Efficacy of Task Type and Involvement Load on EFL Learners’ Vocabulary Knowledge

Bei-Bei Xu 현대영어교육학회 2019 현대영어교육 Vol.20 No.2

This study attempted to investigate how task type and involvement load affected EFL learners’ receptive and productive lexical knowledge across time. A total of 74 participants were randomly assigned to one of four groups and each group learned 6 target words through reading with one of four form-focused tasks inducing different involvement load. The lexical gains of both receptive and productive knowledge were measured by immediate and delayed posttests. It was found that task type had a significant effect on the acquisition of L2 receptive knowledge across time. In terms of productive vocabulary knowledge, the effect of task type was only significant in the immediate test but not significant in the delayed test. The involvement load had no significant effect on the acquisition of L2 receptive and productive vocabulary knowledge across time. This result did not support the Involvement Load Hypothesis, indicating that the theory did not hold true across L2 vocabulary learning conditions and the three components of task-induced involvement, i.e., need, search and evaluation, might give no equal weight to their contributions to L2 vocabulary acquisition.

Brain Metabolic Network Redistribution in Patients with White Matter Hyperintensities on MRI Analyzed with an Individualized Index Derived from 18F-FDG-PET/MRI

Ma Jie,Hua Xu-Yun,Zheng Mou-Xiong,Wu Jia-Jia,Huo Bei-Bei,Xing Xiang-Xin,Gao Xin,Zhang Han,Xu Jian-Guang 대한영상의학회 2022 Korean Journal of Radiology Vol.23 No.10

Objective: Whether metabolic redistribution occurs in patients with white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) is unknown. This study aimed 1) to propose a measure of the brain metabolic network for an individual patient and preliminarily apply it to identify impaired metabolic networks in patients with WMHs, and 2) to explore the clinical and imaging features of metabolic redistribution in patients with WMHs. Materials and Methods: This study included 50 patients with WMHs and 70 healthy controls (HCs) who underwent 18F-fluorodeoxyglucose-positron emission tomography/MRI. Various global property parameters according to graph theory and an individual parameter of brain metabolic network called “individual contribution index” were obtained. Parameter values were compared between the WMH and HC groups. The performance of the parameters in discriminating between the two groups was assessed using the area under the receiver operating characteristic curve (AUC). The correlation between the individual contribution index and Fazekas score was assessed, and the interaction between age and individual contribution index was determined. A generalized linear model was fitted with the individual contribution index as the dependent variable and the mean standardized uptake value (SUVmean) of nodes in the whole-brain network or seven classic functional networks as independent variables to determine their association. Results: The means ± standard deviations of the individual contribution index were (0.697 ± 10.9) x 10-3 and (0.0967 ± 0.0545) x 10-3 in the WMH and HC groups, respectively (p < 0.001). The AUC of the individual contribution index was 0.864 (95% confidence interval, 0.785–0.943). A positive correlation was identified between the individual contribution index and the Fazekas scores in patients with WMHs (r = 0.57, p < 0.001). Age and individual contribution index demonstrated a significant interaction effect on the Fazekas score. A significant direct association was observed between the individual contribution index and the SUVmean of the limbic network (p < 0.001). Conclusion: The individual contribution index may demonstrate the redistribution of the brain metabolic network in patients with WMHs.

Screening and identification of Aspergillus activity against Xanthomonas oryzae pv. oryzae and analysis of antimicrobial components

Bei Jiang,Zhiying Wang,Chuxuan Xu,Weijia Liu,Donghua Jiang 한국미생물학회 2019 The journal of microbiology Vol.57 No.7

