• Issue 1,2019 Table of Contents
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    • >Special Column: National Young Scholar/Local Science Foundation
    • Effect of the dry friction damping structure on the localized vibration of mistuned bladed disk

      2019, 40(1):1-8. DOI: 10.7535/hbkd.2019yx01001

      Abstract (1609) HTML (0) PDF 1.91 M (1969) Comment (0) Favorites

      Abstract:In order to study the effect of the dry friction damping structure on the localized vibration of mistuned bladed disk, the forced vibration response of a mistuned bladed disk with dry friction damping structure is investigated by using three-dimension microslip friction contact model which could reproduce the characteristics of local micro-motion slip and anti-aliasing hybrid frequency-time domain method. The variation of blade vibration response and the change of localization factor are compared with considering dry friction damping at the blade shroud and not considering dry friction damping. And the influence of the dry friction damping parameters on the vibration control of mistuned bladed disk system is discussed. The results show that the dry friction damping structure can reduce the degree of localization of the vibration response of the mistuned bladed disk system, the friction force between the blades is completely different, and the optimal initial normal pressure and the optimal friction coefficient for each blade are different. Therefore, the effect of the dry friction damping structure to each blade of the mistuned bladed disk is different, and the vibration reduction design of the mistuned bladed disk needs to consider the matching relationship between control parameters and mistuned blade.

    • Study on the icing characteristics of typical wind turbine

      2019, 40(1):9-14. DOI: 10.7535/hbkd.2019yx01002

      Abstract (1464) HTML (0) PDF 1.82 M (2227) Comment (0) Favorites

      Abstract:The icing of wind turbine blade will seriously affect the power output of wind turbine and endanger the safe operation of wind turbine. Computational fluid dynamics (CFD) is used to study the icing characteristics of typical wind wing. Firstly, the impact characteristics of water droplets on NACA0012 type turbine under different attack angle of 0°,4°,8°are calculated. The calculated results are in good agreement with the experimental results, which shows that the calculation method is correct, and, the ice coating on the blade surface of typical wind turbine with different wind speed and temperature was simulated, and the variation trend of water collection coefficient and ice thickness with temperature and velocity was obtained. The results show that: 1) with the increase of wind speed, the ice thickness of blade surface increases and the icing adhesion area increases; 2) with the decrease of temperature, the ice thickness of blade surface increases; and 3) the anti-ice effect of S801 airfoil is obviously greater than that of S802 airfoil. The research result helps logically select turbine under low temperature conditions, providing reference for lowering the blade icing hazard.

    • Survey of environment visual perception for intelligent vehicle and its supporting key technologies

      2019, 40(1):15-23. DOI: 10.7535/hbkd.2019yx01003

      Abstract (1782) HTML (0) PDF 1.01 M (2438) Comment (0) Favorites

      Abstract:Environmental visual perception technology is one of the main means for intelligent vehicles to obtain external environmental information and the precondition for autonomous driving of intelligent vehicles. Based on the comprehensive analysis of the detection technology and methods targeted at different detection objects, the main contents of environmental visual perception research are provided, and the key technologies that the study involves including lane detection technology, vehicle detection technology, the pedestrian detection technology, and traffic signs detection technology are discussed. The advantages and disadvantages of each sub-technique of each technology are analyzed. Finally, on the basis of summarization of the paper, the prospect of unmanned environment of visual perception technology in the future development direction is given:the development of the multi-feature fusion based environment visual perception technology; the fusion application of several environment perception technologies under complicated conditions; the application of the three-dimensional image in picture processing; the application of the improved CNN method in picture processing.

