Effect of Magnetic Field on the Inhibition Performance of Corrosion Inhibitors with Different Dipole Moment Gradients

Hongyu Cen,Zhishun Zhu,Meng Chen,Xingpeng Guo,Zhenyu Chen 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12

Dodecylamine, quinoline, allylthiourea, and thiourea, whose dipole moments were calculated by quantum chemistry and ingradient rise, were used to study the influence of magnetic field on inhibition effect through weight loss experiments, electrochemicalmeasurements, and surface characterizations. Results confirmed that the inhibition efficiency can be improvedto varying extents with the application of the magnetic field. In addition, maximum impedance increased three times morethan that in controlled trial when the magnetic field increased to 12 mT. Furthermore, the inhibition efficiency of inhibitorswith larger dipole moment will be affected more obviously, which was also positively related to the magnetic field strength. The mechanism of variation in polarizability of molecules was proposed to explain the effect of the magnetic field.

Effect of surface quality on hydrogen/helium irradiation behavior in tungsten

Hongyu Chen,Qiu Xu,Jiahuan Wang,Peng Li,Julong Yuan,Binghai Lyu,Jinhu Wang,Kazutoshi Tokunaga,Gang Yao,Laima Luo,Yucheng Wu 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.6

As the plasma facing material in the nuclear fusion reactor, tungsten has to bear the irradiation impact ofhigh energy particles. The surface quality of tungsten may affect its irradiation resistance, and even affectthe service life of fusion reactor. In this paper, tungsten samples with different surface quality werepolished by mechanical processing, subsequently conducted by D2þ implantation and thermal desorption. D2þ implantation was performed at room temperature (RT) with the irradiation dose of 1 1021D2þ/m2 by 5 keV D2þ ions, and thermal desorption spectroscopy measurements were done from RT to900 K. In addition, He irradiation was also performed by 50 eV Heþ ions energy with the fluxes of5.5 1021 m2s1 and 1.5 1022 m2s1, respectively. Results reveal that the hydrogen/helium irradiation behavior are both related to surface quality. Samples with high surface quality has superior D2þretention behavior with less D2 retained after implantation. However, such samples are more likely togenerate fuzzes on the surface after helium irradiation. Different morphologies (smooth, wavy, pyramids)after helium irradiati

Impact of Chronic Lateral Ankle Instability with Lateral Collateral Ligament Injuries on Biochemical Alterations in the Cartilage of the Subtalar and Midtarsal Joints Based on MRI T2 Mapping

Tao Hongyue,Hu Yiwen,Lu Rong,Zhang Yuyang,Xie Yuxue,Chen Tianwu,Chen Shuang 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.3

Objective: To quantitatively assess biochemical alterations in the cartilage of the subtalar and midtarsal joints in chronic lateral ankle instability (CLAI) patients with isolated anterior talofibular ligament (ATFL) injuries and combined calcaneofibular ligament (CFL) injuries using MRI T2 mapping. Materials and Methods: This study was performed according to regulations of the Committee for Human Research at our institution, and written informed consent was obtained from all participants. Forty CLAI patients (26 with isolated ATFL injuries and 14 with combined ATFL and CFL injuries) and 25 healthy subjects were recruited for this study. All participants underwent MRI scans with T2 mapping. Patients were assessed with the American Orthopedic Foot and Ankle Society (AOFAS) rating system. The subtalar and midtarsal joints were segmented into 14 cartilage subregions. The T2 value of each subregion was measured from T2 mapping images. Data were analyzed with ANOVA, the Student’s t test, and Pearson’s correlation coefficient. Results: T2 values of most subregions of the subtalar joint and the calcaneal facet of the calcaneocuboid joint in CLAI patients with combined CFL injuries were higher than those in healthy controls (all p < 0.05). However, there were no significant differences in T2 values in subtalar and midtarsal joints between patients with isolated ATFL injuries and healthy controls (all p > 0.05). Moreover, T2 values of the medial talar subregions of the posterior subtalar joint in patients with combined CFL injuries showed negative correlations with the AOFAS scores (r = -0.687, p = 0.007; r = -0.609, p = 0.021, respectively). Conclusion: CLAI with combined CFL injuries can lead to cartilage degeneration in subtalar and calcaneocuboid joints, while an isolated ATFL injury might not have a significant impact on the cartilage in these joints.

