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1.
《International Journal of Hydrogen Energy》2021,46(60):30818-30827
In this paper, dopamine hydrochloride (DPH) is introduced to synthesize ZIF-8@ZIF-67@DPH in the preparation of ZIF-8@ZIF-67. ZnSe/CoSe/NCDPH (N-doped carbon) composites are calcined in a high-temperature inert atmosphere with ZIF-8@ZIF-67@DPH as the precursor, selenium powder as the selenium source. ZnSe/CoSe/NCDPH has high discharge specific capacity, good cycle stability and outstanding rate performance. The first discharge capacity of ZnSe/CoSe/NCDPH is 1616.6 mAh g−1 at the current density of 0.1 A g−1, and the reversible capacity remains at 1214.2 mAh g−1 after 100 cycles, the reversible capacity is 416.7 mAh g−1 after 1000 cycles at 1 A g−1. Therefore, ZnSe/CoSe/NCDPH composites provide a new step for the research and synthesis of new stable, high-capacity, and safe high-performance lithium ion batteries. The bimetallic selenide composites not only have bimetallic active sites, but also can form synergistic effect between different metal phases, which can effectively reduce the capacity attenuation caused by volume expansion and reactive stress enrichment during lithium storage of metal oxide anode materials. Meanwhile, N-doped carbon can improve the conductivity and provide more active sites to store lithium, thus improving its lithium storage capacity. 相似文献
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This paper proposes an efficient and automated scheme to predict and identify the position and motion errors of rotary axes on a non-orthogonal five-axis machining centre using the double ball bar (DBB) system. Based on the Denavit-Hartenberg theory, a motion deviations model for the tilting rotary axis B and rotary C of a non-orthogonal five-axis NC machine tool is established, which considers tilting rotary axis B and rotary C static deviations and dynamic deviations that total 24. After analysing the mathematical expression of the motion deviations model, the QC20 double ball bar (DBB) from the Renishaw Company is used to measure and identify the motion errors of rotary axes B and C, and a measurement scheme is designed. With the measured results, the 24 geometric deviations of rotary axes B and C can be identified intuitively and efficiently. This method provides a reference for the error identification of the non-orthogonal five-axis NC machine tool. 相似文献
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介绍了一种CE7120斜床身车床数控化改造的方案,包括机械部分改造和电气部分改造。改造后的数控车床在零件的加工精度及加工效率等方面都有明显的提高。 相似文献
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在合理安排工艺过程的基础上,如何编制结构简洁、刀路科学的数控程序很大程度上影响着工件加工效率和质量,探讨如何合理运用子程序和刀具半径补偿功能,实现数控铣削加工程序的模块化、通用化。 相似文献
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Virtual dynamic optimization design can avoid the repeated process from design to trial-manufacture and test. The designer can analyze and optimize the product structures in virtual visualization environment. The design cycle is shortened and the cost is reduced. The paper analyzed the peculiarity of virtual optimization design, and put forwards the thought and flow to implement virtual optimization design. The example to optimize the internal grinder was studied via establishing precise finite element model, modifying the layout of Stiffened Plates and designing parameters of the worktable, and using the technology of modal frequency revision and the technology of multiple tuned damper. The result of optimization design compared the new grinder with the original grinder shows that the entire machine's first orders natural frequency is enhanced by 17%, and the response displacement of the grinding-head has dropped by 28% under the first order natural frequency and by 41% under second order natural frequency. Finally, the dynamic performance of the internal grinder was optimized. 相似文献
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数控加工中产生的接刀痕迹,对产品的使用性能、工作寿命及可靠性有直接影响。分析了接刀痕迹产生的原因,并提出了用软件补偿的方法来改善接刀痕迹,散热器表面加工质量得到了提高,在生产中取得了较好的效果。 相似文献
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