• Volume 35,Issue 6,2014 Table of Contents
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    • >Special Column: National Young Scholar/Local Science Foundation
    • Bionic microstructure surface building and stress field analysis of brake disc

      2014, 35(6):497-503. DOI: 10.7535/hbkd.2014yx06001

      Abstract (1975) HTML (0) PDF 5.59 M (3163) Comment (0) Favorites

      Abstract:The uneven brake disk friction leads to the generation of brake failure, which results in serious traffic accidents frequently. Based on the excellent wear-resisting properties deriving from locust's non-smooth surface structure, different bionic models of the brake disc with microstructure surface were established with three-dimensional mapping software SolidWorks. Based on ANSYS Workbench, we analyzed the braking time and the stress distribution between discs possessing distinct microstructure surface and friction plate during friction braking under different initial velocity. The results presented that the variation of the bionic brake disc surface structure performs effect on braking performance and wear resistance. Brake disc with straight groove surface exhibits relatively good braking performance and wear resistance. The result provides a theoretical basis for seeking an optimization design method which is used to find a bionic brake disc surface with good braking performance and wear resistance.

    • Data-driven rapid modeling of manufacturing system

      2014, 35(6):504-511. DOI: 10.7535/hbkd.2014yx06002

      Abstract (2196) HTML (0) PDF 5.59 M (2806) Comment (0) Favorites

      Abstract:Modeling has become the bottleneck of simulation for complex mechanical system. It is extremely needed to be improved for integrated manufacturing system (IMS) which is currently being implemented widely. Aiming at such problem, three levels of technologies such as data model, controlling model and automatic model are discussed in detail according to the concept of data-driven: 1) using public data zone (PDZ) uniform data structure and data-driven mechanism are put forward; 2) workshop, cell and machine are partitioned to form a three level hierarchical control framework, and their model controllers as well as control rules are explained respectively; 3) data saving and extracting interface, and auto-model generator on the basis of PDZ are developed, so that data-driven auto-model generation is realized. The model is finally realized in eM-Plant simulation platform through secondary development. Multi-type products of a military industry are used for case study. The result shows high efficiency, adaptability and applicable value of this model.

    • Simulation investigations on nonlinear interaction of ocean internal waves via the cylindrical Kadomtsev-Petviashvili model

      2014, 35(6):512-517. DOI: 10.7535/hbkd.2014yx06003

      Abstract (1498) HTML (0) PDF 3.95 M (2920) Comment (0) Favorites

      Abstract:In view of the two-dimensional effects of ocean internal waves, the two-dimensional model containing transverse perturbation can well simulate the propagation character of ocean internal waves. In this paper, the cylindrical Kadomtsev-Petviashvili model has been used to depict the propagation character of nonlinear interaction of ocean internal waves. By making use of the analytical method, the biparabolic solitary solution of this 2-dimensional equation is derived. The elastic collision and the time-varying propogation character of ocean internal waves of Dongsha Islands of the South China Sea are studied and simulated .The simulation results are consistent with that of remote sensing satellites images, and then can be provided as a reference for further research on nonlinear interaction and polar transformation of ocean internal waves.

    • >Mathematics
    • Existence of solutions for fractional differential equation boundary value problems at resonance

      2014, 35(6):518-523. DOI: 10.7535/hbkd.2014yx06004

      Abstract (1824) HTML (0) PDF 3.18 M (1889) Comment (0) Favorites

      Abstract:By defining appropriate Banach space and norm, giving the appropriate projectors , using the coincidence degree theory due to Mawhin and the properties of fractional derivative and integral, the existence of solutions for fractional (n-1,1) conjugate boundary value problems with the Riemann-Stieltjes integral boundary condition at resnonce is investigagted, where the nonlinear term contains fractional-order derivative and may be noncontinuous .An example is given to illustrate the main results.

    • Existence of positive solutions for boundary value problem of third-order differential equations of with p-Laplacian

      2014, 35(6):524-528. DOI: 10.7535/hbkd.2014yx05001

      Abstract (1790) HTML (0) PDF 2.80 M (2280) Comment (0) Favorites

      Abstract:Many researches on the fields of different applied mathematics and physics can be attributed to the boundary value problem with p-Laplacian.So the research on this issue has important theoretical significance and application value.In this paper,we consider the existence of triple positive solutions for third-order differential equation boundary value problems with p-Laplacian (φp(u′))″(t)+a(t)f(t,u(t),u′(t))=0,〓0p(u′)(1)=αφp(u′)(η),(φp(u′))′(0)=0 where φp(s)=|s|p-2s,p>1.By using Avery-peterson's fixed point theorem,under f satisfies cevtain growth conditions,we study the existence of at least three positive solutions for the above boundary value problem.

