• Volume 45,Issue 5,2024 Table of Contents
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    • >Mechanical, Electronics and Information Science
    • Fine modeling of flyback converter based on fractional order

      2024, 45(5):461-470. DOI: 10.7535/hbkd.2024yx05001

      Abstract (159) HTML (0) PDF 2.28 M (260) Comment (0) Favorites

      Abstract:Aiming at the problem that the traditional modeling methods cannot describe the real characteristics of flyback converters more accurately, the average state model of the fractional-order flyback converter operating in the intermittent inductance current mode was established by using fractional-order calculus and state space average method. The DC equilibrium point and small signal transfer function were obtained, and the difference between the model and the integer order mathematical model was compared. The state space model and circuit simulation model of fractional-order flyback converter were built in Simulink, and the experimental circuit of fractional-order flyback converter was constructed. The state space model, circuit model simulation and experimental results were compared to prove the correctness of the fractional-order model. The results show that the fractional order mathematical model can reflect the change of the order of inductance and capacitance, and the theoretical analysis is better consistent with the actual operation of the converter. A more accurate mathematical model of flyback converter can be established by combining fractional calculus theory with state space average method, which provides a reference for the modeling of other converters.

    • AC loss calculation in self-field of NI-HTS coil carrying different transport currents

      2024, 45(5):471-478. DOI: 10.7535/hbkd.2024yx05002

      Abstract (91) HTML (0) PDF 3.21 M (300) Comment (0) Favorites

      Abstract:To solve the problems of the AC loss in self-field for no-insulation (NI) HTS coils carrying different currents, such as AC transport current, the current scanning inverse in order to decrease the screening current, and so on, by using the T-A homogenization model based on the E-J power law, the effects of the transport current, frequency, and the n-value on the magnetic flux density and AC loss of NI-HTS pancack coils were simulated. The instantaneous AC losses of square wave, sawtooth wave, and sinusoidal wave for double-pancake coil were simulated quantitatively. The effects of charging and discharging ramping rates on the current distribution were also discussed by using partial element equivalent circuit (PEEC). The results show that the AC losses increase with the increase of frequency from several hundred to kilo Hz. Due to the transfer of the radial current within coil’s turns, some inverse azimuthal currents may appear in the NI-HTS coil in the early charging period, and some of the azimuthal currents may increase during short discharging period for the same reason. The simulation work can provide some theoretical references for the studies of the stability and AC loss for NI-HTS pancake coils.

    • >Chemistry and Chemical Industry
    • Anti-diabetic effect and mechanism of compound A34 in diabetic mice

      2024, 45(5):479-486. DOI: 10.7535/hbkd.2024yx05003

      Abstract (921) HTML (0) PDF 2.69 M (392) Comment (0) Favorites

      Abstract:In order to detemine the anti-diabetic effect and potential mechanism of a novel soluble epoxide hydrolas inhibitor (A34) on diabetic mice. Type 1 diabetes mellitus (T1DM) mice were induced by streptozotocin (50 mg/(kg·d) for 5 days, ip.)and the hypoglycemic effect of A34 were evaluated by water and food intake, non-fasting and fasting blood glucose, glucose tolerance and plasma insulin level in diabetic mice after water administration.The underlying mechanism was explored via measuring the expression level of sEH in islets, the morphological change of islets and the concerntration of cytokines INF-γ and IL-4 in plasma. Compared with diabetic model group, the water and food intake(p<0.01, p<0.05), blood glucose (p<0.01), glucose tolerance (p<0.01) and plasma insulin level (p<0.05 ) were improved in A34 group. Additionally, A34 could protect pancreatic islet morphology, suppress sEH expression in islet (p<0.01), reduce the ratio of INF-γ to IL-4 in plasma(p<0.05 ). These results showed that A34 prevents hyperglycemia and β-cell dysfunction through regulating the dynamic balance of pro-inflammatory and anti-inflammatory cytokines in diabetic mice.