To screen for Aspergillus activity against Xanthomonas oryzae pv. oryzae and analyse the antimicrobial components involved, 60 Aspergillus spp. were isolated and purified from fruits, soil and other habitats. As-75, an Aspergillus strain that can antagonize Xanthomonas oryzae pv. oryzae, was identified based on the zone of inhibition formed during co-culture. According to morphological, ITS rDNA gene sequencing and phylogenetic tree results, the strain showed close homology to Aspergillus sclerotiorum. The biochemical characterization tests showed that the fermentation broth of strain As-75 exhibited a high capacity for environmental adaptation. The results of the antimicrobial spectrum experiments demonstrated that As-75 exhibited fairly strong antagonistic activity against five plant pathogenic fungi and six plant pathogenic bacteria in vitro. The fermentation broth of strain As-75 displayed maximum stability under fluorescent illumination at temperatures below 60°C at pH 6.5. A substance with antagonistic activity was obtained from strain As-75 via fractional extraction, silica gel column chromatography and thinlayer chromatography. Through mass spectrometry, nuclear magnetic resonance and electrospray ionization mass spectrometry (ESI-MS) analyses, the target compound was identified as (2Z)-2-butenedioic acid-2-(1-methylethenyl)-4-methyl ester; its molecular weight of 170.06 daltons and formula of C8H10O4 identify it as a novel compound. Trials of the preventative and curative effects demonstrated that compound S1 exhibited a better control efficiency than the control against rice bacterial blight. Additionally, the M1 processing method was better, and the efficiency of compound S1 in preventing rice bacterial blight in six rice varieties, TN1, IR24, ZF802, Zhonghua 11, Wuyunjing 21, and Nipponbare, was 78.3%, 77.5%, 74.2%, 75.3%, 70.9%, and 72.1%, respectively.

Monitoring of wind turbine blades for flutter instability

Chen, Bei,Hua, Xu G.,Zhang, Zi L.,Basu, Biswajit,Nielsen, Soren R.K. Techno-Press 2017 Structural monitoring and maintenance Vol.4 No.2

Classical flutter of wind turbine blades indicates a type of aeroelastic instability with fully attached boundary layer where a torsional blade mode couples to a flapwise bending mode, resulting in a mutual rapid growth of the amplitudes. In this paper the monitoring problem of onset of flutter is investigated from a detection point of view. The criterion is stated in terms of the exceeding of a defined envelope process of a specific maximum torsional vibration threshold. At a certain instant of time, a limited part of the previously measured torsional vibration signal at the tip of blade is decomposed through the Empirical Mode Decomposition (EMD) method, and the 1st Intrinsic Mode Function (IMF) is assumed to represent the response in the flutter mode. Next, an envelope time series of the indicated modal response is obtained in terms of a Hilbert transform. Finally, a flutter onset criterion is proposed, based on the indicated envelope process. The proposed online flutter monitoring method provided a practical and direct way to detect onset of flutter during operation. The algorithm has been illustrated by a 907-DOFs aeroelastic model for wind turbines, where the tower and the drive train is modelled by 7 DOFs, and each blade by means of 50 3-D Bernoulli-Euler beam elements.

Study on the Internal Pipeline Inspection Devices with Energy Acquisition Methods

Wang Ming-Xu,차인수,Wang Yue,Bei Lei,최홍준,정경환,김동묵,김봄,오승아,Ye In Cheol,유일준 한국에너지학회 2023 에너지공학 Vol.32 No.1

The pipeline conveying natural gas must be regularly inspected by the detection device, and the cracks and corrosion condition inside the pipeline should be detected. Generally, the detection device consists of three parts: drive part, detection part and energy part. Since pipeline transportation is long-distance transportation and cannot realize wired detection, the energy part needs to provide enough electric energy for the detection part to meet the energy consumption of the detection part. The method of obtaining energy for the energy part is very important. In this paper, the energy part is studied, and an efficient energy part is designed. By analyzing the change law of the positive pressure on the inner wall of the energy acquisition wheel on the pipeline, the corresponding torque and power changes are obtained when the detector moves at different speeds. Through the test platform system, the output power of the energy part at different speeds is collected, and the accuracy of the theoretical calculation is verified.

The Study for Principles and Conceptual Models of Quality Management in Virtual Enterprise

Su, Qin,Xu, Bei 한국품질경영학회 2002 The Asian Journal on Quality Vol.3 No.1

Virtual enterprise is considered as the leading enterprise paradigm of 21st century. Based on the study of a lot of literature on VE, this paper summarizes 7 hypotheses about VE. By comparing the quality management of VE with that of traditional enterprises, 2 key points on quality management of VE were drawn. Firstly, the quality management of VE is a coordinating management; secondly, the management of quality information exchange is the key part of VE's quality management. Furthermore, 5 principles that should be observed by the design of the quality management system of VE are given. Then, the concepts of VE's product module and quality task and the relationship between them are proposed. The conceptual model of the quality management of VE in manufacture process is established and explicated.

