The role of memorization in students’ self-reported mathematics learning: a large-scale study of Chinese eighth-grade students

Qimeng Liu,Xiaofeng Du,Shuxin Zhao,Jian Liu,Jinfa Cai 서울대학교 교육연구소 2019 Asia Pacific Education Review Vol.20 No.3

This study examined over 48,000 eighth-grade Chinese students’ mathematics performance and use of learning strategies. In particular, this study explored how the use of learning strategies and their combinations are related to students’ mathematics performance in Chinese context. This study examined three kinds of learning strategies derived from the Programme for International Student Assessment (PISA) 2012: memorization, elaboration, and control. The findings indicate that few students chose the memorization strategy as their predominant way of learning mathematics. Instead, students usually chose a combination of learning strategies. The choice of combinations of learning strategies was highly correlated with students’ mathematics performance. Students who chose control strategies outperformed those who chose memorization strategies or elaboration strategies. This study also examined the relationship between learning strategy use and mathematics performance of students who were only children (students with no siblings, born under the “one child” policy) and students living in nonagricultural residential locations (hukou status), both of which are background variables unique to Chinese context. The findings indicate that only-child and nonagricultural students outperformed non-only-child and agricultural students when choosing the same learning strategies. However, those who chose control-dominant strategies performed better than those who chose memorization-dominant strategies, regardless of their background. This study provides a new lens for considering the relationship between learning strategy use and mathematics performance, demonstrating that various learning strategies should be considered together rather than separately.

Making Line Undercut Structure by Incremental Laser Shock Forming

Shuxin You,Xiangying Wang,Zhong Ji,Chao Zheng,Guofang Zhang,Ren Liu 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.8

A novel technology to plastically deform line undercut structures by pulsed laser, named as incremental laser shock forming (ILSF) of sheet metal, is presented in this paper and is investigated by experiments and numerical simulations. The deformation of a line undercut structure can be considered as the accumulation of several point undercuts, the shape evolution during ILSF of copper foils was observed, and the thickness distribution on a cross-section was measured. The influences of laser energy E, forming height H, and laser spot overlap rate η on the process were studied and a process window was established to avoid deformation failure. The results show that the plastic deformation at η = 0% is less uniform and more vulnerable than that at η = 50%. Three typical failure modes were concluded and discussed. Finite element method simulation was conducted to verify the feasibility of forming line undercut structure by ILSF, and to analyze its deformation mechanism.

Clinical Reference Strategy for the Selection of Treatment Materials for Maxillofacial Bone Transplantation: A Systematic Review and Network Meta-Analysis

Zhang Shuxin,Zhang Xinyi,Li Yanling,Mao Xuran,Liu Rui,Qi Yanxin,Lee Eui-Seok,Jiang Heng Bo 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.3

Bone graft materials have mixed effects of bone repair in the field of oral maxillofacial surgery. The qualitative analyses performed by previous studies imply that autogenous odontogenic materials and autogenous bone have similar effects on bone repair in clinical jaw bone transplantation. This retrospective systematic assessment and network meta-analysis aimed to analyze the best effect of clinical application of autogenous odontogenic materials and autogenous, allogeneic, and xenogeneic bone grafts in bone defect repair. A systematic review was performed by searching the PubMed, Cochrane Library, and other journal databases using selected keywords and Medical Subject Headings search terms. 10 Papers (n = 466) that met the inclusion criteria were selected. The assessment of heterogeneity did not reveal any overall statistical difference or heterogeneity (P = 0.051 > 0.05), whereas the comparison between autogenous and allogeneic bone grafts revealed local heterogeneity (P = 0.071 < 0.1). Risk of bias revealed nine unclear studies and one high-risk study. The overall consistency was good (P = 0.065 > 0.05), and the local inconsistency test did not reveal any inconsistency. The publication bias was good. The confidence regarding the ranking of bone graft materials after GRADE classification was moderate. The effects on bone repair in the descending order were as follows: autogenous odontogenic materials, xenogeneic bone, autogenous bone, and allogeneic bone. This result indicates that the autogenous odontogenic materials displayed stronger effects on bone repair compared to other bone graft materials. Autogenous odontogenic materials have broad development prospects in oral maxillofacial surgery.

