NP-completeness of some type of p-center problem

In this paper we will define some special p-center problem in view of practical applications and prove its NP-completeness.     

Photochemical reaction of 2-cyclopentenone with ethers : The mechanism of solvent addition

Photochemical addition of several ethers to 2-cyclopentenone has been studied under various conditions, especially in the presence of a few aromatic ketones. The mechanism of the ether addition is suggested to be via direct abstraction of hydrogen by excited 2-cyclopentenone rather than due to a chemical process involving aromatic ketyl radicals.     

Scattering spectra in orthorhombic indium bromide under resonant excitation

Emission spectra in indirect gap InBr are measured at liquid helium temperature under Ar⁺ laser excitation. They consist of many weak lines up to 20 with LO phonon energy (16.4 meV) spacing. They shift with incident laser lines. Even-numbered lines are stronger than odd-numbered lines. They show resonant enhancements when photon energy of scattered light is near the direct exciton energy, 2.33 eV.     

Effect of aberrations on off-axis gaussian beams

The effect of aberrations of an optical system on gaussian beams is analyzed. If an incident position of the beams of the optical system does not coincide with the center of its pupil, the beams suffer from aberrations differently in accordance with the various incident positions. The Strehl definition of the beams is studied as a function of the incident position of the beams and the kind of abberations present in the optical system.     

Microscopic calculation of friction in heavy ion reaction using linear response theory

We present a realistic calculation of the frictional coefficients for²⁸Si+²⁰Ne system using the two-center shell model on the basis of the linear response theory. Adopting the center separationR and the deformationδ as collective variables we study the dependence of frictional coefficients γ _RR , γ _Rδ and γ_δδ on those variables, for various values of the neck parameter?, the temperatureT and the smearing widthΓ. The direct application of the linear response theory to the two-center potential gives non-vanishing friction for the simple translational motion of the two fragments even when they are far apart. A method to avoid this energy dissipation is proposed and is used in the calculation. Results show that the form factor of the frictional force is surface-peaked and the peak becomes lower as the prolate deformation or neck formation increases. Temperature dependence is mild, but is not negligible. We compare our γ _RR and γ_δδ with other models.