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Table of Content

    20 September 2021, Volume 57 Issue 5
    Application of Particle Swarm Optimization on the Multi-body System Dynamics with Singular Positions
    YANG Liusong, YAO Wenli, XUE Shifeng
    2021, 57(5):  795-803.  DOI: 10.13209/j.0479-8023.2021.035
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    Different from the traditional method, the mathematical optimization model is established with Gauss principle to handle the singular problems to deal with the singular problems. Traditional optimization method and intelligent optimization method (particle swarm optimization algorithm, PSO) are combined to solve the above optimization problem, which can fully utilize the fast convergence of the traditional optimization method and the characteristic of global searching of the intelligent algorithm. The numerical example is simulated by Lagrangian formulation, null space method and Gauss optimization method respectively. The simulation results show that Gauss optimization method has higher computational accuracy, keeps the stability of the numerical calculation and would not lead to simulation failure due to the sudden changes of the system degree of freedom, which validates the effectiveness and universality of the proposed method.
    Estimation of Area of Completed Houses Based on Statistical Yearbooks and Online Big Data
    YUAN Wen, WANG Jun, SHEN Hongyi, WANG Xinmin
    2021, 57(5):  804-814.  DOI: 10.13209/j.0479-8023.2021.020
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    The authors select several indicators in the Beijing Yearbook to construct an economic and social factor system, and uses partial least squares regression, LASSO regression and RBF neural network models to predict the area of completed buildings in Beijing in 2017 and 2018. However, considering the difference of statistical channels and granularity of the yearbook indicators, and the delay in the release of some indicator data for the construction industry in 2019, it is hard to estimate the area of the year by model fitting. Therefore, crawler technology is used to obtain high-quality data and dig deep to obtain information of online big data to estimate the completed area. Firstly, a web-based building data acquisition framework is established, to crawl the attribute data of eight types of buildings in Beijing by calling service interface, keyword search and other technologies. Secondly, regular expressions and conditional filtering are used to extract and clean the HTML data returned by web pages. Finally, the area of completed houses in Beijing and the area of each functional partition in 2019 are estimated.
    A Charge Recycling Scheme with Read and Write Assist for Low Power SRAM Design
    ZHANG Hanzun, JIA Song, YANG Jiancheng, WANG Yuan
    2021, 57(5):  815-822.  DOI: 10.13209/j.0479-8023.2021.039
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    In order to cut down the dynamic power of static random access memory (SRAM), a bitline charge cycling based read and write assist circuit for SRAM is presented. Compared with the traditional design, the assist circuit saves and reuses the bitline charge which should be directly discharged during read and write operation to reduce bitlines charging power consumption in the next cycle. The SRAM memory is built by the SMIC 14 nm FinFET spice model, and the power supply voltage is 0.8 V. The simulation results show that the power consumption of the proposed SRAM array is reduced by 23%–43% compared with the traditional design, and the SNM and WNM has increased by at least 25% and 647.9% respectively.
    Floor Plan Arrangement Based on Wafer-To-Wafer Bond Product
    YIN Zhuo, SU Yueyang, LUO Daiyan, MA Ying, WANG Gang, ZHU Na, LIU Lifeng, WU Hanming, ZHANG Xing
    2021, 57(5):  823-832.  DOI: 10.13209/j.0479-8023.2021.023
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    Wafer-to-wafer bond technology has breakthrough semiconductor manufacturing from 2D to 3D, but the bonded wafer brings more locating and patterning rules, it is too complex to layout the frame cells by traditional floor plan arrangement. This article provides a new floor plan arrangement method in face-to-face bonding product. It could setup all floor plans at same time only by flipping the motherboard. The new method is introduced. Final result with new method’s benefit is shown based on actually bonding product taping out procedure.
    Research of Sleep Staging Algorithms Based on ECG and Body Motion Signals
    LIU Zhong, WANG Xin’an, LI Qiuping, ZHAO Tianxia
    2021, 57(5):  833-840.  DOI: 10.13209/j.0479-8023.2021.079
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     In order to study the overnight sleep condition and analyze each stage of the sleep process, polysomnography (PSG) and actigraphy were used to collect the ECG signal and body motion data. The features of ECG signal and heart rate variability (HRV) were extracted and used as the characteristic parameters of the data. In order to improve the recognition rate and prevent over-fitting, the data were divided into training set and test set, and an improved BP neural network model with genetic algorithm was designed to train and predict the samples. The results show that the improved BP neural network can effectively identify the test samples, and the comprehensive recognition accuracy is 86.29%. Wearable devices that detect both ECG and body motion signals with sleep stage classifying algorithms, can be used for family sleep monitoring and as a primary screen method for sleep disorders.
