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Structures and electrochemical hydrogen storage performance of Si added A_2B_7-type alloy electrodes 被引量:6
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作者 张羊换 任慧平 +3 位作者 蔡颖 杨泰 张国芳 赵栋梁 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第2期406-414,共9页
In order to ameliorate the electrochemical hydrogen storage performance of La-Mg-Ni system A2B7-type electrode alloys, a small amount of Si was added. The La0.8Mg0.2Ni3.3Co0.2Six (x=0-0.2) electrode alloys were prep... In order to ameliorate the electrochemical hydrogen storage performance of La-Mg-Ni system A2B7-type electrode alloys, a small amount of Si was added. The La0.8Mg0.2Ni3.3Co0.2Six (x=0-0.2) electrode alloys were prepared by casting and annealing. The effects of adding Si on the structure and electrochemical hydrogen storage characteristics of the alloys were investigated systematically. The results indicate that the as-cast and annealed alloys hold multiple structures, involving two major phases of (La, Mg)2Ni7 with a Ce2Ni7-type hexagonal structure and LaNi5 with a CaCu5-type hexagonal structure as well as one residual phase LaNi3. The addition of Si results in a decrease in (La, Mg)2Ni7 phase and an increase in LaNi5 phase without changing the phase structure of the alloys. What is more, it brings on an obvious effect on electrochemical hydrogen storage characteristics of the alloys. The discharge capacities of the as-cast and annealed alloys decline with the increase of Si content, but their cycle stabilities clearly grow under the same condition. Furthermore, the measurements of the high rate discharge ability, the limiting current density, hydrogen diffusion coefficient as well as electrochemical impedance spectra all indicate that the electrochemical kinetic properties of the electrode alloys first increase and then decrease with the rising of Si content. 展开更多
关键词 A2B7-type electrode alloy si additive structurE electrochemical characteristics
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Fabrication of Anti-reflecting Si Nano-structures with Low Aspect Ratio by Nano-sphere Lithography Technique 被引量:1
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作者 Shenghua Sun Peng Lu +4 位作者 Jun Xu Ling Xu Kunji Chen Qimin Wang Yuhua Zuo 《Nano-Micro Letters》 SCIE EI CAS 2013年第1期18-25,共8页
Nano-structured photon management is currently an interesting topic since it can enhance the optical absorption and reduce the surface reflection which will improve the performance of many kinds of optoelectronic devi... Nano-structured photon management is currently an interesting topic since it can enhance the optical absorption and reduce the surface reflection which will improve the performance of many kinds of optoelectronic devices, such as Si-based solar cells and light emitting diodes. Here, we report the fabrication of periodically nano-patterned Si structures by using polystyrene nano-sphere lithography technique. By changing the diameter of nano-spheres and the dry etching parameters, such as etching time and etching power, the morphologies of formed Si nano-structures can be well controlled as revealed by atomic force microscopy.A good broadband antireflection property has been achieved for the formed periodically nano-patterned Si structures though they have the low aspect ratio(<0.53). The reflection can be significantly reduced compared with that of flat Si substrate in a wavelength range from 400 nm to 1200 nm. The weighted mean reflection under the AM1.5 solar spectrum irradiation can be as low as 3.92% and the corresponding optical absorption is significantly improved, which indicates that the present Si periodic nano-structures can be used in Si-based thin film solar cells. 展开更多
