Towards Lessening Learners’Aversive Emotions and Promoting Their Mental Health:Developing and Validating a Measurement of English Speaking Demotivation in the Chinese EFL Context

While a plethora of studies has been conducted to explore demotivation and its impact on mental health in second language(L2)education,scanty research focuses on demotivation in L2 speaking learning.Particularly,little research explores the measures to quantify L2 speaking demotivation.The present two-phase study attempts to develop and validate an English Speaking Demotivation Scale(ESDS).To this end,an independent sample of 207 Chinese tertiary learners of English as a Foreign Language(EFL)participated in the development phase,and another group of 188 Chinese EFL learners was recruited for the validation of the scale.Exploratory Factor Analysis(EFA)and Confirmatory Factor Analysis(CFA)were employed to determine the factor structure of the scale.The EFA results revealed a six-factor solution with Teacher-related Factors in Learning Spoken English(TFLSE),Interest and Valence in Learning Spoken English(IVLSE),Self-efficacy in Learning Spoken English(SELSE),Negative Peer Influence in Learning Spoken English(NPILSE),Undesirable Environment for Learning Spoken English(UELSE),and Negative Influence of Assessment and Learning Materials in speaking class(NIALM).In the validation phase,Confirmatory Factor Analysis(CFA)was performed to validate the internal structure of the scale.The CFA results showed that the model fits the data well.Overall,the ESDS is a robust and trustworthy psychometric tool that could be utilized to examine L2 speaking demotivation.Implications for diminishing EFL learners’demotivation,lessening their aversive emotions and promoting their mental health are also discussed.

Constructing Bidirectional Fluorine-Rich Electrode/Electrolyte Interphase Via Solvent Redistribution toward Long-Term Sodium Battery

The high concentration electrolytes with specific solvation structure could passivate the electrodes to prolong battery cycle life but at the expense of increased cost,which limits the wide application in commercialization.The regular concentration(1_(M))electrolytes with suitable properties(viscosity,ionic conductivity,etc.)are cost-guaranteed,but undesired reactions would always occur and lead to battery degradation during long cycles.To promote the long-term cycle stability in a cost-effective way,this work constructs bidirectional fluorine-rich electrode/electrolyte interphase(EEI)by redistribution of solvents and electrochemical induction.The fluorinated effect with reasonable zoning planning restricts morphological disintegration,meanwhile,forms spatial confinement on cathode.In particular,the obtained cathode electrolyte interphase(CEI)gets the ample ability of Na^(+)transport,which benefits from the fluorinated organics arranged in the epitaxy and the hemi-carbonate content acting on the thickness.Thus,the electrochemical long cycling performance of F-NVPOFⅡF-CC full cells is significantly enhanced(the decay rate at 1 C per cycle is as low as 0.01%).Such a fluorine-rich EEI engineering is expected to take transitional layers against the degradation of cells and make ultra-long cycle batteries possible.

The transaction behavior of cryptocurrency and electricity consumption

Rapidly increasing cryptocurrency prices have encouraged cryptocurrency miners to participate in cryptocurrency production,increasing network hashrates and electricity consumption.Growth in network hashrates has further crowded out small cryptocurrency investors owing to the heightened costs of mining hardware and electricity.These changes prompt cryptocurrency miners to become new investors,leading to cryptocurrency price increases.The potential bidirectional relationship between cryptocurrency price and electricity consumption remains unidentified.Hence,this research thus utilizes July 312015–July 122019 data from 13 cryptocurrencies to investigate the short-and long-run causal effects between cryptocurrency transaction and electricity consumption.Particularly,we consider structural breaks induced by external shocks through stationary analysis and comovement relationships.Over the examined time period,we found that the series of cryptocurrency transaction and electricity consumption gradually returns to mean convergence after undergoing daily shocks,with prices trending together with hashrates.Transaction fluctuations exert both a temporary effect and permanent influence on electricity consumption.Therefore,owing to the computational power deployed to wherever high profit is found,transactions are vital determinants of electricity consumption.

First-Principles Investigation of Energetics and Electronic Structures of Ni and Sc Co-Doped MgH2

First-principles calculations were used to study the energetics and electronic structures of Ni and Sc co-doped MgH2 system. The preferential positions for dopants were determined by the minimal total electronic energy. The results of formation enthalpy indicate that Ni and Sc co-doped MgH2 system is more stable than Ni single-doped system. The hydrogen desorption enthalpies of these two hydrides are investigated. Ni and Sc co-doping can improve the dehydrogenation properties of MgH2. The lowest hydrogen desorption enthalpy of 0.30 eV appears in co-doped system, which is significantly lower than that of Ni doping. The electronic structure analysis illustrates that the hybridization of dopants with Mg and H atom together weakens the Mg-H interaction. And the Mg-H bonds are more susceptible to dissociate by Ni and Sc co-doping because of the reduced magnitude of Mg-H hybridization peaks. These behaviors effectively improve the dehydrogenation properties of Ni and Sc co-doped cases.

