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Characteristics of Long-term Nonprogressors and Viremia Controllers Infected with HIV-1 via Contaminated Blood Donations or Transfusions Conducted 20 Years Earlier 被引量:3
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作者 LIU Jia FAN Pan Ying +8 位作者 XUE Xiu Juan YAN Jiang Zhou SUN Guo Qing LIU Chun Hua TIAN Sui An LI Ning SUN Ding Yong ZHU Qian WANG Zhe 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2017年第12期907-912,共6页
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
关键词 characteristics of Long-term Nonprogressors HIv-1 v/a Contaminated Blood Donations
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Current–voltage characteristics of hydrogen DC plasma torches with different sizes in an external axial magnetic field 被引量:2
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作者 马杰 闻光东 +2 位作者 苏宝根 杨亦文 任其龙 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第6期425-428,共4页
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
关键词 magnetically rotating hydrogen plasma I-v characteristics similarity theory
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Current-voltage characteristics of an individual helical CdS nanowire rope
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作者 龙云泽 王文龙 +3 位作者 白凤莲 陈兆甲 金爱子 顾长志 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第4期1389-1393,共5页
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
关键词 NANOWIRES CDS I - v characteristics Coulomb blockade
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Analysis of Electrical Characteristics of Photovoltaic Single Crystal Silicon Solar Cells at Outdoor Measurements 被引量:3
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作者 A. Ibrahim 《Smart Grid and Renewable Energy》 2011年第2期169-175,共7页
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
关键词 Silicon Solar Cells I-v characteristics Performance Analyses OUTDOOR Parameters MIRROR BOOSTING
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Physically based analytical model for plateau in gate C-V characteristics of strained silicon pMOSFET 被引量:1
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作者 王斌 张鹤鸣 +3 位作者 胡辉勇 张玉明 周春宇 李妤晨 《Journal of Central South University》 SCIE EI CAS 2013年第9期2366-2371,共6页
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
关键词 高原性能 PMOS器件 应变硅 模型 物理 特性 栅极 MOS场效应晶体管
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Fifty-Six Big Data V’s Characteristics and Proposed Strategies to Overcome Security and Privacy Challenges (BD2)
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作者 Abou_el_ela Abdou Hussein 《Journal of Information Security》 2020年第4期304-328,共25页
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
关键词 Big Data Big Data v’s characteristics Security PRIvACY CHALLENGES Technological Solutions
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V型球阀的米浆流量实验研究
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作者 陆正杰 王一泉 +1 位作者 杜张博 黄俊枫 《阀门》 2024年第3期315-317,341,共4页
建立一种符合实际生产的米浆流量模型对提高米粉生产标准化至关重要。对比以往的一次函数、二次函数和指数函数孔口流量模型,提出一种幂函数孔口流量模型,利用软件Origin的LMA算法的非线性最小二乘法拟合4种函数流量模型。结果表明:4种... 建立一种符合实际生产的米浆流量模型对提高米粉生产标准化至关重要。对比以往的一次函数、二次函数和指数函数孔口流量模型,提出一种幂函数孔口流量模型,利用软件Origin的LMA算法的非线性最小二乘法拟合4种函数流量模型。结果表明:4种模型均通过了卡方检验及F检验,幂函数的调整R平方最高且残差平方和最小,说明幂函数流量模型拟合效果最好。为孔口流量模型提供了一种新的幂函数参考。 展开更多
关键词 孔口排放模型 v型球阀 阀门开度 水位差 流量特性 拟合检验
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TIME-DOMAIN RADIATION CHARACTERISTICS OF V-DIPOLE ARRAYS
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作者 王均宏 《Journal of Electronics(China)》 1993年第4期289-297,共9页
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.
