bluuebunny/crossref_metadata_2025 huggingface dataset:
Assay of sodium carbonate
Authors: Wu Bing , Sobina Alena , Recknagel Sebastian , Meinhardt René , Rivera-Sánchez Griselda , Ortiz-Aparicio José Luis , Rozikova Matilda , Borges Paulo Paschoal , Sobral Sidney Pereira , Zhou Tao , Zhang Jianying , Asakai Toshiaki , Glebov Andrey , Melnikov Aleksandr , Gavrilkin Vladimir , Petrenko Anton , Tkachenko Volodymyr , Mariassy Michal , Hanková Zuzana , Shimolin Alexandr
Published: January 2023

Main text

The CCQM-K173 Assay of Sodium Carbonate key comparison was jointly organized by the Inorganic Analysis (IAWG) and Electrochemical Analysis and Classical Chemical Methods (EAWG) working groups of CCQM to test the abilities of the national metrology institutes (NMIs) to measure the purity or amount content of solid bases. They are important challenges for reference material producers, providers of other measurement services, such as proficiency testing schemes. Evidence of successful participation in formal, relevant international comparisons are needed to support calibration and measurement capability claims (CMCs) made by NMIs and designated institutes (DIs).

Nine NMIs participated in this key comparison CCQM-K173. National Institute of Metrology P. R. China (NIM) and Ural Research Institute for Metrology - Affiliated Branch of the D.I. Mendeleyev Institute for Metrology (VNIIM-UNIIM), Russian Federation, acted as the coordinating laboratories of the comparison.

The measurement methods used by the participants for measuring the amount content of bases expressed as sodium carbonate were coulometry and titrimetry.

In general, good overlap of results was observed, the suitability of coulometry and titrimetry for assay of high purity materials was demonstrated. The majority of results were split in two groups differing from each. This bias was however covered by the stated uncertainty estimates. Various effects have been evaluated that may cause it. However, the reason for the bias has not been identified clearly.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Interfacial engineered PANI/carbon nanotube electrode for 1.8 V ultrahigh voltage aqueous supercapacitors
Authors: Ji Zhichao , Liu Congcong , Xie Wenhe , Liu Shenghong , Zhang Chao , Liu Fuwei , Sun Haibin , Lu Yang , Pan Xuexue , Wang Chunlei , Wang Zhuanpei
Published: January 2023

Flexible three-dimensional interconnected carbon nanotubes on the carbon cloth (3D-CNTs/CC) were obtained through simple magnesium reduction reactions. According to the Nernst equation, the cell voltage based on these pure carbon electrodes without any additives could reach 1.5 V due to the higher di-hydrogen evolution over potential in neutral 3.5 M LiCl electrolytes. In order to improve the electrochemical performance of the electrodes, 3D-CNTs/CC electrodes covered with polyaniline barrier layer (3D-PANI/CNTs/CC) were prepared by in situ electropolymerization using interfacial engineering method. The assembled symmetric supercapacitors display a broadened voltage of 1.8 V, high areal capacitance of 380 mF cm−2, outstanding areal energy density of 85.5 μWh cm−2 and 84% of its initial capacitance after 20 000 charge-discharge cycles. This work demonstrated that the interface engineering strategy provides a promising way to improve the energy density of carbon-based aqueous supercapacitors by widening the voltage and boosting the capacitance simultaneously.
The investigation of linear relationship between domain wall creep parameters in Co/Pt multilayers
Authors: Li Xiaolei , Qiao Huifang , Niu Yabin , Gao Runliang , Wu Huiliang , Ye Yuchen , Liu Qingfang , Wang Jianbo
Published: January 2023

In this work, we investigate the linear relationship between domain wall creep parameters, and evaluate the effect of material parameters on magnetic domain wall creep in a series of Pt/Co/Pt multilayers with perpendicular magnetic anisotropy. The results for the samples with different magnetic layer thicknesses verify the linear relationship between the domain wall creep parameters, which is because in these samples both domain wall creep parameters are mainly affected by Co layer thickness and both of the domain wall creep parameters are proportional to the Co layer thickness. With the assistance of surface acoustic waves, the domain wall creep parameters also follow the linear relationship. This suggests a relationship between the anisotropy density K and local pinning strength

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The above linear relationship does not exist in annealed samples because annealing breaks the relationship between the local pinning strength and material parameters.
Influence of magnetic (Fe) and non-magnetic (In) doping on structural, magnetic, and weak anti-localization properties of Bi2Te3 topological insulator
Authors: Kander Niladri Sekhar , Guchhait Suman , Das A K
Published: January 2023

