1,431 research outputs found

    Kinetic Ballooning Mode Under Steep Gradient: High Order Eigenstates and Mode Structure Parity Transition

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    The existence of kinetic ballooning mode (KBM) high order (non-ground) eigenstates for tokamak plasmas with steep gradient is demonstrated via gyrokinetic electromagnetic eigenvalue solutions, which reveals that eigenmode parity transition is an intrinsic property of electromagnetic plasmas. The eigenstates with quantum number l=0l=0 for ground state and l=1,2,3l=1,2,3\ldots for non-ground states are found to coexist and the most unstable one can be the high order states (l0l\neq0). The conventional KBM is the l=0l=0 state. It is shown that the l=1l=1 KBM has the same mode structure parity as the micro-tearing mode (MTM). In contrast to the MTM, the l=1l=1 KBM can be driven by pressure gradient even without collisions and electron temperature gradient. The relevance between various eigenstates of KBM under steep gradient and edge plasma physics is discussed.Comment: 6 pages, 6 figure

    Improved Estimates of The B(s)VVB_{(s)}\to V V Decays in Perturbative QCD Approach

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    We reexamine the branching ratios, CPCP-asymmetries, and other observables in a large number of BqVV(q=u,d,s)B_q\to VV(q=u,d,s) decays in the perturbative QCD (PQCD) approach, where VV denotes a light vector meson (ρ,K,ω,ϕ)(\rho, K^*, \omega, \phi). The essential difference between this work and the earlier similar works is of parametric origin and in the estimates of the power corrections related to the ratio ri2=mVi2/mB2(i=2,3)r_i^2=m_{V_i}^2/m_B^2(i=2,3) (mVm_V and mBm_B denote the masses of the vector and BB meson, respectively). In particular, we use up-to-date distribution amplitudes for the final state mesons and keep the terms proportional to the ratio ri2r_i^2 in our calculations. Our updated calculations are in agreement with the experimental data, except for a limited number of decays which we discuss. We emphasize that the penguin annihilation and the hard-scattering emission contributions are essential to understand the polarization anomaly, such as in the BϕKB\to \phi K^* and BsϕϕB_s \to \phi\phi decay modes. We also compare our results with those obtained in the QCD factorization (QCDF) approach and comment on the similarities and differences, which can be used to discriminate between these approaches in future experiments.Comment: one figure, twelve Table

    The P-wave Λ\Lambda-type bottom baryon states via the QCD sum rules

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    Our study focuses on the P-wave bottom baryon states with the spin-parity JP=12J^P=\frac{1}{2}^-, 32\frac{3}{2}^-. We introduce an explicit P-wave between the two light quarks in the interpolating currents to investigate the Λb\Lambda_b and Ξb\Xi_b states within the framework of the full QCD sum rules. The predicted masses show that the Ξb(6087)\Xi_b(6087) and Ξb(6095/6100)\Xi_b(6095/6100) could to be the P-wave bottom-strange baryon states with the spin-parity JP=12J^P=\frac{1}{2}^- and 32\frac{3}{2}^-, respectively, meanwhile, the Λb(5912)\Lambda_b(5912) and Λb(5920)\Lambda_b(5920) could be the P-wave bottom baryon states with the spin-parity JP=12J^P=\frac{1}{2}^- and 32\frac{3}{2}^-, respectively.Comment: 17 pages, 12 figure

    Studies on Rheological Behaviors of Bismaleimide Resin System for Resin Transfer Molding

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    AbstractThe rheological behavior of bismaleimide resin for resin transfer molding(RTM) was studied with DSC analysis and viscosity experiments. A rheological model based on the dual-Arrhenius equation was established and used to simulate the rheological behavior of the resin. The model predictions determined from the dual-Arrhenius equation were in good agreement with experimental data. The processing window of the resin system can be well determined based on the developed model. The rheological model is important for processing simulation and quality control of RTM processing for high performance composites

    Chemical composition of Dipsacus asper Wallich ex Candolle (Dipsacaceae) essential oil and its activity against mosquito larvae of Aedes aegypti and Culex pipiens pallens

