Key Issues in Second Language Acquisition since the 1990s

The research field of the second language acquisition has been increasingly widened in recent years, and emerged various kinds of new theories. This thesis summarizes foreign and domestic researches’ key issues in this field since the 1990s according to theoretical framework of the second language research, then sorts out relative achievements from respective points of sociocutural theory; input, interaction and output in SLA; learner differences; external elements of learners, tacit knowledge and explicit knowledge and universal grammar and interlanguage representations, and looks into the future development, so as to make domestic learners better understand the current researches of this field and increase the general level of our foreign language education and teaching

Budgeting and Its Effect on the Financial Performance of Listed Manufacturing Firms: Evidence from Manufacturing Firms Listed on Ghana Stock Exchange

Organizations in both developed and developing countries face high competitions in the business sector. It is essential that businesses that want to remain competitive develop the desire of identifying the role of budgeting and its effect on their financial performance. In this regard, this study explored the role of budgeting and its effect on financial performance of listed manufacturing firms on the Ghana Stock Exchange as a case study. Specifically, the study sought to examine the role of budgeting and to analyze the impact of budgeting on the financial performance of these firms. Both cross-sectional and convenient sampling techniques were used to select fifty-one (51) respondents as the sample size of the study. Questionnaires were used to obtain data from the respondents. The correlation matrix was used to establish a positive relationship between budgeting and financial performance. The study discovered that budgeting plays imperative roles in the financial performance of listed manufacturing firms. The study again unveiled that there is a strong positive correlation between budgeting and financial performance. The study also concludes that planning; monitoring and control; coordination and evaluation plays a vital role and has a positive effect on the financial performance of manufacturing firms. The study recommends that managers must produce comprehensive budgetary plans to enable the employment of long-term plans. Annual budgeting review must also be incorporated permanently to enable the manufacturing firms to identify key financial indicators for their business and how and when to monitor them and to plan for future operations, refine existing strategic plans and considers how they can respond to current competitions. Keywords: Budgeting, Financial Performance, Manufacturing Firms, Ghana Stock Exchang

The impact of e-commerce on environmental sustainability targets in selected European countries

E-commerce plays a crucial role in the digital economy. E-commerce can reduce costs and boost economic growth. Therefore, the global rate of E-commerce is increasing very fast, which has implications for the digital economy. This study analyses the impact of e-commerce on environmental sustainability. The empirical analysis employed OLS, 2SLS, GMM, and panel quantile regression methods using panel data of 10 European economies spanning over 2002–2019. Carbon emissions and GHG emissions measure environmental sustainability. The results from OLS, 2SLS and GMM show that e-commerce negatively impacts carbon emissions. The panel quantile regression results also show that e-commerce negatively impacts carbon emissions at the middle and higher quantiles. This study recommends that environmental sustainability programs pay attention to policies encouraging e-commerce

Impaction of spray droplets on leaves: influence of formulation and leaf character on shatter, bounce and adhesion

This paper combines experimental data with simple mathematical models to investigate the influence of spray formulation type and leaf character (wettability) on shatter, bounce and adhesion of droplets impacting with cotton, rice and wheat leaves. Impaction criteria that allow for different angles of the leaf surface and the droplet impact trajectory are presented; their predictions are based on whether combinations of droplet size and velocity lie above or below bounce and shatter boundaries. In the experimental component, real leaves are used, with all their inherent natural variability. Further, commercial agricultural spray nozzles are employed, resulting in a range of droplet characteristics. Given this natural variability, there is broad agreement between the data and predictions. As predicted, the shatter of droplets was found to increase as droplet size and velocity increased, and the surface became harder to wet. Bouncing of droplets occurred most frequently on hard to wet surfaces with high surface tension mixtures. On the other hand, a number of small droplets with low impact velocity were observed to bounce when predicted to lie well within the adhering regime. We believe this discrepancy between the predictions and experimental data could be due to air layer effects that were not taken into account in the current bounce equations. Other discrepancies between experiment and theory are thought to be due to the current assumption of a dry impact surface, whereas, in practice, the leaf surfaces became increasingly covered with fluid throughout the spray test runs.Comment: 19 pages, 6 figures, accepted for publication by Experiments in Fluid

Lattice strain effects on the optical properties of MoS2 nanosheets.

