The purpose of this study is to investigate the efficiency of the production-oriented approach research (POA-R) teaching approach on academic English courses. The six-week study involved thirty-nine ...postgraduate students from Guilin Medical University studying medical technology. These students were randomly divided into POA-R (19 participants) and non-POA-R (20 participants) groups. The process of study in the POA-R group was divided into three stages, motivating, enabling, and assisting. The instructor gave the class a task at the motivational stage that involved taking the academic IELTS exam, writing a review article and giving an oral presentation about their research topic. At this stage, students are challenged to find relevant information searching PubMed and other literature databases. The teacher served as a facilitator of learning and would not offer information related to the tasks. During the enabling phase, students were encouraged to ask their supervisor for help and guidance. Students ask questions in class, and the instructor discusses the questions with the students and guides them to solve the questions independently. During the assessment stage, students take the academic IELTS exam, finish the review article, given an oral presentation related their research project, and complete an instructional questionnaire. The non-POA-R group was instructed by the teacher lecture method, comprising six lectures and an oral presentation in addition to the completion of a review article. The final grades of course include a review article, an oral presentation, and an academic IELTS test. The results revealed that the students in the POA-R group outperformed the non-POA-R group in terms of mean scores on the IELTS exam, oral presentation, and review article. To further support and demonstrate the advantages of the POA-R teaching approach, an instructional questionnaire using Likert scales and the attitudes of their supervisors was employed. In conclusion, the POA-R teaching approach is a highly successful strategy for enhancing postgraduate students' academic English proficiency. It greatly enhanced the participants' academic knowledge, learning interest, and active learning.
Search frictions in the labor market give rise to a new option-value channel through which uncertainty affects aggregate economic activity, and the effects of which are reinforced by the presence of ...nominal rigidities. With these features, an increase in uncertainty resembles an aggregate demand shock because it increases unemployment and lowers inflation. Using a new empirical measure of uncertainty based on the Michigan survey and a VAR model, we show that these theoretical patterns are consistent with US data. Using a calibrated DSGE model, we show that combining search frictions and nominal rigidities can match the qualitative VAR pattern and account for about 70percent of the empirical increase in unemployment following an uncertainty shock.
•An increase in uncertainty resembles effects of a negative aggregate demand shock.•Uncertainty raises unemployment and lowers inflation in both VAR and DSGE models.•An option-value channel from search frictions amplify effects of uncertainty.•Presence of nominal rigidities reinforces the option-value channel.
To satisfy the increasing energy demands of portable electronics, electric vehicles, and miniaturized energy storage devices, improvements to lithium‐ion batteries (LIBs) are required to provide ...higher energy/power densities and longer cycle lives. Group IVA element (Si, Ge, Sn)‐based alloying/dealloying anodes are promising candidates for use as electrodes in next‐generation LIBs owing to their extremely high gravimetric and volumetric capacities, low working voltages, and natural abundances. However, due to the violent volume changes that occur during lithium‐ion insertion/extraction and the formation of an unstable solid electrolyte interface, the use of Group IVA element‐based anodes in commercial LIBs is still a great challenge. Evaluating the electrochemical performance of an anode in a full‐cell configuration is a key step in investigating the possible application of the active material in LIBs. In this regard, the recent progress and important approaches to overcoming and alleviating the drawbacks of Group IVA element‐based anode materials are reviewed, such as the severe volume variations during cycling and the relatively brittle electrode/electrolyte interface in full‐cell LIBs. Finally, perspectives and future challenges in achieving the practical application of Group IVA element‐based anodes in high‐energy and high‐power‐density LIB systems are proposed.
Group IVA element (Si, Ge, Sn)‐based alloying/dealloying electrodes are promising candidates for anodes in next‐generation lithium–ion batteries owing to their high gravimetric and volumetric capacities, low working voltages, and natural abundance. The recent progress and important approaches in overcoming and alleviating the drawbacks of Group IVA element‐based anodes in full‐cell configurations are reviewed.
Wearable or attachable health monitoring smart systems are considered to be the next generation of personal portable devices for remote medicine practices. Smart flexible sensing electronics are ...components crucial in endowing health monitoring systems with the capability of real‐time tracking of physiological signals. These signals are closely associated with body conditions, such as heart rate, wrist pulse, body temperature, blood/intraocular pressure and blood/sweat bio‐information. Monitoring such physiological signals provides a convenient and non‐invasive way for disease diagnoses and health assessments. This Review summarizes the recent progress of flexible sensing electronics for their use in wearable/attachable health monitoring systems. Meanwhile, we present an overview of different materials and configurations for flexible sensors, including piezo‐resistive, piezo‐electrical, capacitive, and field effect transistor based devices, and analyze the working principles in monitoring physiological signals. In addition, the future perspectives of wearable healthcare systems and the technical demands on their commercialization are briefly discussed.
