23,614 research outputs found

    On the Inverse Problem Relative to Dynamics of the w Function

    Full text link
    In this paper we shall study the inverse problem relative to dynamics of the w function which is a special arithmetic function and shall get some results.Comment: 11 page

    Electron-Phonon Interactions for Optical Phonon Modes in Few-Layer Graphene

    Full text link
    We present a first-principles study of the electron-phonon (e-ph) interactions and their contributions to the linewidths for the optical phonon modes at Ξ“\Gamma and K in one to three-layer graphene. It is found that due to the interlayer coupling and the stacking geometry, the high-frequency optical phonon modes in few-layer graphene couple with different valence and conduction bands, giving rise to different e-ph interaction strengths for these modes. Some of the multilayer optical modes derived from the Ξ“\Gamma-E2gE_{2g} mode of monolayer graphene exhibit slightly higher frequencies and much reduced linewidths. In addition, the linewidths of K-A1β€²A'_1 related modes in multilayers depend on the stacking pattern and decrease with increasing layer numbers.Comment: 6 pages,5 figures, submitted to PR

    Regional estimation of daily to annual regional evapotranspiration with MODIS data in the Yellow River Delta wetland

    Get PDF
    Evapotranspiration (ET) from the wetland of the Yellow River Delta (YRD) is one of the important components in the water cycle, which represents the water consumption by the plants and evaporation from the water and the non-vegetated surfaces. Reliable estimates of the total evapotranspiration from the wetland is useful information both for understanding the hydrological process and for water management to protect this natural environment. Due to the heterogeneity of the vegetation types and canopy density and of soil water content over the wetland (specifically over the natural reserve areas), it is difficult to estimate the regional evapotranspiration extrapolating measurements or calculations usually done locally for a specific land cover type. Remote sensing can provide observations of land surface conditions with high spatial and temporal resolution and coverage. In this study, a model based on the Energy Balance method was used to calculate daily evapotranspiration (ET) using instantaneous observations of land surface reflectance and temperature from MODIS when the data were available on clouds-free days. A time series analysis algorithm was then applied to generate a time series of daily ET over a year period by filling the gaps in the observation series due to clouds. A detailed vegetation classification map was used to help identifying areas of various wetland vegetation types in the YRD wetland. Such information was also used to improve the parameterizations in the energy balance model to improve the accuracy of ET estimates. This study showed that spatial variation of ET was significant over the same vegetation class at a given time and over different vegetation types in different seasons in the YRD wetlan

    Challenges of Primary Frequency Control and Benefits of Primary Frequency Response Support from Electric Vehicles

    Get PDF
    As the integration of wind generation displaces conventional plants, system inertia provided by rotating mass declines, causing concerns over system frequency stability. This paper implements an advanced stochastic scheduling model with inertia-dependent fast frequency response requirements to investigate the challenges on the primary frequency control in the future Great Britain electricity system. The results suggest that the required volume and the associated cost of primary frequency response increase significantly along with the increased capacity of wind plants. Alternative measures (e.g. electric vehicles) have been proposed to alleviate these concerns. Therefore, this paper also analyses the benefits of primary frequency response support from electric vehicles in reducing system operation cost, wind curtailment and carbon emissions

    Responses to Phytohormones, Mg Stress and Dehydration and Its Correlation with Stomatal Density in Bread Wheat

    Get PDF
    ERECTA is an ancient family of leucine-rich repeat receptor-like kinases (RLKs) that coordinate growth and development of plant. TaERECTA, one copy of the ERECTA homologs in wheat, was isolated from bread wheat Chinese Spring. The Ser/Thr kinase of TaERECTA was expressed in E. coli after IPTG induction and confirmed by immunoblot. TaERECTA showed higher expression in younger organs with rapid development, as well as great expression in younger spikes at booting stage. Under exogenous application of gibberellin (GA3) and abscisic acid (ABA), and Mg2+ stress, the expression of TaERECTA was largely suppressed, whereas under exogenous application of indole acetic acid (IAA) and brassinolide (BR), and dehydration stress, its expression was initially suppressed and then up-regulated. Natural variation was apparent in the relative expression of TaERECTA among 9 different bread wheat lines, and its expression level was negatively correlated with the stomatal density. These results suggested that TaERECTA could be exploitable for manipulating agronomical traits important through regulating stomata density, with potential implication for bread wheat improvement

    Gunrock: A High-Performance Graph Processing Library on the GPU

    Full text link
    For large-scale graph analytics on the GPU, the irregularity of data access and control flow, and the complexity of programming GPUs have been two significant challenges for developing a programmable high-performance graph library. "Gunrock", our graph-processing system designed specifically for the GPU, uses a high-level, bulk-synchronous, data-centric abstraction focused on operations on a vertex or edge frontier. Gunrock achieves a balance between performance and expressiveness by coupling high performance GPU computing primitives and optimization strategies with a high-level programming model that allows programmers to quickly develop new graph primitives with small code size and minimal GPU programming knowledge. We evaluate Gunrock on five key graph primitives and show that Gunrock has on average at least an order of magnitude speedup over Boost and PowerGraph, comparable performance to the fastest GPU hardwired primitives, and better performance than any other GPU high-level graph library.Comment: 14 pages, accepted by PPoPP'16 (removed the text repetition in the previous version v5
    • …
    corecore