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Abstract

Ventilation rate is a physical index that is strictly controlled during cigarette manufacturing because an abnormal ventilation rate can affect the release of mainstream smoke, tar, and other components harmful to human health. Therefore, the standard rod is used for measuring the ventilation rate, which necessitates accurate and effective periodic inspections. In this study, we designed and built a set of special tobacco ventilation rate standard rods to assess the standard device during its verification period and used a digital thermal flowmeter as the flow standard.We determined the micro-pressure adjustment interval through fluid simulation, and conducted an experimental verification based on the simulation results. At the adjustment point where the differential pressure value was 0 Pa, the period verification device was tested under the standard values of 27.38%, 58.83%, and 71.95%. The results show that the measurement errors of the device are –0.42%, 0.55%, and –0.13% respectively, which all meet the verification regulation requirements and indicate that the device is applicable in practical situations.
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Authors and Affiliations

Jiacheng Hu
1
Ying Sha
1
Jinhui Cai
1
Ying Liu
2
Suijun Liu
2

  1. China Jiliang University, NO.258 XueYuan Street, Hangzhou, China
  2. Nanyang Cigarette Factory of Henan China Tobacco Industry, No. 6 Xinhua East Road, Nanyang, China
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Abstract

In this study, X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry (DSC) method were used to analyze the main characteristics of sweet potato starch, and to analyze the thermal degradation process of sweet potato starch. Specifically, X-ray diffraction to study its structure, thermogravimetric analysis to study the thermal degradation kinetics, and differential scanning calorimetry to study the thermogram of sweet potato starch. The thermal decomposition kinetics of sweet potato starch was examined within different heating rates in nitrogen atmosphere. Different models of kinetic analysis were used to calculate the activation energies using thermogravimetric data of the thermal degradation process. Activation energies obtained from Kissinger, Flynn-Wall- Ozawa, and Šatava-Šesták models were 173.85, 174.87 and 174.34 kJ/mol, respectively. The values of activation energy indicated that the thermal degradation of the sweet potato starch was a single reaction mechanism or the combination of multi-reaction mechanisms. The differential scanning calorimetry analysis show that two decomposition stages were presented: the first at a low temperature involves the decomposition of long chain; and the second at a high temperature represents the scission of glucose ring. This information was helpful to design the processing process of many natural polymers. Thermogravimetric Fourier transform-infrared (TG–FTIR) analysis showed that the main pyrolysis products included water, methane, carbon dioxide, ammonia, and others.

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Authors and Affiliations

Ying Liu
Liutao Yang
Yingzhe Zhang
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Abstract

Learning resources are massive, heterogeneous, and constantly changing. How to find the required resources quickly and accurately has become a very challenging work in the management and sharing of learning resources. According to the characteristics of learning resources, this paper proposes a progressive learning resource description model, which can describe dynamic heterogeneous resource information on a fine-grained level by using information extraction technology, then a semantic annotation algorithm is defined to calculate the semantic of learning resource and add these semantic to the description model. Moreover, a semantic search method is proposed to find the required resources, which calculate the content with the highest similarity to the user query, and then return the results in descending order of similarity. The simulation results show that the method is feasible and effective.
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Authors and Affiliations

Xiaocong Lai
1
Ying Pan
1
Xueling Jiang
1

  1. Guangxi Key Lab of Human-machine Interaction and Intelligent Decision, Nanning Normal University, Nanning 530001, People’s Republic of China
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Abstract

In the extra-thick coal seams and multi-layered hard roofs, the longwall hydraulic support yielding, coal face spalling, strong deformations of goaf-side entry, and severe ground pressure dynamic events typically occur at the longwall top coal caving longwall faces. Based on the Key strata theory an overburden caving model is proposed here to predict the multilayered hard strata behaviour. The proposed model together with the measured stress changes in coal seam and underground observations in Tongxin coal mine provides a new idea to analyse stress changes in coal and help to minimise rock bursts in the multi-layered hard rock ground. Using the proposed primary Key and the sub-Key strata units the model predicts the formation and instability of the overlying strata that leads to abrupt dynamic changes to the surrounding rock stress. The data obtained from the vertical stress monitoring in the 38 m wide coal pillar located adjacent to the longwall face indicates that the Key strata layers have a significant influence on ground behaviour. Sudden dynamically driven unloading of strata was caused by the first caving of the sub-Key strata while reloading of the vertical stress occurred when the goaf overhang of the sub-Key strata failed. Based on this findings several measures were recommended to minimise the undesirable dynamic occurrences including pre-split of the hard Key strata by blasting and using the energy consumption yielding reinforcement to support the damage prone gate road areas. Use of the numerical modelling simulations was suggested to improve the key theory accuracy.

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Authors and Affiliations

Zhijie Zhu
Yunlong Wu
Jun Han
Ying Chen
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Abstract

The underground complicated testing environment and the fan operation instability cause large random errors and outliers of the wind speed signals. The outliers and large random errors result in distortion of mine wind speed monitoring, which possesses safety hazards in mine ventilation system. Application of Kalman filter in velocity monitoring can improve the accuracy of velocity measurement and eliminate the outliers. Adaptive Kalman Filter was built by automatically adjusting process noise covariance and measurement noise covariance depending on the differences between measured and expected speed signals. We analyzed the fluctuation of airflow flow using data of wind speed flow and distribution characteristics of the tunnel obtained by the Laser Doppler Velocimetry system (LDV) studies. A state-space model was built based on the tunnel airflow fluctuations and wind speed signal distribution. The adaptive Kalman Filter was calculated according to the actual measurement data and the Expectation Maximization (EM) algorithm. The adaptive Kalman filter was used to shield fluid pulsation while preserving system-induced fluctuations. Using the Kalman filter to treat offline wind speed signal acquired by LDV, the reliability of Kalman filter wind speed state model and the characteristics of adaptive Kalman Filter were investigated. Results showed that the adaptive Kalman filter effectively eliminated the outliers and reduced the root-mean-squares error (RMSE), and the adaptive Kalman filter had better performance than the traditional Kalman filter in eliminating outliers and reducing RMSE. Field experiments in online wind speed monitoring were conducted using the optimized adaptive Kalman Filter. Results showed that adaptive Kalman filter treatment could monitor the wind speed with smaller RMSE compared with LVD monitor. The study data demonstrated that the adaptive Kalman filter is reliable and suitable for online signal processing of mine wind speed monitor.

