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41.
DerekWilliams 《中国制造业信息化》2005,34(6):58-58
亚洲在技术应用和创新方面获得了突飞猛进的发展,并将继续保持这种发展势头。亚洲的技术创新能力长期以来已经得到公认。现在与过去不同的是,创新正在与市场增长齐头并进。中国也正在用技术增强实力。看看“数字北京”工程和为主办2008北京奥运会开展的各项工作吧。北京有志提供非常先进的服务,这些服务要比现有数字城市基础设施提供的服务先进得多,甚至与亚洲一些先进城市相比也高出一筹。印度也在用技术增强实力,只要看看印度班加罗尔过去10年的兴旺发展就足够了。 相似文献
42.
Direct utilization of geothermal energy 2010 worldwide review 总被引:4,自引:0,他引:4
This paper presents a review of the worldwide application of geothermal energy for direct utilization, and updates the previous survey carried out in 2005. We also compare data from 1995 and 2000 presented at World Geothermal Congresses in Italy and Japan, respectively (WGC95 and WGC2000). As in previous reports, an effort is made to quantify ground-source (geothermal) heat pump data. The present report is based on country update papers prepared for WGC2010 and other sources of data available to the authors. Final update papers were received from 70 countries of which 66 reported some direct utilization of geothermal energy. Twelve additional countries were added to the list based on other sources of information. Direct utilization of geothermal energy in 78 countries is a significant increase from the 72 reported in 2005, the 58 reported in 2000, and the 28 reported in 1995. An estimate of the installed thermal power for direct utilization at the end of 2009 is used in this paper and equals 48,493 MWt, almost a 72% increase over the 2005 data, growing at a compound rate of 11.4% annually with a capacity factor of 0.28. The thermal energy used is 423,830 TJ/year (117,740 GWh/yr), about a 55% increase over 2005, growing at a compound rate of 9.2% annually. The distribution of thermal energy used by category is approximately 47.2% for ground-source heat pumps, 25.8% for bathing and swimming (including balneology), 14.9% for space heating (of which 85% is for district heating), 5.5% for greenhouses and open ground heating, 2.8% for industrial process heating, 2.7% for aquaculture pond and raceway heating, 0.4% for agricultural drying, 0.5% for snow melting and cooling, and 0.2% for other uses. Energy savings amounted to 250 million barrels (38 million tonnes) of equivalent oil annually, preventing 33 million tonnes of carbon and 107 million tonnes of CO2 being release to the atmosphere, this includes savings for geothermal heat pumps in the cooling mode (compared to using fuel oil to generate electricity). 相似文献
43.
The identification of the space- and time-dependent perfusion coefficient in the one-dimensional transient bio-heat conduction equation is investigated. While boundary and initial conditions are prescribed, additional temperature measurements are considered inside the solution domain. The problem is approached both from a global and a local perspective. In the global approach a Crank–Nicolson-type scheme is combined with the Tikhonov regularization method. In the local approach, we compute both the time first-order and space second-order derivatives by means of first kind integral equations. A comparison between the numerical results obtained using the two methods shows that the local approach is more accurate and stable than the global one. 相似文献
44.
Derek Stewart Pamela M. Norris 《Nanoscale and Microscale Thermophysical Engineering》2013,17(2):89-101
This study examines the influence of radial thickness on the thermal conductivity of thin metallic wires. While size effects on the electrical conductivity of thin wires have been discussed in the literature, research into size effects on thermal conductivity still requires investigation. At such small length scales, the assumption that the reduced electrical conductivity can be simply related to the reduced thermal conductivity through a Wiedemann-Franz relation is subject to question. This study uses the Boltzmann transport equation for electrons to determine the thermal conductivity of a thin wire directly. Electrons are treated as the primary heat carriers in a thin wire with a thermal gradient along the axis. A single-crystal, defect-free, metallic thin wire is considered in the derivation. An expression is presented which accounts for the radial size effects on axial thermal conductivity. The derived thermal conductivity is compared to expressions for the reduced electrical conductivity, and the applicability of the Wiedemann-Franz relation is discussed. 相似文献
45.
