1,368 research outputs found

    CDAL: A Scalable Scheme for Digital Resource Reorganization

    Full text link
    In many circumstances, including e-learning, there is a need to reorganize digital resources, scattered in many places, into a coherently accessible repository. This paper introduces a methodology to do the job efficiently. Specifically, the resources that the scheme needs to handle presents the following challenges, 1) mass, 2) various data types, 3) coming out continuously, i.e., the scheme must support incremental reorganization. 4) usually existing with its own directory structures. We describe the scheme in detail, together with considerations for trade-offs. The following features are highlighted: 1) the reorganization of scattered resources is modeled as a tree-merging process., which results in a good trade-off between efficiency and quality. 2) hierarchical storage arrangement with a uniform index at each level ensures scalability. As an application of the scheme, CDAL (Chinese Digital Assets Library) is briefed, which is a TB-scale archive of digital resources on the Web.Computer Science, Artificial IntelligenceComputer Science, Interdisciplinary ApplicationsComputer Science, Theory & MethodsSCI(E)CPCI-S(ISTP)

    Localized-Surface-Plasmon Enhanced the 357 nm Forward Emission from ZnMgO Films Capped by Pt Nanoparticles

    Get PDF
    The Pt nanoparticles (NPs), which posses the wider tunable localized-surface-plasmon (LSP) energy varying from deep ultraviolet to visible region depending on their morphology, were prepared by annealing Pt thin films with different initial mass-thicknesses. A sixfold enhancement of the 357 nm forward emission of ZnMgO was observed after capping with Pt NPs, which is due to the resonance coupling between the LSP of Pt NPs and the band-gap emission of ZnMgO. The other factors affecting the ultraviolet emission of ZnMgO, such as emission from Pt itself and light multi-scattering at the interface, were also discussed. These results indicate that Pt NPs can be used to enhance the ultraviolet emission through the LSP coupling for various wide band-gap semiconductors

    Smad3 promotes cancer progression by inhibiting E4BP4-mediated NK cell development

    Get PDF
    published_or_final_versio

    Physiological response of natural C-taklimakanensis BRPan et GMShen to unconfined groundwater in the hinterland of the Taklimakan Desert

    Get PDF
    Calligonum. taklimakanensis B.R.Pan et G.M.Shen is an indigenous species that grows in the Taklimakan Desert. This study shows the relationship between C. taklimakanensis B.R.Pan et G.M.Shen and water conditions in the hinterland of the desert. The results show that: (1) Depth of water table is an important factor that affects water potential (Psi(p), Psi(A)), osmotic potential (Psi(sat), Psi(tlp)), relative water content (RWCtlp, ROWCtlp), and transpiration rate. (2) The degree of mineralization has a significant impact on the water potential of plants. A high degree of mineralization can strongly reduce plant productivity. (3) C. taklimakanensis B.R.Pan et G.M.Shen reduces the temperature of assimilation sticks through a high transpiration rate and maintains relatively high water content to adapt to drought and hot weather conditions in the hinterland of the desert. In addition, C. taklimakanensis B.R.Pan et G.M.Shen adapts to the water status in the desert through self-regulation or even sacrificing productivity

    Photosynthesis responses of endemic shrubs of Taklimakan Desert to adverse temperature, humidity and radiation

    Get PDF
    Under the native habitat conditions, the seasonal gas exchange characteristics of two natural endemic plant species, Calligonum taklimakanensis B.R. Pan & GM. Shen and Tamarix taklamakanensis M.T. Liu, which are located in the hinterland of the Taklimakan Desert, are measured and compared by Li-6400 photosynthesis system. The results indicate that temperature (degrees C), solar radiation (PAR), soil water content (SWC), and other environmental factors have obvious seasonal variations and the gas exchange characteristics of two plants have different changes in different growing seasons. For C. taklimakanensis, both in July and September, its daily changes of net photosynthetic rate tend to be obvious double peak curve, but in July its peak appeared earlier. Besides its maximum net photosynthetic rate (P-max), apparent quantum efficiency (Phi), range of effective photosynthetic radiation significantly less than that in September. Moreover, its water use efficiency (WUE) in July was also lower than that in September due to the higher transpiration rate (T-r). For T. taklamakanensis, although its daily change of net photosynthetic rate is a single peak curve in September, its peak time has not changed, and except that its WUE is higher in September like C. taklimakanensis, the maximum net photosynthetic rate (P-max), apparent quantum efficiency (Phi), light saturation point, and range of effective photosynthetic radiation has not changed or slightly declined. That is to say C. taklimakanensis select a season that habitat was better (like September) to progress relative effectively photosynthesis accumulation, in contrast, T. taklamakanensis still keep a relatively stable photosynthesis rate in different growth seasons. The difference of gas exchange characteristics of the two plants in different seasons shows that adaptation strategies of the two plants to extreme conditions in desert are different. Besides, both the higher photosynthetic accumulation rate and the higher water use efficiency in September also indicate that these two endemic desert shrubs possess the abilities and strategies to make the best of limited natural resources

    Langmuir probe potential measurements for reduced-pressure inductively coupled plasma mass spectrometry

    Get PDF
    A floating Langmuir probe was used to measure the apparent de offset potential of a reduced-pressure inductively coupled plasma near a substitute sampling orifice of a mass spectrometer. The experimental results demonstrate that the de offset potential causes the secondary discharge at the sampling orifice. The plasma potential is in the range +3.5 to +20 V and varies with the plasma operating conditions. The manner by which a water-cooled torch is shielded has a substantial effect on the plasma potential, then the secondary discharge. The measured values of the potential give a good explanation for the enhanced capacitive coupling effect in reduced-pressure ICP-MS reported previously
    • …
    corecore