Total ionizing dose responses of different transistor geometries after being irradiated by ^（60）Co γ-rays, in 0.13-μm partially-depleted silicon-on-insulator（PD SOI） technology are investigated. The negative thr...Total ionizing dose responses of different transistor geometries after being irradiated by ^（60）Co γ-rays, in 0.13-μm partially-depleted silicon-on-insulator（PD SOI） technology are investigated. The negative threshold voltage shift in an n-type metal-oxide semiconductor field effect transistor（nMOSFET） is inversely proportional to the channel width due to radiation-induced charges trapped in trench oxide, which is called the radiation-induced narrow channel effect（RINCE）.The analysis based on a charge sharing model and three-dimensional technology computer aided design（TCAD） simulations demonstrate that phenomenon. The radiation-induced leakage currents under different drain biases are also discussed in detail.展开更多
GeSi source/drain structure is purposefully adopted in SOI p MOSFET's to suppress the short channel effect (SCE).The impact of GeSi material (as source only,drain only or both source and drain) on the threshold v...GeSi source/drain structure is purposefully adopted in SOI p MOSFET's to suppress the short channel effect (SCE).The impact of GeSi material (as source only,drain only or both source and drain) on the threshold voltage rolling off and DIBL effect is thoroughly investigated,as well as the influence of the Ge concentration and silicon film thickness.The Ge concentration should be carefully chosen as a tradeoff between the driving current and SCE improvement.The detailed physics is explained.展开更多
The modified powdery mixture of ammonium nitrate and fuel oil （MPANFO） is a new breed of industrial explosives developed years ago in China. As one of the important properties of an industrial explosive, the channel...The modified powdery mixture of ammonium nitrate and fuel oil （MPANFO） is a new breed of industrial explosives developed years ago in China. As one of the important properties of an industrial explosive, the channel effect of MPANFO was reported in this paper. A series of experiments were conducted to determine the channel effect of MPANFO. The blasthole diameter range was estimated to avoid the channel effect of MPANFO. Three empirical formulae for predicting the detonation length of MPANFO were provided in terms of the channel effect. Experiments and theoretical analysis indicate that the channel effect of MPANFO is very serious. The reason why the channel effect of MPANFO is worse than that of other industrial explosives is explained at a theoretical level. In addition, some properties of MPANFO, such as sympathetic distance, detonation velocity and brisance, are determined.展开更多
The bias dependence of radiation-induced narrow-width channel effects(RINCEs)in 65-nm n-type metal-oxidesemiconductor field-effect transistors(NMOSFETs)is investigated.The threshold voltage of the narrow-width65 nm NM...The bias dependence of radiation-induced narrow-width channel effects(RINCEs)in 65-nm n-type metal-oxidesemiconductor field-effect transistors(NMOSFETs)is investigated.The threshold voltage of the narrow-width65 nm NMOSFET is negatively shifted by total ionizing dose irradiation,due to the RINCE.The experimental results show that the 65 nm narrow-channel NMOSFET has a larger threshold shift when the gate terminal is kept in the ground,which is contrary to the conclusion obtained in the old generation devices.Depending on the three-dimensional simulation,we conclude that electric field distribution alteration caused by shallow trench isolation scaling is responsible for the anomalous RINCE bias dependence in 65 nm technology.展开更多
This paper aims to simulate the I–V static characteristic of the enhancement-mode（E-mode） Npolar GaN metal–insulator–semiconductor field effect transistor（MISFET） with self-aligned source/drain regions.Firstly,...This paper aims to simulate the I–V static characteristic of the enhancement-mode（E-mode） Npolar GaN metal–insulator–semiconductor field effect transistor（MISFET） with self-aligned source/drain regions.Firstly, with SILVACO TCAD device simulation, the drain–source current as a function of the gate–source voltage is calculated and the dependence of the drain–source current on the drain–source voltage in the case of different gate–source voltages for the device with a 0.62 m gate length is investigated. Secondly, a comparison is made with the experimental report. Lastly, the transfer characteristic with different gate lengths and different buffer layers has been performed. The results show that the simulation is in accord with the experiment at the gate length of 0.62 m and the short channel effect becomes pronounced as gate length decreases. The E-mode will not be held below a100 nm gate length unless both transversal scaling and vertical scaling are being carried out simultaneously.展开更多