    • >Chemistry and Chemical Industry
    • Preparation of Au/g-C3N4 composite particles and photocatalytic reduction of p-nitrophenol

      2019, 40(1):24-31. DOI: 10.7535/hbkd.2019yx01004

      Abstract (1818) HTML (0) PDF 3.37 M (1887) Comment (0) Favorites

      Abstract:In order to solve the problem of photo-generated electron-hole separation which affects g-C3N4 photocatalytic acti-vity, Au/g-C3N4 composite particles are in situ prepared. The morphology, microstructure and composition of as-prepared Au/g-C3N4 composite particles were characterized by TEM, SEM, XRD, XPS and FTIR, the photoelectric property of the composite particles is also characterized by UV-vis DRS, PL and EIS, and the catalytic activities were examined using the reduction of 4-NP as a model reaction. The results show that the laminated g-C3N4 is hexagonal crystal, while the gold nanoparticles dispersing between the lamella of the g-C3N4 are face-centered cubic crystallites. The visible-light absorption and electron-hole separation efficiency of g-C3N4 matrix are improved by the introduction of gold nanoparticles. When the mass fraction of Au is 0.5%, the amount of substance ratio of sodium chloroaurate and sodium citrate is 1∶3, the Au/g-C3N4 composite demonstrates the best photocatalytic activity. The composite catalyst has strong visible light responsiveness and significantly higher catalytic activity than pure g-C3N4, which provides a theoretical basis for the synthesis of g-C3N4 photocatalyst with high photocatalytic activity.

    • >Food Science and Biological Science
    • Effect of a kind of Chinese herbal compound on the expression of PD-1/PD-L1 in spleen lymphocytes of mice

      2019, 40(1):32-37. DOI: 10.7535/hbkd.2019yx01005

      Abstract (1603) HTML (0) PDF 2.30 M (1484) Comment (0) Favorites

      Abstract:In order to investigate the effect on the expression of PD-1/PD-L1 and the proportion of CD3+CD4+, CD3+CD8+ T lymphocyte in spleen lymphocytes of mice treated with Chinese herbal compound, the extract of Chinese herbal compound is obtained by traditional boiling method. The mice are given intragastric administration once a day with extract of Chinese herbal compound at low, medium and high concentrations. The mice are sacrificed by neck dislocation at the end of experiment time and the spleen is freshly isolated from mice. The expression of PD-1/PD-L1 and the changes of lymphocyte subtypes are detected by Real-time PCR and flow cytometry. The results show that the expression of PD-1 on splenic lymphocytes decreases significantly and the ratio of CD3+CD4+ and CD3+CD8+ T lymphocytes increases significantly with the increase of the concentration of Chinese herbal compound, but the expression of PD-L1 does not change significantly. These results suggest that the Chinese herbal compound can be used in anti-tumor immunotherapy mediated by inhibiting the expression of PD-1 in lymphocytes, activating immune helper cells and effector cells.

    • >Special Column: New Energy Resources, Energy Conservation and Environmental Protection
    • Study of the biological toxicity of oxytetracycline wastewater on zebrafish

      2019, 40(1):38-44. DOI: 10.7535/hbkd.2019yx01006

      Abstract (1809) HTML (0) PDF 2.24 M (1663) Comment (0) Favorites

      Abstract:In order to clarify the biotoxic effects of oxytetracycline wastewater, the toxicity effects of oxytetracycline wastewater on zebrafish are studied by exposure test. The results show that oxytetracycline wastewater is a low toxic substance to zebrafish. The SOD activity and POD activity of zebrafish are differently inhibited at 3~9 d. At 12 d, SOD activity and POD activity are significantly induced (0.01<P<0.05). The SOD activity of 20% volume concentration group reaches the maximum (194.05 U/mg prot), and the POD of 60% volume concentration group reaches the maximum value (2.72 U/mg prot). The SOD activity and POD activity almost returns to control values at 15 d. In addition, there is significant correlation between SOD activity and POD activity in research. The MDA content shows a "Λ" trend in each volume concentration group, and the 80% volume concentration group reaches the maximum value (5.41 nmol/mg prot) at 15 d. The content of γ-H2AX shows a rising trend in zebrafish muscle tissue. At 15 d, the 40% volume concentration group shows extremely significant (400.02 ng/L, P<0.01), which is 1.57 times that of the control group. The DNA of zebrafish muscle cells has been damaged in a certain degree. This study shows that oxytetracycline wastewater is a low toxic substance to zebrafish, and the oxidative stress of zebrafish to oxytetracycline wastewater may be one of the mechanisms causing DNA damage. The biological toxicity of oxytetracycline can provide a scientific basis for further study of the ecotoxicity effect of oxytetracycline in water environment.

