43 research outputs found
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Does âWOWâ translate to an âAâ? Exploring the effects of virtual reality assisted multimodal text on Chinese Grade 8 EFL learnersâ reading comprehension
In recent years, the incorporation of multimedia into linguistic input has opened a new horizon in the field of second language acquisition (SLA). In the reading aspect, the advent of virtual reality (VR) technology extends the landscape of reading repertoire by engaging learners with auditory, visual and tactile multimodal input. However, few studies have yet examined the pedagogical potential of VR technology in enhancing learnersâ reading comprehension. This study aims to fill this gap by assessing the effects of VR-assisted multimodal input on learnersâ expository reading comprehension. Three classes including 140 Chinese 8th grade EFL students participate in this study, and these classes are randomly assigned into two experimental groups and one control group: VR-assisted multimodal text group, video-assisted multimodal text group and print-based monomodal text group. This study adopts mixed methods methodology and triangulates pre-post-retention tests, questionnaires and interview data to compare three modes of text input on learnersâ reading performance and explore learnersâ cognitive processing in the multimodal learning environment. This study is the first attempt to integrate VR technology with input presentation and cognitive processing in second language reading comprehension and offered a new line of theorisation of VR-assisted multimodal learning in the cognitive field of SLA
Correlation between Grafting Density and Confined Crystallization Behavior of Poly(ethylene glycol) Grafted to Silica
The interfacial interactions of polymer-nanoparticles have dramatical effects on the crystallization behavior of grafted polymers. In this study, methoxy polyethylene glycol (MPEG) (molecular weights 750, 2000 and 4000 g molâ1) was grafted onto amino-modified nanosized silica (SiO2-NH2) by the âgrafting toâ method. The effects of the grafting density and molecular weight on the confined crystallization of grafted MPEG (MPEG-g-SiO2) were systematically investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and wide-angle X-ray scattering (WAXS). It was found that confinement effects are stronger when lower molecular weights of grafted MPEG are employed. These grafted MPEG chains are more difficult to stretch out on SiO2-NH2 surfaces than when they are free in the bulk polymer. Both crystallization temperature (Tc) and crystallinity of grafted MPEG chains decrease with reductions of grafting density. Additionally, covalent bonding effects and interfacial interaction confinement effects are strengthened by the decrease in grafting density, leading to an increase in decomposition temperature and to the disappearance of the self-nucleation Domain (i.e., Domain II), when self-nucleation experiments are performed by DSC. Overall isothermal crystallization kinetics was studied by DSC and the results were analyzed with the Avrami equation. An Avrami index of nâ3 was obtained for neat MPEG (indicating that instantaneous spherulites are formed). However, in the case of MPEG-g-SiO2 with the lowest grafting density, the Avrami index of (n) was less than 1 (first order kinetics or lower), indicating that nucleation is the determining factor of the overall crystallization kinetics, a signature
for confined crystallization. At the same time, the crystallization from the melt for this MPEG-g-SiO2 with the lowest grafting density occurs at Tc
â-30 ÂșC, a temperature close to the glass transition temperature (Tg) of MPEG, indicating that this confined MPEG crystallizes from homogeneous nuclei.This project was supported by the National Natural Science Foundation of China (21574141) and the Ministry of Science and Technology of China (2017YFE0117800). The authors gratefully acknowledge the funding of project BIODEST, Research and Innovation Staff Exchange (RISE) H2020-MSCA-RISE-2017-778092. The authors thank beamline BL16B1 (Shanghai Synchrotron Radiation Facility) for providing the beam time and helps during experiments
A Cooperative High-Speed Positioning Control System for Dual-Axis Permanent-Magnet Linear Motor
The Smart Cross Platform guarantees content compatibility of various smart devices and supports numerous programming languages, which is a solution to increasing development productivity. The SVM (Smart Virtual Machine) is the core virtual machine of the smart cross platform. This paper presents a technology which allows the SVM previously operating on smart devices to operate in the web environment. In the whole design and implementation of the SVM operating in the web based environment, this paper focuses on the interpreter, which is used as a method to execute the contents
Probing Interface of Perovskite Oxide Using Surface-specific Terahertz Spectroscopy
The surface/interface species in perovskite oxides play an essential role in
many novel emergent physical phenomena and chemical processes. With low
eigen-energy in the terahertz region, such species at buried interfaces remain
poorly understood due to the lack of feasible experimental techniques. Here, we
show that vibrational resonances and two-dimensional electron gas at the
interface can be characterized using surface-specific nonlinear spectroscopy in
the terahertz range. This technique uses intra-pulse difference frequency
mixing (DFM) process, which is allowed only at surface/interface of a medium
with inversion symmetry. Sub-monolayer sensitivity can be achieved using the
state-of-the-art detection scheme for the terahertz emission from
surface/interface. As a demonstration, Drude-like nonlinear response from the
two-dimensional electron gas emerging at LaAlO3/SrTiO3 or Al2O3/ SrTiO3
interface was successfully observed. Meanwhile, the interfacial vibrational
spectrum of the ferroelectric soft mode of SrTiO3 at 2.8 THz was also obtained
that was polarized by the surface field in the interfacial region. The
corresponding surface/interface potential, which is a key parameter for
