A facile pyrolysis method to prepare vanadium oxides for high performance aqueous Zn-ion battery

Zhu Haitao,Liao Shengyun,Su Boya,Ding Xiaohui,Liu Qiang 한국물리학회 2022 Current Applied Physics Vol.34 No.-

Vanadium oxides, as one of the most promising cathode materials for zinc ion batteries, have attracted extensive attention in recent years. Different from the generally used hydrothermal and solvothermal methods to adjust the composition, structure, morphology and electrical properties of vanadium oxides, we firstly adopt a simple pyrolysis method to synthesize a series of vanadium oxides and use them as cathode materials for aqueous Zn-ion battery, whose electrochemical performances is superior to most state-of-the-art vanadium oxides. The asobtained V4O7 under the calcination temperature of 700 ◦C exhibits excellent zinc ion storage performance with maximum specific capacity of 367.2 mAh g 1 at the current density of 1 A g 1, about 84.9% capacity retention after 100 cycles, excellent rate performance, high capacity. In addition, a series of structural and electrochemical characterization are used to reveal the possible mechanism of charge and discharge.

Experimental and numerical study on mechanical behavior of RC shear walls with precast steel-concrete composite module in nuclear power plant

Xu Haitao,Xu Jinbin,Dong Zhanfa,Ding Zhixin,Bai Mingxin,Du Xiaodong,Wang Dayang 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.6

Reinforced concrete (RC) shear walls with precast steel-concrete composite modular (PSCCM) are strongly recommended in the structural design of nuclear power plants due to the need for a large number of process pipeline crossings and industrial construction. However, the effect of the PSCCM on the mechanical behavior of the whole RC shear wall is still unknown and has received little attention. In this study, three 1:3 scaled specimens, one traditional shear wall specimen (TW) and two shear wall specimens with the PSCCM (PW1, PW2), were designed and investigated under cyclic loadings. The failure mode, hysteretic curve, energy dissipation, stiffness and strength degradations were then comparatively investigated to reveal the effect of the PSCCM. Furthermore, numerical models of the RC shear wall with different PSCCM distributions were analyzed. The results show that the shear wall with the PSCCM has comparable mechanical properties with the traditional shear wall, which can be further improved by adding reinforced concrete constraints on both sides of the shear wall. The accumulated energy dissipation of the PW2 is higher than that of the TW and PW1 by 98.7 % and 60.0 %. The failure of the shear wall with the PSCCM is mainly concentrated in the reinforced concrete wall below the PSCCM, while the PSCCM maintains an elastic working state as a whole. Shear walls with the PSCCM arranged in the high stress zone will have a higher load-bearing capacity and lateral stiffness, but will suffer a higher risk of failure. The PSCCM in the low stress zone is always in an elastic working state.

DYNAMICS CHARACTERISTICS ANALYSIS AND CONTROL OF FWID EV

Dongmei Wu,Haitao Ding,Changqing Du 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.1

Compared with internal combustion engine (ICE) vehicles, four-wheel-independently-drive electric vehicles (FWID EV) have significant advantages, such as more controlled degree of freedom (DOF), higher energy efficiency and faster torque response of an electric motor. The influence of these advantages and other characteristics on vehicle dynamics control need to be evaluated in detail. This paper firstly analyzed the dynamics characteristics of FWID EV, including the feasible region of vehicle global force, the improvement of powertrain energy efficiency and the time-delays of electric motor torque in the direct yaw moment feedback control system. In this way, the influence of electric motor output power limit, road friction coefficient and the wheel torque response on the stability control, as well as the impact of motor idle loss on the torque distribution method were illustrated clearly. Then a vehicle dynamics control method based on the vehicle stability state was proposed. In normal driving condition, the powertrain energy efficiency can be improved by torque distribution between front and rear wheels. In extreme driving condition, the electric motors combined with the electro-hydraulic braking system were employed as actuators for direct yaw moment control. Simulation results show that dynamics control which take full advantages of the more controlled freedom and the motor torque response characteristics improve the vehicle stability better than the control based on the hydraulic braking system of conventional vehicle. Furthermore, some road tests in a real vehicle were conducted to evaluate the performance of proposed control method.