In this article, we have studied the changes in structural, magnetic, and magneto-transport properties of Bi2Te3 topological insulator doped with magnetic (Fe) as well as non-magnetic (In) elements. The un-doped along with Fe, In-doped Bi2Te3 are grown using a melt growth technique. The Rietveld analysis of x-ray diffraction data expresses that both In and Fe-dopants substituted the Bi-position with a little bit of interstitial incorporation in host Bi2Te3. It is also noticed that In-doping is slightly more favorable for Bi-substitution than Fe. The magnetic characterization reveals a mixing of diamagnetic and Pauli paramagnetic behavior of un-doped and In-doped Bi2Te3, whereas, Fe-doping shows overall paramagnetism with local anti-ferromagnetic interactions among Fe-ions without long-range order. The electrical-transport study represents the metallic response of host Bi2Te3, which is well-maintained for In-doping; however, Fe-doping exhibits prominent anomalies in ρ
xx –T profiles. Importantly, magneto-conductance research indicates a notable deviation of host quantum feature, weak anti-localization effect (WAL) upon magnetic (Fe) doping, whereas non-magnetic In-doping shows a comparatively weak deviation in WAL effect for high doping limit.
Orthorhombic and triclinic modifications of the arsenate Cu4O(AsO4)2 and isotypic phosphates Cu4O(PO4)2: strongly frustrated antiferromagnetics
Authors: Volkova L M
Published: January 2023

A structural-magnetic models of the orthorhombic and triclinic modifications of the arsenates Cu4O(AsO4)2 and isotypic phosphates Cu4O(PO4)2 has been built and analyzed. Their base elements are the complicated ribbons composed of antiferromagnetic Cu4 tetrahedra. Structurally, these tetrahedra have no shared copper atoms; however, there are strong antiferromagnetic (AFM) and ferromagnetic (FM) couplings between them, both within the complicated ribbons and between them. It has been established that both modifications are strongly frustrated 3D antiferromagnetics due to competition between the nearest AFM interactions along the edges of the Cu4 tetrahedra and competition between interactions and a multiplicity of long-range secondary AFM and FM interactions. Additionally, a large number of weaker long-range interactions are competing among each other. However, there is a possibility of the ordering Dzyaloshinskii-Moriya (DM) interaction in the centrosymmetric orthorhombic modification (Pnma), because two of the three types of magnetic ions, Cu1 and Cu3, are in the partial position 4c, where the ions are not related by the inversion center. In the triclinic modification (P −1) of Cu4O(As(P)O4)2, all four copper ions are in the centrosymmetric equivalent position 2i, which prevents DM interactions. This centrosymmetry will allow magnetic interactions in the triclinic modification of Cu4O(As(P)O4)2 to be still frustrated at lower temperature. It is possible that the triclinic modification of these compounds is a quantum spin liquid.
Torsional birefringence in metric-affine Chern-Simons gravity: gravitational waves in late-time cosmology
Authors: Boudet S. , Bombacigno F. , Moretti F. , Olmo Gonzalo J.
Published: January 2023

In the context of the metric-affine Chern-Simons gravity endowed with projective invariance, we derive analytical solutions for torsion and nonmetricity in the homogeneous and isotropic cosmological case, described by a flat Friedmann-Robertson-Walker metric. We discuss in some details the general properties of the cosmological solutions in the presence of a perfect fluid, such as the dynamical stability and the emergence of big bounce points, and we examine the structure of some specific solutions reproducing de Sitter and power law behaviours for the scale factor. Then, we focus on first-order perturbations in the de Sitter scenario, and we study the propagation of gravitational waves in the adiabatic limit, looking at tensor and scalar polarizations. In particular, we find that metric tensor modes couple to torsion tensor components, leading to the appearance, as in the metric version of Chern-Simons gravity, of birefringence, characterized by different dispersion relations for the left and right circularized polarization states. As a result, the purely tensor part of torsion propagates like a wave, while nonmetricity decouples and behaves like a harmonic oscillator. Finally, we discuss scalar modes, outlining as they decay exponentially in time and do not propagate.
Formation of hot spots around small primordial black holes
Authors: He Minxi , Kohri Kazunori , Mukaida Kyohei , Yamada Masaki
Published: January 2023

In this paper, we investigate the thermalization of Hawking radiation from primordial
black holes (PBHs) in the early Universe, taking into account the interference effect on
thermalization of high energy particles, known as Landau-Pomeranchuk-Migdal (LPM) effect. Small
PBHs with masses ≲ 109 g completely evaporate before the big bang
nucleosynthesis (BBN). The Hawking radiation emitted from these PBHs heats up the ambient plasma
with temperature lower than the Hawking temperature, which results in a non-trivial temperature
profile around the PBHs, namely a hot spot surrounding a PBH with a broken power-law tail. We find
that the hot spot has a core with a radius much larger than the black hole horizon and its highest
temperature is independent of the initial mass of the PBH such as 2 × 109 GeV × (α/0.1)19/3, where α generically represents the fine-structure
constants. We also briefly discuss the implications of the existence of the hot spot for
phenomenology.
Analysis of Liquid Inclination on the Absorption Performance of the Cavity-containing Coating
Authors: Liu Zhi-gang , Zhao Xian-wen , Li Qi , Chen Zhou , Wang Zheng-wei
Published: January 2023

