Experimental and theoretical understanding on electrochemical activation and inactivation processes of Nb3O7(OH) for ambient electrosynthesis of NH3

2019 ◽  
Vol 7 (28) ◽  
pp. 16969-16978 ◽  
Author(s):  
Tianxing Wu ◽  
Miaomiao Han ◽  
Xiaoguang Zhu ◽  
Guozhong Wang ◽  
Yunxia Zhang ◽  
...  
Keyword(s):  
Theoretical Calculation ◽  
Electrochemical Activation ◽  
Ambient Conditions ◽  
Theoretical Understanding ◽  
Nanoparticle Catalysts ◽  
Calculation Results

Our experimental and theoretical calculation results revealed the electrochemical activation and inactivation processes of ultrafine Nb3O7(OH) nanoparticle catalysts for electrocatalytic N2 reduction to produce NH3 under ambient conditions.

scholarly journals Entropy‐Maximized Synthesis of Multimetallic Nanoparticle Catalysts via a Ultrasonication‐Assisted Wet Chemistry Method under Ambient Conditions

2019 ◽  
Vol 6 (7) ◽  
pp. 1900015 ◽  
Author(s):  
Miaomiao Liu ◽  
Zihao Zhang ◽  
Francis Okejiri ◽  
Shize Yang ◽  
Shenghu Zhou ◽  
...  
Keyword(s):  
Ambient Conditions ◽  
Wet Chemistry ◽  
Nanoparticle Catalysts ◽  
Chemistry Method

MoS2 nanosheets grown on nickel chalcogenides: controllable synthesis and electrocatalytic origins for the hydrogen evolution reaction in alkaline solution

2019 ◽  
Vol 7 (37) ◽  
pp. 21514-21522 ◽  
Author(s):  
Anchun Long ◽  
Wanrong Li ◽  
Min Zhou ◽  
Weicheng Gao ◽  
Bitao Liu ◽  
...  
Keyword(s):  
Experimental Data ◽  
Theoretical Calculation ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Alkaline Solution ◽  
Mos2 Nanosheets ◽  
Controllable Synthesis ◽  
Calculation Results ◽  
Catalytic Mechanisms

Catalytic mechanisms and activity trend of Ni-based heterostructures were revealed by combining experimental data and theoretical calculation results.

Research on the Bearing Capacity of Unsupported Random Launching Site

2012 ◽  
Vol 457-458 ◽  
pp. 1096-1100
Author(s):  
Hong Jie Cheng ◽  
Yuan Zhao ◽  
Bin Mao Li ◽  
Jin Chun Zhan
Keyword(s):  
Theoretical Calculation ◽  
Evaluation Model ◽  
Reaction Force ◽  
Data Acquisition System ◽  
Bilateral Symmetry ◽  
Engineering Properties ◽  
Pressure Data ◽  
Bearing Load ◽  
Calculation Results ◽  
Launching Site

Based on the uncertainty of engineering properties of unsupported launching site, fast assessment of preselective site must be done before missile launching, to provide decision for selecting launching position reasonably, and ensure launching missile safely and reliably. Mostly, the launching site is an elastic-plastic structure, the deformation and destruction of launching site is nearly related to the stress and developing process of strain, the support load of the site must be computed before using. In this paper, the bearing load of launching site is analyzed in missile erecting process with the hypothesis that the launching vehicle is bilateral symmetry object. Jack reaction force in erecting process is calculated while the influence of wind load is considered, which provides load criterion for building evaluation model of launching site. The running curve of jack reaction force related to erecting angle is yielded through using pressure data acquisition system. The amplitude and variation trend of jacks reaction force are in well match with theoretical calculation results by analyzing the running curves, and the rationality of result is verified by this way. The research conclusions can offer references for selecting and judging intensity of missile launching site when unsupported random launching way is applied.

