Table of Content

20 July 2023, Volume 59 Issue 4

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Dynamical Effects of the Load on Self-sustained Oscillators

JU Xiaolin, WANG Hongli

2023, 59(4):  539-546.  DOI: 10.13209/j.0479-8023.2023.029

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The effect of loads on self-sustained oscillators was studied by using numerical simulations and theoretical analysis with simple biological and chemical oscillators. Analyses of dynamical properties of the oscillators revealed that, the scheme in which the oscillators driving the load through indirect coupling via an insulator helped keeping the robustness of dynamical properties of the oscillators. The binding affinity between the load and its upstream module and the total amount of functional insulator were two key parameters that affected the relative amplitude of the load. The introduction of insulator module to the system can break the trade-off between the oscillations of the load and the retroactivity in the direct coupling scheme. Calculations of the free energy dissipation suggested that an increase in the free energy dissipation did not necessarily mean a decrease in the retroactivity or enhanced oscillations in the load.

Regression Analysis of Building Scale Data and Estimation of Demolition Rate

LIU Debin, JIN Zeyu, KE Zhifa, XU Fangfang

2023, 59(4):  547-554.  DOI: 10.13209/j.0479-8023.2023.043

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Since the statistical data of the completed area in different statistical yearbooks are quite different, this paper proposes a weighted regression model to analyze the statistical values of the completed area in order to analyze and confirm the data sources by combining the relevant data in the statistical yearbooks, such as urban land demand, social development level, etc. On the other hand, there are only the cumulative demolition area in the statistical yearbooks, and the annual statistical data of demolition area is missing. To estimate the demolition rate, a constrained regression model is established to calculate the annual demolition area of each province based on the national population census data, urban land demand, social development level, and other relevant data. The numerical results can provide a reference for understanding the actual situation of building scale in China over the last two decades, as well as making policies of energy conservation and emission reduction.

Design and Implementation of an Energy Efficient Dual-Issue Processor

ZHANG Xinyu, LIU Liang, WANG Chunmeng, JIANG Song, YI Jiangfang

2023, 59(4):  555-562.  DOI: 10.13209/j.0479-8023.2022.112

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In order to improve performance with stable power consumption, based on ECore embedded processor platform, which had a single-issue in-order pipeline structure originally, two lightweight superscalar structures were introduced: selective register renaming and dual issue of compact instructions. The experimental data showed that the average utilization of dual-issue structure reached 28% by adding dual issue logic. Using selective register renaming, the average stalling rate caused by name hazard reduced from 7.2% to 0.6%. Compared with the original design, the IPC increased 4.8% and the power consumption only increased 2.5%.

Consistency Assessment of Remote Sensing Dataset Based on Deep Learning

YAO Zhaoyuan, MA Lei, WAN Wei, SONG Benqin, WANG Weihong, DENG Jiwei, XIAO Lei, JI Rui, WEI Zhihao, CUI Yaokui

2023, 59(4):  563-568.  DOI: 10.13209/j.0479-8023.2022.116

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The current deep learning studies on remote sensing mainly focused on deep learning algorithms rather than deep learning datasets. This study proposes a method of dataset consistency assessment based on deep learning, in which the similarity among various types of ships from different sources (such as satellite remote sensing, 3D modeling, and web crawler) is evaluated and then used to characterize the consistency of the ship dataset. The results show that when the consistency of the dataset is the highest, the consistency by the proposed method is 1. When the consistency of the datasets is gradient, the consistency also changes. Images with similar data sources can be considered as same class, and images with greatly differences cannot be merged. Thus, the proposed method can assess the dataset consistency properly, and provide a suggestion to build an image dataset for deep learning training. 

Characteristics of the Northward Propagation of Summer Intraseasonal Oscillation over the Tropical Indian Ocean