During the submarine diving and rising, the coating may be damaged under the effect of alternating pressure of seawater, which may lead to the inflow of water into the cavity, while the liquid level of the cavity is not horizontal due to the cylindrical body of the submarine. For the influence of the liquid surface inclination on the sound absorption performance of the coating under the condition of water inflow, this paper firstly establishes a simplified analysis model, solves the sound reflection of the uniform layered medium based on the transfer function method, and then combines the finite element method to analyze the sound pressure field point. Finally, calculations and data processing are carried out to obtain the sound absorption coefficients. The results show that the inclination of the liquid surface causes the movement of the singularity of the absorption coefficient, and the frequency of the singularity moves to lower frequencies as the inclination angle of the liquid increases.
Experimental Study on the Cumulative Damage of Shipboard Structure Subject to Near-field Underwater Explosions
Authors: Chen Wenge , Cheng Lele , Yu Chao , Wu Haijun , Hang Fenglei , Wu Ziqi
Published: January 2023

To explore the cumulative damage law of near-field underwater explosions on the side of the ship structure, the multi-cabin model of the shipboard local structure is designed and applied to close-in underwater explosion experiments with different explosive masses and model conditions. The pressure load of the explosion shock wave near the water surface is obtained and analyzed. The damage results, such as the damage pattern of the model and the damage range of cabins, are acquired. The comprehensive comparison shows that: the secondary explosion on the side has a significant cumulative damage effect; the damage pattern of the structure is closely related to the proportional distance of the explosion. The damaged power of a single large charge explosion on the shipboard is bigger than the cumulative damage caused by two small explosions. The results of this study can provide a reference for the research on the damage and protection of the ship.
Experimental Study on Flow Characteristics of Large-scale Liquid Oxygen Delivery System
Authors: Ye Xin , Zhang Qing , Zhang Bangshuang , Zhang Lian , Zhang Ming
Published: January 2023

To deeply explore the flow law of the large-scale liquid oxygen delivery system, several liquid oxygen delivery tests have been conducted and measured. On this basis, the model of the pipeline characteristic of the liquid oxygen delivery system is constructed according to the hydrodynamic theory to obtain the relationship equation between the gas cushion pressure and liquid oxygen flow, and the frequency conversion model of the liquid oxygen pump is constructed according to the pump affinity laws to obtain the relationship equation between the liquid oxygen pump frequency, flow, and head. Under the working pressure limitation of the storage tank, liquid oxygen pump, and pipeline, the ultimate capacity of the liquid oxygen delivery system is calculated using the above models. This provides a database and theoretical basis for further optimization of liquid oxygen delivery process parameters and control strategies, as well as evaluation and exploitation of system performance potentials.
Frequency-enhanced triboelectric-electromagnetic hybrid generator integrated with multi-generation units for wind energy harvesting
Authors: Ye Hui , Sha Shujing
Published: January 2023

For a sustainable energy harvesting method, triboelectric nanogenerator (TENG) is becoming more and more important in natural wind energy harvesting. However, harvesting capacity of the TENG is affected by the low frequency of natural wind. To effectively harvest wind energy, a frequency-enhanced triboelectric-electromagnetic hybrid generator (FE-TEHG) is proposed, which integrates generation units. It contains a cam structure with six noses to increase the frequency of the wind. And in the generation units, the TENG module is integrated into the follower, and the electromagnetic generator (EMG) module is integrated into the driving part. Experiments proved that by increasing the input frequency, the output electrical signal of the TENG module becomes six times the original, and this integration method can greatly improve the output capacity of the generator. In the process of charging a 100 μF capacitor to 1.50 V, the charging speed of the FE-TEHG is 1.58 times that of the TENG module. In addition, when the wind speed is about 9 m/s, the FE-TEHG can light up 640 light-emitting diodes (LEDs) and supply power for a thermometer normally. Therefore, this paper provides a valuable method for frequency enhancement and integrated design of the TENG in wind energy harvesting.
Study on the sliding bearing of hot dip galvanized sinking roll
Authors: Chen Shangjun , Wang Wen , Wang Leizhen , Bai Yujian
Published: January 2023

As a key component in the hot-dip galvanizing production line, the sink roller ends of the sliding bearing is affected by the high-temperature zinc liquid corrosion wear, which leads to frequent stop for maintenance. The galvanizing industry is looking for more suitable material for bearing to prolong the service life. To improve the corrosion and wear resistance of the sliding bearing, the laser cladding method was used to prepare the cobalt-based and iron-based coatings on the surface of the superalloy. In this paper, the high-temperature zinc liquid corrosion wear test was carried out on the alumina ceramic bushing and three kinds of metal sleeves (316L stainless steel, cobalt-based alloy, and iron-based alloy). By comparing and analyzing the corrosion and wear conditions of the three metal sleeves after the test, the main failure mechanisms were comprehensively analyzed.
Analysis of the influence of clearance on bending stiffness of space deployable mechanism in the locked state
Authors: Wang Xinyuan , Shui Yongtao , Wang Chaozheng , Yin Dezheng , Ji Hongjuan
Published: January 2023

