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Background People with post-stroke aphasia commonly receive speech-language therapy (SLT) when they are admitted to hospitals. Commonly, these patients reported communication difficulties in in-patient settings. Augmentative and alternative communication (AAC) has been reported as an effective treatment approach to improve communication effectiveness, language performance, decreasing depression, and improving quality of life for this population. However, little evidence has demonstrated the use of AAC intervention (AACT) in early recovery from people with post-stroke aphasia in in-patient rehabilitation settings for improving these patients’ communication effectiveness. The pilot randomized controlled trial (RCT) will explore the effectiveness and feasibility of including AACT in regular SLT for in-patient people with post-stroke aphasia. Method This pilot RCT is a single-blind, randomized controlled trial with two parallel groups. Both groups receive a 1-h treatment session, including either both AACT and SLT or SLT only for ten consecutive days. We aim to include 22 in-patient participants with post-stroke aphasia in each group. Participants will be assessed at pre- and post-intervention and 2 weeks after intervention. The primary outcomes are the ability of communication measured by the communication of basic needs subtest in the Functional Assessment of Communication Skills for Adult (FACS) and the overall language performance measured by the Chinese Standard Aphasia Battery (ABC). The secondary outcomes include a 10-min conversation, the 10-item Hospital version of the Stroke Aphasic Depression Questionnaire (SADQH-10), the Stroke-Specific Quality of Life Scale (SS-QOL), and a patient and caregiver satisfaction questionnaire. Discussion This pilot RCT will contribute to new scientific evidence to the field of aphasia rehabilitation in early recovery during the in-patient period. The paper describes the trial, which will explore the effect of combining AACT and SLT and SLT only, our choice of primary and secondary outcome measures, and proposed analyses. The study results will provide information for implementing AACT in the regular in-patient SLT of future RCTs. Trial registration Chinese Clinical Trial Registry database (ChiCTR) ChiCTR2000028870. Registered on 5 January 2020

Currently, the controversies on the energy saving potential of Variable refrigerant flow (VRF) systems compared with other heating, ventilation, and air conditioning (HVAC) systems for office buildings still exist. In this study, a VRF system for an office building is investigated in field. The actual occupant behavior (OB) was presented statistically and imported to the energy model of VRF systems developed by the authors to compare the energy performance of VRF systems, with and without considering OB. The statistical results indicate the diversity in the on-duration periods and on-off times of each indoor unit (IU) is highly significant. According to the simulated results, the energy consumption of the VRF system under a continuous operation scheme is approximately 1.8 times that of the actual operation scheme owing to the OB. The total energy consumption of IUs with high air volume setting could be more than three times that of the actual operation scheme with a low air volume setting. In addition, the energy consumption intensity of the VRF system was presented by the parametric analysis on the different occupant thermostat setting temperature. Therefore, the OB contributes significantly to the energy performance of VRF systems, which should be considered for comparison with other HVAC systems.

Currently, fin-and-tube heat exchangers (FTHEs) are widely employed in heating, ventilation, air-conditioning, and refrigeration. The proper simulation of FTHEs is crucial for evaluating their thermal performance under various operating conditions and for optimal design, especially under wet conditions that involve simultaneous heat and mass transfer phenomena. In this study, the heat and mass transfer correlations derived experiments for FTHEs under wet conditions have been tabulated. The experimental investigations conducted over the last few decades on the heat transfer characteristics of FTHEs under fully and partially wet conditions were reviewed. The significant factors related to thermal enhancement, such as heat exchanger geometry and air parameters, are analyzed and discussed. Furthermore, a comprehensive set of literature is reviewed with focus on the steady models of FTHEs under wet condition, and in relation to the principles, features, and process line in the enthalpy–humidity ratio diagram. A summary of the comparative findings under wet conditions is provided, which may be treated as an initial process step in order to understand the status and future directions of research. Some recommendations for future research are included, and finally, the main conclusions are presented.

