High-speed wavelength-division multiplexing quantum key distribution system

A high-speed quantum key distribution system was developed with the wavelength-division multiplexing (WDM) technique and dedicated key distillation hardware engines. Two interferometers for encoding and decoding are shared over eight wavelengths to reduce the system's size, cost, and control complexity. The key distillation engines can process a huge amount of data from the WDM channels by using a 1 Mbit block in real time. We demonstrated a three-channel WDM system that simultaneously uses avalanche photodiodes and superconducting single-photon detectors. We achieved 12 h continuous key generation with a secure key rate of 208 kilobits per second through a 45 km field fiber with 14.5 dB loss.     

Application of mixture analysis to crude materials from natural resources (III): NMR spectral studies to analyze chalcones from Angelica keiskei

This study presents the application of the NMR-based analyses, DOSY and ROSY, to the chalcones, xanthoangelol (1) and 4-hydroxyderricin (2) from Angelica keiskei. We investigated whether virtual separation and structural information from each compound can be obtained. DOSY displays spectra of (1) and (2) in one dimension and diffusion spectra in the other. And the 1H slice spectra were analyzed in detail by comparison with authentic samples previously isolated from the same material. The resulting ROSY spectrum clearly showed two distinct peaks in the 1H T1 dimension. Each slice of the ROSY spectrum along the 13C dimension contains over-lapped signals, which are difficult to assign at this time.     

Requirements for soft magnetic underlayer (SUL)—Micromagnetic simulations of single-pole-type write heads and SUL systems

Landau-Lifshitz-Gilbert micromagnetic models were used to analyze the head field distributions and high-frequency responses for various soft magnetic underlayer thicknesses (t-SUL) and saturation magnetization flux densities (B_s) of single-pole-type (SPT) head-SUL systems. It was found that B_s of 10-12 kG and t-SUL of 30-45 nm would be sufficient for the examined head and perhaps for most next generation head-SUL systems. Antiferromagnetic coupling in the SUL affects the head and SUL magnetization and, eventually, the head field. With regard to the head magnetization response, it was found that the magnetization under the coil responded first, while the response at the main pole tip was quite slow, even compared with the head field. The main pole tip of the head was fully saturated and the main pole yoke was almost saturated, while the SUL was not saturated in the examined head-SUL system.     

New cholestane glycosides from the leaves of Cordyline terminalis

Four new cholestane glycosides (1-4) were isolated from the leaves of Cordyline terminalis (Agavaceae). The structures of the new compounds were determined on the basis of spectroscopic analysis and a few chemical transformations followed by chromatographic and spectroscopic analyses.     

High-pressure synthesis, crystal structure, and electromagnetic properties of CdRh2O4: an analogous oxide of the postspinel mineral MgAl2O4

The postspinel mineral MgAl(2)O(4) exists only under the severe pressure conditions in the subducted oceanic lithosphere in the Earth's deep interior. Here we report that its analogous oxide CdRh(2)O(4) exhibits a structural transition to a quenchable postspinel phase under a high pressure of 6 GPa at 1400 °C, which is within the general pressure range of a conventional single-stage multianvil system. In addition, the complex magnetic contributions to the lattice and metal nonstoichiometry that often complicate investigations of other analogues of MgAl(2)O(4) are absent in CdRh(2)O(4). X-ray crystallography revealed that this postspinel phase has an orthorhombic CaFe(2)O(4) structure, thus making it a practical analogue for investigations into the geophysical role of postspinel MgAl(2)O(4). Replacement of Mg(2+) with Cd(2+) appears to be effective in lowering the pressure required for transition, as was suggested for CdGeO(3). In addition, Rh(3+) could also contribute to this reduction, as many analogous Rh oxides of aluminous and silicic minerals have been quenched from lower-pressure conditions.     

