Structure and dynamics of highly charged heavy ions studied with the electron beam ion trap in Tokyo

In this paper, we present the structure and the dynamics of highly charged heavy ions studied through dielectronic recombination (DR) observations performed with the Tokyo electron beam ion trap. By measuring the energy dependence of the ion abundance ratio in the trap at equilibrium, we have observed DR processes for open shell systems very clearly. Remarkable relativistic effects due to the generalized Breit interaction have been clearly shown in DR for highly charged heavy ions. We also present the first result for the coincidence measurement of two photons emitted from a single DR event.     

Development of a simple vent-free interface for capillary gas chromatography-mass spectrometry

A novel and simple interface for capillary gas chromatography-mass spectrometry (GC-MS) was developed using a piece of deactivated stainless-steel tubing. This interface eliminated the need to vent the MS ion source when changing columns. Various chromatographic performance indicators, such as inertness, and thermal and chemical stability, were confirmed to be unaffected by using this interface at an elevated temperature of around 300°C. The new interface should facilitate the characterization of polymeric materials using analytical pyrolysis techniques in which frequent switching is required in the measuring mode, such as evolved gas analysis-MS and flash pyrolysis-GC-MS.     

Flexibility Control of Two-Dimensional Coordination Polymers by Crystal Morphology: Water Adsorption and Thermal Expansion

Layer flexibility in two-dimensional coordination polymers (2D-CPs) contributes to several functional materials as it results in anisotropic structural response to external stimuli. Chemical modification is a common technique for modifying layer structures. This study demonstrates that crystal morphology of a cyanide-bridged 2D-CP of type [Mn(salen)]₂[ReN(CN)₄] ( 1 ) consisting of flexible undulating layers significantly impacts the layer configuration and assembly. Nanoplates of 1 showed an in-plane contraction of layers with a longer interlayer distance compared to the micrometer-sized rod-type particles. These effects by crystal morphology on the structure of the 2D-CP impacted the structural flexibility, resulting in dual-functional changes: the enhancement of the sensitivity of structural transformation to water adsorption and modification of anisotropic thermal expansion of 1 . Moreover, the nanoplates incorporated new adsorption sites within the layers, resulting in the uptake of an additional water molecule compared to the micrometer-sized rods.     

Development of new pyrolysis–GC/MS system incorporated with on-line micro-ultraviolet irradiation for rapid evaluation of photo, thermal, and oxidative degradation of polymers

A new pyrolysis–GC/MS system incorporating with on-line micro-ultraviolet (UV) irradiation was developed to make rapid evaluation of the synergistic material deterioration during UV irradiation under thermal and oxidative atmospheres. The basic effectiveness of the system was demonstrated by polystyrene, polypropylene and polycarbonate as the test samples. The volatile products evolved during deterioration of the polymers were analyzed on-line by thermal desorption GC/MS, and then the residual degraded polymers were analyzed by evolved gas analysis (EGA) and/or Py–GC/MS to obtain specific thermograms and pyrograms. Based on these results, the deterioration mechanism of the polymeric materials during irradiation under thermal and oxidative atmosphere can be evaluated using a sub-milligram polymer sample within a relatively short period of time.     

DWBA analysis of (3He,d) reactions at 90MeV and contributions from the nuclear interior

Differential cross sections of ³He elastic scatterings and (³He, d) reactions have been measured at 90 MeV for ²⁸Si, ⁵⁴Fe, ⁵⁸Ni, ⁹⁰Zr and ¹²⁴Sn. From the optical-model analysis of the elastic scattering, both shallow ($\text{V ? 105}\text{MeV}$) and deep ($\text{V ? 150}\text{MeV}$) potentials of ³He were obtained. The shallow potentials correspond to the ones which were determined uniquely from other measurements extended to more backward angles. The (³He, d) reactions have been analyzed with the DWBA using the shallow and deep potentials for ³He. The calculations using the deep potentials reproduced the data well, but those using the shallow ones did not. The contributions from the nuclear interior were investigated through the radial cutoff in the DWBA. The calculations using the shallow potentials reproduced the data well when the radial cutoffs were introduced. The effects of the radial cutoff were very small when the deep potentials were used. It was found that a much greater reduction of the contributions from the nuclear interior was needed when the shallow potentials were used in the DWBA calculations.     

