15,218 research outputs found

    Anomalous Crossing Frequency in Odd Proton Nuclei

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    A generic explanation for the recently observed anomalous crossing frequencies in odd proton rare earth nuclei is given. As an example, the proton 12[541]{1\over 2} [541] band in 175^{175}Ta is discussed in detail by using the angular momentum projection theory. It is shown that the quadrupole pairing interaction is decisive in delaying the crossing point and the changes in crossing frequency along the isotope chain are due to the different neutron shell fillings

    On the Backbending Mechanism of 48^{48}Cr

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    The mechanism of backbending in 48^{48}Cr is investigated in terms of the Projected Shell Model and the Generator Coordinate Method. It is shown that both methods are reasonable shell model truncation schemes. These two quite different quantum mechanical approaches lead to a similar conclusion that the backbending is due to a band crossing involving an excited band which is built on simultaneously broken neutron and proton pairs in the ``intruder'' subshell f7/2f_{7/2}. It is pointed out that this type of band crossing is usually known to cause the second backbending in rare-earth nuclei.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Let

    Differential photosynthetic adaptation between size-classes of Spruce and Fir juveniles help to explain the co-existence of the two species.

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    Background/Question/Methods 
_Abies sachalinensis_ (Sakhalin Fir) and _Picea glehnii_ (Glehn’s Spruce) are major components of the sub-boreal forests of Hokkaido, Japan. Similar Spruce-Fir forests can be found in many other places in the northern hemisphere and will probably be impacted by global warming. Therefore, detailed knowledge of these species’ physiology and life-history strategies at different growth stages is important to understand present communities and to support reliable prediction of possible consequences of global climate change. 
Accordingly, the objective of this study was to establish relations between community dynamics, life-history strategies and photosynthetic adaptation of these species, on different developmental stages. 
The study is taking place on a sub-boreal forest plot in north Japan (N 44º 19’, E 142º 15’). Twenty shade-growing individuals of both species were divided into two height classes: seedlings, if height < 50cm; and saplings, if height > 100cm. The canopy coverage over each individual was assessed by analyzing hemispherical photography and average light incidence. Leaf pigments are being analyzed by chromatography. Light response curves and chlorophyll fluorescence are being measured seasonally, except in winter. Results are analyzed through General Linear Models. The study period was from spring 2009 to summer 2010. 
Results/Conclusions 
Results show an inversion of the photosynthetic adaptation between seedlings and saplings, and also between species. _Picea_ seedlings and _Abies_ saplings have greater total chlorophyll content and higher photosynthetic rates than _Picea_ saplings and _Abies_ seedlings. As a consequence, the superior competitor between similar sized individuals of both species appears to change between size-classes, with _Abies_ presenting higher photosynthetic rates at the sapling class and _Picea_ at the seedling class. Nevertheless, no significant growth has been observed in any of the groups until now. Results also disagree with some of the previously reported photosynthetic characteristics of these species, with _Picea_ seedlings displaying more traits usually associated with shade adaptation than _Abies_ seedlings.
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    The scaling limit of the incipient infinite cluster in high-dimensional percolation. II. Integrated super-Brownian excursion

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    For independent nearest-neighbour bond percolation on Z^d with d >> 6, we prove that the incipient infinite cluster's two-point function and three-point function converge to those of integrated super-Brownian excursion (ISE) in the scaling limit. The proof is based on an extension of the new expansion for percolation derived in a previous paper, and involves treating the magnetic field as a complex variable. A special case of our result for the two-point function implies that the probability that the cluster of the origin consists of n sites, at the critical point, is given by a multiple of n^{-3/2}, plus an error term of order n^{-3/2-\epsilon} with \epsilon >0. This is a strong statement that the critical exponent delta is given by delta =2.Comment: 56 pages, 3 Postscript figures, in AMS-LaTeX, with graphicx, epic, and xr package

    Pendekatan-Pendekatan dalam Studi Demokrasi di Asia Tenggara dan Relevansinya untuk Indonesia

