排序方式: 共有27条查询结果,搜索用时 46 毫秒
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介绍了无机类富勒烯(Inorganic fullerene-like,简称IF)与过渡金属硫化物(WS2和MoS2)纳米材料的常用合成技术--固-气与气相反应合成方法; 以及用化学复合镀法制备含有IF-WS2纳米颗粒的Ni-P复合镀层的方法. 相似文献
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为了提高双轮式抛投机器人的全向抗冲击性能,提出了一种仿富勒烯张拉式轮毂结构及其优化方法。首先,根据C60的几何特点及正二十面体被截取顶角后的截取比例λ建立模型,利用直接刚度矩阵法对模型进行受力分析,给出了最优截取比例λ。然后,以张拉结构为载荷分布优化单元对C60结构载荷分布进行优化,并对其静力学性能进行了ABAQUS仿真分析,最后将其与同质量的条幅式、轮辐式以及球壳式轮毂结构进行对比。仿真结果表明:所提出的仿C60张拉结构轮毂具有较好的强度及刚度特性,整体承载性能较优;具有较好的承载与散力特性,应力分布较为均匀;同时具有较好的承载全向性,结构受力整体性好且不易失稳,从而验证了所设计结构的有效性。 相似文献
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采用固-气相反应、反应沉淀和溶剂热诱导法实现了IF-MoS2、IF-WS2纳米粉体的宏观量制备.分别用化学共沉积方法在硬铝基体上制备Ni-P-(IF-WS2)复合镀层,磁控溅射和激光溅射技术在硬铝合金和钛合金基体上制各(Ni,Mo)/IF-(Mo,W)S2梯度纳米复合涂层和IF-(Mo,W)S2/(Ni,Mo)-IF-(Mo,W)S2多层纳米复合涂层.用划痕仪、球-盘式摩擦仪评估纳米涂层的结合力及其在真空(10-2 Pa)和大气中的摩擦磨损性能.Ni-P-(IF-MoS2)化学复合镀层的硬度、摩擦因数和磨损率明显低于Ni-P化学镀层.梯度和多层复合结构有利于涂层与合金基体结合力的提高.(Ni,Mo)/IF-(Mo,W)S2纳米梯度复合涂层和(Ni,Mo)-IF-(Mo,W)S2/IF-(Mo,W)S2纳米多层复合涂层在不同环境下都有低的摩擦因数和磨损率.含无机类富勒烯(IF-)WS2或MoS2的纳米复合涂层具有优良的环境稳定性. 相似文献
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L.?RapoportEmail author O.?Nepomnyashchy I.?Lapsker A.?Verdyan Y.?Soifer R.?Popovitz-Biro R.?Tenne 《Tribology Letters》2005,19(2):143-149
Recently, the behavior of inorganic fullerene-like (IF) WS2 nanoparticles in the interface of steel-on-steel pair has been analyzed. It was shown that originally when the gap between the contact surfaces is smaller than the size of the IF nanoparticles, there is no effect of the nanoparticles on the friction force. During the test stiff IF nanoparticles can plough the surface of hard steel samples and penetrate into the interface under friction. Molecular sheets of WS2 from the delaminated IF nanoparticles, which reside in the valleys of the rough surfaces cover the contact spots and thus decrease the number of adhered spots at the transition to seizure. The goal of the present work was to study the behavior of IF nanoparticles in the interface of ceramic surfaces. The friction tests were performed using a ball-on-flat device. A silicon nitride ball was slid against an alumina flat with maximum contact pressure close to 2 GPa. SEM, TEM and AFM techniques have been used in order to assess the behavior of IF nanoparticles in the interface. The behavior of IF nanoparticles in the much harder ceramic interfaces was found to be appreciably different from the steel pair. The pristine IF nanoparticles are damaged in the inlet of the contact during the first few cycles and thin shells of broken nanoparticles gradually cover the middle range of the contact surface. Different modes of deformation and destruction of the IF nanoparticles are exhibited when going from the middle to edge area of the contact. While aggregates of the pristine nanoparticles are formed at the edge of the contact, thin shells of broken IF nanoparticles are observed in the middle area where contact pressure is maximum. Mechanical stability and damage of IF nanoparticles in the ceramic interface are discussed. 相似文献
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In the present work, inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles have been incorporated into polytetrafluoroethylene films using aerosol-assisted deposition process. The hydrophobic behavior of the nanocomposite film has been investigated and the result shows that the hydrophobicity of PTFE films can significantly be improved with the incorporation of IF-WS2 nanoparticles. An oblate spheroid model which takes into the consideration of surface roughness effect has been proposed, to simulate the hydrophobic behavior, based on the surface roughness and peak density of the nanocomposite films. This hydrophobic model can provide a useful guideline to describe and predict the hydrophobicity of nanocomposite films, from the input of parameters such as surface energy, roughness and liquid properties. 相似文献
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Inna Wiesel Hamutal Arbel Ana Albu-Yaron Ronit Popovitz-Biro Jeffrey M. Gordon Daniel Feuermann Reshef Tenne 《Nano Research》2009,2(5):416-424
Inorganic fullerene-like WS2 and MoS2 nanoparticles have been synthesized using exclusively solid precursors, by reaction of the corresponding metal oxide nanopowder,
sulfur and a hydrogen-releasing agent (NaBH4 or LiAlH4), achieved either by conventional furnace heating up to ∼900 °C or by photothermal ablation at far higher temperatures driven
by highly concentrated white light. In contrast to the established syntheses that require toxic and hazardous gases, working
solely with solid precursors permits relatively safer reactor conditions conducive to industrial scale-up.
相似文献
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无机类富勒烯二硫化钼的减摩抗磨特性 总被引:1,自引:1,他引:0
以仲钼酸铵和醋酸为前驱物制得了三氧化钼纳米粉,将其与硫粉混合在氢气氛下通过还原硫化反应合成了无机类富勒烯二硫化钼,其粒径分布为30-200nm,形貌为类球形。用MMU-10G屏显式材料端面高温摩擦磨损实验机测定了无机类富勒烯二硫化钼在混合润滑状态下的摩擦磨损性能,实验表明:无机类富勒烯二硫化钼能够明显改善基础油的减摩抗磨性能,复合油润滑时的最小摩擦因数为0.0127;无机类富勒烯二硫化钼能够显著提高润滑油的成膜和承载能力。润滑机制是无机类富勒烯二硫化钼纳米颗粒的化学惰性和将滑动摩擦变为滚动摩擦。 相似文献
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Uneven malaligned teeth are a problem afflicting large numbers of people, having significant economic and societal repercussions. Sliding a tooth along an archwire during orthodontic treatment involves a frictional type of force which resists this movement, causing a number of adverse effects. First, using excessive orthodontic force, leads to unwanted movements of the anchor teeth and increasing the risk of damage to the roots of the teeth. Furthermore, the frictional force is distributed unevenly between the archwire and the brackets interface, leading to strong adhesion between the wire and the bracket’s corner. This force-asymmetry causes lengthening of treatment and frequent visits for fine-tuning of the orthodontic appliances. Despite numerous efforts to lower the friction, no satisfactory solution to this issue has been obtained. In the present work a self-lubricating metal coating containing fullerene-like WS2 (IF) nanoparticles is demonstrated. Such coatings significantly reduce archwire friction, and may alleviate the adverse complications. Moreover, a number of other medical applications of the self-lubricating coatings are foreseen. 相似文献