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Authors and Affiliations

De Huang
Jian Liu
Lijun Deng
Xuebing Li
Ying Song
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Abstract

Power big data contains a lot of information related to equipment fault. The analysis and processing of power big data can realize fault diagnosis. This study mainly analyzed the application of association rules in power big data processing. Firstly, the association rules and the Apriori algorithm were introduced. Then, aiming at the shortage of the Apriori algorithm, an IM-Apriori algorithm was designed, and a simulation experiment was carried out. The results showed that the IM-Apriori algorithm had a significant advantage over the Apriori algorithm in the running time. When the number of transactions was 100 000, the running of the IM-Apriori algorithm was 38.42% faster than that of the Apriori algorithm. The IM-Apriori algorithm was little affected by the value of supportmin. Compared with the Extreme Learning Machine (ELM), the IM-Apriori algorithm had better accuracy. The experimental results show the effectiveness of the IM-Apriori algorithm in fault diagnosis, and it can be further promoted and applied in power grid equipment.

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Authors and Affiliations

Jianguo Qian
Bingquan Zhu
Ying Li
Zhengchai Shi
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Abstract

Bacterial adsorption on mineral surface is one of the key steps in bioleaching process. The bacteria adsorb on the mineral surface via the extracellular polymeric substances (EPS) layer. In this paper, the behavior of glucuronic acid, one of the key substances in EPS layer, adsorbed on the pyrite surface is studied using DFT and electrochemical methods. Adsorption capacity of glucuronic acid is stronger than that of water. Glucuronic acid adsorbs on pyrite surfaces and it follows a mixed type of interactions (physisorption and chemisorption). Adsorption of glucuronic acid on pyrite surface followed Langmuir’s adsorption isotherm with adsorption standard free energy of –27.67kJ mol–1. The structural and electronic parameters were calculated and discussed.

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Authors and Affiliations

Xu Jia Ning
Yang Hong Ying
Tong Lin Lin
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Abstract

Ladle plays an important role in the metallurgical industry whose maintenance directly affects the production efficiency of enterprises. In view of the problems such as low maintenance efficiency and untimely maintenance in the current ladle passive maintenance scheme, the life prediction mechanism for ladle composite structures is established which bases on the stress analysis of steel shell and ladle lining in the production process, combining conventional fatigue analysis and extended fracture theory. The mechanism is accurate and effective according to the simulation results. Through which, the useful life of steel shell can be accurately predicted by detecting the crack length of it. Due to the large number of factors affecting the life of the lining of the ladle, it is difficult to accurately predict the life of the ladle lining, so a forecasting mean based on the thermal shock method is proposed to predict the service life of the ladle lining in this paper. The life prediction mechanism can provide data support and theoretical guidance for the active maintenance of the ladle, which is the prerequisite for scientifically formulating ladle initiative maintenance program.

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Authors and Affiliations

Gongfa Li
Du Jiang
Ying Sun
Guozhang Jiang
Bo Tao
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Abstract

Q235 steel is widely used in engineering and construction. Therefore, it is important to identify the damage mechanism and the acoustic emission (AE) response of the material to ensure the safety of structures. In this study, an AE monitor system and an in situ tensile test with an optical microscope were used to investigate the AE response and insight into the damage process of Q235 steel. The surface of the specimen was polished and etched before the test in order to improve the quality of micrographs. Two kinds of AE responses, namely a burst and a continuous signal, were recorded by the AE monitor system during the test. Based on the in situ test, it was observed that the damage of Q235 steel was induced by the crystal slip and the inclusion fracture. Since the crystal slip was an ongoing process, continuous AE signals were produced, while burst AE signals were possibly produced by the inclusion fracture which occurred suddenly with released higher energy. In addition, a great number of AE signals with high amplitude were observed during the yielding stage and then the number and amplitude decreased.

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Authors and Affiliations

Ying Zhang
Yue Li
Huan Sheng Lai
Chunmei Bai
Kang Lin Liu
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Abstract

Biochar has been extensively studied as a soil amendment to reduce nutrients losses. However, the comparative effectiveness of biochar adsorption capacity for ammonium (NH4-N), nitrate (NO3-N), and phosphate (PO4-P) remains unknown. In the present study, the effects of feedstock (banana stem and coconut shell) and temperature (300, 500, and 700°C) on biochar adsorption ability for NH 4-N, NO 3-N, and PO 4-P were investigated and fitted by three adsorption models, viz Freundlich, Langmuir, and linear. Freundlich (R 2 = 0.95–0.99) and Langmuir (R 2 = 0.91–0.95) models were found suitable for adsorption of NH 4-N. The maximum adsorption capacity (Q m) for coconut shell biochar increased with pyrolysis temperature (Q m = 12.8–15.5 mg g-1) and decreased for banana stem biochar (Q m = 12.9–9.7 mg g-1). In the case of NO 3-N adsorption, Freundlich (R 2 = 0.82–0.99) and linear model (R 2 = 1.00) were found suitable while Langmuir model showed much less contribution, similarly adsorption of PO 4-P, was not supported by these three models. The minimum concentrations required for adsorption of phosphate were recorded as 36, 8, and 3 mg L -1 using pyrolyzed biochar at the temperatures of 300, 500, and 700°C, respectively. These results indicate that the feedstock and pyrolysis temperature, as well as aquatic nutrient concentration, were important factors for the adsorption of inorganic nitrogen and phosphorus.
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Bibliography

