Diagram Lines Research Articles

Systematic study of the K X-ray spectra for hollow krypton and xenon atoms in collision process

The satellite and hypersatellite of K X-rays resulted from additional vacancies in L-shell and M-shell for Kr and Xe atoms have been calculated systematically by using the multiconfiguration-Dirac–Fock (MCDF) method, in which the Breit interaction, QED corrections are also considered. The present calculations for diagram lines are in good agreement with available previous results. It is found that the number of spectator vacancies in L shell varies nearly linearly with the energy shifts of both K X-ray satellites and hypersatellites for Kr and Xe atoms. While an additional M shell hole has nearly no effect on the Kα energy shifts in comparison with the small but evident energy shifts of Kβ lines. The simulated spectra based on our results show a good agreement with the current experimental spectra at Heavy-ion Research Facility (HIRFL) in Lanzhou. The results of this paper will be helpful in further interpretation of various K X-ray spectra and better understanding of the collision processes.

Phase Behavior and Percolation Properties of the Patchy Colloidal Fluids in the Random Porous Media.

The lack of a simple analytical description of the hard-sphere fluid in a matrix with hard-core obstacles is limiting progress in the development of thermodynamic perturbation theories for the fluid in random porous media. We propose a simple and highly accurate analytical scheme, which allows us to calculate thermodynamic and percolation properties of a network-forming fluid confined in the random porous media, represented by the hard-sphere fluid and overlapping hard-sphere matrices, respectively. Our scheme is based on the combination of scaled-particle theory, Wertheim's thermodynamic perturbation theory for associating fluids and extension of the Flory-Stockmayer theory for percolation. The liquid-gas phase diagram and percolation threshold line for several versions of the patchy colloidal fluid model confined in a random porous media are calculated and discussed. The method presented enables calculation of the thermodynamic and percolation properties of a large variety of polymerizing and network-forming fluids confined in random porous media.

Discontinuous transition of a multistage independent cascade model on networks

We propose a multistage version of the independent cascade model, which we call a multistage independent cascade (MIC) model, on networks. This model is parameterized by two probabilities: the probability T1 that a node adopting a fad increases the awareness of a neighboring susceptible node and the probability T2 that an adopter directly causes a susceptible node to adopt the fad. We formulate a tree approximation for the MIC model on an uncorrelated network with an arbitrary degree distribution pk. Applied on a random regular network with degree k = 6, this model exhibits a rich phase diagram, including continuous and discontinuous transition lines for fad percolation and a continuous transition line for the percolation of susceptible nodes. In particular, the percolation transition of fads is discontinuous (continuous) when T1 is larger (smaller) than a certain value. A similar discontinuous transition is observed in random graphs and scale-free networks. Furthermore, assigning a finite fraction of initial adopters dramatically changes the phase boundaries.

Predictions on the solubility and equiscale line of water content for the quaternary system (Li+Na+Cl+SO4+H2O) at 298.15 K

Pitzer ion-interaction theory is widely used to calculate the solubilities of salt–water systems. In the paper, the solubilities and equiscale lines of water contents of the reciprocal quaternary system (Li+Na+Cl+SO4+H2O) at 298.15K were calculated using Pitzer theory and Harvie, Møller, Weare solubility modeling approach (HMW model). In this predictive calculation, the quasi-Newton and dichotomy methods were used to solve the system of simultaneous equations of the equilibrium expressions among solid and liquid phases, and to obtain the ionic molalities, Jänecke indices of phase diagram and the Jänecke indices of the equiscale lines of water contents in the reciprocal quaternary system. Based on the Jänecke indices, the dry-salt phase diagram and the equiscale lines of water-phase diagram were plotted. The predictive phase diagram via the theoretical calculation agrees well with the experimental phase diagram except for the phase region of double salt 2 (Li2SO4·Na2SO4, Db2). Distributions of equiscale lines of water-phase diagram on the dry-salt diagram of the reciprocal quaternary system reflect that phase areas of double salts of Db1 and Db2 bear maximal water contents. The predictive phase diagram and equiscale lines of water-phase diagram are often necessary in the technological design of chemical engineering for the utilization of inorganic salts in salt lake brines.

