14,821 research outputs found

    Bileptons from Muon Collider Backward Scattering

    Full text link
    There are serious discussions for building a muon collider with μ+μ\mu^{+}\mu^{-} collisions at c.o.m. energies up to 4 TeV. We point out that the bileptonic gauge bosons predicted in some extensions of the Standard Model would be readily discernable from the backward scattering cross-section, for bilepton masses up to a substantial fraction of the c.o.m. energy.Comment: 10 pages Revtex. 4 figures include

    Universal behavior of giant electroresistance in epitaxial La0.67Ca0.33MnO3 thin films

    Full text link
    We report a giant resistance drop induced by dc electrical currents in La0.67Ca0.33MnO3 epitaxial thin films. Resistance of the patterned thin films decreases exponentially with increasing current and a maximum drop shows at the temperature of resistance peak Tp. Variation of resistance with current densities can be scaled below and above Tp, respectively. This work can be useful for the future applications of electroresistance.Comment: 13 pages, 4 figure

    Hertz-level Measurement of the 40Ca+ 4s 2S1/2-3d 2D5/2 Clock Transition Frequency With Respect to the SI Second through GPS

    Full text link
    We report a frequency measurement of the clock transition of a single ^40Ca^+ ion trapped and laser cooled in a miniature ring Paul trap with 10^-15 level uncertainty. In the measurement, we used an optical frequency comb referenced to a Hydrogen maser, which was calibrated to the SI second through the Global Positioning System (GPS). Two rounds of measurements were taken in May and June 2011, respectively. The frequency was measured to be 411 042 129 776 393.0(1.6) Hz with a fractional uncertainty of 3.9{\times}10^-15 in a total averaging time of > 2{\times}10^6 s within 32 days

    Expression of Branching Enzyme I of Maize Endosperm in Escherichia coli

    Full text link

    The extent of continental material in oceans: C-Blocks and the Laxmi Basin example

    Get PDF
    We propose a tectonic interpretation for the outer-SDRs (SDRs: Seaward-Dipping Reflectors) and Pannikar central ridge in the aborted Laxmi Basin west of India from wide-angle seismic reflection data. The outer-SDRs comprise syn-tectonic extrusives (lavas and/or volcaniclastics) emplaced above passively exhumed mid-to-lower mafic crust of continental origin. They erupted following sudden lithosphere weakening associated with isolation of a continental block (a ‘C-Block’). Continuous magmatic addition during crustal extension allowed stretching of the lower crust whilst maintaining constant or even increasing thickness. A similar process occurred at both conjugate margins allowing bulk, pure-shear plate separation and formation of linear magnetic anomalies. The Laxmi example can explain enigmatic features observed in mature oceans such as presence of distal buoyant plateaus of thick continental crust away from the margins

    激光探针等离子体质谱用于错石Pb-Pb定年的分析和校正方法的进一步探讨

    Get PDF
    激光探针等离子体质谱可对错石进行快速准确的Pb一Pb 同位素定年。本文进一步探讨了该方法应用中的几个问题。对不同样品采用不同的聚焦方式可以对U/Pb 分异有一定的控制作用。在一定的条件下, 不连续和连续采样模式都可以得到较高精度和准确度的结果。连续采样模式还可以得到同位素计数的深度剖面。不同的侧量滞留时间会影响测量结果的精度。20Ins 为适合错石ZO7Pb/206Pb 分析的最佳侧量滞留时间。在对侧定结果进行校正时, 可以采用玻璃标样NIST61O 和错石标样两种不同的校正方法。Laser probe-inductively coupled plasma mass spectrometry (LP-ICPMS) provides a rapid,precise and accurate technique for Pb-Pb zircon chronology. Different conditions affect massfractionation during laser ablation. Fixed-focus-mode and active-focus-mode, focus-mode anddefocus-mode, time-average mode (single point method) and time-resolved mode (depth pro-filing method), are compared. Both time-average mode and time-resolved mode can give rel-atively high precise, accurate results, and depth profile can only be obtained by time-resolvedmode. Comparing the results of time-resolved mode using different dwell time, it is found that20 ms is the best dwell time with highest precision and accuracy. It is shown that both NIST610and Zircon Standard give satisfactory calibration results for zircon 207Pb/206Pb isotopic age.Therefore, time resolved mode with dwell time of 20 ms is preferred for zircon analysis.published_or_final_versio

    Influence of traditional ecological knowledge on conservation of the skywalker hoolock gibbon (Hoolock tianxing) outside nature reserves

    Get PDF
    Although many species are threatened by hunting or resource extraction from indigenous human communities, traditional ecological knowledge (TEK) of local communities has the potential to support management and conservation of natural resources and wildlife. The newly described skywalker hoolock gibbon (Hoolock tianxing) is found on the border of China and Myanmar, and a large proportion of the remaining population in China occurs outside nature reserves. We surveyed this species across its range in China, and interviewed 622 people in 99 villages to evaluate the relationship between gibbon status and TEK of local communities. The total confirmed population was estimated to be less than 150 individuals. Gibbon subpopulations appear to have remained stable from 2009 to 2017 both within and outside nature reserves. Sociological and environmental correlates of gibbon survival outside the reserve were: (1) more Lisu than Han people present in villages; (2) greater forest cover; (3) greater distance from county towns; (4) existence of traditional taboos on hunting gibbons; and (5) higher dependency on forest resources by villagers. Interviewees living closer to surviving gibbon populations were more knowledgeable about gibbons, although interviewees living more than 25 km away also knew more about gibbons. Formal education level was also correlated with better knowledge of gibbons, and men were better informed about gibbons than women. TEK appears to limit poaching of gibbons, thus contributing to their survival. The persistence of gibbons outside nature reserves may depend on incorporating TEK within community-based conservation strategies
    corecore