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spatiotemporal characteristics of water exchange between the Andaman Sea and the Bay of Bengal

Acta Oceanologica Sinica 2024年第5期43卷 1-15页

作者： Yihao Wang Feng Zhou Xueming Zhu Ruijie Ye Yingyu Peng Zhentao Hu Haoran Tian Na Li Ocean College Zhejiang UniversityZhoushan 316021China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Observation and Research Station of Yangtze River Delta Marine Ecosystems Ministry of Natural ResourcesZhoushan 316022China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200240China School of Marine Sciences Sun Yat-sen UniversityZhuhai 519080China

A high-resolution customized numerical model is used to analyze the water transport in the three major water passages between the Andaman Sea(AS)and the Bay of Bengal,i.e.,the Preparis Channel(PC),the Ten Degree Channel(TDC),and the Great Channel(GC),based on the daily averaged simulation results ranging from 2010 to *** analysis and Empirical Orthogonal Function(EOF)methods are employed to investigate the spatiotemporal variability of the water exchange and controlling *** results of model simulation indicate that the net average transports of the PC and GC,as well as their linear trend,are opposite to that of the *** indicates that the PC and the GC are the main inflow channels of the AS,while the TDC is the main outflow channel of the *** transport variability is most pronounced at surface levels and between 100 m and 200 m depth,likely affected by monsoons and circulation.A 182.4-d semiannual variability is consistently seen in all three channels,which is also evident in their second principal *** on sea level anomalies and EOF analysis results,this is primarily due to equatorial winds during the monsoon transition period,causing eastward movement of Kelvin waves along the AS coast,thereby affecting the spatiotemporal characteristics of the flow in the *** first EOF of the PC flow field section shows a split at 100 m deep,likely due to *** first EOF of the TDC flow field section is steady but has potent seasonal oscillations in its time ***,the first EOF of the GC flow field section indicates a stable surface inflow,probably influenced by the equatorial Indian Ocean’s eastward current.

关键词： Andaman Sea water exchange Regional Ocean Modeling Systems(ROMS) Kelvin waves spatiotemporal characteristics

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spatiotemporal characteristics of Rural Labor Migration in China: Evidence from the Migration Stability under New-type Urbanization

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Chinese Geographical Science 2020年第5期30卷 749-764页

作者： DENG Wei ZHANG Shaoyao ZHOU Peng PENG Li LIU Ying WAN Jiangjun College of Geography and Resources Science Sichuan Normal UniversityChengdu 610066China Institute of Mountain Haz-ards and Environment Chinese Academy of SciencesChengdu 610041China School of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China School of Architecture and Urban-rural Planning Sichuan Agricultural Uni-versityChengdu 611830China

Although the factors affecting rural-to-urban migration have been discussed and analyzed in detail, few studies have examined the spatiotemporal dynamic characteristics of rural migrants’ employment and working-cities in the post-immigrate era, which is essential for the citizenization and social integration of new-type urbanization in China. This study uses survey data from rural migration laborers across the eastern, central, and western China to construct a comprehensive labor migration stability index, and compares the determinants of the migration stability of rural labor among cities and industries using Geodetector. The results are as follows: 1) Compared with the midwestern cities, eastern cities have attracted younger and more skilled rural labor, and industries with higher technical content have higher migration stability among rural laborers. 2) Rural laborers more often adapt to changes by changing employment instead of changing working-cities. 3) The individual experiences of rural laborers and urban characteristics have significant impacts on the stability of migration, and family and societal guanxi(Chinese interpersonal relationships) enhance migration stability. 4) A unified labor market and convenient transportation have somewhat slowed industrial transfers and labor backflow. This study enhances our understanding of the roles of industrial transfer and new-type urbanization in shaping the labor geography landscape and provides policy implications for the promotion of people-oriented urbanization.

