204 wileyonlinelibrary.com www.particle-journal.com www. MaterialsViews.com Presently, graphene incorporation is one of the most effective strategies to develop superior electrode materials for sodium-ion batteries (SIBs). Herein, it is excitingly found that an incorporated graphene nanosheet in the preparation processes can not only completely protect all the Sb nanoparticles in an Sb/C composite from being inactivated, but also suppresses their growth to undesirable micrometer size. While there are still many exposed Sb particulates on the surface of pristine Sb/C microplates, the graphene-incorporated Sb/C/G nanocomposite consists of uniform Sb nanoparticles of 20-50 nm, all of which have been protected by and wrapped in the mixed carbon network. When used as anode materials for SIBs, the Sb/C/G nanocomposite exhibits the best Nastorage properties in terms of the highest reversible capacity (650 mA h g −1 at 0.025 A g −1 ), fastest Na-storage ability (290 mA h g −1 at a high current density of 8 A g −1 ), and optimal cycling performance (no capacity decay after 200 cycles), in comparison to pristine Sb/C and pure Sb. It is further revealed that the much enhanced performance should originate from the improvement of Na-storage kinetics and increase of electronic conductivity via comparing the electrochemical impedance spectra, and cyclic voltammetry profi les, as well as the polarization variation along with current densities.electrode materials of SIBs with superior electrochemical properties, including high specifi c capacity, excellent high-rate performance, and long cycle life. For the SIBs, developing high-performance anode materials should be one of the most urgent research assignments, because the traditional graphite anode of LIBs can hardly achieve Na-storage. Presently, many anode materials have been proposed including carbonaceous materials with low degree of graphitization, [ 3 ] metallic alloys, [ 4 ] oxides and sulfi des, [ 5 ] and organic compounds. [ 6 ] Among those anode materials, alloying antimony (Sb) element has drawn great attention because of the low and suitable potentials for sodiation/desodiation and high theoretical Na-storage capacity (660 mA h g −1 ) corresponding to the formation of Na 3 Sb phase. Unfortunately, the severe volume expansion and contraction during sodiation and desodiation will lead to the undesirable pulverization of the whole electrode and hence the invalidation of electronic transport pathways, [ 7 ] which makes the common Sb material usually exhibit poor cycle stability, as well as unsatisfactory high-rate capabilities.In order to relieve the volumetric effects to enhance the Na-storage properties of Sb anode material, many strategies have been reported previously. The main ones include: i) preparing special nanostructures such as monodisperse Sb nanocrystals [ 8 ] and porous Sb hollow spheres, [ 9 ] ii) synthesizing Sb-containing alloys or their composites with low volume variation during Na-uptake/release cycles, e.g., Sn-Ge-Sb ternary alloy, [ 10 ] Sb/C...

International audienceText mining is an effective means of detecting potentially useful knowledge from large text documents. However conventional text mining technology cannot achieve high accuracy, because it cannot effectively make use of the semantic information of the text. Ontology provides theoretical basis and technical support for semantic information representation and organization. This paper improves the traditional text mining technology which cannot understand the text semantics. The author discusses the text mining methods based on domain ontology, and sets up domain ontology and database at first, then introduces the “concept-concept” correlation matrix and identifies the relationships of conceptions, and puts forward the text mining model based on domain ontology at last. Based on the semantic text mining model, the depth and accuracy of text mining is improved

Test case prioritization is a method to prioritize test cases to improve the testing efficiency of service-oriented workflow applications. Existing prioritization methods prioritize test cases in different application environments according to different metrics (for example, statement coverage, and path coverage). Web services are orchestrated by service-oriented workflow applications to provide different functions, especially in cloud-based mobile systems. As a result, those applications need more precise scheduling to run test cases that can detect faults earlier. Unfortunately, most regression test case prioritization studies in service-oriented workflow applications neglect the use of activity dependency, which is an important factor that affects test case prioritization. By analyzing the dependences between activities, the modification effects of activities on the modified version of service-oriented workflow applications are calculated. On this basis, this paper proposes a new prioritization method for regression test cases. Experimental results show that our method is more effective than the traditional coverage-based technique in testing case priority.

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