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Community detection is a vital task in many fields, such as social networks, and financial analysis, to name a few. The Louvain method, the main workhorse of community detection, is a popular heuristic method based on modularity. But it is difficult for the sequential Louvain method to deal with large-scale graphs. In order to overcome the drawback, researchers have proposed several parallel Louvain methods (Parallel Louvain Method, PLM), which suffer two challenges: (1) latency in the information synchronization and (2) communities swap. To tackle these two challenges, we propose a graph partition algorithm for the parallel Louvain method. Different from existing graph partition algorithms, our graph partition algorithm divides the graph into subgraphs called isolate sets, in which vertices are relatively decoupled from others, and the PLM computes and synchronizes information without delay and communities swap. We first describe concepts and properties of isolate sets. In the second place, we propose an algorithm to divide the graph into isolate sets, which enjoys the same computation complexity as the breadth-first search. Finally, we propose the isolate-set-based parallel Louvain method, which calculates and updates vertices information without latency and communities swap. We implement our method with OpenMP on an 8-cores PC. Experiments on 18 graphs show that our parallel method achieves a maximum 4.62 × speedup compared with the sequential method, and outputs higher modularity on 14 graphs. [ABSTRACT FROM AUTHOR]

Radical and non-radical oxidation pathways have been universally validated in transition metals (TMs) oxides activated peroxymonosulfate (PMS) processes. However, achieving high efficiency and selectivity of PMS activation remains challenging due to the ambiguous tuning mechanism of TMs sites on PMS activation in thermodynamic scope. Herein, we demonstrated that the exclusive PMS oxidation pathways were regulated by d orbital electronic configuration of B-sites in delafossites (CuBO 2) for Orange I degradation (CoIII 3 d 6 for reactive oxygen species (ROSs) vs. CrIII 3 d 3 for electron transfer pathway). The d orbital electronic configuration was identified to affect the orbital overlap extent between 3 d of B-sites and O 2 p of PMS, which induced B-sites offering different types of hybrid orbital to coordinate with O 2 p of PMS, thereby forming the high-spin complex (CuCoO 2 @PMS) or the low-spin complex (CuCrO 2 @PMS), on which basis PMS was selectively dissociated to form ROSs or achieve electron transfer pathway. As indicated by thermodynamic analysis, a general rule was proposed that B-sites of less than half-filled 3 d orbital tended to act as electron shuttle, i.e., CrIII (3 d 3), MnIII (3 d 4), interacting with PMS to execute an electron transfer pathway for degrading Orange I, while B-sites of between half-filled and full-filled 3 d orbital preferred to be electron donator, i.e., CoIII (3 d 6), FeIII (3 d 5), activating PMS to generate ROSs. These findings lay a foundation for the oriented design of TMs-based catalysts from the atomic level according to d orbital electronic configuration optimization, as so to facilitate the achievement of PMS-AOPs with highly selective and efficient remediation of contaminants in water purification practice. • The exclusive PMS oxidation pathways occurred on delafossite with distinct B-sites. • The d electronic configuration was a pivotal role in regulating PMS oxidation pathway. • The B-sites with 3 d orbital less than half-filled interact with PMS to execute ETP. • The B-sites with 3 d orbital between half- and full-filled activate PMS to evolve ROSs. • Tuning mechanism of B-sites on PMS activation is deciphered in thermodynamic scope. [Display omitted] [ABSTRACT FROM AUTHOR]

Surface-dependent nonradical oxidation of N-doped carbon (NC)-based peroxymonosulfate (PMS) system features high stoichiometric efficiency and target degradation selectivity. However, these are severely limited by the ineffective mass transfer of organics and PMS to NC surface. Herein, we utilize membrane confinement to enhance the interaction between organics/PMS and NC catalyst, and propose the synergy mechanism of surface reaction and membrane confinement towards organics removal. The NC catalyst layer is firstly uniformly loaded throughout the ceramic membrane (NC@CM) via an innovative simultaneous polymerization-coating method. As expected, NC@CM/PMS system significantly expedites the surface reaction dominant oxidation in the filtration-through mode, and its kinetics constant for bisphenol A removal is 3700 times higher than that of NC powder/PMS system. Moreover, it has high selectivity in removal of targeted organics such as BPA (81–100 % removal rate) under various interferences (anions, NOM, water sources) due to the corporation of surface reaction and membrane sieving effect. Mechanism study reveals that the synergy of membrane confinement and surface reaction of NC@CM/PMS system removes large size disturbance and reinforces mass transfer process of reactive species towards target organics, and promotes the generation and transformation of reactive species on the NC surface. Our system can selectively and efficiently remove targeted micropollutants with strong anti-interference capability, which is of great significance in practical application. [Display omitted] • Simultaneous polymerization-coating method is innovatively employed for preparation of NC@CM. • Uniform NC layer guarantees adequate exposure of active sites in limited inner space of CM during AOPs. • Surface reaction dominant oxidation mechanism highlights the advantages of membrane confinement. • Synergy of surface reaction and membrane confinement endows NC@CM/PMS system with selectively efficient pollutant removal. [ABSTRACT FROM AUTHOR]

Abstract The ninth edition of the China Trajectory Optimization Competition (CTOC9) considered the problem of navigation augmentation over a set of Chinese cities, wherein the competitors were expected to design a suitable LEO constellation to obtain the required navigation performance with the aim of minimizing overall system cost. In addition, an economical deployment strategy was also considered. The synthesis methods used by the Xi'an Satellite Control Center (XSCC) are described, along with the promising solution found by the team. Firstly, two techniques, feasible region based reduction and coverage region based reduction, are applied in sequence to narrow the search space. Then, the optimal constellation configuration is obtained through an Differential Evolution Algorithm (DE). Finally, a series of maneuver strategies are searched to inject each navigation satellite from a given initial carrying orbit to its target location. The solution obtained during the competition ranked third, and the improved one, found after the deadline, got the outstanding prize. [ABSTRACT FROM AUTHOR]

Aircraft recognition has great application value, but aircraft in remote sensing images have some problems such as low resolution, poor contrasts, poor sharpness, and lack of details caused by the vertical view, which make the aircraft recognition very difficult. Especially when there are many kinds of aircraft and the differences between aircraft are subtle, the fine-grained recognition of aircraft is more challenging. In this paper, we propose a non-locally enhanced feature fusion network(NLFFNet) and attempt to make full use of the features from discriminative parts of aircraft. First, according to the long-distance self-correlation in aircraft images, we adopt non-locally enhanced operation and guide the network to pay more attention to the discriminating areas and enhance the features beneficial to classification. Second, we propose a part-level feature fusion mechanism(PFF), which crops 5 parts of the aircraft on the shared feature maps, then extracts the subtle features inside the parts through the part full connection layer(PFC) and fuses the features of these parts together through the combined full connection layer(CFC). In addition, by adopting the improved loss function, we can enhance the weight of hard examples in the loss function meanwhile reducing the weight of excessively hard examples, which improves the overall recognition ability of the network. The dataset includes 47 categories of aircraft, including many aircraft of the same family with slight differences in appearance, and our method can achieve 89.12% accuracy on the test dataset, which proves the effectiveness of our method. [ABSTRACT FROM AUTHOR]