Ni Nanoparticle Anchored on MWCNT as a Novel Electrochemical Sensor for Detection of Phenol

Yajing Wang,Jiankang Wang,Zhongping Yao,Chenyu Liu,Taiping Xie,Qihuang Deng,Zhaohua Jiang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.11

Increasing active sites and enhancing electric conductivity are critical factors to improve sensing performance toward phenol. Herein, Ni nanoparticle was successfully anchored on acidified multiwalled carbon nanotube (a-MWCNT) surface by electroless plating technique to avoid Ni nanoparticle agglomeration and guarantee high conductivity. The crystal structure, phase composition and surface morphology were characterized by XRD, SEM and TEM measurement. The as-prepared Ni/a-MWCNT nanohybrid was immobilized onto glassy carbon electrode (GCE) surface for constructing phenol sensor. The phenol sensing performance indicated that Ni/a-MWCNT/GCE exhibited an amazing detection performance with rapid response time of 4s, a relatively wide detection range from 0.01 mM to 0.48 mM, a detection limit of 7.07 μM and high sensitivity of 566.2 μAmM -1 cm -2. The superior selectivity, reproducibility, stability and applicability in real sample of Ni/a-MWCNT/GCE endowed it with potential application in discharged wastewater.

Controlled synthesis of Co₂C nanochains using cobalt laurate as precursor: Structure, growth mechanism and magnetic properties

Zhang, Yajing,Zhu, Yuan,Wang, Kangjun,Li, Da,Wang, Dongping,Ding, Fu,Meng, Dan,Wang, Xiaolei,Choi, Chuljin,Zhang, Zhidong Elsevier 2018 Journal of magnetism and magnetic materials Vol.456 No.-

<P><B>Abstract</B></P> <P>Cobalt carbides (Co<SUB>2</SUB>C and Co<SUB>3</SUB>C) nanocomposites exhibit interesting hard magnetic property, controlled synthesis of individual phase facilitates to clarify the magnetism of each, but it is difficult to obtain the single phase. We present a new approach to address this issue via a polyol refluxing process, using cobalt laurate as the precursor. The single phase Co<SUB>2</SUB>C magnetic nanochains self-assembled by nanoparticles are synthesized. The precursor is the key factor for controlling the growth kinetics of the Co<SUB>2</SUB>C nanochains. Cobalt, instead of cobalt carbides, is produced if cobalt chloride, acetate and acetylacetonate replace cobalt laurate as the precursor, respectively. The evolution of the growth process has been studied. In the formation of Co<SUB>2</SUB>C, first fcc-Co produces, then it transforms into Co<SUB>2</SUB>C by carbon diffusion process, and the produced carbon first exists in disordered state and then a small amount of them transforms into graphite. Saturation magnetization (<I>Ms</I>) of Co<SUB>2</SUB>C nanochains obtained at 300 °C for 20, 60, and 180 min are 27.1, 18.9, and 10.9 emu g<SUP>−1</SUP>, respectively. The decrease of <I>Ms</I> caused by increasing carbon content, and the carbon content are much larger than the stoichiometric ratio value of Co<SUB>2</SUB>C (9.2 wt%). The Co<SUB>2</SUB>C nanochains have mesoporous pore of 3.8 nm and the specific surface area of 48.6 m<SUP>2</SUP> g<SUP>−1</SUP>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Co<SUB>2</SUB>C magnetic nanochains are synthesized using cobalt laurate as the precursor in TEG. </LI> <LI> The precursor of cobalt laurate is the key factor for controlling the growth kinetics of Co<SUB>2</SUB>C nanochains. </LI> <LI> Ms of Co<SUB>2</SUB>C nanochains obtained at 300 °C for 20, 60, and 180 min are 27.1, 18.9, and 10.9 emu g<SUP>−1</SUP>, respectively. </LI> <LI> The decrease of Ms is caused by increasing carbon content with increasing reaction time. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>We present a new approach to obtain single phase Co<SUB>2</SUB>C nanochains by using cobalt laurate as the precursor.</P> <P>[DISPLAY OMISSION]</P>

