High-performance solid-state flexible supercapacitor based on reduced graphene oxide/hierarchical core-shell Ag nanowire@NiAl layered double hydroxide film electrode

Li, Lei,Hui, Kwan San,Hui, Kwun Nam,Zhang, Tengfei,Fu, Jianjian,Cho, Young-Rae Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.348 No.-

<P><B>Abstract</B></P> <P>All-solid-state flexible supercapacitor (AFSC) is a promising energy storage device due to its high flexibility, security, and environmental friendliness. However, high electrical resistance and low specific capacitance of electrodes limit its application for potential portable electronic devices. In this study, we design a novel hybrid film electrode composed of reduced graphene oxide (rGO)/silver nanowire (Ag NW)@nickel aluminum layered double hydroxide (NiAl LDH; herein, GAL) possessing high electrochemical performance by using hydrothermal and vacuum filtration techniques. The Ag NW@NiAl LDH (AL) composites with hierarchical core-shell structure are utilized to increase electroactive surface area and improve electrical conductivity, while the rGO nanosheets serve as a prominent carbon material with outstanding electrical conductivity and mechanical flexibility. The freestanding GAL electrode shows high specific capacitance of 1148 F g<SUP>−1</SUP> at 1 A g<SUP>−1</SUP> compared with rGO/NiAl LDH (GL) of 765.2 F g<SUP>−1</SUP> at 1 A g<SUP>−1</SUP>. Furthermore, the bind-free symmetric AFSC device is successfully prepared using GAL hybrid film as electrodes and PVA-KOH as solid-state gel electrolyte. The GAL//GAL AFSC device delivers a superior specific capacitance of 127.2 F g<SUP>−1</SUP> at 1 A g<SUP>−1</SUP>, a high energy density of 35.75 mWh cm<SUP>−3</SUP> at a power density of 1.01 W cm<SUP>−3</SUP>, and great cycling ability of 83.2% over 10,000 cycles at 5 A g<SUP>−1</SUP>. This study introduces a novel design of flexible electrode structure for advanced energy storage applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A well-designed rGO/Ag NW@NiAl-LDH (GAL) hybrid film was prepared. </LI> <LI> The Ag NWs improved the conductivity of the hybrid film. </LI> <LI> The GAL electrode shows high specific capacitance of 1148 F g<SUP>−1</SUP>. </LI> <LI> The flexible device displays high energy density of 35.75 mWh cm<SUP>−3</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Approach of Self-mixing Interferometry Based on Particle Swarm Optimization for Absolute Distance Estimation

Li Li,Xingfei Li,Ke Kou,Tengfei Wu 한국광학회 2015 Current Optics and Photonics Vol.19 No.1

To accurately extract absolute distance information from a self-mixing interferometry (SMI) signal, inthis paper we propose an approach based on a particle swarm optimization (PSO) algorithm instead offrequency estimation for absolute distance. The algorithm is utilized to search for the global minimumof the fitness function that is established from the self-mixing signal to find out the actual distance. Aresolution superior to 25 μm in the range from 3 to 20 cm is obtained by experimental measurement,and the results demonstrate the superiority of the proposed approach in comparison with interpolated FFT. The influence of different external feedback strength parameters and different inertia weights in thealgorithm is discussed as well

Hybrid simulation tests of high-strength steel composite K-eccentrically braced frames with spatial substructure

Tengfei Li,Mingzhou Su,Jiangran Guo 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.4

Based on the spatial substructure hybrid simulation test (SHST) method, the seismic performance of a high-strength steel composite K-eccentrically braced frame (K-HSS-EBF) structure system is studied. First, on the basis of the existing pseudostatic experiments, a numerical model corresponding to the experimental model was established using OpenSees, which mainly simulated the shear effect of the shear links. A three-story and five-span spatial K-HSS-EBF was taken as the prototype, and SHST was performed with a half-scale SHST model. According to the test results, the validity of the SHST model was verified, and the main seismic performance indexes of the experimental substructure under different seismic waves were studied. The results show that the hybrid simulation results are basically consistent with the numerical simulation results of the global structure. The deformation of each story is mainly concentrated in the web of the shear link owing to shear deformation. The maximum interstory drifts of the model structure during Strength Level Earthquake (SLE) and Maximum Considered Earthquake (MCE) meet the demands of interstory limitations in the Chinese seismic design code of buildings. In conclusion, the seismic response characteristics of the K-HSS-EBFs are successfully simulated using the spatial SHST, which shows that the K-HSS-EBFs have good seismic performance.

