To characterize long-term nonprogressors (LTNPs) and viremia controllers (VCs), infected with HIV-1 through contaminated blood donation or transfusion between 1992 and 1996 in Henan, China. LTNPs and VCs were defi...To characterize long-term nonprogressors (LTNPs) and viremia controllers (VCs), infected with HIV-1 through contaminated blood donation or transfusion between 1992 and 1996 in Henan, China. LTNPs and VCs were defined by CD4+T lymphocyte (CD4) count and viral load (VL). Of 29,294 patients infected with HIV-1 via contaminated blood donation or transfusion that had conducted for more than 20 years, 92 were LTNPs/VCs. There were 70 LTNPs (0.24%), 43 VCs (0.15%), and 48 LTNPs+VCs- (0.16%).展开更多
Current-voltage (l-V) characteristics of hydrogen DC plasma torches with different sizes in an external axial magnetic field under atmospheric pressure are reported. Three anodes with different diameters are adopted...Current-voltage (l-V) characteristics of hydrogen DC plasma torches with different sizes in an external axial magnetic field under atmospheric pressure are reported. Three anodes with different diameters are adopted in a 50-kW torch: 25 mm, 30 mm, and 35 nun, respectively. Two different diameters of anodes, that is, 100 mm and 130 mm, are adopted in a 1-MW plasma torch. The arc voltage shows a negative trend with the increase of arc current under the operating regimes. On the contrary, arc voltage shows a positive trend as the flow rate of carder gas increases, and a similar trend is found with increasing the external magnetic flux density. A similarity formula is constructed to correlate the experimental data of the torches mentioned above. Linear fitting shows that the Pearson correlation coefficient is 0.9958.展开更多
This paper studies the electronic transport in an individual helically twisted CdS nanowire rope, on which platinum microleads are attached by focused-ion beam deposition. The current-voltage (I - V) characteristics...This paper studies the electronic transport in an individual helically twisted CdS nanowire rope, on which platinum microleads are attached by focused-ion beam deposition. The current-voltage (I - V) characteristics are nonlinear from 300 down to 60 K. Some step-like structures in the I - V curves and oscillation peaks in the differential conductance (dI/dV - V) curves have been observed even at room temperature. It proposes that the observed behaviour can be attributed to Coulomb-blockade transport in the one-dimensional CdS nanowires with diameters of 6-10 nm.展开更多
The electrical performance of a photovoltaic (PV) silicon solar cell is described by its current–voltage (I–V) character-istic curve, which is in turn determined by device and material properties. In this study, an ...The electrical performance of a photovoltaic (PV) silicon solar cell is described by its current–voltage (I–V) character-istic curve, which is in turn determined by device and material properties. In this study, an investigation of the performance and device parameters of photovoltaic single crystalline silicon (Si.) solar cell of the construction n+pp++ PESC(Passivatted Emitter Solar Cell) at different conditions of solar irradiance, title angle and mirror boosting effects had been studied. Also the paper reports on the performance data of the Si. cell, using standard I–V characteristic curves to obtain output parameters and to show that there are possible performance degrading defects presents.展开更多
A physically based analytical model was developed to predict the performance of the plateau observed in the gate C-V characteristics of strained-Si/SiGe pMOSFET.Experimental results were used to validate this model.Th...A physically based analytical model was developed to predict the performance of the plateau observed in the gate C-V characteristics of strained-Si/SiGe pMOSFET.Experimental results were used to validate this model.The extracted parameters from our model were tOX=20 nm,ND=1×1016cm 3,tSSi=13.2 nm,consistent with the experimental values.The results show that the simulation results agree with experimental data well.It is found that the plateau can be strongly affected by doping concentration,strained-Si layer thickness and mass fraction of Ge in the SiGe layer.The model has been implemented in the software for strained silicon MOSFET parameter extraction,and has great value in the design of the strained-Si/SiGe devices.展开更多
The amount of data that is traveling across the internet today, including very large and complex set of raw facts that are not only large, but also, complex, noisy, heterogeneous, and longitudinal data as well. Compan...The amount of data that is traveling across the internet today, including very large and complex set of raw facts that are not only large, but also, complex, noisy, heterogeneous, and longitudinal data as well. Companies, institutions, healthcare system, mobile application capturing devices and sensors, traffic management, banking, retail, education etc., use piles of data which are further used for creating reports in order to ensure continuity regarding the services that they have to offer. Recently, Big data is one of the most important topics in IT industry. Managing Big data needs new techniques because traditional security and privacy mechanisms are inadequate and unable to manage complex distributed computing for different types of data. New types of data have different and new challenges also. A lot of researches treat with big data challenges starting from Doug Laney’s landmark paper</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> during the previous two decades;the big challenge is how to operate a huge volume of data that has to be securely delivered through the internet and reach its destination intact. The present paper highlights important concepts of Fifty</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">six Big Data V’s characteristics. This paper also highlights the security and privacy Challenges that Big Data faces and solving this problem by proposed technological solutions that help us avoiding these challenging problems.展开更多
The time-domain radiation characteristics of a three V-dipole array have been stud-ied by direct time-domain method.Some valuable results are obtained.
