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2025,46(3), DOI:
Abstract:
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MA Chao, SUN Tong, CAO Lei, YANG Kun, HU Wenjing
2025,46(3):237-247, DOI: 10.7535/hbkd.2025yx03001
Abstract:
In order to improve the economy of power-split hybrid electric vehicle (HEV),a longitudinal dynamics model of the entire HEV vehicle was established,and an energy management strategy (EMS) based on strategy entropy optimization with an improved proximal policy optimization (PPO) algorithm was proposed. The algorithmic framework was simplified by employing an experience pooling mechanism based on traditional PPO algorithm,and only one deep neural network was used for interactive training and updating to reduce the complexity of parameter synchronization in the policy network. In order to effectively explore the environment and learn more efficient strategies,the strategy entropy was added to the loss function to promote the intelligence to strike a balance between exploration and utilization and to avoid premature convergence of strategies to local optimal solutions. The results show that the EMS based on the improved PPO algorithm with single-policy network maintains the state of charge(SOC) of the battery more effectively than the EMS based on the dual-strategy network PPO under both UDDS and NEDC driving cycle. Additionally,the equivalent fuel consumption is reduced by 85% and 14%,respectively,achieving energy-saving effects comparable to the EMS based on the dynamic programming(DP) algorithm.The proposed improved PPO algorithm can effectively enhance the fuel economy of hybrid vehicles and provide a reference for the design and development of EMS for hybrid vehicles.
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ZHANG Yunkai, GAO Jin, LI Qing, WANG Xu
2025,46(3):248-256, DOI: 10.7535/hbkd.2025yx03002
Abstract:
To address the issue that single traffic data missing value imputation models cannot comprehensively handle the multi-source heterogeneity and complex data volume of traffic data,a multi-classifier imputation model based on adaptive weighting determined by information entropy was proposed. First,information entropy representing "disorder degree" was introduced to evaluate prediction quality and determine multi-classifier weights. Second,a dynamic adaptive weighting method was designed to resolve the problem of different classifiers being suitable for various samples caused by device heterogeneity. Finally,validation was conducted on both public and self-collected datasets. The results demonstrate that the proposed model achieves significant improvement in detection performance compared with other imputation models. It also attains high accuracy in experiments on the public Interstate Highway Traffic Flow Dataset,with an F1 of 0778 and a 10% improvement in RMSE, exhibiting strong generalizability. By enabling weights to adaptively evolve with data streams based on information entropy determination,the algorithm achieves faster detection speed and higher accuracy,providing technical references for the establishment of missing value imputation models in traffic data cleaning.
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2025,46(3):257-267, DOI: 10.7535/hbkd.2025yx03003
Abstract:
To enhance the anomaly recognition ability of traffic time series data, a hybrid model was constructed. Firstly, the multi-head attention, residuals and probabilistic sparse self-attention were combined to form a global feature recognition (GFR) module, enhancing the ability while reducing computational complexity. Secondly, the dilated convolution and multi-scale convolution were combined to form a local feature recognition (LFR) module, further optimizing local feature extraction. Thirdly, the FreeRunning training strategy was used to improve model robustness. Fourthly, the modules and training strategy were combined with LSTM, while the result of the self-attention mechanism replaced the LSTM input gate, so as to optimize long sequence memory ability and reduce computing complexity. Finally, a multivariate Gaussian distribution probability function was used to discriminate anomalies. The results show that adding each module on the basis of LSTM significantly improves the model's prediction and anomaly detection ability; Compared with the general hybrid model Transformer-Bi-LSTM, the proposed model has stronger prediction ability and lower computational complexity. The proposed model performs effectively in recognizing both global and local anomalies in traffic time series data, which provides reference for improving the operational efficiency and safety of the traffic system.