  1. Aghoghovwia, M.P., Hardie, A.G. & Rozanov, A.B. (2020). Characterisation, adsorption and desorption of ammonium and nitrate of biochar derived from different feedstocks. Environmental Technology, 43, pp. 774-787. DOI:10.1080/09593330.2020.1804466
  2. Bao, S.D. (2000). Soil agricultural chemical analysis (3rd Edition), China Agricultural Press, Beijing 2000.
  3. Carpenter, S.R. (2008). Phosphorus control is critical to mitigating eutrophication. PANS, 105, pp. 11039-11040. DOI:10.1073/pnas.0806112105
  4. Chintala, R., Mollinedo, J., Schumacher, T.E., Papiernik, S.K., Malo, D.D., Clay, D.E., Kumar, S. & Gulbrandson, D.W. (2013). Nitrate sorption and desorption in biochars from fast pyrolysis. Microporous and Mesoporous Materials, 179, pp. 250-257. DOI:10.1016/j.micromeso.2013.05.023
  5. Fidel, R.B., Laird, D.A. & Spokas, K.A. (2018). Sorption of ammonium and nitrate to biochars is electrostatic and pH-dependent. Scientific Reports, 8, pp. 1-10. DOI:10.1038/s41598-018-35534-w
  6. Freundlich, H.M.F. (1907). Über die Adsorption in Lösungen. Z Phys Chem, 57, pp. 385–470.
  7. Gai, X., Wang, H., Liu, J., Zhai, L., Liu, S., Ren, T. & Liu, H. (2014). Effects of feedstock and pyrolysis temperature on biochar adsorption of ammonium and nitrate. PloS One, 9, pp. e113888. DOI:10.1371/journal.pone.0113888
  8. Ghodszad, L., Reyhanitabar, A., Maghsoodi, M.R., Lajayer, B.A. & Chang, S.X. (2021). Biochar affects the fate of phosphorus in soil and water: A critical review. Chemosphere, 283, pp. 131176. DOI:10.1016/j.chemosphere.2021.131176
  9. Hale, S.E., Alling, V., Martinsen, V., Mulder, J., Breedveld, G.D. & Cornelissen, G. (2013). The sorption and desorption of phosphate-P, ammonium-N and nitrate-N in cacao shell and corn cob biochars. Chemosphere, 91, pp. 1612-1619. DOI:10.1016/j.chemosphere.2012.12.057
  10. Hu, X., Zhang, X., Ngo, H.H., Guo, W., Wen, H., Li, C., Zhang, Y. & Ma, C. (2020). Comparison study on the ammonium adsorption of the biochars derived from different kinds of fruit peel. Science of the Total Environment, 707, pp. 135544. DOI:10.1016/j.scitotenv.2019.135544
  11. Huang, M., Yang, L., Qin, H., Jiang, L. & Zou, Y. (2014). Fertilizer nitrogen uptake by rice increased by biochar application. Biology and Fertility of Soils, 50, pp. 997-1000. DOI:10.1007/s00374-014-0908-9
  12. Hollister, C.C., Bisogni, J.J. & Lehmann, J. (2013). Ammonium, nitrate, and phosphate sorption to and solute leaching from biochars prepared from corn stover (Zea mays L.) and oak wood (Quercus spp.). Journal of Environmental Quality, 42, pp. 137-144. DOI:10.2134/jeq2012.0033
  13. Hou, J., Huang, L., Yang, Z., Zhao, Y., Deng, C., Chen, Y. & Li, X. (2016). Adsorption of ammonium on biochar prepared from giant reed. Environmental Science and Pollution Research, 23, pp. 19107-19115. DOI:10.1007/s11356-016-7084-4
  14. Jassal, R.S., Johnson, M.S., Molodovskaya, M., Black, T.A., Jollymore, A. & Sveinson, K. (2015). Nitrogen enrichment potential of biochar in relation to pyrolysis temperature and feedstock quality. Journal of Environmental Management, 152, pp. 140-144. DOI:10.1016/j.jenvman.2015.01.021
  15. Kameyama, K., Miyamoto, T., Iwata, Y. & Shiono, T. (2016). Influences of feedstock and pyrolysis temperature on the nitrate adsorption of biochar. Soil Science and Plant Nutrition, 62, pp. 180-184. DOI:10.1080/00380768.2015.1136553
  16. Kim, J., Yoo, G., Kim, D., Ding, W. & Kang, H. (2017). Combined application of biochar and slow-release fertilizer reduces methane emission but enhances rice yield by different mechanisms. Applied Soil Ecology, 117, pp. 57-62. DOI:10.1016/j.apsoil.2017.05.006
  17. Kong, L. L., Liu, W. T. & Zhou, Q. X. (2014). Biochar: an effective amendment for remediating contaminated soil. Reviews of Environmental Contamination and Toxicology, 228, pp. 83-99. DOI: 10.1007/978-3-319-01619-1_4
  18. Langmuir, I. (1916). The constitution and fundamental properties of solids and liquids. Part I. Solids. Journal of the American Chemical Society, 38, pp. 2221-2295. DOI:10.1021/ja02268a002
  19. Laird, D., Fleming, P., Wang, B., Horton, R. & Karlen, D. (2010). Biochar impact on nutrient leaching from a Midwestern agricultural soil. Geoderma, 158, pp. 436-442. DOI:10.1016/j.geoderma.2010.05.012
  20. Lu, C. & Tian, H. (2017). Global nitrogen and phosphorus fertilizer use for agriculture production in the past half century: shifted hot spots and nutrient imbalance. Earth System Science Data, 9, pp. 181-192. DOI.org/10.5194/essd-9-181-2017
  21. Luo, L., Wang, G., Shi, G., Zhang, M., Zhang, J., He, J., Xiao, Y., Tian, D., Zhang, Y., Deng, S., Zhou, W., Lan, T. & Deng, O. (2019). The characterization of biochars derived from rice straw and swine manure, and their potential and risk in N and P removal from water. Journal of Environmental Management, 245, pp. 1-7. DOI:10.1016/j.jenvman.2019.05.072
  22. Norman, R. J., Edberg, J. C. & Stucki, J. W. (1985). Determination of nitrate in soil extracts by dual-wavelength ultraviolet spectrophotometry. Soil Science Society of America Journal, 49, pp. 1182-1185. DOI: 10.2136/sssaj1985.03615995004900050022x
  23. Piekarski, J., Dąbrowski, T., Dąbrowski, J. & Ignatowicz, K. (2021). Preliminary studies on odor removal in the adsorption process on biochars produced form sewage sludge and beekeeping waste. Archives of Environmental Protection, 47, pp. 20-28. DOI: 10.24425/aep.2021.137275
  24. Pratiwi, E.P.A., Hillary, A.K., Fukuda, T. & Shinogi, Y. (2016). The effects of rice husk char on ammonium, nitrate and phosphate retention and leaching in loamy soil. Geoderma, 277, pp. 61-68. DOI:10.1016/j.geoderma.2016.05.006
  25. Pulka, J., Wiśniewski, D., Gołaszewski, J. & Białowiec, A. (2016). Is the biochar produced from sewage sludge a good quality solid fuel. Archives of Environmental Protection, 42, pp. 125-134. DOI:10.1515/aep-2016-0043
  26. Takaya, C.A., Fletcher, L.A., Singh, S., Anyikude, K.U. & Ross, A.B. (2016). Phosphate and ammonium sorption capacity of biochar and hydrochar from different wastes. Chemosphere, 145, pp. 518-527. DOI:10.1016/j.chemosphere.2015.11.052
  27. Tian, H., Lu, C., Melillo, J., Ren, W., Huang, Y., Xu, X., Liu, M., Zhang, C., Chen, G., Pan, S., Liu, J. & Reilly, J. (2012). Food benefit and climate warming potential of nitrogen fertilizer uses in China. Environmental Research Letters, 7, pp. 044020. DOI:10.1088/1748-9326/7/4/044020
  28. Trazzi, P.A., Leahy, J.J., Hayes, M.H. & Kwapinski, W. (2016). Adsorption and desorption of phosphate on biochars. Journal of Environmental Chemical Engineering, 4, pp. 37-46. DOI:10.1016/j.jece.2015.11.005
  29. Vijayaraghavan, K. & Balasubramanian, R. (2021). Application of pinewood waste-derived biochar for the removal of nitrate and phosphate from single and binary solutions. Chemosphere, 278, pp. 130361. DOI:10.1016/j.chemosphere.2021.130361
  30. Xu, D., Cao, J., Li, Y., Howard, A. & Yu, K. (2019). Effect of pyrolysis temperature on characteristics of biochars derived from different feedstocks: A case study on ammonium adsorption capacity. Waste Management, 87, pp. 652-660. DOI:10.1016/j.wasman.2019.02.049
  31. Ye, L., Zhao, X., Bao, E., Li, J., Zou, Z. & Cao, K. (2020). Bio-organic fertilizer with reduced rates of chemical fertilization improves soil fertility and enhances tomato yield and quality. Scientific Reports, 10, pp. 1-11. DOI:10.1038/s41598-019-56954-2
  32. Yin, H., Zhao, W., Li, T., Cheng, X. & Liu, Q. (2018). Balancing straw returning and chemical fertilizers in China: Role of straw nutrient resources. Renewable and Sustainable Energy Reviews, 81, pp. 2695-2702. DOI:10.1016/j.rser.2017.06.076
  33. Yin, Q., Zhang, B., Wang, R. & Zhao, Z. (2018). Phosphate and ammonium adsorption of sesame straw biochars produced at different pyrolysis temperatures. Environmental Science and Pollution Research, 25, pp. 4320-4329. DOI:10.1007/s11356-017-0778-4
  34. Zhang, H., Chen, C., Gray, E.M., Boyd, S.E., Yang, H. & Zhang, D. (2016). Roles of biochar in improving phosphorus availability in soils: a phosphate adsorbent and a source of available phosphorus. Geoderma, 276, pp. 1-6. DOI:10.1016/j.geoderma.2016.04.020
  35. Zhao, H., Xue, Y., Long, L. & Hu, X. (2018). Adsorption of nitrate onto biochar derived from agricultural residuals. Water Science and Technology, 77, pp. 548-554. DOI:10.2166/wst.2017.568
  36. Zhao, S., Wang, B., Gao, Q., Gao, Y. & Liu, S. (2017). Adsorption of phosphorus by different biochars. Spectroscopy Letters, 50, pp. 73-80. DOI:10.1080/00387010.2017.1287091
  37. Zhou, L., Xu, D., Li, Y., Pan, Q., Wang, J., Xue, L. & Howard, A. (2019). Phosphorus and nitrogen adsorption capacities of biochars derived from feedstocks at different pyrolysis temperatures. Water, 11, pp. 1559. DOI:10.3390/w11081559
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Authors and Affiliations