Origin of the satellite observed on the high energy side of Lγ2,3 diagram lines

On the high energy side of the unresolved doublet Lγ23in the L spectra of some elements, a satellite Lγ2,3' has been reported in literature, which has been ascribed to the transition L1Mx − MxN2,3, on the basis of energy considerations alone, by earlier workers. In the present work, apart from energy, calculations have also been done for the intensity of the probable transitions which may give rise to the satellite in the elements from 40Zr to 47Ag and from 57La to 63Eu. Firstly, the probability of creation of a single hole K state has been calculated. Double hole state L1Mx is created by Coster-Kronig transitions (K − L1Mx) as well as by shake off process. The probabilities of these two processes have been calculated. The total probability of creation of the double hole state thus obtained has been statistically distributed among the 24 allowed transitions from the set of L1Mx levels. By taking each of the transitions as a Gaussian line, a composite spectrum has been computed. This theoretical spectrum has been compared with the available satellite energy data. The transitions which give rise to this satellite have thus been identified in the elements studied.

Experimental and Simulation Constructing of Phase Diagram and Quality Lines for a Lean Gas Condensate Reservoir Fluid

Constructing phase diagram and its subsequent quality lines for lean gas condensate reservoirs is always crucial and challenging topic in reservoir fluid studies. Due to small amounts of liquid drop-outs in lean gas condensates at reservoir conditions, full experimental tracking of phase diagram and its relevant quality lines is almost impossible for lean gas condensates. On the other hand, EOS models of reservoir fluid characterization softwares are always unable to estimate condensed liquid drop-outs at different pressures and temperatures precisely. This study aims to present a commingled experimental-simulation method which was designed to pinpoint and keep track full phase diagram with correspondent quality lines for a lean gas condensate fluid.

Fixed and free line ratio DT2 PIXE fitting and simulation package

The DATTPIXE software package, which full extent version become operational in 1992, has been largely used both in academic research and for standard analysis. Developments of a new PIXE setup, having an X-ray Microcalorimeter Spectrometer (XMS) EDS high resolution detection system and a CdTe detector, raised the need for a deep revision of the software used to fit PIXE spectra and interpret data. First steps taken in 2007 essentially comprised a new fitting code based on a proven Bayesian inference routine. Meanwhile, fundamental processes associated to PIXE spectra, which became more evident in X-ray Microcalorimeter spectrometer (XMS) high resolution EDS spectra, made clear the need for a full new code. Using some of the routines developed in DATTPIXE, the new DT2 package is written in Fortran 2003 and includes both the fitting and data handling codes. DT2 is now designed to include in the fitting model and deal with diagram lines as well as with satellite lines (Radiative Auger Emission (RAE), multi-ionization satellites and even chemically shifted lines) or even lines having other origins such as low energy γ-rays. In this communication we present the new DT2 package and discuss its new features, such as the possibility of fixing or leave free the relative intensity of spectra lines, even if they belong to transitions to the same shell.

Identifying and Mapping Linkages between Actors in the Climate Change Innovation System

Promoting innovations in climate change requires innovation partnerships and linkages and also creating an enabling environment for actors. The paper reviewed available information on the identification and mapping of linkages between actors in the climate change innovation system. The findings showed different linkage types and mechanisms that could exist in the climate change innovation system. Actor linkage map, actor linkage matrix, actor determinant diagram and actor time lines were identified as ways of mapping linkages between actors in the climate change innovation system. For effective innovations in the system, it is recommended that linkages between actors be identified and mapped and enabling environment for innovations provided.

