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111.
ABSTRACT Four scenarios for the IS organization of 2020 are described, based on differing assumptions about two drivers: the advances in the reliability of international telecommunications and the value placed on computerization in businesses and society. 相似文献
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113.
Jing Zheng Scott P. Beckman Joe N. Gray Mufit Akinc 《Journal of the American Ceramic Society》2001,84(9):1961-1967
X-ray tomography has been used to investigate the density variations in SiC joints formed using polymer pastes. It has been demonstrated that X-ray tomography provides accurate bulk density measurements and volumetric density gradients. The results suggest that the magnitude of the applied pressure after green state joining and the amount of polymer (polycarbosilane, PCS) in the joining pastes influence the green density of the joints. All joints are prepared and applied in air atmosphere and at room temperature. The green densities of the joints increase from 54% to 66% of theoretical with the increase of the applied pressure from ambient to 138 MPa. Highest joint density without applied pressure is achieved using paste containing 50 vol% PCS. Furthermore, allylhydridopopolycarbosilane- (AHPCS-) containing pastes resulted in higher densities at the joint–matrix interface, indicating infiltration of polymer into the matrix. 相似文献
114.
A steady-state, axi-symmetric, numerical model was developed to investigate the agglomeration of molten particles of sulphide ore in the reaction shaft of a flash smelting process used for extracting copper. The turbulent, particle-laden, gas flow was simulated in conjunction with a population balance model to account for agglomeration. The agglomeration was found to depend primarily on the particle to gas mass loading ratio, and the particle size and turbulence intensity at the shaft inlet. Predictions compared well with the limited experimental data in the literature. Increasing the angle at which the flow enters the shaft from the burner was found to increase agglomeration up to a critical angle at which the flow behaviour changes. The results have implications for the control and reduction of dust levels in the waste gas stream. 相似文献
115.
Antimicrobial effects of pulsed electromagnetic fields from commercially available water treatment devices – controlled studies under static and flow conditions
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Gray DW 《Journal of chemical ecology》2002,28(8):1583-1597
Methylbutenol (MBO) is a major component of the aggregation pheromone of the European spruce beetle Ips typographus and also has been found to be emitted in large amounts by several species of pine native to western North America. This study investigates the influence this signal may have on the behavior of North American bark beetles and examines whether MBO functions as a defensive compound for emitting pines. The response of two North American bark beetles (Ips paraconfusus and Dendroctonus brevicomis) and their predaceous beetles (Trogositidae and Cleridae) to MBO, pheromone, and monoterpenes in varying release rates was investigated in the field using Lindgren funnel traps. MBO exhibited no repellent properties when tested alone, nor did MBO appear to have any effect on the aggregation response of these bark beetles and their predators to their pheromones. These results provide no support for a defensive function of MBO. 相似文献
118.
Past, Present, and Future 总被引:9,自引:0,他引:9
Paul Gray 《Information Systems Management》2006,23(1):90-93
Thomas L. Friedman. the World Is Flat: A Brief History of the Twenty-First Century. N ew York: Farrar, Straus and Giroux, 2005, 488 pp.
Nicholas G. Carr. Does IT Matter? Information Technology and the Corrosion of Competitive Advantage. Boston: Harvard Business School Press, 2004, 193 pp.
John Hagel III and John Seely Brown. the Only Sustainable Edge: Why Business Strategy Depends on Productive Friction and Dynamic Specialization. Boston: Harvard Business School Press, 2005, 218 pp.
John Markoff. What the Dormouse Said. New York: Viking, 2005, 301 pp. 相似文献
Nicholas G. Carr. Does IT Matter? Information Technology and the Corrosion of Competitive Advantage. Boston: Harvard Business School Press, 2004, 193 pp.
John Hagel III and John Seely Brown. the Only Sustainable Edge: Why Business Strategy Depends on Productive Friction and Dynamic Specialization. Boston: Harvard Business School Press, 2005, 218 pp.
John Markoff. What the Dormouse Said. New York: Viking, 2005, 301 pp. 相似文献
119.
Although landmarks are an integral part of navigation, they have rarely been used explicitly within electronic pedestrian navigation aids. We describe a two-part study into the use of landmarks in such aids, using a set of field experiments. The first part investigated whether such devices can be effective for older adults (over 60 years old), who might particularly benefit from them due to declines in sensory, cognitive and motor abilities. The second part compared the effectiveness of different methods of presenting landmark information. We show that a pedestrian navigation aid based around landmarks is particularly useful for older people and demonstrate that text, speech and photographs are all effective ways of presenting landmark information, although speech on its own has some drawbacks. We found that different people prefer information to be presented in different modalities, indicating a need for personalisation, although multi-modality may also help to address this issue. 相似文献
120.
We present an approach to parallel iterative four-atom quantum mechanics calculations in a computing environment of distributed memory nodes, each node consisting of a group of processors with a shared memory. We parallelize the action of the Hamiltonian matrix on a vector, which is the main computational bottleneck in both iterative calculations of eigenvalues and eigenvectors and the iterative determination of quantum dynamics information via, e.g., wavepacket methods. OpenMP is used to facilitate the parallel work within each node, and MPI is used to communicate information between nodes. For a realistic problem the approach is shown to scale very well up to 512 processors at the NERSC computing facility, working at up to 20% of the theoretical peak performance rate. The highest total floating point rate we achieve is 0.16 Tflops, using 768 processors. Our approach should also be applicable to quantum dynamics problems with more than four atoms. 相似文献