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ZHENG Yaxu, WANG Kun, GAO Han, ZHANG Jueling, LI Yongliang, LYU Haojie, NIU Chongyu
2026,47(1):1-11, DOI: 10.7535/hbkd.2026yx01001
Abstract:
To address the issue of significant deformed microstructures and undesirable textures in as-hot-rolled W470 non-oriented silicon steel sheets produced without mold electromagnetic stirring, electron backscattered diffraction(EBSD) was employed to systematically investigate the effects of normalization process parameters on the recrystallization behavior, grain size, and texture evolution. The results reveal that the center layer of the W470 as-hot-rolled sheet retains a substantial fraction of non-recrystallized microstructure. For different normalizing temperatures, the recrystallization fraction in the center layer increases progressively with rising normalization temperature from 840 ℃ to 960 ℃, achieving completeness at 930 ℃. For different normalizing temperatures, at a constant temperature of 900 ℃, extending the holding time from 1 to 9 min leads to gradual recrystallization, with full recrystallization attained after 7 min. The normalized sheets exhibit a surface layer dominated by {110}〈110〉 and {114}〈110〉 textures. In contrast, the center layer is characterized by a combination of γ-fiber texture, copper texture ({112 }〈 111〉), and rotated cube texture. Both increasing the normalization temperature and prolonging the holding time enhance the recrystallization fraction and concurrently weaken the intensity of the magnetically unfavorable γ-fiber texture. This work elucidates the synergistic influence of normalization temperature and holding time on the microstructure and texture development of W470 non-oriented silicon steel produced under conditions of lacking mold electromagnetic stirring, which provides some reference for achieving optimized microstructures and textures.
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ZHANG Liang, CHEN Guanbing, ZHANG Yaxuan, LI Qianning, FU Kai, YANG Xiao
2026,47(1):12-20, DOI: 10.7535/hbkd.2026yx01002
Abstract:
To suppress the formation of brittle magnesium-aluminum intermetallic compounds（IMCs）in the welding joints of magnesium-aluminum dissimilar metals and enhance the joint performance, a friction stir welding (FSW) technique was adopted and copper foil was used as an interlayer metal to weld 7075-T6 aluminum alloy and AZ31B magnesium alloy. A comprehensive suite of analytical techniques, including microstructural characterization, energy-dispersive spectrometer（EDS）, X-ray diffractometer（XRD）, hardness testing, and shear testing were employed to systematically investigate the microstructural evolution and mechanical properties of the magnesium/aluminum dissimilar metal joints with and without the copper interlayer. The experimental results reveal that the incorporation of a copper interlayer in the weld nugget zone establishes a ternary magnesium-aluminum-copper diffusion system. This system effectively suppresses interdiffusion behavior between magnesium and aluminum, which reduces the diffusion layer thickness in the weld nugget zone from 150 μm to 50 μm. Simultaneously, new diffusion layers are formed on both sides of the hook-shaped defects in copper-containing joints that effectively suppresses the formation of magnesium-aluminum IMCs, while promoting the formation of copper-magnesium and copper-aluminum IMCs. Meanwhile, the incorporation of the copper interlayer significantly reduces the area of hook-shaped defects at the joint interface and effectively mitigates stress concentration at the interface. Ultimately, compared to conventional joints, the fracture path of copper-containing joints is changed from the IMCs layer to the weld nugget zone. Average shear strength of the joints increases from 3 407 N to 4 615 N, representing a 35.5% improvement in shear performance. The study identifies the causes for the improvement of the mechanical properties of certain magnesium/aluminum dissimilar metals joints through FSW, providing reference for welding other dissimilar materials.
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LI Bin, GUO Jianye, ZHANG Zenan, XU Shuo, GUAN Zhongzheng
2026,47(1):21-28, DOI: 10.7535/hbkd.2026yx01003
Abstract:
Aiming at the problems of expansion and cracking that may occur in high-strength concrete(HSC) serving in long-term humid or water environments, the influence of further hydration on HSC property was studied by simulation test. Firstly, the influence of slag powder content on the physical and mechanical properties and permeability of HSC was discussed. Secondly, the influence mechanism of further hydration on the strength of concrete with or without slag powder was analyzed. Finally, the influence of loading degree on the strength of pre-damage concrete was expounded. The results show that the variation ranges of the compressive strength and ultrasonic sound velocity value for concretes with or without slag powder are both not obvious, while the decreased degree of the electric flux first decreases and then increases with an increase in the slag powder content. The decreased degree of compressive strength first increases and then decreases with an increase in loading degree and moreover, the increase in splitting tensile strength shows an increasing trend. The further hydration products continuously fill the initial cracks of pre-damage concrete. When the internal space of concrete is not sufficient to accommodate the products, the volume expansion of products leads to the formation of microcracks and a decrease in strength. However, during the late stage of further hydration, the new microcracks provide channels for the entry of extraneous water again, and the new products fill its internal pores and defects. This ultimately causes an increase in strength. The influence laws of slag powder and loading degree on the performance of HSC under further hydration effect are put forward, which provides some reference for the performance evaluation and design of HSC.
