Editor in chief：朱立光
International standard number：ISSN 1008-1542
Unified domestic issue：CN 13-1225/TS
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2016, 37(4):315-321. DOI: 10.7535/hbkd.2016yx04001
Abstract:Laser processing technology can produce various types of surface textures on material. In order to investigate the effect of surface texture type processed by laser on the wettability, line, grid and spot patterns are fabricated on titanium surface based on nanosecond laser processing technology. Then surface morphology, water contact angle, roughness and chemical composition of the processed titanium surface are analyzed by scanning electron microscope, contact angle measuring device, surface analyzer and X-ray photoelectron spectroscopy, respectively. It is found that the roughness of titanium surfaces processed by nanosecond laser increases significantly compared with that of the unprocessed titanium surface, while the surface contact angles of the processed titanium surfaces are all less than 90°. As time goes on, the chemical composition variation of ablated titanium surface results in the change of material surface free energy, which leads to a general increase of the surface contact angle. Finally, the surface contact angle is almost unchanged once the chemical composition of titanium surface reaches steady state. For each type of surface texture, surface contact angle increases as the roughness rises. The surface contact angles of processed titanium surfaces with line, grid and spot patterns can be 157.2°, 153.1° and 134.6°, which verifies the possibility of wettability change of titanium from hydrophilicity to hydrophobicity.
2016, 37(4):322-328. DOI: 10.7535/hbkd.2016yx04002
Abstract:The four-wheel independent drive and four-wheel independent steering (4WID-4WIS) vehicle has the advantages of short transmission chain, high efficiency, compact structure, and high maneuverability. The kinematics and dynamic control of the 4WID-4WIS vehicle are discussed, then key and difficult problems are refined. The distributed network control system is widely used in the vehicle control system, so that real-time and reliable control under non-ideal network is the research challenges, and hierarchical control method is a hot research topic. For the vehicle dynamics control method, the main research focuses on torque distribution method under one or more optimization objectives, and integrated control which harmonizes multi control subjects has become an important research direction. In order to solve the problem of steering mode static switching of the 4WID-4WIS vehicle, the study on the dynamic switching method based on redundant control degree of freedom is a new research direction.
2016, 37(4):329-334. DOI: 10.7535/hbkd.2016yx03002
Abstract:Anti-vibration rubber, because of its superior elasticity, plasticity, waterproof and trapping characteristics, is widely used in the automotive industry, national defense, construction and other fields. The theory and technology of predicting fatigue life is of great significance to improve the durability design and manufacturing of anti-vibration rubber products. According to the characteristics of the anti-vibration rubber products in service, the technical difficulties for analyzing fatigue properties of anti-vibration rubber materials are pointed out. The research progress of the fatigue properties of rubber materials is reviewed from three angles including methods of fatigue crack initiation, fatigue crack propagation and fatigue damage accumulation. It is put forward that some nonlinear characteristics of rubber under fatigue loading, including the Mullins effect, permanent deformation and cyclic stress softening, should be considered in the further study of rubber materials. Meanwhile, it is indicated that the fatigue damage accumulation method based on continuum damage mechanics might be more appropriate to solve fatigue damage and life prediction problems for complex rubber materials and structures under fatigue loading.
2016, 37(4):335-339. DOI: 10.7535/hbkd.2016yx04004
Abstract:Operator theory is an important research content of the analytic function space theory. The discussion of simultaneous operator and function space is an effective way to study operator and function space. Assuming that is an analytic self map on the unit disk Δ, and the normal weighted bloch space μ-B is a Banach space on the unit disk Δ, defining a composition operator C∶C(f)=f on μ-B for all f∈μ-B, integral type operator JhC and CJh are generalized by integral operator and composition operator. The boundeness and compactness of the integral type operator JhC acting from normal weighted Bloch spaces to QT,S spaces are discussed, as well as the boundeness of the integral type operators CJh acting from normal weighted Bloch spaces to QT,S spaces. The related sufficient and necessary conditions are given.
2016, 37(4):340-348. DOI: 10.7535/hbkd.2016yx04005
Abstract:It is difficult to study the existence of solutions for boundary value problems of differential equations at resonance, moreover, to get positive solutions of boundary value problems for differential equations at resonance is more difficult. To research this problem, the existence of positive solutions for a couple of different equations with multi-point boundary value conditions at resonance is studied. On the basis of previous researches, choosing a different operator, the equation is extended to a couple of different equations. By defining the correct norm in the product spaces which become Banach spaces, and using the Leggett-Williams norm-type theorem due to O'Regan and Zima, the nonlinear term satisfies reasonable assumptions, and the existence of positive solutions for a coupled of different equations with multi-point boundary value conditions at resonance is obtained.