Upregulation of miR-223 in the rat liver inhibits proliferation of hepatocytes under simulated microgravity

Yongjie Chen,Ji Xu,Chao Yang,Hongyu Zhang,Feng Wu,Jian Chen,Kai Li,Hailong Wang,Yu Li,Yinghui Li,Zhongquan Dai 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Long-term spaceflight affects numerous organ systems in the body, including metabolic dysfunction. Recently, ample evidence has demonstrated that the liver is a vulnerable organ during spaceflight. However, the changes in hepatocyte proliferation and cell cycle control under microgravity remain largely unexplored. In the present study, we first confirmed that the serum levels of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase, biochemical markers of liver function, were altered in rats under tail suspension (TS) conditions to simulate microgravity, as shown in previous reports. Next, we demonstrated that the cell proliferation activity, determined by Ki67, PCNA and PH3, was significantly decreased at the different TS time points (TS for 14, 28 and 42 days) compared with that in the control group. Consistently, the positive cell cycle regulators Ccna2, Ccnd1, Cdk1, Cdk2 and cyclin D3 were also significantly decreased in the TS groups as shown by quantitative real-time PCR and western blotting analysis. Subsequent analysis revealed that the aberrant hepatocyte proliferation inhibition under simulated microgravity was associated with the upregulation of miR-223 in the liver. We further found that miR-223 inhibited the proliferation of Hepa1-6 cells and identified CDK2 and CUL1 as its direct targets. In addition, the decreased expression of CDK2 and CUL1 was negatively correlated with the level of p27 in vitro and in vivo, which may have been responsible for retarding hepatocyte proliferation. Collectively, these data indicate that upregulation of miR-223 was associated with the inhibition of liver cell growth and reveal the role of miR-223 in rat hepatocyte proliferation disorders and the pathophysiological process under simulated microgravity.

Simulation analysis of cogging torque of permanent magnet synchronous motor for electric vehicle

Qiping Chen,Hongyu Shu,Limin Chen 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.12

This paper proposes a new approach to study generation mechanism and influence factors of cogging torque of permanent magnet synchronous motors, in order to improve the operational performance and riding comfort of electric vehicle. Based on energy method and Fourier expansion, the method of predicting cogging torque is proposed. Two-dimensional finite element model of in-wheel motor is established by Maxwell software, and electromagnetic character of that is analyzed. Skew slot, pole arc coefficient and width of slot mouth are analyzed and studied by finite element method, in order to realize the change regularity of cogging torque. Cogging torque curves under the different skew slots, the different pole arc coefficients and the different widths of slot mouth are obtained, which can effectively reduce the cogging torque of in-wheel motor, but they still exists some limitations. The final simulation analysis results are in good agreement with the theoretical predicting results, which indicates that this method can be used to afford a theoretical basis to reduce the cogging torque and optimize the in-wheel motor of electric vehicle in the future.

In Situ Growth of MOF-Derived NaCoPO4@Carbon for Asymmetric Supercapacitive and Water Oxidation Electrocatalytic Performance

Peng Guo,Zhaojie Wang,Hongyu Chen,Shaohui Ge,Chen Chen,Haowei Wang,Jinbao Zhang,Minglei Hua,Shuxian Wei,Xiaoqing Lu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.15 No.01

The increasing energy crisis promotes the study on novel electrode materials with high performance for supercapacitive storage and energy conversion. Transition metal phosphates have been reported as a potential candidate due to the unique coordination and corresponding electronic structure. Herein, we adopted a facile method for preparing NaCoPO4@C derived from a metal organic framework (MOF) as a bifunctional electrode. ZIF-67 was synthesized before a refluxing process with Na2HPO4 to form a precursor, which is transformed into the final product via calcination in different atmospheres. Specifically, the resultant NaCoPO4@C exhibits a high specific capacitance of 1178.7 F g -1 at a current density of 1 A g -1 for a supercapacitor. An asymmetric supercapacitor (ASC) assembled with active carbon displays a high capacitance of 163.7 F g -1 at 1 A g -1. In addition, as an oxygen evolution reaction (OER) catalyst, the NaCoPO4@C electrode requires only 299 mV to drive a current density of 10 mA cm -2. These results suggest that the rational design of MOF-derived NaCoPO4@C provides a variety of practical applications in electrochemical energy conversion and storage.