Erratum to “A new approach to relativistic multi-configuration quantum mechanics in titanium” [Phys. Lett. A 374 (47) (2010) 4756

In our original paper [1], the satellite contributors to the titanium Kα spectrum are mislabelled in Fig. 3 and Fig 4. The figures presented herein contain the correct labelling. The 3p−1 spectator produces the satellite feature on the high energy side of the diagram lines, commonly referred to as the Kα′′ line. The 3d−1 and 3d−2 spectators reduce the energy of the transition, with the 3d−2 having only full subshells and consequently no fine structure. We would like to thank Professor Marek Polasik and his team from Poland for bringing this to our attention.

On the electron mechanism of suppression of the magnetic moment of nickel in its alloys with copper and zinc

For the first time, the electronic structure of Ni, Cu, and Zn in Ni0.27Cu0.73, Ni0.18Cu0.51Zn0.31, and Cu0.66Zn0.34 and some other chemical compounds has been studied using the method of shifts of the K X-ray lines. Statistically reliable shifts (from the positions for the metal) of all diagram K-lines of Ni have been found for both alloys, whereas the shifts of the K-lines of Cu and Zn (also from the positions for the metals) are close to zero for all the alloys. For the first time, estimates have been obtained for the 3d- and/or 4s-facsimiles, i.e., shifts of all diagram lines caused by the removal of one 3d- and/or 4s-electrons. On the basis of these facsimiles, the found shifts of the K-lines of Ni in Ni0.27Cu0.73 and Ni0.18Cu0.51Zn0.31 have been explained by the transference of ≲0.10 and 0.15 of its 4s-electron to 3d-band of the same atom.

Estimating Outcomes of Astronauts with Myocardial Infarction in Exploration Class Space Missions

We estimate likelihood of presenting rhythms and survival to hospital discharge outcome after acute cardiac ischemia with arrhythmia and/or myocardial infarction (AMI) during long-duration space missions (LDSM) using selected terrestrial cohorts in medical literature. Medical scenarios were risk-stratified by coronary artery calcium score (CAC) and Framingham risk factors (FRF). AMI with and without sudden cardiac arrest (SCA) likelihoods and clinically significant rhythm scenarios and associated outcomes in "astronaut-like" cohorts were derived from two prospective trials identified by an evidence-based literature review. Results are presented using an event sequence diagram and event time line. The association of increasing CAC scores and FRF with AMI and SCA outcomes was calculated. Low AMI likelihoods are estimated in individuals with CAC scores of zero or < 100 and a low number of FRF. Survival rate to hospital discharge after out of hospital SCA in a large urban environment study was 5.2%. EMS-witnessed ventricular tachycardia and/or ventricular fibrillation survival rate of 37.5% represents < 1% of all urban out of hospital AMI, and these patients have a high proportion of known ischemic cardiovascular and pulmonary disease "disqualifying for spaceflight." Multiple factors may be expected to delay or defeat rapid access to "chain of survival" resources during LDSM, lowering survival rates below urban levels of 5.2%. Low CAC and FRF reflect lower risk for AMI events. Zero CAC was associated with the lowest risk of AMI after 3.5 yr of follow-up. Quantifiable incidence and outcome characterization suggests AMI in LDSM outcomes will be relatively independent of in-flight medical resources.

A plastic miniature x-ray emission spectrometer based on the cylindrical von Hamos geometry

We present a short working distance miniature x-ray emission spectrometer (miniXES) based on the cylindrical von Hamos geometry. We describe the general design principles for the spectrometer and detail a specific implementation that covers Kβ and valence level emission from Fe. Large spatial and angular access to the sample region provides compatibility with environmental chambers, microprobe, and pump/probe measurements. The primary spectrometer structure and optic is plastic, printed using a 3-dimensional rapid-prototype machine. The spectrometer is inexpensive to construct and is portable; it can be quickly set up at any focused beamline with a tunable narrow bandwidth monochromator. The sample clearance is over 27 mm, providing compatibility with a variety of environment chambers. An overview is also given of the calibration and data processing procedures, which are implemented by a multiplatform user-friendly software package. Finally, representative measurements are presented. Background levels are below the level of the Kβ(2, 5) valence emission, the weakest diagram line in the system, and photometric analysis of count rates finds that the instrument is performing at the theoretical limit.