关键词： migration stability rural labor Geodetector spatiotemporal characteristics new-type urbanization

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Evaluation and spatiotemporal characteristics of glacier service value in the Qilian Mountains

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Journal of Geographical Sciences 2020年第8期30卷 1233-1248页

作者： SUN Meiping MA Weiqian YAO Xiaojun ZHAO Linlin LI Zhongqin QIN Dahe Northwest Institute of Eco-Environment and Resources CASLanzhou 730000China College of Geography and Environment Sciences Northwest Normal UniversityLanzhou 730070China

Glaciers provide essential resources and services for human well-being and socio-economic development in arid *** is of great significance for regional socioeconomic sustainable development and environmental protection to conduct a glacier service value assessment and to analyze its spatiotemporal *** on the first and second Chinese glacier inventories of the Qilian Mountains,a glacier service value evaluation system was *** the glacier service value and its spatiotemporal variation were assessed by combining the methods of unit area service price,value equivalent factor,and the glacier service value change index(GSCI).Three key results were obtained.(1)The total service value of glaciers in the Qilian Mountains for 2016 was 24.354 billion *** main services provided were climate regulation and runoff regulation,which accounted for 60.58%and 33.14%of the total service value,*** services were freshwater supply and hydropower,which accounted for 3.47%and 1.75%of the total value,*** value of other types of services was about 0.259 billion yuan.(2)Among the various river systems in the Qilian Mountains,the Shule River basin had the highest glacier service value(7.771 billion yuan,31.91%),followed by the Haltang River basin(4.321 billion yuan,17.74%)and the Beida River basin(3.281 billion yuan,13.47%).In terms of administrative divisions,the glacier service value of the Qilian Mountains in Qinghai Province was 1.138 billion yuan higher than that of Gansu Province at 11.608 billion yuan,of which the services in the Haixi Mongol and Tibetan Autonomous Prefecture and Jiuquan City were valued at 11.124(45.68%)and 7.758(31.86%)billion yuan,respectively.(3)During the period from 1956 to 2010,the service value of glaciers in the Qilian Mountains declined by 435 million yuan,with an acceleration in the decreasing trend from west to east.

关键词： glacier functions and services value evaluation spatiotemporal characteristics Qilian Mountains

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spatiotemporal characteristics of wind energy resources from 1960 to 2016 over China

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Atmospheric and Oceanic Science Letters 2020年第2期13卷 136-145页

作者： FENG Yucheng QUE Linjing FENG Jinming School of Information Engineering China University of Geosciences in BeijingBeijingChina Institute of Atmospheric Physics Chinese Academy of SciencesBeijingChina Heilongjiang Province Meteorological Service Center Heilongjiang Province Meteorological BureauHarbinChina

In the paper,daily near-surface wind speed data from 462 stations are used to study the spatiotemporal characteristics of the annual and seasonal mean wind speed(MWS)and effective wind energy density(EWED)from 1960 to 2016,through the methods of kriging interpolation,leastsquares,correlation coefficient testing,and empirical orthogonal function(EOF)*** results show that the annual MWS is larger than 3 m s-1 and the EWED is larger than 75 W m-2 in northern China and parts of coastal ***,the MWS and EWED values in southern China are all smaller than in northern *** the past 50 years,the annual and seasonal MWS in China has shown a significant decreasing trend,with the largest rate of decline in spring for northern China and winter for coastal *** annual MWS in some areas of Guangdong has an increasing trend,but it shows little change in southwestern China,South China,and west of Central *** the MWS is high,the rate of decline is also *** main spatial distributions of the annual MWS and the annual EWED show high consistency,with a decreasing trend year by *** decreasing trend of wind speed and wind energy resources in China is mainly related to global warming and land use/cover change.

关键词： Wind speed wind energy resources effective wind energy density empirical orthogonal function spatiotemporal characteristics

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spatiotemporal characteristics and dynamic mechanisms of agricultural development in China?s intensively urbanized areas: The case of Pearl River Delta

Spatiotemporal characteristics and dynamic mechanisms of agr...

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2016第六届海峡两岸经济地理学研讨会

作者： Rongjun Long Xun Li Chengguo Zhang School of geography and planning Sun Yat-sen University

The spatial patterns and contributing factors of agricultural development have long been a core concern for geographical research conducted on the regional scale in China. Until recently, however, few attempts have been made to investigate the evolution of agricultural development in intensely urbanized areas. Using the weighted regression model（GTWR）, this research explores the spatiotemporal characteristics and dynamic mechanisms of agricultural development in the Pearl River Delta in southern China over the past twenty-five years. Based on county-level data, significant spatiotemporal heterogeneity in the pattern of agricultural production was revealed by the findings. The results of analysis indicate that in the study area: firstly, the gravitational centre of agricultural production has moved both from south to north, as well as from east to west;secondly, while effects of the amount of cultivated land and the quantity of agricultural labor on agricultural GDP have been less significant across time, an increasingly strong correlation has been found between the figure of agricultural GDP and（1） the amount of machinery and（2） a composite index on the fragmentation of cultivated land, respectively. With the development in agricultural technology and its scale management, this research offers fresh understanding of the important role played by agricultural modernization in an intensely urbanized area such as the Pearl River Delta, and lends support to more scientifically-informed policy-making for the development of agriculture in this region.

