• Volume 37,Issue 5,2016 Table of Contents
    Select All
    Display Type: |
    • >Special Column: National Young Scholar/Local Science Foundation
    • Research on static angular stiffness measurement of flexible joint

      2016, 37(5):423-430. DOI: 10.7535/hbkd.2016yx05001

      Abstract (2005) HTML (0) PDF 1.26 M (2266) Comment (0) Favorites

      Abstract:Measurement accuracy of the angular stiffness of flexible joint is directly related to the control accuracy and sensitivity of gyro, but the traditional measurement methods have many problems. According to the principle of angular stiffness measurement of flexible joint, two static measurement methods of angular stiffness are proposed based on different loading ways, namely mechanical loading angular stiffness measurement and piezoelectric loading angular stiffness measurement. The mechanical loading angular stiffness measurement system is built by using a motor driven indexing feeding tilting table, the measure experiment if the angular stiffness of flexible joint is conducted, and the angular stiffness of flexible joint is measured. For the excessive fluctuation problem of the measure result in mechanical load test, a piezoelectric loading structure is designed and a measurement method employing piezoelectric actuator is proposed for angular stiffness measurement of flexible joint. Based on ANSYS Workbench, the displacement output of the piezoelectric loading structure is analyzed by simulations. The simulation results illustrate that the displacement output meets the requirement of static loading angular stiffness measurement of flexible joint, and the theoretical feasibility of piezoelectric loading angular stiffness measurement method is validated.

    • Research status in ultra-precision machining of silicon carbide parts by oxidation-assisted polishing

      2016, 37(5):431-440. DOI: 10.7535/hbkd.2016yx05002

      Abstract (1988) HTML (0) PDF 2.83 M (2941) Comment (0) Favorites

      Abstract:Oxidation-assisted polishing is an important machining method for obtaining SiC parts with high precision. Through plasma oxidation, thermal oxidation, and anodic oxidation, soft oxide can be obtained on the RS-SiC substrate. With the assistance of abrasive polishing to remove the oxide rapidly, the material removal rate can be increased and the surface quality can be improved. The research results indicate that the surface roughness root-mean-square (RMS) and roughness-average (Ra) can reach 0.626 nm and 0.480 nm by plasma oxidation-assisted polishing; in thermal oxidation-assisted polishing, the RMS and Ra can be 0.920 nm and 0.726 nm; in anodic oxidation, the calculated oxidation rate is 5.3 nm/s based on Deal-Grove model, and the RMS and Ra are 4.428 nm and 3.453 nm respectively in anodic oxidation-assisted polishing. The oxidation-assisted polishing can be propitious to improve the process level in machining RS-SiC, which would promote the application of SiC parts in optics and ceramics fields.

    • Magnetic suspension motorized spindle-cutting system dynamics analysis and vibration control review

      2016, 37(5):441-448. DOI: 10.7535/hbkd.2016yx05003

      Abstract (1926) HTML (0) PDF 1.40 M (3389) Comment (0) Favorites

      Abstract:The performance of high-speed spindle directly determines the development of high-end machine tools. The cutting system's dynamic characteristics and vibration control effect are inseparable with the performance of the spindle,which influence each other, synergistic effect together the cutting efficiency, the surface quality of the workpiece and tool life in machining process. So, the review status on magnetic suspension motorized spindle, magnetic suspension bearing-flexible rotor system dynamics modeling theory and status of active control technology of flexible magnetic suspension motorized spindle rotor vibration are studied, and the problems which present in the magnetic suspension flexible motorized spindle rotor systems are refined, and the development trend of magnetic levitation motorized spindle and the application prospect is forecasted.

    • Technology of magnetic abrasive finishing in machining of difficult-to-machine alloy complex surface

      2016, 37(5):449-456. DOI: 10.7535/hbkd.2016yx05004

      Abstract (2012) HTML (0) PDF 2.17 M (3155) Comment (0) Favorites

      Abstract:The technology of magnetic abrasive finishing is one of the important finishing technologies. Combining with low-frequency vibration and ultrasonic vibration, it can attain higher precision, quality and efficiency. The characteristics and the related current research of magnetic abrasive finishing, vibration assisted magnetic abrasive finishing and ultrasonic assisted magnetic abrasive finishing are introduced. According to the characteristics of the difficult-to-machine alloy's complex surface, the important problems for further study are presented to realize the finishing of complex surface with the technology of magnetic abrasive finishing, such as increasing the machining efficiency by enhancing the magnetic flux density of machining gap and compounding of magnetic energy and others, establishing of the control function during machining and the process planning method for magnetic abrasive finishing of complex surface under the space geometry restraint of complex surface on magnetic pole, etc.

