• Issue 3,2019 Table of Contents
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    • >Special Column: National Young Scholar/Local Science Foundation
    • Research on location and layout of auto-body sheet metal based on NSGA-Ⅱ and RBF neural network

      2019, 40(3):189-198. DOI: 10.7535/hbkd.2019yx03001

      Abstract (1536) HTML (0) PDF 1.07 M (1601) Comment (0) Favorites

      Abstract:In order to solve the problem of low efficiency and easy clamping deformation in the location layout design of auto-body sheet metal,alocation layout design method of auto-body sheet metal based on NSGA-Ⅱ and RBF neural network is proposed.With the minimum deviation transfer path and the highest stability as constraints, the first three locating points are optimized by using NSGA-Ⅱ algorithm.With the support of finite element samples, BP and RBF neural network prediction models are constructed and compared, and the results of RBF neural network with higher prediction accuracy are selected as individual fitness values.The GA and PSO are used to optimize and compare the RBF neural network. The solution value of the PSO with faster convergence speed and higher accuracy is chosen as the optimal solution of the fourth location point.Using the seat-mounted beam as a model to verify the research content.The results show that the maximum clamping deformation under the optimized positioning layout is only 27% of the maximum clamping deformation before optimization.Therefore, RBF neural network can effectively predict clamping deformation of sheet metal.The research results have reference value for further research on auto-body welding fixture design and location layout of fuselagethin-walled parts.

    • Mesh reconstruction algorithm based on Laplace harmonic equation

      2019, 40(3):199-207. DOI: 10.7535/hbkd.2019yx03002

      Abstract (1355) HTML (0) PDF 958.34 K (1615) Comment (0) Favorites

      Abstract:Upon the problem of transforming triangular mesh into quadrilateral mesh, gradient field via harmonic equation is created, integral flow is tracked, and parameterized mesh is reconstructed. First, gradient field construction theory, data structure model and solution scheme of sparse matrix are constructed. Then, one uniform algorithm for solving flow line node by integration of local coordinate transformation and parameterized equation is advanced, and schemes like gradient convergence, shortest distance and extreme parameter are optimally occupied upon special cases of no intersection or multiple intersections when tracing flow line. Finally, the algorithm is verified via case studies. The result shows that flow lines are characterized as iso-parameterized and closed, mesh reconstruction of complicate models has no bifurcation, and mesh quality is increased with its density. The result proves that mathematical method has robustness and uniqueness for mesh reconstruction representation compared with traditional geometry method, and it will have more application scenarios.

    • >Chemistry and Chemical Industry
    • Study on quality control methods of Shaofu Zhuyu pills

      2019, 40(3):208-214. DOI: 10.7535/hbkd.2019yx03003

      Abstract (1258) HTML (0) PDF 869.26 K (1128) Comment (0) Favorites

      Abstract:In order to solve the problems in the identification of Shaofu Zhuyu pills in the current pharmacopoeia of the People's Republic of China, such as single items and inconsistent quality control standards among different dasage forms, a more comprehensive quality control method for Shaofu Zhuyu pills was established by qualitative and quantitative research on the main pharmacodynamic components in the prescription. Three medicinal herbs including Pollen typhae, Corydalis Rhizoma and Cinnamon in the prescription are identified by TLC, and the content of Paeoniflorin in Shaofu Zhuyu pills is determined by HPLC. Characteristic spots of Pollen typhae, Corydalis Rhizoma and Cinnamon are observed in the thin-layer chromatogram. The linearity of Paeoniflorin is investigated and the results show a good linear relationship in the range of 0.128~1.28 μg. The RSDs of precision, the stability test and the reproducibility are all no more than 2.0%, the average recovery if of 92.10%, and the RSD is of 1.40%(n=9). It is suggested that the content limit of Paeoniflorin should not be less than 1.20 mg/g. The established method is accurate and reliable with high feasibility and good repeatability, and can provide the basis for the total quality control of Shaofu Zhuyu pills.