    Correlation Analysis of Electromagnetic Disturbance and Earthquakes Based on AETA
    YONG Shanshan, WANG Xin’an, GUO Qinmeng, LIU Cong, YANG Chao, WANG Jing, JIANG Binghui
    2021, 57(5):  841-851.  DOI: 10.13209/j.0479-8023.2021.078
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    According to electromagnetic disturbance (EMD) data based on AETA, a multi-component seismic monitoring and prediction system, this paper conducts features analysis, anomalies identification and correlation analysis combining with seismicity. The result shows that EMD data are different with environmental noise and human noise. It might be generated by the change and movement of free charge near the surface according to the principle of magnetic sensor and the derivation of Maxwell’s equations. Take Jiuzhaigou Ms 7.0 earthquake and Changning Ms 6.0 earthquake in Yibin as examples, a determined connection between EMD anomalies and earthquake was found. Periodic SRSS and ultra-low frequency EMD along the relerant bands of the Longmenshan fault and Xianshuihe fault zones might imply a risk of strong earthquake. We also discuss the physical mechanism of the EMD source and suggest that it may be related to the overflow of charged particles from the molten mantle into the crust. Under movement of earth rotation and revolution, the daily periodic fluctuation of the sunrise and sunset will occur in a specific related latitude and longitude region or area close to epicenter.
    Redescription of Chaohuperleidus Primus (Actinopterygii, Perleidiformes) from Lower Triassic of Anhui Province, South China
    DAI Yanlin, SUN Zuoyu, LU Hao, JIANG Dayong, ZHOU Min
    2021, 57(5):  852-864.  DOI: 10.13209/j.0479-8023.2021.064
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    Chaohuperleidus primus has yet to be completely described due to the limit of the original material which were collected from Upper Member of the Nanlinghu Formation (Spathian, Olenekian, Early Triassic) at Majiashan quarry, Chaohu City, Anhui Province. The taxon was redescribed in detail by adding three complete specimens from the type horizons. The generic diagnosis of Chaohuperleidus was revised mainly based on newly recognized anatomical information, of which the following characters ‘the fused parietal and dermopterotic with anterior, middle and posterior pit-lines; the operculum and suboperculum of nearly equal in height with the latter having a large rounded anterior dorsal process’ were possible apomorphies of Chaohuperleidus. The previous taxonomic assignment of the Chaohuperleidus was confirmed, which was similar to the Ladinian (Middle Triassic) genus Perleidus but differed the latter in having more suborbitals, branchiostegal rays and epaxial fin rays besides its possible apomorphies. The skull pattern of the Chaohuperleridus primus was exhaustively reconstructed and was anatomically compared with the Early Triassic taxa which were wrongly classified into the Perleidiformes and some newly described stem neopterygians. The result herein will provide new anatomical evidences for the phylogeny analysis of the stem neopterygians that is open to discuss.
    Diverse Mechanism of the Tibetan Plateau Effect on the North Atlantic Deep Water Formation on Seasonal Timescale
    SHAO Xing, YANG Haijun
    2021, 57(5):  865-874.  DOI: 10.13209/j.0479-8023.2021.062
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    Using the fully coupled model CESM1.0, the seasonal difference of the Tibetan Plateau (TP) effect on the North Atlantic deep water (NADW) formation mechanism is investigated qualitatively by comparing the sensitivity test without the TP and the control test with realistic topography. The result shows that the TP effect on the mechanism of the NADW formation varies with the seasons. The NADW formation decreases when the TP is removed, the significant increase of net surface heat flux in cold season (October to March of two consecutive years in the Northern Hemisphere) dominates the prominent decrease of the NADW formation, however, the significant increase of freshwater flux due to the mass of sea ice melting leads to the remarkable decrease of the NADW formation in warm season (April to September of the same year). The TP has a more significant effect on the NADW formation in the low resolution coupled model. The main difference of the TP effect on the NADW formation mechanism in different seasons is that the presence of TP topography increases the sea surface heat loss of the NADW formation region in cold season, also leads to decrease of the freshwater input from the northern sea ice in warm season.
