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91.
Ziqian Wang Yalan Chen Yating He Weidong Jiang Yan Long Guangyin Fan 《International Journal of Hydrogen Energy》2021,46(21):11587-11596
Developing high-efficiency and low-cost catalysts for hydrogen evolution from hydrolysis of ammonia borane (AB) is significant and critical for the exploitation and utilization of hydrogen energy. Herein, the in-situ fabrication of well-dispersed and small bimetallic RuNi alloy nanoparticles (NPs) with tuned compositions and concomitant hydrolysis of AB are successfully achieved by using graphitic carbon nitride (g-C3N4) as a NP support without additional stabilizing ligands. The optimized Ru1Ni7.5/g-C3N4 catalyst exhibits an excellent catalytic activity with a high turnover frequency of 901 min?1 and an activation energy of 28.46 kJ mol?1 without any base additives, overtaking the activities of many previously reported catalysts for AB hydrolysis. The kinetic studies indicate that the AB hydrolysis over Ru1Ni7.5/g-C3N4 is first-order and zero-order reactions with respect to the catalyst and AB concentrations, respectively. Ru1Ni7.5/g-C3N4 has a good recyclability with 46% of the initial catalytic activity retained even after five runs. The high performance of Ru1Ni7.5/g-C3N4 should be assigned to the small-sized alloy NPs with abundant accessible active sites and the synergistic effect between the composition-tuned Ru–Ni bimetals. This work highlights a potentially powerful and simple strategy for preparing highly active bimetallic alloy catalysts for AB hydrolysis to generate hydrogen. 相似文献
92.
This paper presents two well-instrumented large-scale field tests of PVD-improved soft soil with vacuum and surcharge preloading, respectively. The two large-scale field tests were conducted adjacent to each other with the same preload. A comparative analysis was performed to investigate the performance of subsoil (i.e., the ground settlement, the layered settlement, the lateral displacement of subsoil and pore water pressure) under vacuum preloading and equivalent surcharge preloading. Some design methods were verified based on the field data. Cone Penetration Tests (CPT) and Vane Shear Tests (VST) were conducted to assess the improvement effects on subsoil after preloading. The results showed that as compared with surcharge preloading, vacuum preloading mitigated the differential settlement of the ground. The vacuum pressure transmitted into the soil with a minor loss through the PVD length. From a practical point of view, the improvement effects by vacuum preloading and surcharge preloading were similar in terms of influence depth and soil strength based on the in-situ tests. 相似文献
93.
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95.
介绍了铁塔加工中角钢零件优化下料管理系统,阐明了系统的模块化结构及工作原理。建立的面向角钢加工工艺的优化下料管理系统可以将生产管理与下料优化两大功能整合为一体,使用极为方便。该系统在铁塔生产中,可节省大量材料,有效地提高了企业的经济效益。 相似文献
96.
Ye Wan Jun Tan Guangling Song Chuanwei Yan 《Metallurgical and Materials Transactions A》2006,37(7):2313-2316
The focused ion beam technique was employed to investigate the atmospheric corrosion morphology of AZ91D. It was found that
the α matrix of the alloy was preferentially corroded in the areas adjacent to intermetallic phases. The most interesting
finding was that the corrosion products in corrosion cavities were pelletlike, which has never been reported before. 相似文献
97.
关于我省数字化城市建设的几点思考 总被引:3,自引:0,他引:3
通过对国内外数字化城市建设现状的分析 ,结合我省实际情况 ,提出我省建设数字化城市的对策及建设内容和原则 ,强调政府的组织行为 ,发挥社会各界的积极性 ,充分利用现有资源 ,以建设数字化城市门户网站为先导 ,快速启动全省数字化城市建设。 相似文献
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100.
Li D. You-Song Gu Xiang-Rong Chang Fu-Shen Li Li-Jie Qiao Zhong-Zhuo Tian Fang G.-D. Qing-Shan Song 《IEEE transactions on magnetics》2003,39(6):3554-3558
We deposited Fe-Ti-N magnetic films with a high sputtering power of 7 W/cm/sup 2/. When the composition of the films was in the range of Fe-Ti(3.9 at.%)-N(8.8 at.%) to Fe-Ti(3.3 at.%)-N(13.5 at.%), the films were composed of /spl alpha/' and Ti/sub 2/N precipitates. With the addition of nitrogen, 4/spl pi/M/sub s/ became higher than that of pure iron, reaching a maximum of 23.8 kG. At the same time, H/sub c/ was reduced to a minimum of 1.12 Oe. The best films can meet the needs of the recording head in dual-element giant magnetoresistive/inductive heads, yielding high storage density (10 Gb/in/sup 2/). The incorporation of N in /spl alpha/-Fe brought about the /spl alpha/' phase with its higher saturation magnetization. Ti additions inhibited the equilibrium decomposition /spl alpha/'/spl rarr//spl alpha/+/spl gamma/'. Because H/sub C//sup D//spl prop/D/sup 6/, where D is average grain diameter, grain size control is very important. The nitrogen induces severe distortion of the /spl alpha/' lattice, which can cause the grains to break into pieces and reduce the grain size. High sputtering power also led to the formation of fine grains, with diameter in the order of 14 nm. Probably Ti/sub 2/N is preferentially precipitated on the grain boundary, pinning the grain boundary and stabilizing the grain size during high-temperature heat treatment. The temperature limit for stability of the structure and its associated low coercivity was not less than 520/spl deg/C. 相似文献