Besides the common short-channel effect(SCE)of threshold voltage(V_(th))roll-off during the channel length(L)downscaling of In GaZnO(IGZO)thin-film transistors(TFTs),an opposite V_(th)roll-up was reported in this work...Besides the common short-channel effect(SCE)of threshold voltage(V_(th))roll-off during the channel length(L)downscaling of In GaZnO(IGZO)thin-film transistors(TFTs),an opposite V_(th)roll-up was reported in this work.Both roll-off and roll-up effects of Vth were comparatively investigated on IGZO transistors with varied gate insulator(GI),source/drain(S/D),and device architecture.For IGZO transistors with thinner GI,the SCE was attenuated due to the enhanced gate controllability over the variation of channel carrier concentration,while the Vth roll-up became more noteworthy.The latter was found to depend on the relative ratio of S/D series resistance(R_(SD))over channel resistance(R_(CH)),as verified on transistors with different S/D.Thus,an ideal S/D engineering with small R_(SD)but weak dopant diffusion is highly expected during the downscaling of L and GI in IGZO transistors.展开更多
In this paper,a microscopic phase-field model was used to investigate the effect of the oriented diffusion channel and the phases' effect mechanism for the Ni75Al6.0V19.0 alloy during a phase transformation proces...In this paper,a microscopic phase-field model was used to investigate the effect of the oriented diffusion channel and the phases' effect mechanism for the Ni75Al6.0V19.0 alloy during a phase transformation process.A diffusion channel of V was formed in the [100] direction.The oriented growth of DO22 in this direction,when an elastic misfit stress field existed,forced Al to form a diffusion channel next to DO22,resulting in L12-oriented growth.With an increase in stress,the oriented growth increased initially and then decreased.At a higher stress,the average values of the occupation probability for V atoms became constant later while Al atoms earlier.展开更多
We systematically examined the mass spectra and their two-body hadronic decays of the beauty-charm meson family considering coupled channel effects.Our results can effectively explain the observed Bemeson spectrum,and...We systematically examined the mass spectra and their two-body hadronic decays of the beauty-charm meson family considering coupled channel effects.Our results can effectively explain the observed Bemeson spectrum,and the prediction of the mass spectrum for unobserved beauty-charm mesons can be tested in future experiments.Compared with previous studies,we systematically examine the beauty-charm meson family within the coupled channel components.The 1S state in beauty-charm meson family has few percent of coupled channel component,while the 2S,1P,and 1D states have more than ten percent of coupled channel component.The two-body hadronic decay widths of the 2^(3)P_(2) state is as narrow as 3 MeV.The two-body hadronic decay widths of 3^(1)S_(0),3^(3)S_(1),2^(3)D_(1),2D,2D',and 2^(3)D_(3) are approximately 109,67,60,57,201,and 76 MeV,respectively.Furthermore,the mixing effects between B_(c)(n^(3)L_(L))and B_(c)(n^(1)L_(L))states are discussed.展开更多
Side channel effects such as temporal disparity and intensity fluctuation of the photon pulses caused by random bit generation with multiple laser diodes in high-speed polarization-based BB84 quantum key distribution(...Side channel effects such as temporal disparity and intensity fluctuation of the photon pulses caused by random bit generation with multiple laser diodes in high-speed polarization-based BB84 quantum key distribution(QKD) systems can be eliminated by increasing the DC bias current condition. However, background photons caused by the spontaneous emission process under high DC bias current degrade the performance of QKD systems. In this study, we investigated the effects of spontaneously emitted photons on the system performance in a high-speed QKD system at a clock rate of 400 MHz. Also, we show further improvements in the system performance without side channel effects by utilizing the temporal filtering technique with real-time fieldprogrammable gate array signal processing.展开更多