The future space station, which can simulate the gravity environment by rotation, has attracted the attention of scholars in recent years. It is considered a feasible scheme to fold the mechanism on the ground and assemble it into an artificial gravity ring after entering orbit. The deployable mechanism used to attach the space station is required to be large-scale and sufficiently high stiffness after deployment to ensure the safety and accuracy of the payload. However, the clearance will significantly reduce the stiffness of the mechanism, which is in the locked state. In this paper, the deployable mechanism with enhanced bending and torsion resistance configuration will be taken as the research object. First, based on the classical hinge stiffness model, the hinge equivalent model and the sliding joint equivalent model are proposed. Then, the finite element model based on equivalent stiffness is analyzed, and the effectiveness of the finite element model is verified by comparing the experimental results. Finally, the finite element model was used to analyze the influence of the clearance of the pin hole, the clearance of the sliding fit, and the position of the clearance on the bending stiffness of the deployable mechanism. The results show that the clearance greatly reduces the stiffness of the mechanism under small loads and weakens the bearing performance of components. At the same time, the position of the clearance should be taken seriously in the mechanism design.
Overall Strength Analysis of Floating Offshore Wind Turbine Foundation
Authors: Lin Jiang , Wu Wensong , Peng Zhongbo
Published: January 2023

The loads on the floating offshore wind turbine foundation are complex, and the evaluation of its overall structural strength is particularly important. This paper establishes a new type of semi-submersible floating wind power infrastructure finite element model based on the three-dimensional potential flow theory. The long-term forecast design wave method is used to carry out a long-term forecast of the wave load under the control parameters of the characteristic sections, with the wind pressure load superimposed and combined. Finally, the overall strength of the floating foundation under self-existing conditions is analyzed. The research shows that the max Von-Mises stress of the mid-transverse section is 115.6% higher than that of the mid-longitudinal section in the most dangerous state, and the overall strength of the structure meets the requirements of the standard. The high-stress areas appear at the connection between the lower floating body, including the cross brace and the column, while the max stress appears at the connection between the cross brace and the column supporting the wind turbine. Attention should be paid to such key parts in the detailed design stage of the floating foundation. The numerical analysis method and research conclusions can also provide a reference for the analysis and optimization of the same type of floating foundation.
Introductory Analysis of Spark Ignition Engine and Extensively Implemented Electric Alternatives
Authors: Wu Kefan , Zhou Chengxiao , Zhu Jiaqi , Zhu Yuqi
Published: January 2023

Energy crises and climate change lead to restricted standards of emission and energy consumption in regular road vehicles. Combustion method, ignition time, and injection time are engine development priorities. Optimal injection and ignition timing at 1600 rpm can save 10% on brake fuel. Perfect injection and ignition timing reduce heat loss and emissions. Various approaches to reducing transportation emissions and energy were implemented. Plug-in electric vehicles and hydrogen fuel cell vehicles (HFCV) were eliminated because of the lack of charging and refilling facilities. Mild hybrid energy recovery devices are considered straightforward and effective. Because of its effectiveness and longevity, Kinetic Energy Recovery System (KERS) is the most popular hybrid system in road automobiles. Future road energy recovery systems may include heat energy recovery methods and solar panels. However, electric vehicles with regenerative technologies own the highest energy efficiency among all the proposed solutions with the advantage of no pollution during the operation.
A review of arc stability analysis methods for aluminum alloy welding
Authors: Zhang Jiaxin , Gan Shiming , Liu Huaying
Published: January 2023

Aluminum alloy has become an essential war material for aerospace manufacturing, transportation manufacturing, and other fields for its superior thermal conductivity, corrosion resistance, and other strengths. In the aluminum alloy welding process, the stability of the arc can indicate the quality of the weld formation. This paper mainly reviews the probability density method, the principle of the approximate entropy method, and the analysis of aluminum alloy welding arc stability in the application. Analyzing the stability of the welding arc can help promote the improvement of welded joint quality and welding fabrication.
Effect of Pulse Duty Cycle and Oxidation Time on Microstructure and Properties of Micro-arc Oxidation Coatings on Ti6Al4V Alloy
Authors: Chen Yuke , Zhou Pengfei , Yuan Meini
Published: January 2023

Micro-arc oxidation (MAO) technology can in-suit generate coatings with high hardness and strong adhesion on the surface of titanium alloy, thereby greatly improve the application range of titanium alloy. The morphology and properties of coatings are controlled by changing electrical parameters such as duty cycle and oxidation time. This work mainly aims to study the influence of different duty cycles and oxidation times on MAO coatings microstructures and properties of Ti6Al4V alloy under the condition of constant voltage and pulse frequency. The scanning electron microscopy (SEM) and X-ray Diffractometer (XRD) were used to investigate into MAO coatings microstructure and phase composition. The roughness, porosity, thickness, and microhardness of MAO coatings were evaluated respectively by roughness tester, thickness gauge, and microhardness tester. The results show that surface morphology of the MAO coatings change from crater-like micropores to foam-like protrusions with the enhancement of duty cycle and oxidation time. When duty cycle is 50% and oxidation time is 30 min respectively, the ejection of the molten material made the MAO coating surface appear foam-like protrusions, and the surface morphology is seriously damaged. When the oxidation time and the duty cycle are 30 min and 10% respectively, the rutile phase intensity is the maximum, and further increasing the duty cycle will lead to a rutile phase decrease. In a limit range, the hardness rise with increase of oxidation time and duty cycle. The highest hardness is 668.85 HV.
Design and optimization of dry powder jet cleaning nozzles for airport navigation lights
Authors: Zhu Qiuhua , Ge Xiaohong , Gu Xiaobin , Li Hui , Wang Jinhuo , Zhang Zhiwen , Lv Fuheng
Published: January 2023