    • >Mechanical, Electronics and Information Science
    • Miner expression recognition based on improved principal component analysis

      2019, 40(1):45-50. DOI: 10.7535/hbkd.2019yx01008

      Abstract (1533) HTML (0) PDF 1.47 M (1427) Comment (0) Favorites

      Abstract:Aiming at the problem that the feature extraction of miners' facial expressions is slower and the recognition accuracy is not high for the traditional miner facial expression recognition method, based on the principal component analysis method, Fisher's linear discriminant method is used to improve the traditional principal component analysis method. Firstly, based on the principal component analysis method, an inter-class discrete matrix is added to make the distance between the feature points of different categories become larger after projection, and the distance between the feature points of the same category is more compact, so that the result of feature extraction to the miners' facial expression images is more representative and targeted. Then, the radial basis network is used to map the low-dimensional and nonlinear separable miner's facial expression feature matrix to the high-dimensional spatially separable class to realize the identification and classification of miners' facial expressions. The experimental results show that the recognition rate of the miner's facial expression reaches 89.0%, which is superior to the traditional miner's facial expression recognition algorithms. The method has a good application prospect in the fields of mine safety monitoring and fatigue driving.

    • Kinematics and singularity analysis of UR5 robot

      2019, 40(1):51-59. DOI: 10.7535/hbkd.2019yx01009

      Abstract (2984) HTML (0) PDF 2.76 M (3894) Comment (0) Favorites

      Abstract:In order to solve the problem that the UR5 robot coordinate system established by the user is inconsistent with the manufacturer's, and the data related to the force, angular velocity, angular acceleration are difficult to be directly used, based on the analysis of the structural characteristics of the UR5 robot, the coordinate system matching the manufacturer's data is established. The kinematics equation of the UR5 robot is established by D-H method to describe the relationship of each joint. According to the structural characteristics satisfying the Pieper criterion of the UR5 robot, the kinematic inverse solution of the UR5 robot is obtained by the separation variable method. The singularity analysis of UR5 robot is completed by differential transformation method, and the singularity analysis and simulation results show the relationship between the joint variables of UR5 robot when the position is singular. The kinematics program is written by using MATLAB software, and the robot system is used to carry out laboratory test and engineering practice verification. The experimental results of MATLAB kinematics program are consistent with the internal data of UR5 system, which verifies the correctness of kinematics analysis. The research result has some reference for further research of UR5 robot continuous trajectory planning.

    • Measurement mechanism study of limb blood vessel velocity profile based on multi-electrode electromagnetic flow meter

      2019, 40(1):60-66. DOI: 10.7535/hbkd.2019yx01010

      Abstract (1607) HTML (0) PDF 3.53 M (1471) Comment (0) Favorites

      Abstract:In order to measure the velocity profile of arterial and venous blood flow of human body and predict major cardiovascular diseases, the multi-electrode electromagnetic flow meter based on region weight function theory is proposed in this paper. The region weight function theory has been derived from traditional Shercliff theory and COMSOL model has been established to simulate the human limb according to the layout and relative position of skin, fat, bone, muscle, artery and vein. The cross section has been divided in to several regions and the induced voltages at different positions along the skin surface have been obtained by the electrode array. The local mean axial velocity profile of the vessel cross section is calculated, and the velocity information of the reverse flow in the arteries and veins is reconstructed. The results of three-dimensional finite element model simulation demonstrate that multi-electrode electromagnetic flow meter based on region weight function is feasible to characterize the velocity profile of arteries and veins with high accuracy. Region weight function based multi-electrode electromagnetic measurement method has some reference value for vessel blood flow velocity measurement and hemorheology anomaly monitoring of human body.

