BCS thermal vacuum of fermionic superfluids and its perturbation theory

The thermal field theory is applied to fermionic superfluids by doubling the degrees of freedom of the BCS theory. We construct the two-mode states and the corresponding Bogoliubov transformation to obtain the BCS thermal vacuum. The expectation values with respect to the BCS thermal vacuum produce the statistical average of the thermodynamic quantities. The BCS thermal vacuum allows a quantum-mechanical perturbation theory with the BCS theory serving as the unperturbed state. We evaluate the leading-order corrections to the order parameter and other physical quantities from the perturbation theory. A direct evaluation of the pairing correlation as a function of temperature shows the pseudogap phenomenon results from the perturbation theory. The BCS thermal vacuum is shown to be a generalized coherent and squeezed state. The correspondence between the thermal vacuum and purification of the density matrix allows a unitary transformation, and we found the geometric phase in the parameter space associated with the transformation.Comment: 14 pages, 2 figure

Systems biology in the frontier of cancer research: a report of the Second International Workshop of Cancer Systems Biology

The report summarizes the Second International Workshop of Cancer Systems Biology held on July 5-6, 2012 in Changchun, China. The goal of the workshop was to bring together cancer researchers with different backgrounds to share their views about cancer and their experiences in fighting against cancer, and to gain new and systems-level understanding about cancer formation, progression, diagnosis, and treatment through exchanging ideas

Study on dynamic response of track structures under a variable speed moving harmonic load

Basing on the dynamic response characteristics of the periodic structure under a moving harmonic load in frequency domain and the superposition principle, the dynamic response of track structure under variable speeds moving harmonic load is investigated. Firstly, the track is simplified as an Euler beam model periodically supported by continuous discrete point, the dynamic differential equation of vertical vibration for the track structure is formulated. Secondly, for convenience of analysis, the analytical expression for the amplitude-frequency response of any point on the track structure under the moving harmonic load is derived in frequency domain. Based on the theory of the infinite periodic structure, the dynamic responses of the track structure under the variable speed moving harmonic load are analyzed theoretically. Finally, the influences of velocity and acceleration on the dynamic response of track structure are numerically analyzed in detail. The research results indicate that the amplitude-frequency response peaks of the track under moving harmonic load with variable and constant speeds occur near the excitation frequency. The displacement response of the track increases slightly with increase of the acceleration, and the variation trend of dynamic response is basically similar. The vibration displacement response of the rail can be effectively improved by increasing the initial velocity of the moving harmonic load, while the peak value of amplitude-frequency response remained constant

On the Values of Travels Literature and its Development & Utilization

Travels literature is employed to record and describe the author's travel experience, impression and feeling which is in prose style. Its component factors and expressive means composed elements determine its multiple value system, which contain the values in literature, aesthetics, science, history, idea and politics. In order to better developing and utilizing the travels literature resources, we need systematical assortment, care arrangement and combination ,gradual realization of the digital travels literature. Keywords: Travels, Literature study, Tourism Résumé Le récit de voyage est un genre de document qui consiste à narrer et décrire par la prose ce que l’auteur voit, entent et ressent durant son voyage. Ses facteurs constituants et façcons d’expression déterminent ses multiples systèmes de valeur qui s’expriment comme suite : valeurs littéraire et esthétique, valeurs scientifique et historique, valeurs de pensée et politique. L’exploitation et l’utilisation du récit de voyage doit commencer par le recensement global des documents de voyage, l’arrangement et la combinaison des ressources d’informations touristiques et la réalisation progressive de la numérisation du récit de voyage. Mots-clés : récit de voyage, recherche du document, voyage 摘要 遊記是以散文形式記敍、抒寫作者親身旅行遊覽見聞感受的文獻類型，其構成要素與表達方式決定了多重的價值體系，主要體現為文學與美學價值、科學與史料價值、思想與政治價值。對遊記的開發利用應從全面普查遊記文獻、整合遊記資訊資源、逐步實現遊記的數位化入手。關鍵詞：遊記；文獻研究；旅

Comparison of form-deprived myopia and lens-induced myopia in guinea pigs

<b>AIM:</b> To study the efficacy difference between form-deprived myopia (FDM) and lens-induced myopia (LIM), the degree of myopia, axial length and pathological changes of the posterior sclera from guinea pigs were evaluated.<b>METHODS:</b> Four-week pigmented guinea pigs were randomly assigned into 3 groups, including normal control (<i>n</i>=6), FDM group with monocular cover (<i>n</i>=11) and LIM group with monocular -7D lens treatment (<i>n</i>=11). FDM group was form-deprived while LIM group was lens-induced for 14 d. Refractive error and axial length were measured prior to and post treatment, respectively. Morphological changes of sclera were examined using both light and electronic microscopes.<b>RESULTS:</b> After 14d treatment, refractive errors for FDM group and LIM group were -3.05±0.71D and -2.12±1.29D, respectively, which were significantly more myopic than that of normal controls and fellow control eyes (<i>P</i>&lt;0.01). As for axial length, it was 7.93±0.03 mm for FDM group and 7.89±0.06 mm for LIM group, which were significantly longer than both normal and fellow controls (<i>P</i>&lt;0.01). With respect to both refractory error and axial length, the differences between FDM group and LIM group were not significant (<i>P</i>&gt;0.05). Under light microscope, both FDM group and LIM group showed thinned sclera, disarrangement of fibrosis and enlarged disassociation between fibers. Consistently, ultrastructural examination showed degenerated fibroblasts and thinned fibers in posterior sclera.<b>CONCLUSION:</b>Following two weeks of myopia induction in guinea pigs, with regard to the degree of myopia, axial length and pathological alterations, there was no significant difference between FDM and LIM models. Therefore, FDM and LIM are equally effective and useful as a model of experimental myopia and guinea pigs are ideal animals for induction of experimental myopia because their high sensitivity to both form-deprivation and lens-induction