Observation of High-j Two-Quasiparticle Bands in Odd-Odd ^174Re

High spin states in ^174Re have been investigated via the ^152Sm （^27 Al, 5nγ） ^174Re reaction. Gamma-ray excitation functions, x-γ and γ-γ coincidences have been measured. Two rotational bands built on the πh9/2 × vi13/2 and πh11/2 × vi13/2 configurations have been identified and extended up to high-spin states. The relative spin and parity of the band levels have been unambiguously fixed due to observations of several inter-band transitions. Both the bands show the low-spin signature inversion, which is consistent with systematic expectations for the high-j two-quasiparticle bands in the A = 170 mass region.     

Nanogel‐Templated Mineralization: Polymer‐Calcium Phosphate Hybrid Nanomaterials

Summary: We report novel organic‐inorganic hybrid nanomaterials that consist of polymer hydrogel nanoparticles (nanogels) and calcium phosphate. Hybrid nanoparticles that measure ca. 40 nm are synthesized from a dilute solution of hydroxyapatite using nanogels as templates for calcium phosphate mineralization. These nanoparticles show a narrow size distribution and high colloidal stability. Nanogel‐adsorbed liposomes act as templates for hierarchical hybrid nanostructures. These nanohybrids can potentially be used as biocompatible drug carriers with controlled‐release properties.

TEM images of calcium phosphate nanoparticles formed in the presence of CHP nanogels (0.5 mg · mL⁻¹) (left) and nanogel‐liposomes (CHP 0.05 mg · mL⁻¹, DPPC 0.08 mg · mL⁻¹)(right).     

Lithium potassium borate and lithium rubidium borate: new non‐linear optical crystals

The title compounds, LiKB₄O₇ and LiRbB₄O₇, are newly developed non‐linear optical crystals containing two kinds of anionic groups, namely (B₃O₈)^7? and (B₅O₁₀)^5?. The (B₃O₈)^7? groups form infinite spiral chains parallel to the [100] direction, which are interconnected by sharing O atoms with (B₅O₁₀)^5? groups.     

Distance dependence of noncontact-AFM image contrast on Si(111) × –Ag structure

Atomic resolution imaging of the Si(111) × R30°–Ag surface was investigated using a noncontact atomic force microscopy (NC-AFM) in ultrahigh vacuum. NC-AFM images showed three types of contrasts depending on the distance between an AFM tip and a sample surface. When the tip–sample distance was about 1–3 Å, the images showed the honeycomb arrangement with weak contrast. When the tip–sample distance was about 0–0.5 Å, the images showed the periodic structure composed of three bright spots with relatively strong contrast. On the other hand, the contrasts of images measured at the distance of 0.5–1 Å seemed to be composed of the above-mentioned two types of contrasts. By comparing the site of bright spots in the AFM images with honeycomb-chained trimer (HCT) model, we suggested the following models: when the tip is far from the sample surface, tip–sample interaction force contributing to imaging is dominated by physical bonding interaction such as Coulomb force and/or van der Waals (vdW) force between the tip apex Si atoms and Ag trimer on the sample surface. On the other hand, just before the contact, tip–sample interaction force contributing to imaging is dominated by chemical bonding such as the force due to hybridization between the dangling bond out of the tip apex Si atom and the orbit of Si–Ag covalent bond on the sample surface.     

Planar array of 1D gold nanoparticles on ridge-and-valley structured carbon

For fabrication of a planar array of 1D chains of gold nanoparticles prepared by a chemical process, the faceted (110) planes of sodium chloride crystals were used as templates to produce nanoscale ridge-and-valley structured carbon layers by a vacuum process. When these carbon layers loaded on copper grids were dipped in toluene solution of 3.4 nm gold nanoparticles followed by natural dry, a planar array of 1D chains of gold nanoparticles were formed on carbon layers, where the nanoparticles were immobilized predominantly in valleys and partly on ridges of carbon layers.     

Rotational alignment of the h11/2 band in 157Dy

High-spin states of ¹⁵⁷Dy were investigated using in-beam γ-ray spectroscopy techniques with a ¹⁵⁰Nd(¹²C, 5n) reaction. Three rotational bands with the h _9/2, i _13/2 and h _11/2 configurations were observed up to (43/2^-), 53/2⁺ and 45/2^-, respectively. Interband M1 transitions in the h _11/2 (high-Ω) band were also measured up to the highest-spin state. The high-spin states were well reproduced by calculations using the tilted-axis-cranking model (TAC). The B(M1)/B(E2) ratio, Routhian and the tilted angle of the angular-momentum vector are found to be in good agreement with the result of the TAC calculation. Received: 22 August 2002 / Accepted: 26 September 2002 / Published online: 19 November 2002 RID="a" ID="a"e-mail: hayakawa@jball4.tokai.jaeri.go.jp Communicated by W. Henning