A Novel Three-Phase Four-Wire Grid-Connected Synchronverter that Mimics Synchronous Generators

Tan, Qian,Lv, Zhipeng,Xu, Bei,Jiang, Wenqian,Ai, Xin,Zhong, Qingchang The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

Voltage and frequency stability issues occur in existing centralized power system due to the high penetration of renewable energy sources, which decrease grid absorptive capacity of them. The grid-connected inverter that mimics synchronous generator characteristics with inertia characteristic is beneficial to electric power system stability. This paper proposed a novel three-phase four-wire grid-connected inverter with an independent neutral line module that mimics synchronous generators. A mathematical model of the synchronous generator and operation principles of the synchronverter are introduced. The main circuit and control parameters design procedures are also provided in detail. A 10 kW prototype is built and tested for further verification. The primary frequency modulation and primary voltage regulation characteristics of the synchronous generator are emulated and automatically adjusted by the proposed circuit, which helps to supports the grid.

A Novel Three-Phase Four-Wire Grid-Connected Synchronverter that Mimics Synchronous Generators

Qian Tan,Zhipeng Lv,Bei Xu,Wenqian Jiang,Xin Ai,Qingchang Zhong 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

Voltage and frequency stability issues occur in existing centralized power system due to the high penetration of renewable energy sources, which decrease grid absorptive capacity of them. The grid-connected inverter that mimics synchronous generator characteristics with inertia characteristic is beneficial to electric power system stability. This paper proposed a novel three-phase four-wire grid-connected inverter with an independent neutral line module that mimics synchronous generators. A mathematical model of the synchronous generator and operation principles of the synchronverter are introduced. The main circuit and control parameters design procedures are also provided in detail. A 10 ㎾ prototype is built and tested for further verification. The primary frequency modulation and primary voltage regulation characteristics of the synchronous generator are emulated and automatically adjusted by the proposed circuit, which helps to supports the grid.

Molecular design of a wide-band-gap conjugated polymer for efficient fullerene-free polymer solar cells

Liu, Delong,Yang, Bei,Jang, Bomee,Xu, Bowei,Zhang, Shaoqing,He, Chang,Woo, Han Young,Hou, Jianhui The Royal Society of Chemistry 2017 ENERGY AND ENVIRONMENTAL SCIENCE Vol.10 No.2

<P>Two p-type conjugated polymers with disparate optical and electronic properties, PB3T and PB2T, were developed and applied in fullerene-free polymer solar cells (PSCs). The photovoltaic performance of the PB3T-based PSC device processed by anisole achieved a high power conversion efficiency of 11.9% with a <I>J</I>sc of 18.8 mA cm<SUP>−2</SUP> and <I>V</I>oc of 1.00 V.</P>

Past Millennium Contrasting Hydroclimate Patterns Between Monsoonal Northern China and Arid Central Asia: a Modeling Study

Youbing Peng,Hai Cheng,Caiming Shen,Ying Xu,Naifang Bei 한국기상학회 2018 Asia-Pacific Journal of Atmospheric Sciences Vol.54 No.3

Widely distributed proxy records show that there were out-of-phase behaviors of moisture change between arid central Asia (ACA) and monsoonal northern China during the Little Ice Age (LIA) and Medieval Climate Anomaly (MCA). We examined spatial pattern differences between the MCA and LIA to identify contrasting patterns of summer precipitation variability, and to diagnose explanatory mechanisms through the analysis of a 1000-year global climate model simulation driven by natural and anthropogenic forcing. The results show that the model was able to roughly produce the general features of MCA-LIA hydroclimatic spatial differences between monsoonal northern China and ACA, with a relatively wet MCA found in monsoonal northern China and a relatively dry MCA found in ACA. A further analysis of associated circulations shows that increased summer precipitation in monsoonal northern China was caused by the strengthening of summer monsoon, while the decline in summer precipitation in ACAwas caused by an anomalous northward displacement of the subtropical westerly jet stream. Our analyses suggest that both effective solar forcing and El-Niño Southern Oscillation (ENSO) may produce these contrasting patterns of precipitation between monsoonal northern China and ACA. Due to a change in the probability of ENSO phases at the centennial time scale found in our experiments may be attributed to solar irradiances, higher effective solar irradiances during the MCA relative to those of the LIA may have been the ultimate forcing mechanism for the simulated precipitation differences between the MCA and LIA.