Design and Simulation of New Tooth Profile of Flexspline for Harmonic Gear Drive

2015 ◽  
Vol 741 ◽  
pp. 99-107
Author(s):  
Li Zu ◽  
Lan Lan Feng ◽  
Yan Yang Sun
Keyword(s):  
Theoretical Calculation ◽  
Process Simulation ◽  
Cutting Tool ◽  
Parametric Design ◽  
Tooth Profile ◽  
Structure Parameters ◽  
Circular Arc ◽  
Gear Drive ◽  
Calculation Results ◽  
Normal Method

We focused on the parametric design and simulation of new tooth profile “circular arc-involute-circular arc” for flexspline in this paper. Based on the MATLAB software, the basic tooth profile of hob was designed. According to gear generating cutting principle, the simulation of processing for flexspline tooth profile has been realized. By tooth profile normal method, we calculated flexspline tooth profile which is conjugated with the basic tooth profile of the cutting tool, and gave the contrastive studies on process simulation and theoretical calculation. Results show that they are feasible in solving the new tooth profile of flexspline. When changing the key structure parameters, the different changing regulations of flexspline tooth profile can be gained. The research results are meaningful to improve the capacity of harmonic gear drive.

Application of Near-Field Acoustic Holography to Identify the Mechanical Noise Sources on the Submarine

2014 ◽  
Vol 635-637 ◽  
pp. 294-298
Author(s):  
Hai Bo Wan ◽  
Shi Jian Zhu ◽  
Qi Wei He
Keyword(s):  
Theoretical Calculation ◽  
Acoustic Field ◽  
Near Field ◽  
Mechanical Equipment ◽  
Pressure Amplitude ◽  
Acoustic Holography ◽  
Noise Sources ◽  
Mechanical Noise ◽  
Calculation Results ◽  
Simulation Results

In order to localize and identify the mechanical noise sources on the submarine, a kind of double-layer submarine model with ring-stiffened was established, and the broadband actuators were put on the inner structure to simulate the mechanical equipment. The radiated acoustic field of the submarine model was reconstructed by the near-field acoustic holography method, which was also compared with the theoretical acoustic field. The simulation results showed that the reconstruction pressure amplitude agreed well with the theoretical calculation results, indicating that the acoustic field of submarine model could be reconstructed accurately by the method of near-field acoustic holography, and the mechanical noise sources would be localized and identified accordingly.

Calculation of Axial Hydraulic Thrust of Francis Turbine

2012 ◽  
Author(s):  
XingYing Ji ◽  
Lai Xu ◽  
Xiao Liu
Keyword(s):  
Numerical Simulation ◽  
Theoretical Calculation ◽  
Significant Role ◽  
Model Test ◽  
Francis Turbine ◽  
Axial Thrust ◽  
Theoretical Methods ◽  
Calculation Results

Put forward a method of calculating the axial thrust of Francis turbine. To use numerical simulation computing the axial thrust on hub, shroud and blade of inner runner, combine theoretical methods calculating the pressure on hub and shroud of outer runner, finally the axial thrust of Francis turbine is obtained. The results of calculation agree with the results of model test. It is an effective way of gathering the theoretical calculation and numerical simulation to calculate the axial thrust of Francis turbine. In addition the static suction of turbine has great effect on calculation results of the axial thrust. The static suction of turbine plays a significant role on the lifting of turbine.

scholarly journals The Design and Implementation of a High-Precision Positioner Fixture

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1227
Author(s):  
Xuesen Zhao ◽  
Rongkai Tan ◽  
Zhe Wang ◽  
Xicong Zou ◽  
Zhenjiang Hu ◽  
...  
Keyword(s):  
Theoretical Calculation ◽  
High Precision ◽  
Tooth Profile ◽  
Alignment Error ◽  
Test Results ◽  
Positioning Accuracy ◽  
Design And Implementation ◽  
Cumulative Error ◽  
Half Angle ◽  
Calculation Results