关键词 v-dipole Array RADIATION characteristic Time-stepping approach
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Analyses and Simulation of V-I Characteristics for Solar Cells Based on P-N Junction
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作者 ZHENG Jian-bang REN Ju GUO Wen-ge HOU Chao-qi 《Semiconductor Photonics and Technology》 CAS 2005年第4期253-258,共6页
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
关键词 太阳能电池 PN节 v-I性质 等价循环
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F4-TCNQ concentration dependence of the current voltage characteristics in the Au/P3HT:PCBM:F4-TCNQ/n-Si(MPS) Schottky barrier diode
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作者 E.Yaglioglu O.Tzn Ozmen 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第11期512-522,共11页
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
关键词 P3HT:PCBM:F4-TCNQ interfacial organic layer F4-TCNQ doping concentration Schottky bar-rier diodes I-v characteristics
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Effect of Temperature on I-V Characteristic for ZnO/CuO
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作者 Mubarak Dirar Farhah Elfadel Omer +5 位作者 Rawia Abdelgani Ali Sulaiman Mohamed Abdelnabi Ali Elamin Bashir Elhaj Ahamed Mona Ali Abdelsakh Suleman Mohamed 《World Journal of Nuclear Science and Technology》 2018年第3期128-135,共8页
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&deg;C to 130&deg;C step 10. 展开更多
关键词 Copper OXIDE ZINC OXIDE THIN Films MONOETHANOLAMINE Temperature CURRENT-vOLTAGE (I-v) characteristic
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Non Ideal Schottky Barrier Diode’s Parameters Extraction and Materials Identification from Dark I-V-T Characteristics
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作者 M. Bashahu D. Ngendabanyikwa P. Nyandwi 《Journal of Modern Physics》 2022年第3期285-300,共16页
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
关键词 SBD Dark Forward and Reverse I-v-T characteristics Different Parameters Extraction Methods Identification of the Structure’s Metal and Semiconductor-Type
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基于不同倾角下水珠形态量化特征的V串复合绝缘子憎水性判定方法 被引量:3
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作者 王维 鲁海亮 +4 位作者 李纯 袁田 苑玉宽 蓝磊 文习山 《高电压技术》 EI CAS CSCD 北大核心 2023年第4期1665-1674,共10页
憎水性是表征复合绝缘子老化状况的重要指标,由于V串复合绝缘子伞裙与水平面呈不同的倾角,常规的检测方法无法对其憎水性进行有效的现场检测与判定。首先采用pH值为14、温度为100℃的Na OH溶液对复合绝缘子样片进行老化,在与水平面呈25&... 憎水性是表征复合绝缘子老化状况的重要指标,由于V串复合绝缘子伞裙与水平面呈不同的倾角,常规的检测方法无法对其憎水性进行有效的现场检测与判定。首先采用pH值为14、温度为100℃的Na OH溶液对复合绝缘子样片进行老化,在与水平面呈25°夹角的条件下采用喷水分级法测试获得了各老化后样片的憎水性等级,提出了采用微量进样器在样片表面滴加体积为20μL水珠的方法,排除了喷水分级法中水雾喷射角度、速度以及喷水量等因素对水珠形态特征的影响。针对不同倾角下水珠在不同憎水性等级样片表面的形态特征,研究了7个水珠形态特征参数与倾角和憎水性等级之间的关系,发现内上角、内顶角相关性较强;结合与倾角和憎水性密切相关的最大稳态水珠体积参数,提出了V串复合绝缘子憎水性等级的综合判定方法。通过对不同倾角下的伞裙开展水珠形态测试,验证了本文提出方法的有效性和准确性,实现了V串复合绝缘子的憎水性检测与判定。 展开更多
关键词 v串复合绝缘子 水珠形态 特征参数 老化 憎水性判定
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双尾撑倒V尾无人机气动特性及静稳定性计算分析
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作者 王晓璐 李卓远 +1 位作者 陆文龙 杨浩男 《航空工程进展》 CSCD 2023年第6期99-108,共10页
在双尾撑无人机上配置倒V形尾翼,其夹角会影响全机的气动特性和静稳定性。提出一种双尾撑倒V形尾翼布局,采用数值方法与U形尾翼布局进行对比分析;对倒V形及U形尾翼布局的计算模型进行校核和验证,分析两种布局在不同迎角和侧滑角下的纵... 在双尾撑无人机上配置倒V形尾翼,其夹角会影响全机的气动特性和静稳定性。提出一种双尾撑倒V形尾翼布局,采用数值方法与U形尾翼布局进行对比分析;对倒V形及U形尾翼布局的计算模型进行校核和验证,分析两种布局在不同迎角和侧滑角下的纵向、横向和航向气动特性及静稳定性。结果表明:倒V形尾翼可减小浸润面积,使全机升阻比提高2.2%,增大了尾翼失速迎角,但横向静稳定度明显下降;当尾翼夹角小于90°时,倒V形尾翼能够增强全机横向稳定性,夹角增大也会使航向静稳定度略有降低,而纵向静稳定度有一定增强。 展开更多
关键词 v形尾翼 双尾撑布局 无人机 气动特性 静稳定性
