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71.
X. Liang X. Wang J. Zhuang Y. Chen D. Wang Y. Li 《Advanced functional materials》2006,16(14):1805-1813
Uniform magnetite, hematite, and goethite nanocrystals were prepared through an attractive method based on an oleic acid/alcohol/water system. By adjusting the synthetic parameters (base concentration, alcohol content, categories of alcohols, etc.), the controlled synthesis of uniform magnetite, hematite, and goethite nanocrystals can be easily achieved. Detailed investigations on the effect of the experimental parameters on the morphology of the final products and the phase transitions among the magnetite, hematite, and goethite phases were carried out. Finally, a method of doping other metal ions into magnetite was developed and the magnetic properties of magnetite doped with different metal elements were studied. 相似文献
72.
D. Twigger M. Byard S. Draper R. Driver R. Hartley S. Hennessy C. Mallen R. Mohamed‡ C. O'Malley§ T. O'Shea‡ E. Scanlon‡ 《Journal of Computer Assisted Learning》1991,7(2):144-155
Abstract This paper outlines the work of the Conceptual Change in Science project, funded as part of the ESRC InTER programme. The aims of this research project are to clarify and describe the process of change in learners' conceptual understandings of natural phenomena. The domain of reasoning selected for study is that of mechanics. Computer software which may be useful in exploring and developing pupils' reasoning and promoting conceptual change in this domain is being developed and evaluated. The group that is carrying out the research is based at the Universities of Leeds, Glasgow and the Open University. 相似文献
73.
Woo-Seok Cheong 《Journal of Electronic Materials》2003,32(4):249-253
For the lowest resistance, it is required to have the epitaxial silicon contact between the silicon plug and the substrate
and good step coverage at the high aspect-ratio contact holes, simultaneously. In this work, a double polysilicon (DPS) deposition
technique was proposed for the requirements. The first, thin silicon layer is deposited in a single-wafer process chamber
with an in-situ H2-RTP (rapid thermal process) treatment for the epitaxial contact, and the second silicon layer is formed in a batch-type furnace
for good step coverage. From chain resistance, Kelvin Rc, and current-voltage (I–V) measurement, the DPS process meets both low resistance and good uniformity, so that it suggests
a breakthrough in the small-sized, semiconductor device application. 相似文献
74.
75.
De Fruyt Filip; Van Leeuwen Karla; Bagby R. Michael; Rolland Jean-Pierre; Rouillon Frédéric 《Canadian Metallurgical Quarterly》2006,18(1):71
Structural, mean- and individual-level, differential, and ipsative personality continuity were examined in 599 patients treated for major depression assigned to 1 of 6 forms of a 6-month pharmaco-psychotherapy program. Covariation among traits from the Five Factor model remained invariant across treatment, and patients described themselves as slightly more extraverted, open to experience, agreeable and conscientious, and substantially more emotional stable after treatment. Trait changes were only to a small extent explained by changes in depression severity. There was evidence for differential, individual-level, and ipsative stability, with stable personality profiles in terms of shape and to a lesser extent in terms of scatter and elevation. Traits remain relatively stable, except for emotional stability, despite the depressive state and the psychopharmacological interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
76.
利用差示扫描量热仪、傅里叶红外光谱仪、广角X射线衍射仪研究了一种新型的以聚乙二醇为软段的聚氨酯相变储能材料。结果表明,当软段含量低于90%(质量分数,下同)时,即使温度高于聚乙二醇的熔点,此类材料仍不会熔化成液体,而表现出一种固-固相变行为。该聚氨酯储能材料相变焓较大,相变温度适中,且随着软段含量的减少,材料相变焓和相变温度呈递减趋势。其相变过程实质是聚氨酯软段聚乙二醇由结晶固态转变为无定形固态的过程。 相似文献
77.
78.
给出了自旋网表象中的两个4价基底,证明了它们之间的变换属酉变换。用重耦理论的图式计算法,推出了体积算符对基底作用的重耦矩阵的表式,并利用体积算符的本征值得到空间量子化的结果。 相似文献
79.
80.
The fabrication of functional textiles able to provide thermal regulation and comfort for the body has attracted increasing interest in recent years. This research investigated fabric coatings containing energy absorbing, temperature stabilizing, phase‐change material microcapsules (PCMMcs), and their methods of application. Specifically, a coated fabric was directly prepared by a dual‐type coating method, in which the PCMMcs were dispersed in a polyurethane coating solution with no binder. The thermal performances of the dual‐coated samples were evaluated by differential scanning calorimetry, and their physical characteristics were examined by scanning electron microscopy, thermal vision camera, porosity, water vapor transmission rate (WVTR), and water entry pressure (WEP) analyses. Furthermore, the microclimate characteristics of the thermally enhanced fabrics were investigated under experimental conditions using a human‐clothing‐environment (HCE) simulator system. The study results confirmed the superior performance of the dual‐coated fabrics in terms of thermal regulation and body comfort, compared with those coated by the dry or wet coating method, because of the improved WEP, WVTR, and thermal performance. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献