Numerical study on failure behavior of open-hole composite laminates based on LaRC criterion and extended finite element method

Decheng Liu,Dongfeng Cao,Haixiao Hu,Yucheng Zhong,Shuxin Li 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.3

A new numerical model combining LaRC failure criterion and extended finite element method (XFEM) is created to describe the failure behavior in fiber-reinforced polymer (FRP) composites. In this model, the onset of intralaminar damages are predicted based on the LaRC failure criterion, and the crack propagation and stiffness degradation are described explicitly by the XFEM. The user subroutine UDMGINI of ABAQUS defines the initial damage criterion and a mixed-mode, energy-based fracture criterion is employed to describe the crack onset and propagation in the enriched region of XFEM. The proposed model is used to investigate the failure behavior of two sets of open-hole laminates under tension. It is demonstrated that the proposed numerical method can predict the experimental data well.

Tissue Inhibitor of Metalloproteinase-1 Pro-motes NIH3T3 Fibroblast Proliferation by Activating p-Akt and Cell Cycle Progression

Yang Lu,Shuxin Liu,Shujia Zhang,Guangyan Cai,Hongwei Jiang,Huabin Su,Xiaofan Li,Quan Hong,Xueguang Zhang,Xiangmei Chen 한국분자세포생물학회 2011 Molecules and cells Vol.31 No.3

Tissue inhibitor of metalloproteinase-1 (TIMP-1) plays various roles in cell growth in different cell types. However, few studies have focused on TIMP-1’s effect on fibroblast cells. In this study, we investigated the effects of TIMP-1 overexpression on NIH3T3 fibroblast proliferation and potential transduction signaling pathways involved. Overexpression of TIMP-1, by transfection of the pLenti6/ V5-DESTTIMP-1 plasmid, significantly promoted NIH3T3 proliferation as determined by the BrdU array. Neither 5 nor 15 nM GM6001 (matrix metalloproteinase system inhibitor) affected NIH3T3 proliferation, but 45 nM GM6001 inhibited proliferation. TIMP-1 overexpression activated the p-Akt pathway, but not the p-ERK or p-p38 pathway. In TIMP-1-transfected cells, cyclinD1 was upregulated and p21CIP1 and p27^(KIP1) were downregulated, which promoted cell entry into the S and G2/M phases. The PI3-K inhibitor LY294002 abolished the TIMP-1-induced effects. Overexpression of intracellular TIMP-1 stimulated NIH3T3 fibroblast proliferation in a matrix metalloproteinase (MMP)-independent manner by activating the p-Akt pathway and related cell cycle progression.

Comparative Study and Electrochemical Properties of LiFePO₄F Synthesized by Different Routes

Huang, Bin,Liu, Suqin,Li, Hongliang,Zhuang, Shuxin,Fang, Dong Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.7

To improve the performance of $LiFePO_4F$, a novel sol-gel process is developed. For comparison, ceramic process is also implemented. From X-ray diffraction results we know that each sample adopts a triclinic $P{\bar{1}}$ space group, and they are isostructural with amblygonite and tavorite. The scanning electron microscope images show that the homogeneous grains with the dimension of 300-500 nm is obtained by the sol-gel process; meanwhile the sample particles obtained by ceramic process are as big as 1000-3000 nm. By galvanostatic tests and at electrochemical impedance spectroscopy method, the sample obtained by sol-gel process presents better electrochemical properties than the one obtained by ceramic process.

Dynamic Response of High Strength Steel Beams Subjected to Explosion Induced Blast Load

Xinchang Feng,Xiyue Liu,Zhiyang He,Shuxin Bai,Shun Li,Yu Tang 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.6

A series of anti-explosion tests were performed on H-type high strength steels (Q460JSC and HQ600) and ordinary steels (Q345B) to address the problem of anti-explosion in the technical application of high strength steel. The dynamic behavior of steel beams during explosion and the propagation of shock waves were analyzed. The effects of proportionate distance, steel strength, high-span ratio, section shapes were investigated. The finite element software (ANSYS/LS-DYNA) was used to analyze the anti-explosion performance of high strength steel beams. The finite element models which adopted modified Johnson–Cook constitutive model and damage criterion were validated by comparing with the experimental results. The influence factors of anti-explosion performance of high strength steel were explored by numerical simulation as well. The results reveal that under near-explosion conditions, the peak values of overpressure predicted by empirical formulas are often less than the experimental outcomes. As the scaled distance reduces, the damage to the steel beam increases, making it more prone to local fracture. By decreasing the scaled distance, increasing the high-span ratio, and strengthening the constraint of H-type steel beam, the deformation and damage of steel beams can reduce. The results provide an effective basis to evaluate the safety of high strength steel beams applied in practical engineering when subjected to explosion.

