The recyclability of alginate hydrogel particles used as a palladium catalyst support

Ming Xia,강성민,이고운,허윤석,박범준 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.73 No.-

We investigated the catalytic efficiency of alginate hydrogels used as a catalyst support. An alginatesolution containing palladium and magnetic nanoparticles was dropped continuously through a taperedglass capillary using a syringe pump, and the generated alginate droplets were collected in an aqueoussolution containing divalent cations. The prepared PdNPs/MNPs-embedded alginate particles were usedas a catalyst, catalyst support, and magnetic stirrer for the reduction of 4-nitrophenol. The catalyticreactions were found to depend on the magnetic stirring of the alginate hydrogels. Furthermore, weexamined the recyclability while changing the alginate concentration, divalent cation species, andincubation protocols.

One-step production of highly anisotropic particles via a microfluidic method

Ming Xia,고은민,최규환,임진현,박범교,유태경,임상혁,곽상규,박범준 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.64 No.-

We introduce a promising protocol that can be used to fabricate polymer particles with a high degree of shape anisotropy; this method can be utilized with a variety of microfluidic generation methods. Low-density microparticles and high-density nanoparticles vertically migrated in a polymer solution confined in emulsion droplets that were produced via a microfluidic method. As the solvent evaporated in individual droplets at ambient conditions, the low-density microparticles migrated upward because their density was lower than that of the polymer solution. The high-density nanoparticles that were initially well-dispersed in the droplet phase became destabilized upon solvent removal, leading to the formation of aggregates and sedimentation in a downward direction. The migration of the particle components during solvent evaporation induced shape deformation/modification of the emulsion droplets; consequently, polymer particles with highly anisotropic shapes were created after drying.

Magnetite-based Biochar Coupled with Binary Oxidants for the Effective Removal of Mixed Dye from Wastewater

Mingxia Yu,Huosheng Li,Keke Li,Yuting Li,Fengli Liu,Gaosheng Zhang,Tangfu Xiao,Ping Zhang,Hongguo Zhang,Jianyou Long 한국섬유공학회 2022 Fibers and polymers Vol.23 No.2

Decolorization and organic degradation of wastewater containing multiple dyes are still challenging inwastewater treatment. Magnetic biochar coupled with advanced oxidation is a potential solution to this issue. In this study,a series of magnetite-based biochar composites (Fe3O4@C) was prepared and compared for the removal of mixed dyes,including methyl orange (MO), rhodamine B (RhB), methylene blue (MB), and an organic macromolecule, humic acid(HA). The pyrolysis of watermelon rinds followed by precipitation of Fe3O4 onto the biochar was selected as the optimummethod to prepare an adsorbent and catalyst to couple binary oxidants (hypochlorite and persulfate) for color and totalorganic carbon removal. Persulfate was prone to degrade HA and MB, while hypochlorite was inclined to oxidize MO andRhB. Fe3O4@C exhibited better dye removal performance in coupling with binary oxidants than with a single oxidant. Formixed dye solutions with an initial concentration of 50 mg/l for each dye, the highest TOC (57.24±3.17 %) and the colorremoval efficiencies (94.13±1.68 %) for the mixed dye solution were achieved at a sorbent dosage of 1 g/l and an oxidantdosage of 5 mmol/l for both hypochlorite and persulfate. Multiple free radicals, including hydroxyl radicals, sulfateradicals, and hypochlorite-induced radicals, play critical roles in the degradation of mixed dyes and color removal. Theregeneratibility and reutilization of the magnetic Fe3O4@C composite were effective and stable. The results obtained inthis study show that the combined Fe3O4@C and binary oxidants technique is promising for the treatment of multi-dyewastewater.

Multi-system vehicle formation control based on nearest neighbor trajectory optimization

Mingxia, Huang,Yangyong, Liu,Ning, Gao,Tao, Yang Techno-Press 2022 Advances in nano research Vol.13 No.6

In the present study, a novel optimization method in formation control of multi -system vehicles based on the trajectory of the nearest neighbor trajectory is presented. In this regard, the state equations of each vehicle and multisystem is derived and the optimization scheme based on minimizing the differences between actual positions and desired positions of the vehicles are conducted. This formation control is a position-based decentralized model. The trajectory of the nearest neighbor are optimized based on the current position and state of the vehicle. This approach aids the whole multi-agent system to be optimized on their trajectory. Furthermore, to overcome the cumulative errors and maintain stability in the network a semi-centralized scheme is designed for the purpose of checking vehicle position to its predefined trajectory. The model is implemented in Matlab software and the results for different initial state and different trajectory definition are presented. In addition, to avoid collision avoidance and maintain the distances between vehicles agents at a predefined desired distances. In this regard, a neural fuzzy network is defined to be utilized in conjunction with the control system to avoid collision between vehicles. The outcome reveals that the model has acceptable stability and accuracy.