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GAO Kairu, ZHANG Xinyao, CUI Maoqi, YUAN Miao, LIU Shaojie
2025,46(3):268-275, DOI: 10.7535/hbkd.2025yx03004
Abstract:
In view of the problem that it is difficult to balance the high catalytic activity and easy recovery of silver nanoparticles(Ag NPs)catalyst in the catalytic reduction of methylene blue (MB), a cellulose-based silver-loaded hydrogel(TOC-CMC-Ag) was prepared and its catalytic reduction performance to MB was studied. Firstly, TOC-CMC hydrogels were prepared with oxidized cellulose (TOC) and carboxymethyl cellulose (CMC) as raw materials and epichlorohydrin(ECH) as cross-linking agent. The effect of CMC substitution degree on their swelling and adsorption properties was studied. Then, TOC-CMC-Ag was prepared by in-situ reduction method using the TOC-CMC hydrogel with the best adsorption performance as the carrier. The production was characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. Finally, the catalytic reduction performance of TOC-CMC-Ag on MB was studied. The results indicate that TOC-CMC-Ag can completely reduce MB within 4 minutes. After 7 catalytic cycles, MB could still be completely reduced. The prepared silver-loaded hydrogel with high catalytic activity and easy recovery provides a new way for the development of catalytic reduction catalyst with excellent comprehensive performance.
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LI Wenhui, WANG Ruopeng, HAN Yuhe, WANG Sai, ZHANG Yumei, LU Qiong, AN Jing
2025,46(3):276-287, DOI: 10.7535/hbkd.2025yx03005
Abstract:
Graphitic carbon nitride (g-C3N4) is a carbon-based conjugated polymer material with a crystal structure similar to graphite, which exhibits unique potential in the field of photocatalytic antibacterial activity. However, factors such as easy recombination of photogenerated electron(e-)-hole(h+) pairs, incomplete sunlight absorption, small specific surface area, and poor adsorption properties of g-C3N4 photocatalysts leaded to low photocatalytic efficiency, limiting their antibacterial effectiveness. To overcome these problems, strategies such as morphology control, precious metal deposition, element doping, and heterostructure construction were employed to functionalize g-C3N4 and fully activated its antibacterial potential. A detailed introduction was given to the optimization strategies for the photocatalytic antibacterial performance of g-C3N4, with a focus on the current state of research on its photocatalytic antibacterial properties in water disinfection, antibacterial dressings, antibacterial textiles, and food packaging. The challenges currently faced in the development of g-C3N4 photocatalytic antibacterial agents were highlighted. In order to address the increasingly severe challenge of microbial contamination, future research directions are suggested: 1) deepening the research on the mechanisms of reactive oxygen species (ROS) induced damage to bacterial cell membranes, intracellular proteins, DNA, et al; 2) exploring the antibacterial applications of g-C3N4 on broad-spectrum bacteria such as drug-resistant bacteria and commonly used fungi; 3) enhancing the adaptability of g-C3N4 in different environments.
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WANG Jiabin, WANG Shijie, YANG Qianyue, ZHANG Rui, GAO Ruihong, YANG Rongling, LUO Hongzhen
2025,46(3):288-295, DOI: 10.7535/hbkd.2025yx03006
Abstract:
In order to establish an efficient process for the pretreatment of lignocellulosic biomass to deconstruct the complex structure and improve enzymatic hydrolysis efficiency of polysaccharide fractions, choline chloride(ChCl) and glycerol(Gly) were used to synthesize green deep eutectic solvent(DES) for corn stover pretreatment.The deconstruction effects of DES on corn stover under different synthesis conditions were compared, and the chemical reagents were added to enhance pretreatment. The results indicate that, pretreatment at 120 ℃ for 3 h by DES (at a molar ratio of 1∶2) with 1% H2SO4 addition improves the glucan content from 334% to 512%. In this case, the removal rates of xylan and lignin reache up to 867% and 390%, respectively. After 72 h enzymatic hydrolysis by cellulase, the productions of glucose and fermentable sugars are relatively high, reaching 290 g and 307 g from 100 g of corn stover. Therefore, the H2SO4-assisted DES system efficiently remove xylan and lignin, which facilitates the improvements of hydrolysis and fermentable sugars production. This study develops a green and high-efficient pretreatment to provide fundamental data and technical support for valorization of renewable and abundant agricultural residues in China.