    • Photocatalytic properties of Ag/h-BNNS/CPAN composite fiber membranes

      2024, 45(5):487-496. DOI: 10.7535/hbkd.2024yx05004

      Abstract (473) HTML (0) PDF 4.14 M (231) Comment (0) Favorites

      Abstract:In order to make better use of solar energy to convert carbon dioxide into value-added products, we synthesized hexagonal boron nitride (h-BNNS) with a specific surface area of 1 009.5 m2/g by boiling method. Then h-BNNS/CPAN fiber film was prepared by electrospinning method with h-BNNS and polyacrylonitrile (PAN) as the raw materials, and then Ag/h-BNNS/CPAN composite film was prepared by vacuum impregnation of silver salt. The morphology, elemental composition, microstructure and photoelectricity characteristics of the composite film were characterized.The results showed that the structure of h-BNNS was not changed after the introduction of Ag NPS, and it was uniformly distributed on the h-BNNS/CPAN composite fiber membrane.The effect of synthesis conditions on the properties of the composite was determined by the reduction of p-nitrophenol (4-NP) to p-hydroxyaniline (4-AP). It was found that the photocatalytic effect of Ag nanoparticles (Ag NPs) was the best when the calcination temperature was 220 ℃ and the content of h-BNNS was 25%. The apparent rate of photoreduction of 4-NP with the catalyst is 0.326 s-1.The photocatalytic reduction performance of Ag/h-BNNS/CPAN composite film was further investigated using CO2 reduction model reaction. The results showed that the photocatalytic activity of Ag/h-BNNS/CPAN composite film was directly proportional to the content of Ag NPs. When the Ag NPs content was 2.0%, the photocatalytic activity of Ag/h-BNNS/CPAN composite film was directly proportional to that of Ag NPs. The yield of CO2 to CO was 181.4 μmol/g after photocatalysis for 2 h.Combined with the photoelectric characteristics of Ag/h-BNNS/CPAN composite fiber film to analyze its photocatalytic performance, the mechanism of photocatalytic CO2 reduction reaction of the composite membrane can be explored, indicating that the synergistic interaction between Ag NPs and h-BNNS/CPAN composite fiber film in the photocatalytic reaction process can achieve high CO2 conversion.This study provides an effective way for the design and synthesis of highly dispersed nano-metal photocatalyst carriers.

    • >Food Science and Biological Science
    • Establishment of a method for detecting nucleotide polymorphism of SLC39A13 gene based on ARMS-PCR

      2024, 45(5):497-507. DOI: 10.7535/hbkd.2024yx05005

      Abstract (970) HTML (0) PDF 20.22 M (208) Comment (0) Favorites

      Abstract:In order to achieve its nucleotide polymorphism (SNP) accurate typing, this paper establishes a molecular diagnostic technique based on fluorescent quantitative PCR for accurate genotyping of the nucleotide polymorphism (SNP) at the rs755555 locus of the SLC39A13 gene. Firstly, Taqman fluorescent ARMS-PCR detection primers and probes were designed for the rs755555 locus and the internal reference gene peptidylprolyl isomerase A (PPIA). Secondly, positive control plasmids were constructed. Finally, based on genotyping accuracy, the primer and probe combinations were optimized, and the PCR reaction system and conditions for the detection reagents were optimized. The optimal primer and probe combination for the wild-type was: WF1, R1, FP1, PIRF5, PIRR5, PIRP5; the optimal combination for the mutant type was: FMF3, R1, FP1, PIRF5, PIRR5, PIRP5. The optimal reaction system for detecting samples was: 0.1 μL each of upstream and downstream primers and probes for the SLC39A13 gene, 0.1 μL each of upstream and downstream primers and probes for the internal standard, 10 μL PerfectStart Ⅱ Probe qPCR SuperMix UDG, 5.4 μL purified water, and 4 μL sample genome. The feasibility of this detection system was confirmed through reproducibility experiments and the detection of 70 samples. This provides a technical foundation for the development of a detection kit for the polymorphism at the rs755555 locus of the SLC39A13 gene.

    • Preparation process and storage stability of Abelmoschus Manihot (L.) medic flowers flavonoids microcapsules

