上海工程技术大学学报

Research progress of carbon deposition resistance of catalyst for dry reforming of methane to hydrogen

YAN Jinbiao, WANG Sha, ZHANG Huarong

2023, 37(1): 1-6, 40. doi: 10.12299/jsues.22-0093

Abstract:
Among modern industrial hydrogen production technologies, methane reforming for hydrogen production has unique advantages in rich reactant sources and high availability, especially dry reforming of methane (DRM) technology, which uses methane and carbon dioxide as raw materials and has both environmental and economic benefits. Carbon deposition on catalyst is one of the main problems affecting the development of DRM technology. To design high-performance catalysts, current research mainly focuses on the active components, supports, and promoters. This article discusses in detail the effects of interaction between active components and supports, active metal particle size, basicity, oxygen storage capacity, and carbon deposition type on the carbon deposition resistance of DRM catalysts. The results indicate that strong interactions between active metals and supports, synergistic effects of bimetallic catalysts, and smaller active metal particles can reduce carbon deposition and improve catalyst activity. Increasing oxygen storage capacity can promote carbon removal. The type and amount of carbon deposition are closely related to the support material, and moderate support basicity can promote CO₂ activation, thereby improving the carbon deposition resistance of the catalyst. This article provides a reference for the design and optimization of DRM catalysts.

[Abstract](667) [FullText HTML] (220) [PDF 866KB](112)

Application of computer vision technology in woven fabric structural parameters testing

YUAN Xiuwen, LUO Jian, XIN Binjie, XU Yingqi

2023, 37(1): 7-11. doi: 10.12299/jsues.21-0290

Abstract:
The two structural parameters of woven fabric density and weave pattern are important data in textile testing, and their testing indicators determine the quality of woven fabric products. Due to the complexity of fabric structure, the testing of woven fabric structure parameters nowadays still depends on manual analysis. With the development of computer vision technology, its application in the testing of structural parameters of woven fabrics has been made new research progress. The research status of automatic testing of two important structural parameters of woven fabric density and weave pattern at home and abroad in recent five years was described in detail, and the shortcomings of the research were summarized. Finally, it is concluded that the computer vision technology based on objective evaluation has a great development prospect in the field of woven fabric structure parameter testing.

[Abstract](376) [FullText HTML] (166) [PDF 1010KB](72)

Preparation of CoFe₂O₄/BiOI magnetic photocatalyst and its application in Cr(VI) removal

YE Hengxuan, JI Xuan, LI Zhiyan, FANG Qing, ZHANG Huiqing, HUANG Tingting, YANG Jingxia

2023, 37(1): 12-19. doi: 10.12299/jsues.21-0259

Abstract:
The heavy metal hexavalent chromium (Cr(VI)) ion in water has serious impact on human body and environment, and its concentration is one of the important indicators of water quality, which needs to be strictly controlled. CFO/BiOI nanometer magnetic photocatalyst material was synthesized with BiOI as photocatalyst and CoFe₂O₄ (CFO for short) as magnetic component of composite material, and the effect of different proportion of CFO/BiOI on the removal performance of hexavalent chromium was studied. It was found that the CFO/BiOI composite exhibited better catalytic performance than pure CFO and BiOI in the application of hexavalent chromium removal. This may be caused by the construction of heterojunction between CFO and BiOI, which accelerated the charge separation. In addition, the introduction of CFO endowed the BiOI material with magnetism, which allowed rapidly separation of the catalyst through magnetic force.

[Abstract](292) [FullText HTML] (126) [PDF 1991KB](42)

Preparation and photocatalytic properties ofBi₂MoO₆/ZnO composite

LONG Yingqiao, GE Jianhua, SONG Fengge, WANG Dan, WANG Siyao, WANG Xin, SUN Yan'gang

2023, 37(1): 20-26. doi: 10.12299/jsues.21-0280

Abstract:
Three-dimensional Bi₂MoO₆/ZnO microflowers composed of nano-sheets were synthesized by two-step hydrothermal method. By changing the content of Bi₂MoO₆ in the composite, a series of Bi₂MoO₆/ZnO microflowers with different molar ratios were prepared. The results showed that the photocatalytic degradation rate of Bi₂MoO₆/ZnO−10% composite to RhB solution reached 79.61% after 20 min of visible light irradiation. Compared with pure ZnO and Bi₂MoO₆, the composite had better photocatalytic performance. Through the analysis of ultraviolet visible (UV−Vis) spectrum and room temperature fluorescence spectra (PL), it is further speculated that the improvement of the photocatalytic performance of Bi₂MoO₆/ZnO microflora is due to the improvement of the optical absorption range of the composite and the formation of heterojunction, which inhibits the recombination of photogenerated carriers.