Structure of the sulfur K x-ray emission spectrum: influence of the oxidation state

The sulfur K x-ray emission was studied in pure sulfur, anhydrite (CaSO4) and sphalerite (ZnS) samples. The ionizations were induced by electron impact and the spectra were recorded with a wavelength dispersive spectrometer. The spectral processing was performed through a methodology based on the optimization of atomic and experimental parameters. Energies and intensities of diagram and satellite lines were determined for a set of transitions in the Kα and Kβ groups. The lines studied include Kα22, Kα2, Kα1, Kα′, Kα3, Kα4, Kα5, Kα6, Kβ1,3, Kβ-RAE, KβIII, KβIV, Kβx, Kβ′ and Kβ″. The main spectral differences between the three oxidation states were analysed, considering the influence of the ligand atoms. The results were compared with data published by other authors and the origin of certain lines was discussed on the basis of data available in the literature.

DoubleL3Mionization of Pd induced by impact with medium-energy electrons

The electron-induced ${L}_{3}M$ two-step double ionization cross sections of metallic Pd were determined experimentally for incident electron beam energies ranging from the double ionization threshold up to 18 keV. The double ${L}_{3}M$ ionization cross sections were derived from the intensity ratios (${I}_{L\ensuremath{\alpha}M}$:${I}_{L\ensuremath{\alpha}}$) of the resolved $M$ satellites to the parent diagram lines. The sample was bombarded with monoenergetic electrons from an energy-tunable 20-kV electron gun. The diagram and $M$-satellite x-ray lines were measured by means of high-resolution x-ray spectroscopy, using a reflection-type von Hamos bent crystal spectrometer. The two-step partial cross sections were determined by subtracting from the measured total double ionization cross sections the contributions due to the shake process and ${L}_{1}$-${L}_{3}{M}_{4,5}$ Coster-Kronig transitions. Despite the thick target employed in the present study, the dependence of the two-step cross sections on the incoming electron energy could be derived using a target slice decomposition method. It is shown that the obtained energy dependence can be well reproduced by the semiempirical parametrization model of Pattard and Rost.

Comparison of methods: Passing and Bablok regression

The comparison of methods experiment is important part in process of analytical methods and instruments validation. Passing and Bablok regression analysis is a statistical procedure that allows valuable estimation of analytical methods agreement and possible systematic bias between them. It is robust, non-parametric, non sensitive to distribution of errors and data outliers. Assumptions for proper application of Passing and Bablok regression are continuously distributed data and linear relationship between data measured by two analytical methods. Results are presented with scatter diagram and regression line, and regression equation where intercept represents constant and slope proportional measurement error. Confidence intervals of 95% of intercept and slope explain if their value differ from value zero (intercept) and value one (slope) only by chance, allowing conclusion of method agreement and correction action if necessary. Residual plot revealed outliers and identify possible non-linearity. Furthermore, cumulative sum linearity test is performed to investigate possible significant deviation from linearity between two sets of data. Non linear samples are not suitable for concluding on method agreement.

