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71.
Asserts that in preparing objectives of television programming for children the instructor must (a) recognize the needs and interests of his/her audience and (b) match them to his/her educational purposes. The techniques used to identify and implement methods of attaining the goals of the television programs "Sesame Street" and "The Electric Company" are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
72.
A representative carbon fiber reinforced plastic/aluminum honeycomb sandwich panel (CFRP/Al HC SP) spacecraft structure has been modeled in the hydrocode AUTODYN using the state-of-the-art ADAMMO material model [Riedel W, Harwick W, White D, Clegg R. Advanced material damage models for numerical simulation codes. ESA CR(P) 4397, 2003] to study the performance of the structure during impact events that cause perforation and fragment ejection. A new procedure combining a series of existing theoretical methods has been developed and applied to derive a full set of coarse material data. The data set has been implemented in AUTODYN, and the results of the numerical simulation have been compared to experimental impact test data. For impact tests performed near the structural ballistic limit, quantitatively accurate results were obtained over a range of impact velocities and angles. A further increase in the projectile size resulted in significant destruction of the sandwich panel front face-sheet and diversion from the experimental damage measurements. Inspection of the numerical model has shown non-localized propagation of inter-laminar delaminations, possibly caused by an under-prediction of the laminate dynamic inter-laminar tensile strength. The effects of the delamination propagation occur over an extended time scale and were not found to affect the state and trends of the fragment cloud ejected into the satellite interior. Accordingly, experimental trends of fragment cloud dispersion have been qualitatively reproduced. 相似文献
73.
BCI Meeting 2005--workshop on signals and recording methods. 总被引:4,自引:0,他引:4
Jonathan R Wolpaw Gerald E Loeb Brendan Z Allison Emanuel Donchin Omar Feix do Nascimento William J Heetderks Femke Nijboer William G Shain James N Turner 《IEEE transactions on neural systems and rehabilitation engineering》2006,14(2):138-141
This paper describes the highlights of presentations and discussions during the Third International BCI Meeting in a workshop that evaluated potential brain-computer interface (BCI) signals and currently available recording methods. It defined the main potential user populations and their needs, addressed the relative advantages and disadvantages of noninvasive and implanted (i.e., invasive) methodologies, considered ethical issues, and focused on the challenges involved in translating BCI systems from the laboratory to widespread clinical use. The workshop stressed the critical importance of developing useful applications that establish the practical value of BCI technology. 相似文献
74.
Z. Radakovic E. Cardillo M. Schaefer K. Feser 《Electrical Engineering (Archiv fur Elektrotechnik)》2006,88(3):183-190
The paper presents the improvement in design of the conductor connecting the windings and bushings in oil power transformers. This is a sensitive part of large transformers and there is a need to optimise its manufacturing time and costs. The thermal problem of the heating of this conductor with increased insulation thickness on a part of it is treated using a non-linear two-dimensional thermal model. The experiments performed made determining of some problematic parameters (heat resistance of oil-paper insulation and the paper to oil convection heat transfer coefficient) of the thermal model feasible. The results obtained are of practical interest in the design practice of interconnections, but also affect the important parameters of heat transfer by devices with oil immersed paper insulation. 相似文献
75.
Paul F. Mlakar Donald O. Dusenberry James R. Harris Gerald Haynes Long T. Phan Mete A. Sozen 《Canadian Metallurgical Quarterly》2005,19(3):197-205
On September 11, 2001, an airliner was intentionally crashed into the Pentagon. It struck at the first elevated slab on the west wall, and slid approximately 310?ft (94.5?m) diagonally into the building. The force of the collision demolished numerous columns and the fa?ade of the exterior wall, and induced damage to first-floor columns and the first elevated slab over an area approximately 90?ft (27.4?m) wide and 310?ft (94.5?m) long. None of the building collapsed immediately. The portion that remained standing, even after an intense fire, sustained substantial damage at the first-floor level. 相似文献
76.
Paul F. Mlakar Donald O. Dusenberry James R. Harris Gerald Haynes Long T. Phan Mete A. Sozen 《Canadian Metallurgical Quarterly》2005,19(3):206-211
On September 11, 2001, the reinforced concrete structure of the Pentagon Building was able to resist, without collapse, the impact of a large commercial airliner despite the total loss of 26 columns and severe damage to 15 columns at the ground level. The ensuing fire and related fire-fighting activities led to the collapse of a portion of the building approximately one-half hour after the impact. In this paper, the reasons for the demonstrated toughness of the reinforced concrete structure are examined and attributed to use of spiral columns, effective splicing of reinforcing bars, strong girders, and short span lengths. 相似文献
77.
Matthew C. Morley Jennifer L. Henke Gerald E. Speitel Jr. 《Canadian Metallurgical Quarterly》2005,131(1):29-37
The high explosive (HE) compounds royal demolition explosive or hexahydro-1,3,5-trinitro-1,3,5-triazocine (RDX) and high melting explosive or octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) have been detected as groundwater contaminants at many military facilities. This research evaluated adsorption of RDX and HMX with granular activated carbon (GAC) to provide guidance for the design and operation of GAC adsorbers for treatment of HE-contaminated groundwater. Five GACs were screened using rapid small-scale column tests (RSSCTs), after which additional tests were performed with the two GACs that most effectively treated mixtures of RDX and HMX (Calgon F400 and Northwestern LB-830). GAC service life as a function of empty-bed contact time (EBCT) was determined using RSSCTs for a range of simulated full scale EBCTs with influent concentrations of 2,200 μg RDX/L and 350 μg HMX/L. Increasing the influent concentration of either contaminant significantly reduced the predicted service life, as did preloading GAC with groundwater natural organic matter. In batch isotherm tests, RDX was less adsorbable than HMX under all conditions studied. Concurrent loading of natural organic matter reduced the Freundlich K for RDX, whereas adsorption of HMX was not affected. Of the GACs tested, Calgon F400 most effectively removed RDX and HMX. 相似文献
78.
The purpose of this study was to investigate the mediating role of self-efficacy in the development of students' intentions to become entrepreneurs. The authors used structural equation modeling with a sample of 265 master of business administration students across 5 universities to test their hypotheses. The results showed that the effects of perceived learning from entrepreneurship-related courses, previous entrepreneurial experience, and risk propensity on entrepreneurial intentions were fully mediated by entrepreneurial self-efficacy. Contrary to expectations, gender was not mediated by self-efficacy but had a direct effect such that women reported lower entrepreneurial career intentions. The authors discuss practical implications and directions for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
79.
Haeffel Gerald J.; Abramson Lyn Y.; Voelz Zachary R.; Metalsky Gerald I.; Halberstadt Lisa; Dykman Benjamin M.; Donovan Patricia; Hogan Michael E.; Hankin Benjamin L.; Alloy Lauren B. 《Canadian Metallurgical Quarterly》2005,5(3):343
Results from studies using a behavioral high-risk design and approximations to it generally have corroborated the cognitive vulnerability hypothesis of depression, whereas results from remitted depression studies typically have not. Suspecting that design features of previously conducted remitted designs likely precluded them from detecting maladaptive cognitive patterns, the authors conducted a study featuring the remitted design that has been successful in studies of a biological vulnerability for depression. Participants' current depressive symptoms, negative cognitive styles (hopelessness theory), dysfunctional attitudes (Beck's theory), and lifetime prevalence of clinically significant depression were assessed. Participants who had remitted from an episode of clinically significant depression had more negative cognitive styles, but not greater levels of dysfunctional attitudes, than did never depressed individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
80.
Higher-Order and Symbolic Computation - 相似文献