Ganghua Zou
1
Ying Shan
1
Minjie Dai
2
Xiaoping Xin
3
Muhammad Nawaz
4
Fengliang Zhao
1

  1. Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, China
  2. Haikou Experimental Station, Chinese Academy of Tropical Agricultural Sciences, Chin
  3. University of Florida, United States
  4. Bahauddin Zakariya University, Pakistan
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Abstract

To improve the power quality of a multi-pulse rectifier, a zigzag 18-pulse uncontrolled rectifier with an auxiliary circuit at the DC side is proposed. When the grid-side currents are sinusoidal waves, the required DC side injection currents to be compensated can be obtained by analyzing the AC-DC side relationship of diode bridge rectifiers. Then the 6 compensation currents generated by an active auxiliary circuit are injected into the DC side to eliminate the grid-side harmonics of the rectifier. The simulation results verifying the correctness of the theoretical analysis show that the proposed rectifier can mitigate the harmonic content, as the total harmonic distortion of the grid-side current is about 1.45%. In addition, the single-phase inverter used in the active auxiliary circuit has the characters of simple circuit structure and easy controllability.

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Authors and Affiliations

Jiongde Liu
Xiaoqiang Chen
Ying Wang
ORCID: ORCID
Tao Chen
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Abstract

The problem of large speed loss exists in the traditional passing through the electric phase-separation method of trains, which is more prominent when trains pass through an electric phase-separation zone in the uphill section of long ramps and may lead to the trains not passing through the phase-separation zone safely. In order to solve this problem, based on the energy storage type railroad power conditioner, a train uninterrupted phase-separation passing system based on the energy storage type railroad power conditioner is proposed. The energy storage railroad power conditioner can realize the recovery and utilization of regenerative braking energy of the electrified railroad. In the structure of the energy storage railroad power conditioner, the single-phase inverter is led from the middle DC side of the energy storage railroad power conditioner and connected to the neutral line through theLCLfilter and the step-up transformer, which constitutes an uninterrupted phaseseparation passing system. The single-phase inverter is controlled using virtual synchronous generator technology, which allows the single-phase inverter to have external characteristics similar to those of a synchronous generator, providing support for the voltage and frequency in the neutral zone. The power required by the train to pass the electric phase-separation is provided by the power supply arm or the energy storage system, which not only improves the utilization rate of regenerative braking energy but also realizes the uninterrupted phaseseparation passing of the train through the control of the voltage in the neutral region.
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Authors and Affiliations

