Mixed Mode Research Articles

Effectiveness of Gamified Cooperation and Competition in Blended Learning Environment for EFL Business Writing in TVET

This research investigated the effectiveness of gamified blended learning environments in fostering EFL writing skills among technical and vocational education and training (TVET) trainees in Saudi Arabia. It compared three distinct learning strategies achieved through gamification design in a blended delivery mode: gamified cooperation, gamified competition, and gamified cooperation-competition. Each strategy leveraged a specific category of gamification features that evoke different goal structure: cooperation, competition, or a combination of both. A quasi-experimental design with a pre-test and post-test was employed. Forty-five trainees were purposively selected and randomly assigned to three groups, each receiving instruction using a different gamified blended learning program for teaching business writing. The findings revealed significant improvement in English as a Foreign Language business writing skills for all three groups. However, a one-way ANOVA and post-hoc Tukey HSD test indicated that the gamified cooperation-competition strategy yielded the greatest improvement compared to the gamified cooperation and gamified competition strategies alone. This suggests that a combination of cooperative and competitive elements within a gamified blended learning environment might be the most effective approach for enhancing English as a Foreign Language business writing skills among Technical and Vocational Training and Education learners.

The application of 2-(3-nitrophenyl)imidazo[1,2-α]pyridine as an effective corrosion-defender for steel in acidic environment

Metal corrosion in acidic settings presents serious problems for many industrial areas. The creation of corrosion inhibitors that are efficient, long-lasting, and ecologically benign is essential. This study introduces a novel corrosion inhibitor, 2-(3-nitrophenyl)imidazo[1,2-α]pyridine (NIP), which was synthesized for protecting mild steel in 1 M HCl. The synthesized NIP was evaluated using Electrochemical Impedance Spectroscopy (EIS), Potentio-dynamic Polarization (PDP), Scanning electron microscopy (SEM), Energy X-ray analysis (EDX), and theoretical approache, including Density Functional Theory (DFT) and Monte Carlo simulations (MCs). NIP demonstrated outstanding protection behavior, reaching a peak of 91.47 % at a concentration of 1.00 mM. PDP studies classified NIP as a mixed-type inhibitor that effectively mitigated both anodic and cathodic reactions. SEM and EDX analysis confirmed the formation of a protective layer on the surface of the structural steels, composed mainly of nitrogen and oxides, indicating the presence of the inhibiting agent. DFT calculations identified the imidazole ring and heteroatoms (N and O) as the active sites for corrosion inhibition. The adsorption behavior of NIP on the metal surface has been studied by means of Monte Carlo simulations. The inhibitory efficiency of NIP was evaluated across a temperature range of 298–323 K, and the results showed a decrease in efficacy with increasing temperature, which provides crucial information for practical applications. The Langmuir model fit indicated a mixed mode of physical and chemical adsorption, with a calculated ΔG°ads value of −33.76 kJ/mol. This novel approach pinpointed reactive sites within the NIP, enhancing our understanding of its protective mechanism at the molecular level.

Microstructure and mechanical property of CoCrFeNiAlxMn(1-x) dual-phase gradient high-entropy alloy coatings prepared by laser cladding

High-entropy alloy (HEAs), known for their balanced strength and ductility, are promising candidates for impact wear-resistant applications. In this study, CoCrFeNiAlxMn(1-x)(x = 0, 0.2, 0.8, 1.0) dual-phase gradient coatings with a layered structure were prepared using laser cladding technology to explore the microstructure evolution, tensile properties and fracture mechanism of gradient coating. As the Al content increased, the single-phase face-centered cubic (FCC) HEA coatings transitioned to dual-phase of FCC+ body-centered cubic (BCC) solid-solution, and finally to a single BCC phase. The remarkable improvement of microhardness is attributed to the dominance of the BCC phase and the impeding effect of the second phase particles on dislocation movement. The gradient coating exhibited a gradual change in internal element composition, microhardness, and structure along the depth direction, with the highest hardness value reaching 530 HV. Compared with the minimum tensile strength (69.03 MPa) and the minimum elongation (0.14 %) of single-layer coating, the gradient coatings exhibited a balance of high tensile strength and good plastic toughness, with a tensile strength of 597 MPa and an elongation of 4.08 %. Fracture analysis indicated a transition from ductile to brittle fracture in single-layer coatings as x values increased. The double-layer and four-layer gradient coatings displayed a mixed mode of brittle and plastic fracture. The study provides valuable insights into the design and fabrication of HEA gradient coatings, offering a novel approach to enhance the durability and performance of laser-clad coatings for various applications.

