552 research outputs found

    Growth and nutrient efficiency of Betula alnoides clones in response to phosphorus supply

    Get PDF
    As phosphorus deficiency limits the productivity of many plantation forests in Asia, there is considerable interest in developing phosphorus-efficient clones for the region through targeted breeding programs. Therefore, we determined growth, nutrient concentrations and nutrient absorption and utility efficiencies of four Betula alnoides clones (C5, C6, 1-202 and BY1) in response to six phosphorus levels of 0, 17, 52, 70, 140 and 209 mg P plant-1 coded as P1 to P6, respectively. Maximum growth occurred in the P4, P5 and P6 plants since they had the largest height, biomass, leaf area and branch number. Phosphorus application increased the phosphorus concentrations of all clones. Nutrient loading was achieved with the P6 treatment because growth and biomass were not significantly higher, but root, stem and leaf phosphorus concentrations were approximately twice those of P4 plants. Clone BY1 had the highest phosphorus-efficiency, and is recommended for field application due to its maximum root collar diameter, biomass, root/shoot ratio, leaf area, nutrient absorption and utility efficiency among the four clones. The findings will help to improve the nutrient efficiency of this species in plantation forestry in Asia

    Unravelling the Interfacial Dynamics of Bandgap Funneling in Bismuth-Based Halide Perovskites

    Get PDF
    An environmentally friendly mixed-halide perovskite MA3Bi2Cl9−xIx with a bandgap funnel structure has been developed. However, the dynamic interfacial interactions of bandgap funneling in MA3Bi2Cl9−xIx perovskites in the photoelectrochemical (PEC) system remain ambiguous. In light of this, single- and mixed-halide lead-free bismuth-based hybrid perovskites—MA3Bi2Cl9−yIy and MA3Bi2I9 (named MBCl-I and MBI)—in the presence and absence of the bandgap funnel structure, respectively, are prepared. Using temperature-dependent transient photoluminescence and electrochemical voltammetric techniques, the photophysical and (photo)electrochemical phenomena of solid–solid and solid–liquid interfaces for MBCl-I and MBI halide perovskites are therefore confirmed. Concerning the mixed-halide hybrid perovskites MBCl-I with a bandgap funnel structure, stronger electronic coupling arising from an enhanced overlap of electronic wavefunctions results in more efficient exciton transport. Besides, MBCl-I's effective diffusion coefficient and electron-transfer rate demonstrate efficient heterogeneous charge transfer at the solid–liquid interface, generating improved photoelectrochemical hydrogen production. Consequently, this combination of photophysical and electrochemical techniques opens up an avenue to explore the intrinsic and interfacial properties of semiconductor materials for elucidating the correlation between material characterization and device performance

    Effects of yeast nucleotide on growth performance, serum immune index and muscle composition of Ancherythroculter nigrocauda Yih & Wu

    Get PDF
    A 50-day feeding trial was conducted to evaluate the effects of yeast nucleotide in diets on growth performance, serum immune indices and muscle composition of Ancherythroculter nigrocauda (mean initial body weight, 23.30±0.59 g). Seven isonitrogenous (approximately 42.76% crude protein) and isoenergetic (17.43 KJ g^−1 gross energy) experimental diets with varying levels of yeast nucleotide (0 [control], 150, 300, 450, 600, 750 and 900 mg kg^−1) were fed near to satiation to triplicate groups of fish. The results showed that the highest weight gain ratio (WGR), specific growth rate (SGR), protein efficiency ratio (PER), and best feed conversion ratio (FCR) were evident in fish fed 450-600 mg kg^−1 yeast nucleotide diet. The intramuscular protein and fat contents of data also supported the above level. The serum enzymes showed that activities of lysozyme (LZS) and superoxide dismutase (SOD) in fish increased first and decreased afterwards with the dietary nucleotide supplemental level increasing. The LZS activity in serum was found to be significantly (p0.05). Alkaline phosphatase (ALP) activity showed significantly (p<0.05) greater but continuous decrease with the increase in the levels of dietary yeast nucleotide. We therefore recommend dietary yeast nucleotide administration at (450-600 mg kg^−1) to promote growth, enhance immunity and intramuscular protein and fat content

    The quantum cryptographic switch

    Full text link
    We illustrate using a quantum system the principle of a cryptographic switch, in which a third party (Charlie) can control to a continuously varying degree the amount of information the receiver (Bob) receives, after the sender (Alice) has sent her information. Suppose Charlie transmits a Bell state to Alice and Bob. Alice uses dense coding to transmit two bits to Bob. Only if the 2-bit information corresponding to choice of Bell state is made available by Charlie to Bob can the latter recover Alice's information. By varying the information he gives, Charlie can continuously vary the information recovered by Bob. The performance of the protocol subjected to the squeezed generalized amplitude damping channel is considered. We also present a number of practical situations where a cryptographic switch would be of use.Comment: 7 pages, 4 Figure

    The energy spectrum of all-particle cosmic rays around the knee region observed with the Tibet-III air-shower array

    Get PDF
    We have already reported the first result on the all-particle spectrum around the knee region based on data from 2000 November to 2001 October observed by the Tibet-III air-shower array. In this paper, we present an updated result using data set collected in the period from 2000 November through 2004 October in a wide range over 3 decades between 101410^{14} eV and 101710^{17} eV, in which the position of the knee is clearly seen at around 4 PeV. The spectral index is -2.68 ±\pm 0.02(stat.) below 1PeV, while it is -3.12 ±\pm 0.01(stat.) above 4 PeV in the case of QGSJET+HD model, and various systematic errors are under study now.Comment: 12 pages, 7 figures, accepted by Advances in space researc

