Sn-state lifetime determination of dyes

The S _n -state lifetime is determined from two-step excited S _n -S₀fluorescence yield measurements with picosecond light pulses. The theoretical analysis includes single pulse and double pulse consecutive excitation and takes into account the anisotropy of excitation and emission. Experimental results of the single pulse two-step excitation technique are presented for the S₄-state lifetimes of the three mode-locking dyes 5, 9740 and 9860 for Nd-glass lasers.     

Sign determination of contour lines

With the usual techniques of contour lining no distinction is possible between elevations and depressions. This distinction is obtainable if two adjacent reference planes are used. The generation and exploitation of two adjacent contour line systems are described and discussed.     

Sequential determination of jet structure

We review the definition of pierce numbers, which are a generalization of the concept of thrust. These quantities provide a useful way to characterize the jet structure of high energy events. Geometrical and topological problems encountered in calculating the pierce numbers of an event are discussed. The degree of hierarchy in the jet structure influences both the calculational problems and the physics results. We have previously developed, and used in a number of simulation studies, a computer program which calculates approximate values of the pierce numbers. We describe here a modification of this program which is slower in operation but more accurate. Values of thrust, as obtained using these programs, are compared with the exact value and with other approximations. The influence of the approximations on the invariant masses of jet combinations is also examined.     

The empirical determination of quantum states

A common approach to quantum physics is enshrouded in a jargon which treats state vectors as attributes of physical systems and the concept of state preparation as a filtration scheme wherein a process involving measurement selects from a primordial assembly of systems those bearing some prescribed vector of interest. By contrast, the empirical experiences with which quantum theory is actually concerned relate measurement and preparation in quite an opposite manner. Reproducible preparation schemes are logically and temporally anterior to measurement acts. Measurement extracts numbers from systems prepared in a specified manner; these data are then regularized by the theory by means of a state concept which is in turn used to characterize succinctly the given mode of preparation. The present paper offers, in a simple spin model, a method for determining the quantum state that represents any reproducible preparation.This investigation was supported in part by funds provided by the Graduate School Research Fund.     

Experimental determination of vibrational anharmonic contributions

This article deals with the experimental determination of separate vibrational anharmonic contributions to the self‐energy of phonons in any crystals based on temperature dependence of their Raman spectra. We propose a new approach to find each anharmonic contribution by using special temperature points. We apply the approach to diamond, silicon, and crystalline α‐S₈ and show that our results for summarized anharmonicity in diamond and silicon are in good agreement with the values obtained previously for these systems by other researchers. Copyright © 2013 John Wiley & Sons, Ltd.     

The determination of the temperature factor

The paper deals with a method for finding the temperature factor when determining crystal structures.     

Sonoelectrochemical determination of nucleosides and nucleotides

We summarize our recent work on sonovoltammetric studies of adenine, guanine, thymine, cytosine and their corresponding nucleosides and nucleotides. Ultrasound is found to be an excellent tool to enhance the reliability of determinations of purine and pyrimidine derivatives and can lead to improved analytical performance characteristics and lower detection limits.     

Optical determination of the Boltzmann constant

The Boltzmann constant k B is a fundamental physical constant in thermodynamics. The present CODATA recommended value of k B is 1.3806488(13) × 10-23J/K(relative uncertainty 0.91 ppm), which is mainly determined by acoustic methods. Doppler broadening thermometry(DBT) is an optical method which determines k B T by measuring the Doppler width of an atomic or molecular transition. The methodology and problems in DBT are reviewed, and DBT measurement using the sensitive cavity ring-down spectroscopy(CRDS) is proposed. Preliminary measurements indicate that CRDSbased DBT measurement can potentially reach an accuracy at the 1 ppm level.     

Structure determination of surface magic clusters

The structure of a type of surface magic cluster is determined by a combination of scanning tunneling microscopy, density-functional calculations, and dynamical low energy electron diffraction. The diffraction method is applicable because these clusters created through hierarchical self-organization of Ga deposited onto a Si(111)-7x7 surface have identical size and structure and form an ordered array with exact translational symmetry. The unprecedented detailed structure information provided by the diffraction measurement is consistent with direct microscopic imaging and theoretical calculations.     

Structure determination of medium-sized sodium clusters

Sodium cluster anions Na(n)(-) with n = 39-350 have been studied by low temperature photoelectron spectroscopy and density functional theory (DFT). The highly structured experimental spectra are in excellent agreement with the electronic density of states (DOS) of the DFT lowest energy structures. Even for the largest sizes, a pronounced sensitivity of the DOS on fine geometric details could be observed, allowing for a reliable identification of a specific icosahedral growth motif. The intermediate sizes between the closed-shell Mackay clusters with 55, 147, and 309 atoms form by growth of overlayers, which often exhibit a twist deformation with respect to regular (Mackay-type) ones.     

Albedo factor determination of rare-earth oxides

ABSTRACT

Gamma-ray albedo factors of rare-earth oxides were determined experimentally. The detection of albedo factors for selected materials includes albedo number, albedo energy and albedo dose calculations. 59.54 keV gamma rays of 5 Ci annular ²⁴¹Am were used as a gamma source. Gamma rays were scattered by selected samples and collected by High Purity Germanium semiconductor detector. The albedo factors were plotted as a function of atomic number of target materials.