Cobalt-Porphyrin Modified Three-Dimensional Graphene Hydrogel Electrode for High Performance Asymmetric Supercapacitors

Yuqing Song,Hongfei Wang,Lifeng Yan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.5

Three-dimensional (3D) graphene-based materials have attracted much attention in the field of supercapacitors for their large surface areas and fast electronic conductivity capability. Faradaic pseudo-capacitance materials inside the architecture can enlarge the electrochemical performance of the electrode. Additionally, metal porphyrins are negative electrode active materials for supercapacitors as they have potential high pseudo-capacitance, conductivity and N-doping. The design and preparation of the 3D cobalt-porphyrin modified graphene hydrogels (3D CoP/GHs) is an interesting topic. Here, we have fabricated the 3D CoP/GH by a two-step method. The composite electrode reaches a specific capacitance of 335 F g -1, twice that of pure GHs. At the same time, resistance of the electrode material decreases and the ion transfer is accelerated due to the addition of cobalt-porphyrin. After 10 000 cycles, the 3D CoP/GH maintains its stable specific capacitance retention of 94.11% indicating its excellent cycle life. The cycle life is much better than that of a hydrogel that has not been doped (81.63%) according to our previous work. Then we fabricated an asymmetrical supercapacitor which uses both the 3D CoP/GH and GH as the two electrodes (3D CoP/GHjjGH), and reaches an outstanding energy density of 30.40 Wh kg -1 at a current density of 1 A g -1 while the power density is 749.5 W kg -1.

Optimization Model of EV Charging and Discharging Price Considering Vehicle Owner Response and Power Grid Cost

Zhaoyang Qu,Jiajun Song,Yuqing Liu,Hongbo Lv,Kewei Hu,Jian Sun,Miao Li,Wei Liu,Mingshi Cui,Wanxin Wang 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.6

The problem of load fuctuation in the distribution network and increasing power grid cost input caused by the unpredictable behavior of electric vehicle (EV) users in response to electricity price is investigated in this paper. An optimization model method for the charging and discharging price of electric vehicles is proposed, considering the vehicle owner response and power grid cost. The rule of EV user travel is frst analyzed, and the travel and battery state constraints are defned. Under the constraints of user charging and discharging behavior and battery characteristics, a user transfer rate and unit energy cost function is designed to construct a multi-objective model of charging and discharging price that minimizes electricity expenditure and avoids an increase in power grid investment. Finally, an improved multi-target fsh swarm algorithm is presented to solve the model optimization problem. The example analysis shows that the proposed method can reduce the peak-valley load diference of the system and cost input of the power grid, as well as provide users with regulation ability to access the power grid at diferent time periods

The Effect of Electronic Characteristics of Molecules in Ester Insulating Oils on Streamer Propagation

Wenxiong Mo,Haoyong Song,Qingdan Huang,Yuqing Chen,Wei Wang 한국전기전자재료학회 2022 Transactions on Electrical and Electronic Material Vol.23 No.6

Ester insulating oils are the preferred dielectric fluids of choice for oil-immersed transformers because of their superior fire safety, environmental friendliness, sustainability, and satisfying operating efficiency compared with traditional mineral insulating oil. However, the ease of streamer propagation and low breakdown voltage in ester fluids at positive lightning impulse (LI) voltage pose a crucial challenge to the safe operation of transformers, signifi cantly limiting their use in power transformers. Currently, most available studies have focused on the morphological analysis of streamers without further investigation at the molecule level. In this work, we investigated the effect of ionization potential (IP) and electron affinity (EA) of molecules in three types of ester fl uids-palm fatty acid ester (PFAE), soybean (FR3) and rapeseed (RDB) insulating oils-on streamer propagation at positive LI voltage. The calculated IP of PFAE oil (8.8 eV) is higher than the other two oils (7.5 eV). 66% faster streamer propagation and 25% lower positive LI breakdown voltage were found in PFAE oil compared with FR3 and RDB oils under positive LI voltage. Under the same applied voltage, the streamer in PFAE oil travelled faster and stopped at a farther distance than in FR3 and RDB oils. The lower EA and viscosity of PFAE oil equipped electrons with higher kinetic energy, leading to a fiercer collision between electrons and molecules and thus a large number of excited molecules. In contrast, relatively higher EAs and viscosities of FR3 and RDB oils limited electron-molecule collision, resulting in a lack of excited molecules for streamer propagation.