    • >约稿:数据分析与计算专栏
    • Research on Digital Twin: Model, problem and progress

      2019, 40(1):68-78. DOI: 10.7535/hbkd.2019yx01011

      Abstract (2988) HTML (0) PDF 1.53 M (9490) Comment (0) Favorites

      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.

    • Numerical modeling to rainfall infiltration into planting-soil-crushed-stone green belt

      2019, 40(1):79-85. DOI: 10.7535/hbkd.2019yx01012

      Abstract (1584) HTML (0) PDF 1.37 M (1478) Comment (0) Favorites

      Abstract:To verify the rationality of the theoretical analytical method to solve the rainfall infiltration into planting-soil-crushed-stone green belt, the finite element model of the rainfall infiltration into unsaturated planting soil is established. The water storage skin is used to model the infiltration and accumulation of rainwater on the upper boundary of the model. The lower boundary is saturated and drained, and the both sides of the model are impervious. Firstly, the infiltration characteristics of road rainwater under uniform rainfall conditions are modeled by the finite element model. Compared with the theoretical analytical solution, the finite element model is proved to be right. Secondly, the infiltration of road rainwater into planted soils is calculated by the finite element model under the condition of 2-year recurrence period and 3-hour design rainstorm of Shijiazhuang city. The beginning time of the surface water, the rainwater depth of stopping rainfall and the coefficient of rainfall runoff are 0.75 h, 13.6 cm and 0.24, respectively. The analytical results of uniform rainfall method are 0.72 h, 14.4 cm and 017, respectively. The results of the both methods are basically identical. Thirdly, the finite element model is employed to calculate the beginning time of the surface water under the condition of different pore pressure at the lower boundary and upper boundary. The results show that with the pore pressure descending at the lower boundary, the beginning time of the surface water rises up. With the pore pressure dropping at the upper boundary, the beginning time of the surface water increases. When the pore water pressure is 0 kPa at the lower boundary and the initial pore water pressure at the upper boundary are -6 and -12 kPa, the beginning time of the surface water are 45 and 50 min, respectively. Obviously the beginning time of the surface water is different. When the initial pore water pressure is -6 kPa at the upper boundary and the pore water pressure at the lower boundary are 0, -1, -2 and -3 kPa, the beginning time of the surface water are 45, 45, 46 and 47 min, respectively. The lower boundary condition has little effects on the beginning time of the surface water. When the permeability coefficient is 6.5×10-9 m/s and the pore water pressure of ground soil are 0, -4.5, -9, -13.5 and-18 kPa, the finite element model is used and the beginning time of the surface water are 54, 54, 55, 55 and 56 min, respectively. Correspondingly the surface water depths are 11.9, 11.7, 11.5, 11.4 and 11.3 cm, respectively. With the pore water pressure in ground soil decreases, the beginning time of the surface water slightly increases, and the surface water depth descends. As a whole, the pore water pressure in ground soil has little effect on the beginning time and the depth of the surface water. When the pore water pressure in ground soil is 0 kPa and the permeability coefficients are 6.5×10-9 and 6.5×10-7 m/s, the beginning time and the depth of the surface water by the finite element model are 54 and 11.9 cm, respectively. The permeability coefficient of the ground soil has little effect. Based on above analysis, our main conclusions are: Uniform rainfall intensity and theoretical analytical method can be used to calculate the beginning time and the depth of the surface water. The lower boundary condition has little effects on the beginning time of the surface water and water depth. The saturated permeability coefficient and the initial water content of the ground soil have no significant influence on the beginning time of the surface water and water depth. It is recommended to employ the analytical solution to analyze the rainwater infiltration in to planting-soil-crushed-stone green belt.

