Editor in chief：朱立光
International standard number：ISSN 1008-1542
Unified domestic issue：CN 13-1225/TS
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2017, 38(4):313-319. DOI: 10.7535/hbkd.2017yx04001
Abstract:In order to avoid friction and scratching between the conveyor and the precision components when conveying object, an compact non-contact acoustic levitation prototype is designed, and the feasibility is theoretically and experimentally verified. The symmetry model is established through kinetic analysis with ANSYS. The modal and the coupled field computation at the central point of the transfer platform are simulated. The simulation results show that pure flexural or mixed flexural wave shapes appear with different wave numbers on the platform. Sweep frequency test is conducted on the compact platform prototype. The levitation experimental results confirm the feasibility of the ultrasound transfer process, the levitation frequency range and the mode of vibration. The theoretical and experimental results show that the optimal design of the modal and the carrying capacity of the driving platform is necessary according to different conditions. The research results provide a reference for the design of the mode and bandwidth of the ultrasonic levitation platform.
2017, 38(4):320-324. DOI: 10.7535/hbkd.2017yx04002
Abstract:According to the tensile properties of typical aerospace material TC11 titanium alloy, the stress-strain relationship is studied using the quasi-static tensile test at different strain rates, and the tensile fracture morphology is analyzed with SEM. The experimental results show that TC11 titanium alloy has certain strain rate sensitivity, and both tensile strength and yield strength are affected by strain rate. During quasi-static tension test, TC11 titanium alloy specimen has the phenomenon of neck shrinkage. The section of the specimen is cuppy, and there is smooth shear lip zone and grey fiber area in the sample fracture. The fracture of the samples belongs to ductile fracture, but its toughness is poor. The tensile fracture morphology of TC11 titanium alloy is mainly the dimple with different sizes, but with the increase of strain rate, the size and the depth of dimple at the tensile fracture are smaller, and the fracture surface produces a small number of tearing edges and quasi-cleavage plane, and the fracture mechanism of the specimen is mainly ductile fracture and quasi-cleavage fracture. Therefore, the mechanical behavior of TC11 titanium alloy is related to strain rate under quasi-static tensile condition.
2017, 38(4):325-334. DOI: 10.7535/hbkd.2017yx04003
Abstract:Some typical living creatures with a non-smooth surface in nature are introduced. The law of the fact that an appropriate micro-structure surface can transform the turbulent structure of near-wall region is briefly stated. The research status of the type of micro-structure surface, the drag reduction of micro-structure surface, the mechanism of drag reduction of micro-structure surface and its application so far are commented. The extended types of grooves are proposed, and it is suggested that the current research on drag reduction should be extended for structures with complex shapes. The analysis indicates that the types of bionic micro-structure surfaces have great effect on drag reduction, the mechanical research and aerodynamic drag reduction are focal points of the bionic micro-structure surface drag reduction technology, which can further improve the efficiency of energy conservation and reduce consumption, and has a great prospect in engineering fields such as aircraft, high-speed trains, cars, etc.
2017, 38(4):335-340. DOI: 10.7535/hbkd.2017yx04004
Abstract:In order to better improve vehicle active safety and realize personalized driving, aiming at the problem of the identification of driver behavior intention and characteristics, the electronic control systems' important role in the automobile and the importance of the driver behavior intention and characteristic identification are discussed. The relative domestic and foreign research is summarized, and the prospect is put forward. In order to improve the performance of automobile electronic control system and realize the intelligent control for the cars, the identification of driver behavior intention and characteristics needs to be studied. How to rationally classify and on-line identify drivers' characteristics correctly for the steering, braking and acceleration characteristics is a long term research topic.
2017, 38(4):341-351. DOI: 10.7535/hbkd.2017yx04005
Abstract:In order to study the existence of solutions for boundary value problems at resonance with nonlinear fractional differential operator, a generalization of Mawhin's continuous theorem is introduced. By defining suitable Banach space and norm, constructing the proper operators and using the extension of Mawhin continuation theorem, the existence of solutions for fractional differential equations systems boundary value problem with p-Laplacian at resonance is studied. An example is given to illustrate the main results. The results are the improvement and generalization of some existing results of boundary value problems at resonance.
