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合成氨(NH3)的发展是现代工业进程和人类生存的基石。受氮气(N2)化学惰性的限制,当前的合成氨工业能源消耗高并且排放大量的二氧化碳。电化学氮气还原反应(NRR),是有望取代高能耗的Haber-Bosch (HB)合成法的一种绿色可持续的合成氨工艺。然而,因氮气以及析氢竞争富反应(HER)导致电催化氮气还原极低的NH3产率和能量转换效率一直是目前人工固氮领域面临的挑战。在本文中,我们报道了一种具有丰富孔结构的磷掺杂碳(PC)负载Zn3(PO4)2/Zn2P2O7纳米复合材料(h-PC/Zn3(PO4)2/Zn2P2O7),在酸性和中性介质中将N2高效催化转化为NH3。其独特的分级多孔结构提高了表面粗糙度并加快了氮气在催... 相似文献
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Study on PTFE/Kevlar49/PA6 Composites 总被引:1,自引:0,他引:1
The mechanical properties and material volume fractions of PTFE/Kevlar49/PA6 composite are studied. The focus of this paper is to get the relationship between the volume fraction of three constituents and the mechanical properties of the composite by doing tensile, hardness and wear test. The effect of the constituent volume fractions was evaluated. Short Kevlar49 fibers reinforced PA6 (Polyamide 6) with PTFE filler were studied in five different combinations. The results of the experiments show that the mechanical properties increase with Keviar fibers increase, then they decrease after the Kevlar fiber volume reaches one number. 相似文献
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王希恩 《广西民族大学学报》2007,(3)
少数民族城市化进程中发生的各类矛盾和纠纷其实都可归结为两个方面的问题:一是现有的城市环境不利于少数民族的融入;二是少数民族自身对于既有城市环境的不适应。前者涉及城市建设的模式或目标设计问题,后者涉及少数民族城市化中的素质准备问题。解决好这两个问题是推进少数民族城市化进程的两大基本环节。 相似文献
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Electronic structures of the Mn^2+ :CdMoO4 crystal axe studied within the framework of the fully relativistic self-consistent Dirac Slater theory, using a numerically discrete variation (DV-Xα) method. The calculated results indicate that the 3d states of Mn have donor energy level in the forbidden band of CdMoO4 crystal. The O^2- transition energy of O 2p→Mn 3d is 3.12eV under excitation corresponding electronic transition being O^2-+Mn^2+→↑hvex=3.12 eV O^-- +Mn^+→↑hvem O^2-+Mn^2+. It is predicted that the wavelength of emission should be located in the range of the 500-600nm. Thus the 500-600mm emission bands peaking at 550nm (2.25eV) of CdMoO4 crystal under excitation may be related to the Mn-like dopant ion in CdMoO4 crystal. 相似文献