Table of Content

20 August 2021, Volume 27 Issue 4

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Invited Review

Coupling characteristics between a hydrofoil's cavitation structural evolution and collapse pressure under multiple modes

ZHU Bing, YANG Pu

2021, 27(4):  611-634.  doi:10.12066/j.issn.1007-2861.2297

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Based on a compressible numerical simulation, cavitation flow under different cavitation numbers was calculated. The mechanism of cavity shedding and the processes of collapse and release, propagation, and coupling characteristics of the pressure wave were investigated. The results revealed the following. The numerical model could capture the release, propagation, and rebound of pressure waves during local cavity collapse. There were different cavity shedding and collapse modes under different cavitation numbers. There may be multiple dynamic evolutionary processes in a shedding cycle of a large cavitation structure at a certain cavitation number. The cavity collapse induced by the condensed shock wave had a long duration and exhibited a small pressure-fluctuation amplitude and high release frequency, while the exfoliating large-scale cavity collapse exhibited a rapid, large pressure amplitude and a short action time, which may cause structural vibration and cavitation erosion damage.



Research Articles

First-principles computation and machine learning of the energies and structures of spinel oxides

LI Yihang, XIAO Bin, TANG Yuchao, LIU Fu, WANG Xiaomeng, LIU Yi

2021, 27(4):  635-649.  doi:10.12066/j.issn.1007-2861.2251

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The formal spinel oxides AB$_{2}$O$_{4}$ can have 5 329 configurations by substituting A and B with 73 elements. The first-principles method was applied to calculate the formation energies and lattice constants of 5 329 spinel oxides. To develop efficient machine learning (ML) methods, centre-environment (CE) feature models were proposed to construct the input variables of the ML methods containing local composition and structure information. Based on the first-principles computational data, random forest algorithm was used to develop an ML model to predict the formation energies and lattice constants of spinel oxides. By comparing the formation energies of hypothetical and experimental structures predicted by ML, 361 new and more stable spinel oxides were discovered. The “good” and “bad” stabilisation elements were disscussed, which helped in guiding theexperimental synthesis of novel stable spinel oxides.



Thiele-type tensor continued fraction interpolation and its application in the computation of the tensor exponential function

JIANG Xianglong, GU Chuanqing

2021, 27(4):  650-658.  doi:10.12066/j.issn.1007-2861.2182

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A continued fraction interpolation method for Thiele-type generalised tensor rational approximation was proposed. This method was used to calculate the value of the tensor exponential function to illustrate the effectiveness of the proposed continued fraction interpolation method.



Brillouin scattering on refractive index and acoustic physical constants of LiTaO₃  single crystal

WU Bingxin, WANG Xianyang, WANG Xu, WU Yongquan

2021, 27(4):  659-665.  doi:10.12066/j.issn.1007-2861.2162

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The in situ refractive index of LiTaO₃  single crystals was obtained by Brillouin scattering under a backscattering configuration. Combined with the platelet scattering configuration, all the independent physical constants, namely six elastic constants, four piezoelectric constants and two dielectric constants, were obtained by conducting the same X-cut LiTaO₃  single crystal. The results agreed well with the reported values.



Preparation of manganese oxide nanoparticles synthesised using a low-oxygen pressure method and its phosphorus absorption performance

XU Jun, YANG Peiyuan, JIAO Zheng, WANG Linjun, WANG Hongbin

2021, 27(4):  666-676.  doi:10.12066/j.issn.1007-2861.2184

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A low-oxygen pressure method was proposed based on an industrial continuous rolling production line. Using this method, a manganese oxide nanoparticle phosphorus adsorbent was prepared by controlling the dew point of manganese-containing cold-rolled sheets. The adsorption performance of the adsorbent was assessed. Results showed that the adsorbent exhibited good thermal stability. Its optimal adsorption time was 24 h, and the best adsorbent dosage was 3.6 g/L. A test was also conducted. It was proved that the adsorbent had excellent performance in strongly acidic environments. The data obtained from the test were fitted to the quasi-second-order kinetic and Langmuir isotherm adsorption models. The maximum adsorption capacity was found to be 8.3 mg/g at a temperature of 30 $^{\circ}$C and pH value of 1.5.



