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1.
聚乙烯/蒙脱土纳米复合材料的研制   总被引:2,自引:0,他引:2  
采用熔融插层复合法制备了一种新型的电(光)缆护套料——聚乙烯/蒙脱土纳米复合材料。傅里叶变换红外光谱(FTIR)测试表明,有机阳离子已和蒙脱土中的钠离子发生了交换作用,X射线衍射(XRD)测试表明聚乙烯已经进入到蒙脱土片层间,形成了插层型纳米复合材料。测试了复合材料的热学性能和力学性能,试验表明聚乙烯/蒙脱土纳米复合材料比传统的聚乙烯护套料在耐热性能和力学性能等方面均有显著提高。  相似文献   

2.
熔融插层制备SBS/蒙脱土纳米复合材料的微观结构研究   总被引:5,自引:0,他引:5  
采用TEM、XRD对熔融插层法制备的SBS/蒙脱土纳米复合材料的微观结构进行了研究,并进行了力学性能测试结果表明制备形成以插层型为主兼有剥离型的混合型纳米复合材料,其力学性能得到明显的提高。  相似文献   

3.
本文用X—ray衍射(XRD)方法研究了磁控溅射制备的MmNi3.5(CoAlMn)1.5/Mg(简写为Mg/MmM5)复合薄膜吸放氢前后的结构变化与储氢性能间的关系。XRD表明Mg/MmM,多层膜中Mg层的储氢性能有一定程度的改善,吸,放氢温度分别为473K和523K。用透射电镜(TEM)分析方法研究了Mg/MmM5多层薄膜的微观结构,Mg/MmM5多层膜中Mg层和MmM5层的结构与衬底的性质有密切关系。Mg层由纳米晶和沿垂直于衬底表面的[001]方向生长的柱状晶组成;MmM5层则由纳米晶和非晶组成。Mg/MmM5多层膜在吸氢过程中表现为(103)面平行于衬底生长的柱状晶先吸氢,然后是(001)面生长的柱状晶再吸氢。  相似文献   

4.
胶乳法制备天然橡胶/蒙脱土纳米复合材料研究   总被引:5,自引:2,他引:5  
目前,国内外制备橡胶,粘土纳米复合材料的主要方法有:(1)单体原位反应插层法;(2)液体橡胶的反应插层法;(3)大分子熔体插层法;(4)大分子溶液插层法;(5)大分子乳液插层法。以上方法均成功地制备了相应的纳米复合材料,但存在着反应复杂、不易控制、粘土含量高时无法均匀分散、成本高等缺点。  相似文献   

5.
介绍导电聚苯胺(PANI)及其复合材料的特点、制备方法、分类、性能优化方法,讨论了掺杂剂的种类、PH值、反应温度等影响聚苯胺复合材料电磁屏蔽性能的因素,并提出要进一步发展需要解决PANI的溶熔性和加工性问题,改善PANI的结构。  相似文献   

6.
在低密度聚乙烯(PE)中添加了纳米氢氧化镁(Mg(OH2))和磷酸三苯酯(TPP)组成的协同阻燃剂,采用共混挤出的方法制备了纳米Mg(OH2)/PE阻燃光缆护套料.对制得的样品进行了氧指数(OI)、示差扫描量热(DSC)法和力学性能的测试,实验结果表明,样品的OI大幅度提高,力学性能和玻璃化温度均满足阻燃光缆护套的要求.  相似文献   

7.
蒙脱土是一种天然无机纳米矿物,是由一片铝氧八面体夹在两片硅氧四面体之间靠共用氧原子而形成的层状结构矿物(2:1型粘土),每一个片层的厚度约为1nm,长和宽各约100nm。由于原材料丰富,价廉,因而蒙脱土/聚合物纳米复合材料得到人们广泛地研究。采用蒙脱土改性天然胶乳医用制品的研究也取得较好的进展,蒙脱土的插层(或剥离)程度对蒙脱土/天然胶乳制品性能有重要的影响。目前普遍使用的是十六烷基三甲基溴化铵(CTAB)的盐酸混合物作为蒙脱土的插层,由于天然胶乳遇到盐酸就产生凝固,因而这种方法不适合用于制备蒙脱土/天然胶乳胶膜。本研究使用CTAB与自制处理剂的混合液作为蒙脱土的插层剂,采用液-液方法制备蒙脱土/天然胶乳胶膜。并采用广角X-射线和TEM研究蒙脱土和蒙脱土/天然胶乳胶膜的超微结构。  相似文献   

8.
新型双空穴注入型高效有机电致发光二极管   总被引:6,自引:6,他引:0  
采用一种新型有机电致发光二极管(OLED)的阳极结构,在玻璃衬底上以半透明的A1膜为出光面,通过在空穴注入层(HIL)和空穴传输层(HTL)中间插入MoOa层,制备了底发射OLED。制备的器件结构为Glass/Al(15nm)/HAT—CN(IOnm)/M003(30nm)/NPB(30nm)/Alq3(60nm)/B...  相似文献   

