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91.
Y. Greenberg Y. Lumelsky M. S. Silverstein E. Zussman 《Journal of Materials Science》2008,43(5):1664-1668
A versatile approach to the synthesis of YBCO (high temperature superconductor ceramics) nanofibers via electrospinning a
polymer precursor solution is reported. The aqueous polymer precursor solution consists of poly(acrylic acid) (PAAc) and a
mixture of yttrium nitrate, barium nitrate, and copper nitrate, henceforth termed (Y,Ba,Cu)–N. The conductivity of the polymer
precursor solution at 27.1 °C was 14.70 mS/cm, its zero shear viscosity was 52.00 cP, and its pH was 1.88. Typical YBCO nanofibers
were 50–100 nm in diameter and around of 10 μm length. The nanofibers also contain relatively small amounts of yttrium oxide
and copper yttrium oxide. 相似文献
92.
We conducted three experiments to assess the hypothesis that mindlessness could be prevented with a simple linguistic variation. Subjects in the first two experiments were either introduced to new objects conditionally (e.g., this could be an X) or unconditionally (e.g., this is an X), and the objects used were either unfamiliar or familiar. In each study a different need was then generated for which the object in question was not explicitly suited but could fulfill. Only those subjects in the conditional-unfamiliar group gave the creative response and met the need. When subjects were asked explicitly to generate novel uses for the target items, they had no difficulty doing so. However, given the way we are traditionally taught, it simply does not occur to us to think creatively unless explicitly instructed to do so. In the third experiment we introduced an unfamiliar item in one of three ways. In addition to the groups used in the earlier experiments, we added a group that was led to believe that the object was identifiable (unconditional) but was currently unknown. We also added a second need to determine whether the original conditional group truly learned conditionally or if they were in search of an absolute understanding of the target object. Significantly more of the subjects in the conditional group gave the creative response to both needs. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
93.
The room temperature modulus of rupture (MOR) and the plane strain fracture toughness (K
IC) of two Co-Mo-Cr-Si wear resistant alloys in various microstructure conditions have been determined. The modulus of rupture varied from 304 to 927 MN m–2 and as such was more structure sensitive thanK
IC, which was in the range 15 to 26 MN m–3/2 for all conditions of the alloys. The best combination of room-temperature properties was associated with an f c c solid solution whereas h c p solid solution with a Widmanstätten precipitate produced the poorest properties. The industrial significance of these results are discussed. 相似文献
94.
The proposition that the difference in memory span between Welsh digits and English digits is accounted for by the longer articulatory duration of Welsh digits is critically reexamined. Two methods of measuring digit duration are contrasted. One is derived from digits spoken in isolation, the other is based on digits spoken in list format. Duration of Welsh digits was greater only when spoken in lists; with isolated production Welsh digits were significantly shorter than English digits. Also, span was shorter for Welsh digits. The results are interpreted in the light of the different articulatory demands made at the junctures between words in the English and Welsh lists. A supplementary experiment, using English words, illustrated that articulatory complexity at item boundaries increased serial recall error. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
95.
Clarke-Stewart K. Alison; Vandell Deborah L.; McCartney Kathleen; Owen Margaret T.; Booth Cathryn 《Canadian Metallurgical Quarterly》2000,14(2):304
Data from the National Institute of Child Health and Human Development Study of Early Child Care were analyzed to explore effects of marital separation on children in the first 3 years of life. The sample included 73 never-married mothers and 97 separated mothers; a comparison group of 170 was conditionally randomly selected from the 2-parent families. Children in 2-parent families performed better than children in 1-parent families on assessments of cognitive and social abilities, problem behavior, attachment security, and behavior with mother. However, controlling for mothers' education and family income reduced these differences, and associations with separated-intact marital status were nonsignificant (the effect size was .01). Thus, children's psychological development was not affected by parental separation per se; it was related to mothers' income, education, ethnicity, childrearing beliefs, depressive symptoms, and behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
96.
J. J. Cassidy M. S. Silverstein A. Hiltner E. Baer 《Journal of materials science. Materials in medicine》1990,1(2):81-89
Time-dependence in the mechanical response of the intervertebral disc has previously been shown to arise from the transport of water out of the disc. A creep model has been devised which describes the water transport in terms of the disc structure. This model assumes that the flow of water is the result of a pressure gradient across the cartilage end-plates, caused by an externally applied stress. The fluid transport properties of the cartilage determine the flow rate. Several cases are studied; those that best fit the experimental results use either a straindependent or a time- and strain-dependent pressure gradient. The permeability of the disc system is in the range (0.20 to 0.85)×10–17 m4N–1 sec–1 and depends on the stress level. These values are lower than those reported in the literature for articular cartilage, but this can be explained in part by the differences in water content of the cartilage types. Permeability is found to decrease with applied stress, and both the strain- and time-dependence parameters increase in magnitude with stress. It can be shown that the analytical models of the creep response of the disc are analogous to three- and four-parameter viscoelastic models that employ springs and dashpots. 相似文献
97.
Seven experiments assessed the hypothesis derived from terror management theory that reminding people of their mortality would increase accessibility of constructs central to their worldview. Experiment 1 found that mortality primes, relative to control primes, increased accessibility of nationalistic constructs for men but not for women. Experiment 2 replicated this finding and also found that mortality salience increased romantic accessibility for women but not for men. Four subsequent experiments supported the role of unconscious death-related ideation in producing these effects. A final experiment demonstrated that situational primes can increase the accessibility of nationalistic constructs for women after mortality salience. The roles of situational cues and individual differences in the effects of exposure to death-related stimuli on worldview-relevant construct accessibility are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
98.
The psychological functioning and behavior of 46 sexually abused girls (ages 6–14) was compared with that of 46 nonabused girls who were matched on age, race, family income, and family constellation. Sexually abused children demonstrated heightened sexual preoccupation and behavior problems, lower cognitive abilities and school achievement, and more stressful past histories. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
99.
This paper argues that intermediation is both a valuable form of occupational self-organization for professional artists and a political act of embedding with socio-spatial ramifications at different local, urban, and global scales. A case study of events organized in Berlin by the interdisciplinary cultural centre Zentrum für Kunst und Urbanistik demonstrates how artists strategically practice intermediation as modes of autopoietic and dissipative self-organization and as an interscalar survival strategy. These artist intermediaries add improvisational flexibility to the state’s understanding of Verstetigung (sustainable anchoring that fosters a reliable relationship between urban policymakers and cultural producers) and challenge neoliberal urban development logics that instrumentalize creativity. 相似文献
100.
风景园林实践在很大程度上受到政府决策的影响,以英国英格兰地区为例,劳动党政府于2008年提出的《儿童计划》和《游戏策略》,在为儿童游戏场地的更新和建设提供资金支持的同时,也间接推动了儿童场地设计导则与标准的发展。然而随着2010年政府换届,儿童户外游戏场地发展方案被移出了英国国家发展计划。将着重介绍在政策变化的背景下,于英格兰北部谢菲尔德市进行的名为“与自然共生”政府资助项目的实践经验,重点探究在政策引导的背景下,通过儿童户外游戏场地自然化改造的方式对社区户外空间进行适儿化提升的过程、方式和成果。将从多元参与协同工作的机制、儿童参与社区改造的方式以及儿童游戏场地的游戏价值提升等多个方面阐释该项目,为中国“十四五”规划背景下儿童友好型城市建设中社区环境优化提升面临的机遇与挑战提供基于英国经验的应对策略;对因地制宜地建设中国儿童友好城市及社区提供基于前沿实践的参考和建议。 相似文献