Urban land use information is critical to urban planning, but the increasing complexity of urban systems makes the accurate classification of land use extremely challenging. Human activity features extracted from big data have been used for land use classification, and fusing different features can help improve the classification. In this paper, we propose a framework to integrate multiple human activity features for land use classification. Features were fused by constructing a membership matrix reflecting the fuzzy relationship between features and land use types using the fuzzy c-means (FCM) clustering method. The classification results were obtained by the fuzzy comprehensive evaluation (FCE) method, which regards the membership matrix as the fuzzy evaluation matrix. This framework was applied to a case study using taxi trajectory data from Nanjing, and the outflow, inflow, net flow and net flow ratio features were extracted. A series of experiments demonstrated that the proposed framework can effectively fuse different features and increase the accuracy of land use classification. The classification accuracy achieved 0.858 (Kappa = 0.810) when the four features were fused for land use classification.

No abstract

The β → α phase transition kinetics of the Ti–3.5Al–5Mo–4V alloy with two different grain sizes was investigated at the isothermal temperature of 500 °C. A method to estimate the function of the precipitate fraction of the α phase with different aging times was developed based on X-ray diffraction analysis. The value of the α precipitate fraction increased sharply at first, then increased slowly with the aging time, and finally reached equilibrium. The value of the α precipitate fraction was higher in the alloy aged for the same time at a higher solution temperature, while the size of the α precipitate was smaller at a higher solution temperature. The β → α phase transition kinetics under isothermal conditions were modeled in the theoretical frame of the Johnson–Mehl–Avrami–Kolmogorov (JMAK) theory. The kinetic parameters of JMAK deduced different transformation mechanisms. The mechanism of the phase transition in the first stage was dominated by mixed transformation mechanisms (homogeneously nucleated and acicular-grown α structure, and grain boundary-nucleated and grown α precipitate), while the second stage was the growth of the fine α precipitate, which was controlled by slow diffusion. As the aging time increased, the hardness of the Ti–3.5Al–5Mo–4V alloy increased sharply. After the hardness of the alloy reached a plateau, it began to decline. The hardness of the alloy was always higher at a higher solution temperature.

In this work, the effect of double-ageing heat treatments on the microstructural evolution and mechanical behaviour of a metastable β-titanium Ti-3.5Al-5Mo-4V alloy is investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The double-ageing treatments are composed of low-temperature pre-ageing and high-temperature ageing, where the low-temperature pre-ageing is conducted at 300 °C or 350 °C for different times, and the high-temperature ageing is conducted at 500 °C for 8 h. The results show that the phase transformation sequence is altered with the time spent during the first ageing stage, the isothermal ω phase is precipitated in the pre-ageing process of the alloy at 300 °C and 350 °C with the change in the ageing time, and the ω phase is finally transformed into the α phase with the extension of pre-ageing time. The existence time of the ω phase is shortened as the pre-ageing temperature increases. The microhardness of the alloy increases with increasing pre-ageing time and temperature. Compared with single-stage ageing, the ω phase formed in the pre-ageing stage changes the response to subsequent high-temperature ageing. After the two-stage ageing treatment, the precipitation size of the α phase is obviously refined after the double-ageing treatment. A microhardness test shows that the microhardness of the two-stage aged alloy increases with extended pre-ageing time.

Abstract. As for China, since the reform and open, domestic industries have shown a quite obvious tendency of agglomeration, which catches the attention of both economic researchers and policy makers. However, although it has been proved by the previous researches that China's opening up to the outside world promoted domestic industrial agglomeration; most of the literature focused on the importance of decreasing trade costs to domestic industrial agglomeration, the importance of FDI was always ignored. This is also the main research purpose of this article, from the aspects of FDI to analyze its influence on industrial agglomeration. As follows is the research method of the paper, using the panel data of the 30 Chinese provinces industrial in 2005-2015, and then constructing the econometric model, then testing the effects of FDI on the China's industrial agglomeration. The empirical results show that FDI significantly promoted the China's industrial agglomeration. As follows are the research conclusions of the paper, FDI act on Chinese economic growth and regional disparity adjustment, which means that Chinese government should make rational use of FDI, to further promote the agglomeration of China's industrial, and effectively promote the economic growth and regional inequality.