Sandwich Structure Electrode as Advanced Performance Anode for Lithium-Ion Batteries

Wei Chengcheng,Sun Xiaogang,Liang Guodong,Huang Yapan,Hu Hao,Xu Yuhao 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.10

In this work, a sandwich structure electrode was prepared by a simple vacuum filtration and rolling process. The SEM showed that the active materials were uniformly embedded in the pores of the three-dimensional conductive network of the carbon nanotube (CNTs) conductive paper. The contact interface area of active material and the conductive network significantly increased and the interface resistance was greatly reduced. The porous anode can accommodate the volume expansion of the silicon and effectively alleviated pressed during cycle. The electrode also exhibited good stability in cycles. Electrochemical tests showed that the first discharge specific capacity of the sandwich electrode reached 2330 mAh/g with a coulombic efficiency of 86%. After 500 cycles, the specific capacity was still maintained at 1512 mAh/g. At a large current density of 2 A/g, the specific capacity hold was 840 mAh/g compared with the copper foil electrode of 100 mAh/g.

Computational investigation of three-faced blade errors on contact behaviors for face-hobbed hypoid gears

Chaosheng Song,Chengcheng Liang,Caichao Zhu,Kunming Liu,Siyuan Liu,Qianhong Huang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.7

An accurate mathematical model of face-hobbed hypoid gear tooth surface based on the three-faced blade is established. The correctness of the mathematical model was verified by comparing the contact pattern results from KIMOS software and finite element tooth contact analysis. Then, the effects of tool errors on mesh characteristics of face-hobbed hypoid gear were investigated by loaded tooth contact analysis. Results show that the influences of pressure angle error and regrind angle error on contact pattern are obvious. The location of contact pattern moves from the root on the heel side to the top on the toe side of the tooth surface when the error value increases. The peak-to-peak value of transmission error gradually increases with those two types of errors. The influences of spheric radius error, rake angle error and cutting side relief angle error on contact behaviors are similar and not obvious for facehobbed hypoid gears.

Influences of rubber cushion and bearing position on the mesh characteristics of small-module spiral bevel gear

Maohao Xia,Chaosheng Song,Chengcheng Liang,Siyuan Liu,Zhengminqing Li,Peitang Wei 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.12

A mathematical model of spiral bevel gear with the application of duplex spread blade method was established. A novel finite element model considering the configuration of shafts and bearings was developed. The influences of shafts, bearing position, and rubber cushion on the mesh characteristics of spiral bevel gear under different loads were investigated. Results show that the peak-to-peak value of transmission error and the ratio of contact area and high stress area all increase with the increase in loads. With the existence of rubber cushion, the contact pattern moves to the heel and root sides of the wheel flank, and the peakto-peak value of transmission error and root edge contact area increase. With the front bearing moving from the original position to the positive position, the peak-to-peak value of transmission error increases. With the movement of rear bearing position from negative to positive, the contact pattern moves to the heel and root sides of the wheel flank. The peak-to-peak value of transmission error increases, and the root edge contact area expands.

Dirac semimetal-enabled multi-bit coding metasurface for dynamic manipulation of terahertz beams

Zhang Yonggang,Yin Kehao,Liang Lanju,Yao Haiyun,Yan Xin,Hu Xiaofei,Huang Chengcheng,Qiu Fu,Zhang Rui,Li Yuanping,Wang Yaru,Li Zhenhua,Wang Ziqun 한국물리학회 2024 Current Applied Physics Vol.58 No.-

In this study, a switchable multi-bit coding metasurface that is applied under a terahertz (THz) frequency by adjusting the Fermi level (EF) of Dirac semimetals (DSMs) is proposed. At a EF of 0.2 eV, a 1-bit coding metasurface can be applied in the 2.58–2.62 THz. At 0.3 eV, a 3-bit coding metasurface is realized at 1.88 THz, and at 0.05 eV, the phase of the coding units coincides in the 1.5–3 THz. So, different functions of the metasurface can be realized. The proposed coding metasurfaces has promising applications in terahertz communication.