[Abstract](350) [FullText HTML] (155) [PDF 1378KB](54)

Modeling and analysis of rate-dependent hysteresis characteristics of Maxwell reluctance actuator based on Prandtl−Ishlinskii model

ZHANG Xu, LAI Leijie

2023, 37(1): 27-33. doi: 10.12299/jsues.21-0307

Abstract:
In order to overcome the strong hysteresis nonlinearity between the internal magnetic field strength and magnetic induction strength of Maxwell reluctance actuator materials and the hysteresis between the actuator control voltage and output displacement caused by the increase of magnetic leakage under the long air gap, a rate-dependent improved Prandtl−Ishlinskii (P−I) model was proposed to model the hysteresis characteristics of reluctance actuator. The structure, magnetic circuit and magnetic force model of reluctance actuator were analyzed, and the experimental system of reluctance actuator micropositioning stage based on flexible mechanism was built for the verification of hysteresis model. In order to overcome the hysteresis nonlinearity of the actuator, the traditional P−I model was optimized and improved to make it have the ability to describe the asymmetric rate-dependent hysteresis characteristics, and the particle swarm optimization algorithm was used to complete the parameter identification. The comparative experiment was used to verify the ability of the rate-dependent P−I model to describe the hysteresis nonlinearity of the reluctance actuator. The results show that the root mean square error between the output of rate-dependent P−I model and the actual output under different frequency input signals is less than 0.0049 mm, which is only 0.245% of the overall stroke, and the effectiveness and high precision of the model are proved.

[Abstract](355) [FullText HTML] (119) [PDF 1344KB](56)

Oscillation characteristics of molten pool in ultra-thin plate pulsed micro-plasma arc welding

JIA Qi, HE Jianping, XU Lei, TAO Xuyang

2023, 37(1): 34-40. doi: 10.12299/jsues.22-0033

Abstract:
Due to the oscillation behavior of the molten pool, the dynamic change of the molten pool profile has a certain fluctuation. Based on the visual sensing detection method, the oscillation behavior of molten pool in pulsed micro-plasma arc welding of 0.1 mm thick ultra-thin stainless steel was studied, and the influence of different pulse parameters of welding current on the oscillation frequency and amplitude of molten pool was discussed. The results show that the size of molten pool fluctuates slightly during the action of base current and peak current, which is caused by molten pool oscillation. The oscillation frequency of the molten pool increases with the increase of the pulse current frequency in a certain range, while the oscillation amplitude of the molten pool decreases with the increase of the pulse current frequency. The oscillation frequency of the molten pool can reflect the quality of the weld seam forming.

[Abstract](232) [FullText HTML] (106) [PDF 2002KB](43)

Residual stress prediction based on equal thickness undeformed cutting thickness

WANG Zhuo, CAO Zhenzhen, YANG Qingping, LIU Gang

2023, 37(1): 41-47, 60. doi: 10.12299/jsues.22-0017

Abstract:
Residual stress caused by machining has always been the focus of manufacturing field. The surface residual stress state can reflect component performance and service life. In order to better understand surface and subsurface residual stress state of milled parts, the milled undeformed cutting thickness of unequal thickness was converted into the undeformed cutting thickness of equal thickness for micro milling force modeling. A 2D equal thickness undeformed cutting thickness model established by simulation was used to study the temperature when cutting titanium alloy, the surface residual stress after milling was predicted by combining the microelement force and temperature model, and predicted value, simulated value and measured value of residual stress were compared. The results show that the variation trend of simulated value and measured value of residual stress is basically the same, and the proposed residual stress prediction model established by equal thickness undeformed cutting thickness can reflect the surface stress state.