Ying Wang
1
ORCID: ORCID
Huan Yang
1
Xiaoqiang Chen
1
Ya Guo
2

  1. School of Automation and Electrical Engineering, Lanzhou Jiaotong University, Lanzhou, 730070 China
  2. School of Automation and Electrical Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China
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Abstract

Transmission lines’ live working is one of an effective means to ensure the reliable operation of transmission lines. In order to solve the unsafe problems existing in the implementation of traditional live working, the paper uses ground-based lidar to collect point cloud data. A tile based on the pyramid data structure is proposed to complete the storage and calling of point cloud data. The improved bidirectional filtering algorithm is used to distinguish surface features quickly and obtain a 3D model of the site. Considering the characteristics of live working, the speed of data reading and querying, the nearest point search algorithm based on octree is used to acquire a real- time calculation of the safe distance of each point in the planned path, and the safety of the operation mode is obtained by comparing with the value specified in the regulation, and assist in making decisions of the operation plan. In the paper, the simulation of the actual working condition is carried out by taking the “the electric lifting device ascending” as an example. The experimental results show that the established three-dimensional model can meet the whole process control of the operation, and has achieved practical effect.
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Authors and Affiliations

Ying Wang
1
ORCID: ORCID
Haitao Zhang
1 2 3
Qiang Lv
3
Qiang Gao
3
Mingxing Yi
3

  1. School of Automation & Electrical Engineering, Lanzhou Jiaotong University, Gansu, China
  2. Key Laboratory of Opto-Electronic Technology and Intelligent Control Ministry of Education, Lanzhou Jiaotong University Gansu, China
  3. The UHV Company of State Grid Gansu Electric Power Company, Gansu, China
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Abstract

In order to meet the lightweight requirements of high-speed trains, the inductancecapacitance (LC) resonance circuits are cancelled in the traction drive system of some high-speed electric multiple units (EMUs) in China, which will lead to large low-order current harmonics on the grid side in the traction drive system of EMUs, seriously affecting the power quality. Therefore, the low-order harmonic current of the traction drive system of an EMU is studied in this paper. Firstly, the working principle of a four-quadrant pulse rectifier in a traction drive system is analyzed, and then the generation mechanism of loworder current harmonics on the grid side is studied deeply. Secondly, the voltage outer loop and current inner loop control of a four-quadrant pulse rectifier are optimized respectively. In the voltage outer loop control, a Butterworth filter is designed to suppress the beat frequency voltage of the DC side voltage, so as to indirectly suppress the low-order current harmonics. In the current inner loop, a quasi-proportional resonance (PR) controller with harmonic compensation is used to suppress low-order current harmonics, and a novel loworder current harmonics suppression strategy based on the Butterworth filter and quasi-PR controller is proposed. Finally, the results of the simulated validation of the proposed control strategy show that compared with the existing method of the notch filter ¸ PR controller, the proposed optimal control strategy has a better effect on low-order current harmonic suppression, and improves the dynamic performance of the control system, further showing the correctness and effectiveness of the optimal control strategy.
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Authors and Affiliations

Feng Zhao
1
Jianing Zhang
1
ORCID: ORCID
Xiaoqiang Chen
1 2
Ying Wang
1 2
ORCID: ORCID

  1. School of Automation and Electrical Engineering, Lanzhou Jiaotong University, Lanzhou, China
  2. Key Laboratory of Opto-Technology and Intelligent Control Ministry of Education, Lanzhou, China
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Abstract

While cycloid pin-wheel precision reducers (referred to as RV reducers) are widely used in industrial robots, a widely accepted design standard or verification method of their test platforms is not available. In this study, a comprehensive sliding-separation test platform of RV reducers was developed. The test platform can test various measurement items such as transmission error, static measurement of lost motion, dynamic measurement of lost motion, torsional rigidity, no-load running torque, starting torque, backdriving torque, and transmission efficiency of the RV reducer for robots. The principle and method of dynamic measurement of lost motion tests based on the two-way transmission error method were studied and this test function was successfully integrated with the comprehensive test platform in order to increase the test items of the dynamic performance parameters of RV reducers. The measurement results of the no-load running torque of the RV reducer were consistent with the Stribeck curve. Based on the concept of optimal measurement speed, a decomposition test method of the geometric component of the dynamic measurement of lost motion and the elastic component of the dynamic measurement of lost motion was proposed in the dynamic measurement test of lost motion. Through precision calibration, function test and repeatability test, the results were compared with the data of enterprise’s samples. The consistent results have proved that the test platform met engineering requirements and measurement accuracy requirements. Based on the new test principle, the developed platform can test more parameters of RV reducers with high precision and display the comprehensive test performance.
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Authors and Affiliations

Huijun Yue
1
Xiangkai Wu
1
Zhaoyao Shi
1
Yue Zhang
1
Yong Ye
1
Lintao Zhang
1
Ying Fu
1

  1. Beijing University of Technology, Beijing Engineering Research Center of Precision Measurement Technology and Instruments, 100, Ping Le Yuan, Chaoyang District, Beijing 100124, China
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Abstract

In order to achieve energy savings and promote on-site integration of photovoltaic energy in electrified railways, a topology structure is proposed for the integration of photovoltaic (PV) and the energy storage system (ESS) into the traction power supply system (TPSS) based on a railway power conditioner (RPC). This paper analyzes the composition and operation principles of this structure. To assess the economic benefits brought by the integration of photovoltaic and energy storage systems, a bilevel optimization model is established, with the objectives of optimizing energy storage capacity configuration and photovoltaic energy integration. The KKT (Karush–Kuhn–Tucker) method is employed to transform the model into a single-layer mixed-integer linear programming model, which is then solved using the CPLEX solver in MATLAB. The research findings indicate that, with the configuration of the ESS, the optimal PV consumption rate achieved is 96.8749%. Compared to a 100% PV consumption rate, the ESS capacity configuration is reduced by 13.14%, and the overall operational cost of the TPSS is at its lowest. The study suggests that the proposed bilevel optimization algorithm can more effectively consider PV consumption, leading to enhanced economic performance of the TPSS operation.
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Authors and Affiliations