LIU Ya, YANG Haijun

2023, 59(4):  569-580.  DOI: 10.13209/j.0479-8023.2023.044

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The propagation process and characteristics of tropical intraseasonal oscillation (TISO) in Indian Ocean from 1985 to 2017 (from May to October) are investigated using high-resolution satellite data and reanalysis data. There are three types of northward propagation of the TISO in Indian Ocean. The stable type: the convective signal is originated from the south of the equator, in the Western Indian Ocean, then steadily propagates northward to the Indian Peninsula. The attenuated type: it is similar to the stable type in the early stage, but attenuates rapidly after it propagating northward to the Bay of Bengal. The enhanced type: there is no strong convective signal in the early stage, about ten days later, the signal changes from the southern of the Indian Peninsula begin to intensify and developed the Himalayas. During the northward propagation of TISO, convective anomalies are accompanied by easterly shear anomalies, sea surface temperature (SST) anomalies and water vapor disturbances in the boundary layer, which have different effects on the three types of propagation. The positive sea surface temperature anomalies on the north side of convective events will promote the northward propagation of convection, playing a significant role in both stable and attenuated equatorial propagation processes, but the positive SST anomalies is more significant on the south side of the convective event in the enhanced type and inhibits the northward propagation of the convective event. The easterly vertical shear mechanism provides a continuous impetus for the stable propagation of the stable and enhanced types of events, with more significant effects later in the events. The disturbed water vapor in the boundary layer aggravates the instability of the atmosphere and induces the convection system to move northward before and after the stable events, the early attenuation events and the occurrence of the enhanced events. The research results can help improving the accuracy of predicting summer intraseasonal precipitation in Southeast Asia. 

Characteristics and Dissimilarity of Turbulent Transport of Heat and Momentum in Summer Unstable Atmospheric Surface Layer in Taklimakan Desert and Its Physical Mechanisms

ZHANG Lu, PENG Yan, LI Qianhui, ZHANG Hongsheng, HE Qing, Ali Mamtimin

2023, 59(4):  581-592.  DOI: 10.13209/j.0479-8023.2023.045

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Based on the near-surface atmospheric turbulence observation in the National Observation and Research Station of Desert Meteorology, Taklimakan Desert of Xinjiang in July 2016, the characteristics of turbulent transport in the unstable atmospheric surface layer in the hinterland of Taklimakan Desert are investigated. With the methods of eddy covariance, quadrant analysis, and spectra analysis, the dissimilarity between the turbulent transport of heat and momentum under different atmospheric instability is analyzed, and its potential physical mechanism is further explored. The results indicate that, under near-neutral conditions, the turbulent transport of heat and momentum is similar. However, as the atmospheric instability increases, the transport dissimilarity between heat and momentum becomes increasingly significant. Heat is transported more efficiently than momentum, while the turbulent transport of momentum shows a great randomness under the strongly thermal condition. This dissimilarity is closely related to the topology of turbulent coherent structures. Under unstable conditions, the coherent structure is dominated by thermal plume. It can induce synchronous changes in potential temperature and vertical velocity, but is difficult to lead corresponding changes in horizontal velocity. The difference in the physical mechanism of turbulent motion is the main reason for the significant dissimilarity between the turbulent transport of heat and momentum with increasing atmospheric instability.

Offshore Comparative Test for HF Ground Wave Radar Based on Integrated Monopole Cross Loop Transceiver Antenna

XU Xinjun, LU Tianyi, YANG Fan, SHI Xinzhi, WEI Jun

2023, 59(4):  593-601.  DOI: 10.13209/j.0479-8023.2023.021

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To verify the feasibility of an antenna system with integrated transmitting and receiving antennas for use on OSMAR-S high frequency radar, an experiment of radar observation with time series of sea currents observed by Acoustic Doppler Current Profiler (ADCP) in situ was conducted within the Pearl River Estuary from November 25 to December 1, 2021. The experimental results show that the radar and ADCP observations are in high agreement, with correlation coefficients as high as 0.916. The magnitudes and changes with time of the amplitudes of the main sub-tides (M2 and K1) obtained by the reconciliation analysis and other methods are in high agreement. The experiment indicates that the transceiver antenna system, on the basis of its advantages of small footprint, low cost and convenience to set up on the seashore, still has high accuracy for in situ current observations.

Mangrove Ecological Management Online System Based on WebGIS

ZHANG Zhi, LI Ruili

2023, 59(4):  602-608.  DOI: 10.13209/j.0479-8023.2023.042

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For the daily management and application of mangrove ecological data, this study developed an efficient and convenient lightweight mangrove ecological management online system based on the express framework of NodeJS, Leaflet map library, MySQL database and GeoServer platform. The system integrated GIS technology, network technology and database technology, and could realize the collection, unification, sharing and visual display of big data of mangrove ground survey. The health status of Futian mangrove forest and the spatial distribution of the pests were analyzed and visualized by the system. The results showed that the experimental area and the core area suffered less pests, while the buffer area suffered more serious pests. The health status of mangrove forest in the core area was higher than that in the buffer area and the experimental area. The system can provide comprehensive and accurate basic data and scientific decision support for mangrove ecological protection, and improve the management level and efficiency of mangrove protection department. 