[Abstract](245) [FullText HTML] (124) [PDF 1949KB](39)

Analysis of influence mechanism of milling stability based on posture of ball end milling cutter

XU Yangyang, ZHANG Liqiang, ZHI Junjie

2023, 37(1): 48-54. doi: 10.12299/jsues.22-0208

Abstract:
Milling chatter will not only cause chatter marks on the surface of the machined parts and reduce the surface quality of the machined parts, but also aggravate tool wear and reduce the life of the machine tool. According to the influence of the tool posture of the ball-end milling cutter affecting on the flutter generated during the machining process, the milling dynamics model under the influence of the tool posture was built. The milling dynamic model was solved by the third-order Newton-Hermite interpolation fully discrete method, and the state transition matrix of the system was obtained. The Floquet theory was used to judge the milling stability of the milling cutter under different tool postures, and the tool posture stability prediction map of the ball-end milling cutter was constructed. The experiment determines that the horizontal upward cutting method has the best stability and the lowest surface roughness of the workpiece, which could verify the validity of the stability prediction map.

[Abstract](368) [FullText HTML] (120) [PDF 2710KB](142)

PMSM vector control based on fractional-order PI of sparrow search optimization algorithm

HAN Yaohui, ZENG Guohui

2023, 37(1): 55-60. doi: 10.12299/jsues.22-0016

Abstract:
The speed loop of permanent magnet synchronous motor (PMSM) vector control system adopts PI controller, which is difficult to meet the requirements of fast dynamic response and strong robustness of the system. A fractional order proportional integral (FOPI) controller was proposed, and the parameters of the FOPI controller were optimized using sparrow search algorithm (SSA). By searching for the sparrow's position with the best fit, the best setting parameters for the controller were obtained, and the time multiplied by the absolute value of the error integral was determined as the target fitness function. The performance of the motor speed regulation of the SSA setting FOPI and particle swarm optimization (PSO) setting PI was compared by experiments. The results show that the FOPI optimized by SSA has the advantages of enhancing robustness and reducing overshoot.

[Abstract](443) [FullText HTML] (195) [PDF 1601KB](52)

Research on method of liner inner diameter measurement based on machine vision

FAN Diqing, LI Jinxin, SHA Ling, FANG Yu

2023, 37(1): 61-67. doi: 10.12299/jsues.22-0368

Abstract:
Liner is an important component connecting brake oil pipe and brake in automobile brake system, and the oversize of inner diameter will seriously affect the brake performance of vehicles. Aiming at the problems of low efficiency, poor accuracy and inconsistent detection standards in the manual measurement of liner inner diameter, a method for measuring liner inner diameter based on machine vision was proposed. The inner diameter of liner was preprocessed and located by using bilateral filtering, improved Otsu threshold method and morphological method. An improved Canny edge detection operator was used to extract the inner diameter contour points, and the least square method was used to fit the circle based on Tukey weight function to calculate the inner diameter size. The experimental verification shows that the measurement error value of the detection algorithm is within ± 0.01 mm, the measurement accuracy is 98.9%, the missing rate is 0, and the passing rate is 1.1%, which can meet the actual measurement requirements of enterprises.

[Abstract](266) [FullText HTML] (95) [PDF 4109KB](40)

Research on FT fuel engine characteristics using neural network

WU Tao, ZHANG Wugao, PENG Haiyong, ZHANG Haibo, MIAO Xuelong

2023, 37(1): 68-75. doi: 10.12299/jsues.22-0140

Abstract:
Based on the strong nonlinear approximation and self-learning ability of Back Propagation (BP) neural network, a three-layer network model was designed, and the engine bench test data were collected as the samples to train and verify the model. The engine speed, torque, fuel supply advance angle and the characteristic parameters of the fuel mixture of Fischer-Tropsch gas-to-liquid (GTL) and diesel, such as cetane number, sulfur content and aromatic hydrocarbon content, were taken as inputs. The BP neural network model was established to predict the characteristics of GTL engine. The results show that the model can predict the power, fuel consumption, exhaust temperature, HC, CO, CO₂, NO_x and soot emission of GTL engine at the same time. Compared with the experimental data, the relative error of the prediction results is nearly within 5%, which shows that the model has high model accuracy and good generalization ability.