Mechanical characteristics and damage model for rock-like specimen with two parallel grout-filled cracks

To investigate the mechanical properties of rock-like specimens with two parallel cracks filled with grout, uniaxial compression tests in combination with digital image correlation (DIC) and acoustic emission (AE) techniques have been performed on grout-filled cracked specimens with different rock bridge dip angles β. Results indicated that with the increase of β, the uniaxial compression strength, cumulated AE count, AE energy, as well as shear crack proportion initially decreases and subsequently increases. The overall AE b-value and the DIC-based maximum principal strain initially increases and subsequently decreases as β increases. The failure mode also varies from tensile to mixed tensile-shear mode. Furthermore, a particle flow code (PFC) model, which considers the grout filling, grout-rock interface, and rock, has been proposed. Numerical results showed that the range of microcracks inclination angle first decrease from 70°−100° to 70°–90° and then increases to 70°–110°. Besides, existence of grout filling and changes of bridge angle leads to significant difference in PFC particle displacement, which can cause the changed of crack initiation positions and failure modes. Finally, a damage model considering stress intensity factor for the grout-filled specimen was established. Both of pre-crack damage and loading damage were considered in this model, and a damage repair factor was proposed to describe effect of grout filling. The results showed that grouting could can effectively suppress stress concentration caused by pre-existing crack, thereby changes the strength of cracked specimen.

In-depth research on azole corrosion inhibitors - effect of N atoms position and quantity on copper corrosion inhibition performance in alkaline environments: Experimental evaluation and theoretical analysis

Copper's superior electrical properties make it ideal for multi-layer interconnections in integrated circuits. Chemical mechanical polishing (CMP) is the main method for achieving copper wiring flatness. However, copper is susceptible to corrosion in glycine-based alkaline polishing solutions. This study examines benzimidazole, indazole, and benzotriazole as corrosion inhibitors for copper in an alkaline environment (pH=9), focusing on the impact of nitrogen atom arrangement on inhibition efficiency. Through electrochemical, contact angle, static corrosion, and surface characterization tests, it's demonstrated that these inhibitors protect copper surfaces effectively. The adsorption of these inhibitors follows the Langmuir equation with a mixed adsorption mode. X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy tests, and density functional theory calculations elucidate the adsorption configuration and corrosion inhibition mechanism. The scope of this research extends beyond merely analyzing the performance of the three corrosion inhibitors; more importantly, it has yielded novel insights that are broadly applicable to the field of corrosion inhibitors. The findings are as follows: 1. The coupled structure of dinitrogen and trinitrogen facilitates charge accumulation, manifesting as the formation of additional Cu-N bonds, which prevents desorption; 2. The multi-nitrogen coupled structures provide sites for the formation of intermolecular hydrogen bonds, which is essential for the establishment of an orderly and dense passivation layer. It is expected that this study will provide valuable insights into the development and design of new and efficient copper corrosion inhibitors.

