scholarly journals Potential spatial expansion of Ulmus macrocarpa population in Keerqin sandy lands, China

Phyton ◽  
2018 ◽  
Vol 87 (1) ◽  
pp. 32-39
Author(s):  
Jianar A ◽  
JH Yuan ◽  
YF Yang
Keyword(s):  
Spatial Expansion ◽  
Keerqin Sandy Lands

scholarly journals Unbalanced Development Characteristics and Driving Mechanisms of Regional Urban Spatial form: A Case Study of Jiangsu Province, China

2021 ◽  
Vol 13 (6) ◽  
pp. 3121
Author(s):  
Guoping Xiong ◽  
Xin Cao ◽  
Nicholas A. S. Hamm ◽  
Tao Lin ◽  
Guoqin Zhang ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Regional Development ◽  
Driving Factors ◽  
Spatial Expansion ◽  
Spatial Form ◽  
Coordinated Development ◽  
Urbanization Level ◽  
Driving Mechanisms ◽  
Urbanization Development ◽  
Southern Jiangsu

Unbalanced regional development is widespread, and the imbalance of regional development in developing countries with rapid urbanization is increasingly apparent. This threatens the sustainable development of the region. Promoting the coordinated development of the region has become a hot spot of scientific research and a major practical need. Taking 99 counties of Jiangsu Province China, a typical coastal plain region, as the basic research unit, this paper explores the unbalanced development characteristics of the regional urban spatial form using three indicators: urban spatial expansion size, development intensity, and distribution aggregation degree. Then, their driving mechanisms were evaluated using spatial autocorrelation analysis, Pearson correlation analysis, linear regression, and geographically weighted regression. Our results found that the areas with larger urban spatial expansion size and development intensity were mainly concentrated in southern Jiangsu, where there was a positive spatial correlation between them. We found no agglomeration phenomenon in urban spatial distribution aggregation degree. From the perspective of driving factors: economics was the main driving factor of urban spatial expansion size; urbanization level and urbanization quality were the main driving factors of urban spatial development intensity. Natural landform and urbanization level are the main driving factors of urban spatial distribution aggregation degree. Finally, we discussed the optimization strategy of regional coordinated development. The quality of urbanization development and regional integration should be promoted in Southern Jiangsu. The level of urbanization development should be improved relying on rapid transportation to develop along the axis in central Jiangsu. The economic size should be increased, focusing on the expansion of the urban agglomeration in northern Jiangsu. This study will enrich the perspective of research on the characteristics and mechanisms of regional urban spatial imbalance, and helps to optimize and regulate the imbalance of regional urban development from multiple perspectives.

Gaming in Spatial Expansion Tracks: The Case of the Swedish Brewery Industry

1992 ◽  
Vol 24 (7) ◽  
pp. 1021-1037 ◽  
Author(s):  
S Finne ◽  
R Laulajainen
Keyword(s):  
Nash Equilibrium ◽  
Population Distribution ◽  
Scale Economies ◽  
Spatial Expansion ◽  
Spatial Strategies ◽  
Market Shares ◽  
Production And Distribution ◽  
Physical Barriers ◽  
Simple Indicator

Two competitors try to maximize their respective market shares by acquiring smaller, passive companies. The heavy logistics bill and inherent scale economies in production recommend contagious expansion. This process is channeled by physical barriers and population distribution. Rationalization of production and distribution is postponed. The historical example is derived from the Swedish brewery industry. It may be seen as a game with a set of rules and some probabilistic parameters. The game is played thirty-seven times, by two persons at a time. The results span a spectrum of spatial strategies, dominated by three main types, one of which corresponds to the historical outcome. To get a firmer hold of ‘good’ strategies, the probabilistic elements are replaced by a simple indicator, the territory is abstracted into a network, and the decisionmaking sequence is analyzed deductively. The same three main types of strategy reemerge. One of them is tentatively considered to be a Nash equilibrium.