9.
采用均相沉淀法使NiCl_2溶液与沉淀剂NaOH反应,制备出纳米级Ni(OH)_2超微粉末。用XRD检测,证实其为电极用β-Ni(OH)_2,用TEM对样品进行形貌分析,结果表明,所得产物为不规则的颗粒状的纳米晶,粒径为 20~40 nm。研究还初步探讨了沉淀剂浓度、反应温度、配合剂用量等实验参数对纳米粉组成和结构的影响。并应用正交实验法,对工艺条件进行了优化。将制备出的纳米级Ni(OH)_2按一定比例掺入普通的球型微米级Ni(OH)_2中,充放电测试结果表明,比容量可增加约10%。  相似文献   

10.
超声技术制备蒙脱土/天然橡胶纳米复合材料   总被引:10,自引:2,他引:8  
采用超声技术制备了有机膨润土、钠基膨润土/天然橡胶复合材料,进行了力学性能和热氧老化性能测试,用TEM研究了粘土在橡胶中的分散结构及结合状态。结果表明,有机膨润土经过超声辐射后产生层间剥离,橡胶能够插层进入粘土层间,形成纳米分散结构的复合材料并具有较好的界面作用,从而提高材料的性能。而钠基膨润土难以产生有效剥离,与橡胶的结合较差;当有机膨润土的填充量为3%时,材料的拉伸强度即达到20mpa,老化后性能下降仅为35%。而钠基膨润土复合材料的拉伸强度为17MPa,老化后性能下降达68%。  相似文献   

11.
聚对苯撑苯并双(口恶)唑发光及其器件制备   总被引:2,自引:0,他引:2  
采用光谱技术,研究了聚对苯撑苯并双(口恶)唑(PBO)溶液的光敏发光特性,并用相对法估算出溶液发光效率在50%范围.结合光谱技术、半导体电学和电化学等研究手段,具体研究了以PBO为发光层的单层电致发光器件,研究结果显示,电致发光与薄膜的光致发光有具有相同的发光中心,峰值位于510 nm左右.同时发现,由于存制备过程中不同处理条件使得不同厚度薄膜残留的掺杂物质浓度不同,从而引起薄膜的导电性的不同.使得器件的阈值场强随PBO厚度的减小而逐渐增加.  相似文献   

12.
在高密度小尺寸的系统级封装(SiP)中,对供电系统的完整性要求越来越高,多芯片共用一个电源网路所产生的电压抖动除了会影响到芯片的正常工作,还会通过供电网路干扰到临近电路和其他敏感电路,导致芯片误动作,以及信号完整性和其他电磁干扰问题.这种电压抖动所占频带相当宽,几百MHz到几个GHz的中频电源噪声普通方法很难去除.结合埋入式电容和电源分割方法的特点,提出一种新型高性能埋入式电源低通滤波结构直接替代电源/地平面.研究表明,在0.65~4GHz的频带内隔离深度可达-40~75 dB,电源阻抗均在0.25ohm以下,实现了宽频高隔离度的高性能滤波作用.分别用电磁场和广义传输线两种仿真器模拟,高频等效电路模型分析这种低通滤波器的工作原理以及结构对隔离性能的影响,并进行了实验验证.  相似文献   

13.
Aluminium was a primary material for interconnection in integrated circuits (ICs) since their inception. Later, copper was introduced as interconnect material which has better metallic conductivity and resistance to electromigration. As the aggressive technology scaling continues, the copper resistivity increased because of size effects, which causes increase in delay, power dissipation and electromigration. The need to reduce the resistor-capacitor??????? delay, dynamic power utilisation and the crosstalk commotion is as of now the fundamental main impetus behind the presentation of new materials. The purpose of this paper is to do a survey of interconnect material used in IC from introduction of ICs to till date. This paper studies and reviews new materials available for interconnect application which are optical interconnects, carbon nanotube (CNT), graphene nanoribbons (GNRs) and silicon nanowires which are alternatives to copper. While doing a survey of interconnect material, it is found that multiwalled CNTs, multilayer GNR and mixed CNT bundles are promising candidates and are ultimate choice that can strongly address the problems faced by copper but on integration basis copper would last for coming years.  相似文献   