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CUI Yaoyao, JIN Yuan, JIANG Haiyang, WU Shaozhe, CUI Can, WU Hanbing, LI Jinyi, YUAN Yuanyuan
2026,47(1):29-39, DOI: 10.7535/hbkd.2026yx01004
Abstract:
This study proposed a method for identifying adulteration in high-quality edible oils by combining laser-induced fluorescence (LIF) technology with partial least squares-discriminant analysis (PLS-DA), aiming to quickly detect low-quality edible oils in the market. Firstly, a laboratory-built LIF system was used to collect fluorescence spectral data of olive oil, sesame oil, peanut oil, and their adulterated samples. Subsequently, PLS-DA was employed to construct adulteration identification models for olive oil, sesame oil, and peanut oil respectively. Finally, the performance of these models was evaluated using a prediction set.The results indicate that the PLS-DA model can accurately capture the differential characteristics in fluorescence spectra between adulterated samples and authentic samples. Under the verification of the experimentally obtained data, a 100% correct classification rate is achieved.This method enables high-precision identification of adulterated edible oil, providing a scientific identification tool for food safety supervision and offers support for technical research.
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SUN Huiqin, HUI Baofeng, WANG Honghui, ZHANG Shiyu, HAI Hongkuan, YANG Xiaorui
2026,47(1):40-48, DOI: 10.7535/hbkd.2026yx01005
Abstract:
In order to enhance the response speed of the permanent magnet synchronous motor(PMSM) in cranes and the robustness of the system, an improved index law was proposed. The new sliding mode control(NSMC) in the speed loop was adopted based on field-oriented control（FOC）. A new function f(s) was introduced to enhance the response speed at which the system state variables approached the sliding mode surface. The sign function sign(s) was replaced by a continuous function h(s) to reduce the chattering caused by the discontinuity of the sign function. A new extended state observer(NESO) was designed to observe disturbances and further optimize the speed controller. The fal(s) function in traditional observer was replaced by a nonlinear smooth function K(s) to eliminate chattering and improve the observation accuracy of the observer. The results show that the motor speed is stable at approximately 0.05 s after starting, with a speed oscillation of about 10 r/min. It verifies the correctness of the controller algorithm. The designed algorithm can effectively improve the response speed of the system and provide reference for the control of PMSM in cranes.
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LIU Zikang, ZHOU Changjie, YAO Wei
2026,47(1):49-59, DOI: 10.7535/hbkd.2026yx01006
Abstract:
To address the limitations of the Chameleon algorithm in terms of parameter sensitivity, noise robustness, and computational efficiency, this study proposed a statistical-MST integrated hierarchical clustering algorithm(SHCA) based on the minimum spanning tree and statistical features. The minimum spanning tree was used to construct a sparse graph, eliminating manual parameter intervention, and the global optimality of the minimum spanning tree was used to avoid false cross cluster connections. The dynamic statistical merging strategy was designed to filter the noise combined with the local distance threshold, and the sub clusters were merged iteratively through the inter cluster connectivity test to ensure the intra cluster compactness and inter cluster separation. Experiment on 20 synthetic datasets and 10 real-world datasets was conducted. The result shows that the proposed SHCA algorithm outperforms existing methods in clustering performance; In cases where performance degradation is observed on certain datasets,the analysis reveals that manifold overlap is the primary contributing factor. Overall, SHCA significantly enhances clustering accuracy and result stability, providing some reference for subsequent research on clustering of large-scale and complex manifold data.
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LIU Wei, SHI Wei, YANG Miao, WANG Jingyang, HUANG Min, YANG Lin
2026,47(1):60-72, DOI: 10.7535/hbkd.2026yx01007
Abstract:
To address the decline in pedestrian detection accuracy caused by complex scenarios such as illumination variations, viewing angles, background interference and small pedestrian targets, which often lead to false positives and missed detections, a pedestrian detection model, YOLOv11-CREP, was proposed based on an improved YOLOv11n. Firstly, CSPDConv, which was formed by integrating standard convolution(Conv) with space-to-depth convolution(SPDConv), was introduced to reduce information loss and enhance critical feature extraction. Secondly, a new RepNCSPELAN4-GC module was proposed, which incorporates GhostConv to optimize the RepNCSPELAN4 module, reducing its parameter count. The improved RepNCSPELAN4-GC module was then used to partially replace the C3k2 modules in the Neck layer. Next, efficient multi-scale attention(EMAttention) and parallel network attention(ParNetAttention) were fused into a new EMPAttention module to enhance the detection ability of the model for small target pedestrians. Finally, considering the characteristics of small target pedestrains and occluded targets, a small-target detection head P2 was added to further improve the model’s recognition capability for small targets. The experiments show that compared with the original YOLOv11n model, YOLOv11-CREP improves the mean average precision(mAP) by 4.6 percentage points at an IoU threshold of 0.5, reaching 95.3%. When evaluated over the IoU range of 0.5 to 0.95, its mAP increases by 9.0 percentage points, reaching 70.2%. The proposed model achieves a balance between high detection performance and real-time requirements, effectively enhancing pedestrian detection performance in complex scenarios. It provides valuable references for modeling pedestrian detection tasks.
