Advanced EFL learners' beliefs about language learning and teaching: a comparison between grammar, pronunciation, and vocabulary

This paper reports on the results of a study exploring learners’ beliefs on the learning and teaching of English grammar, pronunciation and vocabulary at tertiary level. While the importance of learners’ beliefs on the acquisition process is generally recognized, few studies have focussed on and compared learners’ views on different components of the language system. A questionnaire containing semantic scale and Likert scale items probing learners’ views on grammar, pronunciation and vocabulary was designed and completed by 117 native speakers of Dutch in Flanders, who were studying English at university. The analysis of the responses revealed that (i) vocabulary was considered to be different from grammar and pronunciation, both in the extent to which an incorrect use could lead to communication breakdown and with respect to the learners’ language learning strategies, (ii) learners believed in the feasibility of achieving a native-like proficiency in all three components, and (iii) in-class grammar, pronunciation and vocabulary exercises were considered to be useful, even at tertiary level. The results are discussed in light of pedagogical approaches to language teaching

Semiconductor-less vertical transistor with I-ON/I-OFF of 10(6)

Semiconductors have long been perceived as a prerequisite for solid-state transistors. Although switching principles for nanometer-scale devices have emerged based on the deployment of two-dimensional (2D) van der Waals heterostructures, tunneling and ballistic currents through short channels are difficult to control, and semiconducting channel materials remain indispensable for practical switching. In this study, we report a semiconductor-less solid-state electronic device that exhibits an industry-applicable switching of the ballistic current. This device modulates the field emission barrier height across the graphene-hexagonal boron nitride interface with ION/IOFF of 106 obtained from the transfer curves and adjustable intrinsic gain up to 4, and exhibits unprecedented current stability in temperature range of 15–400 K. The vertical device operation can be optimized with the capacitive coupling in the device geometry. The semiconductor-less switching resolves the long-standing issue of temperature-dependent device performance, thereby extending the potential of 2D van der Waals devices to applications in extreme environments. © 2021, The Author(s).1

Mycobacterium tuberculosis Eis Regulates Autophagy, Inflammation, and Cell Death through Redox-dependent Signaling

The “enhanced intracellular survival” (eis) gene of Mycobacterium tuberculosis (Mtb) is involved in the intracellular survival of M. smegmatis. However, its exact effects on host cell function remain elusive. We herein report that Mtb Eis plays essential roles in modulating macrophage autophagy, inflammatory responses, and cell death via a reactive oxygen species (ROS)-dependent pathway. Macrophages infected with an Mtb eis-deletion mutant H37Rv (Mtb-Δeis) displayed markedly increased accumulation of massive autophagic vacuoles and formation of autophagosomes in vitro and in vivo. Infection of macrophages with Mtb-Δeis increased the production of tumor necrosis factor-α and interleukin-6 over the levels produced by infection with wild-type or complemented strains. Elevated ROS generation in macrophages infected with Mtb-Δeis (for which NADPH oxidase and mitochondria were largely responsible) rendered the cells highly sensitive to autophagy activation and cytokine production. Despite considerable activation of autophagy and proinflammatory responses, macrophages infected with Mtb-Δeis underwent caspase-independent cell death. This cell death was significantly inhibited by blockade of autophagy and c-Jun N-terminal kinase-ROS signaling, suggesting that excessive autophagy and oxidative stress are detrimental to cell survival. Finally, artificial over-expression of Eis or pretreatment with recombinant Eis abrogated production of both ROS and proinflammatory cytokines, which depends on the N-acetyltransferase domain of the Eis protein. Collectively, these data indicate that Mtb Eis suppresses host innate immune defenses by modulating autophagy, inflammation, and cell death in a redox-dependent manner

Second language learners' beliefs about language learning and their use of learning strategies : a study of college students of English in Taiwan

This study investigated the beliefs about language learning and use of language learning strategies by college EFL students in Taiwan. The relationship between learners' beliefs and strategy use was also studied. A total of 505 students enrolled in undergraduate English classes in Taiwan participated in the study. An English Learning Questionnaire, which was composed of two self-report measures Horwitz's (1987) Beliefs About Language Learning Inventory and Oxford's (1989) Strategy Inventory for Language Learning and an Individual Background Questionnaire, were translated into Chinese and administered to the students during their regular English classes. Factor analyses were computed to determine the underlying composite belief variables and composite strategy variables. The results showed that many students had positive self-efficacy about learning English. They endorsed ideas about foreign language aptitude and the importance of practice and formal structural studies. These students also reported using a variety of learning strategies, with formal oral-practice strategies and compensation strategies used more frequently and cognitive-memory strategies, least frequently. Two significant canonical correlations between the composite belief and strategy variables were obtained. The first significant linkage related language learners' feelings of self-efficacy about learning English to their use of all types of learning strategies, especially functional practice strategies. The second significant linkage related learners' beliefs about the value and nature of learning spoken English to the use of formal oral-practice strategies. The results of this study suggested that the relationships between beliefs and strategy use might not be unidirectional. As learners' beliefs likely affect their learning strategy use, the use of learning strategies may also influence learners' self-efficacy and other beliefs about language learning. In addition, female students were found to use social strategies more often than male students, and foreign language majors had a greater tendency to believe in foreign language aptitude than did other majors. In brief, the results of this study provided empirical support for a connection between language learners' beliefs and their learning strategy use. A better understanding of the beliefs and learning strategy use of the EFL students in Taiwan, as well as practical suggestions for EFL instruction in Taiwan, has been achievedCurriculum and Instructio

Polymeric artificial solid/electrolyte interphases for Li-ion batteries

During the operation of Li-ion batteries (LIBs), solvent and electrolyte decomposition takes place at the electrode surface to form a so-called solid-electrode interphase (SEI) passivating-layer. The physical structure and chemical composition of the SEI exert profound effects on various aspects of the electrode performance of the batteries. A new concept of forming polymeric artificial SEIs (A-SEIs) based on rational design of multifunctional polymer-blend coating to achieve favorable electrode/A-SEI/electrolyte interfacial properties is described. Three examples using binary and ternary polymer blends to form mechanically robust and highly Li-ion permeable surface coatings with selected functionalities in the cases of graphite and silicon–graphite composite electrodes have demonstrated greatly enhanced capacity, rate and cycle performance. Given the rich chemistry available from polymer blends, this surface preconditioning approach holds great promise for improving the performance of various negative electrodes to meet the requirements for advanced LIBs

Enhancing the open-circuit voltage in narrow-bandgap CuInSe2 solar cells via local contact passivation with Al2O3

A fabrication technique using Al2O3-passivated local contacts was employed to produce narrow-bandgap CuInSe2 (CISe) photoabsorbers, which are well-suited as bottom cell materials in tandem devices. However, the performances of CISe cells with narrow bandgaps are impeded by the recombination of charge carriers, which reduces the open-circuit voltage (VOC). To overcome this limitation, an additional Al2O3 passivation layer was added to CISe solar cells. This enhanced the VOC while maintaining a spectral response of up to 1.0 eV, thereby boosting the photovoltaic conversion efficiency of the devices. Further, the Al2O3 passivation layer within the CISe absorber effectively mitigated the recombination of charge carriers, resulting in a substantial improvement in efficiency. Specifically, the Al2O3-passivated local contact hindered the charge-carrier recombination at the rear contact, leading to a marked increase in the VOC. Consequently, the overall photovoltaic conversion efficiency increased significantly from 10.4 % to 13 %. These results are expected to greatly further the development of CISe solar cells and achieve remarkable photovoltaic conversion efficiencies