Preparation and application of graphene oxide nanocomposites loaded with enzymes and liposomes

Yu Yifan,Wang Ruyuan,Li Meilin,Li Shanshan,Fan Aiping 한국탄소학회 2023 Carbon Letters Vol.33 No.4

The present studies explored the possibility of immobilizing phosphocholine (PC) liposomes on the surface of graphene oxide (GO) which was pre-adsorbed with two kinds of enzymes, horseradish peroxidase and glucose oxidase. The transmission electron microscope images showed that the PC liposomes adsorbed onto the GO surface kept integrity. By using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)-encapsulated liposomes, a one-step colorimetric assay for glucose was developed. In the presence of glucose, the GO nanocomposites catalyzed the cascade enzymatic reaction producing colorimetric signals directly. Under the optimal conditions, the GO nanocomposites produced linearly increased colorimetric signal with increased concentrations of glucose ranging from 50 to 500 µM. The detection limit was 33 µM. The GO nanocomposites also exhibited good selectivity for the detection of glucose and were able to detect glucose in human serum.

A hidden anti-jamming method based on deep reinforcement learning

( Yifan Wang ),( Xin Liu ),( Mei Wang ),( Yu Yu ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.9

In the field of anti-jamming based on dynamic spectrum, most methods try to improve the ability to avoid jamming and seldom consider whether the jammer would perceive the user's signal. Although these existing methods work in some anti-jamming scenarios, their long-term performance may be depressed when intelligent jammers can learn user's waveform or decision information from user's historical activities. Hence, we proposed a hidden anti-jamming method to address this problem by reducing the jammer's sense probability. In the proposed method, the action correlation between the user and the jammer is used to evaluate the hiding effect of the user's actions. And a deep reinforcement learning framework, including specific action correlation calculation and iteration learning algorithm, is designed to maximize the hiding and communication performance of the user synchronously. The simulation result shows that the algorithm proposed reduces the jammer's sense probability significantly and improves the user's anti-jamming performance slightly compared to the existing algorithms based on jamming avoidance.

Poly(3,4-ethylenedioxythiophene)-Coated Conductive Polyester Non-woven Fabric Prepared by Enzymatic Polymerization

Yifan Cui,Zhe Jiang,Yu Zhou,Qiang Wang,Man Zhou,Ping Wang,Yuanyuan Yu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.6

Conductive polyester non-woven fabric was prepared using horseradish peroxidase (HRP) catalytic agent, 3,4-ethylenedioxythiophene monomer and poly(p-styrenesulfonic acid) dopant. The electrical resistance of the preparedconductive polyester non-woven fabric was reduced to 1.3×104 Ω from 1014 Ω of the raw polyester non-woven fabric becauseof the addition of poly(3,4-ethylenedioxythiophene) the conductivity of conductive polyester non-woven fabric decreased byabout 60 % after 300 bending cycles. Notably, the temperature of the conductive polyester non-woven fabric increased by73.1 °C after 150 s of light irradiation from a lamp source, while that of the raw polyester non-woven fabric increased by only19.4 °C under the same conditions.

Synthesis and Structure Properties of Flame Retardant and Cationic Dyeable Polyamide 6 Modified with 5-sulfoisophthalic Acid Sodium and Melamine Cyanurate

Yifan Fu,Yun Teng,Guomin Yu,Cuiyu Yin 한국섬유공학회 2018 Fibers and polymers Vol.19 No.7

Unmodified polyamide 6 commonly dyed with acid dyes, and has no flame-retarded properties. So they are flammable and can be easily stained by foods or drinks that contain acid dyes. However, the acid groups react with amino groups that existed at the end of PA6 chain while using cationic dyes. Thus, the acid dyes can be washed immediately. In this study, the flame retardant and cationic dyeable polyamide 6 (FRCD-PA6) modified with 5-sulfoisophthalic acid sodium (5- SSIPA) and melamine cyanurate (MCA) was successfully prepared by the two-step-melt polymerization method. Firstly, cationic dyeable polyamide 6 (CD-PA6) was prepared with sodium salt from 5-sulfoisphthalic acid. Secondly, melamine cyanurate, as an efficient flame retardant, was blended into the reaction. The chemical and crystalline structures of FRCDPA6 were characterized by the Fourier transform infrared spectroscopy (FT-IR) and wide angle X-ray diffraction (XRD). Their thermal properties were tested by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and morphology was analyzed by SEM, respectively. It had been measured to prove the dispersion of 5-SSIPA and MCA on polyamide 6 matrix. Incorporating with 5-SSIPA created more amorphous regions and rose up the dyeing rate easily, with a highest dyeing rate for about 96.79 %. The effect of varying MCA content on the composites showed more flame retardant and made better heat-resistance. Moreover, with the appropriate addition of MCA content, the limit oxygen index (LOI) reached up to 27, less smoking, no more black smoke, droplet phenomenon was slightly, and flame resistance had greatly improved. Because of the good synergy between 5-SSIPA and MCA, a kind of novel modified polyamide 6 which own both cationic dyeable and efficient flame retardant properties was born.

