排序方式: 共有30条查询结果,搜索用时 15 毫秒
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Jeon Min-Kyung Kim Seunghee Hosseini Zadeh Amin Kwon Tae-Hyuk 《Transport in Porous Media》2020,133(2):207-227
Transport in Porous Media - We investigate viscous fluid flows and concurrent fluid-driven deformations in porous media. The hydro-mechanically (H-M) coupled pore-network model (PNM) is developed,... 相似文献
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Seunghee Woo Seonho Lee Ahmad Zulfikri Taning Tae-Hyun Yang Seok-Hee Park Sung-Dae Yim 《Current Opinion in Electrochemistry》2020
To improve the performance of membrane electrode assemblies used in proton exchange membrane fuel cells, a better understanding is necessitated regarding the nano/microstructure of the catalyst layer and the physicochemical phenomena responsible for the oxygen reduction reaction (ORR) occurring on this layer. In particular, it is very important to understand catalyst/ionomer interfaces in the cathode catalyst layer to apply the advanced ORR catalysts to the cathode catalyst layer in membrane electrode assemblies, which have solid-phase electrolytes; these catalysts are primarily developed under liquid electrolyte conditions. A closer observation of the catalyst/ionomer interfacial structure shows that all the transport processes required for ORR are controlled by the ionomer thin film covering the catalyst. Therefore, this review addresses this issue and introduces recent studies on catalyst/ionomer interfaces. We discuss the current understanding of the structure of the catalyst/ionomer interface, which depends on the surface characteristics of the catalyst and the ionomer, as well as transport of water, ions, and gas; these factors are in turn dependent on the structure of the interface. In addition, we introduce research efforts for improving the properties of catalyst inks, which form the basis for controlling the catalyst/ionomer interfacial structure. Based on the findings of these studies, we propose further opportunities and challenges in the study of catalyst/ionomer interfaces. 相似文献
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Tetsuya Ezawa Seunghee Jung Yuya Kawashima Takuya Noguchi Nobuyuki Imai 《Tetrahedron: Asymmetry》2017,28(1):75-83
Dipeptides and amides were obtained in high yields from N-carbobenzyloxy α-amino acids and 3-phenylpropanoic acid with unprotected α-amino acids via the corresponding mixed carbonic carboxylic anhydrides using ethyl chloroformate and triethylamine by an ecological and convenient method in which the protection of C-terminals is not needed. 相似文献
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Sungyool Bong Yang-Rae Kim In Kim Seunghee Woo Sunghyun Uhm Jaeyoung Lee Hasuck Kim 《Electrochemistry communications》2010,12(1):129-131
Graphene nanosheet was prepared by modified Hummer’s chemical method and utilized as a catalyst support of PtRu nanoparticles for the electro-oxidation of methanol. Home-made graphene nanosheet was clearly characterized by Raman spectroscopy and we applied colloidal method to synthesize with high metal content of 80 wt.% Pt–Ru catalyst, which is extensively clarified by HR-TEM and XRD analysis. 80 wt.% Pt–Ru/graphene nanosheet catalyst showed superior electrochemical activity toward methanol oxidation compared to Pt–Ru/Vulcan XC-72R. It is due to the significant increase of electrochemical active surface area for better catalyst utilization. 相似文献
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Zhang Jingtao Zhang Haipeng Lee Donghee Ryu Sangjin Kim Seunghee 《Transport in Porous Media》2020,131(2):449-472
Transport in Porous Media - Compressed air energy storage (CAES) technology has been re-emerging as a viable energy storage option to address challenges coming from the mismatch between renewable... 相似文献
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Richard S. Agnes Mark D. Schluchter Seunghee Margevicius Xinning Wang Malcolm E. Kenney Clemens Burda James P. Basilion 《Particle & Particle Systems Characterization》2015,32(4):448-457
Targeted drug delivery using epidermal growth factor peptide‐targeted gold nanoparticles (EGFpep‐Au NPs) is investigated as a novel approach for delivery of photodynamic therapy (PDT) agents, specifically Pc 4, to cancer. In vitro studies of PDT show that EGFpep‐Au NP‐Pc 4 is twofold better at killing tumor cells than free Pc 4 after increasing localization in early endosomes. In vivo studies show that targeting with EGFpep‐Au NP‐Pc 4 improves accumulation of fluorescence of Pc 4 in subcutaneous tumors by greater than threefold compared with untargeted Au NPs. Targeted drug delivery and treatment success can be imaged via the intrinsic fluorescence of the PDT drug Pc 4. Using Pc 4 fluorescence, it is demonstrated in vivo that EGFpep‐Au NP‐Pc 4 impacts biodistribution of the NPs by decreasing the initial uptake by the reticuloendothelial system (RES) and by increasing the amount of Au NPs circulating in the blood 4 h after IV injection. Interestingly, in vivo PDT with EGFpep‐Au NP‐Pc 4 results in interrupted tumor growth when compared with EGFpep‐Au NP control mice when selectively activated with light. These data demonstrate that EGFpep‐Au NP‐Pc 4 utilizes cancer‐specific biomarkers to improve drug delivery and therapeutic efficacy over untargeted drug delivery. 相似文献
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The purpose of this study was to identify and compare the temporal characteristics of nasalization in relation to (1) languages, (2) vowel contexts, and (3) age groups. Two distinct acoustic energies from the mouth and nose were recorded during speech production (/pamap, pimip, pumup/) using two microphones to obtain the absolute and proportional measurements on the acoustic temporal characteristics of nasalization. Twenty-eight normal adults (14 American English and 14 Korean speakers) and 28 normal children (14 American English and 14 Korean speakers) participated in this study. In both languages, adults showed shorter duration of nasalization than children within all three vowel contexts. The high vowel context revealed longer duration of nasalization than the low vowel context in both languages. There was no significant difference of temporal characteristics of nasalization between American English and Korean. Nasalization showed different timing characteristics between children and adults across vowel contexts. The results are discussed in association with developmental coarticulation and the relationship between acoustic consequences of articulatory events and vowel height. 相似文献
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Seunghee Jung Yuki TsukudaRie Kawashima Takumi IshikiAyaka Matsumoto Aya NakaniwaMiho Takagi Takuya NoguchiNobuyuki Imai 《Tetrahedron letters》2013
Acetaminophen analogues containing α-amino acid and fatty acids were easily synthesized in 77–99% yields from the corresponding mixed carbonic carboxylic anhydrides of α-amino acid and fatty acids using aniline derivatives in aqueous MeCN. 相似文献