Lp-Lq Estimate of the Stokes Operator and Navier–Stokes Flows in the Exterior of a Rotating Obstacle

We consider the motion of a viscous fluid filling the whole three-dimensional space exterior to a rotating obstacle with constant angular velocity. We develop the L _p -L _q estimates and the similar estimates in the Lorentz spaces of the Stokes semigroup with rotation effect. We next apply them to the Navier–Stokes equation to prove the global existence of a unique solution which goes to a stationary flow as t → ∞ with some definite rates when both the stationary flow and the initial disturbance are sufficiently small in L _3,∞ (weak-L ₃ space).     

Extracorporeal cardiac shock wave therapy for ischemic heart disease

Prognosis of severe ischemic heart disease with no indication of percutaneous coronary intervention or coronary artery bypass grafting still remains poor. Extracorporeal shock wave therapy was introduced for medical therapy more than 20 years ago to break up kidney stones. We have demonstrated that extracorporeal cardiac shock wave therapy at a low level of ~10% of energy density that used for urinary lithotripsy treatment, effectively induces coronary angiogenesis and improves myocardial ischemia in a porcine model of chronic myocardial ischemia in vivo. On the basis of the promising results in animal studies, we have recently developed a new, non-invasive angiogenic therapy with low-energy shock waves for ischemic heart disease. Our extracorporeal cardiac shock wave therapy improved symptoms and myocardial ischemia in patients with severe coronary artery disease. These beneficial effects of the shock wave therapy persisted for at least 12 months. Importantly, no procedural complications or adverse effects were noted. These results indicate that our extracorporeal cardiac shock wave therapy is an effective and non-invasive treatment for ischemic heart disease. To further confirm the usefulness and safety of our SW therapy, we are currently conducting the second clinical trial in a randomized and placebo-controlled manner.      

An analytical solution to non-axisymmetric heat transfer with viscous dissipation for non-Newtonian fluids in laminar forced flow

Forced convection heat transfer in a non-Newtonian fluid flow inside a pipe whose external surface is subjected to non-axisymmetric heat loads is investigated analytically. Fully developed laminar velocity distributions obtained by a power-law fluid rheology model are used, and viscous dissipation is taken into account. The effect of axial heat conduction is considered negligible. The physical properties are assumed to be constant. We consider that the smooth change in the velocity distribution inside the pipe is piecewise constant. The theoretical analysis of the heat transfer is performed by using an integral transform technique – Vodicka’s method. An important feature of this approach is that it permits an arbitrary distribution of the surrounding medium temperature and an arbitrary velocity distribution of the fluid. This technique is verified by a comparison with the existing results. The effects of the Brinkman number and rheological properties on the distribution of the local Nusselt number are shown.     

Asymmetric borane reduction of ketones promoted by menthopyrazole‐zncl2 complex

The enantioselective reduction of ketones was accomplished by borane in the presence of pyrazole derivatives, particularly 2‐methoxymethyl‐3‐phenyl‐1‐menthopyrazole (8). The catalysis of zinc chloride makes it possible to lower the reaction temperature below 0 °C, and to promote enantioselectivity.     

ESR study of Mn2+ in GeTe and GeTeSi glasses

The electron spin resonance spectra of Mn²⁺ ions have been studied in Ge_xTe_100?x with x = 15, 17.5 and 20, and Ge_20?xTe₈₀Si_x with 0 ?x? 20. All samples are found to exhibit six hyperfine lines centered at g = 4.3 with hyperfine interaction constant A = 56 × 10^?4cm^?1. The g = 4.3 line is interpreted as being caused by Mn²⁺ ions incorporated in the amorphous network and surrounded by four Te atoms in an arrangement of orthorhombic symmetry. Some of the samples of GeTe show a g = 2.0 line. This line also appears after heat treatment in air at temperatures above the glass transition temperature. It is concluded that the g = 2.0 line is caused by Mn²⁺ ions in phase separated microcrystalline or concentrated regions of MnO in the glass.