Smart manufacturing is the core in the 4th industrial revolution. Smart shop-floor is one of the basic units of smart manufacturing. With the development of the advanced technologies (e.g. cloud computing, internet of things, model-based definition, advanced simulation, artificial intelligence), a larger number of virtual shop-floors are being built. However, it is very important that how to realize the intelligent interconnection and interaction between physical shop-floors and virtual ones. Digital twin (DT) is one of the key technologies associated to the cyber-physical system. In this paper, we present our vision on the cyber-physical production system (CPPS) towards smart shop-floor at scale via DT. This paper firstly explores a product manufacturing digital twin (PMDT), which focuses on the production phase in smart shop-floor. The proposed PMDT consists of five models: Product Definition Model (PDM), Geometric and Shape Model (GSM), Manufacturing Attribute Model (MAM), Behavior and Rule Model (BRM) and Data Fusion Model (DFM). And then based on PMDT, this paper proposes a new architecture of CPPS, which is composed of five layers (physical layer, network layer, database layer, model layer, application layer). Finally, this paper addresses the opportunities to use DT for the CPPS to support job scheduling during normal operation. Furthermore, the related further work and suggestions are also discussed.

For energy conservation, two-phase thermosyphon loops (TPTLs) have been widely used in air conditioning systems. Unfortunately, the evaluation index and design criterion of the TPTL is currently lacking, and causes for poor performance are inconclusive. In this study, an “ideal cycle” (optimal state) of the TPTL was proposed, and an approaching degree e was defined to evaluate the extent of approaching the “ideal cycle”. Furthermore, a visual experimental platform was developed, and real cycles under different conditions were measured and evaluated. The results indicate that: (1) the performance of the “ideal cycle” is the upper limit of the performances of all real cycles, and the approaching degree provides an effective evaluation index and design criterion; (2) causes for low approaching degree have been identified and illustrated visually, from the perspective of refrigerant distribution, including under-charged refrigerant, over-charged refrigerant, insufficient height difference, and considerable flow resistance; and (3) the “ideal cycle” can be approached, only when the filling ratio (100%) and the height difference (1.2 m) is optimal, and the flow resistance is negligible simultaneously.

Smart manufacturing is the core in the 4th industrial revolution. It is very important that how to realize the intelligent interaction between hardware and software in smart manufacturing. The paper proposes the architecture of Digital Twin-driven Smart ShopFloor (DTSF), as a contribution to the research of the research discussion about Digital Twin concept. Then the scheme for dynamic resource allocation optimization (DRAO) is designed for DTSF, as an application of the proposed architecture. Furthermore, a case study is given to illustrate the detailed method of DRAO. The experimental result shows that the proposed scheme is effective.

Optocoupler is fabricated by applying two separated devices as its two important composition units, the photoemitter (input) and photosensor (output), and then combining them together. It is difficult to realize precise pixel-to-pixel alignment when the active area becomes smaller and smaller, which is a limitation in the microelectronics applications. Based on a double-side indium tin oxide (ITO) substrate, a highly integrable organic optocoupler (OOC) was developed. It can reduce the limitations mentioned above of traditional optocouplers. The current transfer ratio can be enhanced to the maximum 1.87% by changing the light-emitting area. In addition, the isolation voltage can also be improved to over 3000 V by the patterning lithography treatment to ITO substrate. This sort of OOC has a promising application in the micromation of electronic devices and can be also used in low-voltage-control circuits.

Improvement of electron injection is essential for highly efficient low-voltage organic light-emitting diodes (OLEDs). In this work, we report our study on thermally decomposable Li3N as the electron injection layer (EIL) for OLEDs. We use a quartz crystal microbalance method to investigate the decomposition process of Li3N during vacuum thermal evaporation in situ. Thermodynamics study also proves that Li3N decomposes in vacuum to form metallic lithium and nitrogen. OLEDs with Li3N as the EIL outperform those with conventional LiF in every respect of view. An optimized green OLED with a Li3N EIL shows 35% higher efficiency and more than doubled lifetime compared with the control device with a LiF EIL.