Modeling of nanoparticles’ aggregation and sedimentation in nanofluid

Weiting Jiang,Guoliang Ding,Hao Peng,Haitao Hu 한국물리학회 2010 Current Applied Physics Vol.10 No.3

The aggregation and sedimentation of nanoparticles in nanofluid have significant influences on the stability and applicability of nanofluids. The objective of this study is to propose a model to predict the nanoparticles’aggregation and sedimentation characteristics. The characteristics are evaluated by the concentration of nanoparticles in nanofluid at different time. The concentration of nanoparticles can be calculated according to the speed and location of each nanoparticle. Then, the speed and location of each nanoparticle can be yielded when the forces on each nanoparticle are determined. For the forces on nanoparticles are related to the space structure of nanoparticle clusters, the clusters’ space structures are simulated. Case study shows that the mean deviation of predicted nanoparticle concentration from experimental data for Fullerence + H2O, Fullerence + Oil and CuO + Oil nanofluids are 25%, 16% and 13%, respectively. The model can provide quantitative prediction of the aggregation and sedimentation characteristics of nanoparticles in nanofluid.

Molecular Orbital Gating Surface-Enhanced Raman Scattering

Guo, Chenyang,Chen, Xing,Ding, Song-Yuan,Mayer, Dirk,Wang, Qingling,Zhao, Zhikai,Ni, Lifa,Liu, Haitao,Lee, Takhee,Xu, Bingqian,Xiang, Dong American Chemical Society 2018 ACS NANO Vol.12 No.11

<P>One of the promising approaches to meet the urgent demand for further device miniaturization is to create functional devices using single molecules. Although various single-molecule electronic devices have been demonstrated recently, single-molecule optical devices which use external stimulations to control the optical response of a single molecule have rarely been reported. Here, we propose and demonstrate a field-effect Raman scattering (FERS) device with a single molecule, an optical counterpart to field-effect transistors (a key component of modern electronics). With our devices, the gap size between electrodes can be precisely adjusted at subangstrom accuracy to form single molecular junctions as well as to reach the maximum performance of Raman scattering via plasmonic enhancement. Based on this maximum performance, we demonstrated that the intensity of Raman scattering can be further enhanced by an additional ∼40% if the orbitals of the molecules bridged two electrodes were shifted by a gating voltage. This finding not only provides a method to increase the sensitivity of Raman scattering beyond the limit of plasmonic enhancement, but also makes it feasible to realize addressable functional FERS devices with a gate electrode array.</P> [FIG OMISSION]</BR>

PRESSURE DROP CHARACTERISTICS OF R410A-OIL MIXTURE FLOW BOILING IN SMALL SMOOTH TUBES

Gao, Yifeng,Deng, Bin,Ding, Guoliang,Hu, Haitao,Huang, Xiangchao The Society of Air-Conditioning and Refrigerating 2010 International Journal Of Air-Conditioning and Refr Vol.18 No.2

This study presents experimental frictional pressure drop for R410A/oil mixture flow boiling in small horizontal smooth tubes with inside diameters of 4.18mm and 2.0 mm. Experimental conditions cover nominal oil concentrations from 0 to 5%. The test results show that the presence of oil enhances two-phase frictional pressure drop about 0-120% and 0-90% at present tee conditions for 4.18mm I.D. smooth tube and 2.0mm I.D. smooth tube, respectively, and the enhanced effect is more evident at higher vapor qualities where the local oil concentrations are higher. A new correlation to predict the local frictional pressure drop of R410A/oil mixture flow boiling inside conventional size and small smooth tubes is developed based on local properties of refrigerant-oil mixture, and the experimental data of 4.18mm I.D. and 2.0mm I.D. smooth tubes and that of 6.34mm I.D. smooth tube (Hu et al., 2008) are well-correlated with the new correlation.

