Persistent free radicals in carbon-based materials on transformation of refractory organic contaminants (ROCs) in water: A critical review

Qin, Yaxin,Li, Guiying,Gao, Yanpeng,Zhang, Lizhi,Ok, Yong Sik,An, Taicheng Elsevier 2018 Water research Vol.137 No.-

<P><B>Abstract</B></P> <P>With the increased concentrations and kinds of refractory organic contaminants (ROCs) in aquatic environments, many previous reviews systematically summarized the applications of carbon-based materials in the adsorption and catalytic degradation of ROCs for their economically viable and environmentally friendly behavior. Interestingly, recent studies indicated that carbon-based materials in natural environment can also mediate the transformation of ROCs directly or indirectly due to their abundant persistent free radicals (PFRs). Understanding the formation mechanisms of PFRs in carbo-based materials and their interactions with ROCs is essential to develop their further applications in environment remediation. However, there is no comprehensive review so far about the direct and indirect removal of ROCs mediated by PFRs in amorphous, porous and crystalline carbon-based materials. The review aims to evaluate the formation mechanisms of PFRs in carbon-based materials synthesized through pyrolysis and hydrothermal carbonization processes. The influence of synthesis conditions (temperature and time) and carbon sources on the types as well as the concentrations of PFRs in carbon-based materials are also discussed. In particular, the effects of metals on the concentrations and types of PFRs in carbon-based materials are highlighted because they are considered as the catalysts for the formation of PFRs. The formation mechanisms of reactive species and the further transformation mechanisms of ROCs are briefly summarized, and the surface properties of carbon-based materials including surface area, types and number of functional groups, etc. are found to be the key parameters controlling their activities. However, due to diversity and complexity of carbon-based materials, the exact relationships between the activities of carbon-based materials and PFRs are still uncertain. Finally, the existing problems and current challenges for the ROCs transformation with carbon-based materials are also pointed out.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Abundant of PFRs formed in carbon-based materials during the synthesis process. </LI> <LI> The PFRs types and concentrations affected by synthesis conditions. </LI> <LI> The PFRs can activate oxidants and reductants to degrade organic contaminants. </LI> <LI> The PFRs can directly react with organic contaminants. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Enhanced photocatalytic mechanism of Ag₃PO₄ nano-sheets using MS₂ (M = Mo, W)/rGO hybrids as co-catalysts for 4-nitrophenol degradation in water

Zhang, Weiping,Li, Guiying,Wang, Wanjun,Qin, Yaxin,An, Taicheng,Xiao, Xinyan,Choi, Wonyong Elsevier 2018 Applied Catalysis B Vol.232 No.-

<P><B>Abstract</B></P> <P>A chemically modified Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>(M = Mo, W)/rGO composite was firstly synthesized via a liquid-exfoliation solvothermal method. The structure, morphology, optical properties and composition were characterized by X-ray diffraction, FT-IR spectroscopy, scanning electron microscopy, UV–vis diffuse reflectance spectra and X-ray photoelectron spectroscopy, respectively. The characterization results indicated that compact structure could be obtained by using this typical method due to in-situ chemical modification, which could also control the sizes of Ag<SUB>3</SUB>PO<SUB>4</SUB> nano-sheets by adding MS<SUB>2</SUB>/rGO hybrids. More importantly, the resultant Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>/rGO composite exhibited higher photocatalytic activity and stability toward the degradation of 4-nitrophenol than pure Ag<SUB>3</SUB>PO<SUB>4</SUB> under sunlight irradiation. The stable structure of Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>/rGO was closely related with Z-scheme electronic structure and electrical conductivity of MS<SUB>2</SUB>/rGO hybrids, leading to a higher consumption and transfer of photogenerated electrons. However, by controlling the amounts of MS<SUB>2</SUB>/rGO hybrids, more stable but lower photocatalytic activity composites could be obtained. Further analysis found that the holes and O<SUB>2</SUB> <SUP>−</SUP> were the main reactive species involved in the photocatalytic degradation of 4-nitrophenol. In addition, possible photocatalytic degradation pathways of 4-nitrophenol were also proposed based on the identified intermediates. The findings of this work may provide a new method to design efficient composites for photocatalytic degradation of organic pollutants.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>/rGO catalyst was fabricated via a liquid-exfoliation solvothermal method. </LI> <LI> Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>/rGO has high photocatalytic activity and stability under sunlight. </LI> <LI> The stability of Ag<SUB>3</SUB>PO<SUB>4</SUB>@MS<SUB>2</SUB>/rGO was due to its rapid transfer of photogenerated e<SUP>−</SUP>. </LI> <LI> h<SUP>+</SUP> and O<SUB>2</SUB> <SUP>−</SUP> were the main RSs in photocatalytic degradation of 4-nitrophenol. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