2017, 38(4):352-359. DOI: 10.7535/hbkd.2017yx04006
Abstract:In order to study internel axiomatic systems and ordered features of Alexandrov spaces, with the help of some existed results in topology and locale theory, by restricting the related structures into Alexandrov setting, some equivalent descriptions are obtained. The results show that Alexandrov spaces are categorically isomorphic to Alexandrov neighborhood systems, Alexandrov closure operators, Alexandrov interior operators and Alexandrov derived operators; T0 Alexandrov spaces are isomorphic to posets and dual to complete-generated lattices. Alexandrov spaces can be completely characterized by neighborhood systems, closure operators, interior operators, derived system, the specialization order and the point-free order.
2017, 38(4):360-366. DOI: 10.7535/hbkd.2017yx04007
Abstract:Fractional calculus is a theory that studies the properties and application of arbitrary order differentiation and integration. It can describe the physical properties of some systems more accurately, and better adapt to changes in the system, playing an important role in many fields. For example, it can describe the process of tumor growth (growth stimulation and growth inhibition) in biomedical science. The oscillation of solutions of two kinds of fractional difference equations is studied, mainly using the proof by contradiction, that is, assuming the equation has a nonstationary solution. For the first kind of equation, the function symbol is firstly determined, and by constructing the Riccati function, the difference is calculated. Then the condition of the function is used to satisfy the contradiction, that is, the assumption is false, which verifies the oscillation of the solution. For the second kind of equation with initial condition, the equivalent fractional sum form of the fractional difference equation are firstly proved. With considering 0<α≤1 and α>1, respectively, by using the properties of Stirling formula and factorial function, the contradictory is got through enhanced processing, namely the assuming is not established, and the sufficient condition for the bounded solutions of the fractional difference equation is obtained. The above results will optimize the relevant conclusions and enrich the relevant results. The results are applied to the specific equations, and the oscillation of the solutions of equations is proved.
2017, 38(4):367-374. DOI: 10.7535/hbkd.2017yx04008
Abstract:In order to solve the security and reliability problems of the system control in the control theory, considering that time-varying delay is widespread in many systems, thinking about solving problems by fault diagnosis and fault-tolerant control, and aiming at the study of fault-tolerant control of nonlinear time-delay singular systems based on fault diagnosis observers, a new fault diagnosis observer is constructed. With the Lyapunov stability theory, the fault diagnosis observer state estimation error is researched. Then, the state feedback fault-tolerant controller is designed. Using Schur lemma and some basic control theories, the sufficient conditions for linear matrix inequality (LMI) existed in fault diagnosis observer and fault tolerant controller are obtained. The closed-loop system is guaranteed to be stable and satisfies the given performance index. Finally, the Matlab simulation example is given to illustrate the simplicity and practicability of the proposed method, which overcomes effectively problems existed in the system such as: nonlinearity, destabilization, and time-varying delay.
2017, 38(4):375-382. DOI: 10.7535/hbkd.2017yx04009
Abstract:In order to establish an HPLC method for the content determination of palbociclib, HPLC is performed on the column of Agilent C18 （250 mm × 4.6 mm，5 μm）with the mobile phase of acetonitrile-water (300∶700，0.1% TFA included) at the flow rate of 1.0 mL/min, with the sample size of 10 μL, the detection wavelength of 234 nm and the column temperature of 40 ℃. The result shows that the main drug and the related substances could be well separated; the calibration curve of palbociclib is in good linearity over the range of 50~150 μg/mL, and r=0.999 5; the RSD of instrument precision, intermediate precision and stability test of related substances and content are no more than 2.0%; the average recovery is 100.0% with RSD of 0.8% (n=9). The method can rapidly and accurately determine the PD content, effectively eliminate the effects of other external factors. It provides a new reference to the content determination of active pharmaceutical ingredients.
