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排序方式: 共有539条查询结果,搜索用时 62 毫秒
1.
Kim Bohyeong Kim Jaewon Kang Dongjin Baek Hong-Kil Chung Jintai 《Nonlinear dynamics》2021,104(4):3293-3308
Nonlinear Dynamics - This paper presents a method to reduce the squeal noise generated by an automotive water pump. The noise and vibration of the water pump were analyzed through experiments, from... 相似文献
2.
Im Sang-Jin Shim Jae-Hyuk Kim Joo-Yeon Baek Hyeon-Man 《Applied magnetic resonance》2020,51(3):255-276
Applied Magnetic Resonance - Total cerebral volume increases very rapidly in childhood, peaking in early teenage years then declining in adolescence. However, most studies quantified only one or... 相似文献
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Dr. Amitosh Sharma Dr. Jaewoong Lim Seonghwan Lee Dr. Seungwan Han Dr. Junmo Seong Prof. Dr. Seung Bin Baek Prof. Dr. Myoung Soo Lah 《Angewandte Chemie (International ed. in English)》2023,62(29):e202302376
A few metal–organic frameworks (MOFs), which typically use strong acids as proton sources, display superprotonic conductivity (≈10−1 S cm−1); however, they are rare due to the instability of MOFs in highly acidic conditions. For the first time, we report superprotonic conductivity using a moderately acidic guest, zwitterionic sulfamic acid (HSA), which is encapsulated in MOF-808 and MIL-101. HSA acts not only as a proton source but also as a proton-conducting medium due to its extensive hydrogen bonding ability and zwitterion effect. A new sustained concentration gradient method results in higher HSA encapsulation compared to conventional methods, producing 10HSA@MOF-808-(bSA)2 and 8HSA@MIL-101. These MOFs show impressive superprotonic conductivity of 2.47×10−1 and 3.06×10−1 S cm−1, respectively, at 85 °C and 98 % relative humidity, and maintain stability for 7 days. 相似文献
6.
Seong-Wook Kim Hyeonjung Jung Dr. Mahmut Sait Okyay Dr. Hyuk-Jun Noh Sein Chung Young Hyun Kim Jong-Pil Jeon Prof. Dr. Bryan M. Wong Prof. Dr. Kilwon Cho Dr. Jeong-Min Seo Prof. Dr. Jung-Woo Yoo Prof. Dr. Jong-Beom Baek 《Angewandte Chemie (International ed. in English)》2023,62(42):e202310560
The development of covalent organic frameworks (COFs) with efficient charge transport is of immense interest for applications in optoelectronic devices. To enhance COF charge transport properties, electroactive building blocks and dopants can be used to induce extended conduction channels. However, understanding their intricate interplay remains challenging. We designed and synthesized a tailor-made COF structure with electroactive hexaazatriphenylene (HAT) core units and planar dioxin (D) linkages, denoted as HD-COF. With the support of theoretical calculations, we found that the HAT units in the HD-COF induce strong, eclipsed π–π stacking. The unique stacking of HAT units and the weak in-plane conjugation of dioxin linkages leads to efficient anisotropic charge transport. We fabricated HD-COF films to minimize the grain boundary effect of bulk COFs, which resulted in enhanced conductivity. As a result, the HD-COF films showed an electrical conductivity as high as 1.25 S cm−1 after doping with tris(4-bromophenyl)ammoniumyl hexachloroantimonate. 相似文献
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Indranil Roy Dinesh Shetty Raghunandan Hota Kangkyun Baek Jeesu Kim Chulhong Kim Sandro Kappert Kimoon Kim 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(50):15367-15370
Developing a material that can combat antibiotic‐resistant bacteria, a major global health threat, is an urgent requirement. To tackle this challenge, we synthesized a multifunctional subphthalocyanine (SubPc) polymer nanosphere that has the ability to target, label, and photoinactivate antibiotic‐resistant bacteria in a single treatment with more than 99 % efficiency, even with a dose as low as 4.2 J cm−2 and a loading concentration of 10 nM . The positively charged nanosphere shell composed of covalently linked SubPc units can increase the local concentration of photosensitizers at therapeutic sites. The nanosphere shows superior performance compared to corresponding monomers presumably because of their enhanced water dispersibility, higher efficiency of singlet‐oxygen generation, and phototoxicity. In addition, this material is useful in fluorescence labeling of living cells and shows promise in photoacoustic imaging of bacteria in vivo. 相似文献
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Rupture of intracranial saccular aneurysms is the leading cause of spontaneous subarachnoid hemorrhage, which results in significant
morbidity and mortality. Although many have suggested that saccular aneurysms enlarge and rupture due to mechanical instabilities,
our recent nonlinear analyses suggest that at least certain classes of aneurysms do not exhibit a quasi-static limit point
instability or dynamic instabilities in response to periodic loading. Based on an increased understanding of the ubiquitous
role of growth and remodeling within the vasculature and recent histopathological data on saccular aneurysms, it is hypothesized
that a stress-mediated regulation of collagen turnover causes their enlargement. There is a need, however, for a theoretical
framework to explore this and competing hypotheses. In this paper, we present a 2-D constrained mixture model for growth and
remodeling of an ellipsoidally shaped saccular aneurysm and numerically simulate enlargement and changes in material symmetry
in the aneurysmal wall. Results suggest that ellipsoidal aneurysms tend toward spherical shapes, and a competition between
radial expansion and wall thickening plays a critical role in determining the stability of an enlarging lesion. 相似文献
9.
Jin Jeong Chang Nyung Kim Baek Youn Young Saeng Kim 《International Journal of Heat and Fluid Flow》2004,25(6):1006-1014
The thermal contact resistance is a principal parameter interfering with heat transfer in a fin–tube heat exchanger. However, the thermal contact resistance in the interface between tubes and fins has not been clearly investigated. The objective of the present study is to examine the thermal contact conductance for various fin–tube heat exchangers with tube diameter of 9.52 mm and to find a correlation between the thermal contact conductance and effective factors such as expansion ratio, fin type, fin spacing and hydrophilic coating. In this study, experiments have been conducted only to measure heat transfer rate between hot and cold water. To minimize heat loss to the ambient air by the natural convection fin–tube heat exchangers have been placed in an insulated vacuum chamber. Also, a numerical scheme has been employed to calculate the thermal contact conductance with the experimental data. As a result, a new correlation including the influences of expansion ratio, slit of fin and fin coating has been introduced, and the portion of each thermal resistance has been estimated in the fin–tube heat exchangers with 9.52 mm tube. 相似文献
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