Wei Zhang
1
ORCID: ORCID
Xiaoqiang Chen
1
Ying Wang
1
ORCID: ORCID

  1. School of Automation and Electrical Engineering, Lanzhou Jiaotong University Lanzhou,730070 China
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Abstract

Aiming at the problems of the negative sequence governance and regenerative braking energy utilization of electrified railways, a layered compensation optimization strategy considering the power flow of energy storage systems was proposed based on the railway power conditioner. The paper introduces the topology of the energy storage type railway power conditioner, and analyzes its negative sequence compensation and regenerative braking energy utilization mechanism. Considering the influence of equipment capacity and power flow of the energy storage system on railway power conditioner compensation effect, the objective function and constraint conditions of the layered compensation optimization of the energy storage type railway power conditioner were constructed, and the sequential quadratic programming method was used to solve the problem. The feasibility of the proposed strategy is verified by a multi-condition simulation test. The results show that the proposed optimization compensation strategy can realize negative sequence compensation and regenerative braking energy utilization, improve the power factor of traction substations when the system equipment capacity is limited, and it also has good real-time performance.
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Authors and Affiliations

Ying Wang
1
ORCID: ORCID
Yanqiang He
1
ORCID: ORCID
Xiaoqiang Chen
1
Miaomiao Zhao
1
Jing Xie
2

  1. School of Automation and Electrical Engineering, Lanzhou Jiaotong University, Lanzhou, 730070 China
  2. Xi’an Rail Transit Group Co., LTD Operation Branch Xi’an, 710000 China
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Abstract

A three-level multi-input DC/DC converter is proposed to solve the problems of complex interface circuit structure and high economic cost for multi-source access to the joint power supply distribution system. In this structure, multiple dc sources are integrated into a three-level DC/DC converter. In comparison with the two-stage counterpart, two active switches and boost diodes are eliminated, while two blocking diodes are added to block the reverse current from the dc-link capacitors. In addition, when the input inductors work in the discontinuous conduction mode, power sharing among different input sources can be achieved by properly selecting the inductance value. The working principle of the converter is analyzed by introducing nine working modes in detail and deriving the steady-state relationship expressions. The parameter range of the element is determined and the design process of a group of dynamic parameter values is shown. Finally, the power electronics real-time simulation platform is built based on StarSim HIL and the corresponding experimental waveforms are given to verify the topology and analysis.
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Authors and Affiliations

Jingjing Tian
1
Jiaoping Qu
1
ORCID: ORCID
Feng Zhao
1
Xiaoqiang Chen
1 2
Ying Wang
1 2
ORCID: ORCID
Yang Gan
1

  1. School of Automation & Electrical Engineering, Lanzhou Jiaotong University, Lanzhou, China
  2. Key Laboratory of Opto-technology and Intelligent Control, Lanzhou Jiaotong University, Ministry of Education, Lanzhou, China
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Abstract

High-frequency resonance is a prominent phenomenon which affects the normal operation of the high-speed railway in China. Aiming at this problem, the resonance mechanism is analyzed first. Then, model predictive control and selective harmonic elimination pulse-width modulation (MPC-SHEPWM) combined control strategy is proposed, where the harmonics which cause the resonance can be eliminated at the harmonic source. Besides, the MPC is combined to make the current track the reference in transients. The proposed control has the ability to suppress the resonance while has a faster dynamic performance comparing with SHEPWM. Finally, the proposed MPC-SHEPWM is tested in a simulation model of CRH5 (Chinese Railway High-speed), EMUs (electric multiple units) and a traction power supply coupled system, which shows that the proposed MPC-SHEPWM approach can achieve the resonance suppression and shows a better dynamic performance.
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Bibliography

