共查询到20条相似文献,搜索用时 31 毫秒
1.
Ilene H. Morgan Gary L. Mullen Miodrag živković 《Applicable Algebra in Engineering, Communication and Computing》1997,8(1):25-31
We characterize almost weakly self-dual polynomial bases for the finite field over , where denotes the finite field of order q a prime power. We also extend a formula for the excess of certain polynomial bases from the case q = 2 to general q. 相似文献
2.
Anna Ott Ivan A. Verzhbitskiy Joseph Clough Axel Eckmann Thanasis Georgiou Cinzia Casiraghi 《Nano Research》2014,7(3):338-344
We report the gate-modulated Raman spectrum of defective graphene. We show that the intensity of the D peak can be reversibly tuned by applying a gate voltage. This effect is attributed to chemical functionalization of the graphene crystal lattice, generated by an electrochemical reaction involving the water layer trapped at the interface between silicon and graphene. 相似文献
3.
Weifeng Si Jia Li Huanqiao Li Shushuang Li Jie Yin Huan Xu Xinwen Guo Tao Zhang Yujiang Song 《Nano Research》2013,6(10):720-725
We report a fast in situ seeding approach based on zinc(II) porphyrin (ZnP) under white light irradiation, leading to uniform spherical platinum nanodendrites with tunable sizes. The platinum nanodendrites exhibit significantly improved electrocatalytic activities toward oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) compared with commercial platinum black. 相似文献
4.
This perspective provides an overview of the techniques that have been developed for the conjugation of DNA to colloidal quantum dots (QDs), or semiconductor nanocrystals. Methods described include: ligand exchange at the QD surface, covalent conjugation of DNA to the QD surface ligands, and one-step DNA functionalization on core QDs or during core/shell QD synthesis in aqueous solution, with an emphasis on the most recent progress in our lab. We will also discuss emerging trends in DNA-functionalized QDs for potential applications. 相似文献
5.
Aiming to enhance the luminescence yield of carbon nanotubes, we introduce a new class of hybrid nanoplasmonic colloidal systems (π-hybrids). Nanotubes dispersed in gold nanorod colloidal suspensions yield hybrid structures exhibiting enhanced luminescence up to a factor of 20. The novelty of the proposed enhancement mechanism relies on including metal proximity effects in addition to its localized surface plasmons. This simple, robust and flexible technique enhances the luminescence of nanotubes with chiralities whose enhancement has never reported before, for example the (8,4) tube. 相似文献
6.
Liubing Huang Siyuan Lu Paichun Chang Karan Banerjee Robert Hellwarth Jia Grace Lu 《Nano Research》2014,7(2):228-235
Single crystalline CdTe nanowires have been synthesized using Au-catalyzed chemical vapor deposition. X-ray diffraction reveals the existence of non- negligible inhomogeneous compressive strain in the nanowires along the 〈111〉 growth direction. The effect of the strain on the electronic structure is manifested by the blue-shifted and broadened photoluminescence spectra involving shallow donor/acceptor states. Such residual strain is of great importance for a better understanding of the optical and electrical behaviors of various semiconductor nanomaterials as well as for device design and applications. 相似文献
7.
Anomalous moire pattern of graphene investigated by scanning tunneling microscopy: Evidence of graphene growth on oxidized Cu(111) 总被引:1,自引:0,他引:1
Nicolas Reckinger Eloise Van Hooijdonk Frederic Joucken Anastasia V. Tyurnina Stephane Lucas Jean-Francois Colome~ 《Nano Research》2014,7(1):154-162
The growth of graphene on oriented (111) copper films has been achieved by atmospheric pressure chemical vapor deposition. The structural properties of as-produced graphene have been investigated by scanning tunneling microscopy. Anomalous moir6 superstructures composed of well-defined linear periodic modulations have been observed. We report here on comprehensive and detailed studies of these particular moir6 patterns present in the graphene topography revealing that, in certain conditions, the growth can occur on the oxygen-induced reconstructed copper surface and not directly on the oriented (111) copper film as expected. 相似文献
8.
Xiaolong Chen Lin Wang Wei Li Yang Wang Zefei Wu Mingwei Zhang Yu Han Yuheng He Ning Wang 《Nano Research》2013,6(8):619-626
We demonstrate the effects of electron-electron (e-e) interactions in monolayer graphene quantum capacitors. Ultrathin yttrium oxide showed excellent per-formance as the dielectric layer in top-gate device geometry. The structure and dielectric constant of the yttrium oxide layers have been carefully studied. The inverse compressibility retrieved from the quantum capacitance agreed fairly well with the theoretical predictions for the e--e interactions in monolayer graphene at different temperatures. We found that electron-hole puddles played a significant role in the low-density carrier region in graphene. By considering the temperature-dependent charge fluctuation, we established a model to explain the round-off effect originating from the e-e interactions in monolayer graphene near the Dirac point. 相似文献
9.
