Tower of London performance in relation to Magnetic Resonance Imaging following closed head injury in children.

To investigate the relationship of severity of pediatric closed head injury (CHI), the contribution of frontal lobe lesions, and age at testing (6–10 yr olds vs 11–15 yr olds) to cognitive deficit, 134 head-injured patients were given the Tower of London (TOL) task and underwent magnetic resonance imaging. 89 normal controls were given the TOL for comparison. Severity of CHI and age at testing were strongly related to cognitive performance on the TOL, including the frequency of breaking the rules. Volume of frontal lobe lesion (but not extrafrontal lesion) contributed to the prediction of perfomance on the TOL even after severity of injury was taken into account. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nuclear Magnetic Resonance Studies of Silicon Carbide Polytypes

The ²⁹Si MAS NMR spectra of the 2H, 4H, 6H, and 3C polytypes of silicon carbide are presented. An attempt is made to correlate differences in the chemical shifts with local atomic environment. The results of the analysis of the spectra of pure polytypes are used as a basic for the interpretation of the spectra of mixed polytypes and a discussion of the crystallinity and impurity levels of different samples. Carbon-13 chemical shifts obtained from spectra of the same polytypes are also tabulated.     

Phenomena-based thermal-hydraulic modeling requirements for systems analysis of a Modular High Temperature Gas-Cooled Reactor

The Modular High Temperature Gas-Cooled Reactor (MHTGR) is a candidate design for new production and commercial power nuclear reactors. The MHTGR has inherent safety features including: (1) passive shutdown and decay heat removal, (2) reduced requirements for operator intervention, thereby reducing sensitivity to operator error, and (3) long time intervals for corrective action. In support of the Department of Energy's (DOE) initial development of the design, the authors have completed an evaluation of the thermal-hydraulic phenomena that will dominate the plant response during representative normal, off-normal and accident conditions. Phenomena having significance to the plant behavior have been identified, and ranked with respect to their relative importance in satisfying operational, investment and/or safety criteria. The resulting information provides the basis for evaluating the applicability of existing computer codes, and defines the requirements for the development of new codes, for thermal-hydraulic systems analysis. The phenomena-based requirements also support the quality assurance related verification and validation of these codes. This paper briefly describes the methodology employed, and gives illustrative examples of the resulting requirements. References are cited for reports that document the full body of requirements and provide additional information for the methodology.     

Mechanistic investigation into the electrolytic formation of iron from iron(III) oxide in molten sodium hydroxide

Iron(III) oxide tablets were electrolytically reduced to iron in molten sodium hydroxide at 530 °C and recovered to produce iron with 2 wt.% oxygen suitable for re-melting. The cell was operated at 1.7 V and an inert nickel anode was used. The thermodynamics and mechanism of the process was also investigated. By controlling the activity of sodium oxide in the melt, the cell could be operated below the decomposition voltage of the electrolyte with the net sequence of events being the ionization of oxygen, its subsequent transport to the anode and discharge leaving behind iron at the cathode. A reduction time of 1 h was achieved for a 1 g oxide tablet (close to the theoretical reduction time predicted by Faraday’s laws) at a current density of 520 mA cm⁻² with iron phase yields of ∼90 wt.%. The energy consumption was 2.8 kWh kg⁻¹.     

Young children's understanding of interpretive diversity between different-age listeners.

Tested children's understanding of interpretive diversity by assessing their attributions of knowledge to a mother and a preverbal baby, who both had access to an informative verbal message. In Exp 1, most children between ages 4 and 8 yrs overattributed knowledge to the preverbal baby after an informative message. Exps 1a and 1b demonstrated that overattributions were not due to conflating the speaker's intent to inform with the informativeness of the message, nor were they due to overestimating babies' limited knowledge. In Exp 2, 6- and 8-yr-olds acknowledged interpretive differences between the baby and adult listener if the message was not obviously informative. It is concluded that children do not readily view individual differences as related to interpretive differences, especially in the absence of cues inherent to a message that might suggest that the message has multiple interpretations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Double cracking in brittle cylindrical specimens subjected to quenching

A series of quench tests on hollow cylindrical specimens made of the machinable ceramic, Pyrophyllite, has been performed. The specimens consistently fractured with two diametrically opposite longitudinal cracks. Finite element analysis indicates that the primary crack occurred at the stage when the strain energy of the cylinder reached its maximum during the thermal transient process, while the secondary crack was caused by stress waves generated following the primary crack. This is supported by experimental observation of the time of fracture and the crack morphology. The work reported here helps to shed light on the fracture criterion for brittle cylindrical components under transient thermal and dynamic loadings.     

五大法宝抓住客户

如果你正在思考如何提高自己的网上业务,那么你需要首先知道自己的目标市场究竟在哪,以及如何达到.在不久的将来网络市场会是什么样子呢?其实,它跟十几岁的少年有着诸多联系.看一看今天的青少年吧,你就会发现这些现象:     

Attentional task aptitude and performance anxiety.

Anxious responding (trait, state, and test anxiety) has a negative impact on overt performance. Researchers have used a unidimensional method of assessing anxiety and performance, although a more informative approach would involve a comprehensive assessment battery and multiple performance tasks. Incorporating this strategy, the authors measured the impact of anxiety on 4 attentional processing tasks. Results revealed that "types" of anxiety symptoms were differentially related to attentional task performance; test anxiety accounted for the most variance in predicting performance on the Wechsler Adult Intelligence Scale-Third Edition (D. Wechsler, 1997) letter-number sequencing and digit-span subtests, trait anxiety and fear of negative evaluation were more significant in predicting Stroop performance, and math anxiety accounted for the largest variance toward understanding Paced Auditory Serial Addition Task (C. W. Lejuez, C. W. Kahler, & R. A. Brown, 2003) scores. Theoretical and clinical implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)