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1.
Identifying China’s leading world city: a network approach 总被引:3,自引:0,他引:3
This paper reports our research on China’s world cities. Formal network analysis of air passenger linkages for recent years
among China’s most populous cities and among many of the world’s largest cities allows us to identify the country’s leading
world city from among the leading Mainland candidates, Beijing, Shanghai and Guangzhou. We theorize our findings about China’s
world cities in relation to both global forces (and China’s increasing entanglement with them) and the policies and actions
of the national state. We examine the national and global urban network through a longitudinal, two-level analysis of airline
passenger travel for four time points between about 1990 and 2005. We show that Beijing was China’s leading world city at
the beginning of the time period, a status it lost nationally in as early as 1995, and then globally 10 years later. On the
other hand Shanghai became China’s leading world city, and it acquired this status first nationally in 2000, and then globally
in 2005. The changing status of the Chinese capital corresponds to the country’s increasing involvement with the capitalist
world economy. Shanghai’s ascendance as the leading world city in China may indicate that global forces have come to play
an increasingly important role relative to that of the developmental state.
相似文献
Michael F. TimberlakeEmail: |
2.
简要阐述地震小区划在现代城市建设中的重要性以及在实施地震小区划的研究中浅层地震探测的重要作用及其方法原理,并给出应用浅层地震探测在城市地震小区划中的实例。 相似文献
3.
4.
利用TM合成图像研究滨海平原城市东营市的时空扩展 总被引:1,自引:0,他引:1
利用遥感 (RS)与地理信息系统 (GIS)一体化技术 ,对黄河三角洲上的新兴城市——东营市的城市时空扩展进行动态监测。并在地物光谱研究的基础上 ,提出了适合于近海平原地区的遥感波段组合 (TM- R5 G3B1)和本区内最易于识别城镇、居民地的波段组合 TM- R5 G7B4 (7月 )、TM-R3G4 B2 (10月 )和 TM- R5 G2 B4 (5月 )。结果表明 ,东营市自 1983年建市以来 ,迅速向东发展 ,由一块城区扩展为东城、西城并立。国家的政策和规划、石油工业的发展是东营城区迅速扩展的驱动力。 相似文献
5.
广州市地面塌陷分布特征与人为致灾因子分析 总被引:4,自引:0,他引:4
广州市地面塌陷频繁发生,近10年来呈波动式上升趋势。其塌陷类型分为岩溶塌陷和工程地面塌陷两种,岩溶塌陷主要分布在广花盆地的花都区、白云区,工程地面塌陷主要分布在主城区。地面塌陷孕灾环境复杂、致灾因子多样,承灾体脆弱,灾害后果严重,人为因素是地面塌陷的主要诱发因素。岩溶塌陷主要是由于过量抽取地下水或矿山疏干排水、地下采空、暴雨触发所致;工程塌陷主要是人类工程行为所致,其主要致灾因子包括排水疏干与突水(突泥)作用、人工加载、人工振动、人工开挖桩基、地表渗水、地铁等地下工程盾构掘进等。 相似文献
6.
At present, researches on climate change of the Heihe River basin mainly focus on the relationship between basin climate change
and regional water resources, regional desertification and dynamic climatic seasons of sandstorm, but less on climate change
of oasis region, where there are more intense and frequent human activities. Based on data of precipitation, temperature,
strong wind and dust events frequencies obtained from the six meteorological stations of Zhangye region in Heihe River basin,
the features of climate change during 1968–2005 were carefully studied. Results show that the regional temperature rise rate
exceeded the average level of China. The annual precipitation changed a little, but the precipitation had a slowly increasing
trend in spring and winter. Frequencies of strong wind and sandstorm days show obviously descending trends, which had a close
correlation with the regional temperature rise and the precipitation increase in spring and winter. Meanwhile, further human
economic activities and exploitations to the oasis in the inland valley of arid regions also affected the climate change of
this region, which has a sensitive and fragile eco-environment.
__________
Translated from Journal of Desert Research, 2007, 27(6): 1048–1054 [译自: 中国沙漠] 相似文献
7.