关键词： Agricultural development Pearl River Delta spatiotemporal characteristics mechanisms geographical weighted regression

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Measurement of spatiotemporal characteristics of femtosecond laser pulses by a modified single-shot autocorrelation

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Journal of Southeast University(English Edition) 2014年第4期30卷 411-415页

作者：邓杨保邓曙光熊翠秀张光富田野沈连丰东南大学移动通信国家重点实验室南京210096 湖南城市学院通信与电子工程学院益阳413000

To overcome the shortcomings of the single-shot autocorrelation SSA where only one pulse width is obtained when the SSA is applied to measure the pulse width of ultrashort laser pulses a modified SSA for measuring the spatiotemporal characteristics of ultrashort laser pulses at different spatial positions is proposed. The spatiotemporal characteristics of femtosecond laser pulses output from the Ti sapphire regenerative amplifier system are experimentally measured by the proposed method. It was found that the complex spatial characteristics are measured *** pulse widths at different spatial positions are various which obey the Gaussian *** pulse width at the same spatial position becomes narrow with the increase in input average power when femtosecond laser pulses pass through a carbon disulfide CS2 nonlinear *** experimental results verify that the proposed method is valid for measuring the spatiotemporal characteristics of ultrashort laser pulses at different spatial positions.

关键词： spatiotemporal characteristics modified single-shot autocorrelation femtosecond laser pulses ultrafast laser technology

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spatiotemporal distribution characteristics of bridge deck runoff

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Journal of Southeast University(English Edition) 2018年第4期34卷 517-523页

作者： Geng Yanfen Ke Xing Zheng Xin School of Transportation Southeast UniversityNanjing 210096China

The spatiotemporal characteristics of bridge deck runoff under a natural rainfall event are explored. The Taizhou Bridge is taken as a study case,and a hydrodynamic model based on the two-dimensional shallow water equations is used to analyze the runoff characteristics. The results indicate that the runoff velocity rate and depth are positively related to rainfall intensity,yet they have different response degrees to it. The inlet’s effect degree on lane water film has a positive relationship with rainfall intensity. A natural logarithm function( R^2= 0.706) can illustrate this relationship. However,the inlet’s effect degree on ponding at the curb shows a negative relationship with the rainfall intensity. A negative exponential function( R^2= 0.824) can reveal this relationship. With the decrease in the longitudinal slope SL,the ponding depth at the curb increases significantly at the bridge approach slab,whereas the lane water film thickness( WFT) is almost unchanged,but the lane WFT increases greatly at the location with the minimum longitudinal slope. It is concluded that the characteristics of the bridge deck runoff present apparent spatiotemporal differences,the inlet ’s effects on bridge deck runoff are quantitatively correlated with rainfall intensity, and the effective drainage measures are necessary for the bridge approach slab.

关键词： two-dimensional shallow water equations bridge deck runoff spatiotemporal characteristics ponding depth water film thickness

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长三角城市群多情景暴雨人口暴露度时空演变分析

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Journal of Geographical Sciences 2024年第4期34卷 654-680页

作者：张亚茹姚蕊朱治州金恒旭张书亮 Key Laboratory of VGE of Ministry of Education Nanjing Normal UniversityNanjing 210023China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing210023China School of Geography and Tourism Anhui Normal UniversityWuhu 241002AnhuiChina

Population exposure is a dominant representation of rainstorm hazard risks. However, the refined precipitation data in temporal resolution and the comparison of exposure to different rainstorm events remain relatively unexplored. Hourly precipitation data from 165meteorological stations w used to investigate the spatiotemporal evolution of population exposure to different rainstorm scenarios in the prefecture-level cities for different periods and age groups. The Geographical Detector was adopted to quantitatively analyze the influencing factors and contribution rates to changes in population exposure during each period. The results revealed that population exposure to persistent rainstorms and abrupt rainstorms was low in the center and high in the surrounding areas, and the high exposure value decreased significantly in the 2010s. Additionally, as the duration of rainstorm events increased, the center of the high-value area of population exposure shifted southward. The distribution of population exposure was closely related to the age structure, demonstrating strong consistency with the distribution of different age groups. Except for abrupt rainstorms, the contribution rates of the average land GDP and urbanization rate to the exposure of all rainstorm scenarios increased significantly. This implies that the main factors influencing population exposure have shifted from meteorological to socioeconomic factors.