14.
Arsenic deposition as a precursor layer on silicon (211) and (311) surfaces   总被引:2,自引:0,他引:2  
We investigate the properties of arsenic (As) covered Si(211) and Si(311) surfaces by analyzing data from x-ray photoelectron spectroscopy (XPS) and low-energy electron diffraction (LEED) images. We then create a model using total surface energy calculations. It was found that both Si(211) and Si(311) had 0.68±0.08 surface As coverage. Si(211) had 0.28±0.04 Te coverage and Si(311) had 0.24±0.04 Te coverage. The Si(211) surface replaces the terrace and trench Si atoms with As for a lower surface energy, while the Si edge atoms form dimers. The Si(311) surface replaces all terrace atoms and adsorbs an As dimer every other edge site. These configurations imply an improvement in the mean migration path from the bare silicon surface by allowing the impinging atoms for the next epitaxial layer, tellurium (Te), to bind at every other pair of edge atoms, and not the step terrace sites. This would ensure a nonpolar, B-face growth.  相似文献   

15.
光子晶体微腔发光二极管   总被引:1,自引:0,他引:1  
光子晶体微腔因其具有增强自发辐射、定向输出和单模工作的能力而受到广泛关注。介绍了光子晶体微腔发光二极管的基本原理、设计、特性、制作及其典型器件。  相似文献   

16.
The power generation demand is increasing day-by-day throughout the world, therefore, the use of hybrid systems becomes a significant solution. The hybrid renewable energy system (HRES) is used for delivering power in various regions in order to overcome intermittence of wind and solar resources. Because of increasing environmental problems, for example, greenhouse gas emission and energy cost have interested novel research into substitute methods in favour of electrical power generation. Maximum Power Point Tracking (MPPT) control method is a vast deal of novel research used for enhancing the efficiency of HRES. The authors have revealed that the hybrid techniques i.e. Global MPPT, fuzzy-neuro systems, Adaptive Neuro-Fuzzy Inference System (ANFIS), Perturbed and Observe (P&O) + Adaptive Neural Network (ANN) etc. can provide best results as compared to other MPPT control methods. This paper offering a state of art review of MPPT control techniques for HRES.  相似文献   

17.
马治强  徐跃  朱思慧  吴仲 《微电子学》2021,51(4):546-551
基于新型共源共栅电流源的积分方法,设计了一种用于单光子飞行时间(TOF)测量的时间-幅度变换器(TAC).该方法有效简化了 TAC电路结构,减小了 TAC占用面积,显著提高了TOF的满量程范围(FSR).采用0.18 μm标准CMOS工艺设计.集成TAC的单光子探测器像素单元的填充因子可达到26.8%.后仿真结果表明,...  相似文献   

18.
超宽带脉冲信号的光学生成方法研究   总被引:1,自引:0,他引:1  
近年来超宽带(UWB)通信技术迅猛发展,在测量、雷达技术、民用和军事无线通信中有着重要的应用,UWB-over-fiber技术已经成为目前研究的热点,其中就包括UWB脉冲信号的产生方法。区别于传统的电子学方法,光子学产生方法不受电子瓶颈制约,可以实现很高的带宽,并且具有抗电磁干扰、重量轻、结构紧凑的优点。通过对比国内外本领域研究成果,讨论及总结了以下三种原理的UWB脉冲信号的光学生成方法:1)相位调制-强度调制转换(PM-IM);2)半导体光放大器(SOA)的非线性效应;3)频谱塑形和色散所致频域-时域映射,然后对各种方案进行了对比分析。  相似文献   

19.
Impulse radio ultra-wideband (IR-UWB) ranging and positioning require accurate estimation of time-of-arrival (TOA) and direction-of-arrival (DOA). With receiver of two antennas, both of the TOA and DOA parameters can be estimated via two-dimensional (2D) propagator method (PM), in which the 2D spectral peak searching, however, renders much higher computational complexity. This paper proposes a successive PM algorithm for joint TOA and DOA estimation in IR-UWB system to avoid 2D spectral peak searching. The proposed algorithm firstly gets the initial TOA estimates in the two antennas from the propagation matrix, then utilises successively one-dimensional (1D) local searches to achieve the estimation of TOAs in the two antennas, and finally obtains the DOA estimates via the difference in the TOAs between the two antennas. The proposed algorithm, which only requires 1D local searches, can avoid the high computational cost in 2D-PM algorithm. Furthermore, the proposed algorithm can obtain automatically paired parameters and has better joint TOA and DOA estimation performance than conventional PM algorithm, estimation of signal parameters via rotational invariance techniques algorithm and matrix pencil algorithm. Meanwhile, it has very close parameter estimation to that of 2D-PM algorithm. We have also derived the mean square error of TOA and DOA estimation of the proposed algorithm and the Cramer-Rao bound of TOA and DOA estimation in this paper. The simulation results verify the usefulness of the proposed algorithm.  相似文献   

20.
多孔硅发光机制的分析   总被引:4,自引:0,他引:4  
从量子力学的基本理论出发讨论了量子限制效应,推导出多孔硅有效禁带宽度增量并用量子限制效应和表面态及其物质在发光中作用的理论解释了PS光致发光的实验现象。  相似文献   

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