Through theoretical analyses of the Shockley equation and the difference between a practical P-N junction and its ideal model, the mathematical models of P-N junction and solar cells had been obtained. With Matlab sof...Through theoretical analyses of the Shockley equation and the difference between a practical P-N junction and its ideal model, the mathematical models of P-N junction and solar cells had been obtained. With Matlab software, the V-I characteristics of diodes and solar cells were simulated, and a computer simulation model of the solar cells based on P-N junction was also established. Based on the simulation model, the influences of solar cell’s internal resistances on open-circuit voltage and short-circuit current under certain illumination were numerically analyzed and solved. The simulation results showed that the equivalent series resistance and shunt resistance could strongly affect the V-I characteristics of solar cell, but their influence styles were different.展开更多
In this study, we investigate some main electrical parameters of the gold/poly(3-hexylthiophene):[6,6]-phenyl C61 bu- tyric acid methyl ester:2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane/n-type silicon (A...In this study, we investigate some main electrical parameters of the gold/poly(3-hexylthiophene):[6,6]-phenyl C61 bu- tyric acid methyl ester:2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane/n-type silicon (Au/P3HT:PCBM:F4-TCNQ/n- Si) metal-polymer-semiconductor (MPS) Schottky barrier diode (SBD) in terms of the effects of F4-TCNQ concentration (0%, 1%, and 2%). F4-TCNQ-doped P3HT:PCBM is fabricated to figure out the p-type doping effect on the device per- formance. The main electrical parameters, such as ideality factor (n), barrier height (ФB0), series resistance (Rs), shunt resistance (Rsh), and density of interface states (Nss) are determined from the forward and reverse bias current-voltage (l-V) characteristics in the dark and at room temperature. The values of n, Rs, ФB0, and Nss are significantly reduced by using the 1% F4-TCNQ doping in P3HT:PCBM:F4-TCNQ organic blend layer, additionally, the carrier mobility and current are increased by the soft (1%) doping. The most ideal values of electrical parameters are obtained for 1% F4-TCNQ used diode. On the other hand, the carrier mobility and current for the hard doping (2%) become far away from the ideal diode values due to the unbalanced generation of holes/electrons and doping-induced disproportion when compared with 1% F4-TCNQ doping. These results show that the electrical properties of MPS SBDs strongly depend on the F4-TCNQ doping and doping concentration of interfacial P3HT:PCBM:F4-TCNQ organic layer. Moreover, the soft F4-TCNQ dop- ing concentration (1%) in P3HT:PCBM:F4-TCNQ organic layer significantly improves the electrical characteristics of the Au/P3HT:PCBM:F4-TCNQ/n-Si (MPS) SBDs which enables the fabricating of high-quality electronic and optoelectronic devices.展开更多
Research on nonmaterials has become increasingly popular because of their unique physical, chemical, optical and catalytic properties compared to their bulk counterparts. Therefore, many efforts have been made to synt...Research on nonmaterials has become increasingly popular because of their unique physical, chemical, optical and catalytic properties compared to their bulk counterparts. Therefore, many efforts have been made to synthesize multidimensional nanostructures for new and efficient nanodevices. Among those materials, zinc oxide (ZnO) has gained substantial attention owing to many outstanding properties. ZnO besides its wide band gap of 3.34 eV exhibits a relatively large excitons binding energy (60 meV) at room temperature which is attractive for optoelectronic applications. Likewise, cupric oxide (CuO) has a narrow band gap of 1.2 eV and a variety of chemo-physical properties that are attractive in many fields. Moreover, composite nanostructures of these two oxides (CuO/ZnO) may pave the way for various new applications. So in this thesis, eight samples of CuO/ZnO junction were synthesized and exposed to temperatures 60, 70, 80, 90, 100, 110, 120 and 130. The electrical properties of Schottky diode junctions were analyzed by I-V measurements under the influence of direct solar radiation and, lag of radiation (darkness) which shows the semi-logarithmic I-V characteristic curve of the fabricated photodiodes. Also energy band gap was estimated and the morphology and particle sizes of the as-prepared sample were determined by SEM. The SEM images of ZnO + CuO sample films were annealed at 60°C to 130°C step 10.展开更多