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GAO Yan, WANG Runzheng, LI Wang, MA Haikun, MO Honggang, HAN Pengbiao
2026,47(1):73-85, DOI: 10.7535/hbkd.2026yx01008
Abstract:
Aiming to address the issue of increased production costs caused by the five-pass cold drawing forming for the sliding block in the rolling linear guide pair in a factory in Hebei Province, this study investigated the influence of parameters such as die cone angle and sizing belt length on billet deformation. The objective was to determine the optimal parameter combination to reduce the number of drawing passes and lower production costs. A finite element model for slider drawing and forming was established, and whether the stress at the minimum cross-section of the blank exceeded the tensile strength of the material during the drawing process was taken as the failure criterion for the orthogonal experiment. An orthogonal test analysis was conducted with four process parameters including die cone angle, sizing belt length, friction coefficient, and drawing speed, as influencing factors, to study the influence of process parameters on the stress at the minimum cross-sectional area of the billet during the forming process, as well as the primary and secondary relationships of interactions. The optimal parameter combination was obtained by combining range analysis (R-value method). Finally, the number of drawing passes was optimized through theoretical calculation, and the size structure of the die sizing belt was redesigned. The results indicate that the optimized drawing passes are reduced from five to three, and the influence degrees of various process parameters on the stress acting on the minimum cross-section of the billet are in the following order: die cone angle, sizing belt length, friction coefficient, and drawing speed. The optimal process parameters are as follows: the cone angle of the mold is 5 °, the sizing belt length is 10 mm, the friction coefficient is 0.06, and the drawing speed is 83 mm/s. The simulation results indicate that after optimization, the stress on the billet’s minimum cross-section remains below the tensile strength of the material (885 MPa) during all three-pass drawing passes, and the safety factor exceeds 1.25. Theoretical calculations show that the safety factors of the three-pass drawing all meet the requirements, which verifies the feasibility of the optimization scheme. The study reveals the primary and secondary relationships between key parameters of process and mold affecting drawing stress, providing theoretical reference for optimizing the multi-pass drawing process of rolling linear guide sliders.
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CHEN Haili, GUO Hanzhuang, LI Jiang, GAO Tiancheng, LIU Ying, ZHANG Kun, WANG Liwei, LIANG Zhimin
2026,47(1):86-96, DOI: 10.7535/hbkd.2026yx01009
Abstract:
To address the limited 3D structural perception and insufficient feature discrimination in traditional welding joint classification and lack-of-fusion detection methods, this study proposed a 3D point cloud detection network that integrated geometric structure modeling with an attention mechanism, termed CA-PnPNet. First, the network was built upon the PointNet++ framework, in which a point neighborhood processing in 3D(PnP3D) was integrated into multiple feature extraction stages to strengthen the modeling of local spatial geometric relationships. In addition, a channel attention module (CAM) was incorporated to adaptively emphasize key features by capturing semantic dependencies across channels. Finally, the collaborative integration of these two modules at different feature layers enabled unified enhancement of both local point cloud geometric representation and semantic feature expression, resulting in more comprehensive 3D structural characterization. To validate the effectiveness of the method, multiple sets of comparative experiments were conducted. The results demonstrate that CA-PnPNet achieves an accuracy of 97.7% in the welding point cloud classification task, outperforming the baseline model by 1.9%, while improving the inference speed from 33.3 FPS to 36.1 FPS. These results validate the superior accuracy and real-time performance of the proposed method. Overall, CA-PnPNet provides an effective technical reference for intelligent detection and industrial quality monitoring of complex welded structures.
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MA Zhongchen, LI Wencan, ZHANG Baoping, KE Jing, XIN Yuntao
2026,47(1):97-107, DOI: 10.7535/hbkd.2026yx01010
Abstract:
To address the problem of rapid capacity decay of LiMn2O4 during the cycling process, Mn3O4 with different particle sizes and tap densities was prepared by manganese salt method, and used as a precursor to synthesize LiMn2O4 cathode material. The effects of Mn3O4 particle size and tap density on the electrochemical performance were investigated using X-ray diffraction, cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge tests. The results indicate that increasing the particle size of the Mn3O4 precursor leads to a slight decrease in the initial discharge specific capacity, but significantly improves both cycling stability and rate performance. Compared with the material derived from 6 μm Mn3O4, the cathode material prepared from 10 μm Mn3O4 exhibits a 6.2% reduction in initial discharge capacity, while achieving an 8.0% increase in capacity retention after 300 cycles and a 25.2% improvement at 5 C. Moreover, when the tap density of Mn3O4 exceeds 2.5 g/cm3, the rate performance of the material deteriorates sharply. The LiMn2O4 sample prepared with a precursor particle size of 10 μm and tap density of 2.5 g/cm3 demonstrates the best overall electrochemical performance, delivering discharge specific capacities of 122.48, 111.9, and 78.42 mAh/g at 0.1, 1, and 5 C, respectively, along with a capacity retention of 90.3% after 300 cycles. This study clarifies the influence of precursor physical properties on the electrochemical properties of LiMn2O4, providing basis for the synthesis of high-performance LiMn2O4 materials.
