http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Nitrogenation of highly sp2 bonded amorphous carbon
Sunglyul Maeng,A Tagliaferro,John Robertson,W. I. Milne,Soonil Lee 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.1
Amorphous carbon with a high sp2 bonding content is considered to be a poor electronic material due to its very narrow band gap and its excessive density of defect states in the gap, both of which pin the Fermi level. This paper describes the ability of nitrogen to improve the semiconducting properties of highly sp2 bonded ( 80 90 % sp2) amorphous carbon. The electron spin resonance shows a reduction in the density of gap states in nitrogenated amorphous carbon (a-C : N) with increasing nitrogen content. Photo-thermal deflection spectroscopy and ultraviolet-visual spectroscopy measurements show that the opening of the gap and clearing of the gap states occur through nitrogen incorporation into the amorphous carbon film.
Wind-induced fatigue loading of tubular steel lighting columns
Robertson, A.P.,Hoxey, R.P.,Short, J.L.,Burgess, L.R.,Smith, B.W.,Ko, R.H.Y. Techno-Press 2001 Wind and Structures, An International Journal (WAS Vol.4 No.2
Two 12 m high tubular steel lighting columns have been instrumented to determine the wind-induced fatigue loading experienced by such columns. Each column supported a single luminaire mounted on a 0.5 m long bracket. One column was planted in soil, and the other bolted through a welded baseplate to a substantial concrete base. The columns were strain gauged just above the shoulder weld which connected the main shaft to the larger base tube. Forced vibration tests were undertaken to determine the natural frequencies and damping of the columns. Extensive recordings were made of response to winds with speeds from 4 m/s to 17 m/s. Selected records were analysed to obtain stress cycle counts and fatigue lives. Mean drag coefficients were also derived from the strain data to investigate experimentally the effect of Reynolds Number.
Atomic Structure and Dynamics of Epitaxial Platinum Bilayers on Graphene
Robertson, Alex W.,Lee, Gun-Do,Lee, Sungwoo,Buntin, Parker,Drexler, Matthew,Abdelhafiz, Ali A.,Yoon, Euijoon,Warner, Jamie H.,Alamgir, Faisal M. American Chemical Society 2019 ACS NANO Vol.13 No.10
<P>Platinum atomic layers grown on graphene were investigated by atomic resolution transmission electron microscopy (TEM). These TEM images reveal the epitaxial relationship between the atomically thin platinum layers and graphene, with two optimal epitaxies observed. The energetics of these epitaxies influences the grain structure of the platinum film, facilitating grain growth <I>via</I> in-plane rotation and assimilation of neighbor grains, rather than grain coarsening from the movement of grain boundaries. This growth process was enabled due to the availability of several possible low-energy intermediate states for the rotating grains, the Pt-Gr epitaxies, which are minima in surface energy, and coincident site lattice grain boundaries, which are minima in grain boundary energy. Density functional theory calculations reveal a complex interplay of considerations for minimizing the platinum grain energy, with free platinum edges also having an effect on the relative energetics. We thus find that the platinum atomic layer grains undergo significant reorientation to minimize interface energy (<I>via</I> epitaxy), grain boundary energy (<I>via</I> low-energy orientations), and free edge energy. These results will be important for the design of two-dimensional graphene-supported platinum catalysts and obtaining large-area uniform platinum atomic layer films and also provide fundamental experimental insight into the growth of heteroepitaxial thin films.</P> [FIG OMISSION]</BR>
The effect of small embankments on wind speeds
Quinn, A.D.,Robertson, A.P.,Hoxey, R.P.,Short, J.L.,Burgess, L.R.,Smith, B.W. Techno-Press 1998 Wind and Structures, An International Journal (WAS Vol.1 No.4
Full-scale measurements have been made to determine the increase in wind speed over two exposed embankments, one of $23^{\circ}$ slope and 4.7 m in height, the other of $24^{\circ}$ slope and 7.3 m in height. Measurements were made at heights of 5, 10 and 15 m above the upper edge of each embankment and at the same heights approximately 100 m upwind in the lower-level approach fetch. Despite the modest sizes of the embankments, the maximum recorded increase in mean wind speed was 28% and the minimum was 13%; these increase relate to increases in wind loads on structures erected at the top of the embankments of 64% and 28% respectively. The associated increases in gust speeds are estimated at 33% and 18%, which imply increases in gust loading of 77% and 39% respectively. These experimental results are compared with predictions obtained from a computational fluid dynamics (CFD) analysis, using three high Reynolds number eddy-viscosity models and estimates from the UK wind loading code, BS 6399: Part 2. The CFD results are generally in agreement with the experimental data, although near-ground effects on the embankment crest are poorly reproduced.
N.J. Larsen,M.A. Minor,R.H. Cruickshank,A.W. Robertson 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.3
Wemonitored four groups of Hymenoptera in organic apple orchards in New Zealand in order to assess different trapping methods. The factors assessed were trap type (pan traps vs. sticky traps), trap colour, preservative type and trap position within the orchard with regard to the shelterbelt. Yellow sticky traps were the most effective trap type overall for sampling the order Hymenoptera, and the two parasitoid species Anagrus sp. and Aphelinus mali (Haldeman). White pan traps were best for sampling native bees from the family Halictidae. Choice of preservative in the pan traps significantly affected the catch of Hymenoptera overall and Halictidae. Most Hymenoptera were more abundant within the orchards than at the shelterbelt, except the Halictidae, which were more abundant at the shelterbelt. The results support the notion that Hymenoptera surveys should be conducted using methods appropriated for targeted taxa, due to differences in their behavioural responses and ecological trends.
Thin Films of Block Copolymers as Planar Optical Waveguides
Kim, D. H.,Lau, K. H. A.,Robertson, J. W. F.,Lee, O.-J.,Jeong, U.,Lee, J. I.,Hawker, C. J.,Russell, T. P.,Kim, J. K.,Knoll, W. WILEY-VCH Verlag 2005 Advanced Materials Vol.17 No.20
<B>Graphic Abstract</B> <P>Thin films of diblock copolymers with cylindrical microdomains oriented normal to the film plane are employed as planar optical waveguides in the Kretschmann configuration (see Figure). Their waveguiding properties were investigated by optical waveguide spectroscopy. The dielectric constants and the film thickness of the block copolymer layer can be independently obtained from fitting between the waveguide patterns for s- and p-polarization and Fresnel calculations. <img src='wiley_img/09359648-2005-17-20-ADMA200500170-content.gif' alt='wiley_img/09359648-2005-17-20-ADMA200500170-content'> </P>