关键词 Nano-sphere lithograph nano-patterned si structures ANTIREFLECTION
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Al-5Nb-B细化剂对Al-12Si合金组织与性能的影响
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作者 张向东 郭永春 +1 位作者 夏峰 李建平 《热加工工艺》 北大核心 2024年第1期100-104,共5页
采用氟盐法制备了Al-5Nb-B晶粒细化剂,将所制备的细化剂按不同含量(0.0wt%、1.5wt%、3.0wt%、4.5wt%)分别添加到Al-12Si合金中。采用光学显微镜、扫描电镜对添加不同含量晶粒细化剂的Al-12Si合金的显微组织进行观察,并在电子万能试验机(... 采用氟盐法制备了Al-5Nb-B晶粒细化剂,将所制备的细化剂按不同含量(0.0wt%、1.5wt%、3.0wt%、4.5wt%)分别添加到Al-12Si合金中。采用光学显微镜、扫描电镜对添加不同含量晶粒细化剂的Al-12Si合金的显微组织进行观察,并在电子万能试验机(D2-02001)上进行室温力学性能测试。研究了Al-5Nb-B晶粒细化剂对近共晶Al-12Si合金显微组织与拉伸性能的影响。结果表明:氟盐法制备的Al-5Nb-B晶粒细化剂主要包含平均尺寸为20μm的Al3Nb颗粒和5μm的NbB2颗粒。随着Al-5Nb-B晶粒细化剂含量的增大,Al-12Si合金中α-Al晶粒尺寸由未添加的1864μm减小到396μm,铸态合金的抗拉强度由128 MPa增大到145 MPa,且断后伸长率由6.9%提高到9.8%。氟盐法制备的Al-5Nb-B晶粒细化剂提高了NbB2在Al-12Si合金熔体中的形核数,有效细化了α-Al基体,提高了合金力学性能。 展开更多
关键词 Al-5Nb-B晶粒细化剂 AL-si合金 显微组织 力学性能
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SiCp/Al-Si基复合材料界面结构调控及强化机制的研究进展
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作者 苏嶓 王爱琴 +4 位作者 谢敬佩 刘瑛 张津浩 柳培 梁婷婷 《材料热处理学报》 CAS CSCD 北大核心 2024年第2期1-12,共12页
SiCp/Al-Si基复合材料具有高的比强度、比刚度、比模量,良好的导热、导电、耐磨性及尺寸稳定性等优点,作为结构功能性材料应用于空间工程、电子封装、交通运输和精密仪器等领域。其研究热点主要集中在界面结构调控、强化机制及性能调控... SiCp/Al-Si基复合材料具有高的比强度、比刚度、比模量,良好的导热、导电、耐磨性及尺寸稳定性等优点,作为结构功能性材料应用于空间工程、电子封装、交通运输和精密仪器等领域。其研究热点主要集中在界面结构调控、强化机制及性能调控等方面。在SiCp/Al-Si复合材料中存在着增强体与基体界面、析出相与基体界面、析出相与增强体界面,这些界面受各种因素影响,会出现多种界面反应和界面产物,界面结构和结合状态复杂而多样。基于此,本文综述了制备工艺、基体合金成分和SiCp表面改性等方面对SiCp/Al-Si基复合材料界面结构的影响及调控,并总结了影响其力学性能的因素及强化机制的研究现状,最后对复合材料未来的发展及研究方向进行了展望。 展开更多
关键词 siCp/Al-si复合材料 界面结构调控 力学性能 强化机制 多尺度研究
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Effects of Si δ-Doping Condition and Growth Interruption on Electrical Properties of InP-Based High Electron Mobility Transistor Structures 被引量:2
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作者 周书星 齐鸣 +4 位作者 艾立鹍 徐安怀 汪丽丹 丁芃 金智 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第9期112-115,共4页
The InGaAs/InAIAs/InP high electron mobility transistor (HEM:F) structures with lattice-matched and pseudo- morphic channels are grown by gas source molecular beam epitaxy. Effects of Si ^-doping condition and grow... The InGaAs/InAIAs/InP high electron mobility transistor (HEM:F) structures with lattice-matched and pseudo- morphic channels are grown by gas source molecular beam epitaxy. Effects of Si ^-doping condition and growth interruption on the electrical properties are investigated by changing the Si-cell temperature, doping time and growth process. It is found that the optimal Si ^-doping concentration (Nd) is about 5.0 x 1012 cm-2 and the use of growth interruption has a dramatic effect on the improvement of electrical properties. The material structure and crystal interface are analyzed by secondary ion mass spectroscopy and high resolution transmission elec- tron microscopy. An InGaAs/InAiAs/InP HEMT device with a gate length of lOOnm is fabricated. The device presents good pinch-off characteristics and the kink-effect of the device is trifling. In addition, the device exhibits fT = 249 GHa and fmax 〉 400 GHz. 展开更多
关键词 InP InGaAs Doping Condition and Growth Interruption on Electrical Properties of InP-Based High Electron Mobility Transistor structures Effects of si