46.
Derek Pletcher Hantao Zhou Gareth Kear C.T. John Low Frank C. Walsh Richard G.A. Wills 《Journal of power sources》2008
The structure of lead deposits (approximately 1 mm thick) formed in conditions likely to be met at the negative electrode during the charge/discharge cycling of a soluble lead-acid flow battery is examined. The quality of the lead deposit could be improved by appropriate additives and the preferred additive was shown to be the hexadecyltrimethylammonium cation, C16H33(CH3)3N+, at a concentration of 5 mM. In the presence of this additive, thick layers with acceptable uniformity could be formed over a range of current densities (20–80 mA cm−2) and solution compositions. While electrolyte compositions with lead(II) concentrations in the range 0.1–1.5 M and methanesulfonic acid concentrations in the range 0–2.4 M have been investigated, the best quality deposits are formed at lower concentrations of both species. Surprisingly, the acid concentration was more important than the lead(II) concentration; hence a possible initial electrolyte composition is 1.2 M Pb(II) + 5 mM C16H33(CH3)3N+ without added acid. 相似文献
47.
Derek N. Mueller Author Vitae 《Computers and Composition》2009,26(4):240-250
This article offers a theoretical framework for ‘digital underlife’: the distal and potentially transgressive discursive activities proliferated by emerging technologies. Digital underlife is an adaptation of sociologist Erving Goffman's concept of underlife, which figured centrally in Robert Brooke's well-known study of writing activity in 1988. As emerging digital technologies fray the communicative bounds of traditional sites for teaching and learning, such as the classroom and the conference hall, we are confronted anew with a complex array of possibilities for giving and getting attention. Drawing on the work of Charles Moran and Richard Lanham, this article calls for a more receptive disposition toward the productive dimensions of digital underlife. The article promotes a stance that imagines productive digital underlife to be intrinsic to curricula that combine digital writing activity and rhetorical education, rather than short-selling digital underlife as mere distraction, as an impediment to learning, or worse, attempting to banish it altogether. 相似文献
48.
49.
Yasemin Vural Derek B. Ingham Mohamed Pourkashanian 《International Journal of Hydrogen Energy》2009,34(22):9181-9187
In this study, the performance (current–voltage curve) prediction of a Proton Exchange Membrane Fuel Cell (PEMFC) is performed for different operational conditions using an Adaptive Neuro-Fuzzy Inference System (ANFIS). First, ANFIS is trained with a set of input and output data. The trained model is then tested with an independent set of experimental data. The trained and tested model is then used to predict the performance curve of the PEMFC under various operational conditions. The model shows very good agreement with the experimental data and this indicates that ANFIS is capable of predicting fuel cell performance (in terms of cell voltage) with a high accuracy in an easy, rapid and cost effective way for the case presented. Finally, the capabilities and the limitations of the model for the application in fuel cells have been discussed. 相似文献
50.
Caleb King;Peter Parker;Derek S. Young; 《Quality and Reliability Engineering International》2024,40(4):1618-1635
In many industries, the reliability of a product is often determined by a quantile of a distribution of a product's characteristics meeting a specified requirement. A typical approach to address this is to assume a parametric model and compute a one-sided confidence bound on the quantile. However, this can become difficult if the sample size is too small to reliably estimate such a parametric model. Linear interpolation between order statistics is a viable nonparametric alternative if the sample size is sufficiently large. In most cases, linear extrapolation from the extreme order statistics can be used, but can result in inconsistent coverage. In this work, we perform an empirical study to generate robust weights for linear extrapolation that greatly improves the accuracy of the coverage across a feasible range of distribution families with positive support. Our method is applied to two industrial datasets. 相似文献