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YIN Ziru, QIN Fangyuan, HAN Xue
2025,46(3):296-303, DOI: 10.7535/hbkd.2025yx03007
Abstract:
In order to explore the interaction between Maillard reaction and polyphenol oxidation on browning and antioxidant capacity in food systems, based on different sugar-amino acid Maillard reaction models, the effect of apigenin, naringenin and quercetin on the browning intensity, antioxidant activity and anti-tumor cell proliferative activity of Maillard reaction products (MRPs) were discussed. The results show that when heated at 120 ℃ for 60 minutes, fructose browns faster than glucose, and the MRPs in the fructose amino acid model exhibit higher scavenging activity against DPPH and ABTS free radicals compared to the glucose amino acid model, however, there is no correlation between their antioxidant activity and browning intensity. The addition of different polyphenols has different anti proliferative activities. Apigenin has the highest anti-proliferative activity ability of RKO at 6257%, while quercetin has the lowest anti proliferative activity evaluation ability at only 1423%. The addition of dietary polyphenols can effectively control the Maillard reaction in the processing of heated food, which provides theretical reference for its application in food.
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KANG Min, SUO Ran, SUN Jianfeng
2025,46(3):304-311, DOI: 10.7535/hbkd.2025yx03008
Abstract:
To address the lack of understanding of differential volatile compounds in organic and non-organic milk, volatile compounds in organic and non-organic milks from Holstein, Jersey and Yak were comparatively analyzed by gas chromatography-ion mobility spectrometry (GC-IMS) coupled with chemometrics analysis.The results show that a total of 41 compounds were detected. The metabolic compositions between organic and non-organic milk exhibit a high degree of similarity, whereas the metabolic characteristics of Yak milk differed significantly from Holstein milk and Jersey milk. Some compounds were screened as differential compounds for distinguish organic milk from non-organic milk, including beta-ocimene, 2-butanone, 2[DK],5-dimethylfuran, propanol, 2-ethyl-6-methylpyrazine, and 5-methyl-3-heptanone. The study characterized the differential features of organic and non-organic milk, providing data to support the authenticity identification of organic milk.
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ZHAO Quansheng, LI Fei, GUO Feng′ai, YU Jianyou, XU Shizhao, HU Yunpeng, CHU Xiaomeng
2025,46(3):312-321, DOI: 10.7535/hbkd.2025yx03009
Abstract:
To solve the problem of inaccurate carbon emissions prediction during the highway construction period, a method of optimizing the back propagation(BP) neural network by particle swarm optimization (PSO) algorithm was proposed to predict carbon emissions. The 12 key indicators, including route length, subgrade length, pavement length, tunnel length, bridge and culvert length, interchange length, excavation volume, filling volume, diesel consumption, cement consumption, crushed stone consumption and steel consumption, were refined from the four dimensions of project length, construction, energy consumption and material consumption using the analytic hierarchy process (AHP). The data from 36 highway projects were used as empirical samples for model training, and a comparative analysis was conducted based on error indicators. The results show that the R2 value of the obtained PSO-BP model is 0974, while the R2 value of the BP model is 0890, with the former being closer to 1. Compared to the results of life cycle assessment, the PSO-BP model has a smaller deviation from the actual value than the unoptimized BP model. The four layers of the hierarchy and the selected 12 key indicators enable the prediction of carbon emissions during the design and planning stage of highway construction, providing reference for low-carbon highway construction.