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Calculation and analysis of carbon footprint in the production process of needle-punched geotextiles
YANG Mingxin, SHI Zhuoya, CHEN Junxia, WANG Yuheng, DONG Wenxu
2026,47(1):108-118, DOI: 10.7535/hbkd.2026yx01011
Abstract:
To evaluate the carbon emission issue during the production process of needle-punched geotextiles, S factory was taken as the research subject. A carbon footprint model for the production process of needle-punched geotextiles was constructed based on the life cycle assessment (LCA) method to calculate the carbon emissions in stages such as raw material usage, raw material transportation, production manufacturing, and auxiliary equipment operation. Through local sensitivity analysis and global sensitivity analysis, the key influencing factors of the carbon footprint were identified. Combined with the uncertainty assessment results of the Monte Carlo simulation, an optimized path for energy conservation and emission reduction was ultimately proposed. The research results show that for every ton of needle-punched geotextiles produced by S factory, the total carbon footprint of the production process is 4 374.61 kgCO2, with the highest proportion of raw material usage stage, which is the core focus of carbon reduction. The Monte Carlo simulation results also verify that the carbon footprint falls within the 95% confidence interval, confirming the reliability of the model results. The research findings can provide scientific basis for the carbon emission management of needle-punched geotextile production enterprises and facilitate the green and low-carbon transformation of the industry.
Volume 47,2026 Issue 1
National Young Scholar/Local Science Foundation
Mechanical, Electronics and Information Science
Material Science
New Energy Resources, Energy Conservation and Environmental Protection
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DOI:
Abstract:
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WANG Jianxia, LIU Menglin, XU Yunfeng, ZHANG Yan
2021,42(1):48-59, DOI: 10.7535/hbkd.2021yx01007
Abstract:
Most of the real-life networks are heterogeneous networks that contain multiple types of nodes and edges, and heterogeneous networks integrate more information and contain richer semantic information than homogeneous networks. Heterogeneous network representation learning to have powerful modeling capabilities, enables to solve the heterogeneity of heterogeneous networks effectively, and to embed the rich structure information and semantic information of heterogeneous networks into low-dimensional node representations to facilitate downstream task applications. Through sorting out and classifying the current heterogeneous network representation learning methods at home and abroad, reviewed the current research status of heterogeneous network representation learning methods, compared the characteristics of each category model , introduced the related applications of heterogeneous network representation learning, and summarized and prospected the development trend of heterogeneous network representation learning methods. It is proposed that in-depth discussion can be carried out in the following aspects in future: First, avoid predefined meta-paths and fully release the automatic learning capabilities of the model; Second, design heterogeneous network representation learning method suitable for dynamic and large-scale networks.
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2021,42(1):67-74, DOI: 10.7535/hbkd.2021yx01009
Abstract:
As the side effects of antibiotics are becoming increasingly prominent and the number of approvals is declining year by year, it is urgent to develop other active substances that are similar in functions and not easy to develop drug resistance. Antimicrobial peptides (AMPs) have broad-spectrum antibacterial activities, thermal stability and unique mechanism of action. They can not only play the role of anti-bacterial infection in vivo and promote apoptosis of cancer cells, but also be used as chemotherapeutic agents against virus and antibacterial materials for hospital settings. In this paper, developments related to antimicrobial mechanisms and activities of antimicrobial peptides against drug-resistant bacteria, anticancer and antiviral infection in the field of medicine are systematically reviewed. The problems of stability, hemolytic and toxicity of antimicrobial peptides are elucidated and the development prospects of AMPs in medicine are provided. Further research on AMPs can be carried out in the following aspects in the future. 1) Antibacterial mechanism in vivo are studied to promote the development and application of antimicrobial peptides；2）Structures of AMPs are optimized by replacing and modifying amino acid residues and hybrid peptides are synthesized to improve their activities, reduce side effects and prevent drug resistance; 3）Application of delivery systems for AMPs or combination of AMPs with green natural extracts is investigated to improve their antibacterial activity and bioavailability.
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MA Jing, WANG Ruiyang, WEN Ning
2021,42(1):75-81, DOI: 10.7535/hbkd.2021yx01010
Abstract:
In order to improve the oxidation resistance of 304 stainless steel, SiO2 thin film was prepared on the surface of stainless steel by sol-gel method with tetraethyl orthosilicate (TEOS) as raw material. The effect of film layers on the high temperature oxidation resistance of stainless steel at 900 ℃ was studied by means of oxidation kinetics, XRD, SEM and EDS. The results show that the adhesion of SiO2 film to stainless steel matrix is good, which promotes the selective oxidation on the stainless steel surface and the formation of protective Cr2O3 and NiCr2O4 oxide layers. The high temperature oxidation resistance of stainless steel is improved remarkably. The oxidation resistance of the sample coated with three layers of SiO2 film proforms the best, and the oxidation weight gain and oxidation spalling of the sample are only 58.1% and 41.4% of the uncoated sample after 100 hours of cyclic oxidation at 900 ℃. The high temperature oxidation resistance of stainless steel is effectively improved through SiO2 film coating, which is another attempt of surface treatment method applied to high temperature environment, and provides reference for other thin films prepared by sol-gel method.