Precisely tailoring pore structure in sunflower plate-derived N, O co-doped carbons for high-performance supercapacitors

Dong Liu,Tao Sun,Yuqin Hu,Yigang Ding,Baomin Fan,Haitao Wang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-

The controllable adjustment of pore structure is of great significance for the high capacitive performanceof porous carbon materials. In this research, a versatile K2CO3 activation approach is proposed to adjustand control the porosity of sunflower plate-derived hierarchical porous carbon materials (HPC-x) by controllingthe K2CO3/carbons mass ratio. Notably, the variety of pore types, including micropores, mesoporesand macropores, can be detected at different K2CO3/carbons mass ratios (0 4). Impressively,the specific surface area of optimal HPC-2 material is 2526 m2/g. Compare with the other samples(HPC-1, HPC-3 or HPC-4), the HPC-2 possess superior capacitance activity (369.4 F/g at 0.5 A/g). Ontop of that, the energy density of HPC-2 assembled supercapacitors in 1 M Na2SO4 and 6 M KOH solutionscan even reach 32.6 and 7.3 Wh/kg, respectively.

PRESSURE DROP CHARACTERISTICS OF R410A-OIL MIXTURE FLOW BOILING IN SMALL SMOOTH TUBES

YIFENG GAO,BIN DENG,GUOLIANG DING,HAITAO HU,XIANGCHAO HUANG 대한설비공학회 2010 International Journal of Air-Conditioning and Refr Vol.18 No.2

This study presents experimental frictional pressure drop for R410A/oil mixture flow boiling in small horizontal smooth tubes with inside diameters of 4.18 mm and 2.0 mm. Experimental conditions cover nominal oil concentrations from 0 to 5%. The test results show that the presence of oil enhances two-phase frictional pressure drop about 0–120% and 0–90% at present test conditions for 4.18 mm I.D. smooth tube and 2.0 mm I.D. smooth tube, respectively, and the enhanced effect is more evident at higher vapor qualities where the local oil concentrations are higher. A new correlation to predict the local frictional pressure drop of R410A/oil mixture flow boiling inside conventional size and small smooth tubes is developed based on local properties of refrigerant–oil mixture, and the experimental data of 4.18 mm I.D. and 2.0 mm I.D. smooth tubes and that of 6.34 mm I.D. smooth tube (Hu et al., 2008) are well-correlated with the new correlation.

TiO2 nanoparticles anchored on graphene oxide nanosheets as a highly active photocatalyst for decabromodiphenyl ether degradation

Man Yang,Yilun Zou,Lei Ding,Yang Yu,Jinai Ma,Lei Li,Ande Fudja Rafryanto,Jing Zou,Arramel,Haitao Wang 한국탄소학회 2023 Carbon Letters Vol.33 No.5

Decabromodiphenyl ether (BDE209) is a persistent aromatic compound widely associated with environmental pollutants. Given its persistence and possible bioaccumulation, exploring a feasible technique to eradicate BDE209 efficiently is critical for today’s environmentally sustainable societies. Herein, an advanced nanocomposite is elaborately constructed, in which a large number of titanium dioxide ( TiO2) nanoparticles are anchored uniformly on two-dimensional graphene oxide (GO) nanosheets ( TiO2/GO) via a modified Hummer’s method and subsequent solvothermal treatment to achieve efficient photocatalytic degradation BDE209. The obtained TiO2/ GO photocatalyst has excellent photocatalytic due to the intense coupling between conductive GO nanosheets and TiO2 nanoparticles. Under the optimal photocatalytic degradation test conditions, the degradation efficiency of BDE209 is more than 90%. In addition, this study also provides an efficient route for designing highly active catalytic materials.

Motion planning and simulation verification of a hydraulic hexapod robot based on reducing energy/flow consumption

Zongquan Deng,Yiqun Liu,Liang Ding,Haibo Gao,Haitao Yu,Zhen Liu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.10

Minimizing the energy and flow consumption is significant to realize the locomotion of a hydraulically actuated hexapod robot formobile field applications. This paper proposes a low energy cost foot trajectory planning method to realize a constant velocity of the bodyand optimize the power and flow consumption of a hexapod robot. A dephased gait generating method is also proposed to decrease theflow demand. A simulation platform for hexapod robots was developed using C++ and based on the vortex physics engine. Power andflow consumption models were derived to verify the proposed methods. The simulation platform was used to verify the effectiveness ofthe proposed methods at optimizing the power and flow consumption.