The growth of nanocrystal superlattices of 5 nm single domain Au nanocrystals at an air-toluene interface induces formation of well-defined thin films (300--400 nm) with large coherence lengths. High-resolution electron microscopy showed that polyhedral holes (negative supracrystal) were formed on the nanocrystal superlattice surface. Formation of negative supracrystals is attributed to inclusion in the superlattice of organic molecules (dodecanethiol), which are present in concentrated zones at the air-toluene interface. The coexistence of two supracrystalline structures (bcc/fcc) is attributed to diffusion of dodecanethiol molecules resulting in a Bain deformation of the nanocrystal array. 相似文献
10.
Jihye Choi Yoochan Hong Eugene Lee Myeong-Hoon Kim Dae Sung Yoon Jinsuck Suh Yongmin Huh Seungjoo Haam Jaemoon Yang 《Nano Research》2013,6(5):356-364
We have synthesized water-stable polyaniline nanoparticles coated with triarmed polyethylene glycol chains using a solvent-shift method and confirmed their colloidal size and aqueous solubility. Furthermore, we have demonstrated that the polyaniline nanoparticles can be doped with biological dopants to produce distinct color changes allowing the detection of live cancer cells. 相似文献
11.
Qian Zhang Xiangjian Wan Fei Xing Lu Huang Guankui Long Ningbo Yi Wang Ni Zhibo Liu Jianguo Tian Yongsheng Chen 《Nano Research》2013,6(7):478-484
Graphene mesh electrodes (GMEs) with good conductivity and transparency have been fabricated by the standard industrial photolithography and O2 plasma etching process using graphene solutions. Organic photovoltaic (OPV) cells using GMEs as the transparent electrodes with a blend of poly-(3-hexylthiophene)/phenyl-C61-butyric acid methyl ester (P3HT/PC61BM) as the active layer have been fabricated and exhibit a power conversion efficiency (PCE) of 2.04%, the highest PCE for solution-processed graphene transparent electrode-based solar cells reported to date. 相似文献
12.
Sandeep Gorantla Stanislav Avdoshenko Felix Börrnert Alicja Bachmatiuk Maria Dimitrakopoulou Franziska Schäffel Ronny Schönfelder Jürgen Thomas Thomas Gemming Jamie H. Warner Gianaurelio Cuniberti Jürgen Eckert Bernd Büchner Mark H. Rümmeli 《Nano Research》2010,3(2):92-97
In situ low-voltage aberration corrected transmission electron microscopy (TEM) observations of the dynamic entrapment of a C60 molecule in the saddle of a bent double-walled carbon nanotube is presented. The fullerene interaction is non-covalent, suggesting that enhanced π-π interactions (van der Waals forces) are responsible. Classical molecular dynamics calculations confirm that the increased interaction area associated with a buckle is sufficient to trap a fullerene. Moreover, they show hopping behavior in agreement with our experimental observations. Our findings further our understanding of carbon nanostructure interactions, which are important in the rapidly developing field of low-voltage aberration corrected TEM and nano-carbon device fabrication. 相似文献
13.
Mingliang Zhang Christopher M. Earhart Chinchun Ooi Robert J. Wilson Mary Tang Shan X. Wang 《Nano Research》2013,6(10):745-751
Synthetic antiferromagnetic (SAF) nanoparticles are layer-structured particles with high single-particle magnetic moments. In order to covalently bind these nanopartides to cells, they were coated with a silica shell followed by conjugation with streptavidin. The silica coating generates both SAF@SiO2 core-shell nano- particles and silica core-free nanopartides. Using a simple magnetic separation, silica nanoparticles were removed and SAF@SiO2 nanoparticles were purified. After streptavidin conjugation, these particles were used to stain lung cancer cells, making them highly magnetically responsive. The stained cells can rotate in response to an external magnetic field and can be captured when a blood sample containing these cells flows through the sifter. 相似文献
14.
Zachary Lingley Krishnamurthy Mahalingam Siyuan Lu Gail J. Brown Anupam Madhukar 《Nano Research》2014,7(2):219-227
We report on a cross-sectional high resolution transmission electron microscope study of lead sulfide nanocrystal quantum dots (NCQDs) dispersed on electron-transparent silicon nanopillars that enables nearly atomically-resolved simultaneous imaging of the entire composite: the quantum dot, the interfacial region, and the silicon substrate. Considerable richness in the nanocrystal shape and orientation with respect to the substrate lattice is observed. The average NCQD-substrate separation is found to be significantly smaller than the length of the ligands on the NCQDs. Complementary photoluminescence measurements show that light emission from PbS NCQDs on silicon is effectively quenched which we attribute to intrinsic mechanisms of energy and charge transfer from PbS NCQDs to Si. 相似文献
15.