Discovery of new orally active phosphodiesterase (PDE4) inhibitors

A series of 4-anilinopyrazolopyridine derivatives were synthesized and biologically evaluated as inhibitors of phosphodiesterase (PDE4). Chemical modification of 3, a structurally new chemical lead that was found in our in-house library, was focused on 1- and 3-substituents. Full details of the discovery of a new orally active chemical lead 5 are presented. Structure-activity relationship data, pharmacological evaluation, and the subtype selectivity study are also presented.     

Triplet correlation and pair potential functions in liquid neon and sodium

Recent neutron diffraction data for liquid neon and X-ray diffraction data for liquid sodium have been analyzed with the purpose of studying the triplet correlation function in these liquids by means of the method suggested by Egelstaff, Page and Heard. In both cases, it was found that the function H(Q) which expresses the deviation from the superposition approximation indicates the deviation from zero and the effect of the pressure derivative of the structure factor to the function H(Q) is little. Besides, the pair potentials have been investigated from these diffraction data at various pressures using the Born-Green equation. The pair potential functions obtained for three states of liquid neon are the Lennard-Jones type, whereas those obtained for liquid sodium with a provisional assumption based on the experimental data are of the long-range oscillatory type. The pair potentials obtained in this work are useful for the interpretation on the difference in the pressure dependence of the structure factor for liquid neon and sodium.     

Transfer-printing of highly aligned DNA nanowires

We developed a simple method of reproducibly creating highly aligned DNA nanowires without any surface modifications or special equipment. Stretched DNA molecules initially present on the PDMS sheet were transferred onto another surface using transfer-printing (TP). Fluorescent microscopic and atomic force microscopic images revealed that many DNA molecules were highly aligned on surfaces after TP. Furthermore, it was also possible to realize the two-dimensional assembly of DNA nanowires by repeating TP.     

Novel wedge-shaped doubly inclined chamber for the flow-through separation of suspended particles

Combined standing and propagating wave modes have previously been successfully used by the authors for simultaneous agglomeration and transportation of small particles suspended in still water. The present study of this method with flowing water, using a 120 x 350 x 13 mm3 agglomerator, confirmed that the proposed method is applicable with suspended SiO2 particles of varying size. The process was found to be most efficient at flow rates below a certain threshold, which varies with particle size. This threshold was found to be 5 ml/s for a particle size of 7.9 microns at an ultrasonic frequency of 2 MHz corresponding to 0.74 mm wavelength. The existence of a maximum particle transport velocity was demonstrated.     

High-pressure minerals in shocked L6-chondrites: constraints on impact conditions

We have studied the high-pressure phases observed in Yamato 791384 and ALH78003 L6-chondrites. Host meteorite consists mainly of olivine, pyroxenes, and plagioclase glass. Mineral fragments observed in the veins and the vein margin region of these meteorites were partially or totally transformed into high-pressure phases wadsleyite, ringwoodite, majorite, akimotoite, NaAlSi₃O₈ hollandite and jadeite. Whereas matrix of the shock vein contains majorite-pyrope solid solution in both meteorites. The spatial distribution indicates that high-pressure phases are present in the shock veins and host rocks adjacent to the shock veins. Investigation of the high-pressure phases revealed that, in Y791384, fragments and adjacent matrix were subjected to pressures around 18–23 GPa and the vein experienced temperatures around 2,000–2,300°C during the shock event. ALH78003 experienced the shock pressure of about 15–18 GPa at 2,000°C. Ringwoodite lamellae were observed in the host olivine adjacent to the vein in Y791384. Kinetic investigation for ringwoodite lamellar growth in olivine indicates that the meteorite experienced an impact with a pressure around 20 GPa for more than 4 s of the pressure pulse indicating a large impactor with the size greater than 10 km. ALH78003 contains wadsleyite–ringwoodite aggregates in the shock veins. The ringwoodite grains have wadsleyite rim enriched in Mg₂SiO₄ component. The compositional profiles of wadsleyite rim and ringwoodite core of the fragments in the shock veins in ALH78003 cannot be explained by a simple Mg–Fe inter-diffusion process.This paper was based on the work that was presented at the 2nd International Symposium on Interdisciplinary Shock Wave Research, Sendai, Japan, March 1–2, 2005.