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81.
Zou Yang Jin Xin Zhang XiaoPing Kong XiaoLing Zhang Qian Xie XianHua Liu ChangJun Ke LinNan Liu WenGuang Wang Wei 《中国科学:技术科学(英文版)》2021,64(12):2744-2754
Science China Technological Sciences - Biomedical patches play fundamental roles in various applications such as wound closure and tissue regeneration. The hybrid patches integrating versatile... 相似文献
82.
83.
Xue Mi Bo Gao Xiaoyue Tan Minhui Xie Chunjuan Gao Yu Liu Jianping Gao 《International Journal of Hydrogen Energy》2021,46(7):5332-5344
In this paper, iron and nitrogen co-doped carbon material with nanotube structure (Fe/N-CCM-T) was synthesized by pyrolyzing a mixture of Fe salt, chitosan and melamine and displayed high electrocatalytic performance for oxygen reduction reaction (ORR). The structure of the Fe/N-CCM-T was characterized and their ORR performance in alkaline media was investigated by linear sweep voltammetry, cyclic voltammetry and chronoamperometry. Fe/N-CCM-T displayed better ORR performance than other carbon materials like Fe/N-CC-800. The Fe/N-CCM-800 with a large surface area (302.5 m2/g) especially exhibited the best ORR electrocatalytic performance among the prepared carbon materials, which was also proved by its similar Tafel slope (76 mV decade?1) to Pt/C catalyst (74 mV decade?1). Fe/N-CCM-800 showed similar ORR activity as commercial Pt/C catalyst, but superior tolerance to methanol and stability. Such high ORR performance of the Fe/N-CCM-T can be attributed to its nanotube structure, high specific surface area (SSA), high graphitic-N and pyridinic-N contents. 相似文献
84.
Tian Xie Haixia Zhao Zunhang Lv Guangwen Xie Yan He 《International Journal of Hydrogen Energy》2021,46(1):581-588
This work demonstrates a facile Nb2O5-decorated electrocatalyst to prepare cost-effective Ni–Fe–P–Nb2O5/NF and compared HER & OER performance in alkaline media. The prepared electrocatalyst presented an outstanding electrocatalytic performance towards hydrogen evolution reaction, which required a quite low overpotential of 39.05 mV at the current density of ?10 mA cm?2 in 1 M KOH electrolyte. Moreover, the Ni–Fe–P–Nb2O5/NF catalyst also has excellent oxygen evolution efficiency, which needs only 322 mV to reach the current density of 50 mA cm?2. Furthermore, its electrocatalytic performance towards overall water splitting worked as both cathode and anode achieved a quite low potential of 1.56 V (10 mA cm?2). 相似文献
85.
Zijun Li Shubo Wang Weiwei Li Tong Zhu Zhaohu Fan Xiaofeng Xie 《International Journal of Hydrogen Energy》2021,46(31):16693-16707
Water management is crucial to achieve both high-performance and durability of proton exchange membrane fuel cell (PEMFC). Therefore, it is necessary to investigate the dynamic behavior of droplets in PEMFC channel for water management. In this paper, we explore the kinetics of droplets in a 3D flow field by experimental and theoretical analysis. More specifically, we examine the following four perspectives: 1) the movement and falling of droplets, and their force and deformation, 2) the superiority of 3D flow field drainage, 3) the pressure and viscous force under different scenarios including varying droplet sizes and velocities, and 4) the expression describing the shape change of droplets. The results show that the 3D flow field has a greater driving force on droplets and that their deformation affects the discharge of liquid water. Throughout the study, we provide better understanding of droplet dynamic in PEMFC gas channels. It enables to optimize the design and working conditions of these channels. 相似文献
86.
Jia-Ying Xu Han Xu Xiao-Li Yang Rajendra Prasad Singh Tao Li Yan Wu Hai-Liang Song 《International Journal of Hydrogen Energy》2021,46(20):11378-11388
A submerged macrophyte sediment microbial fuel cell (SP-SMFC) was constructed in this study. Ceratophyllum demersum L., Vallisneria natans, Hydrilla verticillate were chosen as the submerged plants to form cer-SMFC, val-SMFC, hyd-SMFC systems. Plant groups showed the advantage of bioelectricity generation and pollutants removal compared with the unplanted system. The cer-SMFC group stood out with the maximum power density as 24.56 mW m?2 and the average pollutants removal in overlying water (COD: 81.16%, TN: 65.27%, TP: 79.10%) and in sediments (TN: 26.40%, TP: 21.79%). The determination of root exudates and radial oxygen loss (ROL) demonstrated that C. demersum L. was superior to other studied submerged macrophytes. More root exudates may contribute to an increase in available substrates for electrochemically active bacteria and other microorganisms. Higher enzyme activities were obtained in three SP-SMFCs (especially in cer-SMFC). ATPase and APA activities in cer-SMFC group were increased by over 40% compared with the control. The results indicated that the presence of plants enhanced the microorganism activities, thereby improving bioelectricity generation and pollutants removal. This study will facilitate the application of SP-SMFC technology as an alternative for in situ remediation of polluted sediments. 相似文献
87.
Journal of Mechanical Science and Technology - For structural bending crashworthiness, previous studies mostly focused on thin-walled tubes with multi-cell cross-sections, while the double-tube... 相似文献
88.
采用直流电化学刻蚀方法制备扫描隧道显微镜钨针尖,研究了电化学刻蚀过程中NaOH溶液浓度、钨丝浸入长度和刻蚀电压对针尖形貌的影响。通过扫描电子显微镜(SEM)测量针尖曲率半径和针尖纵横比值,以表征针尖的尺寸和形状;通过能谱仪(EDS)分析针尖表面成分,以表征表面清洁度;通过场发射显微镜(FEM)得到Fowler-Nordheim (F-N)曲线来检测针尖发射性能。实验结果表明,当溶液浓度为2 mol/L、钨丝浸入长度为4 mm、刻蚀电压为3 V时,可以得到曲率半径约为100 nm、纵横比值为13的针尖,且表面无钨的氧化层。FEM结果显示当对针尖施加500 V的负偏压时,针尖可以稳定发射50 nA量级的电流,且针尖性能具有良好的一致性。 相似文献
89.
90.
The fully-dense multilayer Ti-B4C composite doped with 6 wt% Al was fabricated via tape-casting and hot-pressing sintering at 1800 °C and under a uniaxial pressure of 30 MPa for 60 min. The effects of Al addition on the phase composition, interfacial microstructure and fracture toughness of the laminate composite were investigated. Based on the results of WDS and EDS, Al addition was proved to be effective on accelerating atom diffusion between Ti and B4C due to the melting pool around interface where liquid Al enriched, besides, it helps to transform the interfacial bonding method of physical to metallurgical. Finally, the improvement on toughness of Al doped composite can be attributed to the strong metallurgical bonding and hybrid fracture mode of interface. Our study may provide a potential method for producing high strength and toughness multilayer metal/ceramic composites. 相似文献