Energy calibration of tagged photons by the d(γ,π~-pp) reaction

The energy of tagged photons, which were provided from the internal photon tagging system of the Laboratory of Nuclear Science, Tohoku University, has been calibrated using the d(γ,π-pp) reaction. Charged pions and protons in the final state were detected with the Neutral Kaon Spectrometer (NKS2). Photon energies were obtained from the reaction of d(γ,π-pp). The derived photon energy was consistent with the design of the tagger system and the previous measurement using electron-positron pair production. The consistency demonstrates the performance of NKS2 and the capability of the photon energy calibration using d(γ,π-pp).     

Optimal Decay Rate of the Compressible Navier–Stokes–Poisson System in {\mathbb {R}^3}

The compressible Navier–Stokes–Poisson (NSP) system is considered in ${\mathbb {R}^3}The compressible Navier–Stokes–Poisson (NSP) system is considered in \mathbb R³{\mathbb {R}^3} in the present paper, and the influences of the electric field of the internal electrostatic potential force governed by the self-consistent Poisson equation on the qualitative behaviors of solutions is analyzed. It is observed that the rotating effect of electric field affects the dispersion of fluids and reduces the time decay rate of solutions. Indeed, we show that the density of the NSP system converges to its equilibrium state at the same L ²-rate (1+t)^{-\frac 34}{(1+t)^{-\frac {3}{4}}} or L ^∞-rate (1 + t)^−3/2 respectively as the compressible Navier–Stokes system, but the momentum of the NSP system decays at the L ²-rate (1+t)^{-\frac 14}{(1+t)^{-\frac {1}{4}}} or L ^∞-rate (1 + t)⁻¹ respectively, which is slower than the L ²-rate (1+t)^{-\frac 34}{(1+t)^{-\frac {3}{4}}} or L ^∞-rate (1 + t)^−3/2 for compressible Navier–Stokes system [Duan et al., in Math Models Methods Appl Sci 17:737–758, 2007; Liu and Wang, in Comm Math Phys 196:145–173, 1998; Matsumura and Nishida, in J Math Kyoto Univ 20:67–104, 1980] and the L ^∞-rate (1 + t)^−p with p ? (1, 3/2){p \in (1, 3/2)} for irrotational Euler–Poisson system [Guo, in Comm Math Phys 195:249–265, 1998]. These convergence rates are shown to be optimal for the compressible NSP system.     

Guest‐responsive excimer emission in an α‐helix peptide bearing γ‐cyclodextrin and two naphthalene units

An α‐helix peptide (17 amino acids) bearing γ‐cyclodextrin (γ‐CD) and two naphthyl units (γ‐N₂17) was designed and prepared as a new type of chemosensor. The α‐helix peptide with γ‐CD sandwiched between two naphthyl moieties exhibits excimer emission by inserting the two naphthalene moieties into the γ‐CD cavity from the opposite sides in the side chain of the peptide. The two reference peptides, which have one naphthalene moiety and one γ‐CD unit, exhibit only monomer fluorescence and have larger binding constants for the examined guests than γ‐N₂17.     

Stabilization of p-Phenylenebis(N-tert-butylaminoxyl) Relative to p-Benzoquinonediimine N,N′-Dioxide

Steric interactions between methoxy and tert -butyl groups are the reason that 2 only exists as p-phenylenebis(N-tert-butylaminoxyl) B . The p-phenylenebis(N-tert-butylaminoxyl) 1 has the p-quinonediimine N,N′-dioxide structure Q in solution as well as in the crystalline state.