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101.
I.?B.?Ban’kovskayaEmail author I.?G.?Polyakova D.?V.?Kolovertnov T.?M.?Ul’yanova 《Glass Physics and Chemistry》2017,43(2):170-173
Coatings on graphite that are stable to oxidation and based on the silicon–boron–zirconium boride composite containing from 5 to 50% of fibrous zirconium dioxide as a modifying dopant have been produced by the suspension–annealing method. A nonporous layer is formed at the zirconium dioxide content ranging from 5 to 15%, while a porous layer is formed at its 50% content. A glass-forming melt, as well as zirconium dioxide and silicate, is formed during thermal treatment as a result of the chemical reactions with the oxygen in air. The zirconium silicate content increases, along with the modifier’s concentration and temperature. 相似文献
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103.
用作汽车轮胎增强材料的钢丝帘线是由盘条拉成细丝捻制而成。为满足轮胎的刚度需求,人们开发了不同类型的钢丝帘线。钢丝帘线的结构稳定性是其质量评估的重要因素之一。一般在钢丝帘线捻制工序后评估钢丝帘线的平直性和残余扭转。校直辊是利用周期弯曲变形来改善钢丝帘线的平直性和残余应力的一种装置。校直辊装置的工艺设计大多数情况下是基于工程师经验的反复试验,需要大量的时间和成本。因此需要一个有效工具来节省校直辊工艺设计的时间和成本。有限元分析模拟方法是校直辊工艺设计的一种有效选择。本工作提出通过有限元分析校直辊工艺数值模拟单层钢丝帘线质量的评估方法,以3×0.30单层钢丝帘线作为试验样品。简易模拟方法如 相似文献
104.
Naohisa Tamura Kazuhiro Ban Shinya Takahashi Shoji Obuchi 《The Journal of Adhesion》2013,89(4):355-373
Poly(L-lactic acid) (PLLA) was blended with poly(butylenesuccinate) (PBS) using a single-screw extruder to modify the poor characteristics of these polymers. Furthermore, when both polymers were blended, the graft copolymer that was synthesized by partially saponified poly(vinyl alcohol) (PSPVA) and ?-caprolactone (?-CL) was used as a novel compatibilizer. The structure of the synthesized compatibilizer was determined by 1H or 13C NMR. From this result, the ring-opening polymerization of the ?-CL occurred at the hydroxyl group of PSPVA. The structures of the PLLA/PBS solvent-cast blended films could be observed via an optical microscope. From the optical microscopic observation, the structures of the solvent-cast blended films with the synthesized compatibilizer were more homogeneous than those of the solvent-cast blended films without the compatibilizer. The mechanical properties of the PLLA/PBS extruded blended films were determined by a tensile test. The result showed the tensile strength of the blended films with the synthesized compatibilizer was greater than that of the blended films without the compatibilizer. 相似文献
105.
对"泡沫碳化硅基结构催化剂的设计、制备及应用关键技术"的研究过程及所取得的成果进行了综述,介绍了泡沫碳化硅的制备、性能、活性涂层涂覆、规整填料等多方面的工作,并将所得到的泡沫碳化硅结构催化剂在不同的化学反应中进行应用考察。与颗粒催化剂等传统的催化剂进行比较,泡沫碳化硅结构催化剂传热和传质能力强,结构可设计性高。 相似文献
106.
Enhancing matrix crystallization has been demonstrated to be an effective method to simultaneously improve the impact toughness and heat resistance of poly(l-lactide) (PLLA) modified with flexible polymers, such as poly(ε-caprolactone) (PCL). Unfortunately, increasing PLLA matrix crystallinity alone cannot guarantee the enhancement of impact toughness in most cases, so other structural parameters should be considered. In this work, taking PLLA/PCL (80/20) blend as an example, the combined roles of matrix crystallization and impact modifier particle size in the toughening have been investigated. PLLA matrix crystallinity was controlled by adding a highly effective nucleating agent and PCL particle size was tailored by varying processing conditions while maintaining constant interfacial adhesion. It is interesting to find that toughening is efficient only if matrix crystallinity and particle size are well matched. With the significant increase of matrix crystallinity, an evident decrease of optimum particle size for toughening PLLA has been identified for the first time. Therefore, suitable particle size is the precondition for highly crystalline matrix to work effectively in the toughening because only small particles (0.3–0.5 μm) are effective in trigger shear yielding mechanism of the matrix needed for good toughness, whereas relatively large particles (0.7–1.1 μm) are only capable of toughening amorphous matrix effectively by initiating multiple crazing of the matrix. Importantly, our findings can be used to well explain the reason for the different roles of matrix crystallization in the toughening of different PLLA blends reported in the literature. Furthermore, the heat resistance of the blend with a highly crystalline matrix is much better than that of the blend with an amorphous one as expected. This work could not only provide a new insight into the synergistic roles of matrix crystallization and modifier particle size in the toughening of PLLA but also set up a universal framework for designing high-performance PLLA products with both good impact toughness and high heat resistance. 相似文献
107.
108.
The composite materials and coatings for graphite based on a ZrB2-SiC system were obtained by the formation of a glass-forming melt in air. The effect of the heating mode on the structure and properties of the materials synthesized was shown. The coatings can be used for protecting graphite from oxidation for several hours at temperatures up to 1400°C. 相似文献
109.
110.
为提高催化剂抗砷能力,采用密度泛函理论(DFT)方法研究As2O3在α-Fe2O3(001)表面的吸附行为以及掺杂Mo、Mn、Ni对α-Fe2O3(001)表面As2O3吸附行为的影响。建立As2O3在α-Fe2O3(001)表面吸附模型和Mo、Mn、Ni掺杂的吸附模型,计算As2O3在催化剂表面的吸附能,分析成键态密度以及掺杂前后的As2O3在α-Fe2O3(001)表面的电荷布局。结果表明:这4种体系均发生电子转移,Mo掺杂活化了As2O3分子,使得As2O3倾向于吸附在Mo活性位点上,保护了Fe活性位点,... 相似文献