Band crossing in 162Dy: Characterisation of negative-parity yrast and yrare sequences

The crossing of an octupole band by a rotation-aligned two-quasiparticle band has been observed in detail in ¹⁶²Dy. Both the yrast and yrare states are identified from the band heads (I =2 and I = 5) to high spin (I ～ 14), with band crossing in both the even-spin and odd-spin sequences.     

Example of a rigorous solution for the gravitational field of a hollow,rotating cylinder

A class of exact solutions-depending upon two dimensionless parameters-to the gravitational field equations is obtained, where the source of the field is a rotating, hollow cylinder of infinite length. The material properties, although highly idealised, nevertheless are not unrealistic and chosen in such a way as to allow elementary integration. The solutions show how the inertial frame inside the cylinder is dragged by the rotating material, and also how the drag continues inside the material and in the outside region. They are exact examples for the Lense-Thirring effect.     

Experimental determination of the electron-avalanche and the electron-ion recombination coefficient

The electron-ion recombination coefficient γ and the avalanche coefficient δ = (α ? a) · v_d, where α and a are the ionizat ion and attachment coefficients respectively and v_d the drift velocity of the electrons, have been experimentally determined in a self-sustained CO₂-laser system (1:1:3 mixture) as a function of the E/N value. For low voltages we found the expected decrease of the recombination coefficient for increasing E/N values. However, it appears that for larger voltage the recombination coefficient increases sharply for increasing E/N values. The measurements of δ show a much smaller value than expected from theoretical calculations. This must be explained by a lower value of the electron-energy distribution function for higher energies, which may be consistent with our measured high recombination probability for electrons having high energy.     

Crossing of negative parity bands in even-even nuclei around A≈150

Level energies of negative parity yrast bands (NPB) have been studied with a recently proposed, sensitive method. The irregular behaviour of the NPB's in theN=88 nuclei around spin 9–11 and the smooth behaviour in¹⁵⁶Dy (up toI=13) and in²³⁸U (up to I=19) support calculations by Vogel, where NPB's are described as aligned octupole bands up to a critical spin where intersection with two-quasiparticle bands takes place. Considering the NPB levels (I≦13) in¹⁵⁶Dy as members of an aligned octupole band, we obtain a remarkably good reproduction of their decay properties and energies using the VMI model.     

Preservation of accuracy and precision in the analytical practice of low power ICP-AES

In an inductively coupled argon plasma (ICAP) matrix effects caused by elements constituting major inorganic components in samples of widely different nature have been studied under experimental conditions not primarily aimed at achieving maximum detection power and minimum matrix effects but at optimum reproducibility of the analytical signals. Separate and combined matrix effects on thirteen ICAP analysis lines were investigated. From the results conclusions could be drawn of interest for the practice of ICP analysis. A close examination of acid effects revealed the appearance of an “adaptation” effect.     

Spectral-domain optical coherence phase microscopy for quantitative phase-contrast imaging

We describe a novel microscopy technique for quantitative phase-contrast imaging of a transparent specimen. The technique is based on depth-resolved phase information provided by common path spectral-domain optical coherence tomography and can measure minute phase variations caused by changes in refractive index and thickness inside the specimen. We demonstrate subnanometer level path-length sensitivity and present images obtained on reflection from a known phase object and human epithelial cheek cells.     

In vivo human retinal imaging by ultrahigh-speed spectral domain optical coherence tomography

An ultrahigh-speed spectral domain optical coherence tomography (SD-OCT) system is presented that achieves acquisition rates of 29,300 depth profiles/s. The sensitivity of SD-OCT and time domain OCT (TD-OCT) are experimentally compared, demonstrating a 21.7-dB improvement of SD-OCT over TD-OCT. In vivo images of the human retina are presented, demonstrating the ability to acquire high-quality structural images with an axial resolution of 6 microm at ultrahigh speed and with an ocular exposure level of less than 600 microW.