The Use of Electronic Dictionaries in EFL Classroom

Today’s dictionaries have more information and are easier to access and to understand than ever before. And, with the advent of electronic formats, space is no longer the problem it was. Electronic dictionaries have become more and more attractive, accepted and popular to EFL learners at different levels, using electronic dictionaries in EFL classroom has gradually become an alternative to many. As for teachers, helping students tap into electronic dictionaries effectively is one of the best ways to help them become independent, lifelong language learners. In this essay, the functionality of electronic dictionaries and reasons why they are popular in EFL class will be introduced. Also, some of the current issues related to the integration of electronic dictionaries into EFL instruction and learning will be identified and discussed. The author’s views towards this topic will be presented as well, based on the observation and reflection of using electronic dictionaries in EFL classes at a Chinese university

An enhanced and highly efficient semi-implicit combined Lagrange multiplier approach with preserving original energy law for dissipative systems

Recently, a new Lagrange multiplier approach was introduced by Cheng, Liu and Shen in \cite{cheng2020new}, which has been broadly used to solve various challenging phase field problems. To design original energy stable schemes, they have to solve a nonlinear algebraic equation to determine the introduced Lagrange multiplier, which can be computationally expensive, especially for large-scale and long-time simulations involving complex nonlinear terms. This paper presents an essential improved technique to modify this issue, which can be seen as a semi-implicit combined Lagrange multiplier approach. In general, the new constructed schemes keep all the advantages of the Lagrange multiplier method and significantly reduce the computation costs. Besides, the new proposed BDF2 scheme dissipates the original energy, as opposed to a modified energy for the classical Lagrange multiplier approach in \cite{cheng2020new}. We further construct high-order BDF$k$ schemes based on the new proposed approach. In addition, we establish a general framework for extending our constructed method to dissipative systems. Finally several examples have been presented to demonstrate the effectiveness of the proposed approach

Precheck Sequence Based False Base Station Detection During Handover: A Physical Layer Based Security Scheme

False Base Station (FBS) attack has been a severe security problem for the cellular network since 2G era. During handover, the user equipment (UE) periodically receives state information from surrounding base stations (BSs) and uploads it to the source BS. The source BS compares the uploaded signal power and shifts UE to another BS that can provide the strongest signal. An FBS can transmit signal with the proper power and attract UE to connect to it. In this paper, based on the 3GPP standard, a Precheck Sequence-based Detection (PSD) Scheme is proposed to secure the transition of legal base station (LBS) for UE. This scheme first analyzes the structure of received signals in blocks and symbols. Several additional symbols are added to the current signal sequence for verification. By designing a long table of symbol sequence, every UE which needs handover will be allocated a specific sequence from this table. The simulation results show that the performance of this PSD Scheme is better than that of any existing ones, even when a specific transmit power is designed for FBS

Curriculum-based Sensing Reduction in Simulation to Real-World Transfer for In-hand Manipulation

Simulation to Real-World Transfer allows affordable and fast training of learning-based robots for manipulation tasks using Deep Reinforcement Learning methods. Currently, Sim2Real uses Asymmetric Actor-Critic approaches to reduce the rich idealized features in simulation to the accessible ones in the real world. However, the feature reduction from the simulation to the real world is conducted through an empirically defined one-step curtail. Small feature reduction does not sufficiently remove the actor's features, which may still cause difficulty setting up the physical system, while large feature reduction may cause difficulty and inefficiency in training. To address this issue, we proposed Curriculum-based Sensing Reduction to enable the actor to start with the same rich feature space as the critic and then get rid of the hard-to-extract features step-by-step for higher training performance and better adaptation for real-world feature space. The reduced features are replaced with random signals from a Deep Random Generator to remove the dependency between the output and the removed features and avoid creating new dependencies. The methods are evaluated on the Allegro robot hand in a real-world in-hand manipulation task. The results show that our methods have faster training and higher task performance than baselines and can solve real-world tasks when selected tactile features are reduced

Ruscogenin alleviates palmitic acid-induced endothelial cell inflammation by suppressing TXNIP/NLRP3 pathway

Purpose: To investigate the involvement of ruscogenin in palmitic acid (PA)-induced endothelial cell inflammation. Method: Cultured human umbilical vein endothelial cells (HUVECs) were divided into five groups: control (normal untreated cells), PA (cell treated with palmitic acid), and PA + ruscogenin (1, 10, or 30 μM). Cell viability and apoptosis rate were determined using MTT (3-(4,5)-dimethylthiahiazo(-z-y1)-3,5- di-phenytetrazolium bromide) and flow cytometry assays, respectively. The levels of cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and monocyte chemo-attractant protein-1 (MCP-1) were determined by an enzyme-linked immunosorbent assay. Western blotting and real-time polymerase chain reaction (RT-PCR) were used to evaluate the underlying mechanisms of action. Results: PA treatment decreased the viability of HUVECs and induced apoptosis (p < 0.05). Ruscogenin attenuated PA-induced cell death in a dose-dependent manner (p < 0.05). On the other hand, PA induced an increase in IL-1β, TNF-α, ICAM-1, MCP-1, TXNIP (thioredoxin-interacting protein),as well as NLRP3 (nucleotide oligomerization domain-, leucine-rich repeat- and pyrin domain-containing protein 3), all of which were attenuated by ruscogenin (p < 0.05). Conclusion: Ruscogenin alleviates PA-induced endothelial cell inflammation via TXNIP/NLRP3 pathway, thereby providing an insight into new therapeutic strategies to treat cardiovascular diseases. Keywords: Ruscogenin, Palmitic acid, Endothelial cells, Inflammation, TXNIP, NLRP3, Cardiovascular disease

Energy stable and maximum bound principle preserving schemes for the Q-tensor flow of liquid crystals

In this paper, we propose two efficient fully-discrete schemes for Q-tensor flow of liquid crystals by using the first- and second-order stabilized exponential scalar auxiliary variable (sESAV) approach in time and the finite difference method for spatial discretization. The modified discrete energy dissipation laws are unconditionally satisfied for both two constructed schemes. A particular feature is that, for two-dimensional (2D) and a kind of three-dimensional (3D) Q-tensor flows, the unconditional maximum-bound-principle (MBP) preservation of the constructed first-order scheme is successfully established, and the proposed second-order scheme preserves the discrete MBP property with a mild restriction on the time-step sizes. Furthermore, we rigorously derive the corresponding error estimates for the fully-discrete second-order schemes by using the built-in stability results. Finally, various numerical examples validating the theoretical results, such as the orientation of liquid crystal in 2D and 3D, are presented for the constructed schemes

Layer-by-Layer Self-Assembled Graphene Multilayer Films via Covalent Bonds for Supercapacitor Electrodes

To maximize the utilization of its single-atom thin nature, a facile scheme to fabricate graphene multilayer films via a layer-by-layer self-assembled process was presented. The structure of multilayer films was constructed by covalently bonding graphene oxide (GO) using p-phenylenediamine (PPD) as a covalent cross-linking agent. The assembly process was confirmed to be repeatable and the structure was stable. With the π-π conjugated structure and a large number of spaces in the framework, the graphene multilayer films exhibited excellent electrochemical performance. The uniform ultrathin electrode exhibited a capacitance of 41.71 μF/cm2 at a discharge current of 0.1 μA/cm2, and displayed excellent stability of 88.9 % after 1000 charge-discharge cycles