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SUI Bingdong, ZHANG Pai, WANG Xiaojun
2021,42(1):22-29, DOI: 10.7535/hbkd.2021yx01004
Abstract:
In order to solve the problems of low recognition accuracy and easily affected by illumination conditions in the gesture recognition, an improved YOLOv3 gesture recognition algorithm was proposed. Firstly, a smaller detection scale was added to the original three detection scales to improve the detection ability of small targets; secondly, DIoU was used instead of the original mean square error loss function as the coordinate error loss function, the improved focal loss function was used as the confidence loss function of the boundary frame, and the cross entropy was used as the loss function of the target classification loss function. The results show that when the improved YOLOv3 gesture recognition algorithm is applied to gesture detection, the map index reaches 90.38%, which is 6.62% higher than that before the improvement, and FPS is nearly twice as high as before. After the new model is trained by the improved YOLOv3 method, the gesture recognition accuracy is higher, the detection speed is faster, the overall recognition efficiency is greatly improved, the loss weights of simple samples and difficult samples are balanced, and the training quality and generalization ability of the model are effectively improved.
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XIE Yinghua, LIU Zhaoxia, ZHANG Meimei, ZHANG Dongmei
2021,42(1):60-66, DOI: 10.7535/hbkd.2021yx01008
Abstract:
In order to avoid the irritation of metformin hydrochloride to the stomach and realize its release in the intestine, with metformin hydrochloride as the main drug and chitosan/sodium alginate as the composite support, the optimal formulation and preparation technology of metformin hydrochloride loaded pH-sensitive hydrogel microspheres were selected, and the pH-sensitivity and in vitro drug release characteristics were investigated. The formulation and process were optimized by single factor test and orthogonal test. The morphology was characterized by SEM. The entrapment efficiency and drug-loaded amount were determined by UV. The release degree was studied by rotating basket method. The results show that the optimized prescription is as following: chitosan and sodium alginate with a total concentration of 2%(mass-volume ratio), mass ratio of sodium alginate to chitosan =1∶1, mass ratio of drug to sodium alginate=2∶5, and 3.5% CaCl2(mass-volume ratio). The cumulative release rate is less than 4% in artificial gastric juice within 6 h, and up to 96.4% in artificial intestinal juice within 6 h. The formulation and process are stable and reliable, and the hydrogel microspheres have high mechanical strength, good biodegradability and stability. So it is a new metformin hydrochloride delivery system.
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CHEN Qi, ZHANG Renhui, HE Zhongyi, XIONG Liping
2021,42(1):1-7, DOI: 10.7535/hbkd.2021yx01001
Abstract:
In order to explore the lubrication performance of alcohols under high loads and high speeds conditions, especially the relationship between carbon-chain length and hydroxyl number and lubrication performance, the effects of carbon-chain length and hydroxyl number on the lubrication performance were well studied. The tribological properties of a series of alcohols were investigated by a four-ball tribological machine, and the effects of the carbon-chain length and the hydroxyl number on their lubricating properties were investigated by means of viscometer, transmission electron microscopy (TEM) and Raman. Experiments show that with the increasing of the carbon-chain length, the run-in period and the time for achieving stable friction coefficient were shorted, and the wear was reduced; with the increasing of the hydroxyl number, the wear decreased with no obvious run-in period and consistent fluctuation of friction coefficient for ethylene glycol and continuous decrease of friction coefficient for glycerol. It is found that friction-induced graphene is superior to amorphous carbon in effectively promoting the tribosystem to achieve the stable friction coefficient and shorten run-in period, which provides reference for the application of alcohols in the field of mechanical equipment.
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MENG Zhian, LU Suling, YAN Huajun, HAN Pengbiao, HU Xilei, WANG Tonghui, WANG Hao
2021,42(1):82-90, DOI: 10.7535/hbkd.2021yx01011
Abstract:
In order to solve the problems of backward production technology, long processing cycle and low material utilization rate in traditional U-shaped steel tie rods, an integrated steel tie rod forming process was proposed. Taking the preform forming of 35 steel tie rod U-shaped head as the research object, a three-pass heating upsetting method was designed. The DEFORM-3D finite element software was used to analyze the simulation results of the temperature field and stress field after upsetting under different process conditions. The hot forming process parameters with better forming effect were discussed, and the feasibility of forming was verified through experiments. The results show that the optimum hot forming process parameters of each pass are as follows: the initial forging temperature of the first pass is 1 150 ℃, while the punch speed is 20 mm/s; the initial forging temperature of the second pass is 1 150 ℃, while the punch speed is 30 mm /s; the initial forging temperature of the third pass is 1 100 ℃, while the punch speed is 20 mm/s. Under the hot forming process parameters, the forming forces of each pass are 1 520, 2 090, 5 290 kN, and the expansion forces of each pass are 5 870, 6 710, 8 830 kN, respectively. After upsetting, the metal streamline distribution is reasonable, there is no crossover and folding phenomenon, and the forming effect is good. The equivalent stress distribution inside the part is relatively uniform while preparing the preform in the three-pass hot upsetting method, which can form a good quality part. It provides a certain reference for the upsetting aggregate process design and equipment selection of the U-shaped head perform of 35 steel tie rod.
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2021,42(1):8-14, DOI: 10.7535/hbkd.2021yx01002
Abstract:
In order to improve the positioning ability of ultra wideband network in non-cooperative indoor environment, the theory of centreless positioning algorithm was used to solve and analyze the output distance information of ultra-wideband ranging, and the relative positioning results were obtained. The positioning results of the system were compared with the results of the photoelectric calibration system, and the accuracy was evaluated. The results show that, compared with the traditional ultra-wideband positioning model, the combination of ultra-wideband ranging and centreless positioning algorithm can realize the centreless positioning and the relative positions among nodes, and finally determine the relative positions among nodes. The combination of UWB ranging and centreless positioning algorithm has good stability and accuracy in relative positioning, and can be widely used in various indoor and outdoor scenes.
