The total hadronic cross section for e+e− annihilation between 3.1 and 4.8 GeV center of mass energy

Using the solenoidal magnetic detector PLUTO, we have measured the total cross section for e⁺e^? annihilation into hadrons. Results are presented for center of mass energies between 3.6 and 4.8 GeV, and in the regions of the $\text{J}\text{ψ}$(3.1) and ψ(3.7) resonances. We also present results for the 2 prong cross section in the energy range 3.6 to 4.8 GeV.     

Relativistic effects in nuclear motions

Using the wave functions of the relativistic equivalent harmonic oscillator recently proposed, elastic electron scattering cross sections have been calculated in the Born approximation for helium and lead. Calculations have also been made with the non-relativistic isotropie oscillator wave functions. Comparison with high-energy electron scattering experiments shows that relativistic effects may be significant in a heavy nucleus like lead.     

Non-stoichiometry induced by differential oxygen/lone pair occupation in chiral bicyclic 1,1'-binaphthoxy cyclodiphosphazanes

Non-stoichiometry and isostructurality in a set of chiral phosphorus compounds as a result of lone pair/oxygen exchange, substantiated by the combined use of 31P NMR spectroscopy and X-ray crystallography, is described.     

Liquid mixture excess properties by the hard sphere model

The excess properties of mixing were calculated for seven systems Ar-CH₄; Ar-N₂; Ar-O₂; Ar-CO; CO-CH₄; O₂-N₂; N₂-CO, using the Caranhan and Starling equation of state of rigid spheres and the Longuet-Higgins and Widom model. Two sets of calculations were done one using the experimentalG ^E to calculateS ^E ,H ^E andV ^E , and the other making use of Miller’s cross parameter values. The calculated values are compared with those of Snider and Herrington and Miller’s values and also with the experimental values. The agreement was found to be good.     

Size-dependent pressure-induced amorphization in nanoscale TiO2

We investigated the size-dependent high-pressure phase transition behavior of nanocrystalline anatase TiO2 with synchrotron x-ray diffraction and Raman spectroscopy to 45 GPa at ambient temperature. Pressure-induced amorphization results in a high-density amorphous (HDA) form when the starting crystallite size is < 10 mm. The HDA-TiO2 transforms to a low-density amorphous form at lower pressures. Harnessing the nanometer length scale thus provides a new window for experimental investigation of amorphization in poor glass formers and a synthesis route for new amorphous materials.     

Approximating min-cost chain-constrained spanning trees: a reduction from weighted to unweighted problems

We study the min-cost chain-constrained spanning-tree (MCCST) problem: find a min-cost spanning tree in a graph subject to degree constraints on a nested family of node sets. We devise the first polytime algorithm that finds a spanning tree that (i) violates the degree constraints by at most a constant factor and (ii) whose cost is within a constant factor of the optimum. Previously, only an algorithm for unweighted CCST was known (Olver and Zenklusen in Proceedings of the 16th IPCO, pp 324–335, 2013), which satisfied (i) but did not yield any cost bounds. This also yields the first result that obtains an O(1)-factor for both the cost approximation and violation of degree constraints for any spanning-tree problem with general degree bounds on node sets, where an edge participates in a super-constant number of degree constraints. A notable feature of our algorithm is that we reduce MCCST to unweighted CCST (and then utilize Olver and Zenklusen in Proceedings of the 16th IPCO, pp 324–335, 2013) via a novel application of Lagrangian duality to simplify the cost structure of the underlying problem and obtain a decomposition into certain uniform-cost subproblems. We show that this Lagrangian-relaxation based idea is in fact applicable more generally and, for any cost-minimization problem with packing side-constraints, yields a reduction from the weighted to the unweighted problem. We believe that this reduction is of independent interest. As another application of our technique, we consider the k -budgeted matroid basis problem, where we build upon a recent rounding algorithm of Bansal and Nagarajan (Proceedings of IPCO 2016. arXiv:1512.02254, 2015) to obtain an improved \(n^{O(k^{1.5}/\epsilon )}\)-time algorithm that returns a solution that satisfies (any) one of the budget constraints exactly and incurs a \((1+\epsilon )\)-violation of the other budget constraints.     

Combustion wave propagation in mixtures of JSC-1A lunar regolith simulant with magnesium

Combustion of lunar regolith mixed with energetic additives is a potential method for production of construction materials in future moon missions. Recently, self-sustained combustion in the mixtures of JSC-1A lunar regolith and magnesium has been demonstrated. However, the concentration of magnesium in those mixtures was as high as 26 wt%. Note that magnesium must be either transported from Earth or recovered from lunar minerals or used structures. The present paper focuses on the minimization of magnesium content in JSC-1A/Mg mixtures. The mixtures were compacted into pellets and ignited in argon environment. Initial attempts to decrease magnesium concentration resulted in the observations of a spinning combustion wave at 23 wt% Mg. The observed spin combustion involved periodical motion of two counterpropagating hot spots along a helical path on the sample surface. These observations, including features such as formation of a faster hot spot after collision of the counterpropagating spots, confirm theoretical predictions for spin combustion in solid–solid mixtures. High-energy mechanical milling of JSC-1A in a planetary ball mill significantly increased its reactivity and improved combustion of its mixtures with magnesium. Mixtures of the obtained powder (the median diameter of about 3 μm) with 26 wt% Mg exhibit easy ignition and vigorous combustion. The minimum concentration of magnesium required for self-sustained propagation of a planar combustion front is as low as 13 wt%.     

Synthesis and Antimicrobial Activity of (E)-2-[(1-Substituted Phenyl-1H-1,2,3-triazol-4-yl)methylene]-2,3-dihydro-1H-inden-1-ones

Russian Journal of General Chemistry - A series of novel (E)-2-[(1-phenyl-1H-1,2,3-triazol-4-yl)methylene]-2,3-dihydro-1H-inden-1-one derivatives has been synthesized by condensation of...