    • A flat management platform based on mobile internet

      2019, 40(1):86-96. DOI: 10.7535/hbkd.2019yx01013

      Abstract (1751) HTML (0) PDF 4.37 M (1692) Comment (0) Favorites

      Abstract:The traditional hierarchical management has the characteristics of clear hierarchy, clear responsibilities and strict workflow. It originates from the imitation of military management system and is widely used in various fields such as government agencies, production and manufacturing. At the same time, with the growing size of the organization, the relationship between managers and managed people becomes more complex, and each manager's ability, energy and time are limited. When the number of subordinates directly managed exceeds a certain limit, a management level must be added. With the levels increase, the staff at different levels and even at the same level will easily reduce the timeliness of information transmission because of the objective differences in the degree of recognition of the importance of information, work habits, etc. At the same time, because of the objective differences in the growth background, work experience, knowledge background and understanding ability of the relevant personnel, it is easy to lead to information misunderstanding in the process of interaction, and affects the accuracy of information interactions. Thirdly, in the actual work, it is difficult for a superior to supervise the deployed tasks, whether the subordinates can actually accomplish the tasks and how to accomplish and the quality in the case of non-face-to-face. If we cannot establish a convenient information interaction mechanism, it is difficult to supervise. In response to such problems, OA (Office Automation) systems have been widely used, but the result has proved that most OAs simply transplant the traditional hierarchical management to the Internet. There are still objective problems such as layer-by-layer reporting, layer-by-layer approval, layer-by-layer circulation, and so on. Some departments, no matter how urgent the things are, no matter whether they need to be flexible or not, only depends on the approval result of OA system. Nevertheless, all exemptions aggravate the occurrence of bureaucratic phenomena in departments. At the same time, instant messaging tools such as WeChat and QQ have become the main platform for people's daily interaction because of their main features such as abundant graphics and texts (rich media), self-editing and expressing content (self-media), strong sense of scene, being able to publish contents at any time (spatio-temporal dimension), and being able to immediately reach the audience (point-to-point, point-to-area) and so on. And they also have become the the big data platform that carries ideas, delivers business, communicates work and so on, many units, departments or individuals have been accustomed to handling work affairs on the instant messaging platform such as WeChat and QQ. In fact, this phenomenon contains a lot of risks. The main reasons are as follows: 1) the data generated on the platform are taken away by the third party (Tencent and other companies). The business content of the unit becomes the data resources stored on other people's servers. The privacy of the unit has a great risk of leakage. At the same time, because the data is not in its own hands, it is very difficult for the unit to exploit the data resources and make them become driven power of business and management; 2) WeChat and QQ belong to social platform, with complex social relations and prosperous and diverse platform content. Business information can easily be disseminated or leaked intentionally or unintentionally, which not only affects the image of the unit, but also may cause huge negative economic and social impact; 3) Because of the existing characteristics of the platform, important business information can easily be diluted. For example, important information such as tasks and business guidance issued by different leaders in the same group can easily cross each other, leading to confusion in business discussion clues, and difficult to form clear, complete and clear information topics. In order to solve the above problems, this paper designs and develops a flat management platform supporting business data self-owned and self-analysis, relying on mobile internet, which aims to improve the management efficiency, make data as the core asset, and enhance the information interaction ability and efficiency within the unit. The platform has a dedicated data acquisition, publishing, collation and analysis backstage, which not only improves the timeliness, on-the-spot, rich media and cross-temporal dimension of information interaction, but also combs, excavates and refines the data to form the tracking and objective analysis of business progress. At the same time, in order to enhance the pertinence and practicability of the platform, this paper considers the real needs from Hebei province expressway Zhang-Cheng Chengde Management Office. The platform has been put into use and improved for more than two years. Practice has proved that the platform provides strong support for the management department in discovering hot spots, capturing problems, monitoring the overall situation, effectively improving the cohesion, combat effectiveness and centripetal force of the whole staff, and effectively improving the management efficiency. This platform provides reference support for concerned units and study to realize flat information interaction and management in hierarchical management.

Editor in chief:朱立光

Inauguration:

International standard number:ISSN 1008-1542

Unified domestic issue:CN 13-1225/TS

Domestic postal code:

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