A Core-Periphery Model of Urban Economic Growth: Empirical Evidence using Chinese City-Level Data, 1990-2006

The core-periphery (CP) model of urban systems lacks evidence from real data for the nonlinear relationship between distance to core and market potential. China remains in the process of industrialization and globalization, thereby making it suitable for practical application of the CP model of urban systems. Using Chinese city-level data from 1990 to 2006, this paper estimates the impact of spatial interactions in China's urban system on urban economic growth, and fills the gap between CP model of urban systems and reality. Our results show that a proximity to major ports and international markets is essential for urban growth. Moreover, the geography-growth relationship follows the U-shaped nonlinear pattern implied by the CP model in a monocentric urban system. We also find "border effect" in the administrative boundaries between Chinese provinces. As a centrifugal force, this prevents the absorption of urban economic activities by large cities in other provinces.Core-Periphery Model, Urban Systems, Trade Policy, China

PETROGENESIS AND TECTONIC IMPLICATION OF THE NEOPROTEROZOIC BONINITIC-THOLEIITIC LAVAS AND MAGNESIAN ANDESITES IN THE GORNY ALTAI TERRANE, NORTHWESTERN CENTRAL ASIAN OROGENIC BELT

The late Neoproterozoic tholeiitic-boninitic lavas and minor magnesian andesites cropping out in the Kurai Ridge, southeast of the Gorny Altai terrane, represent magmatic products of the nascent Kuznetsk-Altai intra-oceanic island arc southwest off the Siberian continent. Samples of these rocks can provide key information about sub-arc mantle and slab-mantle interaction during the early phase of ocean-ocean subduction.The late Neoproterozoic tholeiitic-boninitic lavas and minor magnesian andesites cropping out in the Kurai Ridge, southeast of the Gorny Altai terrane, represent magmatic products of the nascent Kuznetsk-Altai intra-oceanic island arc southwest off the Siberian continent. Samples of these rocks can provide key information about sub-arc mantle and slab-mantle interaction during the early phase of ocean-ocean subduction

Algebraic Quantum Error-Correction Codes

Based on the group structure of a unitary Lie algebra, a scheme is provided to systematically and exhaustively generate quantum error correction codes, including the additive and nonadditive codes. The syndromes in the process of error-correction distinguished by different orthogonal vector subspaces, the coset subspaces. Moreover, the generated codes can be classified into four types with respect to the spinors in the unitary Lie algebra and a chosen initial quantum state

Target shape effects on monoenergetic GeV proton acceleration

When a circularly polarized laser pulse interacts with a foil target, there are three stages: pre-hole-boring, hole-boring and the light sail acceleration. We study the electron and ion dynamics in the first stage and find the minimum foil thickness requirement for a given laser intensity. Based on this analysis, we propose to use a shaped foil for ion acceleration, whose thickness varies transversely to match the laser intensity. Then, the target evolves into three regions: the acceleration, transparency and deformation regions. In the acceleration region, the target can be uniformly accelerated producing a mono-energetic and spatially collimated ion beam. Detailed numerical simulations are performed to check the feasibility and robustness of this scheme, such as the influence of shape factors and surface roughness. A GeV mono-energetic proton beam is observed in the three dimensional particle-in-cell simulations when a laser pulse with the focus intensity of 1022W=cm2 is used. The energy conversion efficiency of laser pulse to accelerated proton beam is more than 23%. Synchrotron radiation and damping effects are also checked in the interaction.Comment: 11 pages, 9 figure