2016, 37(4):349-356. DOI: 10.7535/hbkd.2016yx04006
Abstract:In order to understand the viral dynamics processes inclucding infection, duplicate, eliminate, etc. in human body, a viral infection model with infection age of cells and general saturated infection rate is investigated. It is proved that the model has a unique infected steady state when the basic reproduction ratio is greater than one unity. By analyzing the characteristic of relevant equations, the local stability of effective steady state is dislussed. By using suitable Lyapunov functional and LaSalle’s invariance principle, it is proved that when the basic reproduction ratio is less than one unity, the infection-free steady state is globally asymptotically stable; and when the basic reproduction ratio is greater than one unity, the infected steady state is globally asymptotically stable.
2016, 37(4):357-363. DOI: 10.7535/hbkd.2016yx04007
Abstract:In order to enhance the antibacterial activity of chitosan and expand its application field, silver nanoparticles are introduced into the matrix, and the grafting modification is carried out. Chitosan grafted vanillin (CS-g-VA) is prepared with microwave-radiation method, and silver nitrate is reduced by vanillin, so that silver nanoparticles are separated evenly in CS-g-VA sol, which is Ag/CS-g-VA composite sol. The effects on the preparation of Ag/CS-g-VA composite sol are studied, and the structure and thermal property of the obtained composite sol are characterized by SEM, TEM, FTIR, XRD, UV-vis and TG-DSC. The experiment results show that the optimum conditions for the preparation of Ag/CS-g-VA are as following: Vanillin concentration of 6.0%, CS-g-VA concentration of 4.0%, and silver nitrate concentration of 0.20 mol/L. The inhibition of Ag/CS-g-VA composite sol against Escherichia coli and Bacillus subtilis is investigated through antibacterial tests. The results show that the antibacterial activity of Ag/CS-g-VA composite sol is more efficient than that of single CS materials.
2016, 37(4):364-367. DOI: 10.7535/hbkd.2016yx04008
Abstract:In order to meet the market demand, the synthetic process of 2,3-dichloropyridine is studied. 2,3-dichloropyridine is synthesized from 2-chloronicotinic acid via amidation, Hofmann degradation, diazotization and Sandmeyer reaction. The factors influencing the yield (for example the amount of PCl3, the concentration of NaOH, the reaction temperature and the amount of catalyst) are optimized. The results show that the optimum conditions are as following: In amidation reaction, n(2-chloronicotinic acid)∶n(PCl3)=1∶0.45, in Hofmann degradation, the concentration of NaOH is 18%, the reaction temperture is at 75~80 ℃, and in Sandmeyer reaction, n(2-chloro-3-amino pyridine)∶n(CuO)=1∶0.3. Under the optimized conditions, the yield of the products is 70.33%(counted based on 2-chloronicotinic acid), the purity is 98.5%. The structure is characterized by 1H-NMR, which shows that the synthetic process has the advantages of high purity, simple operation and easily obtained raw material.
2016, 37(4):368-375. DOI: 10.7535/hbkd.2016yx04009
Abstract:Dust of blast furnace gas deposits easily on the bottom of seat sealing surface of the tri-eccentric butterfly valve, which causes serious stuck and damage of the valve plate, thereby affects blast furnace product and brings great economic loss. To reduce the dust deposition, a kind of automatic dust removal system is designed and its efficacy is simulated. Based on FLUENT module of ANSYS Workbench, as well as standard k-ε turbulence model and DPM model, simulation analysis of the influence of 3 inlet pressures (0.25,0.30,0.35 ) of working medium (N2) in dust removal system and 2 different valve plate jaw openings (45°,90°) on the dust deposition trajectory in butterfly valve region are conducted, and the influence mechanism of inlet pressure on the dust deposition is analyzed. The results show that the dust removal system can reduce the dust deposition under five combined conditions except under the condition of a valve plate jaw opening of 45°and an inlet pressure of 0.25 MPa. The dust removal system has much better effect under the following conditions: valve plate jaw opening of 45° and inlet pressure of 0.30 MPa, or valve plate jaw opening of 90° and inlet pressure of 0.25 MPa.
2016, 37(4):376-381. DOI: 10.7535/hbkd.2016yx04010
Abstract:The Super-Twisting control algorithm is adopted to analyze the U model based nonlinear control system in order to solve the controller design problems of non-affine nonlinear systems. The non-affine nonlinear systems are studied, the neural network approximation of the nonlinear function is performed, and the Super-Twisting control algorithm is used to control. The convergence of the Super-Twisting algorithm is proved by selecting an appropriate Lyapunov function. The Matlab simulation is carried out to verify the feasibility and effectiveness of the described method. The result shows that the output of the controlled system can be tracked in a very short time by using the designed Super-Twisting controller, and the robustness of the controlled system is significantly improved as well.