SERS study of surface plasmon resonance induced carrier movement in Au@Cu₂O core-shell nanoparticles

Chen, Lei,Zhang, Fan,Deng, Xin-Yu,Xue, Xiangxin,Wang, Li,Sun, Yantao,Feng, Jing-Dong,Zhang, Yongjun,Wang, Yaxin,Jung, Young Mee Elsevier 2018 Spectrochimica acta. Part A, Molecular and biomole Vol.189 No.-

<P><B>Abstract</B></P> <P>A plasmon induced carrier movement enhanced mechanism of surface-enhanced Raman scattering (SERS) was investigated using a charge-transfer (CT) enhancement mechanism. Here, we designed a strategy to study SERS in Au@Cu<SUB>2</SUB>O nanoshell nanoparticles with different shell thicknesses. Among the plasmonically coupled nanostructures, Au spheres with Cu<SUB>2</SUB>O shells have been of special interest due to their ultrastrong electromagnetic fields and controllable carrier transfer properties, which are useful for SERS. Au@Cu<SUB>2</SUB>O nanoshell nanoparticles (NPs) with shell thicknesses of 48–56nm are synthesized that exhibit high SERS activity. This high activity originates from plasmonic-induced carrier transfer from Au@Cu<SUB>2</SUB>O to 4-mercaptobenzoic acid (MBA). The CT transition from the valence band (VB) of Cu<SUB>2</SUB>O to the second excited π-π* transition of MBA, and is of b<SUB>2</SUB> electronic symmetry, which was enhanced significantly. The Herzberg-Teller selection rules were employed to predict the observed enhanced b<SUB>2</SUB> symmetry modes. The system constructed in this study combines the long-range electromagnetic effect of Au NPs, localized surface plasmon resonance (LSPR) of the Au@Cu<SUB>2</SUB>O nanoshell, and the CT contribution to assist in understanding the SERS mechanism based on LSPR-induced carrier movement in metal/semiconductor nanocomposites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We designed a shell-dependent Au@Cu<SUB>2</SUB>O nanoshell for SERS study. </LI> <LI> SERS contribution enables us to understand the possible enhancement of hybrid nanostructures. </LI> <LI> LSPR-induced carrier movement in Au@Cu<SUB>2</SUB>O nanocomposites. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>We designed the shell-dependent Au@Cu<SUB>2</SUB>O core-shell nanoparticles (NPs) for SERS study. For the electron-hole pairs in the Cu<SUB>2</SUB>O, the plasmon induced resonant energy transfer from Au to the Cu<SUB>2</SUB>O and the direct electron transfer simultaneously which can be observed from the SERS intensity.</P> <P>[DISPLAY OMISSION]</P>

The Correlation between Thyrotropin and Dyslipidemia in a Population-based Study

Li Lu,Beibei Wang,Zhongyan Shan,Fengwei Jiang,Xiaochun Teng,Yanyan Chen,Yaxin Lai,Jiani Wang,Haibo Xue,Sen Wang,Chenyan Li,He Liu,Ningna Li,Jiashu Yu,Liangfeng Shi,Xin Hou,Qian Xing,Xue Bai,Weiping Te 대한의학회 2011 Journal of Korean medical science Vol.26 No.2

This study investigated the relationship between serum thyrotrophin levels and dyslipidemia in subclinical hypothyroid and euthyroid subjects. A total of 110 subjects with subclinical hypothyroidism and 1,240 euthyroid subjects enrolled in this study. Patients with subclinical hypothyroidism had significantly lower high density lipoprotein cholesterol (HDL-C) levels than those who were euthyroid. The lipid profiles were each categorized and mean thyrotrophin levels were higher in subjects in the dyslipidemia subclasses than subjects in the normal subclasses. Thyrotrophin was positively associated with serum triglyceride and negatively associated with serum HDL-C in women. Thyrotrophin was also positively associated with total cholesterol (TC) in the overweight population along with TC and LDL-C in overweight women. In the euthyroid population, thyrotrophin was positively associated with TC in the overweight population. In conclusion, serum thyrotrophin was correlated with dyslipidemia in subclinical hypothyroid and euthyroid subjects; the correlation was independent of insulin sensitivity.