Several parameters of a commercial Si-based Schottky barrier diode (SBD) with unknown metal material and semiconductor-type have been investigated in this work from dark forward and reverse I-V characteristics in the ...Several parameters of a commercial Si-based Schottky barrier diode (SBD) with unknown metal material and semiconductor-type have been investigated in this work from dark forward and reverse I-V characteristics in the temperature (T) range of [274.5 K - 366.5 K]. Those parameters include the reverse saturation current (I<sub>s</sub>), the ideality factor (n), the series and the shunt resistances (R<sub>s</sub> and R<sub>sh</sub>), the effective and the zero bias barrier heights (Φ<sub>B</sub> and Φ<sub>B0</sub>), the product of the electrical active area (A) and the effective Richardson constant (A**), the built-in potential (V<sub>bi</sub>), together with the semiconductor doping concentration (N<sub>A</sub> or N<sub>D</sub>). Some of them have been extracted by using two or three different methods. The main features of each approach have been clearly stated. From one parameter to another, results have been discussed in terms of structure performance, comparison on one another when extracted from different methods, accordance or discordance with data from other works, and parameter’s temperature or voltage dependence. A comparison of results on Φ<sub>B</sub>, ΦB0</sub>, n and N<sub>A</sub> or N<sub>D</sub> parameters with some available data in literature for the same parameters, has especially led to clear propositions on the identity of the analyzed SBD’s metal and semiconductor-type.展开更多
As the fourth passive circuit component, a memristor is a nonlinear resistor that can "remember" the amount of charge passing through it. The characteristic of "remembering" the charge and non-volatility makes mem...As the fourth passive circuit component, a memristor is a nonlinear resistor that can "remember" the amount of charge passing through it. The characteristic of "remembering" the charge and non-volatility makes memristors great potential candidates in many fields. Nowadays, only a few groups have the ability to fabricate memristors, and most researchers study them by theoretic analysis and simulation. In this paper, we first analyse the theoretical base and characteristics of memristors, then use a simulation program with integrated circuit emphasis as our tool to simulate the theoretical model of memristors and change the parameters in the model to see the influence of each parameter on the characteristics. Our work supplies researchers engaged in memristor-based circuits with advice on how to choose the proper parameters.展开更多
A 4H-silicon carbide metal-insulator-semiconductor structure with ultra-thin Al2O3 as the gate dielectric, deposited by atomic layer deposition on tile epitaxial layer of a 4H-SiC (0001) 80N-/N+ substrate, has been...A 4H-silicon carbide metal-insulator-semiconductor structure with ultra-thin Al2O3 as the gate dielectric, deposited by atomic layer deposition on tile epitaxial layer of a 4H-SiC (0001) 80N-/N+ substrate, has been fabricated. The experimental results indicate that the prepared ultra-thin Al2O3 gate dielectric exhibits good physical and electrical characteristics, including a high breakdown electrical field of 25 MV/cm, excellent interface properties (1 × 10^14 cm^-2) and low gate-leakage current (IG = 1 × 10^-3 A/cm 2@Eox = 8 MV/cm). Analysis of the current conduction mecha- nism on the deposited Al2O3 gate dielectric was also systematically performed. The confirmed conduction mechanisms consisted of Fowler-Nordheim (FN) tuaneling, the Frenkel-Poole mechanism, direct tunneling and Schottky emission, and the dominant current conduction mechanism depends on the applied electrical field. When the gate leakage current mechanism is dominated by FN tunneling, the barrier height of SiC/Al2O3 is 1.4 eV, which can meet the requirements of silicon carbide metal-insulator-semiconductor transistor devices.展开更多
Current-voltage (I-V) characteristics of a non-transferred DC arc plasma spray torch operated in argon at vacuum are reported. The arc voltage is of negative characteristics for a current below 200 A, fiat for a cur...Current-voltage (I-V) characteristics of a non-transferred DC arc plasma spray torch operated in argon at vacuum are reported. The arc voltage is of negative characteristics for a current below 200 A, fiat for a current between 200 A to 250 A and positive for a current beyond 250 A. The voltage increases slowly with the increase in carrier gas of arc. The rate of change in voltage with currents is about 3-4 V/100 A at a gas flow rate of about 1-1.5 V/10 standard liter per minute (slpm). The I-V characteristics of the DC plasma torch are of a shape of hyperbola. Arc power increases with the argon flow rate. and the thermal efficiency of the torch acts in a similar way. The thermal efficiency of the non-transferred DC plasmatron is about 65-78%.展开更多
