排序方式: 共有237条查询结果,搜索用时 31 毫秒
51.
S. Garbarino A. Ponrouch S. Pronovost J. Gaudet D. Guay 《Electrochemistry communications》2009,11(10):1924-1927
Two types of platinum deposits were obtained by potentiostatic deposition onto Ti substrates, namely platinum black (Pt B) and platinum nanowires (Pt NW) with the latter being achieved through a porous anodic aluminum oxide (AAO) membrane at the solution/substrate interface. Surface characterization of these deposits was performed using scanning electron microscopy (SEM) and cyclic voltammetry (CV) in sulphuric acid solution. Surface properties for Pt NW revealed a predominant presence of (1 0 0) crystallographic planes, not present in Pt B deposit grown in the same conditions. Also, Pt NW exhibits an increased resistance to electrochemically active surface area (EASA) loss upon potential cycling in acidic solution, as compared to Pt B. 相似文献
52.
We present atomistic simulations of the tensile and compressive loading of single crystal face-centered cubic (FCC) nanowires with and orientations to study the propensity of the nanowires to deform via twinning or slip. By studying the deformation characteristics of three FCC materials with disparate stacking fault energies (gold, copper and nickel), we find that the deformation mechanisms in the nanowires are a function of the intrinsic material properties, applied stress state, axial crystallographic orientation and exposed transverse surfaces. The key finding of this work is the first order effect that side surface orientation has on the operant mode of inelastic deformation in both and nanowires. Comparisons to expected deformation modes, as calculated using crystallographic Schmid factors for tension and compression, are provided to illustrate how transverse surface orientations can directly alter the deformation mechanisms in materials with nanometer scale dimensions. 相似文献
53.
Sha MY Walton ID Norton SM Taylor M Yamanaka M Natan MJ Xu C Drmanac S Huang S Borcherding A Drmanac R Penn SG 《Analytical and bioanalytical chemistry》2006,384(3):658-666
Single-nucleotide polymorphisms (SNP) are the most common form of sequence variation in the human genome. Large-scale studies
demand high-throughput SNP genotyping platforms. Here we demonstrate the potential of encoded nanowires for use in a particles-based
universal array for high-throughput SNP genotyping. The particles are encoded sub-micron metallic nanorods manufactured by
electroplating inert metals such as gold and silver into templates and releasing the resulting striped nanoparticles. The
power of this technology is that the particles are intrinsically encoded by virtue of the different reflectivity of adjacent
metal stripes, enabling the generation of many thousands of unique encoded substrates. Using SNP found within the cytochrome
P450 gene family, and a universal short oligonucleotide ligation strategy, we have demonstrated the simultaneous genotyping
of 15 SNP; a format requiring discrimination of 30 encoded nanowires (one per allele). To demonstrate applicability to real-world
applications, 160 genotypes were determined from multiplex PCR products from 20 genomic DNA samples. 相似文献
54.
Hyo Sung Kim Ju Chan Yang Yong Sung Koo Hyoun Woo Kim 《Journal of solid state chemistry》2010,183(10):2445-2450
Nanowires consisting of GaN/Mn3O4 were prepared using a two-step approach that involved dipping the as-synthesized GaN nanowires into an aqueous manganese acetate solution. To examine the effects of annealing, GaN/Mn3O4 core-shell nanowires were heated thermally to 700 °C in N2 ambient. Transmission electron microscopy showed that the continuous Mn3O4 shell layer had agglomerated to expose a bare GaN core surface after thermal annealing. The magnetic measurements showed that the ferromagnetic behavior of the GaN nanowires had been suppressed by coating with the Mn3O4 shell, without significant change by the subsequent thermal annealing. The GaN/Mn3O4 core-shell nanowires exhibited blue, green, and red photoluminescence (PL) emission. The red emission was enhanced by thermal annealing. This paper discusses the associated mechanism for the variations in PL and magnetic properties of GaN/Mn3O4 core-shell nanowires. 相似文献
55.
