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11.
We report on the first demonstration of nanodiamond (ND) as a scattering optical label in a biological environment. NDs were efficiently transfected into cells using cationic liposomes, and imaged using differential interference and Hoffman modulation ‘space’ contrast microscopy techniques. We have shown that 55 nm NDs are biologically inert and produce a bright signal compared to the cell background. ND as a scattering label presents the possibility for extended biological imaging with relatively little thermal or biochemical perturbations due to the optical transparency and biologically inert nature of diamond. 相似文献
12.
B. Fidalgo 《Applied Surface Science》2008,254(11):3553-3557
The aim of this work was to study the growth of nanofilaments on two carbon-based materials (i.e. an activated carbon and carbon fibres) from microwave-assisted decomposition of CH4. It was found that the nature of grown nanofilaments differed depending on the carbon support, probably due to the presence of diverse metals which catalyze the nanofilaments growth. Besides, it was also studied the influence of the composition of the in-flow gases on the growth of nanofilaments. Thus, tests with pure CH4 and different CH4/N2 mixtures were carried out, the yield in nanofilaments being higher when mixtures were fed in. No nanofilaments were found after analogous tests carried out under conventional heating, therefore it can be stated that microwave heating is a promising technology for growing nanofilaments. 相似文献
13.
Ping Guo Lin ZhengJi Ming Zheng Ruizhi ZhangLuna Yang Zhaoyu Ren 《Applied Surface Science》2011,258(2):705-710
A plane-wave density functional theory (DFT) calculations have been performed to investigate structural and electronic properties of TaSin (n = 1-3, 12) clusters supported by graphene surface. The resulting adsorption structures are described and discussed in terms of stability, bonding, and electron transfer between the cluster and the graphene. The TaSin clusters on graphene surface favor their free-standing ground-state structures. Especially in the cases of the linear TaSi2 and the planar TaSi3, the graphene surface may catalyze the transition of the TaSin clusters from an isomer of lower dimensionality into the ground-state structure. The adsorption site and configuration of TaSin on graphene surface are dominated by the interaction between Ta atom and graphene. Ta atom prefers to adsorb on the hollow site of graphene, and Si atoms tend to locate on the bridge site. Further, the electron transfer is found to proceed from the cluster to the surface for n = 1 and 2, while its direction reverses as n > 2. For the case of TaSi, chemisorption is shown to prevail over physisorption as the dominant mode of surface-adsorbate interaction by charge density analysis. 相似文献
14.
Due to different oriented diamond films having different properties, in this paper optical and electrical properties of different oriented diamond films have been investigated. The measured results indicate diamond films are of high quality and the properties of the (0 0 1)-oriented diamond film are better than those of the (1 1 1)-oriented one. Refractive index and extinction coefficient of (0 0 1)-oriented diamond film in the wavelength range of 2.5-12.5 μm is 2.391 and in the order of 10−5, respectively. And for the (1 1 1)-oriented one it is 2.375 and in the order of 10−4. The dark current of the (0 0 1)-oriented diamond film is 33.7 nA under an applied electric field of 100 kV/cm. The resistivity of the (0 0 1)-oriented diamond film obtained is about 2.33 × 1010 Ω cm. The current of (0 0 1)-oriented diamond film is almost no change with the time testing. 相似文献
15.
Behaviour of Self-Standing CVD Diamond Film with Different Dominant Crystalline Surfaces in Thermal-Iron Plate Polishing 下载免费PDF全文
Self-standing CVD diamond films with different dominant crystalline surfaces are polished by the thermal-iron plate polishing method. The influence of the dominant crystalline surfaces on polishing etfficiency is investigated by measuring the removal rate and final roughness. The smallest rms roughness of 0.14 μm is measured with smallest removal rate in the films with the initial (220) dominant crystalline surface. Activation energy for the polishing is analysed by the Arrhenius relation. It is found that the values are 170kJ/mol, 222kJ/mol and 214kJ/mol for the film with three different dominant crystalline surfaces. Based on these values, the polishing cause is regarded as the graphitization-controlling process. In the experiment, we find that transformation of the dominant crystalline surfaces from (111) to (220) always appears in the polishing process when we polish the (111) dominant surface. 相似文献
16.
