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Your search keyword '"Xiao, Huifang"' showing total 183 results
Start Over Author "Xiao, Huifang" Publication Year Range Last 10 years
183 results on '"Xiao, Huifang"'

12. Atomistic simulation of the Coupled adsorption and unfolding of protein GB1 on the polystyrenes nanoparticle surface

Author

Xiao, Huifang, Huang, Bin, Yao, Ge, Kang, Wenbin, Gong, Sheng, Pan, Hai, Cao, Yi, Wang, Jun, Zhang, Jian, and Wang, Wei

Subjects
Physics - Biological Physics, Quantitative Biology - Biomolecules
Abstract

Protein adsorption/desorption upon nanoparticle surfaces is an important process to understand for developing new nanotechnology involving biomaterials, while atomistic picture of the process and its coupling with protein conformational change is lacking. Here we report our study on the adsorption of protein GB1 upon a polystyrene nanoparticle surface using atomistic molecular dynamic simulations. Enabled by metadynamics, we explored the relevant phase space and identified three protein states; each protein state involved both the adsorbed and desorbed states. We also studied the change of secondary and tertiary structures of GB1 during adsorption, and the dominant interactions between protein and surface in different adsorbing stages. From the simulation results we obtained a scenario that is more rational and complete than the conventional one. We believe the new scenario is more appropriate as a theoretical model in understanding and explaining experimental signals. Introduction, Comment: 24 pages, 6 figures

Published
2017
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19. Improved mesh stiffness model of spur gear considering spalling defect influenced by surface roughness under EHL condition.

Author

Xiao, Huifang, Zhang, Fan, Gao, Jinshan, and Li, Zedong

Abstract

AbstractGear tooth spalling is a typical tooth surface defects in gear transmission. The accurate calculation of the time-varying mesh stiffness of the gear pair with spalling defect under mixed elastohydrodynamic lubrication (EHL) plays an important role in tooth damage prediction and fault feature analysis. In this work, an improved time-varying mesh stiffness (TVMS) model of spalling faulty gear in mixed EHL line contact considering the coupled effect of rough surface topography is established. The proposed model considers the combined effect of spalling defect, surface roughness topography, and lubrication on the contact characteristics of the meshing interface to obtain a revised contact stiffness, which is further used to determine the comprehensive TVMS. The cylindrical contact coefficient for curved meshing interface with spalling fault is derived and incorporated into the statistical micro-contact Greenwood and Williamson model (GW model) to obtain the asperity contact stiffness. The revised contact stiffness at the rough faulty gear interface is obtained from the parallel action of the asperity contact stiffness and oil film stiffness under load-sharing concept. The dynamic responses of the gear system are analyzed using the established mesh stiffness model through the six degrees of freedom translational-torsional dynamic model, in which the dynamic meshing force is calculated iteratively using the transit surface topography and geometrical parameters along the line of contact instead of a quasi-static meshing force. Effects of multi-parameters as surface roughness, spalling fault size, and lubricant on the mesh characteristics and dynamic responses of the gear system are further investigated and discussed. [ABSTRACT FROM AUTHOR]

Published
2024
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42. Foreign Aid to Pakistan: Impact on GDP with least square estimation

Author

Salman, Asma and Xiao, Huifang

Abstract

Foreign direct investment flows have increased dramatically in recent decades. Developing countries have long tried to attract a reasonable amount of FDI, and easing foreign exchanges regimes, and removing restrictions have become increasingly popular. Foreign direct investment (FDI) is a potent weapon of economic development, especially in the current global context. It enables a capital-poor country like Pakistan to build up physical capital, create employment opportunities, develop productive capacity, enhance skills of local labor through transfer of technology and managerial know-how, and help integrate the domestic economy with the global economy There are many forms of foreign resources like Foreign Direct Investment, Grants & Loans, Foreign Portfolio Investment, Export Credit, Official Aid, Technical Assistance, Emergency Relief, Project and non project aid. This paper reviews impact of foreign aid on development. By performing Least Squares we analyse the trend and impact of foreign aid on the economic development of Pakistan during a three decade period. From the analysis it is clear that the foreign aid and inflow has a positive impact on the GDP.

Published
2021
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