[1] Mollerstedt E., Bernhardsson B., Out of control because of harmonics-an analysis of the harmonic response of an inverter locomotive, IEEE Control Systems Magazine, vol. 20, no. 4, pp. 70–81 (2000).
[2] Sainz L., Caro M., Caro E., Analytical Study of the Series Resonance in Power Systems With the Steinmetz Circuit, IEEE Transactions on Power Delivery, vol. 24, no. 4, pp. 2090–2098 (2009).
[3] Lee H., Lee C., Jang G., Kwon S., Harmonic analysis of the korean high-speed railway using the eight-port representation model, IEEE Transactions on Power Delivery, vol. 21, no. 2, pp. 979–986 (2006).
[4] Holtz J., Kelin H., The propagation of harmonic currents generated by inverter-fed locomotives in the distributed overhead supply system, IEEE Transactions on Power Electronics, vol. 4, no. 2, pp. 168–174 (1989).
[5] Chang G.W., Lin H.W., Chen S.K., Modeling characteristics of harmonic currents generated by highspeed railway traction drive converters, IEEE Trans. Power Delivery, vol. 19, no. 2, pp. 766–773 (2004).
[6] Hu H., Shao Y., Tang L., Ma J., He Z., Gao S., Overview of Harmonic and Resonance in Railway Electrification Systems, IEEE Transactions on Industry Applications, vol. 54, no. 5, pp. 5227–5245 (2018).
[7] Kolar V., Palecek J., Kocman S. et al., Interference between electric traction supply network and distribution power network - resonance phenomenon, International Conference on Harmonics and Quality of Power, Bergamo, Italy (2010).
[8] Brenna M. et al., Investigation of resonance phenomena in high speed railway supply systems: Theoretical and experimental analysis, Elect. Power Syst. Res., vol. 81, no. 10, pp. 1915–1923 (2011).
[9] Hu H., Gao S., Shao Y., Wang K., He Z., Chen L., Harmonic Resonance Evaluation for Hub Traction Substation Consisting of Multiple High-Speed Railways, IEEE Transactions on Power Delivery, vol. 32, no. 2, pp. 910–920 (2017).
[10] Li J.,Wu M., Molinas M., Song K., Liu Q., Assessing High-Order Harmonic Resonance in Locomotive- Network Based on the Impedance Method, IEEE Access, vol. 7, pp. 68119–68131 (2019).
[11] Hu H., Tao H., Blaabjerg F., Wang X., He Z., Gao S., Train–Network Interactions and Stability Evaluation in High-Speed Railways–Part I: Phenomena and Modeling, IEEE Transactions on Power Electronics, vol. 33, no. 6, pp. 4627–4642 (2018).
[12] Lee H., Kim G., Oh S., Lee C., Optimal design for power quality of electric railway, SICE-ICASE International Joint Conf., Busan, Korea, pp. 3864–3869 (2006).
[13] Hu H., He Z., Gao S., Passive Filter Design for China High-Speed RailwayWith Considering Harmonic Resonance and Characteristic Harmonics, IEEE Transactions on Power Delivery, vol. 30, no. 1, pp. 505–514 (2015).
[14] Zhang X., Chen J., Zhang G., Wang L., Qiu R., Liu Z., An Active Oscillation Compensation Method to Mitigate High-Frequency Harmonic Instability and Low-Frequency Oscillation in Railway Traction Power Supply System, IEEE Access, vol. 6, pp. 70359–70367 (2018).
[15] Holtz J., Krah J.O., Suppression of time-varying resonances in the power supply line of AC locomotives by inverter control, IEEE Transactions on Industrial Electronics, vol. 39, no. 3, pp. 223–229 (1992).
[16] Zhang Y., Xiong J., Kong L., Wang X., A novel in-phase disposition SPWM pulse allocation strategy for cascaded H-bridge inverter, Archives of Electrical Engineering, vol. 67, no. 2, pp. 361–375 (2018).
[17] Cui H., Song W., Fang H., Ge X., Feng X., Resonant harmonic elimination pulse width modulationbased high-frequency resonance suppression of high-speed railways, IET Power Electronics, vol. 8, no. 5, pp. 735–742 (2015).
[18] Song K., Konstantinou G., MingliW., Acuna P., Aguilera R.P., Agelidis V.G.,Windowed SHE–PWM of Interleaved Four-Quadrant Converters for Resonance Suppression in Traction Power Supply Systems, IEEE Transactions on Power Electronics, vol. 32, no. 10, pp. 7870–7881 (2017).
[19] Dahidah M.S.A., Konstantinou G., Agelidis V.G., A Review of Multilevel Selective Harmonic Elimination PWM: Formulations, Solving Algorithms, Implementation and Applications, IEEE Transactions on Power Electronics, vol. 30, no. 8, pp. 4091–4106 (2015).
[20] Rodriguez J. et al., Predictive control of three-phase inverter, Electronics Letters, vol. 40, no. 9, pp. 561–563 (2004).
[21] Aguilera R.P. et al., Selective Harmonic Elimination Model Predictive Control for Multilevel Power Converters, IEEE Transactions on Power Electronics, vol. 32, no. 3, pp. 2416–2426 (2017).
[22] Cui H., Feng X., SongW., Modeling of high-order harmonic load for high-speed train, Electr. Power Equip. Autom., vol. 33, no. 7, pp. 92–99 (2013).
[23] Dolara A., Gualdoni M., Leva S., Impact of high-voltage primary supply lines in the 2 x 25 kV 50 Hz railway system on the equivalent impedance at pantograph terminals, IEEE Transactions on Power Delivery, vol. 27, no. 1, pp. 164–175 (2012).
[24] Dahidah M.S.A., Konstantinou G., Agelidis V.G., A Review of Multilevel Selective Harmonic Elimination PWM: Formulations, Solving Algorithms, Implementation and Applications, IEEE Transactions on Power Electronics, vol. 30, no. 8, pp. 4091–4106 (2015).
[25] Liang T.J., Hoft R.G., Walsh function method of harmonic elimination, Proc. IEEE Appl. Power Electron. Conf., San Diego, CA, USA, Mar. 7–11, pp. 847–853 (1993).
[26] Yang K., Yuan Z., Yuan R., YuW., Yuan J.,Wang J., A Groebner Bases Theory-Based Method for Selective Harmonic Elimination, IEEE Transactions on Power Electronics, vol. 30, no. 12, pp. 6581–6592 (2015).
[27] Kavitha R., Thottungal Rani, WHTD missisation in hybird multilvel inverter biogeographcial based Optimisation, Archives of Electrical Engineering, vol. 63, no. 2, pp. 187–196 (2014).
[28] Rodriguez J. et al., State of the Art of Finite Control Set Model Predictive Control in Power Electronics, IEEE Transactions on Industrial Informatics, vol. 9, no. 2, pp. 1003–1016 (2013).

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Authors and Affiliations

Sitong Chen
1
ORCID: ORCID
Xiaoqiang Chen
1
Ying Wang
1
ORCID: ORCID
Ye Xiong
1

  1. School of Automation and Electrical Engineering, Lanzhou Jiaotong University, Lanzhou, China
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Abstract

MDAP-2 is a new AMP with high inhibitory activity on Salmonella gallinarum, which may be developed as an antimicrobial agent in the agricultural industry and food preservation. To investigate the underlying the action mechanism of MDAP-2 on Salmonella gallinarum, impacts of MDAP-2 on the growth curve and bacterial morphology of Salmonella gallinarum were studied. iTRAQ-based proteomics analysis was also performed on proteins extracted from treated and untreated Salmonella gallinarum cells. The differentially expressed proteins were then analyzed using the KEGG and GO databases. Finally, the function of some differentially expressed proteins was verified. The results showed that 150 proteins (41 up-regulated and 109 down-regulated) were found differentially expressed (fold > 1.8, p<0.05). The results indi- cate that MDAP-2 kills Salmonella gallinarum mainly through two mechanisms: (i) direct inhibi- tion of cell wall/ membrane/ envelope biogenesis, energy production/ conversion, carbohydrate transport/ metabolism, and DNA transcription/ translation through regulation of special protein levels; (ii) indirect effects on the same pathway through the accumulation of Reactive oxygen species (O2 ▪-, H2O2 and OH▪-).

