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Predicting digital informal learning: an empirical study among Chinese University students
Tao He,Chang Zhu,Frederik Questier 서울대학교 교육연구소 2018 Asia Pacific Education Review Vol.19 No.1
Although the adoption of digital technology has gained considerable attention in higher education, currently research mainly focuses on implementation in formal learning contexts. Investigating what factors influence students’ digital informal learning is still unclear and limited. To understand better university students’ digital informal learning (DIL), this study proposed a model based on decomposed theory of planned behavior to investigate students’ behavioral intention to DIL. Different aspects of DIL behavior were further explored, through examining behaviors of cognitive learning, metacognitive learning, and social and motivation learning. This study also integrated digital competence as a new construct into the model, along with other variables to test the proposed model. A sample of 335 students selected from three universities in China took part in this study. The partial least square structural equation modeling was applied to analyze the data. The results provide support and better understanding for the importance of motivation factors such as digital competence and compatibility to explain students’ DIL.
Zhu, Hai-Tao,Ren, Qi-Fang,Jin, Zhen,Ding, Yi,Liu, Xin-Yu,Ni, Xi-Hui,Han, Meng-Li,Ma, Shi-Yu,Ye, Qing,Oh, Won-Chun Materials Research Society of Korea 2020 한국재료학회지 Vol.30 No.8
In this paper, AgCl/Ag<sub>3</sub>PO<sub>4</sub>/diatomite photocatalyst is successfully synthesized by microemulsion method and anion in situ substitution method. X-ray diffraction (XRD), photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and ultraviolet-visible spectroscopy (UV-Vis) are used to study the structural and physicochemical characteristics of the AgCl/Ag<sub>3</sub>PO<sub>4</sub>/diatomite composite. Using rhodamine B (RhB) as a simulated pollutant, the photocatalytic activity and stability of the AgCl/Ag<sub>3</sub>PO<sub>4</sub>/diatomite composite under visible light are evaluated. In the AgCl/Ag<sub>3</sub>PO<sub>4</sub>/diatomite visible light system, RhB is nearly 100 % degraded within 15 minutes. And, after five cycles of operation, the photocatalytic activity of AgCl/Ag<sub>3</sub>PO<sub>4</sub>/diatomite remains at 95 % of the original level, much higher than that of pure Ag<sub>3</sub>PO<sub>4</sub> (40 %). In addition, the mechanism of enhanced catalytic performance is discussed. The high photocatalytic performance of AgCl/Ag<sub>3</sub>PO<sub>4</sub>/diatomite composites can be attributed to the synergistic effect of Ag<sub>3</sub>PO<sub>4</sub>, diatomite and AgCl nanoparticles. Free radical trapping experiments are used to show that holes and oxygen are the main active species. This material can quickly react with dye molecules adsorbed on the surface of diatomite to degrade RhB dye to CO<sub>2</sub> and H<sub>2</sub>O. Even more remarkably, AgCl/Ag<sub>3</sub>PO<sub>4</sub>/diatomite can maintain above 95 % photo-degradation activity after five cycles.
Optimization of formic acid hydrolysis of corn cob in xylose production
Tao Zhu,Pingli Li,Xiaowei Wang,Wandian Yang,Heying Chang,Sai Ma 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.9
Dilute acid pretreatment of lignocellulosic material is one of the significant steps in a biorefinery. We usedresponse surface methodology to determine the important factors of formic acid concentration (2%-6% wt%), treatmenttime (30-150 min), reaction temperature (120-160 oC), and liquid to solid ratio (3-11 mL/g) on dilute acid hydrolysisof corn cob to produce xylose. A xylose yield of 81.6% and selectivity of 15.1 g/g were achieved under the optimalconditions (5% acid concentration, 150 min, 135 oC, and 7 mL/g liquid to solid ratio). The addition of trivalent salts(FeCl3, Fe(NO3)3, and Fe2(SO4)3) to the reaction system enhanced the xylose yield but decreased selectivity. The FeCl3concentration over 0.75 mol/L had a negative effect on xylose production.
