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International Freight Forwarding Services Network in the Yangtze River delta, 2005–2015: Patterns and Mechanisms

Chinese Geographical Science 2019年第1期29卷 112-126页

作者： LIANG Shuangbo CAO Youhui WU Wei GAO Jinlong LIU Weichen ZHANG Weiyang Key Laboratory of Watershed Geographic Sciences Chinese Academy of Sciences Nanjing Institute of Geography and Limnology Chinese Academy of Sciences University of Chinese Academy of Sciences The Center for Modern Chinese City Studies & School of Urban and Regional Science East China Normal University

This study examined the spatio-temporal trajectories of the international freight forwarding service(IFFS) in the Yangtze River delta(YRD) and explored the driving mechanisms of the service. Based on a bipartite network projection from an IFFS firm-city data source, we mapped three IFFS networks in the YRD in 2005, 2010, and 2015. A range of statistical indicators were used to explore changes in the spatial patterns of the three networks. The underlying influence of marketization, globalization, decentralization, and integration was then explored. It was found that the connections between Shanghai and other nodal cities formed the backbones of these networks. The effects of a city's administrative level and provincial administrative borders were generally obvious. We found several specific spatial patterns associated with IFFS. For example, the four non-administrative centers of Ningbo, Suzhou, Lianyungang, and Nantong were the most connected cities and played the role of gateway cities. Furthermore, remarkable regional equalities were found regarding a city's IFFS network provision, with notable examples in the weakly connected areas of northern Jiangsu and southwestern Zhejiang. Finally, an analysis of the driving mechanisms demonstrated that IFFS network changes were highly sensitive to the influences of marketization and globalization, while regional integration played a lesser role in driving changes in IFFS networks.

关键词： international freight forwarding service network pattern mechanism headquarters-branch method Yangtze River delta

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Numerical simulations of leading-edge vortex core axial velocity for flow over delta wings

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Science China(Technological Sciences) 2009年第7期52卷 2029-2036页

作者： CHEN Lan1, 2 & WANG JinJun1 1 Institute of Fluid Mechanics, Beijing University of Aeronautics and Astronautics, Beijing 100191, China 2 China Aerodynamic Research and Development Center (CARDC), Mianyang 621000, China Institute of Fluid Mechanics Beijing University of Aeronautics and Astronautics Beijing China China Aerodynamic Research and Development Center (CARDC) Mianyang China

Numerical simulations have been performed to investigate the characteristics of leading-edge vortex core axial velocity over two delta wings with leading edge swept angles Λ =50°and 76°, respectively. It is obtained that Reynolds number has the most important effect on the axial velocity of the primary leading-edge vortex core. At Reynolds numbers larger than 105, the jet-like flow of the vortex core is the most common type for both the large and the moderate swept delta wings. While if Reynolds number decreases to 103―104, the core axial velocity distributions for these two delta wings present the wake-like profile for all angles of attack considered in the present investigation.

关键词： delta wing low Reynolds number vortex flows

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Background Characteristics of Atmospheric CO2 and the Potential Source Regions in the Pearl River delta Region of China

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Advances in Atmospheric Sciences 2020年第6期37卷 557-568页

作者： Boru MAI Xuejiao DENG Fang ZHANG Hao HE Tian LUAN Fei LI Xia LIU Institute of Tropical and Marine Meteorology China Meteorological AdministrationGuangzhou 510640China College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875China Department of Atmospheric and Oceanic Science University of MarylandCollege ParkMD 20742USA Chinese Academy of Meteorological Sciences Beijing 100081China Guangzhou Meteorological Observatory Guangzhou 511430China

Mole fractions of atmospheric CO2(XCO2)have been continuously measured from October 2014 to March 2016 at the Guangzhou Panyu Atmospheric Composition Site(23.00°N,113.21°E;140 m MSL)in the Pearl River delta(PRD)region using a cavity ring-down *** 66.63%,19.28%,and 14.09%of the observed values were filtered as background,pollutant source,and sink due to biospheric uptake,respectively,by applying a robust local regression *** corresponding mean values were 424.12±10.12 ppm(×10-6 mol mol-1),447.83±13.63 ppm,and 408.83±7.75 *** background XCO2 levels were highest in spring and winter,moderate in autumn,and lowest in *** diurnal XCO2 was at a minimum from 1400-1600 LST(Local Standard Time)and a maximum at 0500 LST the next *** increase of XCO2 in spring and summer was mainly associated with polluted air masses from south coastal Vietnam,the South China Sea,and the southeast Pearl River *** the exception of summer,airflow primarily from marine regions southeast of Taiwan that passed over the Pearl River Estuary had a greater impact on XCO2,suggesting an important potential source region.