Development of high-accuracy water-vapor transmission rate test model using electrical method

LI Zewen, ZHANG Jianhua, GUO Aiying

2021, 27(4):  677-685.  doi:10.12066/j.issn.1007-2861.2174

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A high-precision problem of the traditional electrical method for determining the water-vapor transmission rate (WVTR) was analysed, and a high-accuracy WVTR test model with current distribution characteristics correction was developed. Based on the test model, a complete and simple WVTR test system was designed. The system hardware required high-adaptive fixtures for easy maintenance and a fully enclosed test environment, and the software included multi-threading, time-error compensation, and adaptive correction algorithms. The theoretical analysis and experimental test results showed that the modified WVTR test model and system satisfied the design requirements of low costs, high precision, and high accuracy.



Preparation, phosphorus removal performance and mechanism of lanthanum oxide/expanded graphite composite adsorbents

JIN Suwan, NIU Weiya, ZHANG Ling, MAO Xianyong

2021, 27(4):  686-695.  doi:10.12066/j.issn.1007-2861.2176

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To obtain a highly efficient phosphate removal adsorbent, lanthanum oxide/expanded graphite composite adsorbents were prepared from LaOH load-expanded graphite (EG-LaOH) at 340, 500 and 750 $^\circ$C, namely EG-LaO-340, EG-LaO-500 and EG-LaO-750, respectively. The phosphate removal performances of EG-LaO-340, EG-LaO-500 and EG-LaO-750 were investigated using adsorption kinetics and isotherm experiments. The dephosphorization of the adsorbents was found to be distinctly affected by the preparation temperature, with EG-LaO-340 having the optimal adsorption rate and adsorption capacity. The phosphorus removal mechanism of EG-LaO-340 was investigated by studying its thermodynamics and the pH dependence of adsorption. Additionally, scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy were used to characterise the adsorbents. Adsorption was found to be an endothermic and spontaneous process. Electrostatic and Lewis acid-base interactions, in addition to ion exchange, were found to be the main mechanisms of phosphate adsorption.



Effects of different ZnO nanoparticles on ion absorption in human gastric epithelium cells

WANG Mimi, WU Minghong, WANG Yanli

2021, 27(4):  696-705.  doi:10.12066/j.issn.1007-2861.2170

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This paper systematically studied the effects of different types and low concentrations of ZnO nanoparticles (NPs) on the uptake of Fe$^{3+}$, Ca$^{2+}$ and Mg$^{2+}$ in human gastric epithelium cells-1 (GES-1). The results showed that ZnO NPs had the most significant impact on the absorption of Fe$^{3+}$. The changes in the three ion concentrations in GES-1 were related to the size and concentration of ZnO NPs. Among them, the effect of 50 nm ZnO NPs on the absorption of ions was the most significant, reaching the highest concentration at 15 mg/L. However, the hydrophilic and lipophilic properties of ZnO NPs had no obvious effect on the absorption of ions. Finally, the mechanism of ion adsorption was discussed by detecting the cell viability and reactive oxygen species (ROS) levels of different types of ZnO NPs.



Controlled synthesis of NiFe₂O₄/Co₉S₈ nanocomposites derived from metal-organic frameworks as efficient electrocatalysts for oxygen evolution reaction

WANG Shangdai, HUANG Shoushuang, HU Zhangjun, CHEN Zhiwen

2021, 27(4):  706-716.  doi:10.12066/j.issn.1007-2861.2154

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This paper reported the controlled synthesis of NiFe₂O₄/Co₉S₈ nanocomposites via annealing and sulfuration of metal-organic frameworks (MOFs). Due to the porous structure and the strong synergetic effects between the different composites, the as-prepared NiFe₂O₄/Co₉S₈ nanocomposite catalysts afforded an electrocatalytic oxygen evolution reaction (OER) with a current density of 10 mA/cm2 at a low overpotential of 290 mV and a small Tafel slope of approximately 63.02 mV/dec in 1 mol/L KOH. Moreover, the NiFe₂O₄/Co₉S₈ nanocomposite catalysts showed outstanding stability without obvious decline after 1 000 cycles of sequential cyclic voltammetry (CV) scanning. The findings not only provide a promising strategy for designing efficient and stable OER catalysts but also can be extended to synthesize other novel nanocomposite materials.