    Direct Measurements of the Branching Fractions for D0Ke+νeD^0 \to K^-e^+\nu_e and D0πe+νeD^0 \to \pi^-e^+\nu_e and Determinations of the Form Factors f+K(0)f_{+}^{K}(0) and f+π(0)f^{\pi}_{+}(0)

    Get PDF
    The absolute branching fractions for the decays D0Ke+νeD^0 \to K^-e ^+\nu_e and D0πe+νeD^0 \to \pi^-e^+\nu_e are determined using 7584±198±3417584\pm 198 \pm 341 singly tagged Dˉ0\bar D^0 sample from the data collected around 3.773 GeV with the BES-II detector at the BEPC. In the system recoiling against the singly tagged Dˉ0\bar D^0 meson, 104.0±10.9104.0\pm 10.9 events for D0Ke+νeD^0 \to K^-e ^+\nu_e and 9.0±3.69.0 \pm 3.6 events for D0πe+νeD^0 \to \pi^-e^+\nu_e decays are observed. Those yield the absolute branching fractions to be BF(D0Ke+νe)=(3.82±0.40±0.27)BF(D^0 \to K^-e^+\nu_e)=(3.82 \pm 0.40\pm 0.27)% and BF(D0πe+νe)=(0.33±0.13±0.03)BF(D^0 \to \pi^-e^+\nu_e)=(0.33 \pm 0.13\pm 0.03)%. The vector form factors are determined to be f+K(0)=0.78±0.04±0.03|f^K_+(0)| = 0.78 \pm 0.04 \pm 0.03 and f+π(0)=0.73±0.14±0.06|f^{\pi}_+(0)| = 0.73 \pm 0.14 \pm 0.06. The ratio of the two form factors is measured to be f+π(0)/f+K(0)=0.93±0.19±0.07|f^{\pi}_+(0)/f^K_+(0)|= 0.93 \pm 0.19 \pm 0.07.Comment: 6 pages, 5 figure

    Search for the Lepton Flavor Violation Processes J/ψJ/\psi \to μτ\mu\tau and eτe\tau

    Full text link
    The lepton flavor violation processes J/ψμτJ/\psi \to \mu\tau and eτe\tau are searched for using a sample of 5.8×107\times 10^7 J/ψJ/\psi events collected with the BESII detector. Zero and one candidate events, consistent with the estimated background, are observed in J/ψμτ,τeνˉeντJ/\psi \to \mu\tau, \tau\to e\bar\nu_e\nu_{\tau} and J/ψeτ,τμνˉμντJ/\psi\to e\tau, \tau\to\mu\bar\nu_{\mu}\nu_{\tau} decays, respectively. Upper limits on the branching ratios are determined to be Br(J/ψμτ)<2.0×106Br(J/\psi\to\mu\tau)<2.0 \times 10^{-6} and Br(J/ψeτ)<8.3×106Br(J/\psi \to e\tau) < 8.3 \times10^{-6} at the 90% confidence level (C.L.).Comment: 9 pages, 2 figure

    Moon Shadow by Cosmic Rays under the Influence of Geomagnetic Field and Search for Antiprotons at Multi-TeV Energies

    Full text link
    We have observed the shadowing of galactic cosmic ray flux in the direction of the moon, the so-called moon shadow, using the Tibet-III air shower array operating at Yangbajing (4300 m a.s.l.) in Tibet since 1999. Almost all cosmic rays are positively charged; for that reason, they are bent by the geomagnetic field, thereby shifting the moon shadow westward. The cosmic rays will also produce an additional shadow in the eastward direction of the moon if cosmic rays contain negatively charged particles, such as antiprotons, with some fraction. We selected 1.5 x10^{10} air shower events with energy beyond about 3 TeV from the dataset observed by the Tibet-III air shower array and detected the moon shadow at 40σ\sim 40 \sigma level. The center of the moon was detected in the direction away from the apparent center of the moon by 0.23^\circ to the west. Based on these data and a full Monte Carlo simulation, we searched for the existence of the shadow produced by antiprotons at the multi-TeV energy region. No evidence of the existence of antiprotons was found in this energy region. We obtained the 90% confidence level upper limit of the flux ratio of antiprotons to protons as 7% at multi-TeV energies.Comment: 13pages,4figures; Accepted for publication in Astroparticle Physic

    The σ\sigma pole in J/ψωπ+πJ/\psi \to \omega \pi^+ \pi^-

    Full text link
    Using a sample of 58 million J/ψJ/\psi events recorded in the BESII detector, the decay J/ψωπ+πJ/\psi \to \omega \pi^+ \pi^- is studied. There are conspicuous ωf2(1270)\omega f_2(1270) and b1(1235)πb_1(1235)\pi signals. At low ππ\pi \pi mass, a large broad peak due to the σ\sigma is observed, and its pole position is determined to be (541±39)(541 \pm 39) - ii (252±42)(252 \pm 42) MeV from the mean of six analyses. The errors are dominated by the systematic errors.Comment: 15 pages, 6 figures, submitted to PL
    corecore