    • Preparation of PEG-PCL copolymer nanoparticles with different structures and their quality evaluation

      2019, 40(3):215-225. DOI: 10.7535/hbkd.2019yx03004

      Abstract (1480) HTML (0) PDF 1.12 M (1617) Comment (0) Favorites

      Abstract:In order to compare the properties of polyethylene glycol-polycaprolactone(PEG-PCL)with different structures, the PCL-PEG-PCL and mPEG-b-PCL copolymers are obtained by ring-opening polymerization method and characterized by FT-IR, 1H-NMR and GPC. The curcumin-loaded nanoparticles of "mushroom" and "brush" are prepared via self-assembly method, and the properties of the two structural nanoparticles are studied. The results show that CUR is encapsulated into the nanoparticles with an amorphous state; the nanoparticles show a smooth surface with core-shell structures and good dispersibility. Influenced by the structure of the copolymer, the "mushroom" nanoparticles have a smaller average particle size of (105.71±3.20)nm, a higher drug loading and encapsulation efficiency. Since the surface of the PCL-PEG-PCL nanoparticles forms a dense PEG-layer, protein resistance studies show that the "mushroom" nanoparticles are good in vivo stability. "Brush" nanoparticles have a lower CMC date and better sustained release properties, and have a higher inhibitory effect on HepG-2 cancer cell proliferation. The study of drug-loaded nanoparticles can provide reference for drug delivery system selection and clinical application of nanoparticles with different structures.

    • Determination of residual solvents in synthetic intermediate of Selexipag by headspace gas chromatograhy

      2019, 40(3):226-232. DOI: 10.7535/hbkd.2019yx03005

      Abstract (1194) HTML (0) PDF 862.89 K (1056) Comment (0) Favorites

      Abstract:In order to better control the quality of Selexipag products and ensure drug safety,headspace gas chromatography is established to detect the amount of solvent remaining in the synthesis of Selexipag intermediates 4-\[(5, 6-diphenylpyrazin -2-yl) (isopropyl) amino\]-1-butanol (S5) and N-(2-chloroacetyl) methyl sulfonamide (S7). Gas chromatography is adopted with Kromat PC-624(V) capillary column (30.0 m×0.32 mm×18 μm). The FID detector temperature and injection port temperature are 250 ℃ and 200 ℃, respectively. The headspace sampling is used at temperature 80 ℃ for 30 min. The solvents revolved are methanol, ethanol, acetone, dichloromethane, isopropylacetate, tetrahydrofuran and methylbenzene. The tested component could be completely separated under the chromatographic conditions. The correlation coefficient of each solvent standard curve is greater than 0.997 and the mean recoveries of all components are in range of 95.1%~106.2%. The RSD values of precision, stability and repeatability range from 1.78% to 4.60%. The analytical method is simple, accurate and sensitive, and it can be used for the determination of residual solvents in Selexipag, which provides scientific basis for the quality control of intermediates.

    • >Mechanical, Electronics and Information Science
    • A battery model and its numerical method for the network simulator 3 (NS-3)

      2019, 40(3):233-241. DOI: 10.7535/hbkd.2019yx03006

      Abstract (1229) HTML (0) PDF 979.10 K (1103) Comment (0) Favorites

      Abstract:In order to solve the problem that the network simulator 3 (NS-3) cannot accurately simulate the battery information of the wireless sensor network (WSN) node, the LiIon battery model is used to calculate the output voltage of the available charge well (ACW) of the KiBaM battery model by combining the advantages of the LiIon battery model and the KiBaM battery model, then a KiBaM-LiIon battery model that can reflect the rate capacity effect and recovery effect of the battery, as well as the decrease of the output voltage with the decrease of remaining charge is proposed. For solving the ordinary differential equations without analytical solution in the model, an easy programming numerical solution based on the implicit Runge-Kutta method is proposed. Simulations and experiments show that the proposed model and its numerical solution can accurately predict the voltage and remaining charge at any time during battery use in NS-3, and have the advantage of low computational complexity. The proposed battery model and proposed numerical solution are not only applicable to NS-3, but also to other network simulators, which provides good technical support and guarantee for the research and development of WSN and mobile Ad-hoc networks (MANET).

