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51.
The Am(V) disproportionation in (2–10) × 10?3 M K10P2W17O61 (KPW) solutions in 1–7 M HNO3 was studied spectrophotometrically. Under the experimental conditions, Am(VI) and Am(III) are the final products of Am(V) transformation; the process is described by the rate equation of a reversible reaction. The direct reaction follows the first-order rate equation with respect to Am(V) concentration, and the reverse reaction, the zero-order equation. 相似文献
52.
Mahoney Annette; Pargament Kenneth I.; Jewell Tracey; Swank Aaron B.; Scott Eric; Emery Erin; Rye Mark 《Canadian Metallurgical Quarterly》1999,13(3):321
Ninety-seven couples completed questionnaires about their involvement in joint religious activities and their perceptions regarding the sanctification of marriage, including perceived sacred qualities of marriage and beliefs about the manifestation of God in marriage. In contrast to individual religiousness and religious homogamy (distal religious constructs), these proximal religious variables directly reflect an integration of religion and marriage, and they were associated with greater global marital adjustment, more perceived benefits from marriage, less marital conflict, more verbal collaboration, and less use of verbal aggression and stalemate to discuss disagreements for both wives and husbands. The proximal measures also added substantial unique variance (adjusted R2 change ranged from .06 to .48) to specific aspects of marital functioning after controlling demographic factors and distal religious variables in hierarchical regression analyses. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
53.
Keltner Dacher; Capps Lisa; Kring Ann M.; Young Randall C.; Heerey Erin A. 《Canadian Metallurgical Quarterly》2001,127(2):229
Drawing on E. Goffman's concepts of face and strategic interaction, the authors define a tease as a playful provocation in which one person comments on something relevant to the target. This approach encompasses the diverse behaviors labeled teasing, clarifies previous ambiguities, differentiates teasing from related practices, and suggests how teasing can lead to hostile or affiliative outcomes. The authors then integrate studies of the content of teasing. Studies indicate that norm violations and conflict prompt teasing. With development, children tease in playful ways, particularly around the ages of 11 and 12 years, and understand and enjoy teasing more. Finally, consistent with hypotheses concerning contextual variation in face concerns, teasing is more frequent and hostile when initiated by high-status and familiar others and men, although gender differences are smaller than assumed. The authors conclude by discussing how teasing varies according to individual differences and culture. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
54.
Phase separation of poly(N‐isopropylacrylamide) solutions and gels using a near infrared fiber laser
We used a tunable near infrared fiber laser in the wavelength range of 1533–1573 nm to induce photothermal phase changes in poly(N‐isopropylacrylamide) (PNIPAM) aqueous solutions and hydrogels. The laser induces the hydrophilic to hydrophobic transition of the polymer by heating the surrounding water. We report our observations of the phase changes based on using a novel fiber backreflectance method coupled with visual cloud point measurements. At 1533 nm the phase transition was induced at the end of a single mode optical fiber with 9 mW of power at an ambient temperature of 24°C. We found that the power required to reach the lower critical solution temperature was inversely proportional to the absorption spectrum of water. In addition, phase changes in both solutions and gels occurred very rapidly (<1 s) as the laser was turned on and off. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 相似文献
55.
Afeminist approach to the psychology of women is defined. In terms of this definition four areas central to the psychology of women are examined. These areas are theory building, sex differences research, research describing women's lives, and feminist therapy. For each area past accomplishments are outlined and future directions are suggested. In conclusion, two important methodological paradoxes are presented, and their relevance to a developing feminist psychology of women is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
56.
The systematic analysis of factors that promote or impede physical activity in children is an urgent task for educational researchers. The present study investigated the reciprocal relationship between physical self-concept, teacher-assigned grades in physical education classes, and free-time physical activity, and analyzed positive and negative consequences of being in a class with high class-average physical ability. Data from a large, representative sample of 1,095 preadolescents from 66 classrooms were examined within a longitudinal framework. Multilevel analyses showed that membership in a class with high class-average physical ability was associated with lower physical self-concept and free-time physical activity and highlighted the significant role of teacher-assigned grades in the development of physical self-concept and physical activity. Furthermore, as predicted, there were positive reciprocal effects between physical self-concept and physical activity levels. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
57.
Clinicians today face difficulties in appropriately assisting children with mood disorders, whose parents may challenge diagnostic and treatment decisions based on potentially faulty information obtained from unregulated sources (e.g., the Internet, commercial books, other media). In light of this problem, as well as the U.S. Surgeon General's recent call for increases in evidence-based diagnosis and treatment of childhood disorders, it is important that psychologists educate themselves and their clients about evidence-based practices. Evidence-based assessment and psychosocial and psychopharmacological treatment procedures for childhood unipolar and bipolar mood disorders are reviewed, and specific practice recommendations are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
58.
Y. De Decker J.B. Benziger E. Kimball I.G. Kevrekidis 《Chemical engineering science》2010,65(7):2399-2409
A simple tanks-in-series model is presented, which allows for the understanding of the basic physics behind complex spatiotemporal behaviors observed in self-humidified polymer electrolyte membrane (PEM) fuel cells. Our approach is focused on how the intrinsically nonlinear dynamics of water formation couples with water transport, leading to multistability, inhomogeneous steady state current profiles through the cell and other nonlinear phenomena. We show in particular how the operating parameters determine the location of high current spots and the subsequent propagation of current waves throughout the cell during the ignition procedure. We also reproduce and explain transient current increases seen during the extinction of the cell and the unusual aspect of the polarization curves. Implications for the efficiency of self-humidified PEM fuel cells are highlighted, and possible ways to improve their performances are discussed on these bases. 相似文献
59.
The development and proliferation of antibiotic resistance in pathogenic, commensal, and environmental microorganisms is a major public health concern. The extent to which human activities contribute to the maintenance of environmental reservoirs of antibiotic resistance is poorly understood. In the current study, wastewater treatment plants (WWTPs) were investigated as possible sources of tetracycline resistance via qualitative PCR and quantitative PCR (qPCR). Various WWTPs and two freshwater lakes were surveyed for the presence of an array of 10 tetracycline resistance determinants (tet(R)): tet(A)-(E), tet(G), tet(M), tet(O), tet(Q), tet(S). All WWTP samples contained more different types of tet(R) genes, as compared to the lake water samples. Gene copy numbers of tet(G) and tet(Q) in these samples were quantified via qPCR and normalized to both the volume of original sample and to the amount of DNA extracted per sample (a proxy for bacterial abundance). Concentrations of tet(Q) were found to be highest in wastewater influent while tet(G) concentrations were highest in activated sludge. Investigation of the effects of UV disinfection on wastewater effluent showed no reduction in the number of detectable tet(R) gene types. 相似文献
60.
A model fuel cell with a single transparent straight flow channel and segmented anode was constructed to measure the direct correlation of liquid water movement with the local currents along the flow channel. Water drops emerge through the largest pores of the GDL with the size of the droplets that emerge on the surface determined by the size of the pore and its location under the gas flow channel or under the land. Gravity, surface tension, and the shearing force from the gas flow control the movement of liquid in the gas flow channel. By creating a single large diameter pore in the GDL, liquid water flow emergent from the GDL was forced to be in specific locations along the length of the channel and either under the land or under the channel. The effects of gravity were amplified when the large pore was under the channel, but diminished with the large pore under the land. Current fluctuations were minimised when the dominant water transport from the GDL pore was near the cathode outlet. The results show that it is possible to engineer the water distribution in PEM fuel cells by modifying the pore sizes in the GDL. 相似文献