Donghua University

About: Donghua University is a education organization based out in Shanghai, China. It is known for research contribution in the topics: Fiber & Nanofiber. The organization has 21155 authors who have published 21841 publications receiving 393091 citations. The organization is also known as: Dōnghuá Dàxué & China Textile University.

An Elastic Transparent Conductor Based on Hierarchically Wrinkled Reduced Graphene Oxide for Artificial Muscles and Sensors.

Abstract: Using a 3D stretching method, a highly elastic reduced graphene oxide (rGO)/polyacrylic ester hierarchically wrinkled elastic transparent conductor (HWETC) is fabricated. Periodic hierarchical N-rGO layer wrinkling allows the HWETC to show high conductivity (100-457 Ω ◻-1 ) and transmittance (67-85%) under substantial stretching (>400%) and bending deformation (≈180°), which enables electrothermal actuation and strain sensing.

The effects of variable viscosity and thermal conductivity on a thin film flow over a shrinking/stretching sheet

Abstract: The effects of variable viscosity and thermal conductivity on the flow and heat transfer in a laminar liquid film on a horizontal shrinking/stretching sheet are analyzed. The similarity transformation reduces the time independent boundary layer equations for momentum and thermal energy into a set of coupled ordinary differential equations. The resulting five-parameter problem is solved by the homotopy perturbation method. The results are presented graphically to interpret various physical parameters appearing in the problem.

Space-Time Multiple-Mode Orthogonal Frequency Division Multiplexing With Index Modulation

Abstract: Multiple-mode orthogonal frequency division multiplexing with index modulation (MM-OFDM-IM) improves the spectral efficiency of the conventional OFDM-IM scheme by considering multiple distinguishable constellations for signal modulation. In this paper, we propose a novel scheme, called space-time MM-OFDM-IM (ST-MM-OFDM-IM), to increase the transmit diversity of MM-OFDM-IM. In ST-MM-OFDM-IM, the signal matrix, which consists of multiple signal vectors of MM-OFDM-IM, is transmitted over multiple time slots by following a specific rule. A low-complexity detection is proposed to mitigate the high burden of the optimal maximum-likelihood detection at the receiver side. A closed-form upper bound on the bit error rate is derived to evaluate the performance of ST-MM-OFDM-IM. Moreover, a diversity improving scheme of ST-MM-OFDM-IM is also studied to obtain full transmit diversity. Simulation results verify the theoretical analysis and show that ST-MM-OFDM-IM outperforms the conventional MM-OFDM-IM scheme.

Carbonic anhydrase generates CO2 and H+ that drive spider silk formation via opposite effects on the terminal domains.

Abstract: Spider silk fibers are produced from soluble proteins (spidroins) under ambient conditions in a complex but poorly understood process. Spidroins are highly repetitive in sequence but capped by nonrepetitive N- and C-terminal domains (NT and CT) that are suggested to regulate fiber conversion in similar manners. By using ion selective microelectrodes we found that the pH gradient in the silk gland is much broader than previously known. Surprisingly, the terminal domains respond in opposite ways when pH is decreased from 7 to 5: Urea denaturation and temperature stability assays show that NT dimers get significantly stabilized and then lock the spidroins into multimers, whereas CT on the other hand is destabilized and unfolds into ThT-positive β-sheet amyloid fibrils, which can trigger fiber formation. There is a high carbon dioxide pressure (pCO2) in distal parts of the gland, and a CO2 analogue interacts with buried regions in CT as determined by nuclear magnetic resonance (NMR) spectroscopy. Activity staining of histological sections and inhibition experiments reveal that the pH gradient is created by carbonic anhydrase. Carbonic anhydrase activity emerges in the same region of the gland as the opposite effects on NT and CT stability occur. These synchronous events suggest a novel CO2 and proton-dependent lock and trigger mechanism of spider silk formation.