In this paper, a novel positioner fixture with a high repeated positioning accuracy and a high stiffness is proposed and investigated. A high-precision end-toothed disc is used to achieve the high repeated positioning accuracy of the designed positioner fixture. The mathematical models of the cumulative error of the tooth pitch, the tooth alignment error and the error of the tooth profile half-angle of the end-toothed disc are analyzed. The allowable tolerance values of the cumulative error of the tooth pitch, the tooth alignment error and the error of the tooth profile half-angle of the end-toothed disc are given. According to the theoretical calculation results, a prototype positioner fixture is fabricated and its repeated positioning accuracy and stiffness are tested. The test results indicate that the stiffness of the proposed positioner fixture is 1050.5 N/μm, which is larger than the previous positioner fixtures of the same type. The repeated positioning accuracy of the proposed positioner fixture in the x, y and z directions are ± 0.48 μm, ± 0.45 μm and ± 0.49 μm, respectively, which is significantly higher than the previous positioner fixtures.

scholarly journals Research on the Design Method of a Bionic Suspension Workpiece Based on the Wing Structure of an Albatross

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Siyang Gao ◽  
Bangcheng Zhang ◽  
Jianwei Sun
Keyword(s):  
Theoretical Calculation ◽  
Design Method ◽  
Air Pressure ◽  
Guide Rail ◽  
Structure Mapping ◽  
Air Suspension ◽  
Suspension Process ◽  
Physical Prototype ◽  
Calculation Results ◽  
Suspension Test

An air suspension platform uses air pressure to realize the suspension function during the suspension process, and it has the disadvantage of large air pressure and a small suspension force. In this study, an air suspension platform was built using bionic design to reduce the required air pressure and increase the suspension force. A suspension structure mapping model was established according to the physiological structure characteristics of albatross wings. A bionic model was established by using the theoretical calculation formula and structural size parameters of the structural design. A 3D printer was used to manufacture the physical prototype of the suspended workpiece. Based on this, a suspension test rig was built. Six sets of contrast experiments were designed. The experimental results of the suspension test bench were compared with the theoretical calculation results. The results show that the buoyancy of the suspended workpiece with a V-shaped surface at a 15-degree attack angle was optimal for the same air pressure as the other workpieces. The surface structure of the suspended workpiece was applied to the air static pressure guide rail. By comparing the experimental data, the air pressure of the original air suspension guide rail was reduced by 37%, and the validity of the theory and design method was verified.

scholarly journals Investigation of the structural and electronic properties of CdS under high pressure: an ab initio study

2018 ◽  
Vol 96 (2) ◽  
pp. 216-224 ◽  
Author(s):  
C. Yamcicier ◽  
Z. Merdan ◽  
C. Kurkcu
Keyword(s):  
Phase Transition ◽  
Ab Initio ◽  
Density Functional ◽  
Structural Phase ◽  
Type Structure ◽  
Ambient Conditions ◽  
Space Group ◽  
Space Groups ◽  
Intermediate States ◽  
Calculation Results

An ab initio constant pressure study is carried out to explore the behaviour of cadmium sulfide (CdS) under high hydrostatic pressure. We have studied the structural properties of CdS using density functional theory (DFT) under pressure up to 200 GPa. CdS crystallizes in a wurtzite (WZ)-type structure under ambient conditions. CdS undergoes a structural phase transition from the hexagonal WZ-type structure with space group P63mc to cubic NaCl-type structure with space group [Formula: see text]. Another phase transition is obtained from NaCl-type structure to the orthorhombic CdS-III-type structure with space group Pmmn. The first transformation proceeds via seven intermediate states with space group Cmc21, P21, Pmn21, P21/m, Pmmn, I4/mmm, and Cmcm. The latter transformation is based on two intermediate states with space groups Immm and P21/m. These phase transitions are also studied by total energy and enthalpy calculations. According to these calculations, the phase transformations occur at about 3 and 51 GPa, respectively. Calculation results on the other basic properties, such as lattice constant, volume, and bulk modulus are also compared with those of other recent theoretical and experimental data, and generally, good agreement with the available data are obtained.

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