Molecular Spectroscopy with Coherent Radiation Sources

Various characteristics of molecules have been clarified by spectroscopic methods in which the interactions of molecules with the radiation field were investigated. A stationary response of a molecule excited by a radiation field appears as a spectral line. Information on molecules may be obtained from position (resonance frequency), intensity, and shape and width of the spectral line. So far the interaction of molecules with the radiation field has been studied primarily in a “frequency domain.” Although molecular spectroscopy is one of the research fields in modern science which has the longest history, a variety of important aspects have been demonstrated very recently in this field as radiation sources have been improved. When the radiation field is “weak,” the photon nature of the radiation field is dominant in the interaction with a molecule, such as in the cases of emission, absorption, and scattering of photons. When the radiation field is “strong,” in the sense that many photons exist in a proper mode of the radiation field, the wave nature of the field plays an important role in the interaction. In this case the radiation may be described in the form of the classical field, say, a sinusoidal function of the time and spatial coordinates, coherently interacting with the molecule, which is described quantum mechanically. Here nonlinear properties would appear in the interactions: saturation in absorption, induced scattering, multiphoton processes, coherent transients, etc.     

Chemical etching op fission tracks in ethylene-tetrafluoroethylene copolymer

The chemical etching of fission tracks in ethylene-tetrafluoro-ethylene copolymer was studied. Etched holes 3000–4000 Å in diameter was recognized by electron microscopy for a film bombarded by fission fragments in oxygen and etched in a 12N sodium hydroxide solution at 125°C. The radial etching rate at 125°C was 6–8 Å/hr, which is less than 17 Å/hr for polyvinylidene fluoride in the same sodium hydroxide concentration at 85°C. The smaller rate is a reflection of the larger chemical resistivity of ethylene-tetrafluoro-ethylene copolymer than polyvinylidene fluoride.     

Search for Alpha Inelastic Condensed State in 24Mg

The alpha inelastic scattering from ²⁴Mg was measured to obtain the isoscalar natural-parity excitation strengths and to search for the α-condensed states. The multipole decomposition analysis for the measured cross sections was performed. The strength distributions for the ${{\Delta}L=0{-}3}$ were successfully obtained and the possible candidates for the α-condensed states around the ¹⁶O core were found.     

High-resolution GaP Terahertz Spectrometer and Its Application to Detect Defects in Gamma-irradiated Glucose Crystal

We developed high-resolution GaP THz signal generator using Cr:Forsterite lasers with gratings as both a pump and a signal beam for difference-frequency generation. A line width of less than 500 MHz and a wide tunable frequency range (0.6–6.2 THz) provide sufficient resolution for measuring materials with sharp absorption bands using the generator as the light source for a THz spectrometer. This is suitable for materials such as gases or solid samples at low temperatures. We demonstrated the detection of defects in organic materials, as they appear as slight deviations in the absorption frequency in the THz region.     

Development of silicon nitride fiber from Si-containing polymer by radiation curing and its application

A silicon nitride fiber (Si₃N₄) was synthesized from polycarbosilane (PCS) fiber by radiation application. PCS fibers were cured by electron beam (EB) irradiation in a helium gas atmosphere prior to the pyrolysis. The cured PCS fiber was converted to Si₃N₄ ceramic fiber with flexibility by nitridation in ammonia gas at a high temperature of 500–1000°C. The obtained Si₃N₄ fibre showed a high heat resistance up to 1300°C, a high tensile strength of 2 GPa and excellent electrical resistivity of 10¹³ Ω cm. The ceramic fiber was fabricated to cloth and applied for electric wire insulator. The wire cable is flexible and can be applied at a high temperature atmosphere of around 1000°C.     

ESR study on chemical crosslinking reaction mechanisms of polyethylene using a chemical agent

The reaction mechanisms of thermal crosslinking of polyethylene with dicumyl peroxide (DCP) at high temperatures were investigated by electron spin resonance (ESR). The crosslinking reactions were induced by the alkyl radicals formed by the thermal decomposition of DCP above 120°C. The kinetics of the free radical reaction were followed during crosslinking reactions at temperatures between 145 and 180°C. © 1997 John Wiley & Sons, Inc.     

The RATIO method for time‐resolved Laue crystallography

A RATIO method for analysis of intensity changes in time‐resolved pump–probe Laue diffraction experiments is described. The method eliminates the need for scaling the data with a wavelength curve representing the spectral distribution of the source and removes the effect of possible anisotropic absorption. It does not require relative scaling of series of frames and removes errors due to all but very short term fluctuations in the synchrotron beam.     

Time Invariance as an Additional Constraint on Nonlocal Realism

We assume that time invariance of physical laws is true. We assume that one source of 2N uncorrelated spin-carrying particles emits them in a state, which can be described as a multipartite pure uncorrelated state (+∞>N≥1). We assume that each of them is a spin-1/2 pure state lying in the \(\frac{z+x}{\sqrt{2}}\) direction. We assume that the measurement setup is two-orthogonal-settings for each of the observers. We show that 2N-particle pure uncorrelated quantum state violates a time invariant nonlocal realistic theory. 2N implies that we consider Bose-Einstein statistics.     

Terahertz dichroism of MBBA liquid crystal on rubbed substrate

Terahertz (THz) dichroism of a nematic liquid N-(p-methoxybenzylidene)-p-butylaniline (MBBA) was measured using a GaP Raman THz spectrometer. MBBA on a rubbed plastic substrate generates a band at around 4.0 THz: its liquid crystal phase shows strong dichroism, which well corresponds to that of the IR absorption caused by π(CH) of MBBA molecule reported in the literature. Based on inferences drawn from the present THz and the published IR dichroic results, the 4.0 THz band probably stems from lateral intermolecular or intramolecular interactions of MBBA molecules aligned to the rubbing direction. The results clearly demonstrate that THz spectroscopy is powerful for discussing of phase transition and dichroism of liquid crystals.     

Creating Very True Quantum Algorithms for Quantum Energy Based Computing

An interpretation of quantum mechanics is discussed. It is assumed that quantum is energy. An algorithm by means of the energy interpretation is discussed. An algorithm, based on the energy interpretation, for fast determining a homogeneous linear function f(x) := s.x = s ₁ x ₁ + s ₂ x ₂ + ? + s _N x _N is proposed. Here x = (x ₁, … , x _N ), x _j ∈ R and the coefficients s = (s ₁, … , s _N ), s _j ∈ N. Given the interpolation values \((f(1), f(2),...,f(N))=\vec {y}\), the unknown coefficients \(s = (s_{1}(\vec {y}),\dots , s_{N}(\vec {y}))\) of the linear function shall be determined, simultaneously. The speed of determining the values is shown to outperform the classical case by a factor of N. Our method is based on the generalized Bernstein-Vazirani algorithm to qudit systems. Next, by using M parallel quantum systems, M homogeneous linear functions are determined, simultaneously. The speed of obtaining the set of M homogeneous linear functions is shown to outperform the classical case by a factor of N × M.