Vector Magnetometer for Space Applications Based on a Magnetoresistance

YU Xiangqian, LI Jiawei, XIAO Chijie, HUANG Cong, LIU Si, WANG Jindong, LI Yunpeng, QU Yanan, WANG Yongfu, CHEN Hongfei, ZOU Hong, SHI Weihong, ZONG Qiugang, CHEN Xiaofei, ZHANG Xiaoxin, ZONG Weiguo, WANG Jinsong

2023, 59(4):  609-616.  DOI: 10.13209/j.0479-8023.2022.111

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A low-resource anisotropic magnetoresistance-based vector magnetometer for space science applications is presented. The proposed vector magnetometer can detect magnetic fields in a range of ±65000 nT, has a –3 dB bandwidth of DC to 10 Hz, and a noise power spectral density of ≤0.2 nT/Hz^1/2@1 Hz. Furthermore, the device has a non-linearity error of ≤3.6%oo over the entire range and non-orthogonality error of ≤1.2%oo. The vector magnetometer was equip on a Chinese Feng-Yun meteorological satellite (FY-3E) whose orbit was a sun synchronous orbit. The first in-flight science results show that the sensor can detect transient physical signals with amplitudes of 20–60 nT.

Effect of Logging Quota on Forestry Investment and Forest Protection: Empirical Analysis Based on Structural Equation Model

LIU Shilei, XIA Jun

2023, 59(4):  617-628.  DOI: 10.13209/j.0479-8023.2023.040

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Using a variety of data including forest resources inventory, forestry investment and quota compilation, this paper discusses the real impact of logging quota on forestry investment and forest protection through the two-way fixed effect model and the intermediary effect model. The study results show that the inhibitory effect of logging quota on forestry investment really exists, and its prominent effect is in social investment and foreign capital. At the same time, investment inhibition has played a masking effect between the logging quota and forest protection, offsetting the policy effect of quota management and causing a significant negative impact on forest protection. The conclusion will provide new ideas and references for the optimization of forest logging quota policy.

Study on Bird Species Richness and Its Maintenance Factors in Southwest China

CHEN Wenhua, XU Juan

2023, 59(4):  629-638.  DOI: 10.13209/j.0479-8023.2023.028

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Taking southwest China as an example, the optimal parameters-based geographical detector (OPGD) was used to study the single and comprehensive effects of climate, topography, vegetation and human activities on bird species richness in the region, and determine the optimal range of single factors that promote the maintenance of bird richness. The results suggest that the spatial differentiation of bird species richness in southwest China is mainly affected by vegetation and climate factors. In the independent influence of various factors, the vegetation factor is the most important contribution, and the total contribution rate of enhance vegetation index (EVI) and forest cover height (FCH) is 33.8%?34.7%. The interaction between the two factors enhances the influence of any single factor, and makes a significant nonlinear effect on birds richness. The study shows that the agent index of vegetation factor, especially the agent index of productivity, can better reflect the comprehensive status of the regional environment and is more suitable for the estimation of bird species diversity.

Changes of DOM Spectrum and Characteristic Index in the Tidal Reach of Minjiang River during Dry Season from 2018 to 2020

LIN Laichang, XIE Rongrong, WU Rulin, LI Jiabing

2023, 59(4):  639-648.  DOI: 10.13209/j.0479-8023.2022.107

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Three in-field investigations of dissolved organic matter (DOM) in the dry seasons from 2018 to 2020 were conducted in the Minjiang tidal reach. Three-dimensional fluorescence spectra of DOM of ebb and flow tides in different river sections were obtained. The correlation and principal component analysis (PCA) were used to assess the DOM fluorescence characteristic index. The results suggested that there were three types of fluorescence components in the research area including human-derived humic acid C1 (Ex/Em = 220–240 nm / 330–370 nm), terrestrial humic acid C2 (Ex/Em = 220–240 nm / 405–445 nm) and free amino acid and protein substance C3 (Ex/Em =255–285 nm / 310–360 nm). DOM in the upstream river reach was influenced by the reservoir operation and the human input. while in the middle river segment it was related to DOM component properties and the internal and external source input. The dilution and pollution block of sea water played important roles in the downstream estuary area. Besides, C1 was the characteristic pollutant in the research area. The FI, BIX and Fn(355) fluorescence characteristic index showed a decreasing trend year by year, while the HIX index decreased first and then increased. The FI and HIX index increased along the flow direction while BIX and Fn(355) decreased. Meanwhile, the exogenous and autogenic characteristics of the water close to the estuary were more obvious. Correlation analysis suggested that the DOM fluorescence characteristic index could be affected by the salinity and DO in the research area. Besides, dissolved total nitrogen and dissolved total phosphorus also had a great impact on the DOM fluorescence characteristic index when the upstream discharge flow was large. In addition, the PCA results indicated that the DOM fluorescence characteristics in 2020 were quite different from that in 2018 and 2019, which may also be related to the higher discharge from upstream. 