关键词： Pearl southeast delta

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Sediment transport in the Luanhe River delta:grain size trend analysis

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Journal of Oceanology and Limnology 2019年第3期37卷 982-997页

作者： YU Xiaoxiao LI Tiegang GU Dongqi FENG Aiping LIU Shihao LI Ping XU Guoqiang YAN Wenwen ZHANG Zhiwei ZHU Zhengtao Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China The First Institute of Oceanography Ministry of Natural Resources (MNR)Qingdao 266061China State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200062China

Sediment grain size in the deltaic environment of the Luanhe River(LR),Liaoning,China,contains sediment transport pathway information useful in elucidating the shoreline change and fluvialmarine *** this study,we utilized numerical partitioning of the sedimentary components and geostatistical grain size trend analysis(GSTA)to define the sediment transport pattern in the Luanhe River delta(LRD)and interpolated the sediment transport pattern using content changes of end numbers(EM).EM1(the mean grain size 7.12Ф,fine silt),EM2(2.37Ф,fine sand),and EM3(1.27Ф,medium sand)components were identified by the numerical partitioning by *** interpolation method was used to interpolate the parameters of the grain size for the regular grid,and the interpolation radius was 0.015 decimal *** chose 0.09 decimal degree as the characteristic distance for GSTA in the semivariogram model using the geostatistical *** FB(-)case(finer,better sorted and more negatively skewed)was adopted in GSTA for its satisfaction in the Global Moran’s I *** result of the GSTA shows that the sediments in the south barriers(SBs)were transported to the southwest of the study *** sediments in the north,in the SE direction of sediment transport trend from the river mouth,indicated that the sediments in the north of the study area were transported from the LR to the northern beaches,and to the south and east of the study *** sediment transport trend that simplified by GSTA as the FB(-)case was approved by the content changes of sedimentary components(***1,EM2,and EM3).In addition,the turbulent jet diffusion pattern indicated that the coarse sediments(EM3)were delivered by LR during the flood season,and the EM2 and EM1 were from wave and tide,respectively.

关键词： Luanhe River delta sediment transport grain-size partitioning geostatistical grain size trend analysis(GSTA)

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Effects of key species mud snail Bullacta exarata (Gastropoda) on oxygen and nutrient fluxes at the sediment-water interface in the Huanghe River delta, China

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Acta Oceanologica Sinica 2019年第8期38卷 48-55页

作者： Baoquan Li Tjeerd J. Bouma Quanchao Wang Laura M. Soissons Francesco Cozzoli Guanghai Feng Xiaojing Li Zhengquan Zhou Linlin Chen Yantai Institute of Coastal Zone Research Chinese Academy of Sciences Yantai 264003 China Department of Spatial Ecology Royal Netherlands Institute for Sea Research (NIOZ-Yerseke) Yerseke 140 4400 AC The Netherlands University of Applied Sciences Vlissingen 4382 NW The Netherlands University of Chinese Academy of Sciences Beijing 100049 China Dawenliu Management Station of Yellow River delta National Nature Reserve Dongying 257500 China

Since the mud snail Bullacta exarata was introduced for economic aquaculture in the Huanghe River(Yellow River) delta in 2001, its quick population growth and expanded distribution make it a key-species in the intertidal zone of this area. This significantly contributed to the economic income of the local people, but its potential ecological impact on the benthic ecosystem remains unknown. A mesocosm study was conducted to test whether its bioturbation activities affect the microphytobenthos(MPBs;i.e., sedimentary microbes and unicellular algae)productivity and the nutrient exchange between the sediment-water interface. Our results show that the mud snail significantly impacted the dissolved oxygen(DO) flux across the sediment-water interface on the condition of normal sediment and light treatment, and significantly increased the ammonium efflux during recovery period in the defaunated sediment and dark treatment. The presence of micro-and meiofauna significantly increased the NH4-N flux in dark treatment. Whereas, in light treatment, these small animals had less effects on the DO and NH4-N flux between sediment-water interface. Our results provide better insight into the effect of the mud snail *** on the ecosystem functioning via benthic fluxes.