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ZHANG Chunhui, WANG Laigui, ZHAO Quansheng, LI Weilong
2015,36(1):90-99, DOI: 10.7535/hbkd.2015yx01016
Abstract:
How to quantitatively evaluate the permeability change of coalbed subjected to liquid nitrogen cooling is a key issue of enhanced-permeability technology of coalbed. To analyze the evolution process of permeability of coupled coal deformation, failure and liquid introgen cooling, the coal is supposed as elastic, brittle and plastic material. Its deformation process includes elastic deformation stage, brittle strength degradation stage and residual plastic flow stage. Combined with strength degradation index, dilatancy index of the element and Mohr-Column strength criterion, the element scale constitutive model with the effects of confining pressure on peak-post mechanical behaviors is built. Based on the deformation process of coal rock, there exist two stages of permeability evolution of the element including decrease of permeability due to elastic contraction and increase due to coal rock element's failure. The relationships between the permeability and elastic deformation, shear failure and tension failure for coal are studied. The permeability will be influenced by the change of pore space due to elastic contraction or tension of element. Conjugate shear zones appear during the shear failure of the element, in which the flow follows so-called cubic law between smooth parallel plates. The calculation formulas of the permeability and the aperture of the fractures are given out based on the volumetric strain. When tension failure criterion is satisfied with the rock element fails and two orthogonal fractures appear. The calculation formulas of the permeability and the width of the fractures are given out based on the volumetric strain. Further, combined with the thermal conduction theory the permeability evolution model of coupled coal deformation, failure and liquid nitrogen cooling is presented. Then Fish function method in FLAC is employed to perform the model. The permeability's evolution process for coal bed cryogenically stimulated by flowing liquid nitrogen through gas production well in Wangyingzi mine, Liaoning province, is simulated and the results include: 1) When liquid nitrogen(LN2) is injected into a rock at warm reservoir temperature, heat from the rock will quickly transfer to the liquid nitrogen resulting in rapid cooling and contraction of coal bed. The nearer the position is to bore hole, the bigger the shrinkage deformation and thermal stress and coal fail when tension stress sufficiently built up. In this paper the tension failure band after 10 days' LN2 cooling is 0.65 m. 2) In tension failure area the cracks from cooling stimulation lead to the significant growth of permeability. The maximum permeability for element is 1.97×105 times more than that before cooling. 3) Apart from the bore hole, the thermal tensile stress leads to the growth of permeability at a rate of 1%~14%, far less than that in the tension failure area. 4) With increasing time the failure area gradually slowly grows up. It indicates that the longer cooling time does not mean better effects. 5) The cooling fracturing area is found to have a 1.0 m band. In practical engineering the pressure in hole bore and phase transition of water also influences the deformation and failure of coal, which leads to much more failure zone of cooling. 6) The evolution process of permeability of coupled coal deformation, failure and liquid introgen cooling can be better reflected by the model in this paper. This study is hoped to provide a simple but reasonable description of the permeability evolution of rocks subject to liquid nitrogen cooling.
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YIN Yanan, ZHEN Ran, WU Xiaojing, ZHANG Chunyue, WU Xueli
2021,42(1):38-47, DOI: 10.7535/hbkd.2021yx01006
Abstract:
In order to solve the problem that ant colony algorithm is easy to fall into local optimum in UAV route planning, an improved ant colony algorithm was proposed. The upper and lower limits of pheromone volatilization factor and pheromone were set to prevent ants from falling into local optimum because pheromone on short path was too high or pheromone on long path was too low. At the same time, under the influence of multiple heuristic factors, the overall length of the path was taken as an adaptive heuristic function factor to determine the state transition probability. When the path length was large, the adaptive heuristic function factor was small, which reduced the probability of choosing the path by the ant colony. The experimental results show that the improved algorithm reduces the path length by 6.4% and the variance of the optimal path length by 85.78%, which increases the consideration of environmental integrity, shortens the path length, reduces the number of iterations, and jumps out of the local optimum. In the case of increasing environmental complexity, the algorithm can effectively choose a better path and provide a theoretical basis for UAV route planning after introducing the adaptive heuristic function factor.
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Research on impulse interference suppression method based on short time fractional Fourier transform
WANG Xiaojun, XUE Linbo, WANG Yanpeng
2021,42(1):15-21, DOI: 10.7535/hbkd.2021yx01003
Abstract:
In order to solve the problem that the impulse interference near the service frequency band of aviation radio navigation affects the receiver, and further improve the anti-jamming ability of GNSS system, a impulse interference suppression method based on STFRFT (short time fractional Fourier transform) was proposed. The optimal rotation order of the received signal was determined, and STFRFT was applied to the signal to obtain the two-dimensional distribution of time-frequency surface through coordinate rotation. Under the optimal order, the adaptive time-varying filter was used to separate the interference and the signal, so as to suppress the interference. The simulation results show that the adaptive filtering algorithm based on STFRFT has the best effect of eliminating interference compared with several traditional methods, and retains more useful signals while suppressing impulse interference. By combining STFRFT and adaptive time-varying filtering technology, the ability of suppressing impulse interference is improved, which provides some reference for the impulse anti-jamming technology of aviation radio navigation service.
