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11.
D. Ohlberg J.J. Blackstock R. Ragan S. Kim R. Stanley Williams 《Applied Physics A: Materials Science & Processing》2005,80(6):1327-1334
A recently demonstrated [1] in-vacuo template-stripping process is applied to the study of platinum films stripped from ultra-flat silicon-oxide surfaces. Template-stripped (TS) Pt surfaces, prepared with a range of post-deposition annealing times prior to being stripped from the templating surface in an ultra-high vacuum (UHV) environment, are examined by UHV scanning tunneling microscopy (STM). These studies reveal that without post-deposition annealing, TS Pt surfaces are largely made up of poorly-ordered, granular nanostructures undesirable for many applications. The post-deposition annealing treatments explored in the study result in the emergence and continuous growth of large smooth crystallites. Issues with crystallite orientation relative to the TS surface and artefacts arising as a result of the epoxy used in the template-stripping process are presented and discussed in relation to optimizing the template-stripping procedure for specific applications such as self-assembled monolayer (SAM) formation for molecular electronics. PACS 68.37.Ef; 68.47.De; 68.55.Jk; 81.05.Bx; 81.15.Ef 相似文献
12.
Frank H.G.M. Wijnands Charles G. Crookes Paul M. Charles Richard M. Ash Ian F. Lealman Michael J. Robertson Anthony E. Kelly Kevin A. Williams Aeneas B. Massara Richard V. Penty Ian H. White 《Optical and Quantum Electronics》2002,34(10):959-973
An anomalous modulation in the wavelength spectrum has been observed in lasers with spot-size converters. This intensity modulation is shown to be caused by beating between the fundamental lasing mode and radiation modes in the taper. This results in a periodic modulation in the net gain spectrum, which causes wavelength jumps between adjacent net gain maxima, and a drive current dependent spectral width that is expected to affect system performance. The amplitude of this spectral modulation is reduced significantly by either using an angled rear-facet which reflects the beating radiation modes away from the laser axis, or by using a nonlinear, adiabatic taper. 相似文献
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D. Chithrani R. L. Williams J. Lefebvre P. J. Poole G. C. Aers 《Physica E: Low-dimensional Systems and Nanostructures》2004,21(2-4):290
We discuss the preparation and spectroscopic characterisation of a single InAs/InP quantum dot suitable for long-distance quantum key distribution applications around λ=1.55 μm. The dot is prepared using a site-selective growth technique which allows a single dot to be deposited in isolation at a controlled spatial location. Micro-photoluminescence measurements as a function of exciton occupation are used to determine the electronic structure of the dot. Biexciton emission, shell filling and many-body re-normalization effects are observed for the first time in single InAs/InP quantum dots. 相似文献
15.
Shyam K. Singh Oliver S. Fetzer John B. Hynes Thomas C. Williams 《Journal of heterocyclic chemistry》1991,28(5):1459-1461
Nitration of 2-amino-4-oxo-(3H)-5-trifluoromethylquinazoline is shown to occur exclusively at C6 as determined from an analysis of long range 1H and 19F scalar couplings to ring carbons. Nitration of 2-amino-4-oxo-(3H)-5-fluoroquinazoline is found to occur both at C6 and C8 as evident from an analysis of the 19F and 1H couplings of the ring protons. 相似文献
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Healthcare Operational Research (OR) has had limited success in achieving a sufficient level of stakeholder acceptance to lead to implementation of results. This research study is aimed at combining OR methodologies to achieve greater acceptance of results for organizational change. Patient flow delays in the Paediatric intensive care unit (PICU) at Children's Hospital of Wisconsin were identified using case studies. Patient flow was modelled using hard OR (simulation) using case study findings, with active stakeholder participation, and enhanced with outcomes research. Outcomes research allowed achieving greater clinical relevance of OR findings. Results from hard OR, particularly for politically sensitive issues, were persuasive but inadequate to result in change. Soft OR (cognitive mapping) was used to identify new issues and enhance results. Consequently, the planned PICU expansion was deferred, and resources focused on improving staffing strategies identified independently from both hard and soft OR. These findings suggest that: (1) Outcomes research can play a unique role to enhance results in healthcare OR. (2) After obtaining a holistic understanding of the system using hard and soft OR, stakeholders are willing to implement results from each independently, supporting the development of a common form of knowledge, which is consistent with Mixed-Mode Modelling. (3) Hard OR, enhanced with outcomes research, with active stakeholder participation, and combined with soft OR, results in greater acceptance and sustained organizational change. 相似文献
18.
The gas-phase thermal decomposition rate of peroxy-n-butyryl nitrate (n-C3H7C(O)OONO2, PnBN) has been measured at ambient temperature (296 K) and 1 atm of air relative to that of peroxyacetyl nitrate (CH3C(O)OONO2, PAN) using mixtures of PAN (14–19 ppb), PnBN (22–46 ppb), and nitric oxide (1.35–1.90 ppm). The PnBN/PAN decomposition rate ratio was 0.773 ± 0.030. This ratio, together with a literature value of 3.0 × 10?4 s?1 for the thermal decomposition rate of PAN at 296 K, yields a PnBN thermal decomposition rate of (2.32 ± 0.09) × 10?4 s?1. The results are briefly discussed by comparison with data for other peroxyacyl nitrates and with respect to the atmospheric persistence of PnBN. © 1994 John Wiley & Sons, Inc. 相似文献
19.
Ultrasonic wave propagation in cancellous and cortical bone: prediction of some experimental results by Biot's theory. 总被引:1,自引:0,他引:1
J L Williams 《The Journal of the Acoustical Society of America》1992,91(2):1106-1112
Pulse transmission ultrasound was used to determine the longitudinal wave speed along the direction of trabecular alignment in 32 water-saturated anisotropic tibial bovine cancellous bone samples and in one cortical bone sample also from the bovine tibia. These results are compared to published ultrasound wave-speed data obtained from bovine femoral specimens. Nonlinear regression was used to fit Biot's theory to the data. The correlation coefficient for regression analysis between the experimental ultrasound velocities and the velocities predicted by Biot's theory was r = 0.78. 相似文献
20.
Margaret S. Cheney und Ellen Swallow Richards 《Fresenius' Journal of Analytical Chemistry》1878,17(1):214-216
Ohne Zusammenfassung 相似文献