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Al-Mg-Si合金在均匀化退火过程中的组织演变
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作者 冉继龙 赵经纬 +7 位作者 李学云 亓鹏 周青华 赵丕植 丁力群 陈涛 乐启炽 朱庆丰 《轻合金加工技术》 CAS 2024年第5期46-52,共7页
通过光学显微镜、扫描电镜和差示扫描量热仪等技术手段研究了Al-0.7Mg-0.9Si合金在550℃均匀化退火过程中的显微组织演变。结果表明,合金的铸态组织存在严重偏析,晶界析出长条状Al(Fe, Mn)Si相和短棒状Mg_(2)Si相,晶内析出球状Q-AlCuMgS... 通过光学显微镜、扫描电镜和差示扫描量热仪等技术手段研究了Al-0.7Mg-0.9Si合金在550℃均匀化退火过程中的显微组织演变。结果表明,合金的铸态组织存在严重偏析,晶界析出长条状Al(Fe, Mn)Si相和短棒状Mg_(2)Si相,晶内析出球状Q-AlCuMgSi相;随着均匀化退火时间的延长,枝晶偏析消失,Q-AlCuMgSi相和Mg_(2)Si相逐步回溶于基体,Al(Fe, Mn)Si相发生断续化转变。合金导电率呈先降低后缓慢升高的趋势。结合均匀化动力学计算,确定Al-Mg-Si合金合理的均匀化退火制度为550℃8 h。 展开更多
关键词 AL-MG-si合金 均匀化退火 铸态组织 导电率 第二相
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基于第一性原理GGA+U方法研究Si掺杂β-Ga_(2)O_(3)电子结构和光电性质
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作者 张英楠 张敏 +1 位作者 张派 胡文博 《物理学报》 SCIE EI CAS CSCD 北大核心 2024年第1期296-305,共10页
采用基于密度泛函理论的GGA+U方法,计算了本征和Si掺杂β-Ga_(2)O_(3)的形成能、能带结构、态密度、差分电荷密度和光电性质.结果表明,Si取代四面体Ga(1)更容易实验合成,得到的β-Ga_(2)O_(3)带隙和Ga-3d态峰值与实验结果吻合较好,且贫... 采用基于密度泛函理论的GGA+U方法,计算了本征和Si掺杂β-Ga_(2)O_(3)的形成能、能带结构、态密度、差分电荷密度和光电性质.结果表明,Si取代四面体Ga(1)更容易实验合成,得到的β-Ga_(2)O_(3)带隙和Ga-3d态峰值与实验结果吻合较好,且贫氧条件下更倾向于获得有效掺杂.Si掺杂后,总能带向低能端移动,费米能级进入导带,呈现n型导电性;Si-3s轨道电子占据导带底,电子公有化程度加强,电导率明显改善.随着Si掺杂浓度的增加,介电函数ε_(2)(ω)的结果表明,激发导电电子的能力先增强后减弱,与电导率的量化分析结果一致.光学带隙增大,吸收带边上升速度减慢;吸收光谱结果显示Si掺杂β-Ga_(2)O_(3)具有较强的深紫外光电探测能力.计算结果将为下一步Si掺杂β-Ga_(2)O_(3)实验研究和器件设计的创新及优化提供理论参考. 展开更多
关键词 GGA+U方法 si掺杂β-Ga_(2)O_(3) 电子结构 光电性质
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CO_(2)氧化多孔Mg_(2)Si制备微纳分级Si/C材料及储锂性能
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作者 郑娅 刘娟 +3 位作者 喻强 穆艺臣 赵小玉 李小成 《有色金属科学与工程》 CAS 北大核心 2024年第2期256-264,273,共10页
硅基负极材料储量丰富、能量密度高、工作电压稳定,是最具有前景的锂离子电池负极材料之一。然而硅接近300%的体积膨胀和较低的离子导电率在电池的循环中十分不利。本文以多孔Mg_(2)Si为原料,通过CO_(2)氧化一步法去除了Mg的同时,在微... 硅基负极材料储量丰富、能量密度高、工作电压稳定,是最具有前景的锂离子电池负极材料之一。然而硅接近300%的体积膨胀和较低的离子导电率在电池的循环中十分不利。本文以多孔Mg_(2)Si为原料,通过CO_(2)氧化一步法去除了Mg的同时,在微米级多孔硅体系中引入了纳米级孔隙,并实现了碳层的均匀复合,制备了微纳分级三维多孔Si/C复合材料(MN-p-Si/C)。该结构不仅减轻了硅在脱嵌锂过程的体积膨胀,为离子和电子的传输提供了三维有效通道,碳层还大幅提高了材料的导电性。得益于这些优势,MN-p-Si/C表现出优异的电化学性能,首次充放电比容量分别为2869.2 mAh/g、2364.5 mAh/g,初始库仑效率高达82.41%,在1A/g高电流密度下,200圈循环后MN-p-Si/C可逆容量还保持在1127.1 mAh/g,容量保持率为70.9%,具有良好的应用前景。 展开更多
关键词 硅/碳负极 多孔结构 CO_(2)氧化反应 Mg_(2)si
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SOLIDIFYING STRUCTURES OF Al_2O_3 SHORT FIBER/Al-Si ALLOY MATRIX COMPOSITE PREPARED BY SQUEEZE CASTING 被引量:2
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作者 Zhang, Siqi Huang, Jinsong +2 位作者 Shen, Jian Lu, Bin Xu, Guofu 《中国有色金属学会会刊:英文版》 EI CSCD 1995年第3期133-135,共3页
SOLIDIFYINGSTRUCTURESOFAl_2O_3SHORTFIBER/Al-SiALLOYMATRIXCOMPOSITEPREPAREDBYSQUEEZECASTING¥Zhang,Siqi;Huang,J... SOLIDIFYINGSTRUCTURESOFAl_2O_3SHORTFIBER/Al-SiALLOYMATRIXCOMPOSITEPREPAREDBYSQUEEZECASTING¥Zhang,Siqi;Huang,Jinsong;Shen,Jian;... 展开更多
关键词 composite SHORT FIBER AL-si ALLOY solidifying structures SQUEEZE CASTING
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Structures and Phase Transition of GaAs under Pressure 被引量:1
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作者 崔红玲 陈向荣 +1 位作者 姬广富 魏冬青 《Chinese Physics Letters》 SCIE CAS CSCD 2008年第6期2169-2172,共4页