Deep submicron partially depleted silicon on insulator （PDSOI） nMOSFETs were fabricated based on the 0.35μm SOI process developed by the Institute of Microelectronics of the Chinese Academy of Sciences （IMECAS）. ...Deep submicron partially depleted silicon on insulator （PDSOI） nMOSFETs were fabricated based on the 0.35μm SOI process developed by the Institute of Microelectronics of the Chinese Academy of Sciences （IMECAS）. Mechanisms determining short-channel effects （SCE） in PDSOI nMOSFETs are clarified based on experimental results of threshold voltage dependence upon gate length. The effects of body bias, drain bias, temperature and body contact on the SCE have been investigated. The SCE in SOI devices is found to be dependent on body bias, drain bias and body contact. Floating body devices show a more severe reverse short channel effect （RSCE） than devices with body contact structure. Devices with low body bias and high drain bias show a more obvious SCE.展开更多
As the Reynolds number increases, the skin friction has been identified as the dominant drag in many practical applications. In the present paper, the effects of the Reynolds number on the mean skin friction decomposi...As the Reynolds number increases, the skin friction has been identified as the dominant drag in many practical applications. In the present paper, the effects of the Reynolds number on the mean skin friction decomposition in turbulent channel flows up to Reτ= 5 200 are investigated based on two different methods, i.e., the FukagataIwamoto-Kasagi(FIK) identity(FUKAGATA, K., IWAMOTO, K., and KASAGI, N.Contribution of Reynolds stress distribution to the skin friction in wall-bounded flows.Physics of Fluids, 14(11), L73–L76(2002)) and the Renard-Deck(RD) identity(DECK,S., RENARD, N., LARAUFIE, R., and WEISS, P.′E. Large-scale contribution to mean wall shear stress in high-Reynolds-number flat-plate boundary layers up to Reθ= 13 650.Journal of Fluid Mechanics, 743, 202–248(2014)). The direct numerical simulation(DNS) data provided by Lee and Moser(LEE, M. and MOSER, R. D. Direct numerical simulation of turbulent channel flow up to Reτ≈ 5 200. Journal of Fluid Mechanics,774, 395–415(2015)) are used. For these two skin friction decomposition methods, their decomposed constituents are discussed and compared for different Reynolds numbers.The integrands of the decomposed constituents are locally analyzed across the boundary layer to assess the actions associated with the inhomogeneity and multi-scale nature of turbulent motion. The scaling of the decomposed constituents and their integrands are presented. In addition, the boundary layer is divided into three sub-regions to evaluate the contributive proportion of each sub-region with an increase in the Reynolds number.展开更多
The channeling phenomenon of carbon ions in single-wall carbon nanotubes (SWCNTs) is investigated by using the molecular dynamics simulation with analytical potentials.The relationship between the channeling critical ...The channeling phenomenon of carbon ions in single-wall carbon nanotubes (SWCNTs) is investigated by using the molecular dynamics simulation with analytical potentials.The relationship between the channeling critical angles in the SWCNT and the bonding interaction is analyzed.It was found that,at 200-5000 eV and 10°-20° of incident angle,the ions with the bonding interaction or chemical effect,have decreased dechanneling probabilities and increased critical angles,compared to that of non-bonding ions.So the bonding effect cannot be ignored in the channeling mechanism of carbon ions through a SWCNT.展开更多