A Simple Intermediate Approach of Sputter Deposition at Room Temperature for Improving the Stability of a-InGaZnO Thin Film Transistors

Chunlan Wang,Yebo Jin,Yuqing Li,Gangying Guo,Yongle Song,Hao Huang,Aolin Wang,Han He 대한금속·재료학회 2023 ELECTRONIC MATERIALS LETTERS Vol.19 No.4

Amorphous InGaZnO (a-InGaZnO) thin film transistors (TFTs) with stability and low-temperature deposition are importantchallenges for their application in flexible electronics. Herein, a-InGaZnO films were successfully obtained throughout thewhole process in the room-temperature sputtering system. An intermediate nitrogen treatment a-InGaZnO film link contributedto high performance a-InGaZnO TFTs. The current switching ratio of the optimal nitrogen treatment transistor is closeto 107,the field-effect mobility (μFE) is 11.7 cm2/Vs and threshold voltage (VTH) is − 0.12 V, respectively. And the 4-daythreshold voltage offset (ΔVTH) is reduced from 12.98 to 4.92 V. The improved electrical properties may be attributed to thereduction of defect concentration and average interfacial trap density due to nitrogen occupation of oxygen vacancies (VO).

Differences in Characteristics of Long-Gap Lightning Impulse Breakdown between Vegetable and Mineral Insulating Oil

Wenxiong Mo,Haoyong Song,Qingdan Huang,Yuqing Chen,Wei Wang 한국전기전자재료학회 2021 Transactions on Electrical and Electronic Material Vol.22 No.3

Vegetable insulating oils, with higher fire point, lower biological hazard and better availability compared to traditional mineral insulating oils, have enormous potential to become the substitute of the latter, given the trend of green development of the power equipment, for example, the transformers. However, the obviously different constitution of the vegetable oils makes the circumstance hard when considering their application on the insulation for actual transformers. One of the significant deficiencies of the vegetable oils in working condition is their insufficient lightning impulse endurance under partial high electric fields and large discharge gaps. In this article, three kinds of transformer insulating oils, rapeseed oil, FR3 and 25# mineral oil were chosen to investigate the performances of these insulation materials under long-gap lightning impulses with positive and negative polarity respectively. The variation rules of breakdown voltage and velocity with the gap length were obtained. And the difference of the lightning impulse voltage endurance between the vegetable and mineral insulating oils as well as its causes based on theories of streamer and ionization potential (IP) were analyzed, which led to the conclusion that the gap increase causes more threat to the positive lightning impulse breakdown of vegetable insulating oils, compared to its counterpart.

A Forecasting Method of Electricity Sales Considering the User Churn Rate in a Power Market Environment

Zhaoyang Qu,Wanxin Wang,Nan Qu,Yuqing Liu,Hongbo Lv,Kewei Hu,Jianyou Yu,Manyang Gao,Jiajun Song 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.4

In order to improve the accuracy of forecasts of the electricity sales of power sales companies, a depth forecast model of electricity sales based on the characteristics of the power market is proposed. First, based on survival analysis, the calculation method of the user churn rate in the electricity market is given, and the number of users at a certain moment in the future is predicted. Then, users’ electricity consumption that calculated by the deep belief network and the predicted quantity of users are combined to design a forecast model of electricity sales. Finally, the model is solved utilizing the weighting algorithm of adaptive inertia. The analysis of the example shows that the proposed method achieves a signifi cant improvement in the accuracy of power sales forecasting.