A first-principles plane wave method with the ultrasoft pseudopotential scheme in the frame of the density functional theory (DFT) is performed to calculate the lattice parameters a and c, the bulk modulus B0 and it... A first-principles plane wave method with the ultrasoft pseudopotential scheme in the frame of the density functional theory (DFT) is performed to calculate the lattice parameters a and c, the bulk modulus B0 and its pressure derivative B0 of the zinc-blende GaAs (ZB-GaAs), rocksalt GaAs (RS-GaAs), CsCl-GaAs, NiAs- GaAs and wurtzite GaAs (WZ-GaAs). Our results are consistent with the available experimental data and other theoretical results. We also calculate the phase transition pressures among these different phases. The results are satisfactory. 展开更多
关键词 III-V ELECTRONIC-structurE GALLIUM-ARSENIDE SEMICONDUCTORS STABILITY ALAS IV si
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Effect of annealing on the microstructures and Vickers hardness at room temperature of intermetallics in Mo-Si system 被引量:1
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作者 YANG Haibo LI Wei +1 位作者 SHAN Aidang WU Jiansheng Key Laboratory of Ministry of Education for High Temperature Materials and Tests & Department of Material Science and Engieering, Shanghai Jiao Tong University, Shanghai 200030, China 《Rare Metals》 SCIE EI CAS CSCD 2004年第2期176-181,共6页
The microstructures and Vickers hardness at room temperature of arc-meltingprocessed intermetallics of Mo_5Si_3-MoSi_2 hypoeutectic alloy and hypereutectic alloy annealed at1200℃ for different time were investigated.... The microstructures and Vickers hardness at room temperature of arc-meltingprocessed intermetallics of Mo_5Si_3-MoSi_2 hypoeutectic alloy and hypereutectic alloy annealed at1200℃ for different time were investigated. Lamellar structure consisted of Mo_5Si_3 (D8m) phaseand MoSi_2 (C11_b) phase was observed in all the alloys. For Mo_5Si_3-MoSi_2 hypoeutectic alloy, thelamellar structure was found only after annealing and developed well with fine spacing on the orderof hundred nanometers after annealing at 1200℃ for 48 h. But when the annealing time was up to 96h, the well-developed lamellar structure was destroyed. For Mo_5Si_3-MoSi_2 hypereutectic alloy, thelamellar structure was found both before and after annealing. However the volume fraction andspacing of the lamellar structure did not change significantly before and after annealing. Theeffects of the formation, development and destruction of lamellar structure on Vickers hardness ofalloys were also investigated. When Mo_5Si_3-MoSi_2 hypoeutectic alloy annealed at 1200℃ for 48 h,the Vickers hardness was improved about 19% compared with that without annealing and formation oflamellar structure. The highest Vickers hardness of Mo5Si3-MoSi_2 hypereutectic was increasing about18% when annealing at 1200℃ for 48 h. 展开更多
关键词 material experiment lamellar structure microstructure vickers hardness ANNEAL INTERMETALLICS Mo-si system
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High temperature oxidation of inoculated high Si/SiMo ductile cast irons in air and combustion atmospheres
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作者 Iuliana Stan Mihai Chisamera +5 位作者 Robert Lascu Codrut Cariga Eduard Stefan Stelian Stan Denisa Anca Iulian Riposan 《China Foundry》 SCIE EI CAS CSCD 2024年第5期555-562,共8页