Flexible sensing electronics play crucial roles in wearable health monitoring systems, which is considered to be a convenient and effective way for disease diagnoses and health assessments. The advances of flexible sensing electronics and related nanomaterials in healthcare are summarized.
Humans can naturally and effectively find salient regions in complex scenes. Motivated by this observation, attention mechanisms were introduced into computer vision with the aim of imitating this ...aspect of the human visual system. Such an attention mechanism can be regarded as a dynamic weight adjustment process based on features of the input image. Attention mechanisms have achieved great success in many visual tasks, including image classification, object detection, semantic segmentation, video understanding, image generation, 3D vision, multimodal tasks, and self-supervised learning. In this survey, we provide a comprehensive review of various attention mechanisms in computer vision and categorize them according to approach, such as channel attention, spatial attention, temporal attention, and branch attention; a related repository
https://github.com/MenghaoGuo/Awesome-Vision-Attentions
is dedicated to collecting related work. We also suggest future directions for attention mechanism research.
As a sustainable technology, semiconductor photocatalysis has attracted considerable interest in the past several decades owing to the potential to relieve or resolve energy and ...environmental‐pollution issues. By virtue of their unique structural and electronic properties, emerging ultrathin 2D materials with appropriate band structure show enormous potential to achieve efficient photocatalytic performance. Here, the state‐of‐the‐art progress on ultrathin 2D photocatalysts is reviewed and a critical appraisal of the classification, controllable synthesis, and formation mechanism of ultrathin 2D photocatalysts is presented. Then, different strategies to tailor the electronic structure of ultrathin 2D photocatalysts are summarized, including component tuning, thickness tuning, doping, and defect engineering. Hybridization with the introduction of a foreign component and maintaining the ultrathin 2D structure is presented to further boost the photocatalytic performance, such as quantum dots/2D materials, single atoms/2D materials, molecular/2D materials, and 2D–2D stacking materials. More importantly, the advancement of versatile photocatalytic applications of ultrathin 2D photocatalysts in the fields of water oxidation, hydrogen evolution, CO2 reduction, nitrogen fixation, organic syntheses, and removal pollutants is discussed. Finally, the future opportunities and challenges regarding ultrathin 2D photocatalysts to bring about new opportunities for future research in the field of photocatalysis are also presented.
Recent progress in the study of ultrathin 2D photocatalysts is reviewed. Different strategies to tailor the electronic structures and hybridizations while maintaining the ultrathin 2D structure to further boost the photocatalytic activity are presented. The advancement of versatile photocatalytic applications of ultrathin 2D photocatalysts is also discussed.
Motivated by recent experimental observations in α-RuCl_{3}, we study the K-Γ model on the honeycomb lattice in an external magnetic field. By a slave-particle representation and variational ...Monte Carlo calculations, we reproduce the phase transition from zigzag magnetic order to a field-induced disordered phase. The nature of this state depends crucially on the field orientation. For particular field directions in the honeycomb plane, we find a gapless Dirac spin liquid, in agreement with recent experiments on α-RuCl_{3}. For a range of out-of-plane fields, we predict the existence of a Kalmeyer-Laughlin-type chiral spin liquid, which would show an integer-quantized thermal Hall effect.
In elderly people particularly in postmenopausal women, inadequate bone formation by osteoblasts originating from bone marrow mesenchymal stem cells (BMSCs) for compensation of bone resorption by ...osteoclasts is a major reason for osteoporosis. Enhancing osteoblastic differentiation of BMSCs is a feasible therapeutic strategy for osteoporosis. Here, bone marrow stromal cell (ST)-derived exosomes (STExos) are found to remarkably enhance osteoblastic differentiation of BMSCs in vitro. However, intravenous injection of STExos is inefficient in ameliorating osteoporotic phenotypes in an ovariectomy (OVX)-induced postmenopausal osteoporosis mouse model, which may be because STExos are predominantly accumulated in the liver and lungs, but not in bone. Hereby, the STExo surface is conjugated with a BMSC-specific aptamer, which delivers STExos into BMSCs within bone marrow. Intravenous injection of the STExo-Aptamer complex enhances bone mass in OVX mice and accelerates bone healing in a femur fracture mouse model. These results demonstrate the efficiency of BMSC-specific aptamer-functionalized STExos in targeting bone to promote bone regeneration, providing a novel promising approach for the treatment of osteoporosis and fracture.
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