    • Dynamical simulations of a bi-stable piezoelectric energy harvesting system with elastic support

      2019, 40(3):242-251. DOI: 10.7535/hbkd.2019yx03007

      Abstract (1370) HTML (0) PDF 1.11 M (1141) Comment (0) Favorites

      Abstract:The dynamic behavior of a piezoelectric cantilever energy harvesting system with bi-stable state under elastic support is studied to reveal its complex phenomena. Based on the magnetic force model which can induce bi-stable phenomena, the mathematical model of the system with two degree of freedom under harmonic base motion is firstly established by using Newton's second law and Kirchhoff′s law. By the Routh-Hurwitz criterion, the static bifurcation of equilibrium points, is secondly analyzed for the dimensionless governing equations. At last, the amplitude variations of the displacement of piezoelectric cantilever beam and the variations of the output voltage with the system parameters and excitation parameters and their bifurcation diagrams are obtained by Matlab numerical simulations. The results show that the amplitude-frequency curves of the system are in hard characteristic, while the amplitude variations of the displacement of piezoelectric cantilever beam with mass ratio and stiffness ratio are in soft characteristic. That is, within some parameters intervals, the harmonic response of the system has bifurcation and leads to chaotic motion. The motion of the system can take place near the zero or non-zero equilibrium point, even jump with large amplitude between the two non-zero equilibrium points. For the same parameters, bi-stable systems have richer forms of motion compared to mono-stable ones, and significantly increase voltage output and response frequency band of the system. The research result may provide theoretical reference for how to optimize vibration energy collector in practice.

    • Numerical simulation of convection heat transfer of supercritical carbon dioxide in horizontal straight tube

      2019, 40(3):252-258. DOI: 10.7535/hbkd.2019yx03008

      Abstract (1114) HTML (0) PDF 905.19 K (1101) Comment (0) Favorites

      Abstract:In order to enhance the heat transfer performance of CO2 heat pump, the heat transfer performance of supercritical carbon dioxide in horizontal straight tube is conducted based on Fluent numerical simulation method. Cooling heat transfer of supercritical CO2 in a horizontal tube with diameter of 4 mm and length of 2 000 mm is numerically investigated with k-ε turbulence model. The temperature field and heat transfer coefficient of supercritical carbon dioxide fluid under in-tube cooling conditions are mainly investigated. The effects of mass flow rate and inlet temperature on heat transfer performance in horizontal straight tubes are studied. The simulation results show that the heat transfer coefficient of supercritical carbon dioxide increases with the increase of mass flow, the mass flow increases by 100 kg/(m2·s2), and the average heat transfer coefficient increases by about 12%. With the increase of supercritical carbon dioxide inlet temperature, the average heat transfer coefficient becomes small, but the maximum value of the local heat transfer coefficient doesn’t change, only delaying the appearance of the maximum value of the local heat transfer coefficient. The research result may provide important theory and data support for the application of the horizontal straight tube in CO2 heat pump.

    • >Material Science
    • Effect of microcrystallization on the oxidation resistance of Fe-Cr alloy

      2019, 40(3):259-264. DOI: 10.7535/hbkd.2019yx03009

      Abstract (1029) HTML (0) PDF 1.53 M (1073) Comment (0) Favorites

      Abstract:In order to improve the high temperature oxidation resistance of Fe-Cr alloy, cast Fe-Cr alloys with different Cr contents are treated by electrospark deposition to get microcrystalline structure. The oxidation behavior of as-cast and microcrystalline Fe-Cr alloys at 900 ℃ in air is studied. Oxidation kinetics curves, phase analysis,surface and cross section morphology results show that the diffusion rate of chromium is enhanced by microcrystallized treatment when Cr content is low. Yet the content of Cr is not enough to form continuous oxide film so that the oxidation resistance of Fe-5Cr alloy is decreased. The critical Cr content to form protective oxide scale is reduced by microcrystallized treatment when Cr content increases. The oxidation resistance of microcrystalline Fe-9Cr and Fe-13Cr alloys is obviously improved. The high temperature oxidation resistance of microcrystalline Fe-13Cr alloy is the best, which is due to the formation of continuous dense protective oxide scale on the surface after microcrystallized treatment. Therefore, Microcrystallization treatment is an effective way to improve high temperature oxidation resistance of materials which can be applied in the field of high temperature oxidation.

