Exploring English self-concept and investment of successful EFL learners from a Chinese secondary school

Academic self-concept, a central psychological construct that powerfully explains learners’ varied motivations and learning behaviors, needs to be further explored to deepen our understanding of language learner psychology. Drawing on self-reported learning histories, this study investigates the English self-concept of successful English as a foreign language (EFL) learners and their mediated learning behaviors from the theoretical lens of personal investment theory (Maehr & Braskamp, 1986). Data were collected from 12 students at a key secondary school in Shanghai using retrospective narratives and semi-structured interviews. The analysis revealed three categories of cognitive and affective characteristics in the learners’ English self-concept and the corresponding investment features with subtle differences identified. Participants espoused average to high competency beliefs and moderate to strong positive affect toward English learning, nurtured by positive self-beliefs such as interest and self-efficacy formed through early English learning experience. Their sustainable, targeted, and resilient investment in English learning was also underpinned by the perception of mastery and performance goals appropriately afforded by teachers, parents, peers, or the school. Practical implications for parents and educators are discussed in terms of what they can do to help learners build positive self-perceptions as EFL learners

Analytical simulation of the cantilever-type energy harvester

This article describes an analytical model of the cantilever-type energy harvester based on Euler–Bernoulli’s beam theory. Starting from the Hamiltonian form of total energy equation, the bending mode shapes and electromechanical dynamic equations are derived. By solving the constitutive electromechanical dynamic equation, the frequency transfer function of output voltage and power can be obtained. Through a case study of a unimorph piezoelectric energy harvester, this analytical modeling method has been validated by the finite element method

Analytical Modeling of a Doubly Clamped Flexible Piezoelectric Energy Harvester with Axial Excitation and Its Experimental Characterization

With the rapid development of wearable electronics, novel power solutions are required to adapt to flexible surfaces for widespread applications, thus flexible energy harvesters have been extensively studied for their flexibility and stretchability. However, poor power output and insufficient sensitivity to environmental changes limit its widespread application in engineering practice. A doubly clamped flexible piezoelectric energy harvester (FPEH) with axial excitation is therefore proposed for higher power output in a low-frequency vibration environment. Combining the Euler–Bernoulli beam theory and the D’Alembert principle, the differential dynamic equation of the doubly clamped energy harvester is derived, in which the excitation mode of axial load with pre-deformation is considered. A numerical solution of voltage amplitude and average power is obtained using the Rayleigh–Ritz method. Output power of 22.5 μW at 27.1 Hz, with the optimal load resistance being 1 MΩ, is determined by the frequency sweeping analysis. In order to power electronic devices, the converted alternating electric energy should be rectified into direct current energy. By connecting to the MDA2500 standard rectified electric bridge, a rectified DC output voltage across the 1 MΩ load resistor is characterized to be 2.39 V. For further validation of the mechanical-electrical dynamical model of the doubly clamped flexible piezoelectric energy harvester, its output performances, including both its frequency response and resistance load matching performances, are experimentally characterized. From the experimental results, the maximum output power is 1.38 μW, with a load resistance of 5.7 MΩ at 27 Hz, and the rectified DC output voltage reaches 1.84 V, which shows coincidence with simulation results and is proved to be sufficient for powering LED electronics

Performance Analysis of Magnetostrictive Cantilever Beam with Modeling

A magnetostrictive cantilever beam model is established by combining an energy-based constitutive magnetostrictive model with the classical Euler-Bernoulli beam theory constitutive relations that describe the material behavior are based on energy minimization techniques. We use the saturation magnetization, the magnetostrictive constant and the 4th and 6th order anisotropy constants to calculate the Zeeman, stress-induced anisotropy and magnetocrystalline anisotropy energies per unit volume. The stress of the magnetostrictive cantilever beam is solved by classical beam theory. Experiments and simulations are conducted to study performance of the cantilever. The results demonstrated the sensing is primarily due to the dominating effect of compression over tension. A critical bias magnetic field is required below which the magnetostrictive sensing cannot be observed under bending