    • Research status of hybrid electric vehicle energy management strategy based on the driving cycle

      2016, 37(5):457-463. DOI: 10.7535/hbkd.2016yx05005

      Abstract (1729) HTML (0) PDF 1.07 M (3081) Comment (0) Favorites

      Abstract:The paper analyzes the advantages and disadvantages of two different energy management strategies which are the management strategy based on the dynamic system running state and the management strategy based on the driving cycle. The paper focuses on the study of the strategy based on the driving cycle, and points out that though the operation process of the global optimization strategy based on the driving cycle takes long and large amount of calculation so that it can hardly be used in the real vehicle. The strategy can be taken as the reference for the ideal optimization control target. In order to achieve the real-time optimal control, there are mainly the method based on the driving cycle of recognition control strategy and the method based on model predictive control, etc. It makes the exploration to predict the real-time optimal control strategy based on the driving cycle become real, and the effects of the control results get close to the offline global optimization. The proposed strategy is a new research hotspot and research trend of energy management strategy.

    • >Chemistry and Chemical Industry
    • Visible-light photocatalytic performances of TiO2 nanoparticles modified by trace derivatives of PVA

      2016, 37(5):464-470. DOI: 10.7535/hbkd.2016yx05006

      Abstract (1933) HTML (0) PDF 1.17 M (2384) Comment (0) Favorites

      Abstract:In order to study the visible-light photocatalytic activity and catalysis stability of nanocomposites, a TiO2-based visible-light photocatalyst is prepared by surface-modification of TiO2 nanoparticles using trace conjugated derivatives from polyvinyl alcohol (DPVA) via a facile method. The obtained DPVA/TiO2 nanocomposites are characterized by X-ray diffraction (XRD), Fourier transform infrared Spectra (FT-IR), scanning electron microscopy (SEM), UV-vis diffuse reflection spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). With Rhodamine B (RhB) as a model pollutant, the visible-light photocatalytic activity and stability of DPVA/TiO2 nanocomposites are investigated by evaluating the RhB decomposition under visible light irradiation. The results reveal that the trace conjugated polymers on the TiO2 surface doesn’t change the crystalline and crystal size of TiO2 nanoparticles, but significantly enhances their visible-light absorbance and visible-light photocatalytic activity. The nanocomposite with the PVA and TiO2 mass ratio of 1∶200 exhibits the highest visible-light photocatalytic activity. The investigated nanocomposites exhibit well visible-light photoctatalytic stability. The photogenerated holes are thought as the main active species for the RhB photodegradation in the presence of the DPVA/TiO2 nanocomposites.

    • Study on the turn structure of polypeptides containing glycine and L-proline

      2016, 37(5):471-476. DOI: 10.7535/hbkd.2016yx05007

      Abstract (2468) HTML (0) PDF 882.70 K (2300) Comment (0) Favorites

      Abstract:The formation of turn structure in peptide chains has direct relations with intramolecular hydrogen bonds, therefore the existence of this bond can be tested to research the turn structure. Herein, two tripeptides and three tetrapeptides are synthesized by using glycine and L-proline as raw materials, t-butoxycarbonyl and aniline as capping groups, and HBTU and HATU as condensation reagents. 1H NMR, IR and MS are adopted to characterize the structure of the products. Constant-gradient and variable-temperature 1H NMR spectra test is used to detect the intramolecular hydrogen bond of the synthesized polypeptides, and 1H-1H NOE is used for the speculation of the carbonyl group location of intramolecular hydrogen bond. The test illustrates that intramolecular hydrogen bond is found in three out of the five synthesized polypeptides, and it is not found in the other two. The polypeptides with intramolecular hydrogen bond formed all have the "-Gly-L-Pro-Gly-" segment, while the polypeptides with only "-L-Pro-Gly-" segment or "-Gly-L-Pro-" segment do not have intramolecular hydrogen bond formed. The carbonyl group forming of intramolecular hydrogen bond is attached to the amino group of the capping aniline, and amino group involved in hydrogen bond formation is linked to t-butoxycarbonyl.

