共查询到20条相似文献,搜索用时 656 毫秒
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《IEEE transactions on instrumentation and measurement》2008,57(10):2304-2308
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Yufeng Luo Ke Wang Qunqing Li Shoushan Fan Jiaping Wang 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(15)
Carbon nanotubes (CNTs) are regarded as one of the most promising materials to manufacture high‐performance lithium batteries. This prospect is closely related to the construction of macroscopic architectures of CNTs. The superaligned CNT (SACNT) array is a unique kind of vertically aligned CNT array. Its highly oriented feature and strong intertube force facilitate the fabrication of macroscopic SACNT structures with various forms, including unidirectional films, buckypapers, and aerogels, etc. The as‐produced SACNT macroscopic architectures are successfully introduced into lithium batteries due to their outstanding electrical and mechanical properties. Herein, an overview of the functions of macroscopic SACNTs in lithium batteries is proposed, including their applications in composite electrodes, current collectors, interlayers, and flexible full cells. 相似文献
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Hui Xu Jing Wu Wei Luo Qin Li Weixian Zhang Jianping Yang 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(30)
Electrocatalysis for nitrate reduction reaction (NRR) has recently been recognized as a promising technology to convert nitrate to nitrogen. Catalyst support plays an important role in electrocatalytic process. Although porous carbon and metal oxides are considered as common supports for metal‐based catalysts, fabrication of such architecture with high electric conductivity, uniform dispersion of nanoparticles, and long‐term catalytic stability through a simple and feasible approach still remains a significant challenge. Herein, inspired by the signal transfer mode of dendritic cell, an all‐carbon dendritic cell‐like (DCL) architecture comprising mesoporous carbon spheres (MCS) connected by tethered carbon nanotubes (CNTs) with CuPd nanoparticles dispersed throughout (CuPd@DCL‐MCS/CNTs) is reported. An impressive removal capacity as high as 22 500 mg N g?1 CuPd (≈12 times superior to Fe‐based catalysts), high nitrate conversion (>95%) and nitrogen selectivity (>95%) are achieved under a low initial concentration of nitrate (100 mg L?1) when using an optimized‐NRR electrocatalyst (4CuPd@DCL‐MCS/CNTs). Remarkably, nitrate conversion and nitrogen selectivity are both close to 100% in an ultralow concentration of 10 mg L?1, meeting drinking water standard. The present work not only provides high electrocatalytic performance for NRR but also introduces new inspiration for the preparation of other DCL‐based architectures. 相似文献
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碳纳米管作为增强材料可改善树脂自身性能正备受关注。本文综述了碳纳米管增强树脂力学性能影响因素,同时对目前公开发表的几种预测碳纳米管增强树脂复合材料模量及破坏强度的方法进行了介绍与分析。最后,提出了碳纳米管增强树脂设计研究中面临的问题,并对今后研究动向进行了展望。 相似文献
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Carbon nanotubes (CNTs) have been regarded as ideal reinforcements for high-performance composites. A key factor for the reinforcement efficiency is the interface bonding between the CNTs and the matrix. This paper presents a new constitutive model to predict the mechanical performance of composites made with CNTs. The model takes into account explicitly the performance of the interface between the matrix and the CNTs. The formulation developed is based in the mixing theory. It divides the composite in matrix and in a new material result of coupling the CNTs with the interface. The relation defined between interface and CNTs assumes that the load is transferred to the nanotubes along their ends and that in the central part the CNTs can develop their full strength. The composite non-linear behavior results from the non-linearities of its constituents. In case of interface damage, it also becomes non-linear the law defined to couple the interface with the CNTs. After describing the formulation, it is validated studying the elastic response of several composites made with different types of CNTs reinforcements. The non-linear behavior provided by the formulation is also studied. In both cases the numerical results are compared with experimental data showing good agreement. 相似文献
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Lee BY Heo K Schmucker AL Jin HJ Lim JK Kim T Lee H Jeon KS Suh YD Mirkin CA Hong S 《Nano letters》2012,12(4):1879-1884