[Abstract](356) [FullText HTML] (175) [PDF 1117KB](50)

Finite element simulation on 0# Block with V-shaped support

TANG Yang, WANG Guowei, LIU Xin, WANG Dawei, QI Xingjun

2023, 37(1): 76-82. doi: 10.12299/jsues.21-0245

Abstract:
With the V-shaped support continuous rigid frame bridge as the engineering background, the 0# block with V-shaped support was used for the construction stage analysis and construction working condition analysis. According to the analysis results, the following conclusions can be drawn: The stress of the 0# block with V-shaped support met the specification requirements during the construction process, and the stress characteristics during the construction process can be used for reference by designers and constructors. The 0# block with V-shaped support was more sensitive to horizontal displacement along the bridge and vertical displacement, and structural displacement monitoring should be paid attention to during the construction process. There is a certain gap between the analysis results of the construction working condition analysis and the more real analysis results of the construction stage, and the construction stage analysis is used as much as possible in the calculation and analysis of the actual project.

[Abstract](287) [FullText HTML] (85) [PDF 1497KB](38)

L−hyperoperators on L−topological spaces

SU Shuhua, LI Qi

2023, 37(1): 83-87. doi: 10.12299/jsues.21-0276

Abstract:
Based on L−topological spaces and L−hypergroupoids, the (strong) L−pseudocontinuity of L−hyperoperator was defined, and the L−topological L−hypergroupoids were constructed. The result shows that the classical topological hyergroupoids are special cases of L−topological L−hypergroupoids.

[Abstract](239) [FullText HTML] (177) [PDF 837KB](38)

Public opinion co-performance model based on maximizing influence of positive information sources

LI Chuan, WANG Yaqiong, YAN Ying, CHEN Jingliang

2023, 37(1): 88-95. doi: 10.12299/jsues.22-0210

Abstract:
With the popularity of mobile social networking platforms, individuals can rapidly receive, disseminate and communicate information through mobile devices. However, the widespread dissemination of misinformation on these platforms exacerbates the frequency and extent of crisis propagation. Based on the maximization of the influence of positive information sources, a co-performance of strong-ties and weak-ties social platform (CSWSP) dissemination model was constructed, and the use of influential individuals in social networks to improve the dissemination efficiency of positive information was explored. Through systematic simulation experiments, it was found that the influence of information on individuals and the efficiency of information dissemination in the weak-ties social layer play a crucial role in the process of online crisis co-performance. Increasing the proportion of influential individuals can mitigate or suppress further escalation of public sentiment, thus enhancing public crisis management.

[Abstract](277) [FullText HTML] (101) [PDF 1143KB](28)

Prediction method of bearing remaining useful life based on CNN and attention BiLSTM

GUO Yurong, MAO Jian, ZHAO Man

2023, 37(1): 96-104. doi: 10.12299/jsues.21-0244

Abstract:
The remaining useful life (RUL) prediction of rolling bearings is of great significance for the operation and maintenance of rotating machinery. Although the deep learning method represented by convolutional neural network (CNN) can automatically extract features from bearing vibration signals, it can not adaptively select features to improve the attention of the model to important features. In response to the above problems, a bearing RUL prediction method based on CNN and attention bidirectional long short-term memory (BiLSTM) was proposed. Firstly, the spatial features of vibration signals were extracted by CNN, the temporal features were extracted by BiLSTM. Then, the attention mechanism was used to enhance the attention of the model to important features, and the full connection layer was used as the decoder to predict the health indicator (HI). Finally, the weighted average method was used to modify the HI prediction value, and the polynomial fitting curve was used for RUL prediction. The results show that the absolute percentage error of the proposed method is 14.36% lower than that of convolutional long short-term memory (CNN-LSTM) and 21.28% lower than that of traditional self-organizing map network (SOM), which can be effectively used for RUL prediction in multiple fault modes.

[Abstract](905) [FullText HTML] (842) [PDF 2282KB](162)

2023 Vol. 37, No. 1