Formation of Models for Registering Systemic Processes in The Digital Educational Environment of the University Based on Log File Analysis

It has been demonstrated that technologies and methods of intelligent data analysis (IDA) in the educational domain, particularly based on the analysis of digital traces (DT) of students, offer substantial opportunities for analyzing student activities. Notably, the DT of students are generated both during remote learning sessions and during blended learning modes. By applying IDA methods to DT, one can obtain information that is beneficial for both the educator in a specific discipline and for the educational institution's management. Such information might pertain to various aspects of the functioning of the digital educational environment (DEE) of the institution, such as: the student's learning style; individual preferences; the amount of time dedicated to a specific task, among others. An algorithm has been proposed for constructing a process model in the DEE based on log analysis within the DEE. This algorithm facilitates the description of a specific process in the DEE as a hierarchy of foundational process elements. Additionally, a model based on cluster analysis methods has been proposed, which may prove beneficial for analyzing the registration logs of systemic processes within the university's DEE. Such an analysis can potentially aid in detecting anomalous behavior of students and other individuals within the university's DEE. The algorithms proposed in this study enable research during log file analysis aimed at identifying breaches of information security within the university's DEE.

Interest, Collaboration, Autonomous Learning and satisfaction in the Blended Teaching of Martial Arts

This study involves two classes of education majors taking a general Martial Arts course, using traditional teaching methods for one class and blended teaching methods for the other over a semester. It aims to compare the learning outcomes in terms of student interest in Martial Arts, cooperative learning abilities in sports, and independent learning abilities. The goal is to explore the feasibility and effectiveness of the online and offline blended teaching mode in university Martial Arts instruction. The result showed that compared to traditional teaching methods, the implementation of blended learning based on online teaching platforms complements students' interest in learning martial arts, as well as their ability to learn independently and collaboratively. With the implementation of personalized learning, interest has increased, and the abilities to learn independently and through hands-on learning have been cultivated, resulting in improved satisfaction.

Stress based fracture criteria for mixed-mode I/II delamination of unidirectional composite laminates

Mixed mode delamination is prone to occur in composite laminates subjected to complicated loading. In current study, the modified maximum principal stress (M-MPS) criterion and the modified maximum shear stress (M-MSS) criterion considering the effect of mode ratio on the critical distance are developed to predict the mixed mode delamination of unidirectional laminates. The accuracy of the proposed fracture criteria is validated by the comparison of the predicted fracture locus curve with extensive experimental data available in the literatures, a higher correlation is observed between the predicted results and the experimental data. Finally, comprehensive discussion on the capability of the proposed M-MPS and M-MSS criteria is conducted, a dimensionless parameter named fracture index composed of the difference of elastic properties and the difference of pure mode fracture toughness is proposed to reveal the fracture mechanisms of the unidirectional composites.

Investigation on the interaction evolution and growth behavior of multiple cracks under fatigue loading

In this study, the cracks interaction is investigated on plates with different crack geometry parameters through finite element analysis and experiments. The presence of multiple cracks may lead to an enhancement or shielding effect on stress intensity factors (SIFs) depending on crack relative positions and sizes, thereby potentially accelerating or decelerating the crack propagation rate. When the crack tips of double parallel non-collinear cracks begin to overlap, the interaction between cracks transitions from an enhancement effect to a shielding effect, and the KII values reach their peak at this point, which are explained by the stress field distributions surrounding the cracks. For non-collinear double cracks with an inclined angle α, the shielding effect of inclined cracks becomes increasingly pronounced in comparison to horizontal cracks as the angle α increases. To verify the numerical results, fatigue crack propagation experiments were carried out on Al–Li alloy samples with double non-collinear cracks with different crack vertical distance. The experimental results show that growth direction of two non-collinear cracks underwent a transition when they overlapped, leading to load mode I changing into mixed mode of I + II. Based on both numerical simulations and experimental results, the material parameters C and m in Paris equation are modified, and then a new method for predicting the multiple cracks growth life is presented. By comparing with the experimental values, it was found that this method exhibits high accuracy and reliability.