We report a simple but efficient method to synthesize carbon nanotube-bridged wires (NBWs) with gaps as small as 5 nm. In this method, we have combined a strategy for assembling carbon nanotubes (CNTs) inside anodized aluminum oxide pores and the on-wire lithography technique to fabricate CNT-bridged wires with gap sizes deliberately tailored over the 5-600 nm range. As a proof-of-concept demonstration of the utility of this architecture, we have prepared NBW-based chemical and biosensors which exhibit higher analyte sensitivity (lower limits of detection) than those based on planar CNT networks. This observation is attributed to a greater surface-to-volume ratio of CNTs in the NBWs than those in the planar CNT devices. Because of the ease of synthesis and high yield of NBWs, this technique may enable the further incorporation of CNT-based architectures into various nanoelectronic and sensor platforms. 相似文献
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为提高碳纳米管(CNTs)湿度传感器的检测精度,研制了一种电阻型碳纳米管湿度传感器.阐述了传感器的结构、工作原理与制作过程,并对传感器的稳定性进行了实验与理论分析.建立并求解了对应于两根碳纳米管间势垒的薛定谔方程.分析结果表明传感器内部碳纳米管的稳定决定了传感器的稳定性,并且测试电压会影响碳纳米管的稳定性对传感器电阻波动的影响.实验结果表明传感器的工作电压影响着传感器的稳定性,当测试电压为5V时传感器电阻波动范围大约是工作电压为15 V时的5倍. 相似文献
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Paintable Carbon‐Based Perovskite Solar Cells with Engineered Perovskite/Carbon Interface Using Carbon Nanotubes Dripping Method 下载免费PDF全文
Jaehoon Ryu Kisu Lee Juyoung Yun Haejun Yu Jungsup Lee Jyongsik Jang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(38)
Paintable carbon electrode‐based perovskite solar cells (PSCs) are of particular interest due to their material and fabrication process costs, as well as their moisture stability. However, printing the carbon paste on the perovskite layer limits the quality of the interface between the perovskite layer and carbon electrode. Herein, an attempt to enhance the performance of the paintable carbon‐based PSCs is made using a modified solvent dripping method that involves dripping of the carbon nanotubes (CNTs), which is dispersed in chlorobenzene solution. This method allows CNTs to penetrate into both the perovskite film and carbon electrode, facilitating fast hole transport between the two layers. Furthermore, this method is results in increased open circuit voltage (Voc) and fill factor (FF), providing better contact at the perovskite/carbon interfaces. The best devices made with CNT dripping show 13.57% power conversion efficiency and hysteresis‐free performance. 相似文献
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A facile and reliable electrochemical technique at beta-cyclodextrin incorporated carbon nanotubes modified glassy carbon electrode (beta-CD/CNTs/GCE) was proposed for determination of pentachlorophenol (PCP). The electrochemical behavior of PCP at the beta-CD/CNTs/GCE was investigated by cyclic voltammetry and linear sweep voltammetry. The beta-CD/CNTs/GCE showed good analytical performance characteristics in electrocatalytic oxidation of PCP, compared with the simple carbon nanotube modified electrode (CNTs/GCE) and bare glassy carbon electrode (GCE). After accumulation for 5 min on beta-CD/CNTs/GCE, the peak current increased linearly with the concentration of PCP in the range from 8.0 x 10(-7) to 1.04 x 10(-5) mol/L. The detection limit was 4.0 x 10(-8) mol/L at 3 sigma level. The proposed electrode presented good repeatability for the determination of PCP in artificial wastewater, and the recovery was 97%-103%. This modified electrode combined the advantages of carbon nanotubes and supramolecular cyclodextrin, leading to new capabilities for electrochemical detection of PCP. 相似文献
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S. J. Kim 《Technical Physics Letters》2005,31(7):597-599
New vacuum gauges with emitters based on carbon nanotubes (CNTs) are described. The relation between the field emission from
CNTs and the residual pressure in the vacuum chamber is considered. The operation of the proposed pressure sensor obeys the
electric discharge theory based on the Paschen law, whereby the pressure is determined by measuring the discharge current
as a function of the concentration of a gas (air) ionized as a result of the collisions with electrons emitted from CNTs. 相似文献
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F. Le Pimpec C. GoughV. Chouhan S. Kato 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,660(1):7-14