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Authors and Affiliations

Y. Zhang
S. Yu
X. Ying
B. Jia
L. Liu
J. Liu
L. Kong
Z. Pei
H. Ma
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Abstract

Improper disposal of waste tires will not only bring environmental impact and safety risks but also cause a serious waste of resources. In the field of civil engineering materials, waste tire particles are used as a substitute for non-renewable aggregates to produce flexible rubber-cement composites (RCC). To explore the high-speed slicing stability of RCC, this test took normal cement mortar (NCM) and rubber cement mortar (RCM) as research objects. The SHPB tests with the same impact energy level and the high-speed slicing tests with a slice thickness range of about 1.4 mm ~ 4.4 mm were carried out. The results showed that NCM and RCM showed different stability differences in the process of high-speed slicing. In the case of ensuring the integrity of the slice, the minimum thickness of the slice can be better decreased with the increase of the rubber content. Finally, from the perspectives of split Hopkinson pressure bar (SHPB) test results and mesoscopic structure states, the essential reason for ensuring the stability of high-speed slicing lied in the improvement of rubber particles (dominant role) and pores on material deformation and flexible energy dissipation.
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Authors and Affiliations

Rongzhou Yang
1
ORCID: ORCID
Ying Xu
1
ORCID: ORCID
Pei Yuan Chen
2
ORCID: ORCID

  1. State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan 232001, China
  2. School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan 232001, China
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Abstract

A theoretical formula for large-diameter rock-socket depth is developed to support pail embedding in a large bridge pile foundation project. There is a horizontal additional stress concentration at the place where the soil around the rock-socketed pile meets the soil layer under the horizontal load. When the rock-socketed tip stress and bending moment of the pile are relatively small, the pile shows favourable embedment effect and the pile foundation can be considered safe. The function curve of soil resistance around the pile under the action of horizontal force was obtained by finite element analysis. The force characteristics reveal the depth of the largediameter rock-socketed pile under the horizontal load. As the rock-socketed pile rotates under the action of horizontal force, the rock mass resistance around the pile changes according to the cosine. The distribution of pileside soil resistance is proportional to the displacement and distributed according to the sine. A comprehensive correction coefficient of pile shaft resistance beta is introduced to deduce the theoretical formula of the depth r h of the large-diameter rock-socketed pile embedded in the bedrock. It is verified through both experiments and numerical analysis.
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Authors and Affiliations

Yanfeng F. Li
ORCID: ORCID
Jihe Zhao
1
ORCID: ORCID
Ying Xiong
1
ORCID: ORCID
Qinghe Wang
2
ORCID: ORCID

  1. DSc., School of Transportation Engineering, Shenyang Jianzhu University, Shenyang 110168, China
  2. Prof., PhD., School of Transportation Engineering, Shenyang Jianzhu University, Shenyang 110168, China
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Abstract

The shear lag effect of the steel box girder section in a self-anchored suspension bridge was investigated in this study. Finite element analysis software Midas Civil was used to discretize the girder under analysis into space plate elements and establish a plate element model. The law of shear lag in the longitudinal direction of the girder in the construction and completion stages was determined accordingly. The shear lag coefficient appears to change suddenly near the side support, middle support, side cable anchorage area, and near the bridge tower support of the steel box girder under the imposed load. The most severe shear lag effect is located near the side support and near the side cable anchorage area. Steel box girder sections are simulated before and after system conversion to analyze the shear lag coefficient in the bridge construction stage. The results show that the shear lag coefficient markedly differs before versus after system conversion due to the different stress mechanisms. The finite element analysis results were validated by comparison with the results of an analysis via analogous rod method.
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Authors and Affiliations

Yanfeng Li
1
ORCID: ORCID
Ying He
2
Longsheng Bao
1
ORCID: ORCID
Baoyun Sun
1
ORCID: ORCID
Qinghe Wang
1
ORCID: ORCID

  1. Prof., PhD., School of Transportation Engineering, Shenyang Jianzhu University, Shenyang 110168, China
  2. DSc., School of Transportation Engineering, Shenyang Jianzhu University, Shenyang 110168, China
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Abstract

Ga-free InAs/InAsSb type-II superlattice structures grown on GaSb substrates have demonstrated high performance for mid-wave infrared applications. However, realisation of long wavelength infrared photodetectors based on this material system still presents challenges, especially in terms of reduced quantum efficiency. This reduction is due, in part, to the increased type-II superlattice period required to attain longer wavelengths, as thicker periods decrease the wave-function overlap for the spatially separated quantum wells. One way to improve long wavelength infrared performance is to modify the type-II superlattice designs with a shorter superlattice period for a given wavelength, thereby increasing the wave-function overlap and the resulting optical absorption. Long wavelength infrared epitaxial structures with reduced periods have been realised by shifting the lattice constant of the type-II superlattice from GaSb to AlSb. Alternatively, epitaxial growth on substrates with orientations different than the traditional (100) surface presents another way for superlattice period reduction. In this work, the authors evaluate the performance of long wavelength infrared type-II superlattice detectors grown by molecular beam epitaxy using two different approaches to reduce the superlattice period: first, a metamorphic buffer to target the AlSb lattice parameter, and second, structures lattices matched to GaSb using substrates with different orientations. The use of the metamorphic buffer enabled a ~30% reduction in the superlattice period compared to reference baseline structures, maintaining a high quantum efficiency, but with the elevated dark current related to defects generated in the metamorphic buffer. Red-shift in a cut-off wavelength obtained from growths on high-index substrates offers a potential path to improve the infrared photodetector characteristics. Focal plane arrays were fabricated on (100), (311)A- and (211)B-oriented structures to compare the performance of each approach.
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Authors and Affiliations

Dmitri Lubyshev
1
Joel M. Fastenau
1
Michael Kattner
1
Philip Frey
1
Scott A. Nelson
1
Ryan Flick
1
Ying Wu
1
Amy W. K. Liu
1
Dennis E. Szymanski
1
Becky Martinez
2
Mark J. Furlong
2
Richard Dennis
3
Jason Bundas
3
Mani Sundaram
3

  1. IQE, Inc., 119 Technology Dr., Bethlehem, PA 18015, USA
  2. IQE, Pascal Close, St. Mellons, Cardiff, CF3 0LW, UK
  3. QmagiQ, LCC, 22 Cotton Rd., Unit H, Suite 180, Nashua, NH 03063, USA

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