Kαsatellite transitions in elements with12⩽Z⩽30produced by electron incidence

The emission of x-ray satellite lines in the $K\ensuremath{\alpha}$ region of Mg, Si, Sc, Ti, Cr, Fe, Ni, and Zn induced by electron incidence was studied by means of wavelength dispersive spectroscopy. The satellite lines studied were $K{\ensuremath{\alpha}}^{\ensuremath{'}}$, $K{\ensuremath{\alpha}}_{3}$, $K{\ensuremath{\alpha}}_{4}$, $K{\ensuremath{\alpha}}_{5}$, $K{\ensuremath{\alpha}}_{6}$, and two transitions denoted here as $K{\ensuremath{\alpha}}_{22}$ and $K{\ensuremath{\alpha}}_{12}$. Energy shifts with respect to the main $K{\ensuremath{\alpha}}_{1}$ diagram line and transition probabilities relative to the whole $K\ensuremath{\alpha}$ group were determined for a number of lines through a careful spectral processing. The dependence of these parameters, as well as of the $K\ensuremath{\beta}:K\ensuremath{\alpha}$ intensity ratio, on the atomic number was compared with previous experimental and theoretical determinations when available. A discussion about the different mechanisms responsible for vacancy creation involved in the production of double-ionization satellites was performed in the light of the results obtained. Finally, the behavior of the satellite intensities as a function of the incidence energy was discussed for silicon.

Processing, Properties and Microstructure of a 1.2%Al TRIP Steel

Cold rolled TRIP-600 steels has been developed on a laboratory scale. Composition of the steels is 0.12wt%C-0.30wt%Si-1.6wt%Mn-1.2wt%Al. Effects of Al concentration on phase diagram, TTT curves and T0 line of bainite formation in the steels were calculated and discussed.Cold rolled sheets of 1.7mm thick were annealed between 830 °C and 870 °C followed by austempering at 420 oC. UTS of 660~700MPa, YS 390~420MPa and total elongation 30.5~37.5% is obtained.Volume fraction of the retained austenite is 9~11% and carbon content in the retained austenite is 0.9% ~1.3wt% in the steels. The chemical composition and processing parameters of the experimental steels could be referred for trial-manufacture of TRIP 600 steels.

K-shell diagram and hypersatellite spectra of4dtransition elements

The $K$-shell diagram ($K{\ensuremath{\alpha}}_{1,2}$ and $K{\ensuremath{\beta}}_{1,3}$) and hypersatellite (HS) $({K}^{h}{\ensuremath{\alpha}}_{1,2})$ spectra of Y, Zr, Mo, and Pd have been measured with high energy-resolution using photoexcitation by 90 keV synchrotron radiation. Comparison of the measured and ab initio calculated HS spectra demonstrates the importance of quantum electrodynamical (QED) effects for the HS spectra. Phenomenological fits of the measured spectra by Voigt functions yield accurate values for the shift of the HS from the diagram lines, the splitting of the HS lines, and their intensity ratio. Good agreement with theory was found for all quantities except for the intensity ratio, which is dominated by the intermediacy of the coupling of the angular momenta. The observed deviations imply that our current understanding of the variation of the coupling scheme from $LS$ to $jj$ across the periodic table may require some revision.

Comparison of models for evolution of X‐ray satellite lines

AbstractEvolution of the KL X‐ray satellite line was studied. Four theoretical models based on the adiabatic approximation were fitted to the experimental data for the intensity ratio of the satellite line relative to the diagram line for Fe and Zn as a function of incident photon energy. The Thomas, the Vatai, the Roy and the modified Roy (Roy2) models were considered. Comparison of these four models was made for the case of inner‐shell electron transitions and their difference was clarified. The reason that the models developed for bound–bound transitions can give satisfactory results for bound‐free transitions is discussed. Copyright © 2009 John Wiley &amp; Sons, Ltd.

Systematic multiconfiguration Dirac-Fock method study of the K-X-ray spectra of silicon

Extensive multiconfiguration Dirac-Fock calculations with the inclusion of the transverse Breit interaction and QED corrections have been performed for silicon to explain the influence of removing electrons from L and M shells on the shapes and parameters (the average Kα and Kβ transition energies and the values of Kβ/Kα intensity ratio) of its K-X-ray spectra. For Kα diagram lines and for certain L- and M-satellite lines the theoretical stick spectra (line positions with their relative intensities) have been presented. Moreover for each type of lines two theoretical spectra have been synthesized: one being a sum of the Lorentzian natural line shapes and the other one being a convolution of the sum of the Lorentzian natural line shapes with the Gaussian instrumental response.