The dynamics of entanglement between two qubits in the local damping two-sided channel and singlesided channel are compared through non-Markovian process and Markovian process. The entanglement between two qubits is f...The dynamics of entanglement between two qubits in the local damping two-sided channel and singlesided channel are compared through non-Markovian process and Markovian process. The entanglement between two qubits is found to be longer in the single-sided channel case due to the weakening of the dissipative effects. In the two-sided channel, influenced by the entanglement between qubits, the previous independent dissipative channels incline to the composite effect of the Markovian process. This composite effect results in the dissipative effect of one channel affecting the qubits in the other channel, especially inhibiting the backflow effect in the non-Markovian channel, which is disadvantageous to the entanglement maintenance between qubits. In the Markovian channel, the composite effect of the damping two-sided channels is more obvious since there is no backflow effect, thus more disadvantageous to the entanglement maintenance.展开更多
This paper presents two n-channel organic heterojunction transistors with modified insulator by using hexadecafiuorophthalocyaninatocopper （F16CuPc）/copper phthalocyanine （CuPc） and F16CuPc/pentacene as the active...This paper presents two n-channel organic heterojunction transistors with modified insulator by using hexadecafiuorophthalocyaninatocopper （F16CuPc）/copper phthalocyanine （CuPc） and F16CuPc/pentacene as the active layers. Compared with a single-layer device, it reports that an improved field-effect mobility and a 6-fold higher drain current are observed. The highest mobility of 0.081 cm^2/（V. s） was obtained from F16CuPc/CuPc heterojunction devices. This result is attributed to the dual effects of the organic heterojunction and interface modification. Furthermore, for two heterojunction devices, the performance of the F16CuPc/CuPc-based transistor is better than that of F16CuPc/pentacene. This is attributed to the morphologic match of two organic components.展开更多
This article describes the effective channel length degradation under hot carrier stressing. The extraction is based on the IDs-Vcs characteristics by maximum transconductance （maximum slope of IDs ＆ VGS） in the li...This article describes the effective channel length degradation under hot carrier stressing. The extraction is based on the IDs-Vcs characteristics by maximum transconductance （maximum slope of IDs ＆ VGS） in the linear region. The transconductance characteristics are determine for the several devices of difference drawn channel length. The effective channel length of submicron LDD （Lightly Doped Drain） NMOSFETs （Metal Oxide Semiconductor Field Effect Transistor） under hot carrier stressing was measured at the stress time varying from zero to 10,000 seconds. It is shown that the effective channel length was increased with time. This is caused by charges trapping in the oxide during stress. The increased of effective channel length （△Leff） is seem to be increased sharply as the gate channel length is decrease.展开更多
In restricted channel, the hydrodynamic performance of propeller is affected by the wall. In the present work, two cylindrical channels with different diameters being 1.8D and 5.0D are adopted to study the influence o...In restricted channel, the hydrodynamic performance of propeller is affected by the wall. In the present work, two cylindrical channels with different diameters being 1.8D and 5.0D are adopted to study the influence of wall on the hydrodynamic performance and wake field of the propeller model DTMB4119. The numerical simulations are carried out by the single-phase solver pimpleDyMFoam in open source platform OpenFOAM. The Reynolds Averaged Navier-Stokes equations (RANS) are adopted to solve the flow field. The arbitrary mesh interface (AMI) method is used to simulate the rotation of propeller. The designed advance ratio, J = 0.833, is applied in all the computations. For the 5.0 D case, the predicted results of open water performance are in good agreement with experiment data. In restricted channel, the predicted results of thrust and torque coefficients are larger than the open water case. The pressure on the wall of restricted channel downstream increases and approaches the results in open water gradually. Due to the flux conservation, higher negative induced velocity is investigated in the flow field of the propeller in restricted channel.展开更多
