A Comparative Study of Cognitive Load and Test-Taking Strategy Use in Video-Based While-Listening Vs. Post-Listening Performance Tests

While-listening performance (WLP) and post-listening performance (PLP) tests have been well established as two critical test formats for assessing listening comprehension competence under most second language (L2) assessment conditions. However, there remain a multitude of unknowns including the varying degrees of cognitive load that WLP and PLP tests impose on L2 learners’ working memory (WM), the different types of test-taking strategies elicited by WLP and PLP tests that potentially affect test validity, the reasons why L2 listeners consider one test condition to be more cognitively demanding over the other, and the extent to which the various degrees of cognitive load and strategy use in the WLP vs. PLP test conditions may interact with L2 learners’ listening performance. To address this gap, the present study aimed to explore L2 learners’ cognitive load, strategy use, and reasons for considering a specific test condition to be difficult in video-based WLP vs. PLP tests. Using a mixed-methods research design, this study triangulated three types of data: test performance data, questionnaire data, and interview data from 30 L2 speakers of English aged 19 to 30. The qualitative results indicated that test takers employed a wide range of strategies during the WLP and PLP tests, with the majority of them finding the PLP condition to be more challenging than the WLP condition. While cognitive load measure was not found to be a significant predictor of L2 listening proficiency, the quantitative results demonstrated the role of strategy-related factors in introducing some construct-irrelevant variance. This study implies the significance of integrating some effective strategies into L2 listening instruction to improve learners’ test performance and using more robust instruments such as eye trackers or functional near-infrared spectroscopy (fNIRS) tools in research on cognitive processes

A molecular framework for lc controlled locule development of the floral meristem in tomato

Malformed tomato fruit with multiple locules is a common physiological disorder that significantly affects the quality of tomatoes. Research has shown that the occurrence of malformed fruit in tomatoes is closely linked to the number of locules, and two key QTLs, lc and fas, are involved in controlling this trait. It has been observed that lc has a relatively weaker effect on increasing locule number, which is associated with two SNPs in the CArG repressor element downstream of the SlWUS. However, the precise molecular mechanism underlying lc is not yet fully understood. In this study, we investigated the role of lc in tomato locule development. We found that the number of floral organs and fruit locules significantly increased in tomato lc knockout mutants. Additionally, these mutants showed higher expression levels of the SlWUS during carpel formation. Through cDNA library construction and yeast one-hybrid screening, we identified the MADS-box transcription factor SlSEP3, which was found to bind to lc. Furthermore, we observed an increase in floral organs and fruit locules similar to the lcCR plant on SlSEP3 silencing plants. However, it should be noted that the lc site is located after the 3′ untranslated region (UTR) of SlWUS in the tomato genome. As a result, SlSEP3 may not be able to exert regulatory functions on the promoter of the gene like other transcription factors. In the yeast two-hybrid assay, we found that several histone deacetylases (SlHDA1, SlHDA3, SlHDA4, SlHDA5, SlHDA6, SlHDA7, and SlHDA8) can interact with SlSEP3. This indicated that SlSEP3 can recruit these proteins to repress nucleosome relaxation, thereby inhibiting SlWUS transcription and affecting the number of locules in tomato fruit. Therefore, our findings reveal a new mechanism for lc playing a significant role in the genetic pathway regulating tomato locule development

Optical all-pass filters designing for dispersion compensation in high-speed WDM optical communication systems

A new configuration of tunable chromatic dispersion compensator based on optical all-pass filter utilizing MZIs and ring resonators is described. A two-stage device is demonstrated with FSR of 100GHz, tuning range of ??100ps/nm and a group delay ripple less than 2.3ps. ?2006 OSIA.EI

Prediction Method of Unsteady Flow Load of Compressor Stator under Working Condition Disturbance

Due to the complexity of the compressor operating conditions and the existence of various disturbances and unsteady effects in the flow field, the analysis of compressor stator vibration characteristics becomes particularly critical. The convolutional neural network model combined with a transient CFD method was introduced to solve the difficulty of analyzing the flow load of the compressor stator blade. This paper mainly focuses on two key points: the complex change of the aerodynamic load and the accurate prediction of the blade excitation. Considering the stator–rotor interference, the unsteady effects, and the variable working condition characteristics, the random disturbance analysis model of the flow field boundary was generated to simulate the unsteady flow excitation of the stator under complex working conditions. By establishing the neural network of boundary disturbance and flow excitation characteristics, the prediction model was trained and generated under the support of large-scale data. The most important role of the model was to establish the end-to-end data mapping between the disturbance condition and the aerodynamic load of the stator blade. The conclusions demonstrate that the introduction of an airflow disturbance is helpful to obtain the excitation characteristics of the stator under complex working conditions. The model established in this paper based on 1000 groups of disturbed working condition data can effectively predict the aerodynamic load of the blades under complex working conditions. In addition, the construction of the model is beneficial for saving a lot of computing resources, and the prediction accuracy also reaches a good level. The method presented in this paper provides a reference for the vibration analysis of the compressor stator

Study on the effect of grain size on the microstructure evolution of Q345 steel plate under high-speed impact