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    Purpose: To evaluate the larvicidal activity of the essential oil of Dipsacus asper Wallich ex Candolle (Dipsacaceae) roots against the larvae of Aedes aegypti L. and Culex pipiens pallens Coquillett.Methods: Essential oil was extracted from D. asper roots by hydrodistillation and analyzed for its composition by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The oil was evaluated for larvicidal activity, using World Health Organization (WHO) procedures, against the fourth larvae of A. aegypti and C. pipiens pallens within 24 h, and activity was recorded for various concentrations of the oil ranging from 12.5 – 200.0 μg/mL.Results: A total of 34 components of the essential oil of D. asper were identified. The major compounds of the essential oil were caryophyllene oxide (13.29 %), caryophyllene (9.14 %), cubebene (7.87 %), β-gurjunene (6.43 %), carvone (5.38 %), 1,8-cineole (5.29 %), and calamenene (5.05 %). The oil exhibited larvicidal activity against A. aegypti and C. pipiens pallens at median lethal concentrations (LC50) of 56.29 μg/mL and 47.49 μg/mL, respectively.Conclusion: The essential oil of D. asper roots has potentials for use in the control of A. aegypti and C. pipiens pallens and may be useful in the search for new, safer and more effective natural larvicides.Keywords: Dipsacus asper, Aedes aegypti, Culex pipiens pallens, Essential oil, Larvicidal activity, Caryophyllene, Cubebene, β-Gurjunene, Carvon

    Mapping quantitative trait loci for T lymphocyte subpopulations in peripheral blood in swine

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    <p>Abstract</p> <p>Background</p> <p>Increased disease resistance through improved general immune capacity would be beneficial for the welfare and productivity of farm animals. T lymphocyte subpopulations in peripheral blood play an important role in immune capacity and disease resistance in animals. However, very little research to date has focused on quantitative trait loci (QTL) for T lymphocyte subpopulations in peripheral blood in swine.</p> <p>Results</p> <p>In the study, experimental animals consist of 446 piglets from three different breed populations. To identify QTL for T lymphocyte subpopulations in peripheral blood in swine, the proportions of CD4+, CD8+, CD4+CD8+, CD4+CD8-, CD4-CD8+, and CD4-CD8- T cells and the ratio of CD4+:CD8+ T cells were measured for all individuals before and after challenge with modified live CSF (classical swine fever) vaccine. Based on the combined data of individuals from three breed populations, genome-wide scanning of QTL for these traits was performed based on a variance component model, and the genome wide significance level for declaring QTL was determined via permutation tests as well as FDR (false discovery rate) correction. A total of 27 QTL (two for CD4+CD8+, one for CD4+CD8-, three for CD4-CD8+, two for CD4-CD8-, nine for CD4+, two for CD8+, and eight for CD4+:CD8+ ratio) were identified with significance level of <it>FDR </it>< 0.10, of which 11 were significant at the level of <it>FDR </it>< 0.05, including the five significant at <it>FDR </it>< 0.01.</p> <p>Conclusions</p> <p>Within these QTL regions, a number of known genes having potential relationships with the studied traits may serve as candidate genes for these traits. Our findings herein are helpful for identification of the causal genes underlying these immune-related trait and selection for immune capacity of individuals in swine breeding in the future.</p

    Secure Direct Communication Using Quantum Calderbank-Shor-Steane Codes

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    The notion of quantum secure direct communication (QSDC) has been introduced recently in quantum cryptography as a replacement for quantum key distribution, in which two communication entities exchange secure classical messages without establishing any shared keys previously. In this paper, a quantum secure direct communication scheme using quantum Calderbank-Shor-Steane (CCS) error correction codes is proposed. In the scheme, a secure message is first transformed into a binary error vector and then encrypted(decrypted) via quantum coding(decoding) procedures. An adversary Eve, who has controlled the communication channel, can\u27t recover the secrete messages because she doesn\u27t know the deciphering keys. Security of this scheme is based on the assumption that decoding general linear codes is intractable even on quantum computers
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