紫外光诱导1-甲基-2-苯基吲哚啉的合成与表征——国家自然科学基金项目转化的综合型微量有机化学实验

光化学反应是近年来备受青睐的有机合成策略之一,以吲哚啉杂环为骨架的化合物具有多样生物活性,如抗真菌、灭杀害虫、治疗代谢疾病药物等。基于课题组在自然科学基金项目研究中开创的一种绿色光化学吲哚啉合成方法,将部分研究成果设计转化为一个环保型的微量有机化学实验,即在光照下引发苯乙烯和N-甲基邻碘苯胺发生[3+2]自由基环合反应合成1-甲基-2-苯基吲哚啉。将前沿科研成果引入本科生实验教学,既丰富了实验教学内容,又提高了实验教学层次,同时也有助于学生树立“绿色化学”理念,拓宽知识体系。

Enhanced High-Temperature Cycling Stability of LiMn<SUB>2</SUB>O<SUB>4</SUB>by LiCoO<SUB>2</SUB>Coating as Cathode Material for Lithium Ion Batteries

LiCoO2 surface layer is proposed and prepared through sol-gel method. The physical and electrochemical performances of pristine LiMn2O4 and LiCoO2-coated LiMn2O4 cathode materials were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, electrochemical measurements respectively. Comparing with the pristine LiMn2O4, the LiCoO2- coated LiMn2O4 phase significantly improved cycling stability, especially at 55°C. Additionally, the thermal safety of LiMn2O4 is greatly enhanced after being coated by LiCoO2. ICP-AES measurement, structural analysis, and impedance experiments indicate that the improved electrochemical property of LiCoO2-coated LiMn2O4 should be attributed to the alleviated dissolution loss of manganese, strengthened structural stability.

Rail fastener defect inspection method for multi railways based on machine vision

Purpose–This research aims to improve the performance of rail fastener defect inspection method for multi railways,to effectively ensure the safety of railway operation.Design/methodology/approach–Firstly,a fastener region location method based on online learning strategy was proposed,which can locate fastener regions according to the prior knowledge of track image and template matching method.Online learning strategy is used to update the template library dynamically,so that the method not only can locate fastener regions in the track images of multi railways,but also can automatically collect and annotate fastener samples.Secondly,a fastener defect recognition method based on deep convolutional neural network was proposed.The structure of recognition network was designed according to the smaller size and the relatively single content of the fastener region.The data augmentation method based on the sample random sorting strategy is adopted to reduce the impact of the imbalance of sample size on recognition performance.Findings–Test verification of the proposed method is conducted based on the rail fastener datasets of multi railways.Specifically,fastener location module has achieved an average detection rate of 99.36%,and fastener defect recognition module has achieved an average precision of 96.82%.Originality/value–The proposed method can accurately locate fastener regions and identify fastener defect in the track images of different railways,which has high reliability and strong adaptability to multi railways.

Fabrication of super-elastic graphene aerogels by ambient pressure drying and application to adsorption of oils

Three-dimensional graphene-based aerogels have promising applications in oil adsorption and environmental restoration.However,current research of graphene-based aerogels is often hindered by high preparation cost,poor mechanical properties and low recycling efficiency.Here,superelastic graphene aerogel(SGA)was prepared through one-step freezing and twice hydrothermal reduction followed by drying under ambient pressure.The simple atmospheric drying provides a possibility for large-scale preparation of high performance graphene-based aerogels.The prepared SGA not only has the ability of highly repeatable compression rebound,but also exhibits excellent oil adsorption performance.And the overall performance of SGA is better than most of graphenebased aerogels prepared by freeze drying.After the SGA was cyclically compressed with 70%strain for 300 times,it can return to the original shape and height substantially.SGA retained about 90%of the initial adsorption capacity after 50 cycles of adsorption and compression regeneration for cyclohexane.

Enhanced High-Temperature Cycling Stability of LiMn₂O₄by Coating LiNi_0.5Mn_1.5O₄

To enhance the electrochemical performances of LiMn2O4 at elevated temperature (55°C), we proposed a sol-gel method to synthesize LiNi0.5Mn1.5O4 modified LiMn2O4. The physical and electrochemical performances of pristine and LiNi0.5Mn1.5O4-coated LiMn2O4 cathode materials were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and electrochemical measurements, respectively. The results indicated that about 4-5 nm thick layer of LiNi0.5Mn1.5O4 was formed on the surface of the LiMn2O4 powders. The modified LiMn2O4 exhibited excellent storage performance at 55&degC compared to the pristine one, which was attributed to the suppression of electrolyte decomposition and the reduction of Mn dissolution.

