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961.
Jai-Sug Hawong Dong-Chul Shin Ouk-Sub Lee 《Journal of Mechanical Science and Technology》2002,16(12):1594-1603
In this paper, when the initial propagation angle of a branched crack is calculated from the maximum tangential stress criterion
(MTSC) and the minimum strain energy density criterion (MSEDC), it is essential that you use stress components in which higher
order terms are considered and stress components at the position in a distance 0.005 mm from the crack tip ( =γ . When an interfacial crack propagates along the interface at a constant velocity, the initial propagation angles of the
branched crack are similar to the mode mixities (phase angle) and the theoretical values obtained from MTSC and MSEDC. The
initial propagation angle of the branched crack depends considerably on the stress intensity factor K{IN2}. 相似文献
962.
The aim of this study was to quantitatively investigate the morphologies (surface roughness) and biomechanical properties (Young's modulus) of human anterior lens capsules (ALCs) for noncataract and cataract groups using atomic force microscopy. Eight human ALCs obtained during phacoemulsification from patients with senile cataracts (72 ± 13 years) were investigated in both the hydrated and dehydrated conditions. The cataract group showed clearly the proliferated lens epithelial cells (LECs) with a monomorphic cell structure, a diameter of 12.54 ± 4.31 μm, and a height of 0.23 ± 0.04 μm, whereas the control group showed no LECs. A substantial amount of false-positive calcification was observed caused by the deposition of remnants of dried salt solution. Cataract group showed significantly higher surface roughness (382.06 nm, p ≤ 0.001) than control group in the anterior side of ALCs, whereas cataract group showed significantly lower surface roughness (353.79 nm, p ≤ 0.001) than control group in their posterior side. Cataract group showed significantly higher Young's modulus (69.52 kPa, p ≤ 0.001) compared to the control group, regardless of the ALC side. Therefore, it is significant that this study provides a new method to examine the nanostructural characteristic and biomechanical property of human ALCs through a nanometer-scale resolution microscopy technique. 相似文献
963.
A 81-year-old female was hospitalized with chest discomfort. Findings of CT scan revealed Stanford type A acute aortic dissection, but the dissecting lumen had already closed with thrombus. Aortogram showed no intimal tear, intimal flap or ulcer like projection. Under the diagnosis of "closing aortic dissection", conservative treatment was selected. The dissecting lumen was disappearing gradually, but she had a sudden chest pain on hospital day 4 and CT scan demonstrated an enlarged and enhanced dissecting lumen. She underwent an emergency operation and a hemiarch replacement was performed successfully. Her postoperative course was uneventful and she was discharged from the hospital in good health. 相似文献
964.
JA Hall TE Thorgeirsson J Liu YK Shin H Nikaido 《Canadian Metallurgical Quarterly》1997,272(28):17610-17614
Binding of ligands to the maltose-binding protein (MBP) of Escherichia coli often causes a global conformational change involving the closure of its two lobes. We have introduced a cysteine residue onto each of these lobes by site-directed mutagenesis and modified these residues with spin labels. Using EPR spectroscopy, we examined the changes, caused by the ligand binding, in distance between the two spin labels, hence between the two lobes. The binding of both maltose and maltotetraose induced a considerable closure of the N- and C-terminal lobes of MBP. Little closure occurred upon the binding of maltotetraitol or beta-cyclodextrin. Previous study by fluorescence and UV differential absorbance spectroscopy (Hall, J. A., Gehring, K., and Nikaido, H. (1997) J. Biol. Chem. 272, 17605-17609) showed that maltose and a large portion of maltotetraose bound to MBP via one mode (R mode or "end-on" mode), which is physiologically active and leads to the subsequent transport of the ligands across the cytoplasmic membrane. In contrast, maltotetraitol and beta-cyclodextrin bound to MBP via a different mode (B mode or "middle" mode), which is physiologically inactive. The present work suggests that the B mode is nonproductive because ligands binding in this manner prevent the closure of the two domains of MBP, and, as a result, the resulting ligand-MBP complex is incapable of interacting properly with the inner membrane-associated transporter complex. 相似文献
965.
