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151.
纳微米PZT/水泥基压电复合材料的研究   总被引:1,自引:1,他引:0       下载免费PDF全文
采用溶胶-凝胶法合成了锆钛酸铅(PZT)纳微米粉体.XRD与SEM分析结果表明,经700 ℃煅烧的PZT粉体的平均晶粒尺寸约为26.4 nm,粉体团聚体的平均尺寸约为200 nm.采用干压成型-水化法制备了纳微米PZT/水泥基压电复合材料,研究了复合材料的压电及介电性能.SEM结果表明,PZT陶瓷相在基体中呈网状分布.PZT颗粒之间的良好连通性使复合材料具有优良的压电性能.  相似文献   
152.
碳纳米管的电化学贮氢性能研究   总被引:13,自引:0,他引:13  
研究了碳纳米管电极的电化学性能 ,其电化学储氢量达到 2 0 0mAh·g 1且具有高的电化学活性和良好的循环寿命 .采用循环伏安法研究了氢在碳纳米管电极上吸附 /氧化机理 .  相似文献   
153.
Palecek E  Fojta M 《Talanta》2007,74(3):276-290
Magnetic beads (MBs) are versatile tools in the separation of nucleic acids, proteins and other biomacromolecules, their complexes and cells. In this article recent application of MBs in electrochemical biosensing and particularly in the development of DNA hybridization sensors is reviewed. In these sensors MBs serve not only for separation but also as a platform for optimized DNA hybridization. A hybridization event is detected separately at another surface, which is an electrode. The detection is based either on the intrinsic DNA electroactivity or on various kinds of DNA labeling, including chemical modification, enzyme tags, nanoparticles, electroactive beads, etc., greatly amplifying the signals measured. In addition to DNA hybridization, other kinds of biosensing in combination with MBs, such as DNA-protein interactions, are reviewed.  相似文献   
154.
3D vertically aligned carbon nanotubes (CNTs)/NiCo2O4 core/shell structures are successfully synthesized as binder‐free anode materials for Li‐ion batteries (LIBs) via a facile electrochemical deposition method followed by subsequent annealing in air. The vertically aligned CNTs/NiCo2O4 core/shell structures are used as binder‐free anode materials for LIBs and exhibit high and stable reversible capacity (1147.6 mAhg?1 at 100 mAg?1), excellent rate capability (712.9 mAh g?1 at 1000 mAg?1), and good cycle stability (no capacity fading over 200 cycles). The improved performance of these LIBs is attributed to the unique 3D vertically aligned CNTs/NiCo2O4 core/shell structures, which support high electron conductivity, fast ion/electron transport in the electrode and at the electrolyte/electrode interface, and accommodate the volume change during cycling. Furthermore, the synthetic strategy presented can be easily extended to fabricate other metal oxides with a controlled core/shell structure, which may be a promising electrode material for high‐performance LIBs.  相似文献   
155.
利用聚偏氟乙烯(PVDF)微小结晶的物理交联点作用,制备了形状记忆性能优异的聚偏氟乙烯/丙烯酸酯聚合物(PVDF/ACM)共混材料。为提高其形状回复应力,又将碳纳米管(CNT)引入该共混体系中,系统研究了PVDF/ACM/CNT三元体系纳米复合材料的制备、结构及性能。结果表明,碳纳米管在PVDF/ACM体系中分散均匀;在基本保持其形状记忆性能的前提下,加入质量分数为4%的CNT,材料在25℃时的储能模量由2000 MPa提高至3130 MPa。  相似文献   
156.
碳纳米管在分离科学中的应用研究进展   总被引:1,自引:0,他引:1  
武春霞  王春  王志 《色谱》2011,29(1):6-14
碳纳米管(CNTs)作为一种新型纳米材料已在材料、催化、吸附分离等诸多领域得到了广泛的应用。本文对近年来CNTs在分离科学中的应用研究进展进行了简要评述,主要讨论了CNTs在固相萃取、固相微萃取、膜萃取、色谱固定相和毛细管电泳假固定相等方面的应用。  相似文献   
157.
非共价修饰碳纳米管/二氧化钛复合材料的合成及性能   总被引:2,自引:0,他引:2  
采用溶胶-凝胶法在聚乙烯吡咯烷酮(PVP)非共价修饰的碳纳米管表面均匀沉积二氧化钛粒子制得纳米复合材料。用TEM、XRD、FTIR、N2吸脱附等对复合材料进行了表征。结果表明:纳米二氧化钛纳米粒子均匀沉积在被修饰碳纳米管表面,且二氧化钛为纯锐钛矿晶体结构,没有金红石和板钛矿相。非共价修饰碳纳米管/二氧化钛复合材料具有良好的介孔结构,其孔径分布主要集中在6~10 nm,且比表面积与纯的二氧化钛相比明显增大,在紫外光照射下降解亚甲基蓝,相比纯的二氧化钛和碳纳米管/二氧化钛,具有较高的催化活性。  相似文献   
158.
HNO 3 -pretreated CNTs were employed as supports, and a special ultrasound-assisted impregnation method was designed to prepare supported Cu-Co catalysts for higher-alcohol synthesis from syngas. The catalysts used in this work were characterized by N 2 adsorption-desorption, TEM, XRD, H 2 -TPR, CO-TPD techniques. It was found that the pre-treatment procedure of CNTs remarkably promoted the catalytic properties of the Cu-Co/CNTs catalysts. For the Cu-Co catalyst supported on CNTs pre-treated by 68 wt% HNO 3 , some active components were introduced into the CNTs channels, their dispersions and the amount of strongly adsorbed CO-species were improved. The CO conversion and alcohol yield on the HNO 3 -pretreated Cu-Co/CNTs catalyst were increased by ~21% and ~69%, respectively, compared with those on the normal Cu-Co/CNTs catalyst.  相似文献   
159.
以稀土合金MlNi5-1.35(CoAlMn)1.35为催化剂,C2H2为碳源,H2为还原气和载气,用CVD法合成了纯度较高的CNTs。通过用SEM,TEM,XRD及Raman等表征测试方法,研究了H2流量对合成的CNTs管径、产量、纯度、形态及石墨化程度的影响。结果表明:合金催化剂经还原后其粒径从μm级细化到了nm量级;在催化剂与C2H2反应过程中不通入H2时,催化剂上仍能生长出CNTs,但其长度短而管径粗(约97.8nm),管壁厚而粗糙;随着H2流量增大,CNTs管径先减小后增大,而其产量、纯度及石墨化程度则先提高后下降。当H2流量为50ml·min-1时,CNTs管径达最细(平均管径49.1nm);H2流量为75ml·min-1时,其产物纯度高,产量最大(4.05g·g-1催化剂),CNTs石墨化程度最高;H2流量为100ml·min-1时,CNTs管径最均匀(平均管径97.8nm)。  相似文献   
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