Influences of machine-tool setting errors on mesh behavior for small-module spiral bevel gear

Chaosheng Song,Maohao Xia,Siyuan Liu,Chengcheng Liang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.9

Due to the complex manufacturing process and numerous machine-tool settings, errors easily arise between the actual parameters and theoretical parameters of spiral bevel gear, which contributes to the deviation of geometrical morphology of gear flank. This type of gear pair is very sensitive to tooth flank deviations, and the deviations can affect the mesh behavior of the gear pair and then the performance of the entire device. To investigate the influence of different machine-tool setting errors on the mesh behavior of small-module spiral bevel gear, a mathematical model of this type of gear pair has been established based on the principle of duplex spread blade method, and the finite element analysis model has been developed under the rated condition. The horizontals and radial distances of pinion and wheel as well as the velocity ratio were selected to be investigated. The three machine-tool setting all makes the contact pattern move within the tooth flank. The minimum value of transmission error (TE) appears at the initial horizontal and radial distance. Negative values of the horizontal and radial distance and positive value of velocity ratio both can increase the root bending stress. The errors of machine-tool setting will increase the tooth contact stress. The main influential errors on mesh behavior of small-module spiral bevel gear are in proper order, horizontal, radial distance and velocity ratio. It is convenient and efficient to correct the tooth flanks in this order only by contrasting the contact pattern with the design after the rolling test.

Apoptosis induction by alantolactone in breast cancer MDA-MB- 231 cells through reactive oxygen species-mediated mitochondrion-dependent pathway

Li Cui,Weiquan Bu,Jie Song,Liang Feng,Tingting Xu,Dan Liu,Wenbo Ding,Jianhua Wang,Changyang Li,Binge Ma,Yi Luo,Ziyu Jiang,Chengcheng Wang,Juan Chen,Jian Hou,Hong-mei Yan,Lei Yang,Xiao-bin Jia 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.3

Alantolactone is a sesquiterpene lactone isolatedfrom Inula helenium L. Although alantolactone possessesanti-inflammation and apoptosis-induction activities, theunderlying mechanism of anti-cancer effect on humanbreast cancer cells remains largely unknown. In this study,we explored the possibility of alantolactone as an apoptosis-inducing cytotoxic agent using MDA-MB-231 cells asin vitro model. Alantolactone significantly induced itsapoptosis, demonstrated by cell cycle analysis, annexinV-APC/7-AAD double staining and dUTP nick end labeling. Additionally, alantolactone triggered the mitochondrial-mediated caspase cascade apoptotic pathway, whichwas confirmed by increased Bax/Bcl-2 ratio, loss of MMP,release of cytc from mitochondria to cytoplasm, activationof caspase 9/3, and subsequent cleavage of PARP. Z-VADFMKpartially prevented apoptosis induced by alantolactone. Alantolactone provoked the production of ROS, whileNAC (a scavenger of ROS) reversed alantolactone-mediateddepolarization of MMP and apoptosis. Alantolactonemodulated the activities of MAPKs. As expected, cotreatmentwith SB203580, SP600125 or U0126 could reducedthe apoptotic rate. Furthermore, alantolactone decreasedthe protein expressions of p-NF-kB p65 and p-STAT3,increased p-c-Jun level in a dose-dependent manner. Thesefindings suggested that alantolactone possessed anticanceractivity via ROS-mediated mitochondrial dysfunctioninvolving MAPK pathway, and had an effect on the transcriptionfactors of NF-kB, AP-1 and STAT3.