Adsorption of carbon dioxide on ionic liquids-modified active carbons and amino-modified polymer
Tao Zhu,노경호,Wentao Bi 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.3
Active carbons with various particle sizes (38-150, 300-500 and 800-1,200 μm) were modified by ionic liquids (ILs), and organic polymer was modified by acrylamide using a simple procedure, and these materials were applied to capture carbon dioxide (CO_2). The CO_2 adsorption amounts were calculated using a mass balance equation at three different temperatures (298.15, 308.15 and 318.15 K), respectively, and the influences of gas pressure, particle size and temperature on adsorption were discussed. Experimental results showed that the CO-2 adsorption capacity of ILs-modified active carbons was better than amino-modified polymer, and the smaller particle size (38-150 μm) ILsmodified active carbons had the largest adsorption capacity at 298.15 K. Compared with previous research about polyethyleneimine (PEI)-modified silica gel, the adsorption amount of CO_2 on ILs-modified active carbons has been greatly improved with lower cost.
Zhu, Tao,Bi, Wentao,Row, Kyungho WILEY‐VCH Verlag 2011 Chinese journal of chemistry Vol.29 No.8
<P><B>Abstract</B></P><P>A short ionic liquids (ILs)‐based monolithic cartridge was prepared and used as the selective extraction sorbent. After the material was evaluated by field emission‐scanning electron microscopy (FE‐SEM), a new approach for the extraction and determination of quercetin and myricetin from <I>Chamaecyparis obtusa </I>(<I>C. obtusa</I>) by using ILs‐based, monolithic cartridge system was developed. Chromatographic analysis was conducted on a C<SUB>18</SUB> column with UV detection at 372 nm, an eluting solution consisting of acetonitrile‐water (25/75,<I>V/V</I>) as the mobile phase, and a flow rate of 0.7 mL·min<SUP>−1</SUP>. A good linear relationship was demonstrated when the concentrations of quercetin and myricetin were in the range of 0.5–100.0 µg·mL<SUP>−1</SUP>. The recoveries ranged from 101.6% to 104.6% and the inter‐ and intra‐day relative standard deviations (RSD) were less than 5.0%. This method effectively removed the impurities and avoided tedious pretreatment. It provided a fast, economic and effective method for assaying trace drugs from natural plants.</P>
Zhu Mingkang,Zhu Jianyang,Zhang Tao 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.4
Understanding the effect of fluctuating wind on the aerodynamic performance of the wing is important for designing practical using flapping-wing micro air vehicles (FMAV). This paper aims at providing a systematic synthesis on the fluctuating wind influence on the performance of the three dimensional lumped flexibility wing based on the numerical analysis approach. The fluctuating wind is simplified as a sine type function, and the flexibility of the wing is modeled as the passive pitching motion by connecting a rigid wing to a torsional spring at the root of the wing. The interaction between the fluctuating wind and the lumped flexibility wing is performed on a high-resolution computational grid. The evaluation is based on validation with published experiment data. The results indicate that the fluctuating wind cannot enhance the flexible wings’ propulsive and lifting performance simultaneously, however, it influences the aerodynamic characteristics of the wing greatly. Comparing to the rigid wing, the suppress leading edge vortex and trailing edge vortex are observed of the flexible wing under appropriate fluctuating wind, which leads the flexible wing to not only have better propulsive and lifting performance, but also flight stability performance.
Tao, Hengcong,Sun, Xiaofu,Back, Seoin,Han, Zishan,Zhu, Qinggong,Robertson, Alex ,W.,Ma, Tao,Fan, Qun,Han, Buxing,Jung, Yousung,Sun, Zhenyu Royal Society of Chemistry 2018 Chemical Science Vol.9 No.2
<▼1><P>The doping of Pd with a small amount of Te can selectively convert CO<SUB>2</SUB> to CO with a low overpotential.</P></▼1><▼2><P>Designing highly selective and energy-efficient electrocatalysts to minimize the competitive hydrogen evolution reaction in the electrochemical reduction of aqueous CO<SUB>2</SUB> remains a challenge. In this study, we report that doping Pd with a small amount of Te could selectively convert CO<SUB>2</SUB> to CO with a low overpotential. The PdTe/few-layer graphene (FLG) catalyst with a Pd/Te molar ratio of 1 : 0.05 displayed a maximum CO faradaic efficiency of about 90% at –0.8 V (<I>vs.</I> a reversible hydrogen electrode, RHE), CO partial current density of 4.4 mA cm<SUP>–2</SUP>, and CO formation turnover frequency of 0.14 s<SUP>–1</SUP> at –1.0 V (<I>vs.</I> a RHE), which were 3.7-, 4.3-, and 10-fold higher than those of a Pd/FLG catalyst, respectively. Density functional calculations showed that Te adatoms preferentially bind at the terrace sites of Pd, thereby suppressing undesired hydrogen evolution, whereas CO<SUB>2</SUB> adsorption and activation occurred on the high index sites of Pd to produce CO.</P></▼2>