235 research outputs found

    Existence and multiplicity of solutions for a class of fractional Kirchhoff-type problem

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    In this paper, we establish the existence and multiplicity of solutions to the following fractional Kirchhoff-type problem begin{equation*}M(|u|^2)(-Delta)^s u=f(x,u(x)), mbox{ in } Omega ,,, u=0 mbox{ in } mathbb{R}^NbackslashOmega, end{equation*} where N>2sN>2s with sin(0,1)sin(0,1), OmegaOmega is an open bounded subset of mathbbRNmathbb{R}^N with Lipschitz boundary, MM and ff are two continuous functions, and (Delta)s(-Delta)^s is a fractional Laplace operator. Our main tools are based on critical point theorems and the truncation technique

    The comparison between China and UK of the construction of city community sports service system in the scope of eco-civilization

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    The construction of urban community sports public service is not only an important part of urban community public service management, but also an important content of building the national fitness public service system. In this paper, the author analyse the comparison between China and UK of the construction of city community sports service system in the scope of eco-civilization. With the rapid development of society and economy, people's demand for sports is more and more urgent, and community sports is the most effective and direct way to meet people's needs. Therefore, it has practical significance to study the construction and management mode of community sports facilities

    BEC-BCS Crossover in the Nambu--Jona-Lasinio Model of QCD

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    The BEC-BCS crossover in QCD at finite baryon and isospin chemical potentials is investigated in the Nambu--Jona-Lasinio model. The diquark condensation in two color QCD and the pion condensation in real QCD would undergo a BEC-BCS crossover when the corresponding chemical potential increases. We determined the crossover chemical potential as well as the BEC and BCS regions. The crossover is not triggered by increasing the strength of attractive interaction among quarks but driven by changing the charge density. The chiral symmetry restoration at finite temperature and density plays an important role in the BEC-BCS crossover. For real QCD, strong couplings in diquark and vector meson channels can induce a diquark BEC-BCS crossover in color superconductor, and in the BEC region the chromomagnetic instability is fully cured and the ground state is a uniform phase.Comment: 18 pages, 15 figures. V2: typos corrected, references added. V3: typos in Appendix B correcte

    Analysis of 116 cases of rectal cancer treated by transanal local excision

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    BACKGROUND: The purpose of this research was to evaluate the therapeutic effects and prognostic factors of transanal local excision (TAE) for rectal cancer. METHODS: We retrospectively analyzed 116 cases that underwent TAE for rectal cancer from 1995 to 2008. A Cox regression analysis was used to analyze prognostic factors. RESULTS: The survival times for the patients were from 14 to 160.5 months (median time, 58.5 months). The 5-year and 10-year overall survival rates were 72% and 53%, respectively. In all 16 cases experienced local recurrence (13.8%). Pathological type, recurrence or metastasis, and depth of infiltration (T stage) were the prognostic factors according to the univariate analysis, and the latter two were independent factors affecting patient prognosis. For patients with T1 stage who underwent adjuvant radiotherapy, there was no local recurrence; for those in T2 stage, the local recurrence rate was 14.6%. In addition, there was no difference between the patients who received radiotherapy and those who did not (T1: P = 0.260, T2: P = 0.262 for survival rate and T1: P = 0.480, T2: P = 0.560 for recurrence). CONCLUSIONS: The result of TAE for rectal cancer is satisfactory for T1 stage tumors, but it is not suitable for T2 stage tumors

    Spatial representativeness and uncertainty of eddy covariance carbon flux measurements for upscaling net ecosystem productivity to the grid scale

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    Eddy covariance (EC) measurements are often used to validate net ecosystem productivity (NEP) estimated from satellite remote sensing data and biogeochemical models. However, EC measurements represent an integrated flux over their footprint area, which usually differs from respective model grids or remote sensing pixels. Quantifying the uncertainties of scale mismatch associated with gridded flux estimates by upscaling single EC tower NEP measurements to the grid scale is an important but not yet fully investigated issue due to limited data availability as well as knowledge of flux variability at the grid scale. The Heihe Watershed Allied Telemetry Experimental Research (HiWATER) Multi-Scale Observation Experiment on Evapotranspiration (MUSOEXE) built a flux observation matrix that includes 17 EC towers within a 5 km × 5 km area in a heterogeneous agricultural landscape in northwestern China, providing an unprecedented opportunity to evaluate the uncertainty of upscaling due to spatial representative differences at the grid scale. Based on the HiWATER-MUSOEXE data, this study evaluated the spatial representativeness and uncertainty of EC CO2 flux measurements for upscaling to the grid scale using a scheme that combines a footprint model and a model-data fusion method. The results revealed the large spatial variability of gross primary productivity (GPP), ecosystem respiration (Re), and NEP within the study site during the growing season from 10 June to 14 September 2012. The variability of fluxes led to high variability in the representativeness of single EC towers for grid-scale NEP. The systematic underestimations of a single EC tower may reach 92(±11)%, 30(±11)%, and 165(±150)% and the overestimations may reach 25(±14)%, 20(±13)%, and 40(±33)% for GPP, Re, and NEP, respectively. This finding suggests that remotely sensed NEP at the global scale (e.g., MODIS products) should not be validated against single EC tower data in the case of heterogeneous surfaces. Any systematic bias should be addressed before upscaling EC data to grid scale. Otherwise, most of the systematic bias may be propagated to grid scale due to the scale dependence of model parameters. A systematic bias greater than 20% of the EC measurements can be corrected effectively using four indicators proposed in this study. These results will contribute to the understanding of spatial representativeness of EC towers within a heterogeneous landscape, to upscaling carbon fluxes from the footprint to the grid scale, to the selection of the location of EC towers, and to the reduction in the bias of NEP products by using an improved parameterization scheme of remote-sensing driven models, such as VPRM

    Reform and practice of vocational basic skills training course under the concept of curriculum ideology and politics

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    The curriculum ideology and politics of practice courses in the undergraduate specialty of food quality and safety were explored by taking the Vocational Basic Skills Training course as an example. The teaching content, teaching methods, assessment system and also other aspects of this course were reformed. Our practice and exploration have obtained some good results. The preliminary practical teaching was integrated and developed with ideological and political elements. To improve the training quality of innovative and applied talents of undergraduate specialty of food quality and safety in our university, we need to carry out long-term and continuous exploration and practice
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