Dan Bai 《Applied Surface Science》2010,256(8):2643-1994
Free-standing multiwall carbon nanotubes (MWNTs) films were coated, using chemical vapor deposition method, with a thin layer of nanostructural ZnO. The morphology and crystal structure of the as-grown products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman scattering analyses. Field emission (FE) results demonstrated that the needle-like and spherical ZnO-MWNTs composite structure films possessed good performance with a turn-on field of 1.3, 2.2 V μm−1 and a threshold field of 2.6, 4.5 V μm−1, respectively. The glucose-sensing characteristic has also been studied. The multi-layer electrode (PDDA/GOx/ZnO/MWNTs) exhibited significant electrocatalysis to the oxidation and reduction of H2O2 than the PDDA/GOx/MWNTs electrode, which provided wide potential applications in clinical, environmental, and food analysis. 相似文献
17.
We have investigated the influence of the vacuum level upon the growth of carbon nanotubes (CNTs) on 6H-SiC () surface.CNTs of about 160 nm in length were formed densely and uniformly on the 6H-SiC surface during annealing at 1700 °C in a high vacuum (∼10−2 Pa). CNTs of about 1 μm in length were formed during annealing at 1700 °C in an ultra-high vacuum (∼10−7 Pa). However, CNTs were not formed and SiO2 layers were formed on the SiC surface at 1700 °C in air. It is found that longer CNTs can grow up in an ultra-high vacuum, moreover, a little aligned and low-density graphite layers, or carbon nanofibers can also grow up. 相似文献
18.
Dependence of Crystal Quality and β Value on Synthesis Temperature in Growing Gem Diamond Crystals 总被引:3,自引:0,他引:3 下载免费PDF全文
High quality Ib gem diamond single crystals were synthesized in cubic anvil high-pressure apparatus (SPD- 6 × 1200) under 5.4GPa and 1230℃-1280℃. The (100) face of seed crystal was used as growth face, and Ni70Mn25Co5 alloy was used as solvent/catalyst. The dependence of crystal quality andβ value (the ratio of height to diameter of diamond crystal) on synthesis temperature was studied. When the synthesis temperature is between 1230℃ and 1280℃, theβ value of the synthetic high-quality gem diamond crystals is between 0.4 and 0.6. The results show that when theβ value is between 0.4 and O. 45, the synthetic diamonds are sheet-shape crystals; however, when theβ value is between 0.45 and 0.6, the synthetic diamonds are tower-shape crystals. In addition, when theβ value is less than 0.4, skeleton crystals will appear. When theβ value is more than 0.6, most of the synthetic diamond crystals are inferior crystals. 相似文献
19.
Chunxu Bai 《Physics letters. A》2008,372(5):725-729
Spin-polarized transports of relativistic electrons through graphene-based ferromagnet/insulator/ferromagnet (FG/IG/FG) single junctions have been investigated theoretically. Large oscillating tunnel magnetoresistance (TMR) has been found in monolayer and bilayer FG/IG/FG junctions. The oscillating amplitudes of TMR do not decrease with the increase of the thickness and the height of barrier, in contrast to the exponential decay in conventional ferromagnet/insulator/ferromagnet single junction. The physical origin for such a phenomenon has also been analyzed. It is anticipated to apply such a phenomenon to design the spin-polarized electron device based on the graphene materials. 相似文献
20.
Jaanus Eskusson Raivo Jaaniso Enn Lust 《Applied Physics A: Materials Science & Processing》2008,93(3):745-749
DLC (Diamond-like carbon films) were prepared by pulsed laser ablation of a liquid target at substrate temperatures from 18
to 600°C using 248 nm KrF excimer laser. The sp3 hybridization state carbon formation was additionally promoted by gaseous H2O2 flow through the reaction chamber and substrate excitation by the same laser beam.
Deposited DLC films were characterised by Raman scattering spectroscopy and atomic force microscopy (AFM). Comparative AFM
and Raman study shows that the increase in the content of sp3 type bonding in DLC is in correlation with the increase of the surface roughness of the samples prepared. 相似文献