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Cubic and hexagonal sodium yttrium fluoride were successfully synthesized from yttrium nitrate, sodium fluoride and poly-ethanediol in propanetriol solvent under a facile hydrothermal route. By regulating the molar ratio of yttrium and fluoride, hydrothermal tem-perature and reaction time, the phase and shape of sodium yttrium fluoride were commendably controlled. The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectrum (EDS) techniques. It was revealed that the hollow-structured Na(Y1.5Na0.5)F6 nanotubes self-assembled and arrayed orientedly to be bamboo raft-shaped. The for-mation of hexagonal Na(Y1.5Na0.5)F6 nanotube arrays was attributed to solid-liquid-solid process and Oswald ripening. This study provided a simple method to prepare hexagonal bamboo raft-shaped Na(Y1.5Na0.5)F6 on a large scale, which broadened their practical applications. 相似文献
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在当今推动“碳中和”战略目标实现的背景下,用于通信基站节能的功能材料的研发具有重要意义。鉴于相变材料(phase change materials,简写为PCM)在储热方面的独特优势,对PCM的种类和它们各自的优缺点进行了罗列;针对3种不同应用场景的通信基站,全面综述了PCM储热在基站节能中应用的进展;从促进PCM储热在基站节能中普及的角度,介绍了PCM的导热率提升、封装技术、热循环稳定性提升方面的代表性研究成果。将为通信基站节能和PCM储热领域的未来研究方向提供参考。 相似文献
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使用P123作为模板剂,采用不同的硅源(正硅酸甲酯,正硅酸乙酯,硅酸钠)在弱酸性的条件下(pH=4.4,乙酸-乙酸钠缓冲溶液)合成掺杂铁的介孔氧化硅材料.正硅酸甲酯和硅酸钠形成有序的二维六方相的介孔结构,而正硅酸乙酯形成了囊泡结构.紫外可见漫反射光谱和紫外共振拉曼光谱表明,在环境友好的条件下,采用硝酸铁和硅酸钠可以合成出高度隔离的铁物种.缓冲溶液提供了一条便捷的途径,通过简单改变硅源来控制介孔结构.掺杂铁的介孔氧化硅材料在苯酚的羟化反应中表现出优异的催化性能,主要由于铁物种高度分散在氧化硅载体上,介孔结构使铁活性位更易于接近反应物分子. 相似文献
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