基金supported by grants from The National Key Science and Technology Projects on Major Infectious Disease Grant[2012ZX10001‐002 and 2017ZX10105009]Key Projects for Science and Technology Development of Henan Province[142102310076 and 162300410123]
文摘To characterize long-term nonprogressors (LTNPs) and viremia controllers (VCs), infected with HIV-1 through contaminated blood donation or transfusion between 1992 and 1996 in Henan, China. LTNPs and VCs were defined by CD4+T lymphocyte (CD4) count and viral load (VL). Of 29,294 patients infected with HIV-1 via contaminated blood donation or transfusion that had conducted for more than 20 years, 92 were LTNPs/VCs. There were 70 LTNPs (0.24%), 43 VCs (0.15%), and 48 LTNPs+VCs- (0.16%).
基金Project supported by the Special Fund for Basic Scientific Research of Central Colleges,China(Grant No.2012FZA4023)
文摘Current-voltage (l-V) characteristics of hydrogen DC plasma torches with different sizes in an external axial magnetic field under atmospheric pressure are reported. Three anodes with different diameters are adopted in a 50-kW torch: 25 mm, 30 mm, and 35 nun, respectively. Two different diameters of anodes, that is, 100 mm and 130 mm, are adopted in a 1-MW plasma torch. The arc voltage shows a negative trend with the increase of arc current under the operating regimes. On the contrary, arc voltage shows a positive trend as the flow rate of carder gas increases, and a similar trend is found with increasing the external magnetic flux density. A similarity formula is constructed to correlate the experimental data of the torches mentioned above. Linear fitting shows that the Pearson correlation coefficient is 0.9958.
基金Project supported by the National Natural Science Foundation of China (Grant No 10604038)Program for New Century Excellent Talents in University,China (Grant No NCE72007)
文摘This paper studies the electronic transport in an individual helically twisted CdS nanowire rope, on which platinum microleads are attached by focused-ion beam deposition. The current-voltage (I - V) characteristics are nonlinear from 300 down to 60 K. Some step-like structures in the I - V curves and oscillation peaks in the differential conductance (dI/dV - V) curves have been observed even at room temperature. It proposes that the observed behaviour can be attributed to Coulomb-blockade transport in the one-dimensional CdS nanowires with diameters of 6-10 nm.
文摘The electrical performance of a photovoltaic (PV) silicon solar cell is described by its current–voltage (I–V) character-istic curve, which is in turn determined by device and material properties. In this study, an investigation of the performance and device parameters of photovoltaic single crystalline silicon (Si.) solar cell of the construction n+pp++ PESC(Passivatted Emitter Solar Cell) at different conditions of solar irradiance, title angle and mirror boosting effects had been studied. Also the paper reports on the performance data of the Si. cell, using standard I–V characteristic curves to obtain output parameters and to show that there are possible performance degrading defects presents.
基金Projects(51308040203,6139801)supported by National Ministries and Commissions,ChinaProjects(72105499,72104089)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2010JQ8008)supported by the Natural Science Basic Research Plan in Shaanxi Province of China
文摘A physically based analytical model was developed to predict the performance of the plateau observed in the gate C-V characteristics of strained-Si/SiGe pMOSFET.Experimental results were used to validate this model.The extracted parameters from our model were tOX=20 nm,ND=1×1016cm 3,tSSi=13.2 nm,consistent with the experimental values.The results show that the simulation results agree with experimental data well.It is found that the plateau can be strongly affected by doping concentration,strained-Si layer thickness and mass fraction of Ge in the SiGe layer.The model has been implemented in the software for strained silicon MOSFET parameter extraction,and has great value in the design of the strained-Si/SiGe devices.
