielectric responses, in DFM experiments. Local transport barriers in nanotubes, which influence the device transport behaviors, are also detected with nanometer scale resolution.展开更多
Clusters of water molecules have low ionization energies because of stabilization of charge from the dipole moment of surrounding molecules,and thus can form potential traps resulting in the undesirable photovoltaic p...Clusters of water molecules have low ionization energies because of stabilization of charge from the dipole moment of surrounding molecules,and thus can form potential traps resulting in the undesirable photovoltaic performance in organic solar cells(OSCs).Herein,we demonstrated a solvent-water evaporation(SWE)strategy,which can effectively remove the water-induced traps that are omnipresent in photoactive layers,leading to a significant improvement in device performance.A higher power conversion efficiency of 17.10%and a better device photostability are achieved by using this SWE method,as compared with the untreated binary PM6:Y6 system(15.83%).We highlight the water-related traps as a limiting factor for carrier transport and extraction properties,and further reveal the good universality of the SWE strategy applied into OSCs.In addition,organic light-emitting diodes and organic field-effect transistors are investigated to demonstrate the applicability of this SWE approach.This strategy presents a major step forward for advancing the field of organic electronics.展开更多
文摘A new type water-cooled heat dissipater for multiple high-power thyristors in explosion-proof shell used in coal mine was designed, and then, the numerical computation of the three-dimensional steady-state temperature distributions under different working conditions for cooling core was conducted in order to understand in detail the heat transfer performance. Based on the computation results, the temperature differences and the maximum heat transfer rates were given. These results of the study on the heat dissipater lay a basis for optimising its structure design and guiding its operation.
基金This work was supported by the National Natural Science Foundation of China (Nos. 61377033 and 91123008), the 973 Program of China (No. 2011CB933300), and the Program for New Century Excellent Talents of the University in China (Grant No. NCET-11-0179).
文摘Transparent metal oxide nanowires (NWs) have attracted intense research interest in recent years. We report here the synthesis of interesting ladder-like metal oxide NWs, including In2O3, SnO2, ZnO, and Ga2O3, via a facile chemical vapor deposition (CVD) method. Their structural features and growth mechanism are demonstrated in detail by using the ladder-like In2O3 NWs as an example. Single ladder-like NW-based field-effect transistors (FETs) and photodetectors (PDs) of SnO2 were fabricated in order to investigate their electrical transport and light absorption properties. Compared with straight NW-based FETs which operate in an enhancement mode (E-mode), FETs build on ladder-like NWs operate in a depletion mode (D-mode). The ladder-like NWs also give higher carrier concentrations than conventional single nanowires. Finite-difference time-domain (FDTD) simulations have been performed on the ladder-like NWs and the results reveal a great enhancement of light absorption with both transverse-electric (TE) and transverse-magnetic (TM) polarization modes, which is in good agreement with the experimental results.
文摘Intrinsic carrier transport properties of single-walled carbon nanotubes have been probed by two parallel methods on the same individual tubes: The contactless dielectric force microscopy (DFM) technique and the conventional field-effect transistor (FET) method. The dielectric responses of SWNTs are strongly correlated with electronic transport of the corresponding FETs. The DC bias voltage in DFM plays a role analogous to the gate voltage in FET. A microscopic model based on the general continuity equation and numerical simulation is built to reveal the link between intrinsic properties such as carrier concentration and mobility and the macroscopic observable, i.e. dielectric responses, in DFM experiments. Local transport barriers in nanotubes, which influence the device transport behaviors, are also detected with nanometer scale resolution.
基金the National Natural Science Foundation of China(NSFC)(51773157 and 52061135206)the Fundamental Research Funds for the Central UniversitiesThe authors also thank the support of the opening project of Key Laboratory of Materials Processing and Mold and Beijing National Laboratory for Molecular Sciences(BNLMS201905).
文摘Clusters of water molecules have low ionization energies because of stabilization of charge from the dipole moment of surrounding molecules,and thus can form potential traps resulting in the undesirable photovoltaic performance in organic solar cells(OSCs).Herein,we demonstrated a solvent-water evaporation(SWE)strategy,which can effectively remove the water-induced traps that are omnipresent in photoactive layers,leading to a significant improvement in device performance.A higher power conversion efficiency of 17.10%and a better device photostability are achieved by using this SWE method,as compared with the untreated binary PM6:Y6 system(15.83%).We highlight the water-related traps as a limiting factor for carrier transport and extraction properties,and further reveal the good universality of the SWE strategy applied into OSCs.In addition,organic light-emitting diodes and organic field-effect transistors are investigated to demonstrate the applicability of this SWE approach.This strategy presents a major step forward for advancing the field of organic electronics.