Inhalation of panaxadiol alleviates lung infl ammation via inhibiting TNFA/ TNFAR and IL7/IL7R signaling between macrophages and epithelial cells

Yifan Wang,Hao Wei,Zhen Song,Liqun Jiang,Mi Zhang,Xiao Lu,Wei Li,Yuqing Zhao,Lei Wu,Shuxian Li,Huijuan Shen,Qiang Shu,Yicheng Xie 고려인삼학회 2024 Journal of Ginseng Research Vol.48 No.1

Background: Lung inflammation occurs in many lung diseases, but has limited effective therapeutics. Ginseng andits derivatives have anti-inflammatory effects, but their unstable physicochemical and metabolic propertieshinder their application in the treatment. Panaxadiol (PD) is a stable saponin among ginsenosides. Inhalationadministration may solve these issues, and the specific mechanism of action needs to be studied. Methods: A mouse model of lung inflammation induced by lipopolysaccharide (LPS), an in vitro macrophageinflammation model, and a coculture model of epithelial cells and macrophages were used to study the effectsand mechanisms of inhalation delivery of PD. Pathology and molecular assessments were used to evaluate efficacy. Transcriptome sequencing was used to screen the mechanism and target. Finally, the efficacy andmechanism were verified in a human BALF cell model. Results: Inhaled PD reduced LPS-induced lung inflammation in mice in a dose-dependent manner, includinginflammatory cell infiltration, lung tissue pathology, and inflammatory factor expression. Meanwhile, the dose ofinhalation was much lower than that of intragastric administration under the same therapeutic effect, which maybe related to its higher bioavailability and superior pharmacokinetic parameters. Using transcriptome analysisand verification by a coculture model of macrophage and epithelial cells, we found that PD may act by inhibitingTNFA/TNFAR and IL7/IL7R signaling to reduce macrophage inflammatory factor-induced epithelial apoptosisand promote proliferation. Conclusion: PD inhalation alleviates lung inflammation and pathology by inhibiting TNFA/TNFAR and IL7/IL7Rsignaling between macrophages and epithelial cells. PD may be a novel drug for the clinical treatment of lunginflammation.

Correction to: A Forecasting Method of Electricity Sales Considering the User Churn Rate in a Power Market Environment

Zhaoyang Qu,Wanxin Wang,Nan Qu,Yuqing Liu,Hongbo Lv,Kewei Hu,Jianyou Yu,Manyang Gao,Jiajun Song 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.6

Due to unfortunate mistake the grant numbers have been omitted in the acknowledgments section: This work is supported by the National Natural Science Foundation of China (No. 51437003), Jilin Province Science and Technology Development Plan Project of China (20160623004TC, 20180201092GX), Jilin Science and Technology Innovation Development Plan Project of China (201830817).

Fabrication and environmental applications of multifunctional mixed metal-biochar composites (MMBC) from red mud and lignin wastes

Cho, Dong-Wan,Yoon, Kwangsuk,Ahn, Yongtae,Sun, Yuqing,Tsang, Daniel C.W.,Hou, Deyi,Ok, Yong Sik,Song, Hocheol Elsevier 2019 Journal of hazardous materials Vol.374 No.-

<P><B>Abstract</B></P> <P>This study fabricated a new and multifunctional mixed metal-biochar composites (MMBC) using the mixture of two abundant industrial wastes, red mud (RM) and lignin, via pyrolysis under N<SUB>2</SUB> atmosphere, and its ability to treat wastewater containing various contaminants was comprehensively evaluated. A porous structure (BET surface area = 100.8 m<SUP>2</SUP> g<SUP>−1</SUP>) was created and metallic Fe was formed in the MMBC owing to reduction of Fe oxides present in RM by lignin decomposition products during pyrolysis at 700 °C, which was closely associated with the transformation of liquid to gaseous pyrogenic products. The potential application of the MMBC was investigated for the removal of heavy metals (Pb(II) and Ni(II)), oxyanions (As(V) and Cr(VI)), dye (methylene blue), and pharmaceutical/personal care products (para-nitrophenol and <I>p</I>CBA). The aluminosilicate mineral, metallic Fe, and porous carbon matrix derived from the incorporation of RM and lignin contributed to the multifunctionality (<I>i.e.</I>, adsorption, chemical reduction, and catalytic reaction) of the MMBC. Thus, engineered biochar composites synthesized from selected industrial wastes can be a potential candidate for environmental applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel MMBC fabrication from RM and lignin wastes via one-step pyrolysis in N<SUB>2</SUB> atmosphere. </LI> <LI> MMBC exhibited hierarchical porous structure, various functional groups, and metallic Fe. </LI> <LI> Incorporated RM promoted syngas generation and hydrocarbons decomposition of lignin. </LI> <LI> Demonstrated multifunctionality (adsorption, reduction, and catalysis) of MMBC. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>