This study used a two-stage light gas gun to launch reactive fragments at high speeds into steel plates with different grain sizes (large and small). In addition, utilizing material characterization technologies like SEM, EBSD, and TEM, the microstructure evolution of steel plates with varying grain sizes was measured and analyzed both before and after impact. The results indicate that small-grain steel plates are more prone to intergranular or transgranular crack propagation, and they produce more macroscopic and microscopic cracks on the perforated surface under high-speed impact than large-grain steel plates. At the grain boundaries of both large and small grains of steel plate, as well as high-density dislocations, the impact process produces a significant number of minor angles with local misorientation ranging from 2 to 10°. A small-grain steel plate has an obvious grain boundary-strengthening effect. Small grains are more likely than large grains to cause changes in the crystal structure of BCC-HCP close to the perforation, and some grains form a lot of nanoscale elongated structures with the same crystal structure as the matrix. The interaction between dislocations or the emission of a large number of dislocation cells from grain boundaries may occur within some of the larger grains. The study's findings, which are illustrated in this article, can be used as a reference to understand how grain size influences the steel plates' microstructure changes after impacts

Effect of Fe: Cu ratio on microstructure and mechanical properties of Fe-Co-Cu-based diamond tools

Co-based diamond tools are widely appreciated for their exceptional mechanical properties and good holding ability for diamonds. However, the reliance on cobalt (Co) poses challenges due to its high cost and scarcity as a strategic resource. A potential alternative is the Fe–Co–Cu alloy, emerging as a promising substitute for Co matrix alloys. In this work, hot-press sintering was utilized to create pure matrix and diamond tools utilizing Fe–Co–Cu pre-alloyed powders of varying compositions as raw materials without the use of any sintering additives. The investigation explores the influence of different Fe: Cu ratios on the mechanical properties of diamond tools produced from Fe–Co–Cu alloys, focusing on the diamond holding force, microstructure, and phase structure evolution. Results indicate that at a Co content of 15 wt% and Fe: Cu ratios ranging from 7.5:1 to 1:7.5, the Fe–Co–Cu alloy's phase structure primarily comprises α-Fe and a Cu-rich phase. Co predominantly exists in α-Fe as a solid solution. As the Fe: Cu ratio decreases, the alloy's phase structure gradually transitions from α-Fe to a Cu-rich phase, accompanied by a progressive decline in both bending strength and hardness, while the densities gradually increase. The matrix's holding force on the diamond exhibits an increasing and then diminishing trend, peaking at the Fe: Cu ratio of 6:1. The Fe–Co–Cu alloy sintered by hot-pressing has a nearly equiaxed grain structure with no obvious texture

Preparation of Continuous Alumina Fiber with Nano Grains by the Addition of Iron Sol

Continuous alumina fiber exhibits excellent mechanical properties owing to its dense microstructure with fine grains. In this study, alumina fiber was prepared by the sol–gel method using iron sol as a nucleating agent. It was proposed that the α-Al2O3 grain size be adjusted based on the modification of colloidal particle size. The effect of holding temperature and reaction material ratio on the iron colloidal particle size was studied. The microstructure of alumina fiber was characterized by scanning electron microscopy (SEM). The experiment results indicated that iron colloidal particle size increases with the holding temperature and the NH4HCO3/Fe(NO3)3·9H2O ratio. The alumina fiber with uniform nano α-Al2O3 grains was obtained by calcination at 1400 °C for 5 min. The mean grain size tends to rise with the mean colloidal particle size. Using the iron sol as a nucleating agent, the fiber with a mean grain size of 22.5 nm could be formed. The tensile strength of fibers increased with the decrease of grain size

Experimental and Molecular Dynamics Simulation Study on Sol–Gel Conversion Process of Aluminum Carboxylate System

Due to the lack of relevant in situ characterization techniques, the investigation of aluminum sol–gel progress is lacking. In this study, combined with molecular dynamics simulation and conventional experimental methods, the microstructures, rheological properties, and gelation process of the carboxylic aluminum sol system were studied. The experimental results showed that, with the increase in solid content, the microstructure of the colloid developed from a loose and porous framework to a homogeneous and compact structure. The viscosity of aluminum sol decreased significantly with the increase in temperature, and a temperature above 318 k was more conducive to improving the fluidity. The simulation results show that the increase in free volume and the connectivity of pores in colloidal framework structure were the key factors to improve fluidity. In addition, free water molecules had a higher migration rate, which could assist the rotation and rearrangement of macromolecular chains and also played an essential role in improving fluidity. The Molecular dynamics simulation (MD) results were consistent with experimental results and broaden the scope of experimental research, providing necessary theoretical guidance for enhancing the spinning properties of aluminum sol

The complete mitochondrial genome of Pheropsophus occipitalis MacLeay, 1825 (Coleoptera: Carabidae)

Pheropsophus occipitalis MacLeay is a predatory enemy prey heavily on agricultural pests. The length of the complete mitochondrial genome of P. occipitalis was 16,800 bp with 20.4% GC content, including 41.2% A, 11.9% C, 8.4% G, 38.5% T. The genome encoded 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNA), two ribosomal RNA genes (rRNA). Phylogenetic analysis showed that P. occipitalis was clustered with Pheropsophus bimaculatus and Pheropsophus sobrinus. This study provided a scientific basis for the population genetics, phylogeny, and molecular taxonomy of P. occipitalis