      2024, 45(5):508-517. DOI: 10.7535/hbkd.2024yx05006

      Abstract (880) HTML (0) PDF 2.08 M (307) Comment (0) Favorites

      Abstract:In order to improve the storage stability and extend the application range of the Abelmoschus Manihot (L.) medic flowers flavonoids(AMF), A.Manihot flowers flavonoids microcapsules (AMFM) were prepared by ultrasonic-assisted embedding-freeze drying method with the flavonoids extracts of AMF as core material and β-cyclodextrin as wall material. The preparation parameters of microcapsules were determined by single factor and response surface test, and AMFM was characterized by scanning electron microscopy, infrared spectroscopy and antioxidant activities. The effects of different storage conditions of temperature, humidity, light and oxygen on the retention rate of the microcapsules were investigated. The results show that the optimal preparation process of AMFM is ultrasonic power of 210 W, ultrasonic temperature of 56 ℃, ultrasonic time of 40 min and core-wall ratio of 1.6 mL∶1 g. Under these conditions, the flavonoid embedding rate of microcapsules was 96.89%. The prepared microcapsules are amorphous glassy solids, and the infrared spectrum analysis shows that the AMF are embedded by the wall material. AMFM has good antioxidant capabilities and can effectively improve the stability of flavonoids. This study provides a theoretical basis for the development of AMF for the application of new food natural antioxidants.

    • >Civil and Architectural Engineering
    • Seismic performance of K-EBF structures considering aftershock sequences and link failure

      2024, 45(5):518-529. DOI: 10.7535/hbkd.2024yx05007

      Abstract (1212) HTML (0) PDF 2.30 M (414) Comment (0) Favorites

      Abstract:Aiming at the problems that the failure of members can change the stress state of the structure, and the building may be severely damaged or even collapsed due to aftershock sequences, the effect of aftershock sequences and link failure on the seismic performance of K-eccentrically braced steel frames (K-EBF) was investigated. Incremental dynamic analysis, fragility analysis, and collapse-resistant performance evaluations of 12-story and 18-story K-EBF were conducted by using the maximum inter-story drift as the seismic demand parameter and peak seismic acceleration as the ground motion intensity parameter. The results show that compared with non-considering the effect of aftershock sequences and link failure, under the fortification earthquakes, the two factors (aftershock sequences and link failure) make the θmax of the 12-story and 18-story K-EBF structures increase by 2.3% and 8.4%, and the probability of severe damage increase by 0.6% and 2.8%, respectively; Under rare earthquakes, the θmax of the 12-story and 18-story K-EBF structures increase by 21.0% and 42.1%, and the probability of severe damage failure increase by 11.6% and 19.4%, respectively; In addition, the minimum structural collapse reserve factor decreases by 32.1% and 31.2% for 12-story and 18-story structures, respectively; Overall, aftershock sequences will aggravate the structure damage accumulation, and the negative effect on the structure increases with the intensity of the earthquakes;The failure probabilities of different limit state will further increase after considering the link failure, which will result in a further decrease with the minimum structural collapse reserve factor; Therefore, the effects caused by aftershock sequences and link failure should be fully considered in the seismic performance analysis of K-EBF to reveal the structural real dynamic response under earthquakes. Taking both the damage failure of link failure and the effect of aftershocks into consideration can comprehensively analyze the seismic performance of K-EBF structures, which provides a more reliable basis for seismic design.

    • Study on surface wind load zoning of long-span roof based on improved Canopy-k-means algorithm

      2024, 45(5):530-538. DOI: 10.7535/hbkd.2024yx05008

      Abstract (1108) HTML (0) PDF 1.46 M (197) Comment (0) Favorites

      Abstract:In order to solve the problem that random selection of clustering number k can easily lead to instability and low computational efficiency of k-means clustering algorithm in the zoning calculation of wind load on the surface of long-span roof structures, an improved Canopy-k-means clustering algorithm was proposed. Firstly, the Canopy algorithm was introduced, and the selection of its initial threshold and clustering center was improved to reduce the blindness of the initial value selection so as to improve the reliability of the results of wind load zoning. Secondly, the improved Canopy algorithm was used to preprocess the wind load dataset to determine the cluster number k quickly and accurately. Thirdly, the improved Canopy algorithm was combined with k-means to achieve the accurate identification of the optimal classification number k, so that the improved Canopy-k-means clustering algorithm can get the zoning results quickly and accurately when the wind load on the surface of long-span roof structure was divided. Finally, taking a long-span cylindrical roof dry coal shed structure as an example, based on the test results of the surface wind load data obtained from the wind tunnel test, the improved Canopy-k-means clustering algorithm was used to calculate the surface wind load. The results show that by using the improved Canopy-k-means clustering algorithm, the wind loads on the surface of long-span roofs at 0 °, 50 °and 90 °wind angles are divided into three different zones, and the corresponding SD values are 2.36,3.51 and 2.52,respectively, which are significantly lower than those obtained by the traditional k-means clustering algorithm, and the intra-class compactness and inter-class dispersion are obviously improved. Therefore, the improved Canopy-k-means clustering algorithm can obtain the optimal zoning results quickly and accurately, and has good engineering application value for wind load zoning on the surface of long-span roofs.

