The study area in Shenzhen, China, and travel flows extracted from the mobile phone positioning data at the base tower level.

There are 5,929 cell phone towers, and the polygons were approximated by Voronoi tessellation of the towers representing the corresponding service areas. This dataset contains the positioning data of 9.7 million phone users (approximately 57.5% of the total population) during a workday in March 2012. The thicker lines indicate that more travel flows occurred between the two Voronoi polygons. The figure was created with an open source visualization toolkit: Processing (https://processing.org/). The administrative division of a shapefile sourced from the Bureau of Planning and Natural Resources of Shenzhen (http://pnr.sz.gov.cn/ywzy/chgl/bzdtfw/).</p

The probability distributions of <i>D</i>_<i>ave</i> and parameters at the motif level.

(a) and (c) for the LBM set and (b) and (d) for the ABM set. The different colors represent corresponding LN values or AN values, as shown on the top legend. Because certain groups have no Dave data, their parameters are always expressed as zero. The dashed horizontal lines in (a) and (b) indicate the parameter values for the LN set and AN set, respectively, as shown in Fig 7, and the blue solid line represents the parameter values for the ensemble distribution. The solid lines in (c) and (d) represent the curves of the best-fitted distributions for each group of LBM and ABM, some of which are the power law with an exponential cut-off, and some are the pure power law. For instance, LBM 31 is fitted with a pure power law with α = 2.46.</p

The probability distributions of <i>D</i>_<i>ave</i> and parameters at the node level.

(a) and (c) for the LN set and (b) and (d) for the AN set. The different colors represent corresponding LN values or AN values, as shown on the top legend. As the group with LN = 1 represents those individuals who only have visited one location in one day, their parameters are always expressed as zero. The dashed horizontal line in (a) and (b) indicates the parameter values for the ensemble distribution, as referred to in Fig 5. The solid lines in (c) and (d) represent the power law with an exponential cut-off fit for each group of the LN set and AN set.</p

Characterizing preferred motif choices and distance impacts - Fig 5

(a)-(b) Rank-frequency distributions separated by different location nodes and activity nodes, respectively. The different points in colors indicate the number of nodes, and the red lines represent the DGBD fit. (c)-(d) Density maps of correlations of F(r) and ⟨k⟩ for the location-based and activity-based motifs, respectively.</p

Fitted parameters (<i>β</i> and <i>γ</i>) of <i>DGBD</i>, sample size <i>N</i> (number of <i>LBMs</i>, <i>ABMs</i> and, <i>JMs</i>), and <i>p-values</i> for chi-square test.

Fitted parameters (β and γ) of DGBD, sample size N (number of LBMs, ABMs and, JMs), and p-values for chi-square test.</p

The illustration of location-based and activity-based motifs constructed from stay sequences and activity chains.

The illustration of location-based and activity-based motifs constructed from stay sequences and activity chains.</p

The probability distribution of <i>D</i>_<i>ave</i> for the overall travels in the data.

The solid blue line represents the power law with an exponential cut-off fit, of which the functional form is shown as well, while the red points refer to the log-transformed data. The vertical green line indicates the cut-off value κ. It should be noted that the log-transformation is only for visualize data but not for fit data.</p

Boosting the Photoluminescence Quantum Yield and Stability of Lead-Free CsEuCl₃ Nanocrystals via Ni²⁺ Doping

Colloidal CsPbX3 (X = Br, Cl, or I) perovskite nanocrystals (PNCs) have emerged as low-cost, high-performance light-emitting materials, whereas the toxicity of lead limits their applications. Europium halide perovskites offer promising alternatives to lead-based perovskites due to their narrow spectral width and high monochromaticity. Nonetheless, the photoluminescence quantum yields (PLQYs) of CsEuCl3 PNCs have been very low (∼2%). Herein, Ni2+-doped CsEuCl3 PNCs have been first reported, exhibiting bright blue emission centered at 430.6 ± 0.6 nm with a full width at half-maximum of 23.5 ± 0.3 nm and a PLQY of 19.7 ± 0.4%. To the best of our knowledge, this is the highest PLQY value reported for CsEuCl3 PNCs so far, an order of magnitude higher than in previous work. DFT calculations demonstrate that Ni2+ enhances PLQY by concurrently increasing the oscillator strength and removing Eu3+ which hinders the photorecombination process. B-site doping offers a promising approach to enhance the performance of lanthanide-based lead-free PNCs

Time evolution of the average distance of infected nodes from the center of the lattice in network A.

<p>The infection rate is <i>λ</i> = 0.24. Initially, 16 nodes in the center of network A are infected. The density of interconnection links is <i>q</i> = 1. The spatial length is <i>R</i> = 1. The network size is <i>N</i> = 10000. The results have been averaged over 100 realizations.</p

Density <i>ρ</i> of infected nodes as a function of the infection rate <i>λ</i> for various rewiring probabilities.

<p><i>ρ</i> is the average of the infection density <i>ρ</i>_<i>A</i> and <i>ρ</i>_<i>B</i>. The density of the interconnection links is <i>q</i> = 1, and the spatial length constraint is <i>R</i> = 1. Initially, 10% of the nodes in network A are randomly chosen to be infected. The network size is <i>N</i> = 10000. The results have been averaged over 100 realizations.</p