분배공정성과 이직의도 및 조직시민행동 간의 관계에서 상호작용 공정성의 역할 연구

왕아정 ( Yajing Wang ),김주엽 ( Joo-yup Kim ) 충북대학교 산업경영연구소 2017 産業과 經營 Vol.30 No.1

본 연구는 중국 소형 기업의 조직구성원을 대상으로 분배공정성, 상호작용 공정성이 이직의도 및 조직시민행동에 미치는 영향과 분배공정성과 이직의도, 조직시민행동 간의 관계에서 상호작용 공정성의 조절역할을 규명하는 데 목적을 두었다. 중국은 개혁개방 경제체제로의 변화에 따라 일한만큼 받는 보상시스템의 중요성이 강조되고 있고, 중국의 전통문화인 유가와 도가사상에 따라 대인 관계적인 측면이 강조되고 있는데, 이러한 개념들이 분배공정성, 상호작용 공정성으로 파악할 수 있고, 중국 조직구성원을 대상으로 이러한 공정성 유형들이 이직의도, 조직시민행동에 미치는 효과 및 분배공정성과 상호작용 공정성의 상호작용 효과를 규명해 볼 필요가 있다고 판단하였다. 중국 소형 기업의 조직구성원 335명을 대상으로 실증 분석하였고, 검증결과를 보면, 첫째, 분배공정성, 상호작용 공정성은 이직의도와 유의적으로 부적인 영향관계가 있는 것으로 나타났다. 둘째, 분배공정성, 상호작용 공정성은 조직시민행동과 유의적으로 정적인 영향관계가 있는 것으로 나타났다. 셋째, 분배공정성과 이직의도, 조직시민행동 간의 관계에서 상호작용 공정성은 조절효과가 있는 것으로 나타났다. 이러한 연구결과를 토대로 분배공정성, 상호작용 공정성이 이직의도, 조직시민행동에 미치는 함의와 시사점을 제시하였다. Recently, Chinese employees are more and more paying attention to whether they are fairly treated in payment and interpersonal relationships as Chines society are getting exposed more to the diverse western management systems. Reflecting such current tendency, the number of studies focusing on organizational justice and its influence on turnover intention and organizational citizenship behavior are increasing these days. However, there is relatively little research on interactional justice in China. Hence this study attempts to explore the concept of interactional justice and its meaning in Chinese corporations, particularly focusing on its role on the relationships among distributive justice, turnover and organizational citizenship behavior. Consequently, this study attempts to offer Chinese enterprises the efficient human resource management practices in terms of organizational justice. Through the literature review on organizational justice including distributive and interactional justice, and on both turnover intention and organizational citizenship, a number of research hypotheses were developed. To test the hypotheses, a set of questionnaires which was proved to be valid in western employees are translated into Chinese. The questionnaires were distributed to the employees working in the companies mainly located in vicinity in Chung Ching, China. The result shows that all of the hypotheses induced in this study are proved to be true, that is, both distributive justice and interactional justice impact on turnover intention and organizational citizenship behavior. In addition, interactional justice plays a moderating role in the relationship between distributive justice and turnover intention, and in the relationship between distributive justice and organizational citizenship behavior as well. Finally, some managerial implications of this study were discussed.

The Clinical Manifestation, Executive Dysfunction, and Caregiver Strain in Subthreshold Attention-Deficit/Hyperactivity Disorder

Yajing Tang,Sunwei Qiu,Haimei Li,Feifei Si,Mengjie Zhao,Min Dong,Meirong Pan,Xinxin Yue,Lu Liu,Qiujin Qian,Yufeng Wang 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.9