Multi-wall Carbon Nanotube (CNT) emitters were tested in a combined diode-RF electron gun. Field emission of the nanotubes was observed at 5-30 MV/m, using a 250 ns FWHM long pulse with a peak voltage of 80-470 kV. The field emission threshold is compatible with that found from previous DC testing. We have extracted from a continuous field emitter up to a nanoCoulomb of charge and measured an emittance of 4 mm mrad with a 2 pC electron beam. The total charge emission during RF operation, using the 1.5 GHz, 2 cell RF structure, was found dependent on its period. RF operation showed that back bombarding electrons with up to 5 MeV did not impair the emission stability of the CNTs. 相似文献
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The scalable preparation of multi-functional three-dimensional (3D) carbon nanotubes and graphene (CNTs-G) hybrids via a well-controlled route is urgently required and challenging.Herein,an easily operated,oxalic acid-assisted method was developed for the in situ fabrication of a 3D lasagna-like Fe-N-doped CNTs-G framework (LMFC) from a precursor designed at the molecular level.The well-organized architecture of LMFC was constructed by multi-dimensionally interconnected graphene and CNTs which derived from porous graphene sheets,to form a fundamentally robust and hierarchical porous structure,as well as favorable conductive networks.The impressive oxygen reduction reaction (ORR) performances in both alkaline and acidic conditions helped confirm the significance of this technically favorable morphological structure.This product was also the subject of research for the exploration of decisive effects on the performance of ORR catalysts with reasonable control variables.The present work further advances the construction of novel 3D carbon architectures via practical and economic routes. 相似文献
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通过溶液共混法制备了聚乳酸/碳纳米管(PLA/CNTs)复合材料,并利用差示扫描量热分析(DSC)研究了CNTs的种类、长度、直径和质量分数对不同升温速度下PLA非等温冷结晶性能的影响,结果表明,PLA/CNTs复合材料的玻璃化转变温度(Tg)和结晶峰温度(Tc)都随升温速度降低而逐渐降低,而结晶度和熔融温度(Tm)则升高。添加质量分数为0.1%的多壁碳纳米管(MWNTs)即可有效促进PLA的异相成核,提高其结晶速度和结晶度,以10℃/min升温冷结晶时,当CNTs用量达1%时会阻碍PLA的非等温结晶过程,并导致PLA复合材料的Tg、Tm和结晶度降低。MWNTs对PLA非等温结晶的促进作用比SWNTs或DWNTs明显,而较短的MWNTs比长MWNTs的作用略为明显。 相似文献
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Saied M. Abd Elatty Konstantinos A. Lizos Z.M. Gharsseldien Amr Tolba Zafer A.L. Makhadmeh 《IET nanobiotechnology / IET》2018,12(2):201
There have been recent advances in the engineering of molecular communication (MC)‐based networks for nanomedical applications. However, the integration of MC with biomaterials such as carbon nanotubes (CNTs) presents various critical research challenges. In this study, the authors envisaged integrating MC‐based nanonetwork with CNTs to optimise nanonetwork performance. In neural networks, a chronic reduction in the concentration of the neurotransmitter acetylcholine (ACh) eventually leads to the development of neurodegenerative diseases; therefore, they used CNTs as a molecular switch to optimise ACh conductivity supported by artificial MC. Furthermore, MC enables communication between transmitter neurons and receiver neurons for fine‐tuning the ACh release rate according to the feedback concentration of ACh. Subsequently, they proposed a min/max feedback scheme to fine‐tune the expected throughput and ACh transmission efficiency. For demonstration purposes, they deduced analytical forms for the proposed schemes in terms of throughput, incurred traffic rates, and average packet delay.Inspec keywords: carbon nanotubes, cellular biophysics, diseases, feedback, nanomedicine, nanosensors, neural nets, neurophysiologyOther keywords: carbon nanotubes, neural sensor nanonetworks, nanomedical applications, biomaterials, molecular communication‐based nanonetwork, neural networks, neurotransmitter acetylcholine, neurodegenerative diseases, transmitter neurons, receiver neurons 相似文献
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Here we develop a simple method by using flow fluctuation to synthesize arrays of multi-branched carbon nanotubes (CNTs) that are far more complex than those previously reported. The architectures and compositions can be well controlled, thus avoiding any template or additive. A branching mechanism of fluctuation-promoted coalescence of catalyst particles is proposed. This finding will provide a hopeful approach to the goal of CNT-based integrated circuits and be valuable for applying branched junctions in nanoelectronics and producing branched junctions of other materials. 相似文献