Analysis on the influencing factors of online promotion of air environmental protection technologies

LIU Zhaoxiang, WANG Shutang, WANG Jing, TANG Yandong, ZHANG Xiaolan, GAO Lili, SUN Jialiang

2021, 27(4):  717-729.  doi:10.12066/j.issn.1007-2861.2203

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At present, the development of the online platform for the promotion of air environmental protection is still in its initial stages. Furthermore, little data analysis has been conducted on the factors influencing the platform, which is not conducive to the development and promotion of the platform. Therefore, this paper used the analogy and research methods to analyse the users' behaviour and users' needs of online platforms. It was found that users in places such as Beijing, Jiangsu, Fujian and Shandong paid the top four attention to online platforms, accounting for 12.69%, 8.6%, 8.73%, and 8.49% of the total page views (PV), respectively. China, South Korea, and the United States were the top three sources of air environmental protection technology in the world, with China accounting for 61% of the total. Although the environmental protection technology had developed at a rapid pace in China, users still showed a high degree of interest and trust in foreign technology, resulting in only 10% of users using or considering domestic technology. The denitration technology received the most users' attention. In addition, the government platform had the strongest credibility, whereas the commercial platform, although rich in resources, had low credibility. The analysis of users' access interactive data within the platform revealed that the factors influencing the promotion of environmental protection technology online included the technology promotion platform's influence, integrity, friendliness and value. Therefore, the development of an online promotion platform for air environmental technology should involve solving the problem of platform promotion, as well as ensure the integrity of platform technology, enterprises, content and other information, specification and value promotion.



Monitoring and evaluation of noise at Baoshan Campus of Shanghai University: a case study

XU Xueli, CAO Lina, DONG Xianling, SHI Xiang, LI Yang, WEI Songliang, LI Zheng, LI Hanye, DONG Shaodong, NIU Yinghu, LI Yuanhang, DONG Peng, BAI Yuxing, ZHANG Xiaolan, HAO Ying, ZHU Chenguang, CHEN Xueping

2021, 27(4):  730-740.  doi:10.12066/j.issn.1007-2861.2185

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To develop a high-quality learning and living environment for staff and students, noise was monitored and evaluated at Baoshan Campus of Shanghai University. Ten sampling sites representing three functional regions, study and work areas, living areas, and sports areas, were established. Noise was monitored continuously in the fields for 7 d, and the data were analysed using the equivalent continuous A sound level method and the noise pollution index method and assessed according to the national sound environmental quality standards. The sound environmental quality in living areas was relatively good at night, however, sports areas exhibited heavy noise pollution during this time, affecting the students and staff's work, study and life. The sound environment of Shanming canteen during the day and the Fengyu playground during the day and night exceeded the standard seriously. The sound environment quality of the building of School of Mechatronics and Automation during the whole day is good. In summary, the sound environmental quality at Baoshan Campus of Shanghai University, was generally acceptable for people's study, work and life.



Preparation of PDMA_s-PS_x block copolymer nanoparticles by RAFT dispersion PISA

LIANG Haiyang, YANG Yongqi, ZHANG Ling

2021, 27(4):  741-748.  doi:10.12066/j.issn.1007-2861.2166

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Reversible addition-fragmentation-chain transfer (RAFT) polymerization-induced self-assembly (PISA) is a versatile and powerful strategy for preparing block copolymer nanoparticles with specific morphologies. Ethanol was used for the RAFT dispersion polymerisation of styrene (St) at 70 $^\circ$C. PDMA$_{23}$ and PDMA$_{38}$ were chosen as macromolecular chain transfer agents (CTAs). The transformation of the morphologies was altered by varying the degree of polymerizations (DPs). The experimental results showed that spheres, worms, vesicles, and compound vesicles were obtained using PDMA$_{23 }$ as the CTA. However, only well-distributed spherical nanoparticles were obtained when PDMA$_{38 }$was employed as the CTA.



Strategy of cross-border E-commerce dual-channel supply chain under different cooperation scenarios

ZHOU Huijun, YAN Wei, HE Junliang, LI Hui

2021, 27(4):  749-765.  doi:10.12066/j.issn.1007-2861.2254

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This study considerd the impacts of responsibility cost and quality improvement on supply-chain enterprises' decisions and profits. Stackelberg decision models ofnon-, one-way-, and two-way-cooperation were constructed based on a structure of a cross-border E-commerce dual-channel supply chain composed of an overseas supplier and a domestic retailer. In addition, the pricing strategy, quality selection decision, and profit were analysed using comparison under different cooperation scenarios. The results revealed that the overseas supplier's wholesale prices of domestic retail channels were reduced in three cooperation scenarios, and was the lowest in the two-way-cooperation of the overseas supplier and domestic retailer. In the one-way-cooperation, the profit of the overseas supplier or the domestic retailer could be increased, and the Pareto improvement couldn't be achieved. In the two-way-cooperation, the Pareto improvement could be achieved, but the space of cooperation was limited.