Electrochemical Properties of Supercapacitors Using Boron Nitrogen Double-Doped Carbon Nanotubes as Conductive Additive

Hao Hu,Xiaogang Sun,Wei Chen,Jie Wang,Xu Li,Yapan Huang,Chengcheng Wei,Guodong Liang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.7

Carbon nanotubes (CNTs) were doped by ammonium borate as the sources of nitrogen and boron. Under the protection of Ar gas, boron-nitrogen doped CNTs were prepared through nitriding and boronization at high temperature. It is a conductive additive. Then, the obtained CNTs were mixed with activated carbon (AC), SP, sodium dodecyl sulfate (SDS), and cellulose fiber to prepare electrodes. With all the materials, a symmetric electric double-layer supercapacitor (EDLC) was assembled. Next, the materials and electrodes were also characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The factors, chemical connections, and specific surface area of the CNTs were analyzed by X-ray energy spectrum analysis (EDS), X-ray photoelectron spectroscopy (XPS), as well as a specific surface area and porosimetry analyzer (BET). In addition, the electrochemical performances of electric double-layer capacitors were tested with the help of cyclic voltammetry, constant-current charging and discharging, and so on. From the results, we can make a conclusion, that is, both B and N atoms were added into the CNTs and formed bonds successfully with carbon atoms mutually. Besides, the specific surface area is about 1.5 times than that of the CNT. When the charge/discharge current density reaches 50 mA/g, we can find that the mass specific capacitance of the capacitor can run up to 32.19 F/g. Also, we observe that the maximum power density is close to 220 W/kg (700 mA/g), and the energy density can arrive 9.31 Wh/kg (50 mA/g). Based on the impedance test, the electrodes are characterized with low impedance. After 2000 cycles, the boron-nitrogen doped double-layer capacitors maintain a capacitance retention ratio of above 95%. Its power density can still achieve 220 W/kg when the energy density keeps at 3.46 Wh/kg. In other words, the electrochemical performance functions of the electric double-layer capacitors are enhanced while the CNTs serve as the electrodes.

Epithelial CST1 Promotes Airway Eosinophilic Inflammation in Asthma via the AKT Signaling Pathway

Du Lijuan,Xu Changyi,Tang Kun,Shi Jia,Tang Lu,Lisha Xiao,Lei Chengcheng,Liu Huicong,Liang Yuxia,Guo Yubiao 대한천식알레르기학회 2023 Allergy, Asthma & Immunology Research Vol.15 No.3

Purpose: Epithelial cystatin SN (CST1), a type 2 cysteine protease inhibitor, was significantly upregulated in asthma. In this study, we aimed to investigate the potential role and mechanism of CST1 in eosinophilic inflammation in asthma. Methods: Bioinformatics analysis on Gene Expression Omnibus datasets were used to explore the expression of CST1 in asthma. Sputum samples were collected from 76 asthmatics and 22 control subjects. CST1 mRNA and protein expression in the induced sputum were measured by real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and western blotting. The possible function of CST1 was explored in ovalbumin (OVA)-induced eosinophilic asthma. Transcriptome sequencing (RNA-seq) was used to predict the possible regulated mechanism of CST1 in bronchial epithelial cells. Overexpression or knockdown of CST1 was further used to verify potential mechanisms in bronchial epithelial cells. Results: CST1 expression was significantly increased in the epithelial cells and induced sputum of asthma. Increased CST1 was significantly associated with eosinophilic indicators and T helper cytokines. CST1 aggravated airway eosinophilic inflammation in the OVA-induced asthma model. In addition, overexpression of CST1 significantly enhanced the phosphorylation of AKT and the expression of serpin peptidase inhibitor, clade B, member 2 (SERPINB2), while knockdown using anti-CST1 siRNA reversed the trend. Furthermore, AKT had a positive effect on SERPINB2 expression. Conclusions: Increased sputum CST1 may play a key role in the pathogenesis of asthma through involvement in eosinophilic and type 2 inflammation through activation of the AKT signaling pathway, further promoting SERPINB2 expression. Therefore, targeting CST1 might be of therapeutic value in treating asthma with severe and eosinophilic phenotypes.