No abstract

Rail transit is a significant measure for the comprehensive development of large cities, which influences the land use patterns and the spatial patterns of residential prices around the rail. This study considered Beijing Metro Line 10 and Line 13 as examples, based on a semi-logarithmic hedonic price model, combined with facility point-of-interest (POI) data and residential unit transaction data, to study how rail transit affects the spatial differentiation of urban residential prices. Within the 2 km study area along the line, factors such as community grade (property fee), living environment (park), and living convenience (shopping mall) significantly affected the residential prices. Factors influencing residential prices in different rail locations also differed. The residential prices within the fourth ring (Line 10) were correlated significantly with population density (plot ratio) and station distance, while residential prices outside the fourth ring (Line 13) were correlated with community environment (greening rate), community-built time (age of residence), and public transportation conditions. The conclusions of this study are as follows: (1) Within the urban area of a single central city, the average residential price on the inner side of the rail transit line adjacent to the city center is higher than on the outer side. (2) Neighborhood characteristics significantly affect residential prices along rail transit lines in urban areas, while the architectural and neighborhood characteristics have equally important effects on residential prices along suburban rail transit lines. (3) Urban residential patterns affect residential prices along rail transit lines, with rail transit in urban areas having lesser value-added effect on areas with higher residential prices and suburban rail transit having higher value-added effect on areas with lower residential prices. The innovation of this study is to analyze the spatial differentiation from two location perspectives: the residential price pattern of the city and the city’s own ring division, and to add new location characteristic variables at a unit distance of 200 m. This study confirms that the spatial effect of rail transit on residential prices in different locations of the same city is not the same, and it also provides policy suggestions for strengthening the combination of Transit-Oriented-Development (TOD) model and the layout of residential land.

An organic template of polystyrene colloidal crystals was fabricated through dip-coating in a polystyrene emulsion. Based on the template, an ordered porous TiO 2 film doped with Gd 3+ was deposited on a conductive glass. x-ray diffractometry (XRD), scanning electron microscopy (SEM), UV-vis spectroscopy were used to characterize the structures and properties of the film. The as-produced film was used as an electrode in dye-sensitized solar cells with a sandwich structure. XRD showed that anatase TiO 2 was obtained. SEM images clearly demonstrated that these films had an ordered porous structure, mainly in a hexagonal orientation. UV-vis spectroscopy revealed that the absorption was improved in both the ultraviolet and the visible areas. Under simulated solar illumination, a short circuit current of 0.618 mA and an open circuit voltage of 0.538 V were attained, which were better than the performances of only a TiO 2 film electrode and an ordered porous TiO 2 film electrode.

A series of Zn 2+ and Eu 3+ co-doped TiO 2 catalysts were prepared by a modified sol-gel method. The prepared catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy(TEM) and ultraviolet-visible diffuse reflection spectroscopy(UV-vis DRS). Characteristic results clearly show that all of Zn 2+ and Eu 3+ co-doped TiO 2 samples exclusively consist of primary anatase crystallites, the co-doping can retard the grain growth of TiO 2 and decrease the aggregation of TiO 2 nanoparticles. Zn 2+ and Eu 3+ co-doping increased the visible-light absorption ability of TiO 2 catalysts and a red shift appeared when compared to pure TiO 2 . The photocatalytic activity of samples was evaluated by the photodegradation of methyl organge under natural light irradiation. Optimal doping amounts for Zn 2+ and Eu 3+ are 1.0% and 1.5% respectively, and two dopants of Zn 2+ and Eu 3+ in nanocrystalline TiO 2 show a synergistic effect, which significantly increases the photocatalytic activity of TiO 2 . The photocatalytic mechanisms of Zn 2+ and Eu 3+ co-doped TiO 2 catalysts were tentatively discussed.

This paper presents a novel hard decision decoding algorithm for low-density parity-check (LDPC) codes, in which the stand matching pursuit (MP) is adapted for error pattern recovery from syndrome over GF(2). In this algorithm, the operation of inner product can be converted into XOR and accumulation, which makes the matching pursuit work with a high efficiency. In addition, the maximum iteration is theoretically explored in relation to sparsity and error probability according to the sparse theory. To evaluate the proposed algorithm, two MP-based decoding algorithms are simulated and compared over an AWGN channel, i.e., generic MP (GMP) and syndrome MP (SMP). Simulation results show that the GMP algorithm outperforms the SMP by 0.8 dB at BER = 10 − 5 .