Objective Subthreshold attention-deficit/hyperactivity disorder (ADHD) has been suggested to be a “morbid condition” which also needs medical attention.Methods The present study recruited 89 children with subthreshold ADHD (sADHD), 115 children with diagnosed ADHD (cADHD), and 79 healthy controls (HC) to explore the clinical manifestation, executive functions (EFs) of sADHD, and the caregiver strain. The clinical manifestation was evaluated through clinical interviews and parent-reports. Executive functions were assessed both experimentally and ecologically. Caregiver strain was measured by a parent-reported questionnaire.Results For the clinical manifestation, both sADHD and cADHD indicated impairments when compared with HC. The comorbidities and the scaled symptoms indicated that the externalizing behaviors were relatively less serious in sADHD than cADHD, whereas the internalizing behaviors between two groups were comparable. For ecological EFs, sADHD scored between cADHD and HC in inhibition and working memory. For experimental EFs, sADHD was comparable to cADHD in inhibition, shifting, and was worse than cADHD in verbal working memory. For the caregiver strain, all scores of sADHD were between that in cADHD and that in HC.Conclusion Our present findings supported the suggestion of subthreshold ADHD as “morbid condition,” which should be treated with caution in clinical practice, especially for the internalizing behaviors and some key components of EFs.

Learning-based Predictive Control for Vehicle Following Problems

Ziliang Wang,Shuyou Yu,Yajing Zhang,Xiaohui Yu,Hong Chen 제어로봇시스템학회 2023 제어로봇시스템학회 국제학술대회 논문집 Vol.2023 No.10

FACTORS INFLUENCING CONSUMER SHOPPING ENJOYMENT AND PURCHASE INTENTION IN METAVERSE VIRTUAL STORES

Chunlin Yuan,Yajing Yin,Shuman Wang,Hakil Moon,Kyunghoon Kim,Yang Liu 글로벌지식마케팅경영학회 2023 Global Marketing Conference Vol.2023 No.07

The present study choose to conduct consumer behavioral research in Metaverse situation, explores factors that influence consumer shopping enjoyment and purchase intention from product, service and technology perceptive. The research team gathered the primary data through questionnaire subjecting to Chinese consumers (n=300) who know about TaoBao future city which themes on virtual buying in Metaverse. In addition, structural equation modeling is employed to examine the hypothesized relationship among the variables. The result shows that all the driving factors positive effects consumer shopping enjoyment and then influence purchase intention positively. The finding is significantly fundamental to establish theoretical framework future about virtual shopping in Metaverse, and help marketers realize how to set virtual stores in Metaverse to enhance consumer shopping experience so that they could improve consumer purchase intention in the context.

Wavelet packet transform and improved complete ensemble empirical mode decomposition with adaptive noise based power quality disturbance detection

Yu Mei,Yajing Wang,Xiangke Zhang,Shiqi Liu,Qinqin Wei,Zhenhai Dou 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.8

Given the low accuracy of power quality disturbance (PQD) detection, a PQD detection method based on the wavelet packet transform (WPT) and improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) is proposed in this paper. First, the wavelet packet transform is used to preprocess the signal to suppress noise interference. Then, ICEEMDAN technology is adopted to calculate the local mean value by adding adaptive noise. In addition, different intrinsic mode functions (IMFs) are obtained through residual subtraction. Furthermore, the effective IMFs are calculated by the permutation entropy method to reduce false modal components and to suppress residual noise. Finally, a Hilbert transform (HT) is performed to extract the detection signal parameters. The obtained results demonstrate that this method can improve the detection accuracy and PQD speed, which results in a strong anti-noise capability.

Excellent microwave absorption of FeCo/ZnO composites with defects in ZnO for regulating the impedance matching

Bao, Xiukun,Wang, Xiaolei,Zhou, Xinao,Shi, Guimei,Xu, Ge,Yu, Jin,Guan, Yinyan,Zhang, Yajing,Li, Da,Choi, Chuijin Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.769 No.-