The present work aims to investigate the effect of heating temperature(400,600 and 800°C)and inoculating elements(Ca,Ca-Ba,Ca-RE)on oxidation behavior of ductile irons containing 5.25%Si and 4.8%Si-2.3%Mo in dry ... The present work aims to investigate the effect of heating temperature(400,600 and 800°C)and inoculating elements(Ca,Ca-Ba,Ca-RE)on oxidation behavior of ductile irons containing 5.25%Si and 4.8%Si-2.3%Mo in dry air and combustion gas containing water vapour(natural gas burning).The oxidation is influenced by the gas atmosphere type,the iron alloying system,and the inoculating elements depending on the heating temperature.The weight gain increases from 0.001%-0.1%(400°C)to 0.05%-0.70%(600°C)and up to 0.10%-2.15%(800°C).No particular effects of the considered influencing factors are found when heating at 400°C,while at 600°C,mainly the oxidation gas atmosphere type shows a visible influence.At the highest heating temperature of 800°C,a limited increase of the weight gain is found for dry air atmosphere(up to 0.25%),but it drastically increases for combustion atmospheres(0.65%-2.15%).The water vapour presence in the combustion atmosphere is an important oxidising factor at 600-800°C.The alloying system appears to influence the oxidation behavior mainly at a heating temperature of 800°C in the combustion atmosphere,as evidenced by the lower weight gain in 5.25%silicon cast iron.Positive effects of inoculating elements increase with the heating temperature,with Ca and Ba-FeSi inoculation generally showing better performance.Irons inoculated with CaRE-FeSi exhibit a higher degree of oxidation.These results are in good relationship with the previous reported data:Ca-Ba-inoculation system appears to be better than simple Ca for improving the graphite parameters,while RE-bearing inoculant negatively affects the compactness degree of graphite particles in high-Si ductile irons.As the lower compactness degree is typical for graphite nodules in high-Si ductile irons,which negatively affects the oxidation resistance,it is necessary to employ specific metallurgical treatments to improve nodule quality.Inoculation,in particular,is a potential method to achieve this improvement. 展开更多
关键词 ductile iron spheroidal graphite si/siMo oxidation air/combustion atmospheres FesiCaMgRE treatment Ca Ca-Ba Ca-RE inoculation structure characteristics
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Temperature-dependent dielectric properties of Au/Si_3N_4/n-Si (metal insulator semiconductor) structures
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作者 T.Ataseven A.Tataroglu 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第11期541-546,共6页
The dielectric properties of Au/Si3N4/n-Si (MIS) structures are studied using the admittance measurements (C–V and G/ω–V) each as a function of temperature in a range from 80 K to 400 K for two frequencies (10... The dielectric properties of Au/Si3N4/n-Si (MIS) structures are studied using the admittance measurements (C–V and G/ω–V) each as a function of temperature in a range from 80 K to 400 K for two frequencies (100 kHz and 1 MHz). Experimental results show that both the dielectric constant (ε’) and the dielectric loss (ε") increase with temperature increasing and decrease with frequency increasing. The measurements also show that the ac conductivity (σac) increases with temperature and frequency increasing. The lnσac versus 1000/T plot shows two linear regions with different slopes which correspond to low (120 K–240 K) and high (280 K–400 K) temperature ranges for the two frequencies. It is found that activation energy increases with frequency and temperature increasing. 展开更多
关键词 Au/si3N4/n-si (metal-insulator-semiconductor) structure admittance measurements dielectricproperties ac conductivity
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Electronic structures and optical properties of Si-and Sn-doped β-Ga_2O_3: A GGA+U study 被引量:2