E. Ovando-Shelley 《Geotechnical and Geological Engineering》1995,13(1):1-16
Summary This paper presents results of static and cyclic direct shear tests performed on undisturbed and remoulded samples of Mexico City clays, including results of soil-on-interface tests. Experiments show that the static adhesion coefficient depends on the soils' liquidity index and that it diminishes due to the effect of repeated dynamic loads. Dynamic overstrength effects were not apparent, as has been observed when testing this clay in other apparatus. Interface strength in remoulded clays is initially less than half the strength of interfaces with undisturbed materials but it increases with time. At least in the materials tested in this research, it did not equal the strength of interfaces with undisturbed materials. Correction factors derived from experimental data can be used to modify the adhesion coefficient to account for dynamic and remoulding effects. 相似文献
8.
9.
Low temperature volatile production at the Lost City Hydrothermal Field, evidence from a hydrogen stable isotope geothermometer 总被引:1,自引:0,他引:1
Giora Proskurowski Marvin D. Lilley Deborah S. Kelley Eric J. Olson 《Chemical Geology》2006,229(4):331-343
Although commonly utilized in continental geothermal work, the water-hydrogen and methane-hydrogen isotope geothermometers have been neglected in hydrothermal studies. Here we report δD-CH4 and δD-H2 values from high-temperature, black smoker-type hydrothermal vents and low-temperature carbonate-hosted samples from the recently discovered Lost City Hydrothermal Field. Methane deuterium content is uniform across the dataset at − 120 ± 12‰. Hydrogen δD values vary from − 420‰ to − 330‰ at high-temperature vents to − 700‰ to − 600‰ at Lost City. The application of several geothermometer equations to a suite of hydrothermal vent volatile samples reveals that predicted temperatures are similar to measured vent temperatures at high-temperature vents, and 20-60 °C higher than those measured at the Lost City vents. We conclude that the overestimation of temperature at Lost City reflects 1) that methane and hydrogen are produced by serpentinization at > 110 °C, and 2) that isotopic equilibrium at temperatures < 70 °C is mediated by microbial sulfate reduction. The successful application of hydrogen isotope geothermometers to low-temperature Lost City hydrothermal samples encourages its employment with low-temperature diffuse hydrothermal fluids. 相似文献
10.
Wei ZHANG Congqiang LIU Zhiqi ZHAO 《中国地球化学学报》2006,25(B08):172-172
Boron has two stable isotopes (^10B and ^11B) with relative abundances of about 20% and 80%, respectively. Boron isotopic ratios in natural materials show a huge range of variations, from -70‰ to +60‰, when expressed with the classical δ^11B notation. Most of these isotopic variations occur at the surface of the Earth. Hence, boron isotopic composition can be used as a sensitive tracer in geochemical study, for instance, to identify the different sources of contamination and factors controlling the salinity of groundwater. During the last decade, boron isotopes have been used to discriminate between the influences of seawater intrusion and anthropogenic discharge. But few of those researches can precisely identify the different sources of contamination. We measured the boron concentrations and boron isotopic ratios of groundwater samples collected in Guiyang City, as well as the major ions. The results indicate that the major ion composition of the groundwater in the investigated area is mainly controlled by the interactions between water and the dominant rock i.e. carbonates. All the water compositions are characterized by high concentrations of Ca^2+, Mg^2+, HCO3^-, SO4^2-, and NO3^-, which are the dominant contaminants. Both dissolved boron concentrations and isotopic ratios show large variations among the ground waters, from 2 μg/L to 90 μg/L and from -6‰ to +26‰, respectively. The boron concentrations and isotopic ratios indicate that the river across the studied city has been seriously contaminated by urban discharge. Boron concentrations of fiver water samples varied from 20 μg/L to 140 μg/L, with an average δ^11B value of +2.0‰. Using boron isotopic compositions and different geochemical indices allowed us to clearly identify and distinguish the two major sources of contamination, agricultural activity and urban wastewater. Both of the two sources are characterized by high boron concentrations but their boron isotopic compositions significantly differ. 相似文献