Frequency manipulation of a light-activated shape-memory polymer-laminated cylindrical shell

A light-activated shape-memory polymer is a novel smart material that exhibits a dynamic Young's modulus when exposed to light. The non-contact actuation feature facilitates the lamination of a light-activated shape-memory polymer on host structures for realising frequency control. In this study, we investigated the natural frequency of a simply supported cylindrical shell coupled with light-activated shape-memory polymer patches located arbitrarily on the shell. Initially, we compared the natural frequency of a completely laminated cylindrical shell using two different approaches. Further, we analysed the effect of changes in the length and location of the light-activated shape-memory polymer patch pair on the natural frequency of the cylindrical shell. Based on the experimental results, we propose an optimal scheme, wherein several light-activated shape-memory polymer patch pairs are distributed on the surface of the shell, and the frequency control capability of the proposed scheme is evaluated comprehensively. The results verify that the optimal scheme has an adequate control effect on the natural frequency of the cylindrical shell.

High-performance normally-off recessed Tri-Gate GaN MIS-FETs in micrometer scale

In this study, a normally-off AlGaN/GaN MIS-FET based on the combination of tri-gate and recessed MIS gate is fabricated and characterized. The recessed tri-gate MIS-FET is manufactured by micro-level trenches, defining the fin-shaped channel and improving the gate control capability. The recessed surface is cleaned by a diluted BOE, HCl solution, and TMAH treatment before a 20-nm Al2O3 deposition by ALD. After deposition, post-deposition annealing was carried out. Recessed tri-gate MIS-FET demonstrates a high threshold voltage of 3.1 V, a high drain current of 1121 mA/mm, and an on/off current ratio of 2×108. A smaller on-resistance of 5.4 Ω·mm compared with recessed planar MIS-FET of 12.7 Ω·mm is achieved. Besides, the devices show a low I-V hysteresis. All experimental results confirm micro-level trenches realize the advantages of the recessed tri-gate structures, which supports a promising technique to pursue the normally-off operation of GaN HEMTs.

Media features and communication control in the digitalized workplace: a study about regulating negative emotional communication

PurposeOne challenge facing the digitalized workplace is communication control, especially emotion regulation in which individuals try to manage their emotional experiences and/or expressions during organizational communication. Extant research largely focused on the facilitating role of a few media features (e.g. fewer symbol sets). This study seeks to provide a deeper understanding of media features that individuals, as receivers of negative emotions expressed by communication partners, could leverage to support regulating negative emotional communication in the workplace.Design/methodology/approachThis study used qualitative research methods to identify media features that support regulating negative emotional communication at work. Data were collected using interviews and was analyzed using directed content analysis in which media features discussed in media synchronicity theory (MST) were used as the initial coding schema but the researcher was open to media features that do not fit with MST.FindingsIn addition to media features (and capabilities) discussed in MST, this study identified five additional media features (i.e. message broadcasting, message blocking, receiving specification, recipient specification and compartmentalization) and two underlying media capabilities (i.e. transmission control capability and participant control capability) that may support regulating negative emotional communication. Two major mechanisms (i.e. reducing or eliminating emotion regulation workload, and providing prerequisites or removing obstacles for emotion regulation) via which media features support emotion regulation were also identified.Originality/valueThis paper provides a more comprehensive understanding regarding communication media features that may support emotion regulation in particular and communication control in general. Findings of this study contribute to several literatures and may also transfer to other similar contexts.

A Novel Multi-Objective Process Parameter Interval Optimization Method for Steel Production

Customized small batch orders and sustainable development requirements pose challenges for product quality control and manufacturing process optimization for steel production. Building a multi-quality objective process parameter optimization method that converts the original single target optimization into multi-objective interval capability optimization has become a new method to ensure product quality qualification rate and reduce production costs. Aiming at the multi-quality objective control problem of plate products, we proposed a novel multi-objective process parameter interval optimization model (MPPIO) with equipment process control capability and parameter sensitive analysis. The multi-output support vector regression method was used to establish a multi-quality objective prediction model, which was settled as a verification model for the process parameter optimization results based on the particle swarm optimization algorithm (PSO). The process control capability functions of key parameters were fitted based on the real data in production. With these functions, each optimized particle of the classical PSO was converted into the particle beam of the MIPPO. The iteration process was weight controlled by calculating the Morris sensitivity between each input parameter and output index in the multi-quality objective prediction model, and finally the processing control window of each key parameter was determined according to the process parameter optimization results. The experimental results show that the MPPIO model can obtain the optimal parameter optimization results with the maximum processing capacity and meet the customized processing range requirements. The MPPIO model can reduce the difficulty of control and save production costs while ensuring the product properties is qualified.

Lattice-Matched AlInN/GaN/AlGaN/GaN Heterostructured-Double-Channel Metal-Oxide-Semiconductor High-Electron Mobility Transistors with Multiple-Mesa-Fin-Channel Array

Multiple-mesa-fin-channel array patterned by a laser interference photolithography system and gallium oxide (Ga2O3) gate oxide layer deposited by a vapor cooling condensation system were employed in double-channel Al0.83In0.17N/GaN/Al0.18Ga0.82N/GaN heterostructured-metal-oxide-semiconductors (MOSHEMTs). The double-channel was constructed by the polarized Al0.18Ga0.82N/GaN channel 1 and band discontinued lattice-matched Al0.83In0.17N/GaN channel 2. Because of the superior gate control capability, the generally induced double-hump transconductance characteristics of double-channel MOSHEMTs were not obtained in the devices. The superior gate control capability was contributed by the side-wall electrical field modulation in the fin-channel. Owing to the high-insulating Ga2O3 gate oxide layer and the high-quality interface between the Ga2O3 and GaN layers, low noise power density of 8.7 × 10−14 Hz−1 and low Hooge’s coefficient of 6.25 × 10−6 of flicker noise were obtained. Furthermore, the devices had a unit gain cutoff frequency of 6.5 GHz and a maximal oscillation frequency of 12.6 GHz.