The research of this work is based on the nozzle design and optimization of dry powder (NaHCO3) jet cleaning system for airport navigation aid lamps. In this cleaning system, compressed air drives dry powder (NaHCO3) abrasive, and a gas-solid mixed high-speed jet is sprayed onto the surface of the luminaire through the nozzle to scour and clean the dirt attached to the surface of the luminaire. Based on the computational fluid dynamics and flow field theory, three types of nozzle structures, namely tapered nozzle, Laval nozzle, and flat nozzle, were studied; the DPM (Deformable part model) model in Fluent was used to analyze the internal and external flow fields of the nozzle mixed with the gas-solid two-phase flow to obtain the velocity field, pressure field and nozzle wear rate of the mixed gas, and the flat nozzle was selected and the nozzle parameters were optimized. The optimized level combination of flat type nozzle structure is obtained with a flat width of 4mm, flat height of 24.5mm, and flat length of 55mm.
Impact of electromechanical coupling of main drive system of cold rolling mill on amplitude-frequency characteristics
Authors: Jia Xingdou , Wang Shen , Yan Xiaoqiang , Hou Peng , Shao Huazhuang
Published: January 2023

Main drive mechanical system of a cold rolling mill was simplified to a three-inertia model, and natural frequency of mechanical system was obtained by using Matlab simulation. Combining the main motor speed control system and the mechanical system into an electromechanical coupling system, it was found that natural frequencies of mechanical components in coupled system are different from those of the independent mechanical system. The proportional control coefficient (P value) of the speed loop would affect amplitude of system at resonance point, whereas frequency of resonance point was rarely changed and the integral control coefficient (I value) almost had no effect on the amplitude-frequency characteristics. The notch filter whose limit frequency is the resonance frequency has the best vibration suppression effect. The load observer completely suppressed torsional vibration of motor but amplified torsional vibration of gears and rolls.
A cross-spectral target tracking method based on a hidden Markov model
Authors: Wang Liming , Su Peilin , Huang Di
Published: January 2023

Aiming at the problem of target tracking stability in the case of low signal-to-noise ratio and multi-target cross-motion, this paper combines the hidden Markov model and complementary tracking and proposes a new automatic tracking method. The stability of the new algorithm is proved by theoretical analysis and computer simulation experiments. In the case of low signal-of-noise ratio and multi-target cross-motion, the new algorithm has good performance.
A Dual-Band Shared-Aperture Antenna Array Design
Authors: Ding Kaicheng , Sun Lei , Yu Daqun
Published: January 2023

Aiming at solving the difficult problem of shared-aperture integration of dual-band antenna arrays, the research of P-band/S-band shared-aperture antenna arrays is carried out, focusing on the design of broadband wide-angle scanning, planarization, miniaturization, and low-profile of the two-band shared-aperture antenna arrays. And certain work is carried out for the shared-aperture antennas in terms of the improvement of isolation and suppression of the blocking effect. The simulation results of the antenna model show that this antenna works well and can meet the specification requirements.
A High-Resolution Imaging Method for ISAR Based on Sparse Reconstruction
Authors: Fang Xinxiang , Yang Wenjun , Xie Jie , Hou Yingni , Chen Peng , Kong Ge
Published: January 2023

For the problem of first-order and second-order range migration in ISAR imaging under the condition of wide angle and wide bandwidth, a method for sparse azimuth data is proposed to obtain high-resolution ISAR images. After stretch processing, envelope alignment and residual video phase removal, the sparse recovery algorithm that sparse base is constructed by the Keystone transform is used to achieve range migration correction and the missing range profile reconstruction, and then the second-order phase estimation method based on fractional Fourier transform is used to estimate and compensate the second-order rotational phase. Simulation results show the method can effectively improve the imaging quality.
Research on the adsorption of melamine for Cu(II) and Pb(II)
Authors: Zhang Chaojian , Duan Qianqian , Yang Tianrui , Liu Junsheng
Published: January 2023