First-Principles Investigation of the Effect of M-Doped (M = Zr, Hf) TiCoSb Half-Heusler Thermoelectric Material

The M-doping (M = Zr, Hf) effects on the electronic structures and thermoelectric performance of TiCoSb were studied by first-principles calculations. The band structure analysis shows that substituting Ti with M does not change the band structures of these systems significantly. Most of the M-doped systems have a lower band gap value than that of TiCoSb;especially Ti0.5Zr0.5CoSb has the lowest energy band gap value of 0.971 eV. Besides, the amplitudes of the density of states in the region of the valence bands for M-doped systems show a similar but slightly higher value than TiCoSb. Those suggest that these compounds could have better thermoelectric performance than TiCoSb. The phonon dispersion relations show that the larger mass of Zr/Hf with respect to Ti lowers the optical modes and induces mixing with the acoustic branches. Our calculations offer a valuable insight on how to characterize complicated crystal structures of thermoelectric materials and optimize the material composition.

Quantitative analysis of peripheral retinal defocus checked by multispectral refraction topography in myopia among youth

To the Editor:Myopia is the most common refractive error and a major reason for visual impairment.The prevalence of myopia is increasing worldwide and is particularly high in Asian countries.It affects 80%to 90%of young people in some parts of East and Southeast Asia.[1]High myopia,which is more than-6.00 D,increases the possibility of visual impairment due to ocular complications caused by extended axial length(AL),which include posterior uveioma,retinal detachment,choroidal new vascularization,and so on.Thus,the prevention and control of myopia is a difficult and important public health issue that has attracted great attention from the World Health Organization and the Chinese government.

Comparative study of the pathogenicity of the mosquito origin strain and duck origin strain of Tembusu virus in ducklings and three-week-old mice

Dear Editor,Duck Tembusu virus(DTMUV)is the causative agent of a new,acute and severe infectious disease in ducks(Su et al.,2011).TMUV was first isolated from Culex tritaeniorhynchus in Malaysia in 1955(Platt et al.,1975),and this strain is regarded as a reference strain.In our previous study,an infectious clone for the mosquito-derived Tembusu virus prototypical strain MM_1775(GenBank:JX477685.2)was constructed,and the rMM_1775 virus was rescued successfully(Wang et al.,2021).And the TMUV strain rCQW1 was rescued by a reverse genetic system using the viral RNAs of CQW1(GenBank:KM233707.1)(Chen et al.,2018;Guo et al.,2020),which was isolated from ducks in 2013(Zhu et al.,2015).

老挝苗佬民族关系发展变迁探析

老挝是一个多民族国家,其苗佬民族关系错综复杂,问题突出。文章在田野调查和历史文献的基础上认为,老挝苗佬民族关系经历了从依生、竞生到共生的演化路径,最终形成了互惠共生的族群互动模式。在依生阶段,其主要矛盾是能量获取与民族生存之间的矛盾;在竞生阶段,其主要矛盾是资源稀缺与民族强弱之间的矛盾,民族冲突与斗争是这一阶段的主要特征;在共生阶段,形成了“主民”和“客民”的关系,其主要矛盾是民族发展不平衡的矛盾,关注的焦点是经济协作与文化共享。如今,老挝各民族从资源争夺的竞争思维转向了和合共生的发展思维。当前的民族关系研究应该抛弃“二元对立”的理论框架,借鉴中华民族的古老智慧,采用一种关注互惠与共生的思维,强化各民族政治互信、经济协作、文化共享以及各民族交往交流交融的研究。

Van der Waals epitaxy of ultrathin crystalline PbTe nanosheets with high near-infrared photoelectric response

Lead telluride(PbTe)is one of the reliable candidates for infrared(IR)optoelectronics with optimum band-gap as well as excellent photoelectric properties.Great interests had been paid on the growth and device applications with PbTe for the development of high-performance IR photodetectors especially those working in the near-infrared regime.Although a great deal of effort had been made to prepare PbTe nanostructures for miniaturized detectors,it is difficult to synthesize high-quality two-dimensional(2D)PbTe crystals due to its rock-salt non-layered structure.Herein,a facile strategy for controllable synthesis of ultrathin crystalline PbTe nanosheets by van der Waals epitaxy is reported.With an optimized growth temperature,which determines the morphology transit from triangular pyramid islands to regular square 2D planars,PbTe nanosheets in lateral size of tens of microns with thickness down to~7 nm are achieved.Meanwhile,ultrasensitive near-infrared detectors(NIRDs)based on the as-grown 2D PbTe nanosheets have been demonstrated with an ultrahigh responsivity exceeding 3,847 A/W at the wavelength of 1,550 nm under room temperature.Our approach demonstrates that 2D PbTe nanosheets have great latent capacity of developing high-performance miniaturized IR optoelectronic devices.