RESEARCH ON MILLIMETER WAVE RADAR SIMULATION MODEL FOR INTELLIGENT VEHICLE

Xin Li,Weiwen Deng,Sumin Zhang,Yaxin Li,Shiping Song,Shanshan Wang,Guanyu Wang 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.2

Radar simulation models can effectively overcome the drawbacks of real vehicle experiment and speed up the development process of intelligent vehicle technologies based on millimeter wave radar via virtual testing. However, there are still many gaps between the radar model using in the virtual driving environment and the real radar. In this paper, a novel simulation model of intelligent vehicle millimeter wave radar is proposed. Based on the analysis of the real radar performance in typical application scenes, the radar model considers the mechanism and characteristics of the vehicle radar synthetically and a systematic radar modeling architecture with innovation is introduced. The highlights of this radar model include the design of the RCS simulation model for radar targets with both high accuracy and real-time performance, the establishment of the quantitative false alarm model, missed detection model and measurement error simulation model. Vast amounts of data collected by real vehicle radar are applied to fetch model parameters and verify the accuracy of the radar model. Simulation results show that the proposed model can reach both high reliability and computational efficiency.

Simultaneous activation of KHSO5 and BuOOH by iron octacarboxyphthalocyanine loaded on fly ash microspheres to boost pollutant degradation

Dapeng Li,Peng Zhang,Jiangtao Duan,Yaxin Wu,Na Ding,Zhenyu Wan,Longqi Chen,Jingli Xu,Suxiang Ge,Juntao Ma 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.114 No.-

Utilization of fly ash (FA) wastes as the carriers of catalysts for the environmental application is an economicand practical strategy for their low cost, easy accessibility and thermal stability. However, mostcatalysts immobilized on fly ash were metal or metal oxides, some potential catalysts such as metalphthalocyanine complexes have not been reported upon their heterogeneous catalysis with FA as the carriers. In this paper, highly active iron octacarboxyphthalocyanine were immobilized onto the bird nestlikesurfaces of fly ash microspheres after NaOH activation. It is noted that the FeOCPc@FA compositeswith only 2 wt.% exhibited the high catalytic efficiency in the organic dye degradation. The high concentrationof 30 mg/L rhodamine B and methylene blue could be fast decolorized in the presence ofFeOCPc@FA–2 % and KHSO5. Moreover, the ultrafast decolorization of these dyes could be observed inthe catalytic system composed of FeOCPc@FA–2 %, KHSO5 and BuOOH (tert-butyl hydroperoxide). Simultaneous activation of KHSO5 and BuOOH could be realized in our designed catalytic system. Based on the structural characterizations of composites and active species generated during the catalyticprocesses, the probable generation pathway of metal–oxygen active species and various radicals wereanalyzed to explicate the catalytic mechanism. Our investigation provides a high efficiency, low costand environmentally friendly strategy for advanced oxidation treatment of organic pollutants.

An Enhanced Model Predictive Controller for Quadrotor Attitude Quick Adjustment with Input Constraints and Disturbances

Bin Li,Yaxin Wang 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.2

In this paper, a fuzzy model predictive controller based on disturbance observer is proposed for attitude control of quadrotor Unmanned Aerial Vehicle (UAV) subject to input constraints and disturbances. The proposed algorithm consists of a fuzzy predictive controller based on a T-S fuzzy model and a disturbance observer. FMPC can handle the constraints of the system and disturbance observer is designed to compensate the disturbance effect. In this work, the Takagi-Sugeno fuzzy model is used for the predictive controller, which is used to more approximate the nonlinear model to obtain a faster convergence speed. To test the effectiveness of the proposed algorithm, simulations for the quadrotor are implemented and the tracking performance among the proposed method, existing linear predictive controller and PID algorithm is compared with each other. Both simulation and experiment results show the effectiveness of using fuzzy model and disturbance observer.