Melamine contains three aromatic nitrogen atoms and three free amino groups, which have great adsorption potential for heavy metallic ions in wastewater. The sorption performances of melamine for Cu(II) and Pb(II) ( They are denoted as Cu&Pb) were studied. Some major effects such as adsorption time, original concentration, and temperature on its adsorption performances were studied. The effects confirmed that melamine had true adsorption for Cu&Pb, and higher selectivity for the adsorption of Cu&Pb in a binary blended system. The adsorption amount of Pb(II) on melamine reached 4.91 mg/g at pH 5, adsorption equilibrium time of 12 h, and temperature of 55 °C, while the sorption amount of Cu(II) was only 2.70 mg/g, with a difference of about 1.8 times. The adsorption mechanism shows that the sorption of Cu&Pb on melamine follows the Lagergren quasi-second-order kinetic model. This result indicates that the mixture of Cu&Pb can be separated by stepwise processes from a binary mixed system.
Optimization Analysis of Meshing Worm Drive Structure with Roller Enveloping Ring Surface
Authors: Lui Huan , Huang Geng
Published: January 2023

Based on the meshing theory of the worm drive with the roller enveloping ring surface and the mathematical model of transmission efficiency of transmission mechanism, the mathematical calculation model of transmission efficiency for simultaneous meshing of multiple teeth has been set up; the geometrical parameters of transmission countershaft, the influence of friction parameters on transmission efficiency of transmission pair have been analyzed. The analysis and optimized results are that the transmission efficiency is negatively correlated with friction parameters and with other structural geometric parameters and positively correlated with the center distance in the structural geometric parameters. Thereinto, friction parameters and throat-neck coefficient have a great influence on transmission efficiency, and the roller radius and center distance have little influence on it. After structure optimization, the transmission efficiency is improved by 3.86% compared with before optimization.
Research on the technology rule of high-power laser pretreatment of granite slitting
Authors: Li Can , Liu Lie , Han Lianghua
Published: January 2023

In order to provide new pretreatment damage morphology for TBM rock breaking, the author used a ten-thousand-watt laser beam to perform cutting experiments on granite. Different laser power and cutting speed were set, and the cutting depth, width, rock removal and mass ratio were measured, calculated and analyzed. The experimental results showed that the laser power increased, the depth of cut, width and rock removal increased, and the mass ratio decreased; the cutting speed increased, the depth of cut, width and rock removal decreased, and the mass ratio increased. Under this experimental condition, the cutting effect is better when the laser power is 12kW and the cutting speed is 6mm/s.
Research progress and Prospect of Laser Cladding Technology
Authors: Li Changqi
Published: January 2023

Laser cladding technology is an advanced material surface modification technology, which has the advantages of a small dilution rate, a dense microstructure of the cladding layer, a good combination between coating and substrate, and no pollution of the working environment. The research progress of laser cladding is reviewed from three aspects: background types, basic principles, and research status. In the background category, the preset coating method and synchronous powder feeding method used in laser cladding technology are described. The research status of laser cladding technology is summarized from the aspects of cladding material, performance, and industrial application. Finally, some suggestions are put forward to obtain the cladding layer with no crack and good mechanical properties, and more technologies and laser cladding technology are expected to be combined in the future.
Fusion of remote sensing images based on multi-resolution analysis
Authors: Qi Ji , Yang Haitao , Kong Zhuo
Published: January 2023

A fast and reliable fusion algorithm is the key to the practical application of image fusion technology, so the research of the fast fusion algorithm with a good fusion effect is particularly important. Based on the multi-resolution analysis, this paper discusses the principles of the PCNN fusion algorithm, wavelet transform and Laplace pyramid algorithm, and then performs image fusion experiments. Experimental results show that the fusion effect of the wavelet transform and PCNN algorithm is significantly higher than that of the Laplace pyramid algorithm.
Research on improved character recognition technology of wagon number based on Faster-RCNN
Authors: Zhu Wangrui , Zhong Wei
Published: January 2023

Aiming at the characteristics of wagon number character printing with location features, we propose a wagon number character recognition technique based on the Faster-RCNN algorithm for the output layer to improve the accuracy of recognition by eliminating and filling the misjudged and missed characters in the output layer of image recognition. Using the relative position of each wagon number character to form a relative position matrix, the correct candidate frame is output by calculating the similarity of the relative position matrix of the candidate frame and the standard frame, and the correct wagon number is retrieved by comparing with the wagon number in the database.
Speed Control of Secondary Regulation Heave Compensation Based on Fuzzy PID
Authors: Yan Xuechen , Yan Fei , Zhao Danyao , Li Shizhen
Published: January 2023

Aiming at the problem that the widely used heave compensation technology is difficult to balance the compensation effect and energy consumption, based on the secondary regulation technology, the fuzzy PID control method is selected to design a winch heave compensation system with energy recovery. Firstly, a mathematical model is established and analyze the energy-saving characteristics of the heave compensation system. Then, the swash plate controller and speed outer loop controller are designed, and the simulation is model with the AMESim-MATLAB co-simulation platform. Finally, the simulation results are tested by experiments. And the test result reflects that the compensation efficiency of the compensation is more than 90%, and part of the energy can be recovered. The controller has good control accuracy and stability. The compensation system can effectively compensate for the position deviation caused by waves, thus providing a safety guarantee for offshore operations.
Application of Singular Value Decomposition and Adaptive Noise Cancellation Method in AUV Sonar Pulse
Authors: Deng Leilei , Leng Kaijing
Published: January 2023

