Hybrid nanofiltration membranes prepared by a simultaneous synthesis method for precise molecular separation

Chenwei Li,Guoying Feng,Zhiguo Yan,Shaoping Li,Man Xu,Cunwen Wang,Yanbo Li 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.116 No.-

Incorporation of nanofillers is an option to break through the trade-off of nanofiltration membranes. Inthe present work, a simultaneous synthesis method, ZIF and selective layer formed in one step, was proposedto prepare hybrid nanofiltration membrane. Co2+ ions pre-assembled on hydrolyzed polyacrylonitrile(PANH) support provided nucleation sites for ZIF-67 formation. The growth of ZIF-67 and theformation of polyethyleneimine (PEI) selective layer on the support completed in one step through codepositingof a solution of PEI and Hmim (2-methylimidazole). The feasibility of the simultaneous synthesismethod was verified by using different supports, PEIs, and the precursor concentrations. All resultsshow that ZIF-67 incorporation improved the water permenace, without significant compromising ofmembrane rejection. At an optimized condition, the obtained hybrid composite membrane showed highpermeance of 35 L/(m2*h*bar) and rejection of 93% toward PEG 200. The permeance increased by about150%–200% compared with the membrane without ZIF-67. Meanwile, the rejections of salts of the hybridmembrane were very low, exhibiting outstanding organic selectivity.

Surface nanobubbles and their roles in flotation of fine particles – A review

Chenwei Li,Haijun Zhang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.106 No.-

The study in the field of surface nanobubbles has received great progresses since surface nanobubbleswere imaged with atomic force microscopy in 2000. Meanwhile, the interest in developing new flotationtechniques for separating fine particles keeps increasing. Surface nanobubbles are showing a great potentialof application in the field of mineral processing. The formation of agglomerations composed of fineminerals and the easier attachment of a mineral particle to a flotation bubble are the mechanism forthe improved flotation performance in the presence of surface nanobubbles. In this work, various aspectsregarding surface nanobubbles including the methods for generation, measurement and identification ofsurface nanobubbles, the responses of surface nanobubbles to external stimuli including pH, salts, surfactants,temperature, pressure, ultrasonication et al., where flotation is usually performed are summarized. At last, we reviewed recent progresses for surface nanobubbles in flotation. This review gives perspectivesfor further research in the future.

Effects of a naturally derived surfactant on hydrate anti-agglomeration using micromechanical force measurement

Mingzhong Li,Sanbao Dong,Bofeng Li,Chenwei Liu 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.67 No.-

The performance of a hydrate anti-agglomerant (AA) on cyclopentane (CyC5) hydrate anti-agglomeration at various concentrations (0–1 wt%, based on the oil phase) using MMF apparatus has been investigated. At low AA concentrations up to 0.01 wt%, the AA reduces the cohesion force (capillary force) by reducing the CyC5-water interfacial tension. At concentrations higher than 0.1 wt%, hydrate hydrophobicity alternation and AA’s thermodynamic inhibition effects are the main part of AA’s mechanism. Additionally, a “temporary agglomeration” phenomenon caused by surface melting of the hydrate particles is also observed, which may indicate the AA’s weak ability to produce stable water-CyC5 interface.

WLSD: A Perceptual Stimulus Model Based Shape Descriptor

( Jiatong Li ),( Baojun Zhao ),( Linbo Tang ),( Chenwei Deng ),( Lu Han ),( Jinghui Wu ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.12

Motivated by the Weber`s Law, this paper proposes an efficient and robust shape descriptor based on the perceptual stimulus model, called Weber`s Law Shape Descriptor (WLSD). It is based on the theory that human perception of a pattern depends not only on the change of stimulus intensity, but also on the original stimulus intensity. Invariant to scale and rotation is the intrinsic properties of WLSD. As a global shape descriptor, WLSD has far lower computation complexity while is as discriminative as state-of-art shape descriptors. Experimental results demonstrate the strong capability of the proposed method in handling shape retrieval.

From Traditional Payment Habit to Mobile Payment Habit: Examining the Mechanisms of Payment Habit Change

Cong Qi,Chenwei Li 한국경영정보학회 2023 Asia Pacific Journal of Information Systems Vol.33 No.2

In recent years, mobile payments gradually entered the lifestyles of consumers. For some economies, mobile payment service is exploding at an impressive rate. While for others, the adoption speed remains slow and most of the consumers are hesitating to continue using these mobile payment platforms after an initial try. We believe this is largely because of the presence of the entrenched traditional payment habits. Based on psychology theory of habit, this study focuses on the habit change from the traditional payment habit to the new mobile payment habit. It discusses how is mobile payment habit formed, and how does mobile payment habit nudge continuous use. Data are collected among 154 Hong Kong students. The data analysis results reveal that traditional payment habit, compatibility dimension of facilitating conditions, perceived usefulness and perceived enjoyment have significant influences on the formation of and change to mobile payment habit; mobile payment habit also has a significant impact on continuance use. However, satisfaction was not found to be influential in mobile payment habit formation. Our study highlights the importance of traditional psychology theory of habit in the area of mobile payment habit substitution. It also innovates in verifying the co-existence of traditional payment habit and mobile payment habit and understand the mechanism of which traditional payment habit influences mobile payment habit.

