Speed Tuning of the Formation/Dissociation of a Metallorotaxane

Switching between the formation/dissociation of rotaxanes is important to control the function of various types of rotaxane-based materials. We have developed a convenient and simple strategy, the so-called “accelerator addition”, to make a static rotaxane dynamic without apparently affecting the chemical structure. As an interlocked molecule that enables tuning of the formation/dissociation speed, a metallorotaxane was quantitatively generated by the complexation of a triptycene-based dumbbell-shaped mononuclear complex, [PdL₂]²⁺ (L=2,3-diaminotriptycene), with 27C9. As a result of the inertness of the Pd²⁺-based coordination structure, the metallorotaxane was slowly formed (the static state). This rotaxane formation was accelerated 27 times simply by adding Br⁻ as an accelerator (the dynamic state). A similar drastic acceleration was also demonstrated during the dissociation process when Cs⁺ was added to the metallorotaxane to form the free axle [PdL₂]²⁺ and the 27C9-Cs⁺ complex.     

Reactions of a 2-picolyl-bridged palladium(ii) complex with some pyrazole derivatives

A 2-picolyl-bridged dinuclear complex, [Pd(2-picolyl)Cl(PPh₃)₂] (I) reacted with alkali metal salts of poly(1-pyrazolyl)borates, Na(BPz₄) (Pz = 1-pyrazolyl), Na(HBPz₃),and K(H₂BPz₂) to afford the complexes, [Pd(2-picolyl)(BPz₄)₂] (II), [Pd(2-picolyl)(HBPz₃)(PPh₃)] (III), and [Pd(2-picolyl)(H₂BPz₂)₂] (V), respectively. Complexes II and V retained the 2-picolyl bridge, whereas III was mononuclear without the bridge. Complex I was treated with hydrated silver perchlorate in the presence of tris(1-pyrazolyl)methane to give [Pd(2-picolyl)(OH₂)(PPh₃)₂](ClO₄)₂ (VI) without incorporating the neutral ligand.     

Crack-Free,Thick Ceramic Coating Films via Non-Repetitive Dip-Coating Using Polyvinylpyrrolidone as Stress-Relaxing Agent

BaTiO₃ and PZT films were prepared from alkoxide-acetate solutions containing polyvinylpyrrolidone (PVP) by non-repetitive dip-coating. It was demonstrated that PVP incorporated in gel films suppresses crack formation during heating and increases the critical thickness, the maximum thickness achievable without crack formation via single-step deposition. Using PVP crack-free BaTiO₃ and PZT films 1.2 and 0.5 m in thickness could be prepared, respectively, via single-step dip-coating. The films were fairly transparent and dense in microstructure. The tensile stress in heat-treated BaTiO₃ films was also demonstrated to decrease significantly by incorporating PVP in gel films.     

Fundamental study of the influence of pixel size on the quality of scintigrams

The effect of pixel size on image quality was investigated. The image quality was examined by abnormality detection and image preference for clinical images displayed with different pixel sizes. Smaller pixel size was found to be superior to large one in image quality using large field of gamma camera (FWHM 6.42 mm), 1.6mm pixel size (a 256 x 256 matrix) was found to be the best in image quality. Examined image minification effect, 3.2 mm pixel size (image size: 5 cm phi) was found to be superior to 1.6 mm pixel size (image size: 10 cm phi) in image preference and to be almost equal to 1.6 pixel size in abnormality detection.     

Efficient algorithm of the transcorrelated method for periodic systems

The transcorrelated (TC) method is one of the promising wave-function-based approaches for the first-principles electronic structure calculations. In this method, the many-body wave function is approximated as the Jastrow-Slater type and one-electron orbitals in the Slater determinant are optimized with a one-body self-consistent-field equation such as that in the Hartree-Fock (HF) method. Although the TC method has yielded good results for both molecules and solids, its computational cost in solid-state calculations, being of order O(N(k)(3)N(b)(3)) with N(k) and N(b) the respective numbers of k-points and bands, has for some years hindered its wide application in condensed matter physics. Although an efficient algorithm was proposed for a Gaussian basis set, that algorithm is not applicable to a plane-wave basis that is suited to and widely used in solid-state calculations. In this paper, we present a new efficient algorithm of the TC method for the plane-wave basis or an arbitrary basis function set expanded in terms of plane waves, with which the computational cost of the TC method scales as O(N(k)(2)N(b) (2)). This is the same as that of the HF method. We applied the TC method with the new algorithm to obtain converged band structure and cell parameters of some semiconductors.     

