Experimental Research on the Influence of Innovative After-Class Activities on Primary Students’ Attention

Nowadays, due to factors such as long teaching time of the teacher, students often show problems of inattention. The purpose of this article is to explore whether innovative after-class activities can significantly improve the attention level of third-grade primary students. Through teaching experiment intervention, the attention levels of boys and girls in the experimental group and the control group were compared. According to the principle of no significant difference in the previous test, four classes of the third grade of Xiangtan Road Primary School in Qingdao, Shandong Province were selected, two as experimental classes (60 students, including 30 boys and 30 girls) and two as control classes (60students , including 30 boys and 30 girls).Students in the experimental class conducted half-hour innovative after-class activities, including youth boxing competitions, and football、basketball and volleyball competitions etc.; the control class only conducted regular 800-meter running exercises. The D2 attention test tool was used to test the students\u27 attention level before and after the experiment. The intervention lasted 8 months, and in the present study, the appropriate IRB approval has been obtained from East China Normal University. Using SPSS23.0 data analysis software, the independent sample T test was used to analyze the difference in attention levels between the experimental group and the control group before and after the experiment. This article only presents results with significant differences. The experimental group was significantly higher in processing speed (TN) and anti-interference ability (E1 \ E2) than the control group [(TN) T = -1.851 P = 0.003 \u3c 0.01] [(E1 \ E2) T = 2.842 P= 0.005 \u3c 0.01]; the processing speed (TN) of the boys in the experimental group was significantly higher than that in the control group (T = -2.490 P = 0.016 \u3c 0.05); the girls in the experimental group were able to resist interference with the distractions (E1 \ E2) higher than the control group (T = 2.842 P = 008 \u3c 0.01). Innovative after-class activities include a wide range of sports events, especially based on competitions can significantly improve the attention level of third-grade students. Boys are more focused on quick tasks, and girls are more focused on noisy tasks. Schools should carry out more innovative after-class activities to enrich the student\u27s learning life and improve students\u27 level of attention

Experimental Study of the Water Heating Performance of a Novel Tile-shaped Dual-function Solar Collector

AbstractSolar collectors are widely used in buildings for energy saving. However, the conventional solar collector does not match the tile roof of the building in appearance. To solve this problem, we propose a novel dual-function solar collector with tile-shaped Polymeric Methyl Methacrylate (PMMA) covers to match the roof appearance. This novel dual-function solar collector can provide hot air in winter and hot waterin other seasons, with high annual solar thermal utilization ratio. Experiments are conducted to investigate the performance of the tile-shaped collector. The efficiency of the novel tile-shaped dual-function solar collector varied from 53.2% to 69.1% in water heating mode in the test. The daily thermal efficiency of the water heating system with this tile-shaped collector system varied from 54.0% to 61.8%, while the daily thermal efficiency of the dual-function solar collector with semicircle covers varied from 44.7% to 59.2%, compared with the daily efficiency of the conventional dual-function solar collector without PMMA covers varied from 35.5% to 67.4%. It shows that the tile-shaped collector can greatly integrate the solar collector technology in to the local special feature buildings with slightly decrease of thermal efficiency

DNA methylation-mediated Rbpjk suppression protects against fracture nonunion caused by systemic inflammation

Challenging skeletal repairs are frequently seen in patients experiencing systemic inflammation. To tackle the complexity and heterogeneity of the skeletal repair process, we performed single-cell RNA sequencing and revealed that progenitor cells were one of the major lineages responsive to elevated inflammation and this response adversely affected progenitor differentiation by upregulation of Rbpjk in fracture nonunion. We then validated the interplay between inflammation (via constitutive activation of Ikk2, Ikk2ca) and Rbpjk specifically in progenitors by using genetic animal models. Focusing on epigenetic regulation, we identified Rbpjk as a direct target of Dnmt3b. Mechanistically, inflammation decreased Dnmt3b expression in progenitor cells, consequently leading to Rbpjk upregulation via hypomethylation within its promoter region. We also showed that Dnmt3b loss-of-function mice phenotypically recapitulated the fracture repair defects observed in Ikk2ca-transgenic mice, whereas Dnmt3b-transgenic mice alleviated fracture repair defects induced by Ikk2ca. Moreover, Rbpjk ablation restored fracture repair in both Ikk2ca mice and Dnmt3b loss-of-function mice. Altogether, this work elucidates a common mechanism involving a NF-κB/Dnmt3b/Rbpjk axis within the context of inflamed bone regeneration. Building on this mechanistic insight, we applied local treatment with epigenetically modified progenitor cells in a previously established mouse model of inflammation-mediated fracture nonunion and showed a functional restoration of bone regeneration under inflammatory conditions through an increase in progenitor differentiation potential

Numerical Analysis and Preliminary Experiment of a Solar Assisted Heat Pump Drying System for Chinese Wolfberry