运用连续恒电势三脉冲的电化学阶边精饰法在高定向石墨(HOPG)上制备钯镍合金纳米线阵列, 并研究了合金成分的影响因素. 结果表明,改变镀液组成可以调整钯镍合金成分,调整生长时间和生长电势来控制钯镍合金纳米线的直径. 用7 mmol•L-1 PdCl2,3 mmo•L-1 NiSO4, 0.2 mol•L-1 NH4Cl,pH 8.5的混合溶液,控制脉冲电势-2.0 V形核0.2 s,在脉冲电势-0.4 V生长1 h,可以获得平均直径为200 nm, 长度约400 μm的钯镍合金纳米线阵列, 纳米线的合金成分中镍含量为12.4%(质量分数,w). 相似文献
56.
Y. Watanabe N. Yamamoto S. Bhunia T. Kawamura S. Fujikawa 《Physica E: Low-dimensional Systems and Nanostructures》2004,23(3-4):305
Vertically aligned InP nanowires were successfully grown by metalorganic vapor phase epitaxy under metal-catalyzed vapor–liquid–solid growth processes. Au nanoparticles with a nominal diameter of 20 nm were used as the seed to control the diameter of the nanowires. Scanning and transmission electron microscopic studies showed highly dense nanowires with uniform diameters along the length direction, and the zinc-blende structure of the nanowires with 1 1 1 growth direction, respectively. Cathodeluminescence measurements showed a significant blueshift in the spectral peak position compared to bulk InP due to the quantum confinement of the carriers in the nanowires. 相似文献
57.
The results on surface modification of materials of different structures; morphology, grain sizes, density and porosity by exposure to nanosecond laser light are given. Laser induced changes in their surface characteristics are presented. Surface layers of Si3N4, SiC dense ceramics and BN graphite and turbostratic pressed powders are studied by scanning electron microscopy to reveal the new nanostructures (nanowires or nanotubes) and new morphologies. A pronounced evolution in structure and grain size of BN graphite powders was demonstrated in laser processing layers. 相似文献
58.
J.Z. Guo Y. Zuo Z.J. Li W.D. Gao J.L. Zhang 《Physica E: Low-dimensional Systems and Nanostructures》2007,39(2):262-266
SiC nanowires with fins have been prepared by chemical vapor deposition in a vertical vacuum furnace by using a powder mixture of milled Si and SiO2 and gaseous CH4 as the raw materials. The products were characterized by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). These investigations confirm that the nanowires with fins are cubic β-SiC. The diameter of the fins is about 100–120 nm and the diameter of the inner core stems is about 60–70 nm. The formation process of the β-SiC nanowires with fins is analyzed and discussed briefly. 相似文献
59.
Zhihong Liu Jia Sha Qing Yang Zixue Su Hui Zhang Deren Yang 《Physica E: Low-dimensional Systems and Nanostructures》2007,38(1-2):27
In this paper we present a flower-like silicon nanostructure grown by combining the oxidation-assisted growth (OAG) mechanism and the vapor–liquid–solid (VLS) growth mechanism. It is found that the flower-like silicon nanostructures are nucleated initially via the VLS mechanism and then grown on silicon wafer via the OAG mechanism. Furthermore, light emission was observed, which is considered to be the enhanced photothermal effect. 相似文献
60.
In this work we study the optical properties of hydrogen-passivated, free-standing silicon and germanium nanowires, oriented along the [1 0 0], [1 1 0], [1 1 1] directions with diameters up to about 1.5 nm, using ab-initio techniques. In particular, we show how the electronic gap depends on wire’s size and orientation; such behaviour has been described in terms of quantum confinement and anisotropy effects, related to the quasi one-dimensionality of nanowires. The optical properties are analyzed taking into account different approximations: in particular, we show how the many-body effects, namely self-energy, local field and excitonic effects, strongly modify the single particle spectra. Further, we describe the differences in the optical spectra of silicon and germanium nanowires along the [1 0 0] direction, as due to the different band structures of the corresponding bulk compounds. 相似文献