This article investigates an unbiased analysis for the unsteady two-dimensional laminar flow of an incompressible, electrically and thermally conducting fluid across the space separated by two infinite rotating permea...This article investigates an unbiased analysis for the unsteady two-dimensional laminar flow of an incompressible, electrically and thermally conducting fluid across the space separated by two infinite rotating permeable walls.The influence of entropy generation, Hall and slip effects are considered within the flow analysis. The problem is modeled based on valid physical arguments and the unsteady system of dimensionless PDEs (partial differential equations) are solved with the help of Finite Difference Scheme. In the presence of pertinent parameters, the precise movement of the flow in terms of velocity, temperature, entropy generation rate, and Bejan numbers are presented graphically, which are parabolic in nature. Streamline profiles are also presented, which exemplify the accurate movement of the flow. The current study is one of the infrequent contributions to the existing literature as previous studies have not attempted to solve the system of high order non-linear PDEs for the unsteady flow with entropy generation and Hall effects in a permeable rotating channel. It is expected that the current analysis would provide a platform for solving the system of nonlinear PDEs of the other unexplored models that are associated to the two-dimensional unsteady flow in a rotating channel.展开更多
基金Project supported by the Weapon Equipment Pre-Research Foundation of China(Grant No.9140A11020114ZK34147)the Shanghai Municipal Natural Science Foundation,China(Grant No.15ZR1447100)
文摘Total ionizing dose responses of different transistor geometries after being irradiated by ^（60）Co γ-rays, in 0.13-μm partially-depleted silicon-on-insulator（PD SOI） technology are investigated. The negative threshold voltage shift in an n-type metal-oxide semiconductor field effect transistor（nMOSFET） is inversely proportional to the channel width due to radiation-induced charges trapped in trench oxide, which is called the radiation-induced narrow channel effect（RINCE）.The analysis based on a charge sharing model and three-dimensional technology computer aided design（TCAD） simulations demonstrate that phenomenon. The radiation-induced leakage currents under different drain biases are also discussed in detail.
文摘GeSi source/drain structure is purposefully adopted in SOI p MOSFET's to suppress the short channel effect (SCE).The impact of GeSi material (as source only,drain only or both source and drain) on the threshold voltage rolling off and DIBL effect is thoroughly investigated,as well as the influence of the Ge concentration and silicon film thickness.The Ge concentration should be carefully chosen as a tradeoff between the driving current and SCE improvement.The detailed physics is explained.
基金supported by the National Natural Science Foundation of China (No.50704005)
文摘The modified powdery mixture of ammonium nitrate and fuel oil （MPANFO） is a new breed of industrial explosives developed years ago in China. As one of the important properties of an industrial explosive, the channel effect of MPANFO was reported in this paper. A series of experiments were conducted to determine the channel effect of MPANFO. The blasthole diameter range was estimated to avoid the channel effect of MPANFO. Three empirical formulae for predicting the detonation length of MPANFO were provided in terms of the channel effect. Experiments and theoretical analysis indicate that the channel effect of MPANFO is very serious. The reason why the channel effect of MPANFO is worse than that of other industrial explosives is explained at a theoretical level. In addition, some properties of MPANFO, such as sympathetic distance, detonation velocity and brisance, are determined.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11605282,11505282 and U1532261the West Light Foundation of the Chinese Academy of Sciences under Grant No 2015-XBQN-B-15
文摘The bias dependence of radiation-induced narrow-width channel effects(RINCEs)in 65-nm n-type metal-oxidesemiconductor field-effect transistors(NMOSFETs)is investigated.The threshold voltage of the narrow-width65 nm NMOSFET is negatively shifted by total ionizing dose irradiation,due to the RINCE.The experimental results show that the 65 nm narrow-channel NMOSFET has a larger threshold shift when the gate terminal is kept in the ground,which is contrary to the conclusion obtained in the old generation devices.Depending on the three-dimensional simulation,we conclude that electric field distribution alteration caused by shallow trench isolation scaling is responsible for the anomalous RINCE bias dependence in 65 nm technology.