"Strain engineering" in functional materials has been widely explored to tailor the physical properties of electronic materials and improve their electrical and/or optical properties. Here, we exploit both in plane and out of plane uniaxial tensile strains in MoS2 to modulate its band gap and engineer its optical properties. We utilize X-ray diffraction and cross-sectional transmission electron microscopy to quantify the strains in the as-synthesized MoS2 nanosheets and apply measured shifts of Raman-active modes to confirm lattice strain modification of both the out-of-plane and in-plane phonon vibrations of the MoS2 nanosheets. The induced band gap evolution due to in-plane and out-of-plane tensile stresses is validated by photoluminescence (PL) measurements, promising a potential route for unprecedented manipulation of the physical, electrical and optical properties of MoS2

Influence of core competence on voice behavior of clinical nurses : a multicenter cross-sectional study

Background: Voice behavior, referred to as a positive guarantee for organizational development, is influenced by several kinds of individual, collective and organizational features. However, the impact of individual competence on voice behavior is unclear. The aim of the present study was to investigate the status quo of core competence and voice behavior of clinical nurses and explore the impact of core competence on nurses’ voice behavior. Methods: A multicenter cross-sectional survey. A total of 1717 nurses were recruited from nine tertiary and secondary hospitals between March and June 2019. An online questionnaire, including socio-demographic variables, employee voice behavior scale and competence inventory for registered nurses, was used to investigate prohibitive and promotive voice behavior and core competence of clinical nurses. Pearson correlation and hierarchical multiple regression were performed in the data analysis. Results: The mean score for prohibitive and promotive voice behavior of nurses were 3.46 (SD 0.77) and 3.46 (SD 0.88), respectively. The mean score for core competence was 2.46 (SD 0.77). Critical thinking/research aptitude was the most important predictor for both prohibitive and promotive voice behavior (each p < 0.05), but its influence on promotive voice behavior was greater (p < 0.05). Leadership was another significant predictor for prohibitive voice behavior (p < 0.05). Legal/ethical practice, teaching-coaching, professional development and shift work were other predictors for promotive voice behavior (each p < 0.05). Conclusion: Clinical nurses experience modest levels of prohibitive and promotive voice behavior and their core competence is moderate. Core competence, especially critical thinking/research aptitude, impacts significantly on voice behavior of clinical nurses. Cultivating nurses’ core competence could positively increase their voice behavior for organizational development. © 2021 Guo et al

Microbial Succession and Nitrogen Cycling in Cultured Biofilms as Affected by the Inorganic Nitrogen Availability

Biofilms play important roles in nutrients and energy cycling in aquatic ecosystems. We hypothesized that as eutrophication could change phytoplankton community and decrease phytoplankton diversity, ambient inorganic nitrogen level will affect the microbial community and diversity of biofilms and the roles of biofilms in nutrient cycling. Biofilms were cultured using a flow incubator either with replete inorganic nitrogen (N-rep) or without exogenous inorganic nitrogen supply (N-def). The results showed that the biomass and nitrogen and phosphorous accumulation of biofilms were limited by N deficiency; however, as expected, the N-def biofilms had significantly higher microbial diversity than that of N-rep biofilms. The microbial community of biofilms shifted in composition and abundance in response to ambient inorganic nitrogen level. For example, as compared between the N-def and the N-rep biofilms, the former consisted of more diazotrophs, while the latter consisted of more denitrifying bacteria. As a result of the shift of the functional microbial community, the N concentration of N-rep medium kept decreasing, while that of N-def medium showed an increasing trend in the late stage. This indicates that biofilms can serve as the source or the sink of nitrogen in aquatic ecosystems, and it depends on the inorganic nitrogen availability.</p