788 research outputs found
SOCIO-ECONOMIC DRIVING FORCES OF LAND USE CHANGE IN HANOI URBAN FRINGE, CASE STUDY IN THANH TRI DISTRICT
Joint Research on Environmental Science and Technology for the Eart
EDMODO USE IN ESP WRITING: STUDENTS’ PERCEPTIONS
A growing body of literature has examined the nature of blended learning and its effects on language teaching and learning, including the use of Edmodo to promote student writing. However, this type of integration of face-to-face instruction and online learning remains relatively new for EFL contexts. Also, teaching writing at the Vietnamese contexts, particularly in the ESP tertiary education, is still largely dependent on conventional way. This paper therefore reports students’ perceptions about Edmodo use in writing classes at a Vietnamese university. This paper draws on data collected as part of a larger mixed methods project including tests and interviews over a fifteen-week semester of an ESP writing class. In this paper, the focus is the data from interviews, which explored how students perceived the effects of Edmodo use in their writing learning process. The findings indicate students’ positive perceptions about this supportive learning delivery method in writing classes. Implications for teachers and school administrators with regard to practical applications of Edmodo as a potential tool are also discussed. Article visualizations
USING AUTHENTIC MATERIALS IN TEACHING SPEAKING TO GRADE 10 STUDENTS: TEACHERS’ PERCEPTIONS AND PRACTICES
Authentic materials are considered as a beneficial tool for teachers and students in teaching speaking English as a foreign language. Speaking is one of the most significant skills for EFL students to communicate with other peers. It is also important for tertiary students in the Vietnamese context. However, a few studies about the relationship between authentic materials and speaking ability were conducted in Vietnamese high school contexts. Therefore, the current study aimed to find out high school teachers’ perceptions and practices of using authentic materials in teaching English speaking to Grade 10 students in a Vietnamese context. Data collected in this study include questionnaire and semi-structured interviews. Participants in this study were seventy-seven high school teachers in five provinces in the Mekong delta. Findings from this study reveal that teachers had positive perceptions of using authentic materials in teaching English speaking to Grade 10 students. Pedagogical implications for teachers and school administrators are also made. Article visualizations
Linear transformation models for censored data under truncation
In many observational cohort studies, a pair of correlated event times are usually observed for each individual. This paper develops a new approach for the semiparametric linear transformation model to handle the bivariate survival data under both truncation and censoring. By incorporating truncation, the potential referral bias in practice is taken into account. A class of generalised estimating equations are proposed to obtain unbiased estimates of the regression parameters. Large sample properties of the proposed estimator are provided. Simulation studies under different scenarios and analyses of real-world datasets are conducted to assess the performance of the proposed estimator
Intrinsic antiferromagnetic topological insulator and axion state in V2WS4
Intrinsic magnetic topological insulators offers an ideal platform to explore
exotic topological phenomena, such as axion electrodynamics, quantum anomalous
Hall (QAH) effect and Majorana edge modes. However, these emerging new physical
effects have rarely been experimentally observed due to the limited choice of
suitable materials. Here, we predict the van der Waals layered VWS and
its related materials show intralayer ferromagnetic and interlayer
antiferromagnetic exchange interactions. We find extremely rich magnetic
topological states in VWS, including an antiferromagnetic topological
insulator, the axion state with the long-sought quantized topological
magnetoelectric effect, three-dimensional QAH state, as well as a collection of
QAH insulators and intrinsic axion insulators in odd- and even-layer films,
respectively. Remarkably, the N\'eel temperature of VWS is predicted to
be much higher than that of MnBiTe. These interesting predictions, if
realized experimentally, could greatly promote the topological quantum physics
research and application.Comment: 7 pages, 4 figure
Characterization of the Complete Mitochondrial Genomes of Cnaphalocrocis medinalis and Chilo suppressalis (Lepidoptera: Pyralidae)