Multi-class expressway traffic control for reducing congestion and emissions based on fuzzy non-dominated sorting genetic algorithm

CHEN Juan, JING Hao, SUN Xiangyang

2021, 27(4):  766-784.  doi:10.12066/j.issn.1007-2861.2244

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To minimise traffic congestion and emissions on urban multi-class expressways, five performance indicators were considered, such as total travel spent (TTS), total travel distance (TTD), ramp queuing, exhaust emissions, and fuel consumption. The macro traffic flow model (Multi-class METANET) and emission model (Multi-class VT-macro) were improved. A new high-dimensional multi-objective optimisation algorithm, fuzzy non-dominated sorting genetic algorithm (FNSGA-Ⅲ), was proposed to optimise the on-ramp inflow rate on expressways and the variable speed limit (VSL) on main roads. The new algorithm, FNSGA-Ⅲ, aimed to alleviate traffic congestion, save energy, and reduce emissions simultaneously. This proposed algorithm, which was based on an adaptive network-base fuzzy inference system (ANFIS), could effectively guide the evolution direction of the optimisation algorithm in the iteration process and improve the convergence speed. Based on the actual road network of Guangzhong Road in Shanghai, a simulation was performed. The results showed that the proposed FNSGA-Ⅲ algorithm and the improved multi-class macro traffic flow model could reasonably set the desired speed and ramp control strategy. Hence, compared with the existing single-objective genetic algorithm and multi-objective NSGA-Ⅲ, the proposed algorithm and improved model could effectively alleviate traffic congestion and reduce emissions.



Coupling synergy measure of Sci-Tech innovation and financial development in China: screening based on VIF-variation coefficient

ZHU Jiahui, YU Liying

2021, 27(4):  785-794.  doi:10.12066/j.issn.1007-2861.2169

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A preliminary evaluation system consisting of 89 indicators was established based on the connotation of Sci-Tech innovation and financial development in China. The coupling synergy measurement indicator system was determined using data from 28 provinces and cities in China and the VIF-variation coefficient method. First, the coupling synergy measurement model for Sci-Tech innovation and financial development was constructed. Subsequently, the coupling synergy measurement and evaluation of the Sci-Tech innovation and financial development in China and 15 pilot areas in the past decade were conducted. The research showed that, overall, the comprehensive development indicator of China's Sci-Tech innovation and financial development was on the rise. The coupling degree of Sci-Tech innovation and financial development was low, and the coupling synergy degree gradually developed from high-level non-synergy to low-level synergy. Regionally, the degree of the pilot areas' coupling synergy had steadily increased and was higher than the overall level. The coupling synergy degree of eastern regions was higher than that of central and western regions. The results indicated that the development of Sci-Tech finance in the pilot areas was better. However, it was unsynchronised and unbalanced in the eastern, central, and western regions.



xperimental analysis and calculation of a hydration heat model for concrete

LI Dong, ZHANG Yechen

2021, 27(4):  795-802.  doi:10.12066/j.issn.1007-2861.2181

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Owing to the temperature field generated by early-hydration heat, mass concrete causes temperature stress cracking, affecting structural safety and normal use. The accuracy of the thermal parameters of concrete affects the accuracy of the concrete temperature-field calculations. Based on the hydration reaction of cementitious materials in concrete, theory of chemical reaction kinetics, and experimental data for cement hydration heat from different fly ash additives, a formulation of the hydration heat model for concrete was developed, considering the effects of fly ash and temperature. The model could accurately predict the heat release and temperature rise of the concrete hydration reaction with age, and the prediction results were in good agreement with the experimental data.



Evolutionary game analysis and control of public opinions during emergencies under different stages of communication and limited rationality

LI Mingkun, LI Hui, HE Hailong, GE Yibo

2021, 27(4):  803-814.  doi:10.12066/j.issn.1007-2861.2178

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Public opinion during emergencies has a great deal of impact on social stability and development. Hence, the government focuses on methods of controlling public opinion, using methods that can solve a problem in its infancy. This paper used the evolutionary game method and introduced the punishment game model, wherein the government punished public opinion, and the incentive game model, wherein the government provided positive news on emergencies so as to deduce the evolutionary direction of the behavior of public groups. The results showed that during the early stages of public opinion communication, increasing punishment or positive publicity by government departments would increase the punishment cost of public opinion communication, or increase the psychological benefits of public opinion non-communication, so as to further achieve the goal of controlling public opinion. This paper analyzed the characteristics of different development stages of emergencies by analyzing the “Kunshan anti-killing” and Shandong “insulting mother and killing” cases. It put forward suggestions for decision-making for the government to control public opinion during emergencies.