Yoo Seung Song Shin Kyung Lee Jeong Woo Lee Do Wook Kang Kyoung Wook Min 《ETRI Journal》2019,41(6):703-714
Many use cases have been presented on providing convenience and safety for vehicles employing wireless access in vehicular environments and long‐term evolution communication technologies. As the 70‐MHz bandwidth in the 5.9‐GHz band is allocated as an intelligent transportation system (ITS) service, there exists the issue that vehicular communication systems should not interfere with each other during their usage. Numerous studies have been conducted on adjacent interfering channels, but there is insufficient research on vehicular communication systems in the ITS band. In this paper, we analyze the interference channel performance between communication systems using distribution functions. Two types of scenarios comprising adjacent channel interference are defined. In each scenario, a combination of an aggressor and victim network is categorized into four test cases. The minimum requirements and conditions to meet a 10% packet error rate are analyzed in terms of outage probability, packet error rate, and throughput for different transmission rates. This paper presents an adjacent channel interference ratio and communication coverage to obtain a satisfactory performance. 相似文献
966.
967.
Jae Hoon Yang Hyoung Woo Yang Byoung Ok Jun Jeong Hee Shin Seunguk Kim A‐Rang Jang Seong In Yoon Hyeon Suk Shin Deoksoo Park Kyungho Park Duhee Yoon Jung Inn Sohn SeungNam Cha Dae Joon Kang Jae Eun Jang 《Advanced functional materials》2019,29(18)
Graphene has been gradually studied as a high‐frequency transmission line material owing to high carrier mobility with frequency independence up to a few THz. However, the graphene‐based transmission lines have poor conductivity due to their low carrier concentration. Here, it is observed that the radio frequency (RF) transmission performance could be severely hampered by the defect‐induced scattering, even though the carrier concentration is increased. As a possible solution, the deposition of the amorphous carbon on the graphene is studied in the high‐frequency region up to 110 GHz. The DC resistance is reduced by as much as 60%, and the RF transmission property is also enhanced by 3 dB. Also, the amorphous carbon covered graphene shows stable performance under a harsh environment. These results prove that the carrier concentration control is an effective and a facile method to improve the transmission performance of graphene. It opens up the possibilities of using graphene as interconnects in the ultrahigh‐frequency region. 相似文献
968.
Tae Yong Lee Sangmin Lee Yeong Hwa Kim Dong Jae Kim Esther Amstad Chang‐Soo Lee Shin‐Hyun Kim 《Advanced functional materials》2019,29(48)
Metal nanoparticles are frequently employed for the colorimetric detection of specific target molecules using an aggregation‐induced shift of the localized surface plasmon resonance. However, metal nanoparticles dispersed in bulk solutions are prone to be contaminated by adhesive molecules and the dispersions tend to be diluted by sample fluids, restricting direct application to unpurified pristine samples. Here, a versatile capsule sensor platform is proposed that can encompass a variety of different types of nanoparticle‐based sensors. The capsule sensors are microfluidically prepared to obtain close control over their dimensions and composition. Their aqueous cores that are loaded with sensing materials are surrounded by an ultrathin inner oil shell and an outer hydrogel shell. The hydrogel shell prevents the diffusion of large adhesive molecules into the core, thereby preventing contamination of the sensing materials. The oil shell is selectively permeable such that it further improves the sensor selectivity. Importantly, these shells confine the sensing materials and prevent them from being diluted, securing a consistent optical property. Moreover, the capsule‐based sensors display a higher sensitivity than bulk dispersions because a smaller amount of sensing materials is used. The power of nanoparticle‐loaded capsule sensors is demonstrated using lysine‐coated gold nanoparticles to detect mercury ions. 相似文献
969.