Spatial substructure hybrid simulation tests of high-strength steel composite Y-eccentrically braced frames

Tengfei Li,Mingzhou Su,Yan Sui 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.34 No.5

High-strength steel composite Y-eccentrically braced frame (Y-HSS-EBF) is a novel structural system. In this study, the spatial substructure hybrid simulation test (SHST) method is used to further study the seismic performance of Y-HSS-EBF. Firstly, based on the cyclic loading tests of two single-story single-span Y-HSS-EBF planar specimens, a finite element model in OpenSees was verified to provide a reference for the numerical substructure analysis model for the later SHST. Then, the SHST was carried out on the OpenFresco test platform. A three-story spatial Y-HSS-EBF model was taken as the prototype, the top story was taken as the experimental substructure, and the remaining two stories were taken as the numerical substructure to be simulated in OpenSees. According to the test results, the validity of the SHST was verified, and the main seismic performance indexes of the SHST model were analyzed. The results show that, the SHST based on the OpenFresco platform has good stability and accuracy, and the results of the SHST agree well with the global numerical model of the structure. Under strong seismic action, the plastic deformation of Y-HSS-EBF mainly occurs in the shear link, and the beam, beam-columns and braces can basically remain in the elastic state, which is conducive to post-earthquake repair.

Resequencing 302 wild and cultivated accessions identifies genes related to domestication and improvement in soybean

Zhou, Zhengkui,Jiang, Yu,Wang, Zheng,Gou, Zhiheng,Lyu, Jun,Li, Weiyu,Yu, Yanjun,Shu, Liping,Zhao, Yingjun,Ma, Yanming,Fang, Chao,Shen, Yanting,Liu, Tengfei,Li, Congcong,Li, Qing,Wu, Mian,Wang, Min,Wu, Nature Publishing Group, a division of Macmillan P 2015 Nature biotechnology Vol.33 No.4

Understanding soybean (Glycine max) domestication and improvement at a genetic level is important to inform future efforts to further improve a crop that provides the world's main source of oilseed. We detect 230 selective sweeps and 162 selected copy number variants by analysis of 302 resequenced wild, landrace and improved soybean accessions at >11× depth. A genome-wide association study using these new sequences reveals associations between 10 selected regions and 9 domestication or improvement traits, and identifies 13 previously uncharacterized loci for agronomic traits including oil content, plant height and pubescence form. Combined with previous quantitative trait loci (QTL) information, we find that, of the 230 selected regions, 96 correlate with reported oil QTLs and 21 contain fatty acid biosynthesis genes. Moreover, we observe that some traits and loci are associated with geographical regions, which shows that soybean populations are structured geographically. This study provides resources for genomics-enabled improvements in soybean breeding.

A Youla-parameterized Gap Control for Next Generation of Optical Storage Systems

Tengfei Yue,Zhizheng Wu,Feng Li,Tao Wang,Lu Wang,Dziki Mbemba 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.6

With the development of ultra-high-density optical storage technology, the density of storage media is getting higher and higher, but the increase of the capacity of the optical disk leads to the reduce of the lens-disk interface gap and the tolerance of the focus error dramatically. In the case of extremely small spacing, various external disturbances are highly likely to cause a collision between the optical lens and the disc. In order to avoid the collision between the optical lens and disk, effectively eliminate the deterministic disturbance and suppress the unknown random disturbance, in this paper a multi-objective optimal output feedback controller design approach is proposed within the Q (Youla)-parameterized regulator scheme. The optimal Q parameter in the controller is obtained by solving the properly formulated linear matrix inequalities (LMIs). The experimental results show that the designed Q-parameterized controller can eliminate the influence of various disturbances and suppress the occurrence of collisions effectively.

Preparation of highly efficient self-healing anticorrosion epoxy coating by integration of benzotriazole corrosion inhibitor loaded 2D-COF

Tengfei Liu,Wen Li,Chenyang Zhang,Wei Wang,Wenwen Dou,Shougang Chen 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.97 No.-

In this work, multi-layer stacked two-dimensional (2D) covalent organic framework of TpPa-1 wassynthesized as nanocontainer to fabricate self-healing epoxy coating. The corrosion inhibitor ofbenzotriazole (BTA) was loaded into porous TpPa-1 (Tp: 1,3,5-Triformylphrogroglucinol, Pa-1: 1,4-phenylenediamine), and the load capacity was further improved by electrostatic adsorption. Then, 0.5 wt. % BTA/TpPa-1 and 0.5 wt.% TpPa-1 were added to the epoxy coating, respectively. The electrochemicalImpedance Spectroscopy (EIS) test shown that after 60 days of immersion, the impedance of the BTA/TpPa-1/EP in low-frequency region was 6.45108V cm2, while the impedance corresponding to theTpPa-1/EP coating was 9.04107V cm2. In addition, in the localized electrochemical impedancespectroscopy (LEIS) test, as the immersion time was extended, the impedance of TpPa-1/EP coating at thedefect continued to decrease, while the impedance at the defect of the BTA/TpPa-1/EP coating shown anupward trend, showing self-healing performance. This was due to the pH change when the metal at thedefect is corroded, which caused the BTA to be released from the nanocontainer and adhered to the metalsurface to form a protectivefilm. The improvement of the anti-corrosion performance of BTA/TpPa-1/EPcoating mainly comes from two aspects: (1) The good dispersion of TpPa-1 in EP coating improves thephysical shielding effect of the coating; (2) The controlled release of BTA can Realize the continuousformation of the bare metal surface protective layer.

