10-Gbit/s Serial Optical Interconnection for an ATM Switch

Serial optical interconnection is proposed for connections in a Torus asynchronous transfer mode switch. A cross-point switch was developed that operates at a bit rate of 20 Gbit/s. The switching operation was successfully performed using cascaded cross-point switches through an optical interconnection configuration consisting of commercial optoelectronics devices. The measured switching rate was 10 Gbit/s, and it was limited by the responses of the optoelectronics devices.     

Stochastic Komatu–Loewner evolutions and BMD domain constant

For Komatu–Loewner equation on a standard slit domain, we randomize the Jordan arc in a manner similar to that of Schramm (2000) to find the SDEs satisfied by the induced motion $\xi \left(t\right)$ on $?\mathbb{H}$ and the slit motion $\mathbf{s}\left(t\right)$. The diffusion coefficient $\alpha$ and drift coefficient $b$ of such SDEs are homogeneous functions.Next with solutions of such SDEs, we study the corresponding stochastic Komatu–Loewner evolution, denoted as ${\mathrm{SKLE}}_{\alpha ,b}$. We introduce a function $b_{\mathrm{BMD}}$ measuring the discrepancy of a standard slit domain from $\mathbb{H}$ relative to BMD. We show that ${\mathrm{SKLE}}_{\sqrt{6},?b_{\mathrm{BMD}}}$ enjoys a locality property.     

Crystallized state,thickening process,and crystal transformation of single crystal of trans-1,4-polybutadiene

The effect of heat treatment of trans-1,4-polybutadiene single crystals prepared from dilute benzene solution was studied by dilatometry, X-ray diffraction, and dynamic viscoelastic measurement. The crystal transformation temperature of the single crystal is 55.5[ddot]C, 20[ddot]C lower than that of the bulk crystallized sample. After heat treatment of the single crystal above 55.5[ddot]C, their crystal transformation temperature increases to 69.5[ddot]C. At the same time, thickening of the lamellae suddenly occurs and the viscoelastic primary absorption observed in the single crystal mat disappears. It is suggested that this means that the amorphous region attached to the single crystal rapidly crystallized above this temperature, in particular the loose loops attached to the end surface of the crystal are dragged into the crystalline phase to form tight loops as a result of the sliding diffusion of molecules along their axes. This is accompanied by the sudden thickening of the lamellae at the crystal transformation temperature. These observations confirmed more thoroughly our previous prediction that the single crystal of trans-1, 4-polybutadiene, as formed, contains loose loops. The thickening phenomena and the change in the crystal transformation temperature of the trans-1,4-polybutadiene single crystal by heat treatment are also discussed from the thermodynamic viewpoint.     

Production of hyperpolarized nuclei for MRI

The project in producing the hyperpolarized ³He and ¹⁹F are addressed in pursuit of radiation free medical diagnosis. The program for production of the hyperpolarized ³He by the brute force method with the Pomeranchuk cooling and the rapid melting of the solid 3He started a few years ago, and is still on the way, while a new program for production of the hyperpolarized ¹⁹F by means of the PHIP (ParaHydrogen Induced Polarization) has just got started. Particular attention is placed upon a new idea of the hyperpolarization catalyst to be used for ¹⁹F.     

Strain‐Promoted Double Azide Addition to Octadehydrodibenzo[12]annulene Derivatives

Octadehydrodibenzo[12]annulenes (DBAs), readily available by the oxidative acetylenic coupling of 1,2‐diethynylbenzene derivatives, were reacted with organic azides. As compared to the well‐known strain‐promoted azide‐alkyne cycloaddition (SpAAC) of 5,6,11,12‐tetradehydrodibenzo[a,e][8]annulene, the reactivity of the DBA alkynes was lower due to the lower strain energy. However, the regioselective double azide addition occurred without any side reactions under mild conditions, yielding bis‐triazole products. The structures of the products were confirmed by an X‐ray crystal structure analysis, and the reaction mechanism was studied by ¹H‐NMR spectroscopy and computational studies. It was also found that the DBAs were hardly fluorescent, while the bis‐triazole products showed a green fluorescence with quantum yields up to 5.1 %. Finally, the new strain‐promoted double azide addition to the DBAs was used for step‐growth polymerization, successfully producing a high molecular weight triazole polymer.     

A versatile scaffold for facile synthesis of fluorescent cyano-substituted stilbenes

Here we report the facile derivatization of a cyano-substituted stilbene into higher π-extended analogues. The cyano-substituted stilbene, which serves as a synthetic scaffold, has a bromo group and a formyl group on its 4- and 4′-position of the phenylene rings and thus readily undergoes selective transformation into other functional groups using various simple organic reactions. The resultant π-conjugated molecules that contain a cyano-substituted stilbene skeleton exhibit fluorescence in solution and in the solid state.     

Colorimetric detection of spermine and spermidine by zincon in aqueous solution

The anionic organic dye, zincon, was found to be a colorimetric probe for spermine and spermidine at pH 4.0 in pure aqueous solution through its aggregation by electrostatic interactions with them. The addition of spermine and spermidine led to bathochromic shifts with color changes from yellow to purple and dark brown, respectively, while other amines and basic amino acids induced no or minimal spectral and color changes. From Job’s plot and titration experiments, zincon interacted with spermine (+4 charges) and spermidine (+3 charges) in 4:1 and 3:1 stoichiometric ratios, respectively, indicating that each positive charge was bound to one zincon molecule. The detection limits were determined to be 25.1 for spermine and 30.7 nM for spermidine, which were sufficient below the critical concentration for cancer diagnosis. The results indicated that zincon can be a good candidate for simple, convenient colorimetric detection of spermine and spermidine in aqueous solution.     

Joint temporal density measurements for two-photon state characterization

We demonstrate a technique for characterizing two-photon quantum states based on joint temporal correlation measurements using time-resolved single-photon detection by femtosecond up-conversion. We measure for the first time the joint temporal density of a two-photon entangled state, showing clearly the time anticorrelation of the coincident-frequency entangled photon pair generated by ultrafast spontaneous parametric down-conversion under extended phase-matching conditions. The new technique enables us to manipulate the frequency entanglement by varying the down-conversion pump bandwidth to produce a nearly unentangled two-photon state that is expected to yield a heralded single-photon state with a purity of 0.88. The time-domain correlation technique complements existing frequency-domain measurement methods for a more complete characterization of photonic entanglement.     

Color superconducting matter in a magnetic field

We investigate the effect of a magnetic field on cold dense quark matter using an effective model with four-Fermi interactions. We find that the gap parameters representing the predominant pairing between the different quark flavors show oscillatory behavior as a function of the magnetic field. We point out that due to electric and color neutrality constraints the magnetic fields as strong as presumably existing inside magnetars might induce significant deviations from the gap structure at a zero magnetic field.