    Accessibility of Public Service Facilities in Beijing and Its Impact on Housing Prices
    LI Ranhao, GONG Shize, GAO Yong
    2021, 57(5):  875-884.  DOI: 10.13209/j.0479-8023.2021.065
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    With the purpose of analyzing the spatial distribution and fairness of public service facilities in Beijing, Gauss two-step floating catchment area method is applied to assess the accessibility within the Fifth Ring Road of Beijing in 5 dimensions, including education, healthcare, commerce, transportation, and culture leisure service, and the weighted composite accessibility is calculated. Then, hedonic price model is adopted to further analyze the impact of public service facilities accessibility on housing prices. It is found that the accessibility of public service facilities is unevenly distributed, and most resources are concentrated on certain district. The accessibility of education and healthcare service is significantly higher in the central urban area than that in other regions, and commerce accessibility in the eastern area is higher than that in the western. Transportation and culture leisure resources are relatively scattered. There is a significant positive impact of healthcare and transportation accessibility on housing price, a significant negative impact of commerce accessibility and no significant effect of education and culture leisure accessibility on housing price. The comprehensive accessibility is also proved to have a significant positive impact on housing price. These results provide support for urban planning, especially for the rational distribution of public service facilities.
    Travel Movement Pattern Extraction Based on Social Media Data
    SUN Qi, ZHANG Yi, ZHAO Pengfei, WU Mengtong
    2021, 57(5):  885-893.  DOI: 10.13209/j.0479-8023.2021.063
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    The authors propose a method to extract individual travel spatiotemporal behaviors from social media data, and then mine the group based on massive spatiotemporal behaviors. This study collects more than 40 million global geographic microblogs from users who have visited Suzhou, extracts 88270 tourism trajectories, and identifies 36 classes of inter-city tourism movement patterns in five categories. It is found that the extracted patterns conform to the LCF theoretical model; besides the simple movement patterns, there are more complex composite movement patterns. Based on big data, more accurate tourism movement patterns can be obtained, which helps tourism managers understand tourists’ trends and preferences, adjust destination marketing strategies, optimize tourism resource allocation, and provide better services for tourists.
    Effects of Microplastics and PFOS Co-exposure on the Filtration Rate and Antioxidant System of Perna viridis
    XU Peng, Muhammad Junaid, LIU Yan, CHEN Yupeng, BI Chunqing, XU Nan
    2021, 57(5):  894-902.  DOI: 10.13209/j.0479-8023.2021.066
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    In order to explore the composite pollution toxicity mechanism of microplastics and perfluorooctane sulfonate (PFOS) in Perna viridis, the effects of PFOS (10, 100, 1000 μg/L) and microplastics (0.2 μm, 4.55×108 numbers/L) were studied under single- or co-exposure on the filtration rate, reactive oxygen level (ROS), malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, catalase (CAT) activity, glutathione S-transferase (GST) activity and gluathione reductase (GR) activity. The results showed that the filtration rate of mussels after exposure to microplastics and PFOS did not change significantly compared to the solvent control. In gills, visceral mass and gonads of mussels, the stress of microplastics and PFOS could cause significant changes in enzyme response. After co-exposure of microplastics and 1000 μg/L PFOS, compared with single-PFOS exposure groups, ROS level significantly increased in gills and gonads, whereas decreased in visceral mass; MDA content increased in gills and visceral mass, whereas decreased in gonads; GST and GR activity was significantly reduced in gills, whereas increased in gonads. The results indicated that microplastics could change the oxidative stress response of mussels to PFOS.
    Salinity Influencing the Formation of Special Niches of Bacterioplankton in Pearl River Estuary, China
    MEI Siyu, YU Ke, CHEN Baowei
    2021, 57(5):  903-915.  DOI: 10.13209/j.0479-8023.2021.067
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    This paper investigated the ecological status of bacterioplankton in the Pearl River Estuary (PRE) through processing and analysis of 16S rRNA gene sequences obtained by high-throughput sequencing and detecting the most influenced environmental factor and the ecological niche formed by it. The results indicated that salinity was the main environmental parameters affecting the Alpha and Beta diversity of bacterioplankton in the PRE. The salinity was divided into three sequential groups: low, middle, high. The bacterioplankton in the low salinity samples had relatively high genetic diversity. The community composition analysis showed that the taxonomic information of the dominant and core OTUs of bacterioplankton under total samples and salinity groups in the study area varied widely. The dominant OTU in the total samples were Proteobacteria and the core OTUs were mostly from Acidobacteria. While the low salinity’s core OTU family were mainly C111, but the middle and high salinity samples’ were OCS111 from Acidobacteria. Moreover, the core OTUs in low salinity did not overlap with the middle and high salinity’s. Cross-grouping based OTU level on salinity and co-occurrence network analysis of the bacterioplankton showed that under the subdivided salinity grouping, OTU community formed closely related and respectively independent co-network modules, and the species composition within the modules was complex. The results showed that the salinity can effectively explain the formation of complex, closely related and independent modules of bacterioplankton, and ecological niches with specific functions, in the PRE.
