Anomalous H/D isotope effect on 35Cl NQR frequencies in piperidinium p-chlorobenzoate

Anomalous isotope effects were detected in the ³⁵Cl nuclear quadrupole resonance (NQR) frequency of piperidinium p-chlrobenzoate (C₅H₁₀NH· ClC₆H₄COOH) by deuteration of hydrogen atoms. The atoms were determined to form two kinds of N–H···O type H-bonds in the crystal structure. Large frequency shifts of the ³⁵Cl resonance lines reaching 288 kHz at 77 K and 278 kHz at room temperature were caused upon deuteration, in spite of the fact that the Cl atoms in the molecule do not form hydrogen bonds in the crystal. Results of single crystal X-ray diffraction measurements and density-functional-theorem calculations suggest that a dihedral-angle change of 1.8° between benzene and the piperidine ring contributes to ³⁵Cl NQR anomalous frequency shifts.     

Basic to industrial research on neutron platform in Japan

The co-location of reactor- and accelerator-based neutron sources offers a great opportunity for complementary use of steady and pulsed neutron beams in a wide variety of neutron science and technology areas ranging from basic research to industrial applications. In Japan, such a balance of two kinds of neutron sources has a long tradition and now we are entering into a new era with the commissioning of the world’s most intense pulsed neutron beams at JSNS/J-PARC plus the existing JRR-3 reactor both co-located within 1 km of each other in Tokai. The joint operation of these neutron facilities in close proximity under a program called ‘neutron platform’, will allow neutron beam access not only to professional users, familiar with both pulsed and steady state techniques but also to first-time academics and industrial researchers to neutron scattering.      

Static optical cross phase modulation in active multimode interference couplers

The static performance of active multimode interference (MMI) couplers is analyzed in the presence of two different optical signals using a beam propagation method (BPM)-based simulation. To examine the feasibility of a novel all-optical switch based on active MMI; the simulation is mainly used to evaluate the amount of phase change resulting in the output of one optical signal by varying the intensity of the other at different injected carrier density. The simulation code is based on the finite difference (FD)-BPM and is including the distribution of photon density, carrier density, and refractive index.     

Theory of resonant photoemission in black phosphorus

Resonant photoemission in black phosphorus is studied theoretically with a model of simplified energy bands. It is shown that a core exciton state plays an essentially important role both in the resonant enhancement of the photoemission peak at the binding energy 10.8eV and the Fano type interference at 2.7eV, which have recently been observed experimentally.     

Antireflection microstructures fabricated upon fluorine-doped SiO(2) films

Two-dimensional periodic structures were fabricated upon a fluorine-doped SiO(2) film in which the fluorine content changed gradually in the direction of film thickness. The films were deposited by plasma-enhanced chemical-vapor deposition. The film was periodically patterned into a 1-mum period and an ~1-mum -groove depth by inductive coupled plasma reactive-ion etching followed by chemical etching in a diluted HF solution. A surface reflectance of 0.7% was attained at 1.85-mum wavelength, a value that is one fifth as large as the 3.5% Fresnel reflection of a SiO(2) substrate with a flat surface.     

Magnetic behavior of tetrakis[4-(N-tert-butyl-N-oxylamino)pyridine]bis(isocyanato-N)cobalt(II) in frozen solution

A complex of cobalt(II)(OCN)(2) coordinated with four pyridines having a stable tert-butyl aminoxyl exhibited in frozen MTHF a slow magnetic relaxation for the reorientation of magnetization with activation barrier, Delta/k(B) = 50 K, and a hysteresis loop having a fast relaxation at 0 Oe below 2.5 K.