The detection signal-to-noise ratio determines the underwater acoustic reconnaissance ability of AUV in complex marine environments. In this paper, the singular value decomposition method and adaptive noise cancellation method are used to improve the signal-to-noise ratio of dual channel sonar signal. The experimental data processing results show that the singular value decomposition method has a stronger noise reduction ability, but the noise reduction effect is greatly affected by the singular value threshold, and the performance of the algorithm is unstable; Although the noise reduction ability of adaptive noise cancellation method is limited, it has strong environmental adaptability and more stable algorithm performance.
A Self-Supervised Bearing Failure Detection Method with STFT and Point-wise CNN Feature Extraction
Authors: Li Xiaoyu , Yang Jie , Shen Hao , Liu Qing
Published: January 2023

As the most important parts, bearings are widely used in many types of mechanical and electronic equipment. Bearing failure often leads to serious consequences. Therefore, the fault detection of bearings is the key to ensuring the safe and reliable operation of equipment. At present, most feature extraction methods are based on signal processing algorithms. However, for some types of bearings, these feature extraction methods may lose some important information. The bearing vibration data is unbalanced data, which may lead to diagnostic errors. A new self-supervised bearing failure detection method with STFT point-wise CNN feature extraction and auto-encoder is proposed in this paper. Firstly, a point-wise CNN extracts the features from the signal after STFT. Then the auto-encoder compresses and reconstructs the features. Finally, the distance between the auto-encoder input and output is used to judge the signal is abnormal or not. The CWRU bearing vibration signal data set is used as test case. We also proposed the distance ratio as an evaluation index in the experiment. The proposed bearing fault detection method in this paper has a lower data requirement and better effect based on the results.
A brief introduction to the typical fuels for SI engine and its future projections
Authors: Teng Fei
Published: January 2023

Spark Ignition (SI) engine has been widely used and developed in the engineering field due to its high performance and safety. At present, the SI engine has received extensive attention from many experts and scholars and has become a research hotspot and focus in the field of heat engines. This paper studies the development status of SI engines from multiple perspectives. The research status of performance and pollutant emissions of commercial SI engines were analyzed by literature search. The numerical simulation principle and application method of the current SI engine were studied, and the emissions of the traditional engine and the SI engine were compared. It was found that the SI engine has irreplaceable advantages in terms of performance and emissions. In addition, this paper also looks forward to the development of the SI engine, and proposes that the future development of the SI engine should focus on improving its performance; the use of clean fuel is also an important research content of the SI engine.
Effect of the ultrasonic phased array on defect detection of HDPE electro-fusion joint
Authors: Li Qiang , Lu Qi , Chen Yingchun , Su Junwei , Yang Jie
Published: January 2023

As a common welding method for polyethylene natural gas pipelines, electro-fusion welding has been widely used. However, defects are easy to occur in the fusion area during the welding. In this paper, high-density polyethylene (HDPE) pipes with different types of electric welding joint defects are processed, and the detection effect of the ultrasonic phased array on joint defects is explored. The results show that: Ultrasonic phased array detection technology is easy to operate and reliable. It can detect three common defects: inadequate socket, cold welding, and scratch of oxide scale. In addition, according to the inspection result chart, the defect type can be accurately judged.
Ultrasonic phased array detection method for butt fusion welding defects of HDPE pipes
Authors: Li Qiang , Chen Yingchun , Tang Yu , Liu Hongyan
Published: January 2023

The welding joint is the weak link of the high-density polyethylene pipeline. The continuous development of ultrasonic phased array technology is expected to replace traditional non-destructive testing methods. In this paper, ultrasonic phased array technology is used to detect the defects of butt fusion welding. The results show that the ultrasonic phased array can distinguish between metallic and non-metallic inclusions, and the inclusion size can be displayed. Besides, insufficient fusion defects have no obvious defect features in the sector scan results. The types of insufficient fusion defects can be judged from the end-face line scan results.
Finite element analysis and simulation of cargo fork dynamics
Authors: Wu Jing
Published: January 2023

The forklift truck, as an industrial transport vehicle, is widely used in stations, workshops, warehouses, ports, and other places. At the same time, with the rapid development of today’s economy and the emergence of express industries, the number of forklifts in China is increasing by the day. At the same time, the accidents caused by forklifts are also increasing. The current research on forklifts mainly focuses on the dynamic and static analysis and structural optimization of the vehicle body and parts, among which there are few studies on a forklift. In order to verify the reliability of the forklift, this paper uses the function of SolidWorks Simulation to conduct finite element analysis on the dynamic characteristics of forklifts and sets the forklift’s mass as 2 tons to increase external irregular vibration. When the damping is 0.7, it is found that the maximum stress is 3333Pa. Based on the completion of the physical modeling, with the help of SolidWorks animation, the load situation of the forklift truck in different scenes is simulated. It is found that within the permissible range of strength, the greater the slope rate, the less the mass of the safe load.
Fault Diagnosis of Rolling Bearing Based on ICEEMDAN and SSA-RVM
Authors: Qin Jian , Fei Taiyong , Qu Zhiguo , Zhang Yinan , Yu Xinyi
Published: January 2023