基金supported by the Young Fund of the National Natural Science Foundation of China(No.11104226)the Ph D Start-Up Fund(No.11zx7132)
文摘This paper aims to simulate the I–V static characteristic of the enhancement-mode（E-mode） Npolar GaN metal–insulator–semiconductor field effect transistor（MISFET） with self-aligned source/drain regions.Firstly, with SILVACO TCAD device simulation, the drain–source current as a function of the gate–source voltage is calculated and the dependence of the drain–source current on the drain–source voltage in the case of different gate–source voltages for the device with a 0.62 m gate length is investigated. Secondly, a comparison is made with the experimental report. Lastly, the transfer characteristic with different gate lengths and different buffer layers has been performed. The results show that the simulation is in accord with the experiment at the gate length of 0.62 m and the short channel effect becomes pronounced as gate length decreases. The E-mode will not be held below a100 nm gate length unless both transversal scaling and vertical scaling are being carried out simultaneously.
基金supported financially by National key Research and Development Program under Grant 2021YFB3600802Shenzhen Municipal Scientific Program under Grant KJZD20230923114111021。
文摘Besides the common short-channel effect(SCE)of threshold voltage(V_(th))roll-off during the channel length(L)downscaling of In GaZnO(IGZO)thin-film transistors(TFTs),an opposite V_(th)roll-up was reported in this work.Both roll-off and roll-up effects of Vth were comparatively investigated on IGZO transistors with varied gate insulator(GI),source/drain(S/D),and device architecture.For IGZO transistors with thinner GI,the SCE was attenuated due to the enhanced gate controllability over the variation of channel carrier concentration,while the Vth roll-up became more noteworthy.The latter was found to depend on the relative ratio of S/D series resistance(R_(SD))over channel resistance(R_(CH)),as verified on transistors with different S/D.Thus,an ideal S/D engineering with small R_(SD)but weak dopant diffusion is highly expected during the downscaling of L and GI in IGZO transistors.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51075335, 10902086, 50875217)the NPU Foundation for Fundamental Research (Grant No. JC201005)the Doctorate Foundation of Northwestern Polytechnical University (Grant No.CX201007)
文摘In this paper,a microscopic phase-field model was used to investigate the effect of the oriented diffusion channel and the phases' effect mechanism for the Ni75Al6.0V19.0 alloy during a phase transformation process.A diffusion channel of V was formed in the [100] direction.The oriented growth of DO22 in this direction,when an elastic misfit stress field existed,forced Al to form a diffusion channel next to DO22,resulting in L12-oriented growth.With an increase in stress,the oriented growth increased initially and then decreased.At a higher stress,the average values of the occupation probability for V atoms became constant later while Al atoms earlier.
基金Supported by the National Natural Science Foundation of China(12322503,12047503,12075124)the Natural Science Foundation of Jiangsu Province,China(BK20211267)。
文摘We systematically examined the mass spectra and their two-body hadronic decays of the beauty-charm meson family considering coupled channel effects.Our results can effectively explain the observed Bemeson spectrum,and the prediction of the mass spectrum for unobserved beauty-charm mesons can be tested in future experiments.Compared with previous studies,we systematically examine the beauty-charm meson family within the coupled channel components.The 1S state in beauty-charm meson family has few percent of coupled channel component,while the 2S,1P,and 1D states have more than ten percent of coupled channel component.The two-body hadronic decay widths of the 2^(3)P_(2) state is as narrow as 3 MeV.The two-body hadronic decay widths of 3^(1)S_(0),3^(3)S_(1),2^(3)D_(1),2D,2D',and 2^(3)D_(3) are approximately 109,67,60,57,201,and 76 MeV,respectively.Furthermore,the mixing effects between B_(c)(n^(3)L_(L))and B_(c)(n^(1)L_(L))states are discussed.
基金ICT R&D Program of Ministry of Science,ICT and Future Planning(MSIP)/IITP(1711035342)Electronics and Telecommunications Research Institute(ETRI)
文摘Side channel effects such as temporal disparity and intensity fluctuation of the photon pulses caused by random bit generation with multiple laser diodes in high-speed polarization-based BB84 quantum key distribution(QKD) systems can be eliminated by increasing the DC bias current condition. However, background photons caused by the spontaneous emission process under high DC bias current degrade the performance of QKD systems. In this study, we investigated the effects of spontaneously emitted photons on the system performance in a high-speed QKD system at a clock rate of 400 MHz. Also, we show further improvements in the system performance without side channel effects by utilizing the temporal filtering technique with real-time fieldprogrammable gate array signal processing.