关键词： bioturbation mud snail Bullacta exarata oxygen flux nutrient flux benthic metabolism Huanghe River(Yellow River) delta

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Effects of flexibility on aerodynamic performance of delta wings with different sweep angles

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Science China(Physics,Mechanics & Astronomy) 2010年第5期53卷 915-922页

作者： LIU Yang,ZUO LinXuan & WANG JinJun Institute of Fluid Mechanics,Beijing University of Aeronautics and Astronautics and Fluid Mechanics Key Laboratory,Ministry of Education,Beijing 100191,China Institute of Fluid Mechanics Beijing University of Aeronautics and Astronautics and Fluid Mechanics Key Laboratory Ministry of Education Beijing China

Force measurement and surface oil flow visualization experiments were conducted in a wind tunnel to investigate the effects of flexibility on aerodynamic performance of delta wings with different sweep *** experimental results indicate that the maximum lift coefficient is increased and the stall angle is delayed as the sweep angle increases for both rigid and flexible *** is also found that the maximum lift coefficients of the flexible wings with a sweep angle from 35° to 50° are higher than those of the rigid *** increment of the maximum lift coefficient in particular achieves 32.9% compared with the case without lift enhancement for the 40° flexible delta ***,the surface oil flow visualization experiments show that the stall of the flexible wing of the moderate low sweep angle is accompanied by helical flow structure,while the vortex bursting appears on the corresponding rigid wing.

关键词： delta wing wing flexibility aerodynamics sweep angle

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Seasonal and Spatial Variations of Macro Benthos in the Intertidal Mudflat of Southern Yellow River delta,China in 2007/2008

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Journal of Ocean University of China 2018年第2期17卷 437-444页

作者： ZOU Li YAO Xiao YAMAGUCHI Hitomi GUO Xinyu GAO Huiwang WANG Kai SUN Mingyi Key Laboratory of Marine Environmental Science and Ecology Ministry of EducationOcean University of ChinaQingdao 266100China College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China Environmental Protection Bureau Dongying 257091China Faculty of Agriculture Kagawa University2393 IkenobeKitaMiki 7610795Japan Affiliation&Position National University Corporation Ehime University Ehime 79085775Japan Department of Marine Sciences University of GeorgiaAthens 30602-3636USA

In order to examine the seasonal and spatial distributions of benthic animals in the intertidal mudflat of the southern Yellow River delta,field investigations were carried out in 2007 and 2008 and multiple methods were *** showed that,the biomass of macro benthos ranged at 0.75-1151.00 g wet m^(-2) and averaged at 156.31 g wet m^(-2),in which Mactra veneriformis accounted for 75.6%-93.4% of the total macro benthic *** than 90% of macro benthos inhabited in the middle and low tide lines,and higher biomass occurred in early summer and lower in *** analysis showed that:1)*** growth was primarily favored at higher temperature and lower salinity;2)after long time interaction,benthic bivalve grazers led to patching distributions of Chlorophyll a(Chl a);3)macro benthic biomass positively related with Chl a when the concentration of Chl a was low,but they were negatively related when Chl a concentration was high;and 4)furthermore,the biomass of benthic bivalves peaked in the sediment with median grain size about 0.55 mm,but decreased gradually in coarse or fine *** secondary productivity ranged at 0.37-283.68 g m^(-2)yr^(-1) and averaged at 47.88 g m^(-2) yr^(-1),in which 69.7% was contributed by *** It was estimated that primary production was transformed to secondary production at a rate of 6.87%approximately,which implies that there is a local sustainability of high bivalve production.

关键词： macro benthos Mactra veneriformis distribution intertidal mudflat southern Yellow River delta

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Dominant Synoptic Patterns and Their Relationships with PM2.5 Pollution in Winter over the Beijing–Tianjin–Hebei and Yangtze River delta Regions in China

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Journal of Meteorological Research 2019年第4期33卷 765-776页

作者： Yuzhi LIU Bing WANG Qingzhe ZHU Run LUO Chuqiao WU Rui JIA Key Laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric SciencesLanzhou UniversityLanzhou 730000 Meteorological Observatory Unit 95021 Yichang 441000

This paper concerns about the episodes of PM2.5 pollution that frequently occur in China in winter *** severity of PM2.5 pollution is strongly dependent on the synoptic-scale atmospheric *** combined PM2.5 concentration data and meteorological data with the Hybrid Single Particle Lagrangian Integrated Trajectory model(HYSPLIT4)to investigate the dominant synoptic patterns and their relationships with PM2.5 pollution over the Beijing–Tianjin–Hebei(BTH)and Yangtze River delta(YRD)regions in the winters of 2014–*** transport of PM2.5 from the BTH to YRD regions was examined by using cluster analysis and *** is found that the level of PM2.5 pollution over the BTH region was higher than that over the YRD *** concentration of PM2.5 in the atmosphere was more closely related to meteorological factors over the BTH *** episodes of PM2.5 pollution over the BTH region in winter were related to weather patterns such as the rear of a high-pressure system approaching the sea,a high-pressure field,a saddle pressure field,and the leading edge of a cold *** contrast,PM2.5 pollution episodes in the YRD region in winter were mainly associated with the external transport of cold air,a high-pressure field,and a uniform pressure *** analysis shows that the trajectories of PM2.5 were significantly different under different weather ***2.5 would be transported from the BTH to the YRD within 48 h when the PM2.5 pollution episodes were associated with three different kinds of weather patterns:the rear of a highpressure system approaching the sea,the high-pressure field,and the leading edge of a cold front over the BTH *** suggests a possible method to predict PM2.5 pollution episodes based on synoptic-scale patterns.

