Transparent and Ultra-lightweight Design for Ultra-Broadband Asymmetric Transmission of Airborne Sound

© 2018 Chinese Physical Society and IOP Publishing Ltd. Acoustic one-way manipulations have recently attracted significant attention due to the deep implications in many diverse fields such as biomedical imaging and treatment. However, the previous mechanisms of asymmetric manipulation of airborne sound need to use elaborate heavyweight structures and only work in certain frequency ranges. We propose a mechanism for designing an ultra-lightweight and optically transparent structure with asymmetric transmission property for normally incident plane waves. Instead of fabricating solids into complicated artificial structures with limited bandwidth and heavy weight, we simply use xenon to fill a spatial region of asymmetric shape which allows the incident plane wave to pass along one direction while reflecting the reversed wave regardless of frequency. We demonstrate both analytically and numerically its effectiveness of producing highly-asymmetric transmission within an ultra-broad band. Our design offers new possibility for the design of one-way devices and may have far-reaching impact on various scenarios such as noise control

Myoelectrically controlled robotic system that provide voluntary mechanical help for persons after stroke

Author name used in this publication: R. SongAuthor name used in this publication: K. Y. TongAuthor name used in this publication: X. L. HuRefereed conference paper2006-2007 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Combined first-principles calculation and neural-network correction approach for heat of formation

A promising new approach to improve the results of first-principles quantum mechanical calculations and to calibrate their uncertainties is presented. The approach is highly efficient compared to much more sophisticated first-principles methods of similar accuracy, and more importantly, is expected to be applied to much larger systems.published_or_final_versio

The sustained influence of prior experience induced by social observation on placebo and nocebo responses

Background: Social observation is one of the main ways to gain experience. Similar to first-person experience, observational experience affects the effectiveness of subsequent treatments. Yet, it is still undetermined whether the influence of social observation on placebo and nocebo effects to subsequent treatments remains even if related experience occurred a few days ago.</p

Muscle synergies in chronic stroke during a robot-assisted wrist training

Author name used in this publication: X. L. HuAuthor name used in this publication: K. Y. TongAuthor name used in this publication: R. SongAuthor name used in this publication: K. H. LuiRefereed conference paper2006-2007 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Antisense-induced suppression of taxoid 14β- hydroxylase gene expression in transgenic Taxus × media cells

The enzyme taxoid 14β-hydroxylase (14OH) directs a side-route of taxol pathway to 14β-hydroxy taxoids. Suppression of this side-route could increase the production of taxol. To suppress taxoid 14β- hydroxylase gene (14OH) expression in the Taxus × media TM3 cell line, antisense RNA inhibition approach was used in this study. Following the construction of an antisense RNA expression vector of 14OH from Taxus chinensis, the antisense 14OH cDNA (as14OH) was introduced into TM3 cells by Agrobacterium tumefaciens-mediated transformation. Southern blot analysis of hygromycin phosphotransferase gene (HYG) revealed that this selection gene was integrated successfully into the genome of Taxus × media cells. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that the 14OH mRNA level in transgenic cells dropped dramatically, suggesting that the expression of endogenous14OH gene was significantly suppressed by the exogenous as14OH gene. Correspondingly, the total yield of three major C-14 oxygenated taxoids (yunnanxane, taxuyunnanine C, sinenxan C) was markedly reduced in the silenced cell lines when compared with those of the nontransgenic controls. These results indicated that the antisense RNA strategy is a useful tool in suppressing the expression of genes in Taxus and this method could be used to silence other important genes that divert Taxol pathway to side-route metabolites.Key words: Taxus × media, taxoid 14β-hydroxylase, antisense, gene suppression

A comparison between electromyography-driven robot and passive motion device on wrist rehabilitation for chronic stroke

Author name used in this publication: Hu, Xiao Ling.Author name used in this publication: Tong, Kai-yu.Author name used in this publication: Zheng, Xiu Juan.Author name used in this publication: Leung, Wallace W. F.2009-2010 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Electric-field-induced alignment of electrically neutral disk-like particles: modelling and calculation

This work reveals a torque from electric field to electrically neutral flakes that are suspended in a higher electrical conductive matrix. The torque tends to rotate the particles toward an orientation with its long axis parallel to the electric current flow. The alignment enables the anisotropic properties of tiny particles to integrate together and generate desirable macroscale anisotropic properties. The torque was obtained from thermodynamic calculation of electric current free energy at various microstructure configurations. It is significant even when the electrical potential gradient becomes as low as 100 v/m. The changes of electrical, electroplastic and thermal properties during particles alignment were discussed