A water-soluble carbon nanotube network conjugated by nanoparticles with defined nanometre gaps

Cage-shaped proteins with an affinity for carbonaceous materials were constructed and used to assemble a nanostructure in which single-walled carbon nanotubes are surrounded by cobalt oxide nanoparticles with nanometre gaps. By changing the size of proteins and materials incorporated inside the cavity, similar structures with distinctively different properties can be fabricated.     

139La and63Cu-NQR of high-T c oxide superconductors

Nuclear quadrupole resonances (NQR) of¹³⁹La in La_2−xM_xCuO₄ (M=Ba, Sr) and⁶³Cu in YBa₂CU₃O₇ have been investigated with substitution of Cu by magnetic impurities. For La-system, the strong enhancement of the nuclear relaxation rate, 1/T ₁ atT _c ^*≈10 K (suggesting the occurrence of magnetic instability with hole-doping), is suppressed by 3D-antiferromagnetism induced by magnetic impurities. In the superconducting region, fluctuations of Cu moments at low temperatures remain extremely fast as at high temperatures. For Y-system, Fe-ions are substituted for both Cu(1) and Cu(2) sites, But Co-ions are preferentially substituted to Cu1 sites. The peaks in the relaxation rate of Cu indicate the appearance of magnetic ordering without destroying superconductivity for the 0.5%-Fe doped sample.     

Site selection NMR study on electronic state in and near vortex core of YBa2Cu4O8

We report a site-selective ¹⁷O spin-lattice relaxation rate T₁⁻¹ in the vortex state of YBa₂Cu₄O₈. We found that T₁⁻¹ at the planar sites exhibits an unusual nonmonotonic NMR frequency dependence. Based on T₁⁻¹ in the vortex core region, we establish strong evidence that the local density of states within the vortex core is strongly reduced.     

NMR study of the self-induced vortex in (Ce1−xGdx)Ru2

NMR measurement of ¹⁵⁷Gd has been performed in zero external field in (Ce_1?xGd_x)Ru₂ for x = 0.100and 0.119 at low temperature down to 25 mK. Zero field NMR is observed with large enhancements both of H₁ and the intensity of the signal that are characteristic in ferromagnet. T₁T increases rapidly with decreasing temperature, which is attributed to the appearance of the superconducting energy gap whose magnitude is estimated to be 0.066kT_Cforx = 0.100. The NMR intensity in the superconducting state decreases not so drastically as expected in the perfect Meissner state. These results are qualitatively the same as reported previously for x ≥ 0.105 and T ≥ 60 mK. The results suggest that the system is in the state of self-induced vortices predicted theoretically.     

Liquid Drops on an Inclined Plane: The Relation between Contact Angles, Drop Shape, and Retentive Force

Contact angle hysteresis, drop shape, and drop retention were studied with a tiltable plane. Contact liquids were water and ethylene glycol. Four polymers and silicon wafers were used as substrates. When the plane was inclined, the shape of drops distorted, exhibiting advancing and receding contact angles. Drops remained stationary until a critical angle of tilt was exceeded, and then they began to move. The difference in the advancing and receding contact angles, or contact angle hysteresis, ranged from 9° to 66°, depending on the liquid and the substrate. Roughness did not seem to influence the hysteresis as much as the chemical nature of the surfaces. Elongation and back-to-front asymmetry were greater on surfaces with high hysteresis. We found a linear correlation between the aspect ratio of drops and their contact angle hysteresis. Also, the retentive force increased with elongation of the drops.     

Hydrogen-bonding abilities for phenols assessed by quantitative analyses of their partition coefficients derived from different partitioning systems

We recently proposed a new hydrogen-accepting scale, S(HA), on the basis of the heat of formation calculated by the conductor-like screening model (COSMO) method. In this work, the same approach was applied to a series of compounds with a common hydrogen-donor group. Thus the S(HA) values for monosubstituted phenols were calculated and used for correlating their log P(oct) values (P(oct): 1-octanol/water partition coefficient) with log P(CL) (P(CL): chloroform/water partition coefficient) and log P(E) (P(E): butyl ether/water partition coefficient). It was demonstrated that the S(HA) parameter works effectively, providing excellent correlations whose physicochemical meanings are well rationalized in terms of hydrogen-bonding characteristics of the substituents.     

Reversible ferromagnetic-antiferromagnetic transformation upon dehydration-hydration of the nanoporous coordination framework, [Co3(OH)2(C4O4)2].3H2O

Reversible crystal-to-crystal transformation accompanied by change from ferromagnetic to antiferromagnetic ground states at 8 K upon dehydration-rehydration of the nanoporous coordination framework [CoII3(OH)2(C4O4)2].3H2O.     

Microstructure control of low-resistivity tin-doped indium oxide films grown by photoreaction of nanoparticles using a KrF excimer laser at room temperature

A tin-doped indium oxide (ITO) film on a SiO₂ substrate was prepared by photo-irradiation of spin-coated nanoparticles using a Xe excimer lamp and a KrF excimer laser. The effects of the excimer lamp and the excimer laser on the resistivity, mobility, and carrier concentration of the film were investigated. To better understand how to control the microstructure of the film, we investigated the effect of thickness on the resistivity of a film prepared by the two-step process, and found that the resistivity was higher in a thicker film. Using two-step irradiation plus one-step KrF irradiation in N₂ at room temperature, we produced an ITO film with lowest resistivity of any in this study. The electrical resistivity of this film was 5.94×10⁻⁴ Ω cm. On the other hand, when using a simple thermal process, the resistivity of a film sintered at 500°C in N₂ was 4.10×10⁻³ Ω cm. The differences in resistivity are discussed on the basis of the microstructure of the films using atomic force microscopy and Hall measurements.