关键词： PM2.5 pollution episodes synoptic patterns Beijing-Tianjin-Hebei (BTH) Yangtze River delta (YRD)

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Real-world effectiveness of mRNA COVID-19 vaccines in the elderly during the delta and Omicron variants:Systematic review

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World Journal of Meta-Analysis 2023年第5期11卷 167-180页

作者： Harvey Palalay Riddhi Vyas Barbara Tafuto Department of Health Informatics Rutgers UniversityPiscatawayNJ 08854United States

BACKGROUND As of 31 December 2022,there were over 6.6 million coronavirus disease 2019(COVID-19)deaths and over 651 million cases across 200 countries *** the increase in vaccinations and booster shots,COVID-19 cases and deaths continue to remain *** the effectiveness of these vaccines has already been established by different manufacturers,the fact remains that these vaccines were created quickly for global emergency use,tested under controlled clinical conditions from voluntary subjects and age groups whose general characteristics may differ from the actual general *** To conduct a systematic review to determine the real-world effectiveness of mRNA COVID-19 vaccines in the elderly during the predominance of delta and Omicron variants in preventing COVID-19 related infection,hospital,intensive care unit(ICU)admission and intubation,and *** A combination of Medical Subject Headings and non–Medical Subject Headings was carried out to identify all relevant research articles that meets the inclusion and exclusion criteria from PubMed,Cochrane,CINAHL,Scopus,ProQuest,EMBASE,Web of Science,and Google Scholar databases,as well as qualified research studies from pre–print servers using medRxiv and Research Square,published from January 1,2021-December 31,*** As per the inclusion and exclusion criteria,the effectiveness of Pfizer-BioNTech and Moderna vaccines were evaluated from an estimated total study population of 26535692 using infection,hospital,ICU admission and intubation,and death as outcome measures from studies published between 2021 and 2022,conducted in New York,Finland,Canada,Costa Rica,Qatar,Greece,and *** risk of bias was evaluated using risk of bias in nonrandomized studies of interventions(ROBINS-I)tool for cohort,case-control,and cross-sectional *** clinical trial data on Pfizer-BioNTech and Moderna vaccines demonstrated 94%vaccine effectiveness in the elderly,the results in this study show

关键词： COVID-19 mRNA Vaccine Effectiveness Elderly delta Omicron Systematic review

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Neutralization of the SARS-CoV-2 delta variant after heterologous and homologous BNT162b2 or ChAdOx1 nCoV-19 vaccination

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Cellular & Molecular Immunology 2021年第10期18卷 2455-2456页

作者： Swantje I.Hammerschmidt Berislav Bosnjak Günter Bernhardt Michaela Friedrichsen Inga Ravens Alexandra Dopfer-Jablonka Markus Hoffmann Stefan Pöhlmann Georg M.N.Behrens Reinhold Förster Institute of Immunology Hannover Medical SchoolHannoverGermany Department for Rheumatology and Immunology Hannover Medical SchoolHannoverGermany Infection Biology Unit German Primate Center-Leibniz Institute for Primate ResearchGöttingenGermany Faculty of Biology and Psychology Georg-August-University GöttingenGöttingenGermany German Center for Infection Research(DZIF) Partner Site Hannover-BraunschweigHannoverGermany German Center for Lung Research(DZL) HannoverGermany Cluster of Excellence RESIST(EXC 2155) Hannover Medical SchoolHannoverGermany

Since the beginning of the COVID-19 pandemic,divergent variants of concern(VoCs)of SARS-CoV-2 have evolved and become the most prevalent SARS-CoV-2 variants in distinct locations at different ***,the delta variant(B.1.617.2)dominates infection events in large parts of the *** campaigns,however,still use SARS-CoV-2 vaccines based on the spike(S)protein of the original Wuhan virus.

关键词： delta homologous campaign

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