文摘The amount of data that is traveling across the internet today, including very large and complex set of raw facts that are not only large, but also, complex, noisy, heterogeneous, and longitudinal data as well. Companies, institutions, healthcare system, mobile application capturing devices and sensors, traffic management, banking, retail, education etc., use piles of data which are further used for creating reports in order to ensure continuity regarding the services that they have to offer. Recently, Big data is one of the most important topics in IT industry. Managing Big data needs new techniques because traditional security and privacy mechanisms are inadequate and unable to manage complex distributed computing for different types of data. New types of data have different and new challenges also. A lot of researches treat with big data challenges starting from Doug Laney’s landmark paper</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> during the previous two decades;the big challenge is how to operate a huge volume of data that has to be securely delivered through the internet and reach its destination intact. The present paper highlights important concepts of Fifty</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">six Big Data V’s characteristics. This paper also highlights the security and privacy Challenges that Big Data faces and solving this problem by proposed technological solutions that help us avoiding these challenging problems.
文摘The time-domain radiation characteristics of a three V-dipole array have been stud-ied by direct time-domain method.Some valuable results are obtained.
文摘Through theoretical analyses of the Shockley equation and the difference between a practical P-N junction and its ideal model, the mathematical models of P-N junction and solar cells had been obtained. With Matlab software, the V-I characteristics of diodes and solar cells were simulated, and a computer simulation model of the solar cells based on P-N junction was also established. Based on the simulation model, the influences of solar cell’s internal resistances on open-circuit voltage and short-circuit current under certain illumination were numerically analyzed and solved. The simulation results showed that the equivalent series resistance and shunt resistance could strongly affect the V-I characteristics of solar cell, but their influence styles were different.
文摘In this study, we investigate some main electrical parameters of the gold/poly(3-hexylthiophene):[6,6]-phenyl C61 bu- tyric acid methyl ester:2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane/n-type silicon (Au/P3HT:PCBM:F4-TCNQ/n- Si) metal-polymer-semiconductor (MPS) Schottky barrier diode (SBD) in terms of the effects of F4-TCNQ concentration (0%, 1%, and 2%). F4-TCNQ-doped P3HT:PCBM is fabricated to figure out the p-type doping effect on the device per- formance. The main electrical parameters, such as ideality factor (n), barrier height (ФB0), series resistance (Rs), shunt resistance (Rsh), and density of interface states (Nss) are determined from the forward and reverse bias current-voltage (l-V) characteristics in the dark and at room temperature. The values of n, Rs, ФB0, and Nss are significantly reduced by using the 1% F4-TCNQ doping in P3HT:PCBM:F4-TCNQ organic blend layer, additionally, the carrier mobility and current are increased by the soft (1%) doping. The most ideal values of electrical parameters are obtained for 1% F4-TCNQ used diode. On the other hand, the carrier mobility and current for the hard doping (2%) become far away from the ideal diode values due to the unbalanced generation of holes/electrons and doping-induced disproportion when compared with 1% F4-TCNQ doping. These results show that the electrical properties of MPS SBDs strongly depend on the F4-TCNQ doping and doping concentration of interfacial P3HT:PCBM:F4-TCNQ organic layer. Moreover, the soft F4-TCNQ dop- ing concentration (1%) in P3HT:PCBM:F4-TCNQ organic layer significantly improves the electrical characteristics of the Au/P3HT:PCBM:F4-TCNQ/n-Si (MPS) SBDs which enables the fabricating of high-quality electronic and optoelectronic devices.
文摘Research on nonmaterials has become increasingly popular because of their unique physical, chemical, optical and catalytic properties compared to their bulk counterparts. Therefore, many efforts have been made to synthesize multidimensional nanostructures for new and efficient nanodevices. Among those materials, zinc oxide (ZnO) has gained substantial attention owing to many outstanding properties. ZnO besides its wide band gap of 3.34 eV exhibits a relatively large excitons binding energy (60 meV) at room temperature which is attractive for optoelectronic applications. Likewise, cupric oxide (CuO) has a narrow band gap of 1.2 eV and a variety of chemo-physical properties that are attractive in many fields. Moreover, composite nanostructures of these two oxides (CuO/ZnO) may pave the way for various new applications. So in this thesis, eight samples of CuO/ZnO junction were synthesized and exposed to temperatures 60, 70, 80, 90, 100, 110, 120 and 130. The electrical properties of Schottky diode junctions were analyzed by I-V measurements under the influence of direct solar radiation and, lag of radiation (darkness) which shows the semi-logarithmic I-V characteristic curve of the fabricated photodiodes. Also energy band gap was estimated and the morphology and particle sizes of the as-prepared sample were determined by SEM. The SEM images of ZnO + CuO sample films were annealed at 60°C to 130°C step 10.