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作者 Jun-Ning Dang Shu-wen Zheng +1 位作者 Lang Chen Tao Zheng 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第1期502-510,共9页
The electronic structures and optical properties of β-Ga_2O_3 and Si-and Sn-doped β-Ga_2O_3 are studied using the GGA + U method based on density functional theory. The calculated bandgap and Ga 3d-state peak of β-... The electronic structures and optical properties of β-Ga_2O_3 and Si-and Sn-doped β-Ga_2O_3 are studied using the GGA + U method based on density functional theory. The calculated bandgap and Ga 3d-state peak of β-Ga_2O_3 are in good agreement with experimental results. Si-and Sn-doped β-Ga_2O_3 tend to form under O-poor conditions, and the formation energy of Si-doped β-Ga_2O_3 is larger than that of Sn-doped β-Ga_2O_3 because of the large bond length variation between Ga–O and Si–O. Si-and Sn-doped β-Ga_2O_3 have wider optical gaps than β-Ga_2O_3, due to the Burstein–Moss effect and the bandgap renormalization effect. Si-doped β-Ga_2O_3 shows better electron conductivity and a higher optical absorption edge than Sn-doped β-Ga_2O_3, so Si is more suitable as a dopant of n-type β-Ga_2O_3, which can be applied in deep-UV photoelectric devices. 展开更多
关键词 density functional theory GGA + U method si-doped β-Ga2O3 Sn-doped β-Ga2O3 electronic structure OPTICAL property
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Structures and Properties of Nanocrystalline Nd_(4.5)Fe_(75)Co_1Si_1B_(18.5) Composite Magnets
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作者 Wenli PEI, Fazeng LIAN and Guiqin ZHOU (Department of Materials Science and Engineering, Northeastern University, Shenyang 110006, China) Jinguo LI (Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第2期121-122,共2页
In this article, the quenched Nd_4.5Fe_75Co_1Si_l B_18.5 ribbons were prepared, and the structures and properties were investigated. The results show that the change of structures of Nd_4.5 Fe_75 Co_1 Si_1 B_18.5 qu... In this article, the quenched Nd_4.5Fe_75Co_1Si_l B_18.5 ribbons were prepared, and the structures and properties were investigated. The results show that the change of structures of Nd_4.5 Fe_75 Co_1 Si_1 B_18.5 quenched amorphous ribbons is Am→Am'+Fe_3B+Nd_2Fe_23B_3+Nd_2Fe_14B→Nd_2- Fe_14B when it is heated. The effect of crystallizing treatment temperature and time on the magnetic properties of the quenched alloy was studied. The magnetic properties of 16 m/s quenched ribbons for 710℃×1200 s crystallizing treatment reach _iH_c=238.6 hA/m, B_r=0.8987 T and (BH)max=51.39 kJ/m^3. The grain size is about DFe3=32 nm and DNd2Fe14B=22 nm. 展开更多
关键词 Composite Magnets FE structures and Properties of Nanocrystalline Nd si
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Illumination and Voltage Dependence of Electrical Characteristics of Au/0.03 Graphene-Doped PVA/n-Si Structures via Capacitance/Conductance-Voltage Measurements
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作者 SAHAR Alialy AHMET Kaya +1 位作者 I Uslua EMSETTIN Altmdal 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第11期92-96,共5页