Projectile fragmentation in hadron collisions

A model is formulated for projectile fragmentation in hadron collisions and is used to study the longitudinal-momentum dependence of the single-particle inclusive cross sections. The inclusive cross section consists of two parts due to the initial decay and many-particle production effects, the latter decreasing more rapidly than the former as the longitudinal momentum increases. The variety in the longitudinal-momentum dependence of the cross sections is explained naturally by the different weights of the two effects for the produced particles.     

Observation of light propagation by holography with a picosecond pulsed laser

We demonstrate the propagation of a light pulse undergoing refraction and total refraction inside a glass block as well as diffraction at a grating. Observation of a frameless, continuous motion picture of the light propagation is possible by recording of hologram with a picosecond pulsed laser. It is shown that the direction of the pulse changes as a result of refraction, the pulse's speed decreases inside a glass block, and the pulse travels a zigzag path by total refraction. The pulse fronts of the diffracted light propagating parallel to the grating surface are also demonstrated.     

Provenance determination of prehistorical pottery from Oshima Island belonging to Izu islands (Tokyo,Japan) using X-ray fluorescence spectrometry

A total of 41 pottery shards originating in the Jomon period (14000–300 BC) and Yayoi period (300 BC–250 AD) were excavated from the Shimotakabora site on Oshima Island of the Izu islands (Tokyo, Japan). X-ray fluorescence spectrometry was used to determine the chemical composition (10 major oxides and 12 minor elements) of the potteries to identify the potteries' provenance, that is, local or nonlocal product. The calibration curves were drawn by synthetic standards prepared from a mixture of chemical reagents containing analytes, which presented good accuracy and reproducibility by analysis of the geochemical references. The pottery samples were classified by multivariate statistics such as principal component analysis and cluster analysis based on their chemical composition. Additionally, the X-ray fluorescence results were compared with geochemical data from Oshima Island using scatter diagrams. The pottery provenance was identified by their classification. This provenance estimation indicates that 37 of the 41 potteries were brought to Oshima island from Japan's main island, Honshu, in the prehistoric age.     

Dynamical and symmetry groups of the SU(2) Kepler problem

It is well known that the MIC–Kepler problem, an extension of the three-dimensional Kepler problems, admits the same dynamical and symmetry groups as the Kepler problem. This paper aims to study dynamical and symmetry groups of the SU(2) Kepler problem, where the SU(2) Kepler problem is defined to be the dynamical system reduced from the eight-dimensional conformal Kepler problem through an SU(2) symmetry and turns out to be an extension of the five-dimensional Kepler problem. It is shown that the SU(2) Kepler problem admits a dynamical group SO^*(8) and that the phase space of the SU(2) Kepler problem is symplectomorphic with a co-adjoint orbit of SO^*(8), on which the Kirillov–Kostant–Souriau form is defined. It is further shown that the subgroups, SU(4), SU^*(4), and Sp(2)×_SR⁵, of SO^*(8) provide the symmetry groups, SU(4)/Z₂SO(6), SU^*(4)/Z₂SO₀(1,5), and (Sp(2)×_SR⁵)/Z₂SO(5)×_SR⁵, of the SU(2) Kepler problem with negative, positive, and zero energies, respectively, where ×_S denotes a semi-direct product. Furthermore, constants of motion for the SU(2) Kepler problem are found together with their Poisson brackets. The symmetry Lie algebra formed by constants of motion is shown to be isomorphic with so(6)su(4), so(1,5)su^*(4), or so(5)_SR⁵sp(2)_SR⁵, depending on whether the energy is negative, positive, or zero, where _S denotes a semi-direct sum. These Lie algebras are subalgebras of so^*(8)so(2,6).     

New primitive whose degree is a Mersenne exponent

All primitive trinomials over with degree 859433 (which is the 33rd Mersenne exponent) are presented. They are and its reciprocal. Also two examples of primitive pentanomials over with degree 86243 (which is the 28th Mersenne exponent) are presented. The sieve used is briefly described.