Characterization of the brittleness of hard rock at different temperatures using uniaxial compression tests

Chen, Guoqing,Li, Tianbin,Wang, Wei,Guo, Fan,Yin, Hongyu Techno-Press 2017 Geomechanics & engineering Vol.13 No.1

The failure mechanism of a deep hard rock tunnel under high geostress and high geothermalactivity is extremely complex. Uniaxial compression tests of granite at different temperatures were conducted. The complete stress-strain curves, mechanical parameters and macroscopic failure types of the rock were analyzed in detail. The brittleness index, which represents the possibility of a severe brittleness hazard, is proposed in this paperby comparing the peak stress and the expansion stress. The results show that the temperature range from 20 to $60^{\circ}C$ is able to aggravate the brittle failure of hard rock based on the brittleness index. The closure of internal micro cracks by thermal stress can improve the strength of hard rock and the storage capacity of elastic strain energy. The failure mode ofthe samples changes from shear failure to tensile failure as the temperature increases. In conclusion, the brittle failure mechanism of hard rock under the action of thermal coupling is revealed, and the analysis result offers significant guidance for deep buried tunnels at high temperatures and under high geostress.

A Solar Stationary Type IV Radio Burst and Its Radiation Mechanism

Hongyu Liu,Yao Chen,Kyungsuk Cho,Shiwei Feng,Veluchamy Vasanth,Artem Koval,Guohui Du,Zhao Wu,Chuanyang Li 한국천문학회 2018 天文學會報 Vol.43 No.1

Rhombic TiO2 grown on g-C3N4 nanosheets towards fast charge transfer and enhanced Cr(VI) and NO removal

Hongyu Zhang,Ling Chen,Baogang Xu,Ping Yang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.111 No.-

The strong band-to-band visible light absorption obtained by changing the bandgap of photocatalysts isdesirable but challenging for TiO2. In this paper, a mechanochemical pre-reaction and subsequent heattreatmentprocess were used to create TiO2/g-C3N4 heterojunctions. Acid-treated H2Ti3O7 nanobelts andsuperior thin g-C3N4 nanosheets (CN) were ground evenly and further heat-treated to grow rhombic TiO2in situ on the nanosheets. The heterojunctions exhibited a band gap with the absorption in visible lightregion. Heterojunction formation effective tunes the surface and electronic structures of the composite,resulting in significant decrease of bandgap. g-C3N4-based heterojunctions (5TCN) exhibited excellent H2generation (4991 lmol/g/h) and NO removal. In contrast, a TiO2-based composite (95TCN) revealed efficientphoto reduction of Cr(Ⅵ) which was 2 times of that of TiO2 sample and 22 times of that of CN. Thephotochemical reaction mechanism of TiO2 and g-C3N4-based composites was discussed with the ratio ofTiO2 and g-C3N4. The excellent performance is ascribed to single crystal rhombic TiO2 nanoparticlesgrown in situ on g-C3N4 to form well-developed heterojunctions which accelerate the carrier transfer. These results inspire the electronic structure engineering of photocatalysts to improve visible lightabsorption and provide a magic strategy for excellent photochemical activities.

EEG-based Safety Driving Performance Estimation and Alertness Using Support Vector Machine

Hongyu Sun,Lijun Bi,Bisheng Chen,Yinjing Guo 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.6

Safety driving performance estimation and alertness (SDPEA) has drawn the attention of researchers in preventing traffic accidents caused by drowsiness while driving. Psychophysiological measures, such as electroencephalogram (EEG), are accurately investigated to be robust candidates for drivers’ drowsiness evaluation. This paper presents an effective EEG-based driver drowsiness monitoring system by analyzing the changes of brain activities in a simulator driving environment. The proposed SDPEA system can translate EEG signals into drowsiness level. Firstly, Independent component analysis (ICA) is performed on EEG data to remove artifacts. Then, eight EEG-band powers- related features: beta, alpha, theta, delta, (alpha plus theta)/beta, alpha / beta, (alpha plus theta)/(alpha plus beta) and theta / beta are extracted from the preprocessed EEG signals by employing the Fast Fourier Transform (FFT). Subsequently, fisher score technique selects the most descriptive features for further classification. Finally, Support Vector Machine (SVM) is employed as a classifier to distinguish drowsiness level. Experimental results show that the quantitative driving performance can be correctly estimated through analyzing driver’s EEG signals by the SDPEA system.