文摘Deep submicron partially depleted silicon on insulator （PDSOI） nMOSFETs were fabricated based on the 0.35μm SOI process developed by the Institute of Microelectronics of the Chinese Academy of Sciences （IMECAS）. Mechanisms determining short-channel effects （SCE） in PDSOI nMOSFETs are clarified based on experimental results of threshold voltage dependence upon gate length. The effects of body bias, drain bias, temperature and body contact on the SCE have been investigated. The SCE in SOI devices is found to be dependent on body bias, drain bias and body contact. Floating body devices show a more severe reverse short channel effect （RSCE） than devices with body contact structure. Devices with low body bias and high drain bias show a more obvious SCE.
基金Project supported by the National Basic Research Program of China(973 Program)(No.2014CB744802)the National Natural Science Foundation of China(No.11772194)
文摘As the Reynolds number increases, the skin friction has been identified as the dominant drag in many practical applications. In the present paper, the effects of the Reynolds number on the mean skin friction decomposition in turbulent channel flows up to Reτ= 5 200 are investigated based on two different methods, i.e., the FukagataIwamoto-Kasagi(FIK) identity(FUKAGATA, K., IWAMOTO, K., and KASAGI, N.Contribution of Reynolds stress distribution to the skin friction in wall-bounded flows.Physics of Fluids, 14(11), L73–L76(2002)) and the Renard-Deck(RD) identity(DECK,S., RENARD, N., LARAUFIE, R., and WEISS, P.′E. Large-scale contribution to mean wall shear stress in high-Reynolds-number flat-plate boundary layers up to Reθ= 13 650.Journal of Fluid Mechanics, 743, 202–248(2014)). The direct numerical simulation(DNS) data provided by Lee and Moser(LEE, M. and MOSER, R. D. Direct numerical simulation of turbulent channel flow up to Reτ≈ 5 200. Journal of Fluid Mechanics,774, 395–415(2015)) are used. For these two skin friction decomposition methods, their decomposed constituents are discussed and compared for different Reynolds numbers.The integrands of the decomposed constituents are locally analyzed across the boundary layer to assess the actions associated with the inhomogeneity and multi-scale nature of turbulent motion. The scaling of the decomposed constituents and their integrands are presented. In addition, the boundary layer is divided into three sub-regions to evaluate the contributive proportion of each sub-region with an increase in the Reynolds number.
文摘The channeling phenomenon of carbon ions in single-wall carbon nanotubes (SWCNTs) is investigated by using the molecular dynamics simulation with analytical potentials.The relationship between the channeling critical angles in the SWCNT and the bonding interaction is analyzed.It was found that,at 200-5000 eV and 10°-20° of incident angle,the ions with the bonding interaction or chemical effect,have decreased dechanneling probabilities and increased critical angles,compared to that of non-bonding ions.So the bonding effect cannot be ignored in the channeling mechanism of carbon ions through a SWCNT.