    • New research progress of vegetable oil-based polyurethanes

      2016, 37(5):477-484. DOI: 10.7535/hbkd.2016yx05008

      Abstract (2135) HTML (0) PDF 1.17 M (2770) Comment (0) Favorites

      Abstract:This paper summarizes the latest progress for vegetable oil-based polyurethanes mainly from the view of thermoset and thermoplastic. Firstly, the modification methods for traditional thermoset polyurethane are introduced, including physical modification methods (filling and alloying) and chemical modification methods (copolymerization grafting, crosslinking and interpenetrating polymer network). Materials used for physical modification mainly contain inorganic materials such as SiO2 and organic substances such as cellulose. Grafting copolymerization of styrene, acrylate and other monomers with polyurethane is the main method of chemical modification. The characteristics, preparations and application fields of thermoplastic polyurethane are reviewed, and the preparations, performances and applications of oleic acid-based thermoplastic polyurethane are chiefly presented. The development prospects of vegetable oil-based polyurethane are put forward. Surface-initiated living polymerization and other methods are used to controllable chemical modification of the traditional thermoset polyurethane and click chemistry method is uesd to promote multi-functionalization of the thermoplastic polyurethane.

    • >Mechanical, Electronics and Information Science
    • Detection and recognition of bridge crack based on convolutional neural network

      2016, 37(5):485-490. DOI: 10.7535/hbkd.2016yx05009

      Abstract (3046) HTML (0) PDF 1.10 M (2900) Comment (0) Favorites

      Abstract:Aiming at the backward artificial visual detection status of bridge crack in China, which has a great danger coefficient, a digital and intelligent detection method of improving the diagnostic efficiency and reducing the risk coefficient is studied. Combing with machine vision and convolutional neural network technology, Raspberry Pi is used to acquire and pre-process image, and the crack image is analyzed; the processing algorithm which has the best effect in detecting and recognizing is selected; the convolutional neural network(CNN) for crack classification is optimized; finally, a new intelligent crack detection method is put forward. The experimental result shows that the system can find all cracks beyond the maximum limit, and effectively identify the type of fracture, and the recognition rate is above 90%. The study provides reference data for engineering detection.

    • Study of the aircraft conflict resolution method based on modified particle swarm optimization

      2016, 37(5):491-496. DOI: 10.7535/hbkd.2016yx05010

      Abstract (2302) HTML (0) PDF 878.84 K (2271) Comment (0) Favorites

      Abstract:Conflict resolution requires the aircraft to adopt an effective method to meet the constraints of the working space. Aiming at the problem of conflict resolution in multi obstacle environment, a novelty algorithm based on particle swarm optimization (PSO) is proposed for conflict resolution which meets the mentioned constrains. The proposed DARPSO is similar to PSO with two modifications: firstly, it takes into account the obstacle avoidance; secondly, it has a mechanism to escape from local optima. Various experimental results obtained in simulations show that the proposed DARPSO is much more superior than PSO. The DARPSO is applied to the process of conflict resolution of aircrafts, and it is simulated. The simulation results show that the proposed algorithm can avoid the obstacles and complete conflict resolution effectively.

    • Study of Chinese Super League schedule optimization based on simulated annealing algorithm

      2016, 37(5):497-502. DOI: 10.7535/hbkd.2016yx05011

      Abstract (2020) HTML (0) PDF 1.02 M (2348) Comment (0) Favorites

      Abstract:To optimizethe scheduleof Chinese Super League by establishing the mathematical model can not onlypromotefairness, obtain the humanization designation, but also achieve the aim of savingmileages, resources and protecting environment effectively.Assuming the distance between any two cities was the Baidu map of direct distance, promoting fairness and humanization as well as pursuing the shortest mileage. Wholetraveling distance of 2015 Chinese Super League schedule was optimized based on the improved simulated annealing algorithm and the model was established by Matlab. The results indicated that the whole traveling distance of optimized tournament is 5.022×105 km, which reduced 12.08% compared with that of actual schedule of 2015 Chinese Super League. Furthermore, 14.5 tons of fuel can be saved, 43.9 kg of sulfur dioxide emissions can be reduced, SO2 contribution can be reduced to 11.11% and 91 467.4 yuan can be saved in the optimized designation.