In order to effectively improve the fault identification rate of correlation vector machine (RVM) in bearing fault model diagnosis and identification, a rolling bearing troubleshooting method improvement-based adaptive white noise complete integrated empirical mode decomposition (ICEEMDAN) and sparrow search algorithm (SSA) optimized correlation vector machine (RVM) is proposed. A rolling bearing troubleshooting method improvement-based adaptive white noise complete integrated empirical mode decomposition (ICEEMDAN) and sparrow search algorithm (SSA) optimized correlation vector machine (RVM) was presented. First, the ICEEMDAN method is used to decompose the raw vibration signal, and the power entropy and the proportion of the power of the intrinsic mode component (IMF) to the total power of the signal are taken as the fault characteristics. Optimization of the width factor and hyperparameters of RVM using SSA algorithm, and the RVM model is built to realize fault Identification of rolling bearings. The test results indicate that the SSA-RVM model has a high fault identification rate and dramatically improves the accuracy of fault diagnosis.
Modeling and Simulation Analysis of Junctionless Transistors with Double Gates
Authors: Ma Liuhong , He Fan , Fu Yifan , Duan Zhiyong , Zhong Yinghui , Hu Mengwen , Fu Yingchun
Published: January 2023

A simple analytical model for the drain current and threshold voltage for junctionless transistors with double gates is presented. This model provides a relatively exact and continuous description of junctionless transistor behaviour in all operating regions. Besides, the influence of different structure parameters such as the channel length, silicon layer thickness, gate oxide thickness, and the doping density on the drain current and threshold voltage is discussed. The analytical model solutions are compared with the numerical results obtained by using the COMSOL Multiphysics simulator. In addition, the influences of the channel length on the sub-threshold swing, threshold voltage, and Drain Induced Barrier Lowing are investigated in the simulation model. Moreover, by adding interface traps to the gate in the model, the effects of interface traps on transferring characteristics and the threshold voltage of junctionless transistor are studied.
The method of navigation performance optimization analysis for high speed monohull ships
Authors: Yang Zhaolong , Zou Zaojian , Wang Xuegang
Published: January 2023

This paper is based on the drag resistance test data of the high-speed monohull model, a mathematical model for comprehensive optimization of the navigation performance of a high-speed monohull taking into account the rapidity, maneuverability, seakeeping and static performance of the ship is constructed. The optimization calculation software based on particle swarm, standard genetic algorithm and growth mechanism genetic algorithm is designed and written. Taking a high-speed monolithic sea-going ship with a displacement of 1500 tons and a large inclination-measuring single propeller as the object of discussion, the comparison of optimization methods, the comprehensive navigation performance of different ship types and the sensitivity analysis of design variables are carried out respectively. It provides a practical approach and an effective and practical scientific method for analysis and evaluation of how to maintain the comprehensive optimal navigation performance of high-speed monohull ships. At the same time, it provides a way to quickly evaluate the comprehensive performance of similar high-speed monolithic ships in the preliminary design stage, and can also obtain the model diagram with the best comprehensive performance through this software or method, which is useful for shortening the preliminary design cycle of the ship and improving the design quality of the ship. It has important reference value.
Performance Study of Two Bearings-only Target Tracking Algorithms
Authors: Zhang Haozheng , Li Xiong , Meng Yu
Published: January 2023

For the bearings-only target tracking for single array, the tracking performance of extended kalman filter algorithm in cartesian coordinates and modified polar coordinates is studied. The result shows that the performance of extended kalman filter algorithm in polar coordinates is more general than that in cartesian coordinates. In addition, the tracking performance of these two algorithms decreases with an increase in azimuth measurement error.
Study on intelligent fuzzy assessment of failure effects for marine power plants
Authors: Guo Xiaojie , Zheng Wei , Ke Zhiwu , Feng Yi , Sun Quqin
Published: January 2023

Due to its advantages like zero carbon dioxide emissions, high power density, and long life cycle, power devices show great application prospects in civil cargo ships and icebreakers. The equipment composition and structure configuration of power plants are complex, with harsh operating conditions, which will yield to increased failure rates and serious security threats. Given that the relative importance relying on precise data, an intelligent assessment method of failure effects based on fuzzy logic is proposed. Marine power plant hierarchy division is descripted, suitable for the failure effect assessment process. The fuzzy sets and fuzzy numbers are used to get the fuzzy evaluations and relative weights. The alpha-level sets of fuzzy risk priority numbers (RPNs) are calculated with the proposed benchmark adjustment search strategy. Meanwhile, using the synthesized alpha-level set and centroid defuzzification, the fuzzy RPNs are defuzzied. The comparative analysis of examples reveals that the suggested assessment method can improve the confidence level of risk prioritization for marine power plants.