Ион-парная ВЭЖХ производных пиримидина и пурина

ПИРИМИДИНЫГЕТЕРОЦИКЛИЧЕСКИЕ СОЕДИНЕНИЯ ОДНОКОЛЬЦЕВЫЕПУРИНЫГЕТЕРОЦИКЛИЧЕСКИЕ СОЕДИНЕНИЯ ДВУХКОЛЬЦЕВЫЕХРОМАТОГРАФИЯ ЖИДКОСТНАЯ ВЫСОКОГО ДАВЛЕНИЯХРОМАТОГРАФИЯ ИОНООБМЕННАЯДНКРНКПРОТИВООПУХОЛЕВЫЕ СРЕДСТВАПРОТИВОВИРУСНЫЕ СРЕДСТВ

Hand grip strength should be normalized by weight not height for eliminating the influence of individual differences: Findings from a cross-sectional study of 1,511 healthy undergraduates

BackgroundHand grip strength (HGS) is a fast, useful, and inexpensive outcome predictor of nutritional status and muscular function assessment. Numerous demographic and anthropometric factors were reported to be associated with HGS, while which one or several factors produce greater variations in HGS has not been discussed in detail. This is important for answering how should HGS be normalized for eliminating the influence of individual differences in clinical practice.AimsTo compare the contribution of age, sex, height, weight, and forearm circumference (FCF) to variations in HGS based on a large-scale sample.MethodsWe enrolled 1,511 healthy undergraduate students aged 18–23 years. Age, weight, height, and sex were obtained. HGS was measured using a digital hand dynamometer, and FCF was measured at the point of greatest circumference using a soft ruler in both hands. Pearson’s or Spearman’s correlation coefficients were calculated with data of women and men separated and mixed for comparison. Partial correlation analysis and multivariate linear regression were used to compare the effect of variables on HGS.ResultsAnalysis results confirmed the correlates of higher HGS include higher height, heavier weight, being men and dominant hand, and larger FCF. The correlation between HGS and FCF was the highest, and the bivariate correlation coefficient between weight and HGS was largerata of women and men were mixed, than that between height and HGS. When data of women and men were mixed, there were moderate correlations between HGS and height and weight (r = 0.633∼0.682). However, when data were separated, there were weak correlations (r = 0.246∼0.391). Notably, partial correlation analysis revealed no significant correlation between height and HGS after eliminating the weight effect, while the correlation between weight and HGS was still significant after eliminating the height effect. Multivariate linear regression analyses revealed sex was the most significant contributor to the variation in HGS (Beta = –0.541 and –0.527), followed by weight (Beta = 0.243 and 0.261) and height (Beta = 0.102 and 0.103).ConclusionHGS and FCF reference values of healthy college students were provided. Weight was more correlate with hand grip strength, at least among the healthy undergraduates.Clinical trial registrationhttp://www.chictr.org.cn/showproj.aspx?proj=165914, identifier ChiCTR2200058586

The Use of Integrative Therapies in Patients with Amyotrophic Lateral Sclerosis in Shanghai, China

Objective. To investigate the current use of integrative therapies (IT) in the treatment of patients with amyotrophic lateral sclerosis (ALS). Methods. A cross-sectional, multicenter clinical epidemiological survey was conducted in 12 hospitals in Shanghai. We investigated the type and frequency of IT use and determined whether the use of IT correlated with demographic, social, or disease-specific characteristics in our patient population. Results. A total of 231 (89.5%) of 258 patients with ALS were eligible for the study and 229 (99% of all) of 231 reported the use of at least one IT for the treatment of ALS. Vitamins and Chinese herb decoctions, Chinese herb compounds, massage therapy, and acupuncture were the 5 most commonly used therapies. There was a strong association between education level, income, and use of IT. A household income of more than 75,000 RMB ($49,995) correlated with multiple IT use, and married patients used IT more often than single individuals. The main reasons for using IT were to treat weakness and fatigue, muscle atrophy, the development of ALS, depression, insomnia, limb pain or numbness, and side effects associated with Riluzole. Conclusion. The use of IT is common in patients with ALS in Shanghai. Vitamins and TCM are the most used additional therapies and the widespread and largely unexamined use of IT for ALS requires more attention

Preparation and Characterization of Modified Polycarbonate/ABS Blends

In this study, the polycarbonate (PC) was blended with styrene-based thermoplastics, including acrylonitrile-butadiene-styrene (ABS), acrylonitrile-styrene-acrylate (ASA), or styrene-butadiene-styrene (SBS) with different mass ratios. Mechanical tests indicated that the appropriate blending could result in good compatibility, and specific improved mechanical strengths.</p