    • Influence of welding parameters on weld forming appearance in VPPA welding of Al-Mg alloy

      2019, 40(3):265-272. DOI: 10.7535/hbkd.2019yx03010

      Abstract (1067) HTML (0) PDF 958.76 K (1113) Comment (0) Favorites

      Abstract:In order to reveal the influence of VPPAW on the weld appearance of 5A06 aluminum alloy, the weld appearance is measured and analyzed by single factor control comparison test. Four parameters including positive and negative current, plasma gas flow, positive and negative current duration and wire feed aped are tested and analyzed for their influence on the weld forming. The experiment results show that with the increase of welding current, the reinforcement and width of top weld increases first and then decreases, while the reinforcement of back weld increases dramatically, but the changes of back weld width are not obvious; as the plasma gas flow rate increases, the plasma arc force and the fluidity of weld metal both increase, the reinforcement of back weld increases obviously, while that of top weld decreases; in the case of increasing the duration of the negative current, the reinforcement and width of top weld increase slightly, and the reinforcement and width of back weld decrease; as the wire feed speed increases, the reinforcement of weld increases dramatically and the width of weld increases slightly. The research results may provide some welding process support for VPPA welding of aluminum alloys.

    • >Food Science and Biological Science
    • Study on the false positive problem caused by HRP-labeled secondary antibody in detecting heme binding protein

      2019, 40(3):273-278. DOI: 10.7535/hbkd.2019yx03011

      Abstract (1292) HTML (0) PDF 900.14 K (1140) Comment (0) Favorites

      Abstract:In order to study the false positive problem during detecting heme binding protein with horseradish peroxidase (HRP) as secondary antibody, spinach cytochrome [WTBX]b6f[WTBZ] complex (Cyt [WTBX]b6f[WTBZ]) and ferredoxin-NADP+ oxidoreductase (FNR) are used as the test material (the former contains the heme binding protein Cyt f, and the latter does not contain heme group). A comparative experiment is designed through the use of the primary antibody of spinach FNR and secondary antibodies labeled with HRP and alkaline phosphatase (ALP). The results indicate that in the HRP-labeled secondary antibody system, Cyt f could be colored even without the incubation by the primary antibody and the secondary antibody, which is a significant false positive. In the ALP-labeled secondary antibody system, the Cyt f doesn't show color, and only the FNR is colored. In western blot experiments, if the protein to be detected is a heme-binding protein or contains a small amount of heme-binding protein, HRP-labeled secondary antibodies should be avoided and ALP-labeled secondary antibodies or other secondary antibodies should be recommended. It is speculated that the heme-binding protein has an HRP-like oxidoreductase activity, namely it can react with the color developing solution, thereby generating a false positive and interfering with the judgment of the experimental results.

    • >Special Column: New Energy Resources, Energy Conservation and Environmental Protection
    • Research progress of simulation research on application

      2019, 40(3):279-284. DOI: 10.7535/hbkd.2019yx03012

      Abstract (1042) HTML (0) PDF 799.14 K (971) Comment (0) Favorites

      Abstract:In order to promote the in-depth development of simulation research of biofuel application , the development of the chemical reaction mechanism of biofuel combustion was explained, and application of Computational Fluid Dynamics Model in Combustion Simulation of Internal Combustion Engines were also explored. The technical idea of biofuel combustion mechanism construction and simplification was analyzed.The research progress of biofuel combustion simulation based on CFD combustion model was explored.By calling the biofuel combustion mechanism,Study on the combustion process and emission generation law of internal combustion engine was effective.The review showed that the chemical kinetics of biofuel combustion can be generated by the coupling and simplification of a typical single component combustion mechanism.By calling this synthesis mechanism,the combustion process analysis and emission generation analysis of biofuel.can be realized.Research showed that simulation research was an important technical approach to achieve biofuel application research.

Editor in chief:朱立光


International standard number:ISSN 1008-1542

Unified domestic issue:CN 13-1225/TS

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