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81.
Christopher L Brown Gillian Bushell Michael W Whitehouse DS Agrawal SG Tupe KM Paknikar Edward RT Tiekink 《Gold bulletin》2007,40(3):245-250
Nanosized gold particles (27 +/− 3 nm) have been proven to be effective in ameliorating the symptoms of mycobacterial-, collagen-
and pristane-induced arthritis in rat models. This contrasts with the drug sodium aurothiomalate that was only effective against
mycobacterial-induced arthritis but not to the same extent as Au0. Gold in the traditional Indian Ayurvedic medicine,Swarna bhasma (gold ash), has been characterized as globular particles of gold with an average size of 56–57 nm. 相似文献
82.
Janaina Braga do?CarmoEmail author Christopher?Neill Diana?C.?Garcia-Montiel Marisa?de Cássia Piccolo Carlos?C.?Cerri Paul?A.?Steudler Cristiano Alberto?de Andrade Caio?C.?Passianoto Brigitte?J.?Feigl Jerry?M.?Melillo 《Nutrient Cycling in Agroecosystems》2005,71(3):213-225
The clearing of tropical rain forest in the Amazon basin has created large areas of cattle pasture that are now declining in productivity. Practices adopted by ranchers to restore productivity to degraded pastures have the potential to alter soil N availability and gaseous N losses from soils. We examined how soil inorganic N pools, net N mineralization and net nitrification rates, nitrification potential and NO and N2O emissions from soils of a degraded pasture responded to the following restoration treatments: (1) soil tillage followed by replanting of grass and fertilization, (2) no-till application of non-selective herbicide, planting of rice, harvest followed by no-till replanting of grass and fertilization, and (3) the same no-till sequence with soybeans instead of rice. Tillage increased soil NH4+ and NO3? pools but NH4+ and NO3? pools remained relatively constant in the control and no-till treatments. Cumulative rates of net N mineralization and net nitrification during the first 6 months after treatment varied widely but were hightest in the tilled treatment. Emissions of NO and N2O fluxes increased with tillage and with N fertilization. There were no clear relationships among rates of N fertilizer application, net N mineralization, net nitrification, NO, N2O and total N oxide emissions. Our results indicate that pasture restoration sequences involving tilling and fertilizing will increase emissions of N oxides, but the magnitude of the increase is likely to differ based on timing of fertilizer application relative to the presence of plants and the magnitude of plant N demand. Emissions of N oxides appear to be decreased by the use of restoration sequences that minimize reductions in pasture grass cover. 相似文献
83.
Styrene/hexadecane miniemulsions were polymerized at 50°C using a redox initiator. The miniemulsions and their corresponding latexes were characterized in terms of size, polymerization rate, and surface properties. The resulting data were analyzed to elucidate the miniemulsion stabilization and polymerization mechanisms. It was found that the free surfactant concentration exceeded the critical micelle concentration when large amounts of surfactant (60 mM sodium lauryl sulfate) were used, resulting in simultaneous micellar and droplet nucleation. Most surfactant was on the surface of the droplets (85%) or particles (95%). The fractional surface coverage was proportional to the surfactant concentration to the 0.55 power. Using a particle diameter equation, the number of particles was calculated to be proportional to the surfactant concentration to the 1.35 power. Through direct particle size measurements, a power of 1.38 was confirmed. The rate of polymerization was determined by reaction calorimetry to be proportional to the number of particles to the 0.59 power, in contrast to classical Smith–Ewart kinetics for conventional emulsions (1.0 power). The average number of radicals per particle was estimated from the rate and number data, and varied with the particle diameter to the 0.97 power. The observed kinetic dependencies were validated through an extension of Smith–Ewart theory. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3987–3993, 2003 相似文献
84.
Zhan Yu Xuan Yu Christopher Thorpe Scott Grauer-Gray Feng Li Jingyi Yu 《The Visual computer》2014,30(1):45-58
The ability to produce dynamic Depth of Field effects in live video streams was until recently a quality unique to movie cameras. In this paper, we present a computational camera solution coupled with real-time GPU processing to produce runtime dynamic Depth of Field effects. We first construct a hybrid-resolution stereo camera with a high-res/low-res camera pair. We recover a low-res disparity map of the scene using GPU-based Belief Propagation, and subsequently upsample it via fast Cross/Joint Bilateral Upsampling. With the recovered high-resolution disparity map, we warp the high-resolution video stream to nearby viewpoints to synthesize a light field toward the scene. We exploit parallel processing and atomic operations on the GPU to resolve visibility when multiple pixels warp to the same image location. Finally, we generate racking focus and tracking focus effects from the synthesized light field rendering. All processing stages are mapped onto NVIDIA’s CUDA architecture. Our system can produce racking and tracking focus effects for the resolution of 640×480 at 15 fps. 相似文献
85.
