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91.
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
92.
Reusable electronics have received widespread attention and are urgently needed. Here, nanocellulosebased liquid metal(NC-LM) printed circuit has been fabricated by the evaporation-induced transfer printing technology. In this way, the liquid metal pattern is embedded into the nanocellulose membrane, which is beneficial for the stability of the circuit during use. Besides, the NC-LM circuit is ultrathin with just tens of microns. In particular, the finished product is environmentally friendly because it can be completely dissolved by water, and both the liquid metal ink and the nanocellulose membrane can be easily recollected and reused, thereby reducing waste and pollution to the environment. Several examples of flexible circuits have been designed to evaluate their performance. The mechanism of evaporation-induced transfer printing technology involves the deposition, aggregation, and coverage tightly of the nanosized cellulose fibrils as the water evaporated. This study provides an economical and environmentally friendly way for the fabrication of renewable flexible electronics. 相似文献
93.
Xilin Zhang Lu Chen Qian Sun Yudong Pang Xinwei Yang Zongxian Yang 《International Journal of Hydrogen Energy》2021,46(50):25457-25467
Modulating the surface electronic properties of the 2D MXenes is of significant importance to boost their hydrogen evolution reaction (HER) activity. Herein, a series of transition metal adatoms are employed to tune the surface electronic properties of Cr-based MXenes with oxygen function group for realizing impressive HER performance. The Results show that the charge of surface oxygen atoms, which is affected by both the host metal atoms and the adsorbed transition metal atoms, play critical role in the adsorption strength of hydrogen. The optimal performance is achieved by depositing Cr atom on the Cr2TiC2O2 MXene, which results in the adsorption free energy of hydrogen very close to zero (0.03 eV). Systematic electronic structure analyses confirm that the charge transfer from the adsorbed transition metals to the neighboring surface oxygen atoms could tune the orbital occupancy of oxygen and their adsorption strength to hydrogen atom and therefore the HER activity. These findings and concepts may be useful for the design of advanced MXene-based HER catalysts. 相似文献
94.
Jiajia Lu Guangfu Qian Lin Luo Huibing He Shibin Yin 《International Journal of Hydrogen Energy》2021,46(1):676-682
The tungsten trioxide attracts less attention due to the low electron transfer kinetics that hinders the interaction of electrons and ions during the hydrogen evolution reaction (HER). But the oxygen vacancy strategy can inspire its electrocatalytic activity for HER because it has a positive effect on improving the charge transfer and compensating for the weak hydrogen adsorption of the tungsten trioxide. By synthesizing a series of substoichiometric tungsten oxides, we reveal the linear relationship between the catalytic activity and the content of oxygen vacancies, which indicates that the oxygen vacancy strategy is an achievable route to enhance the HER for metal oxides. 相似文献
95.
96.
Caizhi Zhang Hao Liu Tao Zeng Jiawei Chen Pengfeng Lin Bo Deng Fujian Liu Yifeng Zheng 《International Journal of Hydrogen Energy》2021,46(45):23489-23497
During the operation of proton exchange membrane fuel cell (PEMFC), it always suffers from reversible performance loss caused by the oxidation of platinum catalyst on its electrode, which reduces the electrochemical active surface area. Short circuit method has been found to improve the performance of fuel cells by stripping of oxides and other adsorbed species from platinum, which needs systematical understanding the effective parameters of short circuit method on fuel cell performance. In this paper, the effects of different short circuit activation parameters (duration, interval, cycles, cut-off voltage, operating current) are carefully studied and analyzed during short circuit operations. In addition, the mechanism revealing how relevant parameters influence short circuit activations is deeply analyzed. The results show that five groups of activation parameters have obvious influence on the activation of fuel cell, indicating that the short-circuit activation effect can be optimized. Among these parameters, the short-circuit duration parameter have the greatest impact on activation, because the platinum hydroxides and oxides is gradually removed during short-circuit duration and results in a larger effective surface area of the platinum catalyst for the electrochemical reaction. However, the smallest impact is short-circuit interval. Another finding is that the five activation parameters are not independent, so the optimal activation parameter value needs to be analyzed in combination with the operating conditions. Finally, according to the activation principle, selection of appropriate short circuit activation parameters for application are proposed to further improve performance and fuel utilization by considering the safety of the stack. 相似文献
97.