Au/n-Si (MS) structures with a high dielectric interlayer (0.03 graphene-doped PVA) are fabricated to investigate the illumination and voltage effects on electrical and dielectric properties by using capacitance-v... Au/n-Si (MS) structures with a high dielectric interlayer (0.03 graphene-doped PVA) are fabricated to investigate the illumination and voltage effects on electrical and dielectric properties by using capacitance-voltage (C-V) and conductance-voltage (G/w-V) measurements at room temperature and at 1 MHz. Some of the main electrical parameters such as concentration of doping atoms (ND), barrier height ( ФB( C - V) ), depletion layer width (WD) and series resistance (Rs) show fairly large illumination dispersion. The voltage-dependent profile of surface states (Nss) and resistance of the structure (Ri ) are also obtained by using the dark-illumination capacitance (Cdark- Cm) and Nicollian-Brews methods, respectively, For a clear observation of changes in electrical parameters with illumination, the values of ND, WD, ФB(O- V) and Rs are drawn as a function of illumination intensity. The values of ND and WD change almost linearly with illumination intensity. On the other hand, Rs decreases almost exponentially with increasing illumination intensity whereas ФB(C - V) increases. The experimental results suggest that the use of a high dielectric interlayer (0.03 graphene-doped PVA) considerably passivates or reduces the magnitude of the surface states. The large change or dispersion in main electrical parameters can be attributed to generation of electron-hole pairs in the junction under illumination and to a good light absorption. All of these experimental results confirm that the fabricated Au/0.03 graphene-doped PVA/n-Si structure can be used as a photodiode or a capacitor in optoelectronic applications. 展开更多
关键词 si PVA Illumination and Voltage Dependence of Electrical Characteristics of Au/0.03 Graphene-Doped PVA/n-si structures via Capacitance/Conductance-Voltage Measurements
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四氢呋喃对SIS聚合反应、产品物性及应用性能的影响
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作者 池曙辉 邹浩 +1 位作者 王占高 向贞芬 《弹性体》 CAS 2024年第3期60-63,共4页
研究了制备热塑性弹性体SIS时,溶剂中四氢呋喃含量对聚合反应、产品结构、力学性能及应用性能的影响。结果表明,提高溶剂中四氢呋喃含量,虽然可以加快聚合反应速率,但会导致产品中聚异戊二烯段的支链结构含量上升,进而降低产品的拉伸强... 研究了制备热塑性弹性体SIS时,溶剂中四氢呋喃含量对聚合反应、产品结构、力学性能及应用性能的影响。结果表明,提高溶剂中四氢呋喃含量,虽然可以加快聚合反应速率,但会导致产品中聚异戊二烯段的支链结构含量上升,进而降低产品的拉伸强度和热熔压敏胶的持黏力。 展开更多
关键词 苯乙烯-异戊二烯-苯乙烯嵌段共聚物 四氢呋喃 支链结构 力学性能 热熔压敏胶
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Formation mechanism of periodic layered structure in Ni_3Si/Zn system
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作者 刘亚 董振 +2 位作者 宋媛媛 苏旭平 涂浩 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第12期4053-4058,共6页
The formation of periodic layered structure in Ni3Si/Zn diffusion couples with Zn in vapor or liquid state was investigated by SEM-EDS, FESEM and XRD. The results show that the diffusion path in solid-liquid reaction ... The formation of periodic layered structure in Ni3Si/Zn diffusion couples with Zn in vapor or liquid state was investigated by SEM-EDS, FESEM and XRD. The results show that the diffusion path in solid-liquid reaction is Ni3Si/(T+γ)/γ/…T/γ/Ni4Zn12Si3/γ/…Ni4Zn12Si3/γ/Ni4Zn12Si3/δ…/Ni4Zn12Si3/δ/liquid-Zn, and the diffusion path in solid-vapor reaction is Ni3Si/θ/(T+γ)/γ/…/T/γ/…T/γ/vapor-Zn. With increasing Zn diffusion flux, the diffusion reaction path moves toward the Zn-rich direction, and the distance from the Ni3Si substrate to the periodic layer pair nearest to the interface decreases. In the initial stage of both reactions,γphase nucleates and grows within T matrix phase at first, and then conjuncts together to form a band to reduce the surface energy. Based on the experimental results and diffusion kinetics analysis, the microstructure differences were compared and the formation mechanism of the periodic layered structure in Ni3Si/Zn system was discussed. 展开更多
