Abstract Understanding magnetotransport properties in semiconductors plays a vital role in either developing future spintronic or unveiling the underpinning physics of electronic dynamics. In recent years, the high‐field magnetoconductance (HFM, B ~ 1 T) in polymers has drawn intense discussions and always been attributed to thermal spin polarization (TSP). In this work, the HFMs in several benchmark polymers are proposed to be correlated to the ∆ g spin‐mixing effect, determined from their remarkable anisotropy in response to magnetic fields, which cannot be explained only by TSP. It is the fundamental difference between two spins' Lande factors stemming from the random orientations of molecular backbones that contributes to the intense ∆ g spin‐mixing effect, leading to HFMs' anisotropy as high as 150%. It is further found that the ∆ g spin‐mixing mechanism greatly correlates with the charge transport dynamics in polymers, in which a slow‐ to fast‐hopping crossover was observed and further verified by pressure‐dependent HFMs characteristics.
It has been recently reported that ultraviolet harmonic vortices can be produced when a high-power circular-polarized laser pulse travels through a micro-scale waveguide. However, the harmonic generation quenches typically after a few tens of microns of propagation, due to the build-up of electrostatic potential that suppresses the amplitude of the surface wave. Here we propose to utilize a hollow-cone channel to overcome this obstacle. When traveling in a cone target, the laser intensity gradually increases, allowing the surface wave to maintain a high amplitude for a much longer distance. The harmonic vortices can be produced with very high efficiency. According to three-dimensional particle-in-cell simulations, the overall efficiency are boosted by almost one order of magnitude, reaching $>20\%$. It is also found that using the cone targets can mitigate efficiency decline due to pre-heating of plasma by laser prepulse. The proposed scheme paves the way to the development of powerful optical vortices sources in the extreme ultraviolet regime - an area of significant fundamental and applied physics potential.
The visualization of deep learning models has been widely studied as an effective means of exploring the decision-making processes within these models. However, current visualization methods suffer from several limitations, such as low resolution and poor visualization of multiple occurrences of the same class. In this paper, we propose a novel visualization technique called MSG-CAM, which is an improvement on the existing Group-CAM method. Our method uses the feature maps and gradients of the last layer of the convolutional neural network to create masks through multi-scale enlargement of the original input image and fusion of the resulting feature maps and gradients. Through both qualitative and quantitative analysis, we have demonstrated that the saliency maps generated by our method are more reasonable and accurately reflect the internal decision-making processes of the neural network.
A scheme for generating intense high-harmonic optical vortices is proposed. It relies on spin-orbit interaction of light when a relativistically-strong circularly polarized laser pulse irradiates a micro-plasma-waveguide. The intense laser field drives a strong surface wave at the inner boundary of the waveguide, which leads to high-order harmonic generation as the laser traveling inside. For a circularly polarized drive laser, the optical chirality is imprinted to the surface wave, which facilitates conversion of spin angular momentum of the fundamental light into orbital angular momenta of the harmonics. A "shaken waveguide" model is developed showing that the aforementioned phenomena arises due to nonlinear plasma response that modifies electromagnetic mode at high intensities. We further show the phase velocities of all the harmonic beams are automatically matched to the driving laser, so that the harmonic intensities increase with propagation distance. The efficiency of harmonic production are related to the surface wave breaking effect, which can be significantly enhanced using a tightly focused laser. Our simulation suggests an overall conversion efficiency $\sim5\%$ can be achieved.
High frequency words, which are key to a text, must be mastered to achieve minimum levels of reading proficiency. However, knowledge about the frequency of items in a language is very limited. Given this consideration, WordSift ( www.wordsift.org ), a word cloud tool based on high frequency and key words can assist English as a Foreign Language learners of intermediate level who have difficulty in reading the text due to limited vocabulary knowledge and all of its distinctive features can be applied in varied stages of reading instruction.
Abstract Thin film transistors (TFTs) based on amorphous oxide semiconductors (AOS) are promising candidates for panel displays. However, the trade‐off between mobility and reliability in AOS‐TFTs hinders their further applications in next‐generation display techniques and newly developed logic and memory circuits. Here, a structural strategy is proposed for the mobility‐reliability trade‐off, via a triple‐layer channel containing a Ga‐free high‐mobility layer (amorphous InSnZnO, a‐ITZO) sandwiched by two Ga‐rich layers (amorphous InGaZnO, a‐IGZO) with higher reliability. Gate‐induced carrier accumulation is verified mainly being energetically confined within the high mobility a‐ITZO layer, at the newly defined a‐ITZO/a‐IGZO interface. Compared to single layer a‐ITZO‐TFTs, triple‐channel a‐IGZO/a‐ITZO/a‐IGZO TFTs (GTG‐TFTs) exhibit outstanding stability and electrical transport performances, with suppressed positive/negative‐bias‐stress voltage shifts from 1/0.3 to 0.1/0.004 V, enhanced field effect mobility from ≈40 to 56 cm 2 V −1 s −1 , and optimized sub‐threshold swing down to 80 mV dec −1 . Further numerical simulations and charge transport characterizations, including magnetotransport and gate‐induced Hall effect, indicate that charge transport in tri‐layer structure is less affected by energetic disorders present at gate insulator interfaces.
In order to cope with climate change, accounting for carbon emissions from electricity consumption has become particularly important. A standardized carbon emission accounting system can, on the one hand, protect the rights and interests of users and mobilize enterprises to consume green electricity, and on the other hand, can systematically grasp the overall situation of carbon emissions from the national electricity consumption, and promote the whole society to realize low-carbon transformation. In this study, we propose a user-side electricity carbon emission accounting model based on the electricity transaction flow formed by user electricity transactions. The model has four modules, which are used to deal with user power activity data, regional carbon emission factors and dynamic adjustment, user power activity carbon emissions, and carbon offsets of user environmental interest products. The spatial and temporal resolution of the model can be accurate to the provincial day scale. This study also virtualizes the electricity consumption arithmetic example of a manufacturing enterprise in Guangdong, China, which shows that the model can well capture the total carbon emissions of the enterprise's electricity consumption at different time scales and dynamically update the carbon emission factors. The example demonstrates that the model has a wide range of application potentials, which can more accurately account for user-side electricity carbon emissions, improve the spatial and temporal resolution of carbon measurement, promote the organic combination of the electricity market and the carbon market, and help China realize its dual-carbon goals.
The quick spread of the COVID-19 pandemic across the globe has seriously affected all aspects of individuals’ lives including the educational sector. In response to this pandemic in Malaysia, the government implemented a Movement Control Order (MCO) on 18 March 2020, where the whole country was put on lockdown. Yet, the teaching and learning activities had to continue during this period, a process that was carried out through a full reliance on e-learning. This paper attempted to investigate the level of e-learning technological readiness among English language teachers to utilize e-learning in teaching during the MCO in Malaysia. A total of 68 English language teachers responded to an online cross-sectional survey that measured technological skills readiness based on Chapnick’s (2000) e-learning readiness model. Results showed that during the MCO in Malaysia, English language teachers were technologically ready to use e-learning in teaching. However, these findings contradict the latest reports that highlight a number of challenges faced by Malaysian teachers in conducting online classes. This inconsistency could be attributed to the limitations identified in the existing e-learning surveys and questionnaires that deal with extremely limited aspects of technological readiness. Hence, this research stresses the urgent need to develop up-to-date scales that can comprehensively address the various aspects of the advanced technological skills that should be mastered by teachers and educators, especially in this era of the Fourth Industrial Revolution (IR4.0).
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)