2017, 38(4):383-388. DOI: 10.7535/hbkd.2017yx04010
Abstract:In order to study the feasibility of hot forging forming process for rigging joints, the numerical simulation of hot inverse extrusion forming technology of the hole of a rigging joint is analyzed with finite element method, and the formability of rigging joint hole is analyzed from both metal flow regularity and metal streamline distribution. The relationships of rigging joints under different extrusion conditions between stress field, strain field and change of grain size of the extrusion parts are studied. The extrusion technological parameters are obtained which are initial temperature of 1 100~1 150 ℃ and extrusion speed of 10 mm/s. Through finite element analysis, after forming of the hole under extrusion, the simulation results show that the distribution of metal flow line is reasonable, there is no obvious cross or fracture, the forming result is good, and the dimensional accuracy is high. So the hot inverse extrusion forming of the hole of the rigging joint is feasible.
2017, 38(4):389-394. DOI: 10.7535/hbkd.2017yx04011
Abstract:The risk of the reservoir dam seepage will bring the waste of water resources and the loss of life and property. The ground penetrating radar (GPR) is designed as a daily inspection system of dams to improve the existing technology which can't determine the actual situation of the dam seepage tunnel coordinates. The finite difference time domain (FDTD) is used to solve the Yee's grids discreatization in two-dimensional space, and its electromagnetic distribution equation is obtained as well. Based on the actual structure of reservoir dam foundation, the ideal model of air layer, concrete layer, clay layer and two water seepage holes is described in detail, and the concrete layer interference model with limestone interference point is established. The system architecture is implemented by using MATLAB, and the forward modeling is performed. The results indicate that ground penetrating radar can be used for deep target detection. Through comparing the detection spectrum of three kinds of frequency electromagnetic wave by changing the center frequency of the GPR electromagnetic wave of 50 MHz, 100 MHz and 200 MHz, it is concluded that the scanning result is more accurate at 100 MHz. At the same time, the simulation results of the interference model show that this method can be used for the detection of complex terrain.
2017, 38(4):395-402. DOI: 10.7535/hbkd.2017yx04012
Abstract:Unidirectional water-transport fabric is a kind of functional fiber assembles used to realize unidirectional conduction of liquid water, and it could be used for the design and development of clothing with the function of thermal-wet comfort. The development of unidirectional water-transport fabrics from the mechanism of the unidirectional water-transport, selection of fiber and preparation method is summarized. Five key methods to achieve the unidirectional water-transport effect have been reviewed, including the designing of fabric structure, chemical finishing, plasma treatment, electro spinning and photocatalytic treatment. According to the current problems in the research on unidirectional water-transfer fabric, it is proposed that multi-functional unidirectional water-transfer fabrics should be developed by post-treatment finishing technology with adding special functional additives to expand the practical applications.
2017, 38(4):403-410. DOI: 10.7535/hbkd.2017yx04013
Abstract:The microbubble ozonation was used to treat acid red 3R wastewater in order to investigate the influencing factors on its performance. The effects of ozone dose, initial acid red 3R concentration and activated carbon on the performance of microbubble ozonation treatment of acid red 3R wastewater are investigated. The decolorization rate, TOC removal rate, pH variation and ozone utilization efficiency in the microbubble ozonation treatment are compared under different treatment conditions. The results indicate that when increasing ozone dose or decreasing initial acid red 3R concentration, both decolorization rate and TOC removal rate of acid red 3R wastewater increase, but ozone utilization efficiency decreases. The coal-based activated carbon shows strong catalytic activity for microbubble ozonation, which could enhance the decolorization rate and TOC removal rate of acid red 3R wastewater. The better performance of microbubble ozonation treatment is achieved when the ozone dose is 48.3 mg/min and the initial acid red 3R mass concentration is 100 mg/L. Under these conditions, the decolorization efficiency reaches to 100% after treatment for 30 min, the TOC removal efficiency reaches to 78.0% after treatment for 120 min, the reaction rate constant of TOC removal is 0.015 min-1 and the ozone utilization efficiency is higher than 99%. With addition of the coal-based activated carbon of 5 g/L, the decolorization efficiency reaches to 100% after treatment for 15 min, the TOC removal efficiency reaches to 91.2% after treatment for 120 min and the reaction rate constant of TOC removal increases to 0.037 min-1.The accumulation and following degradation of intermediate products of small molecule organic acid happens during treatment process, and as a result, the solution pH decreases initially and then increases. Therefore, the optimization of influencing factors for microbubble ozonation could increase both contaminant removal rate and ozone utilization efficiency, and then improve treatment performance significantly.