Variational nodal methods for neutron transport: 40 years in review

Zhang Tengfei,Li Zhipeng 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.9

The variational nodal method for solving the neutron transport equation has evolved over 40 years. Based on a functional form of the Boltzmann neutron transport equation, the method now comprises a complete set of variants that can be employed for different problems. This paper presents an extensive review of the development of the variational nodal method. The emphasis is on summarizing the whole theoretical system rather than validating the methodologies. The paper covers the variational nodal formulation of the Boltzmann neutron transport equation, the Ritz procedure for various application purposes, the derivation of boundary conditions, the extension for adjoint and perturbation calculations, and treatments for anisotropic scattering sources. Acceleration approaches for constructing response matrices and solving the resulting system of algebraic equations are also presented

Dual NURBS Path Smoothing for 5-Axis Linear Path of Flank Milling

Dongdong Li,Weimin Zhang,Wei Zhou,Tengfei Shang,Jürgen Fleischer 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.12

Linear path is still widely used to describe the five-axis machining trajectory. Five-axis tool path consists of two parts, one trajectory describes the tool tip position, and the other one represents the second point on tool axis to define the tool orientation. The natural disadvantages of G01 path are tangential and curvature discontinuities at freeform surface, which will lead to feedrate fluctuation and accuracy decrease due to the drive constraints of machine tool. In this study, a path smoothing method is proposed to smooth and optimize the linear path by using dual NURBS curves. Firstly, according to the accuracy requirements, the tool tip spline can be fitted. Secondly, the tool orientation spline can also be obtained by a coordinate system mapping method. Then, the synchronization equation of the two spline parameters is established to achieve interpolation synchronization of cutter location points. Finally, the smoothing dual NURBS tool path can be obtained with continuous curvature to improve the surface quality, motion stability and machining efficiency. Simulations and experiments validate its practicability and reliability. This method is no need to upgrade the CAM, and also could be integrated into CAM system to perform the 5-axis path smoothing.

Multifunctional nanozyme‑reinforced copper‑coordination polymer nanoparticles for drug‑resistance bacteria extinction and diabetic wound healing

Jiahui Zhao,Tengfei Xu,Jichao Sun,Haitao Yuan,Mengyun Hou,Zhijie Li,Jigang Wang,Zhen Liang 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Drug-resistant bacterial infections in chronic wounds are a persistent issue, as they are resistant to antibiotics and can cause excessive inflammation due to generation of reactive oxygen species (ROS). An effective solution would be to not only combat bacterial infections but also scavenge ROS to relieve inflammation at the wound site. Scaffolds with antioxidant properties are attractive for their ability to scavenge ROS, and there is medical demand in developing antioxidant enzyme-mimicking nanomaterials for wound healing. Methods In this study, we fabricated copper-coordination polymer nanoparticles (Cu-CPNs) through a self-assembly process. Furthermore, ε-polylysine (EPL), an antibacterial and cationic polymer, was integrated into the Cu-CPNs structure through a simple one-pot self-assembly process without sacrificing the glutathione peroxidase (GPx) and superoxide dismutase (SOD)-mimicking activity of Cu-CPNs. Results The resulting Cu-CPNs exhibit excellent antioxidant propertiesin mimicking the activity of glutathione peroxidase and superoxide dismutase and allowing them to effectively scavenge harmful ROS produced in wound sites. The in vitro experiments showed that the resulting Cu-CPNs@EPL complex have superior antioxidant properties and antibacterial effects. Bacterial metabolic analysis revealed that the complex mainly affects the cell membrane integrity and nucleic acid synthesis that leads to bacterial death. Conclusions The Cu-CPNs@EPL complex has impressive antioxidant properties and antibacterial effects, making it a promising solution for treating drug-resistant bacterial infections in chronic wounds. The complex’s ability to neutralize multiple ROS and reduce ROS-induced inflammation can help relieve inflammation at the wound site.