scholarly journals Spatial Expansion of Human Settlement during the Longshan Period (~4.5–~3.9 ka BP) and Its Hydroclimatic Contexts in the Lower Yellow River Floodplain, Eastern China

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 712
Author(s):  
Kaifeng Li ◽  
Wenhua Gao ◽  
Li Wu ◽  
Hainan Hu ◽  
Panpan Gong ◽  
...  
Keyword(s):  
Yellow River ◽  
Asian Summer Monsoon ◽  
Spatial Expansion ◽  
Human Settlement ◽  
Human Settlements ◽  
Lower Yellow River ◽  
River Floodplain ◽  
The Lower Yellow River ◽  
Asian Summer ◽  
Longshan Period

Obvious spatial expansion of human settlement occurred in the lower Yellow River floodplain during the Longshan period, but the external factors driving this expansion remain unclear. In this study, we first delineated the hydroclimatic changes at both regional and local scales within and around the lower Yellow River floodplain and then examined the relationships of human settlements with hydroclimatic settings between the pre-Longshan and Longshan periods. The results indicate that the site distribution, site density and hydroclimatic conditions exhibited significant shifts during the pre-Longshan and Longshan periods. In the pre-Longshan period, the intense East Asian summer monsoon and abundant monsoon-related precipitation caused widespread development of lakes and marshes in the lower Yellow River floodplain. As a result, the circumjacent highlands of the lower Yellow River floodplain contained concentrated human settlements. However, the persistent weakening of the East Asian summer monsoon and consequent precipitation decline, in conjunction with accelerated soil erosion due to decreasing forest vegetation and strengthening of human activities on the upstream Loess Plateau in the Longshan period, are likely to have jointly caused both shrinking and faster filling of preexisting lakes and marshes. Subsequently, a large area of arable land had been created in the lower Yellow River floodplain and thus was occupied by locally rapid increasing population, resulting in the notable spatial expansion of human settlements during the Longshan period.

Leaf traits and their interrelationship of 23 plant species in southeast of Keerqin Sandy Lands, China

2008 ◽  
Vol 3 (3) ◽  
pp. 332-337 ◽  
Author(s):  
Jinhuan Liu ◽  
Dehui Zeng ◽  
Don Koo Lee ◽  
Zhiping Fan ◽  
Lei Zhong
Keyword(s):  
Plant Species ◽  
Leaf Traits ◽  
Keerqin Sandy Lands

LUCC and its spatial expansion in frontier zone of the Longitudinal Range-Gorge Region

2007 ◽  
Vol 52 (S2) ◽  
pp. 98-105 ◽  
Author(s):  
Shu Gan ◽  
DaMing He ◽  
Yan Feng ◽  
QingYan Deng ◽  
WenHua Chen
Keyword(s):  
Spatial Expansion ◽  
Frontier Zone

scholarly journals Dependence of center radius on temporal frequency for the receptive fields of X retinal ganglion cells of cat.

1989 ◽  
Vol 94 (6) ◽  
pp. 987-995 ◽  
Author(s):  
J B Troy ◽  
C Enroth-Cugell
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Signal To Noise Ratio ◽  
Temporal Frequency ◽  
Receptive Fields ◽  
Retinal Ganglion ◽  
Spatial Expansion ◽  
Neuronal Membranes ◽  
Inductive Elements ◽  
X Cells

We examined the dependence of the center radius of X cells on temporal frequency and found that at temporal frequencies above 40 Hz the radius increases in a monotonic fashion, reaching a size approximately 30% larger at 70 Hz. This kind of spatial expansion has been predicted with cable models of receptive fields where inductive elements are included in modeling the neuronal membranes. Hence, the expansion of the center radius is clearly important for modeling X cell receptive fields. On the other hand, we feel that it might be of only minor functional significance, since the responsivity of X cells is attenuated at these high temporal frequencies and the signal-to-noise ratio is considerably worse than at low and midrange temporal frequencies.

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