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光强自助校准的太阳能电池J-V自动测试系统 被引量:1
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作者 刘野 刘振泰 +2 位作者 张健 韩炜 李传南 《吉林大学学报(信息科学版)》 CAS 2018年第3期293-299,共7页
为解决现有太阳能电池测试系统结构复杂、价格昂贵和使用不便等问题,研制了一种具有光强自动校准功能的太阳能电池J-V(Current Density-Voltage)特性测试系统,能实现多个太阳能电池器件的自动测量。系统由计算机及测试软件、数字源表Kei... 为解决现有太阳能电池测试系统结构复杂、价格昂贵和使用不便等问题,研制了一种具有光强自动校准功能的太阳能电池J-V(Current Density-Voltage)特性测试系统,能实现多个太阳能电池器件的自动测量。系统由计算机及测试软件、数字源表Keithley2400、输出功率为500 W的氙灯光源及其驱动电源、多器件自动切换及其测量电路、标准光电二极管组成的光电流测量电路及光强校准电路、氙灯工作时长测量电路等模块构成,上位机测试软件采用Visual Basic语言编写。测试软件依据在标准光电二极管测到的光电流,并通过单片机控制的调光电路输出相应的直流电压到氙灯驱动电源,实现了氙灯光强的自动校准和标准100 m W/cm^2AM1.5太阳光谱的输出,同时测试软件通过数字源表和多器件自动测量电路分别测得各器件的J-V特性,并计算出器件的效率等参数。测试结果表明,该系统达到了既定的设计目标,具有成本低、自动化程度高且使用方便等特点。 展开更多
关键词 太阳能电池 j-v特性 测量系统 多器件自动测量 光强自动校准
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The influences of model parameters on the characteristics of memristors 被引量:4
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作者 周静 黄达 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第4期576-585,共10页
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
关键词 MEMRISTOR I-v characteristics simulation program with integrated circuit emphasis
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摩擦型V带传动的工作特点与几何计算 被引量:2
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作者 酒建刚 许庆峰 +2 位作者 吴蒙 杨广军 吴孟高 《拖拉机与农用运输车》 2023年第2期77-82,共6页
摩擦型V带传动是依靠带和带轮之间的摩擦力来进行工作的,它属于外摩擦的应用范畴,同时发挥了很好的主动力效应。在非道路柴油机上,根据工程应用的实践分析,本文重点阐述了其工作特点与几何计算,主要涉及了摩擦型带传动的本源与结构形式... 摩擦型V带传动是依靠带和带轮之间的摩擦力来进行工作的,它属于外摩擦的应用范畴,同时发挥了很好的主动力效应。在非道路柴油机上,根据工程应用的实践分析,本文重点阐述了其工作特点与几何计算,主要涉及了摩擦型带传动的本源与结构形式、工作组成与运行特点、楔形增压原理与几何关系、当量摩擦系数与轮槽匹配等内容。 展开更多
关键词 摩擦型 v带传动 非道路柴油机 工作特点
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The electrical characteristics of a 4H-silicon carbide metal-insulator-semiconductor structure with Al_2O_3 as the gate dielectric 被引量:1
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作者 刘莉 杨银堂 马晓华 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第12期366-372,共7页
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
关键词 AL2O3 4H-silicon carbide metal-insulator-semiconductor capacitor gate leakage current C-v characteristics
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V/Pd界面氢吸附扩散行为的第一性原理研究
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作者 张江林 王仲民 +4 位作者 王殿辉 胡朝浩 王凤 甘伟江 林振琨 《物理学报》 SCIE EI CAS CSCD 北大核心 2023年第16期298-306,共9页
采用钒/钯(V/Pd)金属复合膜渗氢是从混合气体中分离氢气的一种有效实用方法.为深入地了解催化Pd层与金属膜结合处的界面结构与吸氢/渗氢特性的关联性,进而提升合金膜提纯氢气的能力,本文采用基于密度泛函理论的第一性原理研究了V/Pd金... 采用钒/钯(V/Pd)金属复合膜渗氢是从混合气体中分离氢气的一种有效实用方法.为深入地了解催化Pd层与金属膜结合处的界面结构与吸氢/渗氢特性的关联性,进而提升合金膜提纯氢气的能力,本文采用基于密度泛函理论的第一性原理研究了V/Pd金属复合膜界面的氢吸附/扩散行为.研究结果表明:由于V/Pd界面的电荷密度随着V/Pd成键而增加,导致氢原子(H)溶解能随着接近界面而增大,在V/Pd界面附近具有最高的溶解能(0.567 eV).氢迁移能垒计算表明,与H沿V/Pd界面水平扩散的最大能垒(0.64 eV)相比,H垂直V/Pd界面能垒(0.56 eV)更小,因而H倾向于垂直V/Pd界面进行迁移,并由Pd层扩散到V基体一侧,因V/Pd界面处Pd层的氢溶解能(0.238 eV)高于V膜侧(-0.165 eV),H将在界面的V膜侧积累,易引起氢脆.V基体掺杂Pd/Fe的计算表明,与未掺杂的能垒(0.56 eV)相比,掺杂Pd/Fe可明显地降低界面扩散路径中的最大能垒(0.45 eV/0.54 eV),利于氢的渗透扩散,且掺杂界面能一定程度抑制V和催化Pd层的相互扩散,提高复合膜的结构稳定性. 展开更多
关键词 v/Pd界面 第一性原理 氢渗透性能 拉伸应变
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Characteristics and Thermal Efficiency of a Non-transferred DC Plasma Spraying Torch Under Low Pressure
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作者 鲍世聪 郭文康 +2 位作者 叶民友 须平 张晓东 《Plasma Science and Technology》 SCIE EI CAS CSCD 2008年第6期701-705,共5页
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
关键词 I-v characteristics thermal efficiency DC plasmatron vACUUM
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