文摘Several parameters of a commercial Si-based Schottky barrier diode (SBD) with unknown metal material and semiconductor-type have been investigated in this work from dark forward and reverse I-V characteristics in the temperature (T) range of [274.5 K - 366.5 K]. Those parameters include the reverse saturation current (I<sub>s</sub>), the ideality factor (n), the series and the shunt resistances (R<sub>s</sub> and R<sub>sh</sub>), the effective and the zero bias barrier heights (Φ<sub>B</sub> and Φ<sub>B0</sub>), the product of the electrical active area (A) and the effective Richardson constant (A**), the built-in potential (V<sub>bi</sub>), together with the semiconductor doping concentration (N<sub>A</sub> or N<sub>D</sub>). Some of them have been extracted by using two or three different methods. The main features of each approach have been clearly stated. From one parameter to another, results have been discussed in terms of structure performance, comparison on one another when extracted from different methods, accordance or discordance with data from other works, and parameter’s temperature or voltage dependence. A comparison of results on Φ<sub>B</sub>, ΦB0</sub>, n and N<sub>A</sub> or N<sub>D</sub> parameters with some available data in literature for the same parameters, has especially led to clear propositions on the identity of the analyzed SBD’s metal and semiconductor-type.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 61003082) the Science Fund for Creative Research Groups of the National Natural Science Foundation of China (Grant No. 60921062)
文摘As the fourth passive circuit component, a memristor is a nonlinear resistor that can "remember" the amount of charge passing through it. The characteristic of "remembering" the charge and non-volatility makes memristors great potential candidates in many fields. Nowadays, only a few groups have the ability to fabricate memristors, and most researchers study them by theoretic analysis and simulation. In this paper, we first analyse the theoretical base and characteristics of memristors, then use a simulation program with integrated circuit emphasis as our tool to simulate the theoretical model of memristors and change the parameters in the model to see the influence of each parameter on the characteristics. Our work supplies researchers engaged in memristor-based circuits with advice on how to choose the proper parameters.
基金supported by the 2010 School Fundamental Scientific Research Fund of Xidian University (Grant No. K50510250008)
文摘A 4H-silicon carbide metal-insulator-semiconductor structure with ultra-thin Al2O3 as the gate dielectric, deposited by atomic layer deposition on tile epitaxial layer of a 4H-SiC (0001) 80N-/N+ substrate, has been fabricated. The experimental results indicate that the prepared ultra-thin Al2O3 gate dielectric exhibits good physical and electrical characteristics, including a high breakdown electrical field of 25 MV/cm, excellent interface properties (1 × 10^14 cm^-2) and low gate-leakage current (IG = 1 × 10^-3 A/cm 2@Eox = 8 MV/cm). Analysis of the current conduction mecha- nism on the deposited Al2O3 gate dielectric was also systematically performed. The confirmed conduction mechanisms consisted of Fowler-Nordheim (FN) tuaneling, the Frenkel-Poole mechanism, direct tunneling and Schottky emission, and the dominant current conduction mechanism depends on the applied electrical field. When the gate leakage current mechanism is dominated by FN tunneling, the barrier height of SiC/Al2O3 is 1.4 eV, which can meet the requirements of silicon carbide metal-insulator-semiconductor transistor devices.
文摘Current-voltage (I-V) characteristics of a non-transferred DC arc plasma spray torch operated in argon at vacuum are reported. The arc voltage is of negative characteristics for a current below 200 A, fiat for a current between 200 A to 250 A and positive for a current beyond 250 A. The voltage increases slowly with the increase in carrier gas of arc. The rate of change in voltage with currents is about 3-4 V/100 A at a gas flow rate of about 1-1.5 V/10 standard liter per minute (slpm). The I-V characteristics of the DC plasma torch are of a shape of hyperbola. Arc power increases with the argon flow rate. and the thermal efficiency of the torch acts in a similar way. The thermal efficiency of the non-transferred DC plasmatron is about 65-78%.