SrTiO3-based interface superconductivity and photocatalysis, can now be
determined optically via quantitative analysis on the polarized phonon
spectrum. The interfacial species with resonant frequencies in the THz region
revealed by our method provide more insights into the understanding of physical
properties of complex oxides.Comment: arXiv admin note: substantial text overlap with arXiv:2207.1461
Enhanced Global-Brain Functional Connectivity in the Left Superior Frontal Gyrus as a Possible Endophenotype for Schizophrenia
The notion of dysconnectivity in schizophrenia has been put forward for many years and results in substantial attempts to explore altered functional connectivity (FC) within different networks with inconsistent results. Clinical, demographical, and methodological heterogeneity may contribute to the inconsistency. Forty-four patients with first-episode, drug-naive schizophrenia, 42 unaffected siblings of schizophrenia patients and 44 healthy controls took part in this study. Global-brain FC (GFC) was employed to analyze the imaging data. Compared with healthy controls, patients with schizophrenia and unaffected siblings shared enhanced GFC in the left superior frontal gyrus (SFG). In addition, patients had increased GFC mainly in the thalamo-cortical network, including the bilateral thalamus, bilateral posterior cingulate cortex (PCC)/precuneus, left superior medial prefrontal cortex (MPFC), right angular gyrus, and right SFG/middle frontal gyrus and decreased GFC in the left ITG/cerebellum Crus I. No other altered GFC values were observed in the siblings group relative to the control group. Further ROC analysis showed that increased GFC in the left SFG could separate the patients or the siblings from the controls with acceptable sensitivities. Our findings suggest that increased GFC in the left SFG may serve as a potential endophenotype for schizophrenia
Phytic acid modified NH2-MIL-101 via Mannich reaction for highly efficient uranium (â „) extraction from seawater
An essential part of achieving sustainable uranium resource development was the search for a suitable adsorbent capable of efficiently capturing uranium (â
„) from seawater. Here, a modified metal-organic framework (PA-MIL-101) was prepared by phosphorylation of NH2-MIL-101 with phytic acid (PA). PA-MIL-101 exhibited a specific surface area of 252Â m2âgâ1 and proved exceptionally adept at extracting uranium (â
„) from seawater. Batch experiments were conducted to examine how environmental conditions such as pH and natural seawater affect the uranium adsorption performance of the materials. The adsorption capacity of PA-MIL-101 exhibited a remarkable performance, showcasing a substantial 41.8% increase compared to NH2-MIL-101 (the adsorption capacity increased to 416.7Â mgâgâ1 at pHÂ =Â 7 in 100Â mgâLâ1Â U(â
„) solution). Due to the fast adsorption kinetics, PA-MIL-101 achieves a saturation level of 72.1% within the first 5Â min. The removal rate was further elevated to 88.48% in the more intricate natural seawater. The reusability of PA-MIL-101 was demonstrated through five recycling cycles. The porous material PA-MIL-101 has abundant P=O and PâOH active sites, which can strongly complex with uranium (â
„). This feature makes PA-MIL-101 perform effective in natural seawater. Therefore, PA-MIL-101 is considered as a promising supersorbent for efficient removal of uranium (â
„)
The Synergistic Effect of Microwave Radiation and Hypergravity on Rats and the Intervention Effect of Rana Sylvatica Le Conte Oil
Aim: The phenomena of hypergravity and microwave radiation are widespread, which cause more and more concern for the hazards to human health. The aim of this study was to investigate the synergistic effect of microwave radiation and hypergravity on rats and observe the protective effect of Rana sylvatica Le conte oil. Methods: Rats were exposed to microwave radiation and hypergravity, and the rat weight, the climbing pole height, serum enzyme activities, blood urea nitrogen concentration, and total antioxidant capacity were detected. Results: The climbing pole height, the activities of choline acetyl transferase and cholinesterase, and the total antioxidant capacity decreased, whereas the activities of alanine aminotransferase, aspartate aminotransferase, areatine kinase, isocitric dehydrogenase, hydroxybutyrate dehydrogenase, and the blood urea nitrogen concentration increased in the hypergravity irradiation group as compared with the others. Conclusion: These results imply that the motion and nervous system of rats might be affected critically by the synergistic effect of microwave radiation and hypergravity, and it causes damage to most rat organs, such as the bone, skeletal muscle, liver, heart, and kidney, and the antioxidant effect is also damaged, while the injury resulted from it could be protected by Rana sylvatica Le conte oil
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A novel scheme for ultrashort terahertz pulse generation over a gapless wide spectral range: Raman-resonance-enhanced four-wave mixing
Ultrashort energetic terahertz (THz) pulses have created an exciting new area of research on light interactions with matter. For material studies in small laboratories, widely tunable femtosecond THz pulses with peak field strength close to MV cm-1 are desired. Currently, they can be largely acquired by optical rectification and difference frequency generation in crystals without inversion symmetry. We describe in this paper a novel scheme of THz pulse generation with no frequency tuning gap based on Raman-resonance-enhanced four-wave mixing in centrosymmetric media, particularly diamond. We show that we could generate highly stable, few-cycle pulses with near-Gaussian spatial and temporal profiles and carrier frequency tunable from 5 to >20âTHz. They had a stable and controllable carrier-envelop phase and carried ~15 nJ energy per pulse at 10âTHz (with a peak field strength of ~1âMVâcm-1 at focus) from a 0.5-mm-thick diamond. The measured THz pulse characteristics agreed well with theoretical predictions. Other merits of the scheme are discussed, including the possibility of improving the THz output energy to a much higher level