<P><B>Abstract</B></P> <P>FeCo/ZnO composites have been successfully prepared through liquid-phase reduction process for the formation of FeCo polyhedrons and sequentially thermal decomposition of colloidal mixture of FeCo and Zn(Ac)<SUB>2</SUB>·2H<SUB>2</SUB>O under nitrogen atmospheres. ZnO nanoparticles are homogeneously deposited on the surface of FeCo polyhedrons and the level of oxygen-vacancy defects in ZnO can be elevated with the increase of ZnO content. By comparison with FeCo polyhedrons, FeCo/ZnO composites exhibit excellent microwave absorption. The optimal RL value can reach −34.8 dB at 14.8 GHz and effective bandwidth (RL < −10 dB) is 5.1 GHz in the frequency range of 12.4–17.5 GHz with a matching thickness of 1.5 mm. The integrated bandwidth with RL < −10 dB can reach 14.1 GHz covering 3.4–17.5 GHz. Theory analysis demonstrates the interfacial polarization, dipole polarization and high conductivity due to oxygen-vacancy defects in FeCo/ZnO composites contribute to enhancement of dielectric loss capacity, which is more favorable for impedance matching.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The preferable impedance matching of FeCo/ZnO composites can be achieved by regulating the ZnO content. </LI> <LI> The optimal reflection loss (RL) can reach −34.8 dB with a matching thickness of 1.5 mm. </LI> <LI> The effective bandwidth with RL < −10 dB achieve 14.1 GHz covering 3.4–17.5 GHz with integrated thickness of 1.5–5 mm. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Residual current fault type recognition based on S3VM and KNN cooperative training

Zhang, Xiangke,Wang, Yajing,Dou, Zhenhai,Wang, Wei,Bai, Yunpeng The Korean Institute of Power Electronics 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.11

It is difficult to detect the residual current of specific fault types in low-voltage distribution networks, which results in few labeled residual current samples. Thus, it is difficult to recognize the fault types of residual current. To solve this problem, a cooperative training classification model based on an improved squirrel search algorithm (ISSA) for a semi-supervised support vector machine (S3VM) and the k-nearest neighbor (KNN) is proposed (ISSA-S3VM-KNN). First, the residual current is decomposed into k intrinsic mode functions (IMFs) by variational mode decomposition (VMD), and the characteristic parameters of the IMFs are extracted to obtain a characteristic dataset for establishing a classification model. Second, to solve the problem where it is difficult to the select parameters (such as the penalty factors, slack variables and kernel function) of a S3VM, an ISSA parameter optimization method is proposed to self-adaptively select the optimal combination of parameters for the S3VM. Finally, the KNN is used to verify the classification results of an ISSA-S3VM through cooperative training, which further improves the classification accuracy of the S3VM for unlabeled residual current samples. Classification results of measured and simulation data show that the classification accuracy of the ISSA-S3VM-KNN is higher than that of the SVM-BPNN, WE-AE-BPNN, and PSO-SVM. The ISSA-S3VM-KNN provides a certain theoretical basis for achieving fast and accurate residual current fault type recognition.

Recent insights into autophagy and metals/nanoparticles exposure

Li Qiong,Feng Yajing,Wang Ruike,Liu Rundong,Ba Yue,Huang Hui 한국독성학회 2023 Toxicological Research Vol.39 No.3

Some anthropogenic pollutants, such as heavy metals and nanoparticles (NPs), are widely distributed and a major threat to environmental safety and public health. In particular, lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), and mercury (Hg) have systemic toxicity even at extremely low concentrations, so they are listed as priority metals in relation to their significant public health burden. Aluminum (Al) is also toxic to multiple organs and is linked to Alzheimer’s disease. As the utilization of many metal nanoparticles (MNPs) gradually gain traction in industrial and medical applications, they are increasingly being investigated to address potential toxicity by impairing certain biological barriers. The dominant toxic mechanism of these metals and MNPs is the induction of oxidative stress, which subsequently triggers lipid peroxidation, protein modification, and DNA damage. Notably, a growing body of research has revealed the linkage between dysregulated autophagy and some diseases, including neurodegenerative diseases and cancers. Among them, some metals or metal mixtures can act as environmental stimuli and disturb basal autophagic activity, which has an underlying adverse health effect. Some studies also revealed that specific autophagy inhibitors or activators could modify the abnormal autophagic flux attributed to continuous exposure to metals. In this review, we have gathered recent data about the contribution of the autophagy/mitophagy mediated toxic effects and focused on the involvement of some key regulatory factors of autophagic signaling during exposure to selected metals, metal mixtures, as well as MNPs in the real world. Besides this, we summarized the potential significance of interactions between autophagy and excessive reactive oxygen species (ROS)-mediated oxidative damage in the regulation of cell survival response to metals/NPs. A critical view is given on the application of autophagy activators/inhibitors to modulate the systematic toxicity of various metals/MNPs.