Comparative Study and Electrochemical Properties of LiFePO4F Synthesized by Different Routes

Bin Huang,Suqin Liu,Hongliang Li,Shuxin Zhuang,Dong Fang 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.7

To improve the performance of LiFePO4F, a novel sol-gel process is developed. For comparison, ceramic process is also implemented. From X-ray diffraction results we know that each sample adopts a triclinic P1 space group, and they are isostructural with amblygonite and tavorite. The scanning electron microscope images show that the homogeneous grains with the dimension of 300-500 nm is obtained by the sol-gel process; meanwhile the sample particles obtained by ceramic process are as big as 1000-3000 nm. By galvanostatic tests and at electrochemical impedance spectroscopy method, the sample obtained by sol-gel process presents better electrochemical properties than the one obtained by ceramic process.

Development and Validation of 18F-FDG PET/CT-Based Multivariable Clinical Prediction Models for the Identification of Malignancy-Associated Hemophagocytic Lymphohistiocytosis

Yang Xu,Lu Xia,Liu Jun,Kan Ying,Wang Wei,Zhang Shuxin,Liu Lei,Li Jixia,Yang Jigang 대한영상의학회 2022 Korean Journal of Radiology Vol.23 No.4

Objective: 18F-fluorodeoxyglucose (FDG) PET/CT is often used for detecting malignancy in patients with newly diagnosed hemophagocytic lymphohistiocytosis (HLH), with acceptable sensitivity but relatively low specificity. The aim of this study was to improve the diagnostic ability of 18F-FDG PET/CT in identifying malignancy in patients with HLH by combining 18F-FDG PET/CT and clinical parameters. Materials and Methods: Ninety-seven patients (age ≥ 14 years) with secondary HLH were retrospectively reviewed and divided into the derivation (n = 71) and validation (n = 26) cohorts according to admission time. In the derivation cohort, 22 patients had malignancy-associated HLH (M-HLH) and 49 patients had non-malignancy-associated HLH (NM-HLH). Data on pretreatment 18F-FDG PET/CT and laboratory results were collected. The variables were analyzed using the Mann-Whitney U test or Pearson’s chi-square test, and a nomogram for predicting M-HLH was constructed using multivariable binary logistic regression. The predictors were also ranked using decision-tree analysis. The nomogram and decision tree were validated in the validation cohort (10 patients with M-HLH and 16 patients with NM-HLH). Results: The ratio of the maximal standardized uptake value (SUVmax) of the lymph nodes to that of the mediastinum, the ratio of the SUVmax of bone lesions or bone marrow to that of the mediastinum, and age were selected for constructing the model. The nomogram showed good performance in predicting M-HLH in the validation cohort, with an area under the receiver operating characteristic curve of 0.875 (95% confidence interval, 0.686–0.971). At an appropriate cutoff value, the sensitivity and specificity for identifying M-HLH were 90% (9/10) and 68.8% (11/16), respectively. The decision tree integrating the same variables showed 70% (7/10) sensitivity and 93.8% (15/16) specificity for identifying M-HLH. In comparison, visual analysis of 18F-FDG PET/CT images demonstrated 100% (10/10) sensitivity and 12.5% (2/16) specificity. Conclusion: 18F-FDG PET/CT may be a practical technique for identifying M-HLH. The model constructed using 18F-FDG PET/CT features and age was able to detect malignancy with better accuracy than visual analysis of 18F-FDG PET/CT images.

Aldol condensation of acetic acid with formaldehyde to acrylic acid over SiO2-, SBA-15-, and HZSM-5-supported V-P-O catalysts

Jing Hua,Zhipeng Lu,Hengbo Yin,Wuping Xue,Aili Wang,Lingqin Shen,Shuxin Liu 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.40 No.-

Aldol condensation of acetic acid with formaldehyde to acrylic acid was catalyzed by the SiO2-, SBA-15-,and HZSM-5-supported vanadium phosphorous oxide (V-P-O) catalysts prepared by the incipientwetness impregnation. The supports obviously increased the surface areas and changed the acid–baseproperties of the as-prepared catalysts. V-P-O/SBA-15 catalysts with high acid and alkali quantitiesexhibited high catalytic activities for the aldol condensation of acetic acid with formaldehyde to acrylicacid. When the V-P-O/SBA-15 catalyst with the P/V mole ratio of 2.0:1 catalyzed the reaction at 330–370 8C, the acrylic acid selectivities were 90.8–70.2% at the formaldehyde conversions of 14.3–68.7%.