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81.
The phenol amount of Lygodium japonicum extracted by the pressure-assisted water extraction (PAWE) was noticeably increased to 12.8mg GAE/g when compared to the conventional extraction (9.3 mg GAE/g) (p<0.05). The highest antioxidant activity was observed at Polygonum aviculare extracted by the PAWE, showing the lowest EC50 value of 0.09 mg/mL. The lowest minimum inhibitory concentrations (MIC99) of L. japonicum extracted by the PAWE were 2.59, 3.33, and 7.37 mg/mL, respectively, against Listeria monocytogenes, Salmonella Typhimurium, and Propionibacterium acnes. These results suggest that the PAWE can be an appropriate extraction method for enhancing biological and pharmaceutical properties of medicinal plants. 相似文献
82.
Automobile industry tries to reduce the weight of automobile using high-strength steels.However,the high-strength steels are highly susceptible to delayed-fracture caused by hydrogen embrittlement.With increasing the strength,hydrogen embrittlement is more sensitive to diffusible hydrogen.The mechanism of delayed-fracture and the relationship with the microstructure and alloying elements are still ambiguous.This study analyzed the effect of the size and the spheroidization rate for the carbides on hydrogen-induced delayed fracture for 1GPa TS steel. 相似文献
83.
Sanghoon Ahn Dong Wook Kim Young Won Kim Jung Yul Yoo 《International Journal of Precision Engineering and Manufacturing》2010,11(5):799-802
microfluidic channel system to generate Janus droplets is designed and fabricated, where the term Janus droplet refers to a chemically biphasic droplet. It is demonstrated that Janus droplets are formed from elongational breakup of coflowing core fluids which are constrained by a sheath fluid on both sides of them. Rhodamine B is adopted as an indicator to indentify generated Janus droplets. Monodisperse Janus droplets have been generated in a controllable manner such that those with average diameters of 26 ± 1.24 μm, 31 ± 1.44 μm and 34 ± 2.28 μm are formed in accordance with flow rate ratios between the sheath fluid and the core fluids, 30.7, 36.4 and 44.4, respectively. Generation of Janus droplets, demonstrated in the present study, has seen a new application in the areas of biotechnology and bioengineering, where enhanced mixing inside the micro bubbles can be utilized without the aid of other means of droplet generation and merging. 相似文献
84.
Md. Golam Mostofa J. H. Noh H. Y. Kim J. H. Ahn D. B. Kang 《Journal of Mechanical Science and Technology》2010,24(8):1623-1629
PMMA optical components that are used as one of the most important parts of high precision equipments and machines are increasingly replacing the glass due to the various advantages of PMMA. Especially in Light Guide Panels, the PMMA sheet that is used in Liquid Crystal Displays plays an important role in scattering the incident light and requires very fine machining as the sheet is directly related to the optical characteristics of the panels. The High Speed End milling and High Speed Shaping processes that are widely adopted and applied to the precise machining of Light Incident Plane still have quality problems, such as cracks, breakages, poor waviness, and straightness. This paper presents the tooling device design for machining a Light Incident Plane through vibration-assisted High Speed Shaping for increasing the optical quality by minimizing the above-mentioned problems. The cutting tool and the tool post presented in this paper are designed by the authors to increase the magnitude of the cutting stroke by adopting the resonant frequency without weakening the stiffness and to reduce vibrations during even high speed feeding. The dynamic characteristics of the cutting tool and the tool post are evaluated through simulation and experiment as well. The results reveal very appropriate dynamic characteristics for vibration-assisted High Speed Shaping. 相似文献
85.
Existing models of causal induction primarily rely on the contingency between the presence and the absence of a causal candidate and an effect. Yet, classification of observations into these four types of covariation data may not be straightforward because (a) most causal candidates, in real life, are continuous with ambiguous, intermediate values and because (b) effects may unfold after some temporal lag, providing ambiguous contingency information. Although past studies suggested various reasons why ambiguous information may not be used during causal induction, the authors examined whether learners spontaneously use ambiguous information through a process called causal assimilation. In particular, the authors examined whether learners willingly place ambiguous observations into one of the categories relevant to the causal hypothesis, in accordance with their current causal beliefs. In Experiment 1, people's frequency estimates of contingency data reflected that information ambiguous along a continuous quantity dimension was spontaneously categorized and assimilated in a causal induction task. This assimilation process was moderated by the strength of the upheld causal hypothesis (Experiment 2), could alter the overall perception of a causal relationship (Experiment 3), and could occur over temporal sequences (Experiment 4). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
86.
87.
2D Materials: Rotation‐Misfit‐Free Heteroepitaxial Stacking and Stitching Growth of Hexagonal Transition‐Metal Dichalcogenide Monolayers by Nucleation Kinetics Controls (Adv. Mater. 25/2015) 下载免费PDF全文
88.
Ahn Seoyeon Nam Chanhyuk Choi Sungjin An Daekwon Kim Ingi Seo Kyungsoo Sohn Changhyun 《Journal of Mechanical Science and Technology》2021,35(5):1923-1933
Journal of Mechanical Science and Technology - In this paper, to help reduce the squeal noise produced during the braking of urban railway vehicles, the shape of the disc brake pad was investigated... 相似文献
89.
Jaehong Lee Daekyu Park Kihak Lee Namshik Ahn 《The Structural Design of Tall and Special Buildings》2013,22(5):454-470
In this paper, the geometric nonlinear behavior of wall‐frame tall building structures is analyzed. The governing equations of the wall‐frame systems with outrigger trusses are formulated through the continuum approach, and the whole structure is idealized as a shear‐flexural cantilever with rotational spring. The effect of shear and flexural deformation of the wall frame and outrigger trusses are considered and incorporated in the formulation of the governing equations. Geometric nonlinearity in the sense of von Karman is included in the formulation, and Newton–Raphson iterative method is employed to solve the nonlinear equations. A displacement‐based one‐dimensional nonlinear finite element model is developed. Numerical results for wall frame and mega‐column structures with outriggers are obtained and compared with the finite element package MIDAS. The proposed method is found to be simple and efficient, providing reasonably accurate results in early design stages of tall building structures. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
90.