1,620 research outputs found

    Convergence of Scaled Delta Expansion: Anharmonic Oscillator

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    We prove that the linear delta expansion for energy eigenvalues of the quantum mechanical anharmonic oscillator converges to the exact answer if the order dependent trial frequency Ω\Omega is chosen to scale with the order as Ω=CNγ\Omega=CN^\gamma; 1/301/30 as NN\rightarrow\infty. It converges also for γ=1/3\gamma=1/3, if Cαcg1/3C\geq\alpha_c g^{1/3}, αc0.570875\alpha_c\simeq 0.570875, where gg is the coupling constant in front of the operator q4/4q^4/4. The extreme case with γ=1/3\gamma=1/3, C=αcg1/3C=\alpha_cg^{1/3} corresponds to the choice discussed earlier by Seznec and Zinn-Justin and, more recently, by Duncan and Jones.Comment: 37 pages (with 11 figures uuencoded at the end of the file,to be stripped off), GEF-Th-7/199

    Improved Convergence Proof of the Delta Expansion and Order Dependent Mappings

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    We improve and generalize in several accounts the recent rigorous proof of convergence of delta expansion - order dependent mappings (variational perturbation expansion) for the energy eigenvalues of anharmonic oscillator. For the single-well anharmonic oscillator the uniformity of convergence in g[0,]g\in[0,\infty] is proven. The convergence proof is extended also to complex values of gg lying on a wide domain of the Riemann surface of E(g)E(g). Via the scaling relation \`a la Symanzik, this proves the convergence of delta expansion for the double well in the strong coupling regime (where the standard perturbation series is non Borel summable), as well as for the complex ``energy eigenvalues'' in certain metastable potentials. Sufficient conditions for the convergence of delta expansion are summarized in the form of three theorems, which should apply to a wide class of quantum mechanical and higher dimensional field theoretic systems.Comment: some bugs of uuencoded postscript figures are fixe

    The Effect of Solvents on the Adduct Formation of Uranyl Thenoyltrifluoroacetonate with Tributyl Phosphate

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    Addition compound formation between uranyl bis-thenoyltrifluoroacetonate (UO_2A_2) and tributyl phosphate (S) was studied by partition method, using uranium-237 as the tracer. The formula of the adduct complex was shown to be UO_2A_2S. The solvent effect on the adduct formation constant was taken into account in connection with the activity ; the activity coefficients of each species in various solutions were calculated from the molar volume and the solubility parameter. The formation constants based on the molar fraction, K_x, in a number of solvents were preestimated, employing log K_x=7.08 in carbon tetrachloride as a reference. They are in agreement with the observed values. The formation constant in terms of activity was found to be constant log K°_s=5.77±0.30. A correlation between the formation constant of the two adducts, UO_2A_2S and ZnA_2S, was demonstrated

    On the Study of Early Modern“ Elegant” Literature

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    Longitudinal case study of fixed revenue accounting at a Japanese semiconductor distributor / Kenichi Suzuki, Kohsuke Matsuoka and Hiromune Ishii.

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    Fixed revenue accounting (FRA) is a management control system for relationship marketing strategy. Although FRA has been investigated among some Japanese companies since it was proposed in 2005, there has not been any study examining the effects FRA has on employees' awareness and behaviors based on longitudinal investigation. In this paper, we state a longitudinal case study about FRA at a Japanese semiconductor distributor during 2006–2014. We found that at Company A, only senior management used FRA to understand its strategy until 2012. After they became convinced FRA could guide relationship marketing, they started using FRA as a management control system in 2013 by binding it with its strategic plan and annual budgets. We interviewed with twelve core employees in 2014 and clarified that FRA motivated employees to accept relationship marketing strategy, deepened common understanding between departments, and facilitated an understanding of how to achieve goals

    Spontaneous strain due to ferroquadrupolar ordering in UCu2_2Sn

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    The ternary uranium compound UCu2_2Sn with a hexagonal ZrPt2_2Al-type structure shows a phase transition at 16 K. We reported previously that huge lattice-softening is accompanied by the phase transition, which originates from ferroquadrupolar ordering of the ground state non-Kramers doublet Γ5\Gamma_5. A macroscopic strain, which is expected to emerge spontaneously, was not detected by powder X-ray diffraction in the temperature range between 4.2 and 300 K. To search the spontaneous strain, we have carried out thermal expansion measurements on a single-crystalline sample along the aa, bb and cc axes using a capacitance technique with the resolution of 10810^{-8}. In the present experiment, we found the spontaneous exxeyye_{xx} - e_{yy} strain which couples to the ground state doublet Γ5\Gamma_5. The effect of uniaxial pressure along the aa, bb and cc axes on the transition temperature is also discussed.Comment: 4 pages, 5 figures, submitted to Phys. Rev.

    Activities of bone morphogenetic proteins in prolactin regulation by somatostatin analogs in rat pituitary GH3 cells

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    Involvement of the pituitary BMP system in the modulation of prolactin (PRL) secretion regulated by somatostatin analogs, including octreotide (OCT) and pasireotide (SOM230), and a dopamine agonist, bromocriptine (BRC), was examined in GH3 cells. GH3 cells are rat pituitary somato-lactotrope tumor cells that express somatostatin receptors (SSTRs) and BMP system molecules including BMP-4 and -6. Treatment with BMP-4 and -6 increased PRL and cAMP secretion by GH3 cells. The BMP-4 effects were neutralized by adding a BMP-binding protein Noggin. These findings suggest the activity of endogenous BMPs in augmenting PRL secretion by GH3 cells. BRC and SOM230 reduced PRL secretion, but OCT failed to reduce the PRL level. In GH3 cells activated by forskolin, BRC suppressed forskolin-induced PRL secretion with reduction in cAMP levels. OCT did not affect forskolin-induced PRL level, while SOM230 reduced PRL secretion and PRL mRNA expression induced by forskolin. BMP-4 treatment enhanced the reducing effect of SOM230 on forskolin-induced PRL level while BMP-4 did not affect the effects of OCT or BRC. Noggin treatment had no significant effect on the BRC actions reducing PRL levels by GH3 cells. However, in the presence of Noggin, OCT elicited an inhibitory effect on forskolin-induced PRL secretion and PRL mRNA expression, whereas the SOM230 effect on PRL reduction was in turn impaired. It was further found that BMP-4 and -6 suppressed SSTR-2 but increased SSTR-5 mRNA expression of GH3 cells. These findings indicate that Noggin rescues SSTR-2 but downregulates SSTR-5 by neutralizing endogenous BMP actions, leading to an increase in OCT sensitivity and a decrease in SOM230 sensitivity of GH3 cells. In addition, BMP signaling was facilitated in GH3 cells treated with forskolin. Collectively, these findings suggest that BMPs elicit differential actions in the regulation of PRL release dependent on cellular cAMP-PKA activity. BMPs may play a key role in the modulation of SSTR sensitivity of somato-lactotrope cells in an autocrine/paracrine manner
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