    Climate, Health Impacts, and Social Costs of Electric Vehicles in China: A Cost-Benefit Analysis
    HU Yuhan, JIN Yana, ZHANG Shiqiu
    2021, 57(5):  916-926.  DOI: 10.13209/j.0479-8023.2021.068
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    By applying the probabilistic benefit-cost analysis with Monte Carlo simulation, this study reveals the energy- and life-cycle climate and pollution-related health impacts, and various social costs in China of gasoline-to-electric vehicle (GV-to-EV) substitutions. Key factors influencing these estimates are also elicited. Results indicate that a GV-to-EV substitution can annually achieve benefits of 324 yuan on climate, 343 yuan on health, and 4315 yuan on energy savings in the energy cycle under current technical conditions and the dynamics of power grid development. However, these benefits are offset by the incremental manufacturing cost (16000 yuan/car-year), and the social welfare improvement over the life cycle is negative in the short run. This study highlights the importance of prioritizing GV-to-EV substitutions only in areas with high health, climate, and energy-saving benefits.
    Microbial Structure and Function of Activated Sludge in Landfill Leachate Treatment Plant
    ZHANG Xue, QIAO Xuejiao, SU Jia, ZHANG Liyu, YU Ke
    2021, 57(5):  927-937.  DOI: 10.13209/j.0479-8023.2021.069
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    16S rRNA gene and metagenomic sequencing was applied to study the structure of microbial community, functional microorganisms and genes in activated sludge of landfill leachate treatment. The results showed that Calditrichaeota was the most abundant phylum (58.77%), followed by Proteobacteria (16.80%) and Bacteroides (6.19%). Calrithrix was the dominant genus of the activated sludge (58.77%). Five nitrogen cycle pathways were detected to form the microbial community of activated sludge, including nitrification, denitrification, assimilation nitrate reduction, dissimilation nitrate reduction and nitrogen fixation. Denitrification genes were the most abundant among nitrogen cycling process (78.84%), which mainly distributed in Calditrichaeota, Proteobacteria and Choroflexi. Nitrification was achieved by ammonia oxidizing bacteria Nitrosomonas. There were abundant organic pollutants degradation genes in activated sludge. Proteobacteria, Bacteroides, Planctomycetes, Calditrichaeota and Choroflexi were typical functional microorganisms that can degrade organic pollutants. 
    Forecasting Ozone and PM2.5 Pollution Potentials Using Machine Learning Algorithms: A Case Study in Chengdu
    WANG Xinlu, HUANG Ran, ZHANG Wenxian, LÜ Baolei, DU Yunsong, ZHANG Wei, LI Bolan, HU Yongtao
    2021, 57(5):  938-950.  DOI: 10.13209/j.0479-8023.2021.070
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    Potential forecast models have been developed for air pollution of summertime (Apr.–Aug.) ozone and wintertime (Nov.–Feb.) PM2.5 in Chengdu using the multiple linear regression (MLR), back-propagation (BP) neural network (NN) and random forest (RF) algorithms. The key predicting factors for each of the models are selected from various potential factors that may impact the spatiotemporal distribution of pollutions. The models are trained and established with 2016–2018 datasets and evaluated with a data-withheld method and further with independent 2019 dataset. The results show that the MLR, NN and RF models are all capable to accurately predict O3 and PM2.5 pollution potentials in short lead-time (1–3 days) in Chengdu. The models are also found having quite stable performances in medium- and long-term (7–15 days lead time) forecasts. Among the three models, the MLR model performs the best in prediction of O3, while RF model performs the best for PM2.5.
    Optimization of Energy Consumption Right Quotas through the Consideration of Responsibility Transfer Among Industrial Sectors
    YANG Shunshun
    2021, 57(5):  951-962.  DOI: 10.13209/j.0479-8023.2021.072
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    The historical method and benchmarking method ignore the responsibility transfer among industrial sectors which result from embodied energy consumption. The author established a quotas optimization model considering the responsibility transfer among industrial sectors based on input-output analysis and consumer responsibility, and conducted case studies taking 2025 as the target year. The results show that under “historical and benchmarking method”, the tasks of energy conservation and emission reduction will be mainly undertaken by sectors of energy supply raw and material production with weak energy intensity reduction targets in the future. The quota optimization process considering the responsibility transfer among industrial sectors is divided into two stages: historical quota compensation and trend quota correction. The author designed a scenario of weak stable development which considered the impact of COVID-19. After quota optimization which is carried out with direct and total industrial energy consumption as the core indicators, the responsibility for energy conservation and emission reduction are extended from the sectors of energy supply and raw material production to the discrete manufacturing sector. The main beneficiary sectors are textile sector, papermaking and printing sector, manufacture of wood and furniture. Due to the quota flow relationship among various sectors, the energy sector, mining and quarrying, foods, textile, papermaking, petrochemical, metal smelting sectors, manufacture of electrical machinery can preferentially access to the energy consumption right quotas trading market. This work provides suggestions for the operation of China’s energy consumption rights trading market.