Individual Aesthetic Differences Evaluation of Yan’an Urban Forests in the Loess Plateau China

Mingxia Zhang,Dexiang Wang,Zhitao Wang,Xinping Zhang,Ganggang Zhang,Yong Xu 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.10

Effect of pH on Types of Acidogenic Fermentation of Fruit and Vegetable Wastes

Mingxia Zheng,Mingyue Zheng,Yuanyuan Wu,Hailing Ma,Kaijun Wang 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.2

The effect of pH (4.0, 5.0, and 6.0) on acidification and fermentation of fruit and vegetable wastes was investigated using batch and semi-continuous experiments under mesophilic condition. Results showed that fermentation types change with pH variation. The pH of acidification system containing fruit and vegetable wastes could automatically decrease to 3.0 ~ 4.0. At this pH range, a stable ethanol production was observed, at which ethanol-type fermentation was obtained. Based on the results, the fermentation types were classified into ethanol-type, mixed acid-type, propionic acid-type, and butyric acid-type fermentations, which occurred at pH 4.0 ~ 4.5, 4.5 ~ 5.0, 5.0 ~ 5.5, and 5.5 ~ 6.5, respectively.

A Composite Index-based Approach for Hierarchical Assessment of Forest Ecosystem Health : An Example of Pinus tabulaeformis

Mingxia Zhang,Dexiang Wang,Zhao Xu,Qiuju Guo 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.7

A Corpus-based Study on Chinese College Students’ Personal References in Argumentative Essays

Mingxia Gao 한국외국어대학교 외국어교육연구소 2020 외국어교육연구 Vol.34 No.2

Personal reference, one of the most important cohesion feature in text has aroused tremendous attentions in English writing literature. Previous studies, however, have reported mixed results with some researchers finding that ESL students tend to use first-person pronouns much more frequently than their L1 English counterparts (Cobb, 2003; McCrostie, 2008; Paquot,Hasselgard, & Ebeling, 2011; Petch-Tyson, 1998) and others reporting that L2 students' texts include far fewer first-person pronouns/determiners than L1 student papers (Lee & Deakin, 2016; Leedham, 2015). Besides these inconsistent findings, research on how Chinese students as EFL learners utilize cohesive devices and in what extent they differ from L1 English speakers remain insufficient in terms of empirical studies. This article, with Halliday and Hason’s cohesive theory as the framework, employing AntConc3.4.4 to retrieve argumentative essays in TECCL and LOCNESS for data collecting and analysis, aims to find out how Chinese college students and native college students differ in using personal references in their argumentative essays. The results of the analysis displayed a significant difference of personal references as cohesive devices between Chinese college students and English native college students. A further exploration of plural pronoun “we” showed that Chinese students lacked varieties concerning the collocation features of “we” compared with native students. Their weak cognitive identification on the function of cohesive devices, English writing proficiency may cause the collocation features and differences.

Small-conductance Ca2+-activated K+ channels: insights into their roles in cardiovascular disease

Mingxia Gu,Yanrong Zhu,Xiaorong Yin,Dai-Min Zhang 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Life-threatening malignant arrhythmias in pathophysiological conditions can increase the mortality and morbidity of patients with cardiovascular diseases. Cardiac electrical activity depends on the coordinated propagation of excitatory stimuli and the generation of action potentials in cardiomyocytes. Action potential formation results from the opening and closing of ion channels. Recent studies have indicated that small-conductance calcium-activated potassium (SK) channels play a critical role in cardiac repolarization in pathophysiological but not normal physiological conditions. The aim of this review is to describe the role of SK channels in healthy and diseased hearts, to suggest cardiovascular pathophysiologic targets for intervention, and to discuss studies of agents that target SK channels for the treatment of cardiovascular diseases.

On the Current Situation and Prospect of Yanbian Korean-Chinese English Education

Gao Mingxia(고명하),Ren Xueqin(임설금) 전남대학교 글로벌디아스포라연구소 2015 디아스포라 연구 Vol.9 No.1

중국 연변지역의 삼중언어 교육은 중국 정부의 소수민족 교육정책에 의해 개발되었다. 삼중언어 교육은 모국어(한국어), 공식어(중국어), 그리고 외국어(이 연구에서는 영어)를 향상시키기 위해 시행되었다. 그럼에도 불구하고 이론과 현실에서는 소수민족 교육이 복잡하고 다양하게 나타나고 있다. 삼중언어 교육으로써 조선족의 영어 학습을 정의하자면, 조선족이라는 특수성을 반영해야 한다. 이 연구는 1995부터 2015년까지 연변조선족자치주 교육 통계자료를 대상으로 조선족 영어 교육의 변천 과정과 현황을 분석하였다. 이를 통해 현 상황에서 직면하고 있는 문제점을 파악하고, 향후 조선족의 민족교육이 지구화시대 잘 통합되고, 전문 인력을 양성하기 위한 전망을 제시하였다. Trilingual education in Yanbian Area of China has been developed as a result of China’s education policy for minorities to improve not only their native language(Korean) but also their official language(Chinese) and their foreign language(English in this study).Nevertheless,both in theory and practice,Korean minority English education in this area has appeared to be complicated and diversified,leaving some problems to be dealt with. This study, defining Korean-Chinese English learning as a trilingual education with its unique characteristics and features, basing the data source from the combined 1995-2015 Yanbian Educational statistics, focuses on the historical development and present situation of Korean-Chinese English education in Yanbian Area. Through exploring some existing problems, this thesis points out the countermeasures for the prospect of Korean-Chinese English education, which is hoped to help Korean-Chinese English education better integrate into both ethnic English education and national English education so that more globalized ethnic Korean-Chinese talents will be cultivated.