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991.
992.
We study spectral distortions of diffuse ultra-high energy (UHE) neutrino flavour fluxes resulting due to physics beyond the Standard Model (SM). Even large spectral differences between flavours at the source are massaged into a common shape at earth by SM oscillations, thus, any significant observed spectral differences are an indicator of new physics present in the oscillation probability during propagation. Lorentz symmetry violation (LV) and neutrino decay are examples, and result in significant distortion of the fluxes and of the well-known bounds on them, which may allow UHE detectors to probe LV parameters, lifetimes and the mass hierarchy over a broad range. 相似文献
993.
994.
Plasma Treatment Enhanced Magnetic Properties in Manganese Doped Titanium Nitride Thin Films 下载免费PDF全文
The ferromagnetic manganese doped TiN films were grown by plasma assisted molecular beam epitaxy on MgO(001) substrates. The nitrogen concentration and the ratio of manganese at Ti lattice sites increase after the plasma annealing post treatment. TiN(002) peak shifts toward low angle direction and TiN(111) peak disappears after the post treatment. The lattice expansion and peak shift are mainly ascribed to the reduction of nitrogen vacancies in films. The magnetism was suppressed in as-prepared sample due to the pinning effect of the nitrogen vacancies at defect sites or interface. The magnetism can be activated by the plasma implantation along with nitrogen vacancies reduce. The decrease of nitrogen vacancies leads to the enhancement of ferromagnetism. 相似文献
995.
996.
《Journal of computational chemistry》2017,38(17):1509-1514
We study the orbital‐dependence of three (parameter‐free) double‐hybrid density functionals, namely the PBE0‐DH, the PBE‐QIDH models, and the SOS1‐PBE‐QIDH spin‐opposite‐scaled variant of the latter. To do it, we feed all their energy terms with different sets of orbitals obtained previously from self‐consistent density functional theory calculations using several exchange‐correlation functionals (e.g., PBE, PBE0, PBEH&H), or directly with HF‐PBE orbitals, to see their effect on selected datasets for atomization and reaction energies, the latter proned to marked self‐interaction errors. We find that the PBE‐QIDH double‐hybrid model shows a great consistency, as the best results are always obtained for the set of orbitals corresponding to its hybrid scheme, which prompts us to recommend this model without any other fitting or reparameterization. © 2017 Wiley Periodicals, Inc. 相似文献
997.
《中国化学》2017,35(11):1678-1686
Polydiacetylenes (PDAs), an organic layered compound, show a series of intriguing properties, such as thermochromism and fluorescence emission in the red‐phase. However, their irreversible color change, and weak and single‐color fluorescence emitted only from the red‐phase PDAs, have limited their applications. Herein, we report double‐reversible PDA‐Tb3+ nanosheets of which both the color and the fluorescence can be reversibly switched between two colors. PDA‐Tb3+ nanosheets have the nearly defect‐free intercalated structure in which a layer of Tb3+ ions was intercalated in between each two PDA bilayers to tether almost all of the carboxyl groups at the end of the side chains of the PDA. When the PDA is in the blue phase, the PDA‐Tb3+ nanosheets emit the green fluorescence of Tb3+ ions. When the PDA is in the red phase, the Tb3+ fluorescence disappears while the intrinsic red fluorescence of PDA is effectively enhanced through the fluorescence resonance energy transfer (FRET) process; the PDA‐Tb3+ nanosheets emit stronger red fluorescence compared with the PDA in red phase. Moreover, the tethering of almost all of the carboxyl groups at the end of the side chains of the PDA endows the nanosheets with the double reversibility in both the color and fluorescence transitions. 相似文献
998.
The absence of guidance from fundamental physics about the mechanism behind cosmic acceleration has given rise to a number of alternative cosmological scenarios. These are based either on modifications of general relativistic gravitation theory on large scales or on the existence of new fields in Nature. In this Letter we investigate the observational viability of some accelerating cosmological models in light of 32 age measurements of passively evolving galaxies as a function of redshift and recent estimates of the product of the cosmic microwave background acoustic scale and the baryonic acoustic oscillation peak scale. By using information-criteria model selection, we select the best-fit models and rank the alternative scenarios. We show that some of these models may provide a better fit to the data than does the current standard cosmological constant dominated (ΛCDM) model. 相似文献
999.
Devendra Adhikari 《Physica B: Condensed Matter》2011,406(3):445-448
The concentration dependent asymmetry in mixing properties of MgPb liquid alloys at 973 K has been investigated on the basis of regular associated solution model. The analysis suggests that heterocoordination leading to the formation of chemical complex Mg2Pb is likely to exist in the melt. 相似文献
1000.
Cyanoacetamides 3 were prepared via reacting ethyl cyanoacetate with benzylamine. Yields and reaction times needed for reaction completion at room temperature, by microwaves (μω) heating and under ultrasound (US) irradiations are compared. The formed cyanoacetamides were coupled with aromatic diazonium salts and the formed arylhydrazones were used as precursors to title triazoles and pyrazoles via reacting the former with hydroxylamine and chloroacetonitrile. Yields of products formed via conventional heating are compared with those of μω and US irradiation. 相似文献