We demonstrate high performance blue, yellow and tandem white organic light-emitting diodes with low driving voltages using a novel electron transporting material. The blue and yellow OLEDs achieve low turn-on voltage of 2.6 V and 2.2V, respectively, equivalent to their energy gaps. The tandem white OLED shows an extremely low driving voltage of 5.9 V at 1000 cd/m2, together with an efficacy of 28.6 lm/W, a current efficiency of 53.7 cd/A, and an external quantum efficiency of 24.6%. A 64 × 64 mm2 panel has been produced with the same architectures as the tandem OLED pixel, the efficiency is further improved to 45 lm/W with the use of a micro-lens film.

Based on the analysis of assembly process for the chip-shooter machine, a hybrid genetic algorithm (GA) for printed circuit board (PCB) assembly optimization was presented to minimize the assembly time. During the assembly process, the speed of PCB table movement and turret rotation is inconstant; it is affected by placement sequence and component size. According to the size of component and component placement sequence, all the components are classified into key components and free components. Polychromatic set (PS) contour matrix is used to describe the classification and the relationship of key components and free components. Through appropriate coding method and genetic operation, GA is used to simultaneously optimize two complex combinatorial optimization problems which include component placement sequence and feeder arrangement. The contour matrix combines with generation initialization, calculation of fitness value and genetic operation. The search space of GA is obviously reduced, and the solution efficiency is improved. Compare with other algorithm, hybrid GA can optimize the assembly time accurately and effectively.

Tandem organic light emitting diodes (OLEDs) are ideal for lighting applications due to their low working current density at high brightness. In this work, we have studied an efficient electron transporting layer of KBH(4) doped 9,10-bis(3-(pyridin-3-yl)phenyl)anthracene (DPyPA) which is located adjacent to charge generation layer of MoO(3)/NPB. The excellent transporting property of the DPyPA:KBH(4) layer helps the tandem OLED to achieve a lower voltage than the tandem device with the widely used tris-(8-hydroxyquinoline)aluminum:Li. For the tandem white OLED with a fluorescent blue unit and a phosphorescent yellow unit, we've achieved a high current efficiency of 75 cd/A, which can be further improved to 120 cd/A by attaching a diffuser layer.

Ideal n-type layers are highly desired for high performance organic light emitting diodes (OLEDs). For the first time, we studied the combination of a low-temperature-evaporable n-dopant KBH₄ and a high mobility electron transport material 9,10-bis(3-(pyridin-3-yl)phenyl)anthracene (DPyPA). The excellent transporting property of the DPyPA: KBH₄ layer allows the fine tuning of the OLED performance by varying the thickness of the n-doped layer in a wide range (from 10 nm to 50 nm, 100 nm, 150 nm and 200 nm). The device with the optimized n-type layer thickness of 150 nm shows the best performance with a high current efficiency of 27.60 cd/A at the brightness 10,000 cd/m², which is about 40% higher than the device with a 10 nm n-type layer (19.95 cd/A at 10,000 cd/m²). The high performance is attributed to the optimization of optical path and the decrease of the loss in the organic layer/cathode interface due to the thick n-doped layer.

In this work, KBH4 was studied as a novel electron injection material (EIM) for organic light-emitting diodes (OLEDs). Optimized OLEDs using KBH4 as the EIM showed a high efficiency of 11.0 cd/A at 1000 cd/m2, comparable to that of a control device using LiF (9.2 cd/A). The lifetime of the device with KBH4 was also comparable to that of the control device. Thermal evaporation behavior was studied by thermodynamic calculation and X-ray photoemission spectroscopy (XPS), demonstrating that the improved electron injection was attributable to the low-work-function metallic K released by the thermal decomposition of KBH4.