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LI Chunhua, QIN Yunfan, LIU Yukun
2021,42(1):30-37, DOI: 10.7535/hbkd.2021yx01005
Abstract:
Aiming at the problem of poor precision performance of traditional Bayesian model saliency detection algorithm, a Bayesian model saliency detection algorithm based on improved convex hull was proposed. Firstly, the foreground of the image was extracted by the manifold ranking algorithm, which was used as the prior probability in Bayesian model. Secondly, Harris corner detection algorithm based on color enhancement was used to detect the feature points of the image in three color spaces of RGB, HSV and CIELab; the convex hulls in RGB, HSV and CIELab spaces were constructed respectively; and the intersection of convex hulls were obtained. Thirdly, the saliency region map was calculated by Bayesian model according to the prior probability and the observed likelihood probability obtained by combining convex hulls and color histograms. Finally, the proposed algorithm was tested in two public data sets MSRA and ECSSD. The experimental results show that the proposed algorithm can suppress the background noise effectively and detect the salient areas completely. The test results of F-measure value in MSRA and ECSSD databases are 0.87 and 0.71 respectively, and the accuracy-recall rate curve is higher than that of traditional classical algorithms in complex image databases. The proposed algorithm improves the detection effect of the traditional classical algorithm and the accuracy of saliency map detection.
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LIU Qing, LIU Bin, WANG Guan, ZHANG Chen, LIANG Zhixing, ZHANG Peng
2019,40(1):68-78, DOI: 10.7535/hbkd.2019yx01011
Abstract:
In recent years, the research on Digital Twin is in the ascendant. As a new paradigm or concept, it shows great potential. However, the connotation and scope of the Digital Twin concept is still uncertain, especially the Digital Twin Model definition is not clear.According to the pattern category, the Digital Twin Model can be divided into general model and special model, in which the special model is still the focus of current research, and the research content is mainly embodied in the use of Digital Twin method to model specific projects. It also includes concept for developing specialized models. These specific projects in addition to the traditional manufacturing related to parts measurement and quality control, manufacturing, design and work processes, as well as system management, but also in the field of biomedical applications and applications for petroleum engineering and so on. There are many tools and techniques for developing special models, such as general industrial software, special industrial software, simulation platform and self-developed secondary development tools, etc.The research object of the Digital Twin general model is not specific to a specific project, but how to represent the controlled elements of the model as a group of common objects and the relationships between these objects. This provides a consistent approach to the management and communication of controlled elements between different environments. The research on the general model is mainly divided into the conceptual research and the model implementation method; the research heat of the two directions is almost the same. Conceptual research ranges from product lifecycle management to system behavior description, such as general system behavior and system reconfiguration, and to product configuration management, to specific workflow, such as design methods, manufacturing systems and manufacturing processes. The research content is relatively divergent, and there is no particularly prominent hot spot. The research of Digital Twin general model implementation is mainly reflected in the modeling language construction, the model development methods exploration, the specific tools usage, the Meta-model concept implantation and the model algorithm exploration.Digital Twin Model is one of the core areas of Digital Twin research. Its future research focuses on how to integrate the external features and intrinsic properties from different Digital Twin artifacts into a model with interoperability, interactivity and scalability for more efficiently realizing the information flow between the physical world and the digital world, thus achieving the universal Digital Twin application, and then supporting the CPS (Cyber Physical Space) and CPPS (Cyber Physical Production System) construction. To this end, the next problem in the Digital Twin Model needing to be solved first is how to dock the standard reference architecture, such as the RAMI4.0 (Reference Architecture Model Industrial 4.0) proposed by Germany and the IMSA (Intelligent Manufacturing System Architecture) by China, etc. Secondly, the Digital Twin Model needs a unified method to describe and it also needs consistent conclusions, in order to standardize the models established by independent development, thus improving the interoperability and scalability of the model. Otherwise, the performance of the model will decrease significantly as the system scales raise. Thirdly, the research on China's Digital Twin Model requires the support of domestic professional industrial software and modeling software, so that the Chinese scholars can carry out in-depth research that is more in line with national conditions.
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QIN Si-liang, WANG Qing-guo, QU Zhao-ming, LEI Yi-san
2012,33(4):309-312, DOI: 10.7535/hbkd.2012yx04007
Abstract:
The permittivity of carbon fibers in different composites is calculated and discussed by using M-G equations, Bruggeman equations and generalized M-G equation. Results show that for high draw ratio fibers, all the three equations can calculate out the permittivity with the same numerical level and variation trend. Generalized M-G equation and M-G equation have a similar result but Bruggeman''s result is smaller. All three equations become invalidation when fibers'' concentration reaches its percolation threshold, which means that all three equations are useful at low concentration.
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WEN Juan, LI Fu, DING Junjun, LI Gang
2015,36(1):1-8, DOI: 10.7535/hbkd.2015yx01001
Abstract:
Urban rail transit vehicles have been more and more attractive to people as a kind of fast, comfortable, energy-saving, environmental protection and safe transportation. But because of the vehicle noise and vibration, urban rail vehicles also face severe challenges. The research of resilient wheels has been continuously developed and improved. Based on the review of development background and structure sorts of resilient wheels, the advantages of resilient wheels are described, and the research status of noise and vibration reducing, infinite element strength analysis, vehicle dynamic analysis and the wheel-rail wear of resilient wheels are discussed. Taking the low-floor LRVs (light rail vehicles) in domestic and overseas as example, the development and application of the resilient wheels in city rail transit is described, and the application prospects of the resilient wheels in LRVs in domestic and the future research direction of elastic wheel are discussed.