2016, 37(4):382-389. DOI: 10.7535/hbkd.2016yx04011
Abstract:The traditional mechanical encoder has been used to detect the position and speed of rotors in permanent magnet synchronous motor control system, which has the problems of high cost, low system reliability, being susceptible to interference and difficult to apply in a complex environment. A novel speed estimation method based on sliding mode adaptive system is proposed in this paper, which improves the speed estimation accuracy and system robustness to achieve motor speed sensorless control. The simulation results indicate that the control strategy could avoid the limitations of traditional mechanical encoders, and estimate the rotor speed and position angle accurately when suddenly applied load.
2016, 37(4):390-395. DOI: 10.7535/hbkd.2016yx04012
Abstract:For the minimization of terramycin bacterial residue, microwave-alkaline pretreatment is used. By measuring the changes of suspended solids and pH in the reaction system，the effect of different dosage of NaOH，microwave power and initial moisture on the minimization of the terramycin bacterial residue is investigated. Orthogonal experiment and single fact experiment are applied to determine the optimal reaction conditions. The results show that the best operating conditions are the dosage of NaOH is 0.09 g/g， microwave power is 700 W and the initial moisture is 96%. Under these conditions the removal rate of SS is more than 56%. In addition，the effect of the solution is analyzed by scanning electron microscopy. This study achieves ideal minimization results of terramycin residue，which provide technical reference for antibiotics residue minimization.
2016, 37(4):396-405. DOI: 10.7535/hbkd.2016yx04013
Abstract:In order to study the effect of the different ratios on the anaerobic fermentation rate is investigated, and the rate-limiting factors are preliminarily determined, at mesophilic (38±1)℃ condition, with anaerobic granular sludge as inoculums, different ratios of cow manure and corn straw are used as substrate for mixed anaerobic fermentation. By measuring daily biogas production, the concentrations of CH4 and CO2 in the marsh gas, TC, the concentration of VFAs and pH value, The results show that under the mixture ratio of 2∶1, the hydrolysis rate constants, cumulative biogas yield and biodegradability CH4 reach their high limits, which are 0.043 7 d-1, 271.93 mL/g and 71.59%, respectively. Moreover, it is found that the concentration of acetic acid is proportional to the amount of cow manure at the beginning (the first day) of mixed fermentation, and the concentration of propionicacid is proportional to the amount of corn straw in medium fermentation stage (the fifth day). In addition, rate-limiting step of biogas production is related to the ratio of cow manure and corn in fermentation material. With the increasing of corn straw proportion, on the 1st day, it tends to hydrolysis acidogenesis; from the 2th day to 15th day, it tends to hydrogen-production acetogenisis; and from the 16th day to 30th day, it is hydrolysis acidogenesis. The paper focuses on the relationship between the ratio of cow manure and corn straw and the rate-limiting step for biogas production, which could provide a theoretical and experimental support for improving the efficiency of biogas production in mixed fermentation.
2016, 37(4):407-415. DOI: 10.7535/hbkd.2016yx04014
Abstract:Aiming at the four outstanding problems of informationized supervision for judicial publicity, the judicial public data is classified based on data driven to form the finally valuable data. Then, the functional structure, technical structure and business structure of the data processing system are put forward, including data collection module, data reduction module, data analysis module, data application module and data security module, etc. The development of the data processing system based on these structures can effectively reduce work intensity of judicial open iformation management, summarize the work state, find the problems, and promote the level of judicial publicity.
2016, 37(4):416-422. DOI: 10.7535/hbkd.2016yx04015
Abstract:A plenty of XML documents exist in petroleum engineering field, but traditional XML integration solution can’t provide semantic query, which leads to low data use efficiency. In light of WeXML(oil&gas well XML data) semantic integration and query requirement, this paper proposes a semantic integration method based on extraction rules and ontology mapping. The method firstly defines a series of extraction rules with which elements and properties of WeXML Schema are mapped to classes and properties in WeOWL ontology, respectively; secondly, an algorithm is used to transform WeXML documents into WeOWL instances. Because WeOWL provides limited semantics, ontology mappings between two ontologies are then built to explain class and property of global ontology with terms of WeOWL, and semantic query based on global domain concepts model is provided. By constructing a WeXML data semantic integration prototype system, the proposed transformational rule, the transfer algorithm and the mapping rule are tested.