1,075 research outputs found

    Clustering and Triaxial Deformations of 40^{40}Ca

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    We have studied the positive-parity states of 40^{40}Ca using antisymmetrized molecular dynamics (AMD) and the generator coordinate method (GCM). Imposing two different kinds of constraints on the variational calculation, we have found various kinds of 40Ca^{40}{\rm Ca} structures such as a deformed-shell structure, as well as α\alpha-36^{36}Ar and 12^{12}C-28^{28}Si cluster structures. After the GCM calculation, we obtained a normal-deformed band and a superdeformed band together with their side bands associated with triaxial deformation. The calculated B(E2)B(E2) values agreed well with empirical data. It was also found that the normal-deformed and superdeformed bands have a non-negligible α\alpha-36^{36}Ar cluster component and 12^{12}C-28^{28}Si cluster component, respectively. This leads to the presence of an α\alpha-36^{36}Ar higher-nodal band occurring above the normal-deformed band.Comment: 11pages, 9 figure

    Nitrogen Flow to Duodenum of Steers Grazing on Orchardgrass and Meadowfescue Pastures

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    This experiment was conducted to evaluate nitrogen flow to the duodenum of steers grazing on orchardgrass (Dactylis glomerata L., OG) or meadowfescue (Festuca elatior L., MF) pasture. Holstein steers fitted with cannulas in the rumen and duodenum were used. Nitrogen content and in vitro dry matter digestibility of herbage did not differ between OG and MF pastures. Herbage nitrogen intake of steers grazing on OG and MF pastures averaged 229 and 271 g/day, respectively. Nitrogen flows to the duodenum of steers grazing on orchardgrass and meadowfescue pastures averaged 187 and 195g/d, respectively. Microbial nitrogen flow to the duodenum also did not differ between OG and MF pastures. Efficiencies of nitrogen utilization for microbial protein synthesis per kg organic matter apparently digested in the rumen of steers grazing on OG and MF pastures averaged 31.4 and 29.0g, respectively. There was no significant difference in nitrogen absorption from the intestine between steers grazing on OG and MF pastures. In both pastures, steers were supplied with more than 3.5 times metabolizable protein as much as required for maintenance without supplements

    16O+16O^{16}{\rm O} + ^{16}{\rm O} nature of the superdeformed band of 32S^{32}{\rm S} and the evolution of the molecular structure

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    The relation between the superdeformed band of 32S^{32}{\rm S} and 16O+16O^{16}{\rm O} + ^{16}{\rm O} molecular bands is studied by the deformed-base antisymmetrized molecular dynamics with the Gogny D1S force. It is found that the obtained superdeformed band members of 32S^{32}{\rm S} have considerable amount of the 16O+16O^{16}{\rm O} + ^{16}{\rm O} component. Above the superdeformed band, we have obtained two excited rotational bands which have more prominent character of the 16O+16O^{16}{\rm O} + ^{16}{\rm O} molecular band. These three rotational bands are regarded as a series of 16O+16O^{16}{\rm O} + ^{16}{\rm O} molecular bands which were predicted by using the unique 16O^{16}{\rm O} -16O^{16}{\rm O} optical potentil. As the excitation energy and principal quantum number of the relative motion increase, the 16O+16O^{16}{\rm O} + ^{16}{\rm O} cluster structure becomes more prominent but at the same time, the band members are fragmented into several states

    Effect of Potato Pulp Silage Supplementation on Milk Production in Cows Grazing Temperate Pasture

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    In a dairy farming system based on pasture in Japan, maize grain is generally used as an energy source for milking cows, with almost all grain been imported. Potato-pulp is one of the agricultural by-products derived from the starch industry in the northern island of Japan. In our previous study (Aibibula et al., 2004), it was demonstrated that potato pulp could be preserved for a long time by ensiling without additives, and that the digestible energy value of potato pulp silage (13 MJ/kg DM) was almost the same as beet pulp. From these results, it is possible that some part of the maize grain fed to grazing cows could be substituted with potato pulp silage (PPS). The objective of this study was to compare PPS with rolled-maize as an energy source for cows grazing on temperate pasture

    Two-color photoassociation spectroscopy of ytterbium atoms and the precise determinations of s-wave scattering lengths

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    By performing high-resolution two-color photoassociation spectroscopy, we have successfully determined the binding energies of several of the last bound states of the homonuclear dimers of six different isotopes of ytterbium. These spectroscopic data are in excellent agreement with theoretical calculations based on a simple model potential, which very precisely predicts the s-wave scattering lengths of all 28 pairs of the seven stable isotopes. The s-wave scattering lengths for collision of two atoms of the same isotopic species are 13.33(18) nm for ^{168}Yb, 3.38(11) nm for ^{170}Yb, -0.15(19) nm for ^{171}Yb, -31.7(3.4) nm for ^{172}Yb, 10.55(11) nm for ^{173}Yb, 5.55(8) nm for ^{174}Yb, and -1.28(23) nm for ^{176}Yb. The coefficient of the lead term of the long-range van der Waals potential of the Yb_2 molecule is C_6=1932(30) atomic units (Eha069.573×1026(E_h a_0^6 \approx 9.573\times 10^{-26} J nm^6).Comment: 9 pages, 7 figure

    Effects of Cultural Ethnicity, Firm Size, and Firm Age on Senior Executives’ Trust in their Overseas Business Partners: Evidence from China