Process-Based Simulation of Spring Flowering and Autumn Leaf Coloration of Main Ornamental Plants in Beijing Botanical Garden

TANG Lingpei, CHEN Xiaoqiu, QIAN Siwei, MO Zhihong

2023, 59(4):  649-658.  DOI: 10.13209/j.0479-8023.2023.034

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Accurately simulating occurrence dates of spring flowering and autumn leaf coloration of ornamental plants is of significant importance for revealing phenological response of urban vegetation to climate change and predicting the optimum timing for flower and foliage viewing. This study employed the Unified Forcing Model (UniForc) and Unified Chilling Model (UniChill) to fit the first flowering and 50% flowering dates of 20 plant species from 1979 to 2019 in Beijing Botanical Garden, and the Low Temperature and Photoperiod Multiplicative Model (TPM) to fit the first leaf coloration and 100% coloration dates of 10 plant species. The errors of optimum models in simulation and prediction were evaluated. Results show that spring flowering of ornamental plants is mainly driven by forcing temperature during ecodormancy and growth periods, but less restricted by chilling temperature during endodormancy period. First leaf coloration of ornamental plants is mainly driven by the process of leaf senescence induced by daily minimum temperature decrease, and 100% leaf coloration is mainly driven by the process of leaf senescence induced by photoperiod shortening. The average simulated root-mean square errors (RMSE) for first flowering and 50% flowering are 3.7 days and 3.2 days, respectively, and simulated RMSEs for the two spring phenophases show good interspecific synchronization. The average simulated RMSEs for first leaf coloration and 100% leaf coloration are 9.4 days and 5.6 days, respectively, but simulated RMSEs for the two autumn phenophases do not display interspecific synchronization. Simulated RMSEs of flowering dates and leaf coloration dates of various plants correlate significantly and positively with their standard deviation of interannual variations. The simulated and extrapolating RMSEs of optimum spring and autumn process-based models are very close, indicating that the models have high robustness. 

Spatial Characteristics of Economic Relations of American Snow Sports and Its Enlightenment to China

FANG Yan, LIU Wenting, ZHANG Youyin, BU He

2023, 59(4):  659-670.  DOI: 10.13209/j.0479-8023.2023.035

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This paper measures the strength, direction, scope and pattern of the economic ties of American snow sports through the comprehensive use of gravity model, social network analysis and nuclear density analysis, so as to clarify the spatial characteristics of the economic ties of American snow sports, with a view to summing up its reference significance to China. The results show that the economic connection intensity of snow sports in the United States shows a decreasing pattern from east to west to middle. The economic connection direction of snow sports in the United States has regional proximity, economic development level, snow resource abundance and population size. The economic connection range of snow sports is distributed in four major ranges, and the radiation capacity is gradually decreasing from northeast to central to south to west. The economic connection pattern of snow sports in the United States is distinct, showing four vertical subgroups from east to west. Based on the development experience of snow sports in the United States and the current situation of China, the following suggestions are put forward. Based on resource advantages, fully radiate the vitality of the ski industry; taking economic development as the engine, innovate and tap the potential of skiing industry; guided by resource integration, give play to the regional synergy effect of skiing industry; guided by the leading effect, build four high-quality skating industry development zones in the east, west, north and south.

Impact of Lead Market on Transition Towards New Energy Technology in Automobile Industry in China

GAO Jian, TONG Xin, HE Canfei

2023, 59(4):  671-680.  DOI: 10.13209/j.0479-8023.2023.037

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This paper takes Chinese automobile industry as an example, and analyzes the technological transition towards new energy under the combined effects of market, policy and local cluster. The aim is to study the influencing factors of enterprises’ green technology adoption with a framework based on lead market theory. The results show that target market is an important driving force for enterprises to adopt new energy technology. But unlike the electronics and other export-oriented products, the enterprises of the automobile supply chain is mainly driven by the domestic market. The demand-side incentive policies through subsidies to new energy vehicle buyers are not sustainable, while the supply-side policies, such as the policy targeting close-loop supply chains for circular economy, have long-term effects on the adoption of new energy technology of enterprises. The enterprises are highly dependent on the technology diffusion of local traditional automobile industry clusters, while collaborative innovation among local new energy automobile enterprises needs to be further strengthened. In conclusion, the synergy of circular economy and low carbon development can be achieved through local collaboration within the industrial cluster in building the sustainable competitiveness for Chinese new energy automobile industry.

