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991.
Sung Hyun Hwang Soon Ki Kim Jun-Tae Nam Jong-Sung Park 《International Journal of Hydrogen Energy》2021,46(1):1076-1084
Composite anodes of nano-sized Ni and Ba(Zr0.85Y0.15)O3-δ (BZY) were fabricated by infiltrating a single precursor solution of BZY and Ni into the BZY scaffold, and decreasing the calcination temperature to 1173 K. This decrease in the fabrication temperature of the Ni-cermet anode prevents the chemical reaction between the electrolyte and nickel, thus preventing a reduction in the conductivity of the electrolyte. By optimizing the amount of Ni in the Ni-cermet and infiltrating additional catalysts such as CeO2 and Pd, the non-ohmic ASR of the Ni-cermet anode could be optimized. This resulted in a smaller non-ohmic ASR of anode than one that was fabricated by the conventional co-sintering method. Consequently, a high power density of 790 mW/cm2 at 973 K can be obtained from electrolyte-supported cells. 相似文献
992.
In Seop Lim Jin Young Park Eun Jung Choi Min Soo Kim 《International Journal of Hydrogen Energy》2021,46(2):2543-2554
The temperature of a fuel cell has a considerable impact on the saturation of a membrane, electrochemical reaction speed, and durability. So thermal management is considered one of the critical issues in polymer electrolyte membrane fuel cells. Therefore, the reliability of the thermal management system is also crucial for the performance and durability of a fuel cell system. In this work, a methodology for component-level fault diagnosis of polymer electrolyte membrane fuel cell thermal management system for various current densities is proposed. Specifically, this study suggests fault diagnosis using limited data, based on an experimental approach. Normal and five component-level fault states are diagnosed with a support vector machine model using temperature, pressure, and fan control signal data. The effects of training data at different operating current densities on fault diagnosis are analyzed. The effects of data preprocessing method are investigated, and the cause of misdiagnosis is analyzed. On this basis, diagnosis results show that the proposed methodology can realize efficient component-level fault diagnosis using limited data. The diagnosis accuracy is over 92% when the residual basis scaling method is used, and data at the highest operating current density is used to train the support vector machine. 相似文献
993.
Improving the Stability and Performance of Perovskite Light‐Emitting Diodes by Thermal Annealing Treatment 下载免费PDF全文
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利用三苯基膦将合成的酸性丝光沸石进行表面修饰处理,使酸性丝光沸石外表面的部分酸性中心被三苯基膦吸附而失活,经过外表面修饰的酸性丝光沸石用于催化油酸支链化的反应,可明显提高目标产物C18饱和支链脂肪酸的选择性,加氢产物的C18饱和支链脂肪酸产率可提高约5个百分点。经过响应面法优化后,表面修饰的酸性丝光沸石催化油酸支链化反应最优工艺条件为:催化剂用量7.0%(基于油酸质量),加水量4.5%(基于油酸质量),反应温度270℃,反应时间4.5 h。在最优反应条件下,C18饱和支链脂肪酸产率可达到87.25%。反应动力学研究表明,该油酸支链化反应的反应活化能为22.46 k J/mol,指前因子为3.2×103。 相似文献
996.
Dissolving microneedles are transdermal delivery systems designed to mechanically penetrate the skin and fully dissolve in the skin in a minimally invasive manner. In this study, the skin permeability of compounds encapsulated in microneedles was controlled by changing the composition of microneedle materials. Sodium hyaluronate (SH) and carboxymethyl cellulose (CMC) were chosen as structural materials and amylopectin was used to increase the mechanical strength of microneedles. To determine the effect of microneedle composition on skin permeability, microneedle properties such as mechanical strength and solubility were investigated according to various compositions of SH and CMC. When the CMC fraction in the needle increased, the mechanical strength of the microneedle increased, leading to high skin permeability of rhodamine B, a model compound. Using microneedles, significantly higher skin permeability of niacinamide was also obtained. These results indicate that the microneedles developed in this study improved the skin permeability of compounds loaded in the needle, and the skin permeability could be tuned by changing the composition of microneedle materials. 相似文献
997.
Tae-Kyun Oh Sung Oh Seongdae Kim Jae Sung Park Nagarajan Vinod Kyung Min Jang Sei Chang Kim Chang Won Choi Suk-Min Ko Dong Kee Jeong Rajangam Udayakumar 《International journal of molecular sciences》2014,15(9):15571-15591
A full-length phytase gene (phy) of Aspergillus nidulans was amplified from the cDNA library by polymerase chain reaction (PCR), and it was introduced into a bacterial expression vector, pET-28a. The recombinant protein (rPhy-E, 56 kDa) was overexpressed in the insoluble fraction of Escherichia coli culture, purified by Ni-NTA resin under denaturing conditions and injected into rats as an immunogen. To express A. nidulans phytase in a plant, the full-length of phy was cloned into a plant expression binary vector, pPZP212. The resultant construct was tested for its transient expression by Agrobacterium-infiltration into Nicotiana benthamiana leaves. Compared with a control, the agro-infiltrated leaf tissues showed the presence of phy mRNA and its high expression level in N.
benthamiana. The recombinant phytase (rPhy-P, 62 kDa) was strongly reacted with the polyclonal antibody against the nonglycosylated rPhy-E. The rPhy-P showed glycosylation, two pH optima (pH 4.5 and pH 5.5), an optimum temperature at 45~55 °C, thermostability and broad substrate specificities. After deglycosylation by peptide-N-glycosidase F (PNGase-F), the rPhy-P significantly lost the phytase activity and retained 1/9 of the original activity after 10 min of incubation at 45 °C. Therefore, the deglycosylation caused a significant reduction in enzyme thermostability. In animal experiments, oral administration of the rPhy-P at 1500 U/kg body weight/day for seven days caused a significant reduction of phosphorus excretion by 16% in rat feces. Besides, the rPhy-P did not result in any toxicological changes and clinical signs. 相似文献
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