Numerical investigation on the crack resistance curve of thermally treated quartz‐diorite rock under mixed mode I + II loading

AbstractTo investigate the effects of thermal treatment and loading conditions on the crack initiation and propagation characteristics of quartz‐diorite, mixed mode I + II fracture tests were conducted by using three‐point bending (TPB) specimens. The numerical model, established on ABAQUS, couples the initial fracture toughness criterion and cohesive zone model to predict the crack initiation and propagation. The effects of thermal treatment and loading conditions on the crack propagation process, crack resistance curve, fracture path, and some fracture parameters at peak load have been analyzed and discussed. The results demonstrate that the thermal treatment has an obvious influence on the crack resistance curve of the specimen. The crack of the specimen will be dominated by the mode I fracture component with crack extension. The numerical results also show that the temperature and loading condition affect the crack length and fracture toughness at peak load.

An Investigation on the Application of Online and Offline Hybrid Teaching in Local Anatomy Course of Acupuncture and Moxibustion Specialty

The purpose of this paper is to explore the application of online and offline blended teaching in local anatomy courses of acupuncture specialty. It introduces the concept and characteristics of blended teaching mode and analyzes the respective advantages of online and offline teaching as well as the advantages and application prospects of blended teaching mode. The teaching status quo of local anatomy courses in acupuncture and moxibustion is analyzed, pointing out the problems of the traditional teaching mode and the application prospect of the blended teaching mode. In the practical part, the preparation and design of online teaching resources, the design of offline practical teaching sessions, and the evaluation methods of teaching effect are introduced in detail. This study aims to provide new teaching modes and ideas for teaching acupuncture and moxibustion and promote the improvement of teaching quality.

The inhibitive action of lemon verbena plant extract as an economical and eco-friendly corrosion inhibitor for mild steel in acidic solutions

The inhibitive effect of lemon verbena (lemon v.) extract as a green corrosion inhibitor (CI) for mild steel (st37) in 0.5 M H2SO4 and 1 M HCl media at room temperature is investigated by employing electrochemical current noise (ECN), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and scanning electron microscopy (SEM). The achievements demonstrated that the inhibition efficiency increases with increasing the extract concentration up to 2000 ppm in 0.5 M H2SO4 and up to 2500 ppm in 1 M HCl solutions and decreases with an increase in temperature. The ECN results show when Lemon V. extract is included to both acidic media, the values of commotion charges (Q) diminished. The least value of the Q is 15 and 60 mCoul in H2SO4 and HCl media, respectively. The EIS measurements depicted that by addition of the inhibitors up to a certain concentration, the charge transfer resistance increases up to 186 Ω cm−2 in H2SO4 and 350 Ω cm−2 in HCl, besides the double layer capacitance (Cdl) decreases. Potentiodynamic polarization assessments indicated that Lemon V. acts as mixed type inhibitor. Certain thermodynamic parameters were determined based on the temperature impact on inhibition and corrosion processes. The extract adsorption on the surface of the alloy follow the Langmuir adsorption pattern. A mixed mode of adsorption was observed, wherein the extract in H2SO4 and HCl predominantly underwent chemisorption. Thermodynamic parameters indicated spontaneous adsorption and exothermic process with increasing entropy in H2SO4 and decreasing entropy in HCl. SEM investigation also validated the adsorption performance of the inhibitor.

Experimental and simulation study on quasi-static and dynamic fracture toughness of 2A12-T4 aluminum alloy using CTS specimen

Based on the study of dynamic fracture toughness of mixed mode I/II fracture crack, using compact tensile shear (CTS) specimen and the method of split Hopkinson tensile bar (SHTB) combined with special fixture, which complete the experiments of complex fracture modes of 2A12-T4 aluminum alloy material under quasi-static and dynamic tensile tests. By combining the results of finite element simulation with experimental–numerical method, the feasibility of Richard’s theory formula in dynamic fracture experiment is discussed. The variation law of fracture toughness under quasi-static and dynamic complex fracture under mixed-mode was analyzed by finite element simulation and experiment. The results show that, in the process of quasi-static and dynamic fracture, the fracture toughness of CTS specimen under mixed mode I/II crack loading is the highest. The conclusion is proved by Richard theorical formula and experimental–numerical methods jointly. When the specimen is subjected to pure mode I fracture, the quasi-static fracture toughness is consistent with that is in condition of dynamic experiment. However, when the specimen is subjected to mode II and mixed mode I/II fracture, the dynamic fracture toughness changes greatly compared with the quasi-static fracture toughness. In addition, in the dynamic fracture experiment, the dynamic fracture toughness of mixed mode I/II depends on the initiation time, and the quasi-static fracture criterion is no longer applicable.