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ZHOU Huizi, LIU Yuelin, LIU Qing, LI Jianwu
2025,46(3):323-332, DOI: 10.7535/hbkd.2025yx03010
Abstract:
Aiming at the bottleneck that deep learning algorithms are not compatible with device detection and new sample collection,as well as poor detection timeliness and generalization ability,a traditional template matching detection algorithm based on SURF features was proposed. Firstly,SURF algorithm was used to extract features from the image,and the product quantization theory was used to construct search trees. The matching points were quickly screened based on spatial position information of feature points. Secondly,the homography matrix and affine transformation matrix were obtained from the matching points,and the two matrices were combined to screen the "interior points" for offset calculation and image registration. Finally,combined with the idea of local defect density measurement,the defect density was calculated by integrating the regional foreground and background weighting method,and the qualification of the label was determined by the defect density. At the same time,for the scene of small characters with few features and local offset,an improved method was proposed to avoid misjudgment. The results show that the algorithm improves the stability and detection accuracy of feature point matching. The accuracy,recall and F1 on the self-built data set are 9867%,9769% and 9818%,respectively,which are better than the mainstream methods. The practical application on the device meets the real-time requirements. The algorithm can effectively improve the stability of feature points and the detection accuracy,meet the detection timeliness of equipment,and provide technical reference for its practicability.
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LIU Bin, LEI Xiaoyu, LIU Gege, ZHAN Shiyuan, GAO Xin, YANG Xiaoyan
2025,46(3):333-341, DOI: 10.7535/hbkd.2025yx03011
Abstract:
To improve the accuracy of job recommendations,a multi-behavioral job recommendation integrating knowledge graph (MB-JRIKG) was proposed based on the implicit preference information of both job seekers and recruiters in the process of [DK]"browsing job positions → submitting resumes → receiving feedback from recruiters". This method constructed a knowledge graph of job seeking based on real job data,and proposed a multi behavior preference propagation strategy based on preference propagation theory. [DK]"Recruiter recognition" in each stage of job seeking was set as the target behavior,and the auxiliary behaviors of job seekers browsing job positions and submitting resumes were set to comprehensively predict job seekers′ preferences. Firstly,the user′s historical records under different behaviors were used as user-interested seed sets,and preference propagation was carried out along the relationships between nodes in the knowledge graph to infer the user′s potential preferences and enhance user representation; Then,the user representation vector and position representation vector were input into the prediction function to calculate the interaction probability of the user under each behavior type,and the weighted sum was used as the interaction probability of the target behavior. Finally,the click-through rate prediction experiment was conducted using the competition dataset of Alibaba′s human job intelligent matching. The results show that compared with the four benchmark models (MF,XGBoost,KGCN and RippleNet),MB-JRIKG achieves a 0014 5 improvement in AUC and a 0028 8 improvement in ACC over the sub optimal benchmark model RippleNet,verifying the effectiveness of the model and achieving full utilization of data. This model effectively combines the interactive behavior of both parties seeking employment for recommendation,introduces attribute association of job knowledge graph,and has reference value for achieving personalized job recommendation.
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ZHANG Hongbin, MI Jiamei, ZUO Jun, LIU Bin
2025,46(3):342-354, DOI: 10.7535/hbkd.2025yx03012
Abstract:
A dynamic risk assessment model for network systems based on attack and defense game theory was proposed to address the problem that the existing models are overly simplified in dealing with the complex dependencies and potential threat paths in the open source software supply chain,and it is difficult to cope with the problem of open source risks in network systems under the background of the big data era. Firstly,system topology information,open source component information,and vulnerability information were integrated to build a knowledge graph of open source risk propagation; Secondly,a threat path generation algorithm was designed based on knowledge graphs to acquire threat paths,and the potential risks of each threat path were evaluated to identify the most likely threat path; Finally,the idea of stochastic game theory was introduced to establish NSRAM-RG,a risk assessment model of network system based on risk game,to analyze the game behaviors of the attacker and defender regarding the most likely threat path. The knowledge graph was dynamically updated,and the risk of the network system was quantitatively evaluated according to the utility function. The experimental results show that fitting degree of the assessment results to the true values is better than the HMM and AHP methods,which can more accurately respond to the risk changes of the system. The proposed model can effectively quantify and assess the open source risk in the system,which provides a new idea for the security management of the open source software supply chain.
Volume 46,2025 Issue 3
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Mechanical, Electronics and Information Science
Chemistry and Chemical Industry
Food Science and Biological Science
Civil and Architectural Engineering
Data Analysis and Calculation
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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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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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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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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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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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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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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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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.
