Flux-lattice melting in LaO1−x_{1-x}Fx_{x}FeAs: first-principles prediction

We report the theoretical study of the flux-lattice melting in the novel iron-based superconductor $LaO_{0.9}F_{0.1}FeAs$ and $LaO_{0.925}F_{0.075}FeAs$. Using the Hypernetted-Chain closure and an efficient algorithm, we calculate the two-dimensional one-component plasma pair distribution functions, static structure factors and direct correlation functions at various temperatures. The Hansen-Verlet freezing criterion is shown to be valid for vortex-liquid freezing in type-II superconductors. Flux-lattice meting lines for $LaO_{0.9}F_{0.1}FeAs$ and $LaO_{0.925}F_{0.075}FeAs$ are predicted through the combination of the density functional theory and the mean-field substrate approach.Comment: 5 pages, 4 figures, to appear in Phys. Rev.

A Study on the Ideological Connotation and Significance of Agricultural Poetry in the Northern Song Dynasty

The agrarian-related poems of the Northern Song Dynasty are far from the realistic creation tradition of the Book of Songs, the Yuefu folk songs of the Han Dynasty, “those who are hungry sing about their food, those who are working about their work”, and the realistic spirit of Du Fu’s “Three officials” and “three different” and Bai Juyi’s New Yuefu Movement, “Only songs live the people’s disease”. Through multiple contrast techniques, they fully show the miserable fate of the peasants under the heavy pressure of land, taxation, labor and other systems in the Northern Song Dynasty. It exposes the social situation of extreme disparity between the rich and the poor and sharp contradictions between classes, and expresses the complex feelings of compassion, hatred and guilt of scholars and literati. Influenced by the social culture of the Song Dynasty, the agriculture-related poems of the Northern Song Dynasty also showed the creative tendency of argumentation and prose culture, which was different from the previous poetry, and demonstrated the unique artistic style of the Song poetry

A Trust Model Based on Service Classification in Mobile Services

Internet of Things (IoT) and B3G/4G communication are promoting the pervasive mobile services with its advanced features. However, security problems are also baffled the development. This paper proposes a trust model to protect the user's security. The billing or trust operator works as an agent to provide a trust authentication for all the service providers. The services are classified by sensitive value calculation. With the value, the user's trustiness for corresponding service can be obtained. For decision, three trust regions are divided, which is referred to three ranks: high, medium and low. The trust region tells the customer, with his calculated trust value, which rank he has got and which authentication methods should be used for access. Authentication history and penalty are also involved with reasons.Comment: IEEE/ACM Internet of Things Symposium (IOTS), in conjunction with GreenCom 2010, IEEE, Hangzhou, China, December 18-20, 201