86.
S. M. Ali Eslami Nicolas Heess Christopher K. I. Williams John Winn 《International Journal of Computer Vision》2014,107(2):155-176
A good model of object shape is essential in applications such as segmentation, detection, inpainting and graphics. For example, when performing segmentation, local constraints on the shapes can help where object boundaries are noisy or unclear, and global constraints can resolve ambiguities where background clutter looks similar to parts of the objects. In general, the stronger the model of shape, the more performance is improved. In this paper, we use a type of deep Boltzmann machine (Salakhutdinov and Hinton, International Conference on Artificial Intelligence and Statistics, 2009) that we call a Shape Boltzmann Machine (SBM) for the task of modeling foreground/background (binary) and parts-based (categorical) shape images. We show that the SBM characterizes a strong model of shape, in that samples from the model look realistic and it can generalize to generate samples that differ from training examples. We find that the SBM learns distributions that are qualitatively and quantitatively better than existing models for this task. 相似文献
87.
Robert A. Regtop John Ellis Phillip T. Crisp Alfred Ekstrom Christopher J.R. Fookes 《Fuel》1985,64(12):1640-1646
Aliphatic compounds (alkanes, alkenes, alkanoic acids, ketones, alcohols and amines) were passed through beds of spent oil shales (Condor brown, Condor carbonaceous, Julia Creek), minerals (quartz, calcite, K-feldspar, pyrite, kaolinite) and charcoal at temperatures of 300–600 °C and the products were analysed by g.c.m.s. All the materials catalysed isomerization, aromatization and cracking to varying degrees: non-clay minerals < kaolinite ≈ spent oil shales < charcoal. Products included branched alkanes, isomeric alkenes, nitriles, ketones and alkyl-substituted benzenes, naphthalenes, pyridines, phenols, thiophenes and pyrroles. These compounds occur in shale oils and may be derived from secondary reactions of aliphatic products arising from kerogen cracking. 相似文献
88.
P. C. Christopher 《应用聚合物科学杂志》1976,20(11):2989-3003
A practical method for the overall performance evaluation of a GPC system (columns) is described. System performance is defined as the ability of the system to give experimental M?n and M?w values (uncorrected for instrumental spreading and other distorting factors) which agree with the theoretical values, and it is expressed as the per cent deviation between the theoretical and experimental values. The method consists of running blends of monodispersed polystyrene standards of known compositions through the GPC system to be evaluated. From the resulting chromatograms, their M?n and M?w values are calculated (experimental). The theoretical M?n and M?w values of the same standards are also calculated from the formulas on the basis of their composition. By plotting the per cent difference of the experimental values from the theoretical values versus the theoretical values on a semilog scale, the overall performance of the GPC system under investigation is pictorially depicted. Results indicate that performance under experimental conditions can vary significantly from system to system. Results also indicate that performance of a system can be improved and optimized by proper column selection and system modifications. 相似文献
89.
Sanja Dogramadzi Maria Elena Giannaccini Christopher Harper Mohammad Sobhani Roger Woodman Jiyeon Choung 《Journal of Intelligent and Robotic Systems》2014,76(1):73-117
Robot manufacturers will be required to demonstrate objectively that all reasonably foreseeable hazards have been identified in any robotic product design that is to be marketed commercially. This is problematic for autonomous mobile robots because conventional methods, which have been developed for automatic systems do not assist safety analysts in identifying non-mission interactions with environmental features that are not directly associated with the robot’s design mission, and which may comprise the majority of the required tasks of autonomous robots. In this paper we develop a new variant of preliminary hazard analysis that is explicitly aimed at identifying non-mission interactions by means of new sets of guidewords not normally found in existing variants. We develop the required features of the method and describe its application to several small trials conducted at Bristol Robotics Laboratory in the 2011–2012 period. 相似文献
90.
Christopher M. Kellett 《Mathematics of Control, Signals, and Systems (MCSS)》2014,26(3):339-374
The use of comparison functions has become standard in systems and control theory, particularly for the purposes of studying stability properties. The use of these functions typically allows elegant and succinct statements of stability properties such as asymptotic stability and input-to-state stability and its several variants. Furthermore, over the last 20 years several inequalities involving these comparison functions have been developed that simplify their manipulation in the service of proving more significant results. Many of these inequalities have appeared in the body of proofs or in appendices of various papers. Our goal herein is to collect these inequalities in one place. 相似文献