Curriculum teaching of mechatronics in the information age

Abstract: In the wave of digital education, the teaching design and practice of mechatronics integration courses in the information age become the key to innovative education. The course combines online teaching, virtual experiments and remote control techniques to break the limitations of a traditional classroom. Through multimedia courseware, real-time interactive platform and virtual simulation laboratory, students can not only master theoretical knowledge flexibly, but also conduct practical training online. Remote control technology enables students to operate practical equipment in real time and enhance their practical skills. The preliminary practice shows that this mixed teaching mode effectively improves students' interest in learning and practical ability, and provides a new direction and opportunity for mechatronics education.

Multi-objective mixed mode sugarcane transportation model using fuzzy NSGA

Multi-objective mixed mode sugarcane transportation model using fuzzy NSGA

Retention mechanism in combined hydrodynamic and slalom chromatography for analyzing large nucleic acid biopolymers relevant to cell and gene therapies

Slalom chromatography (SC) was discovered in 1988 for analyzing double-stranded (ds) DNA. However, its progress was impeded by practical issues such as low-purity particles, sample loss, and lack of a clear retention mechanism. With the rise of cell and gene therapies and the availability today of bio-inert ultra-high-pressure liquid chromatography (UHPLC) columns and systems, SC has regained interest. In SC, the elution order is opposite to that observed in hydrodynamic chromatography (HDC): larger DNA molecules are more retained than small ones. Yet, the underlying SC retention mechanism remains elusive.We provide the physicochemical background necessary to explain, at a microscopic scale, the full transition from a HDC to a SC retention mechanism. This includes the persistence length of the DNA macromolecule (representing DNA stiffness), their relaxation time (τR) from the non-equilibrium contour length to the equilibrium entropic configuration, and the relationship between the mobile phase shear rate (〈γ̇〉) in packed columns and the DNA extended length. We propose a relevant retention model to account for the simultaneous impact of hydrodynamic chromatography (HDC) and SC on the retention factors of a series of large and linear dsDNAs (ranging from 2 to 48 kbp). SC data were acquired using bio-inert MaxPeakTM Columns packed with 1.7μm BEHTM 45 Å, 1.8μm BEH 125 Å, 2.4μm BEH 125 Å, 5.3μm BEH 125 Å, and 11.3μm BEH 125 Å Particles, an ACQUITYTM UPLCTM I-class PLUS System, and either 1 × PBS (pH 7.4) or 100 mM phosphate buffer (pH 8) as the mobile phase. SC is a non-equilibrium retention mode that is dominant when the Weissenberg number (Wi=〈γ̇〉τR) is much larger than 10 and the average extended length of DNA exceeds the particle diameter. HDC, on the other hand, is an equilibrium retention mode that dominates when Wi<1 (DNA chains remaining in their non-extended configuration). Maximum dsDNA resolution is observed in a mixed HDC-SC retention mode when the extended length of the DNA is approximately half the particle diameter. This work facilitates the development of methods for characterizing various plasmid DNA mixtures, containing linear, supercoiled, and relaxed circular dsDNAs which all have different degree of molecular stiffness.