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    Democratization in Southeast Asian countries is often perceived as transforming the countries into a kind of Western liberal democracy. By using Indonesian case, this paper, however, shows that this perception does not reflect current complexities in political arena. The transition to democracy in Indonesia has both the elements of modern and traditional political cultures and institutions. The paper suggests that democratization is better seen from the process of adaptation and hybridization of the modenrn and traditional aspects of Indonesian politics

    1D Modeling for Temperature-Dependent Upflow in the Dimming Region Observed by Hinode/EIS

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    We have previously found a temperature-dependent upflow in the dimming region following a coronal mass ejection (CME) observed by the {\it Hinode} EUV Imaging Spectrometer (EIS). In this paper, we reanalyzed the observations along with previous work on this event, and provided boundary conditions for modeling. We found that the intensity in the dimming region dramatically drops within 30 minutes from the flare onset, and the dimming region reaches the equilibrium stage after \sim1 hour later. The temperature-dependent upflows were observed during the equilibrium stage by EIS. The cross sectional area of the fluxtube in the dimming region does not appear to expand significantly. From the observational constraints, we reconstructed the temperature-dependent upflow by using a new method which considers the mass and momentum conservation law, and demonstrated the height variation of plasma conditions in the dimming region. We found that a super radial expansion of the cross sectional area is required to satisfy the mass conservation and momentum equations. There is a steep temperature and velocity gradient of around 7 Mm from the solar surface. This result may suggest that the strong heating occurred above 7 Mm from the solar surface in the dimming region. We also showed that the ionization equilibrium assumption in the dimming region is violated especially in the higher temperature range.Comment: accepted for publication in The Astrophysical Journa

    Transition region features observed with Hinode/EIS

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    Two types of active region feature prominent at transition region temperatures are identified in Hinode/EIS data of AR 10938 taken on 2007 January 20. The footpoints of 1 MK TRACE loops are shown to emit strongly in emission lines formed at log T=5.4-5.8, allowing the temperature increase along the footpoints to be clearly seen. A density diagnostic of Mg VII yields the density in the footpoints, with one loop showing a decrease from 3x10^9 cm^-3 at the base to 1.5x10^9 cm^-3 at a projected height of 20 Mm. The second feature is a compact active region transition region brightening which is particularly intense in O V emission (log T=5.4) but also has a signature at temperatures up to log T=6.3. The Mg VII diagnostic gives a density of 4x10^10 cm^-3, and emission lines of Mg VI and Mg VII show line profiles broadened by 50 km/s and wings extending beyond 200 km/s. Continuum emission in the short wavelength band is also found to be enhanced, and is suggested to be free-bound emission from recombination onto He^+.Comment: 11 pages, 9 figures, submitted to PASJ Hinode first results issu

    New Lower Bounds on the Self-Avoiding-Walk Connective Constant

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    We give an elementary new method for obtaining rigorous lower bounds on the connective constant for self-avoiding walks on the hypercubic lattice ZdZ^d. The method is based on loop erasure and restoration, and does not require exact enumeration data. Our bounds are best for high dd, and in fact agree with the first four terms of the 1/d1/d expansion for the connective constant. The bounds are the best to date for dimensions d3d \geq 3, but do not produce good results in two dimensions. For d=3,4,5,6d=3,4,5,6, respectively, our lower bound is within 2.4\%, 0.43\%, 0.12\%, 0.044\% of the value estimated by series extrapolation.Comment: 35 pages, 388480 bytes Postscript, NYU-TH-93/02/0

    Vertex operators for quantum groups and application to integrable systems

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    Starting with any R-matrix with spectral parameter, obeying the Yang-Baxter equation and a unitarity condition, we construct the corresponding infinite dimensional quantum group U_{R} in term of a deformed oscillators algebra A_R. The realization we present is an infinite series, very similar to a vertex operator. Then, considering the integrable hierarchy naturally associated to A_{R}, we show that U_{R} provides its integrals of motion. The construction can be applied to any infinite dimensional quantum group, e.g. Yangians or elliptic quantum groups. Taking as an example the R-matrix of Y(N), the Yangian based on gl(N), we recover by this construction the nonlinear Schrodinger equation and its Y(N) symmetry.Comment: 19 pages, no figure, Latex2e Error in theorem 3.3 and lemma 3.1 correcte
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