Effects of Florfenicol and Chromium (III) on Humoral Immune Response in Chicks

Cao, Jiyue,Li, Kui,Lu, Xiaocong,Zhao, Yaxin Asian Australasian Association of Animal Productio 2004 Animal Bioscience Vol.17 No.3

One hundred and sixty day-old Hainan chicks were randomly allotted into eight pens to investigate the effect of different dietary concentrations of chromium (Cr) in the form of chromium chloride, and different dosages of florfenicol on humoral immune responses by determining antibody titers to Newcastle disease (ND) vaccines using the hemagglutination inhibition test. The results indicated that ND antibody titers were significantly higher in chicks receiving Cr at low (5 mg/kg feed) and middle (10 mg/kg feed) dose compared with the control (p<0.01). However, ND antibody titers were significantly decreased in chicks receiving Cr at a high dosage of 500 mg/kg feed (p<0.01), though the ND antibody titers of the early days (d 21 and d 28 of age) were higher than that of the control group. It is suggested that excessive Cr intake has detrimental effects on ND antibody production in chicks. No significantly lower response was measured in chicks that received florfenicol at a low dosage of 50 mg/kg feed (p>0.05), but the ND antibody titers were significantly decreased in chicks receiving 200 and 400 mg/kg feed of the drug (p<0.01). The ND antibody titers of group receiving 200 mg/kg feed of florfenicol plus 10 mg/kg Cr were slightly higher than that of the group receiving single florfenicol of 200 mg/kg although, no significant differences were observed between these two treatments. It is suggested that the humoral immune response impaired by florfenicol (200 mg/kg feed) could not be significantly reversed by Cr (10 mg/kg feed).

Effects of Pressure and Deposition Time on the Characteristics of In2Se3 Films Grown by Magnetron Sputtering

Yong Yan,Shasha Li,Yufeng Ou,Yaxin Ji,Zhou Yu,Lian Liu,Chuanpeng Yan,Yong Zhang,Yong Zhao 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.6

Crystalline In2Se3 films were fabricated by magnetron sputtering from a sintered In2Se3-compound target and the effects of the deposition parameters, including the working pressure and deposition time, on the phase composition, structure, morphology, and optical properties were clarified. Single-phase κ-In2Se3 was prepared at 4.0 Pa, but γ-In2Se3 was recognized when the working pressure was lower than 4.0 Pa. The optical transmittance of the films decreased to 45% and the optical band gap varied from 2.9 to 2.0 eV with increasing film thickness from 80 to 967 nm. Metal-semiconductor-metal (MSM) photodetectors based on γ-In2Se3 thin films with various thicknesses were also fabricated. The result of photosensitivity research on such MSM photodetectors suggests that it may be impossible to fabricate wide-absorption-range MSM devices by just using a single material (γ-In2Se3) because of spatial potential fluctuations in the layers.

Facile preparation and characterization of tough poly(vinyl alcohol) organohydrogels with low friction and self-cleaning properties

Jia Yang,Jiajia Hao,Chen Tang,Yaxin Guo,Mingxin Guo,Zhipeng Li,Shuzheng Liu,Hui Yu,Gang Qin,Qiang Chen 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.116 No.-

Although many hydrogels have been applied to wearable sensors, it is still challenging to simultaneouslyrealize hydrogels with optical transparency, superior mechanical properties, excellent sensing performance,and anti-freezing by using inexpensive raw materials and an easy preparation process. Herein,using ethylene glycol/H2O (EG/ H2O) as a solvent, poly(vinyl alcohol)/EG organohydrogel (PVA/EGOHG) was prepared by a simple heating and frozen-thawing method. Owing to the multifunctionalityof EG (i.e., physical cross-linker, anti-freezer and co-solvent), PVA/EG OHG demonstrated excellent integratedproperties, including high strength, high toughness, and anti-freezing performances. Besides, PVA/EG OHG also showed low friction, self-cleaning, and frost resistance properties. After the introduction ofLiCl, ionically conductive PVA/EG @LiCl organohydrogel was served as a self-cleaning strain sensor, whichcould be long-term stable to detect the motions of human under room and low temperatures. The studyprovides to further understanding of the organohydrogel, which will help us design next-generationhigh-performance organohydrogels.