    • Hermitian least squares solutions of constrained A2XA*2 = C2

      2014, 35(6):529-537. DOI: 10.7535/hbkd.2014yx06007

      Abstract (1629) HTML (0) PDF 4.00 M (1234) Comment (0) Favorites

      Abstract:Through study of the Hermitian least squates solutions of A2XA*2 = C2, under the limits of min x=x* ‖ A1XB1-C1 ‖.By applying the rank and index of inertia of matrix function,we derive the equivalent condition about Hermitian least squares solution of A2XA*2 = C2, and the solution of matrix inequality A*2A2XA*2A2>(<,≥,≤)A*2C2A2 ,In particular case,we study the existence problem about the (half) positive(negative) definite's Hermitian least squares solution of A1XB1 = C1.

    • Functions preserving involutory matrix over fields

      2014, 35(6):538-542. DOI: 10.7535/hbkd.2014yx06011

      Abstract (2179) HTML (0) PDF 2.29 M (1940) Comment (0) Favorites

      Abstract:Being inspired by some functions which preserve certain propties of matries,this paper studies the preserving problem of functions in matrix space over a field with the characteristic not being 2. By using the knowledge of linear algebra, starting from the way of searching new invariants and finding special involutory matrices, we depict the functions preserving involutory matrices on the upper triangular matrix space and the matrix space over a field with the characteristic not being 2.

    • >Chemistry, Chemical Industry and Biological Engineering
    • Preparation of Zn/ZnO electrode and its application in flexible hybrid solar cells

      2014, 35(6):543-547. DOI: 10.7535/hbkd.2014yx06012

      Abstract (1908) HTML (0) PDF 3.53 M (2439) Comment (0) Favorites

      Abstract:Uniform ZnO nanowires arrays are grown directly from and on Zn foils under hydrothermal conditions at a relatively low temperature. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis showed that the prepared ZnO grown perpendicular to the substrate, and the X-ray diffraction (XRD) confirmed this structure. Zn/ZnO/P3HT hybrid electrode was obtained by coating poly 3-hexylthiophene (P3HT) on Zn/ZnO film, and the ultraviolet visible absorption spectra (UV-vis) indicated the broadened light response range for the presence of P3HT. It was found from the photoluminescence (PL) spectra of Zn/P3HT and Zn/ZnO/P3HT electrodes that the PL emission intensity decreased for the latter one, indicating the excitons dissociate at the ZnO/P3HT heterojunction interface before charge recombination. Based on the prepared electrode, flexible hybrid solar cell with the structure of Zn/ZnO/P3HT/PEDOT:PSS/ITO was assembled and the photovoltaic performance was measured under simulated sunlight (100 mW/cm2). The cell gave open-circuit voltage (Voc) of 334 mV, short-circuit current (Jsc) of 1.72 mA/cm2, fill factor (FF) of 0.39, and the photoelectric conversion efficiency (η) is 0.22%.

    • Synthesis and characterization of carboxymethyl Cassia tora gum

      2014, 35(6):548-554. DOI: 10.7535/hbkd.2014yx06018

      Abstract (1834) HTML (0) PDF 4.36 M (1858) Comment (0) Favorites

      Abstract:Carboxymethyl (CM)-Cassia tora gum (CTG) with high degree of substitution (DS) was prepared with CTG as raw material, monochloroacetic acid (MCA) as carboxymethyl ether agent, isopropanol as dispersant. The variables studied were the dosage of reactants, the ratio of solid to liquid, alkalization time and temperature, etherification time and temperature, to find the influence on the DS. The results show that when the n(MCA)/n(CTG) is 1.6∶1, the ratio of solid to liquid is 1∶2.5, alkalization temperature is 40 ℃, the alkalization time is 60 min, the etherification temperature is 53 ℃ and the time is 3.0 h, the DS of CM-CTG is 0.64 and the reaction efficient is 79.5%. Compared with the original powder, the CM-CTG solution stability was longer, little change in viscosity within 6 days. The structure and thermal properties were analyzed by FTIR, 13C-NMR and TGA.

    • Partition behaviors of main ingredients in Rhodiola Tibetica in solvent extraction systems

      2014, 35(6):555-560. DOI: 10.7535/hbkd.2014yx06013

      Abstract (1708) HTML (0) PDF 4.06 M (2067) Comment (0) Favorites

      Abstract:Salidroside and p-tyrosol are the main active ingredients. Their partition behaviors are not clear in different solvent extraction systems. Separation of salidroside and p-tyrosol from Rhodiola Tibetica extract was investigated in different solvent extraction systems. Effect of extraction conditions such as pretreatment, pH and extractants on partition behaviors was also studied. Results showed that pretreatment of tannins removal from the extract can avoid emulsification during solvent extraction. For liquid-liquid solvent extraction, mass fraction of salidroside and p-tyrosol in tributyl phosphate (TBP) phase can reach 60% and 98%, respectively when pH is below 9.0. Purified salidroside solution can be obtained in the lower aqueous phase. For the three-liquid-phase system composed of TBP, PEG2000 and ammonium sulphate, salidroside is mainly partitioned into the middle phase and the top phase, 70% of salidroside in the middle phase. p-tyrosol is mainly partitioned into the top phase, above 65%, but its mass fraction in the bottom phase is below 5% .

