Robustness and edge addition strategy of air transport networks : a case study of 'the Belt and Road'

Air transportation is of great importance in "the Belt and Road" (the B&R) region. The achievement of the B&R initiative relies on the availability, reliability, and safety of air transport infrastructure. A fundamental step is to find the critical elements in network performance. Considering the uneven distributions of population and economy, the current literature focusing on centrality measures in unweighted networks is not sufficient in the B&R region. By differentiating power and centrality in the B&R region, our analysis leads to two conclusions: (1) Deactivating powerful nodes causes a larger decrease in efficiency than deactivating central nodes. This indicates that powerful nodes in the B&R region are more critical than central nodes for network robustness. (2) Strategically adding edges between high powerful and low powerful nodes can enhance the network's ability to exchange resources efficiently. These findings can be used to adjust government policies for air transport configuration to achieve the best network performance and the most cost effective

Assessment of the quantitative accuracy of Rietveld/XRD analysis of crystalline and amorphous phases in fly ash

An internal standard method based on Rietveld/XRD whole-pattern fitting analysis of fly ash is used to assess the quantitative accuracy to determine its crystalline and amorphous phases under various conditions such as internal standards (types, SiO2 or Al2O3 and dosages, 10–50%), incident X-rays (laboratory or synchrotron) and refinement software (GSAS or TOPAS). The results reveal that the quantitative stability is quite sensible to minor phases, identical to the internal standard, in fly ash. Errors positively correlate with the weight fraction of that minor phase and negatively correlate with the dosage of an internal standard and amorphous phase content in fly ash. The original equation for the amorphous phase calculation is not applicable for a case with a higher inherent quartz content (>2.5%) in fly ash while the dosages of the internal standard is lower than 20%. The original equation is modified as proposed. Based on it, the quantitative results of five different patterns report a good reproducibility with the arithmetic mean errors and the standard errors of identified main phases of around 1%.The access to the beamline BL14B1 facilities at the SSRF is appreciated and the support of SSRF management, User Office and beamline staff is highly appreciated. This Research is supported by the National Natural Science Foundation of China (No. 51602126), the National Key Research and Development Plan of China (2016YFB0303505) and the Program for Scientic Research Innovation Team in Colleges and Universities of Shandong Province

Spinor Field Realizations of the half-integer W2,sW_{2,s} Strings

The grading Becchi-Rouet-Stora-Tyutin (BRST) method gives a way to construct the integer $W_{2,s}$ strings, where the BRST charge is written as $Q_B=Q_0+Q_1$. Using this method, we reconstruct the nilpotent BRST charges $Q_{0}$ for the integer $W_{2,s}$ strings and the half-integer $W_{2,s}$ strings. Then we construct the exact grading BRST charge with spinor fields and give the new realizations of the half-integer $W_{2,s}$ strings for the cases of $s=3/2$, 5/2, and 7/2.Comment: 16 pages, 2 tables, references adde

Accelerating polygon beam with peculiar features

We report on a novel kind of accelerating beams that follow parabolic paths in free space. In fact, this accelerating peculiar polygon beam (APPB) is induced by the spectral phase symmetrization of the regular polygon beam (RPB) with five intensity beam (RPB) with five intensity peaks, and it preserves a peculiar symmetric structure during propagation. Specially, such beam not only exhibits autofocusing property, but also possesses two types of accelerating intensity maxima, i.e., the cusp and spot-point structure, which does not exist in the previously reported accelerating beams. We also provide a detailed insight into the theoretical origin and characteristics of this spatially accelerating beam through catastrophe theory. Moreover, an experimental scheme based on a digital micromirror device (DMD) with the binary spectral hologram is proposed to generate the target beam by precise modulation, and a longitudinal needle-like focus is observed around the focal region. The experimental results confirm the peculiar features presented in the theoretical findings. Further, the APPB is verified to exhibit self-healing property during propagation with either obstructed cusp or spot intensity maxima point reconstructing after a certain distance. Hence, we believe that the APPB will facilitate the applications in the areas of particle manipulation, material processing and optofludics

Bulk experimental evidence of half-metallic ferromagnetism in doped manganites

We report precise measurements and quantitative data analysis on the low-temperature resistivity of several ferromagnetic manganite films. We clearly show that there exists a T^{4.5} term in low-temperature resistivity, and that this term is in quantitative agreement with the quantum theory of two-magnon scattering for half metallic ferromagnets. Our present results provide the first bulk experimental evidence of half-metallic ferromagnetism in doped manganites.Comment: 4 pages, 4 figure

Explaining city branding practices in China’s three mega-city regions: The role of ecological modernization

As global cities, Hong Kong, Shanghai and Beijing operate in international economic networks; however, they are also each firmly embedded within a regional context and are surrounded by less populous and less internationally recognized neighbors. Together they form so-called mega-city regions referred to as the Greater Pearl River Delta, the Yangtze River Delta, and the Bohai Rim, each encompassing a dozen or so cities. In the wake of staggering economic growth and threatening pollution, these cities are compelled to respond to the challenge of ecological modernization (EM): aim for higher economic value added at lower environmental cost. Cities have particular industrial and regional profiles; consequently they follow different developmental pathways. In order to attract coveted investors, green and high-tech corporations, well-endowed residents and talented workforce, these cities engage in city branding practices. In this contribution, a typology of EM developmental pathways is presented and the 41 cities in the three Chinese mega-city regions are analyzed in terms of their respective pathways and city branding practices. We argue that different industrial and regional profiles allow for different developmental pathways making different city branding strategies likely. Most cities brand themselves in comformity with what their pathway would lead us to predict, except cities with a strongly manufacturing oriented profile; the brands of the latter type deviate markedly from their current reality. Cities adopting branding strategies that contrast sharply with their historical legacy and current profile risk promoting themselves in ways that the outside world is likely to perceive as lacking in credibility

The multi-level governance of formulating regional brand identities: Evidence from three Mega City Regions in China

The emergence and expansion of clusters of large metropolitan areas also known as Mega City Regions (MCRs) is a worldwide phenomenon. In China, governmental attempts are made to develop so-called regional brand identities for them. Regional brand identities, as a subspecies of place brand identities, differ from regional identities in the sense that they are the result of conscious branding efforts on the part of public authorities rather than more historically evolved regional identities as experienced by citizens. In this study, the establishment of regional brand identities for three MCRs in China is examined, as these are constituted through and institutionally embedded in intergovernmental relations. We map the perceptions of national, provincial and municipal governments of regional brand identities based on planning documents and relevant interviews. The emergence and stabilization of the regional profiles for China's largest MCRs Pearl River Delta (PRD), Yangtze River Delta (YRD) and Jing-Jin-Ji (JJJ) are featured in their dynamic territorial boundaries, centralized institutionalization and various symbolic meanings. The national government promotes the regional brands to reinforce the strategic awareness and future direction of the region, and these profiles are diffused at the provincial and municipal level