P-CSREC: A New Approach for Personalized Cloud Service Recommendation

It is becoming a challenging issue for users to choose a satisfied service to fit their need due to the rapid growing number of cloud services and the vast amount of service type varieties. This paper proposes an effective cloud service recommendation approach, named personalized cloud service recommendation (P-CSREC), based on the characterization of heterogeneous information network, the use of association rule mining, and the modeling and clustering of user interests. First, a similarity measure is defined to improve the average similarity (AvgSim) measure by the inclusion of the subjective evaluation of users’ interests. Based on the improved AvgSim, a new model for measuring the user interest is established. Second, the traditional K-Harmonic Means (KHM) clustering algorithm is improved by means of involving multi meta-paths to avoid the convergence of local optimum. Then, a frequent pattern growth (FP-Growth) association rules algorithm is proposed to address the issue and the limitation of traditional association rule algorithms to offer personalization in recommendation. A new method to define a support value of nodes is developed using the weight of user’s score. In addition, a multi-level FP-Tree is defined based on the multi-level association rules theory to extract the relationship in higher level. Finally, a combined user interest with the improved KHM clustering algorithm and the improved FP-Growth algorithm is provided to improve accuracy of cloud services recommendation to target users. The experimental results demonstrated the effectiveness of the proposed approach in improving the computational efficiency and recommendation accuracy

Prussian blue analog Co-3[Co(CN)(6)](2) as a cathode material for lithium-sulfur batteries

In this work, the authors proposed a unique strategy to prepare a high performance Lithium-Sulfur (Li-S) battery cathode by an N-rich nano-graphene hollow sphere from the Prussian blue analog Co-3[Co(CN)(6)](2). The one-pot solution method with low cost materials was designed to synthesize the cathode by annealing with different temperatures and consistent HCl etching steps for the precursor. The Li-S batteries made by this precursor showed remarkable charge-discharge stability (570.4mA h g(-1) after 500 cycles at a 1C current density) and outstanding rate performance (1145.5, 717.9, and 672.5mA hg(-1) at 0.1, 1.0, and 2.0 Ag-1 current densities) at 800 degrees C. The results indicated that the stable three-dimensional multi-layer hollow sphere structure relieved the volume expansion of sulfur, which had a significant impact on the polysulfide adsorption, inhibiting the "shuttle effect." Also, the rich doping of nitrogen in this structure produced many defects and active sites that improved the interfacial adsorption of polysulfides. While Co-3[Co(CN)(6)](2) shows its potential as a cathode material, the material design method used in this paper provides a unique approach to realizing a high performance sulfur cathode for Li-S batteries. Published under license by AIP Publishing. https://doi.org/10.1063/5.002428

The reallocation effect of China's provincial power transmission and trade on regional heavy metal emissions

Summary: Coal-fired power plants (CFPPs) are key point sources to atmospheric heavy metal (HM) emissions in China. Unevenly distributed CFPPs lead to large-scale interregional power transmission, as well as corresponding environmental emissions transfer. However, the effect of power transmission on HM reallocation remains poorly understood. Here, we traced HM (including Hg, As, Se, Pb, Cd, and Cr) emission flows through electricity transmission and regional trade and calculated China's multi-perspective electricity-related HM emissions from 2010 to 2015. Results show that in 2015, power transmission and regional trade caused 226.5 t (14% of total emissions) and 453.6 t (28%) of HM emission flows, respectively, leading to great differences in provincial HM emissions under different perspectives (e.g., Beijing's consumption-based emission was 15.5 times higher than the city's production-based emission in 2015). Our study provides valuable insights for fairly allocating provincial HM emission reduction responsibility and formulating synergistic emission mitigation strategies among regions

Synergistic effect of cobalt, nitrogen-codoped hollow carbon sphere hosts for high performance lithium sulfur batteries