Efficient beam-based model for reinforced concrete walls considering shear-flexure interaction

This paper presents an efficient beam-based modelling scheme for the seismic analysis of reinforced concrete structural walls. The model combines a force-based beam element with a fibre section for flexural response and a zero-length element for shear response. The fibre-based element simulates the nonlinear flexural behaviour through uniaxial material laws that account for concrete cracking, concrete crushing, and yielding and rupture of reinforcing bars. The zero-length element represents the shear behaviour with a trilinear lateral force-displacement curve representing, in a phenomenological way, nonlinear deformations caused by diagonal cracking. The reduction of shear resistance caused by inelastic flexural deformations is accounted for in the model to reproduce failures due to shear-flexure interaction. The model has been validated using data from 52 tests on wall specimens exhibiting flexure, shear and mixed shear-flexure modes from experimental campaigns reported in the literature, showing good accuracy in predicting the effective stiffness, maximum strength and displacement capacities obtained in the tests. Model results for ultimate displacement capacity correlate better with experimental results than simplified code-oriented expressions in performance-based evaluation standards and recommendations. Considering its balanced accuracy and computational efficiency, it is concluded that the proposed modelling scheme can effectively be used for performance-based seismic design and assessment of RC wall buildings.

Identifying Community-Bridge Network Structures via Bayesian Learning With Mixed Sparsity Mode.

Identifying structures of complex networks based on time series of nodal data is of considerable interest and significance in many fields of science and engineering. This article presents a sparse Bayesian learning (SBL) method for identifying structures of community-bridge networks, where nodes are grouped to form communities connected via bridges. Using the structural information of such networks with unknown nodal dynamics and community formations, network structure identification is tackled similar to sparse signal reconstruction with mixed sparsity mode. The proposed method is theoretically proved to be convergent. Its superiority to mainstream baselines is demonstrated via extensive experiments without the need for manual adjustment of regularization parameters.

To Cultivate Talents for the Party and the Country, Comprehensively Improve the Teaching Quality of Curriculum Ideological and Politics in Courses Related to Economics

The report of the 20th National Congress of the Party pointed out that "adhere to the education of the Party and the education of the country, comprehensively improve the quality of independent training of talents, and implement the fundamental task of cultivating morality and cultivating people." In view of the practical difficulties in ideological and political teaching of economics majors, this paper explores the path to comprehensively improve the quality of ideological and political teaching of economics majors under the mixed teaching mode in the age of digital intelligence from the four aspects of "teaching materials, construction paths, teaching modes and assessment systems", and has achieved remarkable results and provided useful references for peers.

Mixed planting mode is the best measure to restore soil quality in alpine mines

In ecologically fragile areas heavily affected by human disturbance, it is imperative to restore soil quality to preserve nutrient cycling and ensure ecosystem stability. However, our understanding about the underlying mechanisms of dynamic change in soil quality associated with revegetation in alpine areas remains incomplete. In this study, data from 96 plots were collected to reveal the response of soil quality to vegetation restoration in alpine mines. The soil quality index (SQI) was developed utilizing 19 measured indicators to assess differences in soil quality between various vegetation restoration modes (natural restoration (CK), planting with Elymus dahuricus (ED), Medicago sativa (MS), and multi-plant mixed (Avena fatua L. + Elymus dahuricus + Medicago sativa + Oxytropis coerulea, MM)) and restoration periods (1, 3, 4, and 6 years). A partial least squares structural equation model (PLS-SEM) was constructed to recognize the impact of 14 variables related to topographical features, plant biodiversity and community stability, aboveground plant productivity characteristics, root functional traits, and soil erosion on soil quality. The results revealed significant variations in soil quality among different vegetation restoration modes. Within the initial four years following vegetation restoration, the discernible discrepancies in SQI values were as follows: ED > MM > MS > CK; by the sixth year, the order shifted to MM > ED > MS > CK. Aboveground plant productivity characteristics and functional root traits significantly contribute to soil quality. In contrast, plant biodiversity and community stability had no significant effects on soil quality. Topographical features and soil erosion adversely affected soil quality, with soil erosion exerting the most prominent effect.