The present work investigated a solar assisted heat pump system for drying Chinese wolfberry. The kinetic characteristic was firstly analyzed through a series of lab experiments. It was concluded that the Page model was the most suitable for predicting the heat and mass transfer of the wolfberry. Based on the wolfberry kinetic model, solar collector model and chamber air model, the coupled drying system model was developed. The accuracy of the mathematic model was determined through comparing with the preliminary experimental results. The influence of operating conditions on the thermal and energy performance of the dryer for the different operating mode was discussed. The drying weight of no more than 75 kg may be preferable in the stand-alone solar drying mode, and less than 15 h was needed to be dried. The electric energy consumption in the solar assisted the heat pump drying mode was lower than that in the stand-alone heat pump mode, and it was recommended that about 50 kg of wolfberry to be dried in the solar assisted heat pump system. Compared to the autumn drying, the reduction in the electric energy consumption was around 9.1 kWh during the 11 h summer drying process. The obtained results demonstrated the feasibility of the combined system for drying wolfberry, and also can provide the basic theoretical and experimental data support for the following research

The performance analysis of a novel TC-Trombe wall system in heating seasons

Thermal-catalytic-Trombe (TC-Trombe) wall system can simultaneously realize the dual functions of space heating and air purification without added energy. Adopting the established coupled kinetic, thermal and mass model of TC-Trombe wall system, in terms of the seasonal performance of space heating and formaldehyde degradation in heating seasons in Hefei, the effect of the thermal storage by the massive wall and the comparisons with conventional Trombe wall system are investigated. The results indicate to some degree, the thermal storage by the massive wall decreases the performance of formaldehyde degradation and space heating for TC-Trombe wall system. Compared with the performance of conventional Trombe wall system, although existing the reduction of 28.3% in terms of the total thermal load reduction for TC-Trombe wall system, this combined system can constantly produce the total volume of clean air of 8328.7 m(3)/m(2). Based on the analytical results, TC-Trombe wall with the sandwich structure is proposed. And the calculation results show that with the adding of the sandwich structure in TC-Trombe wall system, the total volume of clean air and total thermal load reduction increases by 20.9% and 34.9%, respectively. And TC-Trombe wall with the sandwich structure obtains the total volume of clean air of 10068.4 m(3)/m(2) and total thermal load reduction of 270.6 MJ/m(2) when the thermal insulation layer thickness is 20 mm. Therefore, TC-Trombe wall with the sandwich structure provides an efficient energy-saving strategy for obtaining a healthy and comfortable indoor environment using the solar energy

Topology Structural Design and Thermal Characteristics Analysis of High-Efficiency Heat Conductive Path for the Spindle System

In order to enhance the heat dissipation of the spindle under working condition, thermal conductivity paths were designed based on the topology optimization method. The heat conductive path was proposed to be constructed in the bearing housing and the spindle housing, which was simplified as a toroidal model. Taking the heat dissipation weakness as the optimization objective, the topological structure with the highest thermal conductivity was obtained based on the OC and IPTO algorithms. In order to analyze the influence of the heat conductive path on the circumferential heat distribution of the spindle, the thermal characteristic of the model with heat conductive paths filled with copper was investigated. Compared with the general model, the heat conductive path could reduce the temperature of the spindle from 47 °C to 33 °C when the volume proportion of the high thermal conductivity material was 40%. At the same time, the strength of the heat conductive path was analyzed, and the size of the stress was not more than 3MPa, which verified the effectiveness of the heat conductive path for efficient heat conduction

Study on a high-performance photocatalytic-Trombe wall system for space heating and air purification

This article proposes a novel solar gradient-utilization photocatalytic-Trombe wall system that can realize the dual functions of space heating and removal of indoor formaldehyde. A photocatalytic layer is coated on the internal surface of the glazing cover in conventional Trombe wall system. Under solar radiation, ultraviolet light is absorbed by the photocatalytic layer to activate the photocatalytic oxidation of formaldehyde, and the rest of visible and infrared parts are collected by the absorber plate to heat indoor environment. In this article, firstly, an experimental testing set-up of photocatalytic-Trombe wall was constructed and a full-day experiment was conducted to investigate the performances of air heating and formaldehyde degradation. Secondly, a coupled kinetic, thermal and mass model was derived and verified by the experimental data. Finally, adopting the established model, the seasonal energy saving analysis and economic analysis in Hefei were conducted. Results are: (1) Based on the experimental results, the daily air heating efficiency was 0.351, and daily generated clean air and degradation mass of formaldehyde were 164.0 m(3)/(m(2) day) and 100.0 mg/(m(2) day), respectively; (2) Experimental results confirmed the model accuracy within 8%; (3) Compared with the total thermal load reduction of 246.9 MJ/m(2) in heating seasons for conventional Trombe wall, photocatalytic-Trombe wall not only has a higher value of 309.9 MJ/m(2), but also an additional valuable total generated clean air of 4764.9 m(3)/m(2); (4) Photocatalytic-Trombe wall system takes about 12.1 years to recoup the initial investment only considering the saving electrical by indoor space heating