    Spatial Evolution Characteristics and Influence Mechanism of Retail Businesses in National New Area: Evidence from Liangjiang New Area of Chongqing
    HUANG Shengyi, CHAO Heng, LI Guicai
    2021, 57(5):  963-974.  DOI: 10.13209/j.0479-8023.2021.076
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    Based on the POI (point of interest) data of retail businesses and the field investigation information in Liangjiang New Area of Chongqing during 2010–2019, using GIS space analysis and qualitative research method, this article discusses and analyzes the evolution characteristics and influencing mechanism of retail business space in National New Area. The research states that: 1) in 2010–2019, the retail outlets in Liangjiang New Area was in “multiple point” increasing and “circle type” spreading, and the overall space distribution mode was transforming from “single center” to “multi centers”. 2) The distribution of comprehensive retail outlets and food outlets is less affected by the spatial location, showing the evolution characteristics of “largely spread and largely gathered”. The distribution of outlets such as shopping mall, textile and clothing, sports, medicine and home appliances prefer mature business circles, showing the evolution characteristics of “small spread and largely gathered”. Automobile and furniture outlets expand significantly in the peripheral groups, showing the evolution characteristics of “largely spread and small gathered”. 3) With the inter impacts on elements of opening up the window of opportunity under national strategy, outlets gather forced by external demands and scale effect, the path dependency and historical contingency in the evolution of retail formats, location specificity selection among retail profession, institutional thickness constructed by “entrepreneurial government”, and so on, the evolution of retail business space is being influenced. 
    Study on Characteristics of Three-Dimensional Cool Island Effect and Evapotranspiration Contribution of Individual Urban Tree
    WEN Haiyan, YAN Chunhua, GAO Huihui, CHEN Zhi, HUANG Wanbin, QIU Guoyu
    2021, 57(5):  975-982.  DOI: 10.13209/j.0479-8023.2021.077
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    Through three-dimensional observation and numerical analysis of evapotranspiration characteristics and cool island response of individual urban trees, the cause of vegetation cold island effect was analyzed quantitatively. The results show that 1) the absolute value of cool island intensity in various parts of Ficus microcarpa was basically above 3.0°C, while at surface front (SF), the temperature difference could reach the maximum of ?5.19°C and surface top (ST) can reach to ?3.57°C. 2) The evapotranspiration rate of leaves in the east, SF and SR (surface right), was start to rise firstly, and the leaves in the west, SL (surface left) and SBa (surface back), have the highest evapotranspiration rate at noon while the leaves in the west (SL, SBa) reached the peak later. The transpiration of all parts at night was very weak, less 0.05 mm/h. 3) The overall cool island effect intensity were positively correlated with evapotranspiration rate (pearson correlation coefficient was 0.70, with a significance lower than 0.01). For every 1 mm/h increase in evapotranspiration, the temperature of the whole tree decreased by 3.56°C. Evapotranspiration of surface top contribute obviously to the cool island effect of surface top itself with a correlation coefficient ?0.61. Evapotranspiration of surface top, surface front and surface right have the largest contribution to cool island effect of the whole tree (correlation coefficient absolute value is greater than 0.60). Contribution order of different parts’ evapotranspiration to overall cool island effect is: SF>ST>SR>SL> SBa>SBo (surface bottom), that means east and top side>west side>bottom.
    Impact of Socioeconomic Status Expectation on the Academic Achievement among Rural Students
    DAI Yuwan, HOU Yubo
    2021, 57(5):  983-990.  DOI: 10.13209/j.0479-8023.2021.071
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    Using the Wisconsin model of status attainment as a theoretical basis, the effect of students’ and parents’ expectations of socioeconomic status on student academic achievement was explored through a paired survey of high school students from rural areas and their parents. The result showed that expected future SES was a significant and positive predictor of students’ academic achievement, but there was no correlation between current SES and academic achievement. These findings suggest that it is not the current status of family class that affects rural students’ academic achievement, but rather students’ expectations of the future class they will be in. Therefore, stimulating rural students’ positive expectations about their future is an effective path to improve their academic achievement and ultimately break the class rigidity.