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CUI Hai-ting, ZHANG Gai, JIANG Jing-zhi
2012,33(5):453-458, DOI: 10.7535/hbkd.2012yx05016
Abstract:
By using the solidification/melting model of FLUENT software, the melting and solidification process of the aluminum-silicon alloy in a cylinder heat storage with double wall were simulated numerically. Considering the third kind of boundary condition, the dynamic temperature field distribution and the position of the phase interface change moving with time are obtained. And the melting and solidification duration time is also calculated. The results have important reference value for the numerical simulation of the phase change problem and the design of phase change energy storage device.
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2021,42(2):180-194, DOI: 10.7535/hbkd.2021yx02011
Abstract:
As one of the important supporting technologies for the construction of CPS(cyber-physical space),the digital twin has been applied in many fields,such as aerospace,intelligent manufacturing,smart city,smart medical care,smart education,etc.However, some problems in the practice process has also appeared: the generalization of the concept of digital twin leads to the misunderstanding,which results in the inconsistency of production,teaching,research and application goals,and the practice results are not recognized by the target users; The lack of general and effective methods in concrete implementation leads to the limitation of the results,which results in the lack of universal practical cases and difficulty in forming recognized typical cases.To solve these problems,it is necessary to restrict the concept boundary of digital twin and extend the boundary of digital twin method,so as to form a new boundary of digital twin,promote the formation of consensus,increase implementation methods and promote its better development. 河北科技大学学报 2021年 第2期 刘〓青，等：数字孪生的新边界 Conceptually,physical entity is a collection of materials with various properties,which is characterized by complexity,authenticity and immediacy,and can dynamically evolve with the change of external conditions according to objective laws.In the study of mapping physical entities to digital twins,it is easy to expand the scope of concept to include simulation (the simulation of dynamic evolution process),data (external conditions),and even physical entities (objects).As a result,the concept of digital twin will lose its core and it is difficult to from a consensus.In terms of methods,based on the detailed investigation and analysis of related applications in multi-scenarios,the existing research on digital twin often goes beyond the perception process of physical entities,and directly relies on the models or modelconstruction methods in the original professional fields.While this method has made some progress,its limitations have already been revealed.Firstly,the existing models are mostly focused on subdivision fields,which can not be used universally among fields.Secondly,there are few existing models that reflect the characteristics of high fidelity,multi-scale and multi-physical fields of the digital twin model,and even less information flow corresponding to the whole life cycle.Direct application can not guarantee the effective realization of digital twin; Thirdly,entering the modeling process directly from the height of existing cognition may cause huge costs.For example,the ADT program,a world recognized typical case of US military,was constructed in ten years and with huge investment in manpower and material resources,which further hinders the industry from entering the practice of digital twin.In order to meet these challenges,in terms of conceptual boundary,this paper proposed that the digital twin should return to the essence of its digital model,and effectively restrict the model as the center,so as to promote the understanding of all parties involved in production,teaching and research to reach an agreement.As for the extension of method boundary,this paper put forward a multi-sensory oriented digital twin model construction method,that is,according to the general process of human understanding of the physical world,firstly obtained perceptual knowledge of features through various perception methods,and then further formed rational knowledge through various cognitive processes,from shallow to deep,from easy to difficult,from simple to complex.At first,the digital twin initial model of physical entity was established by multi-sensory methods,such as visual perception,auditory perception,tactile perception and dynamic perception,gustatory/taste perception,and combination with control data reflecting the change of conditions,thus focusing on the complexity and authenticity of physical entity at the beginning of the model establishment,fully embodying the characteristics of the digital twin model,and effectively enhancing the practicability and universality of the model. Then,the initial model was gradually matched with the existing cognitive knowledge framework,and the control data returned from the physical entity was used for continuous iteration.In this way,information of various property changes,real-time/near-real-time reactions,various objective laws and behavioral logic affecting the physical entity under specific external conditions can be gradually added to the digital twin model according to the actual needs of the research field,thus effectively controled the scale and cost of the model and gradually realized the information flow in the whole life cycle. Third,the optimized digital twin model was further used in theoretical and practical research,such as simulation,planning,optimization,decision-making,etc.,so as to promote the development of various studies.The application prospect of the multi-sensory oriented digital twin model in computer image scanning,cultural heritage protection,medical treatment,education and some special fields was prospected.
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2008,29(4):299-304, DOI: 10.7535/hbkd.2008yx04010
Abstract:
Based on the developed rehabilitation manipulator, study on the control system is carried out, such as embedded system platform with the ARM microprocessor S3C2410as its core, motor control module and data acquisition module based on serial peripheral interface (SPI) bus, control software and graphical user interfaces (GUI) etc. According to the mechanical system, a sensor system is also designed to realize the function of acquisition of rehabilitation dada during rehabilitation motion. The test proves the feasibility of the system which can be used in clinic in future.