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Applications of carbon nanotubes (CNTs) in flexible and complementary metal‐oxide‐semiconductor (CMOS)‐based electronic and energy devices are impeded due to typically low CNT areal densities, growth temperatures that are incompatible with device substrates, and challenges in large‐area alignment and interconnection. A scalable method for continuous fabrication and transfer printing of dense horizontally aligned CNT (HA‐CNT) ribbon interconnects is presented. The process combines vertically aligned CNT (VA‐CNT) growth by thermal chemical vapor deposition, a novel mechanical rolling process to transform the VA‐CNTs to HA‐CNTs, and adhesion‐controlled transfer printing without needing a carrier film. The rolling force determines the HA‐CNT packing fraction and the HA‐CNTs are processed by conventional lithography. An electrical resistivity of 2 mΩ · cm is measured for ribbons having 800‐nm thickness, while the resistivity of copper is 100 times lower, a value that exceeds most CNT assemblies made to date, and significant improvements can be made in CNT structural quality. This rolling and printing process could be scaled to full wafer areas and more complex architectures such as continuous CNT sheets and multidirectional patterns could be achieved by straightforward design of the CNT growth process and/or multiple rolling and printing sequences. 相似文献
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采用沉淀法合成了不同钴锰含量的碳纳米管(CNTs)/钴锰氧化物纳米复合材料. 利用XRD、SEM、TEM、BET和FT-IR等方法对材料进行了表征, 考察了不同复合材料对锂空气电池放电及充电过程的影响, 同时对循环性能进行了研究. 结果表明: 钴锰比例为4:0与0:4时, 产物为CNTs/Co3O4与CNTs/Mn3O4, 钴锰比例为3:1、2:2、1:3时, 产物为CNTs/(Co, Mn)(Co, Mn)2O4。产物具有良好的分散性能, 氧化物负载在碳管表面, 其中CNTs/Mn3O4的分散性能最好。随着锰含量的增加, 电池的放电性能提高, CNTs/Mn3O4的放电电压达到2.92 V。随着钴含量的增加, 电池的充电性能提高, 充电电压最低为3.80 V。钴锰比为3:1时的产物充放电过电势(△V)仅为1.05 V, 5次循环后依然保持着良好的放电性能。 相似文献
19.
A packet switch architecture and a method for load-balancing are described, which involve no centralised schedulers. The method is implemented by distributing extended cross-point queues (a threedimensional structure) over all elements of the switch and deploying pollers to append packets and to select the queues to be served, together with simple local work-conserving schedulers. The queue structure is such that it renders the proof that no packet will be mis-sequenced trivial. The architecture is practical and shows enhanced performance compared with other state-of-the-art load-balancing architectures, not only for the average delay but also for the distribution of individual delays, the latter being measured by a custom tool that compares the performance of the architecture to the ideal operation of an output queued switch. The queue structure permits the fair penalisation of only the offending input?output flows within the switch in the case of buffer overflow. The basic scheme is enhanced to avoid improper operation in the presence of packet drops, a problem that reintroduces mis-sequencing and that has not been properly addressed in the class of architectures that use pollers to distribute packets. 相似文献
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Nanoscale electronic devices made from carbon nanotubes (CNTs) such as transistors and sensors are much smaller and potentially more versatile than those built using conventional IC technology. In this paper, we present a method that uses dielectrophoretic (DEP) manipulation process for the fabrication of single-channel and multi-channel carbon nanotube field effect transistors (CNT-FETs). For a typical fabrication process, single-walled carbon nanotubes (SWCNTs) are first pre-aligned to micron-precision range between two microelectrodes using DEP technique. The typically applied alternating current (AC) voltage to generate the DEP force for manipulation has a frequency of 1 MHz and amplitude of 10 V. We first demonstrated single-channel or multi-channel structures of CNT-FETs. An AFM is then used to "clean" or "sweep away" unwanted particles or CNTs around the electrodes. Lastly, the fabricated FETs were covered in a polymethylmethacrylate (PMMA) thin film and treated with an annealing process. The PMMA covered devices show improved performances over the non-covered devices. 相似文献