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81.
Abstract The sensitivity of the output power of stable resonators in multimode operation to mirror tilt was investigated both theoretically and experimentally. It is shown that the decrease of power is only caused by the decreasing mode volume inside the active medium. A simple geometrical model including the refractive power of the medium is used to derive expressions for the tilt angles at which the power has decreased by 10%. Experiments were performed with pulsed Nd : YAG lasers, the results showing good agreement with the theoretical predictions. 相似文献
82.
Brockmole James R.; Wang Ranxiao Frances; Irwin David E. 《Canadian Metallurgical Quarterly》2002,28(2):315
Using a temporal integration task, subjects in 5 experiments were expected to combine information from temporally separated visual presentations. Evidence from these experiments indicated that perceptual information can be integrated with previously generated and currently maintained visual images to form a representation that contains information from each source. Properties and limitations of this integration process were also explored, including the time required to generated the image, the speed at which percepts were integrated with images, and the capacity of the representation. Implications for theories of visual processing and memory are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
83.
This article reviews issues concerning the training and credentialing of vascular surgeons in the use of endovascular techniques in the peripheral vascular system. These guidelines update a prior document that was published in 1993. They have been rewritten to accommodate the rapid evolution that has occurred in the field and to provide the appropriate requirements that a vascular surgeon should fulfill to be competent in the basic skills needed to safely and effectively perform all presently accepted diagnostic and therapeutic endovascular procedures. 相似文献
84.
Carter Frances A.; McIntosh Virginia V. W.; Joyce Peter R.; Bulik Cynthia M. 《Canadian Metallurgical Quarterly》2008,117(4):936
The authors attempted to replicate previous findings that weight suppression is a significant predictor of treatment completion and treatment outcome (M. L. Butryn, M. R. Lowe, D. L. Safer, & W. S. Agras, 2006) and weight gain over treatment (M. R. Lowe, W. Davis, D. Lucks, R. A. Annunziato, & M. L. Butryn, 2006) among women with bulimic disorders. The authors also examined 2 alternative measures of weight variability. Participants were 132 women with bulimia nervosa treated with cognitive-behavioral therapy. Participants who dropped out of treatment did not have significantly higher levels of weight suppression than did treatment completers. Among those who completed treatment, weight suppression did not significantly predict binge eating and purging at post-treatment. Weight suppression did significantly predict weight change and, in particular, weight gain (≥5 kg) over treatment. Alternative measures of weight variability did not significantly predict treatment completion or treatment outcome, but 1 measure significantly predicted weight gain over treatment. In conclusion, the authors failed to replicate the previous finding that weight suppression predicts treatment compliance and treatment outcome, but they did replicate the finding that weight suppression predicts weight gain over treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
85.
The new daily generation scheduling model for the Ontario Hydro system is presented. The model is capable of considering the thermal and hydraulic systems together with system reserve requirement and transmission losses. The hydraulic system is considered in a detailed formulation that can handle river couplings in a complete manner. Inability to do this was a major weakness in the peak shaving technique used since early 1970s. A special network programming technique has been used to solve the problem. This method has proved to be very efficient from a computational point of view. Test results from application of the new technique are presented and compared to the peak shaving method. The user has estimated 1.4 million dollars per year of savings from the new computer package 相似文献
86.
A. N. H. Al-Ajili A. K. Ray J. R. Travis S. N. B. Hodgson A. P. Baker C. J. Goodhand 《Journal of Materials Science: Materials in Electronics》2000,11(6):489-495
Thermal decomposition and electrical conductivity of oxide cathode emission materials used for cathode ray tubes (CRTs) have been studied under different heat treatment conditions for commercial sprayed cathode systems based on barium-strontium carbonate precursors. Conversion of the carbonate precursor commenced at temperatures above approximately 700 K in vacuum, evidenced by increases in conductivity, however, the rate of the conversion reaction increased dramatically as the temperature was increased. The corresponding chemical and microstructural changes have also been investigated by thermo-gravimetric analysis (TGA) and scanning electron microscopy (SEM), with multiple decomposition stages identified corresponding to the conversion of the carbonate precursor and separate activation steps associated with the reaction of barium oxide with the Mg and Al activating agents in the nickel cathode substrate. © 2000 Kluwer Academic Publishers 相似文献
87.
88.
Swain Ralph W. Lynn Walter R. Hodgson Thomas A. Becker Niels G. Johnson Kenneth G. 《IEEE transactions on bio-medical engineering》1972,(2):120-125
Epidemiological simulation models to be used primarily to augment the teaching of epidemiology to medical students and other individuals concerned with public health and control of epidemics are presented. Interactive simulations are used to expose students to ``realistic' epidemic situations and permit them to experiment with various control strategies. Criteria by which simulations for such teaching purposes may be evaluated are proposed and operating simulations, MEASLES and INFLU, are described in detail. Information is provided regarding user experience with the above simulations. 相似文献
89.
Two-, 3-, and 4-year-old children viewed 10 stimulus sets. Each set contained a sample picture (e.g., a dog), a basic-level taxonomic match (e.g., another dog), a thematic match (e.g., a bone), and an irrelevant match (e.g., a pen). The children were asked to choose a match that "goes with" each sample. Sample pictures were either animate entities or artifacts. The children's choice behavior indicated that a shift occurs between 3 and 4 years of age from a taxonomic bias to a thematic bias and that, at both ages, animate sample stimuli enhance the children's tendency to adopt thematic conceptual strategies. These data are consistent with recent suggestions that thematic thinking presupposes basic-level taxonomic thinking during early conceptual development and that this developmental progression occurs more rapidly in some domains of knowledge than in others. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
90.
Thom J. Hodgson Russell E. King Kristin Thoney Natalie Stanislaw Alexander J. Weintraub Andrew Zozom 《IIE Transactions》2000,32(2):177-180
We consider the problem of minimizing maximum lateness in a job shop. A conceptually simple simulation based procedure described in a recent paper by Hodgson et al [1] is modified to provide improved schedules. Computational experimentation is provided to identify the conditions under which the approach is most viable, and to report the procedure's performance on known test problems. 相似文献