关键词 NI3si ZN periodic layered structure INTERFACE DIFFUsiON
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First-principles investigations of structural, mechanical, electronic and optical properties of U_3Si_2-type AlSc_2Si_2 under high pressure
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作者 张旭东 王峰 姜伟 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第1期148-156,共9页
The structural, elastic, electronic and optical properties for U3Si2-type AlSc2Si2 compound under pressure were systematically investigated by using the first-principles calculations. The values of elastic constants a... The structural, elastic, electronic and optical properties for U3Si2-type AlSc2Si2 compound under pressure were systematically investigated by using the first-principles calculations. The values of elastic constants and elastic moduli indicate that AlSc2Si2 keeps mechanical stability under high pressure. The mechanical properties of AISc2Si2 are compared with those of Al3Sc. The results indicate that AlSc2Si2 is harder than AI3Sc. Anisotropic constant AU and 3D curved surface of elastic moduli predict that AISc2Si2 is obviously anisotropic under pressure. The electronic structure of AlSc2Si2 exhibits metallic character and the metallicity decreases with the elevated pressure. In addition, optical properties as a function of pressure were calculated and analyzed. The present work provides theoretical support for further experimental work and industrial applications. 展开更多
关键词 U3si2-type AlSc2si2 mechanical properties electronic structure optical properties first-principles calculations
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Fabrication,characterization and electrochemical properties of porous coral-structured Si/C composite anode for lithium ion battery 被引量:1
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作者 唐芬玲 雷建飞 +3 位作者 崔朝阳 欧阳剑 刘钢 赵灵智 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第12期4046-4053,共8页
A porous coral-structured Si/C composite as an anode material was fabricated by coating Si nanoparticles with a carbon layer from polyvinyl alcohol(PVA), erosion of hydrofluoric(HF) acid, and secondary coating wit... A porous coral-structured Si/C composite as an anode material was fabricated by coating Si nanoparticles with a carbon layer from polyvinyl alcohol(PVA), erosion of hydrofluoric(HF) acid, and secondary coating with pitch. Three samples with different pitch contents of 30%, 40% and 50% were synthesized. The composition and morphology of the composites were characterized by X-ray diffractometry(XRD) and scanning electron microscopy(SEM), respectively, and the properties were tested by electrochemical measurements. The results indicated that the composites showed obviously enhanced electrochemical performance compared with that without secondary carbon coating. The second discharge capacity of the composite was 773 m A·h/g at a current density of 100 m A/g, and still retained 669 m A·h/g after 60 cycles with a small capacity fade of less than 0.23%/cycle, while the content of secondary carbon source of pitch was set at 40%. Therefore, the cycle stability of the composite could be excellently improved by regulating carbon content of secondary coating. 展开更多
关键词 si/C composite secondary coating coral structure anode material Li-ion battery
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