Effects of Phytosterol Ester on the Fatty Acid Profiles in Rats with Nonalcoholic Fatty Liver Disease

Lihua Song,Haiyue Zhou,Wenjuan Yu,Xinwen Ding,Li Yang,Jiayi Wu,Chenwei Song 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.2

Both serum and hepatic fatty acid (FA) compositions differ among nonalcoholic hepatic steatosis, nonalcoholic steatohepatitis, and healthy subjects. The severity of the above liver disease is closely associated with the concentration and composition of FAs. Our previous study found that phytosterol ester (PSE) could alleviate hepatic steatosis in nonalcoholic fatty liver disease rats. The aims of this work were to explore the effects of PSE (0.05/100 g·body weight) on FA profiles and the mRNA levels of FA metabolism-related genes. Compared with a high-fat diet alone group, PSE treatment significantly decreased hepatic saturated fatty acid levels (P < .05) and increased monounsaturated fatty acid (especially C16:1 n-7) levels in the liver, serum, and adipose tissue and polyunsaturated fatty acid levels in the serum and liver (P < .05) after 12 weeks of intervention. In particular, PSE treatment increased the level of C22:5 n-3, an FA that was negatively correlated with the degree of hepatic steatosis in the serum, liver, and adipose tissue. The increases in some unsaturated fatty acids are probably related to the upregulation of stearoyl-coenzyme A desaturase-1 and fatty acid desaturase-1.

Room temperature pH-dependent ammonia gas sensors using graphene quantum dots

Chen, Wei,Li, Fushan,Ooi, Poh Choon,Ye, Yun,Kim, Tae Whan,Guo, Tailiang Elsevier 2016 Sensors and actuators. B, Chemical Vol.222 No.-

<P><B>Abstract</B></P> <P>We report a simple solution-process route to realize ammonia (NH<SUB>3</SUB>) gas sensor based on graphene quantum dots (GQDs). Transmission electron microscopy analysis confirmed that the 8–10nm GQDs were formed from multi-walled carbon nanotubes by using ultrasonication treatment. The as-fabricated gas sensor showed promising selectivity response when expose to NH<SUB>3</SUB> ambient at room temperature. It is indicated that by adjusting the pH value of the aqueous GQDs in acidic and neutral, two types of gas sensors with contrary current responses could be obtained, which might be resulted from quantum confinement, edge effects and presence of functional groups on GQDs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We report an NH<SUB>3</SUB> gas sensor at room temperature based on graphene quantum dots. </LI> <LI> GQDs were formed from multi-walled carbon nanotubes by ultrasonication treatment. </LI> <LI> Adjusting the pH value of the GQDs can lead to gas sensors with different behavior. </LI> <LI> Sensing mechanism might be resulted from the unique properties of GQDs. </LI> </UL> </P>

A Patent Pool Partner Selection Method Based on Time Degrees and Intuitionistic Fuzzy Entropy

Chen Wei,Li Jinqiu,Lin Chaoran,Yang Zaoli 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.7

Patent pool partner selection is a typical multi-attribute decision making (MADM) problem, and that based on intuitionistic fuzzy (IF) theory is widely applied in this research field. In this paper, a dynamic MADM method based on time degrees and intuitionistic fuzzy entropy (IFE) is proposed. We determine the attribute weights under different time sequence based on IFE; and establish a non-linear programming model combining the principle of time degrees with grey entropy theory to calculate time weights vector; the dynamic intuitionistic fuzzy weighted geometric-operator(DIFWG) is used to aggregate different periods of weighted intuitionistic fuzzy decision-making matrix; TOPSIS was integrated into dynamic intuitionistic fuzzy multiple attribute decision making (DIF-MADM), by calculating the relative closeness of alternatives with ideal solution, we obtain the optimum alternative; finally, an example is given to illustrate the applicability and rationality of the proposed approach.

Experimental investigation of the whirl and generated forces of rotating cylinders in still water and in flow

Chen, Wei,Rheem, Chang-Kyu,Lin, Yongshui,Li, Ying The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1

The whirl and generated forces of rotating cylinders with different diameters placed in still water and in flow are studied experimentally. For the rotating cylinders in still water, the Same Frequency Whirl (SFW) and Different Frequency Whirl (DFW) have been identified and illustrated. The corresponding SFW and DFW areas are divided. The Root Mean Square (RMS) values of the generated force coefficient dramatically increase in the defined ranges of Resonance I and Resonance II. For the rotating cylinders in flow, the hydrodynamics, SFW and DFW are illustrated. The hydrodynamic, SFW and DFW areas are divided. The RMS values of the generated forces in the range of Resonance II are much smaller than those in still water due to the generated lift forces. The discussion suggests that the frequency of the DFW may equal multiple times or one-multiple times that of the rotating frequency: the whirl direction of the DFW with multiple times the frequency of the rotating frequency is the same as the rotating direction. The whirl direction of the DFW with one-multiple times frequency of the rotating frequency is opposite to the rotating direction.

Experimental investigation of the whirl and generated forces of rotating cylinders in still water and in flow

Chen, Wei,Rheem, Chang-Kyu,Lin, Yongshui,Li, Ying The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

The whirl and generated forces of rotating cylinders with different diameters placed in still water and in flow are studied experimentally. For the rotating cylinders in still water, the Same Frequency Whirl (SFW) and Different Frequency Whirl (DFW) have been identified and illustrated. The corresponding SFW and DFW areas are divided. The Root Mean Square (RMS) values of the generated force coefficient dramatically increase in the defined ranges of Resonance I and Resonance II. For the rotating cylinders in flow, the hydrodynamics, SFW and DFW are illustrated. The hydrodynamic, SFW and DFW areas are divided. The RMS values of the generated forces in the range of Resonance II are much smaller than those in still water due to the generated lift forces. The discussion suggests that the frequency of the DFW may equal multiple times or one-multiple times that of the rotating frequency: the whirl direction of the DFW with multiple times the frequency of the rotating frequency is the same as the rotating direction. The whirl direction of the DFW with one-multiple times frequency of the rotating frequency is opposite to the rotating direction.