排序方式: 共有38条查询结果,搜索用时 46 毫秒
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HCI and the older population 总被引:1,自引:0,他引:1
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K Ogura MR Amin K Minami XD Zheng Y Suzuki WS Kim T Watanabe Y Carmel VL Granatstein 《Canadian Metallurgical Quarterly》1996,53(3):2726-2729
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P. E. Latham V. L. Granatstein Y. Carmel 《Journal of Infrared, Millimeter and Terahertz Waves》1993,14(6):1217-1227
For imaging radar and for satelitte and space communication (e.g. NASA's deep space network), it is important that the bandwidth be as large as possible. Here we derive a formalism for computing the phase locking bandwidth that can be achieved in a gyrotron oscillator while varying the beam voltage. As an example, a second harmonic TE02/03 gyrotron is considered. For this device, the effective bandwidth can be increased by a factor of about 3 compared with the fixed voltage case by allowing the beam voltage to change together with the input locking signal. 相似文献
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Wasserman Edward A.; Gagliardi Joseph L.; Cook Brigette R.; Kirkpatrick-Steger Kim; Astley Suzette L.; Biederman Irving 《Canadian Metallurgical Quarterly》1996,22(2):205
Four experiments used a 4-choice discrimination learning paradigm to explore the pigeon's recognition of line drawings of 4 objects (an airplane, a chair, a desk lamp, and a flashlight) that were rotated in depth. The pigeons reliably generalized discriminative responding to pictorial stimuli over all untrained depth rotations, despite the birds' having been trained at only a single depth orientation. These generalization gradients closely resembled those found in prior research that used other stimulus dimensions. Increasing the number of different vantage points in the training set from 1 to 3 broadened the range of generalized testing performance, with wider spacing of the training orientations more effectively broadening generalized responding. Template and geon theories of visual recognition are applied to these empirical results. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Y. Carmel K. R. Chu D. Dialetis A. Fliflet M. E. Read K. J. Kim B. Arfin V. L. Granatstein 《Journal of Infrared, Millimeter and Terahertz Waves》1982,3(5):645-665
Gyrotron oscillators are of great interest as sources of high power mm wave radiation for electron cyclotron resonance heating and current drive in magnetic fusion research devices. Gyrotrons capable of efficiently generating cw power ? 1 megawatt will be required in future magnetic fusion studies. However, as gyrotron power approaches the megawatt level, a very large, overmoded cavity must be employed in order to keep ohmic power losses in the cavity at an acceptable level, and the problem of mode overpopulation becomes severe. Also, it becomes increasingly important to optimize gyrotron efficiency for a number of important reasons including minimizing the problem of collecting the electron beam energy. In the present paper, a detailed experimental and theoretical study of mode competition and mode locking in an overmoded gyrotron is presented. Efficiency enhancement (to 60%) and high peak power (430 kW) were achieved in the TE2,4,1 mode using magnetostatic profiling in the cavity. With selective mode suppression, peak power of 475 kW was generated in the TE0,4,1 mode. 相似文献
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Granatstein V. Schlessinger S. Vigants A. 《Antennas and Propagation, IEEE Transactions on》1963,11(4):489-496
Waveguiding properties of a homogeneous circular column of plasma imbedded in free space are examined in the two limits of zero and large axial magnetic field. The plasma is assumed to be cold and collisionless with ion motion neglected. The modes with azimuthal variation are included in the investigation, and dispersion curves are presented. For the zero field case the higher-order modes are found under certain conditions to exhibit backward-wave characteristics. For the case of large magnetic field, the occurrence of unique waveguiding features is discussed. The assumptions made are approximated by certain laboratory plasmas and hence the results may be of practical importance. 相似文献
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Astley Suzette L.; Peissig Jessie J.; Wasserman Edward A. 《Canadian Metallurgical Quarterly》2001,27(3):252
Three experiments examined superordinate categorization via stimulus equivalence training in pigeons. Experiment 1 established superordinate categories by association with a common number of food pellet reinforcers, plus it established generalization to novel photographic stimuli. Experiment 2 documented generalization of choice responding from stimuli signaling different numbers of food pellets to stimuli signaling different delays to food reinforcement. Experiment 3 indicated that different numbers of food pellets did not substitute as discriminative stimuli for the photographic stimuli with which the food pellets had been paired. The collective results suggest that the effective mediator of superordinate categories that are established via learned stimulus equivalence is not likely to be an accurate representation of the reinforcer, neither is it likely to be a distinctive response that is made to the discriminative stimulus. Motivational or emotional mediation is a more likely account. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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A simple quantum-electronic approach to the gyrotron and its application to the solid-state gyrotron
A simple, unifying theory of the gyrotron is presented. It is of the Lamb type. Within its framework, important results from different approaches can he easily obtained. As an application, gyrotron action in InSb is reexamined, and coherent emission at 1012Hz appears possible with an output power of about 0.5 mW/mm2of the device. 相似文献
9.
Tate J.P. Hezhong Guo Naiman M. Leemian Chen Granatstein V.L. 《Microwave Theory and Techniques》1994,42(10):1910-1917
Proof-of-principle results for a mode selective input coupler are presented. Transmission and reflection measurements for the TE02 cylindrical waveguide mode are given along with the output mode pattern. The results show good agreement for the cutoff frequency, mode pattern general behavior and variation with frequency for signals above cutoff. A maximum passband of 1.2 GHz (~7%) has been achieved. Comparisons with theory for overall frequency response (from 15 to 18 GHz) and mode pattern characteristics (at 17.5 GHz) are also presented. The design and concept are promising for harmonic gyrotron-traveling-wave-tube amplifier and phase-locked gyrotron oscillator applications 相似文献
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