Lithium-sulfur (Li-S) batteries are considered to be one of the most promising candidates for the next generation of rechargeable batteries due to their high theoretical energy density and low cost. However, the practical application of Li-S batteries is seriously hindered by the dissolution of polysulfide and the intrinsic insulation of sulfur. Herein, we demonstrate a novel strategy to address these two problems by designing and synthesizing a cobalt, nitrogen-codoped hollow carbon sphere (Co, N@CPDA-HCS) with a highly conductive carbon shell to accommodate the sulfur. In this unique material architecture, each component synergistically serves a specific purpose: the highly conductive shell carbon can provide fast electron conduction paths and structural stability; the superfine Co nanoparticles uniformly embedded in the carbon shell can accelerate the conversion kinetics of the polysulfides by strong chemical interaction; moreover, the hollow structure provides a buffer space for the volume change of sulfur during charging and discharging, thus leading to a good cycle stability of sulfur cathodes. Co, N@CPDA-HCS exhibits balanced high electrochemical performance with respect to specific capacity, rate capability, and cycling stability. Specifically, S/Co, N@CPDA-HCS presents a high initial gravimetric capacity of 1365 mA h g(-1) at 0.1 A g(-1). The discharge capacity of 588 mA h g(-1) still remained at the current density of 1 A g(-1) after 300 cycles

Controllable Li3PS4-Li4SnS4 solid electrolytes with affordable conductor and high conductivity for solid-state battery

International audienceHigh ionic conductivity, low grain boundary impedance, and stable electrochemical property have become the focus for all-solid-state lithium-sulfur batteries (ASSLSB). One of the approaches is to promote the rapid diffusion of lithium ions by regulating the chemical bond interactions within the framework. The structure control of P5+ substitution for Sn4+ on lithium-ion transport was explored for a series of Li3PS4-Li4SnS4 glass-ceramic electrolytes. Results showed that the grain boundary impedance of the glass electrolyte was reduced after heat treatments. The formation of LiSnPS microcrystals, a good superionic conductor, was detected by X-ray diffraction tests. Electrochemical experiments obtained the highest conductivity of 29.5 S cm(-1) at 100 degrees C and stable electrochemical window from -0.1 to 5 V at 25 degrees C. In addition, the cell battery was assembled with prepared electrolyte, which is promoted as a candidate solid electrolyte material with improved performance for ASSLSB

Hillock formation and suppression on c-plane homoepitaxial GaN Layers grown by metalorganic vapor phase epitaxy

Hillocks on c-plane homoepitaxial GaN epilayers were investigated. They were observed on epilayers grown on [1 (1) over bar 00] direction miscut free-standing GaN substrates with miscut angle not larger than 0.2 degrees and were absent when substrate miscut angle increased to 0.4 degrees. Atomic force microscopy (AFM) and cathodoluminescence measurements reveal a close correlation between hillocks and dislocation clusters, while hillocks are absent on layers grown on GaN substrate free of dislocation clusters. We believe that the hillocks originate from spiral growth around dislocation clusters. Larger strain induced by dislocation accumulation may be responsible for the hillock formation around dislocation clusters. (C) 2013 Elsevier B.V. All rights reserved

Proteomics analysis of chicken peripheral blood lymphocyte in Taishan Pinus massoniana pollen polysaccharide regulation.

The natural polysaccharides extracted from the pollen of Pinus massoniana (TPPPS) have been shown to be a promising immune adjuvant against several viral chicken diseases. However, the exact mechanism through which TPPPS enhances the host immune response in chicken remains poorly understood. In the current study, chicken peripheral blood lymphocytes were treated with varying concentrations of TPPPS and pro-inflammatory cytokines such as IFN-γ, iIL-2 and IL-6 were measured to determine the optimal dose of the polysaccharide. A comparative analysis was subsequently performed between the proteome of lymphocytes subjected to the best treatment conditions and that of untreated cells. Protein identification and quantitation revealed a panel of three up-regulated and seven down-regulated candidates in TPPPS-treated chicken peripheral blood lymphocytes. Further annotation and functional analysis suggested that a number of those protein candidates were involved in the regulation of host innate immune response, inflammation and other immune-related pathways. We believe that our results could serve as a stepping stone for further research on the immune-enhancing properties of TPPPS and other polysaccharide-based immune adjuvants