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《中学化学教学参考》2020,(1):69-69
中国科学技术大学杜平武教授课题组通过精确分子设计,在世界上合成了首例单一手性指数单壁碳纳米管的长共轭链段。该成果以封面文章的形式发表于《美国化学会志》杂志。碳纳米管可被认为是仅包含sp^2键合原子的全碳基管状共轭聚合物,然而直径特定的碳纳米管片段长共轭聚合物尚无研究报道。具有单一直径和手性的纯碳纳米管材料,在纳米科技和电子学领域有着重要的应用潜力,但合成这样的碳纳米管是合成化学和材料化学领域的一个重要挑战。催化剂表面介导生长的方法在制备碳纳米管方面表现出巨大的潜力,然而纳米管纯度始终是一个难以克服的问题。 相似文献
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碳纳米管是材料科学领域研究的热点,在许多方面有吸引人们的应用前景.综述了近年来碳纳米管作为催化剂载体的应用情况.介绍了碳纳米管的结构和性质,重点讨论了碳纳米管分别作为金属、金属氧化物、金属合金及非晶态合金催化剂载体的催化应用效果. 相似文献
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醛以其来源广、毒性大、污染水平高、污染时间长等特点,已成为我国最主要的室内空气污染物之一.随着碳纳米材料的广泛应用,作为一种新型的水体和空气污染物,碳纳米材料的安全性已经成为环境科学领域的一个研究热点.本实验采用KCl-SDS沉淀法测量甲醛和单笔碳纳米管所致小鼠脑组织DNA-蛋白质交联(DNA—Proteincrosslinks,DPC)的程度.结果表明,低浓度的气态甲醛和单壁碳纳米管均不能导致小鼠产生DPC效应,而高浓度时均能显著诱导脑组织产生DPC效应. 相似文献
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果蔬保鲜中壳聚糖的应用研究 总被引:1,自引:0,他引:1
壳聚糖是一种原材料丰富的天然高分子材料,被广泛应用于防腐、保鲜、水处理等领域.从果蔬保鲜技术的两个主要方面,介绍了壳聚糖成膜特性、保鲜机理及在果蔬保鲜中的应用效果,提供了果蔬保鲜的一种新的途径. 相似文献
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《实验室研究与探索》编辑部 《实验室研究与探索》2009,28(1)
光伏电池在能源、通讯等领域具有巨大的应用,受到了广泛的关注和研究.碳纳米管由于其独特的一维纳米结构和优异的光电特性,有望成为新一代太阳能光伏电池的良好构筑材料.但是,如何使用碳纳米管构筑高光电转换效率的太阳能光伏电池仍是当前研究的难点. 相似文献
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王伟 《长江工程职业技术学院学报》2012,29(3):11-12
土壤固化剂是一种由多种无机、有机材料合成的用以固化各类土壤的新型节能环保工程材料,广泛应用于公路的基层及底基层、水利护坡等工程建设当中,可以就地取材,有利于加快施工进度,减少建筑耗材的运量,并无环境污染。 相似文献
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本文简要概述了原生动物在环境监测中的优势,论述了原生动物在水体监测、土壤监测和化学物质毒性评价中的应用进展,提出了原生动物在环境监测中存在的问题,对其应用前景作了展望。 相似文献
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分析染料废水的特点及其处理现状,重点对目前国内外TiO2及其复合物、Fe3O4及其复合物、碳纳米材料、其他纳米吸附材料在染料废水处理中的应用进行了详尽的归纳,对比与总结.纳米材料是高效廉价的现代高新材料的先驱,若能对纳米吸附材料多加研究,将为染料废水处理技术开辟一条崭新的途径.提高染料废水处理技术,不仅有利于环境保护,而且还可以促进工农业的发展以及人类社会的进步. 相似文献
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随着现代生物技术不断的发展,环境生物技术在废水净化领域中显示出了独特的优势和巨大的潜力。本文综述了活性污泥法、固定化酶法、生物膜法、生物流化床技术、生物脱氮技术、以及微生物絮凝技术等生物技术在水处理中的应用进展。 相似文献
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Emily J. Solari Tricia A. Zucker Susan H. Landry Jeffrey M. Williams 《Early education and development》2016,27(7):1060-1076
With increased demand for improved early childhood education services, it is important to better understand the essential professional development resources that have the greatest impact on both teacher and child outcomes. This study compared the effectiveness of two teacher-training models in bilingual Migrant and Seasonal Head Start and Head Start classrooms. Both conditions included the use of a technology-based student progress-monitoring tool. The progress monitoring provided detailed feedback on students’ progress 15 across the academic year and helped organize instructional groupings. The comprehensive treatment condition included biweekly professional development sessions, in-class mentoring, and provision of classroom materials, whereas the treatment-control condition included only the provision of a limited set of classroom materials. Across multiple sites in Texas, 49 pretest and posttest teacher observations and bilingual child assessments were collected on a subsample of students (n = 387). Research Findings: Improvements in teaching behaviors were observed in both experimental conditions; no significant differences were observed between teachers across conditions. Three measures of child language and literacy growth differed significantly, favoring the comprehensive treatment model, but most outcomes did not differ significantly between groups. Practice or Policy: Implications of these mixed findings and future research directions are discussed. 相似文献
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王有朋 《兰州石化职业技术学院学报》2010,10(3):12-14
综述了坡缕石酸活化、偶联剂处理和表面活性剂等处理方法,分析了坡缕石在聚合物材料中的应用现状,坡缕石/聚合物材料应用前景和研究方向。 相似文献
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Melissa A. Romain Keith A. Millner Victoria E. Moss Marguerite Held 《Reading and writing》2007,20(6):619-641
The purpose of this article was twofold. First, the assessment materials from four core reading programs were informally reviewed
for their adherence to Texas Reading First progress monitoring guidelines for kindergarten and the beginning of Grade 1. Conclusions
support existing concerns regarding the variability in the quality and quantity of assessment materials within and across
programs as well as concerns about whether the materials lend themselves to progress monitoring purposes at 2-week intervals
for students who are struggling readers. Second, recommendations are made for the development of progress monitoring tools
that are concise, easy for teachers to use, and that provide clear guidelines regarding the use of progress monitoring data
to drive instruction. Accordingly the recent development of a progress monitoring tool that parallels the Texas Primary Reading
Inventory (TPRI), which is an assessment tool used in approximately 95% of Texas Reading First schools was discussed. 相似文献