Impact of Urbanization and Industrial Collaborative Agglomeration on Land Use Efficiency of Resource-Based Cities in the Yellow River Basin, China

LI Xiaojing, HAO Jianhua, CAI Yinfei, SUN Yanan

2023, 59(4):  681-694.  DOI: 10.13209/j.0479-8023.2023.009

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Based on the panel data of 41 prefecture-level resource-based cities in the Yellow River Basin from 2000 to 2019 and the relationship between urbanization and industrial collaborative agglomeration on land use efficiency, this paper uses spatial autocorrelation analysis and spatial Durbin model to analyze the spatial spillover effect of urbanization and industrial collaborative agglomeration on land use efficiency. The threshold regression model is used to discuss the threshold characteristics of industrial collaborative agglomeration in resource-based cities, and the crowding effect matrix table is innovatively constructed. The results show that the land use efficiency among resource-based cities in the Yellow River Basin is geographically correlated with the same high agglomeration or the same low agglomeration in space, and the spatial spillover inhibitory effect of urbanization accounts for 70% of the total inhibitory effect, showing an inhibitory effect. The spatial spillover growth effect of industrial collaborative agglomeration accounts for 70% of the total growth effect, and the spatial spillover inhibitory effect accounts for 20% of the total inhibitory effect, which shows the role of rapid promotion and gradual inhibition. After 2014, the agglomeration effect of some resource-based cities in the Yellow River Basin has accelerated to the threshold, among which Luoyang, Shizuishan, Shuozhou, Wuhai and Jinchang perform well and have the best agglomeration. Baotou and Ordos form a collaborative relationship between cities. The industrial agglomeration of most resource-based cities is still insufficient or crowded, and the future development should combine the characteristics of the city itself to play a synergistic role between adjacent cities.

Nonlinearity Strength Indicators for Numerical Simulation Based Load Reduction-Water Quality Responses

SU Han, ZOU Rui, LIANG Zhongyao, YE Rui, WANG Zhiyun, LIU Yong

2023, 59(4):  695-703.  DOI: 10.13209/j.0479-8023.2023.036

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This study developed four nonlinearity strength indicators for water quality responses based on cross sample entropy, Fourier transformation, non-sequence counting, and adjusted R² according to typical nonlinear load reduction-water quality responses suggested by previous studies. All the indicators were applied on typical numerical water quality simulation samples. Based on the calculation, the four indicators were compared with each other to provide suggestions on how to use them to detect the nonlinearity and measure the nonlinearity strength. Results show some overlaps among the four indicators, however, they are not interchangeable. The four indicators suggest seasonal differences, peak changes, short-term water quality deterioration, and averaged water quality changes respectively. After providing suggestions on how to use the four indicators to detect nonlinearity of water quality responses, this study further discusses the limitations on the nonlinearity definition and potential applications of the four indicators. This study will contribute to understanding, distinguishing, and analyzing the type of nonlinear water quality responses.

Utilization Status and Development Countermeasures of Mangrove Medicinal Resources in the Marine-Terrestrial Interlaced Zone

WANG Lingli, ZHANG Xin, WANG Jiansong, SHEN Xiaoxue, TANG Lili, LI Ruili

2023, 59(4):  704-718.  DOI: 10.13209/j.0479-8023.2023.041

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This study summarizes and reviews Chinese medicinal mangroves’ chemical constituent and medicinal effect researches in the past 50 years. Since 2000, the research on medicinal mangroves has increased exponentially, and the most attention is paid to Pongamia pinnata. 27 kinds of medicinal mangroves have been confirmed, and the main medicinal components include terpenoids, flavonoids, steroids, quinones, carbohydrates, phenylpropanoids and alkaloids. Most medicinal mangroves have anti-tumour, antioxidant and anti-inflammatory effects, and some mangrove plants have unique medicinal effects, including anti-depression and anti-Alzheimer's disease. Existing research mainly focuses on the medicinal effects of mangrove plants, but the pharmacological mechanism needs further study. In view of the problems in medical components and the pharmacological effect of mangroves, some suggestions are put forward for their further development and utilization.