关键词： rainstorm events population exposure multiple scenarios spatiotemporal characteristics Geographical Detector

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A New Evaporation Duct Climatology over the South China Sea

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Journal of Meteorological Research 2015年第5期29卷 764-778页

作者：史阳杨坤德杨益新马远良 School of Marine Science and Technology Northwestern Polytechnical University

The climatology of evaporation ducts is important for shipborne electromagnetic system design and application. The evaporation duct climatology that is currently used for such applications was developed in the mid 1980s; this study presents efforts to improve it over the South China Sea （SCS） by using a state- of-the-art evaporation duct model and an improved meteorology dataset. This new climatology provides better evaporation duct height （EDH） data over the SCS, at a higher resolution of 0.312°×0.313°. A comparison between the new climatology and the old one is performed. The monthly average EDH in the new climatology is between 10 and 12 m over the SCS, higher than that in the old climatology. The spatiotemporal characteristics of the evaporation duct over the SCS in different months are analyzed in detail, based on the new climatology.

关键词： atmosphere duct evaporation duct climatology spatiotemporal characteristics the SouthChina Sea electromagnetic wave propagation

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characteristics and chemical reactivity of biogenic volatile organic compounds from dominant forest species in the Jing-Jin-Ji area,China

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Forest Ecosystems 2021年第4期8卷 699-712页

作者： Ying Lin Xiaoxiu Lun Wei Tang Zhongzhi Zhang Xiaoxi Jing Chong Fan Qiang Wang College of Environmental Science and Engineering Beijing Forestry University100083 BeijingChina Institute of Atmospheric Environment Chinese Research Academy of Environmental Sciences100012 BeijingChina

Background:Biogenic volatile organic compounds(BVOCs)play an essential role in tropospheric atmospheric chemical *** are few studies conducted on BVOCs emission of dominant forest species in the Jing-Jin-Ji area of *** on the field survey,forest resources data and the measured standard emission factors,the Guenther model developed in 1993(G93)was applied in this paper to estimate the emission of BVOCs from several dominant forest species(Platycladus orientalis,Quercus variabilis,Betula platyphylla,Populus tomentosa,Pinus tabuliformis,Robinia pseudoacacia,Ulmus pumila,Salix babylonica and Larix gmelinii)in the Jing-Jin-Ji area in *** the spatiotemporal emission characteristics and atmospheric chemical reactivity of these species were extensively ***:The results showed that the total annual BVOCs emission was estimated to be 70.8 Gg C·year^(−1),consisting 40.5%(28.7 Gg C·year^(−1))of isoprene,36.0%(25.5 Gg C·year^(−1))of monoterpenes and 23.4%(16.6 Gg C·year^(−1))of other *** emissions from Platycladus orientalis,Quercus variabilis,Populus tomentosa and Pinus tabulaeformis contributed 56.1%,41.2%,36.0% and 31.1%,*** total BVOCs emission from the Jing-Jin-Ji area accounted for 61.9% and 1.8%in summer and winter,*** to 28.8% of emission was detected from Chengde followed by Beijing with 24.9%,that mainly distributed in the Taihang Mountains and the Yanshan ***,the Robinia pseudoacacia,Populus tomentosa,Quercus variabilis,and Pinus tabulaeformis contributed mainly to BVOCs reaction ***:The BVOCs emission peaked in summer(June,July,and August)and bottomed out in winter(December,January,and February).Chengde contributed the most,followed by *** orientalis,Quercus variabilis,Populus tomentosa,Pinus tabulaeformis and Robinia pseudoacacia represent the primary contributors to BVOCs emission and atmospheric reactivity,hence the planting of these species sho

关键词： Biogenic volatile organic compounds(BVOCs) Isoprene Monoterpenes Jing-Jin-Ji area spatiotemporal characteristics Chemical reactivity

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