The preferential use of renewable energy sources such as wind power has been proposed as one of the most effective strategies in reducing greenhouse gas emissions in the energy sector. However, wind energy resources are vulnerable to climate change, which might have a huge impact on the area under consideration. In this research, we used the wind speed data obtained from the seven coupled global climate models in the Coupled Model Intercomparison Project Phase 6 (CMIP6) to quantitatively analyze the differences in wind energy resource (WER) between the future and the historical period, geared toward understanding the impact of climate change on wind energy sources. Relevant results show that the future WER would decreases below 20% in the region south of the Northwest Passage, while would significantly increase in the north region of 72°N (specifically in the Beaufort Sea). Further, reports predict that by the end of the 21st century, if no interventions are made to mitigate greenhouse gas emissions, the northern region's WER would increase even more with some grid points exceeding 30% and have a significant growth trend, but at the same time the intra‐annual variability in these region would also increase significantly with some grid points exceeding 140% of that in the historical period. Moreover, the maximum wind speed values would encounter a noteworthy increase of up to 20%, which will bring great challenge to the development of wind energy in these region. Although the current models still have great uncertainties in the future climate prediction, our work still has certain guiding significance for the future development of wind energy over the Northwest Passage. 相似文献
98.
99.
Qian Hua Yingying Sun Yanshun Xu Pei Gao Wenshui Xia 《International Journal of Food Science & Technology》2021,56(12):6752-6764
The microbial dynamics, diversity and succession characterisation during the fermentation of fish-chili paste, with and without starter cultures by high-throughput sequencing, were investigated to identify the relationship between microbial composition and the accumulation of biogenic amines. Results showed that Firmicutes was the predominant phylum, and Lactobacillus and Weissella were the main genera during fermentation process, regardless of the inclusion of starter cultures. Compared with naturally fermented samples (NS; no starter cultures), Pediococcus and Staphylococcus flourished in samples inoculated with SBM-52 starter culture (Staphylococcus xylosus + Staphylococcus carnosus + Pediococcus pentosaceus + Pediococcus acidilactici). Staphylococcus also accounted for a larger proportion in samples inoculated with WBX-43 starter culture (Staphylococcus xylosus + Staphylococcus carnosus). Furthermore, Enterobacter was inhibited in inoculated samples. Unweighted pair-group method with arithmetic means and principal component analyses revealed that microbiota structures were different among NS, SBM and WBX samples. In case of biogenic amines, the concentration of putrescine, cadaverine and tyramine increased to higher levels in NS samples compared with inoculated samples. Our work also investigated the relationship between core bacterial communities and biogenic amines. This study provided an improved understanding for the effects of starter cultures on the microbial community and the quality of fish-chili paste. 相似文献
100.
Guiyu Liu Jinlong Liu Beibei Liu Chunming Yang Dong Qian Junhua Li 《International Journal of Hydrogen Energy》2018,43(51):22942-22948
We demonstrate an extremely facile in-situ pyrolysis followed by the reduction of partial Co2+ route to synthesize novel Ketjen black carbon (KB) supported CoO@Co?N?C (denoted as CoO@Co?NC/KB) nanochains using KB, urea and cobalt (Ⅱ) acetate as co-precursors. The as-prepared CoO@Co-NC/KB displays higher electrocatalytic activity, smaller Tafel slope and better durability for the oxygen evolution reaction than those of the benchmark commercial RuO2 catalyst in 1.0 M KOH solution, far outperforming the control groups (i.e. CoO@Co?g-C3N4/KB, Co?NC/KB, CoO?NC/KB, CoO@Co/KB, CoO@Co?NC and Co3O4?NC/KB). The remarkable electrocatalytic performance of CoO@Co?NC/KB is primarily credited to the synergistic effect between Co and CoO species with a core-shell structure, increased active sites and considerably enhanced electronic conductivity. 相似文献