基金Supported by the National Natural Science Foundation of China under Grant No.11164009
文摘The dynamics of entanglement between two qubits in the local damping two-sided channel and singlesided channel are compared through non-Markovian process and Markovian process. The entanglement between two qubits is found to be longer in the single-sided channel case due to the weakening of the dissipative effects. In the two-sided channel, influenced by the entanglement between qubits, the previous independent dissipative channels incline to the composite effect of the Markovian process. This composite effect results in the dissipative effect of one channel affecting the qubits in the other channel, especially inhibiting the backflow effect in the non-Markovian channel, which is disadvantageous to the entanglement maintenance between qubits. In the Markovian channel, the composite effect of the damping two-sided channels is more obvious since there is no backflow effect, thus more disadvantageous to the entanglement maintenance.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60806007)the Shanghai ‘Post-Qi-Ming-Xing Plan’ for Young Scientists,China (Grant No. 07QA14023)the Shanghai Committee of Science and Technology (Grant Nos. 08DZ1140702 and 08520511200)
文摘This paper presents two n-channel organic heterojunction transistors with modified insulator by using hexadecafiuorophthalocyaninatocopper （F16CuPc）/copper phthalocyanine （CuPc） and F16CuPc/pentacene as the active layers. Compared with a single-layer device, it reports that an improved field-effect mobility and a 6-fold higher drain current are observed. The highest mobility of 0.081 cm^2/（V. s） was obtained from F16CuPc/CuPc heterojunction devices. This result is attributed to the dual effects of the organic heterojunction and interface modification. Furthermore, for two heterojunction devices, the performance of the F16CuPc/CuPc-based transistor is better than that of F16CuPc/pentacene. This is attributed to the morphologic match of two organic components.
文摘This article describes the effective channel length degradation under hot carrier stressing. The extraction is based on the IDs-Vcs characteristics by maximum transconductance （maximum slope of IDs ＆ VGS） in the linear region. The transconductance characteristics are determine for the several devices of difference drawn channel length. The effective channel length of submicron LDD （Lightly Doped Drain） NMOSFETs （Metal Oxide Semiconductor Field Effect Transistor） under hot carrier stressing was measured at the stress time varying from zero to 10,000 seconds. It is shown that the effective channel length was increased with time. This is caused by charges trapping in the oxide during stress. The increased of effective channel length （△Leff） is seem to be increased sharply as the gate channel length is decrease.
文摘In restricted channel, the hydrodynamic performance of propeller is affected by the wall. In the present work, two cylindrical channels with different diameters being 1.8D and 5.0D are adopted to study the influence of wall on the hydrodynamic performance and wake field of the propeller model DTMB4119. The numerical simulations are carried out by the single-phase solver pimpleDyMFoam in open source platform OpenFOAM. The Reynolds Averaged Navier-Stokes equations (RANS) are adopted to solve the flow field. The arbitrary mesh interface (AMI) method is used to simulate the rotation of propeller. The designed advance ratio, J = 0.833, is applied in all the computations. For the 5.0 D case, the predicted results of open water performance are in good agreement with experiment data. In restricted channel, the predicted results of thrust and torque coefficients are larger than the open water case. The pressure on the wall of restricted channel downstream increases and approaches the results in open water gradually. Due to the flux conservation, higher negative induced velocity is investigated in the flow field of the propeller in restricted channel.
基金Support of the National Natural Science Foundation of China under Grant Nos.51709191 and 51706149Key Laboratory of Advanced Reactor Engineering and Safety,Ministry of Education under Grant No.ARES-2018-10
文摘This article investigates an unbiased analysis for the unsteady two-dimensional laminar flow of an incompressible, electrically and thermally conducting fluid across the space separated by two infinite rotating permeable walls.The influence of entropy generation, Hall and slip effects are considered within the flow analysis. The problem is modeled based on valid physical arguments and the unsteady system of dimensionless PDEs (partial differential equations) are solved with the help of Finite Difference Scheme. In the presence of pertinent parameters, the precise movement of the flow in terms of velocity, temperature, entropy generation rate, and Bejan numbers are presented graphically, which are parabolic in nature. Streamline profiles are also presented, which exemplify the accurate movement of the flow. The current study is one of the infrequent contributions to the existing literature as previous studies have not attempted to solve the system of high order non-linear PDEs for the unsteady flow with entropy generation and Hall effects in a permeable rotating channel. It is expected that the current analysis would provide a platform for solving the system of nonlinear PDEs of the other unexplored models that are associated to the two-dimensional unsteady flow in a rotating channel.