    • >Food Science and Biological Science
    • Effect of Bacillus subtilis microecological probiotics on livestock breeding

      2016, 37(5):503-508. DOI: 10.7535/hbkd.2016yx05012

      Abstract (1982) HTML (0) PDF 1.03 M (2483) Comment (0) Favorites

      Abstract:As a kind of green and healthy microecologics, Bacillus subtilis could balance the intestinal flora, promote the nutrient absorption and enhance immunity. Microecologics is one of the ideal antibiotics alternative, which are effective in preventing and treating animal disease and promoting the growth and development of the animal. Because of its advantages, such as no toxin side effect and no residual or drug-resistant, microecologics has been used in livestock breeding widely. Here, we concluded the characteristics and mechanism of Bacillus subtilis,elaborated application of microecologics on livestock breeding, discussed its problems and suggested its solved methods. In the end, the future of microecologics was expected in order to provide a reference for subsequent livestock breeding.

    • >Textile Science
    • Research on feature extraction and classification of AE signals of fibers' tensile failure based on HHT and SVM

      2016, 37(5):509-515. DOI: 10.7535/hbkd.2016yx05013

      Abstract (1686) HTML (0) PDF 1.06 M (2278) Comment (0) Favorites

      Abstract:In order to study the feature extraction and recognition method of fibers' tensile failure, AE technology is used to collect AE signals of fiber bundle's tensile fracture of two kinds of fibers of Aramid 1313 and viscose. A transform called wavelet is used to deal with the signals to reduce noise. A method called Hilbert-Huang transform (HHT) is used to extract characteristic frequencies of the signals after the noise is reduced. And a classification method called Least Squares support vector machines (LSSVM) is used for the classification and recognition of characteristic frequencies of the two kinds of fibers. The results show that wavelet de-noise method can reduce some noise of the signals. Hilbert spectrum can reflect fracture circumstances of the two kinds of fibers in the time dimension to some extent. Characteristic frequencies' extraction can be done from marginal spectrum. The LSSVM can be used for the classification and recognition of characteristic frequencies. The recognition rates of Aramid 1313 and viscose reach 40%, 80% respectively, and the total recognition rate reaches 60%.

    • Research on tensile fracture process of polyester woven fabric based on AE technique and HHT

      2016, 37(5):516-521. DOI: 10.7535/hbkd.2016yx05014

      Abstract (1957) HTML (0) PDF 1.09 M (1959) Comment (0) Favorites

      Abstract:In order to obtain and study time-frequency characteristics of fabric tensile failure modes, four kinds of fabrics is woven with changing different fabric organizational structures and weft densities, dynamic audio signals for different fabrics in tensile failure process is collected with the aid of self-built acoustic emission detection system on the conventional fabric tensile tester, and the collected signal is analyzed and processed by using Matlab software to run a program compiled based on Hilbert Huang transform. The results show that AE signal curve is completely corresponding to tensile load-displacement curve in fabric tensile process, and characterizations of three failure modes about structure change, yarn deformation, and yarn fracture can be clearly distinguished. The characteristic frequency of four kinds of fabrics in structure change stage is the same as 100 Hz, which can be derived from the same source (orthogonal friction of yarns), and has nothing to do with the fabric organizational structure or density. The structure change stage has something to do with yarn strength utilization in such aspects as the AE signals characteristics of duration, amplitude, energy, and so on.

    • >Civil and Architectural Engineering
    • Formula study for plate heat exchanger in the central heating regulation of the indirect connection hot water heating system

      2016, 37(5):522-526. DOI: 10.7535/hbkd.2016yx05015

      Abstract (1773) HTML (0) PDF 529.92 K (2080) Comment (0) Favorites

      Abstract:Plate heat exchanger has unique advantages and becomes dominant heat exchange equipment in heating engineering, but there is no heating regulation formula of plate exchanger applied in central heating regulation of indirect connection hot water heating. This paper analyzes the condition that the heating user's system adopts quality regulation method and the hot water network system adopts quality-flow regulation method, and obtains the regulation formulas of plate exchanger applied in central heating regulation of indirect connection hot water heating used for the above two systems. Empirical calculation shows that the formula can be applied to the quality regulation and the mass flow regulation of the different flow optimization adjustment coefficient, and it is an all-round formula.

Editor in chief:朱立光

Inauguration:

International standard number:ISSN 1008-1542

Unified domestic issue:CN 13-1225/TS

Domestic postal code:

  • Most Read
  • Most Cited
  • Most Downloaded
Press search
Search term
From To