The complete mitochondrial genomes (mitogenomes) of Cnaphalocrocis medinalis and Chilo suppressalis (Lepidoptera: Pyralidae) were determined and analyzed. The circular genomes were 15,388 bp long for C. medinalis and 15,395 bp long for C. suppressalis. Both mitogenomes contained 37 genes, with gene order similar to that of other lepidopterans. Notably, 12 protein-coding genes (PCGs) utilized the standard ATN, but the cox1 gene used CGA as the initiation codon; the cox1, cox2, and nad4 genes in the two mitogenomes had the truncated termination codons T, T, and TA, respectively, but the nad5 gene was found to use T as the termination codon only in the C. medinalis mitogenome. Additionally, the codon distribution and Relative Synonymous Codon Usage of the 13 PCGs in the C. medinalis mitogenome were very different from those in other pyralid moth mitogenomes. Most of the tRNA genes had typical cloverleaf secondary structures. However, the dihydrouridine (DHU) arm of the trnS1(AGN) gene did not form a stable stem-loop structure. Forty-nine helices in six domains, and 33 helices in three domains were present in the secondary structures of the rrnL and rrnS genes of the two mitogenomes, respectively. There were four major intergenic spacers, except for the A+T-rich region, spanning at least 12 bp in the two mitogenomes. The A+T-rich region contained an 'ATAGT(A)'-like motif followed by a poly-T stretch in the two mitogenomes. In addition, there were a potential stem-loop structure, a duplicated 25-bp repeat element, and a microsatellite '(TA)13' observed in the A+T-rich region of the C. medinalis mitogenome. A poly-T motif, a duplicated 31-bp repeat element, and a 19-bp triplication were found in the C. suppressalis mitogenome. However, there are many differences in the A+T-rich regions between the C. suppressalis mitogenome sequence in the present study and previous reports. Finally, the phylogenetic relationships of these insects were reconstructed based on amino acid sequences of mitochondrial 13 PCGs using Bayesian inference and maximum likelihood methods. These molecular-based phylogenies support the traditional morphologically based view of relationships within the Pyralidae
Impact of Sucrose Addition on the Physiochemical Properties and Volatile Compounds of “Shuangyou” Red Wines
“Shuangyou,” a Vitis amurensis Rupr. variety, is widely cultivated in northeastern and western China. Its berries have high acidity and low sugar content. In this study, different proportions of sucrose were added to the must samples during fermentation to investigate the effect of sugar on the physicochemical properties and volatile compounds of “Shuangyou” wines. The addition of sucrose significantly improved yeast growth and alcohol production, altered the color qualities, and slightly decreased titratable acidity during fermentation. The highest tested proportion of added sucrose resulted in the highest maximum yeast counts and final ethanol concentrations. Moreover, 37 volatile compounds (esters, alcohols, fatty acids, ketones, and aldehydes) were identified and quantified by solid-phase microextraction with gas chromatography-mass spectrometry. The concentrations of these compounds were correlated with the addition of sucrose. Furthermore, the addition of 100 g/L sucrose was sufficient for improving the concentrations of the aromatic compounds. The increase in ester, alcohol, and fatty acid concentration led to a positive OAVs impact (odor activity value > 1) at the end of fermentation
Waiting Endurance Time Estimation of Electric Two-Wheelers at Signalized Intersections
The paper proposed a model for estimating waiting endurance times of electric two-wheelers at signalized intersections using survival analysis method. Waiting duration times were collected by video cameras and they were assigned as censored and uncensored data to distinguish between normal crossing and red-light running behavior. A Cox proportional hazard model was introduced, and variables revealing personal characteristics and traffic conditions were defined as covariates to describe the effects of internal and external factors. Empirical results show that riders do not want to wait too long to cross intersections. As signal waiting time increases, electric two-wheelers get impatient and violate the traffic signal. There are 12.8% of electric two-wheelers with negligible wait time. 25.0% of electric two-wheelers are generally nonrisk takers who can obey the traffic rules after waiting for 100 seconds. Half of electric two-wheelers cannot endure 49.0 seconds or longer at red-light phase. Red phase time, motor vehicle volume, and conformity behavior have important effects on riders’ waiting times. Waiting endurance times would decrease with the longer red-phase time, the lower traffic volume, or the bigger number of other riders who run against the red light. The proposed model may be applicable in the design, management and control of signalized intersections in other developing cities
(E)-2-(2H-Benzotriazol-2-yl)-4-methyl-6-(phenyliminomethyl)phenol
In the title compound, C20H16N4O, the non-H atoms of the benzotriazole ring system and those of the methylphenol group are essentially coplanar, with an r.m.s. deviation of 0.004 (2) Å. The mean plane of these atoms forms a dihedral angle of 60.9 (2)° with the phenyl ring. There is an intramolecular O—H⋯N hydrogen bond between the phenol and benzotriazole groups
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