    • Dynamic characteristics and microscopic pores structure of remolded soft clay under influence of nano-CaCO3

      2024, 45(5):539-548. DOI: 10.7535/hbkd.2024yx05009

      Abstract (925) HTML (0) PDF 2.52 M (225) Comment (0) Favorites

      Abstract:To study the dynamic characteristics and microstructure of nano-CaCO3 remolded soft clay under cyclic loading, GDS dynamic triaxial and NMR tests were conducted to analyze its dynamic stress-strain, dynamic elastic modulus, damping ratio, and micro pore changes. The results show that as the content of nano-CaCO3 increases and the confining pressure increases, the dynamic strain of the remolded soft clay gradually decreases and the dynamic elastic modulus gradually increases; The increase in consolidation stress ratio leads to a decrease and then an increase in dynamic strain of nano-CaCO3 remolded soft clay, and an increase and then a decrease in dynamic elastic modulus; The increase in confining pressure and consolidation stress ratio can effectively reduce the damping ratio of the soft clay; There is a significant nonlinear relationship between the hysteresis energy dissipation of soft clay and the dynamic strain curve; The main peak and peak area of the T2 distribution curve of nano-CaCO3 soft clay are significantly reduced compared to plain soft clay, and the decrease in pore ratio makes the soil structure more stable. The obtained dynamic characteristics of remolded soft clay based on nano-CaCO3 provides some reference for practical engineering.

    • >Management Science and Engineering
    • Robust optimization of medical waste recycling network in uncertain environment

      2024, 45(5):549-561. DOI: 10.7535/hbkd.2024yx05010

      Abstract (64) HTML (0) PDF 1.54 M (313) Comment (0) Favorites

      Abstract:Aiming at the uncertainty of medical waste recycling network, with the quantity and transportation cost of medical waste as the key variables, a multi-objective nonlinear integer programming model with multiple uncertain parameters was constructed, and robust optimization was introduced to deal with the uncertain factors. Multi-objective particle swarm optimization (MOPSO) and genetic algorithm (GA) were combined to solve the model. The outer GA was responsible for location decision, and the inner MOPSO was responsible for distribution path optimization based on location selection results. A domestic city was selected as the empirical object for the simulation. The results show that compared with the traditional genetic algorithm, the proposed algorithm reduces the total cost by 10.37%, the total risk by 1.86% and the workload deviation by 50.18%; Sensitivity analysis proves that the uncertainty of medical waste volume has more significant influence on the objective function. The proposed mode can help the decision makers adjust the uncertain parameters according to the risk appetite to obtain the best medical waste recycling network optimization scheme, which provides some reference for further study of medical waste recycling.

    • Research on hybrid option pricing model based on FFT and Transformer algorithm

      2024, 45(5):562-572. DOI: 10.7535/hbkd.2024yx05011

      Abstract (65) HTML (0) PDF 2.48 M (360) Comment (0) Favorites

      Abstract:In order to solve the problem of the large deviation between the classical option pricing model and the actual price data, based on the BS option pricing model, the Fast Fourier Transform (FFT) combined with the Transformer's multi-head attention mechanism of deep learning algorithm was used to conductthe empirical research on the 300ETF options and Shanghai gold options data. The model was quadratically trained by the improved Transformer algorithm on the residual values between the option pricing model based on the FFT algorithm and the option price data of the actual financial market. The results show that compared with other algorithms (BS model, FFT-BS model) and other hybrid algorithm models (FFT-BS+ARIMA model, FFT-BS+LSTM model), the proposed model has a good performance in the statistical indexes such as R2, MSE, NRMSE and MAE, and the hybrid algorithm model achieves a better performance for different volatilitiesand different varieties of options. The study innovatively applies the improved Transformer algorithm to option pricing, which compensates for the shortcomings of the classical option pricing model and provides a more accurate option pricing model.

Editor in chief:李铁军

Inauguration:1980

International standard number:ISSN 1008-1542

Unified domestic issue:CN 13-1225/TS

Domestic postal code:

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