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    We investigate trust relationships between senior business executives and their overseas partners. Drawing on the similarity-attraction paradigm, social categorization theory, and the distinction between cognition- and affect-based trust, we argue that executives trust their overseas partners differently, depending on the partners\u27 cultural ethnicity. In a field survey of 108 Chinese senior executives, we found that these executives have higher affect-based trust in overseas partners of the same cultural ethnicity as themselves; cognition-based trust is associated with affect-based trust differently when overseas partners are of the same or different cultural ethnicity. We also examine the role of relative firm size and age in shaping intra- and intercultural trust. Relative firm size has a stronger negative effect on executives\u27 cognition-based trust if their partners are of a different cultural ethnicity. Although firm age does not have a negative effect on executives\u27 affect-based trust as hypothesized, we found firm age to be positively associated with affect-based trust for partners of the same cultural ethnicity. We discuss theoretical and practical implications of this pattern of inter- and intra-cultural trust on international business and networking (guanxi) dynamics in China

    Deformed Base Antisymmetrized Molecular Dynamics and its Application to ^{20}Ne

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    A new theoretical framework named as deformed base antisymmetrized molecular dynamics that uses the localized triaxially deformed Gaussian as the single particle wave packet is presented. The model space enables us to describe sufficiently well the deformed mean-field structure as well as the cluster structure and their mixed structure within the same framework. The improvement over the original version of the antisymmetrized molecular dynamics which uses the spherical Gaussian is verified by the application to 20Ne^{20}{\rm Ne} nucleus. The almost pure α+16Og.s\alpha + ^{16}{\rm O_{g.s}} cluster structure of the KπK^\pi=00^- band, the distortion of the cluster structure in the KπK^\pi=01+0^+_1 band and the dominance of the deformed mean-field structure of the KπK^\pi=22^- band are confirmed and their observed properties are reproduced. Especially, the intra-band E2 transition probabilities in KπK^\pi=01+0^+_1 and 22^- bands are reproduced without any effective charge. Since it has been long known that the pure α+16Og.s.\alpha + ^{16}{\rm O}_{g.s.} cluster model underestimates the intra-band E2E2 transitions in the KπK^\pi=01+0^+_1 band by about 30%, we consider that this success is due to the sufficient description of the deformed mean-field structure in addition to the cluster structure by the present framework. From the successful description of 20Ne^{20}{\rm Ne}, we expect that the present framework presents us with a powerful approach for the study of the coexistence and interplay of the mean-field structure and the cluster structure

    ASCA Observations of the Sgr B2 Cloud: An X-Ray Reflection Nebula

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    We present the ASCA results of imaging spectroscopy of the giant molecular cloud Sgr B2. The X-ray spectrum is found to be very peculiar; it exhibits a strong emission line at 6.4 keV, a low energy cutoff below about 4 keV and a pronounced edge-structure at 7.1 keV. The X-ray image is extended and its peak position is shifted from the core of the molecular cloud toward the Galactic center by about 1--2 arcminute. The X-ray spectrum and the morphology are well reproduced by a scenario that X-rays from an external source located in the Galactic center direction are scattered by the molecular cloud Sgr B2, and come into our line of sight. Thus Sgr B2 may be called an X-ray reflection nebula. Possible implications of the Galactic center activity related to this unique source are presented.Comment: 15 pages, 8 figures, AAS LaTeX, To be published in The Astrophysical Journa

    Leptogenesis with Almost Degenerate Majorana Neutrinos

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    We investigate the leptogenesis with almost degenerate neutrinos, in the framework of democratic mass matrix, which naturally explains the large mixing angles for neutrino oscillations as well as quark masses and mixing matrix. We find that the baryon asymmetry in the present universe is explained via the decays of right-handed neutrinos produced nonthermally by the inflaton decay. The model predicts neutrinoless double beta decays accessible in near future experiments.Comment: 17 pages, LaTeX, 2 figure

    P and K additions enhance canopy N retention and accelerate the associated leaching

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    This study evaluated the interactive effects of combined phosphorus (P) and potassium (K) additions on canopy nitrogen (N) retention (CNR) and subsequent canopy leaching at a long-term N manipulation site on Whim bog in south Scotland. Ambient deposition is 8 kg N ha-1 year-1 and an additional 8, 24, and 56 kg N ha-1 year-1 of either ammonium (NH4+) or nitrate (NO3-) with or without P and K has been applied over 11 years. Throughfall N deposition below Calluna vulgaris and foliar N and P concentrations were assessed. Results showed that 60% for low dose and 53% for high dose of NO3- contrasting with 80% for low dose and 38% for high dose of NH4+ onto Calluna was retained by Calluna canopy. The CNR was enhanced by P and K addition in which 84% of NO3 - and 83% of NH4+ for high dose were retained. CNR for NO3- increased the canopy leaching of dissolved organic N (DON) and associated organic anions. NH4+ retention increased canopy leaching of magnesium and calcium through ion exchange. Even over 11-years N exposure without P and K, foliage 29 N:P ratio of Calluna did not increase, suggesting that N exposure did not lead to N saturation of Calluna at Whim bog. Our study concluded that increases in P and K availability enhance CNR of Calluna, but accelerate the associated canopy leaching of DON and base cations, depending on foliar N status
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