Kilian Mergenthaler Azhar Iqbal Jesper Wallentin Sebastian Lehmann Magnus T. Borgström Lars Samuelson Arkady Yartsev Mats-Erik Pistol 《Nano Research》2013,6(10):752-757
Realizing photon upconversion in nanostructures is important for many next- generation applications such as biological labelling, infrared detectors and solar cells. In particular nanowires are attractive for optoelectronics because they can easily be electrically contacted. Here we demonstrate photon upconversion with a large energy shift in highly n-doped InP nanowires. Crucially, the mechanism responsible for the upconversion in our system does not rely on multi-photon absorption via intermediate states, thus eliminating the need for high photon fluxes to achieve upconversion. The demonstrated upconversion paves the way for utilizing nanowires--with their inherent flexibility such as electrical contactability and the ability to position individual nanowires--for photon upconversion devices also at low photon fluxes, possibly down to the single photon level in optimised structures. 相似文献
16.
Kai Yang Wende Xiao Liwei Liu Xiangmin Fei Hui Chen Shixuan Du Hong-Jun Gao 《Nano Research》2014,7(1):79-84
Low-dimensional H2 aggregates have been successfully fabricated on Au(111) surfaces and investigated by means of low temperature scanning tunneling microscopy. We use manganese phthalocyanine (MnPc) molecules anchored on the Au(111) surface to efficiently collect and pin hydrogen molecules. A two-dimensional (2D) molecular hydrogen cluster is formed around the MnPc. The hydrogen cluster exhibits bias-dependent topography and spatial-dependent conductance spectra, which are rationalized by the exponentially decreasing threshold energy with distance from the central MnPc to activate the motion of the H2 molecules. This exponential drop reveals an interfacial phase behavior in the 2D cluster. 相似文献
17.
Céline Mayousse Caroline Celle Alexandre Carella Jean-Pierre Simonato 《Nano Research》2014,7(3):315-324
We demonstrate the hydrothermal synthesis of long copper nanowires based on a simple protocol. We show that the purification of the nanowires is very important and can be achieved easily by wet treatment with glacial acetic acid. Fabrication of random networks of purified copper nanowires leads to flexible transparent electrodes with excellent optoelectronic performances (e.g., 55 Ω/sq. at 94% transparency). The process is carried out at room temperature and no post-treatment is necessary. Hybrid materials with the conductive polymer PEDOT:PSS show similar properties (e.g., 46 Ω/sq, at 93% transparency), with improved mechanical properties. Both electrodes were integrated in capacitive touch sensors. 相似文献
18.
Yanfen Wan Hervé Portalès Nicolas Goubet Alain Mermet Marie-Paule Pileni 《Nano Research》2013,6(8):611-618
A colloidal solution of 5 nm Au tetradecanethiol-coated nanoparticles is syn-thesized. After fast evaporation of one drop, ordered monolayers both composed of single domain and polycrystalline nanocrystals are obtained. On increasing the amount of materials and the evaporation time, nanocrystal films with irregular outlines are produced together with close-packed 3D superlattices exhibiting a truncated-tetrahedral shape. Using low-frequency micro-Raman scattering spectroscopy and electron microscopy the building block nanocrystallinity is characterized. Spontaneous nanocrystallinity segregation is revealed: the truncated-tetrahedral supracrystals are shown to mainly contain single domain building blocks while the supracrystalline films are composed of a mixture of single domain and polycrystalline nanocrystals. This observation points out the correlation between the nanocrystallinity segregation involved in the growth of the nanocrystal superlattices and their morphology. 相似文献
19.
Hongyi Li Jinshu Wang Man Liu Hong Wang Penglei Su Junshu Wu Ju Li 《Nano Research》2014,7(7):1007-1017
To improve the contact between platinum catalyst and titanium substrate, a layer of TiO2 nanotube arrays has been synthesized before depositing Pt nanoflowers by pulse electrodeposition. Dramatic improvements in electrocatalytic activity (3x) and stability (60x) for methanol oxidation were found, suggesting promising applications in direct methanol fuel cells. The 3x and 60x improvements persist for Pt/Pd catalysts used to overcome the CO poisoning problem. 相似文献
20.
Ning Guo Jinquan Wei Yi Jia Huanhuan Sun Yuhang Wang Kehan Zhao Xiaolan Shi Liuwan Zhang Xinming Li Anyuan Cao Hongwei Zhu Kunlin Wang Dehai Wu 《Nano Research》2013,6(8):602-610
Highly reliable and bendable dielectrics are desired in flexible or bendable electronic devices for future applications. Hexagonal boron nitride (h-BN) can be used as bendable dielectric due to its wide band gap. Here, we fabricate high quality h-BN films with controllable thickness by a low pressure chemical vapor deposition method. We demonstrate a parallel-plate capacitor using h-BN film as the dielectric. The h-BN capacitors are reliable with a high breakdown field strength of -9.0 MV/cm. Tunneling current across the h-BN film is inversely exponential to the thickness of dielectric, which makes the capacitance drop significantly. The h-BN capacitor shows a best specific capacitance of 6.8 F/cm^2, which is one order of magnitude higher than the calculated value. 相似文献