A Novel Design of Hybrid Energy Storage System for Electric Vehicles

In order to provide long distance endurance and ensure the minimization of a cost function for electric vehicles,a new hybrid energy storage system for electric vehicle is designed in this paper.For the hybrid energy storage system,the paper proposes an optimal control algorithm designed using a Li-ion battery power dynamic limitation rule-based control based on the SOC of the super-capacitor.At the same time,the magnetic integration technology adding a second-order Bessel low-pass filter is introduced to DC-DC converters of electric vehicles.As a result,the size of battery is reduced,and the power quality of the hybrid energy storage system is optimized.Finally,the effectiveness of the proposed method is validated by simulation and experiment.

Bottlebrush inspired injectable hydrogel for rapid prevention of postoperative and recurrent adhesion

Postsurgical adhesion is a common clinic disease induced by surgical trauma,accompanying serious subsequent complications.Current non-surgical approaches of drugs treatment and biomaterial barrier administration only show limited prevention effects and couldn’t effectively promote peritoneum repair.Herein,inspired by bottlebrush,a novel self-fused,antifouling,and injectable hydrogel is fabricated by the free-radical polymerization in aqueous solution between the methacrylate hyaluronic acid(HA-GMA)and N-(2-hydroxypropyl)methacrylamide(HPMA)monomer without any chemical crosslinkers,termed as H-HPMA hydrogel.The H-HPMA hydrogel can be tuned to perform excellent self-fused properties and suitable abdominal metabolism time.Intriguingly,the introduction of the ultra-hydrophilic HPMA chains to the H-HPMA hydrogel affords an unprecedented antifouling capability.The HPMA chains establish a dense hydrated layer that rapidly prevents the postsurgical adhesions and recurrent adhesions after adhesiolysis in vivo.The H-HPMA hydrogel can repair the peritoneal wound of the rat model within 5 days.Furthermore,an underlying mechanism study reveals that the H-HPMA hydrogel significantly regulated the mesothelial-to-mesenchymal transition(MMT)process dominated by the TGF-β-Smad2/3 signal pathway.Thus,we developed a simple,effective,and available approach to rapidly promote peritoneum regeneration and prevent peritoneal adhesion and adhesion recurrence after adhesiolysis,offering novel design ideas for developing biomaterials to prevent peritoneal adhesion.

Construction of an Infectious Clone for Mosquito-Derived Tembusu Virus Prototypical Strain

Dear Editor,Duck Tembusu virus(DTMUV),a member of the Flavivirus genus within the Flaviviridae family,has caused huge economic losses to the poultry industry in China and even in Asia since 2010(Zhang et al.2017).The first strain of Tembusu virus(TMUV)MM_1775 was isolated from mosquitoes in 1955 in Malaysia(Platt et al.1975).DTMUV CQW1 strain(GenBank:KM233707.1)was isolated from the liver tissue of Cherry Valley ducks in southwest China in 2015(Zhu et al.2015).The positive control rCQW1 was rescued from an infectious clone that contained the full-length cDNA of CQW1.And the complete cDNA was positioned under the control of the T7 promoter elements for in vitro transcription(Chen et al.2018).The relationship between TMUV evolution and pathogenic variants has not been revealed.The fundamental reason is the lack of the in vitro operation platform for the prototypical strain genome.

Dual-labeled visual tracer system for topical drug delivery by nanoparticle-triggered P-glycoprotein silencing

Using nanoparticle-based drug delivery systems as enhancers is a robust strategy for transdermal delivery;however, the mechanisms by which these systems promote transdermal penetration are still unclear.Here, we fabricated a dual-labeled nano drug delivery system that allows discrete visualization of both the drug and the nanoparticle carrier. To comprehensively examine its potential mechanism, we investigated its effects on human epidermal keratinocyte Ha Ca T cells, including changes in cell membrane potential, intracellular Ca;concentration, and Ca;-ATPase activity. P-glycoprotein(P-gp) expression in nanoparticle-treated human dermal microvascular endothelial cells was detected by western blotting and immunofluorescence. Furthermore, the transdermal absorption and biodistribution of the dual-labeled nanoparticles were deeply investigated by skin permeability study in vitro and in vivo using fluorescence microscopy and in vivo imaging, respectively. In addition to reducing membrane potential, increasing the intracellular Ca;concentration, and decreasing Ca;-ATPase activity, our results indicate that the duallabeled nanoparticles can downregulate P-gp to promote transdermal absorption. Fluorescence and in vivo imaging visually demonstrated that the nanoparticle delivery system penetrated into the dermis through the stratum corneum. All these results indicate that this dual-labeled nano delivery system provides a new method for future in-depth visual explorations of transdermal drug delivery mechanisms.