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Porous carbon nanofibers are synthesized by CVD method from acetylene with use of iron-containing catalysts. Activation of the nanofibers in melted potassium hydroxide results in increasing surface area from initial 300–400 m2 g−1 to 1700 m2 g−1. As follows from XRD data, activated nanofibers do not contain regular packages of graphene layers, but retain high electric conductivity. Deposition of copper improves electrochemical hydrogen storing characteristics of carbon nanofibers. Carbon nanomaterials obtained can be used as hydrogen storing materials in batteries instead of hydride forming metals. 相似文献
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It was hypothesized that exposure to complementary representations of the poor as happier and more honest than the rich would lead to increased support for the status quo. In Study 1, exposure to "poor but happy" and "rich but miserable" stereotype exemplars led people to score higher on a general measure of system justification, compared with people who were exposed to noncomplementary exemplars. Study 2 replicated this effect with "poor but honest" and "rich but dishonest" complementary stereotypes. In Studies 3 and 4, exposure to noncomplementary stereotype exemplars implicitly activated justice concerns, as indicated by faster reaction times to justice-related than neutral words in a lexical decision task. Evidence also suggested that the Protestant work ethic may moderate the effects of stereotype exposure on explicit system justification (but not implicit activation). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
14.
用DTA结合XRD了Fe73.5Cu1Nb3Si13.5B9晶合金的晶化动力学。表明,该事金在500℃时析出α-Fe(Si)相。晶化初期激活能最小为242kJ/mol,它随晶化量的增加,在XC为0.4-0.8时,呈极大值为520kJ/mol。在624℃时析出Fe2B相。 相似文献
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从分析石油焦原料着手,考察了其热解特性、孔隙率和石墨化程度。由于石油焦结构致密,属易石墨化碳,因此用水蒸气法直接活化得到的炭质材料吸附性能差,其碘吸附值小于350mg/g。不同来源的石油焦由于组成不同,其活化性能也有差异。通过成型法,以金山石油焦为原料轻预炭化、预氧化和炭化,得到炭化料,再用水蒸气活化得到的活性炭的碘吸附值达800.40mg/g、亚甲蓝值达120.40mg/g。以独山子石油焦为主要原料制得的活性炭的碘吸附值与亚甲蓝值分别达871.58mg/g、100..67mg/g。 相似文献
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RM Martín‐Aranda E Ortega‐Cantero ML Rojas‐Cervantes MA Vicente‐Rodríguez MA Baares‐Muoz 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(2):234-238
α,β‐Unsaturated nitriles have been synthesized by Knoevenagel condensation of a carbonylic compound with malononitrile, assisted by sonochemical irradiation. Two alkaline‐promoted clays (Li+‐ and Cs+‐exchanged saponites) have been employed as catalysts. The influence of the carbonylic compound (benzaldehyde or cyclohexanone) and the use of a solvent on the catalytic activity have been studied. Remarkable increase in the conversion values has been found when the reaction is activated by ultrasound, as compared with the thermal activation. In this green, solvent‐free procedure, α,β‐unsaturated nitriles have been produced in very high yields (97%) when the Cs+‐saponite is used as catalyst. Copyright © 2004 Society of Chemical Industry 相似文献
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活性炭的制备及应用新进展 总被引:32,自引:0,他引:32
综述了活性炭材料研究开发的新进展。重点介绍了煤、石油焦、沥青基活性炭的制备方法及针对不同用途的活性炭改性技术,为选择合适的活化方法和制备特殊功能的改性活性炭提供了参考。 相似文献
19.
Pretreatment of acetylene cokes at 450 °C with a mixture of nitrogen, oxygen and water vapour creates a relatively large surface area and some initial microporosity, further developed by water activation at 800 °C. For the same degree of burn-off, but without pretreatment, large micropores (L > 2–3 nm) are obtained and the external surface area remains small. 相似文献
20.
Tillmann Barbara; Janata Petr; Birk Jeffrey; Bharucha Jamshed J. 《Canadian Metallurgical Quarterly》2003,29(2):470
Harmonic priming studies have shown that a musical context, with its established tonal center, influences target chord processing. This study investigated costs and benefits of priming tonal centers for target processing by adding a baseline condition (sequences without a specific tonal center). Results confirmed harmonic priming, with faster processing for related than for unrelated and less related targets (tonic chord, out-of-key chord, subdominant chord). Comparing targets in baseline contexts with targets in sequences with well-established tonal centers revealed a benefit of processing for related targets but a cost of processing for unrelated and less related targets. Findings are discussed in terms of tonal knowledge activation and suggest that an activated tonal center gives rise to strong expectations for the tonic. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献