A new method of phenol degradation by microarc plasma electrolysis

Yifan Zhang,Xiaoyue Jin,Jiahao Yu,Guijun Liu,Ying Wang,Wenbin Xue 한국표면공학회 2017 한국표면공학회 학술발표회 초록집 Vol.2017 No.11

A Case of Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type with Dermatomyositis

( Yu Gong ),( Ke Xue ),( Yifan Hu ),( Rong Wei ),( Yeqiang Liu ),( Hua Cao ),( Yuling Shi ) 대한피부과학회 2021 Annals of Dermatology Vol.33 No.2

The Response of Plant Photosynthesis and Stomatal Conductance to Fine Particulate Matter (PM2.5) based on Leaf Factors Analyzing

Yifan Li,Yujie Wang,Bin Wang,Yunqi Wang,Weiqing Yu 한국식물학회 2019 Journal of Plant Biology Vol.62 No.2

The effects of particles on the photosynthesis ofvegetation, which is a sink for fine particulate matter (PM2.5)deposition, are still not well understood. Here, we carried outindoor measurements to evaluate the variation dynamics ofnet photosynthetic rate and stomatal conductance of fourplant species with different leaf characteristics under differentPM2.5 levels. Then tree leaves were sampled and the grooveproportion, leaf trichome density, stomatal density and stomatalsize were quantitatively studied by scanning electron microscopy(SEM). The stomatal conductance of the 4 species had aclose positive correlation with photosynthetic rate. Netphotosynthetic rate and stomatal conductance declined overtime at elevated PM2.5, and the rate of the decline becamemore rapid with higher concentration of PM2.5. The inhibitingeffect might be caused by the closure of the stomata and thedecrease of stomatal conductance, which was proved by thereduction of the stomatal size of under the condition of PM2.5pollution. Leaf trichome and groove seemed to show aprotective role for plants from PM2.5 exposure and be responsiblefor the difference of photosynthetic rate and stomatal conductanceunder the condition of PM2.5 pollution. The higher grooveproportion and the presence of trichomes on the leaf surfacein Neolitsea aurata and Lindera kwangtungensis absorbedsome particulate matters and buffered the effect of PM2.5pollution on stomata.

Loss and Efficiency Analysis of the Brushless Direct Current Motor with an Amorphous Stator Core

Lai Yifan,Hu Xiaolu,Shi Guibing,Yu Juntao,Wang Li,Gao Zhifeng 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

Due to the demand for energy conservation, the loss and efficiency of a brushless direct current (BLDC) motor is investigated. In order to improve the motor efficiency, we make efforts to reduce the loss by replacing the silicon steel (SS) stator with amorphous metal (AM) stator and improving the motor design. The motor performance is analyzed by simulations and experiments, and the processing influence on loss of AM material is also considered. It shows that the performance of the AM core deteriorates due to the stress introduced during the core processing, but the utilization of AM material and the optimization design can improve the motor efficiency by 4.76%. In addition, the weight of the motor is reduced by 11.36% than that of the initial motor. This research can provide a reference for the initial design and performance evaluation of AM BLDC motors.

Deposition path-dependent lightweight support design and its implication to self-support topology optimization

Wang Yifan,Wu Tao,Liu Jikai,Yu Huangchao 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.6

This paper presents a lightweight support design method for material extrusion-type three-dimensional printed panel structures that innovatively involves the deposition path curvature information for support point determination. Specifically, this support design method provides a robust segmentation algorithm to divide the filament deposition paths into segments based on the curvature sign alternating condition, and then searches for the fewest support points for the filaments counting on the experimentally calibrated relationship between the maximum allowable self-support distance and the local mean curvature. The proposed method features in generating thin-walled skeleton-ray styled support structures that are lightweight while providing firm support for the panels. More importantly, the support design method provides a new type of self-support criterion for structural topology optimization involving non-designable planar panels, i.e., only a sparse point set would be sufficient to support the panel. Consequently, more materials could be spent on enhancing the load-bearing capacity instead of being wasted on oversupporting. The achievable structural performances from self-support topology optimization with this new self-support criterion can improve significantly. Support design and printing tests were conducted on a few panel structures that validated the improved support effect compared with equal-volume supports generated by commercial software. Equidistant and gap-free deposited filaments, no filament collapse due to insufficient support, and no isolated voids reflect the improved support effect. The improved self-support topological design was also validated through a comparative numerical case study, and a compliance reduction of 7.76% was achieved.

Investigation of the interstitial oxygen behaviors in vanadium alloy: A first-principles study

Xingming Zhang,Yifan Li,Qiaoling He,Ruilian Li,Lei Deng,Liang Wang,Xunlin Liu,Jianfeng Tang,Huiqiu Deng,Wang-Yu Hu 한국물리학회 2018 Current Applied Physics Vol.18 No.2

This study aims at characterizing the interstitial Oxygen (O) behaviors in the Vanadium (V) Alloy by means of the first-principles calculations. For this, the interations between vacancy (Vac) and O interstitil atom are studied in detail to obtain the binding energies and stable structures of the complexes. It can be seen that monovacancy binding with two O atoms occupied the opposing octahedral stie are particularly stable, and is liable to form VacO2 cluster in the V alloys. According to the mass action analysis, the predicted temperature dependence of the concentration for VacOn complexes are presented. Apart from monovacancy, we also consider the trapping behavior of vacancy cluster on the O atoms. The results also prove that one vacancy can trap two O atoms in the V alloys. Based the diffusion theory, we obtain the diffusion coefficients as a function of temperature with or without the vacancy effect in the V alloys. The predicted O diffusion coefficients in defect-free V alloys from our first-principles calculations are in excellent ageement with the experimental data, meanings that the vacancy-limited mechanism does not play the key role for O diffusion in V alloys. Regarding the interactions between vacancy, solutes and O atom, combining with the diffusion barriers of O affected by vacancy and solute, we infer the formation mechanism of the precipitates in the V alloys.