    • Biodiversity of yeast in natural fermented dairy and the traditional Kefir grain

      2014, 35(6):561-568. DOI: 10.7535/hbkd.2014yx06019

      Abstract (1787) HTML (0) PDF 5.07 M (2053) Comment (0) Favorites

      Abstract:Biodiversity of yeast in natural fermented dairy and traditional kefir grain from Inner Mongolia was investigated. The purpose was to explore the main microflora and yeast species, laying the foundation for selecting yeast which can ferment low alcohol degree dairy. Yeast strains were isolated by gradient diluting and streaking plates, and then classified preliminarily according to colony morphology and cell morphology, followed by 5.8S rDNA-ITS restriction fragment length polymorphism (RFLP) analysis, 130 selected yeast strains were divided into 10 phenotypes and 6 molecular types. The species identified by 5.8S ITS-RFLP corresponded to Kluyveromyces marxianus, Cryptococcus sp., Saccharomyces cerevisiae, Candida tropicalis, Issatchenkia terricola and Pichia guilliermondii. Among them, K. marxianus, S. cerevisiae and P. guilliermondii were the dominant species, which had the potential for fermenting low alcohol degree dairy.

    • >Automation Technology
    • The modeling and simulation of a multi-electrode electromagnetic blood flow meter

      2014, 35(6):569-576. DOI: 10.7535/hbkd.2014yx06015

      Abstract (1856) HTML (0) PDF 5.43 M (2170) Comment (0) Favorites

      Abstract:Based on the theory of weight function of the electromagnetic flow meters, the multi-electrode electromagnetic measurement method is applied to the limb arteriovenous blood flow velocity measurement. Through dividing the flow cross-sections into different areas, using the weight function theory to reconstruct the average axial velocities of different areas along the flow section, the measurement of velocity information for the mutual-reverse flowing within arteriovenous and intravenous veins can be realized. Based on this, by deriving different chord terminal voltages and adopting the regional weighting functions' computation methods, the weighting functions of different positions on the flowing cross-section can be determined, and then the local axial average velocities of different areas of flowing cross-section can be calculated. The three-dimensional finite element model of simulation and calculation results show that the positions and number of the electrodes, different classifying methods have different reconstruction results, realizing the velocity reconstruction and measuring the local velocity distribution.

    • A non-uniform dynamic subband division adaptive modulation algorithm of OFDM

      2014, 35(6):577-582. DOI: 10.7535/hbkd.2014yx06016

      Abstract (1850) HTML (0) PDF 4.01 M (2071) Comment (0) Favorites

      Abstract:In view of the system BER with fixed subband division algorithm is higher, the uniform dynamic subband division algorithm requires multiple iterations and high algorithm complexity, A non-uniform dynamic subband division adaptive modulation algorithm of OFDM is proposed. The algorithm according to the channel frequency response relationship can complete subband dynamic division without iterations. The random selection scheme was defined subband equivalent SNR. The bit adjustment method selected the priority way used the subband with maximum equivalent SNR. The proposed algorithm can reduce iteration number of bit adjustment, thus the complexity is low. The simulation results show that the algorithm compared SBLA algorithm and 4QAM modulation mode can obtain 2 dB, 2.6 dB SNR gain in BER 10-3.

    • Anti-swing control for 3D crane based on variable gain LQR method

      2014, 35(6):583-589. DOI: 10.7535/hbkd.2014yx06014

      Abstract (1786) HTML (0) PDF 4.33 M (2017) Comment (0) Favorites

      Abstract:The dynamic model of three dimension (3D) crane system is built. Then the linear time-varying system is obtained by using the method of separating variables, and the controllability is discussed. As to the anti-swing control problem for the 3D crane under the condition of variable length of the rope, the variable gain LQR controller is designed, and the good control performance is obtained. The comparative simulation results demonstrate that the variable gain LQR controller has higher adaptability and stability, and the effectiveness is improved obviously.

    • Numerical simulation study on blowing of semi-steel dephosphorization in ladle

      2014, 35(6):590-596. DOI: 10.7535/hbkd.2014yx06017

      Abstract (2107) HTML (0) PDF 4.82 M (1951) Comment (0) Favorites

      Abstract:In order to study the stirring effect of combined blowing on liquid steel of the 100 t ladle in Chengde steel. The results show that, liquid steel velocity, turbulent kinetic energy, impact area increase with the side flow rate rises, the dead pool decreased gradually, the stirring ability of gas on the weld pool increases. Increase the side air-blowing quantity has effect on the stirring of ladle slag layer, and it promotes the dephosphorization ability of molten steel.

Editor in chief:朱立光


International standard number:ISSN 1008-1542

Unified domestic issue:CN 13-1225/TS

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